一种非线性系统的N阶线模型及其辨识方法

广义脉冲响应函数模型由于其辨识对输入激励的苛刻要求,限制了其在非线性系统故障诊断方面的应用.提出了一种基于广义脉冲响应函数的可以描述非线性系统动态响应过程的N阶线模型.它将广义脉冲响应函数的各阶空间特征压缩到一条边线上,减少模型的表征量,从而降低辨识的输入激励要求,使被压缩的模型更易于被辨识.并且,根据广义脉冲响应函数的特性,提出了模型的辨识方法.最后,仿真验证了模型的辨识,并分析了故障对模型的影响特征.表明该模型适用于非线性系统的故障诊断.

Nonlinear nth-Degree Line Model and Identification

Generalized Impulse Response Functions (GIRF) is hard to apply in nonlinear system fault detection due to its limit by input power. A nonlinear nth-order line model was propounded with the purpose of describing dynamic response model of nonlinear system. This novel model compressed spatial feature of GIRF into a margin. As a result, it reduced the qualification of input power to make the identification easier. Whereafter, according to characteristic of GIRF, a method of identification was proposed. A simulation was carried out to check the effect of identification and the fault to the model. The result shows this model can be applied to the fault diagnosis for nonlinear system.