An analysis of discrete time anti-windup system subjected to saturation: An observer based approach

This paper focuses on the issue of stability and performance of the discrete time system subjected to actuator saturation. An anti-windup scheme based on observer approach is proposed. In the proposed criteria the saturation components are considered as external disturbances imported to the controller and to mitigate the effect an auxiliary controller is designed minimizing mismatch between the controller output and input. A linear matrix inequality based criteria has been formulated and L₂ stability condition has been stated. By solving resulting linear matrix inequality optimization problem the performance attenuation is minimized ensuring stability of the controller.