A Safety Zone Expansion Guidance Method for Planetary Landing Obstacle Avoidance

Abstract

A safety zone expansion guidance method for avoiding obstacles in planet landing disclosed by the invention belongs to the field of deep space exploration. The method includes the following steps: defining a landing point fixed connection coordinate system and an error ellipsoid spindle coordinate system; building a landing dynamics equation under the landing point fixed connection coordinate system; determining an ellipsoid expansion safety zone according to the position error n(sigma) ellipsoid of a detector, and calculating the safety distance index value of the detector relative to an obstacle; and constructing a Lyapunov function based on the state of the detector and the safety distance index value of the detector relative to the obstacle, designing an obstacle avoiding guidance lawbased on the Lyapunov stability principle, and using an acceleration command a to control the landing track of the detector in order to reduce the influence of the multi-disturbance and uncertain environment on the planet surface on the obstacle avoiding guidance of the detector, thus avoiding the obstacle on the planet surface and realizing autonomous safe precision landing. The control acceleration command is analytic. The method does not contain complex operations such as integration, meets the requirement for real-time online feedback control, and is conducive to engineering application.

Description

technical field [0001] The invention relates to a planetary landing obstacle avoidance guidance method, in particular to a safety zone expansion guidance method for planetary landing obstacle avoidance, and belongs to the field of deep space exploration. Background technique [0002] The avoidance of planetary landing obstacles is an important issue in planetary landing exploration, which is related to the success or failure of planetary landing exploration missions and the safety of the probe. Due to the limited accuracy of on-orbit mapping and the limited range of the sensor, the craters, rocks, slopes, hills, etc. existing on the surface of the planet are difficult to conduct complete and accurate mapping during the orbiting stage. Real-time detection and avoidance of obstacles. In order to obtain more scientific returns, future planetary landing missions will seek to land in complex terrain areas with more scientific value. Therefore, the probe must have online obstacle...

AI Technical Summary

Problems solved by technology

When there is a large uncertainty in the state of the detector, the traditional method represented by the above prior art may not be able to effectively evaluate the threat degree of the obstacle relative to the actual state of the detector, resulting in the failure of obstacle avoidance

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