JP2012037601A - Map data distribution system, terminal device and map data distribution method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To update map data within an allowable time without causing inconsistencies.SOLUTION: A map data distribution server maintains a first map data corresponding to a plurality of regions and a second map data which is a version newer than the first one. A terminal device maintains the first map data, and the map data distribution server prepares a plurality of update elements to update the first map data to the second map data and calculates time required to update the first map data on the basis of each of the update elements, based on the amount of the data included in each of the update elements and the number of the regions to be updated by each of the update elements. The terminal device updates the first map data based on the update elements of which calculated total time required for updating is less than a specified update time, among the update elements transmitted from the map data distribution server.

Description

  The present invention relates to a technique for providing a user with a service using map data, and more particularly to a technique for updating map data held by a navigation device.

  Various navigation devices represented by in-vehicle navigation devices hold map data in order to provide services such as route search and display. When an actual road is changed due to new construction or replacement, it is necessary to reflect the change in the stored map data in order to provide an appropriate service. However, for example, it takes a considerable amount of time to update all the map data in Japan. For this reason, the technique which acquires the newest map data of a desired area in a short time by updating map data for every predetermined area | region on a map is proposed.

  For example, Patent Documents 1 and 3 describe a technique for holding information for managing an area where map data needs to be updated and updating the map data based on the information. Further, these patent documents describe a technique for presenting the time required to acquire update information for updating map data held by the map information processing apparatus.

  Patent Document 2 describes a technique for realizing efficient data acquisition by considering communication time for acquiring map data based on the amount of map data included in the mesh.

  In said patent document, map data are updated for every predetermined area generally called a mesh or a parcel. However, for example, when a road that spans multiple areas is changed, if only the map data of some of those areas is updated, inconsistencies such as road breaks at the boundary of the areas in the updated map data occur. There is a case. A technique for preventing the occurrence of such contradiction is described in Patent Document 4 or Non-Patent Document 1, for example. According to Patent Document 4, in order to prevent the road from being interrupted, the map data of the area adjacent to the designated area is also updated as necessary. According to Non-Patent Document 1, a set of update data reflecting a continuous road change (addition or deletion, etc.) is treated as a minimum unit (that is, an update element) of map data update.

JP 2003-65770 A Japanese Patent Application Laid-Open No. 2004-347685 JP 2009-258124 A JP 2007-241033 A

“Map Update Service / Solution”, [online], [Search on 01/07/2010], Internet <URL: http://www.hitachi-automotive.co.jp/products/cis/02.html>

  In general, in-vehicle navigation devices cannot provide services such as route search to the user while map data update processing is being performed, or services that can be provided are greatly limited. Therefore, in order not to impair the user's convenience, it is desirable to update the map data during a time period when the user is not driving the automobile. However, the time period when the user is not driving the car is often limited to a relatively short time, such as a time period when the driver of the car is resting or a time period when the user is refueling. Furthermore, when the engine is stopped, if the remaining capacity of the in-vehicle battery is insufficient due to the power consumption for the update, problems such as the engine cannot be started occur, and the convenience for the user is impaired. Therefore, in order not to impair user convenience, it is necessary to limit the update time. However, conventionally, the update process cannot be controlled so as to end within a designated time. For example, in Patent Documents 1 to 3 described above, it is described that the time required for communication of map data is taken into account, but the time required for update processing is not described.

  Furthermore, it is desirable that the update of the map data is executed so that there is no contradiction in the map data such as road breaks. For example, when updating is performed for each mesh, in order to prevent inconsistency, not only a mesh requested to be updated but also the surrounding meshes may need to be updated as shown in Patent Document 4. Since it is difficult to predict in advance how many meshes need to be updated in order to prevent the occurrence of contradiction, it cannot be guaranteed that the update will be completed within a specified time.

  As shown in Non-Patent Document 1, if map data is updated for each update element, no contradiction in map data occurs. However, since the data size of the update element varies greatly, it is necessary to predict the time required for the update for each update element. Non-Patent Document 1 does not describe such prediction of update time.

  The present invention has been made in view of the above problems, and provides a highly convenient navigation apparatus by executing map data update processing so as not to cause inconsistencies in accordance with allowable update time. The purpose is to do.

  A typical example of the present invention is as follows. That is, a map data distribution system comprising a map data distribution server connected to a network and a terminal device that communicates with the map data distribution server via the network, wherein the map data distribution server is connected to the network. A first interface connected; a first processor connected to the first interface; and a first storage device connected to the first processor; and defined by dividing a space on a map First map data corresponding to a plurality of areas, and second map data of a version newer than the first map data corresponding to the plurality of areas are stored, and the first map data and the first map data The map data 2 includes information indicating nodes corresponding to intersections on the map and links corresponding to roads connecting the intersections. The terminal device includes a second interface that communicates with the map data distribution server, a second processor connected to the second interface, and a second storage device connected to the second processor, The map data distribution server holds the first map data corresponding to a plurality of areas, and each of the map data distribution servers has a single difference data for updating the first map data to the second map data. Or creating a plurality of update elements, including data indicating addition, deletion or change of a plurality of successive links, the amount of data contained in each update element, and the region updated by each update element Based on the number, the time required for updating the first map data based on each update element is calculated, and the terminal device A map data distribution request including the region to be updated of data is transmitted to the map data distribution server, the map data distribution server transmits the update element for updating the region to be updated to the terminal device, and The terminal device updates the first map data based on the update elements in which a total value of the calculated update times does not exceed a specified update time among the transmitted update elements. It is characterized by that.

  According to one embodiment of the present invention, it is possible to provide a highly convenient navigation device by executing map data update processing so that no contradiction occurs according to an allowable update time.

