JP2004061913A - Structure of map data, map data processing device and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of map data which can efficiently read out map data provided by a recording medium or the like and efficiently making data different in level correspond to each other, to provide a map data processing device using map data having the structure, and to provide a recording medium in which map data having the structure is recorded. <P>SOLUTION: A plurality of levels with different reduction scales are defined. The national map is divided into a plurality of blocks in each level, each block is divided into a plurality of meshes, and data for route computation is managed in each divided mesh. Further, concept of a mesh set comprising a plurality of divided meshes is introduced and a table to manage the mesh sets in a block is assigned to each block. The table includes the information indicating the position of the reference meshes representative of the mesh set and the information relating to the number of the reference meshes constituting the core mesh of the mesh set in the longitudinal direction and to the number in the latitudinal direction. The information in the table is used to gain the matching relation of the mesh sets among the levels. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a map data structure, a map data processing device, and a recording medium that records data having the map data structure.
[0002]
[Prior art]
2. Description of the Related Art Navigation devices that calculate a route, display a recommended route, and perform navigation are known. It is also known that route calculation data used for route calculation is managed in units of a map divided into meshes. It is also known that route calculation data is divided into a plurality of levels having different scales and managed, and a plurality of levels of route calculation data are properly used for route calculation.
[0003]
[Problems to be solved by the invention]
However, when the path calculation data is read in units divided into meshes, the number of seeks of the read head of the read device increases, and there has been a problem that the read time is increased.
[0004]
The present invention relates to a map data structure capable of efficiently reading map data provided on a recording medium or the like and efficiently performing correspondence between levels, and map data using map data having such a structure. It is an object of the present invention to provide a processing device and a recording medium on which map data having such a structure is recorded.
[0005]
[Means for Solving the Problems]
The invention according to claim 1 is applied to a structure of map data that has information about a map and can be processed by a map data processing device, and has a structure having information about a map in a plurality of level units having different scales. Each time, the map is divided into a plurality of mesh-shaped sections, and the information on the map is divided according to the divided section units, and the information on the map is managed in a section set unit in which a plurality of adjacent sections are collected. , A structure that is processed by the map data processing device in units of partition sets, and a structure that includes a management table having information for managing the partition sets in each level, wherein the management table is provided between the levels of the partition sets of each level. Has information that can be obtained by calculation.
According to a second aspect of the present invention, in the map data structure according to the first aspect, the management table includes information indicating a position of a reference section representing the section set, information on the number of vertical division directions of the section set, And information on the number in the horizontal direction.
According to a third aspect of the present invention, in the map data structure according to the second aspect, the section set has a rectangular shape, and the reference section representing the section set is a section located at the lower left of the section set. It is.
According to a fourth aspect of the present invention, in the map data structure according to the third aspect, the information for managing the section sets is stored in an order in which reference sections representing the section sets are arranged on the basis of the divided horizontal direction and the vertically divided direction. It shall be.
According to a fifth aspect of the present invention, in the structure of the map data according to any one of the first to fourth aspects, in each level, the map is divided into a plurality of mesh-like blocks, and the plurality of sections form each block. It is a section obtained by further dividing, and the management table is provided for each block.
According to a sixth aspect of the present invention, in the map data structure according to any one of the first to fifth aspects, the information on the map acquired by the map data processing device can be updated on a partition set basis using a management table. It is assumed that
According to a seventh aspect of the present invention, in the structure of the map data according to any one of the first to sixth aspects, an intersection of a road on a map is set as a node, the information on the map has information on the node, and the information is divided into sections. The information related to the map further includes inter-level node correspondence information between nodes in the section and corresponding nodes at other levels, the correspondence between levels of the section set and the inter-level nodes of the sections constituting the section set. Using the correspondence information, it is possible to grasp the correspondence between the levels of the nodes.
According to an eighth aspect of the present invention, in the map data structure according to any one of the first to seventh aspects, the information on the map is information on a route on a map used for route calculation. .
The invention according to claim 9 is applied to a map data processing device, and includes a recording medium driving unit mounted with a recording medium on which map data having the structure of the map data according to any one of claims 1 to 8 is recorded, Processing means for processing the map data based on the map data recorded on the recording medium.
According to a tenth aspect of the present invention, there is provided a recording medium driving unit which is applied to a map data processing device and has a recording medium on which map data having the structure of the map data according to the eighth aspect is recorded, and a map recorded on the recording medium. Processing means for performing a route calculation based on the information on the route.
The invention of claim 11 is applied to a recording medium readable by a computer or a map data processing device, and records map data having the structure of map data according to any one of claims 1 to 8.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram for explaining transmission and reception of map data such as map display data and route calculation data in the present embodiment. The in-vehicle navigation device 1 reads map data, management information, guidance search data, and the like from a recording medium 2 such as a CD-ROM or a DVD-ROM. Update data such as map data is provided from the removable memory 3. The removable memory 3 is a replaceable recording medium on which update data and the like are recorded for updating a part of the map data.
[0007]
The navigation device 1 can also be connected to a communication device 4 such as a mobile phone. The navigation device 1 can be connected to the Internet 5 via the communication device 4 and can be connected to the map server 6 via the Internet 5. The map server 6 holds old map data to the latest map data in the map database 7, and holds old guide search data to the latest guide search data in the guide search database 8. Therefore, the map server 6 can provide the navigation device 1 with update data for updating a part of the map data via the Internet 5. The guidance search data is data storing attribute information such as position information such as POI, type, and name.
[0008]
The navigation device 1 has a control device 11 and a nonvolatile memory 12. The control device 11 includes a microprocessor and its peripheral circuits. The nonvolatile memory 12 is a nonvolatile memory such as a hard disk and a flash memory provided inside the navigation device 1. The nonvolatile memory 12 may be any storage device as long as the written data is not erased even when the power of the navigation device 1 is turned off.
[0009]
Once the recording medium 2 is mounted on the navigation device 1, the recording medium 2 remains mounted on the navigation device 1 unless replaced with a new recording medium 2. Therefore, the removable memory 3 may be referred to as a fixed medium. The map database 7 and the guidance search database 8 are mother data databases because they have all new and old map data and guidance search data. The map server 6 can use the map database 7 and the guidance search database 8 to prepare the recording medium 2 having initial (pre-update) map data and the like, and the removable memory 3 having update data.
[0010]
FIG. 2 is a block diagram of the vehicle-mounted navigation device 1. The navigation device 1 includes a control device 11, a nonvolatile memory 12, a current position detection device 13, a DVD drive device 14, a memory 15, a communication interface 16, a removable memory reading device 17, a monitor 18, and an input device 19.
