METHOD AND COMMUNICATION CONTROL UNIT FOR DATA TRANSMISSION IN A VEHICLE

Description

[0001] The invention relates to a method for transmitting data packets in a vehicle according to the preamble of claim 1. Furthermore, the invention relates to a communication control unit for a vehicle according to the preamble of claim 4. Furthermore, the invention relates to an arrangement of components in a vehicle according to the preamble of claim 6.

[0002] Stationary data transmission devices, installed along traffic routes, for example, are known for various channels, such as transmitting data via ultrashort wave (VHF), microwave, or infrared light. These data transmission devices can be used to send data packets to moving vehicles and / or receive data packets sent by these vehicles. Such data packets can contain, for example, information on traffic flow, traffic disruptions, restricted usability of traffic routes depending on vehicle weight, vehicle type, vehicle height, or similar parameters, or on applicable road user charges (tolls).

[0003] Furthermore, distributed data exchange systems for vehicles are known, for example from publication DE 10 2018 221 933 A1, which have a locally stationary buffer for temporarily storing data. A distributed data exchange system further comprises a transmitting device in a first vehicle for transmitting the data to be temporarily stored to the locally stationary buffer via a first short-range interface, a receiving device in a second vehicle passing the buffer for receiving the temporarily stored data from the locally stationary buffer via a second short-range interface, and a processor connected to the buffer. The processor is configured to process the data sent to the buffer, generate environment model data, write the environment model data to the buffer, and transmit it to the second vehicle.

[0004] Document WO 2021 / 043841 A1 describes a device for controlling access to a wireless communication network using a time-division multiplexing method. The device comprises a time-slice allocation module configured to allocate a time slice for data transmission from a first node to a second node, and a validation module configured to validate a data packet prior to transmission from the first node to the second node based on a latency requirement for the data packet and an expected latency of the data packet as a function of the time of the assigned time slice. The validation module is provided to distinguish between data packets to be transmitted and data packets not to be transmitted.Furthermore, the device comprises a timing module which is configured to temporally classify a data packet to be transmitted into the time slice provided for transmission from the first to the second node.

[0005] US 2020 / 0077278 A1 describes a method for predicting a quality of service for a communication between at least two moving communication partners. The prediction is based on at least one connection-based quality of service map, which is updated in a connection-based creation process.

[0006] Data received from a moving vehicle via a data transmission device and / or from a stationary buffer is subject to very different requirements with regard to maximum permissible latency (i.e., a delay before processing and / or display in the respective vehicle). Some information, such as general information on road conditions or traffic congestion at a distance, is not particularly time-critical or not at all. Other information, such as warnings about catastrophic events such as tsunamis or earthquakes, as well as payment requests related to road tolls, must be processed and / or displayed immediately or within a very short period of time.

[0007] Such data packets are usually small, typically between 10 and 100 kilobytes in size. However, a data transmission channel between the stationary data transmission device and the vehicle must have a transmission rate that ensures the complete reception of all payload data and all metadata and security data required to secure the transmission protocol within a time window that can be severely limited by the maximum speed of the vehicle and the minimum range of the data transmission device.

[0008] The resulting required transmission rate of such a channel often significantly exceeds the bandwidth or transmission rate typically provided for data transmission between components within a vehicle, sometimes by one or more orders of magnitude.

[0009] Therefore, it was necessary to equip communication control units designed for data reception via such channels with special data transmission interfaces (hereinafter also referred to as gateways) that enable a higher data transmission rate than is typically provided in a vehicle. On the one hand, such special gateways lead to higher manufacturing costs, particularly since they must be provided not only for a communication control unit, but also for other components that are intended to process and / or display data received via such a channel.

[0010] In addition, data transmission links with higher bandwidth are more sensitive to interference, particularly from electromagnetic interference, and therefore place higher demands on cable routing and installation.

[0011] There is therefore a need for a method by which data packets received via a high-speed channel are distributed within the vehicle via data transmission links that have a significantly lower transmission rate than the channel, without compromising requirements for a maximum permissible latency in the delivery of such data packets.

[0012] The invention is based on the object of providing an improved method for transmitting data packets in a vehicle. This object is achieved according to the invention by a method having the features of claim 1.

[0013] Furthermore, the invention is based on the object of providing an improved communication control unit for a vehicle. This object is achieved according to the invention with a communication control unit having the features of claim 4.

