具有Lipschitz非线性系统的航天器故障检测

对存在未知干扰的Lipschitz非线性系统,探讨了基于滑模观测器的执行器故障检测的方法。通过等价状态变换,可以得到2个子系统,其中一个子系统与执行器故障和未知干扰耦合,而另一个子系统则只与执行器故障耦合。在此基础上,提出了一种免受未知干扰影响,可对执行器故障敏感的滑模观测器设计方法。这种滑模观测器可以作为故障检测工具,而将其输出估计误差作为残差发生器,用于执行器故障检测。相比滑模观测器的故障重构方法,该方法大大放宽了对数学假设条件的要求。最后,对一个大攻角状态下的航天器的简化模型进行了数字仿真,仿真结果表明了所提方法的有效性。

Spacecraft Fault Detection with Lipschitz Nonlinear System

This paper presents a sliding-mode observer based method of actuator fault detection for a class of Lipschitz nonlinear systems with unknown disturbances.Through equivalent state transformation,the state equation of the system is partitioned into two parts.The first sub-system is involved with both actuator faults and unknown disturbances while the second is only involved with actuator faults.Then we design sliding-mode observer for the first subsystem and a linear observer for the second sub-system.When no actuator faults occur,the observers are able to track system state asymptotically.And the output error can be viewed as residual to detect actuator faults.By using such a detection method,the strong conditions to reconstruct faults based on equivalent output injection can be removed.Simulation results to a simplified dynamics of High Incidence Research Model (HIRM) spacecraft show that the proposed method is effective.