Submerging And Surfacing Simulation And Computer-aided Control System Of A Semi-Submersible Vessel

With the development of economy, the demand of global energy has sharply increased, the land resource has been exhausted day after day, all the countries in the world have increased the efforts to develop offshore oil, in order to transport the offshore drilling platforms and other ancillary equipments safely, the demand for semi-submersible vessels is increasing. But currently there are only about 30 seagoing semi-submersible vessels around the world and because of the special nature of this kind of ship, most people are lacking of perceptual knowledge about the semi-submersible vessel on how it works when it is carrying cargoes. For the purpose of transporting the offshore structures safely and training the semi-submersible vessel crew well, the study of the submerging and surfacing simulation of semi-submersible vessel is particularly important.This thesis is based on the original ballast water simulation of a semi-submersible vessel "TaiAnKou", after analyzing and studying the submerging and surfacing working of this vessel, an automatic control algorithm of the submerging and surfacing operation for this vessel has been designed; and also a real-time animated simulation function is added to the system.Under the VB 6.0 development environment, a computer-aided control system of ballast water in submerging and surfacing of a semi-submersible vessel has developed which changes the original simulation system from manual control to computer-aided automatic control. The program has realized the automatic submerging and surfacing control function of this vessel which includes submerge without cargo, surfacing without cargo, submerge with cargo, surfacing with cargo through controlling the air compressor and pump start or not, drainage of ballast tank. By using the Macromedia Flash 8, a submerging and surfacing surveillance interface and a real-time animated simulation interface of the vessel has developed, both of these two interfaces are beautiful with their strong visibility. The surveillance interface presents the control results of the control logic, and the other one shows the progress of the vessel's submerging and surfacing procedure in the form of flash animation.The controlled results are satisfactory by using the control logic to debug and control the ballast simulation system of the vessel. It not only realizes the submerging and surfacing function but also dynamically displays the entire drainage process of ballast tanks working in the way of free controlled, air compressor controlled and pump controlled. This thesis's research results have a certain reference value and significance as to the semi-submersible vessel automation research and the training of the semi-submersible vessel crew.