Optimal design of unmodeled linear systems using control-based continuation

This thesis describes the use of control-based continuation for design optimization, in the presence of constraints and without access to a model, of the response of a linear system to harmonic input. A proof of concept of this paradigm is presented in the context of an armature-controlled DC motor. Specifically, three design problems are formulated with the objective function equal to the maximum angular velocity response to a harmonic torque disturbance, and a constraint that is imposed on each of three distinct stability margins, respectively. The analysis shows that the simulation model for the DC motor may be treated analogously to an actual experiment with all information drawn from real-time measurements, rather than from the model itself. The control-based continuation paradigm is formulated in terms of a non-invasive, yet locally stabilizing control scheme, which can be tuned to accelerate convergence to the steady state response. The numerical analysis uses the matlab-compatible continuation platform coco to determine the implicit relationship between model parameters that results from the constraint, and to evaluate the objective function along the corresponding constraint manifold. A comparison between a scheme that relies on finite differences for approximating the problem Jacobian and an algorithm based on the Broyden update is also included.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2017

Author dc:creator

• Cui, Tonghui

Contributors dc:contributor

• Dankowicz, Harry

• Control-based continuation
• Model-free
• Optimization

Statement dc:rights

• Copyright 2017 Tonghui Cui

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/97472

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/97472