JP5881842B2 - Map data storage device, map display device - Google Patents

Description

  The present invention relates to a map data storage device and a map display device using the map data storage device.

  Usually, since map data has a large amount of data, map data is managed by dividing a space in which map data including backgrounds and roads exist into rectangles of a predetermined range called a mesh.

  Further, in order to execute map display of map data, route search, and the like at high speed, map data management is performed by hierarchizing (layering) map data according to a reduced scale.

  In such a map data management method, names used between layers or between meshes of the same layer often overlap. Therefore, for example, in Patent Document 1, among the name data included in the map data, the name data common between layers or between meshes of the same layer is collected as common name data, thereby reducing the data amount of the entire map data. The technology to do is proposed.

JP 2004-126036 A

  However, the map data management method disclosed in Patent Document 1 does not disclose the data structure of the common name data and does not adopt a spatial management form, and thus there is a problem in accessibility to desired data. It was. For example, when acquiring a plurality of name data, there is a possibility that desired data may be scattered in the common name data, so access (disk access when the common name data is stored on the disk) is performed. There is a problem that it occurs randomly and degrades the data access performance.

  In view of the above-described problems, an object of the present invention is to provide a map data storage device capable of efficiently accessing data and a map display device using the map data storage device.

The map data storage device of the present invention is hierarchized for each scale, partitioned into meshes of a size determined for each hierarchy, the mesh is identified by a mesh number for each hierarchy, and the lowest mesh is used as a reference mesh, A map data storage unit that stores map data representing features for each mesh, and a name information storage unit that stores a name list consisting of name records set one-on-one for the features that display names. in the data, the each feature belongs to people mesh respectively for each hierarchy to hierarchy determined for each each feature from the bottom layer, the name records, name information including at least one of the name or symbol of the feature, the feature The maximum display hierarchy number indicating the maximum display hierarchy, which is the maximum hierarchy in which the name information is displayed, and the affiliation reference mesh indicating the affiliation reference mesh to which the feature belongs. A data linked to the number, name list, the name records displayed maximum layer number, belonging reference mesh number, and based on the display up to the hierarchy belonging mesh number that indicates the maximum display hierarchy belonging mesh is belonging mesh in maximum display hierarchy This is a list sorted in the order of priority of display maximum hierarchy number, display maximum hierarchy affiliation mesh number, and affiliation reference mesh number .

The name list stored in the name information storage unit of the map data storage device of the present invention is the display maximum indicating the display maximum hierarchy belonging mesh whose name record is the display maximum hierarchy number, the belonging reference mesh number, and the belonging mesh in the display maximum hierarchy. This is a list sorted in the priority order of the maximum display hierarchy number, the maximum display hierarchy belonging mesh number, and the belonging reference mesh number based on the hierarchy belonging mesh number . Therefore, when displaying a map, name information can be efficiently acquired from the name list.

  Objects, features, and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

It is a block diagram which shows the structure of a navigation apparatus. It is a figure explaining the concept of the hierarchy of map data, and a mesh. It is a figure which shows the data structure of map information. It is a figure which shows the presence hierarchy range and display hierarchy range of a feature. It is a figure which shows the data structural example of a name list. It is a figure which shows the specific example of a name list. It is a figure showing the state where a feature straddles a plurality of meshes. It is a figure which shows the specific example of a name list. It is a figure which shows the data structural example of a name reference list. It is a figure which shows the specific example of a name reference list. It is a flowchart which shows a map display process. It is a flowchart which shows a name acquisition process. It is a flowchart which shows a name drawing process. It is a figure which shows the specific example of background data.

<A. Embodiment 1>
<A-1. Configuration>
FIG. 1 is a block diagram showing a configuration of a navigation device 10 including a map data storage device and a map display device of the present invention. The navigation device 10 is mounted on a moving body such as a vehicle.

  The navigation device 10 includes an input unit 1, a position detection unit 2, a map information storage unit 3, a control unit 4, a display unit 5, and an audio output unit 6.

  The input unit 1 is a group of operation switches to which a user's operation and instruction are input, and a signal corresponding to the input operation and instruction is given to the control unit 4.

  The position detection unit 2 is a unit that detects the current position of a moving body on which the navigation device 10 is mounted, and is configured using, for example, a GPS (Global Positioning System) receiver, a vehicle speed sensor, an acceleration sensor, an angular velocity sensor, or the like. . Position information indicating the current position detected by the position detector 2 (hereinafter referred to as current position information) is given to the controller 4. The position detection unit 2 may be configured as a device different from the navigation device 10.

  The map information storage unit 3 is a storage medium for storing map information, and is realized by, for example, a hard disk drive, a DVD and its drive device, a Blu-ray disc and its drive device, a semiconductor memory, and the like.

  The control unit 4 uses the instruction signal from the input unit 1, the current position information from the position detection unit 2, and the map information read out from the map information storage unit 3 to perform various types of map display and route guidance around the current location. Perform the navigation process. The control unit 4 includes, for example, a processor, and includes a drawing processing unit 41 that performs drawing processing, a drawing memory 42 that stores drawing data of the drawing processing unit 41, and a display control unit 43 that controls display of the display unit 5. ing.

  The display unit 5 displays the content drawn in the drawing memory 42 by the drawing processing unit 41 of the control unit 4 according to the control of the display control unit 43, and is configured by a liquid crystal display, for example.

  The voice output unit 6 presents information obtained as a result of various navigation processes by the control unit 4 to the user by voice. The information to be output by voice includes, for example, guidance information for performing guidance from the departure point to the destination according to the route to the destination obtained by the route search process on the map, and the destination information obtained by the search process. Facility information. The display unit 5 and the audio output unit 6 may be configured as devices different from the navigation device 10.

<A-2. Map information>
FIG. 3 shows the data structure of the map information stored in the map information storage unit 3. The map information has map management information, map data, feature name information, and search information for searching for various information. That is, the map information storage unit 3 is a map data storage unit that stores map data. The map data is managed in a hierarchical (layered) and meshed manner, and FIG. 2 shows the situation.

  FIG. 2 shows map data composed of four layers with layer numbers 0 to 3. The map data of each hierarchy shown here is map data for drawing the same range on the map at different scales. In the following description, the layer having the layer number n is also simply referred to as “layer n”.

