JP7575345B2 - Navigation device, map data editing device, and route search method - Google Patents

Description

The present invention relates to a navigation device, a map data editing device, and a route search method, and is particularly suitable for use in a system that performs route searches using map data in which no-entry traffic regulation information is set as attribute information for nodes.

In general, navigation devices use map data to automatically search for the least costly route connecting the current location to the destination, and draw the route found as the guided route on the map screen in a bold color different from other roads. In addition, when the vehicle approaches within a certain distance of a guided intersection on the guided route, an enlarged view of the intersection is displayed to provide intersection guidance, guiding the driver to the destination.

A high cost is set for points or sections with traffic restrictions, making it difficult to find a guided route that passes through those points (see, for example, Patent Documents 1 and 2). The navigation device described in Patent Document 1 performs route search by referring to road information, taking into account vehicle height or weight. That is, the traffic restriction information received by the traffic restriction information receiving device is taken into consideration, and if traffic restrictions related to vehicle height or weight are in place, the roads subject to the restrictions are excluded from the search for the shortest route.

The navigation device described in Patent Document 2 searches for places with traffic restrictions on the candidate route, which is the optimal route that has been searched for, extracts the conditions of the traffic restrictions, compares the extracted conditions of the traffic restrictions with the vehicle information of the vehicle, and if the conditions of the traffic restrictions apply to the vehicle, performs a re-search for the route by disabling passage through the places with the traffic restrictions. The route obtained by the re-search is then set as a new candidate route, and the above process is repeated until a candidate route for which the vehicle does not fall under the conditions of the traffic restrictions is determined.

There is also known technology that allows the search for an appropriate route by considering the vehicle information of the vehicle even on road sections where no traffic regulations are set (see, for example, Patent Documents 3 and 4). The navigation device described in Patent Document 3 sets search conditions according to the type of vehicle (compact car, regular car, large car, special vehicle) input from the operation unit, and searches for a guide route that avoids narrow roads that the vehicle cannot pass through and roads with height or weight restrictions.

The navigation device described in Patent Document 4 extracts drivable roads based on vehicle information acquired from a vehicle information storage unit, in which at least one of the vehicle's overall length, overall width, overall height, total weight during normal driving, minimum turning radius, and climbing performance is stored as vehicle information, and road data acquired from a road data storage unit, and performs a route search using the extracted drivable roads.

The map data used for route search includes traffic regulation information similar to that set on actual roads. For example, in the case of traffic regulations such as height restrictions or weight restrictions, or one-way traffic regulations as described in Patent Documents 1 and 2, corresponding traffic regulation information is set for the road links. Therefore, a large cost is set for the road links for which traffic regulation information is set, and route searches are performed while avoiding road sections with traffic regulations. In the navigation devices described in Patent Documents 3 and 4, drivable roads are also extracted based on attribute information set for the road links, and route searches are performed while avoiding road sections that are not drivable from the viewpoint of vehicle height, vehicle width, vehicle weight, etc.

In contrast, on actual roads, traffic control signs prohibiting entry of large vehicles are installed only at points where entry is prohibited. Correspondingly, traffic control information prohibiting entry of large vehicles is set as a link-to-link attribute in the map data for intersection nodes corresponding to points where local traffic control signs are installed. When traffic control information such as prohibition of entry of large vehicles is set as attribute information of a node, a route search is performed by avoiding the node of the restriction point. However, since traffic control information prohibiting the travel of large vehicles is not set in the road link of the road section starting from the restriction point prohibiting entry of large vehicles, there is a problem that a route 113 that pinpoints the restriction point 111 and passes through the road section 112 where the travel of large vehicles is restricted may be searched for, as shown in FIG. 11.

According to the technology described in Patent Documents 3 and 4, even if traffic regulation information is not set for a road link, a route is searched for that avoids road sections where large vehicles cannot travel in terms of vehicle height, width, etc. However, a restricted section that starts from a restricted point where large vehicles are prohibited from entering is not necessarily restricted in terms of vehicle height, width, etc. In other words, even if a road section has an underpass at a height that allows large vehicles to travel, or a road section with a width that allows large vehicles to travel, traveling may be restricted because it is, for example, a residential road, a city road, or a school route. In such cases, when using the technology described in Patent Documents 3 and 4, there is a problem that a route that passes through such a restricted section will be searched for.

Japanese Patent Application Publication No. 11-271078 JP 2007-33331 A Japanese Patent Application Publication No. 11-2535 Japanese Patent Application Publication No. 8-278157

The present invention was made to solve such problems, and aims to prevent a route that bypasses a restricted point and passes through a road section where travel is restricted when no-entry traffic regulation information is set as attribute information of a node.

