EP1654520A1

EP1654520A1 - Method for updating a digital map

Info

Publication number: EP1654520A1
Application number: EP04763944A
Authority: EP
Inventors: Mario Aleksic; Alexander Bracht
Original assignee: DaimlerChrysler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2003-08-16
Filing date: 2004-08-10
Publication date: 2006-05-10
Also published as: WO2005019773A1; US20070126605A1; DE10337621A1; DE10337621B4

Abstract

The invention relates to the updating of a digital map, comprising elements of a highway network, in a user-side device, on which at least one user application of the digital map runs, using a second digital map provided in a central processor. According to the invention, only a partial amount of the elements of the digital map necessary for a current user application are updated. As the above occurs at a time close to the time at which the corresponding elements of the digital map are required by the current user application, the current user application is always provided with the most up-to-date state of the digital map. As the partial amount of elements of the digital map required by the user-side device for the current user application may be precisely defined, only a minimum amount of data, in other words, a minimum requirement for data transfer is generated. At least one additional partial amount of elements for the digital map is automatically selected such that after receipt and making available the data of the additional partial amount of elements, the digital map has a uniformity which always provides a current digital map which permits a problem-free functioning of the or any user application running for the user on the device.

Description

Procedure for updating a digital map

The invention relates to updating elements of a digital map of a traffic network in a user-side device, e.g. a vehicle navigation device or a telematics center for map-based telematics services. Such updates are using a centrally located second digital map, e.g. is always brought up to date by the manufacturer of the digital card. The update removes elements of the second digital map that are not included in the digital form of the user device in the present form, since the elements e.g. have been added to the second digital map or have been changed or deleted in the second digital map, made available to the digital map of the user device.

A digital map (for example in the form of a CD-ROM, DVD-ROM or a file stored in a read / write memory) in a device arranged at a user enables access to a user application running on this device (for example vehicle route guidance) on the geo-based information of the digital map. Examples of such devices are a portable navigation unit, a navigation device permanently arranged in a vehicle. onsgerät, a 'geo-data sensor', ie a vehicle-side control unit that has access to a digital map, or a telematics center, which in turn offers card-based telematics services to an end user, for example "off-board" navigation (telematics center-based vehicle navigation). When using such devices, the problem arises that data stored in the digital map, which represent elements of a traffic network, 'become out of date', for example when new roads are being built or detours are being set up, or when POI ('points of interest', places of interest) change their position or change opening times. Since modern user-side devices have digital maps that cover entire countries or even continents, the update of these digital maps to the most current state requires either extensive data transfer to the user-side device or a complete exchange of the digital map (for example by exchanging the DVD used -ROM) necessary. Especially in the case of mobile user-side devices which are supplied with data via an air interface, high costs are incurred and / or the data transmission takes a long time.

As a generic state of the art reference is made to US 6317753 B1.

The problem thus arises of providing an up-to-date digital map on the user-side device with minimal effort for data transmission, which ensures problem-free functioning of the user applications running on the device for the user.

The object is achieved by the features of the independent claims 1 and 2. The subclaims relate to advantageous developments and developments of the invention. According to the invention, a subset of elements of the digital map to be updated can be selected on the user-side device and an update of this subset of elements can be requested from the central unit via an at least temporarily data-technical connection by the user-side device, the central unit additionally receiving after receiving such a request element subset to be updated, an additional subset of elements in the second digital map is automatically selected such that the digital map has consistency after the update, and wherein data for updating the subset of items to be updated and data of the additional subset of elements are sent from the control center to the user-side device via the data connection at least at times and made available to the digital map. Alternatively, in a first step, after receiving a request from the user-side device, the control center sends data for updating the subset of elements to be updated to the user-side device via the at least temporarily data-technical connection and makes them available to the digital card, whereupon in a second Step from the. User-side device is checked whether additional subsets of elements of the digital map are affected by the update and, depending on the result of the check, an update of these additional subsets of elements is automatically requested by the control center in such a way that the digital map after receipt and the availability of the Data of the additional element subsets has consistency.

