Optimal Robust Control of Path Following and Rudder Roll Reduction for a Container Ship in Heavy Waves

Sisi Wang,Fengshan Li,Zixuan Qiao,Lijun Wang

doi:10.3390/app8091631

Sisi Wang, Fengshan Li + Show 2 more

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https://doi.org/10.3390/app8091631

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Journal: Applied Sciences	Publication Date: Sep 12, 2018
Citations: 7	License type: CC BY 4.0

Affiliation: Guangdong Ocean University

Abstract

This paper presents an optimal approach to the multi-objective synthesis of path following and rudder roll reduction for a container ship in heavy waves. An improved line of sight principle with course-keeping in track-belt is proposed to guide the ship in accordance with marine practice. Concise robust controllers for the course and roll motion based on Backstepping and closed-loop gain shaping are developed. The control parameters have obvious physical significance. The determination method is given and much effort is made to guarantee the uniform asymptotic stability of the closed-loop systems by Lyapunov synthesis. Furthermore, the multi-objective optimization method a fast and elitist multi-objective genetic algorithm (NSGA-II) is used to solve the restrictions caused by the model perturbation, external disturbance and performance trade-off. Contrasting with the existing literature, the research strategy and control performance are more in line with marine engineering practice. Simulation results illustrate the performances and effectiveness of the proposed system.

Highlights

With the development of automation, ship autopilot has been used to keep course, change course, follow path and roll reduction for the purpose of safety and economy
To accomplish the path following autopilots with rudder roll reduction (PFA-RRR) control design in field of marine practice, a novel guidance system proposed to achieve better economic and safety performances in Section 3.1, and one develops is proposed to achieve better economic and safety performances in Section 3.1, and one develops concise course and RRR control laws based on Backstepping for underactuated ships in Equation (1), concise course and RRR control laws based on Backstepping for underactuated ships in Equation (1), whose parameters have typical physical meaning, and a method of parameter determination is given
The simulation results of the PFA with RRR in a seaway are shown in Figures 8–10, which indicate that the proposed scheme can achieve good performances of path following, course changing, course keeping and roll reduction

Summary

Introduction

With the development of automation, ship autopilot has been used to keep course, change course, follow path and roll reduction for the purpose of safety and economy. Most merchant ship autopilots are underactuated mechanical systems, especially for the path following autopilots with rudder roll reduction (PFA-RRR), which have become an active research field [1,2]. For the PFA-RRR, some theoretical challenges hinder its widespread use on board surface ships, such as underactuated mechanism, non-minimum phase, performances trade-offs, the engineering significance of the control schemes and the uncertainties caused by the model perturbation and disturbances [3,4]. Underactuated ships are only equipped with rudders and propellers for yawing and surging motions, while there are no actuators for direct control of roll and sway motions. Several novel control strategies have been proposed to solve the path following of underactuated ships [6,7,8,9]

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Results

Conclusion