Programa de Pós-graduação
em Engenharia Elétrica


Defesa Pública da Tese de Doutorado do Mestre em Engenharia Elétrica RAFAEL DA SILVEIRA CASTRO.

Data: 31/01/2019 - quinta-feira
Horário: 14h00min
Local: Salão de Eventos do Instituto Eletrotécnico da UFRGS (Av. Osvaldo Aranha, 103 - 1º andar - Campus Centro)

Banca Examinadora:

Prof. Dr. Alexandre Trofino Neto - DAS-UFSC (Relator)
Prof. Dr. Romeu Reginatto - Centro de Engenharia e Ciências Exatas - UNIOESTE
Prof. Dr. Alexandre Sanfelici Bazanella - PPGEE-UFRGS
Profa. Dra. Lucíola Campestrini - PPGEE-UFRGS
Prof. Dr. Diego Eckhard - PPGEE-UFRGS
Orientador: Prof. Dr. Jeferson Vieira Flores - PPGEE - UFRGS



"This thesis deals with the output regulation of rational nonlinear systems subject to input saturation. The output regulation problem considers a controlled plant subject to non-vanishing perturbations or reference signals produced by an exogenous autonomous system, where the goal is to ensure asymptotic convergence to zero of the plant output error. This work develops systematic methodologies for stability analysis and design of anti-windup compensated dynamic output feedback stabilizing controllers able to solve the output regulation problem for rational nonlinear systems with saturating inputs. In order to obtain these results, the proposed method employs the differential-algebraic representation, a theoretical framework that treats rational nonlinear systems by a differential equation combined with an equality relation. This tool is utilized in order to cast the stability analysis and control synthesis by optimization problems subject to linear matrix inequality constraints. Towards ensuring asymptotic output regulation, itis initiallyassumedthepriorknowledgeofaproperinternalmodelstage, capableofrendering an invariant and zero-error manifold. This assumption is later relaxed, where the results are extended for the practical regulation problem. In this last scenario,an approximated internal model may be considered and the devised methodology ensures ultimate boundedness of the output error. Overall, the main innovation of this thesis is the application of differential-algebraic representation into the nonlinear output regulation context, in turn providing a solution to a new set of problems intractable by state-of-the-art nonlinear methods.

Key-words: Output regulation, differential-algebraic representation, linear matrix inequalities, rational nonlinear systems, input saturation, anti-windup"