In other words, only a subset of elements of the digital map required for a current user application is updated. Since this is done promptly at the time, For which the corresponding elements of the digital map are required by a current user application, the current user application is always provided with the most current version of the digital map. Since the element subset of the digital card required for a current user application can be precisely delimited by the user-side device, only a minimally required amount of data, ie a minimal effort in data transmission, is always realized according to the invention. By automatically selecting at least one additional subset of elements of the digital map in such a way that the digital map after receiving and making available the data of the additional subset of elements is inherently consistent and thus also with respect to the or each user application running on the user device according to the invention, a current digital map is always provided, which ensures problem-free functioning of the or each user application running on the device for the user. In other words, a corresponding addition with an additional subset of elements ensures that the update of the digital map with respect to the data of the current application on the user-side device is consistent.

The subset of elements to be updated preferably comprises a specific geographical area, for example a route planned by the user together with a corridor surrounding the route, a specific class of road, for example federal highways, POI ('points of interest', ie user-interested locations such as, for example, gas stations or restaurants ), and / or classes of POI.

The consistency of the or each user application running on the user-side device is particularly advantageously ensured by the additional subset of elements is automatically selected in such a way that after the data for updating the at least one additional subset of elements has been made available for the digital map of the user-side device, no route exists, at the end of which traffic route network users must inevitably reverse (ie a dead end) if this Route is not also included in the second digital map (ie is also formed as a dead end), and / or there are no two routes, at the ends of which traffic route network users must inevitably reverse if these two routes are connected in the second digital map by a few edges (i.e. these few edges are included as elements of the second digital map), and / or there are no routes on which there are split turning restrictions that are included in the second digital map as a sequence of routes (e.g. when turning from edge A to Edge B is prohibited, both the elements are "Edge A" as well Update "edge B", since otherwise in the event that an adjacent subset is updated later, the element "edge B" would not be added, but the turning ban, since this is included in the already updated subset), and / or for reaching POI-relevant data of a route are as up-to-date as the data of the POI itself (e.g. if a new POI is added as an element of the digital map, a newly created route leading to the POI is automatically selected for the update even if only an update of POI was requested) and / or element dependencies are transferred completely (ie if an element transaction is dependent on a previous element transaction).

An almost nationwide use of the invention is particularly easy to implement if the at least temporarily data-technical connection between user-side devices device and central office is designed as a mobile radio connection, since nowadays mobile radio networks are available almost everywhere. Alternatively or additionally, short-range communication (eg 'bluetooth ¹ ) can also be used. In special cases, for example with a portable navigation unit inserted in a stationary battery charging and synchronization unit ('cradle') or with a telematics center, a landline connection (for example ISDN) can also be provided.

Preferably, the central device automatically requests an update when starting a user application of the digital map and / or periodically by the user device. This ensures an always up-to-date digital map in the user device. As an alternative or in addition, corresponding information is provided to the user-side device by the control center.

It is advantageously proposed that corrections of element inaccuracies in the second digital map (for example a change in the route geometry of an already existing route due to a renewed, more precise measurement) be specially marked, with further data from the control center together with the additional element subset are sent to the user-side device via the at least temporarily data-technical connection and made available to the digital card, which can be used to re-establish a logical connection between elements which have been corrected for inaccuracies and not corrected by an update. Alternatively, if the cleanings of element inaccuracies are not specifically identified, a comparison between new and old properties of an element can be used in the user-side device to determine whether there is a cleanup of inaccuracies, for example by maintaining the topology (ie logical ties to other elements) and only slightly changed geometry to conclude element inaccuracies. If necessary, a logical connection to corresponding non-cleaned elements can then be established in the user device.

