Research On Measuring System For Geometric Parameters Of Railway Contact Wire

As railway transportation develops to be high-speed and heavy-haul,the status of electrified railway is improving day by day.Contact wire is an important part of power supply system in electrified railway.Reliable contact between contact wire and pantograph is the basic requirement for the proper operation of electrified railways.The geometric parameters of the contact lines will affect the current-receiving quality of electrified railways.In order to prolong the life of contact wires and ensure the safety of railways,it is necessary to inspect the geometric parameters of contact lines regularly.At present,the measurement system used in the daily measurement of the geometric parameters of contact wire has the problem of low measurement efficiency.Based on this situation,this paper studied the development of a rapid measurement system for the geometric parameters of contact wire.The main contents include:1.In order to realize high-precision non-contact measurement,a measuring method based on binocular stereo vision is adopted.To solve the dilemma of feature matching in traditional binocular vision measurement,a scheme combining binocular vision with laser scanning is proposed.2.The measurement principle of the selected scheme is analyzed,the calibration method of system parameters is studied,and the resolution of the measurement system is calculated,which provides a theoretical basis for the design of the system structure.3.A special linear array CCD camera is designed to meet the actual needs,and the corresponding driver is developed,which can realize fast image acquisition and transmission,and automatically adjust the exposure intensity according to the external light.The hardware and control method of laser scanning light source are designed,and the scanning range and scanning frequency can be precisely controlled.4.The image processing method of linear CCD camera is studied,and a centroid localization algorithm based on partial interpolation is proposed.The positioning result of the algorithm is verified by simulation experiment.The software of the measurement system is written based on Visual C++.Through a series of experiments,the feasibility of the measurement scheme proposed in this paper is verified.The time required for measuring geometric parameters of contact wire at fixed point is less than 2 seconds,the measurement accuracy can reach ±4mm,and the repeatability accuracy can reach 1.5mm.Compared with the laser measuring equipment which is widely used in the static measuring of contact wire,the measuring efficiency has been greatly improved.High precision measurement of geometric parameters of contact wire can be realized.