Autonomous Soaring; Flight Test Results of a Thermal Centering Controller

In this paper the stability and effectiveness of a thermal centering controller for autonomous soaring applications was investigated. The controller was evaluated in flight trials to verify theoretical stability properties obtained in earlier work by the author. The outcome of the trials confirmed stability of the controller under a variety of conditions encountered from November 2009 to May 2010. In addition to the evaluation of the centering controller, the outcome of the flight tests indicated that the concept of autonomous thermal soaring is a viable option for significantly extending endurance of small unmanned aerial vehicles, UAVs.