Research On Three-dimensional Dimension Measurement Technology Of Workpiece Based On Binocular Stereo Vision

In the tide of intelligent manufacturing,it is particularly important to measure the three-dimensional dimension of a workpiece quickly and accurately by non-contact measurement method.In this context,the research is carried out to restore depth and disparity,reconstruct three-dimensional information and realize three-dimensional dimension measurement of objects by using binocular vision algorithm through two-dimensional image acquisition.The research work is carried out in the following four steps: binocular camera calibration,image processing,stereo matching and 3D reconstruction.The research contents are as follows:Firstly,the mathematical formula of binocular stereo vision model is deduced,and the imaging principle is elaborated in detail.The research on Zhang's calibration method is proposed by using OpenCV and MATLAB joint calibration method to reduce the reprojection error of the original calibration method.Secondly,the image distortion is compensated by studying the image correction;the filtering algorithm is studied,the median filter is removed to remove the salt and pepper noise,the Gaussian filter is used to remove the Gaussian noise,and the signal to noise ratio is calculated experimentally to determine the optimal filtering window;for the Canny operator The double threshold search for edge threshold uncertainty is improved by combining the maximum inter-class variance threshold segmentation method to determine the optimal segmentation threshold.Thirdly,study a variety of dense parallax matching algorithms to compare matching effects and time.According to the matching quality and time-consuming selection algorithm based on variational matching,the method of reducing the image resolution by combining image pyramid technology is proposed to accelerate the matching process.Finally,the three-dimensional reconstruction of the European space is carried out by using the matched disparity map,and the three-dimensional point cloud coordinates of the object are obtained,and the three-dimensional size of the object is calculated.The experiment verifies the practicability and stability of the proposed algorithm and determines the range of measurement and the accuracy of the measurement.