Study On The Detection System Of Rail Silhouette Based On Machine Vision

Rail silhouette detection is an important requirement for rail detection. At present rail silhouette detection mainly used with contacting instrument and by manual operation, which are inefficient, unsafe, and heavy. Here, based on machine vision, a new method of rail silhouette detection is given in this paper, and a non-contact detection system is developed.At present, the non-contact method is not only heavy but also influencing measurement result, which is convert the image coordinates to the world coordinates by calibrating. A new nonlinear model is given which transform the silhouette coordinates from image coordinates to world coordinates directly, avoid calibration errors and convert the image coordinates to the world coordinates more accurately. Base on this method, a detection system of rail silhouette is developed, and a non-contact detection method is realized. The precision of the system is smaller than0.06mm.The measurement accuracy is influenced by the accuracy of rail silhouette extraction. The rail silhouette centerline extraction algorithms of different image are studied in this paper. These image processing algorithms include grayscale transformation, filtering algorithm, edge detection, centerline extraction, automatic threshold determination, corrosion, dilation, region labeling, Hough transformation and so on. And the accuracy is verified by processing laboratory collection image and spot collection image. The accurate rail silhouette centerline extraction is realized. In addition, a video collection and image processing software is developed based on the Visual c++in this paper, realize different data saving and data presentation function based on different requirements.Finally, some verification experiments are done on this detection system in the laboratory condition, and the feasibility of these experiments are analysed. The accuracy of system is verified by simulation analysis. Through measuring the ruler and the rail silhouette to verify the precision and the repeatability precision of system,...