A time-varying fault diagnosis method for anti-jamming of civil aircraft flight control system

Abstract

Disclosed is an anti-interference time-variant fault diagnosis method of a civil aircraft automatic flight control system. The method comprises the following steps which are carried out sequentially: establishing a civil aircraft automatic flight control system nonlinear mathematics model comprising external interference and internal fault vectors; setting constraint conditions of a fault estimation algorithm; designing a state observer; and designing a self-adaptive fault estimation algorithm. The anti-interference time-variant fault diagnosis method has the following advantages: 1, the method is not based on an ideal parsing model, and at a design state, external interference is already taken into consideration in advance, so that the accuracy of subsequent fault diagnosis is improved; 2, system state vectors and specific forms of faults can be simultaneously obtained; 3, the method is not sensitive to fault types; 4, the external interference and system internal assembly faults can be rapidly time-variant (neither a constant type nor a slow time-variant type); 5, the fault diagnosis method is based on a nonlinear system model rather than a conventional linear model; and 6, the algorithm is small in scale, simple in operation and easy in engineering realization. The technology provided by the invention can be further popularized and applied to fault diagnosis of general nonlinear control systems.

Description

A time-varying fault diagnosis method for anti-jamming of civil aircraft flight control system technical field The invention belongs to the technical field of fault diagnosis and fault-tolerant control, in particular to an anti-interference time-varying fault diagnosis method for a flight control system of a civil aircraft. Background technique In recent years, driven by the development of the civil aviation industry, the complexity, performance and automation of the civil aircraft automatic flight control system (hereinafter referred to as the civil aircraft flight control system) have continued to increase, which requires that the civil aircraft flight control system must have better reliability and safety. At present, the reliability of civil aircraft flight control system has become one of the most critical and urgent technical issues in the field of aircraft design and manufacturing. One of the most direct ways to increase system reliability is to improve the quality...

AI Technical Summary

Problems solved by technology

However, there are several problems at the same time, such as: (1) The model used is an ideal analytical mathematical model, which does not consider the influence of external disturbances, which can easily cause confusion between disturbances and faults in the final diagnosis results, that is, external disturbances are not faults, so This diagnostic method cannot distinguish disturbances from faults very well

(2) The output form of the diagnosis result is an over-limit warning, that is, the fault reminder information is output, but the specific form of the fault cannot be given

(3) The proposed fault diagnosis algorithm is only suitable for "oscillating" faults, and is invalid for other types of faults, such as "slope type", "parabolic" and other types of faults

(4) The proposed fault diagnosis algorithm is complex, large in scale and computationally intensive, and difficult to implement in engineering

L. Lavigne used an improved Kalman filter for the simultaneous estimation of faults and system state variables, but this method is only suitable for the detection of constant or slow time-varying faults, and the detection performance for fast time-varying faults is extremely severe decrease, so it is prone to false negatives or false alarms

Images