Decentralized Control Based on Fuzzy Anti-Windup for a Class of Uncertain Systems Subject to State and Control Constraints

In this work, a new nonlinear robust fuzzy decentralized constrained controller (NRFDCC) based on robust fuzzy anti-windup is proposed to improve the overall robustness and tracking ability of nonlinear dynamic systems subject to a wide range of parameter uncertainties and disturbances. Saturations on both control and the states are also taken into account. The studied system is considered as composed of several overlapping nonlinear subsystems. The nonlinear interaction between the several subsystems is considered a disturbance which is compensated by the proposed strategy. Sufficient conditions are derived for robust stabilization in the sense of Lyapunov stability and are formulated with linear matrix inequalities (LMIs) to obtain the controller gains and anti-windup gains. First, the proposed controller is designed subject to a disturbance with parameter uncertainties. Next, an additional anti-windup is designed to mitigate the adverse effects due to state and control constraints. The main contributions of this article are: 1) stabilizes the nonlinear system over a wide range of operating conditions, disturbance, and parameter uncertainties; 2) robustness is improved to provide good responses with input and/or state constraints; and 3) improves the performances of the stability of the power nonlinear system, for instance, short circuits with expected robust transient stability. The proposed control system is compared with alternative frameworks existing in the literature based on robust control via simulations performed with MATLAB software, to illustrate the effectiveness and robustness of the proposed method.