Route search device, route search method, and computer program

Abstract

The present invention provides a route search device that can suppress guidance on routes that include dead ends or cul-de-sacs. [Solution] The route search device comprises a route information storage unit that stores road network data including node information and link information connecting the nodes, and a route search unit that searches for a route from the starting point to the destination. The route search unit searches for a route from the road network data, excluding terminal links (links where only one of the nodes at both ends of the link is connected to another link), and outputs the searched route.

Description

Technical Field

[0005]

[0001] The present invention relates to a route search device, a route search method, and a computer program.

Background Art

[0002] A navigation device for guiding a route from a departure point to a destination is known. Since such a navigation device is often mounted on a vehicle and used for guiding the moving route of the vehicle, there is a desire not to search for a route including a dead end or a cul-de-sac where a U-turn of the vehicle occurs.

[0003] In this regard, for example, Patent Document 1 discloses that in a navigation device, when there is first information indicating that it is a dead end within or beyond a predetermined section, the predetermined section is excluded from the selection setting of the travel route, so as not to search for a route that cannot be a travel route. For example, Patent Document 2 discloses that in a navigation device, when a guidance route for making a U-turn at the end of a cul-de-sac is set, a U-turn guidance image is displayed. For example, Patent Document 3 discloses that in a car navigation device, when it is determined that a road is a cul-de-sac road, guidance regarding the cul-de-sac road is provided.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in recent years, the demand for logistics services has increased due to the spread of internet shopping, and the number of people engaged in the work of delivering goods and other packages to designated delivery destinations (hereinafter also referred to as "delivery personnel") has increased. From the perspective of improving work efficiency, delivery personnel are assigned predetermined areas and deliver packages to individual homes within their assigned area. Here, areas with many individual homes are characterized by having many dead ends and cul-de-sacs where vehicles make U-turns, and by a lot of traffic from pedestrians and bicycles, compared to ordinary main roads. For this reason, route search devices (navigation devices) used in delivery services are particularly required to suppress guidance on routes that include dead ends and cul-de-sacs.

[0006] In this regard, the navigation device described in Patent Document 1 uses first information to determine if a road is a dead end, which presents a problem in areas where first information is unavailable, as it guides users along routes that include dead ends or cul-de-sacs. In particular, residential areas with many private homes tend to have less readily available information compared to office districts, but in delivery services, suppressing guidance to such routes (routes including dead ends or cul-de-sacs) in residential areas is even more important from both a demand and safety perspective. Furthermore, the navigation devices described in Patent Documents 2 and 3 only provide information on U-turns and dead-end roads, and do not consider suppressing guidance to routes that include dead ends or cul-de-sacs. It should be noted that, as mentioned above, this problem is not limited to route search devices used in delivery services, but is also common to route search devices for general users.

[0007] Therefore, there was a need for a route search device that could suppress guidance on routes that included dead ends and cul-de-sacs. [Means for solving the problem]

[0008] The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following forms.

[0009] (1) According to one embodiment of the present invention, a route search device is provided. This route search device comprises a route information storage unit that stores road network data including node information and link information connecting the nodes, and a route search unit that searches for a route from a starting point to a destination, wherein the route search unit searches for a route from the road network data, excluding terminal links, which are links where only one of the nodes located at both ends of the link is connected to another link, and outputs the searched route.

[0010] A "dead end" refers to a road where only one of its ends connects to another road. With this configuration, the route search unit searches for a route from the road network data, excluding terminal links (i.e., links that are dead ends) where only one of the nodes at both ends of the link connects to another link. Therefore, it is possible to provide a route search device that can suppress the guidance of routes that include dead ends. Furthermore, with this configuration, the determination of whether or not a link is a terminal link (a link that is a dead end) is made using the link connection relationships in the road network data used for route search. Therefore, compared to cases where special information is required separately, it is possible to suppress the guidance of routes that include dead ends without being affected by the availability of information.

[0011] (2) In the above-described path search device, the path search unit may search for the path by excluding specific links from the road network data, in addition to the terminal links, in which one of the nodes located at both ends of the link is connected only to the terminal link. A "dead end" refers to a group of roads that are shaped like a bag and cannot be passed through. With this configuration, the route search unit searches for a route from the road network data, excluding not only terminal links but also specific links where one of the nodes at both ends of the link is connected only to the terminal link (i.e., links that lead to dead ends). Therefore, it is possible to provide a route search device that can suppress the guidance of routes that include dead ends. Furthermore, with this configuration, the determination of whether or not a link is a specific link (a link that leads to a dead end) is made using the link connection relationships in the road network data used for route search. Therefore, compared to cases where special information is required separately, it is possible to suppress the guidance of routes that include dead ends without being affected by the availability of information.

[0012] (3) In the above-described pathfinding device, the pathfinding unit searches for a path from the starting point to the destination via predetermined intermediate points, and when the node located at both ends of the terminal link that is not connected to other links is designated as the terminal node, if the link length from the terminal node to the intermediate point is greater than or equal to a predetermined threshold, the pathfinding unit may search for the path without excluding the terminal link from the search. Even if a road is a dead end, if the road length is long, there is a request to be guided along a route that includes the dead end. In this regard, with this configuration, the route search unit, when it sets a node located at both ends of a terminal link that is not connected to other links as the endpoint node, will not exclude the terminal link (the dead end link) from the search if the link length from the endpoint node to the intermediate point is greater than or equal to a predetermined threshold. Therefore, even if a road is a dead end, if the road length is long, the route search unit can guide along a route that includes the dead end.