The data for updating the subset of elements to be updated preferably also include those elements of the second digital map which are only partially contained in the subset of elements to be updated. This enables a simplified selection of possible additional element subsets through "protruding" elements. In an advantageous development, dependencies between elements of the second digital map are stored on the central side, the additional subset of elements also comprising those elements of the second digital map on which the elements only partially contained in the subset of elements to be updated are dependent and their Data is more current than the data of the elements of the digital map in the user device.

It is particularly advantageous if information about partitions, that is to say a special geographical area decomposition of the digital map in the user-side device, can be stored on the central side and a geographical area to be updated can be identified via a corresponding partition reference. In the case of complex polygonal area boundaries, for example, the entire polygon in the update request of the user-side device therefore does not have to be transmitted to the control center.

A particularly simple update of the digital map is obtained when the user device is registered with the control center and when there is a request to the Head office identified in each case. In this case, an update ('version') that has already been transmitted from the center to the user-side device can be stored by the center, for example for a respective geographical area.

A simple determination of the additional element subset is made possible that the user-end device upon a request ^'to the central unit a version information of an element subset of the digital map sends, for example, in a peripheral region to be updated element subset.

It is particularly advantageous if an upper limit value is provided for the size of the or each additional subset of elements. This limits the amount of data to be transmitted from the control center to the user-side device, which is usually subject to a charge, and instead accepts an inconsistency in the digital map in the user-side device. As an alternative or in addition, an upper limit value can also be provided for a subset of elements to be transferred overall per update.

It is advantageously proposed to send logically related updates of elements of the digital map together, for example also in the event that an update of an individual element could be made without inconsistency in the digital map. For example, if you move a motorway exit by 500 m, deleting the old exit will preserve the consistency of the digital map as well as inserting the new exit. However, if these two updates of individual items are not sent together, the update of Elements of only one sub-area of the motorway are either only deleted the old exit, so that no exit is provided in the digital map at all, or only the new exit is inserted, and thus an exit appears twice on the digital map.

In the event that the digital map in the user-side device has only a partial area of the second digital map arranged in the central office, an inconsistency of the digital map is permissible at those points at which there is a boundary between a partial area and that of the digital map is included in the device on the user side, and a non-encompassed portion extends. In particular when a new geographical area is entered, it is ensured that the complete, additionally recorded geographic area - which updates the second digital map on the central side - does not have to be made available as an update of the digital map.

Various embodiments of the invention are explained in more detail with reference to a drawing, starting from the prior art together with the problems that arise. 1 schematically shows an example of the use of versions and partitions of the central second digital map, FIG. 2 shows schematically an example of use of partitions of the digital map in the user-side device together with partitions of the second digital map on the central side, FIG. 3 shows schematically one further exemplary use of partitions of the digital map in the user-side device together with partitions of the central-side second digital map, Fig. 4 schematically ensuring consistency by avoiding dead ends,

Fig. 5 schematically ensures the consistency when element inaccuracies are corrected,

Fig. 6 an example of a first, permitted inconsistency,

Fig. 7 an example of a second, permitted inconsistency,

Fig. 8 an example of a third, permitted inconsistency,

Fig. 9 exemplary dependencies on update transactions.

The exemplary use of partitions and versions of a digital map is illustrated schematically with reference to FIG. 1. Partitions - as a special geographical area breakdown of the digital map - and versions - that is, data statuses of elements of the digital map at a specific time - form the basis of the update according to the invention. Modern digital maps are broken down into geographical areas in various ways. The card manufacturers usually deliver their digital cards in pieces that are related to administrative subdivisions (e.g. national borders). The digital map in the user end device is often disassembled in a manner (e.g. as 'tiles' according to the memory size) that allows simple processing of the elements included in the digital map, even from computing systems with limited computing power and limited processing means, such as from a vehicle navigation device ,

To perform the update, the digital map is broken down into partitions as special geographic areas. An update transaction is an update of a set of elements of exactly one partition of the digital card. Each partition has a version as a number of update transactions for that partition. A 'later' version contains at least all update transactions of 'earlier' versions and possibly one Update other items. Complete partitions are always updated, and only individual elements of a partition are not updated today due to the administrative effort involved in managing individual elements of a digital map. To update a partition, all update transactions that have a later version than the version of the digital card in the user-side terminal are provided to the digital card using the central-side, second digital card up to the latest version available in the central. In order to update any subset of elements of the digital map in the user-side terminal, it is automatically checked which partitions overlap with the subset of elements to be updated. All of these partitions are then updated.

