| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation technique for performing a quick route search of high quality. SOLUTION: For a route connecting, for example, boundary nodes between blocks not adjacent to each other, a preliminarily calculated data of route is recorded in a block-to-block route data-base 122 and used for an actual route search, whereby the required time for route calculation is shortened. Since the calculation can be performed for the route between blocks to be preliminarily calculated without being conscious of the calculation time as a conventional directivity searching method or hierarchical method in the following process, and it is only the calculation quantity concerning the blocks at both ends that substantially has an influence on the whole required time for route calculation, the whole calculation quantity can be minimized even if the route closer to the minimum cost is calculated by use of a complicated method or condition judgment, and the quality of route can be also improved. |
