A Spacecraft Fault Diagnosis Method Based on Second-Order Sliding Mode Observer

Abstract

The invention relates to a spacecraft fault diagnosis method based on a second-order sliding mode observer. A rigid spacecraft attitude mathematical model is established by using Rodrigues parameters,a non-linear kinetic equation is established according to the rigid spacecraft attitude mathematical model, the non-linear kinetic equation is rewritten, and the second-order sliding mode observer isdesigned according to the rewritten non-linear kinetic equation; and low-pass filtering is carried out on equivalent injection items the second-order sliding mode observer, the outer contour of a fault is estimated, and an estimated value of the fault is compared with a set threshold to complete the system fault diagnosis. The spacecraft fault diagnosis method enables a spacecraft system to obtain fault information and concrete fault conditions in time after the fault occurs and suppresses the influence of external interference on a fault diagnosis result. Therefore, the spacecraft fault diagnosis method can effectively improve the fault diagnosis efficiency of the system and improve the safety and the reliability of the operation of a spacecraft.

Description

technical field [0001] The invention relates to the field of spacecraft fault diagnosis, in particular to a spacecraft fault diagnosis method based on a second-order sliding mode observer. Background technique [0002] The structure of the spacecraft system is complex, consisting of a large number of devices and components, and it needs to work in the harsh space environment for a long time. It is affected by various environmental factors, and it is inevitable that various problems will occur during the flight. Therefore, the failure Diagnostic techniques are very important in the launch and operation of spacecraft systems. [0003] The attitude control system is the most complex subsystem in the spacecraft system. Its task is to obtain the attitude information of the spacecraft and maintain its attitude orientation in space. Losing attitude and losing control in a short period of time is often fatal for on-orbit missions. The fault diagnosis technology can effectively imp...

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Problems solved by technology

[0005] Aiming at the deficiencies of the prior art, the present invention provides a spacecraft fault diagnosis method based on a second-order sliding mode observer, which solves the problem that the spacecraft system cannot obtain fault information and specific fault conditions in time after a fault occurs, as well as external interference Problems Affecting Troubleshooting Results

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