Research On The Control System Of Autonomous Mobile Wall-climbing Welding Robot For All Position Moving And Across Obstacle

In the manufacture process of huge unstructured equipment,such as shipbuilding,welding technology is an indispensable and basic workmanship,which most often determine the production efficiency and quality.Welding work cunsumes a big part of manufacture time,and the working environment is hazardous,which occupy the main production cost.In order to improve these problems,this paper focused on the welding work on vertical wall completed by intelligent wall-climbing robot,which can move on long-distance and large-range complex wall.The all-position robot is capable of obstacle rossing,attitude adjusting smoothly,and coordinate trajectory controlling.The all-position wall-climbing robot adopt wheel-foot mechanism to move and cross obstacle,which has the flexibility of wheel and overcoming obstacle ability of foot,adapting to large unstructured equipments.The manipulator with 5-DOF equipped on the vehicle handle a welding torch,to achieve a coordinate welding trajectory.This paper focuses on the research of robot design,theoretical analysis and experiment.The main work includes five parts as follow:Firstly,the research background of wall-climbing welding robot is analyzed.The recent achievement of welding robots and wall-climbing robots are introduced respectively.Based on the backgroud,the requirements of the project are carried out.Secondly,in order to realize all-position welding in huge equipment manufacture,the structure of wheel-foot mechanism and 5-DOF manipulator are disigned.The permanent-magnetic suction cup is optimized to have enough load capacity.The control system based on CAN bus is built,including electromechanical control,sensor network and stereo vision.Thirdly,the lift model of wheel group and suction cup is analized,and the control strategy which just use one motor to adjust the wheel height and suction cup air gap simultanuously is proposed.The vehicle turning use differential rotation method and the capability of turning is studied.The algorithm of kinematic,inverse kenematic and Jacobian matrix is solved in this part too.Fourthly,the motion DOF is analized based on screw theory.Two trajectory planning algorithms is proposed based on inverse kinematics and screw theory respectively.A new optimization algorithm is developed to improve the efficiency and accuracy.Finally,The controlling software is introduced.The architecture is designed to execute parallel tasks,and the workflow is organized.Corresponding experiments are carried out to verify the performance of movement,turning,wall-climbing,obstacle-crossing and welding.Based on the research,a all-position welding robot prototype is carried out,which satisfied the require of the project.