Longitudinal control method for hypersonic flight vehicle based on online identification of aerodynamic parameter

Abstract

The invention discloses a longitudinal control method for a hypersonic flight vehicle based on online identification of an aerodynamic parameter. The method firstly employs an iteration extension Kalman filtering algorithm combining an extension Kalman filtering algorithm and an iteration filtering theory to perform the online identification on the aerodynamic parameter, and provides a more accurate model for subsequent control; and then, based on the identified aerodynamic parameter, a adaptive filtering back-step controller is designed to precisely controls a longitudinal equation of the hypersonic flight vehicle. Compared with a traditional extension Kalman filtering algorithm, the iteration extension Kalman filtering algorithm employed by the method is higher in precision, and can identify the aerodynamic parameter more accurately. A control strategy proposed by the invention can effectively overcome a phenomenon of "inconsistent parameters of heaven and earth", the accuracy of a model is improved through the online identification, and the pressure of a control system is alleviated.

Description

technical field [0001] The present invention relates to a hypersonic vehicle longitudinal control method based on online identification of aerodynamic parameters, in particular to an iterative extended Kalman filter algorithm for online identification of aerodynamic parameters, providing an accurate model for subsequent control systems. Background technique [0002] Hypersonic aircraft has the advantages of fast flight speed, good maneuverability, strong defense penetration capability and long-range precision strike, which makes it occupy an important military strategic position. However, these characteristics also bring corresponding disadvantages to hypersonic vehicles. High-speed flight and large-scale flight cause strong nonlinearity and complex external environment, which also brings strong uncertainty in the model, etc. Specifically, the main There are the following points: [0003] (1) Strong nonlinearity: The hypersonic vehicle may cross the stratosphere, the middle...

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Problems solved by technology

[0004] (2) Strong coupling: For an air-breathing aircraft, there is a coupling effect between its propulsion system and aerodynamics, the aerodynamic parameters will affect the propulsion system, and the propulsion system is also affected by the pitch rudder surface; For example, since it mainly controls the aerodynamic force, there will be a coupling between the orbit and the attitude

[0005] (3) Strong uncertainty: Under hypersonic flight conditions, the flight airflow of a hypersonic vehicle will cause the disturbance of the shock boundary layer, thereby affecting the aerodynamic characteristics; parameter perturbation

However, in the process of introducing the virtual control variable from front to back, the adaptive backstepping method needs to be differentiated multiple times, which leads to a high complexity of the final control law

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