WO2015059872A1

WO2015059872A1 - Map data delivery system, server, and navigation device

Info

Publication number: WO2015059872A1
Application number: PCT/JP2014/004897
Authority: WO
Inventors: 鈴木　孝光
Original assignee: 株式会社デンソー
Priority date: 2013-10-23
Filing date: 2014-09-25
Publication date: 2015-04-30
Also published as: JP2015082045A

Abstract

A map data delivery system (100) includes: a server (2) having a server-side map storage unit (22), an update data generation unit (S213), and a delivery processing unit (S215) for delivering update data to a navigation device; and a navigation device (1) having a navigation-side communication unit (11), a navigation-side map storage unit (17), a navigation-side update unit (10B), and a map provision unit (10A). The map provision unit provides the updated map data to a read requestor when updated map data is stored in the navigation-side map storage unit; provides updated map data generated by connecting pre-update map data and differential data to the read requestor when the differential data is stored in the navigation-side map storage unit; and provides the pre-update map data to the read requestor when both the updated map data and the differential data are not stored in the navigation-side map storage unit.

Description

Map data distribution system, server, and navigation device

Cross-reference of related applications

This disclosure is based on Japanese Application No. 2013-220525 filed on October 23, 2013, the contents of which are incorporated herein by reference.

The present disclosure relates to a map data distribution system, a server, and a navigation device that update map data included in the navigation device.

In recent years, there has been proposed a map data distribution system in which map data provided in a navigation device can be updated at any time according to a change in a road connection relationship or the like by communication between a server and a navigation device (for example, Patent Document 1).

In the map data distribution system disclosed in Patent Document 1, the recording area is divided into a plurality of sections and provided with map data. When the map data of a certain section is updated, the server creates difference data representing the difference between the map data before the update of the section and the updated map data, and distributes the difference data to the vehicle navigation device. This difference data is generated as different versions of difference data for each update. The navigation apparatus can update its own map data by acquiring a version of difference data that it does not have.

Also, some navigation devices used in this type of map data distribution system hold the acquired difference data and original map data in a storage device (this is a conventional device). In this conventional apparatus, each time a map data read request is received from a read request source such as a route calculation process, the map data reflecting the update by combining the difference data of the section designated by the read request and the original map data (This is used as updated map data) and is provided to the read request source.

If the map data of a certain section is updated multiple times, the difference data of the number corresponding to the number of times will be delivered. Therefore, in the conventional device, the difference data stored in the storage device increases each time it is updated.

As the difference data increases, the difference data to be read for generating the update map data increases, so the speed from receiving the read request to providing the update map data to the read request source (read this) The speed is reduced).

In addition, there is a problem that the connectivity of roads that cross sections is not guaranteed, for example, only by updating one of the consecutive sections across the road (if the other section is not updated), the roads are displayed broken. Arise.

Japanese Patent No. 3956759

The present disclosure suppresses a decrease in reading speed in the navigation device that generates the updated map data by combining the difference data and the original map data every time the map data is read, and the map data included in the navigation device It is an object of the present invention to provide a map data distribution system, a server, and a navigation device that can guarantee connectivity.

In the first aspect of the present disclosure, the map data distribution system includes a server and a navigation device that communicates with the server. The server updates map data before update, which is the map data before the map element is updated, and map elements included in the map data before update as map data for each section obtained by dividing the map recording area. The navigation device includes a server-side map storage unit that stores updated map data that is later map data and difference data that indicates changes in map elements updated from the pre-update map data. An update data generation unit that generates update data for updating the map data of the predetermined section; a distribution processing unit that distributes the update data generated by the update data generation unit to the navigation device; . The update data is a map element included in the updated map data of the target section that is the section to be updated and the difference data of the non-target section that is the section other than the target section. When the map data before update of the target section provided in the navigation device is replaced with the updated map data, if the map element is not provided, the map element updated in the target section is another map element. And the difference data including the dependency map element that is a map element that is inconsistent with each other. The navigation device stores in advance the navigation side communication unit that receives the update data distributed by the distribution processing unit, and the map data before update of a plurality of the sections, and is further distributed from the server. A rewritable navigation-side map storage unit that stores the updated map data and the difference data, and when the update data is received, all the map data of the target section stored in the navigation-side map storage unit Is replaced with the updated map data of the target section, which is included in the update data, and the navigation side update unit that stores the difference data of the non-target section in the navigation side map storage unit, A map providing unit for providing the map data of the section designated by the read request to a read request source. The map providing unit provides the updated map data to the read request source when the updated map data of the section specified by the read request is stored in the navigation side map storage unit. When the updated map data of the section designated by the read request is not stored in the navigation-side map storage unit and the difference data is stored, the map data before update and The updated map data corresponding to the updated map data generated by combining with the difference data is provided to the read request source, and the navigation side map storage unit has the section of the section designated by the read request. When both the updated map data and the difference data are not stored, the pre-update map data is provided to the read request source.

In the above configuration, when updating the map data of the target section stored in the navigation side map storage unit, the server updates the updated map data of the target section, the difference data of the non-target section including the dependent map element, Are generated and distributed to the navigation device.

When the navigation device receives the update data, the navigation side update unit replaces the pre-update map data of the target section stored in the navigation side map storage unit with the updated map data included in the update map data. To do. Further, the difference data of the non-target section including the dependency map element is stored in the navigation side map storage unit.

According to the above configuration, when the target section is specified by the read request, the map providing unit may read the updated map data and provide it to the read request source. That is, since it is not necessary to combine the pre-update map data and the difference data to generate the update map data, it is possible to suppress a decrease in reading speed.

In addition, dependent map elements that have a dependency relationship with the map elements that are updated in the target section are stored as differential data of the non-target sections, so that the changed map element and the other map elements are consistent. It has become. For example, when the map element is a road, road connectivity can be guaranteed.

In the second aspect of the present disclosure, the server includes map data before update, which is map data before a map element is updated, as map data for each section obtained by dividing a map recording area, and the map before update. Server-side map storage storing updated map data, which is the map data after updating the map elements included in the data, and difference data indicating changes in map elements updated from the pre-update map data An update data generation unit for generating update data for updating the map data of the predetermined section provided in the navigation device, and the update data generated by the update data generation unit in the navigation device A delivery processing unit for delivering to The update data is a map element included in the updated map data of the target section that is the section to be updated and the difference data of the non-target section that is the section other than the target section. When the map data before update of the target section provided in the navigation device is replaced with the updated map data, if the map element is not provided, the map element updated in the target section is another map element. And the difference data including the dependency map element that is a map element that is inconsistent with each other.

In the above server, the map data provided in the navigation device while suppressing the decrease in the reading speed in the navigation device that generates the updated map data by combining the difference data and the original map data every time the map data is read, and in the map data provided in the navigation device The server function used in the map data distribution system that can guarantee the connectivity of the server is provided.