  The map data of the hierarchy 3 consists of 4 meshes. The map data of level 2 is composed of 16 meshes obtained by dividing each mesh in the map data of level 3 into four. The map data of the hierarchy 1 consists of 64 meshes obtained by dividing each mesh in the map data of the hierarchy 2 into four. The map data of the hierarchy 0 is composed of 256 meshes obtained by dividing each mesh in the map data of the hierarchy 1 into four. In addition, although the square mesh is shown in FIG. 2, the shape of the mesh is not limited to this, and may be another shape such as a rectangle or a rhombus.

  In FIG. 2, the numbers in the square frames indicating the meshes represent the mesh numbers assigned to the meshes. A mesh number is assigned to zigzag and 0, 1, 2, 3 in the order of lower left, lower right, upper left, and upper right in the mesh of level 3. In the following, the mesh having the mesh number n is also simply referred to as “mesh n”.

  In the mesh of layer 2, mesh numbers are given in the order of mesh numbers of the corresponding meshes of the upper layer (hierarchy 3), and for the four meshes having the same mesh number of the corresponding mesh of the upper layer, the lower left, Mesh numbers are assigned in the order of lower right, upper left, and upper right. In this specification, “mesh corresponds” means that the two-dimensional coordinates of the mesh between different layers are the same.

  In the hierarchy number 2, mesh numbers 0, 1, 2, and 3 are assigned to the four meshes corresponding to the mesh 0 of the hierarchy number 3 in the order of lower left, lower right, upper left, and upper right. Also, mesh numbers 4, 5, 6, and 7 are assigned to the four meshes of the layer number 2 corresponding to the mesh 1 of the layer number 3 in the order of lower left, lower right, upper left, and upper right. Similarly, a mesh number 2 is assigned to the mesh of layer number 2 corresponding to the meshes 2 and 3 of layer number 3, as shown in FIG.

  A mesh number is assigned to the meshes of the hierarchy numbers 1 and 0 as well as the hierarchy number 2. Note that the mesh with the layer number 0 is also called a reference mesh, and the mesh number is called a reference mesh number.

  When the mesh number is assigned in this way, the mesh number of the mesh corresponding to the reference mesh in each layer can be obtained for an arbitrary reference mesh.

  Returning to FIG. 3, the information included in the map information will be described.

  The map management information includes version information indicating the version of map information, hierarchy management information for managing map data for each hierarchy, name management information for managing feature name information and search information, search information management information, and the like. Yes. The hierarchy management information has information such as the mesh number of each mesh, the storage position of the map data in the map information, and the data size for each hierarchy.

  The map data includes a map data header, road data, background data, route guidance data, and the like. That is, the map information storage unit 3 is a map data storage unit that stores map data.

  The map data header has information for managing each data in the map data.

  The road data is a set of road records provided corresponding to roads in the mesh. The road record has information representing the position, shape, type, and the like of the road in addition to the connection relationship between the roads and the feature ID for identifying the road.

  The background data is data representing each feature (background) other than the road in the mesh, and is a set of background records for displaying each background in the mesh. The background record includes information representing a feature ID for identifying the background, the position and shape of the background, the type of background, and the like. Examples of backgrounds include planes representing rivers, seas, etc., linear rivers, lines representing railways, points representing representative positions of facilities, and the like.

  The route guidance data includes information necessary for route guidance at an intersection or the like.

  The feature name information includes a name information header for managing various data in the feature name information, a name list representing the names of the features, a name reference list for referring to a desired name of the name list, and the like. Details of the name list and the name reference list will be described later.

  When the map is displayed, which level of map data is used is determined by the display scale. At the most detailed (narrow area) scale, the map data of the lowest layer mesh is used, and at the coarsest (wide area) scale, the map data of the uppermost layer mesh is used to display the map. For example, in FIG. 2, when the scale is 1 / 50,000 or more to 1 / 25,000, the hierarchy is 0, and when the scale is 1 / 100,000 or more to less than 1 / 50,000, the hierarchy 1 is 1/2000 or more to 1 The map data of the layer 2 is used when it is less than 100,000, and the mesh data of the layer 3 is used when it is 1/4000 to 1/2000.

  The feature represented by the map data of each layer is obtained by thinning out the feature represented by the lower-level map data. The map data in the lowest layer represents all the features on the map, but up to which level (existing level range) differs depending on the features.

  For example, in the example of the map data shown in FIG. 2, the feature that exists only in the hierarchy 0, the feature that exists in the hierarchy 0, 1, the feature that exists in the hierarchy 0, 1, 2, and the hierarchy 0, 1, 2, 3 Divided into features that exist in

  In the map display, the shape of the feature and the name or symbol of the feature may be shown. A symbol is a mark (icon) that directly represents a feature. The display of feature names will be described below. However, when only the name of the feature is actually displayed, when only the symbol is displayed, both the name and the symbol may be displayed. .

  If the names are displayed for all the features present in each layer, the characters are overlapped and the map display becomes complicated, and therefore the display layer range of the names may be limited to a layer lower than the existing layer range of the features. For example, for a feature whose existence hierarchy range is 0 to 3, the display hierarchy range of the feature name may be 0 to 2. Thus, the feature existing hierarchy range and the name display hierarchical range do not necessarily match. The maximum hierarchy number in the display hierarchy range is called the display maximum hierarchy number.

  In addition, there may be a feature having no name such as a rural farm road.

  FIG. 4 shows the features and their names in each layer of the map data. The feature F0 and the feature F5 exist only in the hierarchy 0, and their names N0 and N1 are displayed only in the hierarchy 0. Therefore, the existence hierarchy range is 0, the display hierarchy range is 0, and the maximum display hierarchy number is 0. is there. Since the features F1 and F6 exist in the hierarchy 0 and 1, and their names N1 and N6 are displayed in the hierarchy 0 and 1, the existence hierarchy range is 0 and 1, the display hierarchy range is 0 and 1, and the maximum display hierarchy number Is 1. The features F2 and F7 are present in the hierarchy numbers 0 to 2, and their names N2 and N7 are displayed in the hierarchy numbers 0 to 2, their existence hierarchy range is 0 to 2, and the display hierarchy range is 0 to 2. The maximum display hierarchy number is 2. Since the feature F4 exists in the hierarchy numbers 0 to 3 and the name N4 is displayed in the hierarchy numbers 0 to 3, the existence hierarchy range is 0 to 3, the display hierarchy range 0 to 3, and the maximum display hierarchy number is 3. The feature F3 exists in the hierarchy numbers 0 to 3, but since the name N3 is displayed in the hierarchy numbers 0 to 2, the existence hierarchy range is 0 to 3, the display hierarchy range is 0 to 2, and the display maximum hierarchy The number is 2.

