Development And Its Related Theories Of Deep-sea Pipeline Pose Measurement System

There are about 44%of the global offshore oil and gas resources stored in the 300m deep waters, which means more and more submarine pipelines will be lay on deep sea. A key technology of submarine pipeline connecting, pipe flange relative pose measurements, is that two pipe flanges relative distance between the spatial location and relative angle measurement. Accurate measurement of these parameters is the premise in the construction of prefabricated pipe sections on board which is the basis to ensure the smooth connection of submarine pipeline network. The Topics comes from the National "863" major projects. The aim of the project is that the exact position and orientation measurement device is to connect two underwater pipelines, which could provide technical support for the laying of submarine pipelines.Paper first reviews the domestic and international developments of underwater pose measurement techniques, describes the characteristics and development of rope measuring technology, satellite positioning technology, acoustic measurement techniques, and comparatives advantages and disadvantages of each measurement system. Paper analyzes the divers assisted rope measuring system, underwater ROV auxiliary flange measuring system and other typical auxiliary rope measuring system works. In addition, the measurement system of rope-related technologies (cable length theory, underwater cable theory and error correction technology) is briefly reviewed.According to the indicators and the actual deep-sea operating environment, paper completes the overall program of the measurement system. Paper establishes the mathematical model of magnetic coupling winch and screw base model, and designs in detail measuring devices, magnetic power winch rope and screw positioning base through analyzing system working principle and scope of operations. Then using 3DS MAX three-dimensional modeling software completes the virtual operating system operation simulation to verify the feasibility. For deep-sea environment, equipment has anti-corrosion treatment and buoyancy material design.Through analyzing the rope and the rope micro-element mechanical model of the underwater, the equilibrium differential equations of underwater rope are established. Using the cable length parabolic theory and the initial conditions solves the two measurements devices support pitch and height difference and comes to the relative distance of two measuring devices. Based on the theory of robot technology pose, the transition matrix theory and the principle of vector operations, the key algorithm (the pose transition matrix algorithm) is proposed. Through the algorithm for relative position and orientation calculation, the expression derived vector AB, the reference coordinate system and basis for the transition point coordinate system, flange center vector is are received and achieve the two pipe angle relative distance and relative position.Paper presents system of measurement error, model error, calculation error and positioning error of the composition, and analysis the relationship of error propagation on the system. For example, in the operating system conditions, the calculation error and angle error from the specific values, and the simulation of each error source distance and angle relative to system error. Paper uses segmented least squares method and find the length and angle error correction coefficient, and make sure the error correction function by its expression and design error prevention measures to further reduce the error from the root formation.Paper designs the overall program, completes the orthogonal angle detection testing, design of magnetic coupling angle sensor circuit and debugging rope length detection and achieves quadrature angle, deep perspective, rope long test. ARM control chip collect each sensor data. Base on Labview software control interface, system completes serial communication module, winch control module, the results of the transition algorithm module and data module programming in order to operate rope, exquisite parameter, display the results and storage data functions.Through prototype system debugging experiment, paper verifies length method of rope and rope required tension. Through integrated test, equipment simulates in the working process of water, system compares to the position and orientation measurement error and true value. Then, the experiment simulated deep sea environment of 8000 m deep-sea by using high pressure test chamber for experimental, to analyze anti-hypertensive equipment. In order to simulate marine environment, the experiment investigated in 10-meter pool experiment in Harbin Engineering University by measuring the relative water pose the two pipelines and analyzing accuracy of measurement.The research results provide a good platform for measurement system prototype design for the project success and the subsequent pose algorithms study. Study will also be opening up the new and extensive idea for State measurement of deep-depth. I believe, deep water oil and gas pose measurement system will play an important role in the seabed pipeline project.