JP2917825B2 - Route selection method and system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route selection system, and more particularly, to a system for automatically selecting an optimum route between a starting point and a destination designated on a map.

[0002]

2. Description of the Related Art In recent years, with the development of electronic technology, a navigation system for guiding a vehicle has been rapidly spreading. By the way, in a conventional navigation system, an optimum route from a starting point to a destination (for example, a shortest distance reaching route or a minimum time reaching route).
Some are equipped with a route selection system for automatically selecting a route.

In a conventional route selection system, as a method of obtaining an optimum route for guiding a vehicle, there is, for example, an automatic vehicle guidance method disclosed in Japanese Patent Application Laid-Open No. S59-105113. In this method, an optimal route between a departure point and a destination point is obtained from data representing a road network by using the Dijkstra method, which is one of the optimal route determination methods. The theory of the Dijkstra method is described in, for example, A. V. This is shown in "Data Structures and Algorithms", written by Aiho et al. And translated by Yoshio Ohno, published by Baifukan Co., Ltd., 1990, pp. 179-183.

[0004] In order to reduce the calculation time, a search is performed using map data having a hierarchical structure as in a route search method disclosed in Japanese Patent Application Laid-Open No. 2-56591, for example, and an optimum route is determined. There is also a way to ask.

[0005]

However, as described above, when searching for the optimal route between any two points on the network, the more the number of intersections and the number of roads included in the network, the greater the number of routes. The time to seek is increased. As a result, the waiting time of the user becomes longer (2 to 3 minutes), and the usability is deteriorated. Further, the road network data generally provided has a detailed road network and an enormous amount of data (several Gbytes), and finding a route using this data as it is is difficult to realize on a vehicle-mounted device. there were.

[0006] In order to reduce the route selection time,
It is conceivable to select a route using thinned-out coarse road network data (for example, road network data excluding general roads other than national roads and expressways) (for example, Japanese Patent Laid-Open No. 2-5).
No. 6591), the details of the required route are reduced as compared with the case where detailed road network data is used, and inconvenience occurs when guiding the route (for example, a road other than a national road or an expressway that should be passed) Became unknown).

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a route selection method and system capable of greatly shortening a search time for an optimum route. Another object of the present invention is to provide a route selection method and system that can significantly reduce the search time for an optimum route without deteriorating the details of the route to be selected.

[0008]

The invention according to claim 1 is
This is a method for selecting an optimal route on a map. In an original data describing a detailed road network, intersections satisfying predetermined conditions are integrated into one intersection, thereby reducing the number of intersections. A first step of creating route selection data, and a second step of searching for an optimal route between the designated departure point and destination using the route selection data.

According to a second aspect of the present invention, in the first aspect of the present invention, the route selection data is obtained by integrating the intersection with the road network data describing the road network after intersection integration. The second step includes a case where the optimum route found by searching is passed through an intersection in which a link that has been deleted but actually passes is recorded according to the relationship between the entering and exiting links. ,
It is characterized in that the deleted link is supplemented with the corresponding passing link recorded in the passing link table.

According to a third aspect of the present invention, in the second aspect of the present invention, when there is a traffic regulation extending over a plurality of intersections in the actual road network, the first step is to set those intersections on the original data to one. It is characterized in that the traffic link is imposed on the intersection integrated in connection with traffic regulation in the passage link table.

According to a fourth aspect of the present invention, in the second aspect of the present invention, an evaluation value when passing through the integrated intersection is recorded in the passage link table for each relationship between the entrance and exit links. The second step is to search for an optimal route by reading a passage evaluation value corresponding to the approaching / exiting direction from the passage link table and referring to the integrated intersection.

According to a fifth aspect of the present invention, in the second aspect of the present invention, further, the traffic information provision number for the integrated intersection is recorded in the passing link table for each relationship between the entrance and exit links. The second step is characterized in that an optimum route is searched for in consideration of traffic information provided corresponding to the traffic information providing number.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the road network described in the original data is divided into predetermined regions, and traffic information is provided for each of the regions. In the road network data in the route selection data, if there is an intersection integrated beyond the boundary of the predetermined area, the passing link table,
In addition to the traffic information provision number corresponding to the area to which the intersection belongs after the integration, the traffic information provision number corresponding to the area to which the intersection belongs before the integration is also recorded.

According to a seventh aspect of the present invention, in the first aspect, when a plurality of roads exist between two adjacent intersections due to the integration of the intersections, these roads are connected. It is characterized in that it is integrated into one road.

