Patrol route guidance system and virtual map information acquisition system

Abstract

To provide a technique for processing a route search at high speed.SOLUTION: A patrol route guidance system includes: a map information acquisition unit that acquires map information indicating a road network represented by a link and a node that is an end point of the link; a virtual map information acquisition unit that acquires virtual map information indicating a virtual road network configured by converting a plurality of continuous links into a single virtual link; a patrol route acquisition unit that acquires a patrol route that starts from a departure point and patrols around a plurality of points based on the virtual map information; and a guidance control unit that causes a guidance unit to guide the patrol route using the map information.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a route guidance system and a virtual map information acquisition system. [Background technology]

[0002] Conventionally, there are known techniques for searching for a route between a departure point and a destination. For example, Patent Document 1 discloses a technique for searching for a route using map data configured in a hierarchical structure, such as Level 1, which contains detailed map data including general roads, Level 2, which contains map data including national roads and prefectural roads, and Level 3, which contains map data including expressways, toll roads, and national roads. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-202140 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional technology aims to speed up route searches by using hierarchical map data, but when searching for a circular route that visits multiple locations, the search takes a long time even when using conventional map data. The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a technique for processing route searches at high speed. [Means for solving the problem]

[0005] In order to achieve the above-mentioned objectives, the circular route guidance system includes a map information acquisition unit that acquires map information indicating a road network represented by links and nodes that are the end points of the links; a virtual map information acquisition unit that acquires virtual map information indicating a virtual road network formed by converting multiple consecutive links into a single virtual link; a circular route acquisition unit that acquires a circular route that departs from a starting point and travels around multiple points based on the virtual map information; and a guidance control unit that uses the map information to cause the guidance unit to guide the circular route.

[0006] In other words, the route guidance system generates a virtual road network that is different from a road network made up of real roads by performing a contraction process that converts multiple links in a road network into a single virtual link. Because multiple links are converted into a single virtual link in the virtual road network, the number of cases that must be considered when searching for a virtual route using virtual links is reduced compared to when searching for a route using a road network.

[0007] Therefore, using a virtual road network makes it possible to search for a virtual route using virtual links more quickly than when a road network is used. Because virtual links are generated from road links, once a virtual route using virtual links has been obtained, a route using the original road links can be easily obtained. Therefore, using a virtual road network makes it possible to search for a circular route that travels around multiple points more quickly than when a road network is used. Furthermore, even if the circular route is a route on a road network and the search is performed using a virtual road network, it is possible to guide a user to a circular route that corresponds to an actual road, allowing the user to recognize a circular route on an actual road. [Brief explanation of the drawings]

[0008] and delivery charges [Figure 1] FIG. 1 is a block diagram of a route guidance system. [Figure 2]FIG. 2 is a diagram showing the relationship between a road network and a virtual road network. [Figure 3] FIG. 10 is a diagram illustrating an example of virtual cost information. [Figure 4] 10 is a flowchart of a route guidance process. [Figure 5] FIG. 5A is a diagram showing how an area is specified, and FIG. 5B is a diagram showing the costs of all combinations of two locations. [Figure 6] FIG. 6A is a diagram showing an example of a road network at the 0th layer, and FIG. 6B is a diagram showing an example of a road network at the 1st layer. [Figure 7] FIG. 10 is a diagram for schematically explaining an example of searching for a virtual route based on a virtual road network. [Figure 8] FIG. 10 is a diagram for schematically explaining an example of searching for a virtual route based on a virtual road network. [Figure 9] FIG. 10 is a diagram for schematically explaining an example of searching for a virtual route based on a virtual road network. DETAILED DESCRIPTION OF THE INVENTION

[0009] Here, the embodiments of the present invention will be described in the following order. (1) Configuration of the route guidance system: (2) Route guidance processing: (3) Other embodiments:

[0010] (1) Configuration of the route guidance system: FIG. 1 is a block diagram showing the configuration of a route guidance system 10 according to one embodiment. Route guidance system 10 is a computer having a function for acquiring a route that travels around multiple locations, and works in cooperation with a client terminal 50. In this embodiment, the route is a route used for delivering packages, and is information indicating the order in which multiple locations are reached and the route between each location. In this embodiment, a vehicle driver drives the vehicle, travels around multiple locations along the route, and performs at least one of delivering and collecting packages at each location.

[0011] In this embodiment, route guidance system 10 is implemented by a server operated from client terminal 50. Client terminal 50 is a terminal used by a user who creates a route, such as a route manager or a vehicle driver. Client terminal 50 can be implemented, for example, by a general-purpose computer or a mobile terminal, and includes a control unit 50a, a user I / F unit 50b, and a communication unit 50c.

[0012] The control unit 50a includes a CPU, RAM, ROM, etc., and is capable of executing various programs stored in a storage medium (not shown). In this embodiment, the control unit 50a is capable of executing a program that issues an instruction to create a circular route and displays the created circular route.

[0013] The user I / F unit 50b includes a guide unit such as a display (not shown), and input units such as a keyboard and a mouse. The communication unit 50c is a device for performing wired or wireless communication with other devices. The control unit 50a can communicate with the route guidance system 10 via the communication unit 50c. The user can cause the route guidance system 10 to create a route by operating the input unit of the client terminal 50. Once the route is created, the route guidance system 10 displays the route on the guide unit of the user I / F unit 50b. The user can recognize the route displayed on the guide unit.

[0014] In this embodiment, it is assumed that a vehicle driver departs from a base point, visits multiple points along a predetermined route, delivers or collects packages at each point, and returns to the base point. However, it is also possible to use multiple vehicles. That is, multiple routes may be generated and provided for multiple vehicles driven by multiple drivers. Furthermore, there may be multiple base points, and a route plan may be generated so that one point is visited multiple times at different time periods. For simplicity, an example of creating a route plan for visiting multiple points from one base point will be described here.

