JP2003295765A - Data base for shape matching and shape matching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shape matching data base and a shape matching device capable of presenting positional information on a map without requiring excess maintenance for a map data base and quickly displaying or presenting road information such as traffic information. <P>SOLUTION: A map data base for restricting nodes and links to be used for shape matching from a road network consisting of an uppermost hierarchy having important roads and lower hierarchies is used as a data base constituted of a plurality of hierarchies and expressing the road network by nodes and links. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information transmission method for transmitting position information such as traffic jams and accidents in a traffic information providing system, and an apparatus for exchanging position information using the method. In particular, it is a shape matching database and a shape matching device capable of accurately and quickly transmitting a position on a digital map.

[0002]

2. Description of the Related Art In recent years, the number of vehicles equipped with an on-vehicle navigation device has been rapidly increasing. The in-vehicle navigation system used by the in-vehicle navigation device holds a digital map database and displays a map around the vehicle position on the screen based on the latitude / longitude data received by the GPS receiver, and the traveling locus and purpose. The route search result to the ground can be displayed together on the map.

However, the digital map database contains an error as the fate of the scale map. The degree of error differs depending on the digital map database, but for example, the scale is 1/250.
00 commercially available digital map databases include:
Depending on the location, some may have an error of about 50 m.

Further, the navigation vehicle-mounted device receives traffic information such as traffic jam information and accident information provided from the traffic information providing system, displays the traffic jam and accident position on a map, and conditions such information. In addition to the route search. w

In the above traffic information providing system, as shown in FIG. 15, the traffic information is supplied from the government control center 71 which controls the area to the traffic information distribution center 72, and each medium (FM broadcast, road beacon, mobile phone, etc.). The traffic information edited for each is transmitted through each medium. The government control center 71 exchanges traffic information with the government control centers 78 in other areas to collect traffic information in a wide area including the surrounding area.

[0006] In the traffic information supplied by the traffic information providing system, for example, when latitude / longitude data of a traffic jam position or an accident position is presented alone in order to convey the position, as described above, the on-vehicle navigation device Since the stored digital map database has different errors depending on the type, if different types of digital map databases are used by the traffic information provider and the destination, the navigation in-vehicle device of the destination will be on different roads. There was a risk that the position of would be identified as the accident position.

In order to improve the inaccuracy of such information transmission or information display, the in-vehicle navigation system uses the map information shown in FIG. As shown in FIG. 1A, the intersections a and b of the road network are used as nodes, and the road c between the nodes is used as a link. Each node has a node number (a = 1111, b = 333
3) is set, and a link number (c = 11113333) that uniquely represents the link is set for each link. Then, the node number and the link number set for each intersection and road are stored in association with each other in the digital map database of each company.

Further, in traffic information indicating a traffic jam position, an accident position, etc., a link number is specified to represent a position on the road, and a point on the road is expressed in terms of how many meters from the head of the road indicated by the link number. Shows. For example, “200 from the beginning of the road with the link number =“ 11113333 ””
If it is traffic information such as "position of m", no matter what digital map database is used by the in-vehicle navigation device, by tracing the point 200 m from the node of node number "1111" on the road of link number "11113333" , It is possible to obtain the position on the same road, that is, the point indicated by the traffic information.

[0009]

However, as shown in FIG. 16B, when the node number and the link number defined in the road network are newly established or the road d is changed,
It will be necessary to change to a new number, but if the node number or link number is changed, the digital map data of each company must be updated.

Since new roads and new roads will be continuously installed in the future, a large amount of work is required for maintenance of the digital map database as long as the conventional road position display method using node numbers and link numbers is used. There has been a problem in that the costs associated therewith have to be invested permanently, and the maintenance thereof is a heavy burden.

There is also a method of identifying a road by a shape matching method (also called a map matching method) based on the traffic information provided by the traffic information providing center 72. Depends on the processing performance of the decoder). The conventional map matching performed by the in-vehicle navigation device requires only one map matching in a limited area (usually about several hundreds of meters square) around the vehicle position. good. On the other hand, the routes (roads) targeted by the traffic information providing system are usually
There are many highways, national roads, and major local roads, and in urban areas, some general prefectural roads and city roads are included.
In addition to the existing links, information collection routes may increase.

Therefore, with the processing capability of the conventional navigation vehicle-mounted device, it takes a lot of time to identify the road by performing shape matching based on the received traffic information and display the traffic information. was there.