[0011]
The current position detection device 13 is a current position detection device that detects the current position of the vehicle. For example, a direction sensor that detects the traveling direction of the vehicle, a vehicle speed sensor that detects the vehicle speed, and a GPS that detects a GPS signal from a GPS (Global Positioning System) satellite. It consists of sensors and the like. The DVD drive device 14 is a device that mounts the recording medium 2 and reads map data and the like. In the present embodiment, the recording medium 2 is a DVD-ROM. Note that a CD-ROM or another recording medium may be used.
[0012]
The memory 15 is a memory that stores vehicle position information and the like detected by the current position detection device 13 and stores node information and link information on a recommended route calculated by the control device 11. Further, a mesh management table described later may be stored. The memory 15 is a working area of the control device 11. The communication interface 16 is an interface for connecting the communication device 4. Use of a mobile phone and connection to the Internet are possible via the communication interface 16. The removable memory reading device 17 is a device capable of loading the removable memory 3 and reading data from the removable memory 3.
[0013]
The monitor 18 is a display device that displays a map, a recommended route, and various information. The monitor 18 may be provided integrally as a part of the navigation device body, or may be provided separately as a housing. Further, only the monitor 18 may be connected to the navigation device main body by a cable or the like and provided at a separated position. The input device 19 is an input device for inputting a destination or the like of the vehicle when searching for a route. It may be a remote control or a touch panel provided on the screen of the monitor 18. The control device 11 uses the current position information of the vehicle detected by the current position detection device 13 and the map data stored in the recording medium 2 or the non-volatile memory 12 to display a road map, calculate a route (route search), Various navigation processes such as route guidance are performed. Note that various processing programs executed by the control device 11 are incorporated in a ROM (not shown) provided in the control device 11.
[0014]
-Map data structure-
The data structure of the above-described map data will be described in more detail. The map data is information relating to a map, and includes background (for map display) data, locator data, route calculation data, guidance data (intersection name / road name / direction name / direction guide facility information, etc.). The background data is data for displaying the background of a road or a road map. The locator data is data used for specifying the current position of the vehicle, map matching, and the like. The route calculation data is network data including branch information that is not directly related to the road shape, and is mainly used when calculating a recommended route (route search). The guidance data is data including names of intersections and the like, and is used when guiding a recommended route to a driver or the like based on the calculated recommended route.
[0015]
The map data of the present embodiment is managed based on the concept of levels, blocks, and meshes. In the present embodiment, map data is divided into seven levels having different scales, the level of the most detailed scale is set to level 0, and the level of the widest area map is set to level 6. Although each level includes map data with different scales, the target area is the same for each level. That is, if the whole country is the target, the map data of the whole Japan having different scales for each level is provided. For example, at level 0, the scale is 1/6250, at level 1, the scale is 1/25000, at level 2, the scale is 1/100000, at level 3, the scale is 1/400000, at level 4, the scale is 1/16000, and at level 5, At a scale of 1/6400000 and at a level of 6, the map data has a scale of 1/12800000 in Japan. That is, there are seven sets of map data corresponding to levels 0 to 6.
[0016]
FIG. 3 is a conceptual diagram illustrating the relationship among the levels, blocks, and meshes of map data. Representatively, levels 1 and 2 are shown. Reference numeral 101 indicates a target area of the main map data. Assuming that map data of the whole of Japan is handled, the area 101 is a range including the whole of Japan. Both level 1 and level 2 cover the same area. At level 1, the area 101 is managed by being divided into a plurality of 4 × 4 = 16 blocks 102. One block 102 is divided into a plurality of meshes 103 and managed. In the present embodiment, management is performed using m × n meshes. The number of divided meshes between the blocks 102 is the same number m × n at the same level.
[0017]
At level 2, the area 101 is managed by being divided into a plurality of 2 × 2 = 4 blocks 104. One block 104 is divided into a plurality of meshes 105 and managed. In the present embodiment, management is performed using p × q meshes. The number of divided meshes between the blocks 104 is the same number p × q at the same level.
[0018]
At level 1 and level 2, the number of blocks obtained by dividing the area 101 and the number of meshes obtained by dividing each block are different. This is handled in level 2 which handles a wide-area map when the scale is small (the value of the denominator is large), and in level 1 where the detailed map is used when the scale is large (the value of the denominator is small) compared to level 2. This is because the data amount is different. That is, appropriate division is performed according to the amount of data handled at each level. However, within the same level, the size of one block and the size of one mesh are the same. Note that the number of divided blocks at each level in FIG. 3 is one example, and is not necessarily limited to this number.
[0019]
The vertical direction of the division corresponds to the latitude direction, and the horizontal direction corresponds to the longitude direction. The names of the blocks and meshes are given for convenience in the present embodiment. Therefore, it is not necessarily limited to these names. A mesh may be called a parcel, a block may be called a first division unit, and a mesh may be called a second division unit. In addition, these blocks and meshes may be referred to as geographically divided units.
[0020]
-Route calculation data-
Hereinafter, the route calculation data in the map data will be described. The route calculation data is divided and managed in mesh units as described above. In the present embodiment, the concept of a mesh set is further introduced.
[0021]
FIG. 4 is a diagram illustrating the concept of a mesh set. Reference numeral 201 denotes the mesh described above. Hereinafter, each mesh is referred to as a reference mesh. A unit in which a plurality of reference meshes 201 are collected is called a core mesh 202. In the example of FIG. 4, six reference meshes 201 adjacent to each other are collected to form a core mesh 202. Around the core mesh 202, a reference mesh 201 indicated by a broken line is appropriately arranged. This is called an overlap mesh 203. The mesh set 204 is configured by combining the core mesh 202 and the overlap mesh 203.
[0022]
The number of reference meshes 201 constituting the core mesh 202 differs depending on the mesh set 204. In the example of FIG. 4, the number is six, but one or more reference meshes 201 constitute a mesh set 204. In the present embodiment, the shape of the core mesh 202 is rectangular (quadrangle). However, the shape may be not only rectangular but also L-shaped. That is, a mesh set 204 of any shape composed of a plurality of adjacent reference meshes 201 may be used. However, a rectangular shape is most preferable.
[0023]
The core mesh 202 is set without overlapping and with no gap in the block. The overlap mesh 203 set around the core mesh 202 overlaps with the reference mesh forming the core mesh of another mesh set. In addition, the mesh may overlap with a reference mesh forming an overlap mesh of another mesh set. There is also a mesh set including a single reference mesh and an overlap mesh including one or more reference meshes.
