The Study On Ship Motion Intelligent Control And Its Virtual Simulation

Ship motion modeling, intelligent control (IC) algorithm and virtual reality based visual simulation are systemically investigated in the thesis. The mainly parts of the paper are: 1) theorizing the ship model for ship steering; 2) research on intelligent PID control algorithms, fuzzy control algorithms and multi-mode control; 3) development of VR based simulation software for ship motion control.Establishing a mathematical model of ship motion is the foundation for ship control and simulation. The linear and nonlinear ship plant motion models with the forms of state equation and transfer function are particularly discussed in the thesis. By means of joining the related research project the author establishes the mathematical model of the fifth generation 5446TEU containerships in the world. The computing data based simulating model fit trial voyage results.The main difficulties faced for controlling ship motion are uncertainty and nonlinear problems of ship dynamics, the interference of stochastic environment and imprecise survey. The combination of intelligent control strategies and the classical control algorithms provides the possibility of solving above problems and designing ship intelligent controller with high performance. Taking ship as a controlled plant intelligent PID controller, self-tuning PID controller based neural network, fuzzy logic steering controller, multi-mode controller are investigated in detail. The simulation results demonstrate effectiveness of above-mentioned IC algorithms.Building a suitable simulation environment is an effective mean to test the control algorithms. Simulation technique has already become an important tool to analyze and study different systems especially complicated ones.This thesis focuses on studying and completing ship motion control including steering and main diesel engine as well as simulation system based VR that it gives prominence to the operation of the user. It can work by real time on line and support virtual equipment such as digital helmet and stereoscopic glasses. The user can observe the 3-D immersion environment for ship motion by means of VR facilities.This simulation environment provides manifold control algorithms to ship motion such as PID, intelligent PID, VAPID, neuron-PID, and fuzzy logic control and multi-mode controller with tuning parameters. All the algorithms are constructed to the module form, which is easily to be modified and extended for attaining optimal purposes.