In the third aspect of the present disclosure, the navigation device includes map data before update, which is map data before a map element is updated, for each section obtained by dividing a map recording area, and the map data before update. Update data delivered from a server comprising updated map data, which is the map data after updating a map element, and difference data indicating changes in map elements updated from the pre-update map data The pre-update map data is stored in advance for the navigation side communication unit and the plurality of sections, and the updated map data and the difference data distributed from the server are stored in a rewritable manner. A navigation-side map storage unit; a navigation-side update unit that updates data stored in the navigation-side map storage unit based on the update data; And a map providing unit for providing the map data divided into the read request source. The update data is a map element included in the updated map data of the target section that is the section to be updated and the difference data of the non-target section that is the section other than the target section. When the map data before update of the target section provided in the navigation device is replaced with the updated map data, if the map element is not provided, the map element updated in the target section is another map element. And the difference data including the dependency map element that is a map element that is inconsistent with each other. The navigation side update unit replaces all the map data of the target section stored in the navigation side map storage section with the updated map data of the target section included in the update data. In addition, the difference data of the non-target section is stored in the navigation-side map storage unit. The map providing unit provides the updated map data to the read request source when the updated map data is stored in the navigation-side map storage unit in the section designated by the read request. When the updated map data is not stored in the navigation-side map storage unit and the difference data is stored in the navigation-side map storage unit in the section designated by the read request. The updated map data corresponding to the updated map data generated by combining the map data before update and the difference data is provided to the read request source, and in the section designated by the read request, If both the updated map data and the difference data are not provided, the pre-update map data is provided to the read request source.

In the navigation device described above, in the map data provided in the navigation device while suppressing a decrease in the reading speed in the navigation device that generates the updated map data by combining the difference data and the original map data each time the map data is read. Provided is a navigation device function used in a map data distribution system that can guarantee road connectivity.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing
FIG. 1 is a block diagram showing an example of a schematic configuration of a map data distribution system according to the present embodiment, FIG. 2 is a block diagram showing an example of the structure of map data. FIG. 3 is a conceptual diagram for explaining the hierarchical structure of map data. FIG. 4 is a diagram for explaining all map data and difference data. FIG. 5 is a block diagram showing an example of the configuration of difference data. FIG. 6 is a diagram illustrating an example of a mode in which map data transitions. FIG. 7 is a diagram illustrating an example of a dependency relationship between map elements. FIG. 8 is a flowchart showing an example of the flow of the map providing process. FIG. 9 is a diagram for explaining a process of generating updated map data. FIG. 10 is a conceptual diagram for explaining the map data stored in the navigation-side map DB before the navigation-side update process is performed. FIG. 11 is a flowchart illustrating an example of a flow of update data distribution processing performed by the server-side control device. FIG. 12 is a conceptual diagram showing the process of update data distribution processing. FIG. 13 is a flowchart showing an example of the flow of the navigation side update process performed by the navigation side control device. FIG. 14 is a conceptual diagram for explaining the map data stored in the navigation-side map DB after the navigation-side update process is performed. FIG. 15 is a diagram corresponding to FIG. 10 in another aspect.

Hereinafter, an example of an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram illustrating an example of a schematic configuration of a map data distribution system 100 including a navigation device 1 and a server 2 according to the present embodiment. The navigation device 1 in this embodiment is assumed to be mounted on a vehicle, and the vehicle on which the navigation device 1 is mounted is called a host vehicle. In the present embodiment, the navigation device 1 is mounted on a vehicle, but may be a portable navigation device that can be brought into the vehicle. The navigation device 1 and the server 2 are configured to perform wireless communication with each other and to transmit and receive data.

Here, before describing the configuration of the navigation device 1 and the server 2 included in the map data distribution system 100, the configuration of the map data used by the map data distribution system 100 will be described first.

(Structure of the entire map data)
As shown in FIG. 2, the map data used in the map data distribution system 100 includes map data for each section obtained by dividing the map recording area into a plurality of sections. Below, the map data for every division with which map data is provided is called main division data. A group of these main section data is stored in association with the geographical arrangement of the sections, for example. Here, the K-th main section data in the order according to the geographical arrangement is expressed as the K-th main section data. Here, it is assumed that the map recording area is composed of N (N is a positive integer) number of main sections.

Each of the main section data is configured as map data obtained by hierarchically expressing the road network in the corresponding main section by the road case. As an example, when the road case is defined in three levels, upper, middle, and lower, the main division data is the third-tier data representing the road network with the highest road case in the corresponding division, and the road case is medium. The second layer data representing the higher-order road network, and the first layer data representing the road network with a lower road rating.

<About road case>
Here, the relationship between the above-mentioned road case and road type will be described. The types of roads include highways, national roads, prefectural roads, ordinary roads, and narrow streets. The road type is classified into those for long distance movement, medium distance movement, and short distance movement. It can be classified into any of the three levels. For example, highways and national roads can be defined as high-order roads, prefectural roads as medium-level roads, general roads and narrow streets as low-grade roads. According to such classification, the main division data represents the road network of the expressway and the national road in the division by the third layer data, and the road network of the prefectural road in the division by the second layer data. . Further, the first layer data is configured as data expressing the road network of the general road and the narrow street in the section.

<About the second layer data>
Next, the second layer data constituting the main partition data will be described. The second layer data is managed in units of sections (hereinafter referred to as “medium sections”) obtained by further dividing the corresponding main section into a plurality of parts. Each of the 2nd layer data divided | segmented by the unit of medium division (this is set as medium division data) is comprised as map data showing the road network of the middle road rank in the corresponding middle division. More specifically, in the present embodiment, the middle section data has a configuration in which the area corresponding to the main section is divided into 16 as shown in FIG. The main section data corresponds to the section surrounded by the thick line in FIG. 3, and one middle section data corresponds to one square of the second layer data in FIG. A group of these middle section data (that is, second layer data) is configured as a data group in which corresponding middle section data is arranged, for example, in an order according to the geographical arrangement of the middle section.

<About the first layer data>
The first layer data is managed in units of sections (hereinafter referred to as “small sections”) obtained by further dividing the corresponding middle section into a plurality of parts. Each of the 1st layer data divided | segmented by the subcompartment unit (this is made into subcompartment data) is comprised as map data showing the road network of the low-order road case in a corresponding subcompartment. In this embodiment, the small section has a configuration in which the corresponding middle section is divided into 16 sections. One small section data corresponds to each cell in the first layer in FIG. For this reason, the first layer data of one main section has a configuration including 256 pieces of small section data. A group of these subsection data (that is, first layer data) is configured as a data group in which corresponding subsection data is arranged in an order according to the geographical arrangement of the subsections. Hereinafter, each of the main partition data, the medium partition data, and the small partition data is also simply expressed as “partition data”.

<Detailed description of partition data>
Next, the configuration of the partition data will be described. Each block data is connected to each road that constitutes the road network of the corresponding road case (for example, medium rank road in the case of medium block data), and multiple roads intersect, merge, and branch. It is represented by node data relating to points to be linked and link data relating to roads connecting the points.