Fig.l shows schematically an exemplary use of partitions Pa, Pb, Pc, Pd, Pe, Pf Pg of the central second digital card with updated elements 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18. The partitions are based on administrative subdivisions such as country and district borders, and form subsets of elements of a digital map that are to be updated. The digital map is designed here as a road map, with route planning for a vehicle navigation device being provided as a useful application. Each time the road map is updated in the vehicle navigation device, new elements are made available, for example when updating partition Pb, elements 17 and 3. Here, “made available” can mean that these elements are new to the road map, or that only existing elements are updated, the elements being made available to the vehicle navigation device using the second road map arranged in the control center, and the second road map being kept up to date at all times. The updated elements 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 refer either to punctiform elements (triangles without connecting line) such as POI ('point of interest', interesting locations such as restaurants), or on route elements (triangles or circles with connecting line). Updated plug elements are either completely within a partition (triangles with connecting line) or are only partially contained in one partition and 'protrude' into an adjacent partition (circles with connecting line). Then, when this element change is split into several parts - each part describing the element change 'in exactly one partition - a uniform numbering of the versions of a partition can be guaranteed. However, the consistency of the road map is not guaranteed after updating individual partitions that do not include all parts of an element change. With the update of such a partition, a reference to further partitions, which comprise a part of the element changes, can be provided, whereby the user-side device can automatically effect a corresponding update of further partitions. However, this usually leads to the updating of a large number of other partitions, in extreme cases the entire road map.

If, for example, partition Pc from FIG. 1 is updated, a reference to further updates in partition Pd would be provided for an element 4 to be updated and a reference to further updates in partition Pe for an element 12 to be updated. When Part Pe was subsequently updated, a reference to updates in Part Pf would be provided. Instead of actually updating partition Pc, partitions Pc, Pd, Pe and Pf would be updated to maintain the consistency of the road map. The road map in the user-side device is usually broken down in a way that enables efficient computing access and processing of the elements. For this purpose, a division into 'rectangular' partitions, for example as 'tiles' corresponding to the memory size, is usually used, as part of the user application (PSF, 'physical storage format'). Such an exemplary use of partitions of the road map in the user-side device in the element subset from FIG. 1 is shown schematically in FIG. 2.

In any case, the PSF-oriented partitioning of the road map in the user-side device will differ from the administration-oriented partitioning of the second road map in the central office. It is more efficient to update the road map in the user device for the PSF-oriented partitions and not for the administration-oriented partitions. It must therefore be possible to update subsets of the road map in the user-side device that do not correspond to an administration-oriented partition.

If, for example, an update of a PSF-oriented partition, as a subset of the road map in the user-side device, is requested by the control center, this can be partially or completely covered by several of the administration-oriented partitions of the second road map in the control center. 2 schematically shows an exemplary use of PSF-oriented partitions P1, P2, P3, P4, P5, P6, P7, P8 of the road map in the user-side device together with administration-oriented partitions Pa, Pb, Pc, Pd, Pe, Pf, Pg of the central second road map for the element subsets from Fig.l. Partition framed by dashed lines partially covers partitions Pb, Pc and Pg. While each of these (central-side) partitions Pb, Pc and Pg in the second road map can have a different version, a uniform version number is provided by the partition P5 of the road map to be updated (in the user-side device). Again, there arises the problem already explained here that the updating of an element can affect several partitions - see the dashed line in FIG. 2 - and thus inconsistencies in the updated road map can occur in the user device. Here too, in accordance with the explanation already made, it is possible for the user-side device to 'reload' further partitions of the second road map. However, in this case the PSF-oriented partitioning of the road map in the user-side device is not known in the control center. The required PSF-oriented partitions are thus to be determined by the user-side device by checking the or each element change provided by the control center to determine whether a part of the element change relates to an “adjacent” (ie further) partition. In the case shown in FIG. 2, such a determination would result (for example using the geo coordinates of the element shown in broken lines) that the central office would also have to request an update of the partition P4. However, such an additional requirement is not necessary if a change in the element, which also affects an adjacent partition, does not lead to an inconsistency in the road map in the device on the user side. An example of such an element change is the change in the number of tracks of a track “protruding” into an adjacent partition from one to two tracks.

