Adaptive Fuzzy Output-Feedback Method Applied to Fin Control for Time-Delay Ship Roll Stabilization

Rui Bai

doi:10.1155/2014/791932

Abstract

The ship roll stabilization by fin control system is considered in this paper. Assuming that angular velocity in roll cannot be measured, an adaptive fuzzy output-feedback control is investigated. The fuzzy logic system is used to approximate the uncertain term of the controlled system, and a fuzzy state observer is designed to estimate the unmeasured states. By utilizing the fuzzy state observer and combining the adaptive backstepping technique with adaptive fuzzy control design, an observer-based adaptive fuzzy output-feedback control approach is developed. It is proved that the proposed control approach can guarantee that all the signals in the closed-loop system are semiglobally uniformly ultimately bounded (SGUUB), and the control strategy is effective to decrease the roll motion. Simulation results are included to illustrate the effectiveness of the proposed approach.

Highlights

Stabilization of ship roll motion induced by wave disturbances has received considerable attention
Since the lift force depends on the relative inflow speed, the stabilizing fins are effective only when the ships are sailing at relatively high speed
Motivated by the above observation, this paper investigates the adaptive fuzzy output-feedback control problem of the time-delay ship roll stabilization

Summary

Introduction

Stabilization of ship roll motion induced by wave disturbances has received considerable attention. A multivariable control approach to the design of antirolling fins for a war ship has been proposed, where the rudder and the fins are considered simultaneously to reduce the wave-induced roll motion without sacrificing the yaw control performance [2]. A novel sliding backstepping controller was designed to decrease the roll motion of fin stabilizer control system for the system with nonlinear disturbance observer. Motivated by the above observation, this paper investigates the adaptive fuzzy output-feedback control problem of the time-delay ship roll stabilization. In this paper, assuming that angular velocity in roll cannot be measured, an adaptive fuzzy output-feedback control design problem is investigated, and a fuzzy state observer is designed to estimate the unmeasured states. Compared with other control strategies, the unmeasured angular velocity is considered during the design process of the controller, and the control strategy is effective to decrease the roll motion

Nonlinear Model Descriptions of Fin Control System

Fuzzy Logic Systems

Fuzzy State Observer Design

Adaptive Fuzzy Backstepping Control Design and Stability Analysis

Simulation Study

Conclusions