Fault diagnosis method for actuator of flight control system

Abstract

The invention provides a fault detection and fault locating method based on a differential geometry theory for an actuator of a flight control system. The actuator faults include damage, loose floating, stuck situations and saturation. In a non-linear flight control system, homeomorphic transformation can be performed in state and output space so that the original system is transformed into a plurality of observable quotient subsystems influenced by a single channel fault input. Design problems of residual error generators in the original system are transformed into the design problems of observers of the observable quotient subsystems in each channel so that residual errors can decouple from faults and structural interferences of other channels. A reasonable fault detection threshold is arranged. A channel has faults when the threshold output by the residual error generator exceeds the detection threshold. Fault detection and fault location can be realized and multiple faults can be effectively diagnosed. In the invention, a plurality of faults in the actuator can be timely detected; flight safety can be guaranteed; hardware structures of the flight control system can be simplified; and system costs can be reduced.

Description

technical field [0001] The invention relates to the field of flight control systems, in particular to a fault detection and fault location method for actuator faults of nonlinear flight control systems. Background technique [0002] Fly-by-wire control technology is widely used in modern flight control systems, but the reliability of single-channel fly-by-wire control systems is lower than that of mechanical control systems. Therefore, the existing fly-by-wire control system is equipped with redundant hardware for some key components such as sensors and main control computers, and uses hardware redundancy to improve system reliability, but this method is relatively expensive and subject to space and load constraints. limit. For the structural failure and damage of aircraft systems, hardware redundancy technology is almost powerless. Therefore, it is necessary to perform fault diagnosis based on analytical redundancy for the flight control system of aircraft, especially sma...

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Problems solved by technology

[0007] Moreover, there must be errors between the established mathematical analysis model and the actual system. When the system is working, there are inevitably external random interference, unknown input and other unpredictable factors, which will reduce the performance of the detection and diagnosis system and increase the false alarm rate.

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