The node data includes a node ID with a unique number for each node, a node coordinate (latitude and longitude), a node name, a connection link ID in which link IDs of all links connected to the node are described, and an intersection type. Composed of each data.

Link data includes a link ID with a unique number for each road, a link length indicating the length of the link, link start and end node IDs, coordinates of points within the link, road type such as expressway, road width, link It consists of each data such as direction, road name, number of lanes, speed limit. These node data and link data are also referred to as road shape data.

Each section data includes background data, text data, audio data, image (2D image, 3D image, and polygon image) data and the like.

The background data is configured as data that associates each facility or terrain on the map with the corresponding coordinates on the map. Regarding the facility, data such as a telephone number and an address are also stored in association with the facility. The text data is used to display place names, facility names, road names, and the like on a map, and is stored in association with coordinate data corresponding to the positions to be displayed. The sound data is data for outputting sound, and the image data is image data for drawing a map image.

The elements on the map represented by various data such as link data, node data, and background data described above are hereinafter referred to as map elements. Map elements can change with updates. The section data may include a POI (Points of Interest) as a map element.

<All map data and difference data>
Map data is managed for each section, and is updated in units of sections. For example, updating of map elements included in a certain section is caused by opening or closing of roads, addition, deletion, or change of facilities, addition, deletion, or change of names of intersections, directions, roads, or the like.

Here, two types of map data generated by updating the map data, that is, all map data and difference map data will be described. In addition, since the detail of difference map data is demonstrated later, an outline | summary is described here.

全 All map data is equivalent to the map data described above, and has all the map elements that should be recorded in that section. All the map data is distributed as a plurality of version numbers (hereinafter referred to as versions) as the map elements are updated. For example, the first version (that is, the first version) of all map data is all map data distributed when the operation of the map data distribution system 100 is started. Here, the first version of all map data is referred to as version 1 of all map data or first version of all map data, and the update of the first version of all map data is reflected in the next version of all map data. Or it is called the 2nd edition full map data. That is, version X means the Xth version.

The difference map data is data representing the difference between the version of all map data before updating the map element data and the version of all map data after updating the map element data. In other words, this difference corresponds to map element data updated in each version. Similar to all map data, the difference map data also includes a plurality of versions as the map elements are updated.

The relationship between all these map data and difference map data is shown in FIG. All map data (Ver1) in the figure represents version 1 all map data, and all map data (Ver2) represents version 2 all map data. That is, the number following Ver indicates the version number of all map data.

As shown in FIG. 4, the difference map data of version 1 represents the difference between all map data of version 1 and all map data of version 2. In other words, the version 2 total map data corresponds to map data obtained by combining the version 1 total map data and the version 1 difference map data.

Here, all map data with a relatively old version corresponds to pre-update map data, and all map data with a relatively new version corresponds to updated map data. For example, if the latest version of all map data and difference map data are distributed, the latest version of all map data corresponds to updated map data, and all map data distributed before that is This corresponds to pre-update map data.

In addition, the map data in which the update is reflected by combining the difference map data of the version distributed after that with all the map data of a certain version is referred to as update map data. The process for generating the update map data will be described later with reference to FIG. 8. However, the generated update map data is deleted without being saved when the use of the data ends.

Also, multiple consecutive versions of difference map data can be used by being stacked. For example, by combining all the difference map data from version 1 to version 4 with all version 1 map data, updated map data corresponding to all version 5 map data can be obtained.

All map data described above consists of a group of data for each section, and can be managed (data moved, replaced, deleted, etc.) for each section. In the present embodiment, as an example, the configuration can be managed in units of main partitions, but of course, other configurations that can be managed in units of smaller partitions are also possible. The difference map data is also composed of a data group for each section, and can be managed in units of sections. However, the difference map data can be subjected to data processing such as copying and moving only a part of the data.

<Configuration of difference map data>
As described above, the difference map data is composed of a data group for each section. In the following, a data group in which all the data in a certain main section of a certain version are gathered is referred to as difference map data. On the other hand, a whole map such as a part of difference map data or a group of a plurality of difference map data. Data indicating a change from the data is referred to as difference data. Difference map data is also included in this difference data. This difference data corresponds to the difference data.

In the following, difference data for a certain section is also expressed as section difference data. For example, the difference data for the first main section is represented as first main section difference data, and the difference data for the first middle section is represented as first middle section difference data. Therefore, the Nth main section difference data represents difference data for the Nth main section.

As shown in FIG. 5, the section difference data includes third layer difference data, second layer difference data, and first layer difference data. The third layer difference data has a road case in the corresponding section. The upper new road network is represented by the difference from the previous version. In addition, the second layer difference data represents a new road network with a middle road grade in the corresponding section by a difference from the previous version, and the first layer difference data has a lower road case in the corresponding section. The new road network is represented by differences from the previous version.

The definition of road case and section in the difference data is the same as all map data. For example, the 3/2/1 layer difference data constituting the version 1 difference data represents a change in the road network of the upper / middle / lower road case from the entire map data of version 1 in the corresponding section.

However, the difference data of each layer is described by a command group indicating a correction location and correction contents for the corresponding layer data in all map data of the previous version, unlike each layer data constituting all map data. In the difference data of each version, the section difference data of the section having no correction portion may be configured as empty data.

<Difference group>
Further, the difference map data is an ID (hereinafter referred to as a difference group ID) for identifying the difference group with respect to a group (difference group) of updated map element data for each version to which the difference map data is distributed. It has.

The difference group is, for example, 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 a road section across the intersection. When the updated map element is an intersection, it is 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.

In addition, the difference data constituting the difference map data includes data representing the dependency between map elements. Next, this dependency relationship will be described.

<Dependency>
Dependency refers to updating the data of another map element (hereinafter referred to as the second map element) in advance when using the data of the map element (hereinafter referred to as the first map element) included in the difference map data of a certain version. Otherwise, it indicates that the first map element is in an inconsistent relationship with other map elements. The state in which the first map element is inconsistent with other map elements refers to, for example, a state in which a certain road (first map element) is not connected to any other road (other map elements). .

Here, the dependency relationship will be described with reference to FIG. FIG. 6 shows a case where the update is performed twice on the first version of all map data, that is, the case where all the map data of version 2 and version 3 is distributed. The schematic diagram of the map shown in FIG. 6 shows the entire map data, and the change from the previous version in each version represents the difference map data of version 1 and version 2.

When the road sections “a” to “d” have been laid from the beginning of the first version of the entire map data, the road sections “a” to “d” are included as shown in the bottom of FIG. The first edition of all map data is created. When the road sections “e” to “h” are opened from this state, as shown in the middle part of FIG. 6, the second edition full map reflecting the addition of the road sections “e” to “h” in the first version of all map data Data is created.

Here, a group of data indicating the road section “e” and its attribute data, which are updated map elements, and its attribute data are referred to as a difference group A1, and a group of data indicating the road section “f” and its attribute data are referred to as a difference group A2. Further, a group of data indicating the road section “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.

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 changed to the road section “b”. It is assumed that the road section “h” is opened so as to extend from the road section “g”.

