Affiliation:
1. Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210, Japan
Abstract
This paper proposes a method for solving a three-dimensional propellant-optimal powered descent guidance problem under a thrust pointing constraint, where the thrust direction is restricted. Incorporating a thrust pointing constraint is as essential as pursuing propellant optimality for modern powered descent guidance, particularly when a lander uses terrain relative navigation sensors. However, the theoretical knowledge of optimal solutions is limited. One of the paper’s contributions is a method for finding the optimal solution under an upward-pointing constraint with an active–inactive–active switching structure. Usually, there is a maximum–minimum–maximum structure for the optimal thrust magnitude. Another contribution is compact propellant-optimal powered descent guidance under a thrust pointing constraint. The guidance may find the solution by establishing analytical models to evaluate switching points from the switching functions and predict the final-state errors. Numerical simulations provide the solutions of lunar pinpoint-landing scenarios, in addition to demonstrating the excellent propellant optimality, smooth convergence, and fast execution.
Publisher
American Institute of Aeronautics and Astronautics (AIAA)
Subject
Applied Mathematics,Electrical and Electronic Engineering,Space and Planetary Science,Aerospace Engineering,Control and Systems Engineering
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