基于改进全局滑模的GMAW系统电流与弧长控制  

Current and arc length control of GMAW system based on improved global sliding mode

作　　者：李银锋 佃松宜[1] 

机构地区：[1]四川大学电气信息学院,成都610065

出　　处：《焊接学报》2018年第6期126-128,共3页Transactions of The China Welding Institution

摘　　要：针对熔化极气体保护焊(gas metal arc welding,GMAW)自由过渡方式中电弧负载具有时变性、非线性的特点,对外部干扰及内部参数摄动较为敏感,为了增强系统的鲁棒性,采用全局滑模控制.使得电弧在起弧开始就具有较强的抗干扰能力,改善系统的瞬态响应,在此基础上,提出改进的全局滑模控制,在保证系统具有全局鲁棒性的条件下,让系统快速稳定,进一步改善系统的动态性能.该方法主要通过控制焊接电流来控制电源的外特性,进而控制电弧的稳定性,为稳定电流引入滤波器.最后应用Matlab对系统进行仿真.结果表明,该方法正确有效.In gas metal arc welding( GMAW) free transition mode,the arc load is time-varying and nonlinear,which is sensitive to external disturbance and internal parameter perturbation. In order to enhance the robustness of the system,the global sliding mode control is adopted,which makes the arc strong antiinterference ability at the beginning of arcing and improves the transient response of the system. On this basis,an improved global sliding mode control is proposed. Under the condition of ensuring the global robustness of the system,the system can be stabilized rapidly and the dynamic performance of the system can be further improved. The method mainly controls the external characteristics of the power supply by controlling the welding current,and then controls the stability of the power-arc,What is more,introduces the filter for the steady of current. Finally,Matlab is used to simulate the system and the results show that the method is correct and effective.

关 键 词：自由过渡 鲁棒性 全局滑模 电弧 

分 类 号：TG431[金属学及工艺—焊接]