Luggage lying around unattended at an airport justifiably triggers the jitters. The hazardous task of getting up close to inspect what could potentially be a bomb that could explode any time invariably falls to the bomb squad. Researchers have come up with a way to minimize the risk by creating a sophisticated, robot-mountable, sensor system that allows authorities to scan a piece of luggage and get an accurate image of its contents. The contact-free detection system could not only potentially help bomb specialists assess the danger quickly, but it could also help them obtain vital evidence.
Developed by scientists at the Fraunhofer Institute for High Frequency Physics and Radar Techniques (FHR), along with industry partners and criminal investigation authorities, the multi-modal sensor system consists of a high-resolution digital camera, a millimeter wave scanner and a 3D environment monitoring system. Once mounted on a robot platform, investigators can control the robot remotely as it makes its way to the luggage, using swiveling 3D sensors to completely survey the crime scene and take high resolution pictures for evidence. When the robot nears the luggage, it uses the millimeter wave scanner to survey it. The information is sent to the authorities via a built-in embedded computer on the robot, giving them a clear picture of the object's contents.
"Up to now our techniques have not allowed us to form a 3D outline of suitcase bombs, and it has been impossible – or only partially possible – to make a spatial map of the contents," says Stefan A. Lang, team leader at the FHR and the project's coordinator. "With the sensor suite we can visualize in three dimensions what's inside a luggage item, and so determine the composition of the bomb and how the parts are arranged in the luggage."
Using a sensor that moves along set trajectories, the millimeter wave scanner scans the luggage and the Doppler information generated during the process is used to create in-depth high resolution images.
The entire sensor system is compact, light and platform independent, enabling it to be easily mounted on any robot. In addition to speedy reconnaissance, the team says that the system could also help authorities preserve as much evidence as possible.
Bomb disposal engineers have typically been forced to destroy luggage bombs, which makes identifying perpetrators difficult for want of evidence. Getting an accurate three-dimensional image of the bag as well as the surrounding area, could help authorities quickly determine the danger to take the appropriate action.
Ways to determine the optimum trajectory to survey an object depending on its shape, its position in its surroundings and the robot's position are under further study.
The team expects to demonstrate the millimeter wave scanner in April 2016 and field tests of the remote-controlled sensor suite will begin in mid 2017. The complete multi-modal sensor suite is expected to launch in 2019.