Radar system could detect fallen objects on railway tracks
Radar systems used to detect aircrafts and ships could soon be fitted in train stations to detect objects on the tracks and prevent serious accidents.
Researchers in France have developed a device that sends ultra wideband radio waves towards objects and then records them as they bounce back, revealing the intricate characteristics of the object in question.
The aim of the system, says project leader Ali Mroué, is to identify any objects or persons that may have fallen onto the tracks and then feedback to a system that stops oncoming trains and cuts the high voltage of the lines.
"In a large, capital city underground, this can happen two to three times a week and lead to significantly long service interruptions," Mroué explained. "With the possibility of trains, passengers and even poor lighting, in some instances, obscuring the view of CCTV cameras, radar techniques could certainly be effective in these scenarios."
The researchers, from IFSTTAR and IEMN, created the technology using an Automatic Target Recognition procedure whereby the characteristics of an object are defined and then trimmed down so only the most important ones are stored. The characteristics are then compared to those of other objects on a database, with the overall classification depending on the degree of similarity.
Using a computer model, the researchers tested a number of objects, ranging from suitcases to glass bottles, and several models of the human body: an adult, a teenager and a child.
Real-life experiments were then performed in a small, echo-free chamber, using a 3m long waveguide – a solid beam-like structure that guides the radio waves in a certain direction.
Mroué says the system successfully differentiated between the luggage bags and people, meaning a potential system could highlight the urgency of a response.
"We hope these devices will be used in the near future since they are very complementary to existing video systems and have a similar final cost," concluded Mroué. "The complementary use of video and radar systems could lead to low levels of false detection, which is mandatory for this application, and maximise the chance of survival for passengers who have fallen on the line."
