Welding Seam Tracking System Basing On Image Sensor Technology

At present, with the development modern technology, people pay more and more attention on welding quality. We use auto-welding seam tracking system for this. Vision sensing method is widely used, because a great number of information can be acquired without contacting with workpiece and easy to auto-welding seam tracking. We design the welding seam tracking system basing on image sensor technique for this.The system consists of two parts that respectively are hardware part and software part. Hardware part is composed of camera, image acquiring card, auxiliary light, welding operate machine and cross slide. Software part makes dynamical control on robot by dada acquired by image information. To begin with, image data are acquired by image acquiring facilities, and then, original welding seam image characters are obtained by calculating acquired image data with image process program. Next, calibrating program turn image coordinate into world coordinate, this is consistent with robot environment. Finally, robot joint variables are acquired by robot anti-calculating. With the use of the variables, the system starts to track welding seam.The paper studied method of image processing applied to welding seam tracking, which mainly consist of image analysis and process, gray morphologic and pattern matching. Method of calibration applied for welding seam tracking is analyzed and studied in the paper. The conversion model is created among world coordinate, camera coordinate, image coordinate and pixel coordinate according to the principle of photic. Calibration and image process time are shortened with the laser incline and sensor upright technique in terms of great number of image information data. The system is of positive meaning for welding which man can't finish, such as nuclear environment or space environment. The system complete simulate seam tracking test without reality welding because the time is not enough. The system is of auto-modified function basing on sensing information, which provides essential study for entirely auto-welding of welding robot in the future.