To solve the above problems, the present invention detects a no-entry node, which is a node for which no-entry traffic regulation information is set, detects a number of road links that are connected in series from the detected no-entry node and are in a specific section where it is possible to assume that travel is restricted, sets travel regulation information for route search on the detected road links, and then performs a route search using the road links for which the travel regulation information is set as restricted sections.

According to the present invention configured as described above, when no-entry traffic regulation information is set as attribute information of a node, travel regulation information in route search is set for a road link of a specific section that is connected cascade-connected from the node and where travel can be assumed to be restricted. This makes it possible to prevent a route search that bypasses a node with no-entry traffic regulation information set and passes through a road section where travel is restricted, and makes it possible to search for a route that avoids the restricted section that connects from a restricted point where entry is prohibited.

1 is a block diagram showing an example of a functional configuration of a navigation device according to an embodiment of the present invention; 4 is a block diagram showing a specific example of a functional configuration of a route search unit according to the present embodiment. FIG. FIG. 2 is a diagram for explaining a plurality of road links along a road. FIG. 13 is a diagram for explaining a plurality of road links that are cascade-connected up to another entry prohibited node. FIG. 11 is a diagram showing an example of a route searched for when the present embodiment is applied; 5 is a flowchart showing an example of the operation of a route search unit according to the present embodiment. 13 is a diagram showing another example of a plurality of regulated road links detected by the road link detection unit; FIG. 13 is a diagram showing another example of a plurality of regulated road links detected by the road link detection unit; FIG. FIG. 11 is a block diagram showing another example of the functional configuration of the route search unit according to the present embodiment. 1 is a block diagram showing an example of a functional configuration of a map data editing device according to an embodiment of the present invention; FIG. 1 is a diagram for explaining problems in the conventional art.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of the functional configuration of a navigation device 100 according to this embodiment. The navigation device 100 of this embodiment may be mounted on a vehicle, or may be a mobile terminal such as a smartphone or tablet on which a navigation application is installed.

As shown in FIG. 1, a map data storage unit 10, a GPS receiver 20, and a display 30 are connected to a navigation device 100 according to this embodiment. The map data storage unit 10 may be mounted on a vehicle or may exist on a server via the Internet. The map data storage unit 10 may also be built into the navigation device 100.

As shown in FIG. 1, the navigation device 100 according to this embodiment includes, as its functional components, a map data acquisition unit 11, a GPS information acquisition unit 12, a vehicle position determination unit 13, a map display unit 14, a route search unit 15, and a driving guidance unit 16. The navigation device 100 according to this embodiment also includes, as storage media, a map data memory 101 and a guided route memory 102.

The above-mentioned functional blocks 11 to 16 can be configured using either hardware, a DSP (Digital Signal Processor), or software. For example, when configured using software, the above-mentioned functional blocks 11 to 16 are actually configured with a computer's CPU, RAM, ROM, etc., and are realized by the operation of a program stored in a storage medium such as the RAM, ROM, hard disk, or semiconductor memory.

The map data storage unit 10 stores map data required for map display, route search, etc., and is configured, for example, by a hard disk. Note that in addition to a hard disk, the storage medium that configures the map data storage unit 10 may also be a DVD, a CD-ROM, or a semiconductor memory. The map data includes various drawing data required for map display, as well as road data and facility data required for various processes such as map matching, route search, and route guidance.

The road data includes information about nodes that correspond to points where multiple roads intersect, such as intersections and forks, and information about road links that correspond to roads, lanes, etc. that connect a node on a road to another node adjacent to it. Specifically, the road data includes a connection node table that contains detailed data on all nodes, and a link table that contains detailed data on all road links.

The connection node table contains information such as the node number, connecting link number, normalized longitude and latitude of the node, attribute flags, and traffic regulations for each existing node. The connecting link numbers indicate the link numbers of each road link of which the node is one end, for the number of links. The normalized longitude and latitude indicate the relative position in the longitude and latitude directions based on the block. The attribute flags include an intersection flag that indicates whether the node is an intersection or branching point node.

The traffic regulations indicate the details of traffic regulations, such as no right turns or no U-turns, for the road links connected to the node. In this embodiment, for nodes corresponding to controlled points where there are traffic regulations prohibiting large vehicles from entering, traffic regulation information prohibiting large vehicles from entering is set as a link-to-link attribute.

