基于观测器的离散时滞系统的故障诊断

研究含有测量时滞的线性离散系统的故障诊断问题,提出一种测量时滞的无时滞转换方法和基于降维状态观测器而不利用残差体现故障的故障诊断方法.首先通过构造一个含有故障状态的增广系统和进行测量时滞的无时滞转换,将时滞系统的故障诊断问题转化为无时滞增广系统的状态观测问题;然后给出了其诊断误差能按预先指定的指数速率趋于零的故障诊断器的设计方法.仿真算例验证了该方法的可行性和有效性.

Fault diagnosis for discrete-time delayed systems based on observers

The problem of fault diagnosis is researched for linear discrete-time systems with delayed measurements. A delay-free transformation approach for delayed measurements is proposed, and a reduced-order observer-based fault diagnosis approach is presented, which needn’t residual to embody faults. Firstly, by constructing an augmented system which comprises the faults’ states and doing the delay-free transformation of the delayed measurements, the problem of fault diagnosis for time-delay systems is transformed into the problem of state observation for a delay-free augmented system. Then, the design approach of a fault diagnoser is given which makes the diagnosis error of the fault diagnoser approach to zero at the preseted exponential rate. Simulation results show the feasibility and effectiveness of the proposed approach.