JP6052035B2 - Map difference data distribution device and map difference data distribution system - Google Patents

Description

  The present invention relates to a map difference data distribution device that distributes map difference data, and a map difference data distribution system including the map difference data distribution device.

  Conventionally, for example, the difference between the map data of a version (hereinafter referred to as version) before updating a map element such as a road and the map data of a version after updating the map element is distributed to the vehicle navigation apparatus as map difference data. The technology to do is known. The vehicle navigation apparatus that has received the map difference data updates the map data with the map difference data.

  For example, Patent Document 1 discloses map difference data distribution that distributes map difference data created in units of map elements to a vehicle navigation device instead of map difference data created in units of sections obtained by dividing a layer of map data into a plurality of sections. An apparatus is disclosed. In addition, in the technology disclosed in Patent Document 1, the map elements having dependency relations are grouped retroactively to the update of the map elements with different versions of map data, and map difference data is created. Attempts have been made to avoid inconsistencies. The dependency relationship means that when a certain map element is updated, if the map element is not updated in advance, the map element becomes inconsistent with other map elements.

JP 2013-29595 A

  If map data can be updated in units of map elements, it is considered that the degree of necessity for updating differs for each user or situation from the viewpoint of communication size restrictions and communication charges. For example, a certain user or situation may not need to reflect a narrow street change among road changes, while another user or situation may require a narrow street change to be reflected. It is done. In addition, there is a case where the voice data of the intersection name is not required for a certain user or situation, whereas the voice data of the intersection name is required for another user or situation. Therefore, it is considered that there is a demand for a service capable of delivering a plurality of patterns with different combinations of map difference data to be delivered.

  However, since the map difference data distribution device disclosed in Patent Document 1 does not consider the combination of map difference data, it is difficult to realize distribution of a plurality of patterns with different combinations of map difference data to be distributed. It was.

  In addition, when distributing a plurality of patterns with different combinations of map difference data that can be distributed, there is a request to avoid the cost of providing a separate map difference data distribution device for each combination. .

  The present invention has been made in view of the above-described conventional problems, and the object thereof is to be a distribution target while preventing costs from being inconsistent while preventing inconsistencies in the relationship between updated map elements. An object is to provide a map difference data distribution device and a map difference data distribution system that enable distribution of a plurality of patterns having different combinations of map difference data.

  The map difference data distribution device of the present invention is a map difference data which is a difference between map element data between a version of map data before updating the map element data and a version of map data after updating the map element data. The map difference data storage unit (12) that stores the map difference and the distribution unit (137) that distributes the map difference data are updated in advance when the map element data is updated. The map difference data distribution device (1) that stores the map element data that has a dependency relationship that would otherwise cause the map element to become inconsistent with other map elements if it is not present, is distributed. About the distribution pattern which is the combination of the target map difference data, the pattern storage unit (13) storing a plurality of types of patterns in advance and the pattern storage unit A distribution target that extracts map difference data to be distributed according to the distribution destination from the map difference data stored in the map difference data storage unit based on multiple types of distribution patterns And an extraction unit (141). The distribution unit distributes not only the map difference data extracted by the distribution target extraction unit but also map difference data that is dependent on the map difference data.

  According to this, map difference data to be distributed according to the distribution destination is extracted based on a plurality of types of distribution patterns that are combinations of map difference data to be distributed. Therefore, it is possible to extract map difference data to be distributed according to the distribution destination only by switching the distribution pattern according to the distribution destination. Therefore, even if a different map difference data distribution device is not provided for each combination of map difference data to be distributed, a plurality of patterns with different combinations of map difference data to be distributed can be distributed.

  In addition, map difference data that is dependent on the map difference data extracted by the distribution target extraction unit is also distributed, so that inconsistencies in the relationship between updated map elements will not occur in the update of map element data. Is possible. As a result, it is possible to distribute a plurality of patterns with different combinations of map difference data to be distributed, while suppressing costs while preventing inconsistencies in the relationship between updated map elements.

  In addition, since the map difference data distribution system of the present invention uses the map difference data distribution device, this also suppresses costs while preventing inconsistencies in the relationship between updated map elements. However, it is possible to distribute a plurality of patterns with different combinations of map difference data to be distributed.

1 is a diagram illustrating an example of a schematic configuration of a map difference data distribution system 100. FIG. It is a functional block diagram which shows an example of the schematic structure of the extraction server side control part 13 of the map difference extraction server 1. FIG. It is a figure which shows an example of the aspect in which map data changes. It is a figure which shows an example of the dependency of a map element. (A)-(b) is a figure which shows an example of the aspect in which map data changes. (A) And (b) is a schematic diagram which shows an example of a management table. It is a schematic diagram which shows an example of a model table. It is a sequence diagram which shows an example of the flow of a process in the map difference data delivery system. It is a schematic diagram which shows another example of a model table.

  Embodiment 1 of the present invention will be described below with reference to the drawings.

<1. Map difference data distribution system 100>
FIG. 1 is a diagram showing an example of a schematic configuration of a map difference data distribution system 100 to which the present invention is applied. A map difference data distribution system 100 shown in FIG. 1 includes a map difference extraction server 1, an update management server 2, and a navigation device 3. The map difference extraction server 1 corresponds to the map difference data distribution device in the claims.

<2. Map difference extraction server 1>
As shown in FIG. 1, the map difference extraction server 1 includes an extraction server side communication unit 11, a map difference database (DB) 12, a table storage unit 13, and an extraction server side control unit 14. The extraction server side communication unit 11 communicates with the update management server 2 and the navigation device 3 via a communication network.

  The map difference DB 12 stores map difference data. Therefore, map difference DB12 is equivalent to the map difference data storage part of a claim. Map difference data is the data of the part which needed to be updated with respect to map data (base map), and map data has shown the arrangement | positioning aspect of a map element. Accordingly, the map difference data is map element data of a portion whose arrangement mode has changed from the base map.

  Map elements are various elements constituting map data. For example, data such as road shapes, POIs (Points Of Interest), backgrounds, voices and texts indicating names, images (2D images, 3D images, and polygon images). is there. The map difference DB 12 may be configured to store map difference data provided from an external server (not shown). The map difference data will be described in detail later.

  The table storage unit 13 stores a management table for each distribution destination classification in which distribution destinations of map difference data are classified into a plurality of categories. The management table will be described in detail later. The table storage unit 13 stores a model table. The model table will be described in detail later.

