WO2014171071A1 - Map data, map display device, and method for using map data - Google Patents

Abstract

Provided is map data (1) provided with road data (10) categorized into a plurality of separate road levels, and background data (20) categorized into a plurality of separate background levels corresponding to a display scale of a map image, said map data (1) wherein, during map-image rendering, the background level of the background data (20) referred to is determined by the display scale of the map image, and the presence of the road data (10) referred to and the road levels are also determined by the display scale of the map image. In the map data (1), background data (20) for which corresponding road-level road data (10) is not present, among the plurality of pieces of background data (20), is provided with road-shape data determined in accordance with the display scale.

Description

Map data, map display device, map data usage method Cross-reference of related applications

This application is based on Japanese Patent Application No. 2013-85990 filed on April 16, 2013, the contents of which are incorporated herein by reference.

The present disclosure relates to map data of a map including roads, a map display device that displays a map using the map data, and a map data use method that uses the map data.

There is known map data having data for each road level divided into a plurality (for example, Patent Document 1). The map data described in Patent Document 1 includes road data that stores data relating to roads, and background data that stores data of a background (for example, a river or a building) necessary for drawing a map image.

Roads have road levels set based on the type of road (for example, expressways, national roads, narrow streets, etc.) and connection relationships, and the road data has a hierarchical structure for managing roads by road level. . The road data of each hierarchy has a connection relationship (network) of roads belonging to the road level and its shape. Therefore, data relating to a certain road is described only in road level road data to which the road belongs, and is not described in road data of other road levels. Therefore, when a certain road is newly created, the road data may be updated only in the hierarchy to which the road belongs. With this structure, road data can be updated more easily than in the KIWI format in which data for one road is described in a plurality of layers.

In this way, each level of road data having a hierarchical structure has a corresponding relationship with the display scale of the map image, and the display scale determines the presence or absence of road data in the hierarchy corresponding to the display scale. In the case of a display scale in which there is a hierarchy that is referred to when a road is drawn, the hierarchy of road data serving as a reference for use in drawing a map image is determined. The background data also has a hierarchical structure managed at different levels according to the display scale of the map image.

JP 2012-163908 A

The inventors of the present application have found the following regarding map data.
In the map data structure of Patent Document 1, since the data is divided into hierarchies at the road level, even if the road exists in the same region, the data is described in different hierarchies if the road level is different.

When drawing a road in a map image, if it is a small scale, there is a possibility that only the upper one level road is targeted for drawing. However, when the scale is large, a road from a road belonging to an upper level (for example, a highway) to a road belonging to a lower level (for example, a narrow street) must be drawn. Therefore, when drawing a large-scale road map that displays lower-level roads, it is necessary to read not only lower-level data but also higher-level data, which slows down the drawing speed. It was.

Therefore, in order to easily update the data and increase the drawing speed of the road map, it is conceivable that the data relating to the road shape is provided redundantly on a plurality of road levels. That is, a configuration of map data can be considered in which road data at each road level is provided with data relating to the shape of roads belonging to a road level higher than the road level.

When the map image is drawn in this map data, the levels of road data and background data to be referred to draw the map image are determined according to the display scale. In other words, the map image is drawn using one level of road data and background data determined according to the display scale. Since roads belonging to a road level higher than the corresponding road level also have shape-related data, they can be drawn without reading high-level road data.

By the way, the background data has a plurality of hierarchies corresponding to the display scale of the map image, whereas the number of road data hierarchies is basically set based on the number of road types. The number of background data hierarchies required from the difference in display scale is often larger than the number of road types. In this case, the number of road data hierarchies is smaller than the number of background data hierarchies. Then, when the number of road data layers is smaller than the number of background data layers, when the respective layers are associated in order from the larger scale (the one that draws finer map data), for example, At a small scale where the entire country is displayed, there is background data but no road data. As a result, on a small display scale where the entire country is displayed, the map image is drawn only by the background data of the background level corresponding to the display scale, and the road shape is not drawn.

The present disclosure has been made based on this situation, and the purpose of the present disclosure is to classify data describing road connection relationships and shapes into a plurality of road levels according to road types and connection relationships. Road data provided, and background data provided with map data necessary for drawing a map image divided into a plurality of background levels corresponding to the display scale of the map image, and when the map is drawn, the display scale of the map image is provided. The map data that determines the background level of the background data to be referred to and the road level of the road data to be referenced corresponding to the background level is set even when a display scale that does not have the corresponding road data is set. Another object of the present invention is to provide map data, a map display device, and a map data use method capable of drawing a road on a map image.

The map data according to the first example of the present disclosure includes road data including data describing road connection relations and shapes divided into a plurality of road levels based on road types and connection relations, Background data necessary for drawing, and background data divided into a plurality of background levels corresponding to the display scale of the map image, and the background referred to by the display scale of the map image when drawing the map image Map data in which the background level of the data is determined and the presence / absence of the road data referred to by the display scale of the map image and the road level are determined, and road data corresponding to the road level exists among the plurality of background data The background data that is not included includes road shape data determined according to the display scale.

According to the above configuration, the map image is drawn using the road data and the background data determined by the display scale of the map image. At this time, even if there is no road level road data determined from the display scale, road shape data is provided in the background level background data corresponding to the display scale. Can be drawn.

Therefore, map data configuration that takes into account map data renewability and road map drawing speed, that is, data describing road connection relationships and shapes is divided into multiple road levels based on road types and connection relationships. Map data including road data provided as background data and background data required to divide background data necessary for drawing a map image into a plurality of background levels corresponding to the display scale of the map image. Even when a non-existing display scale is set, a road can be drawn on a map image.

A map display device according to the second example of the present disclosure includes a storage unit that stores the map data of the first example, a position detection unit that detects a current position, and a map stored in the storage unit. A control unit that sequentially creates a display map representing a predetermined range including the current position with reference to data and the current position detected by the position detection unit; and a display unit that displays the display map created by the control unit; Is provided.

Further, the map data usage method according to the third example of the present disclosure includes road data including data describing road connection relations and shapes divided into a plurality of road levels based on road types and connection relations. , Background data necessary for drawing a map image, divided into a plurality of background levels corresponding to the display scale of the map image, and referred to by the display scale of the map image when drawing the map image Map data in which the background level of the background data is determined, the presence or absence of the road data to be referred to by the display scale of the map image, and the road level are determined. The map data using the map data including the road shape data determined according to the display scale is the background data for which no road data exists The display map is a method for determining a current position, acquiring data representing a predetermined range including the current position from the map data based on the current position, and sequentially creating a display map. Is a method of using map data for sequentially displaying on the display unit.

