Self-adaptive guidance method based on real-time estimation of lift-drag ratio

Abstract

Provided is a self-adaptive guidance method based on real-time estimation of a lift-drag ratio. The lift-drag ratio of a returning capsule is calculated in real time mainly through device information and guidance information of a guidance navigation and a control system of a reentry vehicle according to physical principles and definitions; real-time compensation design is carried out on reentry longitudinal flight guidance laws and transverse flight guidance laws according to the estimated lift-drag ratio, so that the influences of the fact that the lift-drag ratio deviates from a nominal design value on guidance precision are eliminated or relieved. The guidance law design, carried out according to the method, of the reentry vehicle can improve the guidance precision and the robustness of a guidance circuit, and the guidance demands of high speed aircrafts in the atmosphere can be met to the maximum extent.

Description

technical field [0001] The present invention relates to an adaptive guidance method, in particular to an adaptive guidance method based on real-time estimation of lift-to-drag ratio, in which the lift-to-drag ratio of the reentry capsule is estimated in real time and an adaptive guidance law is designed accordingly to carry out self-adaptation of a manned spacecraft Guidance belongs to the field of entry / reentry guidance for high-speed aircraft in the atmosphere. Background technique [0002] This invention originated from our research on the return and reentry control technology of manned spacecraft, and it is also used for the moon-earth return orbit jump reentry of the Chang'e 5 return tester, and it is also of general significance to other reentry spacecraft that can generate lift. . [0003] The practice of return control of manned spacecraft in the United States and the former Soviet Union as well as our research have shown that the uncertainty of the lift-to-drag rat...

AI Technical Summary

Problems solved by technology

[0004] It is a very difficult problem from an engineering point of view to obtain an accurate value of the lift-to-drag ratio of the aircraft

First of all, due to the limitation of experimental capabilities, ground wind tunnel experiments cannot simulate the hypersonic characteristics of the reentry capsule; secondly, due to the difficulty of aerodynamics itself, the method of obtaining accurate lift-to-drag ratio estimation through aerodynamic calculations is often It is also difficult to work; finally, during the real flight of the aircraft, the attitude is not always in the trim state, but oscillates near the trim attitude, which will have a certain impact on the lift-to-drag ratio

[0005] Just in order to overcome the re-entry guidance problem caused by the inaccurate acquisition of the lift-to-drag ratio introduced above, we propose an engineering-practical adaptive method for online estimation of the lift-to-drag ratio to improve the robustness of the guidance algorithm against aerodynamic parameter perturbations sex

Images