METHOD, DEVICES AND COMPUTER-READABLE STORAGE MEDIUM CONTAINING INSTRUCTIONS FOR DETERMINING APPLICABLE TRAFFIC RULES FOR A MOTOR VEHICLE

Description

[0001] The present invention relates to methods, devices, and a computer-readable storage medium with instructions for determining applicable traffic regulations for a motor vehicle. The invention further relates to a motor vehicle in which a method or device according to the invention is used.

[0002] In modern vehicles, drivers are often provided with information about traffic signs along the roadside or about current speed limits or overtaking bans, for example, by displaying it on an instrument panel or a head-up display. This information can also be used by various control units in the vehicle, for example, to automatically regulate vehicle speed or to warn of unauthorized overtaking maneuvers. The reliable availability of such information is essential for autonomous or semi-autonomous driving.

[0003] Currently, there are essentially two approaches to providing information about traffic signs or traffic regulations currently applicable to a vehicle. The first approach is based on the use of navigation maps that display traffic signs. A second approach involves traffic sign recognition using camera systems.

[0004] For example, DE 10 2013 013 799 A1 describes an assistance system that supports a driver during an overtaking maneuver by determining whether the overtaking maneuver can be completed safely based on the speed difference to the vehicle being overtaken and taking into account the remaining overtaking distance. The remaining overtaking distance can be determined using traffic sign recognition or GPS-based maps.

[0005] DE 10 2007 034 505 A1 describes a method for traffic sign recognition. Based on provided image data, traffic sign recognition is performed using a country-specific traffic sign database with at least partially country-specific classification features or at least partially country-specific classification methods. If the traffic sign recognition exhibits a low quality, the traffic sign recognition is repeated using another alternative country-specific traffic sign database, using stored image regions with detected traffic signs. This process is repeated until the traffic sign recognition result exhibits sufficient quality. The country-specific traffic sign database is then preset for further traffic sign recognitions for which at least a sufficient quality was determined during the traffic sign recognition.

[0006] DE 10 2008 043 756 A1 discloses a method for providing traffic sign information. In a first step, traffic sign data is stored in the vehicle. Subsequently, the stored traffic sign data is assigned to a current position of a vehicle. Finally, traffic sign information is provided based on the traffic sign data assigned to the current position of the vehicle. The traffic sign data can be retrieved section by section from an online service based on the vehicle's position information.

[0007] A disadvantage of camera-based solutions is their limited range, meaning predictive detection of traffic signs is only possible to a limited extent. Furthermore, the reliability of detection decreases with increasing vehicle speed.

[0008] A disadvantage of solutions based on navigation maps is that these maps must always be up-to-date, meaning they must be continuously updated, for example, through online updates. The required maps incur licensing costs and are usually only sold together with a navigation function. This incurs additional costs for the user.

[0009] DE 102 10 546 A1 describes a method for automatic vehicle guidance in which infrastructure data is wirelessly transmitted to the vehicle, and vehicle guidance commands are calculated based on the infrastructure data. The infrastructure data is loaded into the vehicle's own memory for at least one immediately ahead section of the route. A precise positioning system continuously determines the vehicle's current position. The commands are then calculated based on the position data and the stored infrastructure data.

[0010] US Patent No. 9,539,901 B1 describes a method for warning about speed limits. The method determines the current location of a user traveling in a vehicle. Based on the current location, a posted speed limit for the vehicle is determined. This is compared with a measured speed of the vehicle. If the posted speed limit is exceeded by too much, an acoustic or visual warning is issued.

[0011] It is an object of the invention to provide further solutions for determining applicable traffic regulations for a motor vehicle, which enable a reliable provision of the desired information without having to keep a map in the motor vehicle.

[0012] This object is achieved by a method having the features of claim 1 or 3, by a computer-readable storage medium with instructions according to claim 8, and by a device having the features of claim 9 or 10. Preferred embodiments of the invention are the subject of the dependent claims.

[0013] According to a first aspect of the invention, a method for determining applicable traffic rules for a motor vehicle comprises the steps: Transmitting at least one position and one direction of movement of the motor vehicle to a backend via a transmission device of the motor vehicle; and receiving information on traffic regulations applicable at the position of the motor vehicle via the transmission device; wherein the information on the traffic regulations applicable at the position of the motor vehicle includes at least one validity distance which indicates a minimum distance until a change in the applicable traffic regulations, and wherein upon reaching the minimum distance the transmission of at least one position and one direction of movement of the motor vehicle to the backend is carried out again.

