Model Based Control of Nonlinear and Linear Plants

Abstract

First, the focus is on the control of nonlinear plants. This commences with traditional linearisation about the operating point, which enables linear control system design provided the plant states are restricted to lie in the region of the operating point. This is followed by feedback linearising control, which removes the operating point restriction and is applicable to multivariable as well as single input, single output plants.

The underlying principle of feedback linearising control, which forces the closed-loop system to obey a prescribed differential equation, is extended in two directions. First, feedback linearising control is applied to linear plants, which is found to be straightforward for multivariable plants. This is further extended to the discrete domain. Second, the prescribed closed-loop differential equation is allowed to be nonlinear, catering for control strategies such as near time-optimal control. In both these cases, the title, feedback linearising control, is replaced by the more appropriate title, forced dynamic control.