Uncertainty-upper-bound-estimation-based discrete sliding-mode adaptive control method of aircraft

Abstract

The invention relates to an uncertainty-upper-bound-estimation-based discrete sliding-mode adaptive control method of an aircraft, thereby solving a technical problem of poor practicability of the existing discrete control method of the existing aircraft. Euler discretization is carried out on a longitudinal channel dynamic model of an aircraft to obtain a discrete form of an original system; withconsideration of the system causality, an equivalent prediction model of a discrete strict feedback system is established; uncertainty of the system is defined and an adaptation law with a dead zoneis designed to carry out online estimation on an unknown uncertainty upper bound; an upper bound estimation error is introduced into an uncertainty upper bound update law to improve the estimation precision; a sliding mode surface is defined, a current control input is designed by using a future expected output, and a discrete sliding-mode adaptive controller based on a backstepping method is designed. According to the invention, on the basis of characteristics of computer control, a non-causal problem is solved effectively by using a discrete sliding-mode controller based on model conversiondesign; the robustness and adaptability of the flight control system are improved; and the uncertainty-upper-bound-estimation-based discrete sliding-mode adaptive control method is suitable for the engineering application.

Description

Technical field [0001] The invention belongs to the field of aircraft control, and in particular relates to an aircraft discrete sliding mode adaptive control method based on uncertainty upper bound estimation. Background technique [0002] In actual engineering, with the development of computer technology, many high-performance aircraft are equipped with computer systems, and most of their control tasks need to be realized by airborne computers. Therefore, the study of advanced control methods in discrete situations is of great significance to the research of aircraft control And there is an urgent need. [0003] The design of discrete controller usually adopts two methods: 1) First design the controller according to the continuous control object, and then discretize the continuous controller; 2) Design the discrete controller directly according to the discrete control object. The first method requires a faster sampling rate and requires higher system hardware. In actual enginee...

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Problems solved by technology

[0006] In order to overcome the shortcomings of poor practicability of existing discrete control methods for aircraft, the present invention provides a discrete sliding mode adaptive control method for aircraft based on uncertainty upper bound estimation

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