[0014] According to a further aspect of the invention, a computer-readable storage medium contains instructions which, when executed by a computer, cause the computer to perform the following steps for determining applicable traffic regulations for a motor vehicle: Transmitting at least one position and one direction of movement of the motor vehicle to a backend via a transmission device of the motor vehicle; and receiving information on traffic regulations applicable at the position of the motor vehicle via the transmission device; wherein the information on the traffic regulations applicable at the position of the motor vehicle includes at least one validity distance which indicates a minimum distance until a change in the applicable traffic regulations, and wherein upon reaching the minimum distance the transmission of at least one position and one direction of movement of the motor vehicle to the backend is carried out again.

[0015] The term "computer" should be understood broadly. In particular, it also includes control units and other processor-based data processing devices.

[0016] According to a further aspect of the invention, a device for determining applicable traffic rules for a motor vehicle comprises: a transmission device for transmitting at least one position and one direction of movement of the motor vehicle to a backend and for receiving information on traffic regulations applicable at the position of the motor vehicle; and a data processing unit for evaluating the information on the traffic regulations applicable at the position of the motor vehicle; wherein the information on the traffic regulations applicable at the position of the motor vehicle includes at least one validity distance which indicates a minimum distance until a change in the applicable traffic regulations, and wherein the transmission device is configured to transmit at least one position and one direction of movement of the motor vehicle to the backend again when the minimum distance is reached.

[0017] With regard to a method that can be used in a motor vehicle or a device that can be installed in a motor vehicle, only the position and direction of movement are recorded in the vehicle and transmitted to a backend. Based on this information, the backend determines details of the applicable traffic regulations, which are then transmitted to the vehicle. The vehicle therefore requires neither sensors to detect traffic signs nor special, constantly up-to-date map information, which leads to significant cost savings. The traffic regulations are queried again when a validity distance is reached, which indicates the minimum distance until the applicable traffic regulations change. In this way, only manageable amounts of data need to be transmitted, making data transmission between the vehicle and the backend very efficient.

[0018] According to one aspect of the invention, a history of the motor vehicle's positions is transmitted to the backend. The history of positions, i.e., a trace of past waypoints, is extremely helpful for correctly assigning the vehicle's position to a road, particularly to the correct lane in the case of multi-lane roads.

[0019] According to a further aspect of the invention, a method for determining applicable traffic rules for a motor vehicle comprises the steps: Receiving at least one position and one direction of movement of the motor vehicle; determining information on traffic regulations applicable at the position of the motor vehicle; and transmitting the information on the traffic regulations applicable at the position of the motor vehicle to the motor vehicle; whereby the information on the traffic regulations applicable at the position of the motor vehicle includes at least a validity distance which indicates a minimum distance until a change in the applicable traffic regulations.

[0020] According to a further aspect of the invention, a computer-readable storage medium contains instructions which, when executed by a computer, cause the computer to perform the following steps for determining applicable traffic regulations for a motor vehicle: Receiving at least one position and one direction of movement of the motor vehicle; determining information on traffic regulations applicable at the position of the motor vehicle; and transmitting the information on the traffic regulations applicable at the position of the motor vehicle to the motor vehicle; whereby the information on the traffic regulations applicable at the position of the motor vehicle includes at least a validity distance which indicates a minimum distance until a change in the applicable traffic regulations.

[0021] The term "computer" should also be understood broadly here. In particular, it also includes workstations, distributed systems, and other processor-based data processing devices.

[0022] According to a further aspect of the invention, a device for determining applicable traffic rules for a motor vehicle comprises: a transmission device for receiving at least one position and one direction of movement of the motor vehicle and for transmitting information on traffic regulations applicable at the position of the motor vehicle to the motor vehicle; and a computing unit for determining the information on the traffic regulations applicable at the position of the motor vehicle; wherein the computing unit is configured to provide the information on the traffic regulations applicable at the position of the motor vehicle with at least a validity distance which indicates a minimum distance until a change in the applicable traffic regulations.

