On-board communication device and communication method

Abstract

When this on-board communication device communicates with a portable information terminal (11), which is a first portable device, using a UWB antenna (30), the on-board communication device sets a communication setting for communication using the UWB antenna (30) to a first setting that is compatible with the specification of the portable information terminal (11). In a state in which the on-board communication device communicates with the portable information terminal (11) using the UWB antenna (30), and when there is a request for communication, using the UWB antenna (30), from a smart key (21) which is a second portable device, the on-board communication device switches the communication setting for the communication using the UWB antenna (30) from the first setting to a second setting that is compatible with the specification of the smart key (21). Then, the on-board communication device starts communication with the smart key (21), the communication using the UWB antenna (30) being in accordance with the second setting.

Description

In-vehicle communication device and communication method

[0001] The present disclosure relates to an in-vehicle communication device and a communication method.

[0002] Patent Document 1 describes an in-vehicle communication device that communicates with a mobile device using an antenna.

[0003] Japanese Patent Application Laid-Open No. 2021-63428

[0004] The in-vehicle communication device of Patent Document 1 is not designed to communicate simultaneously with multiple mobile devices with different specifications. When communicating with multiple mobile devices with different specifications, the in-vehicle communication device needs to change its communication settings to match the specifications of the mobile devices with which it is communicating. In other words, the in-vehicle communication device cannot simultaneously communicate with multiple mobile devices with different specifications using the same antenna. Therefore, when the in-vehicle communication device is communicating with a first mobile device, even if a second mobile device with different specifications from the first mobile device attempts to communicate with the in-vehicle communication device, the communication is not possible.

[0005] A first aspect of the present disclosure provides an in-vehicle communication device including a first antenna, a second antenna, and a processing circuit, wherein the processing circuit is configured to: when communicating with a first mobile device using the first antenna, set a communication setting for the communication using the first antenna to a first setting that matches specifications of the first mobile device; and when, while communicating with the first mobile device using the first antenna with the first setting, a second mobile device having specifications different from those of the first mobile device requests communication using the first antenna based on a communication result using the second antenna, switch the communication setting for the communication using the first antenna from the first setting to a second setting that matches specifications of the second mobile device, and start communication with the second mobile device using the first antenna with the second setting.

[0006] A second aspect of the present disclosure provides a communication method applicable to an in-vehicle communication device including a first antenna, a second antenna, and a processing circuit, the communication method including: when communicating with a first mobile device using the first antenna, by the processing circuit, setting a communication setting for communication using the first antenna to a first setting that matches specifications of the first mobile device; when, while communicating with the first mobile device using the first antenna with the first setting, the processing circuit receives a request for communication using the first antenna from a second mobile device having specifications different from those of the first mobile device based on a communication result using the second antenna, switching the communication setting for communication using the first antenna from the first setting to a second setting that matches specifications of the second mobile device; and when, by the processing circuit, starting communication with the second mobile device using the first antenna with the second setting.

[0007] FIG. 1 is a schematic diagram showing the configuration of a communication system including an in-vehicle communication device according to an embodiment. FIG. 2 is a diagram showing a range in which the in-vehicle communication device according to an embodiment can communicate with other portable devices. FIG. 3 is a sequence diagram showing communication performed by the in-vehicle communication device according to an embodiment to measure distance to a portable information terminal. FIG. 4 is a sequence diagram showing communication performed by the in-vehicle communication device according to an embodiment when the in-vehicle communication device operates a vehicle in response to a user's operation in a digital key system. FIG. 5 is a sequence diagram showing communication performed by the in-vehicle communication device according to an embodiment to measure distance to a smart key. FIG. 6 is a sequence diagram showing communication performed by the in-vehicle communication device according to an embodiment when the in-vehicle communication device operates a vehicle in response to a user's operation in a smart key system. FIG. 7 is a diagram showing communication performed by the in-vehicle communication device according to an embodiment to alternately switch targets for distance measurement. FIG. 8 is a sequence diagram showing communication performed by the in-vehicle communication device according to an embodiment when the target for distance measurement is switched from a portable information terminal to a smart key. FIG. 9 is a sequence diagram showing communication performed by the in-vehicle communication device according to an embodiment when stopping distance measurement in a digital key system. FIG. 10 is a sequence diagram showing a mode of communication when the in-vehicle communication device of the embodiment responds to an operation by a user of a portable information terminal while performing UWB communication with a smart key.

[0008] An embodiment of an in-vehicle communication device will be described below with reference to Figures 1 to 10. <Configuration of communication system 50> As shown in Figure 1, the communication system 50 is configured with a mobile information terminal 11, a smart key 21, and an in-vehicle communication device provided in a vehicle 40.

[0009] The in-vehicle communication device includes a plurality of ECUs (Electronic Control Units), a first antenna, a second antenna, and a third antenna, and includes a digital key ECU 12 and a smart key ECU 22 as the ECUs.

[0010] The digital key ECU 12 includes a storage device 14 that stores programs, and a processing circuit 13 that executes various processes by running the programs stored in the storage device 14. The processing circuit 13 includes a processor.

[0011] The digital key ECU 12 is connected to a Bluetooth low energy (BLE) antenna 16. In this embodiment, the BLE antenna 16 is a third antenna in the in-vehicle communication device.

[0012] The smart key ECU 22 includes a storage device 24 in which programs are stored, and a processing circuit 23 that executes various processes by executing the programs stored in the storage device 24. The processing circuit 23 includes a processor.

[0013] The smart key ECU 22 is connected to a low frequency (LF) antenna 25 and a radio frequency (RF) antenna 26. In this embodiment, the LF antenna 25 and the RF antenna 26 are second antennas in the in-vehicle communication device.

[0014] The in-vehicle communication device includes a UWB (Ultra Wideband) antenna 30. In this embodiment, the first antenna in the in-vehicle communication device is the UWB antenna 30. The UWB antenna 30 includes a main antenna 31 and a sub-antenna 32. Although two sub-antennas 32 are shown in FIG. 1 , the number of sub-antennas 32 included in the communication device is not limited to two.

[0015] The main antenna 31 includes a storage device 36 in which programs are stored, and a processing circuit 35 that executes various processes by running the programs stored in the storage device 36. The processing circuit 35 includes a processor.

[0016] As described above, the in-vehicle communication device includes, as processing circuits, the processing circuit 13 of the digital key ECU 12, the processing circuit 23 of the smart key ECU 22, and the processing circuit 35 of the main antenna 31 of the UWB antenna 30. The in-vehicle communication device also includes, as memory devices, the memory device 14 of the digital key ECU 12, the memory device 24 of the smart key ECU 22, and the memory device 36 of the main antenna 31 of the UWB antenna 30.

[0017] In the in-vehicle communication device, the digital key ECU 12, the smart key ECU 22, and the UWB antenna 30 are connected to each other so as to be able to communicate with each other via, for example, CAN (Controller Area Network) communication.

[0018] The in-vehicle communication device can communicate with the first mobile device by using a first antenna, the UWB antenna 30. The in-vehicle communication device can also communicate with the first mobile device by using a third antenna, the BLE antenna 16. In this embodiment, the first mobile device is the mobile information terminal 11.

[0019] The mobile information terminal 11, the digital key ECU 12, and the UWB antenna 30 constitute a digital key system 10. A digital key for a vehicle 40 is registered in the mobile information terminal 11. A user of the mobile information terminal 11 can lock and unlock the vehicle 40 by operating the mobile information terminal 11. The user of the mobile information terminal 11 can also lock and unlock the vehicle 40 by operating the vehicle 40 while holding the mobile information terminal 11. For example, the user of the mobile information terminal 11 can lock and unlock the vehicle 40 by gripping the door handle of the vehicle 40 while holding the mobile information terminal 11.

[0020] 1 , the digital key ECU 12 can perform BLE (Bluetooth low energy) communication 15 with the mobile information terminal 11 by using a BLE antenna 16. By performing BLE communication 15 with the mobile information terminal 11, the digital key ECU 12 can perform low-power communication.

[0021] 1, the UWB antenna 30 is capable of UWB (Ultra Wideband) communication 33 with the mobile information terminal 11. By performing UWB communication 33 with the mobile information terminal 11, the UWB antenna 30 is able to perform communication in an ultra-wideband.

[0022] The in-vehicle communication device can also communicate with the second portable device by using the first antenna, the UWB antenna 30. The in-vehicle communication device can also communicate with the second portable device by using the second antennas, the LF antenna 25 and the RF antenna 26. In this embodiment, the second portable device is the smart key 21.

[0023] The smart key 21, the smart key ECU 22, and the UWB antenna 30 constitute a Smart Key System (registered trademark) 20. A user of the smart key 21 can lock and unlock the vehicle 40 by operating the smart key 21. The user of the smart key 21 can also lock and unlock the vehicle 40 by operating the vehicle 40 while carrying the smart key 21. For example, the user of the smart key 21 can lock and unlock the vehicle 40 by gripping the door handle of the vehicle 40 while carrying the smart key 21.

[0024] The smart key ECU 22 includes a storage device 24 in which programs are stored, and a processing circuit 23 that executes various processes by executing the programs stored in the storage device 24. The processing circuit 23 includes a processor.

[0025] 1, the smart key ECU 22 can perform low frequency (LF) communication 27 with the smart key 21 by using the LF antenna 25. By performing the LF communication 27 with the smart key 21, the smart key ECU 22 can communicate in the low frequency band.

