Performance enhancement of fixed regulating systems via actuator saturation

Developed in this paper is a controller design technique that utilizes actu ator saturation to meet stringent output performance specifications for reg ulating systems with fixed components. Regulating performance is achieved v ia the design of a linear controller that saturates the actuator for large step disturbances yet operates linearly for smaller step disturbances. The controller is designed using a pseudo-linearization technique based on a de scribing function approach. Such an approach retains the advantages of a fr equency domain technique including the enforcement of time domain performan ce specifications and the incorporating of model uncertainty. The resulting control law provides an improved regulating performance for large step dis turbances without requiring a larger actuator. For smaller step disturbance s, the control system maintains linear operation and provides desirable sys tem response characteristics.