<A-3. Name list>
FIG. 5 is a data configuration example of a name list included in the feature name information. The name list is an array of name records representing names used for map display. The name record is set on a one-to-one basis for the feature that displays the name, and includes a feature ID, a display maximum hierarchy number, a display maximum hierarchy affiliation mesh number, an affiliation reference mesh number, a name character string, and a symbol code. That is, the map information storage unit 3 is also a name information storage unit that stores a name list including name records.

  The feature ID is an identifier for identifying a feature for which name information is displayed. The maximum display hierarchy affiliation mesh number represents the mesh number of the mesh to which the feature belongs in the hierarchy indicated by the maximum display hierarchy number. The belonging reference mesh number represents the reference mesh number of the reference mesh to which the feature belongs. The name character string is a character string that represents the name of the feature and is displayed when the map is displayed. A plurality of languages may be supported by providing a language code and a character string in the language for each language. The symbol code is a code representing a feature symbol. Symbol image information (not shown) in the map information stores symbol image data provided corresponding to the symbol code, and the control unit 4 refers to the symbol code from the name list when the map is displayed. The corresponding image data is acquired and the symbol is displayed. Note that an invalid value (for example, 0xFFFF) is stored for a feature having no symbol.

  Since the relationship between meshes in each layer is determined in advance as shown in FIG. 2, the maximum display layer affiliation mesh number can be obtained from the maximum display layer number and affiliation reference mesh number, so it is not necessarily retained as data. You don't have to. As will be described later, since the name records are sorted based on the display maximum hierarchy affiliation mesh number, it is necessary to obtain by calculation at that time, but it is not necessary to retain the data after sorting. However, when a name record is acquired from a name list using a name reference list, which will be described later, the name information needs to be linked to the display maximum hierarchy affiliation mesh number.

  The name record is set on a one-to-one basis for the feature displaying the name. That is, it is provided on a one-to-one basis corresponding to the name or symbol of the feature existing in the map data at the lowest layer. Further, the name records are sorted in descending order of the display maximum hierarchy number. Name records with the same maximum display hierarchy number are sorted in ascending order of the maximum display hierarchy affiliation mesh number. Further, name records having the same display maximum hierarchy number and the same display maximum hierarchy affiliation mesh number are sorted in ascending order of the affiliation reference mesh number. That is, the name list is a list sorted by the priority order of the maximum display hierarchy number, the maximum display hierarchy affiliation mesh number, and the affiliation reference mesh number.

  FIG. 6 shows a specific example of the name record representing the feature shown in FIG. Corresponding to the features F0 to F7 in the hierarchy 0 shown in FIG. 4, name records # 0 to # 7 are provided, and the name records # 0 to # 7 are sorted according to the above rules. In the example shown in FIG. 6, the number of name records is only eight for easy understanding, but in reality, a larger number of name records are provided. As the number of name records increases, the reduction of data and the improvement of access efficiency, which are the effects of the present invention, become more prominent.

  Since the name record is provided corresponding to the lowest layer feature, the name record may be stored redundantly for the same feature even though the same feature appears across multiple hierarchies. In addition, the data amount of the name list is reduced. For example, in FIG. 4, the name N2 of the feature F2 is used redundantly in each of the hierarchies 0 to 2, but the name list in FIG. 6 is stored only once as the name record # 1, so Data volume can be reduced.

  In addition, since the name records are sorted according to the above rules, the name records storing the names of the meshes of the respective layers are continuously arranged, and are not stored in a distributed manner on the map information storage unit 3. The control unit 4 can obtain a name record necessary for displaying the mesh map at high speed.

  For example, consider the case where the names N2, N3, N4, and N7 of the features F2, F3, F4, and F7 shown in the mesh 0 of the hierarchy 2 in FIG. 4 are displayed. The names N2, N3, and N7 are respectively stored in name records # 1, # 2, and # 3 in the name list of FIG. 6 where the maximum display layer number is 2 and the maximum display layer affiliation mesh number is 0. Since records are stored continuously, they can be acquired together. Note that since the maximum display hierarchy number is 3 for the name N4, the name record # 0 having the maximum display hierarchy number 3 and the mesh number 0 is acquired.

  Consider the case where the names N1, N2, N3, N4, N6, and N7 of the features F1, F2, F3, F4, F6, and F7 shown in the mesh 0 of the hierarchy 1 in FIG. 4 are displayed. Names N1 and N6 are stored in name records # 4 and # 5, respectively, in the name list of FIG. 6 where the maximum display hierarchy number is 1 and the maximum display hierarchy affiliation mesh number is 0. Since they are stored, they can be acquired together. For the names N2, N3, N4, and N7, name records are acquired in the same manner as the display of the names N2, N3, N4, and N7 in the mesh 0 of the hierarchy 2 described above.

  Up to this point, the name record has been described for the case where a feature is included in one reference mesh. When a feature straddles a plurality of reference meshes, one name record is provided for this feature, and one of the reference meshes that the feature straddles is selected as the belonging reference mesh of the name record. This selected reference mesh is referred to as a representative reference mesh. In other words, the affiliation reference mesh number of a feature straddling a plurality of reference meshes is the mesh number of a representative reference mesh that is one of the plurality of reference meshes.

  As the representative reference mesh, for example, the reference mesh at the leftmost end and the lowest end among the reference meshes including the feature is set as the belonging reference mesh. As a result, duplicate name records are not stored for the same feature.

  FIG. 7 shows an example in which a feature straddles a plurality of meshes. In FIG. 7, the feature F10 straddles the reference mesh with the reference mesh numbers 0 and 1, and the belonging reference mesh is the reference mesh with the reference mesh number 0. Hereinafter, the reference mesh whose reference mesh number is n is simply referred to as reference mesh n. The feature F11 extends over the reference meshes 2, 3, 6, and 7, and the belonging reference mesh is the reference mesh 2.

