Power Contact Wire Altimeter Prototype Developed Based On Binocular Stereo Vision

As an important part of electric railway, if contact wire is too high or too low, it will affect receiving current quality, cause equipment abrasion of the pantograph and even lead to heavy losses of the pantograph when seriously. Therefore, the height measurement of contact wire is significant. At present, in periodical detections of contact wire height, troubleshooters usually use laser phase distance meter which spends a few minutes to measure one point via mechanic scanning with low efficiency of collimation measurement. In view of this situation, the research of efficient and real-time height measurement of contact wire is very urgent.By studying the advanced detection technology of contact wire height domestic and overseas, we choose a non-contact detection technology based on binocular stereovision and apply the ARM embedded high-speed processor to accomplish low-speed and dynamic detection. First, a new coordinate selection method is presented to deduce the formula of contact wire height measurement, which fills up deficiencies of coordinate selection of traditional dual-CCD. Second, based on the analysis of accuracy effects which results from various parameters and the system's functional requirements, the whole system is designed including structural design, lighting design, selection of photographic lens, image sensor and MCU. Finally, the image sensor is driven by ARM to get the image data via automatic exposure and communicate with the host computer to accomplish management of measuring data.In this paper, the design and develop of convenient and efficient "contact wire finder based on binocular stereovision" is preliminarily completed. Combined with corresponding image processing algorithm, this design would be a practical device which will be placed on a tailor-made cart pushed by troubleshooters to accomplish real-time automatic measurement.