[0023] With regard to a method that can be used in a backend or a device that can be installed in a backend, the backend only receives the position and direction of movement of a motor vehicle. Based on this information, the backend determines details of the applicable traffic regulations, which are then transmitted to the motor vehicle. To keep the required data volume low, the backend also determines a validity distance and transmits it to the motor vehicle, which indicates a minimum distance until the applicable traffic regulations change. A query for the traffic regulations by the motor vehicle can then be made based on the validity, so that the backend does not receive more queries than necessary.

[0024] According to one aspect of the invention, determining the information on the traffic regulations applicable at the position of the motor vehicle comprises the steps: Assigning the position of the motor vehicle to a road in a road network; determining traffic rules applicable to the road at the position of the motor vehicle; and determining at least one distance in the road network until a change in the applicable traffic rules.

[0025] After assigning the vehicle's position to a road in a road network, i.e., on a map, the desired information on traffic regulations can be immediately retrieved from the map data. Furthermore, the map can be used to check possible routes for changes in traffic regulations. This makes it easy to determine up to which future vehicle positions no further traffic regulations query by the vehicle is required.

[0026] According to one aspect of the invention, the information on the traffic regulations applicable at the location of the motor vehicle includes several distances until a change in the applicable traffic regulations for different routes. In this case, the transmission of at least one position and one direction of movement of the motor vehicle to the backend is repeated when a distance contained in the validity information is reached. This approach requires a very small number of queries, so the resulting data volume is very low. Furthermore, a permanent data connection is not necessary.

[0027] According to one aspect of the invention, the information on the traffic regulations applicable at the location of the motor vehicle includes detailed information on at least one intersection. Using this detailed information, e.g., an intersection model or an intersection network, a certain degree of anticipation can be achieved in the event of latencies in the request to the backend, thus further increasing the reliability of the method.

[0028] According to one aspect of the invention, the traffic regulations applicable at the location of the motor vehicle describe a speed limit, a right-of-way, or a no-overtaking rule. This covers typical cases of traffic regulations that apply over longer stretches of road and are therefore particularly suitable for the application of the described solutions.

[0029] Preferably, a method according to the invention or a device according to the invention is used in a vehicle, in particular a motor vehicle.

[0030] Further features of the present invention will become apparent from the following description and the appended claims taken in conjunction with the figures. Fig. 1 schematically shows a method for determining applicable traffic regulations for a motor vehicle from the perspective of the motor vehicle; Fig. 2 shows a first embodiment of a device for determining applicable traffic regulations for a motor vehicle, which can be installed in a motor vehicle; Fig. 3 shows a second embodiment of a device for determining applicable traffic regulations for a motor vehicle, which can be installed in a motor vehicle; Fig. 4 schematically illustrates a motor vehicle in which a solution according to the invention is implemented; Fig. 5 schematically shows a method for determining applicable traffic regulations for a motor vehicle from the perspective of a backend; Fig. 6 shows further details for determining the information on the traffic regulations applicable at the position of the motor vehicle; Fig. 7 shows a first embodiment of a device for determining applicable traffic regulations for a motor vehicle, which can be installed in a backend; Fig.Fig. 8 shows a second embodiment of a device for determining applicable traffic regulations for a motor vehicle, which can be installed in a backend; Fig. 9 illustrates a system for determining applicable traffic regulations for a motor vehicle; Fig. 10 illustrates two advantageous algorithms that can be used in the system of Fig. Fig. 9 can be implemented; Fig. 11 shows an intersection model that can be transmitted to a motor vehicle as part of information on applicable traffic regulations; Fig. 12 illustrates a first iteration step of determining a validity distance of a speed limit; Fig. 13 illustrates a second iteration step of determining a validity distance of a speed limit; and Fig. 14 illustrates a final result of determining a validity distance of a speed limit.

[0031] To better understand the principles of the present invention, embodiments of the invention are explained in more detail below with reference to the figures. It is understood that the invention is not limited to these embodiments and that the described features may also be combined or modified without departing from the scope of the invention as defined in the appended claims.

