Method of a vehicle for controlling the transmission power when communicating with a vehicle key, as well as vehicle and vehicle key

Abstract

The invention relates to a method for a vehicle (1) with a control unit (10) and a communication system (20) comprising a communication control unit (21) and a transceiver (22). The transceiver (22) is configured for ultra-high frequency (UHF) communication with a vehicle key (2). The invention further relates to a vehicle (1) configured to carry out this method, a vehicle key (2), and a system consisting of such a vehicle (1) and such a vehicle key (2). The method comprises, as a first step, the transmission (101) of a first message (111) by the control unit (10) to the communication control unit (20). As a further step, the method comprises the setting (102) of a UHF transmit power of the transceiver (22) based on the first message (111) by the communication control unit (21).

Description

[0001] The invention relates to a method for a vehicle to control the transmission power during communication with a vehicle key. The invention further relates to a vehicle configured to perform such a method, a vehicle key, and a system comprising such a vehicle and such a vehicle key.

[0002] Nowadays, electronic vehicle keys and the use of smartphones as vehicle keys are widespread and offer a variety of functions. For example, they allow contactless access to the vehicle or the storage of data relevant for vehicle repairs, which can then be read out in workshops.

[0003] When it comes to communication between a vehicle and its key, regulating the transmission power is crucial to optimizing the energy efficiency of the key and extending battery life, thus improving both the user-friendliness and sustainability of the technology. Furthermore, adjusted transmission power ensures compliance with legal requirements and minimizes potential interference with other electronic devices, contributing to secure and reliable communication between the key and the vehicle.

[0004] Common methods focus on regulating the transmission power of vehicle keys to maximize their energy efficiency. For example, document US 2009 / 0243796A1 describes a method in which the transmission power of the vehicle key is adjusted according to its distance from the vehicle. It also suggests gradually increasing the key's transmission power until a response is received from the vehicle or adjusting the power based on the received signal. Another document, CN 117912143A, proposes controlling the transmission power based on the vehicle's gear information to put the key into a power-saving mode, such as when the vehicle is not in park.

[0005] However, it should be noted that many countries have established specific legal requirements regarding the maximum permissible radio power, particularly in the UHF frequency range and when transmitting large amounts of data. At the same time, it must be ensured that the data transmission is error-free.

[0006] The invention is based on the objective of overcoming or reducing at least some of the disadvantages of the prior art and providing a method, as well as a vehicle, a vehicle key and a system for efficient and compliant communication between vehicle key and vehicle.

[0007] The problem according to the invention is solved by a method, a vehicle, a vehicle key, and a system according to the claims. Preferred embodiments are the subject of the dependent claims.

[0008] A first aspect of the present disclosure relates to a method for a vehicle. For the purposes of this disclosure, a vehicle is preferably a means of transport designed to carry persons and / or loads on Earth, in the air, and / or in space. Preferably, the vehicle is a passenger car with an internal combustion engine, an electric motor, or a hybrid engine.

[0009] The vehicle comprises a control unit and a communication system with a communication control unit and a transceiver. The transceiver is configured for ultra-high frequency (UHF) communication with a vehicle key. For the purposes of this disclosure, a vehicle key is preferably an electronic vehicle key fob and is preferably implemented as a standalone device or within a user terminal device, such as a smartphone. The transceiver is also preferably configured for direct or indirect wireless communication with the vehicle key in frequency ranges other than UHF.

[0010] The method comprises, as a step, the transmission of a first message by the control unit to the communication control unit. The first message preferably contains data indicating a UHF transmit power setting for the transceiver, and most preferably one or more binary flags. The first message is preferably a Controller Area Network (CAN) message transmitted via a CAN bus, most preferably a private CAN bus, between the control unit and the communication system.

[0011] Preferably, the control unit sends the first message based on a command from a central control unit of the vehicle. In other words, the control unit generates the first message, for example, sets one or more binary flags, based on the command from the central control unit, and then sends the first message to the communication control unit after receiving the command. The central control unit is preferably configured as a standalone control unit of the vehicle. Alternatively, preferably, the central control unit is configured as part of the control unit. The command is preferably a command to transmit data to the vehicle key.

[0012] Preferably, the central control unit sends commands to the control unit cyclically. For example, the central control unit sends a command at regular intervals to transmit current vehicle data to the vehicle key so that this data can be read out in the event of a workshop visit. The sending of the commands is also preferably dependent on a characteristic of the vehicle, such as the vehicle's current speed. For example, the command to transmit current vehicle data to the vehicle key is preferably only sent once a predetermined speed has been reached and a predetermined time has elapsed since the engine was started.

