Robust trajectory and guidance optimization for guided powered descent and landing

A robust trajectory optimization approach for guidance algorithm gain and target vector selection for powered descent and landing is developed. A genetic algorithm is used to determine optimal guidance algorithm parameters that minimize the impact of environment, navigation, vehicle property uncertainty. Vehicle state uncertainties are computed rapidly using linear covariance analysis techniques. When implemented in the guidance algorithm, the optimal gains and target vectors shape a trajectory that has more favorable conditions for a given navigation sensor suite. As a demonstration of this method, the optimal guidance parameters are found for a multi-phase trajectory from powered descent initiation to touchdown for a robotic lunar landing mission. Optimal guidance parameters are found for different optimization variable sets, sensor suite compositions and qualities, and with objective functions to minimize variability in propellant usage or terminal position. Multi-objective optimization showing the tradeoff between terminal position uncertainty and total propellant usage is presented for varying sensor suite fidelities and sensor suite compositions. Results show that the optimal guidance algorithm parameters for a given trajectory differ based on the sensor suite and result in performance improvements over the baseline in propellant usage and terminal accuracy. Improvements of up to a 20% reduction in landed footprint size and up to a 5% reduction in total propellant usage can be seen when using robust trajectory optimization, and operating with a lower quality sensor suite becomes viable when optimal guidance parameters are used.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Calkins, Grace Elizabeth

Contributors dc:contributor

• Putnam, Zachary R

• Trajectory Optimization
• Gnc
• Edl
• Aerospace
• Safe And Precise Landing
• Navigation

Statement dc:rights

• Copyright 2023 Grace Calkins

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/120427

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F120427