级联系统执行器故障的自适应诊断

Actuator Fault Diagnosis of a Class of Cascade Systems with Adaptive Observer Method

针对一类非线性级联系统的执行器增益故障诊断问题,提出了基于自适应观测器的故障诊断方法.考虑理想情况下的非线性级联系统模型,研究带有未知扰动的非线性级联系统模型.通过设计的自适应检测观测器而产生残差,将残差与事先设定的阈值比较,来确定故障是否发生.所设计的自适应诊断观测器保证了残差信号的收敛及对故障的准确估计;在具有扰动情况下,可以确保信号指数衰减到残差集.对风力发电机非线性级联系统模型的仿真实验验证了设计方法的有效性.

This study attempts to solve the problem of actuator fault in a nonlinear cascade system by designing an adaptive observer.We gather residuals in consideration of two cases about nonlinear cascaded systems under ideal situations and with unknown disturbances.From the comparison of the residuals and predefined thresholds,the occurrence of the fault can be detected.Furthermore,the convergence of residual signals and estimations of faults can be guaranteed by the designed adaptive diagnosis observer.The method also ensures that certain signals can exponentially decay to residual set under the system with outside disturbance.Finally,a simulation with a class of nonlinear cascade systems has validated the designed method.