Controlling a hands-free device on board a motor vehicle

Abstract

A method (300) for controlling a hands-free device (125) on board a motor vehicle (105) comprises steps of determining a distance of a wireless key (110) from the motor vehicle (105); establishing a wireless communication link between the motor vehicle (105) and a mobile phone (115); and controlling the hands-free device (125) depending on the determined distance.

Description

[0001] The present invention relates to the control of a hands-free system on board a motor vehicle. In particular, the invention relates to activating or deactivating the hands-free system depending on whether a person is on board the motor vehicle or not.

[0002] A motor vehicle includes a hands-free system configured to establish a wireless communication connection to a mobile phone and, in the case of a telephone call, to serve as an acoustic input or output point, allowing a person on board the motor vehicle to make a telephone call without having to hold or operate the mobile phone. The hands-free system can be activated, for example, as soon as the mobile phone is within communication range and the motor vehicle is being prepared for starting. When the motor vehicle is parked, the hands-free system can be deactivated.

[0003] In some situations, however, automatic switching between the hands-free system and the mobile phone is still unsatisfactory. For example, if the vehicle is ready to drive and a person gets out of the vehicle, the hands-free system may remain activated by mistake. The person can deactivate the hands-free system manually, for example by controlling the mobile phone accordingly, but a similar problem may arise when getting back into the vehicle, where the hands-free system is not automatically activated even though the person is back on board with their mobile phone. Even if the vehicle is parked but the person does not leave the vehicle at all, the hands-free system may be deactivated even though it would be better to leave it activated.

[0004] Proposals have been made to control the hands-free system based on the opening status of a vehicle door or hatch. However, such approaches have not proven effective in practice.

[0005] An object underlying the present invention is therefore to provide an improved technology for controlling a hands-free system on board a motor vehicle. The invention achieves this object by means of the subject matter of the independent claims. Subclaims specify preferred embodiments.

[0006] According to a first aspect of the present invention, a method for controlling a hands-free device on board a motor vehicle comprises steps of determining a distance of a wireless key from the motor vehicle; establishing a wireless communication connection between the motor vehicle and a mobile phone; and controlling the hands-free device as a function of the determined distance.

[0007] This allows for the possibility of determining the distance between the vehicle and the wireless key with sufficient precision. It can be assumed that a person carrying the wireless key also carries their mobile phone. This allows for improved control of the hands-free system based on the person's presence in the vehicle.

[0008] It is further preferred that a position of the wireless key be determined. The position can be determined from the determined distance and a determined direction of the wireless key relative to the motor vehicle.

[0009] The wireless key may comprise a digital car key configured to perform two-way authentication with the motor vehicle in order to control a predetermined function of the motor vehicle. This function may, in particular, comprise a security function, for example, unlocking or locking a door or hatch or starting a drive engine. The digital car key may, for example, function according to a specification of the Car Connectivity Consortium, as published in the technical specification "Digital Key Release 3" in version 1.1.0 of July 2022. Different wireless interfaces may be used for a communication method between the wireless key and the motor vehicle, at least one of which may be used to determine the position of the wireless key relative to the motor vehicle.

[0010] Preferably, the method includes determining whether the wireless key is located in an interior of the motor vehicle. The hands-free device can be activated if the wireless key is located in the interior; or deactivated if it is located outside the interior.

[0011] Determining whether the wireless key is inside or outside the vehicle's interior can be easily determined based on the specific relative position of the wireless key and the size and shape of the vehicle. This allows for precise and reliable positioning of the key, and thus usually also of the mobile phone.

[0012] In one embodiment, the communication connection is established depending on the specific distance or position. In other words, the communication connection can only be established when it is required to transmit data between the mobile phone and the hands-free device. This allows electrical energy to be saved for operating the communication connection. In particular, the mobile phone's electrical energy storage device can be less heavily loaded.

[0013] It should be noted that the hands-free control described herein can be performed regardless of whether a call is currently being conducted with the mobile phone. In another embodiment, the communication connection can also be established only when an incoming or outgoing call is detected.

[0014] In one embodiment, the position determination is carried out in a time-controlled manner at predetermined time intervals. In another embodiment, the position or distance of the wireless key relative to the motor vehicle is determined at least when a door or lid of the motor vehicle is opened or closed. The position determination can be performed multiple times over a predetermined period after opening or closing. The position determination can be continued if it is determined that the person is moving. Thus, the position of the wireless key can be determined more frequently when a change in position of a person carrying the wireless key is likely.

[0015] In a further embodiment, activation or deactivation of the hands-free system is only controlled when a motor vehicle is determined to be stationary. Getting a person into or out of the motor vehicle is unsafe if the motor vehicle is not stopped. It can be assumed that getting into or out of a moving motor vehicle will not occur. Accordingly, the location of the wireless key can be determined, in particular, when the motor vehicle is stationary. If the motor vehicle is traveling at a predetermined minimum speed, the position determination can occur less frequently or be suspended.

[0016] According to a further aspect of the present invention, a motor vehicle comprises a first wireless interface for communicating with a mobile phone; a hands-free device; a second wireless interface for determining a distance of a wireless key from the motor vehicle; and a control device. The control device is configured to control the hands-free device depending on the determined distance of the wireless key.

[0017] The control device can be configured to partially or completely execute a method described herein. For this purpose, the processing device can be implemented electronically and comprise, for example, an integrated circuit, a programmable logic module, or a programmable microcomputer. The method can be implemented in the form of a configuration or as a computer program product with program code means for the processing device. The configuration or the computer program product can be stored on a computer-readable data carrier. Features or advantages of the method can be transferred to the device, or vice versa.

