April R&D Round Up

E-mail Melanie Martella

This month we have a tiny timing chip that incorporates inertial sensors, a project to weigh trucks while they're driving, and a novel sensor cable that enables quicker, cheaper perimeter protection.

Do You Know Where You Are?
GPS is, as we know, a great way to track location up and until the point where you lose communication with the GPS satellites, whether that reason is innocuous (tunnels, tall buildings, too many trees) or not so innocuous (the satellite system gets shut down by evil doers). DARPA wants to make sure that our military can navigate accurately even if they lose GPS capability, which means they need to develop some system that picks up where GPS leaves off; in this case, that's a combination timing and inertial measurement unit or TIMU that's being developed by DARPA researchers at the University of Michigan. You can read more in the article, "Extreme Miniaturization: Seven Devices, One Chip to Navigate without GPS" but the basic gist is that the researchers have built a prototype 10 mm3 chip that simultaneously measures time, orientation, and acceleration by integrating the clock, three gyros, and three accelerometers. That is some nifty, nifty engineering right there.

Weighing Trucks in Transit
A vast quantity of cargo is transported to its destinations via heavy vehicles such as trucks and semis. Ensuring that the vehicles are appropriately loaded (and not overloaded) is important for avoiding accidents as well as for avoiding damage to roads. One of the ways that regulatory agencies check that trucks are appropriately loaded is to use weigh stations, which require that the vehicles pull off the road for inspection. What you want to be able to do is to spot the overloaded vehicles and let the law-abiding haulers get on with their work. Random inspections are better than nothing, but wouldn't it be great if you could weigh the trucks while they were on the road and identify just the overloaded ones? That's the idea behind NonStop, a project commissioned by the Norwegian Public Roads Administration (NPRA); SINTEF, the Scandinavian research organization; and Ciber AS.

At the heart of the system are the Weigh-in-Motion sensors that use a piezoelectric cable embedded in the road surface to measure the weight of the vehicle as it passes over the sensor. The weight readings will then be paired with the vehicle by using automatic number plate recognition (ANPR) to read the vehicle's license plates. This data can then be used to decide whether the vehicle is appropriately loaded or not. If it isn't, the inspectors can target it for further inspection; it if is, it can continue on its merry way. For a longer description of the project, read the article, "Weighing trailers on the road."

A Clever Cable for Perimeter Security
One of the problems with perimeters is that they're hard to police and they're also expensive to monitor. That's partly why devices such as unattended ground sensors are so attractive. Saarland University's Uwe Hartmann, Professor for Experimental Physics, working with research assistant Haibin Gao, have developed the VibroMag sensor cable that uses tiny magnetometer chips to provide intrusion detection for fenced areas. The sensors are embedded into a thin cable and this cable is then attached to a fence or whatever you're interested in monitoring. If someone attempts to climb or cut the fence, the cable will sense the vibration and relay where the disturbance occurred. The researchers are still developing the algorithms to reduce false alarms, but if they can get this to work as promised it's another useful security tool. For more information read the Phys.org news article, "New sensor cable enables remote monitoring of miles of perimeter fencing."