  The extraction server side control unit 14 is mainly configured by a microcomputer including a CPU, a ROM, a RAM, a backup RAM, an I / O, etc. (all not shown). And the extraction server side control part 14 performs various processes by executing the various control programs memorize | stored in ROM based on the various information input from the extraction server side communication part 11. FIG.

Further, as shown in FIG. 2, the extraction server-side control unit 14 includes a difference data extraction unit 141, a dependent difference group extraction unit 142, a difference group ID transmission unit 143, a grouping unit 144, and a distribution data creation unit 145 as functional blocks. A data URL transmission unit 146 and a distribution unit 147 are provided. Details of processing in the extraction server side control unit 14 will be described later.
<2-1. Map difference data>
Here, the map difference data stored in the map difference DB 12 will be described. The map difference data is the difference between the version of the map data before updating the map element data and the version of the map data after updating the map element data. In other words, this difference is map element data updated in each version. For example, the update of the map element is caused by the opening and closing of roads, the addition or deletion or change of facilities, the addition, deletion or change of names of intersections, directions, roads, or the like. Further, the map difference data is managed in units of, for example, rectangular sections obtained by dividing the map data into a plurality of pieces. Each section is given a section ID.

  In the map difference data, as an example, for each updated version, an ID (hereinafter referred to as a difference group ID) for identifying the difference group is sequentially assigned to the updated map element data group (difference group). Has been. For example, when the updated map element is a road section sandwiching an intersection, the difference group is a set of road shape data such as link data and node data representing the road section, and attribute data of the road section. When the updated map element is an intersection, it becomes a set of road shape data such as node data representing the intersection and link data connected to the intersection, and attribute data of the road section.

  The attribute data is data associated with road sections and intersections, and includes data related to guidance at the time of guidance (hereinafter referred to as guidance data) and data related to distribution of traffic information. As an example of the guidance data, there are voice data indicating the name of the intersection, data serving as an index of text data, and the like when the guidance data is guidance when passing through a certain intersection.

  Further, the map difference data includes data on the dependency relationship between the map elements. Note that the dependency relationship data may be stored in a memory different from the map difference DB 12. The map difference data may be generated in the same manner as a known method. For example, what is necessary is just to set it as the structure produced by the method similar to the one currently disclosed by patent document 1. FIG. Hereinafter, the dependency relationship will be described.

<2-2. Dependency>
The dependency relationship means that when data of a certain map element (hereinafter referred to as the first map element) is updated, data of another map element (hereinafter referred to as the second map element) must be updated in advance. Is inconsistent with other map elements. Here, the dependency relationship will be described with reference to FIG. In FIG. 3, the dependence relationship in the map difference data when the map data is updated in the order of the second version map data and the third version map data from the first version map data will be described.

  When the road sections “a” to “d” are laid from the beginning of the creation of the first version map data, as shown in FIG. 3, the first version map data including the road sections “a” to “d” is displayed. Created. When the road sections “e” to “h” are opened from this state, the second version map data reflecting the addition of the road sections “e” to “h” in the first version map data is created. Hereinafter, the difference map A1 is a group of data indicating the road section “e” and its attribute data, which is the updated map element, and the difference group A2 is a group of data indicating the road section “f” and its attribute data. A group of data indicating “g” and its attribute data is a difference group A3, and a group of data indicating the road section “h” and its attribute data is a difference group A4.

  As shown in FIG. 3, the road section “e” is opened to branch from the road section “c”, the road section “f” is opened to extend from the road section “e”, and the road section “g” is opened. Is opened so as to intersect the road section “b”, and the road section “h” is opened so as to extend from the road section “g”.

  Further, when the road sections “i” to “l” are opened from this state, the third version map data reflecting the addition of the road sections “i” to “l” in the second version map data is created. In the following, the data indicating the updated road map section “i” and its attribute data group are the difference group B1, the data indicating the road section “j” and the attribute data group are the difference group B2, and the road section. A group of data indicating “k” and its attribute data is a difference group B3, and a group of data indicating the road section “1” and its attribute data is a difference group B4.

  As shown in FIG. 3, the road section “i” is opened to extend from the road section “f”, the road section “j” is opened to extend from the road section “i”, and the road section “k” is opened. , “L” is opened to extend from the road section “g”.

  Of the map elements updated with the second version map data, the road section “f” is isolated from other road sections unless the road section “e” is added. There is a dependency relationship between the road section “e” and the road section “e” with the road section “e” as a dependency destination. Therefore, the difference group A1 and the difference group A2 are in a dependency relationship. In the following, the dependence destination is called “parent” and the relying side is called “child”. When the dependency relationship between the difference group A1 and the difference group A2 is expressed by a parent and child, the difference group A1 becomes “parent” and the difference group A2 becomes “child”.

  Of the map elements updated with the second version map data, the road section “h” is isolated from other road sections unless the road section “g” is added. There is also a dependency relationship between the road section “g” and the road section “g”. Therefore, there is a dependency relationship in which the difference group A3 is “parent” and the difference group A4 is “child”.

  Among the map elements updated with the third version map data, the road section “i” is isolated from other road sections unless the road section “f”, which is the map element updated with the second version map data, is added. Therefore, there is a dependency relationship between the road section “f” and the road section “i” across the versions in which the road section “i” depends on the road section “f”. . Therefore, there is a dependency relationship in which the difference group A2 is “parent” and the difference group B1 is “child”.

  Of the map elements updated with the third version map data, the road section “j” is isolated from other road sections unless the road section “i” is added. There is also a dependency relationship between the road section “j” and the road section “j” with the road section “i” as a dependency destination. Therefore, there is a dependency relationship in which the difference group B1 is “parent” and the difference group B2 is “child”.

  Of the map elements updated with the third version map data, the road sections “k” and “l” have no addition of the road section “h” which is the map element updated with the second version map data. Since the road section is isolated from other road sections, the road sections “k” and “l” are also road sections “h” between the road sections “k” and “l” and the road section “i”. There is a dependency relationship that spans versions. Therefore, there is a dependency relationship in which the difference group A4 is “parent” and the difference groups B3 and B4 are “child”. Note that there is no dependency between the difference group B3 and the difference group B4.

  As shown in FIG. 4, the dependency relationship between the difference groups A1 to A4 and B1 to B4 goes back to the difference groups for different versions. Specifically, the dependency relationships are A1-A2-B1-B2 and A3-A4-B3 / B4 in order from “parent”. The map difference data stored in the map difference DB 12 includes such dependency setting information.