[0024]
Data corresponding to each reference mesh is called mesh data. The route calculation data is managed as mesh data of the reference mesh. The mesh data of the reference mesh forming the overlap mesh is generated by thinning data from the mesh data of the reference mesh forming the core mesh of another corresponding mesh set. That is, the mesh data of the overlapping mesh is composed of coarser data than the mesh data of the core mesh. Details will be described later.
[0025]
In this way, the route calculation data is managed in units of the reference mesh, and further managed in units of the mesh set. Path calculation data managed in units of mesh sets is stored in the recording medium 2 in units of mesh sets. The path calculation data stored in the recording medium 2 for each mesh set can be continuously read from the recording medium 2 for each mesh set. As a result, the number of seeks of the read head of the DVD drive is drastically reduced as compared with the case where data managed on a mesh basis is read out for each mesh, thereby realizing high-speed processing. Basically, data for each mesh set is stored in the order of core mesh data and overlapping mesh data. Further, depending on the application, it is also possible to read mesh data from the position of an arbitrary reference mesh constituting the mesh set.
[0026]
In the present embodiment, the concept of a mesh set is introduced for the route calculation data as described above. The map display data used for displaying the map on the monitor 18 does not need to particularly introduce the concept of a mesh set. This means that the map display data simply needs to read mesh data in a range corresponding to the display screen of the monitor 18. That is, if the mesh data is stored in order in the east-west direction, for example, it may be read out in that order.
[0027]
However, in the route calculation data, it is not always efficient to read mesh data arranged in a certain direction such as an east-west direction. For example, if a mesh set is configured along a main road, efficiency may be high at the time of route calculation. In the present embodiment, the most suitable mesh set for the route calculation is appropriately set according to the location. For example, the setting of the mesh set may be set manually based on experience, or the most efficient configuration may be set by computer simulation, or set according to a certain rule. You may. The certain rule may be set, for example, along an arterial road or an expressway as described above, or may be set according to the administrative division of a prefecture or a municipal government.
[0028]
-Management of mesh set-
Next, management of the mesh set described above will be described. As described above, the route calculation data is managed based on the concepts of level, block, mesh set, and reference mesh. Route calculation data is prepared as mesh data of each reference mesh. In short, blocks are managed by a block management table, and a mesh set in each block is managed by a mesh management table.
[0029]
FIG. 5 is a diagram schematically showing a relationship between a block management table, a mesh management table, and mesh set data which is actual data. Here, the mesh set data is a set of mesh data of the reference meshes constituting the mesh set. First, the level x data indicates that there is one block management table. The block management table has information about all blocks within that level. For example, at level 1 in FIG. 3, there are 16 blocks, and there are corresponding 16 block information. At level 2, four blocks of level 1 are managed as one block, so there are four blocks and corresponding four block information. FIG. 5 further shows that one block has one mesh management table.
[0030]
The mesh set is managed by the mesh management table. For example, access to the recording medium 2 and the non-volatile memory 12 for acquiring mesh set data, management of mesh set correspondence between levels, and the like are managed. To be more precise, the mesh management table has information for managing the mesh set, and the control device 11 uses this table to manage the mesh set.
[0031]
FIG. 6 is a diagram showing a level 1 block management table. The data size of the block management table (item numbers 1 to 23) is stored in the “size of block management table” of item number 1. The size is represented by the number of words as two bytes and one word. The number of block management information in the item number 2 contains the number of block management information in the block management table. At level 1, 16 blocks are stored because there are 16 blocks as shown in FIG. The item numbers 3 to 6 contain numbers indicating the range of this block on the map by latitude and longitude. However, in the case of longitude, a value obtained by subtracting 100 from the longitude is stored, and in the case of latitude, a value obtained by multiplying the latitude by 3/2 is stored. For example, in the case of 136 degrees east longitude, 36 is stored, and in the case of 33 degrees 20 minutes north latitude, (33 + 20/60) × (3/2) = 50 is stored. The “pointer to the mesh management table” of item No. 7 stores identification information indicating whether the storage destination of the mesh management table is on the recording medium 2 or the non-volatile memory 12, and its access address. This content will be further described later.
[0032]
FIG. 7 is a diagram showing the contents of the mesh management table accessed by "pointer to mesh management table" in the block management table. The data size of the mesh management table (item numbers 1 to 7) is stored in “size of mesh management table” of item number 1. The size is contained in words. The number of reference meshes in the latitudinal direction of the item No. 2 contains the number of reference meshes in the latitudinal direction managed by this table. In the example of level 1 in FIG. 3, n × 4 values are stored. The number of reference meshes in the longitudinal direction of item 3 stores the number of reference meshes in the longitudinal direction managed by this table. Considering the level 102 block 102 in FIG. 3, since there are n reference meshes in the north-south direction, there are n in the “reference mesh management number in the latitudinal direction”, and there are m meshes in the east-west direction. M is stored in the “reference mesh management number in direction”.
[0033]
The item Nos. 4 and 5 “lower end latitude” and “left end longitude” indicate the position of the lower left reference mesh constituting the file management table described below. For the latitude and longitude, values obtained by the above-described calculation are stored. The latitude indicating the position of the reference mesh is, for example, the latitude below (south side) the reference mesh, and the longitude is, for example, the longitude on the left side (west side) of the reference mesh. Item No. 6 “file management table classification” indicates the type of file management table. For example, it is indicated by 0 when only the background data is used, and is indicated by 1 when the route calculation data is managed by a mesh set. The file management table of item No. 7 contains information such as the size of each mesh set described below.
[0034]
FIG. 8 is a diagram showing in detail the file management table in the case of the above-described category 1. The arrangement of the reference meshes in the east-west direction is managed as one row in order from the lower row to the upper row. In each line, management is performed in order from the left end (west end) to the right end (east end). However, since the mesh set includes a plurality of reference meshes, the mesh set is managed according to the position of the lower left reference mesh of the core mesh of each mesh set. That is, if the lower left reference mesh of the core mesh of a certain mesh set is located at the lower row, the mesh set is managed as data of the lower row of the file management table. The lower left reference mesh is a reference mesh representing a mesh set. When there are a plurality of mesh sets in which the lower left reference mesh is located in the lower row, the mesh sets are managed in order from the left end (west end). That is, the mesh sets are managed in the order in which the lower left reference meshes are arranged based on the longitude direction and the latitude direction.
[0035]
In FIG. 8, the mesh (mesh set) data head pointer of item number 1 contains the address of the leftmost mesh set data of each row on the recording medium 2. In the case of the bottom row, the address of the recording medium 2 to the mesh set first recorded in the block is stored. Item No. 2 is the relative number of the lower left reference mesh of the core mesh. The relative number of the reference mesh is a number in which the lower left reference mesh of the block is set to 1 and the inside of the row is allocated from left to right and from the bottom row to the top row in ascending order.
