脉冲GTAW熔池动态过程的辨识模型

焊接熔池动态变化过程是一个具有强非线性、多变量耦合作用以及大量随机不确定性因素的高度复杂过程,因此很难得到溶池动态特征的解析数学模型,使得焊接熔池的动态过程建模成为焊接界和控制界的一大难题,也是实现焊接自动化的本质困难。为了对脉冲GTAW（气体保护钨极氩弧焊）熔池动态过程特性有一个基本受控制性能的认识以实现对脉冲GTAW熔池变化过程的有效控制。本从经典控制系统设计的角度考察脉冲GTAW熔池动态特性,利用试验数据采用系统辨识的方法求取其熔池特征动态性能的数学描述,获得了脉冲GTAW熔池动态过程中分别以脉冲峰值时间和焊接速度为输入,以背面熔宽为输出的两个单出（SISO）过程的传递数模型,并对模型进行了检验。所建模型有助于研究脉冲GTAW熔池动态过程的受控性能,对改善其控制系统设计具有参考价值和指导作用。

Identification Models of Weld Pool Dynamic Process in Pulsed GTAW

The dynamic process of the weld pool is a high complex object with strong non linearity,mult variable coupling and a mount of stochastic and uncertain factors.It is very difficult to obtain an analysis mathematic model of weld pool dynamics.Thus the modeling of weld pool dynamics becomes a puzzle problem for weld technique engineers and control system designers,which also is an essence handicap in weld automation.In order to realize the effective control of the pulsed GTAW pool process,this paper investigated the dynamic characters of the pulsed GTAW from the classic control systems,and obtained two SISO transfer function models by the system identification method,one model for input pulsed time of welding current via output back weld width,the another for input weld travel speed via the output back weld width.The established models in this paper would be useful to study the controlled performance of weld pool dynamic process in the pulsed GTAW and can be used as has a valuable references and direction for designing its control system.