DesignNews Magazine, January 2012

PETROSKI ON ENGINEERING Normalization of Deviance 14

January 2012 $15.00

HOT FOR 2012 Cars, Robots, Materials 28

NEW TWIST ON FASTENING Engineers Demand Better Adhesives 46

Accelerating Engineering Innovation

.com

Ethernet Converges on Factory Automation

Standard fosters safety, diagnostics as it displaces plethora of fieldbuses 34

RATED #1 Availability of Product

Data Acquisition Modules, Loggers & Recorders 8/16-Channel Thermocouple/Voltage Input USB Data Acquisition Module

OM-DAQ-USB-2401 $495

• 8 Differential or 16 Single-Ended Analog Inputs • 24 Bit Resolution with Up to 1000 Samples/Sec • User Programmable for Type J, K, T, E, R, S, B, N Thermocouple or Voltage Input Visit omega.com/om-daq-usb-2400

Temperature and Humidity Virtual Chart Recorder iTHX-W3 Series Starts at $295

Visit omega.com/ithx-w3

Miniature Portable Wireless Thermocouple Connector and Data Logger, Records Over 65,000 Process Temperature Data Points The Smart Connector ™

Portable Data Logger OM-SQ2020 Starts at $2445

*MWTC-D Series $150

Visit omega.com/mwtc-d ®

Because of transmission frequency regulations, these wireless products may only be used in the United States and Canada (915 mHz models) or Europe (868 mHz models).

Visit omega.com/om-sq2020

omega.com ®

*PATENT PENDING

© COPYRIGHT 2012 OMEGA ENGINEERING, INC. ALL RIGHTS RESERVED

Our STRIDE family of industrial grade unmanaged Ethernet switches and media converter is specifically built for industrial environments. Install Stride switches and your Ethernet control network will maintain more consistent cycle times even under heavy I/O and data exchange. The aluminum-housed models offer a wider operating temperature range (-40 to +85 deg. C).

Advanced Industrial Hardware • All 10/100BaseT RJ45 ports are auto-detecting, auto-crossover and auto-polarity • Redundant power inputs with surge and spike protection • Optional 100Mbps multimode fiber optic port for distances up to 4km • NEW! SC (push-pull type) fiber optic connector models, in addition to ST (slotted bayonet) style versions

CHECK OUT PRICES ON ETHERNET SWITCHES Product Description 5-port Ethernet switch with five 10/100BaseT RJ45 Ethernet ports

$

8-port Ethernet switch with eight 10/100BaseT RJ45 Ethernet ports

$

5-port Ethernet switch with four 10/100BaseT RJ45 Ethernet ports and one 100BaseFX fiber optic port

$

Ethernet Isolation -1500 VRMS 1 minute Spike protection - 5,000 watts (10x for 10 uS) UL (CUL) listed and CE certified Hazardous locations rated for Class 1, Div. 2

STRIDE METAL MODELS Price/Part Number $

199.00 SE-SW5U-WT

SE-SW5U

172.00

$

259.00 SE-SW8U-WT

172.00

$

259.00 SE-SW5U-ST-WT

$

399.00 SE-SW9U-ST-WT

SE-SW8U

SE-SW5U-ST

$

242.00 SE-SW9U-ST

Ethernet-Fiber converter with one 10/100BaseT RJ45 Ethernet port and one 100BaseFX fiber optic port

$

162.00 SE-MC2U-ST

AutomationDirect prices are U.S. published prices as of October 2011. Prices subject to change without notice.

www.automationdirect.com/ethernet Also Available

True Industrial Design • • • •

99.00

9-port Ethernet switch with eight 10/100BaseT RJ45 Ethernet ports and one 100BaseFX fiber optic port

Real-time Performace • Store and forward wire speed switching - no delays • Full-duplex operation with flow control (no collisions!) • Auto crossover (MDI/MDIX) and auto polarity

AutomationDirect STRIDE PLASTIC MODELS Price/Part Number

www.automationdirect.com Go online or call to get complete information, request your free catalog, or place an order.

1-800-633-0405 Shielded Cat5e cables starting at: $5.00

Super Ion Air Knife™ Produces a laminar sheet of airflow that floods an area or surface with static eliminating ions.

Super Ion Air Wipe™ The uniform 360° ionized airstream neutralizes and cleans continuously moving surfaces.

Prevent Shocks, Jamming, Tearing and Static Cling! When the humidity is low, static electricity problems will happen. • Materials tear, jam or curl

• Hazardous sparks or shocks

• Webs and films cling to themselves

• Product clings to itself, rollers, machine beds

• Electronic sensors fail, making false readings

• Dust attraction ruins surface finishes

Ion Air Gun™ Eliminates static and dust from parts prior to assembly, packaging, painting or fi nishing.

EXAIR manufactures a complete line of static eliminators to remedy common static problems. Many use our engineered airflow products to minimize air use and noise while delivering maximum results by moving more static eliminating ions to the product surface.

Ion Air Cannon™ Ideal for hard to reach spaces or confi ned areas that require a concentrated ionized flow.

Watch Our Brief Video! How To Get Rid of Static & Dust! Ion Air Jet™ Delivers a concentrated blast of ionized air prior to shrink wrapping, packaging and printing.

www.exair.com/14/47014a.htm Ionizing Bar If you would like to discuss an application or request a catalog, contact:

Eliminates static cling, dust attraction and jamming on paper, plastics and fi lm.

Manufacturing Intelligent Compressed Air Products Since 1983 11510 Goldcoast Drive • Cincinnati, Ohio • 45249-1621 • (800) 903-9247 • fax: (513) 671-3363 E-mail: [email protected] • www.exair.com

@EXAIR

www.exair.com/14/470a.htm

Name Peter Simonsen Job Title Design Engineer, Embedded Software Area of Expertise Renewable Energy LabVIEW Helped Me Perform real-world simulations with total control of the application Latest Project Develop a test architecture for verification of wind turbine control systems

NI LabVIEW

LabVIEW makes me better because I can

SIMULATE real-world systems

>>

Find out how LabVIEW can make you better at ni.com/labview/better

©2010 National Instruments. All rights reserved. LabVIEW, National Instruments, NI, and ni.com are trademarks of National Instruments. Other product and company names listed are trademarks or trade names of their respective companies. 2811

800 453 6202

Accelerating Engineering Innovation

Contents

January 2012 vol. 67 no. 1

www.designnews.com

38

34

52

Cover Story 34 Ethernet Converges on Factory Automation Ethernet adoption drives development of infrastructure to support completely networked, plant-wide architectures from field devices up to management level. By Al PrEshEr

Features 38 Micro hybrids hit the road Starter motors with automatic starting capabilities will hit the auto market in a big way in 2012. Within 15 years, every new vehicle could offer “start-stop.” By ChArlEs J. MurrAy

46 Adhesives Put New Twist on Fastening

52 Crowdsourcing Creates CAD Groundswell

MAde BY MonkeYs

18 Are Front-load Washers less reliable?

While user input has the potential to boost innovation, manufacturers have been slow to embrace the strategy.

Bill Schweber’s washer started to shake due to a cracked spider, and repair costs were as much as the machine itself.

By BETh sTACkPolE

C A P tA i n h Y B r i d

Columns

20 is the EV1 still the Best Electric Car Ever? Some engineers still consider the EV1 to be a monument to the art of automotive engineering.

Wolfe’s den

12 2012: year of the Engineer Designers will no longer be the Rodney Dangerfield of the tech world.

By ChArlEs J. MurrAy

By AlEXANDEr WolFE

sherloCk ohMs

58 The Case of the Faulty spring Clutch

P e t ro s k i o n e n g i n e e r i n g

14 Normalization of Deviance

Engineers are demanding multifunction adhesives and more rugged fasteners.

Normalized deviance has plagued the oil drilling industry, where at least some companies have allegedly let the financial bottom line dominate decision-making.

By ANN r. ThryFT

By hENry PETroski

This problem with faulty springs revealed the problem with conventional-wisdom solutions. By JEFFrEy ANTMAN, PE

continued >

Cover Image: Debee rommel

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

5

mouser.com

AS9120A Certified Distributor

Semiconductors and electronic components for design engineers.

Authorized Distributor

Highest Standard for Quality and Control. Mouser has high-level traceability and anti-counterfeit controls to serve aerospace, industrial, and commercial products. Your one source for What’s Next. ■ Widest selection of newest products

■ Fastest introduction of new products

■ Millions of products online

■ 1715+ microsites and resources

■ Localized global support

■ Accurate, same-day shipping

mouser.com |

Mouser and Mouser Electronics are registered trademarks of Mouser Electronics, Inc.

The Newest Products for Your Newest Designs

®

Contents > continued

7

GADGET FREAK

64 The Frankenkindle: An Easier-to-Use Kindle

Supplements

64

Fluid Power/Power Transmission

Glenn Johnson took the controls from a children’s V.Reader and routed them into the Kindle’s interface board to create this easier-to-use Kindle.

Find stories on a pneumatic driver for an artificial heart, and how longtravel piezomotors are being used for applications formally addressed by magnetic motors.

Departments 22 Data Measurement & Analysis

What’s the Noise in a Signal-toNoise Ratio?

24 Mechatronics

59 Social Engineering

These stories also appear online at www.designnews.com.

Standards, Security Add 2012 Angst

60 Design Decisions

DESIGN NEWS® (ISSN 0011-9407) is published monthly by UBM Electronics, 600 Community Drive, Manhasset, NY 11030; 516-562-5000. Periodicals postage paid at Manhasset and at additional mailing offices. SUBSCRIPTIONS – Free to qualified subscribers as defined on the subscription card. Rates for non-qualified subscriptions, including all issues: U.S.A, $150.00 one year, $250.00 two years, $300.00 three years; Canada, $184.90 one year, $314.90 two years (includes 7% GST, GST# 123397457); Mexico, $172.90 one year, $295.90 two years; Foreign air expedited $323.90 one year, $579.90 two years. Except for special issues where price changes are indicated, single copies are available for $10 U.S.A and $15 foreign. For telephone inquiries regarding subscriptions 763-746-2792. Email: [email protected]. CHANGE OF ADDRESS – Notices should be sent promptly to DESIGN NEWS® P.O. Box 47461, Plymouth, MN 55447 – Please provide old mailing labels as well as new address. Allow two months for change. NOTICE – Every precaution is taken to ensure accuracy of content; however, the publisher cannot accept responsibility for the correctness of the information supplied or advertised or for any opinion expressed herein. POSTMASTER – Send address changes to, DESIGN NEWS® P.O. Box 47461, Plymouth, MN 55447, Canada Post: Publications Mail Agreement 40685520. Return undeliverable Canadian addresses to: Pitney Bowes, P.O. Box 25542, London, ON N6C 6B2. Printed in U.S.A. Copyright 2011 by UBM Electronics. All rights reserved. Reproduction in whole or part without written permission is prohibited.

What to Consider When Choosing a Rotary Encoder

Theory & Practice

61 Design Engineering

26 Green Scene Environmental News Engineers Can Use

Products

Best of the Engineering Marketplace

28 News Trends, Developments, Breakthroughs

ICP DAS USA

1-888-971-9888

Data Acquisition - Automation - SCADA -Data Loggers Protocol Converters- Network Switches & Gateways Wireless products - Motion

Touch Screen PLC

Industrial Ethernet

Remote Data Acquisition

FREE Ladder Logic C Language Development Software

Din Rail Mountable & Designed for Extreme Temperatures

Compact and Din Rail Mountable Modules in RS-485, Modbus, CANbus & More

Starting at $199

Starting at $99

Starting at $139

Protocol Converters

SCADA Software

Programmable Controllers

Convert Modbus, Profibus, CANBus, Ethernet/IP, HART & More

PC Based Control & Monitoring Software. Downloadable Free Trials Available

Automation Controllers in CE.NET, Linux, XP Embedded & more, with SDK.

Starting at $129

Starting at $399

Starting at $1199

Los Angeles, CA

www.icpdas-usa.com

Real parts. Really fast. Simply upload your 3D CAD model, and choose the best option for your needs.

CNC Machining in 1–3 days. Best for 1–10 parts. Priced from $95.

Injection Molding in 1–15 days. Best for 10–10,000+ parts. Priced from $1495. Choose from hundreds of engineeringgrade resins, including HDPE, Polypropylene, ABS/PC, Acetal, PBT, Polycarbonate, Nylon 66, Polyamide and LPDE.

Choose from 30 different materials including ABS, Nylon, PC, Delrin, PEEK, ULTEM, aluminum and brass.

It’s easy to work with Proto Labs. Choose CNC machining or injection molding, whichever is best for your project. Upload your CAD model and receive an automated, interactive quote in hours. Once approved, our cluster computing technology and automated manufacturing systems will deliver real parts using real materials in as little as one day. And that’s the real story. ©2012 Proto Labs, Inc.

ISO 9001:2008 Certified

Check out our video design tips!

Get Your Protogami

Our newest design aid is a cool kaleidocycle that shows the effect of materials on finishes. Visit www.protolabs.com/parts today and request your free Protogami! Enter code DN12A.

Call 877.479.3680 or visit www.protolabs.com

NOw ON

.com

automation & control

the top trends of 2011

Ethernet’s move to the industrial automation space is gaining momentum, as engineers make the conversion from the fieldbuses of the 1990s to networks that unify the front office and factory floor. http://bit.ly/susTge

It was a year chock full of cutting-edge technology, and our editors have taken a look back at some of the best in robotics, autos, and materials. Also, be sure to turn to our news section, (pg. 28), where we look ahead to what’s in store for 2012.

gadget Freak

robotics:

Our gadget freak slide show reveals a host of interesting projects, ranging from an interactive beer pong table to jet engines made out of junk, and even a 3D tic-tactoe game. http://bit.ly/t61qY2 Engineering Materials

Is a wave of aerospace component manufacturers buying composite makers about to break? Two acquisitions in the last month and one earlier in the year may portend a trend. http://bit.ly/vnREpH

The five most important robotics trends of 2011 enable volume manufacturing, and aim at further integration of robotics with machine vision and automated systems.

Using virtual-holographic 3D imagery, Infinite Z’s new zSpace immersive 3D environment lets users interact and explore 3D models as if they were real, physical objects. http://bit.ly/tJ2891 Mechatronics Zone

Industrial robots that do welding and metal fabrication are getting both a lot smaller and a lot larger, depending on the size of the company using them and the type of welding configurations they need. http://bit.ly/sajZTw

Product catalog

Maxon’s Brushless EC 8 Motor

Maxon’s new brushless dc motor offers continuous torque up to 0.95mNm, nominal speed up to 80,000rpm, and an efficiency rating of 70 percent. The motor is available with or without Hall sensors and with 6V, 12V, and 24V windings. This motor was produced according to rigid Medical Standard ISO 13485 and is for applications such as sampling robotics, portable analyzers, metering systems, instrumentation, or inspection robots. http://dn.hotims.com/40992-500

automotive:

Editorial WEbcast

An agreement with 13 automakers to increase fuel economy to 54.5 mpg by model year 2025 meant little to consumers in 2011, but will be huge for the engineers designing next-generation autos. http://bit.ly/tPZ39i

The five most important materials trends of this past year enable volume manufacturing. Read more at: http://bit.ly/sNpSv4 Mechatronic solutions: smart integrated actuator technology View now at: http://bit.ly/rJUvk3

Smart actuators incorporating integrated controls and network connectivity options are finding their niche in machine control applications. The key is a single mechanical actuator-motor with onboard electronics that can provide both a broader set of controls and the simplicity of an integrated solution.

CONNECT wITH US

Design News’ System & Product Design Engineering group: http://bitly.com/designnewsLI

RESOURCE CENTER

http://bit.ly/sZTnFy

Materials:

cad/caM corner

ONLINE

Design News’ general Twitter feed: http://twitter.com/designnews Design News’ Sustainable Engineering Twitter feed: http://twitter.com/awolfe58

http://on.fb.me/fanpagedn Get Design News’ RSS feeds at http://www.designnews.com/rss/ and sign up for e-mail newsletters at http://www.designnews.com/register.asp

Energy Efficiency: Motors & Drives

Energy and Efficiency in Motors and Drives looks at the changes that have occurred in recent years. Plants are much more concerned these days about energy consumption. And energy-efficient equipment sends savings to the bottom line. In addition to the positive value of savings from efficiency, plants are also concerned about their carbon footprint. For most companies, the reduction in energy consumption has become an overriding goal. Efficient motors and drives contribute to the goal. http://dn.hotims.com/40992-501 aPPlication notE

Top 5 Things You Need to Know When Selecting Directional Valves

Selecting the right valve to control system pressure, direction of flow, and rate of flow is crucial when designing fluid power circuitry. This online resource features the top five things that must be considered when specifying directional valves for any pneumatic application. http://dn.hotims.com/40992-502

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

9

BRAND DIRECTOR Al Schmidt 972-980-8810 CONTENT DIRECTOR Alexander Wolfe 516-562-7386 MANAGING EDITOR Jennifer Campbell 781-869-7974 Charles J. Murray, Senior Technical Editor Ann R. Thryft, Senior Technical Editor Rob Spiegel, Senior Editor Lauren Muskett, Assistant Editor TECHNICAL SPECIALTIES CAE Software & Hardware: Beth Stackpole [email protected] Electronics & Test: Charles J. Murray [email protected] Fluid Power/Automation & Control: Alexander Wolfe [email protected] Materials & Assembly: Ann R. Thryft [email protected] CONTRIBUTING EDITORS DATA MEASUREMENT & ANALYSIS/ Jon Titus, [email protected] PRODUCTION Donna Ambrosino, Production Director

maxon motor control

Maintaining control has never been easier.

UBM DESIGN CENTRAL Gene Fedele, Vice President/Design Director David Nicastro, Creative Director Debee Rommel, Creative Director Giulia Fini-Gulotta, Art Director Adeline Cannone, Production Manager Laura Alvino, Sr. Production Artist Yoshihide Hohokabe, Production Artist Diane Malone, Production Artist BUSINESS OFFICE Colleen Heckman, Project Manager Esther Aronov, Marketing Project Manager DESIGNNEWS.COM Brian McAvoy, Director, Interactive Media 781-869-7964 U.S. SALES REPRESENTATIVES IL/IN/KY/MI/OH/ON/WI Jami Brownlee 815-893-6052 DC/FL/GA/IA/KY/MD/MN/NC/PA/SC/SD/VA Doug Robertson 781-869-7966 CT/DE/MA/ME/NH/NJ/NY/RI/VT Julie Simoneau 781-869-7962 AZ/CA/CO/ID/MO/NV/OK/OR/TX/WA Chris Bombarger 512-249-0221 REGIONAL/SALES MANAGER CUSTOM PUBLISHING Mike Paul 781-869-7965 INTERNATIONAL REPRESENTATIVES UK Stephen Waddell 011 44 1322 437091 GERMANY Erhardt Eisenacher 011 49 2 28 65 0013 FRANCE Alain Faure 011 33 1 53 21 88 03 JAPAN Toshiyuki Uematsu 011 81 3 5775 6056

If decentralized drive intelligence is called for, maxon motor control provides the answer: All speed and positioning controllers are designed to match with DC motors up to 700 watts power. The EPOS2 positioning controller can be used with CANopen and Interpolated Position Mode. maxon motor is the world’s leading supplier of high-precision drives and systems of up to 500 watts power output. Rely on the quality of the highly specialized solutions which we develop with and for you. www.maxonmotorusa.com

UBM ELECTRONICS MANAGEMENT TEAM CEO, UBM ElECTRONICs/UBM CANON (pUBlIshING) Paul Miller ChIEf INfORMATION OffICER Brent Pearson sENIOR VICE pREsIDENT David Blaza sENIOR VICE pREsIDENT Of CONTENT Karen Field VICE pREsIDENT Of fINANCE Jean-Marie Enjuto VICE pREsIDENT Of pARTNER sERVICEs & OpERATIONs Barbara Couchois VICE pREsIDENT Of MARkETING Felicia Hamerman DIRECTOR Of AUDIENCE ENGAGEMENT AND ANAlyTICs Amandeep Sandhu Design News ® is a member of UBM Electronics 33 Hayden Ave., Lexington, MA 02421 www.designnews.com Subscription Inquiries: 847-559-7597 Reprints: Wrights Media 2407 Timberloch Place, Suite B The Woodlands, TX 77380 281-419-5725

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

In certain environments, HBLEDs may be subject to corrosion… and failure. While this doesn’t happen too often, it is something you should be aware of if the high-brightness LEDs (HBLEDs) in your application will be exposed to the air without the benefit of a suitable enclosure. Perhaps most surprisingly, this problem does not occur with the less-expensive, lowerbrightness “commodity” LEDs that are encased in hard epoxy such as those below.

