非线性系统参数识别的频域法

本文研究非线性构件特性参数的频域识别方法。在概念上,把非线性单元分为“带线性参数的”和“带非线性参数的”两类。首先建立起全部由带线性参数的非线性单元构成的非线性构件时域和频域线性识别方程。接着把含有死区和理想弹塑性滞后回线特性等带非线性参数的非线性单元的一个参数“线性化”,结合上述线性识别方程和单参数优化在时域和频域内识别参数。比较时域和频域识别的过程和结果,表明了频域法在数据处理、抗噪能力和识别精度等各方面都要优于时域法,应用前景较好。

Frequency Domain Identification Technique for Nonlinear System

A frequency domain identification technique for nonlinear systems is developed in this paper. In concept, nonlinear elements are classified into two kinds, one "with linear parameters" and the other "with nonlinear parameters" . The linear identification equations for nonlinear systems composed of nonlinear elements with linear parameters are formed, both in time and frequency domains. For some nonlinear elements with nonlinear parameters, such as element with backlash and element with bi-Hnear hysteresis, one of their parameters is "linearized" . Then, in combination of the linear identification mentioned above and the single parameter nonlinear optimization, all the parameters are identified, both in time and frequency domain. Comparing the identification'procedures and results, we can conclude that the frequency domain technique is advantageous over the time domain method in aspects of data processing,anti-noise ability and identification accuracy.