基于未知输入观测器方法的非线性切换系统故障检测

Fault detection for nonlinear switched systems using unknown input observers

基于非线性未知输入观测器方法对一类离散时间非线性切换系统的故障检测问题进行了研究。给出了两种不同结构的非线性未知输入观测器。针对每一种观测器都考虑了两种切换信号:任意时间切换信号和满足平均驻留时间的切换信号。在任意切换信号下,使用了切换Lyapunov函数的方法来设计非线性未知输入观测器的参数;在满足平均驻留时间切换信号下,使用了多Lyapunov函数方法进行观测器参数的设计。然后利用已知的非线性未知输入观测器,得到残差生成器,进而实现故障检测。通过数值仿真例子,验证了故障检测方法的有效性。

A nonlinear unknown input observer based fault detection method for some discrete time switched nonlinear systems is studied.Two kinds of nonlinear unknown input observers with different struc-tures are proposed.For each observer,two kinds of switching signals which include arbitrary switching signal and switching signal with average dwell time are considered.Under the condition of arbitrary switching signal, switched Lyapunov function method is used for designing parameters of nonlinear unknown input observer;while under the condition of switching signal with average dwell time,multiple Lyapunov function method is employed for designing parameters of observer.All design conditions are formulated as linear matrix inequali-ties.Then,the proposed nonlinear unknown input observers are used to generate residuals for fault detection. A simulation example is given to verify the efficacy of the proposed fault detection method.