[0032] Fig. 1schematically shows a method for determining applicable traffic regulations for a motor vehicle from the perspective of the motor vehicle. First, the position and direction of movement of the motor vehicle are determined 10. The position and direction of movement of the motor vehicle are then transmitted 11 via a transmission device of the motor vehicle. In this case, it can be provided that a history of positions of the motor vehicle is transmitted to the backend. In response to the information transmitted to the backend, information on traffic regulations applicable at the position of the motor vehicle is finally received by the transmission device 12, for example information on a speed limit, right of way, or a no-overtaking zone.The transmission 11 of the position and direction of movement of the motor vehicle to the backend is dependent on information on the validity of the traffic regulations, which is contained in the details of the traffic regulations applicable at the position of the motor vehicle and includes at least a distance until a change in the applicable traffic regulations. The validity information can also include multiple distances until a change in the applicable traffic regulations for different routes. In this case, the query for the applicable traffic regulations at the backend is preferably only carried out again when a distance contained in the validity information is reached. In addition, the details of the traffic regulations applicable at the position of the motor vehicle can include detailed information on intersections.

[0033] Fig. 2shows a simplified schematic representation of a first embodiment of a device 20 for determining applicable traffic regulations for a motor vehicle, which device can be installed in a motor vehicle. The device 20 has an input 21 for receiving information on the position and direction of movement of the motor vehicle, for example from a navigation system, or data that allow the position and direction of movement of the motor vehicle to be determined. A tracking unit 22 extracts or determines the position and direction of movement of the motor vehicle from the received data and selects the data that are to be transmitted to a backend. A transmission device 23 transmits the selected data, i.e. the position and direction of movement of the motor vehicle, to the backend. It can be provided that the transmission device 23 transmits a history of positions of the motor vehicle to the backend.In addition, the transmission device 23 receives information from the backend regarding traffic regulations applicable at the position of the motor vehicle, for example, information regarding a speed limit, right-of-way, or a no-overtaking zone. The transmission device 23 is configured to transmit the position and direction of movement of the motor vehicle to the backend based on information regarding the validity of the traffic regulations, which is contained in the information regarding the traffic regulations applicable at the position of the motor vehicle and includes at least a distance until a change in the applicable traffic regulations. The validity information can also include multiple distances until a change in the applicable traffic regulations for different routes.In this case, the query for the applicable traffic regulations at the backend is preferably only carried out again when a distance contained in the validity information is reached. In addition, the information on the traffic regulations applicable at the position of the motor vehicle can include detailed information on intersections. A data processing unit 24 evaluates the received information on the traffic regulations applicable at the position of the motor vehicle. The data generated by the data processing unit 24 is preferably made available for further use via an output 26 of the device 20. The tracking unit 22, the transmission device 23, and the data processing unit 24 can be controlled by a control unit 25. Settings of the tracking unit 22, the transmission device 23, the data processing unit 24, or the control unit 25 can be changed via a user interface 28 if necessary.The data generated in the device 20 can be stored in a memory 27 of the device 20, for example, for later evaluation or for use by the components of the device 20. The tracking unit 22, the transmission device 23, the data processing unit 24, and the control unit 25 can be implemented as dedicated hardware, for example, as integrated circuits. Of course, they can also be partially or completely combined or implemented as software running on a suitable processor, for example, a GPU. The input 21 and the output 26 can be implemented as separate interfaces or as a combined bidirectional interface.

[0034] Fig. 3shows a simplified schematic representation of a second embodiment of a device 30 for determining applicable traffic regulations for a motor vehicle, which device can be installed in a motor vehicle. The device 30 has a processor 32 and a memory 31. For example, the device 30 is a computer or a control unit. Instructions are stored in the memory 31 which, when executed by the processor 32, cause the device 30 to carry out the steps according to one of the described methods. The instructions stored in the memory 31 thus embody a program executable by the processor 32 which implements the method according to the invention. The device has an input 33 for receiving information, for example data recorded by a sensor system of the motor vehicle. Data generated by the processor 32 are provided via an output 34.In addition, they can be stored in memory 31. The input 33 and the output 34 can be combined to form a bidirectional interface.

[0035] The processor 32 may include one or more processor units, such as microprocessors, digital signal processors, or combinations thereof.

[0036] The memories 27, 31 of the described embodiments can have both volatile and non-volatile memory areas and can comprise a wide variety of storage devices and storage media, for example hard disks, optical storage media or semiconductor memories.