[0026] The smart key ECU 22 also uses an RF antenna 26 to perform RF (Radio Frequency) communication 28 with the smart key 21. By performing RF communication 28 with the smart key 21, the smart key ECU 22 can communicate in a high frequency band.

[0027] In this way, the in-vehicle communication device uses the second antenna to perform LF communication 27 and RF communication 28 with the second mobile device. The smart key ECU 22 communicates with the smart key 21 by selectively using the LF communication 27 and the RF communication 28.

[0028] 1, the UWB antenna 30 is capable of UWB communication 33 with the smart key 21 in addition to the mobile information terminal 11. By performing UWB communication 33 with the smart key 21, the UWB antenna 30 can perform ultra-wideband communication.

[0029] When the in-vehicle communication device performs UWB communication 33 with a mobile device, the in-vehicle communication device sets parameters for the UWB antenna 30 to communicate with the mobile device. At this time, the in-vehicle communication device sets the parameters in accordance with the specifications of the mobile device with which the communication is to be performed. The parameters are, for example, the cycle, period, and number of times that UWB communication 33 is performed between the in-vehicle communication device and the mobile device. By setting the parameters for the UWB antenna 30, the in-vehicle communication device defines the manner in which the in-vehicle communication device and the mobile device perform UWB communication 33. After setting the parameters, the in-vehicle communication device applies the set parameters to adjust the communication settings for UWB communication 33 to the specifications of the mobile device with which the communication is to be performed.

[0030] When there are multiple parameters to be set, the in-vehicle communication device separately sets the multiple parameters corresponding to the mobile device with which it communicates. Alternatively, the in-vehicle communication device may store a table that lists multiple parameters corresponding to each mobile device, and set the parameters by rewriting the parameter setting table each time according to the mobile device with which it communicates.

[0031] As described above, the in-vehicle communication device can communicate with the mobile information terminal 11, which is the first mobile device, and the smart key 21, which is the second mobile device, via UWB communication 33. The specifications of the mobile information terminal 11, which is the first mobile device, and the smart key 21, which is the second mobile device, are different. Therefore, the communication settings of UWB communication 33 are different between the mobile information terminal 11, which is the first mobile device, and the smart key 21, which is the second mobile device.

[0032] When communicating with portable information terminal 11 via UWB communication 33, the in-vehicle communication device sets the communication settings of UWB communication 33 to a first setting that matches the specifications of portable information terminal 11, which is the first portable device. At this time, the in-vehicle communication device sets parameters for UWB antenna 30 that match the specifications of portable information terminal 11. In other words, in the first setting, parameters that specify the cycle, period, number of times, etc., at which UWB communication 33 is performed between the in-vehicle communication device and portable information terminal 11 are set.

[0033] When there are multiple parameters to be set in the first setting, the in-vehicle communication device separately sets the multiple parameters corresponding to the mobile information terminal 11. When the in-vehicle communication device stores a table that compiles multiple parameters corresponding to each mobile device, the in-vehicle communication device may set the parameters in the first setting by rewriting the table for parameter setting to a table corresponding to the mobile information terminal 11.

[0034] When communicating with the smart key 21 via UWB communication 33, the in-vehicle communication device sets the communication settings for UWB communication 33 to a second setting that matches the specifications of the smart key 21, which is the second portable device. At this time, the in-vehicle communication device sets parameters for the UWB antenna 30 that match the specifications of the smart key 21. In other words, the second setting includes parameters that specify the cycle, period, number of times, etc., at which UWB communication 33 is performed between the in-vehicle communication device and the smart key 21.

[0035] If there are multiple parameters to be set in the second setting, the in-vehicle communication device separately sets the multiple parameters corresponding to the smart key 21. If the in-vehicle communication device stores a table that summarizes multiple parameters corresponding to each mobile device, the in-vehicle communication device may set the parameters in the second setting by rewriting the table for parameter setting to the table corresponding to the smart key 21.

[0036] In the UWB antenna 30, the main antenna 31 is communicatively connected to the digital key ECU 12, the smart key ECU 22, and the sub-antenna 32. The main antenna 31 receives, for example, a signal from the smart key ECU 22 indicating that UWB communication 33 with the smart key 21 is to be performed. The main antenna 31 then communicates with the sub-antenna 32 to set parameters for the UWB antenna 30 to communicate with the smart key 21. In this way, the main antenna 31 plays a central role when the UWB antenna 30 performs UWB communication 33. The processing circuit 35 in the main antenna 31 plays a primary role in processing required to perform UWB communication 33, such as parameter setting.

[0037] <Effective communication range of the in-vehicle communication device> Figure 2 shows the effective range for each antenna used by the in-vehicle communication device. The effective range is the range over which the in-vehicle communication device can communicate with the mobile device. As explained with reference to Figure 1, the in-vehicle communication device is equipped with multiple antennas. The range over which the in-vehicle communication device can communicate with the mobile device varies depending on the antenna used.

[0038] 2 , the in-vehicle communication device has the widest BLE effective range 60. The BLE effective range 60 is a range in which the in-vehicle communication device can communicate with the mobile information terminal 11 via BLE communication 15 using the BLE antenna 16. The BLE effective range 60 extends from the vehicle 40 at its center. The mobile information terminal 11 can perform BLE communication 15 with the in-vehicle communication device within the BLE effective range 60.

[0039] The in-vehicle communication device has an RF effective range 61, which is the second widest after the BLE effective range 60. The RF effective range 61 is the range in which the in-vehicle communication device can perform RF communication 28 with the smart key 21 using the RF antenna 26. The RF effective range 61 extends from the vehicle 40 as its center. The smart key 21 can perform RF communication 28 with the in-vehicle communication device within the RF effective range 61.

[0040] In the in-vehicle communication device, the UWB effective range 63 is the second widest after the RF effective range 61. The UWB effective range 63 is the range in which the in-vehicle communication device can perform UWB communication 33 with the portable information terminal 11 and the smart key 21 using the UWB antenna 30. The UWB effective range 63 exists on the sides of the vehicle 40, behind the vehicle 40, and inside the vehicle 40. The portable information terminal 11 can communicate with the in-vehicle communication device via UWB communication 33 within the UWB effective range 63. Furthermore, the smart key 21 can perform UWB communication 33 with the in-vehicle communication device within the UWB effective range 63.

[0041] The in-vehicle communication device has an LF effective range 62, which is the second widest after the UWB effective range 63. The LF effective range 62 is the range in which the in-vehicle communication device can perform LF communication 27 with the smart key 21 using the LF antenna 25. The LF effective range 62 exists on the sides of the vehicle 40, behind the vehicle 40, and inside the vehicle 40. The smart key 21 can perform LF communication 27 with the in-vehicle communication device within the LF effective range 62.

[0042] In this way, the range in which communication is possible using the LF antenna 25 and RF antenna 26, which are the second antennas, is narrower than the range in which communication is possible using the BLE antenna 16, which is the third antenna.

[0043] The vehicle 40 has a defined operational area for the digital key and smart key 21. The operational area is the range within which electronic authentication between the digital key or smart key 21 and the vehicle 40 is validated when the digital key or smart key 21 is operated or when the vehicle 40 is operated while carrying the digital key or smart key 21. The operational area is located inside the UWB effective range 63. By providing such an operational area, the vehicle 40 prevents relay attacks, which relay radio waves emitted by the digital key and smart key 21 to illicitly bypass electronic authentication.

[0044] The digital key ECU 12 permits unlocking and locking of the vehicle 40 and activation of the drive system when electronic authentication with the mobile information terminal 11 located within the operation area is valid. Furthermore, authentication is not valid when the mobile information terminal 11 is not located within the operation area. In other words, even if electronic authentication via BLE communication 15 has been performed as described below, the digital key ECU 12 does not permit unlocking and locking of the vehicle 40 and activation of the drive system when the mobile information terminal 11 is not located within the operation area.

[0045] The digital key ECU 12 measures the distance between the vehicle 40 and the portable information terminal 11 to determine whether the portable information terminal 11 is within the digital key operation area of ​​the vehicle 40. At this time, the digital key ECU 12 measures the distance between the vehicle 40 and the portable information terminal 11 by performing UWB communication 33 with the portable information terminal 11. The digital key ECU 12 determines whether the portable information terminal 11 is within the operation area based on the distance between the vehicle 40 and the portable information terminal 11 measured via UWB communication 33.

[0046] As described above, the BLE effective range 60 is wider than the UWB effective range 63. Therefore, the in-vehicle communication device can perform BLE communication 15 with the mobile information terminal 11 if the mobile information terminal 11 is within the BLE effective range 60, but cannot perform distance measurement by UWB communication 33 if the mobile information terminal 11 is not within the UWB effective range 63.

[0047] The smart key ECU 22 permits unlocking and locking of the vehicle 40 and activation of the drive system when electronic authentication with the smart key 21 located within the operation area is valid. Furthermore, authentication is not valid when the smart key 21 is not located within the operation area. In other words, even if electronic authentication has been performed via RF communication 28 (described later), the smart key ECU 22 does not permit unlocking and locking of the vehicle 40 and activation of the drive system when the smart key 21 is not located within the operation area.

[0048] The smart key ECU 22 measures the distance between the vehicle 40 and the smart key 21 to determine whether the smart key 21 is within the smart key 21 activation area of ​​the vehicle 40. At this time, the smart key ECU 22 measures the distance between the vehicle 40 and the smart key 21 by performing UWB communication 33 with the smart key 21. The smart key ECU 22 determines whether the smart key 21 is within the activation area based on the distance between the vehicle 40 and the smart key 21 measured by UWB communication 33.

