The Research Of Automatic Measurement Of High Speed Rail CPⅢ Based On Binocular Stereo Vision

With the rapid development of high speed railway, how to ensure the safety of the railway becomes an important topic. At present,the method of artificial detection is widely adopt during the construction of high speed railway. The shortage of the method is that it is low efficiency and has a long detection cycle. In the stage of operation, although the high speed railway track inspection car has been used for the detection of railway, but the car is dependent on the overhead lines and has a high requirement for inspectors. So the method can’t meet the detection requirement of the existing railway. According to the situation of track detection, we conduct the research of a new type high speed railway detection car.This paper focused on the measurement system of CPIII marker. The building of the detection system and the measurement model based on binocular stereo vision, the improvement of algorithm in calibration, the research of algorithm in image processing are the main research contents. During the building of the system, we selected line scan cameras, industrial control computer, image acquisition card, rotary encoder, PCI2394 card and other hardware equipment according to the needs. We also developed the software depend on Microsoft Visual Studio 2008, which can realize the function of image acquisition, image storage and image recognition. In the aspect of the improvement of algorithm in binocular stereo vision, we regard the parameter of linear cameras as fixed value to improve the algorithm and make a series of experiments. In the improvement of calibration method, we raise a new calibration method and through the experiment the calibration accuracy can reach 1mm. In the aspect of image processing, we use the software HALCON to realize the image preprocessing, image identify, automatic recognition and the location of the targets.Through a series of experiments, we conclude that the accuracy of the measurement system can reach 1mm. The system not only can meet the requirement of accuracy, but also can work stable. What’s more the results also can be the date base and reference of the measurement of CPIII control network. So the technology can be widely applied in the construction and operation of the high speed railway.