On Hazards of Using Fundamental Anti-windup Technique for H2 State-space Controllers with an Explicit Observer

This paper considers H2 controllers implemented using an explicit observer for systems subjected to input magnitude saturation. It is stressed that the approach of only focusing on controller windup, by using fundamental observer anti-windup technique where the observer is fed by the saturated control signal, could imply severely deteriorated closed-loop characteristics and even sustained oscillations.