Research On Modeling,Simulation And Application Of Ship Mooring System

It is more flexible and lower cost to use virtual reality technology to train the crew.Therefore various navigation simulation systems are widely used in ship practical training.At present,the domestic nautical colleges provide training methods for the crew's berthing and anchoring(hereinafter referred to as mooring)maneuvering mainly carried out in the way of theoretical teaching,and there is few real mooring equipment for the crew to practice.In addition,the evaluation of the ship's mooring operations lacks uniform evaluation rules and standards,unable to give a scientific and reasonable evaluation of the crew's operation level.To this end,the article studies the three aspects of the kinematics and dynamics model of the ship mooring system,the visual simulation method of the mooring maneuvering process,and the simulation evaluation of the ship mooring maneuver.A mathematical model of the ship's six degree of freedom maneuvering motion is established by using the separation-type modeling idea.The model fully considers the multi-quadrant operating conditions of propeller and the environmental effects of wind and current.Carry out cycle test,Z-type test and inertia ship-stopping test,and compare simulation results with the practice ship "YU PENG" as the research object.The simulation results show that the model established meets the accuracy requirements of the ship mooring simulation system.According to the different characteristics of berthing and anchoring in ship mooring operation,the static model based on the catenary and the nonlinear dynamic model by lumped mass method are put forward for cable and chain respectively.For ship berthing,the cable tensions under the conditions of satisfying Hooke's law and not satisfying Hooke's law are calculated respectively,also analyze the cable tension during berthing operation.For ship anchoring,the data obtained by the quasi-static method of the anchor chain is used as the basis for dynamic analysis,and the dynamic model of the anchor chain is established based on the lumped mass method.The dynamic model fully considers the anchor chain's own weight,hydrodynamics force,current and the interaction with the seabed.Finally,coupling the ship motion model and the anchor chain dynamics model to calculate the motion response of the mooring system under the action of current.The numerical method adopted in the paper can ensure the stability and improve the efficiency of numerical calculation.The use of 3D modeling technology to establish 3D model of anchor equipment and mooring equipment,build a virtual scene of maritime navigation with mooring operation.Use human-computer interaction technology designe the human-computer interaction interface of the simulation system,by optimizing scene interaction to improve the friendliness of the interactive interface in the virtual scene.Use the scene roaming technology,virtual human technology and collision detection technology to realize the roaming and interaction of the three-dimensional scene.According to the characteristics of the mooring line,the PBD method is improved on the basis of the distance and bending constraints,and the long-range attachment constraints and pin constraints are proposed,and the Gauss-Seidel iterative method is used to solve the equation.The method effectively improves the calculation efficiency while ensuring the calculation accuracy.The simulation system can complete the calculation,rendering and interactive operation in real time,and realize the interactive simulation of the mooring equipment and the real-time retractable simulation of the mooring line.According to the mooring equipment operation rules and relevant evaluation specifications,the evaluation index of mooring operation is determined by the expert evaluation method.The membership function of each evaluation index is established based on the fuzzy comprehensive evaluation method,and the recommendations of each evaluation index are given in combination with the expert evaluation method and the analytic hierarchy process.The weight value and standard value are used to establish a complete evaluation model.After determining the membership value of each evaluation index,the weighted average method is used to obtain the final evaluation score of the crew.Finally,the automatic evaluation model is integrated into the ship mooring operation simulation system.On the basis of the above research,this paper develops a ship mooring maneuvering simulation system,which is composed of operation training subsystem and automatic evaluation subsystem.The operation training subsystem better realizes the ship mooring system and its visual simulation,and improves the simulation effect of the mooring line.The automatic evaluation subsystem realizes the data recording and evaluation of the operation steps and results of crew mooring operations.