Research On 3D Modeling Optimization Technology Of Transmission Line Based On Photogrammetry

The periodic inspection of transmission lines focuses on the line body and ancillary facilities,as well as defects and hidden dangers in the line protection area.Through helicopters and multi-rotor drones,it is possible to quickly and efficiently patrol the infrared and visible lights of the line body,effectively discovering various hidden defects.The line body application machine patrol can achieve or even surpass the effect of manual patrol.In recent years,the development speed is relatively fast,and the channel patrol of the line protection area has not been carried out by large-scale application machines in China.Photogrammetry is a technique for acquiring images for calculation and acquiring three-dimensional information on the ground.Aerial photogrammetry is to carry out three-dimensional modeling of the ground on the flight platform.Only the ordinary camera can be used to complete the data acquisition,and the complex three-dimensional calculation and complete measurement of the topography and geomorphology can be completed by software.Combined with the principle of stereo imaging,the position information of the wire can also be restored by manual assistance.This paper mainly studies the key technologies of UAV photogrammetry,UAV data acquisition index,image data distortion correction algorithm and data control algorithm quality control measures and the verification of the transmission line 3D modeling method applied in this paper;The specific discussion is as follows:(1)In the data acquisition phase,the UAV tilt photography technology is used to improve the restoration effect on the side texture of the 3D model,and the data is collected on the same line with different tilt angles and overlap degrees to compare the collected image data.Analytical experiments,test and analysis of the most suitable data transmission indicators for the characteristics of the transmission line is 85% heading overlap and 60% of the side overlap and 5 degrees of tilt angle;for the positioning and positioning system,the use of post-mortem dynamic differential processing technology The positioning accuracy error of single-frequency GPS has been raised from the meter level to the decimeter level.(2)In the data processing stage,the commercial calibration software is used to calculate and obtain the camera's internal azimuth parameters and distortion parameters,and the program is programmed to correct the acquired image data.The 3D reconstruction of the corrected image data generates point cloud data,and manually adds the same position in different images by adding a manual connection point to the modeling point cloud,thereby assisting the software to obtain a more accurate matching effect and improving image matching.The effect of adding image control points based on the method of laser radar data fusion improves the accuracy of tree barrier measurement.(3)Collecting high-definition image data for different transmission lines on the same line,then applying different data processing algorithms for image fusion and 3D modeling,and comparing the influence of terrain and data processing methods on the modeling effect.In the 3D model generated by different data processing methods,the elevation information and plane information are measured based on the generated point cloud data and the accuracy analysis is carried out.Finally,compared with the lidar data,the optimized 3D construction is verified.The mode method is more suitable for the patrol work of the transmission line,and also provides a high-precision and reliable operation method for the drone line inspection.(4)Finally,using the three-dimensional modeling method suitable for the characteristics of transmission lines studied in this paper,the application test is carried out on the transmission line of Guangdong Power Grid,and the test results are analyzed and improved,and finally obtained in large scale in Guangdong Power Grid and other power grid companies.Applications.This paper studies the three-dimensional modeling technology of transmission lines based on the South Network technology project "Fast Stereo Aerial Survey Technology and Comprehensive Application of Transmission Lines Based on Light Fixed-wing UAVs",and proposes a set of three-dimensional modeling methods that best meet the characteristics of transmission lines.The research on 3D modeling technology of transmission line based on photogrammetry has certain theoretical guidance and engineering application value.