  FIG. 8 is a name record of the features F10 and F11 added to the name list of FIG. However, the maximum display hierarchy number of the feature F10 is 0, and the maximum display hierarchy number of the feature F11 is 1. The reference mesh number record # 5A of the reference mesh whose reference mesh number is 0 including the feature F10 is stored as the reference mesh number of the representative reference mesh of the feature F10. On the other hand, the name record of the reference mesh whose reference mesh number is 1 including the feature F10 is not stored. The reference mesh number of the representative reference mesh of the feature F11 is set to 2, and the name record # 6A for the reference mesh number 2 including the feature F11 is stored. On the other hand, name records with reference mesh numbers 3, 6, and 7 including the feature F11 are not stored.

  Thus, when a feature belongs across a plurality of meshes, that is, when a feature has a plurality of belonging reference meshes, one representative reference mesh is determined from the belonging reference meshes, Since the name record is provided, the name record is not stored redundantly.

<A-4. Name reference list>
Next, the name reference list constituting the feature name information will be described. The name reference list is provided in order for the control unit 4 to obtain a necessary name record from the name list more quickly, and is not an essential configuration for the navigation device 10.

  FIG. 9 shows a data configuration example of the name reference list. The name reference list is a list of name reference records provided corresponding to each mesh in each layer.

  The name reference record includes a reference hierarchy number, a reference mesh number, a reference head feature ID, a reference name record number, an external representative standard mesh number, and an external representative standard mesh number string. The reference hierarchy number represents a hierarchy number to be referred to when displaying the map. The reference mesh number represents the mesh number of the mesh to be referred to when displaying the map among the meshes of the hierarchy indicated by the reference hierarchy number. Hereinafter, the mesh represented by the reference mesh number in the layer represented by the reference layer number is referred to as a reference mesh.

  A name record (group) having the reference hierarchy number as the maximum display hierarchy number and the reference mesh number as the display maximum hierarchy affiliation mesh number is referred to as a reference mesh name record (group). Each name record of the name record group in the reference mesh is continuously arranged in the name list, and the feature ID of the name record at the head is set as the reference head feature ID. The reference head feature ID may represent the record number of the name record or the offset of the name record (number of bytes from the head of the name list to the name record) instead of the feature ID.

  The number of reference name records represents the number of name records that constitute the name record group in the reference mesh. The external representative standard mesh spans the reference mesh and the other meshes, and the belonging standard mesh represents the representative standard mesh of features that are not included in the reference mesh standard mesh, and the number of external representative standard meshes represents the number. ing. The external representative reference mesh number sequence is obtained by arranging reference mesh numbers of external representative reference meshes by the number of external representative reference meshes.

  FIG. 10 is a specific example of the name reference list for referring to the name list of FIG. 8, and is composed of name reference records # 0 to # 339.

  The name reference record # 0 is a name reference record used when displaying a map of a mesh having a hierarchy number of 3 and a mesh number of 0. 3 is set for the reference layer number and 0 is set for the reference mesh number. The name record group in the reference mesh (name record group in which the maximum display hierarchy number is 3 and the maximum display hierarchy affiliation mesh number is 0) is only the name record # 0. Therefore, ID0 which is the ID of name record # 0 is set as the reference head feature ID, and 1 is set as the number of reference name records. Since there are no features included in the reference mesh of the name reference record # 0 that straddle other meshes, the number of external representative reference meshes is 0, and there is no external representative reference mesh number sequence.

  The name reference record # 4 is a name reference record used when rubbing a map display of a mesh having a hierarchy number of 2 and a mesh number of 0. 2 is set for the reference layer number and 0 is set for the reference mesh number. Name record groups in the reference mesh (name record group having the maximum display hierarchy number 2 and the maximum display hierarchy affiliation mesh number 0) are name records # 1, # 2, and # 3. Therefore, ID1 that is the feature ID of the name record # 1 is set as the reference head feature ID, and 3 is set as the number of reference name records. Since there are no features included in the reference mesh of the name reference record # 4 that straddle other meshes, the number of external representative reference meshes is 0, and there is no external representative reference mesh number sequence.

  The name reference record # 20 is a name reference record used when displaying a map of a mesh having a hierarchy number of 1 and a mesh number of 0. 1 is set to the reference layer number and 0 is set to the reference mesh number. The reference record name record group (name record group having the maximum display hierarchy number 1 and the maximum display hierarchy affiliation mesh number 0) is name record # 4, name record # 5, and name record # 5A. Therefore, ID4 that is the feature ID of the name record # 4 is set as the reference head feature ID, and 3 is set as the number of reference name records. The feature F11 included in the reference mesh of the name reference record # 20 straddles the mesh having the hierarchical number 1 and the mesh number 1, and the name record # 5A representing the name of the feature F11 is included in the reference record name record group. Therefore, the number of external representative reference meshes is 0, and there is no external representative reference mesh number sequence.

  The name reference record # 21 is a name reference record used when displaying a map of a mesh having a hierarchy number of 1 and a mesh number of 1. 1 is set for the reference layer number and 1 is set for the reference mesh number. There is no name record group in the reference mesh (name record group in which the maximum display layer number is 1 and the maximum display layer affiliation mesh number is 1). Therefore, a null value (for example, 0xFFFFFFFF) is set for the reference head feature ID, and 0 is set for the number of reference name records. The feature F11 included in the reference mesh of the name reference record # 21 straddles the mesh with the hierarchical number 1 and the mesh number 0. As shown in the name record # 5A, the representative standard mesh number of the feature F11 is 2, which is outside the reference mesh of the name reference record, so the number of external representative standard meshes is 1, and 2 as the external representative standard mesh number string. Is set.

  The name reference record # 84 is a name reference record used when displaying a map of a mesh having a hierarchy number of 0 and a mesh number of 0. The reference layer number is set to 0 and the reference mesh number is set to 0. The name record group in the reference mesh (name record group in which the maximum display hierarchy number is 0 and the maximum display hierarchy affiliation mesh number is 0) is name records # 6 and # 6A. Therefore, ID6 which is the feature ID of the name record # 6 is set as the reference head feature ID, and 2 is set as the number of reference name records. Since the feature F10 included in the reference mesh of the name reference record # 84 straddles the mesh with the hierarchical number 0 and the mesh number 1, the name record # 6A representing the name of the feature F10 is included in the reference mesh name record group. The number of external representative reference meshes is 0, and there is no external representative reference mesh number sequence.

