WO2012105554A1

WO2012105554A1 - Route calculation apparatus

Info

Publication number: WO2012105554A1
Application number: PCT/JP2012/052136
Authority: WO
Inventors: 智昭蛭田; 奥出　真理子; 山崎　潤; 天谷　真一
Original assignee: クラリオン株式会社
Priority date: 2011-02-01
Filing date: 2012-01-31
Publication date: 2012-08-09
Also published as: JP2012159433A; JP5547106B2

Abstract

A route calculation apparatus is provided with the following: a transit mesh acquisition unit that, on the basis of map data and mesh costs indicating the costs of the minimum cost routes within a mesh, acquires a plurality of transit meshes included in a minimum cost route connecting a first candidate border node which is positioned on the boundary between a start point mesh and a mesh adjacent to the start point, and a second candidate border node which is positioned on the boundary between an end point mesh and a mesh adjacent to the end point; and a route search unit that updates the mesh costs so as to indicate the costs of new minimum cost routes within a mesh based on link cost updates, updates the plurality of transit meshes on the basis of the updated mesh costs, and searches for movement routes on the basis of the updated plurality of transit meshes and the new minimum cost routes within a mesh.

Description

Route arithmetic unit

The present invention relates to a route calculation device that searches for a route of a mobile object.

The route calculation device is included in, for example, an in-vehicle terminal device mounted on a vehicle or a center device arranged in an information distribution center, and calculates a route from a departure point to a destination using digitized map data. Further, the route calculation device provides the calculated route to the user.

A method for calculating a route from a departure point to a destination in a conventional route calculation device is described in Patent Document 1, for example. According to this method, the map is divided into zones, and the cost in the zone is calculated before the route search. At this time, the cost is calculated for each direction passing through the zone. This direction is, for example, from west to east and from south to north. When searching for a route, (1) a zone that passes from the departure point to the destination is determined using the cost for each direction calculated in advance. Next, (2) a route in the zone is searched for each passing zone. Finally, (3) the routes of the passing zones are connected to determine whether or not the route from the departure point to the destination is established, and if so, the route is output. If not, the processes from (1) to (3) are repeated until the route from the departure place to the destination is established.

Japanese Unexamined Patent Publication No. 2005-55915

However, according to the method described in Patent Document 1, a situation that cannot be assumed at the cost calculation stage before the route search cannot be considered. For example, when information on traffic jams caused by a car accident is acquired, even if it is desired to avoid the traffic jams, the traffic jam information cannot be taken into account if the cost has already been calculated.

According to the first aspect of the present invention, in the route calculation device, the map data in which the road link and the mesh partitioning the map are associated with each other, and the mesh and at least one adjacent mesh adjacent to the mesh are the minimum cost route in the mesh. A first position located at the boundary between the start point mesh including the start point of the moving object and the start point adjacent mesh adjacent to the start point mesh, based on the mesh cost representing the cost of the minimum cost path in the mesh when each of the two end nodes is shared A plurality of candidates included in a minimum cost path between candidate map nodes from a candidate map node to a second candidate map node located at the boundary between the end point mesh including the end point of the moving object and the end point adjacent mesh adjacent to the end point mesh. Includes a passing mesh acquisition unit that acquires a passing mesh and a section road link that is included in the minimum cost path between the candidate maple nodes. In the mesh, updated the mesh cost to represent the cost of the new minimum cost path in the mesh based on the link cost update of the section road link, updated multiple passing meshes based on the updated mesh cost, and updated A route search unit that searches for a movement route from the start point to the end point based on the plurality of passing meshes and the new minimum cost route in the mesh is provided.
According to the second aspect of the present invention, it is preferable that the route calculation device according to the first aspect further includes an information acquisition unit for acquiring current traffic information. When the difference between the link cost and the current cost of the section road link based on the current traffic information is equal to or greater than a predetermined threshold, the route search unit updates the mesh cost based on the link cost update.
According to the third aspect of the present invention, in the route calculation device according to the second aspect, the predetermined threshold is a function corresponding to an estimated elapsed time from when the moving body starts from the starting point to when it moves on the section road link. Preferably there is.
According to the fourth aspect of the present invention, it is preferable that the route computation device according to the first aspect further includes mesh cost data in which the mesh cost is associated with both end nodes. The passing mesh acquisition unit acquires a plurality of passing meshes with reference to the mesh cost included in the mesh cost data.
According to the fifth aspect of the present invention, it is preferable that the path computation device according to the first aspect further includes mesh cost data in which the mesh cost is associated with both end nodes. The mesh cost data includes data related to road links constituting the in-mesh minimum cost route.
According to the sixth aspect of the present invention, in the route calculation device according to the fourth or fifth aspect, it is preferable that the mesh cost data includes data relating to a plurality of types of costs corresponding to a plurality of types of route search conditions.

According to the present invention, the user can efficiently execute a route search corresponding to real-time information.

It is a figure which shows the whole structure of a vehicle-mounted terminal device. It is a figure which shows the structure of map data. It is a figure which shows the example of a maple node. It is a figure which shows the structure of mesh cost data. It is a figure which shows the processing flow for mesh cost data preparation. It is a figure which shows the processing flow of a passage mesh calculation apparatus. It is a figure which shows the example of a passage mesh. It is a figure which shows the example of the candidate maple node by the side of departure. It is a figure which shows the processing flow which determines a candidate maple node. It is a figure which shows the example which carries out route search using mesh cost data. It is a figure which shows the structure of the passage mesh stored in a route search result storage device. It is a figure which shows the processing flow of a route search apparatus. It is a conceptual diagram of a route search process. It is a figure which shows the structure of the route search result stored by the route search result storage device. It is a figure which shows the processing flow of a comparison apparatus. It is a figure which shows the processing flow which determines a re-search mesh. It is a conceptual diagram of the re-search by a route search apparatus. It is a figure which shows the example of a display of the route search result by a display apparatus. It is a figure which shows a route search system. It is a figure which shows the structure of the road link corresponding to mesh cost data.

