Abstract:The control function of welding robot motion control system directly determines the quality of welding work. PLC technology is used to optimize the master-slave coordination motion control system of welding robot. In terms of system hardware design, sensor devices such as position, velocity and rotating arc are installed to detect the real-time pose of the welding robot using sensor data. Considering the structure, working principle and dynamic driving mode of welding robot, the mathematical model of welding robot was constructed. Combined with the position relationship between the current pose and the control target, the master-slave coordinated motion trajectory of the welding robot was planned. Under the action of constraints, the PLC controller was used to generate control instructions, which acted on the modified welding robot driver and realized the master-slave coordinated motion control function of the system. Through the system test experiment, it is concluded that compared with the traditional control system, the speed control error and attitude Angle control error of the optimized design system are reduced by 0.075mm/s and 0.38°, respectively. Under the control of the optimized system, there is no significant difference between the motion trajectory and the planned trajectory of the master-slave welding robot.