[0013] (4) In the above-described pathfinding device, if the terminal link is a link facing either the departure point or the destination, the pathfinding unit may search for the path without excluding the terminal link from the search. There is a demand for route guidance that includes a dead end, even if it faces either the starting point or the destination. In this regard, with this configuration, the route search unit does not exclude terminal links (links that are dead ends) from the search if the terminal link faces either the starting point or the destination. Therefore, the route search unit can guide users along a route that includes a dead end, even if it faces either the starting point or the destination.

[0014] (5) In the above-described path search device, if the path search unit finds a route that involves making a U-turn at a certain link, it may exclude the link constituting the U-turn route from the search, re-search for the path, and output the re-searched path. Residential areas, with their many private homes, often have narrow roads where vehicles need to make U-turns, and also experience heavy traffic from pedestrians and cyclists, compared to typical main roads. In this regard, according to this configuration, if the route search unit finds a route that includes a U-turn at a certain link, it excludes the link constituting the U-turn route from the search, re-searches for the route, and outputs the re-searched route. As a result, this route search device further suppresses the guidance of routes that include U-turn routes, thereby improving the ease of driving on the guided route and enhancing safety.

[0015] (6) In the above-described configuration of the route search device, the route search unit may acquire information on one or more delivery destinations that the user of the route search device will stop at for the delivery of a package, and search for the route from the departure point to the destination, passing through the one or more delivery destinations as intermediate stops. In recent years, the spread of internet shopping has increased the demand for logistics services, and the number of people (delivery personnel) engaged in the work of delivering goods and other packages to designated delivery destinations has increased. In this regard, according to this configuration, the route search unit acquires information on one or more delivery destinations that the user of the route search device (delivery person) will stop at for the delivery of the package, and searches for a route from the starting point to the destination via one or more delivery destinations as intermediate stops, thereby providing a route search device specifically for delivery services.

[0016] (7) In the above-described path search device, the path search unit may acquire location information of parking spaces located near a road where it is possible to safely park a vehicle, and may output the acquired location information of the parking spaces along the searched path. In residential areas with many private homes, there are fewer parking spaces compared to areas near typical main roads. In this configuration, the route search unit acquires location information of parking spaces (parking spaces where vehicles can be safely parked) along the searched route and outputs the location information of these parking spaces along with the searched route. Therefore, in residential areas with few parking spaces, it is possible to prevent users (delivery personnel) from parking their vehicles on unsafe roadsides, thereby improving both user convenience and safety.

[0017] Furthermore, the present invention can be realized in various forms, for example, as a route search device, a navigation device, a navigation system, a computer program for realizing the functions of these devices and systems, a server device for distributing the computer program, or a non-temporary storage medium storing the computer program. [Brief explanation of the drawing]

[0018] [Figure 1] This figure shows a schematic configuration of a navigation system as one embodiment of the present invention. [Figure 2] This figure shows an example of delivery plan information. [Figure 3] It is a flowchart showing an example of the processing procedure of the route search processing. [Figure 4] It is a diagram for explaining a specific example of rule a1. [Figure 5] It is a diagram for explaining a specific example of rule a2. [Figure 6] It is a diagram for explaining a specific example of rule a3. [Figure 7] It is a diagram for explaining specific examples of rules a4 and a5. [Figure 8] It is a diagram for explaining a specific example of the excluded target route. [Figure 9] It is a diagram showing an example of the guidance screen displayed to the client. [Figure 10] It is a diagram showing the schematic configuration of the navigation system of the second embodiment. [Figure 11] It is a flowchart showing an example of the processing procedure of the route search processing of the second embodiment. [Figure 12] It is a diagram showing the schematic configuration of the navigation system of the third embodiment. [Figure 13] It is a diagram showing the schematic configuration of the navigation system of the fourth embodiment.

Embodiments for Carrying out the Invention

[0019] A. First Embodiment: FIG. 1 is a diagram showing the schematic configuration of a navigation system 1 as an embodiment of the present invention. The navigation system 1 is a system used by a person (hereinafter also referred to as a "delivery person") engaged in the logistics business, particularly in the business of delivering goods such as packages to a designated delivery destination. The navigation system 1 exemplified here outputs guidance information including route guidance to the delivery destination of the goods to be delivered (hereinafter also referred to as "goods to be delivered") and information regarding the delivery destination to the user (delivery person), and is used to smooth the delivery business.

[0020] The navigation system 1 of this embodiment can suppress guidance of routes that include dead ends and cul-de-sacs through the route search process described later. Here, "dead end" refers to a road where only one of the two ends of the road connects to another road. Also, "cul-de-sac" refers to a group of roads that are shaped like a bag and cannot be passed through.

[0021] Navigation system 1 comprises a server 10 and a client 30. Server 10 is connected to the Internet (INT) via wired communication. Client 30 is connected to the Internet (INT) via wireless communication through a communication carrier (BS). The communication carrier (BS) includes transmitting and receiving antennas, wireless base stations, and switching stations. In other words, server 10 and client 30 can communicate with each other via the Internet (INT).

