JPH03219397A - Course searching device - Google Patents

Abstract

PURPOSE:To always output the shortest distance course even when getting out of the shortest distance course from a starting point to a destination only by once executing search in the beginning by providing a searching means to store the shortest distance course from the destination to respective spots on a road. CONSTITUTION:A searching means 104 inputs the destination stored in a destination storing means 101 and reads out map data to be used for the course search with the destination as a reference from a map data storing means 101 based on the destination. The shortest distance course from the destination to the respective spots is searched and the result of the search is stored in a spot data storing means 103. Then, an output means 105 outputs the searched result of the searching means 104. Thus, when the search is only once executed in the beginning with the destination as the reference, the shortest distance course from the current spot to the destination can be always outputted even when getting out of the scheduled travel course.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a route search device used by a vehicle driver to find a route from a starting point or current point to a destination.

BACKGROUND OF THE INVENTION Conventional route searching devices that search for routes for vehicles include, for example, Japanese Patent Application Laid-Open No. 62-6010.
There is a route guidance device for a vehicle disclosed in Japanese Patent No. 0. This vehicle route guidance device has a required time for a vehicle to pass through each pair of adjacent registered intersection sections, and searches for an optimal route from a departure intersection to a destination intersection based on this required time, The searched optimal route is shown to the driver.

Problems to be Solved by the Invention However, there are cases where returning to the planned driving route when leaving the planned driving route is not necessarily the optimal route. In order to travel, there were issues such as having to reset the starting point to the current location and search again.

In view of these conventional problems, it is an object of the present invention to provide a route search device that always outputs an optimal route suitable for search conditions even when the vehicle deviates from the planned travel route.

Means for Solving the Problems The present invention provides a destination storage means that stores the location of a destination, a map data storage means that stores map data in advance, and a point that is stored as data corresponding to each point on the road. Provided is a route search device comprising a data storage means, a search means for storing the shortest distance route from the destination to each point in the point data storage means, and an output means for outputting the search results of the search means. It is.

Effects According to the above configuration, in order to memorize the shortest distance route from the destination to each point on the road, if the search is performed based on the destination only once at the beginning, even if the route is deviated from the planned travel route. The shortest distance route from the current location to the destination can always be outputted.Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a route searching device according to a first embodiment of the present invention. In the figure, 101 is a destination storage means for storing the location of the destination, 102 is a map data storage means for storing map data in advance, and 103 is a point data storage such as a RAM for storing data corresponding to each point on the road. A storage means 104 is a search means, which stores the shortest distance route from the destination to each point in the point data storage means 103 using, for example, a CPU. Reference numeral 106 denotes an output means, such as a display, for outputting the search results of the search means 104.

The operation of the route searching device of the first embodiment configured as described above will be described below.

The destination storage means 101 inputs and stores the location of the destination to be searched for. The map data storage means 102 stores map data necessary for route searching in advance. The point data storage means 103 stores search result data of the search means 104 corresponding to each point on the road. The search means 104 inputs the destination stored in the destination storage means 1o1, and based on the destination, the search means 104 inputs the destination from the map data storage means 102, which is used to perform a route search based on the destination. Read map data. Then, the shortest distance route from the destination to each of the points is searched, and the search results are stored in the point data storage means 103.

The output means 106 outputs the search results of the search means 104.

As described above, according to the first embodiment, the search means 104 stores the shortest route from the destination to each point on the road.
By providing this, the shortest route can always be output from any point on the road even when the shortest route from the starting point a to the destination is deviated from the shortest route by performing the search once.

FIG. 2 shows a schematic flowchart when the operation of the first embodiment is realized by software. First, in step 201, the location of the destination of the route to be searched is input and stored, and in step 202, map data used for route searching based on the destination is read out. Next, in step 203, the shortest route from the destination to each point on the road is searched for and stored in correspondence with each point. Further, when a search based on the destination has already been performed, the shortest distance route stored at the time of the search corresponding to the point corresponding to the current location of the vehicle is read out. In step 204, the search results obtained in step 203 are output. Step 205 inputs the current location and passes it to step 203.