This is a potential problem in environments with high concentrations of hydrogen sulfide and other reactive gasses. Sometimes these gasses will evaporate from nearby sulfur-treated, rubber-based materials 2 at high temperatures and contaminate the LED; they can also be present in air pollution, near certain industrial processes or over liquids. Metal on the LED’s interior leadframe will react with the gasses, accelerated by the die’s high temperature, and start to corrode the device from the inside-out.

Recently, a manufacturer supplied me with a novel product to evaluate: a low-profile, self-adhesive strip of high-quality HBLEDs to be used for outdoor, marine and industrial applications. My concern was the gas permeability of the overmolded silicone-encapsulated HBLEDs. I thought of a convenient, albeit unscientific, method of testing the product. It just so happened that I needed a little extra light for my aquarium. The HBLED strip was mounted on Figure 1 – Common epoxy encapsulated LEDs the underside of the cover, 10 cm above the surface of the Clear or colored epoxies certainly do have many desirable water. It was subjected to warm water vapor, a small amount characteristics: mechanical hardness (reducing the likelihood of condensate and accumulated gasses. The water is slightly of LED die or bond wire damage due to rough handling), saline, with a salt concentration of 20 ppt (seawater is about moldability (the package itself can be formed into a lens), 35 ppt). Three green spotted pufferfish swam underneath, and low-cost. However they are often not suitable for carefully monitoring the results. encapsulating HBLED die. HBLEDs get quite hot, and After 30 days of continuous operation, some of the epoxies have low melting temperatures. Furthermore, HBLEDs began to fail. As you can see in the photographs ultraviolet and intense blue light tends to make these below, the reactive chemicals quickly diffused through the epoxies brittle. The material turns brown and eventually silicone encapsulate and attacked the LED’s leadframe and opaque—thus limiting an HBLED’s output and lifetime. bond wires. Several developed internal current paths across This is problematic for high-output white LEDs, since they bridges, current levels increased and light output decreased. are constructed from blue-emitting die. 1

Today, silicone is the typical encapsulant for highbrightness and high-power LEDs. Silicone can withstand high temperatures and has excellent optical transmittance across the entire visible spectrum, even down into the UV-A range (400 nm – 315 nm). On white HBLEDs, sometimes the yellow phosphors which cover the blue die are mixed into the silicone before it is deposited into the package cavity and cured. Despite the fact that relative to epoxy, silicone enhances an HBLED’s performance and extends its lifetime, it presents two hazards. The first is mechanical damage to the LED die and its internal connections. We advise people not to touch and never to poke the surface of a silicone-encapsulated HBLED. Silicone is soft and pliable; tiny bond wires are easily dislodged. The second, less-known hazard is corrosion. Silicone is a wonderful sealant; it’s used to make gaskets and glass aquariums. But it is also gas-permeable. 1

Photo by Afrank99

Figure 2 – Going, going… gone. (Internal lead frame corrosion)

Silicone is an outstanding encapsulant, but you must understand its limits. In this case, the LEDs would have fared better if a secondary glass or acrylic window were placed above them. If you’d like more information on high-brightness LEDs, visit our website (www.em.avnet.com/LightSpeed) or send a note to [email protected]. Your questions and comments are always welcomed. 2

Cary Eskow is Global Director of the Solid State Lighting and Advanced LED business unit of Avnet Electronics Marketing. An ardent advocate of energy efficient LED-based illumination, he has worked closely with LED manufacturers, advanced analog IC and secondary optics vendors since his first patent using LEDs was issued two decades ago. Avnet works with customers through their national team of illumination-focused sales engineers who are experienced in thermal, drive stage and optics design. Prior to his LED lighting focus, Cary was Avnet’s technical director and managed Avnet’s North American FAE team. To submit questions or ideas, e-mail Cary at [email protected]

Rubber is sometimes manufactured with sulfur in the vulcanization process

To learn more about designing an LED-based illumination system, go to:

www.em.avnet.com/LightSpeed

12

Wolfe’s Den

Alexander Wolfe, Content Director, [email protected]

2012: Year of the Engineer I’m optImIstIc that the new year will bring newfound respect for engineers, and not of the Rodney Dangerfield variety. I think we’re finally on the verge of getting some credit from the general public for the tough work we do. The first impediment towards elevated esteem is that the average person doesn’t really know what an engineer is or does. Truth be told, I’m not so sure we’re all agreed on it either. When I was at school, we were told that engineers found cost-effective solutions to problems. That’s sometimes but not always true — think defense contracting. In any case, it falls far short of the mark. The always-reliable Wikipedia defines an engineer as “a professional practitioner of engineering.” Gee, thanks, crowdsourcers. Dictionary.com says it’s a person “skilled in the design, construction, and use of engines or machines.” I guess that finally puts the EEs in their place. Henry Petroski made a cogent point in his Design News column, “Distinguishing Between Scientists & Engineers” (October, pg. 16). He noted how newspapers consistently use “science” when they mean “engineering.” Thus scientists become the embodiment of white-coat wisdom and us engineers are back in Dangerfield territory. The reason I think this is finally changing is due to another misconception, but one which works in our favor. It involves Steve Jobs, whose biography was the top selling book of 2011. Most folks mistakenly assume he was an engineer. In fact, he was a college dropout, as is Bill Gates. (Apple cofounder Steve Wozniak is an engineer, having returned to school and earned his degree in 1986.)

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Steve Jobs is revered by the general public. Clearly this is not because of his personality — he was famously a bully, which is inappropriate, though not rare, in titans of industry. It’s because, although he wasn’t an engineer, he “engineered” stuff through managing the design process performed by engineers working for him. Most importantly, he frequently used the one word that’s become anathema within the engineering culture where adding features is thought to be a positive, as well as in the broader culture where collaboration necessitates acquiescence to groupthink. That word was “no.” Saying no is the most effective way of keeping an engineering project within its design constraints, of reining in the cost of bills of materials, and of generally keeping schedules on track. Subjectively, I believe it also enforces an elegance of design which began to flourish in the arts with Bauhaus and Deco. These in turn lead to streamlining, which reached its apex in the era of locomotives. They also begat Harley Earl, the legendary General Motors designer of the mid-twentieth century. Collectively, those influences are reflected in the iPhone and iPad. They’re also fusing into the miniaturized design we’re working on today. I believe miniaturization itself enforces enticing packaging. Petroski writes that engineers exploit scientific principles and discoveries.That’s true, but I think the best definition of good engineering can’t be captured by a dictionary. Rather, you just know it when you see it.

Follow us on:

Technology by THE INNOVATORS

Efficient Automation Efficient  Increased precision and quality through synchronization and real-time capabilities  Reduced costs through scalability and design freedom – PC-based or embedded  Investment security through openness and full compatibility  Increased productivity throughout the entire life cycle through intelligent service and diagnostic functions  Space-savings through compact systems and decentralized topologies

Perfection in Automation

www.br-automation.com

1414

PETROSKI ON ENGINEERING Normalization of Deviance LAST SPRING AND SUMMER, while oil gushed

into the Gulf of Mexico, much of the media coverage following the fatal explosion on the drilling rig Deepwater Horizon focused on the blowout preventer located a mile below the surface. As its name denotes, the device’s function was to prevent exactly the kind of blowout that did occur. It did not work properly because some pipe from the runaway well was forced upwards into the preventer and jammed the mechanism. Over a 25-year per iod, a Henry Petroski pre-accident survey had found blowout preventers on about 15,000 other wells had to be activated in an emergency only 11 times. Unfortunately, in five of those cases the preventer failed, as it did in the Gulf. This 45 percent historical failure rate did not jibe with the 0.07 failure rate claimed during the government-mandated testing of blowout preventers. Even as lax oversight and testing procedures were being called into question, the oil industry was using this low failure rate to argue for less frequent testing of the complex system of valves and rams that were the last line of defense against a blowout. It was estimated that reducing testing requirements could save oil companies almost $200 million per year. A blowout preventer is also an expensive piece of equipment to maintain, with an estimated cost of $700 per minute incurred during the time that drilling had to be stopped, the device disconnected and hauled to the surface, repaired, lowered back down, and reattached to the wellhead. The economics of the situation clearly argued against a conservative maintenance regimen and promoted a culture of risk taking.

In the case of the oil company BP, whose gulf operations were directed out of Houston, the culture that developed around deepwater drilling operations was not unlike that of another Houston-based technology. At the outset of the space shuttle program, the total-failure rate of shuttles was estimated by engineers to be 1 percent and by managers to be 0.001 percent. The Challenger accident proved the actual failure rate then to date to be 4 percent, and after the Columbia accident it still stood at close to 2 percent. Repeated negative experiences with eroding O-rings and shedding insulation were not heeded as warnings but taken as signs of the robustness of the space vehicle and promoted a fault-tolerant culture that allowed for what has been called a “normalization of deviance.”

Over a 25-year period, a pre-accident survey had found blowout preventers on about 15,000 other wells had to be activated in an emergency only 11 times. Normalized deviance has also plagued the oildrilling industry, where at least some companies have allegedly let the financial bottom line dominate decision-making. Just as NASA managers were emboldened by two dozen successful shuttle flights before the accident with Challenger and, after the hiatus, another 87 successful missions before the disintegration of Columbia, so the low incidence

Henry Petroski is the Aleksandar S. Vesic Professor of Civil Engineering and a professor of history at Duke University. His latest book is An Engineer’s Alphabet: Gleanings from the Softer Side of a Profession. He can be reached at [email protected]. D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Enter xx at www.edn.com/info

16

Petroski on Engineering

of needing to call upon the blowout preventer in an emergency promoted a sense of bravado in the operation of offshore oil rigs. It is easy in retrospect to say that the Deepwater Horizon accident did

not have to happen. The design of the blowout preventer should arguably have anticipated that a difficult-to-control well might cause the well pipe to be propelled upwards and buckle and so present a far-from-ideal piping geometry for the

PEM® Brand Captive Panel Screws Ideal for metal panels, pc boards and other thin materials.

PEM brand captive panel screws help keep parts to a minimum while eliminating risks associated with loose hardware that could fall out and damage internal components. These panel fastener assemblies offer a wide selection of product types and features to meet most application requirements.

PEM® Skirted Shoulder Identifier (registered trademark)

“Designed for” • corrosion resistance • tool or hand assembly • flush-mounting • low profile • UL® approved • locating pin • color coding • anti cross-threading • spring loaded • floating for misalignment

Ask about our PEM® C.A.P.S® color capabilities

Mounting styles: • Self-clinching • Broaching • Surface Mount • Floating • Flaring

Go to www.pemnet.com and select the product literature tab to view PEM Bulletin PF

Drive Types: • slot/Phillips • Phillips • slot • six-lobe/slot

70 YEARS

OF EXCELLENCE

1942-2012

www.pemnet.com

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

352 ©2011

so-called blind shear rams in the blowout preventer to deal with. There evidently were warnings that the well being drilled was a difficult one to control, and there were reported irregularities in the condition and status of safety devices and warning systems on the rig. However, instead of these precursors of failure being heeded, they were ignored or accepted as business as usual. In the wake of the spill, the oil company BP, the rig’s owner-operator Transocean, and the contractor Halliburton argued among themselves about who was responsible for the accident.

Even as lax oversight and testing procedures were being called into question, the oil industry was using this low failure rate to argue for less frequent testing. The presence of the blowout preventer provided a sense of backup security, in that it presumably could be called upon to control the well should anything go drastically wrong on the rig. This proved to place unwarranted confidence in an unreliable piece of complex machinery. The relative liability of the companies involved in the drilling operation gone amuck will no doubt continue for some time to be argued among managers and lawyers and regulators, and the final outcome is likely to be a financial settlement that will not get to the heart of the matter. What appears to be clear about the technical, economic, regulatory, and environmental tragedy is that the root cause of the Deepwater Horizon oil spill was at least as much a human problem as a mechanical one. DN

as tough as they come

18

MADE BY

MONKEYS

http://bit.ly/MadeByMonkeys

Potting/Encapsulation Serviceable Up To 500ºF

Are Front-Load Washers Less Reliable?

EP36 • Superior electrical insulation properties • B-stage epoxy system

Hackensack, NJ 07601 USA +1.201.343.8983 [email protected]

www.masterbond.com

Our 7-year-old midrange Sears front-loading washer started to shake. Long story short, the bearing or support spider was starting to fail. We couldn’t figure that out until after it was disassembled in repair — it turned out the spider had indeed cracked. The repair required replacing the tub, drum, and spider. That’s $1,000 in parts alone. It took two guys and two hours. Luckily, the unit was still within the 10-year warranty, so all I had to pay was $130 in labor. That’s OK, since the washer cost $1,000 — the same cost as the repair parts. The repairman — who has 20 years of experience — told me these front loaders are much less reliable than top loaders. So my question is — One: is the reliability difference inherent in the mechanics of a front-loader design? Or two: is it just due to inadequate design and shortcuts? Perhaps three: no design margins, or incorrect choice of materials, or material quality control, or poor assembly. I’m betting on points one, two, and maybe three. Or, are manufacturers taking the opportunity of the trend toward supposedly efficient front-loaders to design-down their machines? Are they trying to cut manufacturing costs while making it up in service calls? Here’s why I wonder about that last point: my machine has a 10-year warranty. But the more recent ones come with a one-year warranty. A one-year warranty is pretty much useless in the real world. I guess I’m one of the very lucky ones with the longer warranty of an older machine. This washer has not had a hard life. It’s just the two of us. Our previous unit, the revered and venerable Maytag A608 top-loader, is well known as one of the most reliable washers ever made. That judgment call came from Consumer Reports, other sources, and user groups. We had it for 25 years, through two kids. All it ever needed was two belt replacements at just $100 a pop. Finally, the main bearing failed. But hey, after kids and 25 years, that’s darn good. With the new ones, you can get a service contract for $140 per year. That’s more than 10 percent of the cost of the machine. Front loaders also have another issue: the repeated on/off hard cycling of the fill valve procures tremendous water hammer, which is both very loud and can cause pipes (both new and old) to develop micro-cracks due to repeated motion. Those micro-cracks can grow into big cracks. The solution is a $15 water-hammer arrestor on each fill line — if you know to do it. If not, you’ll have leaking pipes and joints, or else a major leak in a few years. So, I’m wondering if the question of front vs. top-loader mechanics has become a matter of product down-designing. — BILL SCHWEBER

Made by Monkeys highlights products that somehow slipped by the QC cops. E-mail your examples to Rob Spiegel at [email protected]. D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

SolidWorks is a registered trademark of Dassault Systèmes. ©2011 Dassault Systèmes. All rights reserved.

LOOKING FOR DESIGNERS TO PUSH THIS BABY P R OJECT 3: HOT R OD BABY B U G GY Help host Jeremy Luchini design the first hardcore baby buggy using ® SolidWorks . You’ll share ideas, comment on designs and vote on key decisions throughout the project. If you think you’re ready, let’s go design. Watch. Share. Vote. LetsGoDesign.tv

20

Captain Hybrid designnews.com/blog/Captain_Hybrid

Is the EV1 Still the Best Electric Car Ever? Some engineers still consider the EV1 to be a monument to the art of automotive engineering. By CHARLES J. MURRAY, Senior Technical Editor, Electronics & Test

EvEn today, if you want to make someone’s blood boil, there’s a good chance you can do it by saying, “GM EV1.” For many, the subject still conjures up images of truckloads of cars being hauled off to a crusher. Still, some engineers who have torn down and evaluated electric cars have a different viewpoint. They see the EV1 as a monument to the art of automotive engineering. If it used today’s lithiumion batteries, they say, no electric vehicle ever made could touch it. “When it comes to pure electric vehicles, the EV1 is still the best that’s been built in the last 15 years,” says one engineer, who didn’t want to be named for competitive reasons, but who has torn down and evaluated every production EV that’s been made since the early 1990s. “The EV1 was a fully developed, all-around vehicle. Today, no one has the resources to do what GM did.” For those who don’t remember it well, here’s a short primer on the EV1. Introduced by General Motors (GM) in 1996, the EV1 was a two-seat electric coupe that was designed from the ground up with the best technologies available at the time. It was one of the first vehicles to use an aluminum space frame, which made it about 40 percent lighter than steel. Engineers then joined the frame with aerospace-grade structural adhesives, thereby eliminating many of the welds. They also made body panels from composites — again, to cut weight —and added a lightweight suspension with help from Lotus Engineering. Moreover, the vehicle had the most advanced power

electronics available at the time. Materials weren’t the only way of boosting the EV1’s energy efficiency, however. Design engineers used lowrolling-resistance tires and sculpted the body down to drag coefficient of 0.195, which is still considered to be the lowest in the history of production cars (http://dn.hotims.com/40992-503). By comparison, the Chevy Volt reportedly has a Cd of 0.28 and the Nissan Leaf, 0.29. Both of those figures are better than the auto industry’s average of 0.35 - 0.45, but still far short of the EV1’s. “It’s better than the Leaf,” our contact told us. “And the Tesla — which is certainly faster but costs $120,000 — still is far less sophisticated than the EV1.” To be sure, not everyone agrees with that assessment. As late as 2008, Time Magazine placed the EV1 on its list of “The 50 Worst Cars of All Time.” What’s more, many EV1 detractors have reasonably pointed out that GM spent between $80,000 and $100,000 per vehicle, which is a debatable figure, but one that nevertheless suggests that a comparison of the EV1 and the Leaf isn’t appropriate. Still, it’s hard to argue that the vehicle’s engineering was far ahead of its time. “Microelectronics, miniaturization, better batteries — all of those things have happened since the introduction of the EV1,” our contact says. “But the results don’t indicate that we’ve gotten that much out of it. Yes, we’ve got better batteries today, but imagine what the EV1 could have done with those batteries.” DN

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

High-Precision Motion Control High-Accuracy, Zero Backlash Gearhead The CSF-GH Quick Connect Gearhead easily mounts to any servo motor yet maintains all of the benefits of Harmonic Drive™ gearing including 1arc-min accuracy and zerobacklash. A high capacity cross roller bearing is used at the output and is available with either a Shaft or Flange output interface. The gearhead have rated torques of 76 in-lbs to 9,320 in-lbs and peak torques of 343 in-lbs to 46,550 in-lbs depending on size and ratio. Gear ratios of 50, 80, 100, 120 and 160:1 are available.

CSF/CSG Precision Gearheads The CSF and CSG high torque Precision Gearhead Series are ideally suited for robotic and machine tool applications. The CSG delivers 30% more torque and 40% longer life while maintaining zero-backlash, 1 arc-min accuracy, and +/- 5 arc-sec repeatability. An accurate, highly rigid cross roller bearing is built in to directly support the external load. A wide variety of sizes and reduction ratios are available with maximum peak torques ranging from 450 in-lbs. to 60,500 in-lbs.

