基于广义未知输入观测器的执行器故障估计

摘要

针对一类含有未知扰动广义非线性系统的执行器故障,提出一种重构算法.设计未知输入观测器对干扰鲁棒,作为故障检测观测器.检测到发生故障后,通过提出含有误差比例项和积分项的故障估计算法,形成自适应观测器,实现准确快速地估计故障,同时估计状态变量;根据李雅普诺夫稳定理论给出估计误差一致最终有界的充分条件.最后将故障检测方法与滑模检测方法作比较,用直升机模型算例仿真验证该类观测器的鲁棒性和估计算法的有效性.%This paper proposed an adaptive fault reconstruction algorithm to deal with the actuator fault for a class of genera-lized nonlinear system with unknown disturbance.Firstly,it designed the unknown input observer as a detection observer to achieve robust to unknown disturbance.After detecting the fault,it developed an adaptive observer by using an adaptive law,the law contained the proportional and integral terms of error to simultaneously estimate the fault and states rapidly and accurately.Then,it presented the sufficient conditions to ensure the estimation error to be uniformly bounded according to Lyapunov stable theory.Finally,comparing to fault detection methods of sliding mode,it gave an example of a helicopter model to show the robustness of the developed observers and the effectiveness of fault estimaion algorithm.