Improved robustness and performance for adaptive control of non-linear plants with input saturations

Abstract

In this paper a robust state feedback adaptive control scheme for non-linear plants with input saturations, such as unmanned underwater vehicles, is proposed. For the performance during input saturation the adaptive model recovery anti-windup method is used. To increase robustness, the control law is divided into a nominal and an adaptive one. High adaptation gains are usually needed to reach good tracking performance. Since high adaptation gains decrease the robustness of adaptive controllers, the control scheme is extended by a command governor. The command governor adjusts the trajectory of the given command signal to improve the transient performance at low adaptation gains.