[0015] The route guidance system 10 according to this embodiment acquires creation conditions for creating a tour plan from a client terminal 50, and creates a tour route based on the creation conditions. To create a tour route, the route guidance system 10 includes a control unit 20, a storage medium 30, and a communication unit 40. The control unit 20 can execute a program recorded on the storage medium 30 or the like.

[0016] The communication unit 40 is a device for performing wired or wireless communication with other devices. The control unit 20 is capable of communicating with a client terminal 50 via the communication unit 40. Map information 30a is pre-recorded in the storage medium 30. In addition, in response to a tour route guidance request from the client terminal 50, virtual map information 30b and tour route information 30c are recorded in the storage medium 30.

[0017] The map information 30a is information indicating a road network represented by links and nodes that are the end points of the links. Specifically, the map information 30a includes node data indicating the positions of nodes set on roads on which vehicles travel, i.e., on existing roads, shape interpolation point data indicating the positions of shape interpolation points for specifying the shape of the road between the nodes, link data indicating the connections between nodes, facility data indicating the positions of facilities present around the roads, etc. The link data may be associated with various information for each road section, and in this embodiment, the link data is associated with information indicating the traveling direction of the vehicle on the link, i.e., information indicating the traveling direction in the case of one-way traffic and information indicating two-way traffic.

[0018] The virtual map information 30b is information indicating a virtual road network expressed by virtual link information indicating virtual links and node information indicating nodes that are the endpoints of the virtual links. All links that make up a virtual road network are called virtual links, but virtual links may coincide with links that indicate actual roads. In the virtual map information 30b, the virtual road network is also made up of virtual links and nodes, so the virtual map information 30b includes virtual link data that indicates virtual links and node data that indicate the endpoints of the virtual links. However, because road shapes are not taken into account in virtual links, the virtual map information 30b does not include information indicating the shapes of virtual links.

[0019] Furthermore, in this embodiment, the virtual link data is associated with information indicating the vehicle's traveling direction on the virtual link, i.e., information indicating the traveling direction in the case of a one-way street or information indicating two-way traffic. The virtual map information 30b may be defined in various ways. In this embodiment, multiple virtual hierarchical levels are set, and virtual road networks belonging to each level are defined. In this embodiment, a virtual road network with fewer nodes than the road network indicated by the map information 30a is configured by reducing the number of nodes by converting consecutive links into single links.

[0020] In this embodiment, when converting to virtual links, one node is removed by the conversion to generate a virtual road network at a higher level. This process of removing nodes is repeated until there is only one node left. Therefore, if the map information 30a from which the virtual map information 30b was generated contains N+1 nodes, after the conversion is complete, there will be N levels.

[0021] In this embodiment, the virtual road network generated from the road network indicated by the map information 30a is called the first-layer virtual road network. The virtual road network belonging to the first layer is a network configured by converting multiple consecutive links belonging to the road network into a single virtual link.

[0022] For layers higher than the first layer, conversion is performed as follows: That is, a virtual road network belonging to the M+1th layer (M is an integer from 1 to (N-1)) is constructed by converting multiple consecutive virtual links belonging to the Mth layer into a single virtual link belonging to the (M+1)th layer.

[0023] In FIG. 2, a road network or a virtual road network is shown inside a rectangular frame. In these networks, the straight lines inside the frame indicate links or virtual links, and the black circles indicate nodes. The bottom row of FIG. 2 shows a schematic representation of the links and nodes that make up the road network of the 0th layer Ly(0) shown in the map information 30a. The second row from the bottom of FIG. 2 shows a schematic representation of the virtual links and nodes that make up the virtual road network of the 1st layer Ly(1). Note that the numbers in parentheses indicate the layer, and the road network shown in the map information 30a is considered to be the 0th layer (the same applies below).

[0024] In the example shown in FIG. 2, it is assumed that the road network of the first layer Ly(1) has been generated by deleting node N(0)1 from the road network of the 0th layer Ly(0). That is, consecutive links L(0)1 and L(0)2 are converted into a single virtual link L(1)1, thereby deleting node N(0)1. In addition, as a result of this conversion, consecutive links L(0)3 and L(0)4 are converted into virtual link L(1)2. Furthermore, consecutive links L(0)1 and L(0)4 are converted into virtual link L(1)3, and consecutive links L(0)3 and L(0)2 are converted into virtual link L(1)4. In this way, when moving up one layer, the number of links may not decrease, but the number of nodes will decrease. Therefore, compared to a search using map information 30a at the 0th layer, using virtual links at a higher layer allows for faster search.

[0025] A virtual link generated in this manner is associated with virtual cost information, which is the sum of the costs of passing through multiple links that are the source of the virtual link, and source link information, which indicates the multiple source links. For example, virtual link L(1)1 is obtained by combining links L(0)1 and L(0)2 into a single virtual link, so links L(0)1 and L(0)2 are associated with virtual link information indicating virtual link L(1)1 as source link information. Furthermore, the sum of the costs of links L(0)1 and L(0)2 is associated with virtual link information indicating virtual link L(1)1 as virtual cost information.

[0026] The cost can be defined in various ways, and in this embodiment, it is defined as at least one of the distance of the original link and the time required to travel that link. For example, the virtual cost information associated with the virtual link L(1)1 is associated with at least one of a distance cost indicating the sum of the distances of links L(0)1 and L(0)2 and a time cost indicating the sum of the time required to travel links L(0)1 and L(0)2.

