| 摘要 |
PURPOSE:To prevent the capacity of a memory for storage from increasing by determining the best course which is corrected without any course calculation even if a travel course is out of the best course which is recalculated and showing it to a driver, and storing only calculated course data within a constant range at the periphery of the best course. CONSTITUTION:Map data within a range including a starting point and a destination point are retrieved on a map memory according to the setting of the destination point to calculate the best course (f) (white line) extending from the destination side to the starting point in an opposite order from the travel of a vehicle (e), and the course calculation process data A1, A2,...B2, B3,..., and C2,..., and D2,... within the constant range at the periphery of the best course (f) are stored; if the position of the vehicle (e) is out of the best course (f), a new course is determined according to the calculation process data stored in the memory on condition that the corresponding position or place is in an area stored wherein the course calculation process data are stored. |
