基于线性参照系统的虚拟高速铁路场景建模方法

虚拟高速铁路场景能够直观地表达线路实体及其周围的地形地貌，为高速铁路相关的管理决策和科学实验提供支持。针对高速铁路空间数据的线性分布特征和地物对象结构固定的特性，本文提出了基于线性参照系统的虚拟高速铁路场景建模方法。将高速铁路对象抽象和简化为可重复利用的模型，并使用线性参照工具进行模型的空间定位，以实现虚拟高速铁路场景的构建。本文首先探讨了高速铁路线路和线性参照系统的特点；然后，详细给出了构建虚拟高速铁路场景的流程、模型属性表和事件表的设计，以及几何约束方法；最后，选择案例区域开展试验。结果表明，该建模方法将建模对象以事件表的形式进行空间定位，减少了计算复杂性，并将属性数据与虚拟场景对象进行联接，可用于高速铁路的可视化管理和科学分析。

Virtual High-speed Railway Scene Modeling Method Based on the Linear Referencing System

The high-speed railway and its surroundings is a complex system of ＂people, machine and environ-ment＂. Building the virtual high-speed railway scene can present the railway lines and the terrains around them intuitively, which makes the technicians feel on the spot and allows them to acquire railway attributes and geo-graphic information in a more efficient way so as to support the management decisions and scientific experi-ments. Linear referencing system is a one-dimensional system. It consists of a set of line features, on which events can be quickly located based on a reference to the line itself rather than through absolute x, y coordinates. So, according to the linear distribution characteristic of the high-speed railway spatial data and the fixed struc-ture properties of feature object, this paper proposes a virtual scene modeling method for high-speed railway based on the linear referencing system. This modeling method abstracts and simplifies the complicated high-speed railway models and transforms them into reusable basic-element models. At the meantime, the corre-sponding attribute tables are also created. While doing the modeling work, the modeling objects are stored as the event tables in the database and then using linear referencing tools to do spatial locating. Eventually, the virtual high-speed railway scene can be constructed according to the located spatial positions and attitudes. In this pa-per, we firstly explored the characteristics of high-speed rail line and linear referencing system. Then we dis-cussed some key technologies such as modeling flowchart, model attribute and event table design method, and geometric constraint in detail. Finally, we selected a case study region for carrying out a test. The results show that, this modeling method transforms the objects into event tables to do spatial locating, which reduces the com-plexity of calculations, and associates the attribute data with certain scene objects. Thus, this modeling method can surely be used in the management decisions as well as scientific experiments.