[0027] FIG. 3 is a diagram schematically illustrating an example of virtual cost information. In FIG. 3, the left column shows the original links, and the right column shows the converted virtual links. In FIG. 3, the virtual link L(1) in the first layer is associated with the links L(0)1 and L(0)2 in the 0th layer as the original links. The distance costs of the links L(0)1 and L(0)2 in the 0th layer are CL(0)1 and CL(0)2, respectively, and the time costs are CT(0)1 and CT(0)2. Therefore, the virtual link L(1) in the first layer is associated with at least one of the sum of the distance costs, CL(0)1+CL(0)2, and the sum of the time costs, CT(0)1+CT(0)2. In the virtual map information 30b indicating the virtual road network in the first layer, the identification information of each virtual link is associated with the virtual cost information in the above manner.

[0028] Similarly, in the second and higher layers, the identification information of the 0th link that is the source of conversion and cost information are associated with the identification information of the virtual link, and virtual cost information of the virtual link is also associated. Fig. 3 shows an example in which at least one of the sum of distance costs CL(0)11+CL(0)12+CL(0)14 and the sum of time costs CT(0)11+CT(0)12+CT(0)14 is associated with the virtual link L(3)1 in the third layer. In this embodiment, virtual cost information, which is the sum of the costs of the source links, is associated with the virtual link information. However, in a configuration in which the source links are associated, the sum of the costs of these links may be calculated as necessary and used as the virtual cost information.

[0029] 2 is an example, and virtual road networks for multiple hierarchical levels may belong to a single hierarchical level. In any case, it is sufficient that a virtual link belonging to an arbitrary hierarchical level is configured by converting multiple consecutive links belonging to the road network indicated by the map information 30a into a single link.

[0030] The tour route information 30c is information indicating a tour route, and in this embodiment, includes information indicating the order in which to tour multiple locations, and information indicating the route between locations when touring each location in that order.

[0031] The control unit 20 includes a CPU, RAM, ROM, etc., and is capable of executing programs (not shown) stored in the storage medium 30. In this embodiment, one of the programs includes a route guidance program 21. When the route guidance program 21 is executed, the control unit 20 functions as a map information acquisition unit 21a, a virtual map information acquisition unit 21b, a route acquisition unit 21c, and a guidance control unit 21d.

[0032] The map information acquisition unit 21a has a function of acquiring map information indicating a road network represented by links and nodes which are the end points of the links. That is, the control unit 20 uses the function of the map information acquisition unit 21a to refer to the storage medium 30 and acquire the map information 30a.

[0033] The virtual map information acquisition unit 21b has a function of acquiring virtual map information indicating a virtual road network formed by converting multiple consecutive links into a single virtual link. That is, the control unit 20 acquires map information 30a using the function of the virtual map information acquisition unit 21b, and performs link conversion involving the deletion of one node. The control unit 20 repeats this conversion until there is only one node. Details of this conversion will be described later. When the virtual map information 30b indicating the virtual road network is generated, the control unit 20 stores the virtual map information 30b indicating the generated information in the storage medium 30. In order to perform this processing, the virtual map information acquisition unit 21b can also be considered to function as a virtual map information generation unit.

[0034] The circular route acquisition unit 21c has a function of acquiring a circular route that starts from a departure point and travels around multiple points, based on the virtual map information 30b. In this embodiment, the circular route is a route that travels around multiple points, and if a route search is performed based on the map information 30a using a search algorithm such as the Dijkstra algorithm, the number of cases becomes excessively large, which tends to result in an excessively large computational load. Therefore, in this embodiment, the control unit 20 searches for a virtual route between points based on the virtual map information 30b. As a result, it is possible to process the route search faster than a configuration that searches for a route using the map information 30a.

[0035] In this embodiment, the virtual route searched based on the virtual map information 30b is used to determine the cost of traveling between two points. Specifically, in this embodiment, a route that travels between multiple points needs to be acquired. The control unit 20 acquires the route by solving a vehicle routing problem (VRP). To solve the VRP, the cost of traveling between all possible combinations of two points is required. Therefore, the control unit 20 searches for a virtual route between two points based on the virtual map information 30b and determines the cost between the two points based on the searched virtual route. Once the cost between any two points is acquired, the control unit 20 can acquire the route order for traveling between the multiple points using a known VRP algorithm. Once the route order is acquired, the control unit 20 generates a route by regarding the source link of the virtual link that constitutes the virtual route between two points as the route between the two points.

[0036] Once the tour route is generated, the control unit 20 stores tour route information 30c indicating the tour route, i.e., information indicating the tour order when visiting multiple locations and information indicating the route between the locations when visiting each location in the tour order, in the storage medium 30. Details of the process for obtaining the tour route will be described later.

[0037] The guidance control unit 21d has a function of causing the guidance unit to provide guidance on the circular route using map information. Specifically, the control unit 20 transmits circular route information 30c via the communication unit 40 using the function of the guidance control unit 21d. The control unit 50a of the client terminal 50 acquires the circular route information 30c via the communication unit 50c and controls the guidance unit of the user I / F unit 50b to guide the user along the circular route. The circular route guidance may be provided in various ways, such as by displaying points, a circular order, and the circular route on a map, or by displaying a list of identification information of points arranged in the circular order, or by other various display ways. In this embodiment, an example is assumed in which information regarding the time required to travel along the circular route is provided. Details of this guidance will be described later.

