Optimization Design Of Practical Laser Weld Seam Visual Sensor

In order to improve the quality of welding and productivity, it is necessary tomake arc welding process automatic and intelligent. Utilizing the sensor technology totrack and control weld seam is one of its' important aspects. The core technique aboutweld seam tracking includes weld seam detecting and recognizing technology. Visualsensor for weld seam tracking is a very good and with high potential one which isused to detect and recognize weld seam.The principle of laser structured light visual sensing is applied to weld seamvisual sensor. Area matrix CCD camera receives a diffuse reflection, of laser fringefrom a position above weld parts, which shows different groove of weld seam. Whenlaser fringe is processed A/D change by image collecting card, it will be sent intobuffer area in computer. Then the laser fringe is processed by running the imageprocessing software for tracking to arc welding seam. The position data about weldingtorch departures the weld seam center will be calculated. It will be provided toactuator to compensate and control weld torch.The work environment is very severe for laser visual sensor during arc welding.First, because continuous intensive arc radiation and high temperature produced bycombustion, temperature of visual sensor shell will increase accordingly. So, the roomtemperature of visual sensor will increase also. It results in the increasing of worktemperature of area matrix CCD camera and laser diode. If work environmenttemperature exceeds their upper limit, CCD and laser diode may malfunction even-failed. Second, the spatters and dusts produced during welding are noise signals inlaser fringe image captured by CCD. It will extend image processing time bycomputer, and delay the speed to weld seam tracking. Therefore, it is an urgentproblem to make a laser visual sensor which can run continuously and reliably bybearing under such sever environment high temperature, radiation, spatters and dustsduring welding.A laser seam visual sensor was studied and designed by using ANSYS10.0 finiteelement software. The sensor is with resonable structure, small volumn and lightweight, lower cost, good process and high reliability. The results of cooling,temperature decreasing and dust blowing is obvious by the practical laser weld seamvisual sensing system assembled. It can better meet the requirements to sensor whichis used to track weld seam for arc welding robot.