Embodiments of a path calculation device using the present invention will be described with reference to the drawings.

-First embodiment-
FIG. 1 is a diagram showing an overall configuration of an in-vehicle terminal device 100 as a route calculation device according to the first embodiment of the present invention. The in-vehicle terminal device 100 includes a destination input device 110, an own vehicle position calculation device 130 of the own vehicle on which the in-vehicle terminal device 100 is mounted, map data 140, mesh cost data 150, a passing mesh calculation device 160, a route search device 170, A route search result storage device 180, a real-time information acquisition device 190, a comparison device 200, and a display device 220 are included.

The in-vehicle terminal device 100 and the sensors 120 are connected via an in-vehicle network such as CAN.

The destination input device 110 receives destination information and route search type information that a user inputs through a user interface such as a remote controller of the in-vehicle terminal device 100. The destination information is provided to the passing mesh calculation device 160. When inputting destination information, the user searches and sets the destination POI using the destination address, category, and / or telephone number as a key. POI is an abbreviation for Point Of Interest, and is information regarding points such as store information.

Route search type information is information indicating the type of route search condition. The type of route search type information includes, for example, “minimum time route” for arriving at the destination in the minimum time, and “minimum fuel consumption amount” for arriving at the destination with the minimum fuel consumption. There is a “route” and a “shortest route” aimed at minimizing the distance to the destination. The route search calculation process executed by the passing mesh calculation device 160 and the route search device 170 is executed so as to minimize the index corresponding to the route search type received by the destination input device 110. This indicator is the cost, for example, when the route search type information is “minimum time route”, the travel time to the destination, and when the route search type information is “minimum fuel consumption route” When the fuel consumption to the ground and the route search type information are “shortest route”, it is the distance to the destination.

Sensors 120 refer to GPS, vehicle speed pulses, angular velocity sensors, and the like. By using this sensor, the position, vehicle speed, and angular velocity of the vehicle can be measured. These pieces of information are provided to the vehicle position calculation device 130.

The own vehicle position calculation device 130 calculates the position of the own vehicle on which the in-vehicle terminal device 100 is mounted from the information of the sensors 120. For this calculation, a known technique such as a Kalman filter or dead reckoning is used. Information about the calculated vehicle position is provided to the route search device 170 via the passage mesh calculation device 160. The vehicle position information is represented by latitude and longitude, for example.

The map data 140 is stored in a storage device such as a hard disk or a flash memory, and includes road data and POI information. The road information and POI information included in the map area from the vehicle position to the destination are provided to the passing mesh calculation device 160 and the route search device 170.

The configuration diagram of the map data 140 is shown in FIG. FIG. 2A shows the configuration of road data stored in the map data 140. Road data is composed of links from node to node. There are two types of nodes: normal nodes that are provided at road intersections and map nodes provided at mesh boundaries. A map node is distinguished from a normal node by a map node flag. For example, when the node is a map node, “1” is set to the map node flag, and when the node is a normal node, “0” is set to the map node flag. Each road data includes a link ID that identifies a road, a mesh ID in which the road link exists, a node ID of the start node of the road link, latitude / longitude / altitude information of the start node, and a diagram of the start node. It includes an outline node flag, an end node ID of the road link, latitude / longitude / altitude information of the end node, an outline node flag of the end node, road type, regulation information, and cost data. The restriction information includes speed limit information, one-way information, and the like. When interpolation points are defined on links between nodes, links may be defined between nodes and interpolation points and between interpolation points. The altitude of the road link may be represented by gradient information instead of being represented by the altitude information of the start node and the end node.

A mesh is a unit block obtained by a method of dividing a map into a mesh pattern based on latitude and longitude. The secondary mesh is, for example, a mesh having a side length of about 10 km obtained by dividing a map with a latitude difference of 5 minutes and a longitude difference of 7 minutes 30 seconds. The tertiary mesh is a mesh obtained by dividing the secondary mesh into, for example, 10 equal parts in the latitude and longitude directions, and is a mesh having a latitude difference of 30 seconds and a longitude difference of 45 seconds and a side length of about 1 km. A mesh can be specified by the mesh ID.

The road type is information indicating the type of road link. The road type is, for example, “0” if the road link is an intercity highway, “1” if it is an intracity highway, “2” if it is a national road, and “3” if it is any other road. Is set.

Cost is a weight associated with a road link used for route search. An example of cost data is statistical traffic information. The statistical traffic information is created by statistically processing the accumulated traffic jam information on the road, and is acquired by the real-time information acquisition device 200. By this statistical processing, statistical traffic information is created that is divided by day type such as weekdays and holidays, and by time such as 0:00 and 23:00. FIG. 2D shows the structure of cost data.

The maple node is a node for dividing the road link straddling the mesh at the boundary of the mesh for the convenience of management in the map data 140 when the road link between the normal nodes straddles the mesh. By defining one or both ends with a maple node, a road link that crosses the mesh is divided at the boundary of the mesh, and as a result, there is no road link that crosses the mesh. FIG. 3 shows an example of a map node. When a road link between normal nodes straddles adjacent meshes represented by mesh IDs 001 and 002 (FIG. 3A), the road link is divided at the boundary line of the mesh, and the divided road links are Manage with mesh. The division position on the road link straddling the adjacent mesh is stored in the map data 140 as a map node shared by the adjacent meshes represented by the mesh IDs 001 and 002. The shared map node is managed by distinguishing between a map node defined by one mesh of adjacent meshes and a map node defined by the other mesh. A pair of map nodes defined at the same division position on the same road link before division at the mesh boundary of adjacent meshes has a common node ID 001 between the adjacent meshes. Therefore, the in-vehicle terminal device 100 can determine that the mesh with the mesh ID 001 is connected to the mesh with the mesh ID 002 based on the common node ID 001 included in the road data representing the divided road links (FIG. 3 ( b)).

