Investigation On Constructing Virtual Scene Of High-speed Railway Based On Entity-Relation Conceptual Model

At the end of December2011, the mileage of High-speed railway in China had been nearly10,000kilometers. China has become the country which has the largest, the scale biggest of high-speed railway mileage in the world. Now railway system has changed from traditional technology pattern to wisdom pattern. Virtual environment based representation is an important method to recognize and research the world, which is the profound significance of the informationization construction and the scientific experiment research in many fields. Thus, how to effectively implement the scientific experiment and the management analysis in virtual high-speed railroad environment is great significance to independent technology innovation and safe operation in China.The complexity of the high-speed railway system puts forward the high request to modelling work of virtual scene. Because existing methods do not pay attention to conceptual modeling, the authenticity and the standards of virtual scene will be able to come under the influence. Many experts who are not familiar with3D modeling methods will be hard to implement the modeling work of virtual high-speed railway environment. To solve the above problem, this paper bring in conceptual modeling to construct the virtual environment of high-speed railway. The method aims to make sure that the virtual scene is reasonable and normative. It can be good understand by modeling worker. Based on conceptual modeling method, the modeling work can be more efficient, more economical and less error.Firstly, we analyzed hierarchical structure and restriction condition of the conceptual scene. The relationship and categories of the high-speed railway scene entity were discussed to set up the spatial relation and the condition-action rule. Meantime combination ways were defined by means of these rules. Secondly, we addressed the scene modeling method based on conceptual modeling. The entity-relationship model was used to instruct model combination. The method can deal with the auto-adapted representation of different high-speed railway lines. It is helpful to automatic modeling of virtual scene. Then this paper focused on how to implement virtual high-speed railway environment. The TIN (triangular irregular network) methods was used to construct virtual terrain. The geometric modeling method was used to represent3D object models. Finally, a high-speed railway line was used as case study. A prototype system was developed to implement preliminary modeling experiments of virtual high-speed railway environment. The experimental results show that our methods addressed in this paper are correct and feasible.