A Calculation Method Of Safe Inspection Area For Flying Robot Inspecting Transmission Tower

This paper researches on a calculation method of safe inspection area for flying robot inspecting transmission tower. Due to the high risk, low accuracy and low efficiency of the traditional methods, the robot collects too much invalid data in the process of inspection, not emphasizing on the important inspection items, so this is undoubtedly a big obstacle in the flying robot inspection technology. It has a great significance to improve the quality and quantity of flying robot viewpoint selection on power tower observation. This paper proposes a new calculation method of transmission tower safe inspection area (SIA) namely the safe hovering positions for inspection flying robot which is based on features of point cloud.There are many studies about the viewpoint selection, but most of them are single viewpoint optimization which are based on the image information, having certain limitations in the pylon inspection applications. In this paper, considering the widely applied laser point cloud and the safety and effectivity of inspection process, we put forward the concept and calculation method of the safety review area. Firstly, a safe envelope of the transmission tower is obtained from layer projection and safety constraints. Secondly, essential inspection factors are calculated at any viewpoint according to the number of transmission tower point clouds, the average distance between the viewpoint and other visible point clouds as well as dimensionality feature of those clouds. The multiple attribute decision theory is used to make viewpoint model. Finally, the SIA is selected continuously from the safe envelope using the Particle Swarm Optimization, and this method improves the accuracy of the calculation results compared with discrete optimization. This paper uses the PCL (point cloud library) for discrete optimization algorithm, and uses Matlab to carry on the continuous optimization algorithm, simulating on the platform. The method is based on the laser point cloud data, which is applied more widely than the traditional viewpoint selection method like CAD model. To sum up, Experiments show that the proposed SIA observes the power tower safely, accurately and efficiently and it highlights the important inspection items, at the same time the SIA is the foundation of advanced intelligent functions such as path planning.The target of the method is to solve a much widely safety inspection area, which is more flexible in flying robot compared to a single viewpoint. The method of calculating SIA is not only suitable for pylon but also applied to other 3d objects. This paper chooses the viewpoint in SIA to compare with random candidate viewpoints on safe envelope, and the result simulating image suggests that whether the integrity or the quality of observations, the SIA is more effective. In addition, by comparing the results of discrete and continuous optimization, it is concluded that the continuous optimization finds the SIA accurately.