Research And Application Of Tension Test Method For Guy Cable Of Transmission Line Guyed Tower Based On Visual System

The guyed tower not only plays an important role in the transmission lines of 500 k V and below,but also shows a good application prospect in the UHV lines in Northwest China.The guy cable is the main horizontal force component of the guyed tower.The change of tension has a great influence on the overall force,deformation of the guyed tower and fatigue wear of guy cable.The tension monitoring of guy cable is an important means to ensure the structural safety of the guyed tower.The traditional tension measurement method belongs to contact measurement,which has the problems of poor stability,low precision and low efficiency.Therefore,the tension test method of guyed tower based on visual system is studied in this paper,in order to provide reference for the construction,operation and maintenance of guyed tower of high voltage transmission line.The main work of this paper is as follows:(1)The basic principles of frequency method for guy cable tension measurement and computer vision technology are described,and a new idea for applying frequency method to test guy cable tension measurement of guyed tower is proposed.Visual technology is used to obtain vibration signals and calculate tension based on frequency method.According to the characteristics of the image such as long and thin guy cable,rough edges,and other features,guy cable area is segmented through edge detection and morphological processing to eliminate interference from unrelated areas.The least square method is used to fit the edge points of guy cable area,and the edge coordinate points are smoothed to achieve subpixel level positioning calculation.(2)The steps of the guy cable tension test are introduced comprehensively.The guy cable vibration sequence images are captured by the camera,and guy cable region is accurately located based on edge detection and morphological processing.Then,edge fitting is performed to obtain the vibration displacement time history data of guy cable area.On this basis,the frequency method is used to calculate guy cable tension.The method of target area extraction and target edge coordinate recognition are systematically expounded,and a method based on visual system for measuring the tension of guy cable is proposed.(3)The laboratory test of the guy cable tension test was carried out,and guy cable model was designed and erected.The camera and tension sensor were used to test guy cable tension based on the visual system and the tension sensor respectively.The results of the two methods were compared and analyzed to verify the feasibility of guy cable tension test method based on visual system.(4)Based on the Matlab platform,a GUI software for the guy cable tension measurement is designed,which can directly input guy cable vibration videos and output tension after editing and processing.The engineering application research of guy cable tension test method based on visual system is carried out in an all-round way.Taking a ± 500 k V single mast guyed tower in Hubei Province as the research object,the camera and sensor are used to measure guy cable tension based on visual system and guy cable tension based on tension sensor respectively.The results obtained by the two methods were compared and analyzed,and the engineering practicality of guy cable tension method based on visual system was verified.The results show that the tension test method of transmission line guyed tower based on image visual system has high test accuracy and non-contact advantages.It has a good application prospect in the structural safety assessment of transmission line guyed tower.