FIG. 1 is a basic configuration diagram of map data in the present embodiment. FIG. 2 is a diagram showing the correspondence between road data and background data for each level. FIG. 3 is a configuration diagram of the mesh unit data. FIG. 4 is a configuration diagram of a header included in mesh unit data. FIG. 5 is a configuration diagram of a small section route number list. FIG. 6 is a diagram for explaining a virtual mesh. FIG. 7 is a diagram showing the correspondence between the small block route number list and the small block route list. FIG. 8 is a configuration diagram of the small block route record. FIG. 9 is a diagram for explaining the relationship between a virtual subdivision, a link, and a node. FIG. 10 is a configuration diagram of the route list. FIG. 11 is a configuration diagram of the segment list. FIG. 12 is a configuration diagram of the link list. FIG. 13 is a configuration diagram of the coordinate list. FIG. 14 is a configuration diagram of the upper level link string list. FIG. 15 is a configuration diagram of the upper level link list. FIG. 16 is a diagram for explaining the concept of segments. FIG. 17 is a diagram showing the correspondence between route records, segment records, link records, and coordinate records. FIG. 18 is a conceptual diagram of an array for storing coordinate record groups. FIG. 19A is a diagram for explaining a link connection relationship. FIG. 19B is a diagram for explaining the attention link. FIG. 19C is a diagram for explaining connection link numbers of links. FIG. 20A is a schematic diagram for explaining an example in which a road is not displayed. FIG. 20B is a schematic diagram for explaining an example in which a road is not displayed. FIG. 21 is a block diagram showing a configuration of a navigation device equipped with map data. FIG. 22 is a flowchart showing the flow of the drawing process.

Hereinafter, embodiments will be described with reference to the drawings. As shown in FIG. 1, the map data 1 of this embodiment includes a data file for each mesh (hereinafter referred to as “mesh unit data”) determined by subdividing a map recording area, and a mesh unit data group. A data file group including a management data file for management.

The above mesh is defined by subdividing a rectangular area including the map recording area. In the management data file, information indicating whether or not mesh unit data corresponding to this mesh exists is described for each mesh in the rectangular area. The mesh unit data is arranged in an order corresponding to the arrangement of meshes.

The map data 1 describes road data 10 and background data 20 as mesh unit data with this mesh as a unit. The road data 10 is data relating to the connection relation and shape of roads necessary for route calculation and the like, and the background data 20 is data relating to the background in the mesh necessary for road map drawing. Although the specific description of the mesh unit data will be described later, the mesh unit data of the road data 10 includes link entity data Lb1 (see FIG. 3) describing the road network in the mesh. The road network means a connection relationship between roads, and the link entity data Lb1 describes this connection relationship by link connection. The link is always delimited at the boundary of the mesh without crossing the boundary with the adjacent mesh. Therefore, each mesh unit data is configured as data closed with respect to adjacent meshes. A road straddling between adjacent meshes is represented by a connection at the mesh boundary of each mesh link.

As shown in FIG. 2, the road data 10 and the background data 20 included in the mesh unit data are managed by being divided into a plurality of levels (that is, hierarchies). In the example of FIG. 2, the road data 10 is divided into five layers from level 0 to level 4, and the background data 20 is divided into seven layers from level 0 to level 6. Of course, this is an example, and the number of layers of the road data 10 and the background data 20 is not limited to the example of FIG. As the background data 20 will be described in detail later, road data is first described here.

<Leveling of road data>
The level of road data is determined in consideration of the type of road (such as an expressway or a national road) and the connection relationship between the roads. For example, highways connecting cities are set as level 4 road data, and other highways and main national roads are set as level 3 road data. In addition, national roads and main local roads not included in the level 3 road data are handled as level 2 road data, and ordinary roads running in the city are handled as level 1 road data. Narrow streets and private roads are treated as level 0 road data. Of course, these are merely examples, and may be designed as appropriate.

In addition, since the level classification of the road is performed in consideration of not only the road type but also the connection relation between the roads, for example, even a major national road is not necessarily rated at level 3. Major national roads (assuming National Highway 3) should be rated as Level 3, but if this National Highway 3 is not connected to other Level 3 roads, Due to the connection with the road, it will become impossible to manage this national highway No. 3. That is, if National Highway 3 that does not have a connection point with other Level 3 roads is put into Level 3, National Highway 3 will float in the network of Level 3 roads, causing problems in route calculation. Therefore, in such a case, the national highway No. 3 is rated to another level (for example, level 2) where a road connected to the national highway No. 3 exists. Of course, here, an example has been described in which roads originally rated as level 3 are rated as other levels, but in other types of roads as well, a level different from the original level due to the connection relationship between the roads. May be rated.

Unlike the KIWI format, the road data 10 stores link entity data of the same road only in one level. For example, link entity data at the highest road level (part of a highway is applicable) is stored only at level 4, which is the highest level. Further, the link entity data at the lowest road level (corresponding to narrow streets) is stored only at level 0 which is the lowest level. In this way, the link entity data is stored at a different level depending on the road level of the road described by the link entity data.

<Mesh unit data for road data>
As described above, the road data 10 has mesh unit data as a constituent unit. Note that the background data 20 also has a data structure in units of meshes. However, in the following description, the mesh unit data refers to data for road data unless otherwise specified.

The mesh unit data is a data file representing the road network in the mesh, and one data is provided for each mesh. As shown in FIG. 3, the mesh unit data includes a header, a subdivision route number list Lb11, a subdivision route list Lb12, a route list Lb13, a segment list Lb14, a link list Lb15, a first coordinate list Lb16, and a second coordinate list Lb23. , Road name ID list Lb17, road number name ID list Lb18, road / road number name dictionary Lb19,..., Upper level link list Lb21, upper level link list Lb22, and the like. Among these lists, the upper level link list Lb21, the upper level link list Lb22, and the second coordinate list Lb23 are upper road drawing data Lb2. The others are link entity data Lb1. The upper road drawing data Lb2 corresponds to upper level shape data.

The link entity data Lb1 is used for applications that use the concept of links, such as route calculation and route guidance, and corresponds to road network data.

<Details of mesh unit data>
<Header>
FIG. 4 shows the configuration of the header. The header defines the structure of mesh unit data and is expressed in a fixed length. Specifically, the header has information indicating the size of the data list in the order of arrangement of the data list stored in the mesh unit data.

The size of the data list is described as information on the number of records in the data list in the case of a data list (Lb11 to Lb18, Lb21 to Lb23) composed of a fixed-length record group. That is, as shown in FIG. 4, the number of records B11 of the small section route number list Lb11, the number of records B12 of the small section route list Lb12, the number of records B13 of the route list Lb13, the number of records B14 of the segment list Lb14, and the link list Lb15 The number of records B15, the number of records B16 of the first coordinate list Lb16, the number of records B21 of the upper level link list Lb21, the number of records B22 of the upper level link list Lb22, and the number of records B23 of the second coordinate list Lb23 are described in the header. . On the other hand, in the case of a data list (Lb19) composed of a non-fixed length record group, it is described as information on the data size (number of bytes). Each list is composed of records. Next, each list will be described in detail.

