Design of a master-slave wall climbing robot system for field assembly welding of penstock

In order to improve the working environment and raise the welding efficiency,a master-slave wall-climbing robot system was designed and developed. The master robot carried the welding torch and followed the weld. The slave robot loaded the related welding equipment such as wire feeder,and the force from the cable. The slave robot followed the master robot in motion. The master robot cooperated with the slave robot to complete the field assembling welding. The master robot’s overall weight was relatively light and its motion was flexible,so it could reach the target position quickly and adjust the position of welding gun. The slave robot had strong load capacity and adhesion stability.Both the master robot and the slave robot adopted the non-contact permanent magnetic adhesion and the wheeled motion mechanism. In order to ensure the all-position and all-attitude welding,the design of the adsorption mechanism was optimized through static and dynamic analysis of the robot. The welding mechanism employed depth camera as visual tracking module and its recognition accuracy of weld seam reached 1 mm.On this basis,the software and hardware platform of the control system based on ROS was designed and developed,and a set of robot prototype was developed. The comprehensive experiment results showed that the motion performance and weld recognition and track accuracy of the robot prototype met the requirements of engineering applications.