DE102011077945A1 - Method for updating digital card used by navigation system of vehicle, involves updating generalization plane of digital card if object is represented by nodes by updating attribute of nodes based on information and reference elements - Google Patents

Abstract

The method involves updating a generalization plane of a digital card by updating an attribute e.g. velocity profile, of a node (103), which represents a real object in the plane based on information assigned to the object. A check is made whether the object is represented by an edge in the generalization plane of the digital card. Another generalization plane of the digital card is updated if the object is represented by other nodes (101, 105) by updating an attribute of the nodes based on the information and reference elements (111, 113). The information represents driving time. Independent claims are also included for the following: (1) a navigation device (2) a computer program product comprising a program code for executing a method for updating a digital card.

Description

State of the art

The present invention relates to a method and a device for updating a digital map structured in several generalization levels that can be used, for example, by an information system of a vehicle.

Navigation systems use map information for route calculation. In order to be able to calculate a route as accurately as possible, a continuous updating of the map information is required.

The EP 1 092 127 B1 relates to a method for influencing source data of a digital database for determining a route of a vehicle. The database includes predetermined distances with correspondingly assigned nodes.

Disclosure of the invention

Against this background, the present invention provides a method for updating a digital map structured in several generalization levels, furthermore a device which uses this method and finally a corresponding computer program product according to the independent patent claims. Advantageous embodiments emerge from the respective subclaims and the following description.

Navigation systems use a static map and up-to-date traffic information to calculate the expected travel time for the route search. According to the invention, information about travel times is used, which are determined, for example, by a navigation system on a road segment. Such a "learned" travel time can be used for a more accurate prediction of travel times. Thus, according to the invention, navigation systems are able to dynamically change route attributes.

For various functions in the navigation device, it is state of the art to store the map data at different generalization levels in different detailing. Generalization is one way to simplify the calculation of the "optimal" route under given conditions. The most detailed level contains all known streets. In levels with higher generalization levels, depending on the importance criterion, certain roads and intersections are no longer available and several smaller road segments are grouped together to form larger ones. For example, the residential streets can be omitted or only highways are preserved. The different levels are linked by connections that exist in the affected levels. Normally such connections are realized at intersections. The consistency of the data between the different levels, ie corresponding values, and the integrity of the connections is very important for most applications. Therefore, when changing data on one level, it may be necessary to adjust data at other levels and the links between levels.

According to the invention, in a "learning" navigation system, the knowledge collected can be checked for relevance for the various levels of generalization and, if appropriate, generalized such that it is available at the relevant levels. As a result, the collected knowledge can be available on the generalization levels relevant for a navigation system. In order to make this possible, the knowledge acquired after completing the learning process is checked for relevance to different generalization levels.

Thus, learned knowledge is available on all navigation levels important for generalization and can performant in the navigation functionality, such. As a route calculation has been involved.

The present invention provides a method for updating a digital map in which objects in different generalization levels are stored, comprising the following steps:
Updating a first level of the digital map by updating an attribute of a first element representing an object in the first level based on information associated with the object;
Checking that the object is represented by another element in a further generalization plane of the digital map, the further element being dependent on at least one reference element of the first level or the further generalization level; and
Updating the further generalization level of the digital map when the object is presented by the further element by updating an attribute of the further element based on the information and the at least one reference element.

The method may, for example, be carried out by an information system or navigation system of a vehicle or in general by a device for updating map data. The digital map can be in the form of a data record. The card can have information about one encompassing a real road network or road network within an area imaged by the digital map. The object may represent a section or a segment, for example of such a network. In particular, the object may represent an intersection or connection of at least two roads or a section of a road. An intersection or connection may be represented as a node in the map. A section can be represented as an edge. An edge may be located between two nodes or connected only to a node. Each element of the map can be assigned an attribute. The attribute may, for example, represent a vehicle speed, travel time, waiting time or route length assigned to the element or an assigned road type. The information contained in the map, that is, the elements associated with the associated attributes, can be used to calculate a route between a starting point and a destination point. Also, the information contained in the map can be used for a graphic representation of a road network or the like. When updating an attribute, a value or size of the attribute can be changed. In the first level, the area imaged by the map can be imaged in a finer resolution than in the further generalization plane. Thus, an element encompassed by the first level may not be encompassed by the further level of generalization. Also, a plurality of elements included in the first level may be included in the further generalization level as a common element. Such a common element can then be dependent on several reference elements. Being covered by a generalization level can therefore mean that the corresponding element is displayed in the generalization level or is taken into account in a route calculation that takes place at the generalization level. The map can include a variety of generalization levels, each differing in their resolution. The first level can be seen as the first level of knowledge supplementation. It can be the most detailed level without generalization.

According to one embodiment, the first level may be a generalization level. Prior to supplementing this level of generalization, further levels of generalization may have been added in previous steps. In this way, all levels of the digital map can be gradually updated.