<Small section line number list Lb11>
As shown in FIG. 5, the small section route number list Lb11 is a list of small section route number records. The subdivision route record is a fixed-length record indicating the number of routes in one virtual subdivision, and is provided for each virtual subdivision (see FIG. 7).

Here, the virtual small section is a section defined by further subdividing one mesh, and can also be called a virtual mesh. For example, as shown in FIG. 6, the unit mesh is divided into 64 to form one virtual mesh (that is, one virtual small section).

The term “virtual” means that the data corresponding to the virtual mesh is not configured as an independent data file like the mesh unit data, and the link is not delimited by the virtual mesh as a boundary. This is because the data is not clearly separated and managed based on the boundary of the virtual mesh. The small section route number record represents the number of routes in the virtual small section, and is provided for each virtual small section. In addition, the area | region divided by the dashed-dotted line of FIG.

<Small section route list Lb12>
As shown in FIG. 7, the small section route list Lb12 is a list having the same number of small section route records as the number of routes C represented by the small section route number record. The subdivision route record is provided for each virtual subdivision for each route existing in the virtual subdivision.

In the small block route list Lb12, small block route record groups of the virtual small block are arranged in the order corresponding to the small block route number record in the small block route number list Lb11.

As shown in FIG. 8, this subdivision route record includes (1) information indicating the storage destination of the route record corresponding to the route to be described by this record, and (2) passing through the corresponding virtual subdivision of this route. Information indicating the storage destination of the coordinate record corresponding to the head of the line segment, and (3) Fixed information having information on the number of coordinate points (total number of coordinate records) corresponding to the line segment passing through the virtual subdivision of the route. It is a long record.

Specifically, the information of (1) is described by information of an array number (hereinafter referred to as “route record array number”) in the route list Lb13 of the corresponding route record. For example, when the corresponding route record is stored αth from the top in the route list Lb13, the value α is described as the route record array number.

Similarly, the information of (2) above represents an array number (hereinafter referred to as a coordinate record array number) in the first coordinate list Lb16 of the corresponding coordinate record. For example, when the corresponding coordinate record is stored in the first coordinate list Lb16 in the βth position from the top, the value β is described as the coordinate record array number.

In the information of (2) above, “a line segment passing through the virtual subdivision on the route” is defined as follows. Here, as shown in FIG. 9, the links Lk1, Lk2, and Lk3 are connected in order, and the link Lk2 following the link Lk1 of the virtual small section B is the virtual small section A, the virtual small section B, and the virtual section. A route that passes through the small section C and is connected to the link Lk3 of the virtual small section C will be described as an example.

白 White circles in Fig. 9 represent link connection points (nodes). A connection point between the link Lk1 and the link Lk2 is located in the virtual small section B, and a connection point between the link Lk2 and the link Lk3 is located in the virtual small section C. Moreover, the black circle of FIG. 9 shows the point by which the coordinate is hold | maintained in map data as a coordinate record. However, the coordinates are also retained for white circles (link connection points) in addition to black circles. Black circles are shape interpolation points to be described later, and white circles are nodes. Here, these points are expressed as coordinate holding points P1 to P5.

The above-mentioned “line segment passing through the virtual subdivision among the routes” is classified into a first type partial route and a second type partial route, and the subdivision route record is for each virtual subdivision and each route. It is provided for each of the first and second type partial routes.

The first type partial route is adjacent to the coordinate holding point from the line connecting the coordinate holding points located in the virtual subdivision of the corresponding route and the coordinate holding points located at the end points of the line segment. It is defined by a line segment connecting the coordinate holding point and a route to the coordinate holding point outside the virtual partition. In short, the first type of partial route is defined by a line segment connecting each coordinate holding point located in the virtual subsection and one coordinate holding point outside the virtual subsection. .

On the other hand, a second type of partial route is defined by a line segment connecting adjacent coordinate holding points when adjacent coordinate holding points are connected across other virtual subsections. This second type of “line segment passing through the relevant virtual subsection among the routes” is the virtual subsection to be spanned (for example, the virtual subsection B on which the coordinate holding point P3 and the coordinate holding point P4 straddle). This is the first type of partial route.

More specifically, according to the example shown in FIG. 9, among the routes connecting the links Lk1, Lk2, and Lk3, partial routes that pass through the virtual subsection A are set by connecting the coordinate holding points P1, P2, P3, and P4. it can. Therefore, the subdivision route record corresponding to the virtual subdivision A of this route has coordinates in the first coordinate list Lb16 among the coordinate holding points P1, P2, P3, and P4 for setting partial routes as coordinate record array numbers. The coordinate record array number of the coordinate holding point P1 with the smallest record array number is described. Further, the value 4 is described as the number of coordinate records.

In the first coordinate list Lb16 of the present embodiment, coordinate records representing coordinates at each point on the route indicated by the route record are arranged in the order corresponding to the route record. In addition, the coordinate record group corresponding to each route is arranged so that the point corresponding to the coordinate record advances in one direction along the route along the flow of the route.

On the other hand, two subdivision route records corresponding to the virtual subdivision B of this route are prepared. The portion of the route that passes through the virtual subdivision B includes coordinate holding points P1 and P2 and a coordinate holding point at a point (referred to as P0) that goes back from a coordinate holding point P1 (not shown). Therefore, the coordinate record array number of the first small section route record describes the array number in the first coordinate list Lb16 of the coordinate record corresponding to the coordinate holding point P0. The value 3 is described as the number of coordinate records.

Further, since the portion of the route that passes through the virtual subdivision B includes the coordinate holding points P3 and P4, the coordinate record array number of the second subdivision route record is the first of the coordinate records corresponding to the coordinate holding point P3. An array element number in the coordinate list Lb16 is described. A value 2 is described as the number of coordinate records. Unlike this example, P0, P1, P2, P3, and P4 can be collectively described.

Further, a portion of this route corresponding to the virtual small section C is set by connecting coordinate holding points P3, P4, P5 and a downstream coordinate holding point (not shown) of the same route (P6). Therefore, in the subdivision route record of the virtual subsection C, the coordinate record array number is the coordinate holding point P3 having the smallest coordinate record array number in the first coordinate list Lb16 among the coordinate holding points P3, P4, P5, and P6. The array number of the coordinate record is described.

<Route list Lb13>
The route list Lb13 is a list composed of a plurality of route records, as shown in FIG. The route record is a record for managing the link train in the mesh suitable for route guidance as one group. This route record defines link strings belonging to the same route. “Route” is defined by, for example, a link string of the same road name and the same road number connected to one line. Moreover, a link row | line points out the link group of a part or all group in the same route.