Similar to the administration-oriented partitioning, the problem arises here that further dependencies can be found when updating neighboring partitions. Because of the element change 9, which runs across the boundary of partition P4 and partition Pl, partition P1 should also be added after the update of P4. be asked. The smaller the partitions, the lower the likelihood of further dependency. With flexible PSF-oriented partitioning, which enables the partitioning of a partition into smaller units, the size of neighboring partitions to be updated can be reduced. FIG. 3 shows a division of the partition P4 from FIG. 2 into the partitions P4-1, P4-2, P4-3 and P4-4. Since the dashed element change 10 only affects the partition P4-2, an update of this partition P4-2 is sufficient to restore the consistency of the road map. Element change 9 is therefore not transmitted, as a result of which the transmitted data volume is significantly reduced, namely on the one hand by the (unsolicited) element change 9 itself and on the other hand by updates to the partition P1 which is 'dependent on element change 9'.

Fig. 4 shows schematically how to ensure consistency by avoiding dead ends. A is a subset of elements, in the form of edges and nodes, which have been added to the (central) second digital map. A user-side device requests an update of an element subset of the digital map in accordance with the dashed area. Now only those elements of the second digital map of the digital map of the user-side device would be made available, at least in part. included in the subset of elements to be updated would result in the dead ends shown under B. Therefore, to restore the consistency of the digital map, a single element, as visualized under C, is automatically selected as part of an additional subset of elements and also made available to the digital map of the user device. This single element ensures that there are no routes in the digital map updated in a subset, at the ends of which users inevitably turn around. if these routes are not covered by the second digital map.

Fig. 5 shows schematically how to ensure consistency when correcting element inaccuracies. Shown under A is a subset of elements, in the form of edges and nodes, which was corrected for inaccuracies in the (central) second digital map by a new measurement. A user-side device requests an update of an element subset of the digital map in accordance with the dashed area. Would those elements of the second digital map of the digital map of the user device be made available which have a more current version than the version of the digital map - namely those corrected for inaccuracies, under B within the dashed, i.e. arranged to be updated area - this would result in the dead end shown under B. Therefore, to restore the consistency of the digital map, a single element, as visualized under C, is automatically selected as part of an additional subset of elements and also made available to the digital map of the user device. This single element creates a logical connection between elements of the updated and the non-updated subset of the digital map.

6, 7, 8 each show examples of different permitted inconsistencies. If the digital map in the user-side device has only a partial area of the second digital map arranged in the control center, an inconsistency of the digital map is permissible at those points at which there is a boundary between a partial area comprised by the digital map in the user-side device is, and runs a non-included sub-area. FIG. 6 shows the edge sequence A, B which has been added to the second digital map and is shown in bold in FIG. 6 and which extends across a national border. Here, an inconsistency is allowed in the digital map in the user device, since the portion of the second digital map that lies outside the national border is not covered by the digital map in the user device.

