Research on Hierarchical Motion Planning Method for UAV Substation Inspection

In order to improve the efficiency and quality of unmanned aerial vehicle (UAV) substation inspection, a hierarchical motion planning method for UAV inspection based on front-end path search and back-end trajectory generation is proposed. At the front end, an improved A* algorithm is proposed to increase the planning speed and reduce the path turnings by constraining the direction of node expansion and modifying the heuristic function. At the back end, a minimum-snap trajectory optimization combined with the waypoint filtering method is proposed to generate a smooth trajectory that is beneficial for UAV inspection and tracking. The simulation results show that the improved front-end path planning method can obtain the flight path with fewer turns in less computation time, and the back-end trajectory optimization combined with the key point filtering can generate the trajectory with shorter flight time. Tracking the trajectory by the back-end optimization can provide higher tracking accuracy than path tracking, which is helpful to ensure the flight safety and stability of the UAV during the inspection process.