Fig. 2 (a) shows road data. FIG. 2B shows a mesh management table included in the map data 140. In this mesh management table, the mesh ID of each mesh and the coordinates (latitude and longitude) of the respective vertices of the lower left, upper left, lower right, and upper right of the mesh are set (see FIG. 2C).

The mesh cost data 150 is an intra-mesh route that connects one end node where a mesh is located at a mesh boundary adjacent to another mesh and another end node where the mesh is further adjacent to another mesh. Has data representing the cost of the minimum cost path. If both end nodes are map nodes at the mesh boundary, the mesh cost data 150 includes data representing the cost of the minimum cost path connecting the map nodes. The mesh cost data 150 is generated in advance by a route search referring to the map data 140 by the route search device 170 described later, or a center device outside the in-vehicle terminal device 100 as in the second embodiment described later. And then stored in advance in a storage device such as a hard disk or a flash memory of the in-vehicle terminal device 100.

The passing mesh calculation device 160 acquires destination information from the destination input device 110, acquires own vehicle position information from the own vehicle position calculation device 130, and connects the contour nodes in the mesh from the mesh cost data 150. Get the cost of the route and determine the passing mesh. Further, the passage mesh calculation device 160 acquires map data of the passage mesh from the map data 140 and develops it in the memory.

The route search device 170 acquires the map data developed in the memory by the passage mesh calculation device 160, and calculates the route inside the passage mesh. The calculated route inside the passing mesh is stored in the route search result storage device 180.

The route search result storage device 180 is a storage device such as a hard disk or a flash memory, and stores the route output by the route search device 170 and the information of the passing mesh calculated by the passing mesh calculation device 160. Yes.

The real-time information acquisition device 190 receives travel time for each road link of major roads nationwide from a traffic information service center such as VICS Center (registered trademark), for example. The information update cycle is a predetermined time interval. The travel time for each link is measured by, for example, installing a vehicle detection device on the road for each road link and measuring the time required for the vehicle to travel for each road link, or measuring the probe car for each road link. It is obtained by running while.

The comparison device 200 compares the cost of the road link included in the route search result stored in the route search result storage device 180 with the cost of the road link calculated from the real-time information acquired by the real-time information acquisition device 190. Then, it is determined whether there is a mesh that needs to be searched again. When the comparison apparatus 200 determines that there is a mesh that needs to be searched again, the comparison apparatus 200 transmits information on the mesh that needs to be searched again to the route search apparatus 170.

When the route search device 170 receives information about the mesh that needs to be re-searched from the comparison device 200, the route search device 170 obtains real-time information about the route from the start-side map node to the end-point map node of the re-search target mesh. Search again using the real-time information obtained by the device 190.

The display device 220 is a liquid crystal display or the like and displays the route search result stored by the route search result storage device 180.

Hereinafter, configurations and processing flows of the mesh cost data 150, the passing mesh calculation device 160, the route search device 170, the route search result storage device 180, and the comparison device 200 will be described.

FIG. 4 shows a configuration diagram of the mesh cost data 150. FIG. 4A shows a configuration example of cost data for each mesh stored in the mesh cost data 150. In the mesh cost data 150, the number n of routes connecting the map nodes of a specific road type in the mesh, the map node ID of the start point and the map node ID of the end point corresponding to each route, and the route of each route Cost data is managed in mesh units. Each route is obtained as a result of a route search using a combination of map contour nodes as a start point and an end point, and the cost data of each route is stored in the mesh cost data 150. The cost data of each route includes cost data of route search results for each route search type information that can be input by the destination input device 110 and the number of types of costs.

In the present embodiment, since there are three types of costs such as distance, time, and fuel consumption, the number of types of costs is three as shown in FIG.

The route search result of the shortest route when the map node ID 101 of the mesh ID “001” shown in FIG. 4B is the start point and the map node ID 102 is the end point and the “shortest distance” that is the cost are as follows: It is managed as the cost data shown in FIG. The type of cost at this time is distance. Similarly, the minimum time route is calculated by a route search with the map node ID 101 of the mesh ID “001” as the start point and the map node ID 102 as the end point, and the “minimum time” is the route search result of the minimum time route and its cost. Is managed as the cost data shown in FIG. Similarly, the minimum fuel consumption route is calculated by route search with the map node ID 101 of the mesh ID “001” as the start point and the map node ID 102 as the end point, and the route search result of the minimum fuel consumption route and its cost are used. A certain “minimum fuel consumption amount” is managed as the cost data shown in FIG.

Similarly, although details are omitted, the shortest path, the minimum time path, and the minimum fuel consumption path when the map node ID 101 in the same mesh is the start point and the map node ID 103 is the end point are the same. The search results and the respective costs “shortest distance”, “minimum time”, and “minimum fuel consumption” are managed.

In this way, although not shown, for each combination when any two of the contour node IDs 101 to 103 in the same mesh are set as the start point and the end point, that is, six routes (n = 6 ), The route search result of the shortest route, the minimum time route and the minimum fuel consumption route and the respective costs “shortest distance”, “minimum time” and “minimum fuel consumption” are managed. As will be described later, the in-mesh minimum cost route corresponding to the route search type information input by the destination input device 110 is extracted from the shortest route, the minimum time route, and the minimum fuel consumption route. Based on the cost data of the in-mesh minimum cost route, the minimum cost of the route connecting the contour nodes in the mesh, that is, the mesh cost is determined.

In the cost data for each mesh shown in FIG. 4A, the details of the cost data of the mesh ID “002” are omitted from the details of the cost data of the mesh ID “001” described above. It is managed. In this way, cost data for each mesh is stored in the mesh cost data 150.