[0038] (2) Route guidance processing: Next, the circular route guidance process executed by the control unit 20 will be described in detail. Fig. 4 is a flowchart showing the circular route guidance process. In the circular route guidance process, the control unit 20 starts the circular route guidance process when a circular route guidance request is made from the client terminal 50. When the circular route guidance process starts, the control unit 20 receives an area specification using the function of the map information acquisition unit 21a (step S100). The area is a region that includes multiple points to be patrolled and is the range within which a virtual road network is created, and is specified by the user.

[0039] That is, the user operates the input unit of the user I / F unit 50b in the client terminal 50 to specify an area. FIG. 5A is a diagram showing how an area is specified. In FIG. 5A, roads are indicated by straight lines, and points to be patrolled are indicated by black circles. In the client terminal 50, a map is displayed on the display of the user I / F unit 50b. The user operates the input unit of the user I / F unit 50b, and specifies the desired area, for example, by drawing a rectangle on the map with the mouse pointer Po.

[0040] When an area is specified, the control unit 50a of the client terminal 50 transmits information indicating the area (for example, coordinates of diagonal vertices) via the communication unit 50c. The control unit 20 acquires the information indicating the area via the communication unit 40.

[0041] Next, the control unit 20 acquires the map information 30a by using the function of the map information acquisition unit 21a (step S105). That is, the control unit 20 refers to the storage medium 30 and acquires the map information 30a indicating the links and nodes included in the area specified in step S100.

[0042] Next, the control unit 20 acquires the virtual map information 30b by using the function of the virtual map information acquisition unit 21b (step S110). As described above, the virtual map information 30b is generated by repeating the process of generating the next higher layer by setting a virtual link in accordance with the deletion of one node.

[0043] 6A and 6B are diagrams showing in more detail the setting of virtual links accompanying the deletion of node N(0)1 shown in FIG. 2. FIG. 6A shows links L(0)1 to L(0)5 that exist around node N(0)1 in a road network at the 0th layer Ly(0). FIG. 6A also shows arrows indicating the direction of travel of vehicles on the links, and indicates the time cost of passing through each link. FIG. 6B shows virtual links L(1)1 to L(1)5 that are related to the deletion of node N(0)1 in a virtual road network at the 1st layer Ly(1). Note that while the examples shown in FIGS. 6A and 6B show an example in which node N(0)1 is deleted based on time cost, node N(0)1 may also be deleted based on other costs, for example, distance cost.

[0044] When a link is converted into a virtual link, multiple consecutive links are converted into a single virtual link. Also, if there are multiple virtual links that travel between the same nodes, only the virtual link with the smallest cost remains. Therefore, the control unit 20 generates a virtual link by using, as the source of conversion, the link string with the smallest sum of time costs from among the link strings that start from one of two nodes adjacent to the node to be deleted, pass through the node to be deleted, and arrive at the other node.

[0045] For example, the only route that starts at node N(0)3, passes through node N(0)1, and travels to node N(0)4 is the route that passes through links L(0)3 and L(0)4. Therefore, in this case, the control unit 20 converts links L(0)3 and L(0)4 as the source of conversion and converts them into a single virtual link L(1)2.

[0046] On the other hand, there are two routes from node N(0)2 to node N(0)5: one that passes through links L(0)1 and L(0)2, and one that passes through links L(0)5, L(0)3, and L(0)2. Therefore, the control unit 20 obtains the sum of the costs of these two routes. According to the time costs shown in FIG. 6A, the sum of the time costs of the route that passes through links L(0)1 and L(0)2 is 11 (= 6 + 5), and the sum of the time costs of the route that passes through links L(0)5, L(0)3, and L(0)2 is 21 (= 7 + 9 + 5). Therefore, the control unit 20 converts links L(0)1 and L(0)2, which have the smallest sum, into a single virtual link L(1)1. Similar processing is performed for routes traveling between other nodes, and virtual links L(1)3, L(1)4, and L(1)5 are obtained. In FIG. 6B, information indicating the sum of the costs of the links from which the conversion is to be performed is written for each virtual link.

[0047] When a virtual link is generated, the control unit 20 associates the link on the map information 30a from which the virtual link was generated with the virtual link. In the example shown in FIG. 6B, since the virtual links L(1)1 and L(1)2 do not have a node common to both links, it is not possible to move directly from one of the virtual links L(1)1 and L(1)2 to the other in the virtual road network. In addition, various methods can be used to select nodes to be deleted, and a method can be used in which priorities are set using various methods and nodes are deleted in order of highest priority.

[0048] The control unit 20 performs conversion in a similar manner for layers higher than the first layer. When N+1 nodes exist in the area specified in step S100, the control unit 20 converts multiple consecutive virtual links belonging to the Mth layer into a single virtual link belonging to the (M+1)th layer, thereby generating a virtual road network belonging to the M+1th layer (M is an integer from 1 to (N-1)). That is, the control unit 20 repeats the process of deleting nodes one by one and moving each layer to a higher layer, thereby generating layers from the first to the Nth layers, and generating a virtual road network for each layer. According to the above process, a virtual road network that allows for high-speed route search can be generated.

[0049] Next, the control unit 20 receives a search request using the function of the route acquisition unit 21c (step S115). Specifically, the user of the client terminal 50 operates the input unit of the user I / F unit 50b to specify the locations for which a route is to be created, the search conditions, and the route time period. The locations for which a route is to be created are multiple locations that are visited by the route, such as delivery destinations of packages. Various methods for specifying locations may be used. For example, multiple locations may be specified by specifying the location's name, store name, attributes, etc. For example, if a convenience store is the delivery destination, the location is specified by the store's name, store name, etc. Note that the multiple locations include a departure point. If the departure point has attributes different from those of the other locations, for example, if the departure point is a logistics center and the delivery point is a store, the user may specify the departure point in a different manner from those of the other locations. Of course, the above method is merely an example, and the user may specify each location individually.