Power & Precision SHA Hollow Shaft Actuator • High Torque Density

• Brushless Servo Motor

• 1 arc-min Accuracy

• Harmonic Drive™ Gearing

• ±5 arc-sec Repeatability

• Integrated Brake

• High Capacity Output

• 17 Bit Absolute Encoder

Bearing

SHF/SHG Hollow Shaft Speed Reducers Available in a wide range of sizes, these zero backlash, 1 arc-min accuracy Harmonic Drive™ gearheads enable design engineers to pass shafts, wires, tubing, or other components directly through the center of the gear. They incorporate an output flange supported by a large cross roller bearing, providing exceptional moment stiffness and load capacity. The smallest unit has a hollow shaft I.D. of 14 mm and an outer diameter of just 64 mm. The largest unit of the family has a hollow shaft I.D. of 80 mm and has a rated output torque of 1236 in-lbs, and a peak torque of 6175 in-lbs. Gear ratios from 30:1 through 160:1 are available.

Harmonic Drive LLC 800-921-3332 www.HarmonicDrive.net

The new SHA series of Hollow Shaft Actuators has the highest torque density of any actuator in its class, yet provides excellent positioning accuracy. Several sizes are available with output torques up to 30,000 in-lb. These actuators are ideally suited for robotics, automation, machine tool, and antenna positioning applications where performance and reliability are essential.

Call 800.921.3332 www.HarmonicDrive.net

DATA MEASUREMENT & ANALYSIS

Unbelievably useful info on data measurement, collection and analysis from the test expert

What’s the Noise in a Signalto-Noise Ratio? A SIGNAL-TO-NOISE RATIO (SNR)

lets us express the relationship between signal and noise powers and between the root-mean-square (rms) values of signal and noise voltages: SNR (dB) = 10log10(signal power Jon Titus / noise power) SNR (dB) = 20log10(rms signal voltage / rms noise voltage). In an analog-to-digital converter (ADC), noise — or non-signal power — relates to the ±1/2 LSB quantization error introduced by digitizing a signal into discrete steps. The familiar equation below provides the SNR for an N-bit ADC based solely on quantization error for a pure sine wave over the Nyquist bandwidth; DC to fsample/2: SNR (dB) = (6.02 * N) + 1.76. But this value tells only part of the story. ADC noise can arise from another source called effective input noise, created by the ADC’s electronics. And jitter in the ADC clock signal also affects the ADC output. A poorly designed circuit board can let digital noise and other ambient signals couple to the clock signal and cause jitter. You can find the complete rootsum-of-squares SNR equation that

combines quantization noise, clockjitter noise, and effective input noise in the document, “Fundamentals of Samples Data Systems,” by Walt Kester and James Bryant, available at: tinyurl. com/7uaubbt, page 2.72. The authors also show the theoretical basis for the third SNR equation. You cannot overcome effective input noise except by choosing a different ADC that introduces less noise. Proper PCB layout, decoupling, and use of a stable low-noise clock signal can reduce jitter. The overall jitter time combines aperture jitter, which occurs in the ADC’s sample-and-hold amplifier, with jitter in the ADC’s sampling clock signal. The latter jitter usually predominates. Although clock jitter of a few picoseconds might seem to contribute little to a SNR value, keep in mind that the effect of jitter increases with the frequency of an ADC input signal, as shown in the diagram. The SNR value does not include power contributed by harmonics of the signal of interest because you can — and should — eliminate harmonics with an anti-alias filter. If you include power from harmonics (but not DC), you get a signal-to-noise-and-distortion, or SINAD, ratio also expressed in dB. Because a SINAD value includes

Jon Titus, a former designer and chief editor of EDN and Test & Measurement World magazines, remembers when “fast” signals operated at 10 MHz and programs came on paper tape. D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

A Voltage

2222

B

Time t Jitter

Jitter in an ADC causes a large measurement error (∆V) in a signal with a high slew rate (A) when compared with the error caused at a lower slew rate (B), or frequency. Thus jitter can greatly influence high-frequencysignal measurements.

all non-signal energy, it can provide a good indication of actual ADC performance. DN

For More Information: 1. “ADC Input Noise: The Good, The Bad, and The Ugly. Is No Noise Good Noise?” Analog Devices. http://dn.hotims.com/40992-504. 2. “How Quantization and Thermal Noise Determine an ADC’s Effective Noise Figure,” Tutorial 1197, Maxim Integrated Products. http://dn.hotims.com/40992-505. 3. “Understanding the Effect of Clock Jitter on High Speed ADCs,” Design Note 1013, Linear Technology. http://dn.hotims.com/40992-506. 4. Kester, Walt, ed., “The Data Conversion Handbook,” Newnes, 2005. ISBN: 978-0-7506-7841-4.

AU

M

E A

CE

S

S

I

CE

IC L

Control Electronics

Digital Control Systems

mechatronics Mechanical CAD

Electronic Systems

Electromechanics

TU

RI NG

Software

RAPHY ROG XE

S

M

FA

Y

E

C

Mechanical Systems

S

T

U

M AT E R I ALS PR O

AERO SP A

Control Systems

SE

FRESH IDEAS ON INTEGRATING MECHANICAL SYSTEMS, ELECTRONICS, CONTROL SYSTEMS AND SOFTWARE

G

N FE DE

MECHATRONICS IN DESIGN

N

TIVE MO

D

24

TO

M

S

CO

A

N

S CT NSU MER PRODU

Theory & Practice We all know about the gap, now let’s do something about it! THE THEORY-PRACTICE GAP has existed for decades and

each of us needs to bridge this gap in all we do. As control is an essential element in all multidisciplinary systems, let’s start there, and begin to bridge the gap that exists between the theory of control and its digital implementation. Top 10 Lists are always popular, so here is one for classical control. Control Theory for the Practitioner 1. Feedback control is a pervasive, powerful, enabling technology that, at first sight, looks simple and straightforward, but is amazingly subtle and intricate in both theory and practice. 2. In a dynamic system, changes cannot be effected instantaneously, and so an otherwise correct control decision applied at the wrong time could result in catastrophe. 3. Nonlinearities are always present, e.g., backlash, Coulomb friction, saturation, hysteresis, quantization, dead band, and kinematic nonlinearities. A linearized model can be used to approximate a nonlinear system near an operating point. 4. Stability of a dynamic system must be guaranteed. Closed-loop systems go unstable because of an imbalance between strength of corrective action and system dynamic lags. Stable systems must have adequate stability margins to work once built. 5. Stable systems have a frequency response. If a stable linear system has a sinusoidal input applied, then the steady-state output will be a sinusoid of the same frequency, however, the amplitude ratio and phase difference of the two sinusoids are frequency-dependent. 6. The open-loop transfer function is the product of all the transfer functions in the loop, e.g., controller, actuator, plant, and sensor. Compared to the closed-loop system transfer function, the open-loop transfer function is much less complex. The Nyquist criterion and the Root Locus procedure allow one to use the open-loop transfer function to predict closedloop system performance. 7. After stability, performance is everything. Command following, disturbance rejection, insensitivity to modeling errors, and insensitivity to unmodeled high-frequency dynamics and noise are the main reasons for using feedback D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

control, once a system is guaranteed to be closed-loop stable. 8. Time delays can be deadly. Always conserve phase, the equivalent of time delay. Integral control adds 90 degrees of phase lag at every frequency and digital control adds time delay primarily due to D/A conversion. Imagine trying to make decisions using old information. 9. High control gain has lots of benefits, e.g., good command tracking and Kevin C. Craig, Ph.D., Robert C. Greenheck good disturbance rejection. However, Chair in Engineering there are three areas of concern: roll- Design & Professor of Mechanical Engineeroff, saturation, and noise. 10. People’s lives may be at stake. ing, College of EngiThere are no “details” in control engi- neering, Marquette University. neering, as even the most insignificant “detail” may prove to be important. Real control systems must be extremely reliable, especially if people’s lives depend on them. Maybe you know all this, but it is worth repeating. Now, let’s put some of this theory into practice. On designnews. com, you will find a case study that bridges the theory-practice gap regarding something we all need to be able to do: implement speed control of a motor with an attached incremental optical encoder sensor using a microcontroller with a PWM output to drive an H-bridge. It doesn’t get any more down to earth than that, yet this exercise uncovers gaps that are present for many of us. The microcontroller is the widely used, inexpensive Arduino; the motor is a 12V Pitman brushed dc motor; the optical encoder is three-channel with 500 counts per revolution; and the H-bridge is the L298. MATLAB/ Simulink real-time code generation is used. My resolution is to continue bridging the theory-practice gap with articles and website case studies. Happy New Year! DN

designnews.com Visit the Mechatronics Zone for the latest mechatronics news, trends, technologies and applications: http://mechzone. designnews.com

Tough Application Ingenious Solution

Exactly

Mastering challenges together — Rexroth makes it easy to implement automation. Our many years’ experience in a wide range of industries has given us extensive application knowledge. We offer this comprehensive understanding to the tasks you bring us, leading to ingenious solutions. Regardless of the drive technology used, we thought ahead and integrated intelligence throughout. This consistency makes you more efficient — from planning to start-up and daily operation. Your benefits are real: Increased productivity, improved energy efficiency and maximum machine safety. You can count on Rexroth to have the appropriate drive and control solution to meet your needs exactly.

Bosch Rexroth Corporation www.boschrexroth-us.com

26

GreenScene Environmental news engineers can use \\\ By Rob Spiegel, Senior Editor

Ford Builds Seats from Water Bottles

Car2go deploys 300 electric vehicles in San Diego.

Ford is using Repreve fiber in the seat fabric of its Focus Electric car. The fiber is polyester that is made from a hybrid blend of recycled materials, including used plastic water bottles and post-industrial waste. The f iber is 100 percent sustainable, and Ford says that each Focus Electric will keep 22 plastic bottles out of landfi lls.

Car2go Goes All Electric Car-sharing company car2go is deploying 300 allelectric vehicles throughout San Diego. The Daimler North America subsidiary will use smart fortwo electric drive vehicles for its San Diego program. The cars will be available 24 hours a day, seven days a week. Members of the program pay by the minute for the time they use the vehicle.

GREEN UPDATES

In 2009, Ford mandated that fabric suppliers use a minimum of 25 percent recycled content for all 2009 models and beyond. Since then, 37 different fabrics meeting the requirements have been developed and incorporated into Ford vehicles. For electric vehicles, Ford has taken the extra step of requiring 100-percent sustainable fabric.

Nissan & Sumitomo Deliver Low-Cost Quick Chargers In support of the proliferation of all-electric vehicles, Nissan North America will deliver low-cost DC quick chargers for electric cars in the US market. The DC quick charger is being launched as part of Nissan’s global collaboration with Sumitomo Corp. The fi rst installations are planned for 2012. The starting price for the charger will be $9,900, about a third of the cost of models available on the global market, according to Nissan. The charger will come in two models, a version for indoor use, which was designed for fleets such as daily rental cars, and an outdoor model specifically designed for public and commercial charging.

For regular updates on sustainable engineering news, follow Content Director Alexander Wolfe at http://twitter.com/awolfe58.

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Sooner or later, we all need to start playing with the big toys...

When that time arrives, check out our line of EC centrifugal fans! • Packaged air movers up to 39.4” (one meter) in diameter • Maximum 22,000 CFM or 7.5” static pressure, fully speed controllable • Direct driven by very efficient EC external rotor motors with up to 8HP capacity • Direct digital control, most sizes equipped with RS485 MODBUS RTU interface

See us at booth 2046 at AHR in Chicago

scan this code with any QR reader on your mobile device to go to our plug fan page or go to our website at info.ebmpapst.us/plugfans

www.ebmpapst.us

28

News Trends \\\ Breakthroughs \\\ Developments

Technologies to Watch in 2012 Here’s what to expect this year in the world of automobiles and robotics. 2011 was a year of innovation and

change in many industries, including the automotive and robotic sectors. Now, Design News looks ahead to the latest trends that will emerge in these fields in 2012 (it’s already proving to be exciting)! Be sure to go to designnews.com to also read about what’s coming up in materials & assembly, automation & control, and design hardware & software.

5 Ways Autos Will Change The trend toward fuel efficiency isn’t going away in 2012, or at any time in the foreseeable future. Because automakers are already on the hook to push their Corporate Average Fuel Efficiency (CAFÉ) to 35.5 mpg by 2016, and 54.5 mpg by 2025, they’re going to be working hard on any

feature that can eliminate even the smallest sip of gasoline. The most effective way to accomplish that is through the introduction of electric cars and hybrids of various types. The innovation won’t stop there, however. In 2012, we’ll see the industry pushing the limits on a number of different fronts. Autonomous driving technologies will become more prominent. EV battery sizes will increase. Multicore processors will make a bigger move into the vehicle. And as that happens, engineers will fret about the electronic complexity that’s taking over the automobile. Here’s a look at the five biggest trends for 2012: 1. Micro Hybrids. The automotive world’s migration to hybrid vehicles

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

won’t slow down in 2012. Ford Motor Co. will roll out its C-Max hybrid and C-Max Energi plug-in hybrid, while Toyota unveils its Prius PHV. But the show-stealer could be the “micro-hybrid,” or “start-stop” car. The micro hybrid, which has been quietly waiting in the wings for years, will make its biggest move yet in the coming year. Ford, Chevy, Buick, Kia, and others will roll out the technology in 2012, joining a handful of models from Fiat, Volvo, and Alfa Romeo that already have it. At its most rudimentary level start-stop will enable vehicles to turn off their engines while waiting at stop lights, stop signs, or in heavy traffic. Soon, however, it will go beyond that level, enabling engines to shut down while a vehicle is coasting, in some cases as fast as 75 mph. Experts say

With So Many EPIC® Connector Possibilities...

We’ll sniff out the right solution for you.

NEW !

Check out our NEW! EPIC ® ULTRA Housings

Re the sistant env harsh to iron est wat includments: elecer/corring: trica osio & di l noisen, rt

Rectangular

DIN Circular

Commercial MIL

IEC Pin & Sleeve

(Power, Control, & Data)

(Power & Control)

(Power & Control)

(Power)

• # of Contacts: 2 to 280 • Rated Voltage: Up to 1000V • Amp: Up to 82A

• # of Contacts: 2 to 55 • # of Poles: 1+N+PE, • # of Contacts: 6 to 26 • Rated Voltage: Up to 600V • Rated Voltage: Up to 1000V 2+PE, 3 +PE, 3+N+PE • Amp: Up to 46A • Rated Voltage: Up to 600A • Amp: Up to 22A • Rated Amp: Up to 100A

Lapp, the manufacturer of EPIC® Connectors, ÖLFLEX® Cable, and SKINTOP® Cable Glands, understands exactly how our connectors can best satisfy your specific needs.

800-774-3536 w w w. l a p p u s a . c o m

30 News

that the technology will be employed on every new car by 2025, making it impossible for even the most dedicated gasoline burners to avoid it. (Turn to page 38 to read more about start-stop technology.) 2. Bigger Batteries. Pure electric vehicles from Ford, GM, BMW, Tesla, BYD, and Toyota are on their way. As such, lithium-ion batteries will get bigger. Tesla, for example, will roll out 42-, 65-, and 85-kWh batteries for its Model S vehicle. BYD’s e6 EV will use a 72-kWh pack — about three times the capacity of a Nissan Leaf battery. RollsRoyce has also employed a 71-kWh battery in its 102EX Phantom Experimental Electric. “In late 2012 and early 2013, we expect to see the cost of batteries start to decline, as a lot of the new lithium-ion plants come online,” Dave Hurst, senior analyst for Pike Research, told Design News in a 2011 interview. “Once that happens, you’ll see an upward trend in battery size.” 3. Vehicle Autonomy. Full autonomy won’t happen for a long time, but pieces of the puzzle will continue to hit the market in 2012. Ford rolled

Bosch’s start-stop starters can reduce a vehicle’s fuel consumption by 5 percent.

out lane-keeping capabilities in 2011, enabling vehicles to “know” if a drowsy driver is wandering outside the lane markers. Park assist features, which arrived with luxury automaker Lexus in 2006, are growing more commonplace. Now, many automakers are laying the foundation for autonomous technology

with the addition of electric power assist for vehicle steering. Soon, we’ l l a lso see more adaptive cruise control and collision avoidance capabilities. General Motors engineers predict that fully autonomous vehicles will start to hit the road in 2020. “We believe that the world (of driving) The Buick LaCrosse will employ GM’s eAssist technology, wil l be autonomous which enables the vehicle to shut off fuel to the engine on demand,” says Alan during deceleration, and boost fuel economy by 25 percent. Taub, vice president of global research and development for more on the horizon as cameras, vision GM. “There will still be fun-to-drive sensors, radar systems, and lane-keeping situations. People do enjoy driving, but and collision-avoidance systems creep not all the time.” into the vehicle. To deal with it, au4. Multicore Powertrains. Mul- tomotive engineers are learning how ticore processors, already popular in to pack the functionality of 50 processafety-related applications, will make sors into 25. That means more multitheir move into automotive pow- core and new “up-integration” software ertrains in 2012. With fuel economy schemes, such as domain control. To be demands on the rise, automotive en- sure, automakers say these things every gineers have begun looking at direct year, yet the problem persists. Maybe injection, cylinder deactivation, and in 2012, we’ll finally see the new era of knock detection as ways to make en- simplicity. gines more efficient. All would benefit — By Charles J. Murray, Senior from the number-crunching capabili- Technical Editor, Electronics & Test ties of multicore processors. Moreover, hybrid electric vehicles will be employ- The Role Robotics Will Play ing multicore, as well, as a means of The five most important robotics trends handling the mathematical complexities of this coming year will enable volume of parallel powertrains. “Powertrain is manufacturing and greater integration the last frontier in automotive to adopt of robotics with machine vision and aumulticore” Philip Pesses of Freescale tomated systems. Some trends discussed Semiconductor said in a 2011 interview. below outline very targeted applica“Up to now, we’ve been able to get the tions. Yet once again, the developments performance we needed, but single- in each are relevant to other, often very core has been clocking out at 300 MHz, different types of applications, which and powertrain applications need to concern robot design and the design of increase their throughput.” the systems in which they work. 5. Complexity Conundrum. As 1. Convergence. One of the most consumers demand more features and significant trends in robotics will be the engineers comply, automakers face a convergence and integration of multiple dilemma: The number of electronic technologies that will help speed up and control units is reaching the point of automate the factory. ABB’s Automaunmanageability. Vehicles now employ tion and Power World 2011 conference, 35 to 80 microcontrollers and 45 to 70 described in the Design News story pounds of onboard wiring. And there’s “Convergence of Power and Automa-

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

32 News

ABB Automation & Power World is a comprehensive user’s conference and exhibition that showcases ABB’s extensive automation and power offerings.

tion” (http://dn.hotims.com/40992511), focused on merging power systems with automation, as in smart power grids or factory-wide systems. Midrange robot models increase productivity in material handling, machine tending, and other process applications in factories, as well as related functions in electric utilities. Other key elements that work with robots are distributed control systems and asset optimization software for managing high-voltage circuit breaker performance and availability. 2. Software. The more integrated automated systems become, the more important is the software running them. In the Design News story “In System Integration, Software Rules” (http://dn.hotims.com/40992-512), we learn that improving control now focuses on developing automation system software that helps designers make better use of all the high-steroid hardware available and make automatic systems, well, more automatic. Unifying the development environment, more integration of PCs, and more PC-friendly programming and configuration software are part of this trend. While hardware advances won’t stop, we’re at one of those plateaus where software needs to catch up to what hardware can do.

3. Two-armed Robots. Just like people, robots do things better with two hands. More dexterous robots will be valuable in several applications, from surgery to materials handling, or even picking up samples as they walk across the surface of Mars. A step — perhaps a grasp — in the right direction is the small robot with two arms, two hands, and opposable thumbs described in “Dual-Armed Robot Making InRoads” (http://dn.hotims.com/40992513). At Automate 2011, the SDA5D lifted spherical objects from a table. It’s being adopted in industrial applications from logistics and palletizing to automated assembly and distribution. A larger model is deployed in automotive assembly plants, and by NASA, for space simulation operations. 4.Integrated K inematics. Another way to make robots operate more productively is to make them and the handling systems they are being integrated into more like each other. One method for doing this is to build both from common components and controls. Common design components of both include articulated robots, robots, parallel kinematic systems, gantry systems, and linear axis systems. More integrated control architectures are also a key element, which can reduce component counts and simplify in-system communications. 5. Omni-Directional Movement.

