Introduction

Abstract

The final objective of the research reported in this book is to contribute to the development of a system theoretic framework for control of nonlinear systems that incorporates at a fundamental level the systems physical structure and provides solutions to practical engineering problems. This is, of course, a very ambitious and somehow imprecise objective. To help delineate what we really want to accomplish we underscore the three major keywords of our work: Euler-Lagrange (EL) systems, passivity and applications. The first keyword mathematically defines the class of systems that we study, the second one the main physical property that we focus on, while the last one is our final objective. In this chapter we will develop upon this three keywords to explain the background and the contents of the book, and to motivate our approach.

“A control theorist’s ßrst instinct in the face of a new problem is to find a way to use the tools he knows, rather that a commitment to understand the underlying phenomenon. This is not the failure of individuals but the failure of our profession to foster the development of experimental control science. In a way, we have become the prisoners of our rich inheritance and past successes”.

Y. C. Ho (1982).