A processing flow for the route search device 170 or an external center device to create the mesh cost data 150 will be described with reference to FIG. This process is a process before the route search, and map data is input.

It is determined whether all the meshes of the map data have been processed (Step S101). If processed (Yes in step S101), the process according to this process flow is terminated. If it is not processed (No in step S101), a map node corresponding to a specific road type that is a map node in the target mesh is extracted (step S102). For example, a maple node located at a high speed between cities, a maple node located at a high speed in a city, and a maple node located on a national road are extracted. This is because the number of nodes increases when the map nodes corresponding to all the road types are handled, so the number of nodes is reduced based on the road type.

It is determined whether all map nodes extracted in step S102 in the target mesh have been processed (step S103). If processed (Yes in step S103), the process proceeds to step S101. If it has not been processed (No in step S103), the map node being processed is set as the target map node, and the process proceeds to step S104. The object map node ID at this time is “I”. In step S104, it is determined whether all the map node IDs in the target mesh other than the target map node ID “I” have been processed (step S104). If processed (Yes in step S104), the process proceeds to step S103. If it is not processed (No in step S104), a map node ID “J” (different from I and J) in the target mesh other than the target map node ID “I” is extracted and a route search is performed ( Step S105). At this time, a route is calculated with the target map node ID “I” as the starting point and the map node ID “J” as the end point. The route is calculated using Dijkstra's algorithm, which is a known technique. As the cost used for the search, a cost corresponding to the route search type that can be set by the destination input device 110 is used, and the route search is also executed for each route search type.

The start point map node ID and end point map node ID used in step S105 and the cost from the start point to the end point calculated by the route search in step S105, that is, the mesh cost, to the mesh cost data 150. Store (step S106). However, when there is no road link connecting the map nodes of the specific road type in the target mesh, a value that can determine that no road link exists, for example, “−1” is input in the cost item. . After step S106 ends, the process proceeds to step S104.

As shown in FIG. 7, the passage mesh calculation device 160 determines which mesh M passes from the map node O on the departure point S side to the map node D on the destination G side during the route search. To do. The plurality of meshes M that pass is defined as a passing mesh M0. The starting point side map node O is located at the boundary between the starting point side mesh MS including the starting point S and the passing mesh M0 adjacent thereto. The destination side map line node D is located at the boundary between the destination side mesh MG including the destination G and the passing mesh M0 adjacent thereto. In FIG. 7, the hatched mesh is a passing mesh M0 that connects the map node O on the departure point S side and the map node D on the destination M side.

The passing mesh calculation device 160 uses the mesh cost stored in the mesh cost data 150 to perform a route search from the map node O to the map node D for each mesh M included in the pass mesh M0. In FIG. 7, the map nodes in each passing mesh M0 are connected by line segments, but such notation is provided for convenience to explain the existence of a route connecting the map nodes. The line segment itself is not included in the mesh cost data 150 described above. The same applies to the drawings subsequent to FIG.

The processing flow of the passing mesh calculation device 160 will be described with reference to FIG. Candidate maple nodes around the departure point and candidate maple nodes around the destination are extracted (step S201). The candidate map nodes are map nodes that exist around the departure point and around the destination, respectively, and can be reached from the departure point and the destination, respectively. The candidate map nodes existing around the departure point and the destination are not limited to the candidate map nodes when the candidate map nodes are included in the mesh to which the departure point belongs and the mesh to which the destination belongs, respectively. This is because candidate maple nodes corresponding to specific road types are not necessarily included in the mesh to which the departure place belongs and the mesh to which the destination belongs. Therefore, the candidate map nodes existing around the departure point and the destination are, for example, the candidate map nodes included in the adjacent mesh of the mesh to which the departure point belongs and the adjacent mesh of the mesh to which the destination belongs, respectively. In this case, the candidate map box node may be used.

FIG. 8 shows an example of candidate map nodes O1 to O4 on the departure point S side. Because the road link L12 with the departure place S is connected, the map-line nodes O1 and O2 are candidate map-line nodes. However, since the map outline nodes O3 and O4 are located on the road link L34 and are not connected to the departure place S by a road link, they are not candidate map outline nodes.

The detailed processing flow of step S201 will be described with reference to FIG. The passing mesh calculation device 160 extracts a maple node around the departure point and a maple node around the destination (step S301). Here, all the map nodes of the mesh to which the departure place belongs and the map nodes of the mesh to which the destination belongs are extracted. The passing mesh calculation device 160 determines whether or not all the extracted contour nodes have been processed (step S302). If not all have been processed (No in S302), the passing mesh calculation device 160 searches for a route from the departure point or destination to the extracted map node, and determines whether the extracted map node is a candidate map node. Determination is made (step S303).

Referring to the example of FIG. 8, the passing mesh calculation device 160 determines the map nodes O1, O2, O3, and O4 located from the departure point S to the boundary between the departure point side mesh MS including the departure point S and its adjacent mesh. Until this time, the route search is performed using the map data 140. If there is network data of the road from the departure point S to the maple node, the passing mesh calculation device 160 determines that the map node is a candidate map node (in the example of FIG. 8, the map nodes O1 and O2 are candidates). Corresponds to the map node determined to be a map node). If there is no network data of the road from the departure place to the map outline node, or if the cost is larger than a predetermined value as a result of the route search, the extracted map outline node is not selected as a candidate map outline node (Fig. In the example of FIG. 8, the map nodes O3 and O4 correspond to the map nodes that are not selected as candidate map nodes).

