Multiple Fault Diagnosis and Fault-Tolerant Control Method of Rigid Body Spacecraft Actuator

Abstract

The invention discloses a rigid spacecraft performer multi-fault diagnosis and fault tolerance control method. According to the method, the kinetic and dynamic model of a rigid spacecraft attitude control system is put forward, a fault model for existing of both the performance failure fault and the deviation fault of a rigid spacecraft is established, and then a fault detection observer adopting the adaptive threshold technology and a fault estimation observer based on the adaptive technology are respectively established so that online real-time detection and estimation of the fault time and the concrete situation of the fault can be realized, and finally a backstepping sliding mode fault tolerance controller is designed according to fault information established by the fault estimation observer. Attitude stabilization control of the rigid spacecraft under the condition of the performer efficiency damage and the deviation fault can be realized, and the influence of external disturbance on the system and the observers can also be considered in the design process. Besides, the fault detection observer and the fault estimation observer can be independently designed so that the engineering application can be more easily implemented.

Description

technical field [0001] The invention specifically relates to a multi-fault detection and fault-tolerant control method for a rigid body spacecraft actuator based on the observer technology, which belongs to the technical field of aerospace flight control. Background technique [0002] The rigid body spacecraft attitude control system is a key part to ensure the normal operation of the spacecraft. Due to the harsh working environment and the interference of various external factors, it is more necessary to study the attitude control system of rigid body satellites. It is precisely because of the poor working conditions and various external disturbances that the system will inevitably face the threat of serious consequences caused by the influence of external disturbances and the failure of its own mechanism in the process of operation. In view of the difficulties in the design process of the rigid-body spacecraft attitude control system itself: firstly, the complex dynamic m...

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Problems solved by technology

[0004] (1) In terms of fault detection, due to the nonlinear relationship between the state variables caused by the coupling of the rigid body spacecraft itself, the design difficulty of the fault detection observer is increased. In some existing scientific research achievements, the original The state quantity of the system is used to solve the nonlinear term problem in the observer, but in fact, according to the design definition of the observer, the state quantity in the observer state equation should be taken from itself, not from the object system, so this Treatment options are still under consideration;

[0005] (2) Similarly, in terms of fault detection, in the existing literature, the fault detection threshold is mainly obtained through repeated simulation experiments, and the maximum observation error between the observed state value and the actual value is selected to obtain the fault detection threshold and Usually, this threshold is a certain value, which causes great limitations and conservatism, and it is easy to cause false negatives and false positives of faults;

Not only that, but the types of faults it can handle and the specific changes in fault values ​​are mostly foreseen by the designer. For the aspects that the designer failed to consider, this type of fault-tolerant control scheme is difficult to achieve the original expectations. The effect is achieved, and sometimes even the basic stability requirements are difficult to achieve

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