The link table contains information such as the link number, connecting node number, road link distance, road attributes, road type, route number, and road link cost for each existing road link. The connecting node number indicates a number that identifies the two nodes located at both ends of the road link. The road link distance indicates the actual distance of the actual road corresponding to the road link. The road attributes indicate various attributes related to the road link. Information related to road attributes includes road width, height to overpass, and one-way streets. The road type indicates the actual type of road corresponding to the road link. Road types include expressways, national highways, major regional roads, prefectural roads, general roads, farm roads, minor streets, trunk lines, side roads, and branch roads. The route number indicates the number assigned to the actual road corresponding to the road link.

The cost of a road link is, for example, a value obtained by multiplying the distance of the road link by a predetermined constant depending on the road width, road type, right turns, left turns, etc., and is a numerical representation of the suitability of the road link as a guide route. The cost of a road link is set as a value to which an appropriate weight is added depending on congestion and traffic regulations occurring on the road corresponding to the road link, route search conditions (time priority, distance priority, toll road priority, general road priority, fuel efficiency priority, etc.), and various other factors. The navigation device 100 is configured to search for a guide route based on a calculated value using the costs set for road links on various routes from the current location to the destination.

The map data acquisition unit 11 acquires map data from the map data storage unit 10 and temporarily stores it in the map data memory 101. When displaying a map of the area around the vehicle's current position on the display 30, the map data acquisition unit 11 inputs the vehicle's current position information from the GPS information acquisition unit 12, reads map data of a predetermined range including the vehicle's current position from the map data storage unit 10, and stores it in the map data memory 101. When searching for a guided route, the map data acquisition unit 11 reads map data of a predetermined range including from the current position to the destination from the map data storage unit 10, and stores it in the map data memory 101.

The GPS information acquisition unit 12 acquires GPS information detected by the GPS receiver 20 at a predetermined sampling interval. The GPS information includes latitude and longitude position information, direction information, and time information. The GPS receiver 20 receives radio waves transmitted from multiple GPS satellites with a GPS antenna, and performs three-dimensional positioning processing or two-dimensional positioning processing to calculate the absolute position and direction of the vehicle (the vehicle direction is calculated based on the vehicle's current position and its position one sampling time prior).

Although an example using a GPS receiver 20 as a position detection means has been described here, a self-contained navigation sensor and a position calculation CPU may be used instead of or in addition to the GPS receiver 20. The self-contained navigation sensor includes a vehicle speed sensor (distance sensor) that outputs one pulse per predetermined travel distance to detect the distance traveled by the vehicle, and an angular velocity sensor (relative orientation sensor) such as a vibration gyro that detects the rotation angle (travel orientation) of the vehicle. The self-contained navigation sensor detects the relative position and orientation of the vehicle using the vehicle speed sensor and angular velocity sensor. The position calculation CPU calculates the absolute vehicle position and vehicle orientation based on the data on the relative position and orientation of the vehicle output from the self-contained navigation sensor.

The vehicle position identifying unit 13 identifies the vehicle position on the map at each sampling interval based on the position information included in the GPS information acquired from the GPS receiver 20 by the GPS information acquiring unit 12 at each sampling interval and the map data stored in the map data memory 101. Here, the vehicle position identifying unit 13 performs map matching as necessary. Map matching refers to a process of correcting the vehicle's traveling position on the road in the map data using the GPS information acquired by the GPS information acquiring unit 12 (position information and direction information detected by the GPS receiver 20) and the map data stored in the map data memory 101.

The map display unit 14 generates map image data of the area around the vehicle's position based on the map data stored in the map data memory 101, and displays a map image on the display 30 based on the map image data. At this time, the map display unit 14 displays the map image on the display 30 at a specified scale.

The route search unit 15 uses the map data stored in the map data memory 101 to perform a process of searching for a guided route connecting the current position of the vehicle identified by the vehicle position identification unit 13 to the destination set by the user. For example, the route search unit 15 searches for a route from the current position to the destination that has the smallest total value of costs set for the road links on the route, among various routes from the current position to the destination. The guided route memory 102 temporarily stores data of the guided route searched by the route search unit 15.

The route search unit 15 searches for a route based on, for example, the Dijkstra algorithm. In the Dijkstra algorithm, the cost of the road links is added in order from the current node to the destination node, and search branches are extended along multiple routes. In the process of extending the search branches, if the same node is reached along the way via different routes, the route with the lowest cumulative cost up to that point is adopted, and the route with the highest cumulative cost is discontinued from further search. This is because further search is considered unlikely to be the optimal route from the current node to the destination node. Ending the search for a route that is determined along the way not to be the optimal route is called "branch hunting." In the Dijkstra algorithm, the search is carried out while branch hunting from the current node to the destination node, making it possible to efficiently find the optimal route between two points.

