Rocket power descending stage real-time trajectory planning method capable of guaranteeing convergence

Abstract

The invention discloses a rocket power descending stage real-time trajectory planning method capable of guaranteeing convergence and belongs to the field of rocket recovery guidance. The implementation method comprises the following steps that: a landing optimal control problem model for a rocket power descending stage is established by taking the magnitude and direction of thrust as controlled variables with nonlinear aerodynamic resistance and the constraint conditions of the magnitude and direction of the thrust considered; the problem is simplified through problem dimension reduction, problem decomposition and the advanced planning of certain state variables, and then the original problem is converted into an unconstrained convex optimization problem and a second-order cone programmingproblem through a proper convexification method; and finally, the convex optimization problem and the second-order cone programming problem are solved, so that a flight path and thrust magnitude anddirection change strategy can be obtained. According to the method, the reliable and efficient convex optimization algorithm is fully utilized; the calculation time of the method on a common desktop computer with the main frequency of 3.6 GiHz is about 15-30 milliseconds, and an obtained solution is close to a fuel optimal solution; the method converges to a certain extent, and can realize the reliable real-time planning of the landing trajectory of the rocket power descending stage can be achieved.

Description

technical field [0001] The invention belongs to the field of rocket recovery guidance, and relates to a trajectory planning method for a rocket recovery power descent section, in particular to a trajectory planning method based on convex optimization that ensures convergence and is real-time. Background technique [0002] As early as the 1960s, humans landed on the moon. To achieve this feat, the soft landing technology of the manned lander on the moon is crucial. In the decades since, technological breakthroughs have been made to allow landers to land on planets with thin atmospheres. But landing a rocket on Earth remains challenging. In recent years, reusable rocket technology has attracted a lot of attention worldwide. This technology can greatly reduce the cost of rocket launches and greatly shorten the launch cycle. In order to realize the precise landing of the rocket, the precise guidance of the powered descent stage plays an extremely important role. [0003] La...

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Problems solved by technology

[0004] In view of the lack of reliability and efficiency of the existing rocket power descent trajectory planning method, the technical problem to be solved by the real-time trajectory planning method for the rocket power descent section with guaranteed convergence disclosed in the present invention is: through problem dimension reduction, problem decomposition and advance planning Some state variables simplify the problem, combined with a suitable convexization method, and then only need to solve one unconstrained convex optimization problem and at most two second-order cone programming problems, that is, make full use of reliable and efficient convex optimization algorithms to solve the originally difficult Optimal control problem to improve the efficiency and robustness of real-time trajectory planning during rocket powered descent

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