Observer-based controller for discrete-time systems: a state dependent Riccati equation approach

In this paper, an observer-based controller for discrete-time nonlinear dynamical systems is proposed. After transforming the nonlinear system to a linear structure having state-dependent coefficient matrices (SDC), a recursive regularized least-square (RLS) state estimator is developed. The observed states are then used to generate either a constrained or unconstrained state feedback controller using the state dependent Riccati equation (SDRE) approach. The stability of the observer-based control system is rigorously analyzed in a theoretical frame work. Applications to different numerical examples as well as to a practical case study demonstrate the effectiveness of the proposed procedure.