  The name reference record # 85 is a name reference record used when displaying a map of a mesh having a hierarchy number of 0 and a mesh number of 1. The reference layer number is set to 0 and the reference mesh number is set to 1. The name record group in the reference mesh (name record group in which the maximum display hierarchy number is 0 and the maximum display hierarchy affiliation mesh number is 1) is name record # 7. Therefore, ID7 which is the feature ID of the name record # 7 is set as the reference head feature ID, and 1 is set as the number of reference name records. The feature F10 included in the reference mesh of the name reference record # 85 straddles the mesh with the hierarchical number 0 and the mesh number 0, and the representative reference mesh number of the feature F10 is 0 as shown in the name record # 6A. Since it is outside the reference mesh, the number of external representative standard meshes is 1, and 0 is set as the external representative standard mesh number sequence.

  Other name reference records are set in the same manner as described above.

  The name reference list can obtain the feature ID at the beginning of the name record necessary for map display and the number of reference name records for any mesh in any hierarchy, so that a desired name record can be continuously obtained from the name list. . Further, even when a feature straddles a plurality of meshes, the name record can be acquired because the affiliation reference mesh number of the name record is known.

<A-5. Operation>
FIG. 11 is a flowchart showing map display processing of the navigation device 10. Below, the operation | movement which displays the map centering on the present position of the mobile body carrying the navigation apparatus 10 with the display scale designated by the user is demonstrated.

  First, the control part 4 acquires the display scale which the user input from the input part 1 (step ST100). Moreover, the control part 4 acquires the positional information on the present location from the position detection part 2, and map information from the map information storage part 3, and calculates the present position of a moving body by a map matching process (step ST110).

  Next, the control unit 4 calculates the mesh (hierarchical number and mesh number) necessary for displaying the map centered on the current position acquired in step ST110, based on the display scale acquired in ST100 (step ST120). . The hierarchy (number) and mesh (number) calculated here are referred to as a display target hierarchy (number) and a display target mesh (number).

  Which hierarchy is used at which display scale is determined in advance. Based on this, a hierarchy to be used at the display scale obtained in ST100 is selected, and a necessary mesh is calculated from the current position, the size of the display screen of the display unit 5, and the size of the mesh of the selected hierarchy.

  For example, the display scale acquired in ST100 corresponds to level 2 in FIG. 2, the size of the display screen corresponds to the size of one mesh in level 2, and the current position calculated in ST110 is level 2. 0, 1, 2, and 3 are calculated as the mesh numbers of the necessary meshes.

  Next, the control unit 4 reads the map data of the display target mesh one by one from the map information storage unit 3 every time it comes to the step (step ST130). In the specific example of ST120, the map data of the meshes 0, 1, 2, and 3 in the hierarchy 2 are sequentially read one by one every time the step is reached.

  When the map data is read in step ST130, the drawing processing unit 41 draws, for example, a background of rivers, seas, railways, etc. in the drawing memory 42 based on the map data, and further draws a road in the drawing memory 42 (step ST140). . The drawing position of each feature in the background is calculated from information representing the feature position and shape stored in the background data in the map data, and the drawing position of each road is stored in the road data in the map data. It is calculated from information representing the position and shape of the road. The drawing color is determined by the type of each background in the background data and the type of each road in the road data.

  Then, every time it comes to the step, the control unit 4 acquires the names of the features from the name list of the map information storage unit 3 based on the name reference list of the map information storage unit 3 one by one for the display target mesh. (Step ST150). That is, the control unit 4 operates as a name record acquisition unit that acquires a name record from the map information storage unit 3. The display target mesh (number) subjected to name acquisition processing in step ST150 is referred to as the current display target mesh (number). In addition, when not using a name reference list, the control part 4 acquires the name of a feature directly from the name list of the map information storage part 3. FIG.

  Next, the drawing processing unit 41 draws the name acquired in step ST150 in the vicinity of the corresponding background or road drawn in the drawing memory 42 (step ST160).

  Thereafter, it is checked whether the name drawing process has been completed for all the display target meshes. If not completed, the process returns to step ST130, and the name drawing process is continued for the unprocessed display target mesh.

  If the name drawing process has been completed for all the display target meshes, the display control unit 43 displays the contents of the drawing memory 42 on the display unit 5 and the map display is completed (step ST180). Then, it returns to step ST100 and repeats said process.

  FIG. 12 is a flowchart showing the name acquisition process for the current display target mesh in step ST150. Hereinafter, the name acquisition process of step ST150 will be described in detail. First, initial setting of a reference mesh is performed (step ST200). Here, the display target hierarchy number and the current display target mesh number are stored in a hierarchy number variable and a mesh number variable provided in a storage unit (not shown, for example, a memory) of the control unit 4. For example, taking the map data of FIG. 2 as an example, when the display target hierarchy number is 0 and the current display target mesh number is 0, 0 is stored in the hierarchy number variable and 0 is stored in the mesh number variable. When the display target hierarchy number is 0 and the current display target mesh number is 1, 0 is stored in the hierarchy number variable and 1 is stored in the mesh number variable.

  Next, it is determined whether a reference mesh name reference record has already been acquired (step ST210). If it has already been acquired, step ST250 is executed, and if it has not been acquired, step ST220 is executed. The map data in FIG. 2 will be described as an example. Assume that the display target hierarchy number is 0 and the current display target mesh numbers are sequentially 0, 1, 2, and 3. When the current display target mesh number is 0, in step ST220 described later, a name reference record of a mesh having a hierarchy number of 1 and a mesh number of 0 is read. After that, when the current display target mesh number becomes 1, 2, and 3, the name reference record of the mesh whose hierarchical number is 1 and whose mesh number is 0 is already stored in the storage unit of the control unit 4 by the above processing. Therefore, the process proceeds to step ST250. This determination process prevents duplicate reading of the same name reference record, that is, duplicate reading of the name record.

  If the name reference record of the reference mesh has not yet been acquired (NO in step ST210), the name reference record in which the values stored in the layer number variable and the mesh number variable become the reference layer number and the reference mesh number, respectively, 4 is read from the name reference list of the map information storage unit 3 and stored in the storage unit (not shown) (step ST220).

