【作者】 王宇；

【导师】 陈先桥；

【作者基本信息】 武汉理工大学 ， 计算机科学与技术， 2010， 硕士

【摘要】 随着国民经济的快速增长及交通事业的迅猛发展,我国公路建设进入了新的发展时期,国内拟建及在建的高速公路大量增加。为了提高高速公路交通安全性,及早发现并修正项目方案中的安全隐患,从而设计或改造出具备较高安全性的道路,基于汽车驾驶模拟器的高速公路安全性评价成为重要的研究课题。在交通安全仿真评价实验中,大规模高速公路三维视景仿真成为其中的关键。高速公路视景仿真软件不仅可以作为高速公路安全性评价的基础,同时还可以作为项目招标过程中的效果演示及工程完工后的展示,具有重要的研究意义。本研究在真实的地形和道路数据基础上,研究了大规模高速公路场景的整体划分方案、基于CAD数据的大规模地形快速生成方法、地形和道路匹配算法。并研究了一套快速构建高速公路视景仿真系统的框架模型,基于六武高速公路设计数据生成了六武高速公路视景仿真系统,研究的主要内容包括以下几个方面。(1)研究了大规模高速公路场景的整体划分方案。一般高速公路修建的非常长,决定了高速公路场景的大规模特性。为了对场景进行有效的组织,减少计算机内存的消耗,提高渲染效率,必须对整个高速公路场景进行划分。基于高速公路线性、狭长的特性,本文提出了按照高速公路线形走势进行场景划分,并给出了场景整体划分的方案。(2)研究了基于真实地形数据的地形生成技术。高速公路视景仿真中地形仿真是最重要的部分,为了能够真实再现高速公路周边的地形场景必须采用地形原始数据来生成地形。本文基于CAD地形原始数据,分析了DXF文件格式,研究了离散点提取算法对离散点进行提取。然后采用surfit软件对提取出的离散点进行插值生成格网地形模型,同时研究了格网地形模型的渲染及多重纹理映射技术,并研究了多块地形之间的边缘融合算法解决了多块地形之间的拼接问题。(3)研究了地形与路面匹配问题。在高速公路视景仿真过程中,道路和地形模型是分别通过不同的方式建立的,由于地形数据是在高速公路未建设之前航拍得到的,而在道路修建的过程中需要对地形进行填挖处理,因此建立的地形与路面模型存在不匹配的问题,需要对地形与路面进行匹配。本文根据高速公路仿真中建立的地形与道路模型,提出了基于格网模型的地形与道路匹配算法。(4)研究了高速公路视景仿真框架模型。为了能够快速构建高速公路视景仿真系统,本文研究了基于数据驱动的高速公路视景仿真框架,采用动态调度策略解决了大规模高速公路场景的实时漫游问题,并研究了基于道路线形的高速公路自动漫游方案,采用球面线性插值解决了自动漫游过程中的抖动问题。结合六武高速公路设计数据实现了六武高速公路视景仿真系统。更多还原

【Abstract】 With the rapid development of the national economy and transport services, highway construction in China has entered a new period of development, and is increasing in a large quantity. In order to improve the safety of highway traffic, discover and correct the potential safety problems in the project earlier so that a highway with higher security can be designed and modified. The evaluation of highway safety based on vehicle driving simulator has become an important research topic. The large-scale three-dimensional visual simulation of highway has become a key in the experiment of simulation and evaluation of traffic safety. The visual simulation of the highway can not only be used as the basis for evaluation of highway safety, but also be used as a demo to display the effect of the project during the bidding process or after the completion, which has important research significance.This thesis first describes the overall division scheme of large-scale highway scene based on the real terrain and road data, and then introduces the terrain and road matching algorithm and the fast generation method of large-scale terrain based on the CAD data. Furthermore, a framework for the rapid construction of a highway visual simulation system has been studied. And it’s applied to the LiuWu highway visual simulation system based on the real design data.The main contents of the study are as the following aspects.(1) The overall division scheme of large-scale highway scene is studied. Most of the highways are very long, which determines the large-scale characteristic of highway scene. In order to organize the scene effectively, reduce the consumption of computer memory and improve the rendering efficiency, the entire highway scene must be divided into parts. This thesis has proposed the scene dividing scheme based on the highway’s linear trend due to the linear and narrow features of highway.(2) The terrain generation technology based on the real terrain data is researched. Terrain simulation is the most important part in the highway visual simulation. The original datas are necessary for generating the terrain in order to reproduce the real topography surrounding highway. The thesis has analyzed the DXF file format and discussed the discrete points extraction algorithm based on the the original terrain data from CAD. Then we use the surfit software to interpolate the discrete points and generate grid terrain model. Additionally, the technology for rendering and multiple texture mapping of the grid terrain model has been studied. And the multi-block connection problem between the terrain is solved by using a terrain block fusion algorithm.(3) The matching problem of terrain and road is studied. In the process of highway visual simulation, road and terrain model are created in different ways. Sometimes the established terrain model doesn’t match the road model since the terrain data is obtained through aerial photography before construction of the highway, and will be modified during the process of road construction. Therefore, the matching of the terrain and road is necessary. The thesis introduces a matching algorithm for the terrain and road based on grid terrain model.(4) The simulation framework for the building of highway scene is researched. This thesis discusses a data-driven highway simulation framework to build a highway visual simulation system quickly. A dynamic scheduling strategy was used to solve the problem of real time walkthrough in a large scale highway scene. And a automatic walkthrough program is proposed based on road alignment. The jitter problem during the process of automatic walkthrough has been solved by using spherical linear interpolation. The LiuWu highway visual simulation system based on the original design data has been implemented.更多还原