JP2005265491A - Data structure of road network data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the convenience of road network data. <P>SOLUTION: To the road network data representing the road with nodes and links, feature data for representing a feature A1 etc. on a map PL1 is included as shown in a PL2. The position of the feature is specified by a representative point Rp4 provided on a link L2 and the offset coordinates Xoff, and Yoff from links. By including the feature data in the road network data like this, the route search considering access to the feature, the map display for route guidance by voice or guidance display reflecting the visibility of the feature, can be comparatively easily realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a data structure of road network data used for route search.

  The electronic map data is used, for example, for route search and route guidance from a departure point specified by a user to a destination. Conventionally, as electronic map data, road network data expressing roads as links and nodes for route search and drawing data for map display are prepared. Each of the link and node data has position information such as latitude and longitude corresponding to the passing point of the road. In the route search, since it is possible to set the starting point and the destination from the feature name, search data in which the feature name is associated with position information such as latitude and longitude may be used.

  The route search device searches for a route in the following procedure using the various databases described above. When the user designates the departure point and the destination based on the feature name, the route search device acquires position information corresponding to the designated feature from the search data, and the neighboring nodes are designated as the departure point, Set as destination. Then, a route is searched by referring to the road network data by a technique such as the Dijkstra method. When the route search is completed, a map for route guidance is displayed with reference to the drawing data based on the latitude and longitude corresponding to the passing point of the route.

JP 2001-330460 A Japanese Patent Laid-Open No. 2001-300465

  As described above, conventionally, since a plurality of databases are used in combination, the load is large in improving the convenience of route search and guidance. For example, when performing route search and guidance in consideration of the entrance of a feature, data for specifying the guidance method to the entrance is added to the search data, or new information is added near the entrance of the feature in the road network data. It was necessary to set up a node. In addition, when dynamically displaying a guidance map including features that are visible at each point while moving the viewpoint along the route, there is a processing load on whether or not the feature is visible at each point. There was a fear of becoming very large. The processing load on the display is particularly noticeable when displaying a three-dimensional map. In view of these problems, an object of the present invention is to provide map data that can improve the convenience of route search and route guidance relatively easily.

  The present invention can be configured as a data structure of road network data used for map display or route guidance and route search. The road network data of the present invention includes feature data in addition to link data representing a link including position information of a road passing point and node data representing a link end point as a node. The feature data is data including feature expression data for recognizing the position or shape of the feature so that the user can recognize it, and the position information thereof. Examples of the feature expression data include shape data for displaying features for displaying a map, guidance display for route guidance, guidance data for outputting voice guidance, and the like. The shape data can be polygon data representing the shape of the feature or symbol data representing the feature. The guidance data can be, for example, a feature industry classification code, a genre name, a store name, or the like. The position information can take various forms such as latitude, longitude, and orthogonal coordinates defined on the map. By including the feature data for map display in the road network data in this way, it is possible to perform map display without using drawing data prepared separately. Thus, by integrating the data required for map display and the data required for route search, the linkage between the two can be realized relatively easily.

  In the present invention, the feature data is preferably associated with at least one of a link and a node. By doing so, it is possible to achieve the above-described linkage more efficiently. For example, with a relatively light load, it is possible to easily specify features facing the route when searching for a route, and selectively display only features along the route when displaying a map.

  As an example, for a building that is one of the features, the feature data may be associated with at least one of the links and nodes closest to the building entrance. By doing so, it is possible to relatively easily realize a route search in consideration of the position of the entrance of the building. For example, a route search to the entrance of a building can be realized simply by selecting the starting point and destination for the route search from the link or node associated with the building designated as the starting point or destination. be able to.

  The position information of the feature can be set in various forms. For example, the position information may include representative point data representing the position of an arbitrary point or node on the link as a representative point, and offset data representing a deviation amount from the representative point in a predetermined coordinate system. The representative point data also represents the correspondence with links and nodes. Accordingly, it is possible to easily set the correspondence between the position information and the link and the node. When an arbitrary point on the link is used as the representative point in such a format, for example, a point suitable for accessing the feature from the road may be set as the representative point. By doing this, it is possible to present a route in consideration of access to a feature if a route search is performed by regarding the representative point as a node.