The invention according to claim 8 is a system for selecting an optimal route on a map, wherein the data is created from original data describing a detailed road network, and is determined in advance in the original data. The intersections satisfying the specified conditions are integrated into one intersection, and the route selection data storage means for storing the route selection data with the reduced number of intersections, and the designated route selection data are used. An optimal route searching means for searching for an optimal route between the departure place and the destination.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, the route selection data is obtained by integrating the intersection with the road network data describing the road network after intersection integration. The optimal route searching means includes a passing link table that records deleted but actually passing links for each relationship between the entering and exiting links, and the optimal route searching means passes through an intersection where the searched and obtained optimal routes are integrated. , The deleted link is supplemented with the corresponding passing link recorded in the passing link table.

According to a tenth aspect of the present invention, in the invention of the ninth aspect, when traffic restrictions over a plurality of intersections are present in the actual road network, the intersections on the original data are one in the route selection data. At one intersection,
The passage link table records that traffic regulation is imposed on intersections integrated in connection with traffic regulation.

According to an eleventh aspect of the present invention, in the ninth aspect of the present invention, an evaluation value when passing through the integrated intersection is recorded in the passage link table for each relationship between the entrance and exit links. The optimal route searching means searches an integrated route by reading a pass evaluation value corresponding to the approach / exit direction from the pass link table and referring to the optimum route.

According to a twelfth aspect of the present invention, in the ninth aspect of the present invention, further, the traffic information provision number for the integrated intersection is recorded in the passing link table for each relationship between the entrance and exit links. The optimal route search means
An optimal route is searched for in consideration of traffic information provided corresponding to the traffic information provision number.

According to a thirteenth aspect, in the twelfth aspect, the road network described in the original data is divided into predetermined regions, and traffic information is provided for each of the regions. If there is an intersection integrated beyond the boundary of the predetermined area in the road network data in the route selection data, the transit link table stores the traffic corresponding to the area to which the intersection belongs after the integration. In addition to the information provision number, the traffic information provision number corresponding to the area to which the intersection belongs before integration is also recorded.

According to a fourteenth aspect of the present invention, in the invention of the eighth aspect, when a plurality of roads are present between two adjacent intersections by integrating the intersections in the route selection data, these roads It is characterized by being integrated into one road.

[0022]

In the invention according to claim 1 or 8, route selection data is created from the original data describing the detailed road network by an intersection integration operation, and the departure point and the departure place are determined using the route selection data. The best route to the destination is searched for. As a result, the number of intersections on the map is reduced, the number of intersections for performing a route search is also reduced, and the time for selecting a route is greatly reduced.

In the invention according to claim 2 or 9,
If the links that were deleted due to the integration of the intersection but are actually passing are recorded in the passing link table for each entry / exit link relationship and the optimal route found by searching is passed through the integrated intersection, The deleted link is read from the passing link table and supplemented. Thereby, when displaying and guiding the route in the integrated intersection in detail, the road that passes is clarified.

According to the third or tenth aspect of the present invention, when there is a traffic regulation extending over a plurality of intersections in an actual road network, those intersections on the original data are integrated into one intersection, and the traffic data is stored in the passing link table. , for an intersection which is the integration, and to record the fact that the above traffic regulations are imposed, whereby conventionally can record traffic regulation which could not come representation on the original data,
By selecting a route according to the information, it is possible to select a route more suited to the actual situation.

In the invention according to claim 4 or 11, the evaluation value when passing through each integrated intersection is recorded in the passing link table for each of the relations of the entrance and exit links, and the integrated intersection is routed. When searching,
The pass evaluation value corresponding to the approach / exit direction is read from the pass link table and is referred to. As a result, the passage evaluation value in the integrated intersection can be accurately reflected in the route search.

In the invention according to claim 5 or 12, the traffic information provision number for the integrated intersection is
The information is recorded in the passing link table for each relationship between the entering and exiting links, and the optimum route is searched in consideration of the traffic information provided corresponding to the traffic information providing number. As a result, it is possible to search for an optimal route reflecting traffic information.

[0027] In the invention according to claim 6 or 13, in the road network data in the route selection data, there is an intersection integrated beyond a predetermined area boundary (traffic information provision range). In addition, in addition to the traffic information provision number corresponding to the area to which the intersection belongs after the integration, the traffic information provision number corresponding to the area to which the intersection belongs before the integration is recorded in the passing link table. Thereby, even if there is an integrated intersection beyond the provision range of the traffic information, the traffic information can be accurately reflected in the selection of the optimal route. Conversely, a plurality of intersections can be integrated into one regardless of the unit of traffic information provision.

In the invention according to claim 7 or 14, when a plurality of roads exist between two adjacent intersections by integrating the intersections, these roads are integrated into one road. This reduces the number of roads on the map and the number of roads on which to search for routes,
The time for selecting a route can be further reduced.

[0029]

FIG. 1 is a block diagram of a route selection system according to an embodiment of the present invention. In FIG. 1, a route selection system according to the present embodiment includes a position detection data storage device 1,
A position detection device 2, a traffic information input device 3, a route selection data storage device 4, a point input device 5, an optimal route search device 6, a map display data storage device 7, a map display device 8, And an output device 9.