In the case of the maple node on the destination side, the passing mesh calculation device 160 searches for a route from the destination to the maple node in the same manner as the map node on the departure side. When all the processes are performed (Yes in S302), the passing mesh calculation apparatus 160 determines whether or not there are one or more candidate maple nodes on the destination side and the departure side (step S304). If there is a candidate maple node (Yes in S304), the process according to this process flow is terminated. If there is no candidate maple node (No in S304), the passing mesh calculation device 160 expands the range for searching the mapline node, and proceeds to step S302 (step S305). Extending the search range means that adjacent meshes are also targeted for search. The passing mesh calculation device 160 newly extracts a mesh around the departure place and a map node of the mesh around the destination in the expanded search range.

Referring back to the processing flow in FIG. The passing mesh calculation device 160 determines whether all combinations of the candidate map nodes on the departure side and the destination side have been processed after determining the candidate map nodes in step S201 (step S202). When all combinations of map nodes have been processed (Yes in step S202), the processing according to this processing flow is terminated.

When all the maple node combinations have not been processed (No in step S202), the passing mesh calculation device 160 uses the mesh cost data 150 including the cost data representing the shortest distance, the minimum time, and the minimum fuel consumption. The cost data of the minimum cost route corresponding to the route search type information input by the ground input device 110 is extracted as the cost data representing the minimum cost, and the route search is performed, so that the destination side candidate map line node can be searched. A plurality of meshes included in the minimum connection path between candidate map nodes to the side candidate map node are determined as passing meshes (step S203).

FIG. 10 shows an example of step S203. The combinations of the candidate map nodes O1 and O2 on the departure side and the candidate map nodes D1 and D2 on the destination side are four sets of O1 to D1, O1 to D2, O2 to D1, and O2 to D2. Here, the passing mesh calculation device 160 uses the mesh cost stored in the mesh cost data 150 to search for a route using the candidate map node O1 or O2 as the departure point and the candidate map node D1 or D2 as the destination. . FIG. 10 shows an example in which the combination of candidate map contour nodes O1 and D2 is a combination of the departure point and the destination, and an example in which the combination of candidate map contour nodes O2 and D1 is a combination of the departure point and the destination. Yes. The route search is established when the candidate map node O1 is the departure point and the candidate map node D2 is the destination. On the other hand, in the route search when the candidate map node O2 is the departure point and the candidate map node D1 is the destination, the route connecting the map node N1 to the map node N2 in the middle mesh is in the mesh. Because there is no, it is not established. Therefore, in this example, a plurality of meshes including paths connecting the map nodes between the candidate map nodes O1 to D2 are passing meshes.

When the passage mesh calculation device 160 determines the passage mesh, the passage mesh result storage device 180 stores the information on the passage mesh including the information on the departure-side map node and the destination-side map node (step S204). ). FIG. 11A shows a configuration diagram of the information on the passing mesh stored in the route search result storage device 180 in step S204. When there are a plurality of sets of passing meshes, the route search result storage device 180 stores information on the plurality of sets of passing meshes. The information on the passing mesh includes the map node ID on the departure side, the map node ID on the destination side, the number n of passing meshes, the sum of the mesh costs calculated by the route search in step S203, and the detailed passing. Mesh information DMM.

Information included in the detailed passing mesh DMM will be described with reference to the example of FIG. Detailed passing mesh information DMM is stored for the number of passing meshes, and is stored in ID (001), starting point map node ID (101), end point map node ID (102), and cost data 150 of the passing mesh. And the mesh cost (200 m) from the start point map node ID (101) to the end point map node ID (102). There are two map nodes in the passing mesh. These map nodes are located at both ends of the route obtained in step S203, and the starting map node (101) closest to the starting point is set as the starting map side node and the end point map closest to the destination. The outline node (102) is defined as a destination side map outline node. The detailed passing mesh DMM in FIG. 11A also includes data for passing mesh ID = 002. However, in the example of FIG. 11B, since there is only one passing mesh, the detailed passing mesh DMM of the corresponding passing mesh information is different from the example shown in FIG. Only the data of passing mesh ID = 001 is stored.

The processing flow of the route search apparatus 170 will be described with reference to FIG. FIG. 13 shows an example of a conceptual diagram of route search processing executed in accordance with the processing flow of FIG. The route search device 170 acquires passing mesh information with the minimum cost (step S401). In this process, the route search device 170 obtains the smallest cost sum among the pass mesh information stored in the route search result storage device 180 by the process of the pass mesh calculation device 160. At this time, as shown in FIG. 13 (a), a passing mesh including the contour node N between the departure point and the destination is selected.

The route search device 170 performs a route search for each mesh included in the acquired passing mesh, using the departure side map node O as the departure point and the destination side map node D as the destination (step S402). This route search processing is performed by developing the mesh data to be processed among the road network data stored in the map data 140 on the memory and searching for the route using the cost data for each road link. The route search result is expressed as shown in FIG.

The route search device 170 stores the route search result in the route search result storage device 180 as route data after the route search is completed for all meshes (step S403). FIG. 14 shows an example of the configuration of route data stored in the route search result storage device 180. The route data configuration shown in FIG. 14A will be described using the example of FIG. The route data includes, for each passing mesh, the start point map node ID (101), the end point map node ID (102), the number of road links constituting the route (3), and the road link IDs (1001, 1002, constituting the route). 1003) and its cost (30 m, 50 m, 20 m).

The processing flow of the comparison device 200 will be described with reference to FIG. The processing flow of the comparison device 200 is executed at the timing when the real-time information is acquired or at a predetermined time interval. The comparison device 200 acquires a route search result from the route search result storage device 180 (step S501). The comparison device 200 compares the information acquired by the real-time information acquisition device 190 with the route search result, and determines whether re-search is necessary (step S502).

