利用奉献观测器诊断红外地球敏感器故障的新方法

卫星闭环控制系统中不同敏感器的故障定位是自主故障诊断的难点。基于双观测器的方法能够分离光学敏感器和惯性敏感器的故障,却仍不能确定红外地球敏感器是否发生故障。奉献观测器适用于敏感器系统的故障定位,但由于该方法要求的能观性条件在实际工程中有时难以满足,使其应用受到限制。本文提出了一种利用奉献观测器诊断敏感器故障的新方法,先对不完全能观系统进行能观性分解,再对能观子系统设计奉献观测器,克服能观性条件的限制,实现敏感器故障诊断。最后,将该方法用于卫星红外地球敏感器的故障定位,仿真结果表明,该方法可有效诊断地球敏感器的故障。

A New Fault Diagnosis Approach for Infrared Earth Sensors Based on Dedicated Observers

Fault location of different sensors in satellite close-loop control system is difficult in fault diagnosis.The faults of optic sensors and inertial sensors can be located by using a pair of observers.However,it is still a problem to make sure whether the earth sensors are failed.Dedicated observers are suitable for the fault diagnosis of sensors,but the observability condition,which is not easy to be satisfied in practice,limits its application.To solve this problem,a new fault diagnosis approach for sensors is presented in this paper.We make an observability decomposition of the incompletely observable system and then design dedicated observers for the observable subsystem.Finally,this method is applied to diagnosis the infrared earth sensors' faults in the satellite control system.Mathematic simulation results validate the effectiveness of this method.