[0013] In a further step, the procedure involves setting the UHF transmit power of the transceiver. The UHF transmit power is set by the communication control unit based on the first message. Preferably, the communication control unit reads the data from the first message indicating the required UHF transmit power setting and adjusts the transmit power accordingly.

[0014] The method according to the invention advantageously offers a software-based solution for application-specific adjustment of the transmission power for UHF communication with the vehicle key. This eliminates the need for a hardware solution for adjusting the transmission power, saving energy and installation space, and is therefore more efficient and sustainable.

[0015] In a preferred embodiment, the method includes a further step of the control unit sending a second message to the communication control unit. The second message is preferably a CAN message transmitted via a CAN bus, particularly preferably a private CAN bus, between the control unit and the communication system. The second message preferably contains payload data, such as vehicle data, required for contactless access to the vehicle or for evaluation in a workshop.

[0016] Furthermore, the method preferably includes, as a further step, the control of the transceiver by the communication control unit. The transceiver is thereby controlled to send a data packet based on the second message to the vehicle key at the set UHF transmission power. In other words, the communication control unit evaluates the second message and creates a data packet from the contained payload data, which is then sent to the vehicle key via the transceiver at the set UHF transmission power.

[0017] Preferably, multiple data packets are created from the user data and transmitted by the transceiver at the set UHF transmit power. The number of data packets is preferably determined by the communication control unit based on the first message. Control is preferably achieved via an internal data connection of the communication system, most preferably via a Serial Peripheral Interface (SPI) bus between the communication control unit and the transceiver.

[0018] Preferably, a connection to the vehicle key is established and / or tested before the data packet is sent, preferably using at least one ping message. Also preferably, the vehicle and / or vehicle key is authenticated. The connection establishment, connection test, and / or authentication are preferably performed using low-frequency (LF) radio communication.

[0019] Preferably, after the data packet is sent, the communication control unit resets the transmit power of the transceiver to a standard UHF transmit power. In other words, the transceiver is preferably set to the standard UHF transmit power by default, and after the data packet has been sent at the set transmit power, the communication control unit reverts to the standard UHF transmit power.

[0020] With the method in this preferred embodiment, a specific transmission power can advantageously be set depending on the user data to be transmitted.

[0021] In a preferred embodiment of the method, the UHF transmit power is set as one of at least two predetermined UHF transmit powers. Preferably, the UHF transmit power is set by the communication control unit based on at least two parameter data sets, each relating to a predetermined UHF transmit power. The first message preferably contains at least one binary flag. Based on the at least one binary flag, the communication control unit preferably selects a parameter data set, preferably from a look-up table (LUT). Preferably, the UHF transmit power is set as one of a plurality of predetermined UHF transmit powers.

[0022] This allows for the advantageous use of specific parameter sets for transmission power, depending on the legal situation in a given country. The transmission power can therefore be flexibly adjusted, thus ensuring compliance with legal requirements by the vehicle internationally.

[0023] In a further preferred embodiment of the method, the UHF transmit power is set as either a first predetermined UHF transmit power or a second predetermined UHF transmit power, wherein the first UHF transmit power is lower than the second UHF transmit power. Preferably, the UHF transmit power is set by the communication control unit based on two parameter data sets, each relating to one of the two predetermined UHF transmit powers. The first message preferably contains exactly one binary flag. Based on the binary flag, the communication control unit preferably selects one of the two parameter data sets, preferably from a look-up table (LUT).

[0024] In a further preferred embodiment, it is provided that when the first predetermined UHF transmission power is set, the second message contains data relating to a service for the vehicle. The data relating to a service for the vehicle is preferably data required for a service for the vehicle and which can be read out, for example, in a workshop. Preferably, when the second message contains data relating to a service, the resulting data packet is sent from the transmitter-receiver to the vehicle key using the first predetermined transmission power.

[0025] Simultaneously or alternatively, it is preferably provided that when the second predetermined UHF transmit power is set, the second message contains data relating to vehicle authentication. This vehicle authentication data is preferably data required for authenticating the vehicle key for contactless access to the vehicle. Preferably, when the second message contains authentication data, the resulting data packet is sent from the transmitter-receiver to the vehicle key using the second predetermined transmit power.

