A nonlinear system perspective and guaranteed state estimation

A brief overview of nonlinear systems is presented as relevant for state observation, system identification, process control, and certain biomedical applications. The role of control in state observation is studied, and it is shown that multiplicative control, for example, with bilinear systems, can provide superior observer convergence. In this respect, an optimal control policy is derived for a bilinear example. The guaranteed state estimator or observer requires a priori knowledge only of the finite range of the state variables of interest