Study On Existing Railway Line Digital-aided Design Methods And System

With comprehensive analysis of the features of existing railway reconstruction design as well as comprehensive application of Route Survey and Design Basic Theory, Computation Geometry and Geometrical Modeling Study, Computer Graphics, Visualization in Scientific Computing Scientific Visualization and CAD, this article researched the theory, method, and application of the key technologies as digital terrain model, graphical and data interaction design, existing railway linear model and interaction design and gap query in modern line CAD system completely and systematically. The main achievements have been obtained through this research as followings:1. The research implemented a kind of algorithm to construct DTM rapidly and overall. Based on the main ideas of point-wise insertion method, this algorithm got large numbers optimizations and improvements in the key processes as massive data management, memory optimization, rapid frame network and topographical character line processing. Further, it got researches on integral network-building technology to realize the points with once treatment no limit to generate integral continuous seamless triangulation, thus avoiding the network-building speed up to80000-85000triangles per second on common PIV microcomputer when treating the block processing of massive topographic point data with previous algorithm. Meanwhile, taken topographical character line treatment into consideration, it ensured the precision of number module. Applications show that this algorithm has advantages of good integrality, high-speed, nice shape, high precision, widely use and so on.2. Based on the features of massive lines involved and reference relationship complicated in existing railway reconstruction design, it came up with the section reference design method and built linear model. The relationship between reconstructed railway and existing railway was fully considered in the module, thus inputting the related data of design line only, it can generate the design line with whole transfixion rapidly and automatically.3. Applying Optimization Principle, the automatic optimization calculation which was applicable to the displacements in simple curves and compound curves of declination method and coordinate method was realized, thus solving the problem of existing railway curve adjustment and optimization.4. Applying Two Order Different Quotient Method and Least Square Principle, applying the automatic recognition method of slope changing points with three-step circulation which can recognize the positions of slope changing points rapidly and accurately according to the rail surface data and fitted out existing railway slope with the advantages of high-speed and perfect results.5. Taking traditional vertical section design model for reference, combined with the features of existing railway, it developed vertical design module of existing railway reconstruction. Except realizing the traditional vertical section computer aided design functions, it also made the peculiar functions of existing railway vertical reconstruction as existing railway vertical section data automatic extraction, packing and dropping track amount dynamic display and least ballast thickness dynamic detection come true.6. Gap computer aided design module was developed according to the features of existing railway reconstruction, thus realizing the computer aided design functions as automatic search in gap boundary, vertical section information query, gap planar graph drawing and gap detailed cross section map drawing.7. ERDAS was developed according to the research results and applied in practice successfully.