[0026] Two typical applications of a vehicle key are, in particular, a system for contactless vehicle access (e.g., VW KESSY) and a system for reading current vehicle data for service purposes (e.g., VW Service Key). These two applications often require different permissible UHF transmission powers because the communication involves different telegram lengths. A lower transmission power is therefore necessary for a Service Key application in some countries with UHF restrictions and is also possible without increased susceptibility to errors, since the vehicle key is located inside the vehicle during operation. Contactless vehicle access, on the other hand, requires a higher transmission power, partly because the vehicle key is located outside the vehicle. With the embodiments described above, different transmission powers can advantageously be used for the two applications of the vehicle key.

[0027] In another preferred embodiment, the second message is sent with a preset time interval after the first message. The preset time interval is preferably between 0 ms and 100 ms, and particularly preferably between 5 ms and 20 ms. This advantageously allows the transmission power to be adjusted before the data transmission, which is important because there is usually only a limited time window available for data transmission. The preferred embodiment thus advantageously prevents erroneous data transmissions.

[0028] The method preferably further includes receiving a third message from the vehicle key. This third message is received by the communication control unit via the transceiver. The third message preferably contains an acknowledgment (ACK). Particularly preferably, the ACK is a checksum calculated from the transmitted data packet.

[0029] In a further step, the communication control unit preferably uses the third message to instruct the transmitter / receiver to resend the data packet. Preferably, the communication control unit checks the checksum received with the third message and resends the data packet via the transmitter / receiver if it determines that the checksum is incorrect. For the checksum check, the communication control unit preferably calculates a checksum itself before transmitting the data packet and temporarily stores it in internal memory. Alternatively, the communication control unit preferably stores the data packet temporarily in internal memory for the purpose of checking the checksum.

[0030] This allows for verification that the data packet from the vehicle key has actually been received, and if not, the data packet can be resent. This significantly increases the reliability of the data transmission.

[0031] A second aspect of the disclosure concerns a computer program comprising instructions which, when the program is executed by a computer, such as a vehicle control unit, cause the computer to perform the procedure of a vehicle as described above.

[0032] Another aspect of the present disclosure relates to a vehicle, preferably a means of transport, designed to carry persons and / or cargo on Earth, in the air, and / or in space. Preferably, the vehicle is a passenger car with an internal combustion engine, an electric motor, or a hybrid engine.

[0033] The vehicle comprises a control unit and a communication system with a communication control unit and a transceiver. The transceiver is configured for ultra-high frequency (UHF) communication with a vehicle key. The vehicle key is preferably an electronic key fob and is preferably implemented as a standalone device or within a user device, such as a smartphone. The transceiver is also preferably configured for direct or indirect wireless communication with the vehicle key in other frequency ranges outside of UHF.

[0034] The control unit is configured to transmit a first message to the communication control unit. The first message preferably contains data indicating a UHF transmit power setting for the transceiver, and most preferably one or more binary flags. The first message is preferably a CAN message transmitted via a CAN bus of the vehicle, and most preferably a private CAN bus between the control unit and the communication system.

[0035] Preferably, the vehicle further comprises a central control unit. The central control unit is preferably configured as a standalone control unit of the vehicle. Alternatively, and more preferably, the central control unit is configured as part of the control unit. Preferably, the control unit is configured to transmit the first message based on a command from the central control unit. In other words, the control unit generates the first message, for example, by setting one or more binary flags, based on the command from the central control unit, and then sends the first message to the communication control unit after receiving the command. The command is preferably a command to transmit data to the vehicle key.

[0036] Preferably, the central control unit is configured to send commands to the control unit cyclically. For example, the central control unit sends a command at regular intervals to transmit current vehicle data to the vehicle key so that this data can be read out in the event of a workshop visit. The sending of the commands is also preferably dependent on a characteristic of the vehicle, such as the vehicle's current speed. For example, the central control unit is preferably configured to send the command to transmit current vehicle data to the vehicle key only after a predetermined speed has been reached and a predetermined time has elapsed since the engine was started.

[0037] The communication control unit is configured to set the UHF transmit power of the transceiver based on the first message. Preferably, the communication control unit is configured to read the data from the first message indicating the UHF transmit power to be set for the transceiver and to adjust the transmit power of the transceiver based on this data.

