Small celestial body landing trajectory optimizing method considering gravitation attitude and orbit coupling effect

Abstract

The embodiment of the invention provides a small celestial body landing trajectory optimizing method considering a gravitation attitude and orbit coupling effect. The small celestial body landing trajectory optimizing method considering the gravitation attitude and orbit coupling effect comprises the steps of obtaining coordinate system definition, a small celestial body gravitational field calculation method and a detector discrete mass model; obtaining a detector six-degree-of-freedom kinetic model according to the coordinate system definition, the small celestial body gravitational field calculation method and the detector discrete mass model; using an indirect method to obtain a fuel optimal two-point-boundary-value problem model according to the detector six-degree-of-freedom kineticmodel; and using a two-stage homotopy method to calculate the fuel optimal two-point-boundary-value problem model to obtain a small celestial body landing fuel optimal trajectory considering the gravitation attitude and orbit coupling effect according to the fuel optimal two-point-boundary-value problem model. According to the technical scheme provided by the embodiment of the invention, effectivecalculation of the small celestial body landing trajectory optimizing problem can be realized to obtain a six-degree-of-freedom fuel optimal trajectory; and therefore, additional fuel consumption generated during rigid body detector trajectory tracking under the gravitation attitude and orbit coupling effect is avoided, and the fuel optimality of a landing task is guaranteed.

Description

【Technical field】 [0001] The invention relates to planetary landing technology, in particular to a small celestial body landing trajectory optimization method considering the gravitational attitude-orbit coupling effect. 【Background technique】 [0002] The landing detection and sampling return of small celestial bodies can obtain soil samples and high-resolution data, which has become one of the main forms of small celestial body detection at present. In order to prolong the life of the probe's follow-up mission, the landing trajectory planning is usually upgraded to a landing trajectory optimization problem with the goal of minimizing fuel consumption. [0003] It is worth noting that the current studies on the optimization of the landing trajectory of small celestial bodies all calculate the detector as a mass point instead of a rigid body, ignoring the influence of the gravitational attitude-orbit coupling effect on the movement of the detector. The gravitational attitud...

AI Technical Summary

Problems solved by technology

When the distance between the detector and the celestial body is relatively long, the influence of gravity on the detector is not obvious, and the coupling effect is small and negligible; however, during the process of the detector landing on the small celestial body, the distance between the two gradually approaches, which will lead to the gradual coupling effect. increase

At the same time, the irregular gravitational field caused by the irregular shape of small celestial bodies will also intensify this effect

Therefore, approximating the detector to a particle will cause the trajectory optimization algorithm to be unable to consider the influence of gravitational attitude-orbit coupling effects. When the rigid body detector in the real scene tracks the optimal trajectory based on the particle, it needs to consume additional fuel to offset the coupling effect on the detection. The disturbance of the motion of the vehicle destroys the optimization goal of the landing mission to achieve the least fuel consumption

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