When the route search device 180 searches for a route using the minimum time data included in the mesh cost data, the cost is a travel time passing through the road link. The travel time taken into consideration when creating the mesh cost data is obtained by statistical processing of past travel time. However, when a situation occurs that cannot be covered by past traffic information, re-searching is necessary. For example, when information that a traffic accident has occurred and traffic congestion has occurred on the route is acquired by the real-time information acquisition device 190, it is necessary to perform a re-search to avoid this traffic congestion. This determination as to whether or not to search again is performed in step S502. In step S502, for example, it is detected that the difference between the travel time included in the acquired real-time traffic information and the travel time included in the statistical traffic information obtained by statistical processing of past traffic information is greater than or equal to a threshold value. Affirmative determination is made when the accident occurrence information is acquired.

When it is determined that the search is to be performed again (Yes in step S502), the comparison device 200 requests the route search device 170 to perform a search again, and ends the process (step S503). When the comparison device 200 requests a re-search, the comparison device 200 transmits the ID of the passing mesh that needs to be re-searched to the route search device 170. As will be described later, the route search device 170 performs a re-search on the passing mesh that needs to be re-searched. If it is determined in the determination as to whether or not to search again that there is no need to search again (No in step S502), the processing according to this processing flow is terminated.

FIG. 16 is a diagram showing details of the processing in step S502 as steps S5021 to S5024. Hereinafter, the processing flow of FIG. 16 will be described. However, steps S501 and S503 are the same as those in FIG. After obtaining the route search result in step S501, in step S5021, the comparison apparatus 200 determines whether or not the processing in steps S5022 and S5023 described later has been performed for all the meshes including the route obtained in step S501. . If the determination is affirmative, the process proceeds to step S5024. In the case of negative determination, in step S5022, the comparison device 200 determines the cost included in the real-time information acquired by the real-time information acquisition device 190 and the road included in the route search result stored in the route search result storage device 180. It is determined whether the difference from the cost of the link is equal to or greater than a threshold value.

In step S5022, the comparison device 200 acquires the cost (CR) included in the real-time information of the link corresponding to the link ID stored in the route search result storage device 180 in the processing target mesh. Further, the comparison device 200 acquires the link cost (CM) of the link ID stored in the route search result storage device 180. The comparison device 200 processes the road links on all routes, and if the difference between the cost included in the real-time information and the cost included in the route search result is equal to or greater than the threshold (Yes in step S5022), the presence of the road link. The mesh to be searched is set as a re-search request target (step S5023). The process returns to step S5021.

If there is no road link whose cost difference between the real-time information and the route search result exceeds the threshold in the processing target mesh (No in step S5022), the process returns to step S5021. If the determination in step S5021 is affirmative, the comparison apparatus 200 determines whether there is a mesh that has been a re-search request target in step S5023 (step S5024). If the determination is affirmative, the present process is terminated through step S503 described above, and if the determination is negative, the process is immediately terminated.

For example, the cost CR is the link travel time when the vehicle travels on the road link based on the real-time traffic information, and the cost CM is the link travel when the vehicle travels on the road link based on the statistical traffic information or the regulated speed. It's time. At this time, in step S5022, the cost CR is compared with a threshold value calculated from the cost CM. The threshold is determined in advance and is a cost k * CM obtained by multiplying the cost CM by a factor (k). For example, when the cost is the link travel time, and the cost CM is 60 seconds and the coefficient k is 3, the threshold is 180 seconds. When the cost CR based on the real-time traffic information is 200 seconds, it is larger than the threshold value of 180 seconds, so that the mesh existing in this road link is determined to be a re-search target. This threshold value may be a function corresponding to an estimated elapsed time from when the vehicle departs from the departure place S to travel on the road link.

The re-search process of the route search device 170 will be described. A conceptual diagram of the re-search process is shown in FIG. As shown in FIG. 17, when the re-search by the route search processing 170 is executed, the map node N from the candidate map node O1 closest to the departure point S to the candidate map node D2 closest to the destination G is displayed. The passing mesh MO passing through is already determined. The route search device 170 searches for the minimum cost route in the re-search target mesh MR in the passing mesh MO. In this search, a route search from the departure side map node OR of the re-search target mesh MR to the destination side map node DR of the re-search target mesh MR is performed using real-time information input from the real-time information acquisition device 190. To be executed. As the cost used for the search, a cost corresponding to the route search type that can be set by the destination input device 110 is used. At this time, the map data 140 is used.

Thus, among the passing mesh MOs stored in the route search result storage device 180, the minimum cost route of the re-search target mesh MR determined by the comparison device 200 is updated. The re-searched route RR obtained as the route search result may be different from the route calculated when the mesh cost data 150 is calculated first. Furthermore, the mesh cost data from OR to DR of the mesh MR to be re-searched is updated with the cost data of the minimum cost path. After the update, the total mesh cost of the passing mesh MO is also updated. The route search device 170 updates the cost data of the minimum cost route between the map nodes through which the host vehicle passes as mesh cost data between the map nodes in each passing mesh in all the re-search target meshes MR. After that, the process of step S401 is executed. At this time, the route search device 170 searches for a route using the updated mesh cost.

The display device 220 presents the optimal route display screen showing the route search result stored in the route search result storage device 180 to the user by displaying it on the display screen. In the display example shown in FIG. 18A, when a route search from the departure point S to the destination G is performed, the route search result stored in the route search result storage device 180 on the screen displaying the map is optimal. The route 1810 is displayed in a superimposed manner, and further, the balloon “2020” is presented to the destination by using the balloon 1820.

In another display example shown in FIG. 18B, while the passing mesh is calculated by the passing mesh calculating device 160 and the route searching process is executed by the route searching device 170, information of the passing mesh 1910 is displayed on the display screen. (FIG. 18B) and presented to the user. Furthermore, a “passing mesh” is presented by using the balloon 1920. When the route search result is output from the route search device 170, the displayed information on the passing mesh is replaced with the information on the route search result, whereby the information on the route search result is displayed on the display screen (see FIG. 18 (a)) and presented to the user. In FIG. 18B, information of the passing mesh 1910 is represented by hatching. On the actual display screen, for example, a mesh boundary line is superimposed on the map screen. In the passing mesh represented by hatching in FIG. 18B, the passing mesh is highlighted by being painted on the actual display screen.