  A unit of a set of difference groups in the same version is called a release. Releases are counted once or twice from the oldest version. A set of difference groups indicating map elements updated with the second version map data is a release 1 with one release, and a set of difference groups indicating map elements updated with the third version map data is a release number. There will be two releases. Release 1 is composed of difference groups A1 to A4, and Release 2 is composed of difference groups B1 to B4.

  In FIG. 3, the dependency relationship when the road section is updated as the map element has been described, but the same applies to the map elements other than the road section. For example, when a facility is updated as a map element, if the facility is inconsistent with other map elements if the road section facing the facility is not updated first, the facility and the road There is a dependency relationship with the section. Further, even when the guide data for displaying image data at a certain place is updated as a map element, the guide data is inconsistent unless the image data used by the guide data is updated first. In this case, there is a dependency between the guidance data and the image data.

<2-3. Management table>
Next, the management table stored in the table storage unit 13 will be described. The management table is provided for each distribution destination classification in which the distribution destination of the map difference data is classified into a plurality of categories. The management table corresponds to the distribution pattern of claims and the distribution timing according to usage, and the table storage unit 13 corresponds to the pattern storage unit of claims. The distribution destination classification is, for example, a classification for each vehicle manufacturer or automobile dealer in which the navigation device 3 is used.

  For example, in the management table, for the difference group to be distributed (that is, map difference data), the update contents of the difference group, the distribution timing of the difference group, and the dependency destination of the difference group are associated. The distribution timing of the difference group corresponds to the distribution timing for each usage in the claims. When the difference groups to be distributed are different for each distribution destination classification, the management table for each distribution destination classification is a management table for the different difference groups.

  The update contents of the difference group include “network (hereinafter referred to as NW) change”, “node attribute change”, “link attribute change”, “shape change”, “guidance data change”, and the like. “NW change” is a link addition / deletion and a change of a node or a regulation related thereto. “Node attribute change” is a change in the attribute of a node. “Link attribute change” is a change of a link attribute that is not related to the NW, such as a road type. “Shape change” is a change in the shape of a link or the position of a node. “Guidance data change” is a change in guidance data such as a road name change. Note that the update contents of the difference group are not limited to those described above, but may be related to the background, POI, image, audio, etc., but are omitted here for convenience.

  The distribution timing of the difference group includes “No specification (normal time)”, “With time condition”, “With area condition”, “With distributed condition”, “When dependent (when referring to dependence)”, “Route search” Time (destination setting) "," guidance ", etc.

  “Normal time” is a distribution timing such as when the ACC power is turned on or the destination is set, which will be described later, in the navigation device 3. “With time condition” is a distribution timing at which distribution is performed when the navigation apparatus 3 satisfies a temporal condition such as a specified time or after or a specified period. The distribution timing “with time condition” is set for a difference group that is changed during a known period. “With area condition” is a distribution timing at which the navigation apparatus 3 performs distribution when a spatial condition such as a designated area is satisfied. “With distribution completed condition” is a distribution timing when distribution is performed when the difference group of the dependency destination has been distributed to the navigation device 3. The distribution timing “with time condition” and “with area condition” may be configured to perform distribution when the condition is satisfied and the ACC power is turned on.

  “At dependency reference” is a distribution timing at which distribution is performed at the distribution timing of the “child” difference group, which is “parent” in the dependency relationship. “At the time of destination setting” is a distribution timing at which distribution is performed when a route search is performed in the navigation device 3 (that is, at the time of destination setting). “At the time of guidance” is a delivery timing at which delivery is performed when guidance using guidance data is required in the navigation device 3. For the distribution timing “at the time of guidance”, the difference group including the guidance data is set.

  The distribution timing may be set for each distribution destination classification even for the same difference group. Note that the same distribution timing may be set for the same difference group for each distribution destination classification, or another distribution timing may be set. In addition, the delivery timing is not limited to that described above, but may be when moving to the current location, immediately, or when downloading a PC, but is omitted here for convenience.

  When there is a difference group that is the dependency destination of the difference group, the difference group ID of the difference group that is the dependency destination is set in the dependency destination of the difference group. The existence of the dependency destination may be specified from the aforementioned dependency relationship.

Here, an example of the management table will be described with reference to FIGS. 5A to 6B.
In the present embodiment, the following description will be given by taking as an example a case where the distribution destination classification is a user of a vehicle of company X and a user of a vehicle of company Y.

  Fig.5 (a)-FIG.5 (d) are figures which show an example of the aspect in which map data changes. 5A shows map data for the spring of 2010, FIG. 5B shows map data for the fall of 2010, and FIG. 5C shows map data for the spring of 2011. In FIG. 5, white circles indicate nodes without position correction, black circles indicate nodes with position correction, and line segments indicate links.

  ID11 to ID14 in FIG. 5B are difference groups of map data in the fall of 2010 with respect to map data in the spring of 2010. In ID11, the update content is a link attribute change, and consists of three links. The update content of ID12 is a shape change, and consists of four links and one node. In ID13, the update content is a shape change and consists of one link. The shape change of ID12 and ID13 indicates that the road that was a wavy line in FIG. 5A has been changed to a straight line. The ID 14 is an NW change due to road opening, and consists of 4 links and 4 nodes.

  ID21 to ID22 in FIG. 5B are difference groups of map data in the spring of 2011 with respect to map data in the fall of 2010. The ID 21 is an NW change due to road opening, and consists of 11 links and 9 nodes. The ID 22 is an NW change due to the opening of the sidewalk, and consists of 5 links and 6 nodes.

  With respect to the transition of the map data shown in FIG. 5A to FIG. 5C, the management table for users of the X company vehicle shown in FIG. 6A (hereinafter referred to as the X company management table) and FIG. The combination of map difference groups to be distributed is different from the management table for users of Y company vehicles shown in b) (hereinafter referred to as Y company management table). The distribution result in the management table is different information for each navigation device 3 that is a distribution destination, and thus is actually stored in the update management server 2 instead of the map difference extraction server 1. However, here, for convenience of explanation, the management table stored in the map difference extraction server 1 is added to the diagram for explaining.