The last major trend may be valuable in more than one area. The Design News story “Japan Defense Ministry Spins Flying Spherical Robot” (http:// dn.hotims.com/40992-514) tells us about the development of a remotecontrolled flying sphere that can move in any direction, on land or in the air, and can alight on, or take off from, surfaces of any shape. Designed by Ja-

The Switchblade “kamikaze” reconnaissance drone, one of the smallest used by Army and Air Force special ops forces in Afghanistan, is still larger at 24 inches than the 16-inch flying sphere from the Japanese Ministry of Defense.

pan’s Ministry of Defense engineers during an aircraft R&D project, the remote-controlled robot can hover like a helicopter, take off and land vertically, and immediately take off again in any direction. Onboard gyro sensors let it right itself if jostled. Aside from unmanned aerial vehicles and other aerospace or military applications, this technology may also have applications for machine vision and other industrial or factory-related uses. DN Robotic servo technology developed by Lenze is used to control KUKA robots, among others.

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

— By Ann R. Thryft, Senior Technical Editor, Materials & Assembly

Fluid Power/Power Transmission

the Freedom driver is the first Us portable driver designed to power the synCardia total Artificial Heart. it is undergoing an FDAapproved investigational Device Exemption (iDE) clinical study in the United states.

Pneumatic Driver System Provides Bridge to Life SynCardia's portable Freedom driver offers mobility and reliability for Total Artificial Heart recipients. By Al PrEsHEr, ContriBUting writEr

T

he innovative Freedom pneumatic driver from SynCardia Systems is the first US portable driver, weighing just 13.5 lb, designed to power the company’s Total Artificial Heart both inside and outside the hospital. CE-approved for commercial use in Europe and undergoing an FDA-approved Investigational Device Exemption (IDE) clinical study in the US, the new driver is allowing stable Total Artificial Heart [ w w w. des ig n n e w s . c o m ]

patients to wait for a matching donor heart at home and in their communities. Currently, the only FDA-approved driver is a 418-lb hospital driver nicknamed “Big Blue.” Stable patients supported by this driver are confined to the hospital while they wait for a matching donor heart. The average wait was 144 days in 2009. The SynCardia temporary Total Artificial Heart has six moving parts inside the body. Each ventricle has an inflow valve, an outflow valve, and a diaphragm. The unique

design doesn’t require sensors, motors, or electronics of any type inside the body, so there is never a need to re-operate to repair faulty electronics. The only electronics needed are in the pneumatic driver which powers the heart and monitors blood flow. It is located outside the body. How it works

“Bimba’s cylinders are used as a driver and are actually actuating the diaphragm inside the artificial ventricles surgically

J an uary 2012 f luid p o we r / p o we r tr ans mis s io n / a s up p le me nt to de s ign n e ws F1

Fluid Power/Power Transmission phragms sit inside the plastic ventricles which form the artificial heart, but are actually just static components until they are connected to the external driver. The driver is connected to the heart using two small air tubes, called drivelines, that exit just below the patient’s rib cage through the upper abdomen. The drivelines are then connected to the cylinder which effectively is pumping the artificial heart by actuating. The cylinder pumps the diaphragms of the artificial heart, circulating blood through a patient’s entire body much like a natural heart. Rhythm of the heaRtbeat the total artificial heart from SynCardia eliminates the symptoms and source of endstage biventricular failure. the system does not use motors or electronics of any type inside the body. all electronics are in a pneumatic driver, which powers the artificial heart and monitors the patient’s blood flow.

implanted inside of a patient,” says Tom Carlson, manager of Bimba Manufacturing’s Service Excellence team. “Basically with a patient who has biventricular heart failure, the bottom half of their heart is cut

out and is replaced with essentially today’s version of the Jarvik heart.” Carlson says that two rubber diaphragms are “wetted components” provided as a part of the SynCardia package. These dia-

“We worked very closely with SynCardia to try to perfect what I call the rhythm of the heartbeat,” says Carlson. “Their goal is to have this product give a heart patient quality of life, not just provide a bridge to a transplantation." So they have a challenge of a 100 million cycles for the actuator, because 100 million cycles is approximately the number the typical human heart beats in one year. The Freedom driver is serviced by replacement every 120 days.

How do you make a high quality switch? By switching to Thomas Products, that’s how. Quality Level and Flow Switches... When you buy our products, you receive total quality assurance since we are a full-service operation from raw material purchase to design to product completion.

Model 4000

With more than three decades of business experience, we have established long-term working relationships with clients in diverse industries including: aerospace, automotive, mining, construction, petrochemical, medical, food, and beverage.

Model 1800

Model 4400

Model 1100

Model 5100 designers & manufacturers of quality level & flow sensors DN 10/11

860.621.9101 800.666.9101

ThomasProd.com

Supplament Name Here the concept For syncardia is to provide a Bridge to LiFe. To replicate the rhythm of the heartbeat, SynCardia has developed specific requirements in terms of output pressures that ultimately relate to the performance of the actuator. Consistency of the cylinder’s performance is a major reason why the SynCardia Freedom driver system works. “Bimba’s solution lies with the ability to maintain consistent output pressures, but our product itself is only one part of the entire system that SynCardia uses to make the Freedom driver,” says Carlson. “Software, monitors, and simple position sensing on the cylinders all provide an ability to monitor the performance of the Freedom driver. Pressure sensors are also used to be able to identify what is going on, and how the actuators are actually performing.”

[ w w w. des ig n n e w s . c o m ]

These challenges are not like a typical pneumatic system where you have ready access to be able to do maintenance or provide lubrication. Basically everything is built and has to be truly available, ready, and usable from the factory for long life. “The SynCardia Total Artificial Heart is what is implanted in the patient,” says Carlson. “The actuator is part of the Freedom driver, the component that the person is basically going to have to carry around with them, and makes being lightweight important. Providing a lightweight actuator that offers consistent actuation to replicate a heartbeat with a long life were the challenges we faced.” SynCardia says the Total Artificial Heart is the only device that pumps up to 9.5ℓ/ minute through both ventricles, and offers a physiologically responsive design where blood flow is based on activity level. The uniqueness of its partial fill/full eject design is that it accepts blood based on the needs of the patient’s body at rest. The two artificial ventricles partially fill and then fully eject the amount of blood returned to the heart by the body.

During exercise, increased muscle and body movement causes more blood to enter the ventricles. The ventricles can fill with up to 30 percent more blood but there is no need to adjust the heart rate because the body determines the amount of blood the artificial heart pumps. Inside each ventricle is the diaphragm that is responsible for pumping blood. Vacuum supplied by the pneumatic driver pulls the diaphragm down to allow blood to enter the ventricle. To eject blood, a precisely calibrated pulse of air then pushes the diaphragm to the top of the ventricle. Bridge to LiFe

Carlson says that every year there are approximately 100,000 people who could benefit from a heart transplant, but only about 2,000 hearts are donated annually. That leaves a wide gap that is never going to change and is only going to grow as the baby boomer generation gets older. The concept for SynCardia is to provide a bridge to life. The SynCardia Freedom driver system allows a patient to continue to live and regain their health while they

j an uary 2012 f luid p o we r / p o we r t r ans mis s io n / a s up p le me nt to de s ign n e ws F3

Fluid Power/Power Transmission are waiting for a donor heart. By understanding that the donation gap is always going to be there, the longer term goal of the project is that it allows the potential for a patient to not only check out of the hospital, but then enjoy a long-term, improved quality of life. It can conceivably keep them alive indefinitely while they are waiting for a new heart. The Freedom driver has approvals in Europe and has been used in dozens of patients worldwide. In 2010, a CBS news story showed the first patient walking out of a hospital using the Freedom driver after being hospitalized for two years. He was able to walk out of the hospital without a human heart, instead, using an artificial heart to walk around and sleep in his own bed for the first time. Over 25 years of use, the valves in the SynCardia Total Artificial Heart have never failed. The diaphragm has a failure rate of less than 1 percent over more than 950 implants (1,900-plus diaphragms). In working on the project, the SynCardia and Bimba engineering groups collaborated to develop advances to the

driver technology. “We have a great partnership with SynCardia, and our chief engineer is basically an extension of their engineering staff,” says Carlson. “What we learned is that they are medical people and that is their forte but, when you get into issues that are more fluid power related, they relied on us as a resource to help them develop the system.” In addition to fine-tuning the final design and dialing in the functionality of the actuators, Bimba was also a consultative resource for the overall system, and provided recommendations on how things work within the entire Freedom driver concept. Carlson says the collaboration has actually been very fruitful and Bimba is extremely proud to be part of this because it is a life-saving project. “When you see someone walk out of a hospital without a human heart and know that we have been part of helping to keep that person alive, that is a huge uplifting thing for our entire company,” Carlson says. To achieve high reliability, the key is

tried-and-true cylinder manufacturing and a combination of lubrication, seal materials, seal geometry, and selection of other bearing materials. “As with any specialty actuator design, the seals, pistons, bearings, and lubrication all play a role in its dynamic functionality, so we make sure that the selections provide optimal performance. From a pneumatic standpoint, the goal is not just about optimal life, but also to provide leak-free operation as well,” Carlson says. Bimba used a combination of empirical testing combined with experience, as well as modeling and simulation, to assist in developing its part of the Freedom driver technology. Carlson says that modeling can only take the process so far, but then the proof is in actually trying it out. FMEA analysis can take you so far, but it doesn’t replicate the nuance of an application, so performance validation in the application itself is a must. For more information, go to www.syncardia.com and www.bimba.com.

® PENINSULAR C Y L I N D E R C O.

PENINSULAR’S PROVEN CYLINDER FEATURES KEEP YOUR PLANT UP & RUNNING !

27650 Groesbeck Highway Roseville, Mi 48066-2759 Phone: 586-775-7211 Fax: 586-775-4545 F4 f lui d po wer/ power t r a n s m i s s i o n / a s u p p l e m e n t t o de s ign ne ws ja n u a ry 2012

[ www.designnews.com ]

Fluid Power/Power Transmission

Long-Travel Piezomotors:

new Innovations, new Solutions Piezo actuation is becoming increasingly suitable for applications formerly addressed by magnetic motors. By scott JordaN & steFaN vorNdraN, Pi (Physik iNstrumeNte) l.P.

P

iezoelectric actuation is the • Applications ranging from cell foundation for a myriad phone cameras to endoscopy and of mission-critical highfluid delivery require exceedingly technology applications, small but stiff, responsive, and relifrom semiconductor manufacturable positioning of optics, probes, ing to atomic-force microscopy, shutters, and other small loads. from optical tweezers to sub-pixel Fortunately, a confluence of new imaging, from battlefield targeting piezo-based approaches has breathed to genomic sequencing and medinew capability into the nano- and cal devices. Known for nanometer micro-positioning world. Some of precisions, piezoelectric principles these represent significant incremental are proving highly adaptable to advancement of essentially traditional new configurations and modalities. mechanisms; others represent signifiRecently developed mechanisms cant forks in the road of positioning built on a variety of novel applitechnology. cations of piezoelectric technology have burst through the former travel NaNometer PrecisioN — over millimeters: loNg limitations familiar from classical travel Flexures nanopositioning mechanisms. But Piezo Flexure actuators provide travel ranges from When precision is needed, piezoeleclike those time-tested mechanisms, 0.1mm to 2mm with high force and speed. they tric actuation is the default choice. those built on these newer principles are optimized for microfluidics and nanodosing in offer high axial force, exceptional biotechnology or medical design, and are available Similarly, when high force or high speeds, compactness, fieldlessness, for fast auto-focus applications. the sketch shows a dynamics is required, piezoelectric and stable position-hold without small low-cost flexure actuator and the basic design actuation represents the gold-standard. Piezo actuators have long been dither. These long-travel piezomo- of a precision micro-valve. used in semiconductor manufacturtors offer valuable, proven solutions ing and testing applications for their for engineers grappling with tough ments have, until recently, had no soluextreme speed and precision. Lately, technical and economic needs. tion. Application examples abound: In a variety of fields, applications are • Optic assemblies of escalating microscope manufacturers and medical placing conflicting demands on struc- sophistication require multiple axes device manufacturers have also warmed up tural and motion subassemblies. In- of nano-precision alignment yet must to the benefits of this actuator technology creasingly, positions must be controlled remain aligned for months of around- that has even been embraced by the automotive industry. in more degrees of freedom with higher the-clock usage. Traditionally, piezo stack actuators dynamic and static accuracy, yet faster • Emerging nanoimprint lithogthroughputs and longer travels are nec- raphies demand exquisite positioning offer limited maximum travel, on the essary to meet financial metrics. Com- and trajectory control yet must retain order of 0.1 percent of the stack’s length. pactness is prized, yet high speeds are alignment integrity under significant Helpfully effective flexure lever-amplification approaches have been devised over demanded. These conflicting require- physical and thermal stresses.

[ w w w. des ig n n e w s . c o m ]

J an uary 2012 f luid p o we r / p o we r tr ans mis s io n / a s up p le me nt to de s ign n e ws F5

Fluid Power/Power Transmission

Vibrational behavior of a piezo ceramic slab in a miniature ultrasonic motor (measured with 3D scanning laser vibrometer).

many years which today provide travels up to 2mm. The downside is that the stiffness of lever mechanisms diminishes as the square of the lever ratio. This limits the bandwidth and thus the tracking performance of traditional servo-control techniques. So, demands for longer travels plus faster actuation or higher holding force are at cross-purposes. Furthermore, at some point the granularity of the driving DAC will begin to be seen, limiting coarse positioning resolution or introducing bit-transition noise in position waveforms. This is now addressable by novel controls technologies. Digital Dynamic Linearization, a non-traditional algorithm integrated into the latest digital nanopositioning controls, virtually eliminates following errors in repetitive motion patterns and scanning of these long-travel nanomechanisms. The controller integrates the algorithm into the metrology and servo logic; this optimizes the internal command generated for a repetitive waveform according to

Aurora-Where_the_Action_Is:Aurora 11/5/10 1:10 PM Page 1

Rod Ends and Spherical Bearings designed and manufactured to Aurora's exacting standards for quality and durability. Registered and Certified to ISO-9001 and AS9100. From economy commercial to aerospace approved, we've got it all !

Aurora Bearing Company 901 Aucutt Road Montgomery IL. 60538 Complete library of CAD drawings and 3D models available at:

w w w . a u r o r a b e a r i n g . c o m

F6 f lui d po wer/ power t r a n s m i s s i o n / a s u p p l e m e n t t o de s ign ne ws Ja n u a ry 2012

[ www.designnews.com ]

WE’LL WE’LL Do Do ThE ThE

LIFTING LIFTING & & LoWERING LoWERING

the error signal detected with the internal sensor. A brief (typically <1 second) autooptimization is commanded by the user (or a reload of previously saved optimizations) when application changes occur. After this, following errors are reduced to approximately the noise level of the system. This capability is supported by internal waveform generators and software drivers including COM objects, DLLs and LabVIEW libraries. Eliminating thE travEl/ rEsolution tradE-off

Piezo actuation is roughly proportional to applied voltage, typically generated by a digital-to-analog converter (DAC) driving an amplifier. The number of addressable positions for a piezo mechanism is 2b — where b is the bit-width of the DAC’s digital input. Traditionally, the resolution of the nanopositioner can be no better than its travel divided by this number. With today’s long-travel flexure nanopositioners, achieving tight resolution goals requires higher and higher DAC bitness.

miniature translation stage with ultrasonic linear motor compared to a 9v block battery. this unit provides 0.8 inch of travel with speed to 20 inch/sec, and 10g acceleration. a high-resolution linear encoder is also integrated. smaller versions are feasible.

two-axis ultrasonic motor controller and a compact XY long travel microscope stage. the intrinsic autolocking principle of the ultrasonic motor provides excellent long-term stability in microscope applications.

Settling Test: M-663 Piezo Motor Stage with C-867 Controller, 215g Load Actual Position 0.12

Position (mm)

0.1 0.08 0.06

Without load With load

0.04

ACE Controls Gas Springs ACE Controls Gas Springs provide counterbalance provide control counterbalance motion for lifting and motion control for lifting and lowering lids, hoods, hatches, lowering guards, lids, hoods, hatches, machine panels and more. machineinguards, and more. Offered a wide panels range of body sizes, Offered in a wide of body sizes, stroke lengths andrange forces. stroke lengths and forces. · Solid, Long Life Construction Solid,&Long · Push Pull Life TypeConstruction Designs · Push & Pull Type Designs Models Fixed Force or Adjustable · Fixed Force or Adjustable Models Stainless Steel Models Available Stainless Steel Models Available · Expert Application Sizing · Expert Application Sizing Aerospace, Defense, Transportation, RV, Aerospace, Defense,Packaging, Transportation, RV, Medical, Furniture, Printing, Medical, Furniture, Packaging, Printing, Amusement and More Amusement and More Product Information Product Available Information Online Available Online

0.02 0 0

0.02

0.04

0.06

0.08

0.1

0.12

Time (sec) settling behavior of an ultrasonic stage shows the extreme accelerations and fast settling this motor/controller combination is capable of.

Farmington Hills, MI 48335 tel: 800-521-3320 / fax:MI 248-476-2470 Farmington Hills, 48335 [email protected] tel:e-mail: 800-521-3320 / fax: 248-476-2470 e-mail: [email protected] www.acecontrols.com

www.acecontrols.com

Fluid Power/Power Transmission

High load PiezoWalk linear motor capable of 800N holding force, shown with operating principle.

