Sliding mode control method for hypersonic vehicle based on predictive model

Abstract

The invention discloses a prediction model based hypersonic aircraft sliding-mode control method. The method is used for solving the technical problem of difficulty in engineering realization by existing hypersonic aircraft adaptive discrete control. The method includes: obtaining a strict feedback form of a height subsystem by reasonable assumption, and building a discrete form of an original system through an Eulerian method; building a four-step prediction model of the original system by unceasing forward prediction, wherein the model only includes an equation; enabling the prediction model to provide the relation of height output at a future time and current system state and control input, wherein the relation can be used for computing numerical values of lumped uncertainties of the system at the historical moment, and the numerical values are used for feedback design of a controller; and combining lumped nominal information further, and using a discrete reaching law to design the sliding-mode controller so that robustness of the system is improved. The prediction model based hypersonic aircraft sliding-mode control method has the advantages that the discrete prediction model is built to acquire system nominal and uncertain information, design of virtual control variables is not needed, the controller is simple and practical in design, and the method is suitable for engineering application.

Description

technical field [0001] The invention relates to a control method for a hypersonic aircraft, in particular to a sliding mode control method for a hypersonic aircraft based on a predictive model, and belongs to the field of aircraft control. Background technique [0002] Due to its outstanding flight capability, the hypersonic vehicle has made global real-time strike possible, so it has attracted widespread attention at home and abroad; the NASAX-43A test flight successfully confirmed the feasibility of this technology; affected by its own complex dynamic characteristics and the airframe engine Integrated design, the coupling between the elastic body, propulsion system and structural dynamics of the hypersonic vehicle is stronger, and the nonlinearity of the model is also higher; in addition, due to the influence of flight altitude, Mach number and flight conditions, the vehicle is very sensitive to external conditions . [0003] The control of hypersonic vehicles is mostly c...

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Problems solved by technology

[0004] "Adaptive Discrete-time Controller Design with Neural Network for Hypersonic Flight Vehicle via Back-stepping" (XuBin, SunFuchun, YangChengguang, GaoDaoxiang, RenJianxin, "International Journal of Control", Volume 84, Issue 9, 2011) adopts the second method to transform the height subsystem into a fourth-order model. The virtual control quantity (track angle, pitch angle and pitch angular velocity) realizes the control of altitude, track angle and pitch angle respectively, and finally uses the rudder angle to control the pitch angular velocity; The network is estimated, and four steps are required to achieve a high degree of control. The design process is complicated, which is not conducive to engineering implementation

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