Research On Intelligent Analysis Method Of Power Transmission Corridor Defects Based On Airborne LiDAR Point Clouds

As a key energy essential for the modern society,electricity is related to national defense,economy,and people’s livelihood closely.Greater demands are being placed on the daily maintenance and overhaul of transmission lines for the construction and development of smart grids.Traditional personnel inspection has low efficiency and high risk factors,which is difficult to meet the fast-growing needs of the power grid.The development of measurement technology on airborne LiDAR has effectively improved the efficiency of line inspection,reduced operation and maintenance costs,and provided a new method for power inspection technology.Based on the data collected from the transmission line corridor by UAV in the form of point cloud,the following in this paper were studied:extraction of power line and power tower,three-dimensional power line reconstruction and automatic safe distance detection of transmission lines.The main research results of this paper are as follows:(1)For the problem that the traditional algorithm for the extraction of power line and power tower is sensitive to ground fluctuations,and some points of ground are hard to exclude from the extraction result,a lightweight neural network was proposed with a direct input of the original point cloud data to implement the extraction of power line and power tower.By dividing the original point cloud data into a number of voxel grids of equal size,the feature learning network and the convolutional neural network were used to extract the spatial and structural information in the voxel grid.Then the characteristics of relative height and point density which we can find in traditional algorithms were added to the feature to determine whether the voxel is a type of line or tower point cloud or not.Finally,clustering was used to eliminate isolated voxels to improve the accuracy and obtain the laser point cloud data of power line and power tower.The algorithm has a stable accuracy for different terrains and interferences in the extraction,as the experimental results show.The algorithm can achieve the extraction and the segmentation of power line and power tower effectively.Compared with the method using grid or other methods,the algorithm has a certain improvement in stability and accuracy,and also has a good anti-interference effect on other factors such as the existence of tall trees or vertical occlusion.(2)The reconstruction model for power lines of parabola or catenary based on plane was proposed as an improvement of the model combining straight line and parabola.First,the least square method was used to fit the plane where the power line is located,and then on the basis of the least square method,the parabola model and the catenary model were fitted respectively by solving the linear equations or using the gradient descent method.The experimental results show that the two models proposed have obtained a high accuracy of reconstruction and algorithm efficiency,and can meet the needs of automatic power inspection.(3)An automatic detection process for the safe distance between power lines and ground was proposed.Firstly,a large number of non-dangerous points were eliminated by the method based on spatial features and octree space division;then,the KD tree structure was used to accelerate the point cloud ranging process by radius search and nearest neighbor search algorithm to realize the marking of dangerous points.Experiments have proved that the process proposed has obtained a high accuracy on distance measurement,and the algorithm is highly efficient,which is competent for the automatic inspection.