Today’s trend in winter sports draws more and more people away from the designated slopes. Free riding and ski tours experience a massive boost in popularity. However, every year in Switzerland alone, 25 persons die on average in avalanche accidents. 90% of all victims survive if they can be recovered within the first 15 minutes. After that, the chances of survival decrease rapidly. The drone alcedo helps to find people under avalanches.
Nowadays, an avalanche transceiver (AT) belongs to the standard equipment of every ski tour participant. This device emits a short signal every second. With the aid of these signals, the carrier can be located with another AT in case of an avalanche burial. However, the search for victims is often difficult: Steep slopes, pathless terrain and the psychological burden take the rescuers to their limits. This is where alcedo comes in: The project aims to facilitate the localization of avalanche victims. Therefore, an autonomous drone was developed, which takes on the search without human engagement. While alcedo is searching, the human has time to make an emergency call and prepare optimally for the recovery.
Agile and fast
Four separately controllable rotors allow alcedo to maintain a stable position even against strong winds. They also enable alcedo to perform fast and complex flight manoeuvres. With a top speed of 50 km/h, alcedo outperforms any human rescuer. An ultrasonic sensor measures the distance off ground and maintains the small helicopter at a constant flight height of 2.5 metres. Thus, collisions with the rescuer can be avoided.Figure 3: Alcedo maintains a constant flight heightUltra-portable and user friendlyDuring the development of alcedo, high value was set on a low weight and a compact construction, such that every member of a ski tour party can carry a device. A novel folding mechanism allows the compact stowage of the drone in a shock proof packaging. Thus, alcedo can be mounted on a common backpack and will not be damaged when the carrier falls. A total weight of 1.5 kg corresponds to a 1.5 litre PET bottle. The handling is conceivably easy and can be conducted under great stress. The operator enters the size of the avalanche and his position on the avalanche deposit through the user interface on top of the drone. That way, alcedo knows which area to search. After the start button has been pressed, the drone starts the autonomous search for victims.
Innovative Search Patterns
Only now, alcedo is able to display its lineup of high tech gear. It is equipped with a common avalanche transceiver. By quickly overflying the avalanche deposit, alcedo tries to acquire AT-signals from victims. The orientation on the avalanche is done by GPS and an electronic compass.
Once a victim’s signal is discovered, alcedo follows it and arrive in the closer area of the buried. With more signals and its current position, alcedo then calculates the most probable location of the victim. Once this has been determined, the helicopter reduces the operating height and drops a smoke beacon. The position of the victim is thus clearly visible from afar for the rescuer. The helper can then focus all his energy on the most important part of the rescue: the recovery of the peer. Meanwhile, alcedo searches for more victims. Up to four buried can be marked with marker beacons, but alcedo could land at the location of a fifth.
No Serial Production
The project alcedo has produced a first prototype. However, it is far from ready for marketing. Even with industrial mass production, the drone would still be too expensive to become part of the standard equipment. The project alcedo was initiated as a pure research project: The main goal was to show the possibilities of facilitating the search for avalanche victims. However, a certain interest still exists: the Swiss manufacturer for outdoor equipment Mammut and the Swiss Air Rescue (Rega) support the project as main sponsors.