In addition, when the road section “i” to “l” is opened from this state, the third version all map data reflecting the addition of the road section “i” to “l” in the second version all map data is created. The Hereinafter, a group of data indicating the road section “i” and its attribute data, which are updated map elements, and its attribute data are referred to as a difference group B1, and a group of data indicating the road section “j” and its attribute data as a difference group B2. Further, a group of data indicating the road section “k” and its attribute data is a difference group B3, and a group of data indicating the road section “l” and its attribute data is a difference group B4.

As shown in the upper part of FIG. 6, the road section “i” is opened so as to extend from the road section “f”, and the road section “j” is opened so as to extend from the road section “i”. Each of “k” and “l” is opened to extend from the road section “g”.

Of the map elements updated with the second version of all map data, the road section “f” is isolated from other road sections unless the road section “e” is added. For this reason, there is a dependency relationship between the road section “f” and the road section “e” where the road section “e” depends on the road section “e”. 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 in the second version of all map data, the road section “h” is isolated from other road sections unless the road section “g” is added. For this reason, there is a dependency relationship between the road section “h” and the road section “g” in which the road section “h” depends on 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”.

Of the map elements updated with the third version of all map data, the road section “i” is another road section unless the road section “f”, which is the map element updated with the second version of all map data, is added. Will be isolated. For this reason, there is a dependency relationship between the road section “f” and the road section “i” across 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 in the third version of all map data, the road section “j” is isolated from other road sections unless the road section “i” is added. And the road section “j” also have a dependency relationship in which the road section “j” has 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”.

In addition, among the map elements updated in the third version all map data, the road sections “k” and “l” must be added with the road section “h” which is the map element updated in the second version map data. In other words, it becomes isolated from other road sections. For this reason, between the road sections “k” and “l” and the road section “i”, the road sections “k” and “l” depend on the road section “h” as a dependency destination. There is a relationship. 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.

Fig. 7 shows the dependency of map elements included in each difference map data. The dependency relationships of the above-described difference groups A1 to A4 and B1 to B4 are traced back to the difference groups for different versions as shown in FIG. Specifically, the dependency relationships are A1-A2-B1-B2, A3-A4-B3, and B4 in order from “parent”.

As shown in FIG. 7, there is a dependency not only between the difference map data of one version (here, version 1) and the next version (here, version 2) but also between one section and other sections. Yes. For example, it is assumed that the difference group A1 belongs to the (K-1) main partition, the difference group A2 belongs to the Kth main partition, and the difference group A4 belongs to the (K + 1) th main partition.

In this assumption, when version 1 difference map data is added to the map data of the Kth main section, not only in the Kth main section but also in the K-1 main section due to the dependency relationship between the difference groups A1 and A2. It is necessary to add difference data including at least the difference group A1. This is because when adding difference data including a difference group A2 corresponding to “child”, a difference group corresponding to “child” is not added unless a difference group including difference group A1 corresponding to “parent” is also added. This is because A1 cannot be matched with other map elements. The map elements that constitute the difference group corresponding to “parent” correspond to the dependency map elements.

On the other hand, when adding the difference map data of version 1 in the K-1 main section, it is not necessary to update the K-th main section. This is because the map elements of the difference group A1 are consistent with other map elements without adding the difference data including the difference group A2 corresponding to the “child” in the dependency relationship. As shown in FIG. 7, when the difference group A3 extends over the Kth main partition and the (K + 1) th main partition, it is necessary to update not only the Kth main partition but also the (K + 1) th main partition.

6 and 7, the dependency relationship when the road section is updated as a map element has been described, but the same applies to 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.

Furthermore, in FIG. 7, the dependency relationship between map elements when adding difference map data to all version 1 map data has been explained. Of course, all map data in a certain section is replaced with newer map data. However, it is necessary to pay attention to the same dependency. That is, when the map data of a certain section is replaced with a newer version of all map data, it is necessary to update other sections in which the map elements added with the all map data have dependency relationships.

In order to satisfy the dependency of map elements that change by adding difference map data to all existing map data in a certain section (this is the target section), other sections (this is referred to as the non-target section). If it is necessary to add difference data, the difference data including at least the difference group having the dependency relationship may be added to the non-target partition.

That is, in the non-target section, it is not necessary to add in units of difference map data, and it is only necessary to add difference data including a difference group necessary for satisfying the dependency (this is referred to as dependency difference data). Of course, the same applies when the difference data needs to be added to the non-target section in order to satisfy the dependency relationship of the changing map elements by replacing the target section with a newer version of all map data.

Hereinafter, returning to FIG. 1, the configuration of the navigation device 1 and the server 2 included in the map data distribution system 100 using the map data described above will be described.

(Configuration of the navigation device 1)
As shown in FIG. 1, the navigation device 1 includes a navigation-side control device 10, a navigation-side communication device 11, an external input / output interface (hereinafter abbreviated as external I / F) 12, an input device 13, a position detector 14, and a display. A device 15, a voice output device 16, and a navigation side map database 17 are provided. Hereinafter, the database is abbreviated as DB.

The navigation-side control device 10, the navigation-side communication device 11, the external I / F 12, the input device 13, the position detector 14, the display device 15, the voice output device 16, and the navigation-side map DB 17 are mutually connected by a known communication technique. Each is connected so that it can communicate.

The navigation-side communication device 11 includes a transmission / reception antenna, and communicates with the server 2 via a communication network such as a telephone line or the Internet. Here, as an example, the navigation side communication device 11 employs an in-vehicle communication module such as DCM (Data Communication Module) used for telematics communication. Of course, in addition to this, a communication module used in a known third generation mobile communication system may be adopted. The navigation side communication device 11 corresponds to a navigation side communication unit.

The navigation-side communication device 11 transmits various signals to the server 2 based on instructions from the navigation-side control device 10, receives signals transmitted from the server 2, and outputs them to the navigation-side control device 10. . For example, when power is supplied to the navigation device 1 and the navigation-side communication device 11 is activated, the navigation-side communication device 11 transmits an activation notification signal indicating that the navigation device 1 has been activated to the server 2.

A signal transmitted from the navigation-side communication device 11 such as an activation notification signal to the server 2 includes an identifier (referred to as a vehicle ID) for distinguishing between the navigation device 1 and another navigation device, and will be described later. The vehicle position detected by the position detector 14 is included. As the vehicle ID, a MAC address assigned to the navigation-side communication device 11 may be used in addition to the vehicle and the serial number of the navigation device 1.

The external I / F 12 is an interface for the navigation-side control device 10 to acquire vehicle state information from an ECU (Electronic Control Unit) or sensor mounted on the host vehicle. For example, vehicle status information is input to the external I / F 12 from an ECU or a sensor mounted on the host vehicle via an in-vehicle LAN (Local Area Network) compliant with a predetermined communication protocol. Examples of vehicle state information include a shift position sensor signal, an ignition power on / off signal, and the like.

As the input device 13, for example, a touch switch or a mechanical switch integrated with the display device 15 is used, and the user instructs the navigation-side control device 10 to execute various functions by operating these switches.

