Transmission Line Sag Measurement Algorithm Based on Binocular Vision 3D Reconstruction

Transmission line is the key component of the power system, and its working condition is very important for the safe operational aspect of the power system. Transmission line inspection plays an essential role in ensuring the power system can be operated safely, reliably, effectively. With the escalation of the scale of the national power system, the demand for inspection of power transmission lines is gradually increasing. Due to the shortcomings of traditional human inspection, such as time-consuming, laborious, and not strong real-time, UAV electric inspection develops rapidly. As an important index for the security and reliability operation of transmission lines, the size of sag directly affects the security and stableness of transmission lines, so it’s an essential part for UAV inspection to measure sag. This research studied the sag measurement of transmission lines by relying on the UAV platform, with the baseline of the requirements of transmission line inspection. On the basis of image preprocessing, this paper adopts the method based on 3D reconstruction, introduces the camera calibration method to obtain parameters, calculates the 3D coordinates of the highest point of the tower and the lowest point of the line in the image from the pixel coordinates, and finally calculates the sag value according to the concept of the sag. Compared with traditional measurement methods, this study has smaller error, less calculation and more convenient measurement.