Near spacecraft fault diagnosis and fault-tolerant control method

Abstract

The invention discloses a near spacecraft fault diagnosis and fault-tolerant control method. Firstly, a dynamical model of an attitude control system of a reentry phase of a near spacecraft is established and the dynamical model of the attitude control system is transferred to a nonlinear equation in a general type through coordinate transformation; secondly, a fault model with actuator invalidation and actuator dynamic damage existing simultaneously is established; thirdly, real-time online estimation of self-adaption estimation observer to actuator dynamic damage factors and actuator invalidation factors is respectively established; and finally a sliding module fault-tolerant controller is designed through the estimated actuator dynamic damage factors and the estimated actuator invalidation factors and parameters of the controller is updated in real time. According to the near spacecraft fault diagnosis and fault-tolerant control method, in the condition that when the actuator dynamic damage and the actuator invalidation occur simultaneously in a flight control system, fault information can be estimated rapidly and accurately, strong fault-tolerant capacity is achieved and an expected requirement of the flight control system is reached.

Description

technical field [0001] The invention relates to a fault diagnosis and fault-tolerant control method for a near-space vehicle based on an adaptive sliding mode, and belongs to the field of aerospace flight control. Background technique [0002] The attitude control system of a near-space vehicle is a key component to ensure the normal operation of the vehicle. During the operation of the system, it will inevitably be affected by external disturbances and self-failures, leading to catastrophic consequences. Due to the characteristics of the near-space vehicle itself, there are the following difficulties in the development process: On the other hand, the serious nonlinear coupling characteristics and the rapid change of flight state make the control problem of the flight control system more stringent and difficult. Therefore, during the flight, many components of the flight control system are very likely to fail. Once a failure occurs, the stability of the entire flight contro...

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Problems solved by technology

[0003] At present, there have been many researches on actuator failures of near-space vehicles, but it is quite rare to consider the dynamic damage of actuators at the same time.

There have been many studies on fault diagnosis and fault-tolerant control technologies for near-space vehicles, such as: T-S fuzzy control technology, sliding mode control technology, Backstepping technology, linear variable parameter method, dynamic control allocation, etc. (For details, please refer to: Jiang Bin, et al. .Research progress on fault diagnosis and fault-tolerant control of near-space vehicles, Journal of Nanjing University of Aeronautics and Astronautics, 2012, 44(5):603-610), but as far as adaptive sliding mode technology is concerned, there are still the following problems in the research that have not been well understood Good solution:

[0004] (1) It takes too long for the system to reach the sliding surface

[0005] (2) Switching causes excessive chattering of the system

[0006] (3) Timeliness and accuracy of fault estimation

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