The Detection Method Research Of Catenary Geometry Parameters Based On Image Processing

Electric locomotive with the advantages of high speed, high transport efficiency, environmental protection and low cost of operation and so on, has been becoming the main transportation tool in the domestic and foreign transportation industry. In the entire operating mechanism of electric locomotive, the power source determines the speed of the locomotive is the traction system of electric locomotive. Electric catenary and pantograph are the major components of electric locomotive traction system. In the process of pantograph glide along catenary wire, to achieve the power transmission from the substation to locomotive traction, and drive it operate. Therefore, the operating condition of catenary pantograph system is stable or not, which is the main factors to determine the stability of locomotive operation. The kinetic and structural parameters of the catenary pantograph system embody its mainly working conditions, which catenary geometry parameters is one of the important factors to reflect the catenary pantograph system operating conditions, it is necessary to detect it. Thus, this paper presents an approach based on image processing to detect electric catenary geometry parameters.First of all, on the basis of tracking the detection methods of catenary geometry parameters(such as pull value, wire height) and comparing the advantages and disadvantages of various detection approachs, proposed the method ideas about using of image processing to detect the catenary geometric parameters. Introducing the principles of binocular measurement, then establish theoretical mode of using two CCD cameras with symmetrical arrangement to detect catenary deviation and height, in addition, pushed to the expression of the space point coordinates. Calculate the transformation matrix equation, which represent the conversion of a space point coordinates to corresponding image coordinates in the CCD image plane, then the common methods of camera calibration were introduced. Secondly, elaborated the working principle and the main performance parameters of detection system hardware(such as industrial cameras, lenses, optical source), Combined with the detection requirements, and identify the selected equipment type, then constructed the whole detection system and acquired the image of pantograph-catenary operation. Then, Image segmentation, edge detection, and feature point extraction algorithm are analyzed via using a variety of image processing operators in the professional image processing environment named Halcon, then Acquiring the coordinates of the contact point between pantograph and catenary and center point coordinate of the pantograph image. Finally, taking experiments to verify the feasibility of this detection method based on image processing for catenary stagger and height, and doing error analysis of experiment results. The reason which causing the error of measurement is analyzed, then proposed the ideas to reduce experimental error.The experimental results verify the feasibility of this detection method for measuring catenary geometric parameters, which provides a certain reference for the relevant technical personnel who work in the inspection department of pantograph-catenary system.