Research On Ship Motion Control And Its Simulation Adopted Virtual Reality

With the world economic globalization and the rapid development of it’s economic, China has become one of the largest maritime countries of great influence in the world. The safety and economy of ship sailing get more and more attention; therefore, the research on ship motion control is extremely meaningful for achieving the goal of’safe, efficient, energy saving and environment protection’.This paper establishes the mathematical model of ship motion based on the large container ship, studies on the control rules of ship course control and generates the virtual reality simulation system for the dynamic display of ship course control.Firstly, in this paper, the establishment of mathematical model with three degree of freedom is based on MMG modeling mechanism. The fluid forces and moments acting on hull, propeller, rudder and the interference among them are considered separately, at the same time, the impact of winds and currents is also taken into account. Then with the parameters of real ship-the 9572 TEU container owned by China Shipping Group, the author does the cycle calculation, and compares the results with the data of ship real manipulation test to verify the validity of the simulation results of ship motion mathematical model.Secondly, control algorithms of the ship autopilot are researched. The relay feedback method is introduced in PID controller parameter tuning. On this basis, the paper combines RBF neural network with PID algorithm and then adjusts the PID parameters with the identification of the controlled plant. The simulation is done under different speed and sea conditions. The results reflect that the RBFPID is faster than conventional PID and the output angle of the rudder is smaller and smoother which is of great benefit to ship energy saving and the steering gear conservation.Finally, the author finishes the dynamic simulation of ship control adopted the virtual reality technology. In the virtual marine scene, the three-dimensional solid model of the ship can display the real time changing during ship course control and the vary of vessel speed, rudder angle and course can be observed in digital instruments, which makes the changing and mutual influence of relevant parameters clearer and enhances interactivity and visualization of the simulation process.