自主飞行无人机地理围栏算法设计与实现

Design and Implementation of Autonomous Flight Unmanned Aircraft System Geo-Fence Algorithm

为提高无人机飞行的安全性,提出了一种自主飞行的无人机地理围栏算法。首先,通过对原始地理围栏缩放并进行顶角平滑与自相交检测处理,提出一种对凹凸地理围栏普遍适用的地理围栏预控制层生成算法;然后,在传统射线法的基础上加入缓冲距离以解决交点数误判问题,利用改进的射线法进行地理围栏越界探测,且针对存在越界危险的无人机设计了一种越界航点重规划方法及相应的边界保持自主控制控制律;最后,利用四旋翼无人机搭建的实验系统进行了验证。仿真及实验结果表明:无人机能够在避免地理围栏越界的基础上尽可能小地修正原飞行路径,证明提出的地理围栏算法有效,能够保证自主飞行的无人机在地理围栏内的飞行安全。

To improve the safety of unmanned aircraft system(UAS) flight, an autonomous flight UAS geo-fence algorithm is proposed. Scaling the original geo-fence and performing vertex smoothing and self-intersection detection processing, a geo-fence pre-control-layer generation algorithm is proposed, which is universally applicable to both concave and convex geo-fences. Then the buffer participates are added to the traditional ray method to solve the problem of misjudgement of intersection points. The improved ray casting algorithm is used to detect the violation of geo-fence, and a re-planning method of the violating waypoints is chosen for the UAS with violating danger. The corresponding control law for boundary maintaining autonomous controls is established. Validation experiment is carried out on the system constructed with quad-rotor UAS. Both simulation and experiment indicate that the UAS is able to modify the original flight path as slight as possible in avoiding violation of the geo-fence, thus the effectiveness of the proposed geo-fence algorithm and the flight safety of autonomous UAS in geo-fence are verified.