[0038] The vehicle according to the invention can thus advantageously adjust the transmission power for UHF communication with the vehicle key in a software-based manner, specific to the application. This advantageously eliminates the need for a hardware solution for adjusting the transmission power, saving energy and installation space in the vehicle and consequently making it more efficient and sustainable.

[0039] In preferred embodiments of the vehicle, the control unit, in combination with the communication system, is further configured to execute a method as described above. Preferred embodiments of the claimed vehicle correspond analogously to the preferred implementations of the method according to the invention described above and achieve the same advantages. A further detailed description is therefore omitted.

[0040] Another aspect of the present disclosure relates to a vehicle key. The vehicle key is preferably an electronic vehicle radio key and is preferably implemented as a standalone device or within a user terminal device, such as a smartphone.

[0041] The vehicle key comprises a control unit and a transceiver. The transceiver is designed to communicate with a vehicle via ultra-high frequency (UHF) radio. The transceiver is preferably also designed for direct or indirect wireless communication with the vehicle in other frequency ranges outside of UHF.

[0042] The vehicle key's control unit is configured to receive, via the transceiver, a data packet transmitted by the vehicle at a predetermined UHF transmission power. The predetermined UHF transmission power is preferably one of at least two predetermined UHF transmission powers, or more preferably one of a plurality of predetermined UHF transmission powers.

[0043] Particularly preferred is the UHF transmit power being a first predetermined UHF transmit power or a second predetermined UHF transmit power, wherein the first UHF transmit power is smaller than the second UHF transmit power.

[0044] Preferably, when received with the first predetermined UHF transmit power, the data packet contains data relating to a service for the vehicle. This service-related data is preferably data required for vehicle servicing and which can be read out, for example, in a workshop. Simultaneously or alternatively, it is preferably provided that when received with the second predetermined UHF transmit power, the data packet contains data relating to vehicle authentication. This authentication-related data is preferably data required for authenticating the vehicle key for contactless access to the vehicle.

[0045] Preferably, a connection to the vehicle is established and / or tested before receiving the data packet, preferably by means of at least one ping message. Also preferably, authentication of the vehicle and / or the vehicle key is performed. Preferably, the connection establishment and / or connection test and / or authentication is carried out using low-frequency (LF) radio communication.

[0046] The vehicle key according to the invention can receive data from a vehicle at different transmission power levels. The transmission power can therefore be advantageously adjusted flexibly, so that legal requirements are met while simultaneously minimizing the susceptibility to errors in data transmission.

[0047] In a preferred embodiment, the vehicle key further comprises a data storage device. The control unit is preferably configured to store the data packet on the data storage device. Preferably, the control unit is configured to store the data packet based on the predetermined UHF transmit power with which it was received. More preferably, the control unit is configured to store the data packet when it was received with the first predetermined transmit power. In other words, the control unit is preferably configured to store the data packet when it contains data relating to a service function of the vehicle.

[0048] Preferably, the vehicle key's control unit is further configured to transmit the stored data packet to an external device via the transceiver. The external device is preferably a reader, such as one used in a workshop. This allows the received data packet to be read advantageously, particularly if it contains data required, for example, for vehicle servicing.

[0049] Another preferred embodiment of the vehicle key provides that the control unit is further configured to send a message based on the data packet to the vehicle via the transceiver. Preferably, the control unit is configured to send an ACK (Acceptance Confirmation) based on the data packet to the vehicle. Particularly preferably, the ACK is a checksum calculated from the received data packet. In other words, the control unit is preferably configured to calculate a checksum from the received data packet and send this checksum with the message to the vehicle via the transceiver.

[0050] This allows the vehicle to advantageously verify that the data packet from the vehicle key has been received correctly and completely, and if not, to resend the data packet or receive it again from the vehicle key. This significantly increases the reliability of data transmission.

[0051] In a further preferred embodiment, the control unit is configured to adjust the UHF transmit power of the transceiver based on the received data packet. Preferably, the control unit is configured to match the UHF transmit power of the transceiver to the UHF transmit power at which the data packet was received. Also preferably, the received data packet contains data indicating a UHF transmit power to be set for the transceiver, for example, one or more binary flags. Preferably, the control unit is configured to adjust the transmit power of the transceiver based on this data. Preferably, the control unit is also configured to transmit the message based on the data packet to the vehicle via the transceiver at the set UHF transmit power.

[0052] In a preferred embodiment, the control unit is further configured to determine a UHF transmit power for the received data packet and to process the received data packet according to the determined UHF transmit power.

