Submersible Coordinate. Deep-sea Mining Heave Compensation Given The Depth-control Study

It is a worldwide common knowledge that ocean will be the aim of human in the new century. Heave Compensation for the mining ship is still one of key objectives in technology that must be resolved in the deep sea mining, although many countries have made a great deal of research on the deep sea mining. The heave movement of mining ship must be inspected, and it is used as a signal to operate control system for heave compensation. It is difficult to find a static place in the ocean to be reference frame properly. An idea that a submersible body can be used for a suitable reference frame had been put forward in the previous research on this project. Hence, much research on this is expected to be done. After sucking up the idea, the research work on this thesis is focused on how to control a submersible body in invariable depth which is called a Submersible Reference Frame(SRF).In this thesis, firstly, the background and meaning why to do the research work are discussed and the status in quo about submersible body, home and abroad, are introduced. Usually, when submersible body running in the water, it can go up and down by the force which is produced by drop rudder and elevating rudder and by ship crust. On the other hand, SRF and Argo buoy can suspend under water by means of adjusting their volumes. When the Argo buoy is suspending under water, its depth alteration is bigger than ten meters because it is not purposed to be kept stable. However, that of SRF must be less than 10 cent-meters because it is designed to be kept stable, it makes it much clear that the research work is valuable. Secondly, principle of SRF and structure of control system are described. Thirdly, in this thesis, the hardware blocks, software blocks and mechanical structure are described. Fourthly, Digital PID controller and Proportional-Fuzzy-PID controller are designed and applied to the SRF. The latter is turned out to be better than the former. Finally, summarization of this thesis is made and the development of SRF in the future is discussed.The research is a part of the project, Research on the heave compensation system for deep sea mining system sponsored by National Natural Science Foundation of China, and a part of the project, Research on Submersible Reference Frame sponsored by Natural Science Foundation of Department of Education of Guangdong province. SRF structure research and Proportional-Fuzzy-PID controller design are finished in the research work.