[0050] The search conditions are information for specifying the type of cost to be minimized when searching for a virtual route. Various modes are assumed for specifying this information. For example, the type of cost may be specified, such as specifying either a distance cost or a time cost. Alternatively, in a configuration in which a route is searched based on multiple types of costs, the type of cost to be prioritized (a cost with a relatively large weight) may be specified.

[0051] The patrol time period is information for specifying the time period during which the vehicle travels along the patrol route. Various modes are conceivable for specifying this information. For example, a configuration in which the time or time period of departure from the starting point of the patrol route is specified as the patrol time period can be adopted. When the points for which the patrol route is to be created, the search conditions, and the patrol time period are specified, the control unit 50a transmits information indicating the specified contents via the communication unit 50c. The control unit 20 acquires this information via the communication unit 40 and stores it in a storage medium such as RAM.

[0052] Next, the control unit 20 sets virtual cost information of the virtual link (step S120). Specifically, the control unit 20 associates the virtual cost information with the virtual map information 30b acquired in step S110. In this embodiment, the control unit 20 acquires virtual cost information for each virtual link based on the type of cost corresponding to the search condition specified by the user in step S115, and associates the information with the virtual link.

[0053] For example, if the search conditions indicate a search based on distance cost, the control unit 20 acquires the sum of the distance costs when passing through multiple links that are the source of the virtual link, and acquires virtual cost information based on the distance cost as shown in FIG. 3. The control unit 20 then generates virtual link information in which the virtual cost information is associated with the identification information of the virtual link, and stores the generated information in the storage medium 30 as virtual map information 30b. If the search conditions indicate a search based on time cost, the control unit 20 acquires the sum of the time costs when passing through multiple links that are the source of the virtual link, and performs the same process. If the search conditions indicate a search using both distance cost and time cost, the control unit 20 acquires the sum of the distance costs and the sum of the time costs when passing through multiple links that are the source of the virtual link, and uses these as virtual cost information. With the above configuration, virtual cost information for virtual links can be easily set.

[0054] The time cost indicates the time required to travel through a link or virtual link, but the time cost may be considered to vary depending on the time period. For example, the time required for the same link may be considered to be different in the morning and afternoon. In the following, it is assumed that the time cost varies depending on the time period, and that a time cost is defined for each time period. Therefore, the control unit 20 acquires the time cost for the travel time period and uses it as virtual cost information. If the vehicle requires time to travel the route and the time period changes, the time required for the vehicle to travel through the virtual link may be identified, and the time period when the vehicle travels through the virtual link may be identified based on the required time, and the time cost for that time period may be acquired. The time period may be defined in various ways, for example, every hour or every few hours, or may be distinguished by different lengths of time, such as morning, afternoon, evening, and late night. Of course, the time period may also be distinguished by day of the week, season, etc.

[0055] Next, the control unit 20 uses the function of the tour route acquisition unit 21c to search for virtual routes for all combinations between any two points based on the virtual links (step S125). Specifically, the control unit 20 acquires the coordinates of the multiple points to be toured specified in step S115. Then, the control unit 20 extracts two points from these multiple points as processing targets.

[0056] Next, the control unit 20 sets one of the two processing target points as the departure point and the other as the destination, and searches for a virtual route based on the virtual map information 30b. A virtual route is a sequence of virtual links connecting two points. In this embodiment, the control unit 20 searches for a virtual route from the departure point, searches for a virtual route from the destination, and when the virtual routes meet, combines the virtual route from the departure point to the meeting point with the virtual route from the destination to the meeting point, and acquires them as candidates for the virtual route from the departure point to the meeting point.

[0057] 7 to 9 are diagrams for schematically explaining an example of a search for a virtual route based on a virtual road network. In FIGS. 7 to 9, a road network consisting of a total of seven nodes is illustrated, and from the bottom, the nodes are represented as the 0th layer Ly(0), the 1st layer Ly(1), and the 2nd layer Ly(2). The top layer is the 6th layer Ly(6). In addition, in FIGS. 7 to 9, black circles represent nodes, and straight lines connecting the black circles represent links or virtual links. Each node is assigned identification information for nodes N1 to N7. The numerical values ​​assigned to the links are the costs of each link. In other words, the cost value in the 0th layer Ly(0) is the cost of an actual link, and the cost value in a layer higher than the 0th layer Ly(0) is the cost of a virtual link (virtual cost information). The starting point S is node N2, and the destination G is node N6.

[0058] First, the search for a virtual route from the departure point will be described. When searching for a virtual route after the node of the departure point, the control unit 20 selects an adjacent node and performs a process of extending the virtual route to the adjacent node. When selecting an adjacent node, the control unit 20 selects the adjacent node from among the nodes connected to the virtual link of the highest layer to which the current node belongs. Figure 8 shows an example in which the search for a virtual route is started from the departure point S shown in Figure 7, and nodes N3 and N4 are successively selected as adjacent nodes.

[0059] More specifically, when selecting a node adjacent to the departure point S, the control unit 20 identifies the virtual link of the highest hierarchical level to which node N2, which is the departure point S, belongs. In the example shown in FIG. 8, the highest hierarchical level to which node N2 belongs is level Ly(1). Therefore, the control unit 20 searches for an adjacent node using the virtual links belonging to level Ly(1). In the example shown in FIG. 8, the options are a virtual link connecting nodes N2 and N1 and a virtual link connecting nodes N2 and N3. Here, an example in which the control unit 20 selects node N3 is shown by the dashed-dotted arrow.

