Research On The Control Of Driving Motor Automatic Welder Based On DSP

Welding gets more and more attention in metal processing and manufacturing industry. However, manual welding quality is difficult to ensure, and it is difficult to meet the requirements of modern industrial welding process, especially in the aviation, shipbuilding, nuclear power and other high-tech industrial production, the standard of welding process is very high, Once the welding have quality problem, the consequence is very serious. Automatic welding machine can adapt to bad environment, processing product specification is unified, it can improve the quality of products, and also improve production efficiency. The research of automatic welding machine and automatic welding equipment can help promote the development of metal processing industry and improve the level of automation production.This paper introduces the research situation of automatic welding machine domestic and abroad, expound the advantages of automatic welding machine as well as the necessity of development of automatic welding machine and automatic welding equipment with our country independent property right.Automatic control is the core of the automatic welding machine on automatic welding platform, automatic welding is mainly realize associated control for inverter machine, water, gas path, plasma flow and of multiple axes, this paper selects part of the movement system, study the welding torch swing control.This paper analyzes characteristic of swing control system on welding platform introduces several kinds of welding torch trajectory, selects the step motor as driver of welding torch swing, based on the requirement of welding swing control,selects DSP which good at numerical calculation as the main controller. Aiming at the shortcomings that the precision is not enough of the open-loop control, puts forward closed-loop control system with position encoder, and compares different controller, uses the optimal control algorithm for parameter adjustment. In the choose of stepper motor drive mode, uses German ST company’s advanced control chip L6470 as the driver of the step motor, Enhance motor running protection function at the same time reduce the system resource overhead.This paper establishes the model of the welding system platform and the stepper motor. Swing step motor has the characteristic of starting frequently in the process of welding, if the speed is set very high, stepper motor is easy to lost step when it starts. This paper researches this phenomenon by simulation experiment, adopts low speed to start, and accelerates after a certain period of time, then accelerates several times to the set speed, using this way to overcome the shortcoming. In addition, the paper analyzes and compares the function of fuzzy PID control to the swing system stability.