The present invention solves the above-mentioned conventional problems, and provides a shape matching database and a shape matching device capable of providing position information on a map without performing excessive maintenance on the map database. The purpose is to do. Another object of the present invention is to provide a shape matching database and a shape matching device capable of promptly displaying or presenting road information such as traffic information.

[0014]

Therefore, in the shape matching database according to the present invention, when a road position on a digital map is transmitted, the shape is composed of a plurality of layers, and each layer represents a road network with nodes and links. It is a vector database, and is divided into a lower hierarchy sequentially from the highest hierarchy according to the importance of the highest hierarchy having nodes and links expressing the most important roads and the nodes and links expressing the roads. A map database that limits each layer and the nodes and links to be shape-matched from the road network by using each layer is used. As a result, the nodes and links to be shape-matched can be narrowed down, and the overall processing speed can be increased.

Further, the shape matching apparatus according to the present invention is a shape matching apparatus for performing shape matching using the shape matching database according to claim 1 and a shape vector, and the shape matching is performed from the highest hierarchy. If the shape matching succeeds in the top layer and the nodes and links can be specified, the process ends. If the nodes and links corresponding to the shape vector cannot be specified, the process moves to a lower layer. By performing the shape matching, the target of the shape matching is sequentially moved to the next layer to perform the shape matching. As a result, shape matching can be performed even for nodes and links indicating minute roads.

Further, in the shape matching apparatus according to the present invention, a common node is provided between the plurality of layers, the object of shape matching is moved from the common node to the next layer, and the shape matching in each layer is performed. By connecting the results at the common node and performing shape matching, movement between layers and data connection are facilitated.

Further, in the shape matching device according to the present invention, an identifier is attached to the link defined in the upper layer,
If a road identification method is performed in which the identifier is used to move to the upper layer and shape matching is performed, shape matching can be quickly performed in a layer with coarse links and nodes.

Further, in the shape matching apparatus according to the present invention, when the shape matching fails in the predetermined layer, the absolute position indicating the position is used to sequentially move to the lower layer and perform the shape matching. If so, matching in each layer can be easily connected. Further, if a server that stores such a map database and sends out a part or all of the map database according to a predetermined signal is used, many people can easily use the map database.

In the shape matching database, the number of nodes in the shape vector is made coarser in the higher layers.

Further, the shape vector sending server stores the shape vector database according to claim 1 or 6, and sends part or all of the shape vector database by a predetermined signal.

Further, in the shape matching device according to the present invention, when shape matching is performed in the upper layer, the information of the link length is used for the node sequence forming the shape vector, the nodes are thinned, and the thinned node sequence is used for the shape matching. If matching is performed, the processing speed can be further increased.

Further, in the shape matching apparatus according to the present invention, if additional information such as road type and toll road code is added to the shape vector, and the hierarchy for performing the shape matching is selected first using the additional information, It is possible to eliminate waste caused by performing shape matching from the top.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a shape matching database and a shape matching device according to the present invention will be described below in detail with reference to the drawings.

In this embodiment, a node, a link, or an auxiliary interpolation point of the node is used as the information indicating a specific point or road on the map. Nodes are points on the road that are set corresponding to intersections, tunnel entrances / exits, bridge entrances / exits, and administrative boundaries, and interpolation points are used to reproduce the road shape between nodes. The point is set to, and the link is a line segment connecting the nodes. The following description will be made using nodes and links.

FIG. 1 shows a road information providing system using the shape matching database and the shape matching device of this embodiment. In the figure, event information such as traffic accidents, road construction, traffic jam, rainfall, snowfall, crackdown, etc.
The information is stored in the event information database 85 together with the information on the specified road and area. Further, in the map database 86, information indicating roads, rivers, bridges, buildings, etc. is accumulated by “points” called nodes and “line segments” called links.

2 shows the data structure of the event information, FIG. 3 shows the data structure of the link information, FIG. 4 shows the data structure of the node information, and FIG. 5 shows the data structure of the shape vector. The map data and the data for shape matching (map matching) stored in the map database 86 shown in FIG. 1 are composed of nodes and links, and as shown in FIG. Is expressed as an absolute position or a relative position.

The shape vector data expression information generating unit 84 of the road information providing system shown in FIG. 1 indicates the event occurrence position indicated by the event information by the absolute position such as latitude / longitude and the relative position from the absolute position. A shape vector representing a target road is generated from the nodes and links stored in the map database 86. In this embodiment,
An example of transmitting the shape vector “Ps-Pa-Pb-Pe” shown in FIG. 6 will be described. The expression of the shape vector is to represent the names of the points corresponding to the nodes from the start point in the order of passage.