[0037] Fig. 4schematically illustrates a motor vehicle 40 in which a solution according to the invention is implemented. The motor vehicle 40 has, among other things, a navigation system 41 and an environmental sensor system 42, for example a camera system. The data acquired by the navigation system 41 and, if applicable, the data acquired by the environmental sensor system 42 are transmitted via a network 43 to a device 20 for determining applicable traffic regulations for the motor vehicle. They can also be stored in a memory 44 of the motor vehicle 40. If necessary, the data is transmitted from the device 20 to a backend for evaluation by means of a communication unit 45. The information on the traffic regulations applicable to the motor vehicle transmitted by the backend in response to the transmitted data is communicated to the driver via a user interface 47, for example an infotainment system with a display device.In addition, they can be made available to a driver assistance system 46 of the motor vehicle 40, for example for automatically controlling the vehicle speed.

[0038] Fig. 5shows a schematic of a method for determining applicable traffic regulations for a motor vehicle from the perspective of a backend. In a first step, at least a position and a direction of movement of the motor vehicle are received 50. Based on the received information, information on traffic regulations applicable at the position of the motor vehicle is then determined 51, for example information on a speed limit, a right of way or a no-overtaking zone. The information on the traffic regulations applicable at the position of the motor vehicle includes information on the validity of the traffic regulations, which includes at least a distance until a change in the applicable traffic regulations. Likewise, the information on validity can describe a spatial validity, in particular a spatial validity dependent on a route.In addition, the information on the traffic regulations applicable at the motor vehicle's location may include detailed information on intersections. The information on the traffic regulations applicable at the motor vehicle's location is ultimately transmitted to the motor vehicle. 52

[0039] Fig. 6 shows further details for determining the information on the traffic regulations applicable at the position of the motor vehicle. In a first step, the position of the motor vehicle is assigned 60 to a road in a road network. Subsequently, the traffic regulations applicable to the road at the position of the motor vehicle are determined 61. In addition, at least one validity distance is determined 62, i.e., a distance in the road network until a change in the applicable traffic regulations.

[0040] Fig. 7shows a simplified schematic representation of a first embodiment of a device 70 for determining applicable traffic regulations for a motor vehicle, which device can be installed in a backend. The device 70 has a first interface 71, via which a transmission device 72 can receive information about at least one position and one direction of movement of the motor vehicle. Via the first interface, the transmission device 72 can also transmit information about traffic regulations applicable at the position of the motor vehicle to the motor vehicle, for example information about a speed limit, right of way, or a no-overtaking zone. Based on the information received by the transmission device 72, a location unit 73 locates the motor vehicle on a map. The map can be provided from an external database via a second interface 76.Based on the location, a computing unit 74 determines the desired information on the traffic regulations applicable at the position of the motor vehicle. The computing unit 74 is configured to provide the information on the traffic regulations applicable at the position of the motor vehicle with information on the validity of the traffic regulations, which information includes at least a distance until a change in the applicable traffic regulations. Likewise, the information on the validity can describe a spatial validity, in particular a spatial validity dependent on a route. Furthermore, the information on the traffic regulations applicable at the position of the motor vehicle can include detailed information on intersections. The transmission device 72, the positioning unit 73, and the computing unit 74 can be controlled by a control unit 75.Settings of the transmission device 72, the location unit 73, the computing unit 74, or the control unit 75 can be changed if necessary via a user interface 78. The data generated in the device 70 can be stored in a memory 77 of the device 70, for example, for later evaluation or for use by the components of the device 70. The transmission device 72, the location unit 73, the computing unit 74, and the control unit 75 can be implemented as dedicated hardware, for example, as integrated circuits. Of course, they can also be partially or completely combined or implemented as software running on a suitable processor, for example, a GPU. The first interface 71 and the second interface 76 can be implemented as separate interfaces or as a combined interface.

[0041] Fig. 8shows a simplified schematic representation of a second embodiment of a device 80 for determining applicable traffic regulations for a motor vehicle, which device can be installed in a backend. The device 80 has a processor 82 and a memory 81. For example, the device 80 is a computer or a workstation. Instructions are stored in the memory 81 which, when executed by the processor 82, cause the device 80 to carry out the steps according to one of the described methods. The instructions stored in the memory 81 thus embody a program executable by the processor 82 which implements the method according to the invention. The device has an input 83 for receiving information, for example from a data packet transmitted by a motor vehicle. Data generated by the processor 82 are provided via an output 84.In addition, they can be stored in memory 81. The input 83 and the output 84 can be combined to form a bidirectional interface.

[0042] The processor 82 may include one or more processor units, such as microprocessors, digital signal processors, or combinations thereof.