  For example, when the display target hierarchy number is 0 and the current display target mesh number is 0, as described in step ST240, each time the process comes to step ST220, 0, 1, 2, 3 are sequentially assigned to the hierarchy number variable. In the number variable, 0, 0, 0, 0 are already stored in order. In accordance with the values of these variables, the name reference record in FIG. 10 is stored in the storage unit of the control unit 4 as follows.

  When the hierarchy number variable is 0 and the mesh number variable is 0, the name reference record # 84 in which the reference hierarchy number is 0 and the reference mesh number is 0 is stored. When the hierarchy number variable is 1 and the mesh number variable is 0, a name reference record # 20 having a reference hierarchy number of 1 and a reference mesh number of 0 is stored. When the hierarchy number variable is 2 and the mesh number variable is 0, a name reference record # 4 having a reference hierarchy number of 2 and a reference mesh number of 0 is stored. When the hierarchy number variable is 3 and the mesh number variable is 0, a name reference record # 0 having a reference hierarchy number of 3 and a reference mesh number of 0 is stored.

  When the display target hierarchy number is 0 and the current display target mesh number is 1, each time this step is reached, 0, 1, 2, 3 are stored in the hierarchy number variable in order, and the mesh number variable is in order 1, 0 , 0, 0 are stored. In accordance with the values of these variables, the name reference record in FIG. 10 is stored in the storage unit of the control unit 4 as follows.

  When the hierarchy number variable is 0 and the mesh number variable is 1, a name reference record # 85 having a reference hierarchy number of 0 and a reference mesh number of 1 is stored in the storage unit of the control unit 4. Each name reference record when the hierarchy number variable is 1, 2, 3 and the mesh number variable is 0 has already been acquired in the process when the display target hierarchy number is 0 and the current display target mesh number is 0. Therefore, the determination in step ST210 is YES and the process does not move to step ST220. Thus, the same name reference record is not read twice.

  Next, the control part 4 acquires a name record from the name list of the map information storage part 3 (step ST230). Here, name records corresponding to the number of reference name records are read from the reference head feature ID of the name reference record acquired in step ST220 and stored in a storage unit (not shown) of the control unit 4. That is, the control unit 4 acquires a reference mesh name record. Here, since the name record is continuously read from the name list, it can be read at high speed.

  Further, the control unit 4 reads a name record in which the maximum display hierarchy number matches the display target hierarchy number and the belonging reference mesh number matches the reference mesh number represented by the external reference mesh number string of the name reference record acquired in ST220. Is stored in a storage unit (not shown). That is, the control unit 4 also acquires the name record of the external representative reference mesh.

  Thus, even a name record belonging to other than the mesh indicated by the mesh number variable can be easily obtained by referring to the external reference mesh number string in the name reference record. In addition, since the name records having the same affiliation reference mesh number are continuously arranged in the name list, they can be read at high speed.

  Of the name records read in step ST230, those whose affiliation reference mesh is not included in the display target mesh are not used for map display, and need not be stored in the storage unit of the control unit 4. Thereby, the capacity | capacitance of a memory | storage part can be reduced.

  A specific example of the name record acquisition process in step ST230 is shown below. When the hierarchy number variable is 0, the mesh number variable is 0, and the name reference record # 84 is acquired in step ST220, the reference head feature ID is ID6 and the number of reference name records is 2. Record # 6 (ID6) and name record # 6A (ID6A) are stored in the storage unit of the control unit 4. Thereafter, in step ST240, the display target hierarchy number is set higher by one hierarchy, the hierarchy number variable is 1, and the mesh number variable is 0. Therefore, the second time, name reference record # 20 is acquired in step ST220, and in step ST230, name record # 4 (ID4), name record # 5 (ID5), and name record # 5A (ID5A) in FIG. Stored in the storage unit. Thereafter, in step ST240, the display target hierarchy number is set one level higher, the hierarchy number variable is 2, and the mesh number variable is 0. Therefore, for the third time, name reference record # 4 is acquired in step ST220, and in step ST230, name record # 1 (ID1), name record # 2 (ID2), and name record # 3 (ID3) in FIG. Stored in the storage unit. Thereafter, in step ST240, the display target hierarchy number is set one level higher, the hierarchy number variable is 3, and the mesh number variable is 0. Therefore, for the fourth time, the name reference record # 0 is acquired in step ST220, and in step ST230, the name record # 0 (ID0) of FIG. 8 is stored in the storage unit of the control unit 4. Through the above processing, all the name records representing the names necessary for the map display where the display target hierarchy is 0 and the current display target mesh is 0 are acquired from the name list. That is, the control unit 4 acquires from the name list a name record having a display maximum hierarchy number equal to or higher than the hierarchy of the target mesh (display target mesh) to be displayed on the map and the belonging reference mesh number corresponding to the display target mesh.

  When the hierarchy number variable is 0, the mesh number variable is 1, and the name reference record # 85 is acquired in step ST220, the reference head feature ID is ID7 and the number of reference name records is 1. Record # 7 (ID7) is stored in the storage unit of the control unit 4. Further, since the number of external reference meshes in the name reference record # 85 is 1 and the external reference mesh number string is 0, the name control record 4 is read by reading the name record in which the maximum display hierarchy number is 0 and the belonging reference mesh number is 0. Stored in the storage unit. However, name record # 6 (ID6) and name record # 6A (ID6A) are not stored here because they are already stored in the process when the hierarchy number variable is 0 and the mesh number variable is 0.

  If a name record is acquired by step ST230, the control part 4 will update a reference mesh so that the mesh corresponding to one upper layer may be represented. Specifically, one layer number variable is added, and the mesh number of the mesh corresponding to the current reference mesh is stored in the mesh number variable in the layer represented by the layer number variable after the change (step ST240).

  The operation of step ST240 will be described using the map data shown in FIG. 2 as an example. When the display target hierarchy is 0, the current display target mesh number is 0, and the current hierarchy number variable is 0, 1 that is the hierarchy number higher by 1 hierarchy is stored in the hierarchy number variable. After that, among the meshes with the layer number 1 stored in the layer number variable, the mesh number 0 of the mesh corresponding to the mesh with the display target layer number 0 and the current display target mesh number 0 is stored in the mesh number variable. To do.

