【作者】 曾鸿；

【导师】 张均东；

【作者基本信息】 大连海事大学 ， 轮机工程， 2012， 博士

【摘要】 在当今航海教育领域,船舶轮机模拟器已成为轮机教育与培训的重要手段。传统的轮机模拟器仿真方式多为半物理仿真或二维软件界面仿真。仿真系统较抽象和专业化,在应用中缺乏动态展示,难以看到机舱真实画面。虚拟现实技术为弥补轮机模拟器视景的缺失提供了手段,但现有的相关研究多是基于商业化三维软件的开发和应用,没有涉及视景系统的相关理论。本文研究了视景的生成与交互原理,并实现了一个高品质的轮机视景仿真系统。研究内容如下：(1)建立了调距桨船舶机舱的几何模型并将光照与特效计算应用于场景的实时渲染。给出了机舱场景建模的方法、流程与技巧,建立了考虑衰减的局部光照模型,研究了环境映射、凹凸映射的特效原理。利用图形处理器的最新特性,用着色器实现了光照模型与特效,模拟出了机舱设备表面的各种材质,提升了场景渲染的实时性和灵活性。(2)改进了路径规划算法使之可用于虚拟机舱的自动漫游,对视景系统中的漫游摄像机控制、三维拾取和行为建模等人机交互相关技术进行研究并予以实现。改进了路图骨架节点的数据结构,加入最大自由圆半径用于安全性的判断。使用A*算法做全局路径搜索,基于可见性原理对搜索结果进行优化。设计了虚拟力用于角色自动漫游过程中的实时引导、避障与平滑。实现了各种漫游模式下的摄像机控制,改进了三维拾取操作的有效性,建立了交互点的行为模型。(3)搭建了基于多通道立体投影的轮机模拟器视景仿真环境,实现了多通道投影图像的几何校正与边缘融合。提出使用三次样条函数进行投影图像的边缘融合,改善了画面的融合效果。编程实现了双目立体成像算法并总结了影响立体效果的因素。(4)建立并改进了调距桨船舶的船机桨数学模型,在视景系统中实现了船舶推进系统的可视化仿真。通过对柴油机燃烧模型参数的回归分析,用回归方程式取代插值法计算参数,提高了变工况下柴油机模型的准确性与通用性。在可视化仿真环境中实现了推进系统的虚拟操纵与三维监控。更多还原

【Abstract】 In today’s marine education field, engine room simulator has become an important means of marine engineering education and training. The traditional simulation way of engine room simulator is semi-physical simulation or two-dimensional software simulation. The simulation systems are still too professional, lack of dynamic display during application and can’t see engine room real scene. Virtual reality technology provides a means to compensate for the lack of visual scene in engine room simulator. But the existing relative researches mostly focus on the development and application with commercial three-dimensional software. The relevant theory of visual system is not involved. This paper studies the principles of scene generation and interaction. A high quality engine room visual simulation system is achieved. The contents of this study are as follows:(1) Establish the geometric model of controllable pitch propeller ship engine room. The illumination and effect calculation is applied on the scene real-time rendering. Gives the methods, processes and techniques of engine room scene modeling. Establish the local illumination model with attenuation considered. Study the principle of environment mapping and bump mapping effects. Enhance the real-time and flexibility of scene rendering. Various materials of engine room equipments’s surface is simulated.(2) Improve path planning algorithm so that it can be used to make automatic navigation in virtual engine room. Study and realize the human-computer interaction technologies in visual system, including navigation camera control, three-dimensional pick up and behavioral model. Improve the node’s data structure of road map skelton, add into the max free circle radius for the determination of safety margin. Do global path search by A*algorithm, optimize the search results based on visibility rule. Design a virtual force for real-time guidance and obstacle avoidance and smooth during role’s automatic roaming process. Achieved the camera control under different navigation mode. Enhance the effectiveness of three-dimensional pick up operation. Build the behavioral models of interactive points.(3) Build the engine room simulator visual simulation environment base on multi-channel stereo projection system. Proposed to use cubic spline function as blend function for projection image edge blending, thus improve the scene’s blend effect. Realize the binocular stereo image algorithm by programming. Summarize the factors that affect the stereo effect.(4) Establish and improve the hull-engine-propeller’s mathematical model of controllable pitch propeller ship. Achieve ship propulsion system’s visual simulation in visual system. By regression analysis on parameters of diesel engine combustion model, replace the interpolation method with regression equation to calculate the parameters. Thus improve the diesel engine model’s accuracy and versatility under variable working conditions. Realize propulsion system’s virtual maneuvering and three-dimensional monitoring in virtual simulation environment.更多还原