Vibrational Control of Large Scale Electromechanical Systems

Abstract

In this thesis, our attention focuses on the fundamental role of broad-spectrum mechanical vibrations [1] to favor the working of complex electromechanical systems. Uncertainty has been already proved to allow self-organization in array of non-linear oscillator (pendulums, in particular) [2, 3]. The idea of our thesis is to show that also passive and active mechanical vibrations can play a key role on self-organization in a class of complex electromechanical systems. In fact, large-scale electromechanical systems considered in this work is referred to as imperfect uncertain systems for which classical feedback control design cannot be suitably implemented. For imperfect and uncertain systems, we mean systems including also unmodeled dynamics, intermittently arising, and uncertain parameters. In order to control arrays of such types of systems, made by coupling a large number of linear low order units, it is not convenient to consider classical control approach [4]. The strategy to control each unit with a local feedback loops, indeed, is not practical as it leads to numerous and different control actions. On the contrary, the idea of our research is to use only few control actions, in order to control the whole system, by exploiting its intrinsic properties of self-organization stimulated by the control actions. This work is organized as follows. Chapter I is about the new class of systems that are experimentally realized. Some qualitative exploration about them has been also given with reference to the control task. In the Chapter II the problem is introduced by focusing on the key points of the research and the peculiar aspects of the structures showing some introductive experimental results. In the Chapter III the mathematical framework of the general class of imperfect uncertain systems and the control feedback scheme are discussed. In the Chapter IV the models of specific investigated large scale electromechanical systems are illustrated. In the Chapter V the experimental results related to specific structures are discussed and compared with the numerical results obtained by simulations of the mathematical model. Chapter VI includes the conclusive remarks and outlines the future perspective trends towards which this research could lead.