Introduction

Abstract

The benefits of feedback control have been known to mankind for more than 2,000 years and examples of its use can be found in ancient Greece, notably the float regulator of the water clock invented by Ktesibios in about 270 BC, Vitruvius, The Ten Books on Architecture, 1914, [1]. The formal development of the field as a mathematical tool for the analysis of the behaviour of dynamical systems is much more recent, beginning around 150 years ago when Maxwell published his work on governors Maxwell, Proc. R. Soc. Lond. 16:270–283, 1868, [2]. Since then the field has seen spectacular developments, promoted by the work of mathematicians, engineers and physicists. Laplace, Lyapunov, Kolmogorov, Wiener, Nyquist, Bode, Bellman are just a few of the major contributors to the edifice of what is known today as control theory.