Specifically, as shown in FIG. 10, the route record includes (1) a name attribute of a route to be described, (2) a road attribute of this route, and (3) a coordinate record of a coordinate record corresponding to the head of this route. It has information on the array number, (4) the number of coordinate records corresponding to this route, (5) the segment record array number, and (6) the number of segments constituting the route. The segment record array number in (5) above is the array record number in the segment list Lb14 of the segment record corresponding to the head segment.

The information of (1) to (6) above constituting the route record will be specifically described. The “name attribute” of (1) includes information that can specify the storage position of the road name ID record corresponding to this route in the road name ID list Lb17, and the road number name corresponding to this route in the road number name ID list Lb18. Information capable of specifying the storage position of the ID record.

The road name ID record represents the position where the corresponding road name is registered in the road / road number name dictionary Lb19, and the road name number ID record has the corresponding road number name registered in the road / road number name dictionary Lb19. Represents the position. The road name ID record and the road name number ID record are composed of fixed length records, and the registered words in the road / road number name dictionary Lb19 are composed of variable length records.

(2) “Road attribute” includes information on whether this route is a toll road or a non-toll road, and information on the road type of this route. The road type represents a distinction between an expressway, a general national road, a narrow street, and the like. This road type is different from the road level. The road level is set based on the road type, but does not completely correspond to the road type. For example, different road levels may be given to the same highway. This is because the road data 10 is data describing a road network. If one expressway and another expressway are not connected via a road at the same road level (that is, a network is not configured), a highway on the side that can form a network at a lower level Is the lower level.

Also, the coordinate record array number (3) and the number of coordinate records (4) are used to specify a coordinate record string representing coordinates at each point corresponding to this route in the first coordinate list Lb16. As described above, in the first coordinate list Lb16, coordinate records representing coordinates at each point on the route are arranged along the flow of the route. Therefore, each coordinate record corresponding to the route can be specified by the information of (3), that is, the coordinate record array number of the coordinate record corresponding to the head of the route and the number of coordinate records of (4).

(5) The segment record array number and the number of segments in (6) are used to specify each segment record corresponding to the segment string constituting the route record in the segment list Lb14.

Here, the segment is explained. As shown in FIG. 16, the segment of the present embodiment is a link string that configures a route, and is a unit of a link string that is at least divided at intersections of main roads. This segment is defined so as not to straddle from one route defined in the route record to another route.

FIG. 17 shows the correspondence between route records, segment records, link records, and coordinate records. As can be seen from FIG. 17, a plurality of segment records are usually provided for one route record. However, the segment may include all of the link trains constituting one route defined by the route record. That is, one segment record may be associated with one route record.

It can be decided as appropriate which road is the main road. For example, the main road can be the road level side at which high-speed movement is possible when the road level is divided into two according to the viewpoint of whether or not high-speed movement is possible.

Segments are not defined for routes that are not main roads. That is, the segment record array number and the number of segments in (5) and (6) of FIG. 10 are described only for the route record corresponding to the main road. In a route record corresponding to a route in which no segment is defined (a route that is not a main road), a link record array number and the number of links constituting the route are described instead of the segment record array number and the number of segments. The link record array number is an array number in the link list Lb15 of the link record corresponding to the link at the head of the route.

<Segment list Lb14>
As shown in FIG. 11, in the segment list Lb14, segment records corresponding to the respective segments are arranged according to the route flow, similarly to the first coordinate list Lb16. Specifically, the segment records corresponding to the segments are arranged in the order corresponding to the arrangement order of the coordinate records in the first coordinate list Lb16 and the arrangement order of the route records in the route list Lb13. Accordingly, (5) and (6) in FIG. 10 described in the route record, that is, each segment constituting the route is determined by the segment record array number corresponding to the segment at the head of the route and the number of segments constituting the route. The segment record of the segment can be specified.

Whether or not the link record array number and the number of links are described instead of the segment record array number and the number of segments should use the record array in the road level order described later and the number of records B14 in the segment list Lb14. Can be specified (details will be described later).

<Segment record>
A segment record is provided for each segment. In this embodiment, the road network of main roads is expressed by segment connections, and intersections of main roads are expressed by segment connections. The segment data relating to the segments delimited at the intersections of such main roads is information that can identify each link record of the link string that constitutes the corresponding segment.

As shown in FIG. 11, the segment record includes a link record array number and the number of link records. The link record array number is a number indicating the number in the link list Lb15 in which the link record corresponding to the link located at the head of the link row constituting the segment is arranged. The number of link records represents the number of links constituting the segment.

<Link list Lb15>
In the link list Lb15 shown in FIG. 12, similarly to the first coordinate list Lb16, link records corresponding to the links are arranged according to the route flow. Specifically, the link records corresponding to the links are arranged in the order corresponding to the arrangement order of the coordinate records in the first coordinate list Lb16 and the arrangement order of the route records in the route list Lb13. Therefore, the link record of each link constituting the segment can be specified by the link record array number of FIG. 11 described in the segment record and the number of links constituting the segment.

By the way, as mentioned above, the segment is set only on the main road. In other words, a segment is set for a high road level route, but no segment is set for a low road level route.

For example, it is assumed that segments are set for road levels 2, 3, and 4 but no segment is set for road levels 0 and 1. In this case, segment records corresponding to routes with road levels 2, 3, and 4 are stored in the segment list Lb14, but segment records for routes with road levels 0 and 1 are not stored.

<Link record>
Next, the link record will be described. The link record is information corresponding to each link in the mesh and representing the characteristics of the corresponding link.

FIG. 12 described above also shows the structure of the link record. As shown in the figure, the link record includes (1) the number of coordinate records corresponding to the link, (2) start point side connection link number and start point side connection attribute, and (3) end point side connection link number and end point side connection. Information describing attributes, (4) link length, (5) other road attributes of the link (traffic regulation information such as one-way traffic, number of lanes, legal speed, presence of traffic lights at intersections corresponding to link end points, etc.) Is done.

The direction of each link is determined by the arrangement of the corresponding coordinate record group in the first coordinate list Lb16. The starting point of the link means the youngest end point in the order of arrangement of coordinate records among both ends of the link. The end point of a link refers to the end point on the opposite side of the end point corresponding to the start point among both ends of the link.

(2) The starting point side connection link number is a link record array number of a link record corresponding to another link connected to the starting point of the link. The start point side connection link number and the start point side connection attribute represent a connection relationship with another link connected to the start point of the link.

(3) The connection link number on the end point side is the link record array number of the link record corresponding to the other link connected to the end point of the link. The end point side connection link number and the end point side connection attribute represent a connection relationship with another link connected to the end point of the link. The information of (2) and (3) represents the connection relationship with other links at both ends of the corresponding link.