[0014] Furthermore, the invention is based on the object of providing an improved arrangement of components in a vehicle. This object is achieved according to the invention with an arrangement having the features of claim 6.

[0015] Advantageous embodiments of the invention are the subject of the subclaims.

[0016] According to a first aspect of the invention, in a method for transmitting data packets within a vehicle, which are provided by at least one stationary data transmission device via at least one channel, the data packets are received by a communication control unit of the vehicle using a communication module configured for reception via the at least one channel and are buffered in a memory. In one embodiment, data packets are provided with a timestamp during buffering, which indicates the time of reception by the communication module.

[0017] For each data packet, a permissible delivery latency is determined, which indicates the time period within which this data packet should be processed and / or displayed, for example, in the vehicle after it has been received by the communication module.

[0018] For example, data packets indicating traffic congestion far from the vehicle are assigned a comparatively high delivery latency. Data packets indicating a toll fee that must be paid to drive on a toll road, on the other hand, are assigned a comparatively low delivery latency. Similarly, data packets indicating a warning of a tsunami, earthquake, or embankment fire along the immediate route ahead are assigned a comparatively low delivery latency.

[0019] The data packets are transmitted in a sequence to at least one further component of the vehicle via at least one data transmission link which is set up for data exchange with the communication control unit and whose transmission rate is lower than the maximum transmission rate of the at least one channel for receiving data from the at least one stationary data transmission device.

[0020] The order of transmission of the data packets is determined in such a way that the permissible delivery latency of each data packet is maintained.

[0021] For example, the latest possible delivery time for a data packet can be determined from the timestamp of receipt of a data packet by the communication module using the delivery latency. This means the time by which this data packet must be transmitted over the data transmission link to at least one other component. This allows all buffered data packets to be sorted according to their latest possible delivery times, starting with the earliest (i.e., the closest) possible delivery time, and transmitted in the order of this list. This ensures that all data packets are delivered at the correct time, assuming a sufficient transmission rate along the data transmission link.

[0022] In other words, the data packets received by the communication control unit are buffered and prioritized for forwarding over the data transmission path in such a way that data packets that need to be delivered urgently are given a high priority and data packets that need to be delivered less urgently are given a lower priority.

[0023] In this way, the data received from the channel within the transmission time window limited by the minimum range of the fixed data transmission device and the maximum speed of a vehicle can be distributed to other components in the vehicle over a comparatively longer period of time without data packets being lost or delivery latency requirements being violated.

[0024] This makes it possible to use cost-effective gateways with a lower transmission rate than is possible with the state of the art for at least one data transmission path within the vehicle. In particular, there is no need for specially designed gateways designed for particularly high transmission rates, such as Universal Serial Bus (USB) interfaces or Controller Area Network Flexible Data Rate (CAN-FD) gateways.

[0025] In addition, greater interference immunity is achieved for at least one data transmission path. Furthermore, the requirements for cable routing and installation of such data transmission paths in the vehicle can be relaxed.

[0026] In one embodiment of the method, the data transmitted by the communication control unit via the at least one data transmission link with a lower transmission rate than the maximum transmission rate of the at least one channel comprise at least partially toll payment information.

[0027] By assigning data packets containing such toll payment information a low delivery latency and, accordingly, a high priority for transmission to at least one other component in the vehicle, this data is displayed and / or processed preferentially. This ensures proper processing of the toll payment process despite the relatively limited transmission rate of the communication control unit (relative to the channel).

[0028] In a further embodiment of the method, the data transmitted by the communication control device via the at least one data transmission link with a lower transmission rate than the maximum transmission rate of the at least one channel comprise at least partially urgent warning messages.

[0029] By assigning data packets containing such urgent warning messages a low delivery latency and, accordingly, a high priority for transmission to at least one other component in the vehicle, these warning messages are presented and / or processed preferentially. This ensures proper and reliable notification of vehicle occupants about existing urgent warning messages, despite the relatively limited transmission rate of the communication control unit (relative to the channel).

[0030] According to a second aspect of the invention, a communication control unit for a vehicle comprises a communication module with a transceiver device configured to receive data packets from a stationary data transmission device via at least one channel. According to the invention, the communication control unit further comprises a memory for temporarily storing data packets, a computing unit, and at least one gateway configured to connect to a respective data transmission link whose transmission rate is lower than the maximum transmission rate of the at least one channel. The communication control unit is configured to carry out the method described in the first aspect of the invention for transmitting data packets within a vehicle.In particular, the communication control unit is configured for prioritization and the memory is configured for intermediate storage of data packets received via the channel.