  The position information in the feature data may be recorded separately from the shape data after having an index indicating the corresponding shape data. In this way, a plurality of pieces of position information can be associated with one shape data. Therefore, for example, one building can be associated with a plurality of links and nodes around it. In addition, one shape data can be commonly used in various regions, and the data capacity can be reduced.

  The present invention may be configured as a method for producing road network data. In this case, the steps executed by the computer include link data generation, node data generation, feature data generation, and link data, node data, feature data association, and the like. As described above, the position information of the feature data may be expressed based on the link or the node. The feature data may be input by an operator's operation, or may be read from an existing map database having the feature data. Further, as the above-described “association” step, for example, a pointer indicating a storage location of the position information of the feature data may be associated with the link data and the node data based on the position information set in this way.

  The present invention can also be configured as a route search device, a map display device, or a route guidance device that uses road network data. The route search device is a device that inputs a departure point and a destination and searches for a route from the departure point to the destination with reference to road network data. When the road network data of the present invention is used, the destination can be set based on the feature data. By doing so, it is possible to realize a route search in consideration of access to the feature.

  The map display device refers to the road network data and generates map display data. The feature data is used to generate the display data. By doing so, a map that allows the user to easily grasp the route, such as selectively displaying features along the route, can be presented with a relatively light load. Such display can be easily realized, for example, by selectively displaying only the features associated with the link obtained in the route search. The map display device may use drawing data, for example, 2D or 3D map drawing data or deformed drawing data in addition to road network data.

  The route guidance device refers to the road network data and generates guidance data for guiding the route of the user. The feature data is used to generate the guidance data. The route guidance device performs drawing guidance by guidance display and guidance by voice output based on the guidance data. The feature expression character string corresponding to the content to be displayed in the guidance display or voice may be prepared by being included in the feature data. In the present invention, since the feature is associated with the road network data, for example, “Go ahead 40 m while looking at the pond on the right hand and turn left at the end”, the guidance display etc. include the route and the feature. Can be included relatively easily.

  In addition to this, the present invention may be configured as a route search method, a map display method, and a route guidance method using road network data. The computer program for causing the computer to perform route search, map display, and route guidance, and a recording medium on which the computer program is recorded can also be configured. Recording media include flexible disks, CD-ROMs, magneto-optical disks, IC cards, ROM cartridges, punch cards, printed matter printed with codes such as bar codes, computer internal storage devices (memory such as RAM and ROM), and Various media that can be read by a computer, such as an external storage device, can be used.

Embodiments of the present invention will be described in the following order.
A. System configuration:
B. Road network data:
C. Map DB generation processing:
D. Route search process:
E. Route guidance process:
F. Variations:

A. System configuration:
FIG. 1 is an explanatory diagram showing the overall configuration of a route guidance system as an embodiment. The route guidance system according to the embodiment is configured by connecting a route guidance server 200 and a guidance device 100 used by a user via a network NET. As the network NET, for example, a mobile phone line can be used. The guidance device 100 is not limited to the illustrated example, and a plurality of guidance devices 100 can be connected to the server 200.

  The guidance device 100 can use an in-vehicle navigation device or a mobile phone. The functional blocks of the guide device 100 are also shown in the figure. These functional blocks are configured in software by causing a microcomputer mounted on the guide device 100 to execute a predetermined program, but may be configured in hardware.

  Each functional block implements the following functions under the control of the main control unit 110. The communication unit 120 controls communication via the network NET. The GPS 140 detects the latitude and longitude of the current position of the guidance device 100 using a global positioning system. The command input unit 130 inputs commands related to route search and route guidance based on a user operation on a switch or the like. The display control unit 150 displays a route search menu, a route guide map, and the like on the display of the guidance device 100.

  The server 200 performs a route search based on a command from the guidance device 100 and provides the result to the guidance device 100. Functional blocks for realizing such functions are shown in the figure. These functional blocks are configured by software, but can also be configured by hardware.

  The map DB 210 is an electronic map database used for route search and route guidance. In the present embodiment, the map DB 210 includes a road network DB 212 and a drawing DB 214. The contents of each database will be described later. In addition to these databases, a search DB for supporting the setting of the starting point and destination for route search may be provided.

