DE102019114538A1 - Update a geographic map efficiently - Google Patents

Abstract

A geographical map is divided into several first tiles, each first tile being assigned a version. The map is also divided into a plurality of second tiles, with a second tile comprising a plurality of first tiles. The second tile includes an indication of a most recent version of the first tile for each first tile included. A method for updating a geographic map comprises steps of determining a first tile to be updated; determining a second tile that includes the first tile; and updating the first tile if the version of the first tile does not match the indication of the second tile of the most recent version of the first tile.

Description

The invention relates to updating a geographic map. In particular, the invention relates to updating a plurality of tiles comprised by a map.

A geographical map can be present on board a motor vehicle and can be used, for example, for navigation, searching for a parking space or for autonomous control of the motor vehicle. The map can, for example, be organized according to the specifications of the NDS (Navigation Data Standard) and, in particular, be subdivided into a number of tiles, each of which includes information about an assigned geographic section of the map. A version is usually assigned to each tile.

On board the motor vehicle, only tiles in a predetermined geographic region (“region of interest”) are usually considered. The number of tiles encompassed by the geographic area depends on the size of the geographic area and the size of the tiles or the geographic area encompassed by a tile and is typically in a range from several hundred to thousands.

To update the tiles in the region, you can check for each tile whether a more recent version is available. If this is the case, the tile must be updated, otherwise the existing tile can be used. The availability of the latest version of a tile can be requested from an external point. With such an approach, however, there can be a large number of requests to the external body, so that a large communication bandwidth is used and the external body has to process a large number of requests.

One object of the invention is to provide a technique which enables tiles of a geographic map to be updated in an improved manner. The invention solves the problem by means of the subjects of the independent claims. Sub-claims reproduce preferred embodiments.

A geographical map is divided into several first tiles, each first tile being assigned a version. The map is also divided into a plurality of second tiles, with a second tile comprising a plurality of first tiles. The second tile includes an indication of a most recent version of the first tile for each first tile included.

According to a first aspect of the invention, a method for updating a geographic map comprises steps of determining a first tile to be updated; determining a second tile that includes the first tile; and updating the first tile if the version of the first tile does not match the indication of the second tile of the most recent version of the first tile.

On the basis of the information contained in the second tile, the latest versions of all the first tiles contained are available and do not have to be obtained any further. Based on the latest versions, it can be efficiently decided locally which first tile is to be updated and which not.

Updating a tile can include downloading the tile from an external location. The external point can be set up to provide tiles for a large number of inquirers and, for example, be implemented as a server or service, in particular in a cloud.

The particular second tile can be updated if its version does not correspond to an available latest version. In this case, the version of the second tile usually only has to be compared once with a most recent version for the update of all the first tiles it comprises. The version can be implemented as a change date, for example.

A second tile can be downloaded depending on an available version by means of a conditional request. The request can be expressed as a “conditional request”. At an HTTP interface, the request can include, for example, an “If-Not-Match” or “If-Modified-Since” field as a condition. A second tile can also be downloaded automatically by similar means if it is available in an updated version. Alternatively, an automatic notification can be obtained automatically via an updated tile. The automatic supply of information in this way is also known as a PUSH message.

A tile can be downloaded using a secure connection. A falsification or re-importing of a request or an answer or a man-in-the-middle attack can be made more difficult. The consistency of the geographical information can be improved.

The method can also be carried out in cascade. The map is divided into several third tiles, a third tile comprising several second tiles; a version is assigned to every second tile. The third tile includes an indication of a most recent version of the second tile for each second tile included; and the second tile is updated if the version of the second tile does not correspond to the indication of the third tile of the latest version of the second tile.

For example, versions of a plurality of second tiles can be monitored using third tiles, just as the versions of the first tiles are monitored using the second tiles. Tiles of one type can form a level. Tiles can also be provided in more than three levels, with several tiles of one level being able to be secured by means of a tile of a higher level.

In another variant, one of several levels can be used to check the versions of the first tiles. The levels differ in terms of their sizes or the number of first tiles that are included.

The map can be divided into a plurality of third tiles, wherein a third tile comprises a plurality of second tiles and a second tile comprises a plurality of first tiles; wherein the second tile for each included first tile includes an indication of a most recent version of the first tile; wherein the third tile for each included first tile includes an indication of a most recent version of the first tile; wherein the first tile is updated if the version of the first tile does not correspond to the indication of the second or third tile of the latest version of the first tile.

The topicality of the first tiles can thus be checked either using the information from the second tiles or using the information from the third tiles. A choice as to whether the hints of the second or the third tile should be used can be made depending on the size of the region. The second tile can comprise, for example, N first tiles, and the third tile M first tiles (M> N). If the region comprises more than N tiles, the information from the third tile can be evaluated.

