Real-time Dynamic Simulation Research On The Deepwater Pipelay Crane Vessel Operation

According to the theory model and the measured data, the scene simulation of real-timeof data system was built up based on deepwater piplay crane vessel. It could play an importantrole in training personnel operation abilities and doing engineering process practice. In orderto find the lifelike scene effect about pipelaying and lifting operation of the deepwater pipelaycrane vessel, and in view of the deepwater pipelay crane vessl simulation system of theoperation characteristics, the collaborative simulation software system structure was studiedusing an HLA federal simulation thought. In addion, the hardware-in-the-loop simulationsystem of deepwater pipelay crane vessl for the distribution interactive was designed.According to actual offshore lifting operation process, a variety of factors, such as seaconditions, dynamic positioning, real-time manipulation, ballast to adjust and so on, wereconsidered in the lifting operation simulation system. A real time dynamic model based onmulti-channel discrete data input has been build up. To begin with, considering the motioncharacteristics of flexible cable pendulum, the sling movement of crane vessel wasdecomposed into rope swing component and rope fluctuations component which areindependent mutually. Using string vibration theory, we constructed a wire fluctuationsmathematics model which can ensure existence uniqueness under mixed initial boundaryconditions. Besides, using unconditional stable hidden type difference method, it resolved thefluctuations equation numerical solutions stability. In here, using physics concepts and thedamping theory，it built the mathematical models of hanging objects’swing, and for solvingthe nonlinear coupled2-order differential equation, Breece Approximate integral method wasadopted in order to reduce the accumulated error and improving the operation speed. Finally,we got the lifting operation visual simulation data required by the principle of superposition.For the pipelaying operation simulation system, in order to predict the pipelaying workparameters such as pipeline shape, tension of tensioner, considering Euler-Bernoulli Beammechanics theory and deepwater pipelines deflection theory of computation, we built amathematical model for pipeline shape under constant ocean currents and derived tensionertension prediction formula. The deepwater S-lay pipelaying shape calculation software wasdeveloped on the basis of microsoft excel. On the basis of the actual deep pipe-laying operation characteristics, the use of independent flow field model correction formula Morisonequation and the Bernoulli-euler linear dynamic beam-the general form of the cable equationof the waves was deduced under the mathematical model of the pipeline-cable oscillationunder the action of waves and uses the finite difference method real-time solution wellpipeline-cable oscillation4order partial differential equations. In order to improve stabilityconvergence and accuracy of the pipelaying operation simulation system real time operation,the static mathematical model was applied to calculate the current load caused by pipelinemovement of the static component. Furthermore, the pipeline dynamic component wascalculated by the dynamic mathematical model. Finally, we got the pipe-laying operation forreal-time simulation data by using the principle of superposition.The simulation experiments indicate that the engineers can deliberate carefully theparameter essential to lifting and pipelaying work process through the simulation． Thepreview of the actual operation process can play an essential role in assistence of formulatingtechnological process, reducing marine lifting and pipelaying work risk, enhancing the marineengineering work reliability．...