Patent ID: 6438494
Filing Date: 2002-08-20
Classification: E01C,G01C

Abstract:
An apparatus for designing roads, which is an apparatus for designing roads using line segments, circulararcs, clothoid curves and so on, comprising:input means for inputting information of design conditions and/or a command of design processing; design conditions storage means for storing said information of the design conditions input by said input means; road design processing means for executing road design in accordance with said command of the design processing input by said input means and/or said information of the design conditions stored in said design conditions storage means and for generating a road design map; and output means for outputting said road design map generated by said road design processing means, wherein said road design processing means generates a clothoid curve from a clothoid origin without executing exceptional processing near said clothoid origin in case of generating a curvature transition curve of a road using said clothoid curve, by calculating coordinates of said clothoid curve using the following recurrence equation (1), of which parameters are only the arc length â€œlâ€  from said clothoid origin, expressed as x=&Sum;n=0âˆž&it;(-1)n&it;l4&it;n+1(4&it;n+1)&CenterDot;22&it;n&CenterDot;(2&it;n)!y=&Sum;n=0âˆž&it;(-1)n&it;l4&it;n+3(4&it;n+3)&CenterDot;22&it;n+1&CenterDot;(2&it;n+1)!(Equation&it;â€ƒ&it;1)where â€œlâ€  is the unit clothoid arc length, â€œxâ€  and â€œyâ€  is a coordinate of the arc length â€œlâ€  from a clothoid origin of the unit clothoid curve, and â€œnâ€  is order.