The Research Of Welding Seam Tracking Precision Of Mobile Robots With Arc Sensor

Along with the rapid development of robotics and sensor technology, the application of robotics in the welding seam tracking is becoming more and more mature. And the requirement of the welding seam tracking precision is higher and higher. The application of mobile arc sensor seam tracking robot is wilder, and the tracking precision is higher, tracking process is more stable. The seam tracking precision research of this kind of the welding seam tracking robot has a great significance for the use for the high-speed, high-precision welding production. Firstly, worked on the features of welding seam tracking, combined with the effect of welding process parameters to the seam tracking, a welding seam tracking evaluation system is established based on the coincidence degree of the welding seam. The assessment not only of the seam tracking system deviation of the process, but also the performance of the welding parameters in the weld seam shaping and weld seam tracking.Secondly, to the seam tracking process, established a mathematical model of five parameters in the DH coordinate system based on the evaluation system of the seam tracking, and analyzed the infection of error sources of the seam tracking deviation to the seam tracking precision, the results shows that the seam tracking precison and the repeating positioning accuracy of the robot is the main reasons for welding seam tracking deviation. At last, used the simulation of welding seam tracking process and experiment to prove that the model and the evaluation system is accurate.Third, the adaptive fuzzy PID control is used in seam tracking for the improvement of the laboratory seam tracking arc wheeled seam tracking robot control algorithm. And this paper used the simulation of welding seam tracking process to analysis the seam tracking methods based on the software of Matlab 7.0. Compared with the traditional PID control algorithm, the results shows that the precision of the welding seam tracking method based on the adaptive fuzzy PID control algorithm is higher, the seam tracking process is more stable.Finally, this paper do some research in the design of hardware and software of the arc sensor wheeled seam tracking robot for the adaptive fuzzy PID control algorithm. Hardware circuit of the robot is based on DSPIC30F5015, increased the computing ability of the control system and the system stability, and improve the integrated circuit, the circuit is modular designed that it is more easy to repair the circuit. The control of crossed slider on the seam tracking robot is based on the stepper motor PWM time based controller of the main control chip, It is easy to adjust, control and get high precision. In software control, using the adaptive fuzzy look-up table to implement the fuzzy PID control, the method reduce the amounts of the controller calculates, increased stability of the system. By the actual seam tracking experiment, it is evidenced that the wheeled seam tracking arc sensor robot got a high precision, and the seam tracking process is stable.