| 摘要 |
PURPOSE: To enhance the efficiency of a processing without route searching in an unnecessary area in a route searching apparatus using map data of a hierarchical structure divided in the area. CONSTITUTION: A data memory 20 stores map data which is divided into predetermined areas and sequentially formed in from a sparse state to a dense state in a hierarchical structure. A control computer 16 calculates the optimum route from the present position to a destination by using the map data, and outputs to an output unit 22. The computer 16 uses four adjacent areas of the map data as basic searching units, and sequentially searches with the sparsest hierarchy indicating the positional relation of continuous basic searching units of the present poistion side and the destination side as the upper limit hierarchy. It decides the searching range of the area except the basic searching unit according to the positional relation of the boundary reached within the basic searching unit, and searches only the area considered that the optimum route is excited. |
