ABSTRACT
This chapter introduces an advanced control design methodology to deal with systems with one or even several nonlinearities, either in the plant, or in the controller, or in both. It presents the circle stability criterion to study systems with one bounded and static or even time-variant nonlinearity by reviewing the fundamentals. The chapter also introduces a practical engineering methodology to design controllers for systems with one nonlinearity in the plant, and the same nonlinearity deliberately introduced in the controller based on stability criterion. It explains nonlinear dynamic control - one nonlinearity, which is applied to the design of an anti-windup strategy for a classical PID controller. It also explains nonlinear dynamic control - several nonlinearities, which expand the methodology to systems with more than one nonlinearity. In this case, the nonlinear blocks can be either in the plant, and/or in the controller.
