Digital Terrain Model And The Application In Railway Route

With the rapid development of railway, railway route design, as the basic work of railway construction, has become more and more significant. The digital terrain model, which is closely connected with railway route design, also has achieved great development, due to the gradual development of CAD in railway route and computer technology. As an important basis of modernization of railway route design, if the digital terrain model can not be very well applied in practical engineering, CAD in railway route is difficultly broken through, and the technologies of route survey and design are also hard to be improved. Therefore, it is necessary to conduct further researches on the application of the digital terrain model in route engineering to promote the development of an integrated system of digital terrain models and survey and design of railway route.The thesis deeply investigates the partial functions of the professional software for route design in the integrated system of railway survey and design by using computer graphics, computational geometry, geometric modeling and the theory of human-computer interaction. Through the research and establishment of the digital terrain model, the contour maps are finally produced, which are employed in railway route design to improve the efficiency. To promote the exactitude of the design, the internal interpolate in the digital terrain model is studied, by analyzing factors influencing its exactitude of the moving fitting method, comparing weighed means of various exactitudes, to improve the moving fitting method to get better results. With VBA to compile the process, the module of the digital terrain model is produced, while MATLAB is applied to speed calculation and make it more exact. Based on the requirement of the integration of railway survey and design, the thesis focuses on the research of the new technology and its application of the digital terrain model in line design, which is more practical. The major contents and structures of the thesis are briefly introduced in the following parts:(1) This paper studys digital terrain model construction theory and Delaunay algorithm, which are used in railway route field,and through the point-by-point insert algorithm to construct Delaunay Network.Then through the irregular triangle nets generate contours map.(2) Based on AutoCAD 2004 drawing platform, this paper add digital terrain model in the way of using VBA interaction to railway route CAD system, which is used in railway route design effectively.(3) The moving fitting method which is used in digital terrain models interpolated is improved and achieves good results through contrast test and verify.This paper design the interpolated elevation program using MATLAB powerful computing functions.which is applied to calculate the 100 meters pile elevation.