Control method about partial loss of control power of spacecraft attacked by space debris

The number of space debris is in the high-speed growth, the incidents about the spacecraft attacked by space debris had occurred from time to time. Small space debris impact will cause parts of damage, failure or loss of function of the spacecraft. The author assumes that the spacecraft is impacted, and loss part of the control power. In this paper, an attitude control scheme based on the modified rodrigues parameters (MRPs) for a spacecraft subject to external disturbances and partial loss of three-axis effectiveness is proposed. First of all, this paper establishes the dynamic model of spacecraft and the attitude kinematic equation based on MRPs, and the faults of the angular momentum exchange devices are modeled as multiplicative unknown dynamics. Then, the desired angular velocity of a spacecraft is drawn from the relationship between the desired attitude and the real-time attitude of a spacecraft. Next, an observer is intended to estimate the fault factor of the spacecraft. By using the estimated fault factor, a robust controller based on indirect adaptive method is designed to achieve the attitude maneuver control. Therefore, this method can handle the faults of actuators without utilizing the fault detection and diagnosis (FDD) mechanism. Simulation results are made to verify the performance of the proposed scheme.