  Specifically, among the difference groups of ID11 to ID14 and ID21 to ID22, the X company management table targets ID11 to ID14 and ID21, whereas the Y company management table has ID11 to ID14 and ID21 to ID21. ID 22 is a distribution target. Every time a difference group for a new version of map data is obtained, a setting for the difference group to be distributed is added to the management table. In the example of FIG. 6, the difference groups ID11 to ID14 are difference groups added in the fall of 2010, and the difference groups ID21 to ID22 are difference groups added in the spring of 2011.

  In the management table, the distribution timing is set for each difference group for the difference group to be distributed. In the example of FIG. 6, the distribution timing “normal time” is associated with the difference group of ID11, ID14, ID21, and ID22, and the distribution timing “dependent reference time” is associated with the difference group of ID12 and ID13. It is attached.

  The distribution timing “normal time” is a distribution timing distributed when the ACC power is turned on as described above. Therefore, the difference group of ID11 and ID14 is distributed when the ACC power of the target vehicle is turned on in the fall of 2010 when the setting of the difference group is added to the management table. Further, the difference groups of ID21 and ID22 are distributed when the ACC power of the target vehicle is turned on in the spring of 2011 when the setting of the difference group is added to the management table.

  Also, the distribution timing “during dependency reference” is a distribution timing at which distribution is performed at the distribution timing of the “child” difference group that is “parent” in the dependency relationship as described above. Therefore, the difference group with ID 13 is distributed at the distribution timing of the difference group with ID 21 corresponding to its own “child” in the dependency relationship. Since the difference group of ID21 is distributed in the spring of 2011 as described above, ID13 is also distributed in the spring of 2011. The items “Autumn 2010” and “Spring 2011” in the management table of FIG. The distribution result may not be included in the management table.

  In the example illustrated in FIG. 6, the configuration in which the same distribution timing is set for the same difference group between the management tables of different distribution destination classifications is shown, but the configuration is not necessarily limited thereto. For example, different distribution timings may be set between management tables of different distribution destination classifications for the same difference group. According to this, while using the single map difference DB 12, it is possible to provide a service for distributing the same difference group to different distribution destinations at different distribution timings.

<2-4. Model table>
Next, the model table stored in the table storage unit 13 will be described. The model table includes an area (hereinafter, distribution area) that distributes the map difference data of each subcategory of each category of the map difference data and each subcategory map distribution data for each situation where the distribution destination is requesting the map difference data (hereinafter, request status). ). The model table defines the distribution of the difference group when the distribution timing in the management table is “normal”. Therefore, the model table also corresponds to the delivery pattern of the claims. The model table is provided, for example, for each distribution destination category described above.

  The sub-category of map difference data is a further subdivision of the category of map difference data. For example, the map difference data category includes road shape, background, POI, image, sound, and the like. The update contents “NW change”, “node attribute change”, “link attribute change”, “shape change”, and “guide data change” are all related to the category “road shape”.

  In addition, sub-categories include “wide area NW1” for the main road of the expressway, “wide area NW2” for the expressway interchange (IC), junction (JCT), and service area (SA). There are “detailed NW” for national and prefectural roads, “narrow street” for narrow roads, and so on. The highway may be replaced with a high-speed public road or a high-speed public road. Further, the “detailed NW” may be a road shape for a national road, a prefectural road, or a local road.

  The request status includes, for example, when the ACC power is turned on and when a destination is set, which will be described later. The distribution area includes the whole country, a range of 20 km around the position serving as the base point, a range of 10 km around the position serving as the base point, and the like. The base point is the user position when the ACC power is turned on, and the user position and the destination when the destination is set. If the waypoint is also set when the destination is set, the waypoint also corresponds to the position serving as the base point. Note that the categories, subcategories, request statuses, and distribution areas shown here are merely examples, and needless to say, other modes may be used.

  Hereinafter, an example of the model table will be described with reference to FIG. In the example of FIG. 7, for the sake of convenience, the description will be limited to the subcategory “wide area NW1”, “wide area NW2”, “detailed NW”, and “narrow street” of the category “road shape”. Further, in FIG. 7, description will be given by taking as an example two types of request statuses when the ACC power is turned on and when the destination is set.

  Regardless of whether the request status is ACC power on or destination setting, for the distribution area “Nationwide”, the difference groups of the subcategory “Wide Area NW1” and “Wide Area NW2” in the Difference Group of the category “Road Shape” Is defined as a delivery target. For the distribution area “20 km around the user position”, the subcategory “detailed NW” is defined as the distribution target in the difference group of the category “road shape”. Further, for the distribution area “10 km around the user position”, the subcategory “narrow street” in the difference group of the category “road shape” is defined as the distribution target.

  According to this, for the difference groups of the subcategory “wide area NW1” and “wide area NW2”, the difference group of the whole country is distributed, while for the difference group of the subcategory “detailed NW”, the distribution area “user location periphery 20 km”. Only those that fall under are delivered. Furthermore, for the difference group of the subcategory “narrow street”, only those corresponding to the distribution area “user position periphery 10 km” are distributed.

  In this way, by using the model table, it is possible to distribute a difference group according to the situation of the distribution destination for each area divided into a plurality of stages.

  Although FIG. 7 shows an example in which the correspondence relationship between the distribution target subcategory and the distribution area is the same when the ACC power is turned on and when the destination is set, the present invention is not necessarily limited thereto. For example, the correspondence relationship between the distribution target subcategory and the distribution area may be different for each request situation. Moreover, it is good also as a structure which changes the correspondence of a request | requirement status, the subcategory made into a delivery object, and a delivery area for every model table about a different delivery destination classification | category.

  According to this, while using a single map difference DB 12, it is possible to provide a service for distributing the same difference group to different distribution destinations at different distribution timings, and distribute the difference groups according to the request status and distribution area. It becomes possible to do.

<3. Update management server 2>
Returning to FIG. 1, the update management server 2 includes a management server side communication unit 21, an update management DB 22, and a management server side control unit 23. The management server side communication unit 21 communicates with the map difference extraction server 1 and the navigation device 3 via the communication network.

  The update management DB 22 stores determination information for determining map difference data distributed from the map difference extraction server 1 to the navigation device 3. As the determination information, for example, version information distributed to the navigation device 3 is stored. This is because, if the distributed version information is known, the distributed difference group can also be determined. In addition, the distributed difference group ID is also stored.

  As version information, for example, the number of releases can be used. In the following, the case where the number of releases is used as version information will be described as an example. The number of released releases may be the number of releases for which all map elements have been distributed. The update management DB 22 stores determination information for each user of each navigation device 3 when there are a plurality of navigation devices 3.

