中文摘要：

针对铝合金脉冲熔化极惰性气体保护焊（Metal inert-gas welding,MIG）过程中,焊接参数匹配范围窄、参数间耦合作用强、焊接过程不稳定、焊缝成形差等关键问题,提出双变量解耦的控制方案。利用视觉传感同时反馈熔宽和干伸长信号,一方面调整双脉冲占空因数进行可变双脉冲熔宽控制;另一方面,在熔宽控制的同时,改变送丝速度同步控制干伸长,在控制焊缝成形的同时保证焊接过程的稳定。设计模糊PID控制器,采用基于xPC的实时目标环境,建立铝合金脉冲MIG焊快速原型控制平台,在此基础上,利用图像视觉传感和相应的图像处理算法,采用补偿解耦的方法进行双变量解耦控制试验,获得了良好的解耦控制效果,得到熔宽均匀的焊缝。结果表明,采用双变量解耦的控制方案能够实现铝合金脉冲MIG焊过程的控制,在保证焊接过程稳定的基础上,实现了良好的焊缝成形。

英文摘要：

In view of the key problems such as small match range of welding parameters,strong coupling effect among parameters,unstable welding process and poor weld formation in pulsed MIG welding process,a double-variable decoupling control method is proposed.The weld pool width and wire extension signals are both fed back through vision sensing.On the one hand,weld pool width control is realized by changing double-pulse duty cycle to adjust heat input,on the other hand,wire extension is controlled simultaneously by changing wire feed speed.So the weld formation is improved by control and the stability of welding process is ensured at the same time.A self-tuning fuzzy PID controller is designed and a rapid prototyping control platform is developed for pulsed MIG welding of aluminum alloy by using real-time target environment based on xPC.On this basis,double-variable decoupling control test is carried out by adopting compensation decoupling method and weld beads with uniform pool width and good formation are obtained.The results show that the double-variable decoupling control method can realize the control of pulsed MIG welding process of aluminum alloy and obtain good weld formation on the basis of stable welding process.