Sensors track focused on measurement and detection

Sensors Expo this year premiered a new technical-program track titled “Novel Approaches to Measurement and Detection” in conjunction with EE-Evaluation Engineering. Sessions addressing topics ranging from the world data-acquisition market to a .NET-based embedded watchdog took place June 5-6 in Rosemont, IL. In addition, Sensors Magazine announced the winners of the 2013 “Best of Sensors Expo Awards.”

The measurement and detection track began with a presentation titled “Strategic Insights into the Future of the World Data Acquisition Hardware and Software Market” by Dr. Rajender Thusu, industry principal at Frost & Sullivan. Hardware dominated the market in 2012, he said, taking 88.5% of revenues, or $1.26 billion, vs. $164 million for software. Hardware's share will shrink slightly, to 87.8%, in 2018.

As for hardware and connectivity architectures, he put PXI's 2012 share at 18.8%, vs. Ethernet at 38.3% and USB at 19.1%. In 2018 he expects Ethernet to have a 42.8% share; PXI, 18.3%; and USB, 19.8%. Data-acquisition industry leaders, he said, include National Instruments, Agilent Technologies, and VTI Instruments. Mariano Kimbara, senior research analyst for measurement and instrumentation at Frost & Sullivan has more on the firm's recent research into the topic here.

James Deak, chief technology officer at MultiDimension Technology Co., and Mark Tondra, President of Diagnostic Biosensors gave a presentation titled “Magnetoresistance Field Sensors Compared: AMR, GMR, TMR, and Hall Effect.” Their presentation described the performance attributes of various magnetoresistive sensors, including emerging tunneling magnetoresistance (TMR) sensor technology. They covered specifications such as power, size, sensitivity, and noise. They noted that most cars have more than 100 magnetic sensors and discussed applications such as the use of magnetic beads to monitor bacteria.

In a session titled “Suppressing Sensor Noise with Simple Hardware and Software Techniques,” Keith Curtis, technical staff engineer at Microchip Technology,” said, “Noise is a factor of our lives.” In dealing with noise problems in embedded systems, he said that people often want to solve the problem in software rather than re-spin their circuit board. Ideally, though, he said the place to solve the problem is in the hardware through judicious layout, effective use of ground planes and decoupling capacitors, and isolation of power supplies. Mix your values of decoupling capacitors, he said, because identical capacitors will have identical self-resonant frequencies (SRF).

If all else fails, he said, you can use software solutions as a last resort. Software-based techniques include oversampling, dithering, slew-rate limitation, differential measurement, and quiet-time measurement. But, he said, “Start with a good, solid hardware solution.”

Josh Moses, lead electrical engineer at The Modal Shop, presented a session titled “Active Pre-Compensation to Boost Vibration Calibrator Performance.” Reliable vibration test, he said, is critical for protecting valuable equipment. To calibrate an accelerometer, he said, you need to shake it at a known frequency and amplitude. You can have that done at a high-end calibration lab with full automation and skilled technicians. As an alternative, he presented a battery-operated, NIST-traceable portable instrument for in situ calibration. He described it as a flexure-based system that employs feedback to compensate for nonlinearities.

Wednesday's sessions concluded with a presentation titled “An IEEE 1451.2/.4 Compatible Sensor and Gateway” by Darold Wobschall, president of Esensors Inc. He described IEEE 1451 Smart Transducer Interface Standards (TEDS) promoted by NIST and other agencies, focusing on an open source demonstration version of a serial Transducer Interface Module (IEEE 1451.2 TIM) and a Network Capable Application Processor (NCAP), or gateway. He summarized the various 1451 standards, including dot 0 (the basic set of commands in TEDS), dot 1 (NCAP), dot 2 (serial, as revised this year), dot 4 (TEDS only), dot 5 (wireless), dot 7 (RFID), dot 1.4 (messages over a network using eXtensible Messaging and Presence Protocol, or XMPP), and dot 001 (guidelines for transducer signal processing). The goal of the standards, he said, is to contend with fragmentation within the sensor industry.

Thursday sessions began with a presentation titled “Efficiency Testing on Electrical Drive Trains (eDrive)” by Mike Hoyer, applications engineer at HBM Test and Measurement. Hoyer noted that electric vehicles first appeared in about 1898—a 2,200-lb. model with 904 lbs. of batteries had a range of 31 miles. (He provided no data on acceleration or top speed.) Today, the goal is to improve electric vehicle efficiency—one way to do that is decrease weight, but that has its drawbacks, because a heavier car often feels like a safer one.

In any event, designers are looking to get every possible improvement in drive-train efficiency, and that applies to aircraft auxiliary power units and elevators as well as to vehicles.

Citing electric vehicle drive trains as an example, Hoyer noted that to optimize drive-train efficiency, engineers must know the details of battery output current and voltage, inverter output current, voltage, and frequency, and motor speed and torque. In addition, they must be able to synchronize these various measurements. He provided examples of how to do that, with details available at www.hbm.com/edrive.

Next up, Jim Schwartz, a product manager at National Instruments, delivered a presentation titled “Understanding Key Technologies for In-Vehicle Data Logging.” He addressed both test-track logging and fleet logging, each of which results in copious amounts of acquired data. He commented on the tremendous expansion of computer power in vehicles: the Space Shuttle had about 5k lines of programming code, and a 737 might have 3M lines, but a modern automobile may have more than 100M lines. A purpose-built data-acquisition system won't be able to keep up, he said, and he recommended a flexible platform-based approach that can abstract system complexity.

