基于未知输入观测器的非线性动态系统故障估计

Fault estimation for nonlinear dynamical systems based on unknown input observer

针对一类受扰非线性动态系统的执行器故障估计问题,提出一种未知输入观测器来实现故障估计。首先,通过坐标变换将原系统转化为合适的形式;其次,采用线性矩阵不等式与Lyapunov泛函分别设计H∞输出反馈控制器和未知输入观测器,在此基础上实现对系统中执行器故障的渐近估计;最后,通过机械臂系统仿真分析并验证了所提方法的有效性。与已有方法相比,所提方法不要求故障可导,也不要求故障或干扰上界已知,因此易于在工程实际中实现对非线性系统执行器故障的估计。

Actuator fault estimation for a class of nonlinear dynamical systems with disturbance is considered,and an unknown input observer is proposed to fulfill fault estimation.Firstly,the original nonlinear dynamical system is turned into appropriate form by the coordinate transformations.Secondly,an H∞output feedback controller and an unknown input observer are designed by the linear matrix inequalities and the Lyapunov function respectively.Based on that,the actuator fault estimation for the system is achieved.Finally,simulation for manipulators is displayed to illustrate the effectiveness of the proposed method.Compared with the previous methods,the proposed method does not require that faults should be derivable and the upper bound of faults or disturbance is not necessarily required.The proposed method can be used to fulfill the actuator fault estimation for nonlinear dynamical systems in engineering practice easily.