Until recently, a DAC’s limitations were permanent characteristics of the specific chip chosen by the designer. Popular PC analog I/O interfaces like those from National Instruments typically top out at 16 bits, providing 65,536 possible output voltage states, with update rates to several million per second and useful waveform and synchronization capabilities, plus compatibility with popular programming languages like C++, VisualBASIC, and LabVIEW. OEM engineers designing their own controls might choose a 20or 24-bit DAC for their custom circuit design, but care must be taken, as they can present drift issues, noise, or other drawbacks. Sometimes a new design is not economically practical, necessitating use of lower-bitness legacy DACs, potentially problematic when highly leveraged PZT mechanisms are used. The recently introduced, patented HyperBit technology leverages the under-utilized time-domain capability of today’s DACs, converting it into up to 11 additional bits of physical positioning resolution. HyperBit employs modulation of the DAC’s least-significant bits (LSBs) to accomplish this. For example, the LSBs can be dithered using pulse-width modulation at a high rate. The result is higher positioning resolution without trade-offs. Many

optimized for next-generation microlithography alignment and positioning, NeXact actuator provides 10N power-off holding force and smooth coarse/fine motion over centimeters with picometer-class resolution in a compact, cost-effective format. F8 f lui d po wer/ power t r a n s m i s s i o n / a s u p p l e m e n t t o de s ign ne ws Ja n u a ry 2012

mechanisms and devices can benefit; a video which demonstrates this effect using a commonplace panel meter is available at http://dn.hotims.com/40992-510. For ease of implementation, this technology has now been built into the industry’s first LabVIEW library for analog nanopositioner interfacing. NaNometer PrecisioN over ceNtimeters

To address applications needing longer travels than can be met via lever amplification of piezo stack actuators, engineers have developed an array of new technologies based on novel configurations and actuation modes of piezo ceramics. resoNaNt Piezomotors (UltrasoNic motors)

In one example of this breed of piezomotors, a ceramic wafer is configured so that high-frequency excitation drives one or more resonant modes in its material, conferring a micron-scale oscillatory motion to a friction pusher tip affixed at an antinode. The pusher tip, oscillating like a miniature pogo-stick with nanoscale amplitudes and frequencies of hundreds of kHz, can then be preloaded against a guided workpiece, driving long-travel motion with dynamical behavior somewhat similar to that of DC servomotors. A wide assortment of linear- and rotary-motion configurations have been commercialized by providers in many countries over several decades, both open- and closed-loop. By eliminating lead-screws and their inertia and associated linkages and structures, such mechanisms can be very compact and responsive. For example, offthe-shelf linear stages can provide 19mm of travel at up to 500mm/sec and 10g acceleration with a 0.1μm resolution linear encoder, all in a package 35mm square. In-position stability is superior to conventional stages since the actuator acts as a brake when quiescent. Fieldlessness, vacuumcompatibility, long life, and other signature advantages of piezo actuation also apply. The drawback to these piezomotors has traditionally been their difficulty of control. Ideally, any motor would exhibit a linear stimulus-to-velocity curve. A small amount of friction present in most dcmotor mechanisms means a small but non-zero stimulus produces zero velocity — a departure from the desired linearity. Conventional controls technologies over[ www.designnews.com ]

Custom Hybrid piezoelectric and (brushless torque) motor actuator system with 0.6 inch travel and 200 lb force for astronomical application. The system provides extremely accurate positioning and tracing within less than 2nm rMs.

behavior, though from a different cause. Just as a child on a pogo-stick must achieve a certain threshold “bounce” before he moves, a certain threshold of stimulus must be applied to the resonant piezomotor before motion begins. This deadband behavior is great for in-position stability, but conventional P-I-D controls tend to be unhappy with it: so much integrator gain must be applied to accommodate the deadband that the setting is incompatible with running-at-speed. The controller oscillator frequency also needs to be in tune with the resonant frequency of the ceramic slab in the piezomotor, a fact that in the past required initial tuning and frequent adjust-

Hybrid leadscrew (spindle)/nut system with piezo fine adjustment for elimination of stick/slip effect and velocity variation. The unit is controlled by a special hybrid dual (PzT/DC servo) controller getting its position feedback from one external high-resolution 1 nanometer class linear encoder.

come this stiction with an integrating filter which escalates the stimulus as needed. Resonant piezomotors have a similar

POWER TRANSMISSION-PART CONVEYING

PYRATHANE BELTS With Lifetime Warranty Against Manufacturing Defects ®

ments during operation of a system. Both problems were solved with the latest generation of ultrasonic motor controllers developed by PI. An autotuning circuit constantly keeps the oscillator frequency in the optimum range; and a faster processor now automatically switches between gainsets, enabling the user to take full advantage of high velocity constancy and the exceptional stability these friction motors provide at rest. Piezo Walking Drives

By combining piezo elements acting in longitudinal and transverse directions, the foundation for a walking actuator is comCOLORS AVAILABLE

Samples available at little or no cost

CUSTOM MADE IN INCH, METRIC & O-RING SIZES Round, Flat and Connectable Polyurethane Belts Very Clean in Operation • Eliminates Tensioning Devices Exceptional Abrasion Resistance

Line Shaft Conveyor Belts - Original Equipment & Connectable DIAMETAPE BELT MEASURING TOOL Allows for accurate, non destructive measurements on o-ring and belt inside diameter (ID) or inside circumference (IC). Available in Standard and Metric Sizes.

www.pyramidbelts.com AN ISO 9001 CERTIFIED COMPANY

(P) 641.792.2405 • E-mail: [email protected] 522 North Ninth Avenue East, Newton, IA 50208

[ w w w. des ig n n e w s . c o m ]

Connectable (“PC”) Belts available in diameters ranging from .093” through .562”.

J an uary 2012 f luid p o we r / p o we r t r ans mis s io n / a s up p le me nt to de s ign news

F9

Fluid Power/Power Transmission posed. These elements can be compressed against a longitudinal rod to confer motion. One familiar progenitor of this family of mechanisms was the Burleigh Inchworm. More recently developed mechanisms offer extraordinary stiffness and holding force and are optimized

for reliability in applications requiring long-term position hold while providing centimeters of travel with picometer-class resolution. An even newer solution uses cost-effective bender-type piezo elements. Size and cost are substantially reduced; power-off

stiffness is still remarkable, with 10N holding force. This design also provides centimeters of travel range and picometer-class resolution, ideal for applications like optic positioning in microlithography and sample positioning in electron microscopy. In the case of both these mechanisms, motion occurs in two modes: a long-travel stepping mode, and a fine-motion analog mode in which the actuator elements are sheared but not stepped, providing subnm positioning capability. Hybrid Motorized/Piezo MecHanisMs

While the mechanisms discussed so far can displace magnetic motors, piezo actuation can also be combined with them for coarse/fine motion. Traditional “stacked” coarse and fine mechanisms operate independently; the piezo mechanism greatly improves the minimal incremental motion capability of the system, but the overall repeatability is no better than the motorized stage alone. The advent of linear encoders with nmscale resolution has allowed construction of hybrid mechanisms where both the coarse and fine mechanisms share the same feedback sensor. Coordinated by advanced controls, this hybrid provides piezo-class repeatability and fast dynamics over many cm of travel. conclusion

The field of piezo motion control has expanded rapidly in recent years, with a wealth of new concepts introduced, all aimed at eliminating piezos’ former travel limitations while preserving their unmatched resolution, responsiveness, and throughput capabilities. Consequently, not only is piezo actuation increasingly suitable for applications formerly addressable only by magnetic motors, but significant benefits accrue in terms of size, speed, fieldlessness, reliability, vacuum compatibility, resolution, dynamics and reliability. These in turn are enablers for significant advances in existing and new applications. Scott Jordan is director of NanoAutomation Technologies for PI (Physik Instrumente) L.P. Stefan Vorndran is VP of Marketing at PI (Physik Instrumente) L.P. For more information, go to www.pi-usa.us. F10 F lui d po wer/ powe r t r a n s m i s s i o n / a s u p p l e m e n t t o de s ign ne ws

Ja n u a ry 2012

[ www.designnews.com ]

Fluid Power/Power Transmission

IN THE MARKETPLACE Three-Piece MeTric rod ends

makes use of 1.4301 (304) stainless-steel hubs, precision machined to a high level of concentricity. Laser welded while mounted onto a common shaft to guarantee straightness, the couplings compensate for shaft misalignment and precisely transmit motion with zero backlash. Allowable temperatures range from -40C to 300C.

For high loads or high vibration levels. Metric rod end bearings built to DIN ISO 12240-1 (formerly DIN 648) schedule K typically are made with inner races or inner rings made of brass, bronze, or copper. For many low-demand applications, these bearings have proven to give satisfactory service. However, in applications with high loads and/or high vibration levels, they can quickly develop excess clearance do to the deformation of the softer race material. They are typically manufactured with low carbon steel bodies, with limited high strength options. For applications with high loads or high frequency reversing loads, parts in this type of configuration can give less-than-desired performance. The Aurora MM-M and MW-M series parts are made with a low carbon steel raceway. This construction offers ball/race durability greater than brass race parts, with a load capacity comparable to the more common configurations. For applications with vibratory loads, where the body strength or load capacity is not an issue, but severe demands are placed on the bearing itself, the Aurora KM-M and KW-M series offer a heattreated alloy steel raceway around the alloy steel ball in a low carbon steel body. The AM-M and AW-M series feature the heat-treated raceway bearing construction combined with a heat-treated alloy steel body. Combining the standard feature of a one-piece steel raceway, the MM/MW-M and AM/AW-M series are also offered with Aurora’s exclusive AT series PTFE liner for self lubricating/long life service. Aurora Bearing Co. www.aurorabearing.com [ w w w. des ig n n e w s . c o m ]

R+W America www.rw-america.com

series of orifices Provide dependable control of harsh liquids and gas. Bird Precision offers a unique series of laser drilled, wire lapped Ruby and Sapphire orifices. Orifices and filters are packaged in a variety of stainless, brass, and plastic fittings, connectors, and inserts. With chemical and wear resistance these products insure precise dependable control of even the most harsh liquids and gas.

Pureweld Xl weldaBle TuBing For the bio-pharmaceutical and pharmaceutical industry. PureWeld XL tubing is designed for high purity and secure peristaltic pumping. This weldable tube is capable of completely

Bird Precision www.birdprecision.com coMPacT sTainless-sTeel Bellows couPlings Available in 6 sizes, with torque ratings from 15Nm to 500Nm and English or metric bores from 12mm to 75mm. The newly developed BKS series of stainless-steel, welded bellows couplings from R+W are up to 1/3 shorter in length, reducing moment of inertia and saving space. Manufactured in Germany, the BKS

secure welding and allows for connectorfree fluid paths to be assembled in minutes. PureWeld XL was developed in a state-of-the-art extrusion facility followed with extensive testing inside peristaltic pumps. Test results show that PureWeld allows for the least internal spallation when compared to other weldable tubing, allowing the tube to remain pristine and outlast other brands, making it more economical than alternative products. PureWeld XL is a thermoplastic elastomer tubing and contains no animal-derived components that could leach into precious duty fluids. With a high level of purity and clarity, PureWeld XL is for use in sanitary environments in pharmaceutical and biotechnology processing applications, from research to production including cell media and fermentation, sterile filling and dis-

J An uARy 2012 fluid p o we r / p o we r tr ans mis s io n / a s up p le me nt to de s ign news f11

Fluid Power/Power Transmission pensing, high-purity water transfer, vaccine production, fluid transfer, and filtration. PureWeld XL meets full bio-pharmaceutical testing standards including FDA requirements and USP Class VI certification. Watson-Marlow Tubing www.wmtubing.com Push-to-ConneCt Fittings Fittings are designed for use in challenging applications. Beswick’s push-to-connect miniature fittings provide easy installation during tubing connections and reliability with Beswick’s O-ring seal design. All components, including the release collar, are fabricated from stainless steel.

This construction is useful for corrosive environments or in applications requiring “clean” materials. Models are available for 1/8 inch OD and 1/4 inch OD (stainlesssteel, polyurethane, and polyethylene) tubing. Options for threads include 10-32 UNF straight thread, adjustable position tee, and straight tube to tube connections. Buna-N O-ring seals are standard. Fluorocarbon, Silicone, and EPDM are stocked options. Beswick Engineering www.beswick.com/ ReveRsible DRum vaCuum systems EXAIR’s Premium Reversible Drum Vac Systems come complete with a 30, 55, or 110 gal drum. Its high-powered vacuum fills a 55 gal drum in less than two minutes. Then with the simple turn of a knob, the same stainlesssteel pump quickly empties the drum. The Reversible Drum Vac is compressed air-powered and attaches to the included drum. It is extremely quiet at 86dBA, making it suitable for a wide variety of applications. There are no motors or impel-

High Pressure • Long Lifetime • Quiet

This highly-efficient micro-diaphragm pump offers a high-pressure solution for reliably dosing or transferring liquids or liquid-gas mixtures. It features precision valves and diaphragm technology to realize high levels of efficiency. It can run dry, mounts in any position and is maintenance-free.

• For dosing, transfer, waste removal, recirculation • Compact 1.5 x1.5 x 1.25 in. Low power consumption • Maintenance-free, variety of motors available • Speed control and tach pulse feedback available • Corrosion-resistant material options • KNF welcomes your unique OEM requirements

The Premium Reversible Drum Vac System comes complete with a two-way pump assembly, shut-off valve, 10’ (3m) static resistant hose, 20’ (6m) compressed air hose, heavy-duty tools, spill recovery kit, toolholder (most systems), drum dolly, and 30, 55, or 110 gal drum with lock ring and lid. EXaIr Corp. www.exair.com

ADVERTISERS IN THIS ISSUE

Liquid Diaphragm Pump

5-60 ml/min adj. flow 145 PSIG Pressure NF1.5TT w/Brushless DC

lers to clog or wear out, and it is covered by a five-year warranty.

Ace Controls

F7

Aurora Bearing Co.

F6

Beswick Engineering Co.

F6

Hydraforce Inc.

F3

F12

KNF Neuberger Inc.

Peninsular Inc.

F4

Pyramid Inc.

F9

F10

R+W America

F2

Thomas Product

Liquid Pump Selection Guide

E! FRE

datasheets at www.knf.com/liquid KNF NEUBERGER, INC. 2 Black Forest Road Trenton, NJ 08691 609/890-8600 • knf.com

Publisher does not assume any liability for errors or omissions in this index.

PUMPS

F12 F LU I D PO WER/ POWER T R A N S M I S S I O N / A S U P P L E M E N T TO DE S I gN NE WS Ja n u a ry 2012

[ www.designnews.com ]

BERGQUIST HIGH-PERFORMANCE LIQUID GAP FILLERS

Bergquist’s New Liquid Gap Filler Has All Your Assembly Angles Covered.

Gap Filler1000SR (Two-Part) dispenses in-place without slumping, offering you optimal flexibility in component orientation during assembly. Gap Filler1000SR easily wets out under minimal pressure, The ideal thermal solution for automated dispensing. giving fragile components superior thermal protection. Unlike precured gap filling materials, liquid materials offer infinite thickness options and eliminate the need for specific pad thicknesses Gap Filler 1000SR is a two-component, room temperature cure, or die-cut shapes. Available in cartridge or kit form, Gap Filler 1000SR liquid-dispensable thermal interface material that features superb is just one of many liquid filling solutions available. Whether for autoslump resistance.This material offers ultra precise dispensing, mainmated or manual dispensing, Bergquist has all your angles covered. taining its shape on the target surface, offering you greater flexibility in your component orientation during Get your FREE Sample Card. assembly. As cured, this soft elastomer Take a closer look by getting your FREE Gap Filler provides a thermal conductivity of sample package today. 1.0 W/mK that is ideal for filling unique Simply visit our web and intricate air voids and gaps.The site or call us material flows easily under minimal directly to qualify. pressure resulting in little to no stress on Gap Filler 1000SR dispenses into position without slumping.With fragile components during assembly. minimal pressure, flows in place with little or no stress on components.

Call 1.800.347.4572 or visit www.bergquistcompany.com/slumpfree Request your FREE GF1000SR Sample Card and datasheet.

18930 West 78th Street 7 Chanhassen, MN 55317 7 A ISO 9001:2008 registered facility (800) 347-4572 7 Phone (952) 835-2322 7 Fax (952) 835-0430 7 www.bergquistcompany.com

Thermal Materials

7

Thermal Substrates

7

Fans and Blowers

34

Cover Storyer Story

Ethernet Converges on Factory Automation Ethernet adoption drives development of infrastructure to support completely networked, plant-wide architectures from field devices up to management level. By Al Presher, Contributing Writer, Automation & Control

T

he changing landscape in industrial networking is being shaped by the continuing adoption of Ethernet technology for plant-wide networks, and while the rate of change for convergence may seem like life in slow motion, there is real movement in the design of networks and increased support from infrastructure products. More than ever before, controls and IT groups are working together to improve security and management of networks. Trade groups for competing Ethernet communication protocols are working more closely on convergence topics. All of this ultimately supports the inevitable transition to real-time Ethernet connectivity from the simplest devices, up through the MES/ ERP layers, to help produce more informed business decisions.

D Deessiiggnn N Neew wss JNaonvueamr yb e2r021021 1 w www. wdw.e d s iegsni gnne n wesw . cso. m com

Completely Networked, Plant-Wide Architectures “One of the major trends we see is customers becoming more open and receptive to the idea of transitioning to complete Ethernetbased controls for their automation and motion application solutions,” says Ming Ng, PROFINET manager for Siemens Industry. In the past, Ng says there was more focus on use of fieldbuses, and engineers would use Ethernet for applications that required data capture and monitoring. But now, the solution portfolio has filled out, and the products and protocols have gotten to the point where it’s truly a viable solution. “This transition to Ethernet-based controls for applications leads us to this idea of a completely networked, plant-wide architecture. It’s a situation where you have Ethernet at the field level, going all the way up to the

35

A growing trend in industrial networking is the desire to manage and maintain the entire network from one terminal, including diagnostics and historical reports of the network status. To address this demand, Siemens has developed Sinema Server as a tool geared for automation engineers to provide this comprehensive functionality.

focus on interfacing with IT to address the business concerns of connecting those systems. While the goal is to move large amounts of data regardless if you’re in IT or you are the plant engineer, that production data is going to supply a certain level of business excellence. At the same time there is more need to understand how to plan those networks accurately. Ng says there is also more discussion needed in the advanced planning of networks, accurately segmenting the networks, implementing a comprehensive industrial network security concept, and assigning domain experts. “Now that we are talking about having access to all the data, it comes with a certain level of responsibility,” says Tim Pitterling, industrial Ethernet infrastructure product manager for Siemens Industry. “Planning in advance with these networks is more visible as to why you need it, compared to implementing a fieldbus. When you’re implementing a fieldbus, it can be its own little island,” Pitterling says.“You can implement solutions on the fieldbus network that are dedicated, and you don’t need to take other factors into

account like multiple protocols and network traffic. But the benefit of Ethernet infrastructures is access to data in realtime, and the value of that data is so high, a little bit of planning goes a long way.”

Customers that are familiar with programming Logix PLCs can use the same tools to configure Rockwell Automation’s Stratix 8000 Ethernet switch. The switch appears in the software configuration tree just like a controller, I/O module and drives in the control system architecture.