The in-vehicle terminal device 100 according to the first embodiment described above has the following operational effects.

(1) The in-vehicle terminal device 100 includes a node ID at the start of a road link, latitude / longitude / altitude information at the start of the road link, and a map node flag indicating whether the start of the road link is a map node. Road data including a road link end node ID, latitude / longitude / altitude information of the end of the road link, a map node flag indicating whether the end of the road link is a map node, and cost data And map data 140 that associates mesh IDs defined on the mesh management table. The in-vehicle terminal device 100 includes a real-time information acquisition device 190 that acquires real-time information. The in-vehicle terminal device 100 includes a passing mesh calculation device 160.

In steps S201 to S203 in FIG. 6, the passing mesh calculation device 160, based on the map data 140, includes a plurality of passing meshes M0 including the minimum cost route from the departure point side map node O to the destination side map node D. To get. The departure point side map node O is located at the boundary between the departure point side mesh MS including the departure point S of the vehicle on which the in-vehicle terminal device 100 is mounted and the passing mesh M0 adjacent to the departure point side mesh MS. The destination side map line node D is located at the boundary between the destination side mesh MG including the destination G of the vehicle and the passing mesh M0 adjacent to the destination side mesh MG.

The mesh cost is stored in advance in the storage device. Each of the passing meshes M0 among the plurality of passing meshes M0 has the start point map node and the end point map node at both ends of the minimum cost path in the pass mesh M0 as at least one pass mesh M0 adjacent to the pass mesh M0. The mesh cost represents the cost of the minimum cost path when sharing with the network.

The in-vehicle terminal device 100 includes a comparison device 200. In the processing step S5022 of FIG. 16, the comparison apparatus 200 converts the cost of the road link included in the minimum cost route from the departure side map node O to the destination side map node D and real-time information regarding the road link. Based on this, it is determined whether or not to update the mesh cost between the contour nodes of the passing mesh M0 including the road link. When an affirmative decision is made to perform the update, the route search device 170 updates the mesh cost between the contour nodes of the re-search target mesh MR, and in the re-search target mesh MR corresponding to the updated mesh cost. Find the minimum cost path. The route search device 170 updates the plurality of passage meshes M0 based on the updated mesh costs between the contour nodes of the passage meshes, and the updated plurality of passage meshes M0 and the minimum cost route in the re-search target mesh MR. Based on the above, the route from the departure point S to the destination G is searched.
That is, in the in-vehicle terminal device 100 using the mesh cost calculated in advance, it is determined whether to update the mesh cost of the passing mesh based on the real-time traffic information, and this mesh cost is updated when an affirmative determination is made. Thus, a situation that cannot be assumed at the cost calculation stage before the route search can be taken into consideration. Therefore, a route search corresponding to real-time information can be executed efficiently.

(2) In the in-vehicle terminal device 100, the comparison device 200 determines that the difference between the road link cost CM based on the statistical traffic information or the regulated speed and the road link cost CR based on the real-time information is equal to or greater than a predetermined threshold value of 180 seconds. Affirmative determination is made to update the mesh cost of the passing mesh. Accordingly, when the road link cost CM based on the statistical traffic information or the regulated speed and the road link cost CR based on the real-time information are substantially equal, the route search device 170 updates the mesh cost of the re-search target mesh MR. The route from the starting point S to the destination G searched by the route searching device 170 can be obtained.

(3) As the road link is farther from the departure place S, the validity of the real-time information acquired at the time of departure for the road link may be reduced when the vehicle travels on the road link. In the in-vehicle terminal device 100, the predetermined threshold value may be a function corresponding to an estimated elapsed time from when the vehicle departs from the departure place S until the vehicle travels on the road link. Therefore, by increasing the predetermined threshold as the road link is farther from the departure place S, it is possible to make it difficult to update the mesh cost of the passing mesh based on the real-time information.

(4) The in-vehicle terminal device 100 further includes mesh cost data 150 in which the mesh cost calculated by the passing mesh calculation device 160 is associated with the start point map node and the end point map node. The route search device 170 refers to the mesh cost included in the mesh cost data 150 and acquires a plurality of passing meshes M0. Therefore, a plurality of passing meshes M0 can be quickly acquired simply by referring to the mesh cost data 150 generated in advance when searching for a route.

-Second embodiment-
FIG. 19 is a diagram showing an overall configuration of a route computation system as a route computation device according to the second embodiment of the present invention. The route calculation system includes an in-vehicle terminal device 1000 shown in FIG. 19A and a center device 5000 shown in FIG. 19B. The in-vehicle terminal device 1000 includes a host vehicle position calculation device 130 that calculates the position of the host vehicle from information of the destination input device 110 and sensors 120, a display device 220, and a communication device 310.

The center device 5000 includes map data 140, mesh cost data 150, passing mesh calculation device 160, route search device 170, route search result storage device 180, real-time information acquisition device 190, comparison device 200, mesh cost data creation device 210, communication. It has a device 320. The mesh cost data creation device 210 creates the mesh cost data 150 according to the processing flow shown in FIG.

The in-vehicle terminal device 1000 and the center device 5000 are connected by communication devices 310 and 320. The communication devices 310 and 320 may be a cellular phone, a wireless LAN module, a PDA (Personal Digital Assistance), or a modem integrated with the in-vehicle terminal device 1000 or the center device 5000. In the center device 5000, the processing by the route search device 180 is executed, so that the processing load on the in-vehicle terminal 1000 during the route search can be reduced. The route calculated by the center device 5000 is sent to the in-vehicle terminal device 1000 via the communication device 320.