The position detecting data storage device 1 is a CD-R
It includes a recording medium such as an OM, and stores position detection data describing a detailed road network used to detect the current position of the vehicle. The position detecting device 2 obtains the approximate position and trajectory of the vehicle using the speed of the vehicle, the turning angle, and radio waves (GPS) from a satellite, and further obtains the position of the vehicle stored in the position detecting data storage device 1. By referring to the data, the current position of the car is obtained accurately. Traffic information input device 3
Includes a receiver, a modem, and the like, receives traffic information transmitted by radio waves, telephone lines, and the like, and inputs the traffic information to the optimum route search device 6. The route selection data storage device 4 includes a recording medium such as a CD-ROM, and stores route selection data used for selecting an optimal route. The route selection data includes road network data and data indicating the correspondence between the traffic information input from the traffic information input device 3 and the road. The point input device 5 operates in response to a user's operation, and inputs a destination for which a route is required to the optimum route search device 6 (if necessary, also inputs a departure place).

The optimum route search device 6 uses the route selection data stored in the route selection data storage device 4 and the traffic information input from the traffic information input device 3 to move from the departure place to the destination. Find the optimal route. As the departure point, the current position of the vehicle detected by the position detection device 2 or the departure point information input from the point input device 5 is used. In addition, destination information input from the point input device 5 is used as the destination.

The map display data storage device 7 includes a CD-R
Including recording media such as OM, the shape of roads and land on the map,
It stores map display data including shapes of ports, rivers, and parks. The map display device 8 refers to the map display data stored in the map display data storage device 7, so that the current position of the car obtained by the position detection device 2 and a map in the vicinity thereof, or the user's request. Generate image data for displaying a map of the range. In addition, the map display device 8
If the range to be displayed includes the route obtained by the optimum route searching device 6, the image data is also generated. Further, the map display device 8 provides guidance information for guiding the vehicle based on the current position of the vehicle and the selected optimum route (for example, voice information such as “Please turn right at an intersection 100 m ahead” and And / or display information). The output device 9 includes a display, a speaker, and the like, and displays and audio-outputs image data and audio information provided from the map display device 8.

Next, the position detection data, the route selection data, and the map display stored in the position detection data storage device 1, the route selection data storage device 4, and the map display data storage device 7 of FIG. 1, respectively. A method for creating the application data will be described. FIG. 2 is an explanatory diagram relating to the creation of these data.

In FIG. 2, the original data storage device 21 stores the original data for creating the position detection data, the route selection data, and the map display data. As the original data, for example, map data provided by the Japan Digital Road Map Association (DRMA) is used. The map data provided by this DRMA includes road networks,
Topography, facility shape, correspondence between roads and traffic information, and the like are included. In the road network on the DRMA map data, in order to reduce the data amount, the actual road shape (for example, see FIG. 3A) is determined based on the center line of the road.
It is vectorized and recorded as one line (Fig. 3
(B)). Here, roads that are independent of each other in the traveling direction (for example, an interchange as shown in FIG. 4, a road where the upper and lower lines are slightly separated from each other such as an expressway, a toll road, and their side roads, Overpasses, etc.) are recorded as separate roads. In addition, the positions and shapes of roads are recorded in detail for use in position detection and map display. Further, for a road to which traffic information is provided (for example, a road network as shown in FIG. 5 (A)), as shown in FIG. 5 (B), the road is associated with a provision number of the corresponding traffic information. Data is recorded.

The position detection data stored in the position detection data storage device 1 is obtained by processing data on a road network included in the original data stored in the original data storage device 21 by a position detection data creation process 22. It is created by doing. That is, position detection data creation processing 2
2 creates position detection data with reference to the connection relationship and shape of roads, the coordinates of intersections, and the like. At this time, the position and shape of the road are recorded in detail without omission, and are used when the position detection device 2 compares the traveling locus of the vehicle with the position coordinates. As a result, the current position can be calculated more accurately.

The map display data stored in the map display data storage device 7 includes data such as terrain, facilities and roads, and place names included in the original data stored in the original data storage device 21. It is created by processing by the map display data creation process 23.

The route selection data stored in the route selection data storage device 4 includes road network data used when selecting a route, and data indicating the correspondence between roads and traffic information. The route selection data is created by processing the original data stored in the original data storage device 21 by the route selection data creation process 24.
Hereinafter, a method of creating road network data in route selection data will be described first, and then a method of creating data indicating a correspondence between roads and traffic information will be described.

