基于综合观测器的执行器过程故障量精确诊断

Accurate Diagnosis on Process Fault Parameters of Nonlinear Actuator Based on Adaptive Observer and Extended State Observer

执行器的非线性与输出不可得在一般复杂动力学系统中具有典型性,而其过程故障量的精确诊断是个前沿难点问题。针对该问题,研究一种面向控制系统和执行器的综合观测器方法。提出一种适用于带有非线性执行器复杂系统的新型自适应观测器方法,可克服输出量不可直接获得的条件限制,实现故障诊断并获得执行器真实输出估计;基于执行器输出估计与控制器输出量,采用扩张状态观测器实现过程故障量精确估计,从而为主动容错故障调节提供诊断依据。以卫星姿态控制系统飞轮摩擦力矩增大这一典型非线性执行器故障的过程故障量精确诊断为应用实例验证了本文方案的有效性及优越性。

As an important component of a dynamics system,the actuator is generally nonlinear and its output is immeasurable.It is a challenging problem for diagnosing and estimating process fault parameters of nonlinear actuator.Aimed at this problem,a joint observer method is proposed to observe control system and actuator.A novel nonlinear adaptive observer（NAO） is first proposed to estimate the actuator output of the dynamics system with nonlinear actuator and diagnosis fault.The output estimate and control input is then feed to extended state observer（ESO） to estimate process fault parameters.Finally,the proposed FD scheme is applied to a high-fidelity Reaction Wheel（RW） in Satellite Attitude Control System（SACS）,and a kind of partial Loss Of Effect（LOE） fault named as augmentation of friction torque is considered in our case study.The results of the case study demonstrate the effectiveness and superiority of our FD scheme.