A Guidance Law Design Method Applicable to the Vertical Recovery Section of Launch Vehicle

Abstract

The invention relates to a designing method for a guidance law applicable to the vertical recovery phase of a rocket. The designing method comprises the following steps: acquiring the full-distance standard trajectory of the rocket; according to the full-distance standard trajectory, acquiring the latitude and longitude of a target point, the motion parameters of the rocket at the starting point of an aerodynamic deceleration phase, and the latitude and longitude of a point below the rocket, and constructing an auxiliary coordinate system; based on the auxiliary coordinate system, additionallysetting terminal angular constraints on the basis of a proportional guidance process so as to obtain a biased proportional guidance law; and applying the biased proportional guidance law in the aerodynamic deceleration phase and applying the biased proportional guidance law with an additional main power deceleration algorithm in a vertical descending phase. The improved biased proportional guidance method in the invention can effectively solve problems in guidance control under the condition of multiple constraints by location, velocity and attitude during rocket recovery; the guidance law for a vertical landing phase employs aerodynamic deceleration and tail-phase short-time main-power deceleration, so no impact is exerted on the carrying capacity of the rocket in an in-orbit flying phase; and at the same time, proportional guidance has better adaptability to various non-guidance deviations.

Description

technical field [0001] The invention relates to a guidance law design method suitable for a vertical recovery section of a launch vehicle, belonging to the technical field of navigation and guidance. Background technique [0002] In the reusable launch vehicle technology, the guidance control method of the vertical recovery section of the rocket is a key technology. Taking the recovery of the first sub-stage of the rocket as an example, the return task can be divided into the attitude adjustment section, the deceleration turning section (only when returning to the original field), the sliding section, the power deceleration section, the aerodynamic deceleration section, and the vertical descent section (the last two sections are collectively referred to as the vertical descent section). recycling section). The vertical recovery and precise landing of the rocket needs to meet the constraints of double zero-crossing in both position and velocity. The attitude constraint of th...

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Problems solved by technology

The vertical recovery and precise landing of the rocket needs to meet the constraints of double zero-crossing in both position and velocity. The attitude constraint of the vertical landing of the rocket body is a multi-objective constraint guidance control optimization problem, and the descent process takes a short time and requires high accuracy. Traditional guidance methods incompetent

[0003] The guidance methods used in my country's active launch vehicles, such as perturbation guidance and iterative guidance, cannot be directly applied to the guidance law design of the vertical recovery section of the rocket. The perturbation guidance needs to track the standard trajectory, but the flight trajectory of the rocket in the process of returning to the atmosphere is consistent with the standard trajectory. The ballistic deviation is large, which leads to the inability to guarantee the accuracy of the landing point; the iterative guidance is based on the analytical solution of the optimal control problem, which has high accuracy in the vacuum flight section, but it is difficult to obtain high-precision guidance law analysis results in the vertical recovery section

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