The driving guidance unit 16 uses the map data stored in the map data memory 101, the guided route data stored in the guided route memory 102, and the vehicle position identified by the vehicle position identification unit 13 to provide driving guidance for the vehicle. For example, the driving guidance unit 16 displays a vehicle position mark indicating the vehicle position identified by the vehicle position identification unit 13 superimposed on the map, thereby enabling the driver to see at a glance where the vehicle is currently traveling. The driving guidance unit 16 also uses the guided route data stored in the guided route memory 102 to draw the guided route in a bold color different from other roads. When the vehicle approaches a predetermined distance before a guided intersection on the guided route, the driving guidance unit 16 displays an enlarged image of the intersection on the display 30 to provide intersection guidance in the direction of travel.

Figure 2 is a block diagram showing a specific example of the functional configuration of the route search unit 15. As shown in Figure 2, the route search unit 15 of this embodiment has, as its functional configuration, a search branch extension unit 21, an entry prohibited node detection unit 22, a road link detection unit 23, and a restriction information setting unit 24. In this embodiment, information indicating whether the vehicle is a large vehicle or not is set in the navigation device 100 in advance, and when information indicating that the vehicle is a large vehicle is set, the search branch extension unit 21, the entry prohibited node detection unit 22, the road link detection unit 23, and the restriction information setting unit 24 are executed. When information indicating that the vehicle is a large vehicle is not set, the entry prohibited node detection unit 22, the road link detection unit 23, and the restriction information setting unit 24 are not executed, and a route is searched for by the search branch extension unit 21.

The search branch extension unit 21 adds up the costs of road links from the current location node to the destination node in order, and executes a process of extending search branches along multiple routes while pruning. The entry prohibited node detection unit 22 detects nodes (hereinafter referred to as entry prohibited nodes) where traffic regulation information prohibiting large vehicles from entering is set as the search branch extension unit 21 extends the search branches while adding up the costs from the current location node to the destination node. That is, each time a search branch is extended by the search branch extension unit 21, the entry prohibited node detection unit 22 determines whether traffic regulation information prohibiting large vehicles from entering is set at the node to which the search branch is extended, and detects the node where the traffic regulation information is set as an entry prohibited node.

When an entry prohibited node is detected by the entry prohibited node detection unit 22, the road link detection unit 23 detects multiple road links that are connected in tandem from the entry prohibited node and that are in a predetermined section where it can be assumed that travel is restricted. The road links in a predetermined section where it can be assumed that travel is restricted are, for example, multiple road links that are of the same road type and have a link connection angle equal to or less than a threshold, and that are connected in tandem up to another node where traffic regulation information for entry prohibition is set.

Figure 3 is a diagram for explaining multiple road links along a road. In Figure 3, each arrow indicates road link LK1 to LK8. Of these, road links LK1 to LK7 are related to prefectural roads, and road link LK8 is related to a general road. A circle indicates entry prohibited node ND1. Note that circles are not shown for other nodes. Traffic regulation information is set in entry prohibited node ND1 to prohibit large vehicles from entering road link LK1.

In the example of Fig. 3, the road link LK1 connected to the entry prohibited node ND1 and the road link LK2 connected to it in a cascade manner are both road links that follow the road because their road types are prefectural roads and the link connection angle _θ12 is equal to or less than the threshold. The road link LK3 connected to the road link LK2 in a cascade manner is also a road link that follows the road because its road type is a prefectural road and the link connection angle with the road link LK2 is equal to or less than the threshold. The road link LK4 connected to the road link LK3 in a cascade manner is also a road link that follows the road because its road type is a prefectural road and the link connection angle with the road link LK3 is equal to or less than the threshold. Furthermore, the road link LK5 connected to the road link LK4 in a cascade manner is also a road link that follows the road because its road type is a prefectural road and the link connection angle with the road link LK4 is equal to or less than the threshold.

In contrast, the road link LK8 connected cascade-wise to the road link LK2 is not a road link that follows a road because its road type is a general road and not a prefectural road. The road link LK6 connected cascade-wise to the road link LK4 is not a road link that follows a road because its road type is a prefectural road, but its link connection angle _θ46 with the road link LK4 is not equal to or less than the threshold. The road link LK7 connected cascade-wise to the road link LK4 is also not a road link that follows a road because its road type is a prefectural road, like the road link LK6, but its link connection angle with the road link LK4 is not equal to or less than the threshold.

