Nonlinear State Feedback Synthesis by Global Input/Output Linearization

This paper studies the design of feedback controllers for trajectory tracking in single-input single-output nonlinear systems ⨰ = f(x) + g(x)u, y = h(x). A nonlinear transformation of the form v = κ(x) + λ(x)u that transforms this nonlinear input/output system into a linear system is first constructed. On the basis of this transformation, an approach for designing control laws for trajectory tracking is presented. The control law is robust in the sense that small changes in it do not produce large steady-state errors or loss of stability. The theory provides a unified framework for treating control problems arising in batch chemical processes; this is illustrated by an example.