  Similarly, the hierarchy number variable 2 and the mesh number variable 0 are stored every time this step is reached, and then the hierarchy number variable 3 and the mesh number variable 0 are stored.

  Similarly, when the display target hierarchy is 0 and the current display target mesh number is 1, each time this step is reached, 1 is stored in the hierarchy number variable, 0 is stored in the mesh number variable, and then the hierarchy number variable is 2 0 is stored in the mesh number variable, then 3 is stored in the hierarchy number variable, and 0 is stored in the mesh number variable.

  After updating the reference mesh in step ST240, it is determined whether name records have been acquired for all upper layer meshes corresponding to the display target mesh (step ST250). As a result of adding the hierarchy number variable in step ST240, when the hierarchy number of the uppermost layer of the map data is exceeded, it is determined that the acquisition of the name record for the display target mesh and all the upper layer meshes is completed, and processing Exit. Otherwise, the process returns to step ST210.

  Taking the map data shown in FIG. 2 as an example, when the hierarchy number variable exceeds 3, YES is determined in step ST250, and the process is terminated.

  FIG. 13 is a flowchart showing the name drawing process of the drawing processing unit 41 in step ST160. Hereinafter, the name drawing process of step ST160 will be described in detail. In the name drawing process, the road name and the background name are drawn in the same manner as shown in the flowchart of FIG. In the following description, when the feature is a road, the feature data means road data, and the feature record means a road record. When the feature is the background, the feature data means background data, and the feature record means a background record.

  In the name drawing process, the control unit 4 first extracts a feature record (described later) from the feature data acquired in step ST130 of FIG. 11, and obtains a feature ID for identifying the feature (step ST300).

  Next, the name record stored in the storage unit (not shown) of the control unit 4 in step ST150 of FIG. 11 is searched, and the name record having the feature ID acquired in step ST300 is acquired (step ST310).

  In addition, you may provide the information which shows the necessity of a name or a symbol display in a feature record. For features that do not require a name or symbol display, the process moves to step ST330 without searching for a name record.

  Next, name drawing is performed (step ST320). Here, the name character string of the name record obtained in step ST310 is obtained, and the drawing processing unit 41 draws the name character string in the drawing memory 42. Specifically, information representing the position and shape of the feature is obtained from the feature record obtained in step ST300, the drawing position of the name character string is calculated from the position and shape of the feature, and the name is calculated at the calculated position. Draw a string. As an example, the position of the center of gravity of the shape of the feature or the position along the shape of the feature is calculated as the drawing position.

  When the feature is the background and the background type is a point, the symbol code is obtained from the name record obtained in ST310, and the symbol drawing position is obtained from the information indicating the background position of the feature (background) record obtained in ST300. Draw a symbol image at that position. The name character string may be drawn together with the symbol image.

  The drawing position may be stored in advance in the feature record or name record, and the name character string or symbol may be drawn at the drawing position. As the drawing position, information representing the representative position of the feature, the position of the center of gravity, the drawing position of each character, and the like may be stored. As a result, the calculation of the drawing position is not necessary, and the map can be displayed at a higher speed. In the case where the drawing position information is stored in the name record, the position of the searched feature can be easily displayed when the feature is searched using the name list as search information.

  Further, the feature and the name information drawn in the drawing memory 42 in this way are displayed on the display unit 5 by the display control unit 43 under the instruction of the display unit 5 in a subsequent process (step ST180 in FIG. 11). In other words, the display control unit 43 of the control unit 4 operates as a map display instruction unit that instructs to display name information together with features.

  Next, it is determined whether or not the name drawing has been completed for all the features for which the feature records have been acquired in step ST300 (step ST330). If it has been completed, the process ends. If not, the process returns to step ST300.

  FIG. 14 is an example of the background record of the background data of the mesh whose hierarchy is 0 and the mesh number is 0. In the case where the features F0 to F4 shown in FIG. 4 and the feature F10 shown in FIG. 7 are used as background features. An example is shown. The background record is composed of a feature ID, a background type, and a position / shape of the feature.

  As described above, in step ST150 of FIG. 11, when the display target hierarchy is 0 and the current display target mesh number is 0, name record # 0 (ID0), name record # 1 (ID1), and name record of FIG. # 2 (ID2), name record # 3 (ID3), name record # 4 (ID4), name record # 6 (ID6), name record # 5 (ID5), name record # 5A (ID5A), name record # 6A (ID6A) is stored in the storage unit of the control unit 4.

  Therefore, the name record is referred to by the feature ID of each background record in FIG. 14, and the character string or symbol image of the name of the feature F0 to F4 shown in FIG. 4 and the feature F10 shown in FIG. 7 is drawn. .

  In the above description, the feature ID is provided in the background record. However, the data representing the feature ID is not provided in the background record, and is represented by a hierarchy number, a mesh number, and a number in the order of arrangement of the background records. Also good. The same applies to road records.

  Note that various attributes of features such as an address, a telephone number, a zip code, and an accessible time may be added to the name record according to the type of the feature, and the name list may be used as search information.

<A-6. Effect>
The navigation device 10 that realizes the map data storage device of the present embodiment includes a map data storage unit (map information storage unit 3) that stores map data and a name record that is set one-on-one for the feature that displays the name. A name information storage unit (map information storage unit 3) for storing a name list comprising: The map data is hierarchized at each scale, and is divided into meshes of a size determined for each hierarchy. The mesh is identified by a mesh number for each hierarchy, and the lowest mesh is set as a reference mesh, and each mesh is a feature. Represents. In the map data, each feature belongs to each mesh of each hierarchy from the lowest layer to the hierarchy defined for each feature, and the name record includes name information including at least one of the feature name or the symbol, The name list is the data linked to the maximum display layer number indicating the maximum display layer that is the maximum level in which the name information is displayed, and the belonging reference mesh number indicating the belonging reference mesh that is the reference mesh to which the feature belongs. Is a list in which the name records are sorted based on the display maximum hierarchy affiliation mesh number indicating the display maximum hierarchy affiliation mesh that is the display maximum hierarchy affiliation mesh and the display maximum hierarchy affiliation mesh that is the affiliation mesh in the display maximum hierarchy. Since the name records for the features belonging to the same or nearby mesh are continuously arranged in the name list, it is possible to efficiently acquire the name records when performing map display.