It is a block diagram which shows the structure of the map data delivery system of the 1st Embodiment of this invention. It is explanatory drawing of the apparatus in a motor vehicle containing the navigation terminal of the 1st Embodiment of this invention. It is explanatory drawing of the parcel and the update element in the 1st Embodiment of this invention. It is explanatory drawing of the parcel ID-element correspondence table which the map delivery server of the 1st Embodiment of this invention hold | maintains. It is explanatory drawing of the navigation model number-update time coefficient correspondence table which the map delivery server of the 1st Embodiment of this invention hold | maintains. It is explanatory drawing of the update element management table which the map delivery server of the 1st Embodiment of this invention hold | maintains. It is a flowchart which shows the update time calculation process which the map delivery server of the 1st Embodiment of this invention performs. It is a flowchart which shows the terminal map update process which the map delivery server and navigation terminal of the 1st Embodiment of this invention perform. It is a block diagram which shows the structure of the map data delivery system of the 2nd Embodiment of this invention. It is explanatory drawing of the parcel ID-element correspondence table which the map delivery server of the 2nd Embodiment of this invention hold | maintains. It is a flowchart which shows the terminal map update process which the map delivery server and navigation terminal of the 2nd Embodiment of this invention perform.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a block diagram showing the configuration of the map data distribution system according to the first embodiment of the present invention.

  The map data distribution system of this embodiment includes a map distribution server 10 connected to a network 40 and a navigation terminal 20 that communicates with the map distribution server 10 via the network 40.

  The map distribution server 10 is a computer including a processor 16, a memory 17, a network interface (I / F) 18, a management data storage unit 11, an update data storage unit 12, and a map data storage unit 19 connected to each other.

  The processor 16 executes a program stored in the memory 17.

  The memory 17 is, for example, a semiconductor memory, and stores a program executed by the processor 16, data referred to by the processor 16, and the like. The memory 17 of this embodiment stores at least an update time prediction processing unit 13, an update data extraction unit 14, and an update data management unit 15. Processing realized by the processor 16 executing the program will be described later. In the following description, the processing executed by the update time prediction processing unit 13 and the like is actually executed by the processor 16.

  The network I / F 18 is connected to the network 40 and communicates with the navigation terminal 20 and the like.

  Each of the management data storage unit 11, the update data storage unit 12, and the map data storage unit 19 may be a storage device such as a hard disk drive (HDD) or a flash memory, or a storage area in one storage device. There may be.

  The map data storage unit 19 stores map data. The map data includes a coordinate value indicating the position and shape of a map component (feature). Real features are updated from time to time. An example is the updating of the road network, such as the construction, abolition or replacement of roads. The map data may include information on the feature at a certain point in the past and information on the feature at a later point in time.

  In general, map data is managed for each predetermined rectangular area on the map. This rectangular area is called a parcel or mesh. Each parcel is given a unique identifier (parcel ID).

  The update data storage unit 12 stores map update data (including map information and road network information) in units of features. For example, when the navigation terminal 20 holds a certain version of map data, the map update data is data that is created and transmitted in order to update the map data to a newer version of map data. At least these versions of difference data are included. Specifically, at least the update element management table 600 is stored in the update data storage unit 12. Details of the update element and the update element management table will be described later (see FIGS. 3 and 6).

  The management data storage unit 11 stores information for managing map update data. For example, the management data storage unit 11 stores information indicating the version of the map update data (that is, the difference generation), a parcel ID indicating the position where the map update data should be applied, and the like. Specifically, the management data storage unit 11 stores at least a parcel ID-element correspondence table 400 and a navigation model number-update time coefficient correspondence table 500. Details of these will be described later (see FIGS. 4 and 5).

  The navigation terminal 20 is a mobile terminal that performs route search and output of search results in order to guide the user to a destination. In the present embodiment, as a typical example, a case where the navigation terminal 20 is an in-vehicle navigation terminal mounted on a car as a part of the in-car device 60 will be described (see FIG. 2). The present invention can be applied to various mobile terminals such as navigation terminals.

  The navigation terminal 20 of this embodiment includes a processor 28, a memory 29, a network I / F 21, a screen input / output I / F 25, a management data storage unit 26, and a map data storage unit 27 that are connected to one another.

  The processor 28 executes a program stored in the memory 29.

  The memory 29 is a semiconductor memory, for example, and stores a program executed by the processor 28, data referred to by the processor 28, and the like. The memory 29 of this embodiment stores a distribution request unit 22, a map update unit 23, and a navigation processing unit 24.

  The distribution request unit 22 transmits a map update data distribution request to the map distribution server 10. The map update unit 23 updates the map data stored in the map data storage unit 27 using the distributed map update data. These processes will be described later. In the following description, the processing executed by the distribution request unit 22, the map update unit 23, and the navigation processing unit 24 is actually executed by the processor 28.

  The navigation processing unit 24 searches for a route to the destination based on the map data stored in the map data storage unit 27 and guides the user along the route. Since such route search and guidance are the same as those of the conventional in-vehicle navigation terminal, detailed description thereof will be omitted.

  The screen input / output I / F 25 includes a screen that displays map information and the like for the user, and an input device that receives input from the user. For example, the screen input / output I / F 25 may be a liquid crystal display device with a touch pad.

  The network I / F 21 is connected to the wireless communication device 30. The wireless communication device 30 performs wireless communication with a wireless base station 31 connected to the network 40. The network I / F 21 performs communication with the map distribution server 10 via the wireless communication device 30, the wireless base station 31, and the network 40. Transmission of a map data distribution request and reception of map update data, which will be described later, are realized by such communication.

  Note that the wireless communication device 30 may be built in the navigation terminal 20.

  Each of the management data storage unit 26 and the map data storage unit 27 may be a storage device such as a hard disk drive (HDD) or a flash memory, or may be a storage area in one storage device.

  The map data storage unit 27 stores map data referred to by the navigation processing unit 24. This map data is updated based on the map update data transmitted from the map distribution server 10.

  Information for managing map data is stored in the management data storage unit 26. For example, in the management data storage unit 26, latitude / longitude-parcel ID correspondence information indicating to which parcel the position of the own vehicle (that is, the vehicle on which the navigation terminal 20 is mounted) belongs, and map update applied to the map Data identification information and the like are stored.

  The network 40 is connected to the Internet 41. The map distribution server 10 may acquire a new version of map data via the Internet 41.

  FIG. 2 is an explanatory diagram of the in-car device 60 including the navigation terminal 20 according to the first embodiment of this invention.

  The navigation terminal 20 of the present embodiment is installed in a car as a part of the car equipment 60. The in-vehicle device 60 includes at least the navigation terminal 20, the in-vehicle control device 50, the battery 55, and various sensors (for example, the handle angle sensor 51, the brake pedal sensor 52, the accelerator pedal sensor 53, the voltage / current sensor 54, etc.).

