执行器发生正弦故障的时滞系统的故障诊断

Fault diagnosis for linear time-delay systems with sinusoidal actuator faults

针对含有测量时滞的线性时滞系统,研究其执行器发生频率已知但幅值和初始相位未知的正弦故障时的故障诊断方法.提出了一种基于观测器的故障诊断方法,该方法首先通过建立故障的状态空间模型,将执行器故障的动态特性表示出来;然后利用一种测量时滞的无时滞转换方法,将时滞系统转换成无时滞系统;最后通过构造一种新颖的状态观测器,设计了不利用残差体现故障的故障诊断器,实现了系统执行器故障的在线诊断.仿真实例验证了该方法的可行性和有效性.

The approaches to fault diagnosis were researched for linear time-delay systems with delayed measurements when sinusoidal faults with known frequencies but unknown amplitudes and initial phases happened to the actuators.A novel observer-based fault diagnosis approach was proposed.This scheme first established the state space model for the actuator faults so that the actuator faults′ dynamic characteristics were described.Then,by utilizing the delay-free transformation approach to the delayed measurements,the system with delayed measurements was transformed into a delay-free one in form.Finally,the fault diagnoser which didn′t need the residual to embody faults was designed by constructing a novel state observer,and the on-line diagnosis was realized for the actuator faults.The feasibility and validity of the proposed scheme was demonstrated by a simulation example.