Research On The Automatic Detection System Of Log Volume Based On Machine Vision

The detection of log volume is a key link in the wood processing and timber trade, with the rapid development of social and economic, the demands for accuracy and real-time are getting more and more higher than ever before. Based on the analysis of the characteristics of the detection for log volume, in view of the existing shortcomings in the traditional hand gauging, such as low efficiency, long period, poor accuracy, inconvenient inquiries for results and so on, a set of automatic detection system for log volume based on machine vision is put forward in this paper.This paper has summarized development status about the detection for log volume at home and abroad, studied the machine vision technology, image processing, computer graphics, and other related information in depth; and detailedly described the design and working principle of the automatic detection system, and the binocular vision system's implementation.In this paper, the optical encoder, optical switches, SCM signal acquisition and processing board are used to complete the measurement for log's length with signal sent to PC by RS232 serial port; then two HYC-S600 CCD cameras and a PC are used to build a stereo vision system to detect the log's cross-sectional area. Before using the binocular vision system, calibration is implemented by acquisiting checkerboard target images; then the log's cross-sectional images are acquired and rectified by Bouquet method, bringing about left and right contours of the log's cross-sectional images, between which stereo matching is implemented point-wise according to epipolar geometric relationship and the disparity is calculated to reconstruct the log's three-dimensional cross-sectional contour;finally in terms of the three-dimensional information of this contour, the log's cross-sectional area is measured.The automatic measurement has been analyzed comparatively against manual measurements in terms of results and error, and the results showed that the automatic detection system for log volume on the basis of machine vision can overcome all the shortcomings of artificial hand gauging effectively, and it is of low cost, high accuracy, reliability, and easy to install.