Figure 4 is a diagram for explaining multiple road links that are connected in cascade up to another node for which no-entry traffic regulation information is set. In this Figure 4, the same components as those shown in Figure 3 are given the same reference numerals. In the example of Figure 4, node ND2 at one end of road link LK5 is also a no-entry node, and traffic regulation information is set that prohibits large vehicles from entering road link LK5.

In the example shown in FIG. 4, the road links that are cascade-connected to the entry prohibited node ND1 detected by the entry prohibited node detection unit 22 are sequentially traced by the road link detection unit 23, and multiple road links LK1 to LK5 that are cascade-connected up to another entry prohibited node ND2 for which traffic regulation information forbidding entry is set are detected. Hereinafter, the multiple road links detected by the road link detection unit 23 are referred to as regulated road links.

The restriction information setting unit 24 sets driving restriction information for route search for multiple regulated road links detected by the road link detection unit 23. For example, the restriction information setting unit 24 sets a predetermined cost as driving restriction information for multiple regulated road links detected by the road link detection unit 23. The cost set here is a value with a necessary and sufficient weight to make the regulated road links less likely to be selected as routes (i.e., more likely to be pruned). For example, it is possible to set an infinite cost.

The route search unit 15 searches for a route using multiple regulated road links for which driving restriction information has been set by the restriction information setting unit 24 as regulated sections. That is, when an entry prohibited node is detected by the entry prohibited node detection unit 22, the search branch extension unit 21 stops the search branch extension process while the road link detection unit 23 and the restriction information setting unit 24 are processing. After that, when the restriction information setting unit 24 sets driving restriction information (cost), the search branch extension unit 21 continues the search branch extension process from the entry prohibited node detected by the entry prohibited node detection unit 22, using the multiple regulated road links for which the driving restriction information has been set as regulated sections.

In this way, as shown in FIG. 5, it is possible to prevent searching for a route (e.g., route 113 as shown in FIG. 11) that goes around a controlled point 51 where traffic regulation information prohibiting large vehicles from entering and passes through a controlled section 53 to reach another controlled point 52, and to search for a route 54 that avoids the controlled section 53.

Figure 6 is a flowchart showing an example of the operation of the route search unit 15 according to this embodiment configured as described above. The flowchart shown in Figure 6 starts when a destination is set by the user and an instruction to search for a route is given.

First, the search branch extension unit 21 extends the search branch from the current node to the next node (step S1). Here, the no-entry node detection unit 22 determines whether or not the node to which the search branch is extended has traffic regulation information forbidding large vehicles from entering, i.e., whether or not the node is a no-entry node (step S2).

If it is determined that the node to which the search branch is extended is not a prohibited entry node, the search branch extension unit 21 determines whether the route search to the destination has been completed (step S3). If the route search to the destination has not been completed, the process returns to step S1, and the search branch extension unit 21 continues the search branch extension process.

On the other hand, if it is determined in step S2 that the node to which the search branch is extended is a prohibited entry node, the road link detection unit 23 detects, as regulated road links, a plurality of road links that are cascade-connected from the prohibited entry node and that reach another prohibited entry node (step S4). The regulation information setting unit 24 then sets driving regulation information (cost) for the detected regulated road links (step S5).

Then, the process returns to step S1, and the search branch extension unit 21 continues the process of extending the search branch from the prohibited entry node. Then, if it is determined in step S3 that the route search to the destination has ended, the process of the flowchart shown in FIG. 6 ends.

As explained in detail above, in this embodiment, when traffic regulation information prohibiting large vehicles from entering is set as attribute information of a node, driving regulation information in route search is set for road links of a specific section that are connected cascade-connected from the entry-prohibited node and where it can be assumed that driving is restricted. This makes it possible to pinpoint the restricted point of the entry-prohibited node and prevent the search for a route that passes through the road section where driving is restricted, making it possible to search for a route that avoids the restricted section.

In the above embodiment, an example was described in which multiple road links that connect from the entry prohibited node detected by the entry prohibited node detection unit 22 along the road and that are connected in a cascading manner up to another entry prohibited node for which traffic regulation information forbidding large vehicles is set are detected as regulated road links, but the present invention is not limited to this.

