Near Time-Optimal Feedback Instantaneous Impact Point (IIP) Guidance Law for Rocket

TL;DR

This paper introduces a feedback guidance law that efficiently directs a rocket’s impact point to a target location by using analytic derivatives and near time-optimal control strategies, validated through case studies.

Contribution

It develops a novel feedback guidance law based on analytic derivatives of the IIP, achieving near time-optimal impact point guidance for rockets.

Findings

The guidance law accurately guides the IIP to the target location.

It performs comparably to open-loop trajectory optimization.

The method is validated through case studies.

Abstract

This paper proposes a feedback guidance law to move the instantaneous impact point (IIP) of a rocket to a desired location. Analytic expressions relating the time derivatives of an IIP with the external acceleration of the rocket are introduced. A near time-optimal feedback-form guidance law to determine the direction of the acceleration for guiding the IIP is developed using the de-rivative expressions. The effectiveness of the proposed guidance law, in comparison with the results of open-loop trajectory optimization, was demonstrated through IIP pointing case studies.