Research On Non-Analytical Arc Weilding Robot Control Algorithm And System

Industrial robot is the important automation equipment integrating with machine, electronic, control, computer, sensor technology, artificial intelligence and other advanced technology subject as one in modern manufacturing industry. As a typical representative of industrial machines, welding robots is of great significance to increase productivity, improve product quality and reduce production costs. Therefore the development of high control precision, flexible robotic arc welding has high significance. This paper starting from the arc welding robot kinematics, using Weld seam tracking system getting weld seam information to real-time lead in arc welding robot of movement under the procedures generated by the virtual teaching system, to achieve accurate real-time seam tracking purposes.Firstly, the kinematics model of a welding robot with special structure in this thesis is built. The inverse kinematics solution of the robot realized by the geometric iterative method is found on the basis of no analytical solutions. The simulation experiment of executive line and the curve trajectory producing by robot end operator is performed through MATLAB to prove the method owing the advantages of fast convergence and high accuracy and provide theoretical basis to realize the welding seam track and virtual teaching system in the following.The information of welding seam image obtained by scanning laser vision sensors is processed to access to the central position of welding seam, and transmit the information to the host computer. The functional module of solving inverse kinematics is called by the host computer. Using the central position of welding seam as input, the value of corresponding to each joint variable in the position is solved, and compared with the value of current joint variable to produce motion controlling amount. The motion control is transmitted to the robot controller and the robot is driven to arrive to the welding seam position by the host computer to realize real-time tracking purposes and improve the quality of welding.The functional design of teaching programmer and the overall structure its software is introduced. By the actual working robot, the robot model in the teaching system is chosen. The demonstration and instruction is performed in the teaching system through teaching programmer operating robot model by working task, and the teaching program is generated using programming instruction. According to the welding seam information obtained by welding seam tracking system, the actual welding seam error when the robot is working can be amended, thus real-time welding seam tracking is realized.Finally, the experiment and debug is performed to the robot control system. The interference generating by motor on motion controller is eliminated to achieve the right communication between PMAC and industrial personal computer, and the PID of the motor is adjusted to achieve optimal control performance. The interaction between robot model and actual robot can be realized to achieve controlling demand by carried out the on-line experiment in this virtual teaching system and the actual robot.