[0053] In these preferred embodiments, the vehicle key can therefore communicate with the vehicle at different transmission power levels. The transmission power can thus be advantageously adjusted flexibly, ensuring compliance with legal requirements while simultaneously minimizing the susceptibility to errors in data transmission.

[0054] Another aspect of the present disclosure relates to a system comprising a vehicle and a vehicle key as described above. Preferably, the system comprises several vehicle keys as described above, particularly preferably a first and a second vehicle key, each of the two keys being configured as described above.

[0055] Preferred embodiments of the claimed system correspond analogously to the preferred embodiments of the vehicle and vehicle key according to the invention described above and achieve the same advantages. A further detailed description is therefore omitted.

[0056] Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.

[0057] Unless otherwise stated in individual cases, the various embodiments of the invention mentioned in this application can be advantageously combined with one another.

[0058] The invention is explained below using exemplary embodiments with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a method according to the invention for a vehicle according to one embodiment; Fig. 2 a schematic representation of a vehicle and a system according to the invention in one embodiment; Fig. 3 a schematic representation of a vehicle key according to the invention in one embodiment; and Fig. 4 a flowchart of a method according to the invention in one embodiment.

[0059] Fig. Figure 1 shows a schematic representation of a method according to the invention for a vehicle, in particular a passenger car with an internal combustion, electric or hybrid engine, according to one embodiment. The vehicle has a control unit and a communication system with a communication control unit and a transceiver. The transceiver is designed for ultra-high frequency (UHF) communication with a vehicle key.

[0060] The procedure includes, as step 101, the transmission of an initial message by the control unit to the communication control unit. This initial message contains data indicating the UHF transmit power to be set for the transceiver, in particular one or more binary flags.

[0061] In a further step 102, the procedure involves setting the UHF transmit power of the transceiver. The UHF transmit power is set by the communication control unit based on the first message received in the first step 101. Specifically, the communication control unit reads the data from the first message indicating the UHF transmit power to be set for the transceiver and sets the transmit power of the transceiver based on this data.

[0062] As a further step, the procedure involves the control unit sending a second message to the communication control unit. This second message contains, in particular, payload data, such as vehicle data, which is required for contactless access to the vehicle or for evaluation in a workshop.

[0063] In a further step, 104, the communication control unit activates the transceiver. The transceiver is then instructed to send a data packet, based on the second message, to the vehicle key using the set UHF transmission power. In other words, the communication control unit evaluates the second message and creates a data packet from the contained payload data, which is then sent to the vehicle key via the transceiver using the set UHF transmission power.

[0064] Fig. Figure 2 shows a schematic representation of a vehicle 1 according to the invention, in particular a passenger car with an internal combustion, electric or hybrid engine and a system 3 according to the invention in one embodiment.

[0065] Vehicle 1 has a control unit 10 with a CPU 11 and internal memory 12, which communicate with each other, for example via a suitable data bus. Furthermore, vehicle 1 has a communication system 20 with a communication control unit 21 and a transceiver 22. The communication control unit 21 and the transceiver 22 also communicate with each other via a suitable data bus, in particular via an SPI bus. The control unit 10 and the communication system 20 communicate with each other, in particular via a private CAN bus of the Body Control Module (BCM) 40 of vehicle 1.

[0066] The transceiver 22 is designed for ultra-high frequency (UHF) communication with a vehicle key 2. The vehicle key 2 is an electronic vehicle key fob and is implemented, for example, as a standalone device or within a user device such as a smartphone. The transceiver 22 is also designed for direct or indirect wireless communication with the vehicle key 2 in other frequency ranges outside of UHF.

[0067] The control unit 10 is configured to transmit data to the communication control unit 21 indicating the UHF transmit power of the transceiver 22 to be set. The communication control unit 21 is configured to set the UHF transmit power of the transceiver 22 based on this data.

[0068] Vehicle 1 also has a central control unit 41. The central control unit 41 is designed as a standalone control unit of vehicle 1, but it can also be designed as part of the control unit 10. The central control unit 41 and the control unit 10 communicate with each other, for example via a suitable data bus.

[0069] The central control unit 41 is configured to send a data transmission command to the vehicle key 2 and the control unit 10. Based on the command from the central control unit 41, the control unit 10 is configured to transmit an initial message containing the data regarding the transmission power to be set to the communication system 20.

[0070] In particular, the central control unit 41 is designed to cyclically send commands to the control unit 10. For example, the central control unit 41 sends a command at regular intervals to transmit current vehicle data to the vehicle key 2 so that this data can be read out in the event of a workshop visit.