[0031] By selecting a transmission rate of the at least one gateway lower than the transmission rate of the channel, simpler and less susceptible components can be used for the construction of such a communication control unit according to the invention, in particular gateways that are widely used and inexpensive in automotive manufacturing. The other advantages of the communication control unit according to the invention correspond to those of the method according to the invention for transmitting data packets within a vehicle.

[0032] In one embodiment, the at least one gateway is configured as a Controller Area Network (CAN) gateway with a transmission rate that is lower than the maximum transmission rate of the at least one channel. Such CAN gateways are particularly widespread and cost-effective in automotive manufacturing.

[0033] According to a third aspect of the invention, an arrangement of components, which can be designed, for example, as a control unit, as an infotainment component or as a display and operating device, comprises at least one component which is designed as a communication control unit according to the second aspect of the invention and is set up to receive data packets from a stationary data transmission device via at least one channel and is connected to at least one further component via a data transmission link whose transmission rate is lower than the maximum transmission rate of the at least one channel.

[0034] The advantages of such an arrangement correspond to the advantages of the method for transmitting data packets within a vehicle according to the first aspect of the invention and the advantages of the communication control device according to the second aspect of the invention.

[0035] In one embodiment, at least one further component connected to the communication control unit is designed as an infotainment main unit and is configured to determine a travel route for the vehicle.

[0036] The invention is based on the finding that such an infotainment main unit in its typical operating mode only very rarely receives urgent data packets with a short delivery latency, for example warning messages about natural disasters or toll payment information, but comparatively more frequently, but nevertheless at sufficiently large time intervals, less time-critical or non-time-critical data packets with a high delivery latency.

[0037] By prioritizing data packets according to their permissible maximum delivery latency using the method according to the invention and buffering them in a memory until their transmission over the at least one data transmission link, the burst-like data transmission at a high data transmission rate can be stabilized on the channel. This enables data transmission at a significantly lower data transmission rate without compromising the security or reliability of the infotainment main unit. Further advantages of such an embodiment correspond to the advantages of the method for transmitting data packets within a vehicle according to the first aspect of the invention and the advantages of the communication control unit according to the second aspect of the invention.

[0038] Embodiments of the invention are explained in more detail below with reference to a drawing.

[0039] It shows: Fig. 1 schematically shows a stationary data transmission device and a vehicle with a communication control unit.

[0040] Corresponding parts are provided with the same reference numerals in all figures.

[0041] Figure 1 shows schematically a mobile vehicle 1 and a stationary data transmission device 2. The vehicle 1 comprises a communication control unit 100, an infotainment main unit 200 and further electrical and / or electronic components which are Figure 1 are purely schematically summarized in a vehicle electronics system 300. The infotainment main unit 200, which is also referred to below as head unit 200, is connected to a bidirectional data transmission path 201, 202 for exchanging data and / or control instructions with the communication control unit 100 or with the vehicle electronics system 300.

[0042] The vehicle 1 and the data transmission device 2 are configured to exchange data via a channel 10.

[0043] The channel 10 can, for example, be designed as a unidirectional frequency-modulated channel 10, via which data packets are transmitted from a data transmission device 2, preferably designed as a terrestrial transmitting station, and are thereby made available in the manner of a radio broadcast for reception by a plurality of vehicles 1. Data packets of up to 50 kilobytes can be transmitted over such a frequency-modulated channel 10 at a typical carrier frequency of between 76 MHz and 90 MHz over a typical radius of approximately 10 km to 50 km at a data transmission rate of approximately 16 kilobits per second.

[0044] In another embodiment, the channel 10 can also be configured as a microwave channel 10, in which data packets of up to 25 kilobytes are transmitted over a carrier frequency of typically 5.8 GHz at a data transmission rate of approximately 4 megabits per second. In such an embodiment, the data transmission station 2 is configured as a stationary microwave beacon, which has a typical range of up to 20 meters and is usually installed along traffic routes with high traffic volumes, such as highways and expressways.

[0045] In a further embodiment, the channel 10 can also be designed as an infrared channel 10, in which data packets of up to 10 kilobytes are transmitted via an optical connection between the vehicle 1 and a data transmission station 2 designed as an infrared beacon. Such infrared beacons typically have a range of up to 3.5 meters and are configured for data transmission rates of up to 1 megabit per second from the infrared beacon to the vehicle 1 (downlink) and up to 64 kilobits per second from the vehicle 1 to the infrared beacon (uplink), and are installed along traffic routes with normal or low traffic volumes.

