Design of actuator saturation compensators for absolute stability

Abstract

Actuator saturation is a common problem in practical control systems. Existing saturation compensation schemes are often derived with little consideration for the stability of the closed-loop system. An approach to design a compensator for a given system such that the compensated system is absolute stable is presented. It is shown that a compensation scheme with a pre-determined structure and/or parameters is local stable. The result is general and can be extended to other single valued non-linearities such as deadband.