  The battery 55 is a power source that supplies power to the in-vehicle device 60 including the navigation terminal 20. When the in-vehicle device 60 is installed in a vehicle having an internal combustion engine as a power source, the battery 55 supplies electric power not only to the in-vehicle device 60 but also to a motor that starts the internal combustion engine. When the in-car device 60 is installed in a car that uses an electric motor as a power source (for example, a so-called hybrid car or an electric car), the battery 55 powers not only the in-car device 60 but also the electric motor that is a power source. Supply.

  The voltage / current sensor 54 measures at least one of the output voltage and the output current of the battery 55.

  The in-vehicle control device 50 is generally a processing device including a processor, a memory, and the like, and is connected to various sensors and can execute processing based on data acquired from the various sensors. The in-vehicle control device 50 is further connected to the network I / F 21 and can transmit data acquired from various sensors or a result of processing based on them to the navigation terminal 20. For example, the in-vehicle control device 50 may transmit the voltage and current values acquired from the voltage / current sensor 54 to the navigation terminal 20 and calculate the remaining capacity of the battery 55 based on those values. The remaining capacity value may be transmitted to the navigation terminal 20.

  The in-vehicle control device 50 can calculate the remaining capacity of the battery 55 by a known method. For example, the in-vehicle control device 50 may calculate the remaining capacity based on the fluctuation of the output voltage measured by the voltage / current sensor 54 or may calculate the remaining capacity based on the integrated value of the output current.

  FIG. 2 shows a navigation terminal 20 installed in an automobile as a typical example, but this embodiment can also be applied to other types of navigation terminals, for example, terminals carried by pedestrians. Also in this case, the navigation terminal 20 is connected to the battery 55 and receives power from the battery 55, as in FIG. In addition, a voltage / current sensor 54 is connected to the battery 55.

  FIG. 3 is an explanatory diagram of parcels and update elements in the first embodiment of the present invention. Specifically, FIG. 3 shows an example of updating the road network included in the map data stored in the map data storage unit 19 or the map data storage unit 27.

  As is well known, the map data includes information about the road network, and the road network is expressed by a combination of nodes and links. Nodes correspond to intersections, and links correspond to road sections connecting two intersections. That is, the map data includes information indicating the coordinates of each node, information indicating the shape of the link connecting the nodes, and the like. Since the specific format of such map data may be the same as that used in the conventional navigation system, detailed description thereof is omitted.

  As described above, a parcel is an area of a predetermined size defined by dividing a space on a map. Map data is managed for each parcel. More specifically, for example, the information regarding the nodes and links in one parcel may be one record of a database storing map data. For example, the road network 300 </ b> A illustrated in FIG. 3 is managed for each of nine rectangular parcels 301 to 309. In this example, circular signs represent nodes, and thick lines connecting the nodes represent links.

  Here, management of map data for each parcel will be described.

  For example, the parcel 301 of the road network 300A includes a node 322 and links 362 to 364 connected thereto. The parcel 302 includes a node 323 and links 365 to 368 connected thereto. Usually, data included in one parcel is stored in a continuous area of the map data storage unit 27. On the other hand, data included in different parcels is not always written in a continuous area. For this reason, even when the target data amount is the same, generally, the time required for reading and writing data included in a plurality of parcels is longer than the time required for reading and writing data included in one parcel.

  In addition, when map data corresponding to one parcel is handled as one record as described above, even if only a part of the data in one parcel is updated, the entire map data corresponding to that parcel Must be read and updated, and the updated data must be overwritten on the original data. Therefore, even if the amount of data that is actually updated is the same, the amount of data that is read and written when the data is distributed in multiple parcels rather than when the data is concentrated in one parcel In many cases, the time required for this is increased.

  Further, in such a case, in order to read and write data corresponding to a plurality of parcels, it may be necessary to issue an I / O command for each parcel. In this case, for example, reading and writing of data included in one parcel can be performed by one I / O, but reading and writing of data included in two parcels are performed twice each. Executed by / O.

  For example, when it is necessary to update the shapes of the links 363 and 364 in the map data stored in the map data storage unit 27, the map update unit 23 of the navigation terminal 20 displays all the nodes and links included in the parcel 301. Are read from the map data storage unit 27, the data indicating the shapes of the links 363 and 364 are updated in the read data, and the data of all nodes and links including the updated data are updated. May be overwritten.

  On the other hand, when it is necessary to update the shapes of the links 364 and 365, the map update unit 23 reads, for example, all the node and link data included in the parcels 301 and 302 from the map data storage unit 27 and is read out. The data indicating the shapes of the links 364 and 365 is updated among the acquired data, and the data of all nodes and links including the updated data is overwritten in the map data storage unit 27.

  Assuming that the data amount of each parcel is almost the same, the amount of data read and written in the latter case of the above two cases is the former regardless of the data amount of the link that is actually updated. About twice as much as

  The data read from the map data storage unit 27 for updating is temporarily stored in the memory 29 and updated by the map update unit 23. The typical memory 29 is a dynamic random access memory (DRAM), and the typical map data storage unit 27 is a nonvolatile storage device such as an HDD or a flash memory. Therefore, in general, I / O processing for the map data storage unit 27 is much slower than I / O processing for the memory 29. For this reason, the amount of data read from the map data storage unit 27 and written thereafter, and the number of I / O processes therefor are the total time required for updating the map data in the map data storage unit 27. It has an impact that cannot be ignored.

  Next, the update element will be described.

  In general, map data is updated at a predetermined timing (for example, every several months) so as to reflect actual road changes. The updated map data is created, for example, by a publisher that handles map information and is provided via the Internet 41. When new map data is provided, the map data storage unit 19 of the map distribution server 10 stores the map data before being updated (that is, the old version) and the map data after being updated (that is, the new version). Both are stored. The road networks 300A and 300B in FIG. 3 are examples of road networks indicated by map data of an old version (Ver. 1) and a new version (Ver. 2), respectively.

  Comparing the road networks 300A and 300B, the nodes and links included in the parcels 301, 302, 303, 307, and 308 are not changed.

  In the road network 300A, the parcel 305 includes a link 351 that connects the nodes 311 and 312, and the parcel 306 includes a link 352 that connects the nodes 313 and 314.