The position detector 14 is a known gyroscope, a vehicle speed (distance) sensor, and a GNSS receiver used in a global navigation satellite system (GNSS) that detects the position of the device based on radio waves from satellites (all not shown). ). The position detector 14 sequentially detects the current position of the host vehicle (hereinafter, vehicle position) based on the outputs of these sensors. The vehicle position is, for example, coordinates represented by latitude and longitude.

The sensor groups provided in these position detectors 14 are configured to be used while being complemented by a plurality of sensors, since they have errors of different properties. Depending on the accuracy of each sensor, the position detector 14 may be constituted by a part of the above-described sensors.

The display device 15 displays text and images based on the input from the navigation-side control device 10, and notifies the user of various information. The display device 15 is disposed, for example, in the center of the instrument panel or in a combination meter provided in front of the driver's seat. The display device 15 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 16 includes a speaker, an amplifier, and the like, and outputs a guidance voice and the like based on an instruction from the navigation side control device 10.

The navigation-side map DB 17 is a storage device configured using a rewritable storage medium such as an HDD (Hard Disk Drive) or a flash memory, and stores the above-described map data. The navigation side map DB 17 stores, as map data, all the map data of the version distributed at the time of purchase of the navigation device 1, as well as difference map data and dependency difference data received from the server 2 through the navigation side communication device 11. Memorize etc. Further, the navigation side map DB 17 includes map management data for managing the map data of each section. The map management data indicates the version of all map data provided in each section, whether difference data exists in the section, and the like. The navigation side map DB 17 corresponds to the navigation side map storage unit.

The navigation-side control device 10 is configured as a normal computer, and includes a well-known CPU, nonvolatile memory such as ROM and EEPROM, volatile memory such as RAM, I / O, and a bus line for connecting these configurations ( All are not shown). The nonvolatile memory stores a program for executing various processes. The navigation-side control device 10 performs various processes based on various information input from the navigation-side communication device 11, the external I / F 12, the input device 13, and the position detector 14 and a program stored in the memory. Examples of processing executed by the navigation-side control device 10 include map display processing, route calculation processing, route guidance processing, and the like.

In the map display processing, a road map around the current position detected by the position detector 14 or around the area designated by the user through the input device 13 is displayed on the screen of the display device 15 at a scale designated by the user.

In the route calculation process, for example, a recommended route satisfying preset conditions such as distance priority and time priority from the departure point to the destination such as the current vehicle position is calculated using a known search method such as the Dijkstra method. .

In the route guidance process, the travel of the guidance route is guided. The guide route is a recommended route calculated by route calculation processing, and is a route determined by the user's route determination operation. For example, in the route guidance process, an electronic map indicating the guidance route and the vehicle position of the host vehicle is sequentially displayed on the display device 15, and guidance voices to the destination are sequentially output from the voice output device 16. Guide the run.

Further, as shown in FIG. 1, the navigation-side control device 10 includes a map providing unit 10A and an update processing unit 10B as functional blocks for performing processes other than those described above. In response to a read request from a read request source such as a map display process or a route guidance process, the map providing unit 10A generates and reads map data of a section designated by the read request from the original map data and the difference data. Execute the map provision process provided to the request source. The map providing unit 10A will be described later with reference to FIG.

The update processing unit 10B executes a process of updating the map data stored in the navigation side map DB 17 based on the map data acquired from the server 2 (this is referred to as a navigation side update process). The update processing unit 10B will be described later with reference to FIG. This update processing unit 10B corresponds to the navigation side update unit.

(Configuration of server 2)
As shown in FIG. 1, the server 2 includes a server-side control device 20, a server-side communication device 21, a server-side map DB 22, and a storage unit 23. The server side communication device 21 communicates with the navigation device 1 by a known wireless communication technique. For example, the navigation device 1 and the server 2 perform sequential communication while the navigation device 1 is activated.

The server-side control device 20 is configured as an ordinary computer. The server-side control device 20 is configured as a well-known CPU, a nonvolatile memory such as a ROM or an EEPROM, a volatile memory such as a RAM, an I / O, and a bus line connecting these configurations ( All are not shown). The nonvolatile memory stores a program for executing various processes. The server-side control device 20 is connected to the server-side communication device 21, the server-side map DB 22, and the storage unit 23 so that they can communicate with each other, and performs various processes based on programs stored in the nonvolatile memory. carry out.

The server-side map DB 22 is a storage device realized by using an HDD or the like, and includes data indicating dependency relationships between the difference data, as well as all map data and difference data of all versions (referred to as dependency relationship correspondence data). ) Is also stored. This server side map DB 22 corresponds to a server side map storage unit.

The storage unit 23 is a storage device realized using an HDD or the like, and stores a section where the host vehicle frequently travels (a core area) in association with the vehicle ID of the host vehicle. The core area may be automatically determined based on the frequency with which the user uses the map data of the section, or may be set by the user. When determining automatically, the frequency which uses the map data of the division for every division should be calculated, and the division with the usage frequency more than a fixed value should just be determined as a core area. The usage frequency of map data for each section is calculated from the travel history such as the number of times the host vehicle has traveled on the roads included in the section and the ratio of roads where the host vehicle has traveled among the roads included in the section. It ’s fine. The main section constituting this core area is taken as an example of the target section.

In addition to the core area, the storage unit 23 stores a list of map data that has been distributed to the navigation device 1 (this is a distributed list) in association with the vehicle ID. For example, when all the map data up to version 3 has already been distributed to the navigation device 1, that fact is stored. Therefore, the server-side control device 20 can recognize the map data that the navigation device 1 has acquired by referring to the distributed list stored in the storage unit 23.

(Comparative configuration)
Here, before explaining the operation and effect of the present embodiment, the operation and its problems in the configuration of the conventional map data distribution system (this is a comparative configuration) will be described with reference to FIGS. 8 and 9.

The comparison configuration is mainly the same as the map data distribution system 100 of the present embodiment shown in FIG. However, when the navigation device in the comparison configuration needs to update the map data provided in advance, the navigation device acquires a version of the difference map data representing the update and stores each in the navigation side map DB. I will do it. Accordingly, when all the map data prepared in advance is updated a plurality of times, a plurality of versions of difference data corresponding to these updates are accumulated in the navigation side map DB.

When map data is requested from other applications such as route calculation processing, update map data reflecting the map update is generated by combining all map data and difference map data, and provided to the requester To do. Hereinafter, this map providing process will be briefly described with reference to FIG. In addition, although demonstrated here as the map provision process in a comparison structure, the map provision process which 10A of map provision parts of this embodiment implement is implemented by the same flow.

In the description of the map providing process, the navigation side map DB of the comparison configuration includes all map data of version 1 and difference map data from version 1 to version 4 for all sections. To do.

<Map provision processing>
The flowchart shown in FIG. 8 is started when there is a read request from another process (such as a map display process, a route search process, and a route guidance process). Hereinafter, an application that has made a read request is set as a read request source.

