A Spacecraft Attitude Fault Tolerant Control Method Based on Iterative Learning Disturbance Observer

Abstract

The present invention relates to a spacecraft attitude fault-tolerant control method based on an iterative-learning disturbance observer. In order to solve the problem that actuator faults and external disturbances might occur during the attitude control process of the on-orbit operation of a spacecraft in the prior art, the invention provides an active fault-tolerant control method based on the iterative-learning observer. The method comprises the steps of firstly, establishing a dynamic model for the attitude control system of a spacecraft in considering the fault of an actuator in the attitude control system of the spacecraft and the external disturbance in the space of the spacecraft; secondly, estimating and designing a generalized disturbance torque of the iterative-learning disturbance observer composed of the actuator fault information and the external disturbance; finally, based on the estimated generalized interference, designing an active fault-tolerant controller. Based on the method, the stability of the attitude control system of the spacecraft, when the actuator of the spacecraft has a fault and the external disturbance exists in the space of the spacecraft, can be ensured. Meanwhile, the precision requirement of an actual control system is met. The method is strong in fault-tolerant ability and good in robustness for the external disturbance.

Description

technical field [0001] The invention relates to a spacecraft attitude fault-tolerant control method based on an iterative learning disturbance observer, which is mainly applied to the attitude control system when the spacecraft encounters actuator failure and is affected by external disturbances during space missions. Background technique [0002] The "13th Five-Year Plan" is a period of strategic opportunities for China's aerospace development. By 2020, my country will complete existing major scientific and technological projects such as manned spaceflight, lunar exploration project, Beidou navigation, and high-resolution earth observation system; by 2025 Before and after, the national civil space infrastructure will be fully built to promote the large-scale, commercial, and industrialized development of space information applications; in 2030, it will achieve an overall leap and become one of the aerospace powers, and use the aerospace dream to help the Chinese dream. The a...

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Problems solved by technology

Patent CN201210242175.4 uses the random switching system model to describe the entire operation process of the spacecraft attitude control system with intermittent faults, and then transforms the fault tolerance analysis problem of the attitude control system into the stability analysis of the switching system with unstable modes problem, but this method belongs to passive fault-tolerant control, so when the controller handles faults in different situations, it is difficult to achieve the best control performance for the current fault, and when an unknown fault occurs, it is impossible to talk about the closed-loop stability and stability of the system. Excellent system performance; therefore, relevant researchers proposed an active fault-tolerant control method for online real-time diagnosis, isolation and reconfiguration of faults, which can meet robustness and fault tolerance while achieving control performance; patent CN201510232385.9 design A class of three-axis torque effective fault factor observer is proposed to obtain the effective estimated value of the actuator fault factor, so as to design a robust adaptive fault-tolerant controller to realize the maneuvering control of the spacecraft when the actuator fails. However, This method can only deal with partial failure of the actuator, without considering the installation deviation of the actuator and the influence of external disturbances; The deviation of the installation of the spacecraft and the external disturbance of the spacecraft

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