[0046] For simplified representation, Figure 1 only one channel 10 is shown, however, a vehicle 1 is usually set up for data exchange with various stationary data transmission devices 2, which can take place via several differently designed channels 10.

[0047] The vehicle-mounted infotainment main unit or head unit 200 processes data transmitted via channel 10 and / or makes such data available for transmission.

[0048] For example, the head unit 200 is configured, among other things, for routing, i.e., for calculating a route for vehicle 1 based on position data and map data. For such routing, traffic data provided via at least one channel 10 can be taken into account. Traffic data can include information about traffic flow and / or traffic routing, for example, current closures, traffic jams, or other restrictions along traffic routes that are relevant for routing. The display and processing of traffic data by the head unit 200 is generally not time-critical.

[0049] In addition, a head unit 200 can display important information for the vehicle occupants, for example warnings of severe weather or disaster situations along the route, which are also provided via one or more channels 10 of fixed data transmission devices 2.

[0050] Furthermore, a head unit 200 can display and / or process important information relating to a specific traffic route currently being traveled by the vehicle 1, for example information about a toll obligation (i.e., an indication of an amount of money to be paid directly for using a road section), information about a height restriction or a limited tonnage, for example when driving on a ferry, a tunnel, a bridge, or another traffic structure.

[0051] Such information, which is listed here merely by way of example and is by no means exhaustive, can also be provided via fixed data transmission devices 2. Such information may require an immediate response by the head unit 200 or another component of the vehicle electronics 300 and / or by a vehicle occupant of the vehicle 1.

[0052] The invention is therefore based on the finding that different data received from a vehicle 1 via one or more channels 10 must be processed with different temporal urgency or priority. Some of this data is associated with hard real-time requirements and must be processed and / or presented to a vehicle occupant within a predetermined time period or permissible delivery latency, calculated from the time of receipt by the vehicle 1. Other data is associated with soft real-time requirements, i.e., it must be processed and / or presented within a specific time period on average; however, this time period may also be exceeded in sufficiently rare individual cases. Other data must be processed and / or presented without any special time requirements.

[0053] From this finding, the invention derives the task of organizing the transmission, storage and processing of such data received via one or more channels 10 in the vehicle 1 in such a way that all time requirements are met with particularly low technical effort and no data is lost.

[0054] For this purpose, a communication module 120 with at least one transceiver 121 is provided in the communication control unit 100 for data exchange via the at least one channel 10. For example, a first transceiver 121 can be configured as an ultrashort wave receiver for receiving data via a frequency-modulated channel 10, a second transceiver 121 can be configured as a microwave receiver for receiving data via a microwave channel 10, and a third transceiver 121 can be configured as a bidirectional infrared transceiver for receiving and transmitting data via an infrared channel 10.

[0055] The communication control unit 100 further comprises a computing unit 130 and a memory 140. The computing unit 130 is connected to the communication module 120 and the memory 140 such that data can be transmitted between the computing unit 130 and the communication module 120 and can be stored on and / or read from the memory 140.

[0056] In the presently illustrated embodiment, memory 140 is configured as a separate element from the processing unit 130, for example, as a separate memory module. This makes it easy to produce a communications control unit 100 in various configurations, which are adapted to different requirements by differently configured memories 140, for example, with different storage capacities and / or transfer rates.

[0057] Alternatively, the memory 140 can also be configured as a sub-element of the computing unit 130. This can, for example, achieve a higher transfer rate for reading and writing data to the memory 140.

[0058] Data received by the communication module 120 via a channel 10 is transmitted to the computing unit 130. According to the invention, the computing unit 130 is configured, preferably by means of a computer program implemented thereon, to determine the maximum permissible delivery latency (and thus also the priority for transmission to further components 200, 300 in the vehicle 1) of such received data. In other words, the computing unit 130 sorts this data in an order in which it is to be transmitted to the head unit 200, in such a way that the time requirements regarding the presentation and / or processing of all this data are met.

[0059] Data that is not to be transmitted immediately (i.e., with the highest priority) to the head unit 200 is temporarily stored in the memory 140 and is only read and transmitted from there once the transmission of higher-priority data has been completed. After the data has been transmitted, it can be deleted from the memory 140 to make room for subsequent data to be temporarily stored.