  In addition, as discrimination information for discriminating distributed map difference data, a flag is set for a distributed difference group (that is, map difference data), and the difference group is already distributed by the flag. It may be possible to determine whether or not there is.

  The management server side control unit 23 is mainly configured by a microcomputer including a CPU, ROM, RAM, backup RAM, I / O, etc. (all not shown). And the management server side control part 23 performs various processes by executing the various control programs memorize | stored in ROM based on the various information input from the management server side communication part 21 and the update management DB22. Details of processing in the management server side control unit 23 will be described later.

<4. Navigation device 3>
The navigation device 3 may be an in-vehicle navigation device or a portable navigation device that can be brought into the vehicle. When the navigation device 3 is a portable type, the navigation device 3 may be configured to be used when moving in a vehicle such as an automobile, a motorcycle, or a bicycle, or when the user carrying the navigation device 3 is walking on foot. It is good also as a structure used for. Hereinafter, the case where an in-vehicle navigation device is used as the navigation device 3 will be described as an example. The navigation device 3 corresponds to the map data holding device in the claims.

  When a portable terminal is used as the navigation device 3 and information is acquired from a system such as an in-vehicle LAN of the vehicle, the navigation device 3 is a known system such as the in-vehicle LAN of the vehicle and Bluetooth (registered trademark). A configuration may be adopted in which information is acquired by performing communication such as wireless communication or wired communication through USB connection.

  Here, a schematic configuration of the navigation device 3 will be described. As shown in FIG. 1, the navigation device 3 includes a communication device 31, a position detector 32, an external input interface (I / F) unit 33, a map DB 34, a display device 36, an audio output device 37, an operation switch group 38, a remote control. A terminal (hereinafter referred to as a remote controller) 39, a remote controller sensor 40, and a control device 41 are provided.

  The communication device 31 communicates with the map difference extraction server 1 and the update management server 2 via a communication network. As the communication device 31, for example, various devices such as an in-vehicle communication module such as a DCM (data communication module) used for telematics communication can be adopted.

  Each of the position detectors 32 has a well-known acceleration sensor, gyroscope, and receiver for a satellite positioning system such as GPS (Global Positioning System) that detects the position of its own device based on radio waves from the satellite. The current position of the user of the user apparatus (hereinafter referred to as user position) is sequentially detected. For example, the user position is assumed to be coordinates represented by latitude and longitude. Note that the position detector 32 may be configured by a part of the sensors described above, or may be configured using another sensor.

  The external input I / F unit 33 is an interface for the control device 41 to acquire vehicle state information from an ECU or a sensor mounted on the vehicle. For example, it is assumed that vehicle state information is input to the external input I / F unit 33 from an ECU or a sensor mounted on the vehicle via an in-vehicle LAN or the like. An example of the vehicle state information includes an on / off signal of an accessory (ACC) power source.

  The map DB 34 is stored in a memory card such as an SD card, for example. The map DB 34 stores map data such as the above-described first edition map data. The map data stored in the map DB 34 may be acquired by the control device 41 being downloaded from a center (not shown) through the communication device 31 described later, or may be stored in advance.

  The display device 36 is capable of full color display, for example, and can be configured using a liquid crystal display, an organic EL display, or the like. The voice output device 37 includes a speaker or the like, and outputs a guidance voice or the like based on an instruction from the control device 41.

  For example, a touch switch or a mechanical switch integrated with the display device 36 is used as the operation switch group 38, and an operation instruction for various functions is given to the control device 41 by a switch operation. The remote control 39 is provided with a plurality of operation switches (not shown). By inputting various command signals to the control device 41 via the remote control sensor 40 by the switch operation, the control device 41 has the same function as the operation switch group 38. Can be executed.

  The control device 41 is mainly composed of a microcomputer including a CPU, ROM, RAM, backup RAM, and the like. And the control apparatus 41 performs various processes based on the various information input from the communication apparatus 31, the position detector 32, the external input I / F part 33, map DB34, the operation switch group 38, and the remote control sensor 40. FIG. Details of the processing in the control device 41 will be described later.

<5. Distribution of Map Difference Data in Map Difference Data Distribution System 100>
Next, the processing flow in the map difference data distribution system 100 will be described with reference to the sequence diagram of FIG.

<T1. Extraction information transmission process (navigation device 3)>
First, the control device 41 of the navigation device 3 performs extraction information transmission processing (t1). The extraction information transmission process is performed when a predetermined trigger is detected. The predetermined trigger is, for example, ACC power on of the host vehicle or destination setting in the navigation device 3. The ACC power on of the host vehicle may be detected based on the ACC power on / off signal acquired via the external input I / F unit 33.

  The predetermined trigger may be an approach to a predetermined point such as an intersection. Further, the extraction information transmission process is not limited to a configuration performed when a predetermined trigger is detected, but may be a configuration performed periodically, a configuration performed every time a user position is newly detected, or the like.

  In the extraction information transmission process, information for extracting the map difference data necessary for updating the map data in the map DB 34 of the navigation device 3 by the map difference extraction server 1 and the update management server 2 (hereinafter, information for extraction). Is transmitted to the update management server 2 via the communication device 31.

  As an example, when the ACC power-on of the host vehicle is detected, extraction information including the user position detected by the position detector 32, the version of the map data in the map DB 34, and identification information for specifying the transmission source is included. Send. The identification information for specifying the transmission source may be a vehicle ID or a device ID of the navigation device 3 or the communication device 31. Hereinafter, an example in which the device ID of the communication device 31 is used. Will be described.

  When the destination setting is detected, the user position detected by the position detector 32, the coordinates of the destination (latitude / longitude), the map data version of the map DB 34, and the extraction information including the device ID are transmitted. To do. If the waypoint is also set, the extraction information including the coordinates (latitude / longitude) of the waypoint is transmitted. Hereinafter, the process when the ACC power-on of the host vehicle is detected is distinguished from the process when the destination setting is detected when the ACC is turned on.

<T2. Designated information determination process (update management server 2)>
When receiving the extraction information, the management server side control unit 23 of the update management server 2 performs a designation information determination process (t2). In the designation information determination process, designation information to be transmitted to the map difference extraction server 1 is determined based on the received extraction information. For example, the designation information is a latitude / longitude serving as a base point, the number of releases, and the device ID included in the extraction information. In the designation information determination process, it is determined whether the version of the map data included in the extraction information is the same as the version corresponding to the distributed release count stored in the update management DB 22. If they are the same or older, this number of releases is used as the number of releases of the specified information. In addition, the management server side control part 23 is set as the structure which has beforehand the information regarding the correspondence of the version of map data, and the frequency | count of release.

