| 摘要 |
PROBLEM TO BE SOLVED: To display map in a wide range for all directions centering around the present position without losing the continuity of a road. SOLUTION: A coordinate of a node on a link constituting a map is transformed to polar coordinates (r,θ) by a straight distance r between the present position of a vehicle and the node and angleθof the node direction to the traveling direction of the vehicle (step 103), and the distance r is transformed to a distance R using the logarithmic function so that the variation rate of the distance is made small as the distance becomes large (step 104). Polar coordinates of each node is set to (Rcosθ, Rsinθ) using the transformed distance R and the angleθ(step 15), display data of a map is made using these polar coordinates, and a map is displayed at a display position (step 106). Thereby, a map in which a reduction scale is made continuously large as the distance from the present position becomes large in the circumferential direction making the present position as the origin can be displayed. |