  The communication unit 220 controls communication with the guidance device 100 via the network NET. The information to be communicated includes a departure point, destination designation and other route search commands, and route search results. The route search unit 230 performs a route search with reference to the map DB 210 based on a command designated by the user. For the route search, for example, a known method such as the Dijkstra method can be used.

  The display data generation unit 250 generates display data for causing the guide device 100 to display a map for route guidance based on the map DB 210. The generated display data is transmitted to the guidance device 100 via the communication unit 220 and displayed on the display.

  The guidance data generation unit 260 generates guidance data based on the map DB 210. The guidance data is data for performing guidance display such as a traveling direction and voice output to the user during route guidance. The guidance data generation unit 260 reads information on features existing along the route from the map DB 210, specifies the positional relationship between the route and the feature, and generates guidance data. As the positional relationship, for example, a method can be used in which the position of the feature is represented by a preset division such as right, left, right diagonally forward, and diagonally left forward of the current position. The distance between the current position and the feature may be included. The guidance data generated in this way is transmitted to the guidance device 100 and used for display on a map and voice output.

  The DB management unit 240 manages the map DB 210. In the present embodiment, there is a function of receiving update data generated by the server 200 and a management device 300 prepared separately and updating the contents of the map DB 210. The update data can be received using a medium such as a CD-ROM or via a network.

  The management device 300 is a device for maintaining update data, and can be configured by installing a predetermined program in a general-purpose personal computer, for example. The functional blocks of the management apparatus 300 are also shown. These functional blocks are configured by software, but can also be configured by hardware. By configuring each of these functional blocks in the server 200, the management apparatus 300 and the server 200 may be integrated.

  In the management apparatus 300, the maintenance DB 310 is generated as basic data for generating update data. The maintenance DB 310 is a database in which information equivalent to the map DB 210 is recorded in a format suitable for maintenance. The command input unit 350 updates the maintenance DB 310 based on a user operation on the keyboard and mouse. The display control unit 340 displays the contents of the maintenance DB 310 on the display of the management apparatus 300. Based on the maintenance DB 310, the DB generation unit 330 generates a map DB to be newly stored in the server 200, that is, update data in accordance with an instruction from the user. The output unit 320 outputs the update data generated in this manner in a manner that can be delivered to the server 200.

B. Road network data:
FIG. 2 is an explanatory diagram showing an outline of road network data. Road network data corresponding to the map shown on the upper plane PL1 is shown on the plane PL2. As illustrated, in the road network data, each road is represented by links L1 to L8 defined by the position coordinates of the passing point. The intersection of each link is represented by nodes N11, N12, N23, N33, N44, N55, N67, N77, and N88 defined by the position coordinates. As the position coordinates, latitude and longitude can be used, but in this embodiment, as shown in the figure, orthogonal coordinates X and Y with the origin O at the lower left of the map are used. In the road network data, latitude and longitude are stored for the origin O, and the position coordinates of each link and node can be converted into latitude and longitude.

  The road network data of the present embodiment includes feature data representing features such as buildings as well as link and node data (hereinafter collectively referred to as “node / link data”). In the example of the figure, buildings A1 and A2, a fence A3, and a bridge A4 on the map correspond to the feature data.

  In the road network data shown on the plane PL2, the feature data includes position data representing the position and shape data representing the shape. The position data is given by a representative point set on the node or link and offset data representing the amount of deviation from the representative point.

  The example of the position data regarding building A1 was shown below the figure. The representative point Rp5 of the building A1 is associated with the representative point Rp4 on the link L2. The representative point Rp4 can be arbitrarily set. For example, the representative point Rp4 can be set at a position closest to the entrance of the building A1, or can be set at a position where the building A1 can be visually confirmed. The position of the representative point Rp4 is expressed by a relative position (%) on the link L2. In the example of the figure, the ratio D1 / D2 (%) between the distance D2 from the start point N12 to the end point N23 of the link L2 and the distance D1 from the start point N12 to the representative point Rp4 is used as the representative point position data.

  The position of the representative point Rp5 of the building A1 is defined by the coordinate values of offset coordinates Xoff and Yoff with the representative point Rp4 as the origin. In this embodiment, a coordinate system obtained by translating the coordinate systems X and Y of the road network data is used as the offset coordinate. However, a local coordinate system to which rotation and scale change are added may be defined.

