The Study On Weld Tracking Of TIG Based On Rotating Arc

In this paper, a whole weld tracking system of TIG is designed, based on rotating arc. The hardware and software of the system are studied, as well as the method of processing the welding voltage signals and obtaining the deviations of welding torch. The controller is designed. The experiment results are analyzed and the conclusions are made. These studys that provide the foundation for the realizing weld seam tracking successfully.The hardware system is made up of the welding part, signal acquisition part and control part. The wire feed elbow, the wire feed mouth and the installation mechanism are designed as required. The trial erection result shows that they have rational construction and can be used in the wire feeding device. The circuit wafer for driving motors of crosshead shoe, the circuit wafer for regularizing wave of the output signal from light electric coupler and the circuit wafer for low-pass filtering are designed. Every part and the whole are debugged. The results show that three circuit wafers have reliable performance and meet system's demand.In consideration of the fact that the system will be interfered by high frequency so as not to work normally, least square method based on 7 degrees orthogonal polynomial is applied to process the welding voltage signals. The simulation and experiment results show that the method can be used to remove noises effectively. In order to obtain accurate deviations of welding torch, the methods of gaining the deviations of weld seam across and down are studied.The position type PID with parameter self-tuning controller is designed based on genetic algorithm, as well as the software system for weld seam tracking. The software system is composed of the position type PID part and the position type PID with parameter self-tuning part based on genetic algorithm. The parameter of position type PID part is setting by method of trial and error, whose results provide some references for determining the range of parameter self-tuning based on genetic algorithm. The position type PID with parameter self-tuning based on genetic algorithm control program is simulated and debugged in the meantime.Finally, the experiment datas are analyzed, some suggestions about system improvement are given combining experiment performances.