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

Source: Siemens Industry; Rockwell Automation

management level and interfacing more closely with the business side of companies,” Ng says. Along with complete automation solutions that include HMI, PLC, I/O, wireless remote drops and that level of integration, now there is also the possibility of wireless remote I/O drops that are in hard-to-access areas, and new possibilities when it comes to engineering solutions. With the move toward essentially a plant-wide network, one growing trend is development of more products to support higher backbone data rates. More bandwidth is a key advantage as more functions run from the network, and the escalation requires more bandwidth in the network infrastructure. “With a fieldbus, customers had a very dedicated network and many times they were only transferring I/O,” says Ng. “Now with the Ethernet infrastructure, customers have the ability to have voiceover-IP and multiple protocols all riding on that same infrastructure.” A third major trend is the interest and adoption of wireless, both new wireless standards such as 802.11n or incorporating wireless as another method of engineering a solution. Wireless is being applied to replace physical connections or to eliminate wiring where in the past a physical slip ring and connection was used to provide data to a moving object. People are also investigating wireless solutions to reduce the engineering effort and the points of electro-mechanical failure. Prime examples would be applying wireless technologies in automated guided vehicles (AGVs) or automated storage-retrieval systems (ASRS) applications that are moving a lot of equipment and, at the same time, tracking a lot of data. These kinds of applications are in the sweet spot for going to a plantwide network that focuses on wireless connectivity. Along with the trends comes a certain level of challenges, including people becoming receptive to the plant-wide network, and having large networks for both of their production and business level operations. Plus, there is increased

36 Cover Story also industrially focused,” says Hannah. “Customers used to programming Logix PLCs can use the same tools to configure the Ethernet switch. The switch appears in the software tree just like the controller, I/O module and drives that you would typically see in the control system architecture.” Rockwell Automation also announced a smaller, scaled-down version of the switch that will be released in 2012, a fixed port switch offering up to 20 ports and flexibility for fiber and small form factor pluggable devices. This product is well-suited for entry-level type applications and for small and mid-range machine builders that don’t want to be network experts. “There are a number of things available to the IT community through the Cisco Command Line Interface (CLI) programming,” says Hannah.“If you know how to program in CLI, you can pull all kinds of diagnostic information out of that switch. But typical PLC customers aren’t necessarily CLI experts, so we provide an interface through our Logix program. It puts the diagnostic information into the hands of the programmer, so that EtherNet/IP-enabled devices can see and share the data.” Sercos III Industrial Ethernet Solutions At the recent SPS/IPC Show, Sercos announced a number of developments that strengthen its support for industrial Ethernet networking. One important feature included in the new version 1.3 of the Sercos III specification is an IP Profile which lays out a standardized support infrastructure for slave devices using TCP/IP communications. “Sercos has reached a new level of maturity both in the standard and the feature set within products,” says Scott Hibbard, vice president of technology for Bosch Rexroth. “For the most part, all of the basic and even mid-level inter-operability requirements have been implemented, and we are starting to see companies now coming out with new products.” “Originally, the thought was that with

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Sercos recently introduced EasySlave, an FPGA-based single-chip controller, to enable inexpensive development of slave devices.

the time available on a Sercos III network to allow communications from other devices that suppliers would develop their own ways to use it for communications, such as standard TCP/IP,” says Hibbard. “But we received feedback from product suppliers on the need for a standardized method to read and write the standardized Sercos variables or IDENTs.” Every Sercos device has a MAC address and IP address if they choose to support TCP/IP communications on the network. Most drives in the marketplace provide this capability and can be accessed at any time whether Sercos is running to communicate in a standardized manner, download firmware, and upload parameters. This makes it easier for engineers to include these devices as part of their network for monitoring variables or downloading new values. Sercos has also introduced an EasySlave pre-packaged device designed to make it easier and less expensive for manufacturers to develop simple Sercos III slave devices. This FPGA-based single-chip controller offers a real-time channel with one input and one output connection, and supports cycle times as low as 31.25 usec. The I/O applications are synchronized in the Sercos cycle, and an IP core is provided as a netlist for the Xilinx Spartan-6

Source: Sercos International

Plant-Wide Ethernet Infrastructure “We are definitely seeing the need for transferring data from the plant into the MES/ERP layers in real-time to allow companies to make more informed decisions,” says Mike Hannah, marketing manager — networks for Rockwell Automation. “One key is a plant-wide network infrastructure based on standard Ethernet which creates connections between level devices, all the way up through the MES layer into the enterprise space.” Hannah says that one trend in new product development is to find better ways to communicate diagnostic information and simplify how that information is gathered. It wasn’t too long ago when users who wanted to do a motion application using safety devices, I/O and peer-to-peer interlocking, would have to configure, program and maintain multiple, purpose-built networks. EtherNet/IP has enabled the convergence of these networks, though many companies are still segmenting networks through a physical connection and integrating two EtherNet/IP bridge modules into the rack. Often, one module is managed by the controls professionals to control the machine, and the other is managed by IT to control information. “There is often a cultural struggle between the controls and IT professionals because in many cases they are isolated and totally independent groups working toward different objectives,” says Hannah. “One of the drivers that we are pushing is to make sure people are following the standard. Standard Ethernet shouldn’t require special switches or special infrastructure in the plant because you want to start converging on these networks.” Rockwell Automation and Cisco are working together with ODVA to develop specifications for devices that encourage users to follow a common standard. The companies also work on joint product collaboration, such as the industrial Ethernet switch, the Allen-Bradley Stratix 8000. “It is the best of both worlds, a switch with the Cisco operating system that is

37 FPGA family. The IP core contains all the functions of a Sercos slave connection, including the associated software library for I/O devices (e.g., analog inputs or encoders). Sercos has also been investing time in collaboration and convergence topics, including the ability to communicate more effectively with other Ethernet bus protocols. Earlier this year, they announced an agreement between ODVA (DeviceNet and EtherNet/IP), Sercos International, and the OPC Foundation to work together on common topics. “Each of these standards competes with one another in some areas but there are a lot of application areas where we don’t overlap,” says Hibbard. “The goal is to look for ways when we do have multiple buses in a system to make it easier to move data back and forth.” One example of progress is a joint initiative called the Optimization of Machine Integration. The idea is to look at a piece of machinery, determine what data is needed throughout the system, and to decide on a common method for communications. “I think there is going to be more pressure in the near future on coming up with interoperability solutions to make life easier for engineers applying the technology in the field,” Hibbard says. “What we’re looking at is more common technologies. CIP Safety as a common safety protocol for EtherNet/IP and Sercos networks is a very good example for this. We are confident that further collaboration will be announced in the near future,” says Hibbard. “Customers really don’t care about protocol compatibility. Just like on my PC, I can have different protocols running across my network inside the office. They share a common base protocol but on top of that they do their own thing. It’s harder in real-time but it can be done.” ODVA has announced the availability of a new white paper, Optimization of Machine Integration (OMI), which outlines this strategic vision for an open and interoperable communication framework in the industrial sector. For machine

builders, OMI provides opportunities for creating additional value through simplified communication between machines and from machines to supervisory systems. The white paper is available at www.odva.org. DN

For More Information: Rockwell Automation: www.rockwellautomation.com Bosch Rexroth: www.boschrexroth-us.com Siemens: www.usa.siemens.com

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

38

Electronics & Test

Micro Hybrids Hit the Road Starter motors with automatic starting capabilities will hit the auto market in a big way in 2012. Within 15 years, every new vehicle could offer “start-stop.”

In addition to a heavy-duty starter, start-stop systems require such components as enhanced engine control, battery management, dc/dc converters, and more robust crankshaft sensors. D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Source: PennEngineering

By Charles J. Murray, Senior Technical Editor, Electronics & Test

39

I

f you start your car two or three times a day right now, prepare for a shock. Over the next decade, that figure is likely to rise by a factor of 10. Soon, your car’s engine will automatically shut down at traffic lights and stop signs. It will turn off during heavy rush-hour driving. It may even shut down when you pull your foot from the accelerator and coast, possibly at speeds of up to 75 mph. The so-called “start-stop” wave is coming, say experts, and the auto industry is bracing for its arrival. “It’s going to start happening in 2012,” says Doug Patten, senior vice president of engineer ing for Denso Inter national America, an automotive supplier introducing a family of new starters. “And it’s going to ramp up fast. The start-stop change will affect a large percentage of the market over the next three years.” Indeed, US automakers have begun unveiling a new breed of start-stopequipped vehicles. Ford, Chevy, Buick, Kia and BMW will all roll out the technology early in 2012, joining a handful of models from Fiat, Volvo and Alfa Romeo that already have it. Moreover, start-stop has also taken hold in Europe, rising from about 5 percent of new vehicles in 2008 to more than 20 percent today. The reason for this seemingly sudden phenomenon is obvious: When your engine is turned off, it doesn’t burn gasoline. Brief shutdowns can boost fuel efficiency by 3 to 10 percent, suppliers say. That figure will rise even higher if automakers are willing to shut off the engine while the car is coasting. Chances are, adoption of the technology will be fast, even if consumers don’t demand it. New corporate average fuel economy (CAFÉ) regulations in the US call for cars and light-duty trucks to reach 54.5 mpg by 2025, adding a sense of urgency to start-stop’s uptake. “Eventually, we’ll see 100 percent of new vehicles offering start-stop,” Patten

says. “It will probably happen over the next 10 to 15 years.” More Starts, Better Parts To be sure, the start-stop concept is hardly new. The technology dates all the way back to the mid-1970s, when Toyota is said to have begun testing it on sedans in Tokyo traff ic. In the 1980s and ‘90s and 2000s, Volkswagen, Audi and Citroen introduced it on their production vehicles. Adoption in the US, where gas prices are lower and highway driving is more prevalent, has been slower, however. But it’s coming. To some degree, it has arrived already in the form of motorgenerators on full hybr id vehicles, which inherently incorporate start-stop capabilities. It’s also present in so-called “mild hybrids,” which use a motorgenerator for start-stop capabilities and regenerative braking, but not for elec-

Start-Stop Snapshot Definitions from the start-stop world:

Micro hybrid: A conventional gasoline-burning vehicle that uses a beefedup, 12V, geared starter. The heavy-duty starter must have more durability than today’s conventional starters and, more importantly, must be able to automatically start the engine when a driver moves his or her foot from the brake to the accelerator. Micro hybrid systems can boost fuel efficiency by 3 to 10 percent. Mild hybrid: A conventional gasoline-burning vehicle that incorporates an integrated starter-generator or belt-driven starter-generator. The mild hybrid offers start-stop capabilities, greater fuel efficiency, performance boosts and other features, such as regenerative braking. Mild hybrid powertrains have boosted fuel efficiency by 25 percent or more.

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

Small size, big pump performance

NEW The leader in peristaltic pumps introduces the 114D pump. This new sprung track pump design delivers the performance, reliability and style not previously available in a pump of this size. The 114D joins thousands of off-the-shelf and custom peristaltic pump solutions for:

• Medical Devices • Diagnostic and Chemical Analyzers • Food/Vending Equipment

Call for free catalog or trial.

1-800-282-8823

www.wmpg.com [email protected]

40

Electronics & Test Bosch’s start-stop starters can reduce a vehicle’s fuel consumption by 5 percent.

Continental Automotive’s 15kW belt-driven motor-generator supports start-stop capabilities and regenerative braking, while offering a performance boost for the vehicle.

The Buick LaCrosse will employ GM’s eAssist technology, which enables the vehicle to shut off fuel to the engine during deceleration and boost fuel economy by 25 percent.

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Source: Spiralock

Denso’s TS (tandem solenoid) starter inserts the starter’s pinion into the drivetrain’s ring gear before the vehicle comes to a full stop. Using that strategy, the vehicle is ready to restart almost immediately.

41

Source: General Motors

The Buick Regal and the Buick LaCrosse use eAssist to provide start-stop capabilities and recharge the vehicles’ lithium-ion batteries.

tric propulsion. This decade’s big change, however, will be the emergence of the “micro hybrid” — a conventional gasolineburning vehicle that uses an enhanced 12V, gear-based starter to enable its engine to shut down during short stops. “It’s a big change,” says Robert Martin, director of engine electrical engineering for Denso International America. “We’re talking about 10 times as many starts. If you start your car two or three times a day now, then you might be doing 25 or 30 activations a day with start-stop.” Indeed, suppliers estimate that the new breed of starter motors will have to be able to handle anywhere from 250,000 to 350,000 starts over the lifetime of a vehicle, up from about 30,000 today. As a result, next-generation starters will be designed and built differently. Although starters will still employ magnet-based dc motors and internal planetary gear sets, other changes are imminent. All of the starter’s wear components — such as bushings, commutators, and brushes — will be upgraded. Brushes, for example, will migrate from copper to a harder, coppercarbon blend. Bushings will be replaced

by needle bearings. Commutators will be reinforced. Mechanical components, such as overrunning clutches and engagement mechanisms for the starter’s pinion, will also be upgraded. Stainless steel will replace steel and plastic in some components. Springs will be improved. “You need to consider all kinds of components,” says Frank Fr ister, product manager for the Starters and Generators Division at Robert Bosch LLC, which makes start-stop systems. “The duration of operation is much longer in all of them.” Faster Restart Component durability, however, is only a small part of the start-stop puzzle. Suppliers and automakers alike look at start-stop as a system that’s integral to the overall design of the vehicle. “The key is to make it unnoticeable to the user,” Patten says. “The driver shouldn’t even know the start-stop system is there.” Making that happen, however, isn’t easy. The first step is in the vehicle’s engine control module (ECM). Engineers say the vehicle needs to “know” whether start-stop activation is immi-

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

42

Electronics & Test

nent. To do that, it checks wheel speed sensors to deter mine if the car is stopped and brake pedal sensors to see if the brake pedal is depressed. That’s only the beginning, however. Even when a microcontroller deter-

mines that the vehicle is stopped, it still has to go through a long list of “enablers” and “disablers.” Is the seat belt fastened? Is the eng ine fully war med up? Does the battery have adequate charge to restart the car?

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

In all, a vehicle is likely to go through about 30 items on the checklist. Once satisfied, it will shut down the engine and keep it that way as long as the driver keeps a foot on the brake pedal. When the foot comes off, however, everything changes again. The starter cranks, a pinion is thrust back into the drivetrain’s ring gear, and the engine breathes again. In all, that process — brake pedal to accelerator to motion — is expected to take about half a second. And therein lies one of the start-stop’s great challenges. To make start-stop invisible to the driver, automotive vendors need to supply a system that comes back to life quickly and quietly. Drivers, it seems, don’t want to have to wait five seconds when a traffic light turns green. The key to faster starts lies in the control strategy. In the past, the driver activated the ignition switch, causing a solenoid to engage the starter’s pinion, which, in turn, inserted itself into the drivetrain’s ring gear. Thus, the engine turned over. Now, engineers want to be ready to engage the pinion earlier in the process. Using a more robust crankshaft sensor, they can continually measure the position of the crankshaft, thereby knowing piston position. As a result, the controller “knows” which cylinder needs to have fuel injected into it. “By knowing the crankshaft position from the start, we can eliminate the time that’s required to crank (the engine) for one whole revolution,” explains Frister of Robert Bosch LLC. Advanced solenoid designs are also helping to reduce start times. Denso, for example, has rolled out its TS (tandem solenoid) starter, which inserts the pinion into the ring gear before the vehicle comes to a full stop. Using that strategy, the vehicle is ready to restart almost immediately. “Start-stop sounds very easy,” says Guenther Raab, director of systems engineering for Continental Automotive in North America. “Anybody can stop an engine and re-start it again. But

43 when you have to do it automatically, there are a lot of matters to consider.” Coasting And Comfort I ndeed , a s st a r t- stop tech nolog y evolves, suppliers have also begun to consider some of those other technical matters. Among them: noise; comfort; and turning off the engine while the vehicle coasts. In the interest of being “unnoticeable,” noise has become a growing concern. Suppliers want to minimize the sound of cranking starter, especially since it could be cranking dozens of times per day. Engineers are addressing that with the addition of rubber isolators and noise absorbers in or near the starter. To help further reduce cranking noise, they are also working with

involves the use of a cooling storage evaporator, piggybacked atop the AC evaporator. Such evaporators would incorporate a phase change material that would allow drivers to continue cooling the vehicleJan for 2012 50 seconds, or DNews-Hky+M60 12/19/11

maybe even a minute. “That would cover 90 percent of the stops,” says Frister. “So you’d get your air conditioning effect and your full fuel economy improvement at the same 11:54time.” AM Page 1

“By knowing the crankshaft position from the start, we can eliminate the time that’s required to crank (the engine) for one whole revolution.” automakers to insulate noise in the ring gear, which exists outside the starter. “When you’re talking about 10 times as many starts, you want to do your best to help lower that cranking noise,” says Martin of Denso. Driver comfort is an even bigger concern. In today’s vehicles, engine shutdown means no air conditioning (AC) or cabin heat. To combat that, suppliers are looking at ways to keep the AC and heat going, if just for a minute. The simplest way is to use an ambient temperature sensor, which would enable the vehicle to decide if the car needs to be restarted for comfort reasons. A more advanced solution

The most complete, easy-to-use catalog of quality assured SMT and THM interconnect components and electronic hardware available to the industry. • Battery Clips, Contacts & Holders • Panel Hardware • Pins, Plugs, Jacks and Sockets • Fuse Clips and Holders • PC Board Hardware • Terminals and Test Points • Spacers and Standoffs • Multi-Purpose Hardware

RoHS Compliant

~ ISO 9001 Certified

ELECTRONICS

®

C O R P.

(718) 956-8900 • e-mail: [email protected] • FAX (718) 956-9040 (800) 221-5510 • Website: keyelco.com Available from our global distributor network w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

Electronics & Test

To provide heat during the winter, suppliers are suggesting the use of an electr ic pump that would circulate engine coolant to a heat exchanger. Such pumps would enable the blower to continue running, thus warming the

vehicle cabin. The biggest technical challenge, however, is turning off the engine while coasting. As difficult as it is, though, suppliers and automakers alike see it as an important step forward. Using

start-stop during coasting, they say they could provide an additional 10 percent fuel economy boost, on top of the efficiency savings inherent in the use of start-stop at 0 mph. “The first-generation start-stop systems will be used only at full stops,” says Martin. “But next-generation systems will be shutting the car off at 4, 5, or 6 mph. There’s even talk of eventually going further than that.” Making that happen calls for a multitude of designs changes, not only to the starter, but to the vehicle, as well. The most basic challenge is synchronizing the starter motor to the powertrain’s spinning ring gear during deceleration. There, the more robust crankshaft sensor plays a key role. But the trickier problem lies in the fact that drivers often decelerate without intent to stop. “It takes one second for the engine to go from idle speed to zero,” Frister states. “In that one second, the driver could decide, ‘I don’t want to stop. I want to accelerate.’ In that instance, the starter motor would be accelerated to a certain speed, and then injected back into the rotating ring gear in a synchronized fashion.” Engine shutdown during coast also presents other challenges for the vehicle. Electric steering would be a must. Braking could require an extra battery. “Today, we have an alternator and a battery, so we have a redundancy,” Frister says. “But when you shut off the engine, the redundancy goes away. To regain your redundancy, you would need an extra battery.” Bosch engineers believe they could shut down the engine at speeds as high as 75 mph. “The key is the starter,” Frister says. “It has to be capable of starting in a synchronized way, so it can engage that spinning ring gear.” Mild vs. Micro An alternative to adding start-stop to conventional vehicles is simply to opt for hybr id vehicle capabilities. Full hybr ids inherently offer start-stop

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

ůĞĞĚ

44

45 as part of the electr ic propulsion scheme. Mild hybr ids offer it, too, although they don’t offer direct electric propulsion. Automakers and suppliers alike are working on belt-driven motorgenerators for mild hybrid systems. Continental Automotive now offers a belt-dr iven motor-generator, and General Motors has rolled out a system called eAssist on the 2012 Buick LaCrosse and Buick Regal. Such systems, which cost more than traditional 12V geared starters, offer start-stop and a multitude of additional benefits. eAssist, for example, engages its belt-driven motor-generator during deceleration, allowing it to recharge the LaCrosse’s battery while it slows down. It also offers “torque smoothing,” as well as a performance boost for the engine when a vehicle traverses steep grades. What’s more, systems such

as eAssist don’t shut down the engine during coasting and deceleration; they simply cut off the fuel flow. As a result, they don’t need to repeatedly shut off and restart the engine if a driver is going in and out of the accelerator. “It’s more refined, more consistent,” says Steven Poulos, global chief engineer for General Motors’ eAssist. It’s also more fuel efficient and more expensive than micro hybrids. GM claims that eAssist bumped the LaCrosse fuel efficiency by about 25 percent, with city driving going from 19 mpg to 25 mpg, and highway from 30 mpg to 36 mpg. While the giant automaker won’t talk about cost, it acknowledges that the belt-dr iven motor-generator adds more to the overall cost of a vehicle than a conventional 12V micro hybrid starter would. Ultimately, such schemes are a reflection of the fact that no one knows

which flavor of start-stop will best resonate with consumers. All they really know is that start-stop is coming, so they’re hedging their bets with a number of technological options. What’s more, all are in agreement that it’s best to keep the driver as unaware of the technology as possible. “If it’s integ rated well, customers won’t know that they’re driving a start-stop system,” says Patten of Denso. “As engineers, we feel like we’ve done the best job if they don’t know what it is.” DN

For More Information: Denso International America: http://www.densocorp-na.com/ Robert Bosch LLC: http://dn.hotims.com/40992-508 Continental Automotive in North America: http://dn.hotims.com/40992-509

Industrial and Commercial

Nameplates

ϴϬϬ͘ϲϮϰ͘ϲϲϰϭ ǁǁǁ͘ŵĐůŽŽŶĞ͘ĐŽŵ ͞:^:ƵƐŝŶĞƐƐ͟ w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

46 Materials & Assembly

Adhesives Put New Twist on Fastening Engineers are demanding multi-function adhesives and more rugged fasteners. By Ann R. Thryft, Senior Technical Editor, Materials & Assembly

Engineering-grade, pressure-sensitive silicone adhesives such as FLEXcon’s Densil for brake damping must resist dirt and moisture, temperature extremes, and corrosion by substances such as brake fluid.