First, a method of creating road network data included in route selection data will be described in detail. This road network data is data used when the optimum route search device 6 selects a route from the departure point to the destination, and is data relating to the road network included in the original data stored in the original data storage device 21. Is created by referring to road connection relations, intersection positions, and the like. However, in order to create the above-described position detection data (stored in the position detection data storage device 1) and the like, the positions of roads and intersections must be accurate in the original data. As described above, it is vectorized to reduce the amount of data. Therefore, when selecting a route, a single intersection may be used, but a plurality of intersections are configured as shown in FIG. If the road network of this detailed original data is recorded as it is as route selection data, it takes a long time to search due to the large number of intersections and roads,
The amount of data to be recorded increases. Therefore, in the route selection data creation processing 24, processing for reducing the number of intersections (nodes) and the number of roads (links) from the road network of the original data is performed. That is, route selection data creation processing 2
No. 4 is recorded as a plurality of nodes and links on the original data, but is converted as one node and link from a node and a link which a human usually judges to be one, and then recorded as route selection data. This conversion method will be described in detail below.

First, in a first conversion process, a plurality of adjacent nodes are combined into one. This means that, as shown in FIG. 6 (A), of nodes recorded in the original data, nodes connected and connected to each other by a link are integrated into one node as shown in FIG. 6 (B). It is performed by

Next, in the second conversion processing, the links connecting the two nodes are combined into one. This is because, as a result of integrating the nodes, when there are a plurality of links connecting the two nodes (see FIG. 6B), the link corresponding to the vertical line of the road is changed to one as shown in FIG. 6C. This is done by integrating it into a book.

Next, in a third conversion process, a passing link table is created that can determine what links have been omitted due to the integration of intersections based on the relationship between the incoming links and the outgoing links to the nodes. For example, it is assumed that an intersection as shown in FIG. 7A exists in the original data and the intersection is integrated as shown in FIG. 7B. In this case, as shown in FIG. 7 (C), a link to be passed in the integrated node is specified based on a relationship between a link entering the integrated node and a link exiting after passing through the node. Record it. According to the passing link table, for example, when entering the intersection from link A and exiting to link F, the links passing through the integrated node are a and b, and the order of the passing links is A → a → It can be seen that b → F.

Next, in the fourth conversion processing, the cost when using the passing link (for example, when obtaining the minimum time reaching route, the time required for passing, the shortest distance reaching route, When it is obtained, the distance when the vehicle passes) is recorded. That is, for example, in the passing link table of FIG.
When recording a passing link from the relationship of the exit link,
The cost required to pass through each passing link is calculated, and the total time required for the passing link is calculated.
Then, similarly to the passing link, the cost required for the passing link is also recorded in the passing link table in correspondence with the combination of the entrance / exit link. This makes it possible to derive the time required for passing the links omitted due to the integration from the relationship between the incoming link and the exit link at the integrated node when selecting the optimum route.

As described above, the route selection data also includes data indicating the correspondence between traffic information and roads, in addition to the road network data created by the first to fourth conversion processes. A method for creating this data will be described below.

In the above-mentioned original data, the correspondence between traffic information and links corresponds to, for example, the relationship between the start node and the end node of a link in a road network as shown in FIG. The traffic information provision number is recorded (see FIG. 5B). The traffic information provides information such as the degree of traffic congestion, travel time, and traffic regulation for the road with the provided number, as shown in FIG. 5C, for example. Then, for each link of the road network data included in the route selection data, the correspondence relationship with the traffic information provision number is also referred to by referring to the correspondence data in the original data (see FIG. 5B). Is created.

Here, the original data and the traffic information are divided according to a certain condition (for example, a secondary mesh unit [longitude 7 minutes 30 seconds, latitude 5 minutes unit]) due to a problem of data amount, and each of them is divided into a certain area. Recorded and provided for each area. However, the road network data included in the route selection data may exceed the boundary of the certain area when the nodes and links are integrated.

For example, in a road network as shown in FIG. 8A, if a plurality of nodes and links are integrated without straddling the boundary of the area included in the original data, the route selection data is The data is as shown in FIG. However, in a road network such as that shown in FIG.
When a plurality of nodes and links are integrated, the integrated road network is as shown in FIG. Accordingly, the provision number of the traffic information relating to the link omitted by this integration is also recorded for the area adjacent to the original area, and the data for route selection is made as shown in FIG. 8D. Thus, even if the area where the node or link is recorded moves to the next for integration, the shortest route can be selected using the traffic information without fail.

FIGS. 9 to 12 are flowcharts showing the operation of the route selection system shown in FIG. The route selection operation in the route selection system of FIG. 1 will be described below with reference to FIGS. Here, as an example, a method of selecting a route that has the shortest travel time from the current position of the car to the destination input by the user based on traffic conditions will be described.

First, the optimum route search device 6 inputs the position coordinates (longitude, latitude) of the destination from the point input device 5 in response to the operation of the user (step S101). Next, the optimum route searching device 6 inputs the coordinates (longitude and latitude) of the current position of the vehicle and the traveling direction of the vehicle from the position detecting device 2 (step S102). Next, the optimum route search device 6
Executes a route selection process from the current position of the car to the destination (steps S103 to S106).

