The Measurement Research For Contact Wire Geometry Parameters

This paper designed a system for the measurement of the geometry dimension and the wear of the contact wire. The basic technique used in the system is the principle of the optic triangulation and CCD (Charge Couple Device) image measurement. The system is based on a detection unit of the contact wire which will be installed on the upper part of the vehicle body to realize the dynamic control of the contact wire and guarantee the safety of the railway lines.First of all, the background and meaning of research and development is introduced in the thesis; the geometry dimension and the wire wear's definition are introduced. Then the domestic and overseas development of contact wire detection is summarized, including detecting method, detecting principle; the advantage and disadvantage of all the detections are analysed and compared. After a deep study on these detection techniques, we draw the conclusion that the detection technique based on CCD image will be a leading technique to realize the dynamic control of the contact wire and guarantee the safety of the railway lines. Then the paper gives the composition of the device.The thesis put an emphasis on follow questions: First, detecting principle: the principle of the optic triangulation and the wear measurement. Second, the design of the hardware: the selecting of optics device, camera and capture card. Third, the design of the image processing arithmetic: every arithmetic is introduced and compared , then the best image processing arithmetic is choosed to the thesis. Four, the paper introduces the measurement running status in laboratory, including the relevant parameters of the contact wire and the error analysing. Finally, the paper point out the defects that we should pay attention to in the system.