[0043] The memories 77, 81 of the described embodiments can have both volatile and non-volatile memory areas and can comprise a wide variety of storage devices and storage media, for example hard disks, optical storage media or semiconductor memories.

[0044] In the following, a preferred embodiment of the invention will be described with reference to Figures 9 to 14will be explained. In the example, a speed limit for the vehicle is determined. The same principle can also be used, for example, for priority rules or overtaking bans. When applied to priority rules, no currently valid speed is transmitted, but rather the status of the road, for example, superior or subordinate, as well as the validity distance. With regard to overtaking bans, the permissibility of overtaking maneuvers is transmitted along with the validity distance, for example, permitted, prohibited, prohibited for certain vehicle classes, or prohibited with exceptions.

[0045] Fig. 9illustrates a system for determining applicable traffic regulations for a motor vehicle 40. The system comprises the motor vehicle 40 and a backend 90. In addition to a device 20 for determining applicable traffic regulations, the motor vehicle 40 has a navigation system 41, a driver assistance system 46 and a user interface 47. The backend comprises at least one device 70 for determining applicable traffic regulations and a database 91 with map data and traffic regulation information. The map material can be in NDS format (NDS: Navigation Data Standard), for example. The motor vehicle 40 sends its current position with a trace, i.e. with at least one waypoint from the past, and its direction to the backend 90. This data can be provided, for example, by the navigation system 41. The backend 90 uses this information to assign the motor vehicle 40 to a road.For this purpose, the map material from the database 91 is made available to the device 70 for determining applicable traffic regulations. Based on the assignment, the currently valid speed limit for the motor vehicle 40 is determined and transmitted to the motor vehicle 40. In addition, a valid distance for the speed limit and at least one subsequent speed limit can also be determined and transmitted. This can be done, in particular, taking into account possible route decisions. The current speed limit determined by the device 20 from the received data can be shown on a display of the user interface 47. In addition, the speed limit and, if applicable, subsequent speed limits can also be made available to the driver assistance system 46.If the subsequent speed limits are route-dependent, information about the selected route can be provided by the navigation system 41 as needed. Furthermore, the navigation system 41 can be instructed to restart position tracking as soon as a request for applicable traffic regulations has been transmitted to the backend 90.

[0046] Fig. 10 illustrates two advantageous algorithms 92, 93, which are used in the system of Fig. 9can be implemented. A first algorithm 92 is implemented in the database 91. However, it can also be executed by the device 70 for determining applicable traffic regulations or by a dedicated component of the backend 90. The algorithm 92 is a search algorithm. This determines the speed limit applicable at the position of the motor vehicle 40. In addition, the search algorithm can be able to determine a minimum, possibly route-dependent minimum distance until a change in the speed limit. This will be explained further below using the Figures 12 to 14explained. A further algorithm 93 is implemented in the device 20 arranged in the motor vehicle 40 for determining applicable traffic regulations. This algorithm 93 can also alternatively be executed by a dedicated component of the motor vehicle 40. The algorithm particularly selects those past waypoints that are to be transmitted to the backend 90. Preferably, the past positions are stored in a ring buffer so that the most recent waypoint always replaces the oldest already stored waypoint. In this way, only a small amount of storage space is required and, at the same time, a continuous trace to the current position is provided. The past waypoints should have a certain minimum distance to be meaningful.Waypoints immediately before and after a lane change are particularly interesting for correctly assigning the vehicle position to a road, and especially to the correct lane in the case of multi-lane roads. Such waypoints are therefore preferentially transmitted to Backend 90. Since cornering can be easily identified based on the steering angle, information on the steering angle profile can also be provided. Positions with steering angle changes, such as a corner entry, apex, or corner exit, are particularly interesting. It is also possible to transmit the path curvature, which can be calculated from the steering angle, for each waypoint. Furthermore, the detected lane markings (dashed, solid, double line, none) can also be transmitted. This information can be used to further improve the assignment.

[0047] Querying the applicable traffic rules at Backend 90 can be implemented in various ways, some of which are explained below.