  On the other hand, when the version of the map data included in the extraction information is newer than the version corresponding to the distributed release count stored in the update management DB 22, the release count corresponding to the map data version is designated. Used as the number of releases. The situation in which the version of the map data included in the extraction information is newer than the version corresponding to the number of released releases may be when the user purchases a new version of map data as the map data stored in the map DB 34. .

  In the designation information determination process when the ACC is on, the designation information including the latitude / longitude of the user position, the number of releases, and the device ID is determined. In the designation information determination process when setting the destination, the designation information including the latitude / longitude of the user position, the latitude / longitude of the destination, the number of releases, and the device ID is determined. If the waypoint is also set, the designation information including the latitude and longitude of the waypoint is determined.

<T3. Designated information transmission process (update management server 2)>
The management server side control part 23 performs the designation information transmission process which transmits the designation information determined by the above-mentioned designation information determination process to the map difference extraction server 1 via the management server side communication part 21 (t3).

<T4. Difference data extraction processing (map difference extraction server 1)>
When the difference data extraction unit 141 of the extraction server side control unit 14 of the map difference extraction server 1 receives the designation information, it performs a difference data extraction process (t4). The difference data extraction unit 141 corresponds to the distribution target extraction unit in the claims.

  In the difference data extraction process, a difference group ID is assigned to the update management server 2 from the map difference data stored in the map difference DB 12 based on the received designation information, the aforementioned management table, and the aforementioned model table. Extract the difference group to send. As an example, the difference group is extracted as follows.

  In the differential data extraction process, the distribution destination classification is specified from the device ID included in the designation information. The distribution destination classification may be specified as follows. For example, a table (distribution destination classification table) in which the device ID and the distribution destination classification are associated with each other is stored in advance in the memory of the map difference extraction server 1. The difference data extraction unit 141 identifies the distribution destination classification corresponding to the device ID by referring to the distribution destination classification table based on the device ID included in the designation information.

  In the difference data extraction process, a difference group to be distributed is extracted based on a management table or a model table corresponding to the specified distribution destination classification. Specifically, the difference group is included as a distribution target in the management table corresponding to the specified distribution destination classification, and the difference in which the actual timing corresponds to the distribution timing associated in the management table Extract groups. Further, in the case of a difference group of distribution timing “normal”, a group that matches the request status and distribution area conditions defined in the model table corresponding to the specified distribution destination classification is extracted.

  Here, as an example, the management table corresponding to the specified distribution destination classification is the management table of FIG. 6A, and the model table corresponding to the specified distribution destination classification is the model table of FIG. An example of extraction of a difference group to be distributed is shown.

  The difference group candidates to be distributed are the difference groups ID11 to ID14 and ID21 included in the management table. With respect to the difference groups of ID12 and ID13 at the distribution timing “at the time of dependence reference”, if the difference group corresponding to its “child” in the dependency relationship is not at the distribution timing, it is not an extraction target. The difference group of ID12 is not an extraction target because the difference table corresponding to “child” is not included in the management table. As for the group of ID13, since the difference group of ID21 corresponding to “child” is included in the management table, when the ID21 is the distribution timing, it is an extraction target.

  The difference groups of ID11, ID14, and ID21 at the distribution timing “normal time” are subject to extraction when the request status and distribution area conditions defined in the model table are met, and when the conditions are not met. Is not subject to extraction.

  In the differential data extraction process when ACC is on, the distribution area is specified using the latitude and longitude of the user position included in the designation information as the starting position. The distribution area may be configured to be represented by the above-described section ID in which at least a part of the section is included in a predetermined rectangular range (hereinafter referred to as a requested rectangular range) centered on the position that is the starting point. The predetermined rectangular range may be the entire range of the map in the case of the distribution area “national”. Further, in the case of the distribution areas “20 km around the position serving as the base point” and “10 km around the position serving as the base point”, for example, the range may be 20 km to 10 km in the east-west direction and the north-south direction. Then, the difference group included in the release that is included in the section indicated by the section ID identified as the distribution area and that has a greater number of releases than the number of releases included in the designation information is extracted.

  In the example of the model table of FIG. 7, in the case of a difference group corresponding to the subcategory “wide area NW1” and “wide area NW2”, the one located in the distribution area “national” is the extraction target. Regardless of whether it is located or not, it becomes an extraction target. Further, in the case of a difference group corresponding to the sub-category “detailed NW”, it is an extraction target only when the difference group is located in a section of the distribution area “user position periphery 20 km”. Further, in the case of the difference group corresponding to the subcategory “narrow street”, the extraction is performed only when the difference group is located in the section of the distribution area “user position periphery 10 km”.

  In the difference data extraction process at the time of destination setting, the distribution area is specified using the latitude / longitude of the user position and the latitude / longitude of the destination included in the designation information as the starting position. When the specified information includes the latitude and longitude of the waypoint, the distribution area is specified as the position where the latitude and longitude of the waypoint is also the starting point. In addition, the difference data extraction process at the time of destination setting may be configured such that a route search from the user position to the destination is performed, and a section on which the searched route is located is specified as a distribution area. The route search may be performed according to a known route search method.

<T5. Dependency difference group extraction process (map difference extraction server 1)>
The dependency difference group extraction unit 142 of the extraction server-side control unit 14 performs a dependency difference group extraction process that extracts a difference group that is dependent on the difference group extracted by the difference data extraction process (t5). In the dependency difference group extraction process, a difference group (hereinafter referred to as a dependency difference group) that is dependent on the difference group extracted in the difference data extraction process from the difference group included in the release having a higher number of releases than the number of releases included in the specified information described above. ).

  In addition, when the same difference group is extracted as a dependent difference group of the difference group extracted by the difference data extraction process, the duplicate is excluded.

  If a difference group is not extracted in the difference data extraction process, the result may be returned to the update management server 2 as no difference group. If there is no difference group, the processing after t5 is not performed.

