Research On Comprehensive Positioning Method Of Catenary Detection System

With the rapid development of electrified railways in China,as an important infrastructure of electrified railways,catenary networks have the characteristics of no backup along the line,complex service environment,and the influence of various natural conditions,and its reliability is directly related to the safety of railway operation.Regular dynamic detection of the catenary and timely grasp of the service status of the catenary are important measures to improve the reliability of the catenary.Comprehensive positioning is the key technology of dynamic detection of catenary and plays an irreplaceable role in catenary detection.Through the dynamic inspection of the catenary detection vehicle,the position of the detection vehicle in the line is located in real time,and the spatial coordinates of the data are detected by means of accurate catenary detection data,which effectively improves the timeliness and maintenance efficiency of the on-site defect review of the detection data.In view of the practical problem that the positioning of the catenary detection vehicle is inaccurate,combined with the characteristics of China’s railway operation scenarios and catenary detection technology,the comprehensive positioning technology of the catenary detection vehicle under complex working conditions is systematically studied,and the technical problems of accurate positioning of the catenary dynamic detection are solved by fusing several key technologies such as wheel diameter positioning,pole number,anchor section joint and line fork identification.The main tasks are as follows.Aiming at the problem of large positioning error of catenary detection vehicles,this paper proposes a comprehensive positioning method with wheel diameter positioning as the main positioning method and rod number recognition,anchor section joint and line fork recognition as the correction means.(1)Study the setting scheme of the detection vehicle trigger module,and study the accurate shooting method of the catenary pillar based on the trigger mode according to the characteristics of the catenary pillar of the detection vehicle through the section,and effectively improve the efficiency of the pole number recognition algorithm.(2)Based on the pole number recognition method,the three-step discriminant method of the catenary pillar number is studied and proposed,and the selective correction of the recognition pole number is carried out,and the pole number recognition correction function is integrated on the basis of the traditional positioning method,which effectively improves the positioning accuracy of the catenary detection vehicle.(3)According to the horizontal projection spacing change law of the two contact lines in the anchor section joint and the line fork area of the catenary,combined with the design parameters of the two line spacing in the anchor section joint and the line fork area,the spacing threshold judgment conditions are analyzed and given,so as to locate the section where the detection vehicle is located.(4)Further combined with the inflection point characteristics of the contact line pulling value on the pillar,the anchor segment joint conversion column and the line fork positioning column are identified by comparing the size of the contact line pull value,and the identification correction of the anchor segment joint conversion column and the line fork positioning column is completed in combination with the line database.In this paper,the structure of the integrated positioning system is analyzed and designed,and the system is tested and verified in the Lalin section of the Sichuan-Tibet Railway,and the experimental data shows that the accuracy of the pole number recognition and correction combined with the line database is more than 80% in the tunnel and mountainous areas;the accuracy of the anchor section joint and line fork identification and positioning in the tunnel and mountainous area is more than 90%,and the positioning error on the line of the integrated positioning system is controlled within 7 meters,which meets the positioning requirements of the catenary detection system.