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Source: FLEXcon

S

tructural adhesives and industrial fasteners are becoming more rugged and easier to integrate into the manufacturing process. Both are becoming more resistant to temperature extremes, providing better strength, stability, rigidity and structural integrity, and improved resistance to chemicals and corrosion. Some adhesive technologies are reducing or eliminating the need for mechanical fasteners, and some fastening technologies are replacing assembly methods that used traditional fasteners. The argument for replacing basic fasteners with adhesives has several components. One is the shorter time required to apply adhesives than to insert fasteners. Another is the superior bond coverage of an entire surface compared to bonds made only where fasteners such as bolts or rivets are located. Fasteners also punch holes in substrate materials, compromising their integrity. This creates avenues for moisture or chemicals to enter and corrode metal surfaces in between fastener joints. The definition of a structural adhesive varies with different contexts, according to Bill Sullivan, vice president of FLEXcon’s performance products group. “What are the force and weight placed

4848 Materials & Assembly

Source: PennEngineering

PennEngineering’s PEM self-clinching fasteners speed assembly by reducing the number of steps required and by producing a permanent bond.

on the items to be bonded? Are you suspending a big chunk of concrete over a bridge, or bonding two small, lightweight panels that stand upright on their own?,” he asks. If the application needs an adhesive in the cockpit of a plane, either chemical or pressure-sensitive types would be appropriate. But thermoset or pressure types are not the best fit where a lot of weight and force are involved, since they tend to be viscoelastic. “You can also use two-part liquid systems, such as epoxies, to hang heavy AIR006_DashDemoAd_DN7x3.375ƒ:AIR006

weights,” says Sullivan. “Some heat-activated, chemically activated, time-release chemistries bond over time and work like pressure-sensitive adhesives.” One widely used definition of a structural adhesive from 3M is withstanding 1,000 lb psi in overlap shear, says Heather Doughty, technical application engineer for Fabrico. “With structural adhesives, typically the substrate fails before the adhesive,” she says. There are also acrylic foam tapes permeated with7:31 adhesive throughout the 6/30/10 PM Page 1

foam, such as 3M’s VHB and Norton’s Normount. “Technically, these are not structural according to 3M’s definition,” says Doughty, “but they can replace mechanical fasteners in applications with a lot of vibration, such as box trucks or moving vans.” Here, viscoelasticity is a benef it. “These foam tapes have great flexibility in recovery, as well as excellent resistance to vibration,” says Doughty. Many structural adhesives are so strong that their material cannot also be f lexible. Moving vans or box trucks are often made of aluminum panels and steel struts, but welding aluminum to steel is not usually an option. These trucks must withstand temperature extremes, and a structural adhesive with no give ends up compromising the aluminum. In contrast, foam tapes can stretch as needed. They act almost like a gasket by padding surfaces as well as adhering them. Engineers are asking for more adhesives with multiple functions such as resistance to chemicals, corrosion, humidity, and extreme temperatures, says Sullivan. “We’re also getting more inquiries for bonding solutions, not always structural, in robotics, medical, aerospace, and military applications.”

Get your hands on our free demonstrator. Visit us at airpot.com. With no seals to wear out and no hydraulic fluid to leak out, the super responsive Airpot dashpot can soak up unwanted motion indefinitely. See for yourself. Visit airpot.com and request our free Airpot demonstrator or call us at 800- 848-7681.

We make what you make run smoother. ®Airpot is a registered trademark of Airpot Corporation, 35 Lois Street, Norwalk, CT 06851 D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Airpot.com

49

Self-locking Spiralock fasteners use an innovative wedge ramping technique to improve joints in high-performance aerospace and automotive applications.

are really a big factor for raw steel,” says Doughty. Often an adhesive can protect a substrate against corrosion because it protects so well against water and other liquids. “So as long as the adhesive sticks to the underlying steel, there’s no corrosion problem unless the underlying steel itself is already corroded.” Chemical exposure also affects adhesives. Typically, in many factories there

are hydraulic f luids, machine oil, and various paints or coatings. Some chemical dips used before paint processes can compromise paints not tough enough to resist them. There are also solvents and cleaners like acetone and methyl ethyl ketone that can harm adhesives. Today, plant managers are demanding adhesives that are easier to handle, easier to apply, and faster to use, according

Source: Spiralock

Medical and military/aerospace applications also need these characteristics, as well as more chemical resistance. Pressure-sensitive adhesives also help reduce VOCs, a requirement of many plant managers, according to Sullivan. “We did some work with an aerospace company that used a liquid adhesive to bond two surfaces together in the cockpit of a plane. We went in with a pressuresensitive adhesive, eliminating the need to use a liquid bonding adhesive. This also eliminated the time needed to process the liquid bonding, so they got better throughput in their internal processes.” Throughput and cost are also reduced when fasteners are replaced by laminating. Often, using adhesives can be as fast as a single laminating step. Adhesives that are resistant to temperature extremes also come into play in automotive and aerospace applications, says Doughty. Automobile interiors are hot environments, and an aircraft exterior gets very cold at high elevations. Most applications, however, occur at temperatures below 225F. Most adhesives can handle temperatures up to 225F without compromising their characteristics, and many perform well even above that. “We’re finding that corrosion and rust

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

to Doughty. “For example, they want operators to be able to use them with applicator guns. This is occurring mostly because of pressure to reduce throughput times.” Another trend is more customizable combinations of open times and cure times, says Doughty. The two are not always directly correlated. Super Glue, for example, has a long open time, but a short cure time. With most two-part adhesives, though, like acrylics and toughened epoxies, open and cure times usually are directly correlated. If one has a short cure time, it also probably has a short open time. “What’s changed is that now there’s more variety in the combinations you can get, more versions of one product, so operators and assembly people have adhesives with the properties they need,” says Doughty. At the same time, fasteners are going through their own evolution. Some engineers prefer metal fasteners rather than

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

DIRAK’s D-Snap snap-in fastening technique eliminates fastener hardware used in the assembly of cabinets and enclosures, making the process faster and eliminating tools.

adhesives because it can be difficult to separate the adhesives from other materials before recycling. Another often-cited critique is the fact that adhesives don’t address design-for-disassembly issues. Some fastening methods have replaced other types

of assembly. Meanwhile, several venerable technologies are still going strong. Although PennEngineering developed the self-clinching fastener more than 30 years ago, it’s still used extensively to hold together cabinets and components made of thin sheets of metal by creating a strong screw thread, says Leon Attarian, global director of marketing for PennEngineering. “It’s truly a design-for-assembly product because it reduces the number of steps and components required. It’s more of a component than a fastener in that it becomes part of the host material.” The fastener is squeezed onto the sheet metal, which deforms around the fastener, forming five or six attachment points in the sheet. It becomes permanently mounted, eliminating the problem of an assembly that is not easily assembled or disassembled without losing all the hardware. “From that, we expanded into externally and internally threaded, locking threads; captive screws; and other

Source: DIRAK

50 Materials & Assembly

51 types, all installed the same way,” he says. One of the main changes PennEngineering sees is the shift to smaller systems, such as portable consumer devices, so materials have to be both stronger and thinner, says Attarian. “Before, there was a minimum sheet requirement but no maximum requirement. Now there is. So we had to develop products that could get into these new materials, but still offer the same feature of being permanently fastened.” Another older fastening technology is the self-locking Spiralock. It’s used in difficult, challenging joints and fastening connections in medical, aerospace, and automotive applications, says Brian Mann, chief application engineer for Emhart Teknologies – Spiralock. Aircraft engines are running at higher service temperatures in order to get to higher speeds and better usability, so they are using more high-temperature nickel alloys for resistance to those temperatures.

“So engineers are putting more R&D into developing and testing the actual joints for torque and friction, to make sure that they will stay together,” says Mann. The Spiralock helps objects stay together under environmental stress and vibration. “We’re producing more fasteners out of stainless steel than in the past, because customers are more concerned about corrosion resistance,” says Mann. “Corrosion resistance is better now because of better coatings.” DIRAK started out as a maker of hinges, swing handles and quarter-turn screws, nuts, and bolts, says Gregory Breads, the company’s product manager. DIRAK’s D-Snap technology was originally designed to better fasten these products, such as securing a hinge or a swing-handle, for example. Now it’s integrated into all of them. “D-Snap was designed to replace all traditional fasteners for hardware, whether riveted, screw in or welded,” he says. “The idea is to

Sunnex is the task lighting specialist – providing robust halogen and LED lighting solutions for demanding applications including medical, industrial, machine, marine and military.

Sunnex Brings Powerful Light to Your Design For over 30 years, Sunnex has manufactured lighting products that have set the standard for quality and durability. Design our lights into your equipment or machinery and guarantee ease of use and dependability.

Take us to task!

Do you have a special requirement? Contact us and our engineers will work with you to create your own custom solution.

www.sunnexonline.com 800-445-7869

eliminate tools and cost from the process. Using D-Snap technology, installation time is 80 to 90 percent lower to assemble a full enclosure compared to traditional fasteners. It’s self-centering, so you can even use it to do blind assembly, such as inside a hollow tube.” The company has seen an increase in the number of requests for rugged products from engineers in industries that normally need rugged fasteners, but that are branching out into similar fields, says Breads. “For example, a customer may have been making server cabinets for use in air-conditioned offices, and now they’re making them for use on battleships.” DN

For More Information: FLEXcon: www.flexcon.com Fabrico: www.fabrico.com PennEngineering: www.pemnet.com Spiralock: www.spiralock.com DIRAK: www.dirak.com

Who says you can’t... have it both ways? Type Type 343 343 (stiffer): (stiffer):

More More easily easily directed directed and and “fed” “fed” through through tight tight spaces. spaces.

Type Type A397 A397 (more (more flexible): flexible): Readily Readily conforms conforms to to sharp sharp bends bends and and turns. turns.

Varglas A397 and 343 Acrylic Sleevings

Available as either A397 (flexible) or 343 (less flexible), both Varglas Acrylic Sleevings are resistant to most acids, oils, organic solvents, water, cut–through and abrasion. They are compatible with a wide range of wire enamels and are designed to perform for long periods in a Class 155˚C range, as well as at low temperatures, with no loss of electrical or physical properties. Varglas A397 and 343 Acrylic Sleevings are available in a variety of colors and sizes in coils, cut lengths, or on spools.

Send for our free sample folder.

Under UL’s Component Program, both A337 and 343 Varglas Acrylics in Grade A are recognized for 155˚C, 600 volt service-FiIe E63450. CSA FiIe LR58486. Conforms to MIL-I-3190/3 and is listed on the Qualified Products List (QPL) for 155˚C service. Grade C-3 complies with VW-1-UL File E53690.

Varflex Corporation 512 W. Court St., Rome, NY 13440 315-336-4400 • Fax 315-336-0005 1-800-648-4014 • www.varflex.com E-Mail: [email protected]

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

52

Design Hardware & Software

Earlier this year, President Obama lauded Local Motor’s unique co-creation approach to vehicle product development, saying it could significantly collapse development time and save taxpayer dollars.

Crowdsourcing Creates

CAD Groundswell While crowdsourcing has the potential to boost innovation, manufacturers have been slow to embrace the strategy, put off by quality concerns and engineers’ reticence to participate in an open development forum. By Beth Stackpole, Contributing Editor, Design Hardware & Software

S

ay someone has an idea for a cool product. They develop some early “napkin type” sketches, host regular brainstorming and conceptual design reviews with peers and various stakeholders, and continue to iterate the design based on feedback until it’s refined enough to move into a more structured product development phase. Seems like a pretty traditional scenario that plays out in product development organizations all the time. Yet this time, there’s a twist. All of this early conceptual innovation happens D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

in an open, online forum among a community of participants who don’t necessarily work together and who might not be formally trained engineers or product designers. We’re talking about the phenomenon known as crowdsourcing or in some cases, co-creation.While not necessarily a new practice, it’s one that’s being reinvented and resurrected thanks to the advent of new social networking, visualization, and Web 2.0 technologies and pioneering companies like Local Motors and Quirky, which are erecting whole businesses and novel product development models based on the notion of a co-creation platform.

53 After validating more than 150 design entries, Victor Garcia’s FLYPMode design became the foundation for the DARPA XC2V Combat-support vehicle. It was subsequently built into an operational prototype.

Local Motors, for example, is a start-up car company, which according to its mission statement, is looking to “lead the next generation of crowd-powered automotive manufacturing, design, and technology in order to enable the creation of game-changing vehicles.” Via an open community platform called Local Forge, participants, including everyone from car buffs to industrial designers and car engineers and fabricators, are invited to submit ideas, provide commentary and feedback, and eventually vote on the best design to serve as a final vehicle concept to move into production. There’s a lot of excitement around Local Motors’ cocreation model. The company released its first production model, the Rally Fighter off-road vehicle in 2011, and in partnership with the Defense Advanced Research Projects Agency (DARPA), pushed through a body design for a Combat-support vehicle (XC2V) from concept to working prototype in a scant six months. It was an achievement that won accolades from President Obama last summer as an example of innovation in American manufacturing. “This idea that you can put a request out to a community, have people submit designs, have others critique and help refine them, and through that process, co-create a final design is one of the more exciting aspects,” says Karsten Newbury, senior vice president and general manager for Mainstream Engineering and Velocity Series at Siemens PLM Software. Siemens PLM Software recently tipped its hat to the crowdsourcing approach by partnering with Local Motors to offer its community Solid Edge Design1, a fully featured CAD tool with a $19.95 monthly subscription fee. “Where it gets

Fantastically Flexible Expanded Foils & Polymers Infinite variations, endless possibilities. The smart alternative to perforated and woven materials:

• Advanced Battery • Alternative Energy • Composite Dry Lay-ups • Electrodes • Filters • Fuel Cell • Grilles • Heating Elements • Lightning Strike Protection • Shielding • Your Custom Application

VICTREX® PEEK™ expanded material also offered. Corrugated now available.

www.dexmet.net

203/294-4440

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

54 Design Hardware & Software 

New Series ECV Electric Cylinders

Electrically-driven units based on proven PHD linear designs High thrust and speed capacities

Easy 3 Step Sizing & Motor Selection With...

All ECV powered units are available with inline or foldback motor mounting

Call 1-800-624-8511 or go to phdplus.phdinc.com/am1 Also Available! ESG

saddle slides

ESK/ESL

cantilever slides P.O. Box 9070 • Fort Wayne, IN 46899 USA

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

The Thor ice scraper was modeled by the Quirky development team, using PTC’s Creo CAD tool.

interesting is when people come together as a team and their teamwork yields better results.” It still remains to be seen whether new models like Local Motors or Quirky can yield better engineering results and maintain a sustainable business model. Yet behind any one company’s success, the bigger question is can these same concepts and practices be applied to traditional engineering organizations to foster innovation and streamline product development processes? Newbury and other engineering experts believe there’s a definite opportunity, although it’s still early, and it’s not without challenges. Maintaining quality in a crowdsourced development scenario will be a hurdle, as will reorienting engineers who are steeped in traditional practices to become more open to exploring new paradigms. The likely evolution will be for organizations to apply crowdsourcing techniques to specific phases of the product development process — not use the tactic as a wholesale replacement for conventional engineering practices. “Crowdsourcing is best used as an idea generator,” says Ken Versprille, executive consultant with CIMdata. “You can incorporate it into your business practices, but you can’t build a business model on it. You can’t depend on the fact that every year you’ll get the idea you need — it’s on a year-to-year, product-to-product basis.” The Social Side of Product Development Like Versprille, most engineering experts see crowdsourcing techniques having the greatest impact on the early ideation stage, both as a way to expand the number of new ideas and as an effective tool for sifting through them to zero in on the best options. “I see it as a way to reinvent the suggestion box, using an online social network to gather, iterate, and vote on new ideas, giving people a voice to share their thoughts,” says David Blair, vice president of product development at PTC. “At the same time, you can use the voice of the crowd to help refine the idea and help separate the wheat from the chaff.”

55 Rather than crowdsourcing with an open community, Blair and PTC envision engineering organizations evolving to support social product development processes using tools like PTC’s own SocialLink. SocialLink, which works as part of the Windchill PLM platform, employs Web 2.0 building blocks like activity streams, Wikis, rating systems, and Facebook-like statuses and profiles to help engineering teams collaborate more effectively, find expertise more quickly, and better engage as a community. While crowdsourcing forums might be suitable venues for vetting solutions to thorny design problems or for keeping a running tab on particular projects, Blair and other experts contend they aren’t well suited to serve as the platform of record during the heavy-lifting, coordinated design and development stage. Unlike developing software in an open forum where it is easy to define clear interfaces between people’s work, it’s far more amorphous in a mechanical setting.“You might say you’re going to work on this feeder tray for this copy machine and you’re going to work on this glass plate and this is what the interface between the two should look like, yet it’s hard to describe that even in a perfect world where there are no tolerances or friction or flexing of materials,” says Rick Chin, director of product innovation at SoildWorks. Trying to define those interfaces with all the dynamic influences is difficult, Chin says, and if done without the proper controls and oversight, it can open the door to incompatibilities and design miscues. Even Quirky, which is building its business around a co-creation model, has factored the requirement for top-down design coordination into its processes.The community, which now numbers over 100,000, submits and votes on ideas, but once the Quirky design team selects the winning concept, the process is brought in-house for the internal team to handle 3D modeling, design optimization, and other traditional project management and product development tasks. “One of the things we feel that is unique about what we’re doing differently than generic

crowdsourcing is that we are all about the community plus the experts,” says John Jacobson, head of engineering for Quirky, which, to date, has approximately 200 “lifestyle” products in its portfolio, including close to X40 have made LBP-002 (4.5 7.5).aithat 1 11/29/2010 1:37:42 PM

their way into production.“Our vision of co-creation is a community driving ideas and an expert staff to articulate them and bring them to life.” For some engineers, crowdsourcing is and will never be more than a way for

C

M

Y

CM

MY

CY

CMY

K

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

Find the right O-rings – faster and easier – at the new applerubber.com

O-Ring Gland Calculator

O-Ring Size Search

Material Selection Guide

Chemical Compatibility

Seal Design Guide

Engineering Request

Request for Quote

Our new interactive tools put the app in Apple Rubber. Everything you need for your sealing solutions is now only a click away. With new interactive tools and charts like the O-Ring Size Search, Material Selection Guide, Chemical Compatibility Guide, O-Ring Gland Calculator, and more, it’s never been easier to find the right O-rings for your specific applications.

Now accepting

@applerubber

www.applerubber.com

1.800.828.7745

716.684.6560 • FAX 716.684.8302 • email: [email protected] • 310 Erie Street, Lancaster, NY 14086-9504 USA Copyrights ©2012 Apple Rubber Products, Inc. All rights reserved.

Design Hardware & Software 57

Thor, one of Quirky’s winning designs, is a collapsible, double-blade ice scraper designed to let users employ both hands for more leverage.

companies to get their hands on free ideas and design labor. That’s how Jeff Mirisola, director of engineering at a defense technology company and a SolidWorks user, sees it. “When all is said and done, it seems that by crowdsourcing, you’re taking other people’s ideas and getting engineering for free,” he says. “I know some people buy into the concept and want to give up their services for free, but something seems wrong about it.” Also standing in the way of engineers getting on board with crowdsourcing is their standing perception that an open community lacks the specific skills to handle the nuances of a tough engineering problem. Quirky’s Jacobson, a trained engineer himself, admits many engineers are likely to struggle with those types of lingering misperceptions and also have trouble adapting to the less structured development approach of an open community. “Traditional engineers like to have a pretty tight set of

requirements and design to that,” he says. “When you’re dealing with things that are community-based, it’s more chaotic and messy, and for engineers, it’s sometimes an uncomfortable place to be.” As uncomfortable as it may be today, it’s unlikely that it will remain so. The seemingly unstoppable popularity of social networks and younger engineers’ desire to collaborate in such open forums means traditional engineering organizations are eventually going to have to figure out a way to embrace some aspect of social product development.“The idea of collaborating in a more open and less controlled way is difficult, but not insurmountable,” says SolidWorks’ Chin. “Companies will just have to come up with the processes and frameworks to make it happen.” DN

“Our vision of co-creation is a community driving ideas and an expert staff to articulate them and bring them to life.”

