Application And Research Of Visual Computing For Deformation Monitoring Of Coal Mine Roadway

Coal industry is our country most important foundation energy industry, and the frequent occurrence of coal mine accidents makes the coal mine safety has become highly concern of the state and society. With the rapid development of video surveillance technology, video surveillance technology has been widely used in coal safety production monitoring. This paper has mainly studied three key components, which includes the extraction of the image feature in stereo vision measurement, camera calibration and solving rebuilding coordinates, and taken advantage of stereo vision measurement to monitor the deformation of coal mine tunnel. The main research content and results are as follows:First of all, the paper has studied the extraction method of corner and spot center dot in image. Experiment compared the three kinds of corner detection algorithm, including the Harris, Shi-Tomasi and FAST. The results show that the Harris algorithm is sensitive to the threshold and easy to produce angular point clustering; FAST algorithm is easy to detect false corner and produce angular point clustering;Shi-Tomasi algorithm can make the Angle of the detected points distributed evenly, avoiding Angle of point cluster, it is concluded that Shi-Tomasi corner detection algorithm for the target angular point coordinates extraction pixel level. Spot is obtained by image pretreatment by Canny edge detection algorithm of single pixel edge profile, then extracted the spot center image point by the least squares fitting method.Secondly, the paper has studied the camera calibration plane template method, because using the greater variable pixel in computing homography matrix has affected the initial value of internal parameters and external parameters, calibration precision has been affected. In order to make the initial value of internal parameters and external parameters preferably come near accurate value, the paper only put to use the pixel nearby picture centring in computing homography matrix, thus a better camera calibration precision has been got. Experiments prove that this method can improve precision of camera calibration.Then aiming at solving the point coordinates in stereo vision space, the paper has analyzed three kinds of commonly methods: least squares method、the male in the vertical section point method and based on the reconstruction of the polar constraint method. This paper has put forward to male vertical section for a constraint to the projection image point space point coordinates, solving method of minimum error, experiments has proved that this method can improve precision of camera calibration.Finally, the stereo vision measurement technology is applied to the roadway deformation monitoring, and a roadway deformation monitoring implementation scheme is given, monitoring stations displacement on the roadway were measured, The results have showed that the visual measurement scheme calculate accurately the displacement of monitoring space and monitor on roadway deformation.