  In the road network 300B, the links 351 and 352 are deleted, and nodes 316, 317, 318, 319, 320, and 321 and links 353, 354, 355, 356, 357, 358, 359, 360, and 361 are added.

  When the map distribution server 10 acquires the new version of map data, the map data storage unit 27 of the navigation terminal 20 stores the old version of map data (that is, the road network 300A). Therefore, the distribution request unit 22 transmits a map data distribution request to the map distribution server 10, and the map update unit 23 uses the map data (that is, update data) transmitted in response to the map data in the map data storage unit 27. Update. The map data distribution request can be transmitted in response to various events, for example, that a predetermined time has passed since the previous distribution, a predetermined date and time has arrived, an update request has been input from the user, and the like.

  As a conventional map data update method, update for each parcel and update for each update element are known. In this embodiment, the update for each update element is executed.

  If the update for each parcel is executed, for example, when the update of the parcel 305 is requested, the link 351 is deleted, and the nodes 316, 317, 318, and the links 354, 355, and 357 are added. In this case, links 353 and 358 are not added, so links 354 and 357 are interrupted at nodes 316 and 318, respectively.

  On the other hand, in the present embodiment, update data relating to continuous links is collected as update elements, and update is executed for each update element. In the present embodiment, when two links are connected to one node, it is described that the links are continuous. For example, the links 353 and 354 are continuous because they are connected to one node 316. Similarly, links 354, 355, 356 and 357 are connected to one node 317 and are therefore continuous. Since links 357 and 358 are connected to one node 318, they are continuous. Links 358, 359, and 360 are connected to one node 319 and are therefore continuous. Eventually, the links 353 to 360 are continuous. Therefore, update data indicating the addition of the links 353 to 360 is collected as one update element 371.

  This update element 371 further includes update data indicating addition, deletion or change of nodes connected to these links. In the example of FIG. 3, update data indicating addition of the nodes 316 to 319 is included in the update element 371. Nodes 311 to 315 are nodes connected to any of the above links, and are included in both the new version and the old version of the road network. However, when the coordinates of these nodes or other attribute values are changed, update data indicating the change is also included in the update element 371.

  The link 351 to be deleted in the new version and the link 355 to be added cannot exist at the same time, but since both are connected to one node 311, the update data indicating the deletion of the link 351 is also the update element 371. include. Similarly, update data indicating deletion of the link 352 is also included in the update element 371.

  The link 361 is not continuous with any link included in the update element 371. Therefore, the update data indicating the addition of the link 361 and the nodes 320 and 321 at both ends thereof is included in another update element 372.

  In this example, when the distribution request unit 22 transmits a map data distribution request for the parcel 305 to the map distribution server 10, the update data management unit 15 of the map distribution server 10 updates update data related to the link or node in the parcel 305. The update element 371 including is transmitted to the navigation terminal 20. The map update unit 23 of the navigation terminal 20 executes the deletion of the links 351 and 352 and the addition of the links 353 to 360 and the nodes 316 to 319 according to the transmitted update element 371. As a result, the map data stored in the map data storage unit 27 is updated. Even if the update element 372 is not yet reflected at this time, there is no contradiction such as a road break.

  In the following description, an update element including information indicating a link or node update in a parcel is referred to as an update element corresponding to the parcel. For example, the update element 371 corresponds to the parcel 304 because it includes information indicating that the link 353 is added to the parcel 304. Similarly, update element 371 also corresponds to parcels 305 and 306. Similarly, update element 372 corresponds to parcels 306 and 309. In other words, the parcels 304, 305 and 306 are updated by the update element 371. Similarly, parcels 306 and 309 are updated by update element 372.

  Although FIG. 3 has been simplified for the sake of explanation, there are cases where a plurality of update elements may actually correspond to one parcel, and a plurality of parcels are designated as update targets in one map data distribution request. May be. Therefore, in practice, a large number of update elements may be transmitted in response to one map data distribution request. The update data management unit 15 of the present embodiment transmits only a plurality of update elements related to the specified parcel that are predicted to be updated within the specified time. Details thereof will be described later.

  Next, data held by the map distribution server 10 of the present embodiment and transmission of update elements based on the data will be described.

  FIG. 4 is an explanatory diagram of the parcel ID-element correspondence table 400 held by the map distribution server 10 according to the first embodiment of this invention.

  Parcel ID-element correspondence table 400 includes information associating parcels with update elements, and information indicating the update time of each update element. This table is referred to by the update data management unit 15 that has received the map data distribution request from the navigation terminal 20.

  Specifically, the parcel ID-element correspondence table 400 includes a parcel ID 401, an update element ID 402, an update time 403, and a size 404.

  The parcel ID 401 is an identifier of each parcel.

  The update element ID 402 is an identifier of an update element corresponding to each parcel.

  The update time 403 is a time estimated to be required to reflect each update element on the navigation terminal 20. A method for calculating this time will be described later.

  The size 404 is the data size of each update element.

  For example, the update element ID “11” corresponding to the parcel ID “0001” is stored in the row 412, and the update element ID “11” corresponding to the parcel ID “0002” is stored in the row 413. This is because one update element identified by the identifier “11” (herein referred to as “update element“ 11 ””, the same applies to other update element IDs) is represented by two parcels, namely the identifier “0001”. This indicates that the data is straddling the identified parcel and the parcel identified by the identifier “0002”.

  Further, referring to the rows 411 and 412, when the update element “10” identified by the update element ID “10” is compared with the update element “11”, the former size 404 is larger than that of the latter. The update time 403 is shorter than that of the latter. In general, the larger the size 404 is, the longer the update time 403 is. However, when the number of parcels straddled by the former is smaller than that of the latter, the reversal of the update time as described above can occur.

  FIG. 5 is an explanatory diagram of a navigation model number-update time coefficient correspondence table 500 held by the map distribution server 10 according to the first embodiment of this invention.

  The navigation model number-update time coefficient correspondence table 500 holds information that associates the model of the navigation terminal 20 with the coefficient used when calculating the update time of each update element. Specifically, the navigation model number-update time coefficient correspondence table 500 includes a navigation model number 501 and a coefficient 502.