[0049] As mentioned above, the RF effective range 61 is wider than the UWB effective range 63. Therefore, the in-vehicle communication device can perform RF communication 28 with the smart key 21 if it is within the RF effective range 61, but cannot perform distance measurement using UWB communication 33 if the smart key 21 is not within the UWB effective range 63.

[0050] <Communication Mode in Digital Key System 10> Figure 3 shows communication modes between the mobile information terminal 11, digital key ECU 12, and UWB antenna 30 in the digital key system 10. In Figure 3, the processing performed by the digital key ECU 12 is executed by the processing circuit 13. In Figure 3, the processing performed by the UWB antenna 30 is executed by the processing circuit 35. The communication mode shown in Figure 3 is executed when the mobile information terminal 11, to which the digital key is registered, enters the BLE valid range 60.

[0051] 3 , when the mobile information terminal 11 enters the BLE effective range 60 and becomes capable of BLE communication 15, the processing circuit 13 of the digital key ECU 12 transmits information about the vehicle 40 to the mobile information terminal 11. At this time, the processing circuit 13 transmits the information about the vehicle 40 through BLE communication 15. The information about the vehicle 40 includes information for identifying the vehicle 40.

[0052] The mobile information terminal 11, which has received the information about the vehicle 40, authenticates the vehicle 40 based on the received information. In authenticating the vehicle 40, the mobile information terminal 11 checks whether the information received from the digital key ECU 12 indicates the vehicle corresponding to the digital key registered in the mobile information terminal 11.

[0053] After authenticating the vehicle 40, the mobile information terminal 11 transmits information about the digital key registered in the mobile information terminal 11 to the digital key ECU 12. At this time, the mobile information terminal 11 transmits the information about the digital key via BLE communication 15.

[0054] The processing circuit 13 of the digital key ECU 12 receives the digital key information from the mobile information terminal 11 and authenticates the digital key based on the received information. In the digital key authentication, the processing circuit 13 verifies whether the information received from the mobile information terminal 11 indicates a digital key corresponding to the vehicle 40.

[0055] After the processing circuit 13 of the digital key ECU 12 authenticates the digital key, the mobile information terminal 11 and the processing circuit 13 communicate with each other to set parameters for communication settings of UWB communication 33. At this time, the mobile information terminal 11 and the processing circuit 13 set the parameters via BLE communication 15. In this way, the in-vehicle communication device sets parameters for the UWB antenna 30 that match the specifications of the mobile information terminal 11.

[0056] As shown in the lower part of Figure 3, after the parameters are set, the processing circuit 13 of the digital key ECU 12 transmits the set parameters to the UWB antenna 30. Then, the processing circuit 35 in the UWB antenna 30 receives the parameters and applies the received parameters. By applying the parameters, the UWB antenna 30 becomes able to communicate with the mobile information terminal 11 via UWB communication 33. In this way, the in-vehicle communication device sets the communication setting for UWB communication 33 to the first setting.

[0057] The processing circuit 13 of the digital key ECU 12 that has transmitted the parameters performs distance measurement for the portable information terminal 11 using BLE communication 15. As described with reference to FIG. 2 , the UWB effective range 63 is narrower than the BLE effective range 60. The processing circuit 13 determines whether the portable information terminal 11 is within the UWB effective range 63 by measuring the distance to the portable information terminal 11 through BLE communication 15. At this time, the processing circuit 13 determines that the portable information terminal 11 is within the UWB effective range 63 when the signal strength of the BLE communication 15 is equal to or greater than a predetermined value.

[0058] When the processing circuit 13 detects through distance measurement using BLE communication 15 that the mobile information terminal 11 has reached the UWB effective range 63, it transmits a signal to the UWB antenna 30 indicating that the mobile information terminal 11 has reached the UWB effective range 63.

[0059] The processing circuit 35 in the UWB antenna 30 receives a signal indicating that the portable information terminal 11 has arrived within the UWB effective range 63 and starts measuring the distance to the portable information terminal 11 through UWB communication 33 .

[0060] In the digital key system 10 , after it is detected that the portable information terminal 11 is within the UWB effective range 63 , distance measurement using the UWB communication 33 continues while the portable information terminal 11 is within the UWB effective range 63 .

[0061] <Communication Mode When Responding to User Operation in Digital Key System> Figure 4 shows the communication mode when the in-vehicle communication device responds to a user operation of the mobile information terminal 11. In Figure 4, the processing executed by the digital key ECU 12 is executed by the processing circuit 13. In Figure 4, the processing executed by the UWB antenna 30 is executed by the processing circuit 35.

[0062] An operation by the user is, for example, a user who possesses the portable information terminal 11 that has been authenticated through BLE communication 15 operating the portable information terminal 11 in order to unlock the vehicle 40. An operation by the user is, for example, a user who possesses the portable information terminal 11 that has been authenticated through BLE communication 15 gripping the door handle of the vehicle 40 in order to unlock the vehicle 40. An operation by the user is, for example, a user who possesses the portable information terminal 11 that has been authenticated through BLE communication 15 turning on the ignition switch of the vehicle 40.

[0063] As shown in the upper part of Figure 4, the processing circuit 13 of the digital key ECU 12 accepts an operation by the user. Then, upon accepting the user's operation, the processing circuit 13 requests the UWB antenna 30 to provide the result of distance measurement. The result of distance measurement here is the distance between the in-vehicle communication device and the authenticated mobile information terminal 11.

[0064] The processing circuit 35 in the UWB antenna 30 that has received the distance measurement result transmits the distance measurement result to the digital key ECU 12. The processing circuit 13 that receives the distance measurement result executes a distance measurement result determination process. In the distance measurement result determination process, the processing circuit 13 determines whether the authenticated mobile information terminal 11 is within the operating area of ​​the vehicle 40.

[0065] As shown in Figure 4, when an authenticated mobile information terminal 11 is within the operating area of ​​the vehicle 40, the processing circuit 13 of the digital key ECU 12 transmits a request for a response to a user operation to the target ECU 34. The target ECU 34 is an ECU that must operate in order for the vehicle 40 to perform a specific function in response to a user operation. For example, if a user possessing an authenticated mobile information terminal 11 operates the mobile information terminal 11 to unlock the vehicle 40, the target ECU 34 is the ECU involved in unlocking the doors of the vehicle 40.

[0066] The target ECU 34 that has received a request for a response to a user operation responds to the user operation. For example, when a user who possesses an authenticated mobile information terminal 11 operates the mobile information terminal 11 to unlock the vehicle 40, the target ECU 34 realizes a function for unlocking the vehicle 40. For example, when a user who possesses the authenticated mobile information terminal 11 turns on the ignition switch, the target ECU 34 realizes a function for starting the drive system of the vehicle 40.

[0067] The processing circuit 13 of the digital key ECU 12 continues to communicate with the mobile information terminal 11 via BLE communication 15, even during the period from when the processing circuit 13 receives a user operation until a specific function is implemented in the vehicle 40. For example, when a user carrying the mobile information terminal 11 operates the mobile information terminal 11, the mobile information terminal 11 notifies the digital key ECU 12 of the user's operation via BLE communication 15. In other words, the in-vehicle communication device can be said to refer to the results of distance measurement to the mobile information terminal 11 via UWB communication 33 during the BLE communication 15.

[0068] <Communication Mode in Smart Key System 20> Figure 5 shows communication modes among the smart key 21, smart key ECU 22, and UWB antenna 30 in the smart key system 20. In Figure 5, the processing performed by the smart key ECU 22 is executed by the processing circuit 23. In Figure 5, the processing performed by the UWB antenna 30 is executed by the processing circuit 35. The communication mode shown in Figure 5 is executed when the smart key 21 enters the LF effective range 62.

[0069] As shown in the upper part of FIG. 5, when the smart key 21 enters the LF effective range 62 and the LF communication 27 becomes possible, the processing circuit 23 of the smart key ECU 22 transmits a signal to the smart key 21 requesting a response.

[0070] The smart key 21 receives a signal from the smart key ECU 22 via LF communication 27 and transmits information about the smart key 21 to the smart key ECU 22 via RF communication 28 .

[0071] The processing circuit 23 of the smart key ECU 22 receives the information of the smart key 21 and authenticates the smart key 21 based on the received information. In authenticating the smart key 21, the processing circuit 23 verifies whether the information received from the smart key 21 indicates a smart key that corresponds to the vehicle 40.

[0072] After the processing circuit 23 authenticates the smart key 21, the smart key 21 and the processing circuit 23 communicate with each other to define key information for the smart key 21. The UWB antenna 30 uses the defined key information as information for determining parameters for the UWB antenna 30 to perform UWB communication 33 with the smart key 21. In other words, by defining the key information, information is prepared for setting parameters for the UWB antenna 30 to perform UWB communication 33 with the smart key 21. At this time, the smart key 21 and the processing circuit 23 define the key information through LF communication 27.

[0073] As shown in the lower part of Figure 5, after the key information has been defined, the processing circuit 23 of the smart key ECU 22 transmits the defined key information to the UWB antenna 30. Then, the processing circuit 35 of the UWB antenna 30 that receives the key information sets parameters based on the key information. In this way, the in-vehicle communication device sets parameters for the UWB antenna 30 that match the specifications of the smart key 21. After setting the parameters, the processing circuit 35 applies the parameters it has set. By applying the parameters, the UWB antenna 30 becomes able to communicate with the smart key 21 via UWB communication 33. In this way, the in-vehicle communication device sets the communication settings for UWB communication 33 to the second setting.