According to one embodiment, the first level may be more detailed than the further generalization level. Thus, an update from "bottom to top" is possible. The first changes are made in the most detailed level and then generalized. In principle, it is also conceivable the other way round, that is, that the further generalization level is more detailed than the first level. In this case, the first level is also a generalization level. Thus, the further generalization level can be more detailed than the first level. The first level may be a generalized level, with a more detailed level being updated.

The information may represent data based on driving data determined during at least one trip of at least one vehicle in an area imaged by the digital map. This can be the vehicle in which the method according to the invention is implemented or a foreign vehicle. In this way, the existing map data can be continuously updated with new data. The driving data can be received via a suitable internal or external interface.

The element can be a node or an edge between two nodes. If the element is an intersection or a branch, it may be represented by a node. If the element is a road section between adjacent intersections or branches, the road section may be represented by an edge.

For example, the element may be a third node located between a first node and a second node. In the step of updating the further generalization level, an attribute of the edge connecting the first generalization level to the first edge connecting to the second node can then be updated if the third node is not included in the further generalization level. This may be the case if the object is an intersection or branch that is contained in the first level as a separate element, but in the further generalization level is only shown as part of a parent section. For example, an element of the further generalization level may comprise both an intersection and a road section connected to the intersection, which are each represented by a separate element in the first plane. Even if an object in the further generalization level is not represented by a separate element, the element that relates to the object can still be updated using the travel data.

According to an embodiment, the method may comprise a step of determining in which it is determined whether the object is represented by a first-level element. In a step of pasting, the first element may be in the first level inserted if the object is not represented by any element of the first level.

The present invention further provides a device, in particular a navigation device, which is designed to implement or implement the steps of the method according to the invention in corresponding devices. Also by this embodiment of the invention in the form of a device, the object underlying the invention can be solved quickly and efficiently.

In the present case, a device can be understood as meaning an electrical device which processes sensor signals and outputs control signals in dependence thereon. The device may have an interface, which may be formed in hardware and / or software. In the case of a hardware-based embodiment, the interfaces can be part of a so-called system ASIC, for example, which contains a wide variety of functions of the device. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. In a software training, the interfaces may be software modules that are present, for example, on a microcontroller in addition to other software modules.

A computer program product with program code which can be stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out the method according to one of the embodiments described above if the program is on a computer corresponding to a computer is also of advantage Device is running.

The invention will now be described by way of example with reference to the accompanying drawings. Show it:

1a a schematic representation of data of a digital map in a first level of generalization;

1b a schematic representation of data of a digital map in another Generalisierungsebene; and

2 a schematic representation of a vehicle, according to an embodiment of the present invention;

3 a flowchart of a method, according to an embodiment of the present invention; and

4 a flowchart of a method, according to another embodiment of the present invention.

In the following description of preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and similarly acting, wherein a repeated description of these elements is omitted.

1a shows a schematic representation of elements of a digital map shown in a first level of generalization, according to an embodiment of the present invention. Shown are a first node 101 , a second node 103 and a third node 105 , The second node 103 is between the first node 101 and the third node 105 arranged. The first node 101 is over a first edge 111 with the second node 103 connected. Further, the second node 103 is over a second edge 113 with the third node 105 connected. The knots 101 . 103 . 105 and the edges 111 . 113 can map real objects. For example, the nodes 101 . 103 . 105 Crossings or junctions and the edges 111 . 113 Represent road sections between the intersections. Each of the elements 101 . 103 . 105 . 111 . 113 For example, an attribute may be associated with, for example, information about a travel time required by a vehicle to pass the real object through the respective element 101 . 103 . 105 . 111 . 113 is shown. For example, an attribute may be in the form of a hydrograph, a travel time profile, or a velocity profile. An attribute may include different dates for different times of the day or day of the week. For example, an attribute may be in the form of a table. In the most detailed first level of generalization, every relevant real object can have an element 101 . 103 . 105 . 111 . 113 be assigned. In further generalization levels, the same road network can be represented in different degrees of detail and network densities. On a less detailed, more generalized level of generalization, several road segments, including junctions connecting them, may be grouped together, if at the intersections only crossroads deviate from the corresponding generalization level.

1b shows a schematic representation of elements of the digital map shown in a second level of generalization 1a , according to an embodiment of the present invention. The second level of generalization includes fewer objects. According to this embodiment, the object that is in the first Generalization level of the nodes 103 is no longer encompassed by the second level of generalization. The second level of generalization only includes the nodes 101 . 105 and an edge 121 that the first node 101 with the second node 105 combines. Thus, in the element 121 the Elements 103 . 111 . 113 summarized at the first level of generalization. The edge 121 An attribute is assigned to the information of the attributes of the elements 103 . 111 . 113 includes.

2 shows a schematic representation of a vehicle 230 with a navigation system 232 , according to an embodiment of the present invention. The navigation system 232 can a digital map 234 include, for example, in the 1a and 1b includes data shown. Alternatively, the digital map 234 be stored in another device inside or outside the vehicle. Furthermore, the navigation system has a device 236 to update the digital map 234 on. To update the digital map 234 points the vehicle 230 An institution 238 which is adapted to drive data to the device 232 provide. The device 238 can be part of the navigation system 232 be. Also, the device can 238 an interface for receiving data from outside the vehicle 230 include.