  The navigation model number 501 is information for identifying the model of the navigation terminal 20. Although only one navigation terminal 20 is shown in FIG. 1, a large number of navigation terminals 20 actually transmit a map data distribution request to the map distribution server via the network 40. These may include navigation terminals 20 of different models. The navigation model number 501 stores information for identifying the model of the navigation terminal 20 that may transmit a map data distribution request to the map distribution server 10.

  The coefficient 502 is an update time coefficient corresponding to the model of each navigation terminal 20. Since the processing performance of the navigation terminal 20 depends on the hardware performance of the installed processor 28 and the like and the specifications of the software that controls them, the time required for updating based on the same update element may differ depending on the model. For example, on the basis of the time required for updating the map data based on a certain update element for a certain model of the navigation terminal 20, the time required for updating the map data based on the same update element and the reference update time for each model of the navigation terminal 20 The ratio may be stored as the coefficient 502.

  In the example of FIG. 5, “1.0” and “1.1” are stored as the coefficients 502 corresponding to the values “NAVI-1000” and “NAVI-1001” of the navigation model number 501, respectively. This is because the time required for updating based on a certain update element for the model of the navigation terminal 20 identified by “NAVI-1001” is the same as the update element for the model of the navigation terminal 20 identified by “NAVI-1001”. It is 1.1 times the time required for updating based on.

  FIG. 6 is an explanatory diagram of the update element management table 600 held by the map distribution server 10 according to the first embodiment of this invention.

  When the map distribution server 10 acquires the new version of the map data, the map distribution server 10 creates an update element for updating the old version of the map data to the new version (see FIG. 3). The created update element is stored in the update element management table 600.

  The update element management table 600 includes an update element ID 601 and update data 602.

  The update element ID 601 uniquely identifies each update element.

  The update data 602 is update data included in each update element. Specifically, the update data includes information indicating addition, deletion, and change of a node or a link. Since the format of such update data may be the same as that applied in the conventional navigation system, detailed description is omitted.

  FIG. 7 is a flowchart illustrating the update time calculation process executed by the map distribution server 10 according to the first embodiment of this invention.

  This process is executed at any time after the map distribution server 10 acquires a new version of map data and before the update data of that version is transmitted to the navigation terminal.

  First, the update data management unit 15 acquires a new version of map data (for example, map data corresponding to the road network 300B in FIG. 3), and stores it in the map data storage unit 19 (S701).

  Next, the update data extraction unit 14 compares the new version of the map data with the old version of the map data stored in the map data storage unit 19 (for example, the map data corresponding to the road network 300A in FIG. 3). Then, an update element is created as difference data for updating the old version of map data to the new version of map data, and is stored in the update element management table 600 (S702). The update element is as described with reference to FIG.

  In addition, said S701 and S702 may be the same as what a conventional map delivery server performs.

  Next, for each created update element, the update time prediction processing unit 13 calculates the time required to update the map data in the navigation terminal 20 using the update element, and uses the calculated time as the parcel ID. -It stores as update time 403 in the element correspondence table 400 (S703).

  As described with reference to FIGS. 3 and 5, the time required for updating the map data mainly includes the amount of data included in the update element, the number of parcels over which the update element spans, and the model of the navigation terminal 20. Depends on. Here, the number of parcels that the update element straddles is, in other words, the number of parcels updated by the update element. For example, the update element 371 in FIG. 3 adds at least information indicating that a link 353 is added to the parcel 304, information indicating that a link 354 is added to the parcel 305, and a link 358 or the like is added to the parcel 306. Information indicating that In this case, the update element 371 straddles at least three parcels.

The update time prediction processing unit 13 calculates the update time corresponding to each update element so that the update data becomes longer as the amount of data included in the update element is larger and becomes longer as the number of parcels straddled by the update element is larger. For example, the update time prediction processing unit 13
Update time = A × (amount of data included in the update element) + B × (number of parcels over which the update element straddles) (1)
The update time may be calculated by Here, A and B are coefficients that depend on the model of the navigation terminal 20. In this embodiment, the values of A and B are determined using a representative model (for example, a model identified by the navigation model number “NAVI-1000” in FIG. 5), and the update time for other models is a coefficient 502 in FIG. Calculate using.

  In addition, said Formula (1) is only an example, and various calculation methods can be applied to this embodiment.

  FIG. 8 is a flowchart illustrating a terminal map update process executed by the map distribution server 10 and the navigation terminal 20 according to the first embodiment of this invention.

  First, the distribution request unit 22 of the navigation terminal 20 transmits a map data distribution request to the map distribution server 10 (S801). The map data distribution request includes at least information specifying the desired update time, the identifier of the parcel to be updated, and the version of the map data currently held.

  The desired update time is a time allowed to be used for the update process of the map data based on the current map data distribution request. As will be described later, the update process is controlled so as to end within the designated desired update time.

  As already described, while the navigation terminal 20 performs the update process of the map data, other functions (for example, route search or route guidance) are greatly limited. The navigation terminal 20 of the present embodiment can determine the desired update time based on various criteria so that the user's convenience is not impaired due to such function restrictions.

  For example, the navigation terminal 20 may transmit the desired update time input from the user via the screen input / output I / F 25 as it is included in the map data distribution request. The user can input, as the desired update time, a time during which the function such as the route search of the navigation terminal 20 is not used, typically a time during which the automobile equipped with the navigation terminal 20 is not driven. For example, when a user takes a break or refuels a car, the user may input a scheduled update time until the end of the break or refueling as a desired update time, or desires a time when the car is not used such as at night. You may input as update time. When the navigation terminal 20 is mounted on an electric vehicle, the user may input a time for charging the battery 55 as a desired update time.

  However, in an automobile using an internal combustion engine as a power source, when the engine is stopped, it is necessary to limit the update time so that the remaining capacity of the battery 55 does not become insufficient due to power consumption for updating map data. Therefore, the navigation terminal 20 acquires information indicating the remaining capacity of the battery 55 from the in-vehicle control device 50, and consumes all of the acquired remaining capacity based on the acquired remaining capacity and the power consumption of the navigation terminal 20 itself. A time shorter than the update time may be calculated as the desired update time and transmitted to the map distribution server 10. At this time, it is desirable to calculate the desired update time so that at least the capacity necessary for starting the engine remains in the battery 55.