In other words, the versions of a plurality of first tiles can alternatively be checked by means of second or third tiles. A third tile can be used when a large number of second tiles would otherwise have to be checked in order to check a given set of first tiles. To decide whether to use a third or a second tile, the number of second tiles to be checked can be compared with a predetermined threshold value. If the number is above the threshold value, a third tile can be used, otherwise a second tile.

In one embodiment, a third tile comprises N second tiles and a second tile comprises N first tiles. N is predetermined and can in particular be two. Such an architecture can be supported, for example, by a map based on the Navigation Data Standard NDS. A first tile can relate to NDS level 13, for example, while a second tile can relate to NDS level 11, for example.

In a further embodiment, a contiguous geographic region is predetermined which comprises a number of first tiles to be updated. The number of first tiles comprised by a second tile is preferably selected in such a way that the geographical region does not lie on more than four second tiles. In this way, the number of tiles with version information to be kept up-to-date can remain small, so that only little bandwidth can be required for their updates. A corresponding procedure can be followed for third instead of second tiles. In one variant, the versions of the first tiles can be secured by means of a second tile, as long as no more than four second tiles are required to secure the first tiles in the region. If more than four tiles are required, a third tile can be used instead of the second tile.

The map to be updated may be on board a vehicle, with the region being determined to include a position of the vehicle. A size and / or shape of the region can be determined depending on a task to be solved. For example, an elongated region can be selected for route guidance to a predetermined geographical target position and a round region for the search for a parking space.

According to a second aspect of the invention, a device for updating a geographical map described herein comprises an interface for receiving an indication of a first tile to be updated; a communication device for connection to an external service that provides current tiles; and a processing device. The processing device is set up to determine a second tile, which includes the first tile; and to update the first tile if the version of the first tile does not match the indication of the second tile to the most current version of the first tile.

The processing device can be set up to carry out a method described herein in whole or in part. For this purpose, the processing device can have a programmable Include microcomputers or microcontrollers and the method can be in the form of a computer program product with program code means. The computer program product can also be stored on a computer-readable data carrier. Features or advantages of the method can be transferred to the device or vice versa.

According to a further aspect of the invention, a vehicle, in particular a motor vehicle, comprises a device described herein.

• 1 ein System;
• 2 ein Ablaufdiagramm eines Verfahrens; und
• 3 erste, zweite und dritte Kacheln einer beispielhaften Karte illustriert.

The invention will now be described in more detail with reference to the accompanying drawings, in which:

• 1 a system;
• 2 a flow chart of a method; and
• 3 first, second and third tiles of an exemplary map illustrated.

1 shows a system 100 that is a device 105 exemplified on board a vehicle 110 , in particular a motor vehicle 105 is shown, and an external body 115 includes. Between the device 105 and the external body 115 there is a communication link 120 that can be partially or completely wireless. In particular, the communication link 120 use a cellular network or a WLAN network. Usually the external body is 115 designed as a server or service, in particular in a cloud.

The external body 115 represents a geographical map 125 ready that in a number of first tiles 130 is divided. The first tiles 130 preferably adjoin one another and fill a predetermined geographical area defined by the map 125 is included, more preferably completely. The first tiles 130 are preferably the same size and more preferably have the same shape. The shape can be rectangular and in particular square. The present example is a matrix-like arrangement of rectangular first tiles 130 on the map 125 went out. A first tile 130 can comprise various information relating to the assigned geographical area as useful data. For example, information about streets, paths, political boundaries, buildings, sights, traffic information or route bans can be found in a first tile 130 be saved. It is also preferred that a first tile 130 includes a version.

The map 125 is more preferred in second tiles 132 divided, which are preferably organized as above with reference to the first tiles 130 is described. A second tile 132 covers several first tiles 130 and preferably contains useful data for each first tile included 130 an indication of the latest available version of the first tile 130 . Furthermore, the second tile 132 wear a version.

The card is optional 125 in the same way in third tiles 134 divided, with a third tile 134 several second tiles 132 and thus several first tiles 130 includes. User data of the third tile 134 In a first variant, they include references to the latest available versions of the second tiles included 132 . In a second variant, the useful data include references to the latest available versions of the first tiles included 130 .

It is further preferred that a number N is predetermined, so that a second tile 132 N first tiles 130 includes. A third tile can also be added 134 N second tiles 132 include. Thus, a third tile can 134 N * N first tiles 130 include. The described procedure can be extended to any number of additional (e.g. fourth, fifth, ...) tiles, each of which can include a predetermined number - in particular N - tiles of a next lower level. Preferably N = 2. The card 125 can in particular be structured like the NDS.

The external body 115 typically includes a storage device 135 , a processing facility 140 and a communication device 145 . There are tiles 130 , 132 , 134 the map 125 in the storage device 135 filed. The communication facility 145 is to use the communication link 120 furnished.

