基于相关函数法的焊接过程非线性辨识

Nonlinear Identification of Welding Process Based on Crosscorrelation Function

激光焊接过程是一个典型的带有扰动和噪声的非线性系统.采用相关—最小二乘法对非线性系统进行辨识可以得到未知参数的无偏估计,并且这种辨识方法不需要大量的样本数据.针对高功率二极管激光焊接控制系统,运用相关—最小二乘法的非线性辨识方法,建立了参数为线性的非线性模型.实际阶跃响应数据验证了此模型能够较好地代表焊接过程的稳态及动态特性.

The laser welding process is a typical nonlinear system with disturbances and noises. To obtain unbiased estimation of unknown parameters, the correlation-least square method is used to identify nonlinear system and does not require a large number of sample data. Aiming at the high-power diode laser welding control system, this paper adopts a nonlinear identification method of the colrelation-least square to estab- lish a nonlinear model in which parameters are linear. The actual step response data show that this model can represent the steady-state and dynamic characteristics of welding process very well.