Drawing on the images Hollywood has created for robots, the sensing capability of cockroaches and group behavior of ants and bees, Dr. James McLurkin of the Massachusetts Institute of Technology kicked off Sensors Expo 2008. With a dramatic live demonstration using his Swarmbots, he showed state-of-the-art capability to use robots to accomplish dangerous, dirty or dull tasks. There was nothing dull about his or the other presentations or exhibits and it is difficult to convey the excitement but here are two of the hot topics.
Driving Wireless Sensors
Perhaps the hottest sensor applications involve wireless sensing. Recognizing the challenge created by the diversity of wireless sensor approaches, National Instruments has partnered with a variety of wireless sensor suppliers to make instrument drivers. “The challenges that we’ve seen in the industry is that a lot of companies have come out with a lot of really cool wireless technologies but it’s all different,” says Charlie Stiernberg, product marketing manager, Remote Data Acquisition, National Instruments. “Some people are using 900 MHz radios, some people are using ZigBee, some people are using another variant of 802.15.4, some people are just using a totally proprietary protocol and it’s difficult to integrate all the digital signal systems.” Since one company may not offer all the I/O required for a particular application, NI took an approach similar to its benchtop instruments for the instrument drivers. “We have partnered with Banner and MeshNetics and Crossbow and Accsense and a few other companies to pull them into the logic platform,” says Stiernberg. LabVIEW can communicate with these disparate protocols. “LabVIEW then becomes the glue that pulls all these different standards together and pulls all these different wireless vendors together,” says Stiernberg.
Industrial Vibration Sensing
One of the other hot applications being pursued by several companies is early failure detection. Building on expertise learned by designing, manufacturing and applying accelerometers for cars, Analog Devices demonstrated the ADXL001, a new industrial vibration sensor. Increased bandwidth is the key to the sensor’s detecting capability. In contrast to the majority of vibration sensors that operate below 5 KHz, ADI’s new unit goes up to 22 KHz. The sensor’s sealed package provides essential functionality. “That’s the package we use for safety systems as well,” says Max Liberman, product marketing manager for high g accelerometers in the Micromachined Products Division, Analog Devices. “What that gives us is hermeticity, of course, and the ability to sweep from a -40 to 125C.” The package also provides a very rigid mounting.
PCC Piezoelectronics also introduced a new patented bearing detector. The DIN rail mounted Model 682A05 senses impact within rolling element bearings caused by bearing faults. One of the unit’s two 4 to 20 mA outputs is proportional to peak acceleration and a second 4 to 20 mA signal is proportional to overall velocity. The second signal also provides a raw vibration signal for diagnostic analysis.
Swarmbots in action at Sensors Expo