Minimum-Fuel / Fuel-Optimal
Author: Tianjiang Shuo
Website: https://cislunarspace.cn
Definition
An optimal control strategy that maximizes the spacecraft's remaining mass after soft landing. The terminal performance index is taken as J=m(tf), i.e., maximizing terminal mass, which is equivalent to minimizing total fuel consumption. Unlike zero-fuel optimization, minimum-fuel optimization focuses on achieving the least fuel expenditure while satisfying terminal velocity and position constraints. By Pontryagin's maximum principle, the fuel-optimal control law takes the form of bang-bang engine control: when the switching function S(t) is positive, the engine operates at maximum thrust; when negative, it shuts off, producing a continuously braking optimal descent trajectory.
Application Value
In low-thrust trajectory optimization, this propulsion approach achieves low-energy transfers through sustained acceleration over long durations, offering superior fuel economy compared to high-thrust systems.
Related Concepts
- Lunar Fly-by Method
- Reachability Set
- Maximum-Energy Escape Trajectory
- Laplace Method
References
- Zhou Jingyang and Zhou Di - 2007 - Precise Modeling and Optimal Trajectory Design for Lunar Lander Soft Landing