In the above route selection processing, the optimum route search device 6 sets a range in which the shortest route from the departure place to the destination may pass (usually, a rectangular range including the departure place and the destination is assumed). The road network data and the traffic information corresponding data for each predetermined range existing in the data are read from the route selection data storage device 4 and stored in an internal memory (not shown) (step S103). Next, the optimum route searching device 6
The traffic information provision number and the traffic information data corresponding to the traffic information provision number are input from the traffic information input device 3 for each predetermined range (step S104). Next, the optimum route search device 6 passes through each link of the road network data based on the traffic information data input from the traffic information input device 3 and the traffic information corresponding data read from the route selection data storage device 4. Then, the travel time required to perform the operation is calculated, and the calculated travel time is associated with each link and stored in the internal memory (step S105).

Using the road network data reflecting the traffic information stored in the internal memory as described above, the optimum route searching device 6 checks the link where the car is currently traveling from the coordinates of the current position and the traveling direction. Then, using this link as a starting point, a route that minimizes the travel time to a link near the coordinates of the destination is searched (step S106). The route search processing in step S106 is performed using a shortest route search method such as the Dijkstra method which is conventionally known,
The details are shown in FIG.

Referring to FIG. 10, optimal route searching device 6
First, an initial setting is performed (step S201). That is, the departure place is set as the reference node, the destination is set as the destination node, and it is set that there is no reaching link to the reference node. Next, the optimum route searching device 6 determines whether or not the reference node is the target node (Step S20)
2). Initially, the origin is the reference node, so the reference node cannot be the destination node. Therefore, the optimum route search device 6 investigates a link that can proceed from the departure place,
One of them is selected (step S203). Next, the optimal route search device 6 calculates the arrival cost from the departure point for the node located at the tip of the link selected in step S203 (hereinafter, called the arrival node) (step S204). Next, the optimum route searching device 6
It is determined whether the calculated arrival cost is the minimum cost among the arrival costs calculated so far for the destination node (step S205). First, since the arrival cost to each arrival node is calculated for the first time, step S
The determination at 205 is, of course, YES. Therefore, the optimum route searching device 6 records the calculated arrival cost to the arrival node and the calculated link from the starting point to the arrival node (arrival link) in the internal memory (step S206).

Next, the optimum route searching device 6 determines whether or not unselected links remain among the links that can travel from the departure place (step S207). If there remains any unselected link, the optimum route searching device 6 returns to the operation of step S203 again. That is,
The optimum route searching device 6 selects any one of the remaining links, and executes the calculation and recording process of the arrival cost (steps S203 to S207).

When the processing of steps S203 to S207 is repeated and the calculation of the arrival cost to each destination node is completed for all the links that can travel from the departure point,
The optimum route searching device 6 sets, as a next reference node, a node that has not reached the reference node but has the lowest arrival cost among the nodes whose arrival costs have already been calculated (step S208). Initially, the target node is located at the end of each link that can enter from the departure point. Therefore, the node having the lowest arrival cost among these reachable nodes is set as the next reference node. Next, the optimum route searching device 6 determines whether or not the reference node has been set in step S208 (step S20).
9). If the reference node is not set for some reason, the optimum route searching device 6 determines that the route search has failed (step S210), and returns to the main routine of FIG. Thereafter, the optimum route searching device 6 displays on the output device 9 via the map display device 8 that the route search has failed (step S107), and ends the operation.

On the other hand, if the reference node has been set, the optimum route searching device 6 returns to the operation of step S202, and executes the processing of steps S203 to S209 for the newly set reference node. Hereinafter, the operation when an arbitrary node located between the departure place and the destination is set as the reference node will be described in more detail.

First, it is determined that the current reference node is not the target node (step S202), a link that can proceed through the reference node from the links reached by the reference node is examined, and one of them is selected (step S202). Step S203). Here, each node on the map is
When the shortest route from the place of departure to that node is determined,
Set as reference node. The arrival link of the reference node means a link that is located on the shortest path from the departure place to the reference node and that is directly connected to the reference node. Next, the optimum route search device 6 calculates the cost of reaching the destination node located at the tip of the destination link selected in step S203 (step S203).
204). Details of the cost calculation processing in step S204 are shown in FIG.

