Research on collision avoidance of fixed-wing UAV

In this paper, a hybrid collision avoidance approach, outer planning control and inner emergency control, is designed to solve the problem of avoidance of the non-cooperative target and the cooperative UAVs in the formation. For non-cooperative target, a multi-layer obstacle avoidance model is employed to determine the current situation of the UAV, for which different layer corresponds to different methods. If the UAV is far away from the obstacle, the method of planning control is implemented. A collision cone with a transition domain is introduced to reduce response time and eliminate local minima. If the UAV is closer to the obstacle, an emergency avoidance method is needed to ensure safety. For the cooperative UAVs in the group, we set the avoidance strategy table in advance and select the best response method by optimizing the security value. The feasibility and effectiveness of the proposed strategies are verified by simulations.