ACTIVE VIBRATION MODELLING AND CONTROL FOR MARINE PLATFORM

Abstract

Various industries adopt different techniques for isolating or reducing vibration in marine application. This project investigates vibration control for fitted equipment on marine vessels that are subjected to random sea waves. A suitable controller is therefore designed to ensure that the platform located beneath the equipment as flat as possible regardless of the disturbances. Increasing complexity control of a fitted equipment and accurate determination of vibration measurement due to the unpredictable nature of the external disturbance acting on the system has led to a study carried out to prevent severe consequences such as loss of lives and capsize of goods.In this thesis, a random sea wave, which is as close as possible to the actual sea wave, is modelled as the disturbance to the system.Majority of the works previously presented on ship motions have been on steering control and navigation. The goal in this thesis is to control the flatness of the fitted equipment loaded on a marine vessel. In addition, an approach of attenuating the impact of disturbances on the marine vessel is presented. This analysis is important to ensure that the stability of the platform located beneath the equipment is achieved irrespective of external disturbances. It is important for the actively controlled board which are located beneath the equipment of the ship to be made as flat as possible subsequent to agitation by external disturbances.The plant model considered is illustrated as a two and three-dimensional structures that describe the marine body and platform. The random sea wave acts as the disturbance tothe system, which is described using a set of motion equations. The considered motions in this thesis consist of the pitch, roll and heave. As a result of this disturbance, some linear and non-linear controllers are proposed to suppress the vibration and improve the flatness of the fitted equipment (rigid body). Simulations and analyses of results are consequently presented and discussed to show that the flatness of the fitted equipment is achieved.

Date of Award	1 Aug 2016
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Hong Wang (Supervisor)