  The features include those that can express the position by a point like buildings A1 and A2, and those that should express the position by a section like a fence A3 and a bridge. In the latter case, the section can be defined by a plurality of representative points on the link. In the example of the figure, the section of the fence A3 is specified by the representative point Rp3 on the link L4 and the node N44. For the bridge A4, the section is specified by the representative points Rp6 and Rp7 on the link L3. As in the case of the point, it is also possible to specify a section shifted from the link by using the offset coordinates.

  Features that can be expressed as points include, for example, facilities such as toilets, smoking areas, coin lockers; various counters such as landmarks and service counters; emergency exits, pedestrian crossings, station ticket gates, station platforms, taxi and bus stops Transportation facilities; commercial facilities such as tenants and convenience stores. About these features, you may attach | subject the data which show the kind of feature and its specification as attribute data.

  Examples of features that can be expressed as sections include fences, guardrails, sidewalks, and stairs.

  The position data can be expressed in various formats, and may be given as the coordinate values of the orthogonal coordinates X and Y that define the road network data. In this case, the offset data can be omitted. However, it is preferable to separately include data representing the association between the feature data and the link or node.

  For a feature represented by a polygon such as a building A1, shape data is defined by representing each vertex in an offset coordinate system based on the representative point Rp5 of the building A1. The features include those that should be expressed by individual polygons such as buildings A1 and A2, and those that can use predetermined polygons such as fence A3 and bridge A4. In the latter case, a name representing a predetermined polygon or symbol may be stored as shape data.

  As indicated by the plane PL1, the display as a map may include tabata BG1, sea BG2, and the like in addition to these features. In the present embodiment, these background images are given as polygon data in the drawing DB 214. The background image may also be included in the road network DB 212 like the feature. In this case, for example, it can be included as single feature data that is not associated with any node / link data.

  FIG. 3 is an explanatory diagram showing an example of the structure of road network data. The map DB can take various structures. For example, it may be a table format as shown, or may be object-oriented.

  In this embodiment, the road network data is managed by dividing the area into node / link data and feature data. The node / link data stores information such as a link number, the coordinates of a link passing point, attributes, and related features. “Cost” included in the attribute is an evaluation value of the link used in the Dijkstra method. As for the related features, pointers for specifying the feature data are stored for the total number of times.

  In the position data in the feature data, type, position, and shape data are stored for each feature. The type means a classification of “point” and “section” with respect to the location information designation method. The position is given by the combination of the representative point on the node / link and the offset data, as described above with reference to FIG. The “shape data” column is a pointer indicating the shape data stored in another area.

  In the figure, polygon type data POLY1 and symbol type data MK1 are illustrated as shape data. The symbol type data can be prepared as an image file such as a GIF. The shape data may be associated with a plurality of position data. By doing so, it is possible to associate one shape data with a plurality of nodes / links or to use it in a plurality of regions.

  The map data can further include various data. Examples of such data include 3D object data, data for expressing landmarks in 2D or 3D, building height data, industry type codes of buildings and tenants, and features used for guidance display and voice guidance. This includes expression string data. The height data of the building can be, for example, the number of floors or the height value of the building. For example, the height data can be used to generate a pseudo three-dimensional model by translating a planar shape in the height direction of a building for which no 3D object is prepared. The industry type code is a code that represents the type of building such as a restaurant or public facility. For example, it can be used to colorize the building when displaying a map or to include the type in a guidance display. it can.

C. Map DB generation processing:
4 and 5 are flowcharts of the map DB generation process. This process is executed by the management apparatus 300 shown in FIG. 1 in response to an operator's operation. When this process is started, the management apparatus 300 inputs node / link data (step S10). If an existing database has been created, it may be read, or coordinate values of node / link passing points may be sequentially read in accordance with the operation of the operator.

  Next, the management apparatus 300 inputs feature data (step S12). In the figure, the input of the building A1 is taken as an example, and a screen example for inputting the feature data is also shown. The operator designates the representative point Rp5 of the building A1 and each vertex of the polygon with a pointing device such as a mouse. Further, the representative point Rp4 on the node / link to which the building A1 is associated is designated. The management device 300 calculates the relative position D1 / D2 (%) on the link of the representative point Rp4 according to this designation. Further, for the representative point Rp5 of the building A1, the coordinate values at the offset coordinates Xoff and Yoff with respect to the representative point Rp4 are obtained. Furthermore, the shape of the building A1 is specified by offset coordinates with the representative point Rp5 as a reference. In addition to these inputs, the administrator may be able to separately input attributes such as the name and type of the building A1.