  The map display device of the present embodiment acquires the map data from the map data storage device, the name record acquisition unit (control unit 4) that acquires the name record from the map data storage device, and the map data storage device. A name record acquisition unit comprising: a map display instruction unit (control unit 4) that displays a feature on the basis of this, and displays the name information of the name record acquired by the name record acquisition unit together with the feature. The (control unit 4) acquires a name record from the name list, and the name record acquired by the name record acquisition unit (control unit 4) includes a display maximum hierarchy number equal to or higher than the hierarchy of the target mesh that performs map display, and the target mesh. And a reference mesh number corresponding to. Since the name records for the features belonging to the same or nearby mesh are continuously arranged in the name list, the control unit 4 can efficiently acquire the name records when performing map display.

  In addition, since the name list is a list sorted by the priority order of the maximum display hierarchy number, the maximum display hierarchy affiliation mesh number, and the affiliation reference mesh number, the name records for the features belonging to the same or nearby mesh are the names. It arrange | positions continuously in the list | wrist, and when performing map display, the control part 4 can acquire a name record efficiently.

  The name record is data in which the name information is associated with the display maximum hierarchy affiliation mesh number, and the name information storage unit (map information storage unit 3) indicates the storage location of the name record in the reference mesh in the name list. The name reference list is further stored, and the name record in the reference mesh is a name record in which a reference hierarchy which is an arbitrary hierarchy is set as a display maximum hierarchy, and a reference mesh which is an arbitrary mesh in the reference hierarchy is set as a display maximum hierarchy belonging mesh. . Therefore, since the storage part in the name list of the name record required for map display is known by referring to the name reference list, the control unit 4 can acquire the name record at a higher speed.

  Further, one name record is provided for a feature belonging across a plurality of reference meshes, and the belonging reference mesh number for the feature is a mesh number of any of the plurality of reference meshes. Therefore, even when the feature straddles a plurality of reference meshes, the name record is not redundantly stored for the feature, so that the data amount of the name list can be reduced.

  The name reference list is a representative standard mesh of features straddling the reference mesh and other meshes, and includes information representing an external representative standard mesh that is a representative standard mesh not included in the reference mesh. (Control part 4) acquires a name record in a reference mesh, and a name record of an external representative standard mesh. Therefore, even if there is no representative reference mesh of features straddling a plurality of reference meshes in the name record in the reference mesh, the name record can be easily acquired.

  Further, the map data has a feature ID for identifying the feature, the name record is data in which the name information is linked to the feature ID, and the map display instruction unit (display control unit 43) The name information is displayed together with the feature of the corresponding feature ID. Thereby, it is possible to display name information with respect to a corresponding road and background.

  In addition, the display position of the name information instructed by the map display instruction section (display control section 43) is determined based on the position and shape of the feature, so the name information is displayed at an appropriate position with respect to the corresponding road and background. Is possible.

  In addition, when the name record has position information for displaying the name information, calculation of the display position of the name information is not necessary, so that map display can be performed at a higher speed. Further, when the name list is used as search information, the position of the searched feature can be easily displayed.

  In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

  Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 Input part, 2 Position detection part, 3 Map information memory | storage part, 4 Control part, 5 Display part, 6 Voice output part, 10 Navigation apparatus, 41 Drawing process part, 42 Drawing memory, 43 Display control part

Claims (8)

Layered at each scale, divided into meshes of a size determined for each layer, the mesh is identified by a mesh number for each layer, the lowest mesh is used as a reference mesh, and each mesh represents a feature A map data storage unit for storing map data;
A name information storage unit that stores a name list composed of name records set one-on-one for the feature that displays the name,
In the map data, each feature belongs to each mesh of each layer from the lowest layer to the layer defined for each feature,
The name record includes name information including at least one of a name or a symbol of the feature, a display maximum hierarchy number indicating a display maximum hierarchy which is a maximum hierarchy in which the name information of the feature is displayed, and the location It is data associated with the belonging reference mesh number indicating the belonging reference mesh that is the reference mesh to which the object belongs,
The name list, the names record the displayed maximum layer number, on the basis of the membership criteria mesh number, and display the maximum hierarchy belonging mesh number that indicates the maximum display hierarchy belonging mesh is belonging mesh on the display up to the hierarchy, the display maximum It is a list sorted by the priority of the hierarchy number, the display maximum hierarchy affiliation mesh number, the affiliation reference mesh number ,
Map data storage device. A map data storage device according to claim 1;
A name record acquisition unit for acquiring the name record from the map data storage device;
A map for acquiring the map data from the map data storage device and instructing display of features based on the map data, and for instructing display of the name information of the name record acquired by the name record acquisition unit together with the features A display instruction section;
With
The name record acquisition unit acquires the name record from the name list,
The name record acquired by the name record acquisition unit includes the display maximum hierarchy number that is equal to or higher than the hierarchy of the target mesh that performs map display, and the affiliation reference mesh number that corresponds to the target mesh.
Map display device. The name record is data in which the name information is associated with the display maximum hierarchy affiliation mesh number,
  The name information storage unit further stores a name reference list indicating a storage location of the name record in the reference mesh in the name list,
  The name record in the reference mesh is the name record in which a reference hierarchy that is an arbitrary hierarchy is the display maximum hierarchy, and a reference mesh that is an arbitrary mesh in the reference hierarchy is the display maximum hierarchy belonging mesh.
The map display device according to claim 2. One name record is provided for features belonging to a plurality of reference meshes,
  The affiliation reference mesh number for the feature is a mesh number of a representative reference mesh that is one of the plurality of reference meshes.
The map display device according to claim 3. The name reference list is:
  A representative standard mesh of features straddling the reference mesh and other meshes, including information representing an external representative standard mesh that is a representative standard mesh of features not included in the reference mesh,
  The name record acquisition unit acquires the name record in the reference mesh and the name record of the external representative reference mesh.
The map display device according to claim 4. The map data has a feature ID for identifying the feature,
  The name record is data in which the name information is associated with a feature ID,
  The map display instruction unit instructs to display the name information together with the feature of the corresponding feature ID.
The map display device according to claim 2. The display position of the name information in the map display instruction unit is determined based on the position and shape of the feature.
The map display device according to claim 2. The name record has position information for displaying the name information.
The map display device according to claim 2.

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