[0036]
Item No. 3 is the reference mesh number in the latitude direction in the core mesh. Item No. 4 is the number of reference meshes in the longitude direction in the core mesh. As described above, the mesh set has a rectangular shape in the present embodiment. Therefore, the number of reference meshes constituting the core mesh can be calculated by multiplying the values of the item numbers 3 and 4. If the core mesh is not rectangular, a rough range of the core mesh can be assumed from these values.
[0037]
Item No. 5 is the lower latitude of the mesh set including the overlap mesh (the relative number of reference meshes from the lower left reference mesh in the core mesh). Item No. 6 is the left end longitude of the mesh set including the overlapping mesh (the number of relative reference meshes from the lower left reference mesh in the core mesh). Item No. 7 is the reference mesh number (rectangular area size) in the latitude direction in the mesh set including the overlap mesh. Item No. 8 is the reference mesh number (rectangular area size) in the longitude direction in the mesh set including the overlap mesh. Item No. 9 contains information indicating the storage location of the mesh set data. If the mesh set data has not been updated, information indicating that the data is stored on the recording medium 2 is entered. The storage address can be obtained by adding the contents of the mesh (mesh set) data head pointer of item number 1 and the size of the mesh set data stored sequentially. If the mesh set data has been updated, the fact that it is stored in the nonvolatile memory 12 and the address thereof are entered. Note that an update file name may be used instead of the address. Item No. 10 is the connection / partial restriction mesh set data size. Item No. 11 is the inter-level correspondence mesh set data size.
[0038]
Item numbers 2 to 11 are management information (management data) of one mesh set. Item Nos. 12 to 21 are management information of the mesh set on the right side. Next, management information of the mesh set on the right follows. When it reaches the right end (east end), it goes up one line (north), and similarly, the management information of the mesh set is stored from the left end (west end) to the right end (east end). Since the core mesh of the mesh set is composed of a plurality of reference meshes, there is a row in which the lower left reference mesh of any of the core meshes does not exist. There is no mesh set management information in such a row.
[0039]
FIG. 24 is a diagram for explaining how the mesh set is managed by the file management table. Reference numerals 301 to 309 denote core meshes of each mesh set. The lower left reference meshes of the core meshes 301, 302, and 303 are located in the lower row. The mesh set including the core mesh 301 is managed as a left end mesh set in the bottom row. The mesh set on the right side is a mesh set including the core mesh 302, and the mesh set on the right side is a mesh set including the core mesh 303. Since the core mesh in which the lower left reference mesh is located does not exist at the bottom line + 1, no data exists in the file management table. Since the lower left reference mesh of the core mesh 304 is located at the lower end row + second row, a mesh set including the core mesh 304 is managed as the lower end row + second row left end mesh set. Similarly, a mesh set including the core mesh 305, a mesh set including the core mesh 306, and a mesh set including the core mesh 307 are managed from the left end in the lowermost row + 3rd row. A mesh set including the mesh 308 and a mesh set including the core mesh 309 are managed.
[0040]
-Mesh set data-
Next, the mesh set data will be described. The mesh set data is a set of mesh data of the reference meshes constituting the mesh set. As described above, the route calculation data is managed as mesh data of each reference mesh. The route calculation data is divided into connection / partial regulation data and inter-level correspondence data.
[0041]
FIG. 9 is a diagram showing mesh set data of connection / partial restriction data. The chunk of data shown in FIG. 9 is stored in the recording medium 2 or the nonvolatile memory 12. The number of reference meshes of item No. 1 is the total number of reference meshes constituting the mesh set. This is the sum of the total number of reference meshes constituting the core mesh and the total number of reference meshes constituting the overlap mesh. The reference mesh data is arranged later by that number. Item No. 2 is the offset size to the reference mesh data. The offset and size accommodation fields are arranged by the number of reference meshes. Item Nos. 3 to 7 are reference mesh data. The mesh data of n reference meshes are arranged.
[0042]
-Connection data-
FIG. 10 is a diagram showing the contents of the reference mesh data of the connection / partial restriction data. Item No. 1 is a mesh code. The mesh code is information for specifying each reference mesh, and is determined based on, for example, the latitude and longitude of the lower left corner. The calculation may be performed in the same manner as the latitude / longitude mesh code in the block management table in FIG. 6 and may be combined. Item No. 2 is mesh identification information. This is information for identifying whether the reference mesh data is a reference mesh in the core mesh or a reference mesh in the overlap mesh. Item No. 3 is core mesh identification information. Used for overlapping meshes. At the same level, a plurality of overlapping meshes used in a plurality of core meshes may have the same mesh code. Therefore, in order to specify which mesh set is the overlapping mesh, the mesh code of the lower left reference mesh of the core mesh to which it belongs is set.
[0043]
Item No. 4 is path information list identification information. When attention is paid to the core mesh including the reference mesh, this is information indicating whether or not a route information list exists between the core mesh and the adjacent core mesh. The route information list identification information will be further described later. Item No. 5 is offset information. The offset information is an offset value up to the head of the partial regulation data. That is, it corresponds to the size of the connection part data. Item No. 6 is connection part data. Item No. 7 is partial regulation data. The partial regulation data is a collection of regulation information that can be set for each link.
[0044]
FIG. 11 is a diagram showing details of the connection part data of item No. 6 in FIG. In the present embodiment, a road is represented by the concept of a link, a node, and a link string. A node is an intersection or a specially designated point on a road. A link corresponds to a road between nodes, and a link string represents one road by a plurality of links. The connection part data is connection information of this node. It consists of own node information of a node existing on one link string and information of adjacent nodes of a node connected to the node. The own node information and the adjacent node information store the position coordinates of the node.
[0045]
The following information is added to the own node information in addition to the position coordinate information. (1) Identification information of a “normal upper connection node” or a “terminal upper connection node (a node for which the validity of a route at one higher level to be connected is guaranteed)” in a lower-level node. (2) Identification information indicating whether or not the lower-level node exists in the route information list data. (3) Higher-order node presence / absence flags of up to four levels in the upper direction in the lower-level nodes. (4) The “invalid node flag” is newly added to the own node information. When the invalid node flag is ON, the own node information is left and the corresponding “adjacent node information” is deleted. This is because the overlapping meshes of the same mesh code (each adopted own node is different) are duplicated for each different core mesh, and the criteria of the same mesh code in the overlapping mesh and the core mesh are different. This is a measure for the necessity that nodes and links of the mesh (all the own nodes are valid) need to have the same ID number.
