A Semi-Analytic Shadow Area Forecast Method Applicable to Elliptical Orbits

Abstract

The invention discloses a semi-analytic shadow area forecasting method suitable for an elliptic orbit. A shadow area range of any inclined elliptic orbit in an orbit period is predicted by use of a semi-analytic and semi-numerical method. The method comprises the following steps: first obtaining a possible existence range of the shadow area by use of the analytic method according to a relation of the sun and an orbit; and then roughly judging whether the shadow area exists, and classifying the shadow type; and last solving out the shadow area existence range by use of the numerical method in the finite iteration time according to different shadow types. The analytic method is used for replacing the numerical integration and iteration as far as possible in the process of estimating any orbit shadow area region, the computing quantity of the shadow area forecasting is lowered, and an efficient method is provided for realizing the star automatic shadow area forecasting of an earth satellite and deep space probe using solar energy electric propulsion as the power.

Description

technical field [0001] The invention relates to a semi-analytic shadow area prediction method suitable for elliptical orbits, which is mainly used on earth satellites and deep-space probes powered by solar electric propulsion, and is used to predict arbitrary inclination and eccentricity elliptical orbits on satellites. The extent of the shaded area within one orbital period. Background technique [0002] For solar electric propulsion satellites, the electric thruster is the executive mechanism to realize satellite orbit transfer, position keeping control and angular momentum unloading, which requires continuous and frequent start-up work for a long period of time. However, the solar electric propulsion system is highly dependent on the solar cell array to provide sufficient power for it. If the satellite enters the shadow area, the electric thruster will not work. Therefore, in order to ensure the normal implementation of the on-board autonomous control of the electric pro...

AI Technical Summary

Problems solved by technology

[0003] The existing shadow area prediction methods for arbitrary inclination and eccentricity mainly rely on methods such as full analytical calculation, numerical iteration, and numerical integration. When applied to satellites, they have the following shortcomings: ①Full analytical shadow area prediction The method needs to solve the quartic equation, which involves the solution of the imaginary number equation, and the steps are complicated; ②The calculation amount of the full numerical method is too large, and the accuracy is low in the case of limited computing power on the star; ③The numerical integration method is not suitable for elliptical orbits For , it is necessary to use variable step size integration, and the calculation is very heavy near the perigee

Images