  When the input of the feature data ends, the management device 300 generates the maintenance DB 310 (step S14). The schematic data structure of the maintenance DB 310 is illustrated in the figure. The maintenance DB 310 is also composed of node / link data and feature data. The node / link data is data obtained by omitting only data relating to the related features from the contents of the road network DB (see FIG. 3). The feature data is data including designation of a node / link to which the feature is associated in addition to the contents included in the feature data of the road network DB. In the example shown, this feature is to be associated with link L1.

  In the road network DB described above, the association from the node / link to the feature data is defined by including the related feature in the node / link data. On the contrary, in the maintenance data, the association from the feature data to the node / link is defined. By doing so, there is an advantage that the increase / decrease of the feature data and the change of the nodes / links for associating the feature data can be easily performed, and a data structure suitable for maintenance can be realized.

  Once the maintenance DB is generated, the management device 300 then proceeds to the process of FIG. 5 and executes a process for generating the road network DB. As this process, the management device 300 reads the maintenance data (step S20) and generates related feature data (step S22).

  The related feature data generation method is shown in the figure. As described above, the maintenance feature data includes designation of nodes and links to be associated with each other. In the process of step S22, the feature data associated with each node and link may be aggregated as related feature data based on this designation. In the figure, an example is shown in which feature data associated with the link L1 is aggregated. By this processing, as shown on the right side of the figure, the related feature data can be included in the node / link data of the road network DB.

  On the other hand, the feature data in the road network DB can be generated from the maintenance feature data by omitting designation of nodes and links. However, the data specifying the nodes and links may be included in the feature data as they are.

  The management device 300 outputs the road network DB via the medium or the network based on the data thus generated (step S24). As described above, this data is stored as the road network DB 212 via the DB management unit 240 of the server 200.

D. Route search process:
FIG. 6 is a flowchart of route search processing. This process is executed by the server 200 based on an instruction from the route guidance device 100. First, the server 200 inputs a feature serving as a starting point and a destination for route search from the guidance device 100 (step S30). The departure point may be the latitude and longitude of the current position detected by the GPS 140. As for the destination, it is assumed that the feature can be specified by the name, position, and the like. In order to be able to specify the feature, for example, a search database in which the name or position is associated with the feature may be provided in the map DB 210 of the server 200, or the name is attributed to the feature data in the road network DB 212. It may be included as information.

  The server 200 sets the representative points associated with the feature set in this way as the starting point and destination of the route search (step S32). This is because the route search is performed based on the node / link data. For example, as shown in the figure, when the building A1 is set as the destination, the representative point Rp4 provided on the link L2 is regarded as the destination node. Thus, by setting the representative point on the link as the destination, the route search can be appropriately realized even for the feature that is off the link. In addition, by using the representative point Rp4 provided in consideration of the entrance of the building A1, the route search to the vicinity of the entrance of the building A1 can be performed.

  The destination can be set by various methods. For example, the representative point may be set as the destination as described above, and a node nearest to the representative point may be set as the destination. When a feature is associated with a plurality of nodes and links, a plurality of points may be set as destinations. Further, the representative point Rp4 on the node and the link and the representative point Rp5 of the building A1 are regarded as a temporary node for route search, the line segment connecting the two is regarded as a temporary link, and the representative point Rp5 is set as the destination. A route search may be performed.

  When the starting point and destination are set according to the above-described procedure, the server 200 performs route search processing with reference to the road network DB 212 (step S34), and outputs the result to the route guidance device 100 (step S36).

E. Route guidance process:
FIG. 7 is a flowchart of route guidance processing. This is a process for causing the route guidance device 100 to perform map display according to the current position of the user, and is a process corresponding to the function of the display data generation unit 250 of the server 200. This process may be executed by the route guidance device 100 upon receiving a route search result.

