A Measuring Method For Transmission Line Sag Based On Computer Vision

The transmission lines carry out the responsibility of electric power delivery, and it is great importance to ensure the safe and reliable operation of them, which is directly related to the steady development of economy. Sag is one of the important parameters for operation and maintenance of transmission lines, and it will directly affect security and reliability of the running of transmission lines. To improve the capacity of transmission lines, the maximum allowed operational temperature has been raised from 70℃to 80℃because of the soaring demand of electricity. At this condition, the sag becomes the main factor to ensure the safe operation of the line and should be checked regularly.Based on computer-vision, a method to measure the sag of line is presented in this paper. It finishes non-contact measurement by combining computer vision technology with photoelectric technology. The contents of the paper include the following elements: camera calibration, binocular stereo vision, image matching, curve fitting and calculating sag.