<T6. Difference group ID transmission process (map difference extraction server 1)>
The difference group ID transmission unit 143 of the extraction server side control unit 14 performs a difference group ID transmission process (t6). In the difference group ID transmission process, the difference group extracted in the difference data extraction process and the difference group ID of the dependency difference group extracted in the dependency difference group extraction process are transmitted to the update management server 2 via the extraction server side communication unit 11. .

<T7. Unupdated differential group extraction processing (update management server 2)>
When receiving the difference group ID, the management server side control unit 23 of the update management server 2 performs an unupdated difference group extraction process (t7). In the unupdated difference group extraction process, a difference group that has not been distributed to the navigation device 3 (hereinafter referred to as an unupdated difference group) is extracted from the difference groups indicated by the received difference group ID. As an example, an unupdated difference group is extracted by extracting a difference group ID obtained by removing a distributed difference group ID stored in the update management DB 22 from the received difference group ID.

  When an unupdated difference group is not extracted in the unupdated difference group extraction process, the configuration may be such that the result is returned to the map difference extraction server 1 as no unupdated difference group. If there is no unupdated difference group, the processing after t7 is not performed.

<T8. Unupdated differential group transmission processing (update management server 2)>
The management server side control unit 23 performs an unupdated difference group transmission process (t8). In the unupdated difference group transmission process, the difference group ID of the unupdated difference group extracted in the unupdated difference group extraction process is transmitted to the map difference extraction server 1 via the management server side communication unit 21. The difference group ID of the unupdated difference group is hereinafter referred to as an unupdated group ID. The unupdated difference group corresponds to the unupdated data in the claims.

<T9. Record Processing (Map Difference Extraction Server 1)>
When the extraction server-side control unit 14 of the map difference extraction server 1 receives the unupdated group ID, the grouping unit 144 of the extraction server-side control unit 14 performs record processing (t9). In record processing, based on the above-described dependency setting information, among the unupdated difference groups extracted by the unupdated difference group extraction processing, the unupdated difference groups that are dependent on the same number of releases are grouped together. . A group of grouped unupdated difference groups is called a record.

<T10. Distribution data creation processing (map difference extraction server 1)>
The delivery data creation unit 145 of the extraction server side control unit 14 performs delivery data creation processing (t10). In the delivery data creation process, the delivery data is created by arranging the records grouped in the record process in order from the records for the older versions so as to fit within the prescribed communication size. A record for an older version can be paraphrased as a record with a smaller number of releases.

  The prescribed communication size is arbitrarily prescribed and is, for example, 3 MB. Further, the distribution data may be created so that the communication size after compression fits within the specified communication size. For the records that do not fit within the specified communication size, the next distribution data is created by arranging the remaining records in order from the record for the older version.

<T11. Data URL transmission processing (map difference extraction server 1)>
The data URL transmission unit 146 of the extraction server side control unit 14 performs a data URL transmission process (t11). In the data URL transmission process, the data URL indicating the address of the distribution data created in the distribution data creation process described above and stored in the memory, and the difference group ID of the unupdated group included in the distribution data are sent via the extraction server side communication unit 11. To the update management server 2.
<T12. Data URL Relay Process (Update Management Server 2)>
When the management server side control unit 23 of the update management server 2 receives the data URL transmitted from the map difference extraction server 1, the management server side control unit 23 performs a data URL relay process (t12). In the data URL relay process, the received data URL is transmitted to the navigation device 3 via the management server side communication unit 21.

  Moreover, the management server side control part 23 should just be set as the structure which stores difference group ID transmitted from the map difference extraction server 1 in update management DB22 as distributed difference group ID. Note that the management server-side control unit 23 deletes the difference group ID of the number of releases that have been distributed from the update management DB 22.

<T13. Difference data acquisition process (navigation device 3)>
When the control device 41 of the navigation device 3 receives the data URL transmitted from the update management server 2, the control device 41 performs a difference data acquisition process (t13). In the differential data acquisition process, an address indicated by the received data URL is accessed, and transmission of distribution data stored at the address is requested.

<T14. Distribution processing (map difference extraction server 1)>
The distribution unit 147 of the extraction server side control unit 14 of the map difference extraction server 1 performs distribution processing (t14). In the distribution process, the distribution data requested in the above-described difference data acquisition process is distributed to the navigation device 3 via the extraction server side communication unit 11. In the distribution process, when there are a plurality of distribution data created by the distribution data creation process, the distribution data is distributed in order from the distribution data including the record for the older version.

<T15. Update Process (Navigation Device 3)>
After the control device 41 of the navigation device 3 receives the distribution data distributed from the map difference extraction server 1, the control device 41 performs an update process (t15). In the update process, each time the navigation device 3 reads out map data necessary for an application program that provides guidance based on map data from the map DB 34, the map data in the map DB 34 and the distribution data received so far (that is, , Map difference data). The map data in the map DB 34 is updated based on the received distribution data. Specifically, the map data is updated by reflecting the change according to the change of the map difference group included in the distribution data in the map data of the map DB 34.

  The distribution data created by the delivery data creation process may be stored in a server other than the map difference extraction server 1. In this case, in the differential data acquisition process, the navigation device 3 may request transmission of the distribution data to the server storing the distribution data, and the server storing the distribution data may distribute the distribution data.

  In the sequence diagram of FIG. 8, the case where the navigation device 3 receives distribution of map difference data from the map difference extraction server 1 has been described as an example, but the present invention is not necessarily limited thereto. For example, a memory card in which the map DB 34 is stored may be connected to a PC, the map difference data may be received from the map difference extraction server 1 by the PC, and the map difference data may be stored in the memory card. In this case, the PC connected to the memory card storing the map DB 34 corresponds to the map data holding device in the claims.

  In this configuration, the extraction information transmission process transmits the extraction information from the PC to the update management server 2 when a user operation requesting download of map difference data is received by the operation input unit of the PC. What is necessary is just processing. As the extraction information, the version of the map data in the map DB 34 read by the PC from the memory card and identification information (hereinafter referred to as user ID) for identifying the user may be used.

  Further, when the map difference data is received by the PC instead of the navigation device 3, the distribution areas defined in the model table may be “national”, “region”, and the like. The distribution area “region” is a region where the user resides. It should be noted that instead of the distribution area “region”, a configuration may be adopted in which a distribution area “saving”, which is the province where the user resides, is used. The region or province where the user resides may be configured to be stored in advance in the memory of the map difference extraction server 1 in association with the user ID.