Referring to FIG. 11, optimal route searching device 6
Determines whether the current reference node is an integrated node (step S301). For this integration process,
Since the details have been described with reference to FIGS. 2 and 6 to 8, the description thereof is omitted here. If the current reference node is not an integrated node, the optimum route searching device 6 uses the general cost for moving from the reference node to the traveling link (the link from the reference node to the destination node) as the passing cost of the reference node. It is set (step S302). on the other hand,
In the case where the current reference node is an integrated node, the optimum route searching device 6 sets a reaching link to the reference node as an incoming link, and sets a traveling link from the reference node as an exit link, and FIG. With reference to the passing link table shown in FIG. 8C or FIG. 8D, a passing cost in the integrated reference node is searched (step S303). Next, the optimum route searching device 6 determines the minimum arrival cost (already calculated and recorded in the internal memory) from the departure place to the current reference node, and the passing cost of the reference node (in the above step S302 or S303). What was requested)
And the traveling cost of the traveling link are added to calculate the arrival cost to the arrival node (step S304). Thereafter, the optimum route searching device 6 returns to the route search processing routine of FIG.

Referring again to FIG. 10, optimal route searching device 6 determines whether the arrival cost calculated in step S204 is the smallest of the arrival costs calculated so far for the destination node. It is determined whether or not there is (Step S205). If the calculated arrival cost is the minimum cost so far, the optimum route searching device 6 calculates the arrival cost of the arrival node stored in the internal memory in step S2.
04 is rewritten to the arrival cost calculated, and the reaching link to the reaching node is rewritten to the link from the current reference node to the reaching node (step S20).
6). On the other hand, if the calculated arrival cost is not the minimum cost thus far, the optimum route searching device 6 proceeds to the process of step S207 without rewriting the arrival cost and the arrival link of the arrival node.

Next, the optimum route searching device 6 determines whether or not unselected links remain among the links that can proceed from the current reference node (step S20).
7) If there are unselected links, the processes of steps S203 to S207 are repeated for the remaining links. When the calculation of the reaching cost to each reaching node is completed for all the links, the optimum route searching device 6 has the lowest reaching cost among the nodes that are not the reference nodes but have already calculated the reaching costs. The node is set as the next reference node (step S20)
8). Next, the optimum route searching device 6 performs the above-described step S2
In step 08, it is determined whether or not a reference node has been set (step S209).
Returning to the operation of step 2, the processes of steps S203 to S209 are executed for the newly set reference node.

When the newly set reference node is the target node, the optimum route searching device 6 executes a route configuration process in step S211. This route configuration process is a process of determining the shortest route from the departure place to the destination by going back from the destination side, and details thereof are shown in FIG.

Referring to FIG. 12, optimal route searching device 6
First, the target node is set as the recording node, and the used link is set to none (step S401). Next, the optimum route searching device 6 records the recording node in the route result configuration area of the internal memory (at first, the target node is recorded as the recording node). Next, the optimum route searching device 6
It is determined whether or not the current recording node is a departure place (step S403). If the recording node is not the departure point, the optimum route search device 6 searches the arrival link of the current recording node with reference to the internal memory (step S404). Next, the optimum route searching device 6 determines whether or not the current recording node is the integrated recording node (step S40).
5). If the current recording node is not the integrated recording node, the optimum route searching device 6 records the arrival link of the recording node searched in step S404 in the route result configuration area of the internal memory (step S406). Next, the optimum route search device 6 records the other node connected to the arrival link as the next recording node, and the arrival link as the use link of the next recording node in the route result configuration area of the internal memory. (Step S407). After that, the optimum route searching device 6 returns to the operation of Step S402.

On the other hand, if the current recording node is an integrated recording node, the optimum route searching device 6 sets the arrival link of the current recording node as the incoming link and sets the used link as the exit link (step S408). ). Next, the optimum route searching device 6 determines whether the optimal route
With reference to the passing link table shown in (D), a search is made for a passing link in the integrated recording node from the relationship between the entering link and the exit link (step S409). Next, the optimum route searching device 6 records the found passing link in the route result configuration area of the internal memory (Step S41).
0). Thereafter, the optimum route searching device 6 proceeds to step S40.
Proceed to step 6.

By repeating the operations of steps S402 to S410, that is, by tracing the arrival link of each node from the destination node, the shortest route from the departure point to the destination is constructed. Then, when the recording node coincides with the departure place, the optimum route searching device 6 ends the route configuration processing of FIG. 12 and returns to the route search processing routine of FIG. Then, the optimum route search device 6
Returns to the main routine of FIG. 9, displays the shortest route search configured on the output device 9 via the map display device 8 (step S107), and ends the operation.

FIG. 13 is a diagram illustrating a road network which is preferably integrated when generating route selection data from original data. In FIG. 13A, roads extending at a certain interval or less are integrated into one road. In FIG. 13B, intersections existing within a certain range (within a dotted line) are integrated. In FIG. 13C, an interchange or a ramp is integrated. In FIG. 13D, junctions are integrated. In FIG. 13E, intersections having the same name are integrated.