The device 105 preferably comprises a storage device 150 , a processing facility 155 and a communication device 165 . The communication facility 165 is to use the communication link 120 furnished. The storage device 150 is for storing tiles 130 , 132 , 134 the map 125 furnished. Usually, at least for a predetermined geographic region 160 the map 125 current first tiles 130 on the part of the device 105 exist.

The device 105 preferably comprises a positioning device 170 and / or an interface 175 . By means of the positioning device 170 can the device 105 determine your own geographical position, for example with the help of a satellite-based navigation system, an inertial platform or a podometer. The region 160 can be determined on the basis of the determined position, for example in a predetermined radius around the determined position. Via the interface 175 can be a reference to the region 160 be accepted. Should, for example, route guidance of the motor vehicle 105 can be carried out from one's own position to a target position at the interface 175 an indication of the target position and the region 160 can be determined in such a way that it includes a predetermined geographical area in which the current position and the target position are located.

Geographical information in the first tiles 130 are shown can occasionally change, so that the first tiles 130 in the external body 115 can change occasionally. Adjacent first tiles 130 are usually changed in a synchronized manner in such a way that they are consistent, i.e. the information they comprise matches one another.

To on the part of the device 105 at least in the region 160 current tiles 130 it is proposed to provide a second tile 132 for each included first tile 130 to store a reference to the latest version. Using a second tile 132 a decision can then be made for a number of included first tiles as to whether or not the current versions are current. First tiles determined as not current 130 can then be specifically updated.

2 shows a flow chart of a method 200 to update tiles 130 on the device 105 . The procedure 200 can in particular in connection with a system 100 are executed.

In one step 205 can be the geographic region 160 be determined in the first tile 130 which should be available in a current version. For example, a position of the motor vehicle can be used for this 110 be determined and the region 160 can be determined with a predetermined shape and / or size such that it includes the position. The region 160 but can also be determined in other ways.

In one step 210 can be one of the first tiles 130 of the region 160 to be chosen. The first tile 130 may be entirely or partially dependent on the region 160 be included. Is the region 160 for example circular, so can all first tiles 130 of the region 160 assigned to at least part of the region 160 include.

In one step 215 can add a second tile 132 can be determined from a previously determined first tile 130 is included. This step is usually used for a variety of first tiles 130 carried out, so that a total of all second tiles 132 can be determined, the at least one first tile 130 include those in the region 160 lies. As will be explained in more detail below, the number of second tiles is 132 for the first tiles 130 of the region 160 preferably between one and four.

In one step 220 can use the specific second tiles 132 updated. The second tiles 132 can be downloaded from the external location without further inquiry. Alternatively, a conditional download takes place, namely under the condition that a requested second tile 132 on the part of the external body 115 in a more up-to-date (usually higher) version there is therefore a local copy of the second tile 132 . The version can also be in the form of a creation time, so that the second tile 132 can be downloaded if a corresponding second tile 132 is available at a later date. The conditional download can, for example, be carried out using an HTTP interface from the external location 115 and a conditional GET request. The requirement of the device 105 at the external location 115 can include as a condition an “If-Not-Match” specifying a version, or an “If-Modified-Since” field specifying a determination time.

The external body 115 can be configured to use a newly available second tile 132 automatically to the device 105 to send. Updating the second tile 132 can also be omitted in a further embodiment if, for example, a previous update was less than a predetermined time ago.

The present second tiles 132 now include references to the most current versions of all of the region 160 covered first tiles 130 . The versions of the existing first tiles 130 can in one step 225 be compared with the corresponding notes on the latest versions. Corresponds to a version of a first tile 130 its assigned note, it is up-to-date and does not have to be downloaded again. Corresponds to the version of a first tile 130 otherwise not its assigned note, it is no longer up-to-date and can be processed in one step 230 updated. Checking and, if necessary, downloading can be done for each first tile 130 of the region 160 be performed.

The procedure 200 can support different sequences of said steps in different embodiments. However, it is preferred that the most recent versions of the first tiles be used for the determination 130 required second tiles 132 updated a maximum of once before checking existing first tiles 130 continues to be up to date.

3 shows an exemplary map 125 that are in first tiles 130 (thin boundary lines), second tiles 132 (middle boundary lines) and third tiles 134 (wide boundary lines) is divided. A hierarchical subdivision is provided in which 16 first tiles 130 to a second tile 132 are grouped together, and four second tiles 132 to a third tile 134 . A third tile 134 in this example includes 16 * 4 = 64 first tiles 130 . In an NDS card, for example, the first tiles could 130 on one layer 13 , the second tiles 132 on one layer 11 and the third tiles 134 on one layer 12 be settled. It should be noted that the first tiles are preferred 130 Include geographical information that is necessary for controlling the motor vehicle 110 Can be used while second or third tiles 132 , 134 preferably only carry version information.

