Application Study Of Laser Vision Technology In Measuring Wheelsets Geometric Parameters

Wheelsets play a key role for the safety of railway transportation, as important parts of the railway vehicles. Therefore, it is crucial to measure parameters of wheelsets accurately. However, the parameters of wheelsets are currently measured by hands in most cases, so it is necessary to develop an automatic system for measuring the wheelsets parameters. The measurement method that is based on the advanced structural light vision sensing technology is put forward in this thesis, and the system and the software has been developed to measure the wheelsets parameters.On the base of analysis of several existing static and dynamic detection methods, the advanced structural light vision sensing technology is adopted to measure the wheelsets parameters. The structured light scans the wheelsets and forms distorted shape of light. These changed lights are collected by CCD and processed by the image processing techniques to obtain geometrical information of wheelsets. The thickness of the flange and rim can be non—contact measured in real time. The image then is processed and the distorted shape of light is extracted by the projection method and the tagging method. The calibration of the target is designed for this measurement mechanism. After measuring error analysis, some experiments were made on the developed system.