Size Mesurement Of The Switch Rail Drilling Based On Binocular Stereo Vision

In the production of Turnouts, we need take measurement on the size of the turnouts’ drill to verify the eligibility. Now the most people use the manual measurements to get the size of the turnouts’ dill, while we achieve non-contact measurement on the size of the turnouts’ dill by the method of stereo vision. Binocular stereo vision have many steps as image acquisition, camera calibration, stereo image matching, recover the three-dimensional coordinates. This paper focuses on the core technology of binocular stereo vision, and we carried out researchers and experiments, which based on we develop a rail drill measurement system.The main work of this paper is get the size of turnouts drilling in use of binocular stereo vision measurement, first we have to complete calibration of the industrial camera, then we can obtain the outside parameters and inside parameters of the camera, which lay foundation to build the measurement system.Second, in the preprocessing of the captured image, the image edge was detected by an image containing drilling and extraction rail drilling equation in the image in the image, which is the image of the ellipse detection, this paper presents one kind of real-time algorithm for detecting the ellipse.Then the drilling point on the captured image matching eyes, we get bored after the image equation, you can get the image coordinates of all points on the drill, you can get through the ultimate constraint points in another images in the image coordinates.Finally, the use of these matching points on the three-dimensional coordinates the recovery point to be drilled,after obtaining the coordinates of all points in space of the borehole, we borehole in order to obtain space equation, using the first way of fitting the drill fitted bore hole center coordinates, and then find the average distance of each observation point to the center of the hole, you can obtain the pore size of the drill, then it is easy to obtain measurements of the borehole.Using vc++ to achieve the above algorithm, developed an effective measurement system, which includes image acquisition, camera calibration, image matching, drilling detection, spatial circle fitting functions, the final experimental verification can be measured to meet the requirements of accuracy.