@MASTERSTHESIS{ 2018:772767006,
 	title = {Resonant gain scheduling controller for spiral scanning patterns in atomic force microscopy},
 	year = {2018},
 	url = "http://tede2.pucrs.br/tede2/handle/tede/7931",
 	abstract = "This document presents a dissertation work regarding the study of control strategies for
 the efficient tracking of spiral patterns. Such patterns arise in many areas, as for example
 the Atomic Force Microscopy, where fast and smooth reference signals are required. In order
 to successfully track the above mentioned references, which are composed of amplitude
 and frequency-varying sinusoidal signals, advanced control strategies were investigated.
 The Internal Model Principle is a traditional approach to track reference signals, but
 it cannot be directly applied in frequency-varying signals. Therefore, the present work
 proposed a robust control strategy where the Internal Model Principle was applied as a
 Resonant Control in an augmented time-varying structure. The augmented system and the
 reference frequency values were organized using a polytopic representation and structured
 as an optimization problem subject to constraints in the form of Linear Matrix Inequalities.
 This synthesis was evaluated through a set of simulations, using a numerical model
 of an Atomic Force Microscope and a new suitable scanning reference pattern. Moreover,
 using the premise that the same reference signals are tracked multiple times, an Iterative
 Learning Controller was also designed in order to improve the tracking performance of
 the proposed main strategy. Numerical results demonstrated that the designed controller
 achieved satisfactory results, in comparison to the traditional controller available in the
 area.",
 	publisher = {Pontif?cia Universidade Cat?lica do Rio Grande do Sul},
 	scholl = {Programa de P?s-Gradua??o em Engenharia El?trica},
 	note = {Escola Polit?cnica}
}