Real-time Simulation Of Ship Motion Based On Unity3D

When a ship sails on the sea,it may encounter various waves at different speeds and different heading angles,resulting in six degrees of freedom,including surge,sway,heave,roll,pitch and yaw.These motion parameters are usually described in the form of graphs.However,with the extensive use of scientific computing visualization,people began to consider the visual simulation of complex ship motion data visually.So a navigation simulator was bom,and the core part of the simulator is the visual simulation system.This article will combine the unity3D virtual engine and the Visual Studio program compilation platform to develop the ship motion visual simulation system.First,establish a mathematical model of ship motion.According to the force of the ship suffered from while navigating in the waves,the wave disturbance dynamics and torque received by the ship are derived.The mathematical equation of the ship direct movement is established by the slice theory.And the hydrodynamic coefficient and wave disturbance power(moment)of the whole ship is calculated by the Lewis' method,the Tasai's graph and numerical integration method.Second,compare the calculation results of the theoretical method.Select the Wigley series ships and the "YuKun",verify the accuracy of the slice theory calculation results by comparing with the experimental values,other relevant theoretical values and the nunerical simulation results of a commercial software,and analyze the error reason,considering the nonlinear roll damping.Modified the hydrodynamic coefficients in the slice theory formula.Then,develop the ship motion attitude solver and study its numerical simulation results.Under the Visual Studio compilation platform,the program code is compiled in C#programminglanguage,and the fourth-order Runge-Kutta algorithm is introduced to solve the motion amplitude,velocity and acceleration of the ship at each moment.At the same time,taking the "YuKun" as an example,the movement law of the ship under different sea conditions,different encounter angles and different speeds is studied.Finally,develop a real-time simulation system for ship motion.Take the "YuKun" as an example,under the Unity3D virtual engine,build virtual scenes,including ship model,ocean waves,islands,sky,sound,etc.,and connect extermal input devices,and calculate the ship motion attitude solver through the MonoDevelop development environment.The result is synchronously transmitted to the virtual scene to realize real-time simulation of ship motion.And debug the optimization program code,build the ship motion visual simulation system.The research innovations in this paper are as follows:(1)Under the traditional two-dimensional slice theory,considering the influence of nonlinear roll damping,the hydrodynamic coefficient in the formula is modified to improve the accuracy of the calculation results.(2)Real-time simulation is realized by writing a script program to synchronously transfer the self-compilation solver result to the scene simulation.And building a stand-alone software.