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Six Degree of Freedom Dynamic Modeling of a High Altitude Airship and Its Trajectory Optimization Using Direct Collocation Method

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Date Issued:
2017
Abstract/Description:
The long duration airborne feature of airships makes them an attractive solution for many military and civil applications such as long-endurance surveillance, reconnaissance, environment monitoring, communication utilities, and energy harvesting. To achieve a minimum energy periodic motion in the air, an optimal trajectory problem is solved using basic direct collocation methods. In the direct approach, the optimal control problem is converted into a nonlinear programming (NLP). Pseudo-inverse and several discretization methods such as Trapezoidal and Hermite-Simpson are used to obtain a numerical approximated solution by discretizing the states and controls into a set of equal nodes. These nodes are approximated by a cubic polynomial function which makes it easier for the optimization to converge while ensuring the problem constraints and the equations of motion are satisfied at the collocation points for a defined trajectory. In this study, direct collocation method provides the ability to obtain an approximation solution of the minimum energy expenditure of a very complex dynamic problem using Matlab fmincon optimization algorithm without using Himiltonian function with Lagrange multipliers. The minimal energy trajectory of the airship is discussed and results are presented.
Title: Six Degree of Freedom Dynamic Modeling of a High Altitude Airship and Its Trajectory Optimization Using Direct Collocation Method.
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Name(s): Pierre-Louis, Pradens, Author
Xu, Yunjun, Committee Chair
Lin, Kuo-Chi, Committee CoChair
Das, Tuhin, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2017
Publisher: University of Central Florida
Language(s): English
Abstract/Description: The long duration airborne feature of airships makes them an attractive solution for many military and civil applications such as long-endurance surveillance, reconnaissance, environment monitoring, communication utilities, and energy harvesting. To achieve a minimum energy periodic motion in the air, an optimal trajectory problem is solved using basic direct collocation methods. In the direct approach, the optimal control problem is converted into a nonlinear programming (NLP). Pseudo-inverse and several discretization methods such as Trapezoidal and Hermite-Simpson are used to obtain a numerical approximated solution by discretizing the states and controls into a set of equal nodes. These nodes are approximated by a cubic polynomial function which makes it easier for the optimization to converge while ensuring the problem constraints and the equations of motion are satisfied at the collocation points for a defined trajectory. In this study, direct collocation method provides the ability to obtain an approximation solution of the minimum energy expenditure of a very complex dynamic problem using Matlab fmincon optimization algorithm without using Himiltonian function with Lagrange multipliers. The minimal energy trajectory of the airship is discussed and results are presented.
Identifier: CFE0006779 (IID), ucf:51822 (fedora)
Note(s): 2017-08-01
M.S.A.E.
Engineering and Computer Science, Mechanical and Aerospace Engineering
Masters
This record was generated from author submitted information.
Subject(s): Airship -- Trajectory -- Optimization
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0006779
Restrictions on Access: campus 2022-08-15
Host Institution: UCF

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