ABSTRACT
In this chapter, some aspects of the control of time-varying and non-linear systems are considered. The field of control of non-linear systems is wide. The aim of this chapter is to give the interested reader, with the help of illustrative examples, a flavor of the problems encountered and the solutions available. First, a brief introduction to adaptive control is given and the two main approaches of gain scheduling and indirect adaptive control are presented. In non-linear control, the Wiener and Hammerstein systems are of particular interest, as the non-linear control problem can be reformulated such that linear control design methods can be applied. A general approach for Wiener and Hammerstein systems, based on the availability of an inverse of the static part, is introduced, and illustrated via a simulation example using Wiener GPC for the control of a pH neutralization process. Then a special case of second order Hammerstein systems is considered. This chapter is concluded by a presentation of a 'pure' non-linear predictive control approach, using SNN and optimization under constraints. The control method is illustrated using two examples concerned with a fermentor and a tubular reactor.