3 shows a flowchart of a method for updating a digital map, according to an embodiment of the present invention. As in the 1a and 1b are shown in the digital map objects in different Generalisierungsebenen shown. To refresh the map will be in one step 341 first updates an attribute of an element of the map encompassed by the first level of generalization. For example, an attribute becomes one through the node 103 updated branch shown. The update can be based on current driving data. In one step 343 a check is made as to whether the branch is mapped by an element in the second level of generalization. In the in the 1a and 1b The exemplary embodiments shown are those in the first level of generalization by the node 103 shown branch in the second generalization plane from the edge 221 includes. Thus, in one step 345 an update of an attribute of the edge 221 , The update of the attribute of the edge 221 takes place both in consideration of the driving data required to update the attribute of the node 103 the first level of generalization, as well as attributes of the other elements 111 . 113 the first level of generalization, that of the element 221 the second level of generalization.

4 shows a flowchart of a method for updating a digital map, according to an embodiment of the present invention. In one step 451 there is a recording of driving data. The recorded driving data is used to take one step 453 learning at the most detailed generalization level. This is then done in one step 455 a transfer of knowledge to further generalization levels.

Thus, the accumulated knowledge can be made available to the generalization levels relevant for a navigation system. In order to make this possible, the knowledge that has been learned will be completed at the end of the learning process 453 checked for relevance to different generalization levels.

According to one embodiment, a hydrograph describes the travel time on a segment depending on the time of day and the day of the week. Trajectories can be learned by travel time measurements on segments themselves. If the hydrographs are learned on segments in the most detailed level, the hydrographs for the segments must be aggregated to generalized levels. For this purpose, after the learning has been completed on a segment, it is checked whether the segment is also part of a segment on a higher generalization level. If this is the case, the knowledge becomes step by step 455 transferred to the higher levels.

The structure and the modes of operation of the approach according to the invention can be realized in different variants, which are different depending on the information that is learned. Learner navigation systems can learn at the most detailed map level. It is also conceivable to learn hydrographs on abstracted map layers.

If link-related attributes are learned, these are transferred to the links in higher generalization levels if the link in the higher generalization level also exists as a link or as part of a link. This can also be the case in reverse. So something can be broken down "down".

If the learned attributes are intersection-related, the attributes are transferred to intersections in higher generalization levels if the intersections exist in these planes. If an intersection in a higher generalization level has been omitted by generalization and has become part of a higher-level link, the attributes are transferred to the higher-level link as far as possible.

According to the invention, dynamic information is not used to change the weighting of individual map elements. Instead, general attributes are used. The method of adoption at the various levels is one possible implementation of the method for transferring knowledge to various levels.

Thus, the user may be included in an assessment of the generalization levels and asked to confirm one of several takeover suggestions, if any.

The embodiments described and shown in the figures are chosen only by way of example. Different embodiments may be combined together or in relation to individual features. Also, an embodiment can be supplemented by features of another embodiment. Furthermore, method steps according to the invention can be repeated as well as carried out in a sequence other than that described.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1092127 B1 [0003]

Claims (10)

Method for updating a digital map ( 234 ), in which objects are stored in different generalization levels, comprising the following steps: Updating ( 341 ) a first level of the digital map ( 234 ) by adding an attribute of a first element ( 103 ) representing an object in the first level is updated based on information associated with the object; Check ( 343 ), whether the object from another element ( 121 ) is displayed in a further generalization level of the digital map, wherein the further element of at least one reference element ( 111 . 113 ) depends on the first level or the further level of generalization; and refresh ( 345 ) of the further generalization level of the digital map when the object is presented by the further element by updating an attribute of the further element based on the information and the at least one reference element. The method of claim 1, wherein the first level is a first level of generalization. Method according to one of the preceding claims, wherein the first level is more detailed than the further generalization level. Method according to one of the preceding claims, in which the further generalization level is more detailed than the first level. Method according to one of the preceding claims, in which the information represents data based on driving data obtained during at least one journey of at least one vehicle ( 230 ) were determined in an area imaged by the digital map. Method according to one of the preceding claims, in which the element is a node ( 101 . 103 . 105 ) or an edge ( 111 . 113 . 121 ) between two nodes. Method according to one of the preceding claims, in which the element is a third node ( 103 ), which is between a first node ( 101 ) and a second node ( 105 ) and in which in the step of updating ( 345 ) of the further generalization level an attribute of the first generalization level associated with the first edge ( 121 ) is updated if the third node is not included in the further generalization level. Method according to one of the preceding claims, comprising a step of determining whether the object is from an element ( 101 . 103 . 105 . 111 . 113 ) of the first level and with a step of inserting the first element into the first level if the object is not represented by any element of the first level. Contraption ( 232 ), in particular navigation device, which is designed to perform the steps of a method according to one of claims 1 to 8. Computer program product with program code for carrying out the method according to one of claims 1 to 8, when the program is executed on a computer.

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