(Schwartz concluded his presentation with a few slides on the work of storm-chaser Tim Samaras, who was among the nine people killed in the tornados that struck Oklahoma last month. Schwartz had assisted Samaras and his team in putting together an NI CompactDAQ system to help gather data about violent storms. Although the storms remain incredibly dangerous, Schwartz said progress is being made, with average warning times increasing from seven minutes in the '80s to 10 minutes today.)

Thursday afternoon began with a presentation titled “Understanding Inductive Displacement Sensor Thumb Rules” by Marissa Wolff, mechanical design engineer at Kaman Precision Products. The thumb rules, she said, go by the initialization TERMS&P, which stands for target, environment, range, mounting, speed, and performance. She addressed several of these, noting that, first and foremost, the target must be conductive. As for environment, she said temperature affects skin depth and thus can affect the accuracy of your measurement. Signal-conditioning circuitry, she said, can compensate for temperature variations.

She next commented on range, noting that her company's sensors are designed to be noncontact, but distance does affect mutual inductance, so range must be specified carefully. The last rule she touched on related to mounting. A fixture can represent conductive material that's not part of your target, thereby distorting your measurement. “Take care when mounting your sensors, and they will take care of you,” she concluded.

The measurement and detection track concluded with a presentation titled “Embedded Microcontroller-Based Watchdogs Using .NET Micro Framework” by Donnie Curington, senior associate at Stress Engineering Services Inc. Curington took as his point of departure tubular test frames that are subjected to loads of up to 6 million pounds and pressures up to 40,000 psi. The frame control system in this application has full built-in safety features, but what was wanted was an independent watchdog system that could provide insight into the application. Curington's solution was a watchdog system implemented using .NET Micro Framework and an embedded microprocessor with I²C and TCP communication to the control system. General-purpose desktop software and off-the-shelf embedded hardware proved to be up to the task, he said. Although the application Curington described may seem esoteric, he noted that his approach could be applicable to enhancing any test machines by connecting a single embedded device to all measurement points to complement the use of dedicated built-in process meters with limited functionality.

“Best of Sensors Expo” Award Winners Announced

Also at Sensors Expo, Sensors Magazine announced the winners of the 2013 “Best of Sensors Expo Awards.” For the first time the 2013 awards focused on sensor applications and excellence among engineers, complementing its traditional focus on sensor technology innovations. The awards were presented by Executive Editor Melanie Martella.

“We received outstanding nominations for engineering teams, sensor applications, and new product innovations for this year's Best of Sensors Expo Awards. We applaud all of the winners and look forward to the future where these professionals and products help solve world issues,” said Martella. “The theme of Sensors Expo focuses on sensing technologies driving tomorrow's solutions. What better way to celebrate this theme than recognizing the achievement of many in the industry who are working toward this goal.”

The original Best of Sensors Expo Award recognized novel products, and this focus is retained in the Innovation Award. The expanded program now includes the new Engineers of the Year and Application Awards. In total three gold, two silver, two bronze, and three honorable mentions were awarded by a panel of judges including Martella; Karen Lightman, MEMS Industry Group; Dr. Sergey Yurish, International Frequency Sensor Association; and Randy Frank, R. Frank Associates. Following is a list of the winners.

Engineers of the Year Award

Kenneth Foust, sensor technologist, Intel Corp., and Carlos Puig, principal engineer, Qualcomm, for the creation of the Standardized Performance Parameter Definitions. This effort provides a standard for specifying sensor performance for the sensors most commonly used in consumer devices, providing the people incorporating these sensors into their end devices with an easier way to compare product specifications and thus ease integration.

Application Award

Gold: The Sensor Web Enablement initiative from the Open Geospatial Consortium (OGC). This initiative standardizes Web service interfaces and data encodings that can be used as building blocks for a World Wide Sensor Web, enabling diverse sensors to be accessed in an interoperable, platform-independent, and uniform way.

Silver: S3 from SENSUSS. This is a system of helmet sensors that transmit data wirelessly to the Eurotech Everyware Cloud to provide immediate information to coaches, doctors, and parents about the impact levels sustained by an athlete.

Bronze: The VERASENSE Knee System from OrthoSensor Inc. This intelligent tibial insert trial provides sensor-based information on optimal insert alignment in Total Knee Arthroplasty (AKA total knee replacement) procedures.

Honorable Mention: Thin Film Heat Flux Sensor For Measuring Film Coefficient of Rubber Components of a Rolling Tire from The Goodyear Tire & Rubber Co. and NASA-Glenn Research Center. The heat flux sensor they've developed is thin, fast, and gives real-time heat-flux data for a tire as it is moving; it can also be used by NASA to test the thermal control in its advanced multi-use Extravehicular Activity pressure suits for future lunar missions.

Innovation Award

Gold: Kionix Inc. for its KMX61G integrated accelerometer and magnetometer, which provides a lower-power alternative to a gyroscope.

Gold: ams AG for its SL13A NFC Sensor Tag IC, a combination NFC/RFID tag that incorporates sensors.

Silver: LORD MicroStrain Sensing Systems for its MathEngine cloud-based sensor data-analysis and alerting technology.

Bronze: LeddarTech for its Leddar LED-based 3-D detection platform, Model 75B0003-1.

Honorable Mentions: MultiDimension Technology Co. Ltd. for its MMS2A1H ultra-low-power omnipolar TMR magnetic switch and COTO Technology Inc. for its RedRock RS-A-2505 MEMS-based magnetic switch.

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