For example, as shown in FIG. 7, the road link detection unit 23 may detect a plurality of road links along a road that have the same road type and a link connection angle equal to or less than a threshold, and that have one-way attribute information set. In the example shown in FIG. 7, road links LK11 to LK15 are a plurality of road links along a road that are connected in series from the entry prohibited node ND11 detected by the entry prohibited node detection unit 22. Of these, the road links LK11 to LK14 are set with a one-way road attribute, and the road link LK15 is not set with a one-way road attribute. In other words, the node ND12 at the end of the road link LK14 is the exit of a one-way street. In this case, the road link detection unit 23 detects the plurality of road links LK11 to LK14 that are connected in series from the entry prohibited node ND11 to the one-way exit node ND12 as regulated road links.

As shown in FIG. 8, the road link detection unit 23 may detect multiple road links that are cascade-connected along a road, have the same road type, and have a link connection angle equal to or less than a threshold, and that are connected in a cascade-connected manner up to a point where no road links along the road exist. In the example shown in FIG. 8(a), road links LK21 to LK24 are multiple road links that cascade-connect along a road from the entry prohibited node ND21 detected by the entry prohibited node detection unit 22. The terminal node ND22 of the road link LK24 is a three-way intersection node, and no road links along the road exist beyond that. In this case, the road link detection unit 23 detects the multiple road links LK21 to LK24 that cascade-connect from the entry prohibited node ND21 to the three-way intersection node ND22 as regulated road links.

In the example shown in FIG. 8(b), road links LK31 to LK34 are multiple road links that are connected in a cascade from the entry prohibited node ND31 detected by the entry prohibited node detection unit 22. The end of road link LK34 is a dead end, and there are no road links that are connected in a cascade beyond that. In this case, the road link detection unit 23 detects the multiple road links LK31 to LK34 that are connected in a cascade from the entry prohibited node ND31 to the dead end node ND32 as regulated road links.

In the above embodiment, an example was described in which a prohibited entry node is detected in the process of extending a search branch from the current location toward the destination, but the present invention is not limited to this. For example, the prohibited entry node detection unit 22 may set a predetermined range that includes the current location and the destination, and detect one or more prohibited entry nodes included in the predetermined range. Figure 9 is a block diagram showing an example of the functional configuration of the route search unit 15' when detecting a prohibited entry node in this manner.

In FIG. 9, when a destination is set by the user and a route search is instructed, the entry prohibited node detection unit 22' sets a predetermined range including the current location and destination, and detects one or more entry prohibited nodes included in the predetermined range. Here, the predetermined range may be the same as a range that is generally set when searching for a route. For example, the predetermined range may be a rectangular area whose long sides are two sides parallel to a line connecting the current location and destination, or a rectangular area whose diagonal corners include a circular area of a predetermined radius centered on the current location and a circular area of a predetermined radius centered on the destination.

For each of one or more entry prohibited nodes detected by the entry prohibited node detection unit 22', the road link detection unit 23' detects, as restricted road links, a plurality of road links that are connected in cascade from the entry prohibited node and are in a predetermined section where it can be assumed that travel is restricted. The restriction information setting unit 24' sets a predetermined cost as travel restriction information for the plurality of restricted road links detected by the road link detection unit 23'.

After the driving restriction information is set on the regulated road links in the above manner, the search branch extension unit 21' sequentially extends the search branches from the current location toward the destination, searching for the route with the lowest cost. At this time, the search branch extension unit 21' searches for a route from the current location to the destination, regarding the multiple road links for which driving restriction information has been set by the restriction information setting unit 24' as regulated sections.

When the route search unit 15 is configured as shown in FIG. 2, if the search branch is not extended to the entry prohibition node 51 in which traffic regulation information for prohibiting large vehicles as shown in FIG. 5 is set during the process of extending the search branch, and the search branch is extended to a node in the middle of the regulated section 53, the processing of the entry prohibition node detection unit 22, the road link detection unit 23, and the regulation information setting unit 24 is not executed, and a route that passes through part of the regulated section 53 is searched for. The same applies if the search branch is extended to the entry prohibition node 51, but is extended to a node in the middle of the regulated section 53 beyond that. In contrast, when the route search unit 15' is configured as shown in FIG. 9, travel regulation information is set on the road links in the entire regulated section 53 before starting the route search process to extend the search branch, so that it is possible to prevent a route that passes through part of the regulated section 53 from being searched for.

In the above embodiment, the processing of the no-entry node detection unit 22, the road link detection unit 23, and the restriction information setting unit 24 is executed when the user instructs the execution of a route search. However, they may be executed before the user instructs the execution of a route search. That is, when map data is stored in the map data storage unit 10, the above-mentioned processing may be performed on the map data, and map data in which driving restriction information is added to the restricted road links may be generated and re-stored in the map data storage unit 10. In this case, the map data acquisition unit 11 in FIG. 1 acquires the edited map data from the map data storage unit 10 and stores it in the map data memory 101, and the route search unit 15 executes a route search using the edited map data.

