Output feedback composite nonlinear feedback control for singular systems with input saturation

This paper addresses the output feedback composite nonlinear feedback (CNF) controller design for a tracking control problem of single-input single-output (SISO) singular linear systems with input saturation. The output feedback CNF control law is constructed based on a state feedback CNF control law for the tracking control problem and a state observer. The stability of the closed-loop system under the output feedback CNF control law is established for an output feedback CNF control law with a singular full state observer. The design procedure and the improvement of the transient performance of the closed-loop system are illustrated with an example.