  When this process is started, the server 200 inputs the route search result obtained by the route search process of FIG. 6 (step S40), and inputs the current position from the route guidance device 100 (step S42). Based on the latitude and longitude of the current position, the link and node corresponding to the current position are specified (step S44).

  Next, the server 200 generates display data for displaying a map based on the related feature data (step S46). A road determines the display color and thickness based on link attribute data, that is, the type and lane. The feature is determined using the shape data included in the related feature data. In this embodiment, only the features associated with the node and link corresponding to the current position are displayed.

  As an example, consider the display of the map shown in the figure. In this map, there is a building BLD near the intersection of the roads R1 and R2. The building BLD is associated with a link corresponding to the road R2 at the representative point Rp. A fence FE is provided along the road R1.

  When the current position is the point P2 on the road R2, the building BLD is displayed because it is associated with the link of the road R2. When the current position is the point P1 on the road R1, the building BLD is not associated with the link of the road R1, and thus is not a display target. Since the building BLD cannot be visually recognized at the point P1 because of being blocked by the fence FE, it is possible to perform display according to the actual field of view by excluding the building BLD from the display target.

  In conjunction with the generation of display data, the server 200 may generate guidance data. For example, in the above-described example, when the current position is on the road R2, guidance data for generating a guidance display or outputting a voice such as “I can see the building BLD on the right side” is generated for the building BLD. This guidance display or the like may include the business type and name of the building BLD.

  In the figure, a two-dimensional map display is illustrated. However, when a three-dimensional map display in which the traveling direction is desired from the current position is selected by selecting the feature to be displayed by the above-described method, it is very useful. There is an advantage that it is possible to realize display in accordance with the actual field of view with a light processing load.

  The server 200 repeats the above processing until the user reaches the destination (step S48).

F. Variations:
In the present embodiment, the case where the operator manually inputs the shape of the building polygon, specifies the representative point, and specifies the node link to associate the building is illustrated. This process may be automatically performed by the management apparatus 300 according to the following procedure. First, the management device 300 reads existing map data for drawing, and acquires position information represented by polygon shape, latitude, and longitude for each feature. Next, referring to the latitude and longitude of the feature and the latitude and longitude of the node and link, a node and link near the feature are selected. In addition to associating the features with the nodes and links thus selected, the position information of the features is converted into the offset coordinates described above with reference to FIG. Then, the acquired shape data, generated offset coordinates, etc. are registered as feature data. By doing so, it is possible to reduce the burden on the operator related to the map data generation of this embodiment. This processing does not necessarily have to be performed automatically. For example, the operator may manually specify only the association, or the operator may manually specify the result only for the feature inconsistent in the automatic processing. Modifications and the like may be performed.

  As mentioned above, although the various Example of this invention was described, it cannot be overemphasized that this invention is not limited to these Examples, and can take a various structure in the range which does not deviate from the meaning. For example, the road network DB 212 of this embodiment may be used for generating a deformed map. The deformed map is a simplified map for guidance used in advertisements and the like. For example, it is possible to generate a deformed map by extracting links associated with destinations and buildings that are landmarks along the way as important links and using these links.

  In the present embodiment, the route guidance device 100 and the server 200 are shown as separate devices, but they may be integrated and configured as a route guidance device that functions stand-alone.

It is explanatory drawing which shows the whole structure of the route guidance system as an Example. It is explanatory drawing which shows the outline | summary of road network data. It is explanatory drawing which shows the structural example of road network data. It is a flowchart of map DB generation processing. It is a flowchart of map DB generation processing. It is a flowchart of a route search process. It is a flowchart of a route guidance process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Route guidance apparatus 110 ... Main control part 120 ... Communication part 130 ... Command input part 140 ... GPS
150 ... Display control unit 200 ... Server 210 ... Map DB
212 ... Road network DB
214 ... Drawing DB
DESCRIPTION OF SYMBOLS 220 ... Communication part 230 ... Path | route search part 240 ... DB management part 250 ... Display data generation part 260 ... Guidance data generation part 300 ... Management apparatus 310 ... Maintenance DB
320 ... Output unit 330 ... DB generation unit 340 ... Display control unit 350 ... Command input unit

Claims (13)