[0060] When searching for a node adjacent to node N3, the control unit 20 searches for an adjacent node on the highest layer Ly(3) to which node N3 belongs. In the example shown in FIG. 8, the options are a virtual link connecting nodes N1 and N3 and a virtual link connecting nodes N3 and N4. Here, the example in which the control unit 20 selects node N4 is shown by the dashed arrow. In FIG. 8, the virtual route searched for from destination G is shown by the dashed arrow. In this example, a virtual route from the node that is destination G to node N4 is searched. In this case, the virtual route from the departure point S (nodes N2, N3, N4) and the virtual route from destination G (nodes N6, N4) merge.

[0061] Therefore, the control unit 20 combines the virtual route from the departure point S and the route obtained by reversing the virtual route from the destination G, and acquires the combined result as a single search result. That is, a virtual route that passes through nodes N2, N3, N4, and N6 is acquired as a single search result. Since there are multiple possible virtual routes from the departure point S to the destination G, the control unit 20 searches for each virtual route. For example, as shown in FIG. 9, the control unit 20 searches for a virtual route that passes from the departure point S to nodes N2, N1, and N7, and searches for a virtual route that passes from the destination G to nodes N6 and N7. Since these virtual routes merge at node N7, the control unit 20 acquires the virtual route that passes through nodes N2, N1, N7, and N6 as a search result. In the examples shown in FIGS. 7 to 9, the control unit 20 also acquires a virtual route that passes through nodes N2, N3, N1, N7, and N6 as a search result.

[0062] When the search results for virtual routes between two points are obtained as described above, the control unit 20 selects one virtual route with the smallest virtual cost and determines it as the search result. In the example shown in Figures 7 to 9, the sum of the virtual costs of the virtual routes that follow nodes N2, N3, N4, and N6 is 47 (=12+8+27), the sum of the virtual costs of the virtual routes that follow nodes N2, N1, N7, and N6 is 87 (=9+66+12), and the sum of the virtual costs of the virtual routes that follow nodes N2, N3, N1, N7, and N6 is 111 (=12+21+66+12). Therefore, in this example, the control unit 20 determines the virtual route that follows nodes N2, N3, N4, and N6 as the search result.

[0063] Note that the type of virtual cost included when determining the virtual route is the type of virtual cost set as the virtual cost information in step S120. For example, if the user specifies a search condition that uses a distance cost, the virtual cost of each link is the distance cost, and their sum becomes the virtual cost information of the virtual link. If the user specifies a search condition that uses a time cost, the virtual cost of each link is the time cost, and their sum becomes the virtual cost information of the virtual link. In this embodiment, the time cost is a time cost determined based on the travel time period. Furthermore, if the user specifies a search condition that uses multiple types of virtual costs, the virtual cost of each link and its sum are determined based on the multiple types of virtual costs, and become the virtual cost information.

[0064] As described above, in this embodiment, the virtual cost information is defined by a type of cost selected from multiple types of costs, such as distance cost and time cost, so that the user can specify routes to be searched based on different needs.

[0065] In the above-described virtual route search based on the virtual road network, a virtual route is searched by sequentially selecting adjacent nodes, and a virtual route candidate is identified by merging the virtual route from the departure point and the virtual route from the destination. From the virtual route candidates thus obtained, the virtual route with the smallest sum of costs is selected to obtain the search result. In a search using the virtual road network, when searching for nodes adjacent to each node, adjacent nodes within the highest hierarchical level to which each node belongs are searched. In the hierarchical structure of this embodiment, in many cases, many hierarchical levels can be skipped in the process of searching the highest hierarchical level. Repeated skipping of many hierarchical levels quickly reduces the number of adjacent node candidates. Therefore, compared to searches based on map information 30a using the Dijkstra algorithm or the like, the number of cases is reduced quickly, enabling the virtual route search to be processed quickly. Furthermore, in this embodiment, when searching for a virtual route, there is no process of determining the route with the smallest cost during the route search process, as is the case with the Dijkstra algorithm or the like. Therefore, the route search can be processed quickly.

[0066] After searching for a virtual route between two points extracted as processing targets in the above manner, the control unit 20 searches for a virtual route between two points that are not processing targets. That is, the control unit 20 repeats the process of searching for a virtual route between the two points using a virtual link for each combination obtained by selecting any two points from multiple points, until all combinations that can be extracted from multiple points are covered.

[0067] Next, the control unit 20 sets a cost between two points from the virtual route acquired in step S125 using the function of the tour route acquisition unit 21c (step S130). That is, the control unit 20 sets a cost between the two points for each of the virtual routes between the two points acquired in step S125. Specifically, the control unit 20 sets the minimum value of the sum of the virtual cost information between the two points calculated when identifying the virtual route between the two points in step S125 as the cost of the virtual route between the two points. For example, in the example shown in FIGS. 7 to 9, the cost of the virtual route between the departure point S and the destination G is 47.

[0068] The cost between the two points to be processed may be determined for each direction of travel. That is, the cost when one of the two points is the departure point and the other is the destination, and the cost when one is the destination and the other is the departure point may be obtained. Alternatively, the cost may be considered to be unchanged depending on the direction of travel, and the cost between the two points may be obtained as a single value regardless of the direction of travel. In this embodiment, the explanation will continue assuming the former.

[0069] The control unit 20 acquires costs for all combinations of two locations that can be extracted from multiple locations. FIG. 5B is a diagram showing the costs acquired in the above manner. FIG. 5B shows an example in which costs are acquired for all combinations of two locations selected from multiple locations P1 to P100. Specifically, C12 indicates the cost of a virtual route with location P1 as the departure point and location P2 as the destination, and C21 indicates the cost of a virtual route with location P2 as the departure point and location P1 as the destination. As shown in FIG. 5B, the cost is obtained when location P1 is the departure point and each of locations P2 to P100 is the destination, and similarly, the cost is obtained when each of locations P2 to P100 is the departure point and another location is the destination.

