New sensor helps find parking spaces -- and make air traffic, shipping safer

Published 16 April 2010

Every vehicle — a car in a parking lot or on the road, an airplane on the tarmac, a ship — slightly deforms its surrounding Earth’s magnetic field due to the vehicle’s metallic components and electronic devices; magnetic field sensors can detect these small changes; in contrast to surveillance cameras, which are influenced by fog or rain, magnetic field sensors are unaffected by weather conditions

When drivers look for unoccupied parking lots in front of large shopping malls, they often have to drive in circles and spend minutes. Researchers at Saarland University demonstrate how to make the process shorter.

They have developed easy-to-install magnetic field sensors. Unoccupied parking lot locations can be presented on a display. This monitor system has been applied at airports and it can also be used for improving city traffic guidance, so traffic jams before traffic lights will be reduced.

Researchers will demonstrate application possibilities from 19 to 23 April at Hannover Messe at Saarland Research stand (Hall 2, Stand C44).

Each vehicle slightly deforms its surrounding Earth’s magnetic field due to its metallic components and electronic devices. Magnetic field sensors can detect these small changes. Uwe Hartmann, Professor of Experimental Physics, Saarland University, explains: “These sensors are very sensitive and they can also recognize vehicles at a large distance. In contrast to surveillance cameras, which are influenced by fog or rain, magnetic field sensors are unaffected by weather conditions.” One sensor plus necessary electronics is also comparatively cheap and its power consumption is low, so magnetic field sensors can be used in systems to monitor large areas.

In parking garages or on large surfaces in front of shopping malls, magnetic field sensors can precisely recognize locations of unoccupied parking lots. Large displays present the information to customers and there are still places for advertisements on displays. “Also traffic flow can be monitored by these sensors. They can be integrated into traffic light systems, because they can easily identify the vehicle speed”, Hartmann says. The researcher sees an additional application in shipping. In this case, magnetic field sensors recognize whether a ship passes the door of a large sluice or not.

In a pilot project, on-road tests of magnetic field sensors have been carried out at Frankfurt, Saarbrücken-Ensheim, and Thessaloniki airports. Hartmann warns, “Every year there are several hundred real or near accidents at airports worldwide, due to collisions of aircrafts with other aircrafts or ground vehicles.” Magnetic field sensors will prevent those aircrafts from moving too close on their ways to taxiways. “Especially for areas between buildings, where ground radars are not effective or even impossible to achieve, magnetic field sensors can be equipped,” the Saarbrücken physicist explains.

In the research project together with Fraport at Frankfurt airport, various applications of magnetic field sensors to maintain safety have been investigated. In this area, further development is still needed before market launch.