A data structure of road network data used for map display or route guidance and route search,
Link data representing a link including position information of a road passing point;
Node data representing the end point of the link as a node;
A data structure having position information of a feature and feature data including feature expression data for recognizing the position or shape of the feature so as to be recognized by a user. A data structure according to claim 1, wherein
The feature data is a data structure associated with at least one of the link and the node. A data structure according to claim 2, wherein
The features include buildings,
The building feature data is a data structure associated with at least one of a link and a node closest to the entrance of the building. A data structure according to claim 1, wherein
The position information of the feature includes data including representative point data that represents an arbitrary point on the link or the position of the node as a representative point, and offset data that represents a deviation amount from the representative point in a predetermined coordinate system. Construction. A data structure according to claim 1, wherein
The position information in the feature data is a data structure in which an index indicating the feature expression data corresponding to the position information is attached and recorded separately from the feature expression data. A method of manufacturing road network data used for map display or route guidance and route search,
As a process executed by the computer,
(A) inputting position information of a passing point of a road, and generating link data representing a link including the position information;
(B) generating node data representing an end point of the link as a node;
(C) inputting feature position information and feature expression data for recognizing the position or shape of the feature to the user, and generating feature data including these data;
(D) A manufacturing method including the step of associating the link data, node data, and feature data with each other and storing them as road network data. The manufacturing method according to claim 6,
The step (c)
Inputting the shape data;
Inputting the position information represented on the basis of at least one of the link and the node, and instruction information for specifying the feature expression data corresponding to the position information;
The step (d)
A manufacturing method, which is a step of associating a pointer indicating a storage location of the position information with link data and node data corresponding to the reference link and node. A route search device,
An input section for entering the starting point and destination for route search,
A reference unit for referring to road network data for route search prepared in advance;
A route search unit that performs a route search from the departure point to the destination based on the road network data,
The road network data is
Link data representing a link including position information of a road passing point;
Node data representing the end point of the link as a node;
A data structure having feature expression data for recognizing the position or shape of the feature in a recognizable manner by the user and feature data including the position information of the feature;
The route search device in which the destination can be set based on the feature data. A map display device for displaying an electronic map,
A reference unit for referring to road network data for route search prepared in advance;
A display data generation unit for generating map display data based on the road network data,
The road network data is
Link data representing a link including position information of a road passing point;
Node data representing the end point of the link as a node;
It has a data structure having shape data for displaying features for performing map display and feature data including position information of the features,
The display data generation unit is a map display device that generates the display data using the feature data. A route guidance device that provides route guidance using an electronic map,
A reference unit for referring to road network data for route search prepared in advance;
A guidance data generation unit for generating guidance data for guiding a user based on the road network data;
The road network data is
Link data representing a link including position information of a road passing point;
Node data representing the end point of the link as a node;
A data structure having feature expression data for recognizing the position or shape of the feature in a recognizable manner by the user and feature data including the position information of the feature;
The guidance data generation unit is a route guidance device that generates the guidance data using the feature data. As a route search method, which is executed by a computer,
An input process for entering the starting point and destination for route search,
A reference step for referring to road network data for route search prepared in advance;
A route search step for performing a route search from the departure point to the destination based on the road network data,
The road network data is
Link data representing a link including position information of a road passing point;
Node data representing the end point of the link as a node;
A data structure having feature expression data for recognizing the position or shape of the feature in a recognizable manner by the user and feature data including the position information of the feature;
A route search method in which the destination can be set based on the feature data. A method for generating display data for displaying an electronic map, which is executed by a computer as follows:
A reference step for referring to road network data for route search prepared in advance;
A display data generation step of generating map display data based on the road network data,
The road network data is
Link data representing a link including position information of a road passing point;
Node data representing the end point of the link as a node;
It has a data structure having shape data for displaying features for performing map display and feature data including position information of the features,
In the display data generation step, the display data is generated using the feature data. A route guidance method that performs route guidance using an electronic map, and as a process executed by a computer,
A reference unit for referring to road network data for route search prepared in advance;
A guidance data generation step for generating guidance data for guiding a user based on the road network data,
The road network data is
Link data representing a link including position information of a road passing point;
Node data representing the end point of the link as a node;
A data structure having feature expression data for recognizing the position or shape of the feature in a recognizable manner by the user and feature data including the position information of the feature;
The guidance data generation step is a route guidance method for generating the guidance data using the feature data.

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