A Novel Collision Avoidance Method for Fixed-wing Unmanned Aerial Vehicles

In this paper, we study collision avoidance problems with fixed-wing unmanned aerial vehicles (UAVs). According to the spatial position and relative speed between the UAVs, several sufficient conditions for avoiding collisions are proposed. An emergency control algorithm is designed based on the sufficient conditions to ensure that the UAVs can be driven from a dangerous state to the safe area. In order to prevent frequent switching of states of the UAV between "safe mode" and "danger mode", a conflict buffer is additionally introduced for conflict resolution and smooth transition. The sufficient conditions can not only be applied to the collision avoidance problem with static and dynamic obstacles, but also can be directly extended to the internal collision avoidance between multiple vehicles. Meanwhile, control input saturation is explicitly considered for the emergency maneuver. Simulations are presented to illustrate effectiveness of the proposed algorithm.