Vertical soft landing guidance method for reusable carrier rocket based on sliding mode control

Abstract

The invention discloses a reusable carrier rocket vertical soft landing guidance method based on sliding mode control, and the method comprises the following steps: 1, building a mathematical model with a pseudo height variable tau as an independent variable, 2, designing a guidance law, and 3, obtaining real-time parameters of an aircraft through a missile-borne sensor, 4, inputting the instruction into an actuator, and controlling the flight of the aircraft; and step 5, repeating the step 3 to the step 4 until the rocket vertically and softly lands. According to the method, the sliding mode control theory is used for whole-process guidance of vertical landing of the rocket, various constraints such as fuel are considered, and external conditions such as large space span in the rocket returning process, different tasks in various flight stages, complex and variable flight environments and relatively strong uncertainty interference are overcome; the speed error, the position error and the falling angle error of the rocket during landing are enabled to approach to zero, and vertical soft landing of the rocket is realized.

Description

technical field [0001] The invention relates to a rocket vertical soft landing guidance method, in particular to a reusable carrier rocket vertical soft landing guidance method based on sliding mode control theory. Background technique [0002] Reusable Launch Vehicle (RLV) has become a hot research topic at present. The vertical recovery process of the rocket can be divided into the attitude adjustment section, the power deceleration section, the aerodynamic deceleration section and the vertical landing section. The main purpose of the attitude adjustment segment is to reverse the attitude of the rocket after the rocket is separated so that the engine can be used for subsequent deceleration. The function of the dynamic deceleration section is to reduce the dynamic pressure and heat flow on the rocket body by reducing the speed before the rocket enters the dense atmosphere, so as to avoid the structure of the rocket body from being damaged. The function of the aerodynamic ...

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Problems solved by technology

[0003] The common methods of vertical landing guidance can be divided into trajectory optimization, tracking guidance and explicit guidance, among which: the disadvantage of existing tracking guidance and offline trajectory optimization is weak anti-interference ability , the disadvantage of online trajectory optimization is that the amount of calculation is large, and it is difficult for the arrow-borne computer to generate an ideal trajectory in a short time, while most of the explicit guidance does not consider the problem of fuel constraints, and the anti-jamming performance and robustness need to be improved

[0004]Sliding mode control has fast dynamic response, simple algorithm, easy physical realization, insensitive to parameter perturbation and external disturbance, good robustness and adaptability, suitable for It is used for vertical landing of rockets, but there are few related studies on the direct use of sliding mode control for rocket recovery guidance, and most of them only focus on the aerodynamic deceleration section, without considering the influence of engine thrust and fuel, and the vertical recovery process of rockets cannot be completely realized.

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