First, in step S101, a designated section acquisition process is performed, and the process proceeds to step S103. In the designated section acquisition process in step S101, information about each main section to be read (specified as a designated section) specified by the read request is acquired. The designated section information is, for example, the number of the main section, the address on the navigation side map DB 17 in which the map data of the main section is stored. Depending on the read request, a smaller section (medium section or small section) of the map data of the main section is specified as a reading target. Here, the main section to which these sections belong is set as the specified section.

In S103, first, based on the type of the read request, it is determined whether or not the differential data corresponding to the designated section needs to be read. Here, for example, when the read request is for requesting the use of difference data, it is determined that the difference data needs to be read, and when the read request is not for requesting the use of difference data, It is determined that data reading is unnecessary. The type of read request that needs to read the difference data may be stored in advance in a memory included in the navigation-side control device 10.

In S103, the map management data is referenced for each section that is the designated section, and it is determined whether or not difference data exists in the section. Even if the type of read request is a type that requires reading of difference data, if there is no difference data in the designated partition, there is no need to read the difference data. Therefore, when the type of read request is a type that requires differential data to be read and there is differential data in the designated partition, it is determined that the designated partition needs to be read. .

If it is necessary to read the difference data corresponding to the designated section, step S105 is YES and the process proceeds to step S107. If it is not necessary to read the difference data corresponding to the designated section, step S105 is NO and the process proceeds to step S113.

In step S107, a group of difference data corresponding to the designated section provided in the navigation side map DB is read out. Here, for the sake of convenience, it is assumed that the difference data of the designated section is present in units of difference map data. That is, the difference map data of all versions in the designated section is read out.

In step S109, update map generation processing is executed, and the process proceeds to step S111. In the update map generation processing in step S109, for each piece of partition data read in step S101, the partition data and the partition difference data corresponding to the partition data read in step S107 are combined and updated for each partition. Generate map data. Below, the update map data of each division obtained by this update map production | generation process is also expressed as update division data.

The updated section data refers to the section difference data included in each version of the difference map data in order, and the section data read from all the map data is corrected according to the correction point indicated by the section difference data and the command group indicating the correction contents. By doing so, it can be generated.

For example, the α-th main section data included in the designated section is corrected according to the correction point indicated by the difference data from version 1 to version 4 corresponding to the main section and the command group indicating the correction contents. As a result, updated block data in which the change of the map element indicated by the block difference data is reflected in the main block data of all the map data is generated. The updated section data obtained in step S109 includes the same map elements as the corresponding section data in all version 5 map data.

Also, the section data of the medium section and the small section are corrected according to the command group indicating the correction location and the correction content indicated by the difference data of the same section read in step S107. These updated partition data are temporarily stored in the volatile memory.

In step S111, the updated map data composed of the updated section data generated in the previous step S109 is provided to the read request source, and the map providing process is terminated. In step S113, all map data of the designated section is provided, and the map providing process is terminated. Of course, it is not necessary to provide all the data included in all the map data. If the section specified in the read request is a medium section or a small section, the data about the section may be provided to the read request source.

The application that is the read request source performs various processes using the map data provided in this way. For example, when the map display process is a read request source, the map data provided by the map providing process is used to display the area specified by the user and the road map around the current location at the scale specified by the user. It is displayed on the screen of the display device 15. Note that the updated map data stored in the volatile memory is deleted when the use of the read request source application ends.

In the operation example of the comparative configuration described above, since all map data stored in the navigation side map DB is version 1, the difference map data from version 1 to version 4 is applied to this all map data. To generate updated map data. Of course, if all the map data stored in the navigation side map DB is of version 4, one map (ie, version 4) of the difference map data is combined with this map data, and updated map data is obtained. It only has to be generated.

<Challenges of comparative configuration>
In the comparison configuration, as all map data stored in the navigation-side map DB becomes relatively old, the amount of difference data read to generate updated map data increases. Then, the difference data that is read to generate the update map data increases, so that the delay from receiving the read request to providing the update map data to the read request source increases (that is, the read speed). Decrease) occurs.

Of course, if all the map data stored in the navigation side map DB is a relatively new version (for example, version 4), the number of versions of difference data that need to be combined is small at that time. The decrease in reading speed is relatively small. However, since the number of versions of the difference map data increases with the subsequent update of the map, a decrease in reading speed will become a problem in the future.

(About operation of this embodiment)
Hereinafter, the operation of this embodiment will be described with reference to FIGS. As a premise for the following explanation, all map data is distributed up to version 5 and difference data is distributed up to version 4, respectively, and all these data are stored in the server-side map DB 22.

FIG. 10 is a diagram for explaining the version of the map data for each section provided in the navigation-side map DB 17. The main sections from the first main section to the Nth main section are arranged on the horizontal axis. The vertical axis represents the version of map data included in each main section. In the figure, ΔVer1 represents version 1 difference map data, and ΔVer2 represents version 2 difference map data. The same applies to ΔVer3 and ΔVer4.

As shown in FIG. 10, in this embodiment, the navigation side map DB 17 includes all map data up to version 3 in all main sections. Further, the core area composed of the (K-1) th main section, the Kth main section, and the (K + 1) th main section has version 3 difference map data for each main section. The K-2 main partition and the K + 2 main partition are provided with dependency difference data having a dependency relationship with the version 3 difference map data included in the core area.

The map elements of the version 3 difference map data provided in the core area are matched with the map elements outside the core area by these dependent difference data.

<Update data distribution processing>
First, update data distribution processing performed by the server-side control device 20 will be described with reference to FIG. The flowchart shown in FIG. 11 is started when an activation notification signal is received from the navigation device 1.

First, in step S201, the activation notification signal transmitted by the navigation device 1 is received, and the process proceeds to step S203. In step S203, the core area set in the navigation device 1 that has transmitted the activation notification signal received in step S201 is acquired, and the process proceeds to step S205.

For example, the server-side control device 20 identifies the navigation device 1 that has transmitted the activation notification signal among a plurality of navigation devices that can communicate with the server 2 of the map data distribution system 100 from the vehicle ID included in the activation notification signal. To do. Then, the core area stored in association with the navigation device 1 is read from the storage unit 23. Here, the three main sections of the K−1 main section, the Kth main section, and the K + 1 main section correspond to the core area of the navigation device 1. Also, the map data acquired by the navigation device 1 is acquired with reference to the storage unit 23.

In step S205, the navigation device 1 reads out the unacquired version of the difference map data from all the difference data in the section corresponding to the core area included in the server-side map DB 22, and the process proceeds to step S207. In step S207, of the difference data outside the core area, difference data having a dependency relationship with the difference map data acquired in step S205, that is, dependency difference data is determined with reference to the dependency relationship corresponding data. Then, the corresponding dependency difference data is read out, and the process proceeds to step S209.

In step S209, the latest version of all map data of each section corresponding to the core area is read, and the process proceeds to step S211. In step S211, a part already acquired by the navigation device 1 is removed from the dependency difference data read in step S207, and the process proceeds to step S213.