[0022] Server 10 uses delivery plan information 341 (details described later) obtained from client 30 to search for a route (hereinafter also referred to as the "delivery route") in which the delivery addresses of the packages to be delivered are set as transit points. Server 10 corresponds to a "route search device". Server 10 is equipped with a CPU 110, a communication unit 120, a ROM / RAM 130, and a storage unit 140, and each unit is interconnected by a bus (not shown).

[0023] The CPU 110 controls various parts of the server 10 by loading computer programs stored in the ROM 130 into the RAM 130 and executing them. The CPU 110 also functions as a route search unit 111. The route search unit 111 is a processing unit that searches for a route from the origin to the destination using the route information DB 142. In this embodiment, the route search unit 111 calculates the delivery route described above. The communication unit 120 controls communication with other devices such as the client 30 via a communication interface (not shown).

[0024] The storage unit 140 consists of a hard disk, flash memory, memory card, etc. The storage unit 140 pre-stores a map information database 141, a route information database 142, and a guidance information database 143. In the following explanation, databases will also be simply referred to as "DB".

[0025] Map Information DB141 is a database that stores data representing map images. The data representing map images includes information necessary for map display, such as terrain, buildings, and road shapes. Route Information DB142 is a database that stores road network data. The road network data includes node information related to "nodes" that represent the locations of intersections and landmarks such as stations, and link information related to "links" that represent roads connecting nodes. Node information includes node location information, node type, node name, and other node information. Link information includes link cost for each mode of transport (average travel time on the road represented by the link), link type, link name, link status, and other link information. Route Information DB142 corresponds to the "route information storage unit".

[0026] The guidance information DB143 is a database that stores information about parking spaces. Here, "parking space" means a place located near a road where it is possible to safely park a vehicle. In this embodiment, parking spaces are not limited to so-called parking lots. Information about parking spaces may include not only the location of the parking space, but also the type of parking space (whether it is a parking lot or not, etc.), the size of the parking space, and the time period during which the parking space can be used. Note that the guidance information DB143 may be stored on a server other than server 10. In that case, server 10 may connect to the other server as needed in the processing described later and obtain information about parking spaces.

[0027] The client 30 can be configured as any device, such as a smartphone as shown in the diagram, a personal computer, an in-vehicle device, or a wearable device. The client 30 includes a CPU 310, a communication unit 320, a ROM / RAM 330, a storage unit 340, an input / output unit 350, and a current location acquisition unit 360, and each unit is interconnected by a bus (not shown).

[0028] The CPU 310 controls various parts of the client 30 by loading the computer program stored in the ROM 330 into the RAM 330 and executing it, and also functions as a guidance unit 311. The guidance unit 311 sends delivery plan information 341 to the server 10 and obtains delivery route information 342 from the server 10. Using the obtained delivery route information 342, the guidance unit 311 outputs the delivery route (path) from the input / output unit 350, thereby guiding the user of the client 30 on the delivery route.

[0029] The communication unit 320 controls communication with other devices, such as the server 10, via a communication interface (not shown).

[0030] The storage unit 340 consists of a hard disk, flash memory, memory card, etc. Delivery plan information 341 is pre-stored in the storage unit 340. In addition, delivery route information 342 obtained from the server 10 through a process described later is also stored in the storage unit 340.

[0031] Figure 2 shows an example of delivery plan information 341. The delivery plan information 341 stores information about packages to be delivered on that day by the client 30's users (hereinafter also referred to as "package information"). As shown in the figure, each package information includes, for example, the delivery address, the delivery address's latitude and longitude, whether or not there is a delivery box at the delivery address, nameplate information, remarks, specified delivery time, whether or not a delivery box can be used, and information on unattended delivery. Unattended delivery information may include whether or not unattended delivery is possible, the specified location for unattended delivery, and the specified conditions for implementing unattended delivery (date and time, weather, etc.). Note that package information may also include other information not shown in the figure.

[0032] Returning to Figure 1, let's continue the explanation. The input / output unit 350 is a variety of interfaces used for inputting and outputting information between the client 30 and the user. For example, the input / output unit 350 can be a touch panel as an input unit, a touch panel as a display unit (output unit), an LCD panel, etc. The current position acquisition unit 360 receives radio waves transmitted from artificial satellites that make up the GPS (Global Positioning System) or QZSS (Quasi-Zenith Satellite System) and acquires current position information (latitude and longitude) representing the current position of the client 30. Here, since the client 30 is carried around by the user, the current position acquired by the current position acquisition unit 360 can be considered equivalent to the user's current position.

[0033] Figure 3 is a flowchart illustrating an example of the processing procedure for route search. Route search is a process performed on the server 10 to search for a delivery route. Route search is initiated by a processing request from the client 30. The processing request from the client 30 includes the delivery plan information 341 described in Figure 2. In step S100, the route search unit 111 acquires the delivery plan information 341 included in the processing request from the client 30.

[0034] In step S102, the route search unit 111 refers to the delivery plan information 341 obtained in step S100 and performs a route search, setting each delivery address of the package information 1 to n (where n is any natural number) as an intermediate point. The departure point at this time may be the current location obtained by the current location acquisition unit 360, or a predetermined location (for example, the user's home or the delivery business office). The destination can also be a predetermined location (for example, the user's home or the delivery business office). The route search can be performed using the route information DB 142 and employing the well-known Dijkstra's algorithm or the well-known Aester search algorithm.

