Two-degree-of-freedom output feedback controllers for nonlinear processes

An important class of nonlinear control methods arise from geometric considerations. One method based on input/output linearizing static state feedback is the model-state feedback structure of Kravaris et al. (1994, 1997). However, one limitation of this structure is its reliance on an open-loop observer. In this work, a structure with the same properties as the model-state feedback structure of Kravaris is developed using a closed-loop, constant gain nonlinear observer. The resulting algorithm is a two-degree of freedom control law