An autonomous celestial navigation method for deep space probes in the capture segment based on ephemeris correction

Abstract

The invention discloses an ephemeris correction-based autonomous celestial navigation method for a deep space probe in a capturing stage. The method comprises the following steps: firstly, establishing an ephemeris error state model and an ephemeris error measurement model of a target celestial body, and measuring ephemeris error according to a position difference between a predicted celestial body image and an actual celestial body image; secondly, simultaneously taking the ephemeris error state model and an orbital dynamic model as a celestial navigation system state model, taking the ephemeris error measurement model and a starlight angular distance measurement model as measurement models of a celestial navigation system, estimating the position and speed of the probe and the ephemeris error of the target celestial body by a Unscented Kalman filtering method, feeding back the estimated ephemeris error to the state model, and correcting the ephemeris data of the target celestial body, thereby obtaining the position and speed of the probe, relative to the target celestial body and the heliocenter, after autonomously correcting the ephemeris error. The method provided by the invention belongs to the technical field of aerospace navigation, can perform on-line estimation on ephemeris error of celestial bodies and correct model error of the navigation system, and is suitable for the probe capturing stage.

Description

technical field [0001] The invention relates to an autonomous celestial navigation method for correcting ephemeris based on a target celestial body image and a predicted celestial body image when the deep space probe is in the capture phase, and is a navigation method very suitable for the deep space probe capture phase. Background technique [0002] The capture stage refers to the whole process from when the deep space probe enters the target influence sphere to ignition and braking. The deep space probe at this stage has a fast flight speed, a short flight arc, high control precision requirements, and unique opportunities. The orbital point of the deceleration and braking of the deep space probe is very close to the surface of the target planet (perigee), and being captured is a key time node of the entire deep space exploration mission. The relative navigation accuracy of the capture phase relative to the target celestial body and relative to the sun or the earth The abso...

AI Technical Summary

Problems solved by technology

However, these two methods must rely on the assistance of radio measurement and control information to determine the ephemeris error of the target celestial body, and are still unable to correct the ephemeris error of the target celestial body in real time and its influence on the state model error and navigation results.

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