[0046]
FIG. 12 is a diagram illustrating a connection data section of the overlap mesh. The connection data of the overlapping mesh does not need to be the same data as the connection data of the core mesh. That is, the data may be coarser than the core mesh. Therefore, the mesh data of the reference mesh forming the core mesh at the same position is copied, and a flag indicating whether the own node is enabled or disabled is provided. In the example of FIG. 12, the invalid node flag of the own node information 3 of item No. 5 and the own node information 4 of item No. 6 are turned on, and these data are thinned out. By doing so, mesh data of the overlap mesh can be easily generated. Further, the node which has been invalidated can be easily re-enabled, so that the data can definitely be easily updated.
[0047]
-Inter-level correspondence data-
FIG. 13 is a diagram showing mesh set data of the inter-level correspondence data. The chunk of data shown in FIG. 13 is stored in the recording medium 2. It is stored after the mesh set data of the connection / partial restriction data in FIG. The contents of each item number are the same as in FIG.
[0048]
FIG. 14 is a diagram showing the contents of the reference mesh data of the inter-level correspondence data. The mesh codes, mesh identification information, core mesh identification information, and offset information of the item numbers 1 to 4 are the same as those in FIG. Item No. 5 is inter-level correspondence data.
[0049]
FIG. 15 is a diagram showing details of the inter-level correspondence data of item number 5 in FIG.
Item No. 1 is an interlevel correspondence header. Item No. 2 is the number of corresponding levels. The maximum number of corresponding lower levels is set. Indicates the maximum level of the correspondence (existing position) of the lower level node corresponding to the own level node. The number of the (lower) level that describes the correspondence based on the own level is set. Item Nos. 3 to 7 are correspondence information. The correspondence information is provided for the number n of nodes required for editing existing in the mesh of the own level.
[0050]
FIG. 16 is a diagram showing details of each correspondence information. The item number 1 is the corresponding information of the own node, and the item numbers 2 to 7 are the corresponding information of the adjacent nodes connected to the own node. The example in FIG. 16 is a case where m nodes are connected to a certain node. FIG. 17 is a diagram illustrating details of the own node correspondence information. Item No. 1 contains the number of nodes adjacent to the corresponding node. In the case of the own node in FIG. 16, m is entered. Item No. 2 is own level information. Enter the node number of the corresponding node at the corresponding level. Item Nos. 3 to 6 are lower level information. The number of corresponding levels set in item number 2 in FIG. 15 is set, and lower level information is arranged in order from the closest level based on the level. The lower-level information stores the existence area at the lower level of the own node and the own node number of the lower level. The existence area is information that can identify a corresponding block and a corresponding reference mesh.
[0051]
FIG. 18 is a diagram illustrating details of the adjacent node correspondence information. The item number 1 contains the node number of the node adjacent to the corresponding node at the corresponding level. Item Nos. 2 to 5 are lower level adjacent information. The number of corresponding levels set in item number 2 in FIG. 15 is set, and lower level information is arranged in order from the closest level based on the level. The lower-level adjacent information stores the existence area of the lower level of the adjacent node of the own node and the own node number of the lower level.
[0052]
-Route information list-
Next, the route information list will be described. The route information list is a list in which routes between certain mesh sets are calculated and listed in advance. That is, a route calculation (route search) between a node included in a certain mesh set and a node included in another mesh set is performed in advance, and a route with the minimum cost is selected and listed. The cost is a value in consideration of the distance of the route and other conditions.
[0053]
The route information list is basically created for the combination of all the mesh sets within that level. However, at the lower level, that is, at the level having detailed map data, if the combination of all the mesh sets is created, the processing time and the output result become enormous. Accordingly, only the meshes whose distance between the lower left reference meshes of the core meshes is within a predetermined distance are created. For example, at level 1, a mesh whose distance between the lower left reference meshes is within 40 km is created, and at level 2, a combination of all mesh sets is created. These conditions may be changed as appropriate.
[0054]
By using the route information list created in this way, the time for route calculation is greatly reduced. In the present embodiment, in order to use the route information list, the item of the route information list identification information is provided in the reference mesh data, as described in item 4 of FIG. The route information list identification information will be described in more detail.
[0055]
FIG. 19 is a diagram illustrating the path information list identification information. In FIG. 19 (a), the core mesh of interest is a core mesh x, there is no route information list between the core mesh x and the core mesh d, and the core mesh x and the core meshes a, c, e, and b It is assumed that a route information list has been created in the. In this case, the mesh data of the reference mesh A of the core mesh x is as shown in FIG. The route information list identification information of item No. 4 contains information about the reference mesh adjacent to the reference mesh vertically and horizontally.
[0056]
Specifically, since the upper reference mesh of the reference mesh A belongs to the core mesh d, and there is no route information list between the core mesh x and the core mesh d, data without a route information list is entered. Since the lower reference mesh of the reference mesh A is within its own core mesh, NULL indicating that it is within its own core mesh is entered. Since the left reference mesh of the reference mesh A is also in the own core mesh, NULL indicating that the reference mesh is in the own core mesh is entered. The right reference mesh of the reference mesh A belongs to the core mesh e, and since there is a route information list between the core mesh x and the core mesh e, data having a route information list with the core mesh e is entered. If there is a route information list, a pointer is entered so that the corresponding route information list can be referred to. Similarly, the mesh data of the reference mesh B of the core mesh x is as shown in FIG.
[0057]
In this way, by referring to the item of the route information list identification information of the mesh data of the corresponding reference mesh, it can be determined whether or not there is a route information list between adjacent reference meshes. If there is a route information list, the route information list can be imported, and the route calculation time can be reduced. That is, by taking in the route information calculated in advance, the route calculation such as the Dijkstra method does not have to be performed each time, and the route calculation time can be reduced.
[0058]
-Association of mesh sets between levels-
As described above, in the present embodiment, map data is divided into seven levels with different scales, the level of the most detailed scale is set to level 0, and the level of the widest area map is managed as level 6. Among them, the route calculation data is provided at level 1, level 2, and level 4. When the current location is detected and the destination is specified, the route between the current location and the destination is calculated.
[0059]
In the level 1 map display, the current location is detected and the destination is set. If both the current location and the destination are in the same core mesh of level 1, the route is calculated using the route calculation data of the reference mesh in the core mesh. Perform calculations. In addition, even when the current location and the destination are in the adjacent core meshes, the route calculation is basically performed using the route calculation data of the reference mesh of the adjacent core meshes at the same level.