[0035] Here, in step S102, the route search unit 111 excludes terminal links and specific links from the search in accordance with the following rules a1 to a5. Specifically, it excludes links in the route information DB 142 that correspond to terminal links and specific links from the search by performing processes such as assigning a maximum cost, correcting the link cost to exclude them from selection, or assigning a predetermined flag (hereinafter also referred to as "exclusion processing"). Here, a "terminal link" is a link that corresponds to a dead end (a road where only one of the ends of the road connects to another road). A "specific link" is a link that leads to a dead end (a group of roads that form a cul-de-sac and cannot be passed through).

[0036] (a1) The pathfinding unit 111 excludes links from the search if only one of the nodes located at both ends of the link is connected to another link, as these are considered "end links". (a2) The path search unit 111 excludes links from the search if one of the nodes located at both ends of the link is connected only to the terminal link of rule a1, as it is considered a "specific link". (a3) Even if a link is a terminal link of rule a1, the route search unit 111 will not exclude the terminal link from the search if the link length from the node located at both ends of the terminal link that is not connected to other links (end node) to the intermediate point is equal to or greater than a predetermined threshold. (a4) The route search unit 111 does not exclude a link from the search if it is a terminal link of rule a1, but the terminal link is a link that faces either the origin or the destination. (a5) If all links fall under the terminal links of rule a1 or the specific links of rule a2, the route search unit 111 will not exclude those terminal links and specific links from the search.

[0037] Figure 4 illustrates a specific example of rule a1. Figure 4(A) shows an example of the search route RT before exclusion processing. Figure 4(B) shows an example of the search route RTa after exclusion processing. Note that in Figure 4, nodes with hatched lines represent nodes that are not connected to other links (endpoint nodes). This is also true for Figures 4 and subsequent figures. As shown in Figure 4(A), we assume that the waypoint WP is set on link EL. Of the nodes N2 and N3 located at both ends of link EL, only one (node ​​N2) is connected to another link. In such a case, the route search unit 111, in accordance with rule a1, considers link EL to be an end link and excludes link EL from the search by performing exclusion processing. As a result, as shown in Figure 4(B), route RTa that does not include link EL is calculated. Route RTa is a route that does not include a U-turn on link EL (see route RT before exclusion processing). Furthermore, as shown in Figure 4(B), the route search unit 111 may move the symbol display position of the waypoint WP to the position on the route RTa that is closest to the original waypoint WP position (waypoint WPa).

[0038] Figure 5 illustrates a specific example of rule a2. Figure 5(A) shows an example of a search route RT before exclusion processing. Figure 5(B) shows an example of a search route RTa after exclusion processing. As shown in Figure 5(A), it is assumed that the waypoint WP is set on link L1, and that link L1 is connected to links EL1 and EL2 via node N3. Link EL1 is connected to other links only at one of the nodes N3 and N5 located at both ends of link EL1 (node ​​N3). Similarly, link EL2 is connected to other links only at one of the nodes N3 and N6 located at both ends of link EL2 (node ​​N3). Therefore, the route search unit 111, in accordance with rule a1, considers links EL1 and EL2 to be terminal links and excludes links EL1 and EL2 from the search by performing exclusion processing on links EL1 and EL2, respectively. Furthermore, in link L1, one of the nodes N2 and N3 located at both ends of link L1 (node ​​N3) is connected only to the terminal links (EL1, EL2) of rule a1. Therefore, the route search unit 111, in accordance with rule a2, considers link L1 to be a specific link and excludes link L1 from the search by performing an exclusion process. As a result, as shown in Figure 5(B), a route RTa is calculated that does not include links L1, EL1, and EL2. This is a route that does not include a U-turn on link L1 (see route RT before exclusion processing). Note that the route search unit 111 may also move the symbol display position of the waypoint WP (waypoint WPa), as in Figure 4.

[0039] Figure 6 illustrates a specific example of rule a3. Figure 6(A) shows a specific example of rule a3. The link connections and intermediate points in Figure 6(A) are the same as in Figure 5. However, in Figure 6(A), the link length of link EL1 is longer than in the example in Figure 5. Link EL1 corresponds to a terminal link, as explained in Figure 5. Of the nodes N3 and N5 located at both ends of link EL1, node N5, which is not connected to any other link, is called the "endpoint node". For link EL1, the link length A1 from the endpoint node N5 to the intermediate point WP is greater than or equal to a predetermined threshold X1. Therefore, the route search unit 111 does not exclude link EL1 in accordance with rule a3 and does not exclude it from the search (i.e., it treats link EL1 as a link that does not fall under rule a1). The threshold X1 can be set arbitrarily and may be registered or changed by the user of client 30. Furthermore, since link L1 does not fall under the category of a specific link (where one of the nodes N2 or N3 located at either end of link L1 is connected only to the terminal link of rule a1), it is not excluded and is not excluded from the search.

[0040] Figure 6(B) illustrates rules that may be executed in addition to rule a3. The route search unit 111 may also determine links to be excluded from the search in accordance with the following rule a31, in addition to the rules a1 to a5 described above. (a31) The route search unit 111 will not exclude a link from the search if, even if it is a link that falls under the specific link of rule a2, the link length from a node at both ends of the specific link that is different from the node connected to the terminal link (the entry node) to the intermediate destination is greater than or equal to a predetermined threshold.