Even if there are a plurality of other links connected to the link start point, only the link record array number of a single other link that complies with a predetermined rule is described in the start point side connection link number. Is done. Similarly, even if there are a plurality of other links connected to the link end point in the end point side connection link number, the link record array number of a single other link that follows a predetermined rule among the other links Only described. Details of the description method of the link connection relation including this point will be described later.

The start point side connection attribute described together with the start point side connection link number represents whether the own link is connected to the start point or the end point of the link corresponding to the start point side connection link number at the start point. That is, the start point side connection attribute takes a value representing either “start point” or “end point”. If other links connected to the link start point end point are not in the same mesh, the link record array number of the link is described as the start point connection link number, and “start point” is represented as the start point connection attribute. A value is described. When there is no other link in the same mesh connected to the start point of the link, there is a dead end, or the link start point is a node (boundary node) located at the boundary with the adjacent mesh. The case where it connects to only is mentioned. In this embodiment, since the mesh unit data is closed data, only the link connection relation in the own mesh is described as the connection relation of the link sandwiching the boundary node located at the boundary with the adjacent mesh. .

Similarly, the end point side connection attribute described together with the end point side connection link number indicates whether the link is connected to the start point or the end point of the link corresponding to the end point side connection link number at the end point. When there is no other link in the same mesh connected to the end point of the link, the link record array number of the own link is described as the end side connection link number, and the value indicating “end point” is described as the end side connection attribute. The

(1) The number of coordinate records is the number of coordinate points constituting the link record. In the first coordinate list Lb16, the coordinate records are arranged in the order corresponding to the link records in the link list Lb15. Therefore, by adding the number of coordinate points described in each link record from the top of the link list Lb15, the coordinate record corresponding to each link record can be specified. Therefore, the number of coordinate records corresponding to the link is information that can specify a coordinate record group representing the coordinates of each point of the link in the first coordinate list Lb16.

However, instead of specifying the coordinates of each point of the link by adding the number of coordinate points as described above, the coordinate record array number corresponding to the first coordinate record of each link and the number of coordinate records corresponding to this link A coordinate record group representing the coordinates of each point of the link may be specified in the first coordinate list Lb16 based on the information.

<First coordinate list Lb16>
FIG. 13 is a configuration diagram of the first coordinate list Lb16 and the first type coordinate record. The first coordinate list Lb16 is a list of first type coordinate records. The first type coordinate record is a coordinate record for the end point and shape interpolation point of each link constituting the road level road described by the mesh unit data including the first coordinate list Lb16.

The first type coordinate record has information on the X coordinate (longitude) and Y coordinate (latitude) of the corresponding point. Furthermore, it has attribute information of the point. The attribute information described in the first type coordinate record includes information indicating the type of the corresponding point, and by this information, the point is predetermined as a shape interpolation point, a node, a boundary node provided at the mesh boundary, or the like. Classification. In the first coordinate list Lb16, the first type coordinate records are arranged along the route flow.

<Second coordinate list Lb23>
The second coordinate list Lb23 is a list of second type coordinate records which are coordinate records for roads at a road level higher than the road level described by the mesh unit data including the first coordinate list Lb16 described above.

The second type coordinate record also has information on the X coordinate (longitude) and Y coordinate (latitude) of the corresponding point. This second type coordinate record is for road drawing, and information on whether or not the point is a node is necessary for route guidance, route search, etc., but the attribute of the point is not necessary for drawing. Therefore, the second type coordinate record does not have attribute information. Hereinafter, the second type coordinate record may be referred to as a drawing coordinate record.

The arrangement of the second type coordinate record in the second coordinate list Lb23 is the same as that of the first coordinate list Lb16, and the second type coordinate record is arranged in the second coordinate list Lb23 along the flow of the route. The first coordinate list Lb16 and the second coordinate list Lb23 are a continuous array. Therefore, the first coordinate list Lb16 and the second coordinate list Lb23 can be collectively considered as one coordinate list.

<Upper Level Link Column List Lb21>
FIG. 14 is a configuration diagram of the upper level link string list Lb21 and the upper level link string record. The upper level link string list Lb21 includes a plurality of upper level link string records corresponding to link strings belonging to the upper level. In the upper level link column list Lb21, each upper level link column record is arranged in order along the route flow.

Each upper level link string record has (1) entity data storage level, (2) link record array number, (3) number of links, and (4) link string attribute.

(1) The entity data storage level indicates the level at which the link entity data Lb1 (see FIG. 3) of the corresponding link string is stored. The link record array number (2) is the number indicating the number of the link data corresponding to the first link in the link string in the link list Lb15 at the entity data storage level (1). The number of links in (3) is a number indicating how many links the corresponding link string is composed of. The link string attribute (4) includes a road display class and a display scale flag. The road display class is information indicating which road display class the corresponding link string is. The map to be displayed has a line color and thickness determined by the road display class. Therefore, this information is necessary for drawing. Therefore, the upper level link string record includes information on this road display class. The display scale flag defines at which display scale the road in the link row is displayed.

<Upper level link list Lb22>
FIG. 15 is a configuration diagram of the upper level link list Lb22 and the upper level link record. The upper level link list Lb22 includes a plurality of upper level link records corresponding to individual links constituting a link string belonging to the upper level. In the upper level link list Lb22, each upper level link record is arranged in order along the route flow.

Each upper level link record has the number of coordinates and width / lane number attributes. The number of coordinates describes the number of coordinates of individual links constituting the upper level link string. This number is the number excluding the coordinates of the first point. In the width / lane number attribute, a value indicating the width and the number of lanes of the link row is described.

<Data array of link entity data Lb1>
Next, the data arrangement of the link entity data Lb1 will be described. In the present embodiment, the route record groups of each level constituting the route list Lb13 are arranged in descending order of the road level. The reason why the route record groups are arranged in this order is that the route search or the like requires a search for a route that can reach the destination quickly, so the frequency of data access to a road-level record that can be moved at a high speed increases. This is because there is a tendency.

The rule for arranging records in descending order of road level is also applied to the segment record group constituting the segment list Lb14, the link record group constituting the link list Lb15, and the coordinate record group constituting the first coordinate list Lb16. ing. That is, it is commonly applied to the link entity data Lb1.

Further, focusing on one road level, the route records are arranged in the order along the route flow, and the segment records are arranged in the corresponding arrangement order of the route records as shown in FIG.

Similarly to the segment record, in one level link list Lb15, the link records of the links constituting the route corresponding to the route record are arranged in the arrangement order corresponding to the route record. Therefore, in the link list Lb15, each link record of the link string constituting the segment is arranged in the order of arrangement of the segments registered in the segment list Lb14. For routes that do not have a segment, each link record corresponding to the route is arranged in the order corresponding to the link row that constitutes the route.

