Estabilidade e síntese de controladores e filtros robustos para sistemas com retardo no tempo: novas fronteiras

• Ano de defesa: 2008
• Autor(a) principal: Fernando de Oliveira Souza
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: teoria de Lyapunov-Krasovskii; análise de estabilidade; sistemas sujeitos a retardo no tempo; Desigualdade matricial linear; controle robusto; Engenharia elétrica; Controle robusto
• Link de acesso: http://hdl.handle.net/1843/BUOS-8CLEJY

This thesis is dedicated to the study of some inherent problems in continuous-time systems with time delay. The thesis is divided into two parts; the first one shows that to study the stability of an autonomous linear system with constant time delay is equivalent to assess the roots of a rational function of appopriate degree. The second part deals with a set of stability analysis methods, based on linear matrix inequalities (LMIs), for continuous-time systems, uncertain, linear and non-linear, subject to time delay. It is also proposed a systematic way to extend the new stability tests for synthesis of robust controllers and filters, which can include H-infinity performance. The methodology used in this second part makes use of appropriate selections of Lyapunov-Krasovskii functionals, a strategy of discretization and matrix relaxations. Several computer simulations are presented throughout the thesis and compared with other recent approaches in the literature, which corroborate the efficiency of the proposed results.