Next, the search step 203 will be explained in more detail using the flowchart of FIG. Said step 20
Based on the destination location stored in step 1, the map data read in step 202, and the vehicle's current location input in step 206, the destination and current location are input in step 301, and judgment 302 is made. In step 303, it is determined whether a search has already been performed based on the destination, and if the search has not been performed, the destination is set as a reference point for the search in step 303, and a road is set as the reference point in step 304. Find the point where it connects. And judgment 306
In step 306, it is determined whether the distance reached from the destination to the connected point is the shortest distance so far, and if it is the shortest distance so far, in step 306, the search is carried out corresponding to the connected point. The basic point and the distance reached are memorized. Further, if the reachable distance is not the shortest distance so far, step 306 is not performed. Next, in decision 307, it is determined whether all the points connected to the reference point have been investigated, and if the investigation has not been completed, the process returns to step 304. If the investigation has been completed, it is determined in step 308 whether the current point is a reference point, and if it is not a reference point, in step 309 the current point is selected among the connected points that have not yet become a reference point. The point with the shortest reachable distance from the destination is set as the next reference point, and the process returns to step 304. If the search has been completed, a route from the current location to the destination is created based on the stored search results in step 310, and step 203 is completed. Further, if the search has already been performed based on the destination in the judgment 302, a route from the current point to the destination is created in step 310 and the step 203 is ended.Next, in the search step 203 An example of the data format handled and an example of step 310 will be explained using FIG. 4. 401 is a point number storage area for storing points on the road as numbers;
402 is a reference point number storage area that stores the point number of the reference point corresponding to each point number in the point number storage area 401, and 403 is a shortest distance storage area that stores the shortest distance from the destination to the point number. It is. For example, when point number 1 is the destination point, 0 is written in the reference point number storage area 402 corresponding to point number 1 in the point number storage area 401, and O(m
). Furthermore, if the point number to connect from point number 1 and the reachable distance from the destination point are point number 2 and reachable distance 30 (m), point number 3 and reachable distance 6o (m),
A reference point number 1 is stored in the reference point number storage area 402 corresponding to the point number 2 in the point number storage area 401, and a reachable distance of 30 (m) is stored in the shortest distance storage area 403. Further, the reference point number 1 is stored in the reference point number storage area 402 corresponding to the point number 3 in the point number storage area 401, and the reachable distance so(m) is stored in the shortest distance storage area 403.
). In this way, the searched results are stored, and in step 310, the location number of the vehicle's current location in the location number storage area 401 is sequentially stored in the reference location storage area 402.
The shortest distance route can be found by repeating the procedure of reading the reference point number of , and searching the point number of the read reference point number from the point number storage area 401 again until the destination point is reached.

Next, an example of the output at step 204 will be explained using FIG. 6. 601 is the starting point where the route search was performed, 502
is the destination point of the search. 503 is a display showing the shortest distance route from the starting point to the destination point, 504 is the trajectory the vehicle has traveled, 605 is the intersection where the vehicle took the wrong route, 606 is the current location of the vehicle, and 507 is the shortest distance displayed again It is a distance route. Since the vehicle that has traveled along the shortest distance route 603 from the starting point 601 leaves the shortest distance route 603 at the intersection 606, the shortest distance route 603 is no longer the shortest distance route from the current point 50el to the destination point 502. By displaying again the shortest distance route 507, which is the shortest distance route from the current point 606 to the destination point 602, based on the current point 606, the shortest distance route to the destination point can always be shown.

In addition, in the first embodiment, the shortest distance route is determined based on the distance between each point, but the shortest distance route is determined based on the travel time between each point, or the shortest distance route is determined based on the travel time between each point. A second embodiment may be adopted in which the optimum driving route is determined based on the ease of driving on the road. Also, the search method is the first
Methods other than those described in the embodiments may be used.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, in order to store the shortest route from a destination to each point on a road,
By performing a search based on the destination only once, the shortest distance route from the current location to the destination can always be output even if the vehicle deviates from the planned travel route.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a route searching device according to a first embodiment of the present invention, FIG. 2 is a schematic flowchart showing the operation of the embodiment, FIG. 3 is a flowchart showing an example of a search routine of the embodiment, and FIG. The figure is a configuration diagram of data during a search in the same device, and FIG. 5 is an output diagram for explaining the output in the same device.
・Map data storage means, 103...point data storage means, 104...search means, 105...-
...Output means.

Claims (2)

[Claims] (1) Destination storage means that stores the location of the destination, map data storage means that stores map data in advance, point data storage means that stores data corresponding to each point on the road, and this point data storage. A route search device comprising: a search means for storing the shortest distance route from the destination to each of the points; and an output means for outputting a search result of the search means. (2) The route search device according to claim 1, wherein the search means stores the optimum route from the destination to each point on the road in the point data storage means.