[0074] The processing circuit 35 in the UWB antenna 30 to which the parameters have been applied begins measuring the distance to the smart key 21 via UWB communication 33. As shown in FIG. 2 and explained above, the LF effective range 62 is narrower than the UWB effective range 63. In other words, when the communication shown in FIG. 5 begins, the smart key 21 is already within the UWB effective range 63. Therefore, unlike the digital key system 10, the processing circuit 35 begins measuring the distance to the smart key 21 via UWB communication 33 without checking whether the smart key 21 is within the UWB effective range 63.

[0075] The processing circuit 35 in the UWB antenna 30 transmits the distance measurement result obtained by UWB communication 33 to the smart key ECU 22. The distance measurement result here is the distance between the in-vehicle communication device and the authenticated smart key 21. The processing circuit 23 of the smart key ECU 22 receives the distance measurement result and executes a distance measurement result determination process. In the distance measurement result determination process, the processing circuit 23 determines whether the authenticated smart key 21 is within the operating area of ​​the vehicle 40 based on the distance measurement result.

[0076] After executing the distance measurement result determination process, the processing circuit 23 executes a distance measurement result storage process. In the distance measurement result storage process, the processing circuit 23 stores the determination result in the distance measurement result determination process in the storage device 24. In the distance measurement result storage process, the processing circuit 23 may store the distance information itself in the storage device 24. In this way, when the processing circuit 23 of the smart key ECU 22 obtains the result of distance measurement for the smart key 21 via UWB communication 33, it terminates UWB communication 33 with the smart key 21. Then, when terminating UWB communication 33 with the smart key 21, it stores the result of distance measurement for the smart key 21 via UWB communication 33.

[0077] The processing circuit 23 discards the results of distance measurement for the smart key 21 via UWB communication 33 stored in the storage device 24 after a certain time has elapsed since the results were stored in the storage device 24. Then, the processing circuit 23 updates the results of distance measurement for the smart key 21 via UWB communication 33 by repeating the communication shown in FIG.

[0078] <Communication Mode When Responding to User Operation in Smart Key System 20> Figure 6 shows the communication mode when the in-vehicle communication device responds to an operation by the user of the smart key 21. An example of a user operation is when a user who possesses an authenticated smart key 21 grasps the door handle of the vehicle 40 to unlock the vehicle 40. An example of a user operation is when a user who possesses an authenticated smart key 21 turns on the ignition switch of the vehicle 40. In Figure 6, the processing performed by the smart key ECU 22 is executed by the processing circuit 23.

[0079] As shown in Fig. 6, the processing circuit 23 of the smart key ECU 22 accepts an operation by the user. Then, upon receiving the operation by the user, the processing circuit 23 of the smart key ECU 22 refers to the result of the distance measurement for the smart key 21 via UWB communication 33. At this time, the processing circuit 23 of the smart key ECU 22 refers to the determination result of the distance measurement result determination process stored in the distance measurement result storage process shown in Fig. 5.

[0080] When the smart key 21 is within the operating area of ​​the vehicle 40, the processing circuit 23 of the smart key ECU 22 transmits a request for a response to a user operation to the target ECU 34. Upon receiving a signal indicating that the smart key 21 is within the operating area of ​​the vehicle 40, the target ECU 34 responds to the user operation. For example, when a user possessing an authenticated smart key 21 grips the door handle of the vehicle 40 to unlock the vehicle 40, the target ECU 34 unlocks the vehicle 40. For example, when a user possessing an authenticated smart key 21 turns on the ignition switch, the target ECU 34 activates the drive system of the vehicle 40.

[0081] The processing circuit 23 of the smart key ECU 22 performs LF communication 27 and RF communication 28 with the smart key 21 from the time it accepts a user operation until it performs a specific function in the vehicle 40. For example, when a user who possesses an authenticated smart key 21 grips the door handle of the vehicle 40 to lock the vehicle 40, the processing circuit 23 of the smart key ECU 22 performs LF communication 27 and RF communication 28 with the smart key ECU 22. In other words, the in-vehicle communication device can be said to refer to the results of distance measurement with the smart key 21 performed by UWB communication 33 during the LF communication 27 and RF communication 28.

[0082] <Mode in which the in-vehicle communication device switches the target of distance measurement via UWB communication 33> As explained above, the in-vehicle communication device performs UWB communication 33 with the mobile information terminal 11 and the smart key 21. However, because the mobile information terminal 11 and the smart key 21 have different communication settings for UWB communication 33, the in-vehicle communication device cannot simultaneously perform distance measurement via UWB communication 33 for both the mobile information terminal 11 and the smart key 21.

[0083] In the communication system 50, as shown in FIG. 2 , it is conceivable that both the portable information terminal 11 and the smart key 21 are present near the vehicle 40 at the same time. The in-vehicle communication device can perform UWB communication 33 when the portable information terminal 11 is within the UWB effective range 63. On the other hand, as shown in FIG. 4 and explained, in the smart key system 20, the in-vehicle communication device performs UWB communication 33 after performing LF communication 27 and RF communication 28. Therefore, in FIG. 2 , if the smart key 21 moves in the direction indicated by the arrow, the in-vehicle communication device can perform UWB communication 33 when the smart key 21 approaches the vehicle 40 closer than point B and enters the LF effective range 62. However, in the state shown in FIG. 2 , the in-vehicle communication device cannot perform UWB communication 33 simultaneously with both the portable information terminal 11 and the smart key 21, even if the smart key 21 is capable of performing UWB communication 33.

[0084] Fig. 7 shows which mobile device the in-vehicle communication device will perform UWB communication 33 with when the smart key 21 moves in the direction of the arrow shown in Fig. 2 while the mobile information terminal 11 is in the position shown in Fig. 2. In Fig. 7, the horizontal axis represents the position of the smart key 21. In Fig. 7, at the stage to the left of A, the smart key 21 is located farther from the vehicle 40 than point A in Fig. 2. In Fig. 7, at the stage to the right of A and left of B, the smart key 21 is located between points A and B in Fig. 2. In Fig. 7, at the stage to the right of B, the smart key 21 is located closer to the vehicle 40 than point B in Fig. 2.

[0085] The in-vehicle communication device cannot perform UWB communication 33 with the smart key 21 when the smart key 21 is outside the LF effective range 62. Therefore, the in-vehicle communication device performs UWB communication 33 with the mobile information terminal 11 at the stage to the left of B in Fig. 7. At this time, the in-vehicle communication device sets the communication setting for UWB communication 33 to the first setting.

[0086] On the other hand, when the smart key 21 is inside the LF effective range 62, the in-vehicle communication device can define key information and perform UWB communication 33 with the smart key 21. As shown in FIG. 7 , when the in-vehicle communication device reaches a stage right of B and is able to change the communication settings for UWB communication 33 using the key information, it changes the communication settings and starts UWB communication 33 with the smart key 21. In other words, when the in-vehicle communication device is able to perform UWB communication 33 with the smart key 21, it prioritizes UWB communication 33 with the smart key 21. At this time, the in-vehicle communication device stops UWB communication 33 with the mobile information terminal 11 and then switches the communication setting for UWB communication 33 from the first setting to the second setting. Then, the in-vehicle communication device starts UWB communication 33 with the smart key 21 using the second setting.

[0087] As described with reference to Fig. 5, after the distance measurement result storage process, the in-vehicle communication device terminates UWB communication 33 with the smart key 21. As shown in Fig. 7, after terminating UWB communication 33 with the smart key 21, the in-vehicle communication device resumes UWB communication 33 with the mobile information terminal 11. At this time, the in-vehicle communication device switches the communication setting of UWB communication 33 from the second setting to the first setting.

[0088] As explained with reference to Fig. 5 , after the in-vehicle communication device has ended UWB communication 33 with the smart key 21, it restarts the communication shown in Fig. 5 after a certain time has elapsed. Therefore, as shown in Fig. 7 , when restarting the communication shown in Fig. 5 , the in-vehicle communication device stops UWB communication 33 with the mobile information terminal 11. Then, the in-vehicle communication device switches the communication setting for UWB communication 33 from the first setting to the second setting, and again performs UWB communication 33 with the smart key 21 with priority.

[0089] Thereafter, the in-vehicle communication device alternately performs UWB communication 33 with the mobile information terminal 11 and the smart key 21. <Reasons why the in-vehicle communication device prioritizes UWB communication 33 with the smart key 21> As explained with reference to Figure 7, the in-vehicle communication device prioritizes UWB communication 33 with the smart key 21 once it becomes possible to perform UWB communication 33 with the smart key 21. There are several reasons why the in-vehicle communication device prioritizes UWB communication 33 with the smart key 21.

[0090] The first reason is that there is not enough time for the smart key 21 to be detected by the in-vehicle communication device before it starts measuring distance using UWB communication 33. As mentioned above, the operating areas of the digital key and smart key 21 in the vehicle 40 are defined within the UWB effective range 63. The in-vehicle communication device then measures distance using UWB communication 33 to determine whether the mobile information terminal 11 and smart key 21 are within the operating area.

