Implementation of road horizontal alignment as a whole for CAD

Road horizontal alignment contains three elements: straight line, circular arc, and clothoid. In AutoCAD, clothoid can only be fitted by polyline or spline, and the graphics which are separated from the road data are independent of each other. Therefore, it is necessary to develop a new curve for road horizontal alignment. Firstly, the differential approximation and series integration methods for clothoid were discussed. Secondly, the geometric formulae for road line which contain the three elements were derived as a whole. Then, the advantages and feasibility of customizing a road line class, which was derived from the curve base class, were analyzed based on ObjectARX (AutoCAD Runtime eXtension) techniques. Finally, the data structure and operations for the road line class were stressed. The experimental results show that the road line can integrate the road elements, graphics and data to implement the graphics-oriented design, which can be widely used in road alignment design.

[1]  Xiaojun Li,et al.  Modeling and Visualization of Underground Structures , 2009 .

[2]  Xiao-yan Hou,et al.  Automatic Design of Transmission Lines Using ObjectARX Technology , 2012 .

[3]  Dong Wang,et al.  Hydraulic Calculation Software Development of Water Supply Networks Based on AutoCAD , 2011 .

[4]  Kenjiro T. Miura,et al.  An approximation approach of the clothoid curve defined in the interval [0, /2] and its offset by free-form curves , 2001, Comput. Aided Des..

[5]  Wang Qian.  Design of underground pipeline front-facing data acquisition system on the basis of custom entity of ObjectARX , 2010 .

[6]  Dereck S. Meek,et al.  A controlled clothoid spline , 2005, Comput. Graph..

[7]  J. M. Chacón,et al.  Polynomial approximation to clothoids via s-power series , 2003, Comput. Aided Des..

[8]  Hongzhe Zhang,et al.  An open platform of shape design optimization for shell structure , 2008 .

[9]  Andrzej Kobryń,et al.  Polynomial Solutions of Transition Curves , 2011 .

[10]  Yong Tang,et al.  Synthesis of fractal geometry and CAGD models for multi-scale topography modelling of functional surfaces , 2011 .

[11]  D. Walton,et al.  An arc spline approximation to a clothoid , 2004 .

[12]  Karan Singh,et al.  Sketching piecewise clothoid curves , 2008, SBM'08.

[13]  Yun-ping Han,et al.  The Simulation of Natural Scenery Based on ObjectARX , 2009, 2009 Second International Symposium on Intelligent Information Technology and Security Informatics.

[14]  Yusin Lee,et al.  Optimization Method for Highway Horizontal Alignment Design , 2009 .

[15]  Pu Hao.  Study on interactive design methods for road horizontal alignment , 2006 .