| 摘要 |
PURPOSE:To identify whether the present position is located on a superhighway or on a general road. CONSTITUTION:The average running speed of a vehicle is calculated by an average running speed calculation section 6b based on the vehicle speed signal outputted from a speed sensor 4, the curvature of a road is calculated by a curvature calculation section 6a from the change of the bearing signal based on the bearing signal outputted from a bearing sensor 3, the average running speed of the vehicle and the radius of curvature are compared with the preset reference values respectively by a judgment section 6c, if both the average running speed and curvature exceed the reference values, the judgment section 6c judges the road as a superhighway, if either the average running speed or the curvature is lower than the reference value, it judges the road as a general road. |
