A Nonlinear Control Method for Hypersonic Vehicle Based on High Gain Observer

Abstract

A hypersonic aerocraft nonlinear control method based on a high-gain observer comprises the steps that a dynamical model of a hypersonic aerocraft is determined; the speed, the altitude and an attack angle tracking error of the hypersonic aerocraft are defined; a set sigma is defined as a bicompact set representing that system states of the hypersonic aerocraft are within a set range, and when all system states and inputs of the hypersonic aerocraft is kept in the set sigma, an elastic modal vector has an Euclidean norm upper bound; a speed channel control system of the hypersonic aerocraft is designed, namely the high-gain observer and a speed channel controller are designed, the high-gain observer carries out on-line estimation on unknown functions and disturbance in a speed error system; an altitude channel and attack angle channel control system of the hypersonic aerocraft is designed. According to the method, good robustness for modeling robustness, parameter perturbation and external unknown disturbance of the hypersonic aerocraft is achieved, the calculation amount is small, adjustable control gains are rich, and most flight situations can be met.

Description

technical field [0001] The invention relates to a nonlinear control method for a hypersonic aircraft. In particular, it relates to a hypersonic vehicle nonlinear control method based on a high-gain observer for controlling a class of nonlinear hypersonic vehicle dynamic models. Background technique [0002] The flight environment of hypersonic vehicles has a wide range of changes, the flight dynamics are complex, and they have extremely high nonlinear characteristics. In addition, there is a strong coupling between aerodynamics, propulsion systems, and thermal protection structures. The hypersonic aerodynamic force / aerodynamic heat will cause the thermoelastic deformation and vibration of the airframe structure, and the thermoelastic deformation and vibration of the airframe structure will have a serious impact on the aerodynamic force and the flight control system, making the near-space hypersonic vehicle an aerodynamic / structure / control system. Severely coupled systems p...

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Problems solved by technology

However, when the elastic mode does not tend to a constant value, the control algorithm designed in this paper cannot satisfy the effect of asymptotic tracking, and it is even difficult to prove the stability of the system theoretically, so only a quasi-stabilization problem is considered in this paper (Journal: Journal ofGuidance, Control, and Dynamics; Authors: L. Fiorentini, A. Serrani, M.A. Bolender, and D.B. Doman; Published: 2009; Title: Nonlinear Robust Adaptive Control of Flexible Air-Breathing Hypersonic Vehicles; Pages: 401-416)

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