Abstract of Thesis presented at COPPE/UFRJ as a partial fulfillment of the requirements for the degree of Master of Science (M.Sc.)

Comparative Study of the Transient Behavior of Adaptative Controllers

Priscilla Caroline Moutinho Dinau

December/2012

Advisor:

Ramon Romankevicius Costa

Department:

Eletrical Engineering

      Adaptive control is one of the most employed strategies to deal with inappropriate or insufficient plant modeling, parametric uncertainties, unmodeled dynamics and disturbances. Due to its wide use in real applications, it is of fundamental importance to minimize the undesired initial transient behavior during the adaptation process. Therefore, the objective of this dissertation is to present a study of the recent algorithm, called L₁ Adaptive Control, in comparison with some model-reference adaptive control algorithms proposed in the literature, identifying their advantages and disadvantages, limitations, similarities and differences with a focus on the transient behavior. Additionally, it is presented a new algorithm that, besides improving the transient performance, proposes an alternative solution to the problem of knowledge of an upper bound to the plant uncertainty.