Fig. 10 is a block diagram showing an example of the functional configuration of a map data editing device 200 that edits such map data. As shown in Fig. 10, the map data editing device 200 of this embodiment is configured to include a map data reading unit 31 that reads map data from the map data storage unit 10, and a map data editing unit 32 that edits the map data read by the map data reading unit 31 and stores the edited map data in the map data storage unit 10.

The map data reading unit 31 reads out the entire map data stored in the map data storage unit 10. Alternatively, the map data reading unit 31 may read out the map data of the area that was most recently updated. The map data editing unit 32 has, as its functional components, a no-entry node detection unit 22'', a road link detection unit 23'', and a restriction information setting unit 24'', and edits the map data using these functional components.

The entry prohibited node detection unit 22" detects one or more entry prohibited nodes for which traffic regulation information prohibiting entry of large vehicles is set, using the map data read by the map data reading unit 31. This entry prohibited node detection unit 22" performs the same processing as the entry prohibited node detection unit 22' shown in FIG. 9. However, it is different in that the entry prohibited node detection unit 22' in FIG. 9 detects entry prohibited nodes within a specified range including the current location and destination, whereas the entry prohibited node detection unit 22" in FIG. 10 detects entry prohibited nodes within the entire area of the map data read by the map data reading unit 31.

For each of one or more entry prohibited nodes detected by the entry prohibited node detection unit 22'', the road link detection unit 23'' detects a plurality of road links that are cascade-connected from the entry prohibited node, and that are road links of a predetermined section where it can be assumed that travel is restricted. This road link detection unit 23'' performs the same processing as the road link detection unit 23' shown in Figure 9.

The restriction information setting unit 24" sets driving restriction information for multiple regulated road links detected by the road link detection unit 23", and records the set driving restriction information in the link table of the map data as attribute information of the road link. The driving restriction information recorded here can be the cost for route search described in the above embodiment, but is not limited to this. For example, it may be flag information indicating that the driving of large vehicles is restricted. When the cost is recorded as the driving restriction information, the route search unit 15 adds the cost to the regulated road link and performs the route search. On the other hand, when the flag information is recorded as the driving restriction information, the route search unit 15 adds a predetermined cost to the regulated road link and performs the route search.

In this way, if the map data in the map data storage unit 10 is edited in advance by the map data editing device 200, there is no need to execute the processing of the no-entry node detection unit 22, the road link detection unit 23, and the regulation information setting unit 24 when the user instructs the execution of a route search, and the time required for the route search processing can be shortened.

In the above embodiment, an example was described in which the traffic regulation set in the no-entry node prohibits large vehicles from entering, but the present invention is not limited to this. For example, the above embodiment can be similarly applied to traffic regulations that prohibit the entry of special vehicles, motorcycles, etc.

In addition, the above embodiments are merely examples of how the present invention can be implemented, and the technical scope of the present invention should not be interpreted in a limiting manner. In other words, the present invention can be implemented in various forms without departing from its gist or main features.

15, 15' Route search unit 21, 21', 21" Search branch extension unit 22, 22', 22" No entry node detection unit 23, 23', 23" Road link detection unit 24, 24', 24" Restriction information setting unit 31 Map data reading unit 32 Map data editing unit 100 Navigation device 200 Map data editing device

Claims (13)