[0070] Next, the control unit 20 acquires the visiting order using the function of the visiting route acquisition unit 21c (step S135). In this embodiment, the control unit 20 acquires the visiting order based on the cost set in step S130. Specifically, the control unit 20 acquires the visiting order using a known VRP algorithm.

[0071] When obtaining the route order, various parameters may be specified. For example, the upper limit of the number of vehicles, the upper limit of the working time (the working hours of the user), the maximum load capacity of one vehicle, etc. may be input and used as constraints. Then, the control unit 20 obtains the route order that minimizes a predetermined objective function based on the cost set in step S130. The objective function may take various forms. That is, in addition to minimizing the total cost of visiting each location according to the route order, the objective function may be set to minimize predetermined factors such as the number of vehicles used, the total required time, and the total distance traveled by the vehicles. Note that in VRP, an approximate solution to the solution that minimizes the objective function may be obtained.

[0072] Next, the control unit 20 acquires a tour route along which the user will travel in accordance with the tour order (step S140). Specifically, the control unit 20 identifies the virtual route searched for in step S125 for each of two points that are consecutive when traveling along the tour order. Furthermore, the control unit 20 identifies the virtual links that make up each virtual route, and, with reference to the virtual map information 30b acquired in step S110, considers the sequence of the links that are the source of each virtual link to be the route between the two points.

[0073] For example, in the examples shown in FIGS. 7 to 9, the route searched is a virtual route that passes through nodes N2, N3, N4, and N6. The link between nodes N4 and N6 in the virtual route is converted from the link between nodes N4 and N5 and the link between nodes N5 and N6. Therefore, in this example, the permutation of links when passing through nodes N2, N3, N4, N5, and N6 is identified as the route on an actual road. The control unit 20 performs the above-described process for all two points to identify routes on actual roads between all two points, thereby acquiring a tour route. Once the tour route is acquired, the control unit 20 generates tour route information 30c that includes information indicating the order in which to visit each point and information indicating the route between the points when visiting each point in the order in which to visit the points, and stores the information in the storage medium 30.

[0074] Next, the control unit 20 provides guidance on the circular route using the function of the guidance control unit 21d (step S145). That is, the control unit 20 transmits the circular route information 30c via the communication unit 40. In the client terminal 50, the control unit 50a acquires the circular route information 30c via the communication unit 50c, and causes the guidance unit of the user I / F unit 50b to provide guidance on the circular route.

[0075] In this embodiment, the control unit 20 causes the guidance unit of the user I / F unit 50b to provide information regarding the time required to travel along the route. The information regarding the time required to travel along the route may take various forms. Here, an example is assumed in which the arrival time at each point when traveling along the route is provided. It is also assumed that the travel time period specified by the user includes the departure time from the departure point.

[0076] In this case, the control unit 20 obtains the required time based on the time cost of the virtual route from the departure point to the next point after the departure point, and obtains the arrival time at the next point after the departure point by adding the required time to the departure time. The control unit 20 also obtains the departure time from the next point by adding the work period at the next point (for example, a predetermined time length) to the arrival time. Furthermore, the control unit 20 similarly obtains the arrival time for the second and subsequent points by adding the required time for travel to the departure time from the previous point.

[0077] As described above, the arrival time at each point obtained based on the required time can be said to be information regarding the required time to travel along the route. The control unit 20 associates the arrival time at each point with information indicating the route and transmits it to the client terminal 50, which then causes the guidance unit to provide guidance. With the above configuration, the user can recognize information regarding the required time to travel along the route. This allows the user to recognize the time load of traveling by vehicle, the chronological flow of the tour, etc.

[0078] When the guidance unit is to provide information regarding the time required to travel along a circular route, it is preferable that the cost of obtaining a circular route between two points includes at least the time cost. In other words, if the cost of obtaining a circular route between two points includes the time cost, a route that minimizes or shortens the time required to travel between the two points is searched for. Therefore, by showing information regarding the time required to a user who has specified search conditions that take time cost into consideration, the search results that are searched according to the user's needs can be presented in a more understandable manner.

[0079] (3) Other embodiments: The above embodiment is one example for carrying out the present invention, and various other embodiments are also possible. For example, the route guidance system 10 constituting the above embodiment may be configured with multiple systems. In this case, some of the functions of the route guidance system 10 may be implemented by a client terminal 50 or the like, or may be implemented by a server such as a cloud server. For example, a configuration may be adopted in which processing related to VRP and processing related to route search are executed by a server external to the route guidance system 10.

[0080] 1 may be shared or distributed among other devices. For example, client terminal 50 and route guidance system 10 may be integrated. Client terminal 50 may be provided in a vehicle or may be a portable terminal. At least some of the components constituting route guidance system 10 (map information acquisition unit 21a, virtual map information acquisition unit 21b, route acquisition unit 21c, and guidance control unit 21d) may be distributed among multiple devices. Configurations in which some of the components of the above-described embodiments are omitted, or in which processing is changed or omitted, are also conceivable.

[0081] Furthermore, a system capable of executing some of the functions of route guidance system 10 may be provided. For example, a server may be configured that can execute the functions of map information acquisition unit 21a and virtual map information acquisition unit (virtual map information generation unit) 21b provided in route guidance system 10, and provided as a system for generating virtual map information 30b. Once virtual map information 30b has been generated, it is possible to obtain a route that travels around any point included in the virtual map information 30b. The virtual map may be of any range, and a virtual map may be generated for each of multiple ranges. Furthermore, the virtual cost information included in virtual map information 30b may be generated for each of multiple time periods or multiple types of costs.

