基于双观测器的卫星姿控系统敏感器故障隔离

卫星的姿态测量部件通常包括光学敏感器和惯性敏感器,这两类敏感器的故障隔离是卫星闭环姿控系统故障诊断的难点之一。利用双观测器方法实现两类敏感器的故障隔离,由卫星姿态运动学方程可知,这两类敏感器的输出存在解析冗余,可建立一个"虚拟"系统。对这个系统设计两个不同的观测器,其中一个是Kalman滤波器,能检测两类敏感器的故障;另一个是隔离观测器,能检测光学敏感器的故障,通过比较这两个观测器的输出残差,达到故障隔离的目的。将该方法应用于包含太阳敏感器、红外地球敏感器和陀螺的卫星姿控系统的故障诊断,数学仿真结果验证了这种方法的有效性。

Fault Isolation Method of the Attitude Sensors in the Satellite Attitude Control System

Optical sensors and inertial sensors are two kinds of important attitude measuring components.How to isolate the faults of these two kinds of sensors is a difficult problem in the fault diagnosis of the closed-loop attitude control system of satellite.There is analytical redundance between the outputs of these two kinds of sensors deduced from the kinematical equation,so a virtual system can be established.Two different observers can be used for this system,one of which is the Kalman filter used for detecting the fault of both sensors,the other is the isolating observer detecting the fault of optical sensors.Fault isolation can then be achieved by comparing the residuals of these two observers.The proposed method is applied to the satellite control system with sun sensors,infrared earth sensors and gyroscopes,and the mathematical simulation results validated the efficiency of the method.