Abstract: In order to solve the problem that manned helicopters and compound wing UAVs in high altitude and mountainous areas operate at high relative altitude, are vulnerable to crosswind and have sparse point clouds, this paper proposes a method to obtain three-dimensional laser point cloud data of overhead transmission lines by “tower imitation flight”,optimizes the traditional “ground imitation flight” mode, and obtains point cloud data of a 500kV ultra-high voltage line of Shannan in Tibet.After data processing and analysis, the obtained point cloud data has a high voxel density and high spatial positional accuracy. The experimental results show that the high-capacity multi rotor aircraft conducting “tower imitation flight” operations in high-altitude and mountainous areas not only reduces operational risks, but also obtains high point cloud data density, low noise, and obvious micro characteristics of hardware and wires. At the same time, this method has the advantages of high maneuverability, strong stability, and low operational risks, providing support for the fine autonomous inspection of overhead transmission lines and the intelligent application of the State Grid.

Key words: high altitude and mountainous areas, pointcloud voxel density, LiDAR, tower imitation flight, dual route