[0082] The map information acquisition unit is only required to acquire map information showing a road network represented by links and nodes that are the end points of the links. In other words, the map information acquisition unit is only required to acquire map information showing a road network of existing roads using links and nodes. The road network is only required to be represented by links and nodes. Links correspond to road sections and nodes correspond to intersections, but nodes may also be set at points that are not intersections (for example, tunnel entrances and exits, points where road types change, etc.).

[0083] The virtual map information acquisition unit is only required to acquire virtual map information that indicates a virtual road network formed by converting multiple consecutive links into a single virtual link. In other words, the virtual map information acquisition unit is only required to acquire virtual map information with a reduced number of nodes based on the map information.

[0084] The virtual map information need only indicate a virtual road network composed of virtual links, and is not limited to the above configuration. For example, the number of layers included in the virtual road network may be different from that in the above embodiment. Furthermore, the virtual link may be a virtual link obtained from a plurality of consecutive links, and may be a virtual link in which both ends of the plurality of consecutive links are nodes when the plurality of consecutive links are considered as a single link. Therefore, the plurality of consecutive links that form the basis of the virtual link may be selected in various ways. In other words, the link may be converted into a virtual link in various ways.

[0085] The route acquisition unit is only required to acquire a route starting from a starting point and visiting multiple locations based on virtual map information. In other words, by searching for a virtual route on a virtual road network based on virtual map information, the route search speed should be faster than when searching for a route on a road network based on map information. A VRP is used to acquire the route, and the VRP can use various algorithms.

[0086] The guidance control unit only needs to be able to cause the guidance unit to provide guidance on the circular route using map information. That is, the search is performed using a virtual road network, but the guidance by the guidance control unit only needs to be performed on a circular route, which is a route on an actual road network. Of course, various modes of guidance on the circular route may be used, such as providing guidance on the route on a map, providing guidance on the order of routes, or providing information on the time required to travel along the circular route. Note that the information on the time required to travel along the circular route may be various types of information, such as providing guidance on the arrival time at each location, the time required between locations, or the departure time, as in the above-described embodiment.

[0087] Furthermore, the present invention can also be applied as a program or method. The above-described systems, programs, and methods may be realized as standalone devices or may be realized by using components shared with various devices, and thus include various aspects. They can also be modified as appropriate, such as being partly software and partly hardware. Furthermore, the invention can also be realized as a recording medium for a program that controls a device. Of course, the recording medium for the software may be a magnetic recording medium or a semiconductor memory, and any recording medium developed in the future can be considered in the same way. [Explanation of symbols]

[0088] 10...Round-trip route guidance system, 20...control unit, 21...Round-trip route guidance program, 21a...map information acquisition unit, 21b...virtual map information acquisition unit, 21c...round-trip route acquisition unit, 21d...guidance control unit, 30...storage medium, 30a...map information, 30b...virtual map information, 30c...round-trip route information, 40...communication unit, 50...client terminal, 50a...control unit, 50b...user I / F unit, 50c...communication unit

Claims

1. a map information acquisition unit that acquires map information indicating a road network represented by links and nodes that are end points of the links; a virtual map information acquisition unit that acquires virtual map information indicating a virtual road network configured by converting the plurality of consecutive links into a single virtual link; a route acquisition unit that acquires a route that starts from a departure point and travels around a plurality of locations based on the virtual map information; a guidance control unit that causes a guidance unit to guide the vehicle along the circular route using the map information; A route guidance system comprising:

2. The virtual map information is virtual link information indicating each of the plurality of virtual links; The virtual link information is The virtual link includes virtual cost information that is the sum of costs when passing through the plurality of links that are conversion sources of the virtual link, but does not include information indicating the shape of the virtual link. The route guidance system according to claim 1 .

3. The traveling route acquisition unit For each combination obtained by selecting any two points from the plurality of points, a virtual route is searched for, which is a route for traveling between the two points using the virtual links, and the sum of the virtual cost information of the virtual links constituting each of the virtual routes is obtained as the cost of traveling between the two points; obtaining the tour route based on the obtained cost; The route guidance system according to claim 2 .

4. The virtual cost information is a time cost required for moving the virtual link for each time period; The traveling route acquisition unit obtaining a cost for traveling between the two points based on the time cost for each virtual link according to the time of traveling between the two points; obtaining the travel route based on the obtained cost; The guidance control unit causing the guidance unit to provide information regarding the period of time required to travel along the route; The route guidance system according to claim 3 .

5. The virtual cost information is including at least one type of cost selected from a plurality of types of costs; 4. The route guidance system according to claim 2 or 3.

6. The virtual map information is The virtual road networks belong to N levels (N is an integer of 2 or more), The virtual road network belonging to the M+1th layer (M is an integer from 1 to (N-1)) is configured by converting a plurality of consecutive virtual links belonging to the Mth layer into a single virtual link belonging to the (M+1)th layer.

3. The route guidance system according to claim 1 or 2.

7. a storage medium for storing map information indicating a road network represented by links and nodes that are the end points of the links; a virtual map information generating unit that generates virtual map information indicating a virtual road network configured by converting the plurality of consecutive links into a single virtual link; a route acquisition unit that acquires a route that starts from a departure point and travels around a plurality of locations based on the virtual map information generated by the virtual map information generation unit; a guidance control unit that causes a guidance unit to guide the vehicle along the circular route using the map information stored in the storage medium; A route guidance system comprising:

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