Date of Award

Summer 7-20-2023

Embargo Period

1-1-2025

Access Type

Thesis - Open Access

Degree Name

Master of Aerospace Engineering

Department

Aerospace Engineering

Committee Chair

Merve K. Dogan

First Committee Member

Richard Prazenica

Second Committee Member

Sergey V. Drakunov

College Dean

James W. Gregory

Abstract

Model uncertainties and effector degradation carry risks to weaken the performance of any aerial system and endanger operation during flight. To this end, over-actuated aerial systems are used in flight operations to take precautions for possible incidents, which may result in improper control or a fall of the aerial vehicle. Adaptive control and adaptive control allocation methods are effective solutions for over-actuated uncertain aerial vehicles to overcome these phenomena because of their ability to estimate unknown effects. In this work, a literature search for control allocation methods is first revealed. An adaptive control allocation solution is introduced and implemented for compensating effector degradation effects on controller performance with no information about degradation levels. Moreover, the additional effect of center of gravity location on an aerial vehicle is introduced as a more complex case, where a second adaptive law is presented to estimate an unknown center of gravity position to ensure aerial vehicles achieve successful command tracking in the presence of both unknown effector degradation and unknown center of gravity. Specifically, Lyapunov Stability analysis is provided to prove closed-loop system stability. Simulation results on a multi-rotor mathematical model are presented with effector degradation and model uncertainties (unknown center of gravity position) to show the deterioration of the command tracking performance of a classical full state feedback controller, and to show the performance remedy with adaptive control allocation methods. Simulation results are presented to show that the proposed adaptive methods improve command tracking performance in the presence of unknown effector degradation, unknown center of gravity position, and both respectively.

Available for download on Wednesday, January 01, 2025

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