Fault tolerant observing method of sensor for satellite attitude control system

Abstract

The invention provides a sensor fault tolerance observing method for a satellite attitude control system. Firstly, the control system carries out the sensor fault detecting isolation; if a first sensor is judged to have faults according to an isolation result, a second KX observer is selected to observe; and if a second sensor is judged to have faults, a first KX observer is selected to observe. The first or second KX observer has the ensuring method that if the second or first sensor has faults, the control system is analyzed into a normal subsystem and a fault subsystem by using system feedback stable control as a target, and a low-dimension KX function observer is designed by respectively aiming at the two subsystems to combine and obtain a system KX observer with fault tolerance performance. The two parallel KX observers are designed and are fused into a controlling and switching flow; and when the partial sensor output is unreliable, the satellite attitude control system still can ensure the fault tolerance observation of system rest part observed quantity to ensure the closed loop control integrality of a failure system.

Description

technical field [0001] The invention relates to the field of spacecraft fault diagnosis and fault-tolerant control, in particular to a fault-tolerant observer method for sensor faults in a satellite attitude control system. Background technique [0002] As a typical dynamic control system, the satellite attitude control system is one of the important components that determine the normal operation of the satellite in space. Due to the particularity of the aerospace engineering field, its reliability requirements are extremely high, and any failure of any part of the system may affect the safety of the entire system. Therefore, the satellite attitude control system is monitored in real time and the system continues to operate in the event of a failure. (i.e. completeness) is essential. For general control systems, the available monitoring signals of the system are mainly control input and measurement output. In order to realize state feedback control or diagnosis based on sta...

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Problems solved by technology

If the original system is transformed and the observable subsystem observer is designed, such as the dedicated observer method, although it can meet the requirements of detecting the fault residual of the sensor, it does not necessarily meet the closed-loop feedback stability under the fault condition of the entire original system, that is, it cannot Feedback constraints for controllability and stability are given, therefore, only fault detection and isolation (FDD) is implemented, and the stability of the closed loop is not considered

If the original system is transformed into an equivalent standard triangle and then the observer design of the subsystem is carried out, such as the fault-tolerant dimensionality reduction observer method, although it is not sensitive to the type of sensor fault, the prerequisite for the decomposition of the subsystem is to know which The sensor output is faulty, and the conversion matrix is ​​designed for the faulty sensor output, and it is for the open-loop system, which is not applicable to the feedback control

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