Here, the feature node extracting / shape vector transforming unit 83 sets the shape vector to “Ps-Pa” when the shape vector to be transmitted has no features and the map matching in the receiving device 88 is difficult. -Pm2-Pms
It is also possible to add a node or an interpolation point such as 2-Pm2-Pm3-Pm4-Pb-Pe "so that it is represented by a thin link.

FIG. 6 shows a shape vector "Ps-" indicating a road.
Fig. 7 is an explanatory diagram showing "Pa-Pb-Pe".
It is explanatory drawing which represented typically the mode at the time of the receiver 88 which received the shape vector of FIG. 6 performing shape matching (map matching).

In this embodiment, in addition to the information on the coordinate sequence of the nodes and the interpolation points, detailed information such as road types, road numbers, toll road codes or intersection nodes existing in advance in the digital map database and expressways, Road types such as national roads and major local roads may be added to the node. Also, as additional information, in addition to this, in the case of an intersection node, the name of the intersection is added, and when the node represents the entrance / exit of a tunnel, the entrance / exit of a bridge, the boundary of an administrative division, etc. You may add information. Further, as additional information, in order to convey the standard of accuracy of the transmitted information, it is data obtained from map data at a scale of 1/25000, data obtained from map data at a scale of 1/10000, and so on. Information indicating the accuracy level of the figure may be added.

Here, the receiving device 88 shown in FIG. 6, which has received the data including the shape vector, has a data receiving section 88e.
The data is restored by using the shape vector expression event information section 88b.
The shape vector is reproduced by and the information added to the shape vector is separated. Next, the shape matching unit 88d
The position on the map indicated by the shape vector is specified using the shape matching database 88b for specifying the occurrence location of the event.

The shape matching database 88b of this embodiment has three layers of data (upper layer, middle layer, lower layer).
Are stored separately. The upper layer stores nodes and links indicating national roads, major local roads, roads on which optical beacons, which are road information collection devices installed under the initiative of the police, are installed, and other main roads. In the middle class, nodes and links indicating roads such as prefectural roads, municipal roads, etc., which are on the scale of 1 / 100,000, are stored. Also,
In the lower layer, nodes and links indicating roads of about 1/5000 are stored.

In the present embodiment, the shape matching unit 88d of the receiving device 88 performs shape matching on the shape vector in order from the upper layer, and when the shapes match, the matching operation is completed and the road targeted by the shape vector is selected. Determine.

(First Example) FIG. 8 shows a flowchart of the shape matching method in this embodiment. As shown in the figure, when the shape matching is not successful in the upper layer (in the example shown in FIG. 7, there is no Pb-Pe region in the upper layer (a) as shown in FIG. 7 (c)). ) Moving to the middle layer (b), the matching is performed again from the first point Ps. Although FIG. 7 shows an example in which all the shape matching is completed in the middle layer, if the matching is not completed even in the middle layer, the process moves to a lower layer representing a more detailed road to perform the matching.

(Second Embodiment) FIG. 9 shows shape matching when a common node is set in each layer. As shown in the figure, the upper layer Pa and Pc are the lower layer P1 and
The nodes correspond to P2. Since such a shape matching database has the same hardware configuration as the transmitting device 87 such as the center system and the receiving device 88 such as a navigation device shown in FIG.
Will be explained together. Also in this case, the process itself is performed in each part based on the flowchart shown in FIG.

The shape vector shown in FIG.
When the data is transmitted from Ps to Pd, the shape matching unit 88d of the receiving device 88 exists in the shape matching database 88b because a part corresponding to Pd-Pe exists in the upper layer but does not exist in the upper layer. Move to the next layer and perform shape matching. At this time, nodes Pc (upper layer) and P2 (middle layer) defined in common between the upper layer and the middle layer exist in the path from Ps to Pd.
As shown in FIG. 1, the matching result in the upper layer is used between Ps and Pc, and the matching result in the middle layer is used between P2 and Pe ′ corresponding to Pc.
To complete the shape matching from Pe to Pe.

In this method, a common node is similarly set between the middle layer and the lower layer, so that the shape matching results of each layer can be effectively used by connecting them by the common node.