In step S213, all the map data read in step S209 and the dependency difference data generated in step S211 are combined into one data (that is, packed), and the process proceeds to step S215. Packing does not synthesize / integrate a plurality of data, but indicates that a plurality of data can be processed by a single instruction such as movement. The data packed in step S213 is data for updating the map data provided in the navigation-side map DB 17, and is also referred to as update data. The server-side control device 20 that executes step 213 corresponds to an update data generation unit.

In step S215, the update data packed in step S213 is distributed to the navigation device 1 via the server side communication device 21, and the update data distribution processing is terminated. By packing all the map data to be distributed and the dependency difference data in the previous step S213, they can be distributed together by one distribution instruction. Note that collectively delivering does not mean sending in one data unit such as a frame, but means delivering all data packed in one delivery instruction. Actually distributed data is divided and transmitted in predetermined data units. The server-side control device 20 that implements step S215 corresponds to the distribution processing unit.

Here, the update data generation processing described above will be described with reference to FIG. The vertical axis and the horizontal axis of the diagram shown at the top of FIG. 12 are the same as those in FIG. 10, and hatching is performed on portions related to step S205 and step S207 in the map data included in the server-side map DB 22. Has been given. The type of data indicated by the hatching mode is the same as that in FIG.

First, the operation in step S205 will be described. In the present embodiment, the navigation device 1 uses all the version 3 map data and the version 3 map for the section corresponding to the core area, that is, the (K−1) th main section, the (K) th main section, and the (K + 1) th main section. The difference map data has been acquired. Therefore, in step S205, the server-side control device 20 reads out the difference map data of version 4 of the section corresponding to the core area as the difference map data not acquired by the navigation device 1.

In this embodiment, the navigation apparatus 1 has already acquired version 3 map data for sections outside the core area, such as the K-2 main section. Therefore, in step S207, among the difference data of version 3 or higher in the partition outside the core area, the difference data having a dependency relationship with the difference data acquired in step S205 is acquired as the dependency difference data. Here, as shown in the uppermost row in FIG. 12, there is dependency difference data in the K-3 main section, the K-2 main section, the K + 2 main section, and the K + 3 main section.

As shown in the middle left side of FIG. 12, in step S209, the latest version of all map data in each section corresponding to the core area is read. Further, for the data existing in the partition outside the core area, that is, the dependency difference data read out in step S207, the middle part of FIG. The part on the right side remains. The part acquired by the navigation device 1 corresponds to the part of the dependency difference data shown in FIG. By performing this step S211, it is possible to suppress the distribution of overlapping dependent difference data.

Then, the update data shown in the lower part of FIG. 12 is generated by packing all the map data shown in the middle part of FIG. 12 and the dependency difference data.

By generating update data as described above, all the map elements in the core area are brought to the latest state, and the difference data necessary for guaranteeing the data in the core area as map data is included. Update data can be created. The state in which the data is guaranteed as map data refers to a state in which the map elements that satisfy the above-described dependency and are changed by the update are consistent with other map elements. For example, the road network in the core area is connected to the road network outside the core area, that is, the road network is consistent with the road shape data outside the core area.

<Navi side update process>
Next, the flow of the navigation side update process performed by the update processing unit 10B will be described using the flowchart shown in FIG. The flowchart illustrated in FIG. 13 is started when the navigation-side communication device 11 receives the update data transmitted by the server 2.

First, in step S301, the update data transmitted by the server 2 is received (demodulated, etc.), and the process proceeds to step S303. In step S303, it is determined whether or not the processing described below has been performed on all the sections corresponding to the map data (all map data or difference data) for each section included in the update data. In the present embodiment, the K-3, K-2, K-1, K, K + 1, K + 2, and K + 3 main sections are to be processed.

If the processing is performed for all sections, step S303 is YES, and the navigation side update processing is terminated. On the other hand, when an unprocessed section remains, step S303 is NO and the process proceeds to step S305.

In step S305, one of the unprocessed sections among all the sections corresponding to the map data for each section included in the update data is set as a processing target (this is set as a processing section). ), The process proceeds to step S307. If there are a plurality of unprocessed sections remaining, for example, the process may be performed from the section having the smallest section number.

In step S307, it is determined whether the data for the processing section among the data included in the update data is all map data. If the data for the processing section is all map data, step S307 is YES and the process moves to step S309. On the other hand, if the data for the processing section is not all map data, step S307 is NO and the process proceeds to step S311. Here, when the K-1, K, K + 1 main sections are processing sections, step S307 is YES, while the K-3, K-2, K + 2, K + 3 main sections are processing sections. If YES, step S307 is NO.

In step S309, the entire map data of the processing section stored in the navigation side map DB 17 is replaced with all the map data of the processing section included in the update data, and the process returns to step S303. In addition, when the difference data of the processing section is stored in the navigation side map DB 17, the difference data is deleted.

In step S311, the difference data of the processing section included in the update data is stored in the section data of the processing section stored in the navigation-side map DB 17 in association with the processing section, and the process returns to step S303. In other words, for the sections outside the core area, the dependence difference data acquired in this process is accumulated and stored on the map data acquired so far.

The above process is performed until step S303 determines YES, that is, the map data of the core area stored in the navigation-side map DB 17 is guaranteed as map data by performing all the sections. It will be in the updated state.

Here, FIG. 14 shows the state of the map data stored in the navigation-side map DB 17 after the navigation-side update process is performed. As shown in FIG. 14, by performing step S309, the map data of the (K-1, K, K + 1) main sections corresponding to the core area are replaced with the latest map data (ie, version 5). . Further, in the sections outside the core area, the dependency difference data is accumulated so that the map elements in the core area can be matched with the map elements in the other sections.

(Summary of this embodiment)
In the above configuration, the server 2 has compiled the latest version of all the map data of each section constituting the core area of the navigation device 1 and the dependency difference data of the section outside the core area that is dependent on the entire map data. Update data is generated and distributed to the navigation device 1.

When receiving the update data, the update processing unit 10B replaces the core area map data stored in the navigation-side map DB 17 with the latest all map data included in the update map data. That is, here, the version 3 total map data and the version 3 difference map data of each section constituting the core area stored in the navigation side map DB 17 are all included in the update map data. Replace with map data. Moreover, the dependence difference data of each division outside a core area are preserve | saved in navigation side map DB17.

By updating the map data in the navigation side map DB 17 as described above, the map data in the core area is in the latest state and is composed of all map data. As a result, when the map data of the sections constituting the core area is read, it is not necessary to read and combine the difference data for all the map data as in the comparison configuration. When the map data outside the core area is read out, the updated map data may be generated by combining the difference data with respect to all the map data as in the comparative configuration.

Therefore, according to the above configuration, the section for performing the update map generation process (FIG. 8, S109) can be limited to the periphery of the core area, so that it is possible to suppress a decrease in the reading speed.

Dependent map elements that have a dependency relationship with the map element changed in the navigation-side update process are saved as dependency difference data, so that the changed map element and the other map elements are consistent. It has become. Therefore, road connectivity can also be guaranteed.

