摘要
CMGs(control moment gyros)as satellite actuators have intrinsic structures generating disturbance,like bearings,motors,high-speed rotating wheels,steering gimbal,etc.Disturbances induced by faults in some of these parts shall be detected immediately and identified in real time.A continuous second order sliding mode observer can be applied for the detection of disturbances.In this paper,a nonlinear sliding mode observing algorithm based on the gyro sensor is suggested for the detection of external disturbances.The algorithm is then applied to detect a fault in a CMG,here the wheel fluctuation fault.By distinguishing the direction of disturbance torque by a diagnosis algorithm,the fault CMG can be then identified and isolated from other normal CMGs.The performance of detecting algorithm is verified on the hardware satellite simulator,in which four CMGs are installed.