[0091] As described with reference to Fig. 3 , in the digital key system 10, the in-vehicle communication device and the portable information terminal 11 set parameters for communication settings for UWB communication 33 via BLE communication 15. Also, as described with reference to Fig. 2 , the BLE effective range 60 is wider than the UWB effective range 63. Therefore, even if the in-vehicle communication device sets parameters within the BLE effective range 60, it cannot perform UWB communication 33 until the portable information terminal 11 moves into the UWB effective range 63. In other words, because the BLE effective range 60 is wider than the UWB effective range 63, there is a time leeway for the in-vehicle communication device from setting the parameters until starting UWB communication 33 with the portable information terminal 11.

[0092] 5, in the smart key system 20, the in-vehicle communication device sets parameters for communication settings for UWB communication 33 based on key information defined through LF communication 27 with the smart key 21. Also, as described with reference to FIG. 2, the LF effective range 62 is narrower than the UWB effective range 63. Therefore, by the time the in-vehicle communication device is able to perform LF communication 27 with the smart key 21, the smart key 21 has already entered the UWB effective range 63. In other words, when UWB communication 33 with the smart key 21 is started after the parameters are set, the user possessing the authenticated smart key 21 is already within the UWB effective range 63. Therefore, there is insufficient time to complete the distance measurement result determination process and validate the authentication before the user possessing the authenticated smart key 21 arrives at the vehicle 40.

[0093] The in-vehicle communication device prioritizes UWB communication 33 with smart keys 21 that do not have time to complete the distance measurement result determination process and validate authentication. This allows the in-vehicle communication device to set parameters and execute UWB communication 33 as quickly as possible for smart keys 21 that do not have time to complete the distance measurement result determination process and validate authentication.

[0094] The second reason is that the in-vehicle communication device needs to exchange less information with the smart key 21 to set parameters. As described with reference to FIG. 3 , in the digital key system 10, the in-vehicle communication device sets parameters through BLE communication 15 with the mobile information terminal 11. At this time, the in-vehicle communication device and the mobile information terminal 11 need to exchange various information through BLE communication 15 to set the parameters. This is because the parameters set in the digital key system 10 are affected by the model of the mobile information terminal 11 to which the digital key is registered. Communication characteristics vary depending on the model of the mobile information terminal 11. For example, the communication characteristics of UWB communication 33 differ depending on the model of the mobile information terminal 11. Therefore, the in-vehicle communication device needs to perform model-specific calibration for measuring the distance to the mobile information terminal 11 via UWB communication 33. Thus, the in-vehicle communication device needs to exchange various information with the mobile information terminal 11 to set parameters for UWB communication 33 with the mobile information terminal 11.

[0095] 5, in the smart key system 20, the in-vehicle communication device defines key information for the smart key 21 through LF communication 27 with the smart key 21. The in-vehicle communication device then sets parameters for UWB communication 33 based on the defined key information. In this way, the in-vehicle communication device exchanges information for defining key information with the smart key 21 to set parameters in the smart key system 20. The amount of information exchanged to define key information is less than the information exchanged to perform UWB communication 33 in the digital key system 10. This is because the smart key 21 corresponding to each vehicle 40 is fixed, and there are fewer factors, such as the model, that affect communication characteristics.

[0096] The in-vehicle communication device prioritizes UWB communication 33 with the smart key 21, which requires less information to be exchanged to set parameters for UWB communication 33. Because the in-vehicle communication device needs to exchange less information in the smart key system 20, it can quickly set parameters for UWB communication 33. Because the in-vehicle communication device can quickly set the parameters, it can quickly obtain the results of measuring the distance to the smart key 21 through UWB communication 33. As described with reference to FIG. 7 , after UWB communication 33 with the smart key 21 is completed, the in-vehicle communication device resumes UWB communication 33 with the portable information terminal 11. Because the time required for UWB communication 33 with the smart key 21 is shorter, the in-vehicle communication device stops UWB communication 33 for a shorter period of time.

[0097] <Communication Mode When the In-Vehicle Communication Device Stops UWB Communication 33 with the Portable Information Terminal 11> Figure 8 shows the communication mode from when the in-vehicle communication device switches the target of UWB communication 33 from the portable information terminal 11 to the smart key 21 until UWB communication 33 with the portable information terminal 11 is resumed. The devices in the communication system 50 execute the communication mode shown in Figure 8 in situations such as the area surrounded by the dashed dotted line in Figure 7. The processing performed by the digital key ECU 12 in Figure 7 is executed by the processing circuit 13. The processing performed by the smart key ECU 22 in Figure 7 is executed by the processing circuit 23. The processing performed by the UWB antenna 30 in Figure 7 is executed by the processing circuit 35.

[0098] As shown in the upper right part of Fig. 8, in the communication mode shown in Fig. 8, the mobile information terminal 11 and the processing circuit 35 in the UWB antenna 30 measure the distance to the mobile information terminal 11 of the in-vehicle communication device. This is similar to the mode in the lower part of Fig. 3 where the processing circuit 35 and the mobile information terminal 11 measure the distance by UWB communication 33.

[0099] As shown in the upper left section of Figure 8, the smart key 21 and the processing circuit 23 of the smart key ECU 22 perform authentication and key information definition. This is similar to the communication mode in the upper section of Figure 5, from when the processing circuit 23 of the smart key ECU 22 transmits information about the vehicle 40 until the smart key 21 and processing circuit 23 define the key information. In this way, the in-vehicle communication device prepares to perform UWB communication 33 with the smart key 21 while performing UWB communication 33 with the mobile information terminal 11. When communication with the smart key 21 for authentication and key information definition is completed, the in-vehicle communication device determines that the smart key 21 has requested UWB communication 33 with the in-vehicle communication device. In other words, the in-vehicle communication device determines that the smart key 21 has requested UWB communication 33 with the in-vehicle communication device based on the results of the LF communication 27 and RF communication 28 with the smart key 21.

[0100] As shown in the upper part of Figure 8, once the key information has been defined, the processing circuit 23 of the smart key ECU 22 transmits distance measurement start information to the digital key ECU 12. The distance measurement start information indicates that distance measurement for the smart key 21 via UWB communication 33 will begin. Upon receiving the distance measurement start information, the processing circuit 13 of the digital key ECU 12 transmits the distance measurement start information to the mobile information terminal 11. At this time, the processing circuit 13 transmits the distance measurement start information to the mobile information terminal 11 via BLE communication 15.

[0101] After completing the definition of the key information, the processing circuit 23 of the smart key ECU 22 transmits a ranging start request and the key information to the UWB antenna 30. The manner in which the processing circuit 23 transmits the key information is the same as the manner in which the smart key ECU 22 transmits the key information to the UWB antenna 30 in the lower part of FIG.

[0102] Upon receiving the ranging start information, the portable information terminal 11 stops UWB communication 33 with the UWB antenna 30. Meanwhile, the processing circuit 35 of the UWB antenna 30, which has received the ranging start request, and the processing circuit 13 of the digital key ECU 12, which has received the ranging start information, execute a ranging stop process. The ranging stop process is a process executed by the processing circuit 35 and the processing circuit 13 so that the UWB antenna 30 switches the communication setting of the UWB communication 33 from the first setting to the second setting.

[0103] 9 shows the distance measurement stop process executed by the processing circuit 35 in the UWB antenna 30 and the processing circuit 13 in the digital key ECU 12. As shown in Fig. 9, upon receiving a distance measurement start request, the processing circuit 13 requests the UWB antenna 30 for the distance measurement results. The processing circuit 35 in the UWB antenna 30 that has received the distance measurement results transmits the distance measurement results to the digital key ECU 12. At this time, the processing circuit 35 transmits the distance measurement results for the mobile information terminal 11 that were executed in the upper right corner of Fig. 8.

[0104] The processing circuit 13 receives the distance measurement result and executes a distance measurement result determination process. In the distance measurement result determination process, the processing circuit 13 determines whether the mobile information terminal 11 is within the operation area.

[0105] Meanwhile, the processing circuit 35 in the UWB antenna 30 that transmitted the distance measurement result executes a communication termination process, in which the processing circuit 35 executes processes necessary to terminate the UWB communication 33 with the portable information terminal 11, such as discarding parameters for executing the UWB communication 33 with the portable information terminal 11.

[0106] After executing the distance measurement result determination process, the processing circuit 13 executes a distance measurement result storage process. In the distance measurement result storage process, the processing circuit 13 stores the determination result in the distance measurement result determination process in the storage device 14 as the distance measurement result.

[0107] 9 and the stopping of UWB communication 33 by portable information terminal 11 in the upper part of Fig. 8 are executed, the in-vehicle communication device stops UWB communication 33 with portable information terminal 11. In this way, when switching the communication setting of UWB communication 33 from the first setting to the second setting, the in-vehicle communication device stores the results of the distance measurement to portable information terminal 11 by UWB communication 33 in storage device 14, and then stops UWB communication 33 with portable information terminal 11 in the first setting.

[0108] <Communication status after the in-vehicle communication device stops UWB communication 33 with the mobile information terminal 11> As shown in the middle left of Fig. 8 , the processing circuit 35 of the UWB antenna 30 that has stopped measuring the distance to the mobile information terminal 11 via UWB communication 33 starts measuring the distance to the smart key 21 via UWB communication 33 in the smart key system 20. The communication status at this time is the same as the communication status shown in the lower part of Fig. 5 , from when the processing circuit 35 sets and applies parameters to when the processing circuit 23 of the smart key ECU 22 executes the process of storing the distance measurement results.

