The Research On The Arc-swing-typed TIG Welding Seam Tracking Sensor And Its System

The automatic welding and intelligent welding technologies are put forward to higher and higher requests as the development of the industry and manufacturing. And the key point of the automatic welding is to solve the auto tracking of the seam. It adopts a double-gun construction in this research (the swing arc TIG gun of small electric current places before as the sensor, and the real gun for welding is placed behind the sensor), which realizes the seam tracking successfully.In this paper, we have resolved such key problems:1. Designed the primary signal handling electric circuit, which has a good linear zone, being applicable to this investigate completely.2. We adopt the two-rank Butterworth filter circuit to treat with the sampled voltage signal, and get the proper signal which can reveal the actual condition of the seam. And we use the technology of encoder-rotary to fix the position of the rotating motor, thus we can fix the real time scanning position of the arc.3. By analyzing the characteristics of the grooves and the changing characteristics of the arc voltage, we adopt the integral comparison method to resolve the V-typed groove horizontal tracking problem, and the reference value self-study fix method to resolve the vertical tracking problem; analyzed different tracking strategies for lap joint groove, and put forward an improved integral comparison method.4. This research is different from the traditional arc sensor: the sensor and the real welding gun are independent, that is to say, the sensor and the welding gun are driving by two different sets of crossed slides. Thus, we adopt respective controlling strategies for sensor and welding gun: for the sensor, we take the fuzzy PID control of parameters self fix method, which greatly improves the seam discernment accuracy of the sensor; for the welding gun, its control signal is sent out by the sensor, as the gun lags the sensor a certain time, which belongs to the big hysteretic system, we adopt the PID control method with Smith estimates compensation, and realized seam tracking successfully.5. We have designed the corresponding hardware circuit, completed the program compiling and debugging work.