CASCADE OBSERVER-BASED FAULT DIAGNOSIS FOR NON-LINEAR SYSTEMS

摘要

In this paper, a block-observable method is applied to the problem of fault detection and isolation. The block-observer form is presented and the observers for each subsystem are designed based on the sliding mode control theory. An algorithm proposed to guarantee invariability of the observers to the uncertainty of system parameters and external disturbance. Based on the observers, the fault signal is reconstructed according to the concept of equivalent output injection, and the fault diagnosis and isolation are realized. Thus fault diagnosis of the multi-input and output non-linear system is decoupled. Simulation results are provided to demonstrate the effectiveness of the approach.