Semi-global output regulation for linear systems with input saturation by composite nonlinear feedback control

Abstract

To improve transient performance of output response, this paper applies composite nonlinear feedback (CNF) control technique to investigate semi-global output regulation problems for linear systems with input saturation. Based on a linear state feedback control law for a semi-global output regulation problem, a state feedback CNF control law is constructed by adding a nonlinear feedback part. The extra nonlinear feedback part can be applied to improve the transient performance of the closed-loop system. Moreover, an observer is designed to construct an output feedback CNF control law that also solves the semi-global output regulation problem. The sufficient solvability condition of the semi-global output regulation problem by CNF control is the same as that by linear control, but the CNF control technique can improve the transient performance. The effectiveness of the proposed method is illustrated by a disturbance rejection problem of a translational oscillator with rotational actuator system.

Keywords:

• output regulation
• linear systems with input saturation
• composite nonlinear feedback
• transient performance

Additional information

Funding

The work is partially supported by National Nature Science Foundation of China [grant number 61074004]; the Research Fund for the Doctoral Program of Higher Education [grant number 20110121110017].