Abstract
Log-aesthetic curves (LACs), which are generally used in industrial design for aesthetic shape modeling, are examined for implementation as transition curves despite their non-trivial representation in terms of incomplete gamma functions, or Fresnel integrals which appear in the parametric equations of a certain spirals. The family of log-aesthetic curves includes well-known spirals as Euler, Nielsen, logarithmic spiral, and involutes of a circle. The horizontal geometry of the route can contain classical transition curves, which are formed by transition curve-circular arc-transition curves. In order to compare the examined family of log-aesthetic transition curves with the classical transition curve in terms of vehicle-road kinematics, the curvature and superelevation functions are derived, and functions of lateral change of acceleration (LCA) curves are obtained and illustrated graphically using a constant motion model. The discontinuities in the form of jumps in the graphs of the lateral change of acceleration are taken into consideration in order to compare log-aesthetic curves and clothoids.
Original language | English |
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Pages (from-to) | 509-517 |
Number of pages | 9 |
Journal | Computer-Aided Design and Applications |
Volume | 11 |
Issue number | 5 |
DOIs | |
Publication status | Published - Sept 2014 |
Keywords
- curvature
- lateral change of acceleration
- log-aesthetic curve
- monotone curvature
- pseudospiral
- route alignment
- spiral