[0109] In the middle left of Fig. 8, the processing circuit 35 in the UWB antenna 30 sets parameters based on the received key information, as described in the lower part of Fig. 5. Then, as described in the lower part of Fig. 5, the processing circuit 35 that has set the parameters applies the set parameters. At this time, the in-vehicle communication device switches the communication setting of the UWB communication 33 from the first setting to the second setting.

[0110] In this way, when the in-vehicle communication device is performing UWB communication 33 with the mobile information terminal 11 and receives a request for UWB communication 33 from the smart key 21 based on the results of LF communication 27 and RF communication 28, the communication setting for UWB communication 33 is switched from the first setting to the second setting.

[0111] In the middle left section of Fig. 8, after the communication setting of the UWB communication 33 is switched from the first setting to the second setting, the processing circuit 23 of the smart key ECU 22 starts measuring the distance to the smart key 21 via the UWB communication 33, as described in the lower section of Fig. 5. The processing circuit 23 then stores the results of the distance measurement.

[0112] As shown in the middle right of FIG. 8 , while the processing circuit 35 in the UWB antenna 30 is measuring the distance to the smart key 21, the processing circuit 13 in the digital key ECU 12 responds to operations by the user of the portable information terminal 11 in the manner shown in FIG. 10 .

[0113] As shown in Figure 4, when responding to an operation by a user who owns the authenticated mobile information terminal 11, the processing circuit 13 of the digital key ECU 12 receives the results of distance measurement for the mobile information terminal 11 from the UWB antenna 30 and executes a distance measurement result determination process. However, in the example shown in Figure 8, the in-vehicle communication device is performing UWB communication 33 with the smart key 21, so the processing circuit 13 cannot receive the results of distance measurement for the mobile information terminal 11 from the UWB antenna 30.

[0114] Therefore, as shown in Fig. 10 , when the processing circuit 13 of the digital key ECU 12 receives an operation from a user who owns the authenticated mobile information terminal 11, the processing circuit 13 refers to the distance measurement results stored in the storage device 14. At this time, the processing circuit 13 refers to the determination result stored in the storage device 14 in the distance measurement result storage process of Fig. 9 . In this way, when the processing circuit 13 refers to the distance measurement results in BLE communication 15 with the mobile information terminal 11 while the in-vehicle communication device is performing UWB communication 33 with the smart key 21, the processing circuit 13 refers to the distance measurement results stored in the storage device 14. This allows the in-vehicle communication device to communicate with the mobile information terminal 11 based on the distance measurement results for the mobile information terminal 11 even when UWB communication 33 with the mobile information terminal 11 cannot be performed.

[0115] As shown in the middle right of Figure 8, the processing circuit 13, which responds to a user's operation based on the distance measurement results stored in the storage device 14, discards the stored distance measurement results after a certain period of time has passed. This is because the reliability of the distance measurement results stored in the storage device 14 decreases over time. By discarding the distance measurement results a certain period of time after they are stored in the storage device 14, the processing circuit 13 of the digital key ECU 12 prevents a response to a user's operation based on erroneous distance measurement results.

[0116] <Communication mode when the in-vehicle communication device ends UWB communication 33 with the smart key 21> As shown in Figure 5 and explained above, in the smart key system 20, UWB communication 33 between the in-vehicle communication device and the smart key 21 ends when the ranging result storage process is completed. As shown in the lower part of Figure 8, the processing circuit 23 of the smart key ECU 22 that executed the ranging result storage process transmits ranging end information to the digital key ECU 12. The ranging end information is information indicating that the in-vehicle communication device has ended ranging to the smart key 21 via UWB communication 33.

[0117] As shown in the lower part of Figure 8, the processing circuit 13 of the digital key ECU 12 receives the distance measurement end information and transmits the distance measurement end information to the mobile information terminal 11. At this time, the processing circuit 13 transmits the distance measurement end information to the mobile information terminal 11 via BLE communication 15. In this way, after terminating the UWB communication 33 with the smart key 21 and before resuming the UWB communication 33 with the mobile information terminal 11, the processing circuit 13 notifies the mobile information terminal 11 via BLE communication 15 that the UWB communication 33 with the smart key 21 has ended. This allows the mobile information terminal 11 to prepare for UWB communication 33 with the in-vehicle communication device.

[0118] After executing the distance measurement result storage process, the processing circuit 23 of the smart key ECU 22 transmits a distance measurement stop request to the UWB antenna 30. The distance measurement stop request is a signal requesting the UWB antenna 30 to stop UWB communication 33 with the smart key 21.

[0119] The processing circuit 35 in the UWB antenna 30 that receives the distance measurement stop request executes communication stop processing. As described above, in the smart key system 20, UWB communication 33 between the in-vehicle communication device and the smart key 21 ends when the distance measurement result storage processing is completed. However, the UWB antenna 30 continues to apply the parameters with the smart key 21 even after UWB communication 33 with the smart key 21 ends. The processing circuit 35 executes processing required to stop UWB communication 33 with the smart key 21, such as discarding the parameters used to execute UWB communication 33 with the smart key 21.

[0120] After executing the communication stop process, the processing circuit 35 of the UWB antenna 30 transmits a communication stop notification to the digital key ECU 12. By transmitting the communication stop notification, the processing circuit 35 notifies the digital key ECU 12 that the communication stop process has been completed.

[0121] As shown in the lower right section of Figure 8, after the UWB antenna 30 transmits the communication stop notification, the processing circuit 35 in the UWB antenna 30, the processing circuit 13 in the digital key ECU 12, and the mobile information terminal 11 resume ranging through UWB communication 33, as shown in the lower section of Figure 3.

[0122] The processing circuit 13 transmits the parameters to the UWB antenna 30 as shown in the lower part of Fig. 3. At this time, the parameters transmitted by the processing circuit 13 are the parameters when the in-vehicle communication device was performing UWB communication 33 with the mobile information terminal 11 in the upper right part of Fig. 8.

[0123] The processing circuit 35 in the UWB antenna 30 that has received the parameters applies the parameters to switch the communication setting of the UWB communication 33 from the second setting to the first setting. In this way, after the UWB communication 33 with the smart key 21 ends, the processing circuit 35 in the UWB antenna 30 switches the communication setting of the UWB communication 33 from the second setting to the first setting. In this way, after the communication setting of the UWB antenna 30 has switched from the second setting to the first setting, the in-vehicle communication device resumes the UWB communication 33 with the mobile information terminal 11.

[0124] As shown in the lower left part of Figure 8, while the processing circuit 35 in the UWB antenna 30 is measuring the distance to the mobile information terminal 11, the processing circuit 23 in the smart key ECU 22 responds to the operation of the smart key 21 and the user of the mobile information terminal 11 in the manner shown in Figure 6.

[0125] As shown and explained in Fig. 6 , the processing circuit 23 responds to the operation of the user of the smart key 21 while referring to the results of distance measurement via UWB communication 33 stored in the storage device 24 in the lower part of Fig. 5 . In this way, after terminating UWB communication 33 with the smart key 21, the processing circuit 23 refers to the results of distance measurement stored in the storage device 24 when referring to the results of distance measurement via UWB communication 33 in LF communication 27 and RF communication 28. This allows the in-vehicle communication device to refer to the results of pseudo distance measurement for the smart key 21 via UWB communication 33 even while performing UWB communication 33 with the mobile information terminal 11.

[0126] As shown in the lower part of Figure 8, the processing circuit 23 of the smart key ECU 22 discards the distance measurement result for the smart key 21 after a certain time has elapsed since the result was stored in the storage device 24. As described with reference to Figure 5, the processing circuit 23 discards the stored determination result after a certain time has elapsed, and then updates the distance measurement result obtained by UWB communication 33 by repeating the communication shown in Figure 5. That is, to update the distance measurement result, the processing circuit 23 executes the communication mode shown in the upper left part of Figure 8. Then, when the definition of the key information is complete, the processing circuit 23 transmits distance measurement start information to the digital key ECU 12, as shown in the upper part of Figure 8. In this way, the in-vehicle communication device repeats the communication mode shown in Figure 8 each time it updates the distance measurement result for the smart key 21.

[0127] <Operation of this embodiment> When the in-vehicle communication device is communicating with a first portable device using the first antenna and receives a request from a second portable device to communicate using the first antenna, the in-vehicle communication device switches the communication settings for communication using the first antenna. As described above, the first portable device is the mobile information terminal 11. The first antenna is the UWB antenna 30. The second portable device is the smart key 21.

[0128] Advantages of the Present Embodiment (1) The in-vehicle communication device can communicate with the second mobile device using the first antenna in response to a communication request from the second mobile device.

[0129] (2) In the in-vehicle communication device, the processing circuit 35 switches the communication setting for communication using the first antenna from the first setting to the second setting, and then, when communication using the first antenna with the second mobile device ends, switches the communication setting for communication using the first antenna from the second setting to the first setting. Then, in the in-vehicle communication device, the processing circuit 35 resumes communication with the first mobile device using the first antenna.

[0130] When the communication with the second portable device using the first antenna is terminated, the in-vehicle communication device resumes the communication with the first portable device using the first antenna, thereby allowing the in-vehicle communication device to resume the communication with the first portable device using the first antenna without leaving the communication with the first portable device using the first antenna in an incomplete state.