In FIG. 13 (F), by integrating intersections with special traffic regulations that cannot be expressed by the original data, the traffic regulations can be expressed. For example, in the road network before integration shown in FIG. 13 (F), the road is advanced from the lower road extending in the vertical direction to the upper road,
It is prohibited to make a right turn from the lower road to a road extending in the left-right direction. In the original data, since each road is vectorized and stored, it is not possible to express the traffic regulation over a plurality of intersections as described above. On the other hand, in the route selection data, as shown in FIG. 7C, the relationship between the incoming link and the outgoing link for the integrated intersection is described in the passing link table, so that the route extends vertically. By not writing in the above-mentioned passage link table the relationship of setting the road below the road as the entry link and setting the road on the right side of the road extending in the left and right direction as the exit link, or setting a flag indicating prohibition of progress. , The traffic regulation can be expressed.

In the above embodiment, it has been described that the Dijkstra method is used in the optimum route searching device 6.
Other route search methods may be used. Further, the route selection data is read from the route selection data storage device 4 before the search is performed. However, the data may be read while searching, or may be searched without limiting the range in advance.

[0066]

According to the first or eighth aspect of the present invention, route selection data is created from an original data describing a detailed road network by an intersection integration operation, and departure is performed using the route selection data. Since the optimal route between the destination and the destination is searched, the number of intersections on the map is reduced, and the number of intersections for performing the route search is also reduced, so that the time for selecting a route can be greatly reduced. .

According to the second or ninth aspect of the present invention, the links which have been deleted due to the integration of the intersection but which actually pass through are recorded in the passing link table according to the relationship between the entering and exiting links and searched. When the obtained optimal route passes through the integrated intersection, the deleted link is read from the passing link table and compensated.
The route within the integrated intersection can be displayed and guided in detail.

According to the third or tenth aspect of the present invention, when there is a traffic regulation extending over a plurality of intersections in an actual road network, those intersections on the original data are integrated into one intersection, and the traffic data is stored in the passing link table. Records the fact that the above traffic regulation is imposed on the integrated intersection, so that traffic regulation that could not be expressed on the original data can be recorded. As a result, according to the recorded traffic regulation information, a more realistic route can be selected.

According to the fourth or eleventh aspect of the present invention, an evaluation value when passing through each of the integrated intersections is recorded in the passing link table for each of the entrance and exit links, and the integrated intersection is routed. When the search target is used, the pass evaluation value corresponding to the approach / exit direction is read from the pass link table and referred to, so that the pass evaluation value in the integrated intersection is accurately reflected in the route search. be able to.

According to the fifth or twelfth aspect of the present invention, the traffic information provision number for the integrated intersection is recorded in the passing link table for each of the entry and exit links, and the traffic information provision number corresponding to the traffic information provision number is recorded. The optimal route is searched in consideration of the traffic information provided by the user, so that the optimal route reflecting the traffic information can be searched.

According to the sixth or thirteenth aspect of the present invention, in the road network data in the route selection data, there is an intersection that is integrated beyond a predetermined area boundary (a traffic information providing range). , In addition to the traffic information provision number corresponding to the area to which the intersection belongs after the integration, the traffic information provision number corresponding to the area to which the intersection belongs before the integration,
Since the information is recorded in the passing link table, the traffic information can be accurately reflected on the selection of the optimum route even at such an intersection. Conversely, a plurality of intersections can be integrated into one regardless of the unit of traffic information provision.

According to the seventh or fourteenth aspect of the present invention, when a plurality of roads exist between two adjacent intersections by integrating the intersections, these roads are integrated into one road. , Fewer roads on the map,
The number of roads on which a route search is performed is also reduced, and the time for selecting a route can be further reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a route selection system according to one embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of creating position detection data, route selection data, and map display data used in the route selection system of FIG. 1;

FIG. 3 is a diagram for explaining an example of a representation form of a road network in original data.

FIG. 4 is a diagram exemplarily showing types of roads represented as different roads in original data.

FIG. 5 is a diagram for explaining a relationship between a traffic information provision mode and a recording mode of a traffic information provision number in original data.

FIG. 6 is a diagram illustrating an example of an operation of integrating road networks included in original data in the present invention.

FIG. 7 is a diagram for explaining a relationship between a passing link table included in route selection data used in the embodiment of FIG. 1 and a road network on original data.

FIG. 8 is a diagram for explaining the relationship between a road network on original data and a passing link table integrated across adjacent areas.

