Research On Three-Dimensional Inspection Technology Of Weld Of Hydraulic Torque Converter Based On Machine Vision

With the rapid development of machine vision technology,machine vision detection technology has been widely used in parts size measuring,geomorphology measuring,vehicle tracking and so on.Among them,the three-dimensional visual inspection technology based on line structure is widely used in the field of industrial measurement because of its large range,large field of view,easy access to light bar image information,high detection accuracy and real-time detection of system detection.The key aspects of the technology are these: camera calibration,structural light sensor calibration,light bar image center line extraction.In this paper,the three-dimensional coordinates of the measured object are studied by using the three-dimensional measurement technique of line structure.The main research includes the camera calibration technique based on the distortion factor optimization method of the indirect calibration method basing on plane grid point directional moving plane Line structure light sensor calibration,image feature area window extraction technology and background correction Otsu morphological refinement algorithm to extract the light bar centerline and so on.Firstly,the parameter calibration of the detection system is realized.Firstly,the parameters of the camera are calibrated.The optimization method of the distortion factor based on the plane grid point is adopted.The calibration of the camera parameters is realized by MATLAB's calibration tool box.The comparison with conventional calibration methods proved the effectiveness of the method and improve the calibration accuracy of the parameters.Secondly,the calibration of the structural light sensor is carried out by using the indirect calibration method based on the directional moving plane target.The calibration of the optical plane parameters is realized by MATLAB software.Secondly,the method of morphological refinement based on background correction and Otsu is used to extract the centerline of the light bar,and the windowing method of image feature area can be extracted quickly and accurately.Combined with the calibration parameters of the camera and the light plane,through the MATLAB software interface programming to achieve the workpiece's three-dimensional coordinates of the acquisition.Finally,the theoretical knowledge and the new method mentioned in the line structure measurement are applied to the practical application of the weld height measurement of the torque converter,and a set of liquid with computer control and real-time image acquisition and processing is designed.Torque converter weld detection system,which proved the validity of the new method.