The link records of links that do not constitute a segment are arranged in the latter half of the link list Lb15 by the arrangement in the order of the road level. On the other hand, the link records of the links constituting the segment are arranged in the first half of the link list Lb15. Therefore, in the route record, even if the link record array number and the number of links are described instead of the segment record array number and the number of segments, whether the description is the segment record array number and the number of segments, the link record array number Whether the number of links is the number of segments can be specified from the number of segment records B14. That is, if a number equal to or less than the segment record number B14 is described as the array number, the description is a segment record array number. If a number exceeding the segment record number B14 is described, the description is This is the link record array number.

Also, in the first coordinate list Lb16, similarly to the segment record and the link record, the coordinate records of the respective points on the route corresponding to the route record are arranged in the arrangement order corresponding to the route record. For convenience of illustration, in FIG. 17, coordinate records corresponding to two consecutive link records are not duplicated. However, in actuality, the end point of the front link and the rear link in the two consecutive links are shown. The starting point of is common.

<Array of upper road drawing data Lb2>
The upper level link string record group constituting the upper level link string list 21, the upper level link record group constituting the upper level link list 22, and the second type coordinate record group constituting the second coordinate list 23 are the upper road level. A certain level (hereinafter simply referred to as a lower level) is provided. More precisely, the lower level mesh corresponding to the shape of the road of the upper road level includes the upper road drawing data Lb2. In other words, the position of the link representing the shape of the road at the upper road level is compared with the range of each mesh at the lower level, and the position of the link representing the shape of the road at the upper road level is included in the mesh range. The level mesh includes upper road drawing data Lb2. Since only the lower level includes the upper road drawing data Lb2, the road data 10 of the uppermost road level 4 does not include the upper road drawing data Lb2.

The lower level road data 10 having a plurality of upper levels includes upper road drawing data Lb2 corresponding to each of the plurality of upper levels. That is, road level 3 road data 10 includes upper road drawing data Lb2 corresponding to road level 4, road level 2 road data 10 includes upper road drawing data Lb2 of road levels 4 and 3, The road level 1 road data 10 includes road level 4, 3, 2 upper road drawing data Lb 2, and the road level 0 road data 10 is road level 4, 3, 2, higher road drawing data. Lb2 is provided.

The upper road drawing data Lb2 corresponding to a plurality of upper levels includes a plurality of upper level link row record groups, upper level link record groups, and second type coordinate record groups corresponding to each upper level. Similar to the link entity data Lb1, these multi-level record groups are arranged in descending order of the road level, and are arranged along the route flow when focusing on one road level.

<An array of coordinate records corresponding to the upper level>
As shown in FIG. 18, the coordinate record group corresponding to the upper level, that is, the above-described drawing coordinate record is described following the first type coordinate record group describing the coordinates of the lower level road. When there are a plurality of upper levels in the lower level, the drawing coordinate records are described in order from the highest road level.

<Difference between each coordinate group for drawing>
As shown in FIG. 18, drawing coordinate record groups at the same level are respectively stored in a plurality of lower-level map data. For example, level 4 drawing coordinate record groups are stored in level 0, 1, 2, and 3 road data, respectively. Since the drawing coordinate record groups of these levels 0, 1, 2, and 3 have the same road to be drawn, the display accuracy of each level (in other words, the display scale of each level) is different. Is different.

<How to describe the connection of three or more links at the same point>
In the present embodiment, the information describing the connection relationship with the other link connected to the start point (or end point) of the link described in the link record is the aforementioned start point side connection link number, end point side connection link number, that is, Information that points to a single link.

However, as can be seen by assuming an intersection or a branch point, in practice, a single link may have a plurality of links. That is, the one link and a plurality of links connected thereto are often connected at the same point.

Nevertheless, in this embodiment, the information indicating the connection relationship with other links connected to the start point (or end point) of the link is the start side connection link number and the end point connection link number indicating a single link. This is because the rules described below are followed.

Specifically, in this embodiment, the connection relationship of a plurality of links connected to the same node is described in a clockwise direction in the link record of each link connected to the same node. That is, the link record array number of the adjacent link is described as a connection link number (start point side connection link number or end point side connection link number) clockwise around the node. When map data is used, a plurality of links connected to the same node are specified by referring to the link record clockwise around the node.

FIG. 19a shows the description direction of the connection link number together with an example of the connection relation of the link. As shown in FIG. 19a, each link record describes a connection link in a clockwise direction.

FIG. 19b is a diagram showing the start-point side connection link number and the end-point side connection link number described in the link record of the target link L0 shown in FIG. 19a. In this example, the other links connected to the starting point of the link of interest L0 are the links L1, L2, and L3. Of these links L1, L2, and L3, the link that is adjacent to the target link L0 in the clockwise direction is the link L1. For this reason, the link record array number of the link L1 is described in the link record of the target link L0 as the start point side connection link number.

The other links connected to the end point of the link of interest L0 are the links R1 and R2. Of these links R1 and R2, the link that is adjacent to the target link L0 in the clockwise direction is the link R1. For this reason, the link record array number of the link R1 is described in the link record of the target link L0 as the end-point side connection link number.

FIG. 19c shows the connection link numbers described in the link records of the links L1, L2, and L3 based on the example of FIG. 19a. A link adjacent to the link L1 in the clockwise direction around the start point of the link of interest L0 is the link L2. For this reason, the link record of the link L1 includes the link list array number of the link L2 as the connection link number (start point side connection link number or end point side connection link number) of the link L1 that matches the start point of the target link L0. Is described. Further, the link adjacent to the link L2 in the clockwise direction is the link L3. Therefore, the link list array number of the link L3 is described in the link record of the link L2 as the connection link number of the start point or the end point of the link L2 that matches the start point of the target link L0. Further, the link adjacent to the link L3 in the clockwise direction is the attention link L0. Therefore, the link list array number of the link of interest L0 is described in the link record of the link L3 as the connection link number of the start point or end point of the link L3 that matches the start point of the link of interest L0.

With such a description, the link connection relation of the starting point of the target link L0 is expressed, so when referring to the information representing the connection relation with other links included in the link records of the links connected to each other at the same point in order, It is possible to refer to the start point side connection link number or the end point side connection link number for all links connected to the same point.

In such an expression method, the connection relation of three or more links at the same point is described. Even if node data is provided in the map data, it is necessary to describe the link connection relation in the node data. Absent.

The structure of the road data 10 in the map data 1 of the present embodiment has been described above. The road data 10 is arranged in the order of route records, the order of segment records, the order of link records, and the order of coordinate records. . In addition, the association of records between lists is performed using the array number of the corresponding record in the list and the number of records. This structure is the same as in Patent Document 1. Therefore, as in Patent Document 1, the road data 10 of the present embodiment can efficiently access the records of each list, and the road data 10 can be easily edited.