For More Information: Local Motors: http://dn.hotims. com/40992-507 Quirky: http://www.quirky.com/

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

58

SHERLOCK ΩHMS Famous investigations into engineering’s most diabolical real-world cases

http://bit.ly/SherlockOhms

The Case of the Faulty Spring Clutch By Jeffrey Antman, PE AT MY FIRST JOB out of engineer ing school, I worked with the office products division of a huge corporation. I was assigned to fix the design of a spring clutch that failed prematurely on a copier. The spring-clutch design worked for hundreds of millions of cycles in other applications. On this particular copier, the clutch consistently failed at around 20K cycles. This spring clutch transmitted torque from an input arbor to an output arbor, through a helical clutch spring, all mounted concentric on a shaft. When the input end of the clutch spring is held off of the input arbor, the input arbor spins freely. When the input end of the spring is released, the helical spring wraps down around the arbor. The clutch spring is clamped to the output arbor, so when the spinning input arbor gets that spring wrapped around it, all three components are rotating at the same angular velocity. The load of the output arbor drive had a significant inertia. The conventionalwisdom data was collected by multiple sets of previous engineers who worked on this clutch. They all estimated the torque by multiplying the calculated rotary moment of inertia of the load being accelerated by the angular acceleration. Even back then, we had dc tachometers that gave a dynamic angular velocity output with a reasonable frequency

response that we fed into our storage scopes, and took Polaroid pictures of it. Theta dot vs. time — lay a ruler down, and you can figure out acceleration. But why would the same load yield only 1/10,000 the life in a new application? I calculated that the maximum stress was expected to be about 1/4 of the yield strength of the material I chose — a heattreated steel that still had plenty of ductility. I bought our senior technician a cup of coffee each time he bonded on one of the eight strain gages, which were tiny, to the tiny ribs on the sprocket. The torque sprocket worked immediately and told us the story. In the first actuation of a new clutch, you get the 15-20X conventional-wisdom torque. In very few cycles of starting and stopping, the torque was down to conventional-wisdom level. When the clutch was taken apart, the center coil of the clutch spring was all stretched out. After break-in, each startup would wind up the stretched-out center coil before torque could be transmitted completely, an effective reduction in stiffness resulted in lower starting torque. The conventional-wisdom data takers never had a way to measure that first cycle like we did, so they never saw the higher acceleration and could never infer the higher torque that predicts exceeding yield point of the material. DN

Jeffrey Antman, PE, has more than 30 years of experience in design and manufacturing engineering and engineering management. He has engineered in many industries, including copiers and printers, wastewater and water purification, disk drives, personal transportation, vapor deposition coatings, biopharma, and medical devices. D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

DesignNews.com Case of the Tricky Water Pressure Switch This Sherlock was a tad too quick to identify the problem. The penalty was $75. http://bit.ly/safmr8

Have you applied your deductive reasoning and technical prowess to troubleshoot and solve an engineering mystery that even the fictional Sherlock would find most perplexing? Tell us about it! E-mail Senior Editor Rob Spiegel at: [email protected]

Join 1,000 design engineers who are members of the Sherlock Ohms Investigators Club at LinkedIn: http://designnews. hotims.com/27739-523.

Social

59

engineering

Standards, Security Add 2012 Angst By ALEXANDER WOLFE, Content Director

looking back at 2011, as we did in

last month’s column (December, p.49), participants in our Systems & Product Design Engineering group on LinkedIn told us that jobs were their biggest concern. As we turn the page to 2012, it seems that the design engineering audience is noticing that those jobs are becoming encumbered by lots of stuff that may not result in better end products. Bryan Hoffman, an engineering manager at American Controls, believes overcomplicated standards are at the root of all design evils. “Companies are forgetting the KISS principle and making standards so convoluted that it is difficult to bring someone new on and hit the floor running,” he says. Rich Merritt, a public relations professional who works with automation vendors, agrees that we’ve forgotten the KISS principle. “We’ve made everything so complicated, complex, and convoluted that we’ve entered the age of ‘transoptimal engineering,’” he says. “That is, things are so advanced and have so many features, they don’t work anymore.” Business development manager Herat Shah sees the pressures for complexity and price converging in an unhealthy manner. “The biggest issue for the automation and control supplier is to design and engineer something that’s the cheapest and the best,” he says. “Practically, this is not possible.” If such pressures aren’t enough, many of our correspondents also see bad actors look-

ing to corrupt their designs. “Stuxnet,” warns engineer Thomas Stevic, referring to the worm which took down an Iranian nuclear processing plant in 2010. The incident struck fear into the automation arena because Stuxnet targeted controllers, and made engineers realize that factories aren’t immune to security threats. Adds software consultant Bob Loy, “In a similar vein, the top story some year is going to be the poisoned m icrocode or hidden back doors being inscribed on various chips manufactured overseas, possibly right now as you read this.” Also raising engineers’ fears that their products will be corrupted is a rise in fake parts. “The biggest issue in 2011 was counterfeit electronic components. The war on counterfeits by the US government turned up several instances (of counterfeits), indicating the scope of the deluge of counterfeit electronic components entering the US,” notes Arlin Niernberger, a director of engineering services. Contributing technical editor Jon Titus offers a real-world example of the potential impact of counterfeits. “I talked with a battery-industry expert who told me some of the after-market battery packs for medical devices looked like someone assembled them in a garage — no quality control,” he says. “I wouldn’t want to bet my life — literally — on a battery from an unknown source purchased based on price alone.” DN

System & Product Design Engineering Group http://bit.ly/designnewsLI

“Things are so advanced and have so many features, they don’t work anymore.”

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

Now there’s one place to do it all! NI Supports the improvement of engineering by connecting engineers with social media.

Design

Decisions

Choosing a Rotary Encoder Many factors influence the selection of an appropriate rotary encoder for use in controlled servo drives. By TOM WYATT, HEIDENHAIN Corp.

Controlled servo drives are used in many areas of automation technology, converting, printing, handling, and robotics, including production machines and machine tools. The selection of a rotary encoder or encoder technology for use within the system is dependent on the accuracy requirements of the application whether it is position and/or velocity control. Before making an encoder decision, an engineer should examine this and all the major encoder properties that influence important motor performance.

Positioning Accuracy Positioning accuracy depends solely on the application requirements. Resolvers, for example, mostly have one signal period per revolution. Therefore the position resolution is extremely limited and the accuracy typically is in the range of ~ ±500” (Arc seconds), assuming interpolation in the drive electronics usually results in a total of 16,384 positions per revolution. On the other hand, an inductive scanning system, as found in many rotary encoders, will provide signif icantly higher resolution, typically in the range of 32 signal periods per revolution resulting in an accuracy of ~ ±280”. The interpolation in this case is internal to the encoder resulting in 131,072 positions per revolution. Optical rotary encoders are based on very fine graduations commonly with 2048 signal periods per revolution and, therefore, even much higher resolutions

are possible with internal interpolation electronics. The output resolution here is 25-bits, 33,554,432 absolute positions per revolution with accuracies in the range of ~ ±20”. Speed Stability To ensure smooth drive performance, an encoder must provide a large number of measuring steps per revolution as the first piece of the puzzle. However, an engineer must also pay attention to the quality of the encoder signals. In order to achieve the high resolution required, the scanning signals must be interpolated. Inadequate scanning, contamination of the measuring standard, and insufficient signal conditioning, can lead to the signals deviating from the ideal shape. During interpolation, errors then occur when the periodic cycle is within one signal period. Therefore, these position errors within one signal period are also referred to as “interpolation error.” With high-quality encoders, these errors are typically 1…2 percent of the signal period. The interpolation error adversely affects the positioning accuracy, and also significantly degrades the speed stability and audible noise behavior of the drive. The speed controller calculates the nominal currents used to brake or accelerate the drive depending on the error curve. At low feed rates, the feed drive lags the interpolation error. At increasing speeds, the frequency of the interpolation error also increases. Since the motor can only

Source: HEIDENHAIN Corp.

60

A good fit from the start will provide positive performance in the motor/drive system.

follow the error within the control bandwidth, its effect on the speed stability behavior decreases as the speed increases. However, the disturbances in the motor current continue to increase, which leads to disturbing noises in the drive at high control-loop gains. Bandwidth Bandwidth (relative to command response and control reliability) can be limited by the rigidity of the coupling between the motor shaft and encoder shaft as well as by the natural frequency of the coupling. Encoders are qualified to operate within a specified acceleration range. Values typically range from 55…2,000Hz. However, if the application or poor mounting cause long lasting resonant vibration, it will limit performance and possibly damage the encoder. DN

Tom Wyatt is automation division manager at HEIDENHAIN Corp., North America. For more information, go to www.heidenhain.us. D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Design Engineering

Products

Best of the Engineering Marketplace Compiled by Lauren Muskett, Assistant Editor

Electronics & Test Compact 50W DC/DC Converters Designed for applications requiring small size, high power, and robust performance.

MicroPower Direct’s B5000RW series delivers 50W of isolated, tightly regulated output power in a compact 1 inch x 2 inch x 0.4 inch case. Twelve standard models operate from 12V dc (9V to 18V), 24V dc (18V to 36V), or 48V dc (36V to 75V) inputs, providing single outputs of 3.3V dc, 5V dc, 12V dc, or 15V dc. Standard features include line/load regu-

to 430C (800F). This 316 stainless-steel constructed heater can handle pressures up to 100psi and 50W per square inch. Applications include those where clean air is necessary, as in laboratories, environmental testing areas, packaging, and sealing.

Omega Engineering Inc. www.omega.com

Operates with a supply voltage of 12V dc to 30V dc and is available in cabled and quick-disconnect models.

Banner Engineering’s WL50S HighIntensity LED Spot Light is the latest addition to the company’s popular task light line of lighting and indicators. The extremely bright, sealed spotlight is designed for use in general-purpose

MicroPower Direct www.micropowerdirect.com

Low Flow Air Process & Liquid Circulation Heaters Useful in the automotive, petroleum, and manufacturing industries.

Omega’s AHPF series heaters are used to heat low flows of air, gas, water, or aqueous solutions with air/gas flow up to 15 CFM, and air/gas out temperature up

Banner Engineering www.bannerengineering.com

Automation & Control

High-Intensity LED Spot Lights

lation less than 0.5 percent, input/output isolation of 1,500V dc, continuous shortcircuit protection, remote control input, and efficiency as high as 92 percent. The MTBF (per MIL HDBK 217F) is greater than 328 khours.

with an even pattern of light and no shadows. It offers three lens options — ranging from ±5 degrees to ±20 degrees — which offer varying levels of spotlight intensity to meet diverse application requirements. It has a 50mm diameter with a flat profile and 30mm mounting base. A large selection of accessory brackets allows for simple mounting and alignment. Featuring a IP69K-rated, rugged sealed housing, the WL50S is well-suited for harsh wash-down environments, including applications in the food and beverage processing industries.

applications, providing a long-lasting useful life when used within its specifications. Constructed with three high-intensity LED bulbs, the WL50S Spot Light illuminates a selected area

Basic Line of Soft Motor Starters This series is a substitute for a Star/ Delta starter as it fits into a similar footprint, simplifying installation.

The Stellar SR33 Series basic soft starters are designed for general-purpose applications where traditional across-the-line starting or wye-delta starting would typically be appropriate. The SR33 semi-conductor soft starters, available in 22A to 482A sizes, are suitable to control three-phase ac induction motors with a wide variety of motor loads. All units feature two-phase control, easily

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

61

62 Design Engineering Products and separately adjustable motor start voltage and start and stop times, and depending on model, fault indication of 4 or 7 fault types: SCR or Power Supply, Overheat, Control Power Supply, Bypass Relay Failure, Shearpin, Overload, and Overcurrent. AutomationDirect www.automationdirect.com

Absolute Stainless-Steel Encoders With V4A Housing Can withstand aggressive cleaning processes in food/beverage applications.

MHz ISO 15693 standard. As a result, they promote simplified operation and enhanced productivity in stand-alone or multi-drop applications. In multi-drop applications, users can connect up to 30 RFID read heads together on a single network, and bring the data back to a PC or PLC. These RFID read heads provide a read/write range up to 130mm. They feature 2-wire RS485 connectivity, and 200mm M12 pigtail connectors to facil-

GE404 optical absolute encoders from Baumer deliver precise positioning data, and withstand aggressive cleaning processes. With housings made of class 1.4404 or 1.4435 V4A stainless steel, GE404 encoders feature robust Viton

seals that provide long-term resistance to chemical agents and high temperatures. Leak-proof and IP67-compliant, these encoders will resist harsh washdowns with aggressive cleaning agents over their entire service life. The encoder’s robust ShaftLock bearing minimizes machine downtime by enduring vibration and high shaft loads that occur during processing and cleaning. The optical sensing principle of GE404 encoders allows high, 14-bit single-turn and 12-bit multi-turn resolutions, delivering precise positioning at velocities up to 10,000 rpm. The Baumer Group www.baumer.com/en.html

Stand-Alone RFID Read Head For stand-alone or multi-drop applications.

Pepperl+Fuchs’ RFID Read Head IQTF116-R4M-V1 conforms to 13.56

itate easy connection and removal. A continuous read option is available for point-to-point applications, and a lowprofile design makes the IQT series ideal for use on AGVs (Automated Guided Vehicles), or for mounting under shallow conveyor sections where conventional RFID heads are too large. Pepperl+Fuchs www.pepperl-fuchs.us

Materials & Assembly Macroplast UK 1340 Polyurethane Adhesive Speeds wind blade assembly and meets IEC 61400-23 standard.

Macroplast UK 1340 is a two-part adhesive consisting of a resin and a hardener. When mixed, the adhesive cures in just 60 to 80 minutes at low reaction temperatures up to 75C, dramatically reducing production time and minimizing thermal loading that can lead to stress cracking. The adhesive’s cure speed can be adjusted for the needs of the manufacturer, allowing faster blade production and greater yield per mold (1MPa in 4 hours at 20C). This polyurethane adhesive is Germanischer Lloyd (GL)-approved, cures rapidly at room

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

63 risk of stress cracking. As Macroplast UK 1340 requires no heat cure process or tempering, it minimizes energy consumption, helping to control energy costs for blade manufacturers. Low reaction temperatures also preserve the integrity of heat-sensitive foam inserts.

Henkel www.henkelna.com/windpower

Stainless-Steel Shackle Pins temperature, reduces production costs, and shortens production cycles by 15 percent to 30 percent. Macroplast UK 1340 has demonstrated a tensile shear strength exceeding 20 MPa at -40C to 80C and a Tg of 65C and higher. The adhesive has demonstrated dynamic fatigue strength, which allows wind blades to handle deflection, dynamic load, and stress on the adhesive bond line, and reduces the

Offer increased tensile strength to satisfy the most demanding heavy-lifting applications.

QRP Inc.’s line of shackle pins are manufactured from stainless steel (except for their aluminum button) to promote high corrosion resistance in the harshest environments. The shackles can pivot when unobstructed to move 90 degrees on both sides of vertical to correspond with application dynamics. Full visibility of a contrasting color groove on these pins

Advertisers Advertiser

Page

Airpot Corp.

48, 49,

Allied Electronics Apple Rubber AutomationDirect

64, C3 56 2

Advertiser Haydon Kerk Motion Solutions ICP-DAS USA IMS Schneider Electric Motion

indicates pin status as “fully locked” to promote safety in use. The latest design features a red button allowing for easy identification and serving as a caution in activation. The shackle pins are body hardened to 180/210 KSI or ASTM 2759/3. They are available with shank diameter ranges from ¼ inch (handling up to 2,000 lb maximum load) to 5/8 inch (accommodating up to 7,000 lb maximum load). QRP Inc. www.qrp-inc.com

in this issue

Page 23 7 40, 41

Advertiser

Page

Parker Hannifin Corp.

17

PennEngineering

16

PHD

54

Keystone Electronics

43

Proto Labs Inc.

8

Avnet

11

LAPP USA

29

Smalley Steel Ring Co.

55

B&R Industrial Automation

13

Maple Systems

57

SolidWorks Corp.

19

Bergquist Co.

33

Master Bond Inc.

18

NPE 2012

47

Bosch Rexroth

25

Maxon Precision Motors

10

Sunnex Inc.

51

CIT Relay & Switch

20

McCloone

45

TDK-Lambda Americas Inc.

50

Clippard Instrument Lab.

15

Metal Power Industries Federation

Ulbrich Stainless Steel

37

Dexmet Corp.

53

Mouser Electronics

Varflex Corp.

51

Watson Marlow Pumps Group

39

Yaskawa Electric America

C4

Digi-Key Corp.

C1, C2

EBM Papst

27

EXAIR Corp.

3

Harmonics Drive Technologies

21

National Instruments Nook Industries Omega Engineering Inc. Paneloc Corp. Herriot

42, 44 6 4, 59 31 1 62

Publisher does not assume any liability for errors or omissions in this index.

w w w. d e s i g n n e w s . c o m J a n u a r y 2 0 1 2 D e s i g n N e w s

64

GADGET FREAK The Gadget Freak® Files Case #202

The Frankenkindle: An Easier-to-Use Kindle GLENN JOHNSON, AN ELECTRICAL engineer, wanted to help his sister who has cerebral palsy. She has difficulty with motor control, which makes it difficult for her to manipulate modern electronics. Glenn’s goal was to modify a Kindle into a gadget his sister could use. He took the controls from a children’s V.Reader, which has large buttons that his sister could easily manipulate. Each silicone button on the V.Reader has two wires attached. He routed them into the Kindle’s interface board. He calls the modified gadget the Frankenkindle. DN Are you a Gadget Freak? Design News and Allied Electronics would like to send you a check for $500 to spend on Allied’s website at www.alliedelec.com/gadgetfreak or anywhere you please. And don’t forget to supply us with a video file of your gadget in action. E-mail Design News your proposed project (must incorporate electronic components and involve sensing, motion, timing and/or networking elements) to rob.spiegel@ ubm.com, along with a description of how it works, a parts list, schematic, photos and video. If your project is selected, you’ll receive a $500 check from Design News and will be featured in an upcoming issue of the magazine or at designnews.com with your invention.

ADVERTISEMENT “FRANKENKINDLE” Amt

Part Description Protoboard

237-0119

6

Push Button 33mm, pink

948-7193

1

Wall Charger, 5V

460-0343

1

SOIC Adaptor

673-0032

1

Screw terminal, 2-pin

409-0111

DesignNews.com

Check out the Frankenkindle in action at www.designnews.com/gadget-freak.asp. More of What You Need: Find schematics, build instructions, and a full parts list at www.designnews.com/gadget-freak.asp. Sign up for the Gadget Freak RSS feed and get the posts delivered directly to your desktop at www.designnews.com/rss_simple.asp. To get Gadget Freak delivered directly to your inbox, go to www.designnews.com/register.asp. For parts information, call (800) 433-5700 or go to www.alliedelec.com/gadgetfreak. Sponsored by » Photo: Glenn Johnson

D e s i g n N e w s J a n u a r y 2 0 1 2 w w w. d e s i g n n e w s . c o m

Allied Part #

1

We Do Business Your Way

Catalog

The Allied Catalog features thousands of products from 300+ world-class suppliers.

Online

Choose from more than two million product solutions at alliedelec.com.

Local Service

We are ready to assist you. Call your local sales rep. at 1.800.433.5700.

Buy it your way from Allied Electronics.

THINK ALLIED

SM

1.800.433.5700 © Allied Electronics, Inc 2011. ‘Allied Electronics’ and the Allied Electronics logo are trademarks of Allied Electronics, Inc.

An Electrocomponents Company.

Follow us:

View video:

http://Ez.com/yai264

YA S K A W A A M E R I C A , I N C . - D R I V E S & M O T I O N D I V I S I O N 1 - 8 0 0 - YA S K A W A

YA S K A W A . C O M