Research Of Weld Automatic Tracking Based On Machine Vision And CAM System

Welding is a kind of very important processing technology, it occupies a great proportion in modern mechanical manufacture field, due to the poor working conditions of manual welding, and low machining efficiency, with the emergence of robot, the automatic welding robot technology became a main research direction.The visual identification tracking of welding seam, welding pose control and off-line programming technology in the process of robot welding is studied in this paper, and corresponded machine vision and robot pose control module based on MATLAB was developed, the method makes full use of the advantage of functions integration in MATLAB. At the same time, a development convenient welding program generation module based on UG-CAM was designed, and corresponding G code simulation and compilation module was developed. The plan in this paper can effectively simplify the development process, shorten the development cycle, lower development costs, in addition, increasing real-time welding-torch gesture control function on the basis of the weld-seam visual tracking can effectively improve the quality of welding process, the main research work is as follows:(1) The simulation with the MATLAB image processing toolbox for several kinds of edge detection operators were conducted, and a relative optimal operator was selected by comparing the recognition effects of them. A seam tracking module based on VS and MATLAB hybrid programming was developed, and an experimental verification on the 3-axis engraving machine was done.(2) The space description model of welding seam and torch was built, a welding torch pose real-time control method that combined the seam feature visual information and this mathematical model was proposed, and the simulation verification with MATLAB was done.(3) The camera parameter calibration based on MATLAB and the experimental verification was accomplished. The image effect before and after calibration was compared, and the calibration error of the method was analyzed, and a method for improving the calibration precision was put forward.(4) In consideration of the automatic welding robot structure of the tire storage rack, a welding off-line programming system development plan based on UG-CAM module was confirmed, because the UG-CAM has no welding processing module, an off-line programming method by replacing welding with multi-axis milling was proposed, and the feasibility of this plan was verified on 3-axis engraving machine. A G code compilation and simulation module based on VC for correctness verification of the off-line programming procedures and control of the robot was developed.