<Background data>
As shown in FIG. 2, the background data 20 is managed by being divided into seven layers, and the background data 20 of each level is properly used according to the display scale during the drawing process. For example, the level 0 background data 20 is used when drawing a display image when the display scale is set to 1/2000 to 1/10000, and the level 1 background data 20 has a display scale. This is used when drawing a display image when it is set to 1 / 80,000 to 1/40000. The background data 20 of other levels are also used when the display scale is set to the scale described in the “scale at the time of drawing” column in FIG.

Also, since the requirements for display accuracy differ depending on the display scale, the fineness of each map image is different. For example, when the display scale is set to 1/2000 to 1/10000, it is necessary to display a fine map image such as the position of a house or a parking lot. For this reason, the level 0 background data 20 includes map image data at a density finer than one unit of the upper level background data 20 with a unit having a side length of 2.5 km as one unit. Yes.

On the other hand, when the display scale is set to 1 / 496,600, it is sufficient that the entire country is displayed, and image data such as detailed houses is not necessary. Therefore, the background data 20 of the level 6 includes map image data with a density that is rougher than the background data 20 of the lower level, with a unit having a side length of 10160 km as one unit. Of course, these are merely examples, and may be designed as appropriate.

As a feature of the background data 20 in the present embodiment, the background data 20 includes part of road shape data in addition to general backgrounds such as buildings, rivers, and mountains. The reason why a part of the road is provided as the background data 20 is that the structure of the road data 10 already described, that is, the road data 10 has a hierarchical structure for each road level. This will be described in detail below.

In the present embodiment, when a road map is drawn, the levels of the road data 10 and the background data 20 used for drawing are determined from the set values of the display scale, and the roads and background data 20 belonging to the levels are used. Images and background images are drawn. Regarding the drawing of the road at the level, the road shape and the like are drawn from the link entity data Lb1 of the road data 10 with reference to the coordinate record and the road attribute of the route. Further, for roads higher than the level, the road shape and the like are drawn by referring to the coordinate record, the link row attribute, etc. from the upper road drawing required data Lb2 included in the road data 10.

A problem when the drawing process as described above is performed will be described with reference to FIGS. 20A and 20B. As shown in FIG. 20A, for example, if the data used for drawing is determined to be level 3 from the display scale (1 / 128,000), roads belonging to level 3 (main national road 1) and roads belonging to level 4 (intercity high speed) The shape of the road 2) is drawn, but roads belonging to a level lower than level 3 are not drawn. By the way, as described above in the section of <stratification of road data>, there is a road that is rated at a level different from the original level because of the connection relationship between the roads. The main national road 3 shown in FIGS. 20A and 20B is a main national road, but is a road that is rated at level 2 because of its connection with other roads belonging to level 3. At this time, since the main national highway 3 originally belongs to the level 3, it should be displayed even on a map having a display scale of 1 / 1.28 million. However, since it actually belongs to level 2, it is no longer displayed as shown in FIG. 20A, which may give the user a sense of discomfort. (Indicates that the chain line is not visible.)

Because of the concerns described above, the background data 20 of each level is the same road type as the road type in which the link entity data Lb1 is described at that level, but the link entity data Lb1 is at a lower level than that level. A part or all of the described road (that is, a road that becomes invisible when drawn at the level) is provided as a background (simple image data). Thereby, it can prevent that the road which should be displayed originally is no longer displayed. That is, as shown in FIG. 20B, by displaying the main national road 3 as the background data 20, it is possible to reduce the possibility of giving the user a sense of discomfort.

In addition, since the road data 10 does not exist in the level 5 or 6 hierarchy, in the conventional configuration, for example, when drawn at a display scale (1/4096 million) corresponding to the level 6, the map image is displayed. The road disappears. However, there is a demand for displaying a road even when the drawing is drawn at a display scale that is a hierarchy in which no road data exists. Therefore, in the present embodiment, the background data 20 of the levels 5 and 6 in which there is no road data corresponding to the display scale is provided with a main road such as an intercity highway as a background. This makes it possible to display a map image including a road even when drawing at a display scale corresponding to levels 5 and 6.

<Device configuration>
Next, the configuration of the navigation device 100 on which the map data 1 is mounted will be described. A navigation device 100 illustrated in FIG. 21 includes a storage unit 50, a position detection unit 60, a control unit 30, and a display unit 40. The control unit 30, the storage unit 50, the position detection unit 60, and the display unit 40 are connected to each other via an in-vehicle LAN that conforms to a communication protocol such as CAN (Controller Area Network).

The storage unit 50 includes a storage medium (for example, a DVD or a hard disk) that stores the map data 1 described above, reads various data from the storage medium, and outputs the data to the control unit 30. The position detection unit 60 is for detecting the current position of the vehicle on which the navigation device 100 is mounted, and includes, for example, a known gyroscope, a distance sensor, and a GPS receiver.

The display unit 40 is a display that displays text and images in accordance with instructions from the control unit 30. For example, the display unit 40 displays a current position mark indicating the current position of the vehicle detected by the position detection unit 60, a map drawn based on the road data 10 and the background data 20. The display unit 40 is capable of full-color display and can be configured using a liquid crystal display, an organic EL display, or the like.

The control unit 30 is mainly composed of a microcomputer, and includes a well-known CPU, a memory such as a ROM / RAM / EEPROM, an I / O, and a bus for connecting them. The control unit 30 performs processing based on an application program stored in the ROM on the signals input from the storage unit 50 and the position detection unit 60. The control unit 30 includes a route guide unit 31 and a drawing processing unit 32.

The route guide unit 31 performs a process of calculating a guide route from the current position acquired by the position detection unit 60 to the destination registered by the user. Since a known method may be used for this route calculation method, description thereof is omitted here.

The drawing processing unit 32 is a function for performing processing for drawing an image to be displayed on the display unit 40. For example, the drawing processing unit 32 includes a current position mark indicating the current position of the vehicle detected by the position detection unit 60, a guide route calculated by the route guide unit 31, road data 10, and a map around the current position created from the background data 20. An image or the like is output to the display unit 40.

<Drawing process>
Next, the flow of the drawing process performed by the drawing processing unit 32 will be described with reference to FIG. The flowchart of FIG. 22 is performed sequentially. In step S1, the current position of the vehicle is acquired from the position detector 60, and the process proceeds to step S3. In step S3, the display scale setting value is acquired, and the process proceeds to step S5. In step S5, the level of data used for drawing the display image (that is, the level of the road data 10 and the background data 20) is determined from the display scale setting value acquired in the previous step S3. In the present embodiment, the road data 10 and the background data 20 are set so that the display scales of the respective levels are common, so that the levels of the data used for rendering the display image have the same value. However, for levels 5 and 6, the background data 20 exists but the road data 10 does not exist, so the display scale is set to 1 / 20480,000 to 1 / 1,240,000 (level 5) and 1 / 496,000 (level 6). If so, only the background data 20 is used.

