Lateral guidance method of skip reentry vehicle based on linear pseudospectral parameter correction

Abstract

The invention provides a lateral guidance method of a skip reentry vehicle based on linear pseudospectral parameter correction, comprising the steps of initializing, handling a flight stage, determining heeling reversal in skip stage, predicting trajectory integral in the skip stage, judging precision, correcting control parameters in the skip stage, judging skip off atmosphere, and flying along Kepler rail. The invention is intended to develop, for a skip reentry vehicle with small lift-drag ratio, a reentry guidance method that corrects heeling reversal moment of the skip stage to ensure terminal cross-range constraints; the key technique of the method of the invention is to derive based on a linear pseudospectral formula to obtain an analytical formula between terminal deviation and heeling angle reversal moment; the method has the advantages of high calculating efficiency and high solving precision and is very applicable to online guidance.

Description

technical field [0001] The invention relates to the guidance field of a jumping reentry vehicle, and more specifically relates to a lateral guidance method for correcting linear pseudospectral parameters of a jumping reentry vehicle. Background technique [0002] A class of low lift-to-drag ratio aircraft represented by manned spacecraft usually adopts a jumping reentry scheme in order to achieve a large flight range. Different from the roll and turn control law adopted by general reentry vehicles in the lateral guidance process, the jump trajectory will leave the atmosphere again and enter the Kepler orbital flight state. Theoretically, under the condition of not considering the angular velocity of the earth's rotation, as long as the aircraft's ballistic deflection angle is aimed at the final landing point when it leaves the atmosphere, the lateral landing point accuracy of the aircraft's second re-entry can be guaranteed. However, due to the long flight time of Kepler's ...

AI Technical Summary

Problems solved by technology

[0004] Although this method of lateral guidance for jumping reentry vehicles based on the idea of ​​deflection is easy to understand, there are two problems in practical application: first, in order to satisfy the basic requirement that the theoretical landing point coincides with the predicted landing point after the earth's rotation Conditions, it is necessary to go through repeated integration iterations to determine the appropriate predicted landing point, so that the actual Kepler orbit flight time of the aircraft is the same as the earth's rotation time. The integration iteration process requires a lot of on-board computer capabilities, which seriously affects the actual online application.

Secondly, the termination condition of the iterative process needs to be determined empirically. If the error limit is set too small, although the solution accuracy is guaranteed, the computational efficiency is also sacrificed, and vice versa.

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