FIG. 12 shows a state of shape matching in the case of having an identifier indicating which hierarchy is linked by a common node. The result of the shape matching shown in FIG. 12 is shown in FIG. Even in this case, the hardware configuration is the same as that shown in FIG.

FIG. 3 shows a shape matching database 88.
The data structure of the link information in b is shown. Further, FIG. 14 shows a flowchart of the shape matching method in the second embodiment. The most important feature of this method is that the links have hierarchical affiliation information, so if the matching is performed along this information, quick shape matching as a whole can be performed.

[0040]

As described above, according to the present invention, a road can be identified by shape matching the received information even if the number of target routes for providing traffic information is increased and the car navigation system is not required to have an excessive processing capability. Traffic information can be displayed. Therefore, the position information on the digital map can be transmitted without an excessive burden of maintenance of the road data, and the information about the road such as traffic information can be quickly displayed or presented.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a system for transmitting and receiving event information by shape matching.

[Fig. 2] Example showing the structure of event information

FIG. 3 is a diagram showing a link information format.

FIG. 4 is a diagram showing node information.

FIG. 5 is a diagram showing shape vector data.

FIG. 6 is a diagram showing a shape vector to be transmitted.

FIG. 7 is a conceptual diagram showing shape matching by hierarchy.

FIG. 8 is a diagram showing a processing flow showing shape matching by hierarchy.

FIG. 9 is a conceptual diagram showing shape matching by layer when a layer common node is used.

FIG. 10 is a diagram showing a shape vector to be transmitted when a hierarchical common node is used.

FIG. 11 is a diagram showing a shape vector to be transmitted when a link having a hierarchical identifier is used.

FIG. 12 is a conceptual diagram showing shape matching by hierarchy when using a link having a hierarchy identifier.

FIG. 13 is a diagram showing a matching result when a link having a hierarchical identifier is used.

FIG. 14 is a diagram showing a processing flow showing shape matching by layer when the node has layer information.

FIG. 15 is a diagram showing a conventional example of a center that provides traffic information.

FIG. 16 is a diagram showing a conventional example in which nodes and links are specified.

[Explanation of symbols]

Ps start link Pe end link Pc common link Ps start link 41 upper hierarchy 42 Middle class 61 Upper layer 62 Middle class 64 links 81 Data transmitter 82 Shape vector expression event information data 83 Feature node extraction, shape vector transformation unit 84 Shape Vector Expression Information Generation Unit 85 Event information data 86 map database 87 transmitter 88 receiver

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Claims (9)

[Claims] 1. A shape matching database comprising a plurality of hierarchies, each node representing a road network in each hierarchy, and a top hierarchy having nodes and links representing the most important roads, and a road. According to the importance of the nodes and links expressing the above, each layer is sequentially divided from the uppermost layer into lower layers, and nodes and links to be shape-matched from the road network are limited by using the respective layers. A map database for shape matching. 2. A shape matching device that performs shape matching using the shape matching map database according to claim 1 and a shape vector, wherein shape matching is performed from the top layer, and the shape matching is performed on the top layer. When the shape matching is successful and the node and the link can be specified, the processing ends. When the node and the link corresponding to the shape vector cannot be specified, the process moves to a lower hierarchy to perform the shape matching. The shape matching device is characterized in that the object of shape matching is sequentially moved to the next layer to perform shape matching. 3. A common node is provided between the plurality of layers, the target of shape matching is moved from the common node to the next layer, and the result of the shape matching in each layer is connected by the common node. The shape matching device according to claim 2, wherein the shape matching is performed by performing shape matching. 4. The link is defined in an upper layer, an identifier is attached to the link, the identifier is used to shift to the upper layer, and shape matching is performed.
Shape matching device described. 5. When the shape matching fails in a predetermined layer, the absolute position indicating the position is used to sequentially move to a lower layer and the shape matching is performed.
The shape matching device described in 3 or 4. 6. The shape vector database according to claim 1, wherein the number of nodes of the shape vector is made coarser in the higher layers. 7. A shape vector transmission server, which stores the shape vector database according to claim 1 or 6 and transmits a part or all of the shape vector database according to a predetermined signal. 8. When performing shape matching in an upper layer, information of link length is used for a node sequence forming a shape vector,
The shape matching is performed by thinning out the nodes and using the thinned out node sequence.
Shape matching device described. 9. The additional information is added to the shape vector, and a hierarchy for performing shape matching is first selected using the additional information.
Shape matching device described.