[0060]
However, when the core mesh where the current location is located and the core mesh where the destination is distant at level 1, the route calculation is performed on the intermediate route using the route calculation data of the upper level 2. Also, when the corresponding core meshes are separated from each other at the upper level 2, the path calculation is further performed using the path calculation data at the upper level 4. In this way, the route on the way can use route calculation data of a small capacity at a higher level, so that the processing time of the route calculation can be reduced. However, as described above, when a route information list between mesh sets exists, the route information list is used. For example, at level 1, even if the core meshes are far apart, as described above, if there is a route information list within 40 km between the mesh sets, it is used.
[0061]
At level 1, when there is no route information list, route calculation such as the Dijkstra method is performed using data of the mesh set to which the current location belongs. When reaching the node of the overlap mesh, the node is raised to the upper level, level 2, and the route calculation is further continued. The same processing is performed on the destination side. At level 2, since there is a route information list in principle, a route with the minimum cost between the current-side mesh set and the destination-side mesh set up to level 2 is selected. If there is no route information list, route calculation is performed using the mesh set data of the level 2 mesh set. If necessary, the level is raised from the overlap mesh to the upper level 4, and the route calculation is performed using the level 4 route calculation data. The route calculation is performed in this way, and an optimal route from the current position to the destination can be obtained.
[0062]
In the above, the expression of raising the overlapping mesh from the lower level to the upper level has been described. Raising to a higher level means that a higher-level node corresponding to a lower-level node is specified, and the route calculation is further continued from the specified higher-level node. Here, in order to specify an upper-level node, it is necessary to associate a lower-level node with an upper-level node. In order to perform such association, it is necessary to grasp the association (parent-child relationship) between the lower-level mesh set and the upper-level mesh set. For this association, in the present embodiment, the above-described file management table of the mesh set is used.
[0063]
The association of the mesh set between the levels (targeting at a distance of one or more levels) is such that when the lower left reference mesh in the lower level core mesh is projected to the upper level, the upper level of the upper level located there is located. It is determined by specifying a core mesh constituted by the reference mesh.
[0064]
FIG. 20 is a diagram for explaining association of a mesh set between levels. The reference meshes L1-1 to L1-17 form a mesh set having level 1. The reference meshes L1-1 to L1-9 constitute a core mesh, and the reference meshes L1-10 to L1-17 constitute an overlap mesh. The reference meshes L2-1 to L2-8 constitute a mesh set having level 2. The reference meshes L2-1 to L2-6 constitute a core mesh, and the reference meshes L2-7 to L2-8 constitute an overlap mesh.
[0065]
Since the lower level lower left reference mesh L1-1 is included in the upper level reference mesh L2-5, the lower left reference mesh of the upper level core mesh including the reference mesh L2-5 is obtained from the file management table. This makes it possible to read the reference mesh in the upper level core mesh.
[0066]
Specifically, the following procedure is taken. (1) The relative number of the lower left reference mesh L1-1 itself is known. Thereby, the latitude and longitude information of the lower left reference mesh L1-1 can be obtained by calculation. (2) If the latitude and longitude information of the lower left reference mesh L1-1 can be grasped, it is possible to grasp which block it belongs to by referring to the upper level 2 block management table. (3) When it is possible to grasp which block the block belongs to, it becomes possible to refer to the mesh management table of the block. (4) With reference to the file management table of the corresponding mesh management table, based on the latitude and longitude information of the lower left reference mesh L1-1, it is determined which mesh set of the lower left reference mesh L1-1 is located in the core mesh. You can ask. In this manner, mesh sets can be associated between levels.
When the mesh sets can be associated between the levels, the nodes can be associated by searching the inter-level correspondence data in the mesh data of the reference mesh in the upper level 2 corresponding mesh set. In this way, the node of lower level 1 and the node of upper level 2 are associated with each other, and the route calculation can be performed from lower level 1 to upper level 2.
[0068]
As described above, the lower left reference mesh of the lower level core set belongs to which higher level core set belongs. Therefore, it is theoretically possible that the lower-level core mesh is set so as to straddle the boundary of the upper-level core mesh. However, basically, it is preferable that the lower level core mesh is set so as to be included in the upper level core mesh. This allows the entire lower level core mesh to fit within one higher level core mesh.
[0069]
-Use of overlap mesh-
In the present embodiment, when increasing from a lower level to an upper level, the overlapping mesh of the lower level mesh set is increased. That is, in the lower level mesh set, the route calculation is performed up to the node of the overlap mesh. Then, the node of the overlap mesh is associated with the upper-level node by the above-described method, and the route calculation is further performed from the associated upper-level node.
[0070]
This is to reduce the data capacity of the overlap mesh, reduce the load of the route calculation, and further reduce the load of the calculation of the association with the upper level. This is because, when route calculation is performed by connecting to an upper level, only data necessary for a long distance search as route calculation data for connecting to an upper level may constitute overlap data. Thereby, the route calculation time can be reduced.
[0071]
As described above, the mesh data of the reference mesh forming the overlap mesh is generated by thinning out the data from the mesh data of the reference mesh forming the core mesh at the same position. In the example of FIG. 12 described above, an example has been described in which an invalid node flag is provided in the own node information. However, such a flag may not be provided, and only the information of the nodes necessary for the overlap mesh may be directly generated. By doing so, the data capacity of the mesh data of the overlap mesh can be reduced.
[0072]
Even if the reference mesh is located at the same position, there may be a case where the reference mesh forms an overlap mesh of a different mesh set. In such a case, the mesh data of the overlap mesh is generated differently by different mesh sets. That is, the overlap mesh is generated such that only necessary nodes are left according to the connection from the core mesh. Therefore, even at the same position, the path calculation data to be formed differs depending on which core mesh is adjacent to the overlapping mesh. Of course, the data may be the same.
[0073]
As a method of generating mesh data of the overlap mesh, various methods such as leaving only nodes such as main roads, highways, and the like connected to the core mesh can be considered. This may be manually generated based on the experience of generating the route calculation data, or the most efficient data may be generated by computer simulation. Further, as described above, the road type or the like may be determined and automatically generated under a certain rule. Alternatively, the information of the links required in the specification may be left from the data of the core mesh, and the unnecessary links may be generated by deleting the adjacent node information while leaving only the own node information.
[0074]
-Update management of map data in the navigation device-
FIG. 21 is a diagram illustrating a state of update management of map data in the navigation device 1. The navigation device 1 of the present embodiment can update map data such as route calculation data in units of the mesh set described above. The navigation device 1 can read the mesh management table and the map data from the recording medium 2, read the updated map data from the map server 6 via the removable memory 3 or the Internet 5 and use the latest map data.