In step S7, the mesh unit used for drawing the image data to be displayed on the display unit 40 from the current position of the vehicle acquired in step S1, the set value of the display scale acquired in step S3, and the size per mesh. Determine the data.

In step S9, the road data 10 and background data 20 at the level determined in the previous step S5 are read out from the mesh unit data determined in the previous step S7. In step S11, a background image is drawn based on the background data 20 read in the previous step S9 (that is, background data 20 at a level suitable for the display scale), and the process proceeds to step S13. In step S13, a road image is drawn from the road data 10 read in step S9. More specifically, a coordinate record used for road drawing is determined from the road data 10 read in step S9. The color / thickness of the road indicated by the coordinate record is determined from the link entity data Lb1 for the road related to the level. For roads belonging to a level higher than the level, the upper level link link row record, the upper level link Decide from the record. At this time, from the data array of the upper level link string record, the upper level link record, and the second type coordinate record, it is possible to specify from where to where is the same road and what the road attribute is.

In step S15, an image (display image) is generated by superimposing the image data drawn in steps S11 and S13 so that the road image is positioned on the near side of the background when viewed from the user, and is displayed on the display unit 40. Output and display.

As described above, according to the present embodiment described above, the map image is drawn using the road data and the background data determined by the display scale of the map image. At this time, even if there is no road level road data determined from the display scale, the road shape data is included in the background level background data corresponding to the display scale. You can draw on the image.

In addition, in this embodiment, the background data of each background level is originally provided with the shape data of roads belonging to a road level lower than the corresponding road level because of the connection relationship, although the roads originally belong to the corresponding level. For this reason, roads belonging to a road level lower than the road level determined according to the display scale are not displayed when the display scale is set, thereby preventing the user from feeling uncomfortable.

As mentioned above, although embodiment of this indication was illustrated, embodiment of this indication is not limited to the above-mentioned embodiment, and includes variously changed embodiments within the range which does not deviate from the gist.

(Modification 1)
For example, in the above-described embodiment, the upper level link string list Lb21 and the upper level link list Lb22 are stored next to the link list Lb15 (FIG. 3), but after all the data of the link entity data Lb1, they are stored. It may be stored.

According to the present disclosure, various types of map data, a map display device, and a map data usage method can be provided.

For example, map data of an example of the present disclosure includes road data including data describing road connection relationships and shapes divided into a plurality of road levels based on road types and connection relationships, and map image drawing. Background data provided with necessary background data divided into a plurality of background levels corresponding to the display scale of the map image, and when the map image is drawn, the background data referred to by the display scale of the map image Map data in which the background level is determined and the road data is referred to by the display scale of the map image and the road level is determined, and the road data corresponding to the road level does not exist among the plurality of background data The background data includes road shape data determined according to the display scale.

In the map data, the road data of the plurality of road levels is not connected to other roads of the road level among a plurality of roads having the same road type, and is connected to other roads at a lower road level. Relevant road data is provided as road data at the lower road level, and among the plurality of background data, the background data for which the corresponding road level road data exists is mainly described in the corresponding road level road data. However, it may be provided with road shape data described in road data of a road level lower than the road level. The map data may be stored in a map data storage device.

A map display device according to an example of the present disclosure includes a storage unit that stores the map data described above, a position detection unit that detects a current position, map data stored in the storage unit, and a current detected by the position detection unit. A control unit that sequentially creates a display map that represents a predetermined range including the current position with reference to the position, and a display unit that displays the display map created by the control unit may be provided.

The map data use method according to an example of the present disclosure includes road data including data describing road connection relationships and shapes divided into a plurality of road levels based on road types and connection relationships, and map image drawing. And background data provided with necessary background data divided into a plurality of background levels corresponding to the display scale of the map image,
Map data in which the background level of the background data referred to by the display scale of the map image is determined at the time of drawing the map image, the presence / absence of the road data referred to by the display scale of the map image, and the road level are determined. Among the background data, the background data for which there is no corresponding road level road data is a map data using method using map data including road shape data determined according to a display scale. The map data use method determines the current position, acquires data representing a predetermined range including the current position from the map data based on the current position, sequentially creates a display map, and creates the displayed map for display. A usage method of sequentially displaying on the display unit may be used.

The embodiments, configurations, and aspects of the present disclosure have been illustrated above, but the embodiments, configurations, and aspects according to the present disclosure are not limited to the above-described embodiments, configurations, and aspects. For example, embodiments, configurations, and aspects obtained by appropriately combining technical units disclosed in different embodiments, configurations, and aspects are also included in the scope of the embodiments, configurations, and aspects according to the present disclosure.

Claims (4)

1. Road data (10) provided with data describing road connection relations and shapes divided into a plurality of road levels based on road types and connection relations;
   Background data (20) provided with background data necessary for drawing a map image divided into a plurality of background levels corresponding to the display scale of the map image, and
   A map in which the background level of the background data (20) referred to by the display scale of the map image is determined at the time of drawing the map image, and the presence or absence of the road data (10) referred to by the display scale of the map image and the road level are determined. Data,
   Among the plurality of background data (20), the background data (20) for which there is no corresponding road level road data (10) is map data including road shape data determined according to the display scale.
2. In claim 1,
   The road data (10) at the plurality of road levels has no connection relationship with other roads of the road level among a plurality of roads having the same road type, and has a connection relationship with other roads at a lower road level. A certain road data is provided as road data (10) at the lower road level,
   Among the plurality of background data (20), the background data (20) in which the corresponding road level road data (10) exists is a type of road mainly described in the corresponding road level road data (10). Map data including road shape data described in road data (10) at a road level lower than the road level.
3. A storage unit (50) storing the map data according to claim 1 or 2,
   A position detector (60) for detecting the current position;
   A control unit (30) for sequentially creating a display map representing a predetermined range including the current position with reference to the map data stored in the storage unit and the current position detected by the position detection unit;
   A map display device comprising: a display unit (40) for displaying a display map created by the control unit.
4. Road data (10) provided with data describing road connection relations and shapes divided into a plurality of road levels based on road types and connection relations;
   Background data (20) provided with background data necessary for drawing a map image divided into a plurality of background levels corresponding to the display scale of the map image, and
   A map in which the background level of the background data (20) referred to by the display scale of the map image is determined at the time of drawing the map image, and the presence or absence of the road data (10) referred to by the display scale of the map image and the road level are determined. Data,
   Among the plurality of background data (20), the background data (20) for which there is no corresponding road level road data (10) uses map data including road shape data determined according to the display scale. To use map data,
   Determine the current position,
   Based on the current position, from the map data, obtaining data representing a predetermined range including the current position to sequentially create a display map,
   A map data usage method for sequentially displaying a created display map on a display unit.

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