Study On Key Technologies For Deepwater Pipelines Measuring System

This paper does study on technologies related to deepwater pipelines measuring system,which roots in "The Technology of The Submarine Pipeline Laying", a major project from thenational "863" plan. Deepwater pipeline measuring system is used to measure the relativeposition and orientation between two underwater pipelines. It is the first step of connectingoperation of deepwater pipeline, and provides parameters desired to prefabricate interveningpipe sections for the next step.The actuality for the related field is studied. Then, based on the working principle of theROV assisted taut-line measuring technique, the overall scheme of the deepwater pipelinemeasuring system is presented according to the target of the project. The scheme includs threeparts concretely, which are mechanical structures and detecting systerm and pose algorithm.Firstly, the mechanical structure of the measuring system is designed in detail. Inconsideration of the work environment for1500m underwater, the sealing problemunderwater is very important during the design of mechanical structure. In order to solve thisproblem, a kind of non-contact angle encoder is designed based on Hall Effect and a subseawireline winch is designed which transmits the torque through magnetic coupling directly. Atthe same time, docking mechanism of measuring device is also designed. The finite elementanalysis is conducted upon the sealing properties of O-rings in the electronic warehouse usingABAQUS.Secondly, pose algorithms of two kinds of pipe connection are solved, based on theoriesrelated to robotics. After transformations and operations, the relative pose parameters neededbetween the two pipelines are received from the initial parameters detected by the measuringsystem.Finally, the detecting systerm of deepwater pipeline measuring system is studied,including the multiparameter monitoring of the control systerm underwater and the monitorsystem of upper computer programmed by LabVIEW. As a result, multiparameter monitoringand acquisition, control of the subsea wireline winch, processing and preservation of the data,display of interface and some other functions are achieved.