Design and Experiment of Autonomous Flight UAS Geofence Algorithm
Qixi Fu, Xiaolong Liang, Jiaqiang Zhang, Duo Qi, Xiujun Zhang · 2019
In order to improve the safety of UAS flight, an autonomous flight UAS geofence algorithm is proposed. Firstly, by scaling the original geofence and performing vertex smoothing and self-intersection detection processing, a geofence pre-control-layer generation algorithm which is universally applicable to both concave and convex geofence is proposed. Then, the buffer is added on the basis of traditional ray method to solve the problem of misjudgement of intersection points. The improved ray casting algorithm is used to detect the violation of geofence, and a re-planning method of the violating waypoints is proposed for the UAS with violating danger. The corresponding control law of boundary maintaining autonomous controls is designed. Finally, the validation experiment is carried out by using the experimental system built by the quad-rotor UAS. Experiment result show that the UAS can modify the original flight path as little as possible on the basis of avoiding the violation of the geofence, and the proposed geofence algorithm is effective and can ensure the flight safety of autonomous UAS in geo-fence.