[0048] According to a first implementation variant, vehicle 40 initially queries backend 90 for the current speed limit. Using search algorithm 92, backend 90 determines both the current speed limit and the minimum distance until the speed limit changes. Both pieces of information are transmitted to vehicle 40. Vehicle 40 tracks the route traveled, for example, using vehicle sensors, and queries backend 90 for the speed limit again when the transmitted minimum distance is reached. This variant requires a very small number of queries, so the resulting data volume is very low. Furthermore, no permanent data connection is necessary. Instead of the minimum distance until the speed limit changes, multiple distances for different possible routes can also be transmitted.In other words, the shortest distance to a speed limit change is stored under the direction condition of the first encountered intersection. To give an example, if vehicle 40 turns left at the first intersection in 500 m, the next change is at a distance of 525 m. If vehicle 40 goes straight at the first intersection in 500 m, the next change is at a distance of 751 m. If vehicle 40 turns right at the first intersection in 500 m, the next change is at a distance of 612 m. In this case, vehicle 40 monitors not only the distance traveled but also the selected route.

[0049] According to another variant, backend 90 transmits a simple intersection model in addition to the current speed limit and the distances until a change in the speed limit. An example of such an intersection model is shown in Fig. 11The intersection is represented by a circle that represents the intersection area. The outgoing intersection arms are represented by their position on the circular ring and by the direction of the arm. For example, the position on the circular ring is specified by the position in degrees relative to the intersection center, while the compass direction in degrees is used for the direction of the arm. The vehicle 40 can decide which intersection arm to use based on its own direction. An alternative intersection model uses GPS points to display the intersection arms. By comparing the vehicle position with the GPS points, the vehicle 40 can determine which intersection arm it belongs to. Furthermore, it is possible for the backend 90 to transmit an intersection network for a defined radius. The vehicle 40 then independently locates itself within this network and uses this to determine the current speed limit.With the help of the intersection models or the intersection network, a certain degree of foresight can be achieved in the case of latencies in the request to the backend, thus increasing the reliability of the process.

[0050] Fig. 12illustrates a first iteration step of determining a validity distance for a speed limit. Shown is a section of a road network, with the roads represented by solid and dashed lines. The type of dashed line represents the associated speed limit. Roads with a solid line represent those roads that are irrelevant for the given position of the vehicle. The search performed in the road network corresponds to a tree search. The road network splits into many directions. The shortest path to a speed change in this network is sought. The vehicle is at a position P, which is represented by a circle. The arrow in the circle represents the direction of travel. Another circle VP illustrates a previous position of the vehicle.The vehicle is currently on a road section between two intersections "1" and "2," which could be possible future positions ZP of the vehicle. The speed limit on this road section is 30 km / h. First, the distance to the next intersection "1" in the direction of travel is determined. In addition, the distance to the next intersection "2" in the opposite direction of travel is determined, assuming a U-turn at the next intersection "1" in the direction of travel.

[0051] In the example, the distance to intersection "1" is 150 m, and the distance to intersection "2" is 450 m. The speed limit does not change on the road sections up to these two intersections. The minimum distance until a speed limit change is therefore always greater than 150 m. The current road section is now marked as already used for the search.

[0052] Fig. 13illustrates a second iteration step for determining the validity distance of a speed limit. Since no change in the speed limit was found, the search for further intersections where the speed limit could change continues. Starting from the intersections found in the first iteration, five more intersections "1" to "5" can be reached. Road sections already used are ignored in the search, provided the speed limit applies in both directions and the current route is shorter than the route already used. The distance to intersections "1", "2", and "5" is 200 m each; the distance to intersection "3" is 250 m; and the distance to intersection "4" is 270 m. The speed limit does not change on the road sections up to the intersections.The minimum distance until a speed limit change is therefore always greater than 350 m, i.e., the distance from the starting position P to intersections "1" or "2." The current road sections are now marked as already used for the search.

[0053] Fig. 14 illustrates the final result of determining the validity distance of a speed limit. After several iterations, the search result is as follows: At intersection "1," the speed limit changes to 60 km / h after a total of 550 m. At intersection "3," the speed limit changes to 50 km / h after a total of 700 m. At intersection "4," the speed limit changes to 50 km / h after a total of 720 m. At intersection "5," the speed limit changes to 5 km / h after a total of 650 m. List of reference symbols