In the present embodiment, for convenience of explanation, all map data of version 3 is provided for all sections before the update, and the difference data of version 3 is further provided for the core area. However, it is not limited to this. As shown in FIG. 15, the above-mentioned navigation side update process is performed from a state in which all the map data of version 3 is provided for the sections other than the core area and all the map data of version 4 is provided for the core area. May be.

That is, when a new version of all map data becomes available for the sections included in the core area, the old all map data may be sequentially replaced by the new version of all map data.

In addition, when a certain number or more of the difference map data versions are accumulated in a certain section, the map data of the section may be replaced with the latest version of all map data. The threshold value for determining whether or not to replace the latest version of all map data may be the number of versions that are unacceptable as the reading speed.

For example, in a state in which three versions of difference map data are stored in the navigation-side map DB 17 for a certain main section, if a newer version of all map data becomes available, the new version What is necessary is just to set it as the structure replaced with all the map data. According to such a configuration, every time a new version of all map data becomes available, the amount of communication can be reduced as compared with the above-described navigation-side update process.

In the above, the process of replacing the map data of the sections included in the core area with all the map data has been illustrated, but it goes without saying that the same process may be performed for main sections other than the core area.

In addition, in this embodiment, although it was set as the structure which identifies the main division which comprises a user's core area by the server 2 side, it is not restricted to this. In the navigation device 1, the core area may be determined and the core area may be notified to the server 2 when the update process is performed. The server 2 may generate the distribution data using the core area information received from the navigation device 1.

In the present embodiment, the activation notification signal is transmitted when the navigation device 1 is activated, and the generation and distribution of update data is automatically started when there is data to be distributed. Not exclusively. When an operation to update the map data is received from the user, a series of processes for updating, that is, a distribution data generation process and an update process may be performed.

Here, the flowchart described in this application or the process of the flowchart is configured by a plurality of sections (or referred to as steps), and each section is expressed as S101, for example. Further, each section can be divided into a plurality of subsections, while a plurality of sections can be combined into one section. Further, each section configured in this manner can be referred to as a device, module, or means.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

Server (2);
A map data distribution system (100) comprising a navigation device (1) communicating with the server,
The server
As the map data for each section obtained by dividing the map recording area, the map data before update which is the map data before the map element is updated and the map after updating the map element included in the map data before update Server-side map storage unit (22) that stores updated map data that is data, and difference data that indicates changes in map elements updated from the pre-update map data;
An update data generation unit (S213) for generating update data for updating the map data of the predetermined section provided in the navigation device;
A distribution processing unit (S215) that distributes the update data generated by the update data generation unit to the navigation device;
The update data is
The updated map data of the target section which is the section to be updated; and
A map element included in the difference data of a non-target zone that is the zone other than the target zone, and the map data before update of the target zone provided in the navigation device is replaced with the updated map data And the difference data including the dependent map element which is a map element in a relationship in which the map element updated in the target section becomes inconsistent with other map elements if the map element is not provided. And
The navigation device
A navigation side communication unit (11) that receives the update data distributed by the distribution processing unit;
A pre-update map data of a plurality of the sections is stored in advance, and a rewritable navigation-side map storage unit (17) that stores the updated map data and the difference data distributed from the server;
When the update data is received, all the map data of the target section stored in the navigation-side map storage unit is included in the updated map data of the target section included in the update data. A navigation side updating unit (10B) that replaces and stores the difference data of the non-target section in the navigation side map storage unit;
A map providing unit (10A) for providing the map data of the section designated by the read request to the read request source;
The map providing unit
When the updated map data of the section designated by the read request is stored in the navigation-side map storage unit, the updated map data is provided to the read request source,
When the updated map data of the section specified by the read request is not stored in the navigation side map storage unit and the difference data is stored, the map data before update and the difference are stored. Providing updated map data corresponding to the updated map data generated by combining data to the read request source;
When the updated map data and the difference data of the section designated by the read request are not stored in the navigation side map storage unit, the map data before update is provided to the read request source. To
Map data distribution system.
The target section is the section in which the frequency of use by the user using the navigation device is equal to or greater than a certain value among the sections constituting the map recording area.
The map data distribution system according to claim 1.
The difference data included in the update data is dependency difference data representing the dependency map element.
The map data distribution system according to claim 1 or 2.
The difference data included in the update data includes a map element other than the dependency map element.
The map data distribution system according to claim 1 or 2.
The update data generation unit, when there are a plurality of the target sections, generates the update data that summarizes the updated map data of each of the plurality of target sections.
The map data distribution system according to any one of claims 1 to 4.
As the map data for each section obtained by dividing the map recording area, the map data before update which is the map data before the map element is updated and the map after updating the map element included in the map data before update Server-side map storage unit (22) that stores updated map data that is data, and difference data that indicates changes in map elements updated from the pre-update map data;
An update data generation unit (S213) for generating update data for updating the map data of the predetermined section provided in the navigation device;
A distribution processing unit (S215) that distributes the update data generated by the update data generation unit to the navigation device;
The update data is
The updated map data of the target section which is the section to be updated; and
A map element included in the difference data of a non-target zone that is the zone other than the target zone, and the map data before update of the target zone provided in the navigation device is replaced with the updated map data And the difference data including the dependent map element which is a map element in a relationship in which the map element updated in the target section becomes inconsistent with other map elements if the map element is not provided. Server.
For each section obtained by dividing the map recording area, the map data before update, which is map data before the map element is updated, and the update, which is the map data after updating the map element included in the map data before update Navigation-side communication unit (11) for receiving update data distributed from a server comprising completed map data and difference data indicating changes in map elements updated from the pre-update map data;
Pre-update map data is stored in advance for a plurality of the sections, and the rewritable navigation-side map storage unit (17) stores the updated map data and the difference data distributed from the server. )When,
A navigation-side update unit (10B) that updates data stored in the navigation-side map storage unit based on the update data;
A map providing unit (10A) for providing the map data of the section designated by the read request to the read request source;
The update data is
The updated map data of the target section which is the section to be updated; and
A map element included in the difference data of a non-target zone that is the zone other than the target zone, and the map data before update of the target zone provided in the navigation device is replaced with the updated map data And the difference data including the dependent map element which is a map element in a relationship in which the map element updated in the target section becomes inconsistent with other map elements if the map element is not provided. And
The navigation side update unit
All the map data of the target section stored in the navigation-side map storage unit is replaced with the updated map data of the target section included in the update data, and the non-target section Is stored in the navigation-side map storage unit,
The map providing unit
When the updated map data is stored in the navigation-side map storage unit in the section designated by the read request, the updated map data is provided to the read request source;
In the section specified by the read request, when the updated map data is not stored in the navigation-side map storage unit and the difference data is stored in the navigation-side map storage unit, Providing updated map data corresponding to the updated map data generated by combining the map data before update and the difference data to the read request source,
A navigation device that provides the pre-update map data to the read request source when the section specified by the read request does not include both the updated map data and the difference data.