Radius of curvature detecting apparatus and the method thereof

Abstract

A radius of curvature detecting apparatus and method of a vehicle for detecting a radius of curvature of a curve based on road information obtained from a vehicle navigation system comprises, three-points detection of a first point, a second point and a third point in order of traveling direction of the vehicle from point data showing a road configuration which are provided by the vehicle navigation system, distance comparison of a distance of a straight line connecting the first point and the second point with a distance of a straight line connecting the second point and the third point and for determining a short straight line and a long straight line, respectively, mid-point calculation for finding a mid-point point located at a half distance of the short straight line from the second point, equivalent mid-point calculation for finding an equivalent mid-point located at the half distance from the second point on the long straight line, and radius of curvature calculation for determining a point of intersection of perpendicular lines from the mid-point point and the equivalent mid-point as a center of the curve and for calculating a radius of curvature based on the center of the curve. The calculated radius of curvature is corrected, for example when the road width is small or the distance of the short straight line is large.