Method for directly planning reentry trajectory in high-speed profile

Abstract

The invention provides a method for directly planning a reentry trajectory in a height speed profile. The method comprises the following steps that: S1, the actual working parameters of an aircraft are extracted, a stagnation heat flux maximum value which is indicated by a symbol described in the descriptions of the invention, a dynamic pressure maximum value qmax and an overload maximum value nmax are set according to task requirements, and the height speed boundary of the reentry trajectory, namely, the lower boundary of the reentry trajectory in the height speed profile, is solved; S2, thereentry trajectory of an initial descending section is solved according to a reentry motion differential equation, and the starting point of the trajectory of a gliding section is determined accordingto the trajectory of the initial descending section; and S3, on the basis of the lower boundary in the height speed profile, a trajectory in the high-speed profile, which meets terminal constraints,is planned, a corresponding inclination angle is calculated, and the reentry trajectory is obtained. With the method adopted, the reentry trajectory can be accurately planned; the risk that a reentrytrajectory cannot meet a process constraint caused by ignoring a flight path angle and the change rate thereof can be avoided; the reliability of the reentry trajectory is improved; calculation speedis high; and solving precision is high.

Description

technical field [0001] The invention relates to the field of aerospace technology, in particular to a design method for directly planning a reentry trajectory in a height-velocity profile. Background technique [0002] The lift-type reentry spacecraft has the advantages of fast speed, long range, and strong maneuverability, and can achieve military tasks such as global rapid attack or material delivery. During the reentry flight, this kind of aircraft exhibits dynamic characteristics such as strong nonlinearity, strong coupling, and fast dynamic changes. In addition, the reentry flight needs to meet process constraints such as heat flow at the stagnation point, dynamic pressure, and overload, as well as speed, position, and heading errors. Terminal constraints such as corners make reentry trajectory design extremely difficult. [0003] The differential equation commonly used to describe the reentry motion is as follows (ignoring the earth's rotation); [0004] [0005] ...

AI Technical Summary

Problems solved by technology

[0042] Although the above method considers the influence of "flight path angle and its rate of change", in the process of solving the inclination angle σ, it is necessary to solve the curve in the r-V profile corresponding to the current flight path angle profile through numerical integration

This makes the process of converting from the r-V profile to the flight path angle profile and then from the flight path angle profile to the r-V profile repeated in the solution process, reducing the efficiency of trajectory planning

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