A geographic region 160 is an example of a position 305 the device 105 certainly. Here are all those first tiles 130 of the region 160 comprises, at least in sections in a circle with a predetermined around the predetermined position 305 lie. In other words, here are all those first tiles 130 which cover a geographical area in which at least one geographical point falls, its distance from the position 305 is smaller than the predetermined radius. Other methods of determining a region 160 , or the first tiles it encompasses 130 , are also possible.

To make sure that the region 160 no more than four second tiles 132 extends, the region may 160 in the horizontal and vertical directions each have only an extent of (X + 1) * R, where R is an edge length of a first tile 130 in the corresponding direction and X a number of first tiles 130 is going in the same direction in a second tile 132 lie. In the present case, both a horizontal and a vertical alignment of the region are allowed 160 each be a maximum of 5 * R.

List of reference symbols

100

system

105

contraption

110

Motor vehicle

115

external body

120

Communication link

125

map

130

first tile

132

second tile

134

third tile

135

Storage device

140

Processing facility

145

Communication facility

150

Storage device

155

Processing facility

160

region

165

Communication facility

170

Positioning device

175

interface

200

Procedure

205

Determine geographic region with first tiles

210

Select first tile

215

Determine second tile

220

update second tile

225

Is the version of the selected first tile up to date?

230

update first tile

305

position

Claims (11)

A method (200) for updating a geographic map (125), wherein - The map (125) is subdivided into a plurality of first tiles (130), and a version is assigned to each first tile (130); - the map (125) is divided into a plurality of second tiles (132), a second tile (132) comprising a plurality of first tiles (130), - wherein the second tile (132) for each included first tile (130) comprises an indication of a most recent version of the first tile (130); wherein the method (200) comprises the following steps: - determining (210) a first tile (130) to be updated; - determining (215) a second tile (132), of which the first tile (130) is included; - Updating (230) the first tile (130) if the version of the first tile (130) does not correspond to the reference of the second tile (132) to the latest version of the first tile (130). Method (200) according to Claim 1 wherein updating (230) a tile (130, 132, 134) comprises downloading the tile (130, 132, 134) from an external location (115). Method (200) according to Claim 2 wherein the determined second tile (132) is updated if (225) its version does not correspond to an available latest version. Method (200) according to one of the preceding claims, wherein a tile (130) is downloaded by means of a secure connection (120). The method (200) according to any one of the preceding claims, wherein - the map (125) is divided into a plurality of third tiles (134), a third tile (134) comprising a plurality of second tiles (132); - A version being assigned to every second tile (132); - wherein the third tile (134) for each included second tile (132) comprises an indication of a most recent version of the second tile (132); - wherein the second tile (132) is updated if the version of the second tile (132) does not correspond to the reference of the third tile (134) to the latest version of the second tile (132). Method (200) according to one of the Claims 1 to 4th wherein - the map (125) is divided into a plurality of third tiles (134), wherein a third tile (134) comprises a plurality of second tiles (132) and a second tile (132) comprises a plurality of first tiles (130); - wherein the second tile (132) for each included first tile (130) comprises an indication of a most recent version of the first tile (130); - wherein the third tile (134) for each comprised first tile (130) comprises an indication of a most current version of the first tile (130); - wherein the first tile (130) is updated if the version of the first tile (130) does not correspond to the reference of the second (132) or third tile (134) to the latest version of the first tile (130). Method (200) according to Claim 5 or 6th wherein a third tile (134) comprises N second tiles (132) and a second tile (132) comprises N first tiles (130) and N = 2. Method (200) according to one of the preceding claims, wherein a contiguous geographic region (160) is predetermined which comprises a number of first tiles (130) to be updated; and the number of first tiles (130) comprised by a second tile (132) is selected such that the geographic region (160) is located on no more than four second tiles (132). Method (200) according to Claim 8 wherein the map (125) to be updated is on board a vehicle (110) and the region (160) is determined to include a position of the vehicle (110). Device (105) for updating a geographic map (125), wherein - The map (125) is subdivided into a plurality of first tiles (130), and a version is assigned to each first tile (130); - the map (125) is divided into a plurality of second tiles (132), a second tile (132) comprising a plurality of first tiles (130), - wherein the second tile (132) for each included first tile (130) comprises an indication of a most recent version of the first tile (130); wherein the apparatus (105) comprises: - An interface (175) for receiving an indication of a first tile (130) to be updated; - A communication device (165) for connection (120) to an external service (115) which provides current tiles (130, 132, 134); - a processing device (155) which is set up to ◯ determine a second tile (132) that includes the first tile (130); and ◯ update the first tile (130) if the version of the first tile (130) does not correspond to the reference of the second tile (132) to the latest version of the first tile (130). Motor vehicle (110), comprising a device (105) according to Claim 10 .

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