  When the navigation terminal 20 is not installed in the automobile (for example, when carried by a pedestrian), the remaining capacity of the battery 55 is calculated based on information acquired from the voltage / current sensor 54 by the processor 28 of the navigation terminal 20. Also good.

  The parcel to be updated designated by the map data distribution request may be determined in any way. For example, the user may select an arbitrary parcel as an update target via the screen input / output I / F 25. Specifically, for example, a parcel around the current location or around a destination to be visited may be selected as an update target. Alternatively, the navigation terminal 20 may automatically select an update target. Specifically, for example, when the update process is performed at night, the navigation terminal 20 may designate a parcel in Japan or a specific region as an update target.

  The information indicating the version of the map data included in the map data distribution request includes at least information indicating the version of the parcel designated as the update target. In the present embodiment, the map data is updated for each update element. Therefore, some of the plurality of update elements corresponding to the old version of the parcel may already be reflected in the map data in the navigation terminal 20. In order to identify such update elements, the information indicating the version of the map data described above identifies, in addition to the information indicating the version of each parcel, the update elements corresponding to the parcel that have already been updated. Information may be included.

  Furthermore, the map data distribution request transmitted in S801 may include information for identifying the model of the navigation terminal 20 that transmitted the map data distribution request.

  The update data management unit 15 of the map distribution server 10 that has received the map data distribution request from the navigation terminal 20 within the desired update time based on the specified update target parcel identifier, map data version, and desired update time. A list of update elements for which the update is completed is created (S802).

  Even if it is a parcel designated as an update target, if the version of the map data of the parcel held by the navigation terminal 20 is the latest, it is not necessary to update the map data of the parcel, so this parcel is supported. Update elements to be registered are not registered in the list. Even if the map version of the parcel designated as the update target is not the latest, if the update element corresponding to the parcel is already reflected in the map data of the navigation terminal 20, the update based on the update element is performed. The update element is not registered in the list because it does not need to be executed again. Since the necessity determination of the update based on the version and the selection of the update element based on the determination are the same as those in the conventional map data distribution method, detailed description is omitted.

  The update data management unit 15 refers to the update time 403 of the parcel ID-element correspondence table 400 and registers the update elements corresponding to the parcel designated as the update target and not yet reflected in the navigation terminal. The update elements to be registered in the list are selected so that the total update time of the update elements does not exceed the specified desired update time.

  For example, the update data management unit 15 sequentially refers to the update times 403 of the update elements corresponding to the parcel designated as the update target and not yet reflected in the navigation terminal 20, and the update elements already registered in the list It is determined whether or not the sum of the update time of the update element and the update time of the update element referred to this time exceeds the desired update time, and if it does not exceed the desired update time, the update element referred to this time is added to the list . The list may be created by performing this process for all the update elements that have not yet been reflected in the navigation terminal and that correspond to the parcel designated as the update target.

  In such a process, for example, the update data management unit 15 may refer to the update times of the update elements in descending order of the size 404 value, or may refer to the size 404 in ascending order. You may refer to them in random order.

  A specific example of S802 will be described with reference to FIG. For example, when the parcel 304 is designated as the update target, the update data management unit 15 determines whether the parcel 304 stored in the navigation terminal 20 is the latest based on the version information of the parcel 304 included in the map data distribution request. Determine. For example, when the parcel 304 in the navigation terminal 20 is as the road network 300A and the update element 371 is not yet reflected, the update data management unit 15 determines whether the update time 403 of the update element 371 exceeds the desired update time. Determine whether. If another update element is already registered in the list, it is determined whether or not the total value of the update time 403 of those update elements and the update time 403 of the update element 371 exceeds the desired update time. If the result does not exceed the desired update time, an update element 371 is added to the list.

  When the map data distribution request includes information for identifying the model of the navigation terminal 20, the update data management unit 15 calculates the update time for the model by multiplying the value of the update time 403 by the coefficient 502 corresponding to the model. Then, based on the value, the update element registered in the list is selected.

  Next, the update data management unit 15 transmits the list (update element list) and update element data created in S802 to the navigation terminal 20 (S803). Here, the update element data is update data 602 of the update element registered in the update element list.

  The map update unit 23 of the navigation terminal 20 that has received the update element data and the like from the map distribution server 10 updates the map data stored in the map data storage unit 27 based on the transmitted update element data (S804). . As a result, the addition, deletion and change of the link and node indicated by the transmitted update element are reflected in the map data.

  Note that the above processing is an example, and various processing is allowed as long as the time required for actual updating is controlled so as not to exceed the desired updating time. For example, S802 to S804 may be executed as follows.

  In S802, regardless of the update time, the update data management unit 15 registers in the update element list all the update elements corresponding to the parcel designated as the update target and not yet reflected in the navigation terminal. In S803, the update data management unit 15 transmits to the navigation terminal 20 the update element list created in S802, the corresponding update element data, and the update time of each update element stored in the update element list. In S804, the map update unit 23 selects one or more update elements from the update elements registered in the transmitted update element list so that the total value of the update times does not exceed the desired update time. Update the map data based on it.

  According to the first embodiment of the present invention described above, the map data is updated for each update element, so that there is no contradiction such as a road break in the updated map data. Furthermore, since the update element to be reflected is selected so that the update is completed within the specified update time, the map data can be updated without impairing the convenience for the user.

<Second Embodiment>
FIG. 9 is a block diagram showing the configuration of the map data distribution system according to the second embodiment of the present invention.

  The map data distribution system of the second embodiment is the same as that of the first embodiment except for the following differences. First, the update time prediction processing unit is included in the navigation terminal 20 instead of the map distribution server 10. Second, the management data storage unit 11 does not hold the navigation model number-update time coefficient correspondence table 500. Third, the management data storage unit 11 does not hold information corresponding to the update time 403 of the parcel ID-element correspondence table 400. 4thly, in order to respond | correspond to the said 1st-3rd difference, the procedure which updates the map data of the navigation terminal 20 differs from 1st Embodiment. Hereinafter, these differences will be described. A description of the same parts of the second embodiment as those of the first embodiment will be omitted.

  FIG. 10 is an explanatory diagram of the parcel ID-element correspondence table 1000 held by the map distribution server 10 according to the second embodiment of this invention.

  The map distribution server 10 of the second embodiment holds a parcel ID-element correspondence table 1000 shown in FIG. 10 instead of the parcel ID-element correspondence table 400.