[0060] In this way, compliance with all time requirements related to the data of a channel 10 can be maintained even if the data transmission path 201 between the communication control unit 100 and the head unit 200 has only a low transfer rate. In particular, this data transmission path 201 can have a much lower transfer rate than would be necessary for transmitting all data received from a channel 10 in the order in which they were received by the communication module 120 (i.e., without sorting and buffering according to their temporal priority).

[0061] In other words, the performance requirements for the data transmission link 201 can be relaxed by buffering the data transmitted by a data transmission device 2 in burst form at a high transmission rate, but in a small packet size and in sufficient quantities (relative to the burst duration or effective occupancy time of the channel 10), in the memory 140 of the communication control unit 100 and transmitting them to the head unit 200 in a prioritized manner according to their latency requirements.

[0062] In one embodiment, the data transmission path 201 between the head unit 200 and the communication control unit 100 is formed by interconnected, simple, and cost-effective Controller Area Network (CAN) gateways 210, 110. This advantageously eliminates the need to use gateways with a higher transmission rate, for example, CAN Flexible Data Rate (CAN-FD) gateways. Likewise, the need to additionally or alternatively provide further interfaces, for example, Universal Serial Bus (USB) interfaces, between the communication control unit 100 and the head unit 200 is eliminated. This enables a simpler and more cost-effective design of both the communication control unit 100 and the head unit 200. The design and assembly of cables or cable harnesses for connecting the communication control unit 100 and the head unit 200 can also be simplified.In addition, this simplified design also reduces the risk of failure of the data transmission link 201.

[0063] In a similar manner, performance requirements for the further transmission of data originally received from a channel 10 and transmitted to the head unit 200 can be relaxed on components of the vehicle electronics 300. Thus, the data transmission path 202 between the vehicle electronics 300 and the head unit 200 can also be formed by cost-effective, simple CAN gateways 310, 220. More complex, expensive, and more failure-prone CAN-FD gateways or USB interfaces can also be omitted here.

Claims

1. Method for transmitting data packets provided by at least one stationary data transmission device (2) via at least one channel (10) in a vehicle (1), characterized in that the data packets are received by a communication control unit (100) by means of a communication module (120) configured for reception via the at least one channel (10), and the data packets are temporarily stored in a memory (140), a permissible delivery latency being determined for each data packet, which indicates the time period, from the receipt of the data packet by the communication module (120), within which this data packet is to be processed and / or displayed in the vehicle (1), and the data packets being transmitted in a sequence to at least one further component (200, 300) of the vehicle (1) via at least one data transmission path (201, 202), the transmission rate of which is lower than the maximum transmission rate of the at least one channel (10), the sequence of the transmission of the data packets being determined in such a way that the permissible delivery latency of each data packet is adhered to.

2. Method according to claim 1, characterized in that the data transmitted via the at least one transmission path (201, 202) at least partially comprise toll payment information.

3. Method according to any of the preceding claims, characterized in that the data transmitted via the at least one transmission path (201, 202) at least partially comprise at least one urgent warning message.

4. Communication control unit (100) for a vehicle (1), comprising a communication module (120) which has a transceiver device (121) configured to receive data packets from a stationary data transmission device (2) via at least one channel (10), characterized in that the communication control unit (100) comprises a memory (140) for temporarily storing data packets, a computing unit (130), and at least one gateway (110) for connecting to a data transmission path (201) in each case, the transmission rate of which data transmission path is lower than the maximum transmission rate of the at least one channel (10), and the communication control unit (100) being configured to carry out the method according to any of claims 1 to 3.

5. Communication control unit (100) according to claim 4, characterized in that the at least one gateway (110) is designed as a Controller Area Network (CAN) gateway which has a transmission rate that is lower than the maximum transmission rate of the at least one channel (10).

6. Arrangement of components (100, 200, 300) in a vehicle (1), characterized in that at least one component (100, 200, 300) is designed as a communication control unit (100) according to claim 4 or claim 5 for receiving data packets from a stationary data transmission device (2) via at least one channel (10), and the at least one component is connected to at least one further component (200, 300) via a data transmission path (201, 202), the transmission rate of which is lower than the maximum transmission rate of the at least one channel (10).

7. Arrangement according to claim 6, characterized in that at least one component (100, 200, 300) is designed as an infotainment main unit (200) and is configured to determine a travel route for the vehicle (1).