Millimetre radar system makes it possible to see the invisible
Fri 1 Apr 2016
A new, high-frequency radar scanner has been developed that can cut through dust, smoke and other non-transparent obstructions. Monitoring its surroundings in a 360-degree radius, the scanner has huge potential for increasing safety in environments where people and robots work side by side.
The research team, based at the Fraunhofer Institute for Applied Solid State Physics, are investigating ways to improve people and machine interaction in industry in order to accelerate operations without the use of protective barriers.
The use of robots in industry mandates an extremely strict safety policy – human employees must never be endangered by technology. Laser scanners used in existing systems monitor danger zones and machinery, stopping robots as soon as a person enters the area. However, these current optical sensors are limited as their output can change dependent on light conditions and visibility.
The team has now designed a modular 360-degree radar scanner [PDF] that is no bigger than a pack of cigarettes. Arguing its superiority to standard optical sensors, the scientists explained how the radar uses millimetre waves reflected by the objects it detects.
Both transmitted and received signals are processed and evaluated through algorithms, which help determine the distance, positions and speed of the observed objects. If several radar units are in use, the direction in which the object is moving can also be calculated.
“Our radar is not focused on one point. Instead, it sends out millimetre waves in a club shape. Unlike a laser scanner, the signals are reflected even when visibility is obstructed by an object,” explained Fraunhofer researcher Christian Zech.
While a laser scanner can judge the distance and position of a person, this only works in an unobstructed line of sight. The new radar system can cut through optically opaque materials, meaning that human employees can be picked up, even behind boxes, plastic, snow, wood and other objects.
Speaking on the previously bulky and expensive nature of millimetre radar models, Zech added: “Millimetre wave applications are dominated by waveguides that are extremely expensive to produce. Thanks to a cost-effective mounting and interconnection technology as well as specially developed circuit boards, we can replace the wave guides with our high-frequency module that has been integrated onto a board measuring just 78 x 42 x 28 millimetres.”