[0041] The link connections and intermediate points in Figure 6(B) are the same as in Figure 5. However, in Figure 6(B), the link length of link L1 is longer than in the example in Figure 5. As explained in Figure 5, link L1 corresponds to a specific link, and links EL1 and EL2 correspond to terminal links. Of the nodes N2 and N3 located at both ends of link L1, node N2 that is different from node N3 connected to terminal links EL1 and EL2 is called the "entrance node". For link L1, the link length B1 from the entrance node N2 to the intermediate point WP is greater than or equal to a predetermined threshold Y1. For this reason, the route search unit 111 does not exclude link L1 in accordance with rule a31 and does not exclude it from the search (i.e., it treats link L1 as a link that does not fall under rule a2). The threshold Y1 can be set arbitrarily, and may be registered or changed by the user of client 30. The threshold Y1 may be the same value as the threshold X1 in Figure 6(A).

[0042] The route search unit 111 may, instead of following rules a3 and a31, determine which links are excluded from the search in accordance with the following rules b3 and b31. (b3) The route search unit 111 does not exclude a link from the search even if it is a terminal link of rule a1, if the link length of the terminal link (i.e., the link length stored in the route information DB 142) is greater than or equal to a predetermined threshold. (b31) The route search unit 111 does not exclude a link from the search if the link length of that specific link (i.e., the link length stored in the route information DB 142) is equal to or greater than a predetermined threshold, even if the link falls under the specific link of rule a2.

[0043] The route search unit 111 may, instead of following the rules a3 and a31 described above, determine which links are excluded from the search in accordance with the following rules c3 and c31. (c3) The route search unit 111 does not exclude a link from the search even if it is a terminal link of rule a1, if the endpoint node of the terminal link is not included within the predetermined area from the predetermined position. (c31) The route search unit 111 does not exclude a link from the search if the entry node of the specified link does not fall within the predetermined area from the predetermined position, even if the link falls under the specified link of rule a2. The predetermined locations in rules c3 and c31 can be arbitrarily determined, for example, the location of a waypoint WP or the nearest node N3 from a waypoint WP can be used. The predetermined areas in rules c3 and c31 mean any range demarcated with the predetermined location as the center, for example, a criterion such as the area within a virtual circle with a predetermined radius centered on the predetermined location can be used.

[0044] Figure 7 illustrates specific examples of rules a4 and a5. Figure 7(A) shows a specific example of rule a4. The link connections in Figure 7(A) are the same as in Figure 4, but in Figure 7(A), destination G is set on link EL. Link EL corresponds to a terminal link, as explained in Figure 4. Link EL is a link facing either the origin or the destination (in the illustrated example, destination G). Therefore, the route search unit 111 does not exclude link EL in accordance with rule a4 and does not exclude it from the search (i.e., it treats link EL1 as a link that does not fall under rule a1). As a result, in the example of Figure 7(A), the route RT to destination G on link EL is calculated.

[0045] Figure 7(B) shows a specific example of rule a5. The link connections and intermediate points in Figure 7(B) are the same as in Figure 5, but in Figure 7(B), in addition to nodes N5 and N6, nodes N1 and N4 also correspond to endpoint nodes. Also, in Figure 7(B), destination G is set on link EL3. Link EL3 is an end link in which only one of the nodes N1 and N2 located at both ends of link EL3 (node ​​N2) is connected to another link. Similarly, link EL4 is an end link in which only one of the nodes N2 and N4 located at both ends of link EL4 (node ​​N2) is connected to another link. For this reason, the route search unit 111 does not exclude end links EL1, EL2, EL3, EL4 and specific link L1 in accordance with rule a5, and does not exclude them from the search (i.e., links EL1, EL2, EL3, EL4 are treated as links that do not fall under rule a1, and link L1 is treated as a link that does not fall under rule a2). As a result, the route RT, which includes a U-turn on link L1, is calculated, as shown in Figure 7(B).

[0046] Furthermore, the route search unit 111 does not apply rules a1 to a5 to links that, in terms of link connections, do not fall under the aforementioned terminal links, but are impassable due to road closures or restrictions.

[0047] In step S104 of Figure 3, the route search unit 111 determines whether the route obtained in step S102 includes a route to be excluded. Here, the "route to be excluded" can be arbitrarily defined; for example, a U-turn route can be excluded. In this case, the route search unit 111 analyzes the route (link sequence) obtained in step S102 and determines that a U-turn route is included if it includes a round trip of the same link (specifically, if it includes forward movement of a certain link A and backward movement of link A). If an excluded route is included (step S104: YES), the route search unit 111 proceeds to step S106. On the other hand, if an excluded route is not included (step S104: NO), the route search unit 111 proceeds to step S108.

[0048] Figure 8 illustrates a specific example of a route to be excluded. Assume that the route RT shown in Figure 8 is calculated as a result of the route search in step S102. In this case, the route search unit 111 determines that a U-turn route is included in route RT. Note that in step S104, the route search unit 111 may also consider the link width (road width) when determining whether a route should be excluded. For example, if the link width is greater than a predetermined value, the route search unit 111 may determine that it is a main road where a U-turn is possible and that no route to be excluded is included (step S104: NO). This predetermined value can be arbitrarily determined.

[0049] In step S106, the route search unit 111 excludes links that constitute the excluded route by performing an exclusion process on them, thereby excluding those links from the search. Subsequently, the route search unit 111 performs a route search again and transitions the process to step S108.