[0075]
In the case of a conventional navigation device, the data is read only from a recording medium such as a CD-ROM or a DVD-ROM. In the navigation device of the present embodiment, the map data in the recording medium 2 and the updated map data are used in combination. For this reason, it has a nonvolatile memory 12 which is a readable / writable medium. The nonvolatile memory 12 is constituted by a nonvolatile memory such as a hard disk or a flash memory, and retains data even when the power of the navigation device is turned off. The nonvolatile memory 12 may be called a cache medium 12.
[0076]
The non-volatile memory 12 has the block management table 124 described with reference to FIG. The block management table 124 has identification information indicating whether the mesh management table of the corresponding block is on the recording medium 2 or the non-volatile memory 12 and the access address thereof. When new map data is used for the first time, first, the block management table stored in the recording medium 2 is read into the nonvolatile memory 12. As an initial value, the mesh management table of each block is set as being on the recording medium 2. Thereafter, in response to the update of the map data in units of mesh sets, a mesh management table 125 of the block having the updated mesh is created in the non-volatile memory 12, and in the block management table 124, the mesh management table of the corresponding block is non-volatile. The fact that it is on the memory 12 is set. By referring to the block management table 124, the program can determine whether the mesh management table is on the recording medium 2 or the non-volatile memory 12.
[0077]
Reference numeral 126 denotes a memory in the memory 15 of the navigation device, which is an area for storing a mesh management table. Hereinafter, it is referred to as a memory 126. After determining whether the mesh management table is on the recording medium 2 or the non-volatile memory 12, the program reads the mesh management table from the relevant medium and stores it in the memory 126. The mesh management table 127 read into the memory 126 has the mesh management information described with reference to FIGS.
[0078]
When the map data for each mesh set is updated in the removable memory 3, the map data of the mesh set is read into the non-volatile memory 12 and stored as the map data 133. At this time, the fact that the mesh set data of this mesh set is stored in the nonvolatile memory 12 and the address thereof are written in the storage location of the item No. 9 of the corresponding mesh set in the mesh management table on the nonvolatile memory 12. If the data size of the mesh set data has been changed, the contents of item numbers 10 and 11 are rewritten. The other items do not need to be rewritten by updating. Thereafter, based on the contents, the nonvolatile memory 12 can be accessed. That is, the map data of the mesh set that has not been updated can access the recording medium 2, and the updated mesh set map data can access the nonvolatile memory 12.
[0079]
-Path calculation control flowchart-
FIG. 22 is a diagram illustrating a flowchart of control in which the control device 11 reads route calculation data and performs route calculation. In step S1, the current position of the vehicle is detected using the current position detection device 13. In step S2, the destination set by the user using the input device 19 is set. In step S3, mesh set data of a required mesh set around the current position and the destination of the vehicle is read. In step S4, a route calculation (route search) is performed using the Dijkstra method or the like. In step S5, it is determined whether or not all the route calculations have been completed. That is, it is determined whether or not all the route calculations from the current location to the destination have been completed. If it is determined in step S5 that the process has not been completed yet, the process returns to step S3, where necessary mesh set data of the mesh set is read, and the route calculation is continued. If it is determined in step S5 that the route calculation has been completed, the process ends. During the repetition of steps S3 to S5, the connection to the above-described upper level is appropriately performed as needed.
[0080]
FIG. 23 is a diagram showing a detailed flowchart of the process of step S3 in FIG. In step S21, the block management table in the nonvolatile memory 12 is accessed as described above. In this case, it is assumed that the block management table has already been read into the nonvolatile memory 12. In step S22, based on the contents of the block management table, it is determined whether the file management table of the corresponding block exists on the recording medium 2 or the nonvolatile memory 12. If it is determined in step S22 that the recording medium 2 is present, the process proceeds to step S23. In step S23, the file management table of the corresponding block is read from the recording medium 2 into the memory 126.
[0081]
On the other hand, if it is determined in step S22 that it is not on the recording medium 2, that is, it is on the nonvolatile memory 12, the process proceeds to step S24. In step S24, the file management table of the corresponding block is read from the nonvolatile memory 12 into the memory 126. In step S25, the storage destination address of the mesh set is calculated based on the contents of the file management table read into the memory 126. In step S26, the mesh set data is read from the calculated storage destination. In this case, if the mesh set data has not been updated, the data is read from the recording medium 2 in mesh set units. If the mesh set data has been updated, the data is read from the nonvolatile memory 12.
[0082]
As described above, when the structure of the map data and the navigation device according to the present embodiment are used, the following effects are obtained.
(1) The path calculation data stored in the recording medium 2 is managed by introducing a concept of a mesh set composed of a plurality of reference meshes. As a result, data can be continuously read out from the recording medium 2 in a chunk of data suitable for path calculation. As a result, the number of seeks of the read head of the DVD drive is drastically reduced as compared with the case where data managed on a mesh basis is read out for each mesh, and the processing is speeded up.
(2) Since the concept of an overlap mesh is introduced, it is possible to reduce the processing time of the route calculation when connecting the lower level and the upper level.
(3) An invalid flag for creating overlapping mesh data is provided. This facilitates generation and management of the data of the overlap mesh.
(4) A file management table for managing a mesh set is provided. As a result, the association (parent-child relationship) of the mesh set between the levels can be easily grasped only by referring to the file management table. Furthermore, there is no need to provide a special table that directly defines the correspondence between levels.
(5) Since map data such as route calculation data can be updated in units of mesh sets, when updating only a part of the map data, the entire recording medium such as a DVD-ROM storing the map data is updated. No need. The minimum update unit is the mesh set unit, and the communication amount (cost) required for unnecessary data update can be reduced.
(6) Since the update data is also provided by communication via the Internet, the latest update data can be provided quickly and at low cost.
(7) Since the route information list created in advance is used appropriately, the time for route calculation is greatly reduced.
(8) Since the map data is managed while the mesh management table is stored in the non-volatile memory, the management of the update data can be performed easily and reliably. This facilitates program development of the navigation device and the like.
(9) Since the update data for the whole country is not distributed in a lump but is distributed only in the region selected by the user, the reception time can be minimized. Also, since not all map data is recorded in a readable and writable large-capacity storage device, a storage capacity enough to record only update data requested by the user is sufficient.
[0083]
In the above embodiment, the control program executed by the control device 11 of the navigation device has been described as an example stored in the ROM. However, the present invention is not limited to this. The control program and its installation program may be provided on a recording medium such as a DVD. Note that the recording medium need not be limited to a DVD, and a CD-ROM, a magnetic tape, or any other recording medium may be used.
[0084]
Further, these programs can be provided via a transmission medium such as a communication line represented by the Internet. That is, it is also possible to convert the program into a signal on a carrier wave that carries the transmission medium and transmit the signal. When the program is provided on a recording medium or the Internet, the program may be provided in the same configuration as in FIG. For example, the recording medium 2 may be a recording medium that provides a program, and the map server 6 may be a server that provides an application program.
