Design Of Control System For Welding Seam Tracking Based On DSP

Welding is a kind of important processing method in machinery manufacturing industry. Traditional manual welding is not only low production efficiency, but also hard to ensure welding product quality. With the characteristics of high production efficiency, stable and reliable welding quality, the new automatic welding technology is focused on by more and more people. Welding automation is realized by welding equipment and the welding equipment with mobile welding robot as the main body has become main development trend in welding automation field. Therefore, research on the mobile welding robot has important theoretical value and practical significance. Main works in this paper are as follows:1. The paper focuses on the welding seam tracking of mobile welding robot. The key technologies of welding robot are introduced, including motion mechanism, cross-slider mechanism, sensor detection technology, and control technology and controller architecture. The coordination control strategy of cross-slider and motion mechanism for welding seam tracking is proposed.2. The robot's kinematics model is established, by which the two controllers are designed: PID controller and Fuzzy-P controller. Based on the scope of the welding seam deviation, Fuzzy-P controller will change its working style between fuzzy control and P control. The input of the fuzzy controller is weld deviation e and the slider horizontal adjustment quantity L, and the output is the welding robot body'rotational velocity. The simulation models of PID and Fuzzy-P control for robot are established, and simulating experiments are completed by the welding seam: straight line, broken line and circular arc. Experimental result shows that Fuzzy-P control's adaptability and anti-interference ability is better than PID control.3. The turning control of mobile welding robot is analyzed and realized by adopting different speed of two rear wheels. The control system, which can control the two brushless DC motors simultaneously, is designed utilizing DSP TMS320F2812 chip. The driving left and right wheels'motor control systems are designed to two closed loop systems to ensure them run steadily when the input is different angular speed. Detail design includes overall system design, hardware circuit design and software program design is implemented. The actual output waves of PWM verify that the designed system is feasible and effective.