Fraunhofer Institute for Physical Measurement Techniques IPMUAV-based sensor system for locating buried persons
After a building collapse – e.g., caused by an earthquake – time is of the essence. Emergency personnel need detailed information quickly about where people are trapped. At the same time, the safety of the rescue workers themselves must be ensured. If natural gas pipes or propane gas cylinders are damaged, the risk of leaking gas and thus explosions increases. Currently, rescue workers can only protect themselves to a limited extent. The standard includes portable, sample-taking gas detectors as part of personal protective equipment – with one major disadvantage: when the gas detector sounds, the rescue worker is already in the danger zone.
Sensor system reduces risk for rescue workers
In the joint project »SORTIE« (Sensor Systems for Locating Buried Persons in Collapsed Buildings), funded by the German Federal Ministry of Research, a UAV-based modular sensor system has been developed for locating buried persons, which maps and analyzes debris fields from the air. The research resulted in four modules, including a laser spectrometer from Fraunhofer IPM that detects leaking gases such as propane or methane from a safe distance, thus warning rescue workers of potentially explosive areas.
The device operates in the mid-infrared spectral range (MIR), which shows strong absorption lines for both methane and propane. As an innovation, this enables both gases to be measured with just one device. For use on drones, the module has been optimized using extremely lightweight optics, electronics, and mechanical structures. The module was successfully tested during measurements on a debris field. While flying over an artificial leak scenario in a basement shaft (leak rate of 1 l/min, flying at a height of approx. 3 m), it reliably and sensitively measured methane and positively identified the leak.
The entire system was successfully tested in a simulated real-life scenario at a THW training ground, thereby also evaluating its integration into the organizational structure of the emergency services.