[0054] 10Determining position and direction of movement 11Transmitting position and direction of movement 12Receiving information on applicable traffic regulations 20Device 21Input 22Tracking unit 23Transmission device 24Data processing unit 25Control unit 26Output 27Memory 28User interface 30Device 31Memory 32Processor 33Input 34Output 40Motor vehicle 41Navigation system 42Environmental sensors 43Network 44Memory 45Communication unit 46Driver assistance system 47User interface 50Receiving position and direction of movement 51Determining information on applicable traffic regulations 52Transmitting information on applicable traffic regulations 60Assigning the position to a road 61Determining traffic regulations applicable to the road 62Determining a validity distance of the applicable traffic regulations 70Device 71First interface 72Transmission device 73Location unit 74Computing unit 75Control unit 76Second interface 77Memory78User interface 79Database 80Device 81Memory 82Processor 83Input 84Output 90Backend 91Database 92Search algorithm 93Algorithm PPosition VPPrevious position ZPFuture position

Claims

1. Method for determining applicable traffic rules for a motor vehicle (40), having the steps of: - transmitting (11) at least a position and a direction of movement of the motor vehicle (40) to a backend (90) by means of a transmission device (23) of the motor vehicle (40); and - receiving (12) information on traffic rules applicable at the position of the motor vehicle (40) by means of the transmission device (23); characterized in that the information on the traffic rules applicable at the position of the motor vehicle (40) comprises at least a validity distance that indicates a minimum distance until the applicable traffic rules change, and in that, upon reaching the minimum distance, at least a position and a direction of movement of the motor vehicle (40) are transmitted (11) to the backend (90) again.

2. Method according to Claim 1, wherein a history of positions of the motor vehicle (40) is transmitted (11) to the backend (90).

3. Method for determining applicable traffic rules for a motor vehicle (40), having the steps of: - receiving (50) at least a position and a direction of movement of the motor vehicle (40); - determining (51) information on traffic rules applicable at the position of the motor vehicle (40); and - transmitting (52) the information on the traffic rules applicable at the position of the motor vehicle (40) to the motor vehicle (40); characterized in that the information on the traffic rules applicable at the position of the motor vehicle (40) comprises at least a validity distance that indicates a minimum distance until the applicable traffic rules change.

4. Method according to Claim 3, wherein the determination (51) of the information on the traffic rules applicable at the position of the motor vehicle (40) comprises the steps of: - assigning (60) the position of the motor vehicle (40) to a road in a road network; - determining (61) traffic rules applicable to the road at the position of the motor vehicle (40); and - determining (62) at least one distance in the road network until the applicable traffic rules change.

5. Method according to one of Claims 1 to 4, wherein the information on the traffic rules applicable at the position of the motor vehicle (40) comprises a plurality of distances until the applicable traffic rules change for different routes.

6. Method according to one of the preceding claims, wherein the information on the traffic rules applicable at the position of the motor vehicle (40) comprises detailed information on at least one intersection.

7. Method according to one of the preceding claims, wherein the traffic rules applicable at the position of the motor vehicle (40) describe a speed limit, a rightof-way or a ban on overtaking.

8. Computer-readable storage medium having instructions which, when executed by a computer, cause the computer to carry out the steps of a method according to one of Claims 1 to 7 for determining applicable traffic rules for a motor vehicle (40).

9. Apparatus (20) for determining applicable traffic rules for a motor vehicle (40), having: - a transmission device (23) for transmitting (11) at least a position and a direction of movement of the motor vehicle (40) to a backend (90) and for receiving (12) information on traffic rules applicable at the position of the motor vehicle (40); and - a data processing unit (24) for evaluating the information on the traffic rules applicable at the position of the motor vehicle (40); characterized in that the information on the traffic rules applicable at the position of the motor vehicle (40) comprises at least a validity distance that indicates a minimum distance until the applicable traffic rules change, and in that the transmission device (23) is configured to transmit (11) at least a position and a direction of movement of the motor vehicle (40) to the backend (90) again upon reaching the minimum distance.

10. Apparatus (70) for determining applicable traffic rules for a motor vehicle (40), having: - a transmission device (72) for receiving (50) at least a position and a direction of movement of the motor vehicle (40) and for transmitting (52) information on traffic rules applicable at the position of the motor vehicle (40) to the motor vehicle (40); and - a computing unit (74) for determining (51) the information on the traffic rules applicable at the position of the motor vehicle (40); characterized in that the computing unit (74) is configured to provide the information on the traffic rules applicable at the position of the motor vehicle (40) at least with a validity distance that indicates a minimum distance until the applicable traffic rules change.

11. Motor vehicle (40) having an apparatus according to Claim 9.