FIG. 9 is a flowchart for explaining the operation of the route selection system of FIG. 1;

FIG. 10 is a flowchart showing a detailed operation of subroutine step S106 in FIG. 9;

FIG. 11 is a flowchart showing a detailed operation of subroutine step S204 in FIG. 10;

FIG. 12 is a flowchart showing a detailed operation of a subroutine step S211 in FIG. 10;

FIG. 13 is a diagram exemplarily showing a road network which is preferably integrated in the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 position detection data storage device 2 position detection device 3 traffic information input device 4 route selection data storage device 5 point input device 6 optimal route search device 7 map display data storage device 8 map display Device 9 ... Output device 21 ... Original data storage device 22 ... Position detection data creation process 23 ... Map display data creation process 24 ... Route selection data creation process

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-165406 (JP, A) JP-A-6-119562 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01C 21/00

Claims (14)

(57) [Claims] 1. A method for selecting an optimal route on a map, comprising: integrating, in an original data describing a detailed road network, intersections satisfying a predetermined condition into one intersection; A first step of creating route selection data with a reduced number of intersections; and a second step of searching for an optimal route between the designated departure point and destination using the route selection data. A route selection method comprising: 2. The route selection data includes: road network data describing a road network after intersection integration; and links for each integrated intersection that have been deleted due to integration of the intersection but are actually passing through. And a passing link table recorded for each of the relations of the entering and exiting links. The second step is to delete the deleted link when the optimum route found by searching passes through the integrated intersection. 2. The route selection method according to claim 1, wherein the compensation is made with a corresponding passing link recorded in the route. 3. If there is a traffic regulation across a plurality of intersections in an actual road network, the first step integrates those intersections on the original data into one intersection, and 3. The route selection method according to claim 2, wherein the information that the traffic regulation is imposed is recorded for an intersection integrated in connection with the traffic regulation. 4. 4. The transit link table further includes:
The evaluation value when passing through the integrated intersection is
The second step is to read the pass evaluation value corresponding to the approaching / exiting direction from the passing link table for the integrated intersection and refer to the optimum route by referring to the exit route. The route selection method according to claim 2, wherein the search is performed. 5. The transit link table further includes:
A traffic information providing number for the integrated intersection is recorded for each of the entry and exit links, and the second step takes into account traffic information provided in correspondence with the traffic information providing number. 3. The route selection method according to claim 2, wherein an optimal route is searched. 6. The road network described in the original data is divided into predetermined regions, and the traffic information is provided for each of the regions, and a road in the route selection data is provided. In the network data, when there is an intersection integrated beyond the boundary of the predetermined area, the passing link table includes, in addition to the traffic information provision number corresponding to the area to which the intersection belongs after integration, the integration 6. The route selection method according to claim 5, wherein a traffic information providing number corresponding to an area to which the intersection belongs is also recorded beforehand. 7. The method according to claim 1, wherein, when a plurality of roads exist between two adjacent intersections by integrating the intersections, the first step integrates these roads into one road. The route selection method according to claim 1. 8. A system for selecting an optimal route on a map, comprising: data created from original data describing a detailed road network, wherein the intersection satisfies a predetermined condition in the original data. A route selection data storage means for storing route selection data with a reduced number of intersections by integrating the route selection data into a single intersection; and using the route selection data to indicate a designated departure place and destination. A route selection system for searching for an optimum route between the route and the route. 9. The data for route selection includes: road network data describing a road network after intersection integration; and, for each integrated intersection, a link that has been deleted due to integration of the intersection but actually passes through. And a passing link table recorded for each of the relations of the entering and exiting links, wherein the optimal route searching means deletes the deleted link when passing through the intersection where the optimal route searched and found passes.
9. The route selection system according to claim 8, wherein the route is supplemented with a corresponding passing link recorded in the passing link table. 10. When there is a traffic regulation over a plurality of intersections in an actual road network, in the route selection data, those intersections on the original data are integrated into one intersection, and The route selection system according to claim 9, wherein the table records that the traffic regulation is imposed on the intersection integrated in relation to the traffic regulation. 11. The passing link table further stores an evaluation value when passing through an integrated intersection for each relationship between the entering and exiting links, and the optimal route searching means includes: About the intersection,
The route selection system according to claim 9, wherein an optimum route is searched for by reading and referring to a passage evaluation value corresponding to the approach / exit direction from the passage link table. 12. The traffic information provision number for the integrated intersection is stored in the passing link table.
It is recorded according to the relationship of the entrance and exit links, wherein the optimal route search means, in consideration of the traffic information provided corresponding to the traffic information providing number, to search for an optimal route, The route selection system according to claim 9. 13. The road network described in the original data,
The traffic information is divided for each predetermined area, and the traffic information is provided for each area. In the road network data in the route selection data, the traffic information is integrated across the boundary of the predetermined area. In the case where a crossed intersection exists, the passing link table records, in addition to the traffic information provision number corresponding to the area to which the intersection belongs after the integration, the traffic information provision number corresponding to the area to which the intersection belongs before the integration. 13. The route selection system according to claim 12, wherein the route selection is performed. 14. The data for selecting a route,
9. The route selection system according to claim 8, wherein when a plurality of roads exist between two adjacent intersections due to the integration of the intersections, these roads are integrated into one road.