[0085]
Further, the above-described control program may be executed on a personal computer to realize a car navigation device. In this case, the current position detection device 13 and the input device 19 may be connected to a predetermined I / O port of a personal computer.
[0086]
In the above-described embodiment, an example in which update data is provided from the removable memory 3 has been described. However, the present invention is not limited to this. The update data may be written in a CD-ROM, DVD-ROM, or the like, and the recording medium 2 may be temporarily replaced to be provided.
[0087]
In the above embodiment, an example in which the initial map data is read from the recording medium 2 has been described. However, the present invention is not limited to this. The initial map data may be received via the Internet 5 and stored in the non-volatile memory 12, and then updated and managed by the above-described method. Further, necessary map data may be received via the Internet 5 each time, and may be stored in the non-volatile memory 12 each time, and when there is an update thereafter, update management may be performed by the above-described method.
[0088]
In the above embodiment, an example in which the route calculation data is managed using the concept of the mesh set has been described. In addition, it has been described that the concept of the mesh set need not be used in the map display data. However, the map display data may be managed using the mesh set concept. Although the effect is not as high as that of the route calculation data, the processing speed of reading data may be improved in some cases. Further, the concept of the mesh set can be used in other map data.
[0089]
In the above-described embodiment, the example in which the nonvolatile memory 12 is provided inside the navigation device 1 has been described. However, the present invention is not limited to this. An external storage device connected by a cable or the like may be used.
[0090]
Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other embodiments that can be considered within the scope of the technical idea of the present invention are also included in the scope of the present invention.
[0091]
【The invention's effect】
The present invention is provided with a management table having information from which a correspondence between levels of a section set obtained by collecting a plurality of sections can be obtained by calculation. This makes it possible to easily grasp the correspondence between the levels of the section sets. Also, there is no need to provide a special table that directly defines the correspondence between levels.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining exchange of map data.
FIG. 2 is a block diagram of an on-vehicle navigation device.
FIG. 3 is a conceptual diagram illustrating a relationship among levels, blocks, and meshes of map data.
FIG. 4 is a diagram illustrating the concept of a mesh set.
FIG. 5 is a diagram schematically showing a relationship between a block management table, a mesh management table, and mesh set data which is actual data.
FIG. 6 is a diagram showing a block management table.
FIG. 7 is a diagram showing the contents of a mesh management table.
FIG. 8 is a diagram showing a file management table in detail.
FIG. 9 is a diagram showing mesh set data of connection / partial restriction data.
FIG. 10 is a diagram showing the contents of reference mesh data of connection / partial regulation data.
FIG. 11 is a diagram showing details of connection part data.
FIG. 12 is a diagram showing a connection data part of an overlap mesh.
FIG. 13 is a diagram showing mesh set data of inter-level correspondence data.
FIG. 14 is a diagram showing the contents of reference mesh data of inter-level correspondence data.
FIG. 15 is a diagram showing details of inter-level correspondence data.
FIG. 16 is a diagram showing details of correspondence information.
FIG. 17 is a diagram showing details of own node correspondence information.
FIG. 18 is a diagram showing details of adjacent node correspondence information.
FIG. 19 is a diagram illustrating route information list identification information.
FIG. 20 is a diagram illustrating association of a mesh set between levels.
FIG. 21 is a diagram illustrating a state of update management of map data in the navigation device.
FIG. 22 is a diagram showing a flowchart of control for reading route calculation data and performing route calculation.
FIG. 23 is a diagram showing a detailed flowchart of a process in step S3 of FIG. 22;
FIG. 24 is a diagram for explaining how a mesh set is managed by a file management table.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Navigation device 2 Recording medium 3 Removable memory 4 Communication device 5 Internet 6 Map server 7 Map database 8 Guidance search database 11 Control device 12 Non-volatile memory 13 Current location detection device 14 DVD drive 15 Memory 16 Communication interface 17 Removable memory reading device 18 Monitor 19 input device

Claims (11)

A map data structure that has information about the map and can be processed by the map data processing device;
A structure including information on the map in a plurality of levels having different scales;
For each level, a structure in which the map is divided into a plurality of mesh-shaped sections, and information on the map is divided corresponding to the divided sections.
The information on the map is managed in units of section sets in which a plurality of adjacent sections are collected, and the structure processed by the map data processing device in units of the section sets and the section sets are managed in each of the levels. A structure having a management table having information,
The map data structure, wherein the management table has information capable of calculating a correspondence between levels of the section set of each level by calculation. The structure of the map data according to claim 1,
The map, wherein the management table has information indicating a position of a reference section representing the section set, information on the number of vertical division directions of the section set, and information on the number of divided horizontal directions. The structure of the data. The structure of the map data according to claim 2,
The section set has a rectangular shape,
The map data structure, wherein the reference block representing the block set is a block located at the lower left of the block set. The map data structure according to claim 3,
The map data structure, wherein the information for managing the section sets is stored in an order in which reference sections representing the section sets are arranged on the basis of a divided horizontal direction and a freshly split direction. The structure of the map data according to any one of claims 1 to 4,
Within each of the levels, the map is divided into a plurality of mesh-like blocks,
The plurality of sections are sections obtained by further dividing each of the blocks,
The structure of map data, wherein the management table is provided for each of the blocks. The structure of the map data according to any one of claims 1 to 5,
The map data structure, wherein the information on the map acquired by the map data processing device can be updated on a per-section set basis using the management table. The structure of the map data according to any one of claims 1 to 6,
The intersection of the road on the map is a node,
The information on the map has information on the node,
The information related to the map divided into the block units further includes inter-level node correspondence information between a node in the block and a corresponding node at another level,
Map data, wherein the correspondence between the levels of the nodes can be grasped by using the correspondence between the levels of the division set and the inter-level node correspondence information of the divisions constituting the division set. Structure. The structure of the map data according to any one of claims 1 to 7,
The map data structure is characterized in that the information on the map is information on a route on a map used for route calculation. A recording medium driving means for mounting a recording medium on which map data having the structure of the map data according to any one of claims 1 to 8 is recorded,
A map data processing apparatus comprising: a processing unit that processes map data based on the map data recorded on the recording medium. A recording medium driving means mounted with a recording medium on which map data having the structure of the map data according to claim 8 is recorded;
Processing means for calculating a route based on information on the route on the map recorded on the recording medium. A recording medium readable by a computer or a map data processing device, wherein the map data having the map data structure according to any one of claims 1 to 8 is recorded.

Images