An inconsistency allowed for a sub-area of road classes is visualized in FIG. 7. In the old version of the digital map and the second digital map, which is used by the user-side device or at the central site, only the overland road network is recorded in the area shown. Local roads are now included in the new version of the area. The user-side device now requests the updating of a sub-area shown in bold in FIG. 7 as a subset of the second digital map. Here, an inconsistency at the edge of the sub-area to be updated is permitted in the digital map in the user-side device, since the sub-area of road classes of the second digital map, which lies outside the sub-amount to be updated, is not covered by the digital map in the user-side device.

Another allowed inconsistency is shown in FIG. 8. A sub-area of street classes is again considered. In the old version of the digital map and the second digital map, which is used by the user-side device or centrally, only the interurban road network is recorded in the area shown. In the new version of the area, local roads are now also recorded and a new road in the interurban road network has also been added. added. The user-side device now requests the update of the interurban road network in the entire area as a subset of the second digital map. Here, an inconsistency in connections to local roads is ignored in the digital map in the user-side device, since those in the digital map in the user-side device are only stored in the form of stubbles.

9 shows dependencies on update transactions as an example. The second digital card in the head office, version V2.0, is first brought to a newer version V2.1 by update transactions Tι, ι and Tι _r2 . Version V2.1 is then brought to version V2.2 by an update transaction T ₂ , ι. The elements with a gray background are transferred to the elements with a black background. A dashed area is shown in the lower part of FIG. 9, corresponding to a subset of elements requested and to be updated by a user-side device. The digital map of the user device has version V2.1 in the dashed area. So that the digital map of the user-side device has consistency after the update of the subset of elements to be updated, the update transaction T ₂ , ι, but not the update transaction Tι, _{2 is} to be transmitted as an additional subset of elements for updating the digital map , The update transaction ι, ι is only to be transmitted in the case of updating the digital map if the version of the digital map of the user-side device outside the subset of elements to be updated is older than version V2.1.

In addition, for the or each user device, the version of the or each partition can be stored centrally are saved, and updates of individual partitions can also be saved. In the example of FIG. 9, the control center would know whether an update of the area outside the dashed area to version V2.1 would have been made available earlier to the digital map of the requesting device. In this way, it can be decided in the central office whether the update transaction T _{1 / X} for updating the digital map is also to be transmitted for the new request. It is therefore fundamentally avoidable to resend update transactions that have already been transmitted to the terminal device, as a result of which the data volume to be transmitted is reduced.

In the event that the user-side device checks in a second step whether additional element subsets of the digital map are affected by the update and, depending on the result of the check, the central station automatically requests an update of these additional subsets such that the digital map after receiving and making the data available for the additional element subsets has consistency with regard to the or each user application running on the user-side terminal, two embodiments are to be briefly outlined. It is intended in each case to include only those element changes in the additional element subset that are also part of the element subset to be updated, but not to include element changes on which a selected element change depends and which are completely outside the subset of elements to be updated are located - which means that no dependencies between element changes of the second digital road map have to be stored in the control center - and then the user-side terminal device checks which neighboring areas of the digital road map are affected by the element changes and a further update is requested from the head office for these areas.

In a first embodiment, the check in the user-side terminal whether additional element subsets of the digital map are affected by the update is only started after a calculation of the effects resulting from the data made available for updating the subset of elements to be updated, wherein Depending on the result of the check, an update of these additional element subsets is automatically requested by the head office. This calculation is carried out in such a way that the parts of the update of elements which 'protrude' beyond the element subset to be updated are 'cut off'.

In a second embodiment, no calculation of the effects resulting from the data made available for updating the subset of elements to be updated is started in the user terminal. Rather, the control panel automatically requests the additional element subsets of the digital map that are affected by the update. The calculation of the effects resulting from the data made available for updating the subset of elements to be updated is then started using all the data made available.

Claims

claims

Method for updating a digital map, comprising elements of a traffic route network, in a user-side device on which at least one user application of the digital map is running, using a second digital map arranged in a control center, characterized in that on the user-side device an element to be updated is Subset of the digital map can be selected and an update of this subset of elements can be requested from the control center via an at least temporary data connection, with the control panel receiving an additional subset of elements in the second after receiving such a request in addition to the subset of elements to be updated digital map is automatically selected such that the digital map has consistency after the update, and wherein data for updating the subset of elements to be updated and data of the additional subset of elements from the center ale are sent to the user-side device via the data connection at least at times and made available to the digital map.

