The Design Of Weld Tracker Based On Monocular Sheet-of-light

Machine vision has been widely used in industrial production.In the field of welding,a welding robot equipped with a sheet-of-light vision sensor can realize seam tracking,thereby realizing intelligent welding.This paper designs a weld tracking device based on monocular sheet-of-light,and builds a seam tracking software system.The system is mainly composed of industrial PC,camera,line structure light,FR205 welding robot and its necessary communication equipment.The software system is developed by C ++ / QT / OpenCV / Python / Matlab in Windows system.Software development focus on modular and crossplatform compilation run characteristicsIn order to realize the accurate acquisition of the weld space coordinate,it is necessary to calibrate the seam tracking system.In this paper,an efficient calibration scheme for industrial field environment is proposed.The calibration equation is determined by the method of Zhang Zhengyou calibration,and the relationship between the robot coordinate system and the coordinate system of the reference frame is measured by SVD plane fitting.Complete hand-eye calibration.In order to achieve high efficiency,high precision and high stability of weld image recognition,the image preprocessing flow of weld image is designed based on continuous selection of regions of interest,binarization and refinement of spatial filter.Experimental results show that the weld image preprocessing process can improve the accuracy and efficiency of the algorithm.According to the characteristics of the line-structured optical vision sensor-foresight and hand-eye,this paper designs a variety of feasible motion control schemes for different workpiece applications,and puts forward solutions to the difficulties in these motion control schemes.The welding model analysis and deviation algorithm are discussed and the construction of scanning control scheme is discussed.In the software design,multitask mode is adopted to construct the processing mode of producer-circular buffer-consumer,which solves the problems brought by forward distance and improves the efficiency of motion control algorithm.The linear welding accuracy test experiment was designed to verify that the software system can complete the seam tracking function.The whole system calibration error is ± 0.3mm and the processing frequency is 10 Hz.The prototype of the system is put into test on the industrial site,and the onsite calibration setup scheme has the characteristics of high efficiency and high precision,which realizes the weld tracking of the actual welding workpieces.