Diagnostic design method based on limited-frequency-domain for gradual failure of flight control system

Abstract

The invention discloses a diagnostic design method based on limited-frequency-domain for gradual failure of a flight control system. The diagnostic design method comprises the following steps: firstly, acquiring a state equation and an output equation of the flight control system; secondly, constructing an error equation, an augmented error equation and a failure diagnosis observer gain matrix; finally, according to the acquired state equation and output equation of the flight control system, and the constructed error equation, augmented error equation and failure diagnosis observer gain matrix, obtaining a failure diagnosis observer of a discrete-time flight control system. The failure of the flight control system can be estimated through the failure diagnosis observer. On the basis of the characteristic that the frequency domain of the gradual failure is relatively low, and under the external high-frequency disturbance, the multi-constraint failure diagnosis observer based on limited frequency is designed in allusion to a flight control system model, thereby reducing conservatism of the conventional design method based on all-frequency-domain.

Description

technical field [0001] The invention belongs to the technical field of fault diagnosis of a flight control system, and in particular relates to a diagnosis and design method based on a gradual fault of a flight control system in a limited frequency domain. Background technique [0002] At present, the country is vigorously developing various advanced aircraft such as large aircraft, near-space aircraft, and helicopters. There is an urgent need for research on the reliability of flight control systems, which also provides a good opportunity for the development of disciplines in this direction. In-depth study of new methods and new technologies for fault diagnosis and fault-tolerant control of various advanced aircraft control systems is of great significance for extending the service life of aircraft, improving the safety and reliability of aircraft, and reducing maintenance costs. The control system of the aircraft has important reference value. [0003] Taking the flight c...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the deficiency that the existing fault and noise fault diagnosis observer has a large conservativeness in the whole frequency domain, and to provide a diagnostic design method based on the analysis of flight control system faults in the limited frequency domain, which can Further improve the performance control of fault estimation, and perform online fault estimation on the flight control system

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