2. A method for updating a digital map, comprising elements of a traffic route network, in a user-side device on which at least one user application of the digital map is running, using a second digital map arranged in a control center, characterized in that on the user-side device one to be updated Element subset of the digital map can be selected and an update of this subset of elements can be requested from the control center via an at least temporary data connection, in a first step the control center receiving data to update the element to be updated after receiving such a request. Subset to the user-side device via the at least temporarily data connection and made available to the digital map, whereupon in a second step the user-side device checks whether additional element - subsets of the digital map are affected by the update and, depending on the result of the check, an update of your additional subsets of elements is automatically requested by the control center in such a way that the digital map after receipt and making the data of the subsets of additional items available has consistency in itself.

3. The method according to claim 1 or 2, characterized in that the subset of elements to be updated a geographical area and / or at least one route as a result of edges and / or at least one class of routes and / or one or more point of interest (POI ) and / or classes of POIs.

4. The method according to claim 3, characterized in that the consistency with regard to the or each user application running on the user-side device is ensured by automatic selection of the additional element subset in such a way that after the data are made available for updating the additional element subset in the digital map of the user-side device does not exist a route, at the end of which traffic route network users must inevitably reverse, if this route is not also covered by the second digital map, and / or there are no two routes, at the end of which traffic route network users must inevitably turn back , if these two routes in the second digital map are connected by a few edges and / or there are no routes on which there are split turning restrictions, which are included in the second digital map as a series of routes, and / or for reaching e The POI-relevant data of a route are as up-to-date as the data of the POI itself and / or element dependencies are completely transmitted.

5. The method as claimed in one of claims 1 to 4, such that the at least temporarily data-technical connection between the user-side device and the control center is designed as a mobile radio connection.

6. The method according to any one of claims 1 to 5, characterized in that the user device from the center automatically updates at the start of a user application of the digital map and / or periodically requested.

7. The method according to any one of claims 1 to 6, characterized in that cleanup of element inaccuracies in the second digital map are specifically marked, wherein together with the additional subset of elements further data from the control center to the user-side device on the at least temporarily data technology Connection sent and made available to the digital map, which can be used to restore a logical connection between elements corrected by an update for inaccuracies and not cleaned.

8. The method according to any one of claims 1 to 7, so that the data for updating the subset of elements to be updated also include those elements of the second digital map that are only partially contained in the subset of elements to be updated.

9. The method according to any one of claims 3 to 8, d a d u r c h g e k e n n z e i c h n e t that information on partitions, which represent a geographical area decomposition of the digital map in the user-side device, can be stored centrally and a geographic area to be updated can be identified via a corresponding partition reference.

10. The method according to any one of claims 1 to 9, characterized in that the user-side device is registered at the central site and identifies itself to the central office when requested.

11. The method according to any one of claims 1 to 10, so that the user-side device sends a version information of a subset of elements of the digital card to be updated upon request to the control center.

12. The method according to any one of claims 1 to 11, that an upper limit is provided for the size of the or each additional subset of elements.

13. The method according to any one of claims 1 to 12, d a d u r c h g e k e n n z e i c h n e t that logically related updates of elements are sent together.

14. The method according to any one of claims 1 to 13, characterized in that if the digital card in the user device only has a portion of the second digital card arranged in the center, an inconsistency of the digital card is permitted at those points in which the user-side device runs a boundary between a partial area, which is included in the digital map, and a non-included partial area.

15. Device for carrying out the method according to one of claims 1 to 14 with a user-side device comprising storage means for a digital card and a control center comprising central storage means for a second digital card, the user-side device and control center each having a computing means and a communication means for establishing an at least temporary data connection.