卫星姿态控制系统的故障可诊断性评价研究

在不依赖任何诊断算法的前提下,对卫星姿态控制系统中传感器和执行器的故障可诊断性进行评价,旨在将提高系统故障诊断能力的工作重点前移到设计阶段.由于反馈控制的存在,导致故障会在整个系统中进行传播,使得单故障源表现出多异常征兆,这给闭环系统的故障诊断带来极大挑战.将故障视作扩展状态,并考虑模型不确定性,得到卫星姿态闭环控制系统的状态空间模型;根据可观测性判据,给出并证明考虑建模不确定性的加性故障和乘性故障可诊断性条件.所得相关结论可为卫星姿态控制系统设计提供理论参考依据.

Evaluating Fault Diagnosability of Satellite Attitude Control System

This paper investigates the method for evaluating the diagnosability of sensor faults and actuator faults in satellite attitude control systems without depending on the fault diagnosis algorithms. The purpose is to improve the fault diagnosability of the system in the design phase. Considering the existence of feedback control,the single fault may generate a number of abnormal symptoms due to the fault propagation in the closed-loop systems. Thus,it is a challenge to the fault diagnosability in the closed-loop control systems. The state-space model of a satellite attitude closed-loop control system with model uncertainties is established via extending the fault to the state variables. For the extended system,according to the criterion of the observability,the diagnosability conditions of additive faults and multiplicative faults are presented and proved by rigorous mathematical proofs. The achieved conclusions can be used to guide the design of satellite attitude control systems to improve the fault diagnosability.