Research On Automatic Welding Seam Tracking System Of Trackless Submerged Arc Welding Vehicle

The research background of this project is the welding of ship deck.The length of welding seams of ship deck is from several meters to tens of meters.Rail type submerged arc welding machine is usually used for welding for the long and straight welding seam and the thick steel plate.However,the installation and calibration of rail of this kind of welding machine is complicated,and welding machine hard to move.Also,the length of the track cannot meet the welding requirements of various lengths of welding seams.In order to solve the above-mentioned problems,this project have designed an automatic trackless tracking system for welding seams,which adopted a welding gun carried by a crawler vehicles to omit the process of installing and correcting the track,and the welding equipment can also move faster and easier in the construction site.This system used a high-definition camera as a vision sensor to process the captured image and calculate the welding seam deviation information.And,the movement command,based on data results could be sent to the welding gun feed mechanism for controlling the welding gun movement,so as to realize the real-time correction function of the welding gun during the crawler vehicle moving.In this study,a crawler vehicle that meets the research needs was used.The mechanical design of welding gun feed mechanism,magnetic crawler mechanism,and welding gun clamping mechanism was carried out,meanwhile,the strength of the vehicle body was checked.After all that,a control system based on CTSC-200 PLC was also designed and installed in the crawler vehicle.In terms of software,this study designed a welding image processing program based on open source computer vision library.A complete set of image processing flow has been summed up to find out the welding seam edge information in the image,which is an important feature in welding image recognition,and the recognition program was realized by Python.With the high efficiency and applicability,this program can satisfy the requirements of machine vision guidance system.The interactive interface and motion control program were realized by Visual Basic 6.0,which could provide manual /automatic control function of the welding vehicle and welding gun feed mechanism.Besides,it could automatically control the movement of vehicle and welding gunaccording to the welding seam deviation information given by the image processing program in order to realize the automatic tracking function of welding seams.The operation test shows that the automatic welding seam tracking system of trackless submerged arc welding vehicles can identify welding seams reliably and efficiently,and control welding gun to rectify the deviation in real time,so as to realize the automatic tracking of long straight welding seams without manual intervention.The image processing program can identify the welding seam features in multiple light environments,and the motion control algorithm can meet the welding accuracy requirements.In general,this system achieve the expected goals,and the software algorithm can be used for reference in related fields as well.