[0050] In step S108, the route search unit 111 generates delivery route information and outputs it to the client 30. Specifically, the route search unit 111 searches the guidance information DB 143 and obtains information on parking spaces along the route (delivery route) searched in step S102 or step S104 (location information of the parking space, type of parking space, size of the parking space, time period during which the parking space can be used, etc.). After that, the route search unit 111 sends the route searched in step S102 or step S104 and the obtained parking space information to the client 30 as "delivery route information". Note that the description "step S102 or step S104" means that if a re-search is performed in step S104, the search result of step S104 is used, and if a re-search is not performed in step S104, the search result of step S102 is used.

[0051] Figure 9 shows an example of a guidance screen W1 displayed on client 30. After obtaining delivery route information from server 10, the guidance unit 311 of client 30 outputs screen W1 for guiding the delivery route to the input / output unit 350. As shown in Figure 9, screen W1 includes a map view V1, a delivery destination list view V2, and a guidance view V3.

[0052] Map view V1 displays a map. The map displays the current location symbol PL, the delivery route RT, the delivery destination symbol S1 plotted at the first delivery destination location, the delivery destination symbol S2 plotted at the second delivery destination location, and symbols PS1 to PS3 representing the locations of parking spaces along the delivery route RT. Here, as shown in map view V1 in Figure 9, the first delivery destination S1 is set on a terminal link. However, as a result of the route search process described in Figure 3 suppressing the calculation of routes including dead ends and cul-de-sacs, the delivery route RT is defined as a route that does not include the terminal link that delivery destination S1 faces. Here, when the user taps one of the parking spaces PS1 to PS3, the guidance unit 311 may display detailed information about the tapped parking space (for example, the type of parking space, the size of the parking space, the time period during which the parking space can be used, etc.) in a callout or in a separate window or any other manner. Note that parking space PS3 is located at a location somewhat far from the delivery route RT. Thus, the route search unit 111 may add information about parking spaces surrounding the delivery route RT to the delivery route information, in addition to information about parking spaces along the delivery route RT (Figure 3: Step S108).

[0053] The delivery destination list view V2 displays package information for deliveries (delivery address, delivery latitude and longitude, presence or absence of a delivery box at the delivery destination, nameplate information, remarks, specified delivery time, availability of delivery boxes, unattended delivery information, etc.) in list format. The guidance view V3 displays the estimated arrival time at the first intermediate stop, in other words, the first delivery destination S1, and the distance from the current location PL to the first delivery destination S1. Note that the screen W1 shown in Figure 9 is merely an example, and various changes can be made. For example, the delivery destination list view V2 and the guidance view V3 may be omitted. In this case, for example, when the user taps delivery destinations S1 and S2, package information for deliveries to the tapped delivery destination may be displayed in a callout or in a separate window, or in any other manner. For example, the estimated arrival time at the first delivery destination S1 and the distance from the current location PL to the first delivery destination S1 may be output by voice along with the screen display, or instead of a screen display.

[0054] As described above, according to the navigation system 1 of the first embodiment, the route search unit 111 of the server 10 searches for a route from the road network data stored in the route information DB 142, excluding terminal links (i.e., links that are dead ends) which are links where only one of the nodes located at both ends of the link is connected to another link (step S102: rule a1). Therefore, a route search device (server 10) that can suppress guidance of routes including dead ends can be provided. Furthermore, according to the navigation system 1 of the first embodiment, the determination of whether or not a link is a terminal link (a link that is a dead end) is made using the link connection relationships in the route information DB 142 used for route search (rule a1). Therefore, compared to cases where special information is required separately, guidance of routes including dead ends can be suppressed without being affected by the availability of information (Figure 4).

[0055] Furthermore, according to the navigation system 1 of the first embodiment, the route search unit 111 of the server 10 searches for a route from the road network data stored in the route information DB 142, excluding not only terminal links but also specific links where one of the nodes located at both ends of the link is connected only to the terminal link (i.e., links leading to dead ends) (step S102: rule a2). Therefore, a route search device (server 10) capable of suppressing guidance for routes including dead ends can be provided. Also, according to the navigation system 1 of the first embodiment, the determination of whether or not a link is a specific link (a link leading to a dead end) is made using the link connection relationships in the route information DB 142 used for route search (rule a2). Therefore, compared to cases where special information is required separately, guidance for routes including dead ends can be suppressed without being affected by the availability of information (Figure 5).

[0056] Even if a road is a dead end, if the road length is long, there is a request to be guided along a route that includes the dead end. In this regard, according to the navigation system 1 of the first embodiment, the route search unit 111 of the server 10, when the endpoint node is one of the nodes located at both ends of an endpoint link that is not connected to other links, does not exclude the endpoint link (the link that corresponds to a dead end) from the search if the link length from the endpoint node to the intermediate point is greater than or equal to a predetermined threshold (step S102: rule a3). Therefore, even if a road is a dead end, if the road length is long, the route search unit 111 can guide along a route that includes the dead end (Figure 6(A)).

[0057] Even if a route is a dead end, if it faces either the starting point or the destination, there is a demand for guidance that includes that dead end. In this regard, according to the navigation system 1 of the first embodiment, the route search unit 111 of the server 10 does not exclude terminal links (links that are dead ends) from the search if the terminal link faces either the starting point or the destination (Step S102: Rule a4). Therefore, the route search unit 111 can guide users along a route that includes a dead end, even if it faces either the starting point or the destination (Figure 7(A)).

