An Effective Approach of Collision Avoidance for UAV

In the last decade, the collision avoidance of Unmanned Aerial Vehicles (UAVs) has become increasingly important for the safe operation of UAVs. In this article, an effective conflict detection and alerting principle is firstly proposed based on mixed collision cone and alerting criterion for the collision avoidance of UAV. Second, a reactive collision avoidance and trajectory recovery strategy (RCATRS) is presented based on the model of relative kinematics. In this strategy, by acting an acceleration vector with different magnitude and direction on UAV, a horizontal collision avoidance maneuver is realized in situations of different relative position and velocity vector. When UAV has bypassed the obstacle, the horizontal trajectory recovery maneuver is initiated to make UAV to return to original flight paths. Thus, different recovery trajectories corresponding with different relative velocity vector are planned. Finally, the safety controller is designed to apply RCATRS to autonomous quadrotor. Since a few of computation is off-line, RCATRS is simple in implement and can satisfy the request of running in real time. The results of simulation show the validity of the proposed RCATRS.