  When the map difference data distribution is received by the PC instead of the navigation device 3, the model table receives the distribution of the map difference data by the PC as shown in FIG. It may be configured to add the item ".

<8. Summary of Embodiment 1>
According to the configuration of the first embodiment, since a different management table and model table are provided for each distribution destination classification, a difference group (that is, map difference data) to be distributed according to the distribution destination is extracted. Can do. Therefore, while using a single map difference DB 12, different difference groups are distributed to different distribution destinations, the same difference group is distributed at different distribution timings, or difference groups according to the request status and distribution area are distributed. You can do it.

  In addition, map difference data that is dependent on the map difference data extracted by the difference data extraction unit 141 is also distributed, so that inconsistency in the relationship between the updated map elements is not caused in the update of the map element data. It becomes possible. As a result, it is possible to distribute a plurality of patterns with different combinations of map difference data to be distributed, while suppressing costs while preventing inconsistencies in the relationship between updated map elements.

<9. Modification 1>
In the first embodiment, a configuration is shown in which different management tables and model tables are provided for each distribution destination classification. However, the present invention is not limited to this. For example, a single management table or model table may be provided regardless of the distribution destination classification. However, in this case, in the model table, the combination of difference groups (that is, map difference data) to be distributed for each distribution area is different for each request situation.

  According to this, a different difference group can be distributed according to the request | requirement condition of a delivery destination, using single map difference DB12. Therefore, it is possible to distribute a plurality of patterns with different combinations of map difference data to be distributed while suppressing costs.

<10. Modification 2>
In the first embodiment, the configuration in which the delivery timing is set in the management table is shown, but the configuration is not necessarily limited thereto. For example, a configuration may be adopted in which no delivery timing is set in the management table. In this case, for example, the distribution timing of the difference group to be distributed may be uniformly set to the above-described distribution timing “normal”.

<11. Modification 3>
In the first embodiment, the configuration in which the model table is provided is shown, but the configuration is not necessarily limited thereto. For example, the model table may not be provided. In other words, even if the request status and the distribution area are different, a configuration may be adopted in which a difference is not provided in the combination of difference groups to be distributed (that is, map difference data). In this case, a different management table may be provided for each distribution destination classification.

<12. Modification 4>
In the first embodiment, the configuration including the map difference extraction server 1 and the update management server 2 which are separately provided in the map difference data distribution system 100 is shown, but the present invention is not necessarily limited thereto. For example, the map difference data distribution system 100 may include a server having functions of the map difference extraction server 1 and the update management server 2. That is, it is good also as a structure containing the server which the map difference extraction server 1 and the update management server 2 integrated.

<13. Modification 5>
In the first embodiment, the map difference data distribution system 100 has a configuration that does not include a server (hereinafter referred to as a map difference data generation server) that generates map difference data from map data before and after updating each time map data is updated. However, this is not necessarily the case. For example, the map difference data distribution system 100 may include a map difference data generation server. The map difference data generation server may be integrated with the map difference extraction server 1 and the update management server 2.

<14. Finally>
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Map difference extraction server (map difference data delivery apparatus), 3 navigation apparatus (map data holding apparatus), 12 Map difference DB (map difference data storage part), 13 Table storage part (pattern storage part), 100 Map difference data delivery System, 135 distribution data creation unit, 137 distribution unit, 141 difference data extraction unit 141 (distribution target extraction unit)

Claims (7)

Map difference data storage unit storing map difference data, which is the difference between map element data between the map data of the version before updating the map element data and the map data of the version after updating the map element data (12)
A distribution unit (137) for distributing the map difference data;
When the map difference data storage unit updates the data of the map element, if the map element is not updated in advance, the map element is in a dependency relationship with which the map element becomes inconsistent with other map elements. Is a map difference data distribution device (1) stored as the map difference data,
A pattern storage unit (13) that stores a plurality of types of patterns in advance for a distribution pattern that is a combination of map difference data to be distributed;
Based on a plurality of types of distribution patterns stored in the pattern storage unit, the map difference data stored in the map difference data storage unit is set as a distribution target according to a distribution destination. A distribution target extraction unit (141) for extracting map difference data,
The distribution unit distributes not only the map difference data extracted by the distribution target extraction unit but also the map difference data having the dependency relationship with the map difference data. In claim 1,
The pattern storage unit stores in advance the distribution pattern for each distribution destination classification in which the distribution destination is classified into a plurality of categories.
The distribution target extraction unit is the map difference to be distributed according to which distribution destination category the distribution destination corresponds to based on the distribution pattern stored in the pattern storage unit A map difference data distribution apparatus characterized by extracting data. In claim 1 or 2,
The pattern storage unit stores in advance the distribution pattern for each area divided into a plurality of stages according to the range according to the situation where the distribution destination requests the map difference data,
The distribution target extraction unit is the map difference to be distributed according to the status of the distribution destination for each of the areas divided into a plurality of stages based on the distribution pattern stored in the pattern storage unit. A map difference data distribution apparatus characterized by extracting data. In claim 2,
The pattern storage unit stores in advance the distribution pattern for each area divided into a plurality of stages according to the range for each distribution destination classification,
The distribution target extraction unit determines which of the distribution destination classifications the distribution destination corresponds to according to the areas divided into a plurality of stages based on the distribution pattern stored in the pattern storage unit. The map difference data distribution device according to claim 1, wherein the map difference data to be distributed is extracted. In any one of Claims 1-4,
A delivery timing classified by use, which is a delivery timing classified into a plurality of times set according to the use of the map difference data, is preset for each map difference data,
When the distribution target extraction unit extracts the map difference data, the set distribution timing according to use extracts the map difference data corresponding to the timing to be distributed. Data distribution device. In claim 5,
The pattern storage unit stores in advance the distribution pattern for each distribution destination classification in which the distribution destination is classified into a plurality of categories,
The use-specific delivery timing is preset for each delivery destination category,
When the distribution target extraction unit extracts the map difference data, the distribution timing for each use determined according to which category of the distribution destination classification the distribution destination corresponds to the timing of distribution. The map difference data according to which category of the distribution destination classification the distribution destination corresponds to based on the distribution pattern stored in the pattern storage unit A map difference data distribution apparatus characterized by extracting data. The map difference data distribution device (1) according to any one of claims 1 to 6,
Map data holding device that is a distribution destination of map difference data, which is the difference between map element data between the version of map data before updating the map element data and the version of map data after updating the map element data ( And 3) a map difference data distribution system.

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