[0131] (3) The in-vehicle communication device further includes a third antenna in addition to the first antenna and the second antenna. In the in-vehicle communication device, after communication with the second portable device using the first antenna ends and before communication with the first portable device using the first antenna is resumed, the processing circuit 13 notifies the first portable device that communication with the second portable device using the first antenna has ended through communication using the third antenna. As described above, the second antenna is the LF antenna 25 and the RF antenna 26. The third antenna is the BLE antenna 16.

[0132] When resuming communication with the first portable device using the first antenna, the in-vehicle communication device notifies the second portable device in advance that communication with the first portable device using the first antenna has ended. This allows the first portable device to prepare for resuming communication with the in-vehicle communication device via the first antenna. In other words, the in-vehicle communication device can smoothly resume communication with the first portable device using the first antenna.

[0133] (4) In the in-vehicle communication device, the processing circuit 35 measures the distance between the first portable device and the vehicle 40 equipped with the in-vehicle communication device through communication with the first portable device using the first antenna. Then, in the in-vehicle communication device, the processing circuit 35 measures the distance between the vehicle 40 and the second portable device through communication with the second portable device using the first antenna.

[0134] The in-vehicle communication device measures the distance to the first portable device and the distance to the second portable device through communication using the first antenna. Thus, when the in-vehicle communication device is performing distance measurement for the first portable device and is requested to perform distance measurement by the second portable device, the in-vehicle communication device can interrupt distance measurement for the first portable device and start distance measurement for the second portable device.

[0135] (5) The in-vehicle communication device further includes a third antenna in addition to the first antenna and the second antenna, and also includes a storage device 14. In the in-vehicle communication device, when the processing circuit 13 switches the communication setting for communication using the first antenna from the first setting to the second setting, it stores a result of ranging for the first portable device through communication using the first antenna in the storage device 14 and then stops communication with the first portable device through the first setting using the first antenna. In the in-vehicle communication device, while the processing circuit 13 is measuring the distance to the second portable device through communication using the first antenna, when referring to the result of ranging for communication using the first antenna in communication with the first portable device using the third antenna, it refers to the result of ranging for the first portable device stored in the storage device 14.

[0136] While the communication setting for communication using the first antenna is switched from the first setting to the second setting, the in-vehicle communication device holds the result of distance measurement for the first portable device relative to vehicle 40. This allows the in-vehicle communication device to refer to the result of distance measurement in communication with the first portable device using the third antenna even while communicating with the second portable device using the first antenna.

[0137] (6) In the in-vehicle communication device, the processing circuit 13 discards the results of distance measurement to the first mobile device through communication using the first antenna, which are stored in the memory device 14, after a certain period of time has elapsed since the results were stored in the memory device 14.

[0138] The distance between the vehicle 40 and the first mobile device may change over time, and therefore the reliability of the distance measurement results held by the in-vehicle communication device decreases as time passes.

[0139] The in-vehicle communication device does not retain the distance measurement result for the first portable device for a certain period of time or longer, thereby preventing the in-vehicle communication device from referring to an uncertain distance measurement result when communicating with the first portable device using the third antenna.

[0140] (7) In the in-vehicle communication device, when the processing circuit 35 obtains the result of distance measurement to the second portable device through communication using the first antenna, it executes the termination of communication with the second portable device using the first antenna.

[0141] The in-vehicle communication device waits for the completion of distance measurement for the second portable device before terminating communication with the second portable device using the first antenna, thereby enabling the in-vehicle communication device to more reliably grasp the distance between vehicle 40 and the second portable device.

[0142] (8) The in-vehicle communication device includes a storage device 24. In the in-vehicle communication device, when the processing circuit 23 ends communication with the second portable device using the first antenna, the processing circuit 23 stores a result of distance measurement for the second portable device through communication using the first antenna in the storage device 24. After the processing circuit 23 ends communication with the second portable device using the first antenna, the processing circuit 23 refers to the result of distance measurement stored in the storage device 24 when referring to the result of distance measurement for the second portable device through communication using the first antenna in communication with the second portable device using the second antenna.

[0143] When the in-vehicle communication device terminates communication with the second portable device using the first antenna, the in-vehicle communication device stores the result of distance measurement for the second portable device, thereby allowing the in-vehicle communication device to refer to the result of distance measurement in communication using the second antenna without constantly performing distance measurement through communication with the second portable device using the first antenna.

[0144] (9) In the in-vehicle communication device, the processing circuit 23 discards the results of distance measurement to the second mobile device through communication using the first antenna, which are stored in the memory device 24, after a certain period of time has elapsed since the results were stored in the memory device 24.

[0145] The distance between the vehicle 40 and the second mobile device may change over time, and therefore the reliability of the distance measurement results held by the in-vehicle communication device decreases as time passes.

[0146] The in-vehicle communication device does not retain the distance measurement result for the second portable device for a certain period of time or longer, thereby preventing the in-vehicle communication device from referring to an uncertain distance measurement result when communicating with the second portable device using the second antenna.

[0147] (10) The in-vehicle communication device further includes a third antenna in addition to the first antenna and the second antenna. The range over which the in-vehicle communication device can communicate with the second portable device using the second antenna is narrower than the range over which the in-vehicle communication device can communicate with the first portable device using the third antenna. In the in-vehicle communication device, a processing circuit 35 executes communication using the first antenna with a portable information terminal 11, which is the first portable device and to which a digital key of a vehicle 40 equipped with the in-vehicle communication device is registered. In the in-vehicle communication device, a processing circuit 13 executes BLE (Bluetooth low energy) communication 15 with the portable information terminal 11 using the third antenna. In the in-vehicle communication device, the processing circuit 35 executes communication using the first antenna with a smart key 21 of the vehicle 40, which is the second portable device. In the in-vehicle communication device, a processing circuit 23 executes LF (low frequency) communication 27 and RF (radio frequency) communication 28 with the smart key 21 using the second antenna.

[0148] When the in-vehicle communication device is communicating with the mobile information terminal 11 in which the digital key is registered using the first antenna and is requested by the smart key 21 to communicate using the first antenna, the in-vehicle communication device switches the communication setting to communication using the first antenna. This allows the in-vehicle communication device to communicate with the smart key 21 using the first antenna in response to the communication request from the smart key 21.

[0149] (11) In the in-vehicle communication device, the processing circuit 35 uses the first antenna to perform UWB (Ultra Wideband) communication 33 with the first mobile device and the second mobile device. As a result, even while the in-vehicle communication device is performing UWB communication 33 with the first mobile device, the in-vehicle communication device can perform UWB communication 33 with the second mobile device in response to a request for UWB communication 33 from the second mobile device.

[0150] (12) A communication method is applied to an in-vehicle communication device including a first antenna, a second antenna, and a processing circuit 35. The communication method includes a step in which, when communicating with a first portable device using the first antenna, the processing circuit 35 executes a step of changing a communication setting for communication using the first antenna to a first setting that matches the specifications of the first portable device. The communication method also includes a step in which, when communication with the first portable device using the first antenna is being performed using the first antenna and a second portable device with specifications different from those of the first portable device requests communication using the first antenna based on a communication result using the second antenna, the processing circuit 35 executes a step of switching the communication setting for communication using the first antenna from the first setting to a second setting that matches the specifications of the second portable device. The communication method also includes a step in which the processing circuit 35 executes a step of starting communication with the second portable device using the first antenna using the second setting.

[0151] The communication method includes, when a communication using the first antenna is requested from a second portable device while the first portable device is communicating with the first portable device using the first antenna, switching communication settings for communication using the first antenna, thereby enabling communication with the second portable device using the first antenna in response to the communication request from the second portable device.

[0152] <Modifications> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0153] In the present embodiment, the in-vehicle communication device performs UWB communication 33 with the mobile information terminal 11 as the first mobile device. On the other hand, the in-vehicle communication device may perform UWB communication 33 with a mobile device other than the mobile information terminal 11 as the first mobile device.

[0154] In this embodiment, the in-vehicle communication device performs UWB communication 33 with the smart key 21 as the second portable device. However, the in-vehicle communication device may perform UWB communication 33 with a portable device other than the smart key 21 as the second portable device.

[0155] In this embodiment, the in-vehicle communication device performs UWB communication 33 using the UWB antenna 30 with the first and second mobile devices as communication using the first antenna. However, the communication using the first antenna performed by the in-vehicle communication device is not limited to UWB communication 33.

[0156] In the present embodiment, the in-vehicle communication device performs, as communication using the second antenna, LF communication 27 using the LF antenna 25 and RF communication 28 using the RF antenna 26 with the second mobile device. However, the communication using the second antenna performed by the in-vehicle communication device is not limited to LF communication 27 and RF communication 28.

[0157] In the present embodiment, the in-vehicle communication device performs BLE communication 15 with the first mobile device using the BLE antenna 16 as communication using the third antenna. However, the communication using the third antenna performed by the in-vehicle communication device is not limited to BLE communication 15.

[0158] In the present embodiment, the in-vehicle communication device performs UWB communication 33 with priority given to the smart key 21. On the other hand, the in-vehicle communication device may perform UWB communication 33 with priority given to the portable information terminal 11.

[0159] In this embodiment, the in-vehicle communication device preferentially performs UWB communication 33 with a portable device that does not have time to start distance measurement by UWB communication 33. On the other hand, the in-vehicle communication device may preferentially perform UWB communication 33 with a portable device that has time to start distance measurement by UWB communication 33.

[0160] In this embodiment, the in-vehicle communication device performs UWB communication 33 preferentially with a portable device that requires less information to be exchanged to set parameters. On the other hand, the in-vehicle communication device may perform UWB communication 33 preferentially with a portable device that requires more information to be exchanged to set parameters.