  The parcel ID-element correspondence table 1000 includes a parcel ID 1001, an update element ID 1002, and a size 1003. These are the same as the parcel ID 401, the update element ID 402, and the size 404 shown in FIG.

  Note that the parcel ID-element correspondence table 1000 of the present embodiment may be the same as that held by a map distribution server that distributes map data for each conventional update element.

  Then, the process which the map delivery server 10 and the navigation terminal 20 of this embodiment performs is demonstrated.

  When the map distribution server of this embodiment acquires a new version of map data, it stores it in the map data storage unit 19 and creates an update element based on it. These procedures are as described with reference to S701 and S702 of FIG. 7, and are the same as the procedures executed by the conventional map distribution server that performs map data distribution for each update element.

  That is, the map distribution server 10 of the present embodiment may be the same as a conventional map distribution server.

  FIG. 11 is a flowchart illustrating a terminal map update process executed by the map distribution server 10 and the navigation terminal 20 according to the second embodiment of this invention.

  First, the distribution request unit 22 of the navigation terminal 20 transmits a map data distribution request to the map distribution server 10 (S1101). The map data distribution request includes at least information specifying the identifier of the parcel to be updated and the version of the map data currently held. This map data distribution request is the same as that transmitted in S801 of FIG. 8 except that the desired update time is not included.

  The update data management unit 15 of the map distribution server 10 that has received the map data distribution request from the navigation terminal 20 transmits the update element to the navigation terminal 20 based on the identifier of the designated parcel to be updated and the version of the map data. Is created (S1102). Specifically, the update data management unit 15 registers in the list all the update elements that have not yet been reflected in the navigation terminal and that correspond to the parcel designated as the update target. This procedure is the same as S802 in FIG. 8 except that all update elements satisfying the above conditions are registered regardless of the update time of each update element.

  Next, the update data management unit 15 transmits the list (update element list) and update element data created in S1102 to the navigation terminal 20 (S1103). At this time, the update data management unit 15 transmits information indicating the identifiers of the parcels updated by the update elements registered in the update element list and the sizes of the update elements in addition to the update element data and the like. These pieces of information are acquired from the parcel ID-element correspondence table 1000.

  The update time prediction processing unit 13 of the navigation terminal 20 that has received the update element data or the like from the map distribution server 10 performs each update based on the size of the update element registered in the update element list and the number of parcels updated by them. The time (update time) required for the update based on the element is calculated. Then, the update time prediction processing unit 13 selects update elements to be applied so that the calculated total update time does not exceed the desired update time (S1104).

  The calculation of the update time performed in S1104 is the same as that performed in S703 of FIG. For example, the update time may be calculated by equation (1). In this case, however, the coefficients A and B are determined based on the hardware performance of the navigation terminal 20 itself that executes S1104.

  The size of each update element used for calculation of the update time and the number of parcels over which each update element spans are obtained from the identifiers of parcels updated by the update element and the sizes of those update elements transmitted in S1103. Even if these pieces of information are not transmitted from the map distribution server 10, the update time prediction processing unit 13 can extract similar information from the update element data. However, in order to omit the time required for the extraction, it is desirable that the map distribution server 10 transmits these pieces of information.

  The update element selection performed in S1104 may be the same as that performed in S802 of FIG. The desired update time is determined in the same manner as in the first embodiment (see S801).

  Next, the map update unit 23 of the navigation terminal 20 updates the map data stored in the map data storage unit 27 based on the update element data selected in S1104 (S1105).

  Note that the above processing is an example, and various processing is allowed as long as the time required for actual updating is controlled so as not to exceed the desired updating time. For example, S1104 and S1105 may be executed as follows.

  In S1104, the update time prediction processing unit 13 calculates the update time of each update element. Then, any one of the update elements not yet reflected in the map data is selected, and it is determined whether or not the update time of the selected update element exceeds the remaining time (described later) of the desired update time. When the update time of the selected update element does not exceed the remaining time, the map update unit 23 updates the map data based on the selected update element data (S1105). Then, the process returns to S1104 again, and any one of the update elements not yet reflected in the map data is selected.

  On the other hand, when the update time of the selected update element exceeds the remaining time, the update time prediction processing unit 13 selects another update element that has not yet been reflected in the map data. If the update time of any update element that has not yet been reflected in the map data exceeds the remaining time, the update cannot be completed within the desired update time regardless of which update element is selected. The navigation terminal 20 ends the terminal map update process without executing the update based on the terminal map.

  If the remaining time becomes 0 or less in S1104, the update time of any update element not yet reflected in the map data exceeds the remaining time, and the navigation terminal 20 ends the terminal map update process at that time. .

  The remaining time of the desired update time is the remaining time obtained by subtracting the time from the update start time to the present from the update desired time, that is, the update based on the update element already selected from the update time. It is the remainder after reducing the total value of the actual time required.

  The update control based on the remaining time as described above may be executed in S804 (FIG. 8) of the first embodiment.

  According to the second embodiment of the present invention described above, using the same map distribution server as the conventional one, as in the first embodiment, there is no contradiction in the updated map data and the convenience of the user is improved. Map data can be updated so as not to be damaged.

10 Map distribution server 11, 26 Management data storage unit 12 Update data storage unit 13 Update time prediction processing unit 14 Update data extraction unit 15 Update data management unit 16, 28 Processor 17, 29 Memory 18, 21 Network interface (I / F)
19, 27 Map data storage unit 20 Navigation terminal 22 Distribution request unit 23 Map update unit 24 Navigation processing unit 25 Screen input / output I / F
30 Wireless communication device 31 Wireless base station 40 Network 41 Internet

Claims (14)

