The innovative sensor cable detects everything that changes the earth's magnetic field in any way a few meters around it. It recognizes the smallest changes in the magnetic field, assigns them and reports them. Without collecting data.

Attached to fences...

...it can distinguish, for example, whether it is just the wind shaking the mesh or a bolt cutter.

Installed in the ground...

...it recognizes cars, detects which direction they are driving in and distinguishes them from trucks. It even detects drones flying over the cable at a height of a few meters - as well as the zipper or cell phone of the person walking over it.

At airports, subways or train stations...

...it makes new control systems possible, as well as new monitoring technology on private property, nuclear power plants and industrial facilities.

Various sensor systems developed by his working group...

...are already being used as traffic guidance systems, for example at airports or in parking garages. "We have continuously developed the magnetic field sensors over the past few years and made them increasingly sensitive and selective," explains Professor Uwe Hartmann, project manager at Saarland University. "We can very precisely assign the measured values and signal patterns that arise when our sensors detect changes to the causes of a disturbance."

The small sensors, which the physicists string together like beads on a string...

...in a thin cable, are networked with each other and report their measured values to a microcontroller. This processes the data further.

"The signal patterns differ depending on the type of interference," explains Hartmann. "We have simulated several types of changes in the magnetic field and vibrations in numerous series of tests and assigned them to the respective causes. We used this information to teach the system. It recognizes typical patterns, assigns them to faults independently and sorts out false alarms."

To do this, the physicists have...

...mathematically modeled and programmed and refined the evaluation unit and sensors in ever greater detail. The system shows the exact location of the fault, which is particularly interesting for large monitored areas.

"We can adapt it very flexibly to a wide range of requirements," explains Haibin Gao, who holds a doctorate in physics and is researching the new sensor technology in Hartmann's team. "At the Hannover Messe at the end of April, we will be looking for partners with whom we can develop the system to series production readiness as required," says Gao. The sensor cable does not require a lot of power, and could be powered by solar generators, for example. The sensors are virtually wear-free and their measurements are independent of the weather - they work without any problems even in rain, fog or snow. And the system does not store any data or other information. Hackers also have no target. Messages can be sent to a smartphone or tablet via Bluetooth, for example."

The Federal Ministry of Education and Research funded the research...

...with a total of over one million euros, more than 250,000 euros of which went to Saarland University. The partners involved were Sensitec, based in Mainz and Lahnau, Listec, based in Isen, and GBA-Panek, based in Kahla.