[0058] Residential areas, which consist of many private homes, have many narrow roads where vehicles make U-turns, and also have a lot of traffic from pedestrians and cyclists, compared to typical main roads. In this regard, according to the navigation system 1 of the first embodiment, if the route search unit 111 of the server 10 includes a route that involves making a U-turn at a certain link, it excludes the link that constitutes the U-turn route from the search target, re-searches for the route, and outputs the re-searched route (steps S104, S106, Figure 8). As a result, the route search device (server 10) further suppresses guidance of routes that include U-turn routes, thereby improving the ease of driving on the guided route and improving safety.

[0059] In recent years, the demand for logistics services has increased due to the spread of internet shopping, and the number of people (delivery personnel) engaged in the work of delivering goods and other packages to designated delivery destinations has increased. In this regard, according to the navigation system 1 of the first embodiment, the route search unit 111 of the server 10 acquires information on one or more delivery destinations that the user of the route search device (server 10) will stop at for the delivery of the package (step S100), and searches for a route from the starting point to the destination, passing through one or more delivery destinations as intermediate points (step S102). Therefore, a route search device specialized for delivery services can be provided.

[0060] Furthermore, there are fewer parking spaces near residential areas with many private homes compared to areas near typical main roads. In this regard, according to the navigation system 1 of the first embodiment, the route search unit 111 of the server 10 acquires location information of parking spaces (parking spaces where vehicles can be safely parked) along the searched route (step S108), and outputs the location information of said parking spaces along with the searched route (Figure 9). Therefore, in residential areas with few parking spaces, it is possible to prevent users from parking their vehicles on unsafe roadsides, thereby improving both user convenience and safety.

[0061] B. Second Embodiment: Figure 10 shows a schematic configuration of the navigation system 1A of the second embodiment. The navigation system 1A of the second embodiment includes a server 10A instead of server 10 in the configuration described in the first embodiment. In the second embodiment, the processing content of the route search process executed by server 10A differs from that of the first embodiment.

[0062] Figure 11 is a flowchart showing an example of the processing procedure for route searching in the second embodiment. The CPU 110A of the server 10A has a route searching unit 111A instead of a route searching unit 111. The route searching unit 111A executes the route searching process shown in Figure 11. The route searching process in Figure 11 is the same as the route searching process in Figure 3, except that steps S104 and S106 (Figure 3: re-search when excluded routes are included) are not executed.

[0063] Thus, the configuration of the navigation system 1A can be modified in various ways, and re-searching when excluded routes are included may be omitted. The navigation system 1A of this second embodiment can also achieve the same effects as the first embodiment described above. Furthermore, the navigation system 1A of the second embodiment can reduce the processing load on the server 10A and shorten the time from when a processing request is made from the client 30 until the server 10 makes a response (step S108 in Figure 11: transmission of delivery route).

[0064] C. Third Embodiment: Figure 12 shows a schematic configuration of the navigation system 1B of the third embodiment. The navigation system 1B of the third embodiment has a server 10B instead of server 10 in the configuration described in the first embodiment, and does not have a client 30. The server 10B of the third embodiment performs processing without cooperating with the client 30.

[0065] The storage unit 140B of server 10B stores delivery plan information 144 in addition to the map information DB 141, route information DB 142, and guidance information DB 143. The contents of the delivery plan information 144 are the same as the delivery plan information 341 explained in Figure 2. The storage unit 140B also stores delivery route information 145 as a result of the route search process (Figure 3). The CPU 110B of server 10B has a route search unit 111B instead of a route search unit 111. In step S100 of the route search process (Figure 3), the route search unit 111B retrieves the delivery plan information 144 from the storage unit 140B. In step S108 of the route search process (Figure 3), the route search unit 111B stores the generated delivery route information in the delivery route information 145.

[0066] Thus, the configuration of the navigation system 1B can be modified in various ways, and the server 10B may output the generated delivery route information to the storage unit 140B of the server 10B. The server 10B may also acquire delivery plan information 144 from other devices or servers connected via the network. Similarly, the server 10B may output the delivery route information generated in the route search process (Figure 3) to other devices or servers connected via the network. This third embodiment of the navigation system 1B can achieve the same effects as the first embodiment described above.

[0067] D. Fourth Embodiment: Figure 13 shows a schematic configuration of the navigation system 1C of the fourth embodiment. The navigation system 1C of the fourth embodiment has a client 30C instead of client 30 in the configuration described in the first embodiment, and does not have a server 10. The client 30C of the fourth embodiment performs processing without cooperating with the server 10. In this embodiment, the client 30C corresponds to the "route search device".

[0068] The memory unit 340C of client 30C pre-stores delivery plan information 341, delivery route information 342, as well as map information DB 343, route information DB 344, and guidance information DB 345. Map information DB 343 is the same as map information DB 141 described in Figure 1. Route information DB 344 is the same as route information DB 142 described in Figure 1. Guidance information DB 345 is the same as guidance information DB 143 described in Figure 1. The CPU 310C of client 30C has a guidance unit 311 and a route search unit 312. The route search unit 312 is a functional unit that performs the same processing as the route search unit 111 described in Figures 1 and 3.

