Research On Creepage Distance Measurement System Of Transmission And Transformation Insulator

As an important part of power facilities,the creepage distance(creepage distance)of transmission and transformation insulators is an important parameter to evaluate their insulation state.The contact measurement method can not meet the requirement of in-service measurement.Based on the analysis of the shape characteristics and optical characteristics of the insulators,and the investigation of the application scope and conditions of the existing non-contact measurement methods,this dissertation determines the measurement method of creepage distance realized by the principle of binocular stereo vision,proposes the measurement scheme of the combination of four-eye-camera and structured light,and carries out the system analysis and design.In this dissertation,the principle and method of the measurement with four-eye-camera are given.Based on the measurement distance,the measurement accuracy of the theoretical model of binocular system is simulated and analyzed to guide the optimal design of the structural parameters;the cameras are selected and a kind of lens with internal focusing function is simulated and designed;in order to reduce the difficulty of matching point extraction,the cross structured light source and its use method are designed.A method of simultaneous joint calibration of the four-eye-camera is proposed.The experimental platform of the four-eye measurement system is built and calibrated with Matlab calibration toolbox to obtain camera parameters and system parameters.The mathematical formula of triangle reconstruction of binocular stereo vision intersection measurement is derived.Under the environment of Matlab,the algorithm of three-dimensional point cloud data reconstruction of insulator creepage distance is programmed and debugged.The insulator test area images are collected and processed to get the matching points data.The three-dimensional reconstruction program is used to calculate the insulator creepage distance point cloud data,the method of non-uniform rational B-spline curve fitting is used to obtain the creepage distance.In this dissertation,the preliminary experiment of creepage distance measurement for a given insulator is completed,and the results are compared and analyzed with the contact measurement data.The relative errors of the creepage distance of the three complete periods are 0.77%,0.68% and 0.49%,respectively.The experimental results show that the four-eye measurement system is effective and the measurement accuracy is good.The frame structure of the four-eye measurement system reduces the calibration error of the moving parts,and two groups of binocular cameras are combined to solve the problem of grazing incidence and occlusion,it has high practical value in the measuring field of insulators and some special-shaped workpieces.