A map data distribution system comprising: a map data distribution server connected to a network; and a terminal device that communicates with the map data distribution server via the network,
The map data distribution server
A first interface connected to the network; a first processor connected to the first interface; and a first storage device connected to the first processor;
First map data corresponding to a plurality of areas defined by dividing a space on a map, second map data of a newer version than the first map data corresponding to the plurality of areas, Hold
The first map data and the second map data include information indicating a node corresponding to an intersection on a map and a link corresponding to a road connecting the intersection,
The terminal device
A second interface communicating with the map data distribution server, a second processor connected to the second interface, and a second storage device connected to the second processor,
Holding the first map data corresponding to the plurality of areas;
The map data distribution server
A plurality of update elements each including, as difference data for updating the first map data to the second map data, data indicating addition, deletion, or change of the single or continuous plurality of the links Create
Based on the amount of data included in each update element and the number of regions updated by each update element, the time required for updating the first map data based on each update element is calculated,
The terminal device transmits a map data distribution request including the region to be updated of the first map data to the map data distribution server;
The map data distribution server transmits the update element for updating the region to be updated to the terminal device,
The terminal device updates the first map data based on the update elements in which a total value of the calculated update times does not exceed a specified update time among the transmitted update elements. A map data distribution system characterized by: The map data distribution request includes information specifying the update time,
The map data distribution server
From the update elements that update the region to be updated, select one or more update elements so that the calculated total time required for the update does not exceed the specified update time,
Transmitting the selected one or more update elements to the terminal device;
The map data distribution system according to claim 1, wherein the terminal device updates the first map data based on the transmitted update element.   The map data distribution server sets each update element to be longer as the amount of the difference data included in each update element is larger, and to be longer as the number of regions updated by each update element is larger. 3. The map data distribution system according to claim 2, wherein a time required for updating the first map data based on the first map data is calculated. The map data distribution server holds information associating a model of the terminal device with a predetermined coefficient,
The terminal device transmits information indicating the model of the terminal device to the map data distribution server,
The map data distribution server is based on each update element by the terminal device by multiplying the calculated time by the coefficient corresponding to the model of the terminal device based on information indicating the model of the terminal device. The map data distribution system according to claim 3, wherein a time required for updating the first map data is calculated. The map data distribution server transmits to the terminal device one or more update elements that update the area to be updated, and the time required for updating the first map data based on the update elements.
The terminal device, based on the time required for the update transmitted from the map data distribution server, among the one or more update elements transmitted from the map data distribution server, the total value of the time required for the update is the specified The map data distribution system according to claim 1, wherein the first map data is updated based on a value that does not exceed the updated update time. The terminal device includes an input / output device connected to the second processor,
The map data distribution system according to claim 1, wherein the designated update time is an update time input from the input / output device. The terminal device is connected to a battery that supplies power to the terminal device,
A sensor for measuring at least one of output voltage and output current is connected to the battery,
The terminal device has a shorter time than the usage time of the terminal device that consumes the remaining capacity based on the remaining capacity of the battery calculated based on the value measured by the sensor and the power consumption of the terminal device. 2. The map data distribution system according to claim 1, wherein the map data distribution system calculates and specifies the calculated time as the update time. A terminal device that communicates with a map data distribution server via a network,
The terminal device
An interface for communicating with the map data distribution server, a processor connected to the interface, and a storage device connected to the processor,
Holds map data corresponding to multiple areas defined by dividing the space on the map,
The map data includes information indicating a node corresponding to an intersection on a map and a link corresponding to a road connecting the intersection;
The terminal device further includes:
Transmitting a map data distribution request including information specifying the area to be updated of the map data to the map data distribution server;
Obtaining one or more update elements from the map data distribution server from the map data distribution server;
Each update element includes data indicating addition, deletion or modification of a single or a plurality of consecutive links including links in the specified region;
The terminal device further includes:
Based on the amount of the data included in each update element and the number of regions updated by each update element, the time required for updating the map data based on each update element is calculated,
The terminal device, wherein the map data is updated based on an update element in which the calculated total time required for the update does not exceed a specified update time among the acquired update elements.   The map based on each update element is such that the terminal device is longer as the amount of the data included in each update element is larger, and longer as the number of the regions updated by each update element is larger. The terminal device according to claim 8, wherein a time required for updating data is calculated. The terminal device includes an input / output device connected to the first processor,
The terminal device according to claim 8, wherein the designated update time is an update time input from the input / output device. The terminal device is connected to a battery that supplies power to the terminal device,
A sensor for measuring at least one of output voltage and output current is connected to the battery,
The terminal device has a shorter time than the usage time of the terminal device that consumes the remaining capacity based on the remaining capacity of the battery calculated based on the value measured by the sensor and the power consumption of the terminal device. The terminal device according to claim 8, wherein the terminal device calculates and designates the calculated time as the update time. The terminal device
The remaining time is calculated by subtracting the time from the start of updating the map data to the present time from the specified update time,
If the update time calculated for an update element not yet reflected in the map data does not exceed the remaining time, the map data is updated based on the update element,
If the time required for the update calculated for any update element not yet reflected in the map data exceeds the remaining time, the update of the map data based on any update element not reflected in the map data is also performed. The terminal device according to claim 8, wherein the terminal device is not executed. A map data distribution method executed by a map data distribution server,
The map data distribution server
An interface connected to a network, a processor connected to the interface, and a storage device connected to the processor,
First map data corresponding to a plurality of areas defined by dividing a space on a map, second map data of a newer version than the first map data corresponding to the plurality of areas, Hold
The first map data and the second map data include information indicating a node corresponding to an intersection on a map and a link corresponding to a road connecting the intersection,
The map data distribution method includes:
Data indicating addition, deletion, or change of a plurality of single or continuous links, as difference data for the map data distribution server to update the first map data to the second map data A first procedure for creating a plurality of update elements including:
The map data distribution server updates the first map data based on each update element based on the amount of data included in each update element and the number of regions updated by each update element. A second procedure for calculating the time required;
When the map data distribution server receives a map data distribution request including information specifying the area to be updated of the first map data from a terminal device connected to the network, the area to be updated is updated. A third procedure for transmitting the update element to the terminal device,
The third procedure includes
When the map data distribution request includes information for specifying an update time, the map data distribution server determines the total value of the calculated update time from the update element that updates the update target area. Selecting one or more of the update elements so as not to exceed the updated update time, and transmitting the selected one or more update elements to the terminal device, or
The map characterized in that the map data distribution server includes one of procedures for transmitting to the terminal device a time required for updating the first map data based on the update element for updating the area to be updated. Data delivery method.   In the second procedure, the map data distribution server is longer as the amount of the difference data included in each update element is larger, and longer as the number of the regions updated by each update element is larger. The map data distribution method according to claim 13, further comprising: calculating a time required for updating the first map data based on each update element.

Images