[0069] Thus, the configuration of the navigation system 1C can be modified in various ways, and the client 30C may be configured as a route search device. The map information DB 343, route information DB 344, and guidance information DB 345 are stored in an external data server, and the route search unit 312 may connect to the data server each time during the processing shown in Figure 3 to obtain the necessary data. Furthermore, in order to enable the client 30C, which has inferior processing power compared to the server 10 (Figure 1), to execute the route search process (especially step S102 in Figure 3), constraints may be placed on the search speed and search distance range during the route search process. The navigation system 1C of this fourth embodiment can also achieve the same effects as the first embodiment described above.

[0070] E. Variations: In the above embodiment, some of the configuration implemented by hardware may be replaced with software, and conversely, some of the configuration implemented by software may be replaced with hardware. Other modifications are also possible, as follows.

[0071] · Variation 1: The above embodiment shows an example of the configuration of a navigation system, server, and client. However, the configuration of each device can be arbitrarily chosen. For example, at least a portion of each database held by the server and client may be stored on other devices (including external servers connected via the Internet).

[0072] In the above embodiment, the navigation system was defined as a system that guides delivery routes, in other words, a system used in delivery operations. However, the navigation system can be constructed not only for delivery operations but also as a system for general users that provides normal route guidance.

[0073] • Variation 2: In the above embodiment, the pathfinding process (Figures 3 and 11) was described with an example of the processing procedure. However, these processing procedures can be modified in various ways, and the processing content in each step may be added, omitted, or changed, and the execution order of each step may also be changed.

[0074] For example, in step S102, rules a1 to a5 were provided as examples for excluding terminal links and specific links from the search, respectively. However, one or more of these rules a1 to a5 may be adopted in any combination. For example, rule a1 may be executed alone, or rule a1 and rule a3 may be executed in combination.

[0075] For example, in step S108, it is stated that the delivery route information includes the route explored in step S102 or step S104 and information about parking spaces. However, the information about parking spaces may be omitted. Also, the delivery route information may include other information.

[0076] • Modification 3: The present invention is not limited to the embodiments, examples, and modifications described above, and can be realized in various configurations without departing from its spirit. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-mentioned problems, or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of symbols]

[0077] 1,1A~1C…Navigation System 10, 10A, 10B… Servers 30,30C…Client 110, 110A, 110B…CPU 111, 111A, 111B... Pathfinding Unit 120... Communications Department 130...ROM / RAM 140,140B…Storage section 141...Map Information Database 142…Route Information Database 143... Information Database 144…Delivery plan information 145…Delivery route information 310, 310C…CPU 311…Information Department 312...Route search unit 320... Communications Department 330...ROM / RAM 340,340C…Storage section 341…Delivery plan information 342…Delivery route information 343...Map Information Database 344…Route Information Database 345... Information Database 350…Input / output section 360…Current position acquisition unit

Claims

1. A pathfinding device, A route information storage unit that stores road network data including node information and link information connecting nodes, A route search unit that searches for a route from the starting point to the destination, Equipped with, The aforementioned path search unit, From the aforementioned road network data, terminal links, which are links where only one of the nodes located at both ends of the link is connected to another link, are excluded from the search, and the aforementioned route is then searched. A pathfinding device that outputs the explored path.

2. A pathfinding device according to claim 1, The route search unit searches for a route from the road network data, excluding specific links from the search, in addition to the terminal links, where one of the nodes located at both ends of the link is connected only to the terminal link.

3. A pathfinding device according to claim 1 or claim 2, The aforementioned path search unit, The system searches for a route from the aforementioned departure point to the aforementioned destination, passing through predetermined intermediate points. A route search device that, when a node located at both ends of the terminal link that is not connected to another link is designated as the endpoint node, searches for the route without excluding the terminal link if the link length from the endpoint node to the intermediate point is greater than or equal to a predetermined threshold.

4. A pathfinding device according to any one of claims 1 to 3, The route search unit is a route search device that searches for the route without excluding the terminal link from the search if the terminal link is a link facing either the departure point or the destination.

5. A pathfinding device according to any one of claims 1 to 4, The aforementioned path search unit, If the searched route includes a route that makes a U-turn at a certain link, the link constituting that U-turn route is excluded from the search, and the route is searched again. A pathfinding device that outputs the re-searched path.

6. A pathfinding device according to any one of claims 1 to 5, The aforementioned path search unit, The user of the route search device obtains information on one or more delivery destinations to which the package will be delivered. A route search device that searches for the route from the departure point to the destination, passing through one or more delivery destinations as intermediate stops.

7. A pathfinding device according to claim 6, The aforementioned path search unit, Location information of parking spaces located near a road where vehicles can be safely parked, and location information of such parking spaces along the searched route is obtained. A route search device that outputs the location information of the acquired parking space in addition to the route that was searched.

8. A pathfinding method, wherein the information processing device is Using road network data that includes node information and information about the links connecting nodes, the process of searching for a route from the starting point to the destination is performed. In the aforementioned search process, From the aforementioned road network data, terminal links, which are links where only one of the nodes located at both ends of the link is connected to another link, are excluded from the search, and the aforementioned route is then searched. A pathfinding method that outputs the explored path.

9. A computer program, for use in an information processing device. A computer program that performs the step of searching for a route from a starting point to a destination using road network data that includes node information and information about the links connecting the nodes, In the aforementioned search step, From the aforementioned road network data, terminal links, which are links where only one of the nodes located at both ends of the link is connected to another link, are excluded from the search, and the aforementioned route is then searched. A computer program that outputs the searched paths.

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