Patent ID: 8583366

Claim:
A road shape learning apparatus for a vehicle, the apparatus comprising: a map data storage device configured to store map data; a position acquisition device configured to acquire position information relative to a position of the vehicle; a position extraction section configured to, when it is determined that the vehicle traveled a curve, specify an entrance, a middle, and an exit of the curve based on the map data, and extract an entrance coordinate, a middle coordinate, and an exit coordinate which indicate the positions of the vehicle corresponding to the entrance, the middle, and the exit, respectively, from the position information relative to the vehicle acquired by the position information acquisition device; a position amendment section configured to obtain a post-amendment entrance coordinate, a post-amendment middle coordinate, and a post-amendment exit coordinate, which are obtained by amending the entrance coordinate, the middle coordinate, and the exit coordinate using amendment values which are predetermined depending on a travel tendency; a curvature radius computation section configured to compute a radius of a circular arc passing through the post-amendment entrance coordinate, the post-amendment middle coordinate, and the post-amendment exit coordinate and designate the computed radius as a curvature radius of the curve; and a learned data storage device configured to store the designated curvature radius as learned data associated with the map data, the position amendment section being further configured to perform a curve direction determination as to whether the curve is a left-hand curve or a right-hand curve based on the position information relative to the vehicle acquired by the position acquisition section, and designate a predetermined amendment value responding to an out-in-out tendency of the travel tendency based on either one of the left-hand curve and the right-hand curve, which is determined by the performed curve direction determination, the position amendment section being further configured to define an amendment value relative to each of the entrance coordinate and the exit coordinate as H 1 , define an amendent value relative to the middle coordinate as H 2 , wherein H 1 is different from H 2 ; the position amendment section being further configured to with respect to a left-hand traffic, designate a relation of H 1 <H 2 when the curve is determined to be the left-hand curve relative to a heading direction of the vehicle, and designate a relation of H 1 >H 2 when the curve is determined to be the right-hand curve, relative to a heading direction of the vehicle.