an entry prohibited node detection unit that detects an entry prohibited node, which is a node for which traffic regulation information forbidding entry is set;
a road link detection unit that detects a plurality of road links that are cascade-connected from the entry prohibited node detected by the entry prohibited node detection unit, the road links being in a predetermined section where it can be assumed that travel is restricted; and
a regulation information setting unit that sets driving regulation information for route search for the plurality of road links detected by the road link detection unit,
A navigation device characterized in that a route search is performed by using a plurality of road links for which the travel restriction information has been set by the restriction information setting unit as restricted sections. The navigation device according to claim 1, characterized in that the road link detection unit detects multiple road links along a road that are the same road type and have a link connection angle equal to or less than a threshold, and that are connected in series up to another node for which the no-entry traffic regulation information is set. The navigation device according to claim 1, characterized in that the road link detection unit detects multiple road links along a road that are the same road type, have a link connection angle equal to or less than a threshold, and have one-way attribute information set. The navigation device according to claim 1, characterized in that the road link detection unit detects multiple road links along a road that are the same road type and have a link connection angle equal to or less than a threshold, and that are connected in a cascading manner up to a point where no road links along the road exist. the entry prohibited node detection unit adds up the costs of road links in order from the current location toward the destination, and in the process of extending search branches along a plurality of routes while pruning , detects the entry prohibited node by determining whether or not the node at the destination of the search branch is the entry prohibited node each time the search branch is extended ;
the road link detection unit detects a plurality of road links in the predetermined section cascade-connected from the detected entry prohibited node each time the entry prohibited node is detected by the entry prohibited node detection unit;
5. The navigation device according to claim 1, wherein the restriction information setting unit sets a predetermined cost as the driving restriction information for each of the plurality of road links detected by the road link detection unit. the entry prohibited node detection unit sets a predetermined range including a current location and a destination, and detects one or more of the entry prohibited nodes included in the predetermined range;
the road link detection unit detects, for each of the one or more entry prohibited nodes detected by the entry prohibited node detection unit, a plurality of road links cascade-connected from the entry prohibited node, the road links being in a predetermined section in which it can be estimated that travel is restricted;
the restriction information setting unit sets a predetermined cost as the driving restriction information for each of the plurality of road links detected by the road link detection unit ;
The processes of the entry prohibited node detection unit, the road link detection unit and the regulation information setting unit are executed before starting a route search process in which a cost is calculated while extending a search branch from the current location toward the destination, and the route search process is executed after the driving regulation information is set for a plurality of road links in the predetermined section.
5. The navigation device according to claim 1, wherein the navigation device is a navigation system including: a navigation unit that is connected to the navigation system; a map data reading unit that reads map data from the map data storage unit;
a map data editing unit that edits the map data read by the map data reading unit and stores the edited map data in the map data storage unit,
The above map data editorial department,
an entry prohibited node detection unit that detects one or more entry prohibited nodes, which are nodes for which traffic regulation information indicating entry prohibition is set, in the map data read by the map data reading unit;
a road link detection unit that detects, for each of the one or more entry prohibited nodes detected by the entry prohibited node detection unit, a plurality of road links that are cascade-connected from the entry prohibited node, the road links being in a predetermined section where it can be estimated that travel is restricted;
a restriction information setting unit that sets driving restriction information for the plurality of road links detected by the road link detection unit and records the set driving restriction information as attribute information of the road link. The map data editing device according to claim 7, characterized in that the road link detection unit detects multiple road links along a road that are the same road type and have a link connection angle equal to or less than a threshold, and that are connected in a cascading manner up to another node for which the no-entry traffic regulation information is set. The map data editing device according to claim 7, characterized in that the road link detection unit detects multiple road links along a road that are the same road type and have a link connection angle equal to or less than a threshold, and that have one-way attribute information set. The map data editing device according to claim 7, characterized in that the road link detection unit detects multiple road links along a road that are the same road type and have a link connection angle equal to or less than a threshold, and that are connected in a cascading manner up to a point where no road links along the road exist. A first step in which a route search unit of the navigation device detects an entry-prohibited node which is a node for which traffic regulation information indicating entry-prohibition is set;
a second step in which the route search unit detects a plurality of road links cascade-connected from the entry-prohibited node detected in the first step, the road links being in a predetermined section where it can be estimated that travel is restricted; and
a third step of the route search unit setting driving regulation information for the plurality of road links detected in the second step;
The route search method, wherein the route search unit searches for a route by setting the plurality of road links for which the travel restriction information is set in the third step as restriction target sections. In the first step, the route search unit adds up the costs of road links in order from the current location to the destination, and in the process of extending search branches along a plurality of routes while pruning , detects the entry prohibited node by determining whether or not the node at the destination of the search branch is the entry prohibited node each time the search branch is extended ;
In the second step, the route search unit detects a plurality of road links in the predetermined section that are cascade-connected from the detected entry prohibited node each time the entry prohibited node is detected,
The route search method according to claim 11, further comprising a fourth step in which, after the third step, the route search unit continues the extension process of the search branch by treating a plurality of road links for which the driving restriction information is set as the restricted section. In the first step, the route search unit sets a predetermined range including a current location and a destination, and detects one or more entry-prohibited nodes, which are nodes for which traffic regulation information indicating entry prohibition is set, from the predetermined range;
In the second step, the route search unit detects, for each of the one or more entry prohibited nodes detected in the first step, a plurality of road links cascade-connected from the entry prohibited node, the road links being in a predetermined section in which it can be estimated that travel is restricted;
The route search method according to claim 11, further comprising a fourth step in which, after the third step, the route search unit searches for a route from the current location to the destination by setting a plurality of road links for which the driving restriction information is set as the regulated sections.