ORCID Identifier(s)

0000-0002-9228-3604

Graduation Semester and Year

2018

Language

English

Document Type

Thesis

Degree Name

Master of Science in Mechanical Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Kamesh Subbarao

Abstract

Determination of the set of all possible states, which a system can attain, plays an important role in safety for critical application. Prior knowledge of this set for the complete run-time provides critical information about how a system may evolve, providing accurate information of all the states, which could violate constraints. The knowledge of these states, helps in estimating control input, which can control the system, such that, these states are eliminated from the reachable set. Computation of reachable set of a dynamic system for a set of initial conditions can be easily performed, provided the analytical solution of the system for all initial conditions can be obtained. However, obtaining analytical solutions for nonlinear systems is a non-trivial task. Therefore, numerical methods are constructed, to obtain approximate solutions for these systems. Owing to the recent advancements in computational technology, it is now possible to tackle nonlinear systems using numerical methods. The reduction in computational errors and the increase in the rate of computation have enhanced the quality of results obtained from discrete approximations of continuous systems. The iterative property of these discrete approximations can be implemented in the form of algorithms. These algorithms, in turn, compute precise numerical solutions of systems for which analytical solutions are otherwise difficult to obtain. The primary objective of this thesis is to formulate and construct algorithms to compute reachable sets for linear systems and extending these algorithms to compute reachable sets for linear systems with perturbations. The secondary objective is to apply and verify the algorithms on a real-world application, previously studied in the open literature, and to discuss the results obtained. The computation of a reachable set is carried out in MATLAB and the computed reachable sets for representative mathematical models of dynamic systems are presented and different ideas of reachable states are discussed.

Keywords

Reachable set, Invariant set, Perturbed systems, Nonlinear, Compensation, Lipschitz continuity, Euler 1-step discretization

Disciplines

Aerospace Engineering | Engineering | Mechanical Engineering

Comments

Degree granted by The University of Texas at Arlington

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