Plenary lectures: Modern sliding mode control with application to automotive systems

Sliding Mode Control is a nonlinear control methodology based on the use of a discontinuous control input which forces the controlled system to switch from one structure to another, evolving as a variable structure system. This structure variation makes the system state reach in a finite time a pre-specified subspace of the system state space where the desired dynamical properties are assigned to the controlled system. In the past years, an extensive literature has been devoted to the developments of Sliding Mode Control theory. This kind of methodology offers a number of benefits, the major of which is its robustness versus a significant class of uncertainties and disturbances during the sliding mode. Yet, it presents a crucial drawback, the so-called chattering, which may disrupt or damage the actuators and induce unacceptable vibrations throughout the controlled system. This limits the practical applicability of the methodology, especially in case of mechanical or electromechanical plants. This drawback has been faced by recent theoretical developments, oriented to increase the order of the sliding mode, thus producing efficient Second Order and Higher Order Sliding Mode Control algorithms. Robustness of the controlled system, in addition, has been extended to hold since the initial time instant of the control horizon, via the so-called Integral Sliding Mode Control approach. These “modern” results can be profitably used to efficiently solve automotive control problems, as testified by several recent publications and research projects. The aim of this lecture is to provide an outline of the mentioned theoretical advancements, and an overview of available examples of application of sliding mode control to the automotive field, focusing on recent activities developed by the research group chaired by Prof. Ferrara at the University of Pavia.