[0071] The control unit 10 is also designed to send user data to the communication system 20, such as vehicle data required for contactless access to the vehicle or for evaluation in a workshop.

[0072] The communication control unit 21 is further designed to control the transmitter-receiver to send a data packet based on the user data received by the control unit 10 to the vehicle key 2 with the set UHF transmission power.

[0073] Fig. Figure 3 shows a schematic representation of a vehicle key 2 according to the invention in one embodiment. The vehicle key 2 is in particular an electronic vehicle radio key and is implemented as a standalone device or within a user terminal device, such as a smartphone.

[0074] The vehicle key 2 comprises a control unit 50 with a CPU 51 and internal memory 52, and a transceiver 60. The transceiver 60 is designed to communicate with a vehicle via ultra-high frequency (UHF) radio. The transceiver 60 is also specifically designed for direct or indirect wireless communication with the vehicle in other frequency ranges outside of UHF.

[0075] The control unit 50 of the vehicle key 2 is designed to receive a data packet, which was sent from the vehicle with a predetermined UHF transmission power, by means of the transceiver 60.

[0076] The vehicle key 2 also has a data storage device 70. The control unit 50 is configured to store the received data packet on the data storage device 70. In particular, the control unit 50 of the vehicle key 2 is further configured to transmit the stored data packet to an external device via the transceiver 60. The external device is, for example, a reader used in a workshop. This allows the received data packet to be read advantageously, especially if it contains data that is needed, for example, for servicing the vehicle.

[0077] Fig.Figure 4 shows a flowchart of a method according to the invention for a vehicle 1 in one embodiment. The vehicle 1 has a control unit 10 and a communication system 20 with a communication control unit and a transmitter / receiver.

[0078] In a first step 101, the control unit 10 transmits a first message 111 to the communication system 20. The first message 111 is in particular a CAN message and contains data indicating a UHF transmit power to be set by the transceiver, in particular one or more binary flags.

[0079] In a further step 102, the communication system 20 sets a UHF transmit power based on the first message 111 received in the first step 101. In particular, the communication control unit reads the data from the first message 111 that indicates a UHF transmit power to be set for the transceiver and sets the transmit power of the transceiver based on this data.

[0080] As a further step 103, the procedure involves the control unit 10 sending a second message 112 to the communication system 20. This second message 112 contains, in particular, payload data, such as vehicle data, which is required for contactless access to the vehicle or for evaluation in a workshop. The second message 112 is sent with a preset time interval t1 after the first message 111. This preset time interval is, for example, between 5 ms and 20 ms. This advantageously allows the transmission power to be adjusted before the payload data is transmitted, which is important because only a limited time window t2 is available for data transmission.

[0081] In a further step 104, the transmitter / receiver of the communication system 20 is controlled to send a data packet 114, based on the second message, to the vehicle key 2 at the set UHF transmission power. In other words, the communication system 20 evaluates the second message 112 and creates a data packet 114 from the contained payload data, which is then sent to the vehicle key 2 by the transmitter / receiver at the set UHF transmission power.

[0082] Before sending data packet 114, a connection to the vehicle key is established or tested, in particular by means of at least one ping message 113 using low frequency (LF) radio communication. If the vehicle key 2 has been pinged via LF, a bidirectional data exchange via UHF can then take place between vehicle key 2 and the communication system 20 of vehicle 1, i.e., data packet 114 can be transmitted. However, only a limited time window t2 is available during which the vehicle key 2 is in a receive mode based on the ping message 113.

[0083] Since the transmission power of communication system 20 was already set in step 102, it is now possible to send data packet 114 without delay. Thus, in a further step 105, vehicle key 2 can receive data packet 114, which was sent by vehicle 1 with the predetermined UHF transmission power, within the time window t2.

[0084] In a further step 106, the vehicle key 2 sends a third message 115 based on the data packet 114 to the vehicle 1. In particular, the control unit of the vehicle key 2 calculates a checksum of the received data packet and sends this checksum with the third message 115 to the vehicle 1.

[0085] In step 107, the vehicle 1 receives the third message from the vehicle key 2 via the communication system 20.

[0086] In a further step 108, the communication system checks the checksum received with the third message 115. To check the checksum, the communication system 20 calculates a checksum itself, particularly before transmitting the data packet 114, and temporarily stores it in internal memory, or temporarily stores the data packet 114 in internal memory.