[0161] In this embodiment, as shown in the lower part of Fig. 8 , after executing UWB communication 33 with the smart key 21, which is the second portable device, the in-vehicle communication device resumes UWB communication 33 with the portable information terminal 11, which is the first portable device. On the other hand, the in-vehicle communication device does not need to resume UWB communication 33 with the portable information terminal 11. In this case, the in-vehicle communication device stops UWB communication 33 with the portable information terminal 11 as shown in the upper part of Fig. 8 , and then ends UWB communication 33 with the portable information terminal 11.

[0162] In this embodiment, the in-vehicle communication device performs UWB communication 33 with two mobile devices: the mobile information terminal 11, which is the first mobile device, and the smart key 21, which is the second mobile device. However, the in-vehicle communication device may perform UWB communication 33 with three or more mobile devices.

[0163] In this embodiment, as shown and explained in the lower part of Figure 8, after executing UWB communication 33 with the smart key 21, which is the second portable device, the in-vehicle communication device resumes UWB communication 33 with the mobile information terminal 11, which is the first portable device. On the other hand, when the in-vehicle communication device is executing UWB communication 33 with three or more portable devices, the in-vehicle communication device may execute UWB communication 33 with a third portable device that is neither the mobile information terminal 11 nor the smart key 21, rather than resuming UWB communication 33 with the mobile information terminal 11.

[0164] In this embodiment, the in-vehicle communication device performs distance measurement for the mobile information terminal 11 via UWB communication 33, as shown in Fig. 3. Then, when responding to an operation by the user of the mobile information terminal 11, the in-vehicle communication device receives and determines the result of the distance measurement in Fig. 3, as shown in Fig. 4.

[0165] The manner in which the in-vehicle communication device communicates with the mobile information terminal 11 is not limited to the manner shown in Fig. 3 and Fig. 4. In other words, the in-vehicle communication device may store a determination result for the distance measurement result of the mobile information terminal 11 via UWB communication 33, as in the case of the smart key 21 in Fig. 5, and refer to the stored determination result when responding to a user operation as in Fig. 6.

[0166] In this embodiment, the in-vehicle communication device performs distance measurement for the smart key 21 via UWB communication 33 and stores the results of the distance measurement, as shown in Fig. 5. Then, when responding to a user operation of the smart key 21, the in-vehicle communication device refers to the distance measurement results stored in Fig. 5, as shown in Fig. 6.

[0167] The manner in which the in-vehicle communication device communicates with the smart key 21 is not limited to the manner shown in Figures 5 and 6. In other words, the in-vehicle communication device may measure the distance to the smart key 21 via UWB communication 33, as it does with the mobile information terminal 11 in Figure 3, and receive the result of the distance measurement from the UWB antenna 30 when responding to a user operation as shown in Figure 4. In this case, the in-vehicle communication device does not need to store the result of the distance measurement to the smart key 21 via UWB communication 33, as shown in the lower part of Figure 5.

[0168] In this embodiment, as shown and described in Fig. 9, when the in-vehicle communication device stops UWB communication 33 with the portable information terminal 11, the in-vehicle communication device stores the results of communication by UWB communication 33. On the other hand, when the in-vehicle communication device stops UWB communication 33 with the portable information terminal 11, the in-vehicle communication device does not need to store the results of communication by UWB communication 33. In this case, when responding to the operation of the user of the portable information terminal 11 in the middle part of Fig. 8, the in-vehicle communication device does not refer to the results of distance measurement, as shown in Fig. 10.

[0169] In this embodiment, the in-vehicle communication device discards the results of the distance measurement for the mobile information terminal 11 after a certain period of time has elapsed, as shown in the middle part of Fig. 8. On the other hand, the in-vehicle communication device does not have to discard the results of the distance measurement for the mobile information terminal 11. In this case, the in-vehicle communication device continues to hold the results of the distance measurement for the mobile information terminal 11 until the results of the distance measurement for the mobile information terminal 11 can be grasped, as shown in the lower part of Fig. 8.

[0170] In this embodiment, the in-vehicle communication device discards the results of the distance measurement for the smart key 21 after a certain period of time has elapsed, as shown in the lower part of Figure 8. Then, as shown and explained in Figure 8, after discarding the results of the distance measurement, the in-vehicle communication device performs distance measurement for the smart key 21 again after authenticating the smart key 21. On the other hand, the in-vehicle communication device does not have to discard the results of the distance measurement for the smart key 21. In this case, the in-vehicle communication device continues to hold the results of the distance measurement for the smart key 21 until the results of the distance measurement for the smart key 21 can be determined, as shown in the middle part of Figure 8.

Claims

1. An in-vehicle communication device comprising a first antenna, a second antenna, and a processing circuit, wherein the processing circuit is configured to: when communicating with a first mobile device using the first antenna, change the communication settings for communication using the first antenna to a first setting that matches the specifications of the first mobile device; when, while communicating with the first mobile device using the first antenna with the first setting, a second mobile device having specifications different from those of the first mobile device requests communication using the first antenna based on the communication result using the second antenna, switch the communication settings for communication using the first antenna from the first setting to a second setting that matches the specifications of the second mobile device; and start communication with the second mobile device using the first antenna with the second setting.

2. The in-vehicle communication device according to claim 1, wherein the processing circuit is configured to, after switching the communication setting for communication using the first antenna from the first setting to the second setting, when communication using the first antenna with the second mobile device is terminated, switch the communication setting for communication using the first antenna from the second setting to the first setting, and resume communication using the first antenna with the first mobile device.

3. The in-vehicle communication device according to claim 2, further comprising a third antenna in addition to the first antenna and the second antenna, wherein the processing circuit is configured to, after communication with the second portable device using the first antenna has ended and before communication with the first portable device using the first antenna is resumed, notify the first portable device, via communication using the third antenna, that communication with the second portable device using the first antenna has ended.

4. An in-vehicle communication device as described in any one of claims 1 to 3, wherein the processing circuit is configured to: measure the distance between a vehicle equipped with the in-vehicle communication device and the first portable device through communication with the first portable device using the first antenna; and measure the distance between the vehicle and the second portable device through communication with the second portable device using the first antenna.

5. An in-vehicle communication device as described in claim 4, further comprising a third antenna in addition to the first antenna and the second antenna, and a memory device, wherein the processing circuit is configured to: when switching the communication setting for communication using the first antenna from the first setting to the second setting, store the results of ranging for the first portable device through communication using the first antenna in the memory device, and then stop communication with the first portable device through the first setting using the first antenna; and while ranging for the second portable device through communication using the first antenna, when referring to the results of ranging for communication using the first antenna in communication with the first portable device using the third antenna, refer to the results of ranging for the first portable device stored in the memory device.

6. The in-vehicle communication device according to claim 5, wherein the processing circuit is configured to discard the results of distance measurement to the first mobile device through communication using the first antenna, stored in the storage device, after a certain period of time has elapsed since the results were stored in the storage device.

7. An in-vehicle communication device according to any one of claims 4 to 6, wherein the processing circuit is configured to terminate communication with the second portable device using the first antenna when a distance measurement result for the second portable device is obtained through communication using the first antenna.

8. An in-vehicle communication device as described in claim 7, comprising a memory device, wherein the processing circuit is configured to: when terminating communication with the second portable device using the first antenna, store in the memory device the results of distance measurement for the second portable device through communication using the first antenna; and after terminating communication with the second portable device using the first antenna, when referring to the results of distance measurement for the second portable device through communication using the first antenna in communication with the second portable device using the second antenna, refer to the results of distance measurement stored in the memory device.

9. The in-vehicle communication device described in claim 8, wherein the processing circuit is configured to discard the results of distance measurement to the second mobile device through communication using the first antenna, which are stored in the memory device, after a certain period of time has elapsed since the results were stored in the memory device.

10. An in-vehicle communication device according to any one of claims 1 to 9, further comprising a third antenna in addition to the first antenna and the second antenna, wherein the range in which communication with the second portable device is possible using the second antenna is narrower than the range in which communication with the first portable device is possible using the third antenna, and wherein the processing circuit is configured to: communicate with a portable information terminal, as the first portable device, that has registered a digital key of a vehicle equipped with the in-vehicle communication device, using the first antenna; communicate with the portable information terminal via BLE (Bluetooth low energy) using the third antenna; communicate with a smart key of the vehicle, as the second portable device, using the first antenna; and communicate with the smart key via LF (Low Frequency) communication and RF (Radio Frequency) communication using the second antenna.

11. An in-vehicle communication device according to any one of claims 1 to 10, wherein the processing circuit is configured to perform UWB (Ultra Wideband) communication with the first mobile device and the second mobile device using the first antenna.

12. A communication method applicable to an in-vehicle communication device equipped with a first antenna, a second antenna, and a processing circuit, comprising: a step in which, when communicating with a first mobile device using the first antenna, the processing circuit executes a step of changing a communication setting for communication using the first antenna to a first setting that matches the specifications of the first mobile device; a step in which, when communicating with the first mobile device using the first antenna using the first setting and a request for communication using the first antenna is received from a second mobile device having specifications different from those of the first mobile device based on the communication result using the second antenna, the processing circuit executes a step of switching the communication setting for communication using the first antenna from the first setting to a second setting that matches the specifications of the second mobile device; and a step in which the processing circuit executes a step of starting communication with the second mobile device using the first antenna using the second setting.

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