In the in-vehicle terminal device 1000, the destination information and route search type information from the destination input device 110 and the vehicle position information from the vehicle position calculation device 130 are input and input via the communication device 310. These pieces of information are transmitted to the center device 5000.

The center device 5000 receives these pieces of information via the communication device 320, and inputs these pieces of information to the route search device 170.

The route search result stored in the route search result storage device 180 of the center device 5000 is transmitted to the in-vehicle terminal device 1000 via the communication device 320. The in-vehicle terminal device 1000 receives the route search result information via the communication device 310. Further, an optimum route display screen showing the route search result is displayed on the display screen of the display device 220, and is presented to the user.

In the route calculation system of the second embodiment described above, the in-vehicle terminal device 1000 is replaced with the in-vehicle terminal device 100 of the first embodiment in addition to the operational effects exhibited by the in-vehicle terminal device 100 of the first embodiment. There is an effect that it can be realized as a smaller apparatus.

-Modification-
(1) In the first and second embodiments described above, the mesh cost data 150 includes all the cost data related to the mesh cost obtained as a result of searching the minimum cost path in the mesh for each path search type and all the paths constituting the path in the mesh. It is good also as including road link ID. Since the in-mesh minimum cost route search is performed according to the route search type, the configuration of the road links constituting the in-mesh minimum cost route may differ depending on the route search type.

Fig. 20 (a) shows a configuration diagram of the mesh cost data 150. The mesh cost data 150 includes, in addition to the cost data related to the mesh cost for each route search type, the number of road links constituting the in-mesh route obtained as a route search result for each route search type, and the road link ID. At this time, the road link ID is stored in order from the starting point side map node. The mesh cost data 150 stores cost data related to two types of mesh costs such as “shortest distance” and “minimum time” corresponding to two types of route search types such as “shortest route” and “minimum time route”. Therefore, 2 is set as the number of mesh cost types.

FIG. 20B shows the shortest path corresponding to the “shortest distance” and the minimum time path corresponding to “minimum time”. The number of road links that make up the shortest route is “3”, and the road link IDs that make up the shortest route are “1001”, “1002”, and “1003” in order from the map node on the starting point side. The number of road links constituting the minimum time path is “2”, and the road link IDs constituting the minimum time path are “1004” and “1005” in order from the map node on the starting point side. When the mesh cost data 150 is used, in step S402 (FIG. 12) executed by the route search device 170, the cost data of the road link that constitutes the minimum cost route according to the route search type is referred to.

(2) In the description of the above-described embodiment, regarding the threshold used in the determination processing in step S5022, the threshold when the link cost is the link travel time has been described. When the link cost is the link length, that is, the distance, and when the link cost is the fuel consumption per link, these are both functions of time, and therefore the determination process in step S5022 is executed by converting to the time. can do. For example, the link length is converted into time by dividing the link length by the average moving speed of the corresponding road link. For example, the fuel consumption per link is converted into time by multiplying the fuel consumption per link by a predetermined coefficient.

(3) In the description of the above-described embodiment, the embodiment in which the route calculation device according to the present invention is applied to the in-vehicle terminal device 100 or the route calculation system including the in-vehicle terminal device 1000 and the center device 5000 has been described. . For example, the in-vehicle terminal device 100 or the in-vehicle terminal device 1000 may be included in a car navigation device used by being installed in a vehicle, or may be included in a removable device such as a PND (Personal Navigation Device). However, it may be included in a mobile phone carried by a vehicle occupant. Furthermore, it may be another moving body such as a human instead of the vehicle.

Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other embodiments conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

The disclosure of the following priority application is hereby incorporated by reference.
Japanese Patent Application No. 201120068 (filed on Feb. 1, 2011)

Claims

The map data in which road links and meshes that divide the map are associated with each other, and the mesh and at least one adjacent mesh adjacent to the mesh share each of both end nodes of the minimum cost path in the mesh. Based on the mesh cost representing the cost of the minimum cost path, the end point of the moving object is determined from the first candidate map node located at the boundary between the starting point mesh including the starting point of the moving object and the starting point adjacent mesh adjacent to the starting point mesh. A passing mesh acquisition unit that acquires a plurality of passing meshes included in a candidate inter-map node connection minimum cost path to a second candidate map node located at a boundary between an end-point mesh including the end-point mesh adjacent to the end-point mesh; When,
In the mesh including the section road link included in the candidate maple node connection minimum cost path, the mesh cost is represented to represent the cost of a new in-mesh minimum cost path based on the update of the link cost of the section road link. Updating, updating the plurality of passing meshes based on the updated mesh cost, and moving paths from the start point to the end point based on the updated plurality of passing meshes and the new in-mesh minimum cost route A route calculation device comprising: a route search unit that searches for a route.
The route calculation device according to claim 1,
It further includes an information acquisition unit that acquires current traffic information,
The route search unit is configured to update the mesh cost based on the link cost update when a difference between the link cost and the current cost of the section road link based on the current traffic information is equal to or greater than a predetermined threshold. Arithmetic unit.
The route calculation device according to claim 2,
The predetermined threshold is a route calculation device that is a function according to an estimated elapsed time from when the moving body departs from the start point to when the moving body moves on the section road link.
The route calculation device according to claim 1,
Further comprising mesh cost data in which the mesh cost is associated with the both end nodes;
The passage mesh acquisition unit is a path calculation device that acquires the plurality of passage meshes with reference to the mesh cost included in the mesh cost data.
The route calculation device according to claim 1,
Further comprising mesh cost data in which the mesh cost is associated with the both end nodes;
The mesh cost data is a route calculation device including data relating to the road link constituting the minimum cost route in the mesh.
In the route calculation device according to claim 4 or 5,
The mesh cost data is a route calculation device including data relating to a plurality of types of costs corresponding to a plurality of types of route search conditions.