The Study And Development Of Intelligent System For Elevation Planning In Grade Crossing

Grade crossing is an important constituent part in road system,it is the"throat"of road traffic. This paper researches the elevation planning which is a significant design of grade crossing.The traditional elevation planning method is manual computation and drawing,which is inefficient,slow-footed and of poor quality , it is also difficult to adjust the plan. There are some computer aided design systems for the elevation planning nowadays,but they always have some shortcomings : The domestic softwares are complex to operate,and their functions are not powerful enough to meet the needs of design ; The overseas softwares are uncomfortable to use, there are so many different design customs and design logs that we can't use them habitually and skillfully. So the writer decide to develop a new computer aided design system for elevation planning of grade crossing which is powerful , and suitable to the operation custom of the domestic designers , I hope to increase the efficiency and quality of this work radically .This paper analyzes the advantages and disadvantages of a large number of elevation planning softwares, borrows ideas from their good train of thought and methods, takes advantage of Grid and Triangulated Irregular Network which are the popular expressive forms of Digital Elevation Model in Geographical Information System, puts forward two mathematical models MESH–GRID Model and TIN Model artfully to simulate the vertical design plan of grade crossing. All these works base on studying the elevation planning methods of grade crossing at home and abroad. Then, this paper developes two independent elevation planning system by exploiting the object-oriented programming idea, using Visual Lisp and Visual C++.NET which are computer languages, applying ActiveX technology and ObjectARX,ObjectDCL that as tools . The two systems both are based on AutoCAD which are the current general-purpose draft software in our filed. One system is based on MESH–GRID Model, and the other is based on TIN Model, particularly, MESH–GRID Model is my promethean application.The two systems both adopt traditional compute-aided-wire-mesh method, accord with the design logs and design customs of the domestic designers, they have following merits: They are easy and effectual to operate ; They don't need to be inputted too much design parameters , the systems can search borderline curve and draw ridge routes,road axis,curb curves automatically ; They can general the 3D model of vertical design plan automatically and establish the topology which records the incidence relations of all the entities, if the designer alter one design parameter, all of the other entities and data that have business whit it can change according the alter automatically, so the systems are very intellectualized; They provide powerful tools to observe and adjust the 3D model of vertical design plan, the designer can observe the blown-up 3D view of the plan real-timely and intuitively, so it is very easy and effective to adjust the design by using the two tools ; They can draw contour lines and label the elevation of plate's intersection points accurately and fleetly.