[0087] If the communication system detects that the checksum is incorrect, it restarts step 104, i.e., it resends data packet 114 via the transmitter / receiver. This allows for verification that data packet 114 has been fully received by vehicle key 2, and if not, the data packet 114 is resent. This effectively increases the reliability of data transmission between vehicle 1 and vehicle key 2. Reference symbol list 1 vehicle 2 vehicle keys 3 System 10 Control unit 11 CPU 12 GB internal storage 20 Communication system 21 Communication control unit 22 transceivers 40 BCM 41 central control unit 50 control unit 51 CPU 52 GB internal storage 60 transceivers 70 data storage devices 101 First procedural step 102 second procedural step 103 third procedural step 104 fourth procedural step 105 fifth procedural step 106 sixth procedural step 107 seventh process step 108 eighth procedural step 111 first message 112 second message 113 Ping message 114 Data package 115 third message t1 first predetermined period t2 second predetermined period QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 117 912 143 A

[0004]

Claims

Method of a vehicle (1) with a control unit (10); and a communication system (20) with a communication control unit (21) and a transceiver (22) configured for ultra-high frequency, UHF, communication with a vehicle key (2), the method comprising the steps: transmitting (101) a first message (111) by the control unit (10) to the communication control unit (20), and setting (102) a UHF transmit power of the transceiver (22) based on the first message (111) by the communication control unit (21). Method according to claim 1, further comprising the steps: sending (103) a second message (112) by the control unit (10) to the communication control unit (21), and controlling (104) the transmitter-receiver (22) by the communication control unit (21) to send a data packet (114) based on the second message (112) to the vehicle key (2) with the set UHF transmit power. Method according to one of claims 1 or 2, wherein the UHF transmit power is set as one of at least two predetermined UHF transmit powers. Method according to one of the preceding claims, wherein the UHF transmit power is set as a first predetermined UHF transmit power or as a second predetermined UHF transmit power, wherein the first UHF transmit power is less than the second UHF transmit power. Method according to claim 4, wherein, when the first predetermined UHF transmit power is set, the second message (112) contains data relating to a service for the vehicle (1) and / or wherein, when the second predetermined UHF transmit power is set, the second message (112) contains data relating to an authentication for the vehicle (1). Method according to one of claims 2 to 5, wherein the second message (112) is sent with a preset time interval (t1) after the first message (111). Method according to any one of claims 2 to 6, further comprising the steps: Receiving (107) a third message (115) from the vehicle key (2) by the communication control unit (21) by means of the transmitter receiver (22), and controlling (108) the transmitter receiver (22) by the communication control unit (21) based on the third message (115) to resend the data packet (114). vehicle (1), comprising a control unit (10); and a communication system (20) comprising a communication control unit (21) and a transceiver (22) configured for ultra-high frequency (UHF) communication with a vehicle key (2), wherein the control unit (10) is configured to transmit an initial message (111) to the communication control unit (21), and wherein the communication control unit (21) is configured to adjust a UHF transmit power of the transceiver (22) based on the initial message (111). Vehicle (1) according to claim 8, wherein the control unit (10) in combination with the communication system (20) is further configured to perform the method according to one of claims 2 to 7. vehicle key (2), comprising a control unit (50); and a transceiver (60) configured to communicate with a vehicle (1) via ultra-high frequency, UHF, radio, wherein the control unit (50) is configured to receive, by means of the transceiver (60), a data packet (114) which was transmitted by the vehicle (1) with a predetermined UHF transmit power. Vehicle key (2) according to claim 10, further comprising a data storage device (70), wherein the control unit (50) is further configured to store the data packet (114) on the data storage device (70). Vehicle key (2) according to one of claims 10 or 11, wherein the control unit (50) is further configured to send a message (115) based on the data packet (114) to the vehicle (1) by means of the transmitter receiver (60). Vehicle key (2) according to one of claims 10 to 12, wherein the control unit (50) is further configured to adjust a UHF transmit power of the transmitter receiver (60) based on the received data packet (114). Vehicle key (2) according to one of claims 10 to 13, wherein the control unit (50) is further configured to determine a UHF transmit power for the received data packet (114) and to process the received data packet (114) according to the determined UHF transmit power. System (3) comprising a vehicle (1) according to any one of claims 1 to 5 and a vehicle key (2) according to any one of claims 6 to 8 .

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