Fault detection and isolation of MIMO nonlinear systems based on the cascade observer
基于级联观测器的多输入多输出非线性系统的故障诊断

This paper considers the application of a block_observable method to the problem of fault detection and isolation.First,a block-observable form of nonlinear systems is introduced.The cascade observer of the system can be obtained by decoupling the system into blocks according to the faults of the sensor and the performer.The observer error can be got through the application of the sliding mode state observer.The observer designed in this paper is applied to the problem of the fault detection and isolation of the nonlinear system.The equivalent output injection concept can explicitly reconstruct fault signals,in which the problem of the fault diagnosis for multi-input and output nonlinear system will be decoupled.The isolation of the sensor fault is obtained in the system of an asynchronous motor,and the result of the simulation validates the algorithm.