Online Optimization Method of Planetary Landing Trajectory Based on Inhomogeneous Expanding Ellipsoid

Abstract

The invention, which belongs to the technical field of deep space exploration, discloses an online planet landing trajectory optimization method based on a non-uniform expansion ellipsoid. On the basis of the complex topography and landform of the celestial body surface, a non-uniform expansion ellipsoid model is established in position space by combining a current position and a speed estimationerror of a detector; a dynamic space margin and a maximum dangerous direction vector are calculated by combining the e obtained non-uniform expansion ellipsoid model according to an on-board obstacledetection result, so that real-time evaluation of a landing risk is realized; a landing trajectory optimization problem is formed based on the dynamic space margin and the maximum dangerous directionvector and the problem is solved in a rolling time domain by using a model prediction method and thus a descending trajectory is generated, so that the obstacle avoidance capability of the detector under the condition of uncertain state is enhanced on the premise of ensuring the on-board calculation efficiency and thus a safe and accurate landing target is completed. Therefore, the online optimization of the planet landing trajectory can be realized; and the safety of the detector in the planet landing process is improved.

Description

technical field [0001] The invention relates to an online optimization method for a planetary landing trajectory, in particular to an online optimization method for a planetary landing trajectory based on a non-uniform expansion ellipsoid, and belongs to the technical field of deep space exploration. Background technique [0002] In planetary landing exploration missions, the complex topography on the surface of celestial bodies poses challenges to the safe and precise landing of the probe. At the same time, due to environmental disturbances and modeling errors, the actual state of the detector may deviate from the nominal trajectory under ideal conditions. In order to improve landing safety, future planetary exploration missions require the on-board computer to be able to combine current state estimation information and environmental measurement information to generate a safe and reliable descent trajectory online, so that the probe can achieve the goal of precise landing w...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by an online optimization method for a planetary landing trajectory based on a non-uniform expansion ellipsoid disclosed by the present invention is: to establish a non-uniform expansion ellipsoid model for the complex topography of the surface of the celestial body and the position and velocity estimation errors existing in the descent process , during the descent of the probe, according to the non-uniform expansion ellipsoid, calculate the dynamic space margin and the maximum danger direction vector in real time, form the landing trajectory optimization problem, and solve the problem iteratively in the rolling time domain, so as to realize the planetary landing On-line optimization of trajectory to improve the safety of the probe during planetary landing

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