Thermal highs and pitfall lows - notes on the journey to the first cooperative autonomous soaring flight

This paper discusses the development and flight testing of an algorithm for cooperative soaring by multiple autonomous gliders. Flight test results confirmed that the algorithm functioned as expected and that the gliders worked cooperatively to find and utilize the same updrafts during the test. However, the flight also indicated that the effectiveness of the strategy depends largely on the existing thermal conditions in combination with how restrictively the limits of separation between the cooperating gliders are set. To the best of the authors´ knowledge this was the world´s first cooperative autonomous thermal soaring flight.