[0018] The second wireless interface is preferably configured to determine a position of the wireless key; the control device is configured to control the hands-free device depending on the determined position. The position can be determined based on the distance and a direction of the wireless key relative to the motor vehicle. The direction can be determined by determining distances between the wireless key and different positions on the motor vehicle and contextualizing them. Transceivers of the second wireless interface can be located at the positions.

[0019] The first interface can be implemented according to any standard for wireless data transmission. However, it is preferred that the first interface be implemented as a Bluetooth interface. More preferably, the first interface is implemented as a Bluetooth Low Energy (BLE) interface. An interface according to one of these standards can achieve good ranges at high data transmission rates. The electrical current consumption can be moderate.

[0020] In a first variant, the first and second interfaces are identical. For example, the distance of the wireless key from the interface can be determined based on a received signal strength indicator (RSSI). In some embodiments, the first interface is configured to determine the distance and, if applicable, the direction of the wireless key using channel sounding. With regard to Bluetooth Low Energy, such a technique is described in the "Bluetooth Core Specification v5.4." This allows sufficiently accurate results to be achieved to determine whether the wireless key is on board the motor vehicle or outside.

[0021] In a second variant, the first and second interfaces are implemented separately from one another. It is preferred that the second wireless interface comprises an ultra-wideband (UWB) interface. The determination of a distance and, if applicable, a direction of the wireless key relative to the motor vehicle is described in more detail, for example, in the "Digital Car Key" specification cited herein.

[0022] According to yet another aspect of the present invention, a system comprises a motor vehicle as described herein, a mobile phone, and a wireless key. The wireless key can be embodied as a separate device, in particular as a handheld device. The mobile phone and the wireless key can be assigned to the same person. Thus, the position of the wireless key can be used to determine the location of the person and the location of the mobile phone.

[0023] It is particularly preferred that the mobile phone and the wireless key are integrated with one another. In addition to the first and second wireless interfaces, the mobile phone can also comprise a third wireless interface configured for near-field communication (NFC). Using the third interface, authentication information can be exchanged between the mobile device and the motor vehicle, for example. The third interface typically has a very short range of a few centimeters and is therefore usually only of limited use for determining whether the wireless key is on board the motor vehicle or outside.

[0024] The invention will now be described in more detail with reference to the accompanying drawings, in which: Fig. 1 a system comprising a motor vehicle; Fig. 2 a motor vehicle and a mobile phone; and Fig. 3 illustrates a flow chart of a process.

[0025] Fig. 1 shows a system 100 with a motor vehicle 105. The system 100 further includes an optional wireless key 110 and, optionally, a mobile phone 115.

[0026] The motor vehicle 105 and the mobile phone 115 can be assigned to the same person 120. For example, the person 120 can be a passenger, a driver, or an owner of the motor vehicle 105. The wireless key 110 can be used to utilize a central or security-relevant function of the motor vehicle 105. Although it is preferred that the wireless key 110 be integrated with the mobile phone 115, the key 110 and the mobile phone 115 can also be implemented separately.

[0027] The wireless key 110 can be implemented outside the mobile phone 115 as a handheld device, which can, for example, take the form of a key fob or a remote control, or can be integrated with a mechanical vehicle key. The handheld device can include one or more buttons with which the person 120 can control predetermined functions of the motor vehicle 105.

[0028] A hands-free device 125 is provided in the motor vehicle 105, which can comprise at least one microphone 130 and at least one loudspeaker 135. The hands-free device 135 can be implemented in various ways, for example, as part of an entertainment system. The subject matter of the present invention is to activate the hands-free device 125 for conducting a telephone call with the mobile phone 115, if possible, only when the person 120 or the mobile phone 115 is on board the motor vehicle 105 and in particular in an interior 140 of the motor vehicle 105. For this purpose, it is proposed to determine the position of the wireless key 110 and to use this position to infer a position of the person 120 or the mobile phone 115.

[0029] Fig. 2 shows the motor vehicle 105 and the mobile phone 115 of the system 100 of Fig. 1 in a different representation. For example, the mobile phone 115 is shown separately from the wireless key 110.

[0030] On board the motor vehicle 105 is a control device 205 connected to a first wireless interface 210 and a second wireless interface 215. The first interface 210 is preferably implemented according to the BT or BLE standard, while the second interface 215 preferably operates according to the UWB standard. The first interface 210 can have one or more antennas (transceivers) 220. The transceivers 220 can be controlled transparently through the first interface 210.

[0031] The second interface 215 preferably comprises a plurality of transceivers 220, which are mounted at different locations on the motor vehicle 105. For example, one transceiver 220 can be mounted in each of the front left, front right, rear left, rear right, center left, and / or center right areas. Additionally, one or more transceivers 220 can be mounted in the interior of the motor vehicle 105.

[0032] To determine a distance or position of the wireless key 110 or the mobile phone 115, the transceivers 220 of the second wireless interface 215 can be controlled to each transmit a signal sequentially at a predetermined time interval. The wireless key 110 can receive the signals sequentially and determine intervals between reception times. The wireless key 110 typically maintains different distances from the different transceivers 220. A propagation speed for signals from all transceivers 220 is the same, so that the different distances can be determined based on the time intervals that elapse between the reception of successive signals. In this case, both a distance and a direction, and thus a position, of the wireless key 110 relative to the motor vehicle 105 can be determined.

[0033] It should be noted that a corresponding technique can also be carried out by means of the first interface 210 and, for example, on the basis of Bluetooth signals.

[0034] Furthermore, the UHF frequency at 433 MHz, 868 MHz, or 315 MHz, which is widely used for wireless keys, can be used as the first interface 210, and the LF technology of the keyless entry / passive entry system can be used as the second interface 215. Instead of evaluating signal propagation times, the signal levels to the transceivers 220 can also be evaluated for localization.

[0035] Optionally, the motor vehicle 105 also has a third wireless interface 225, which can operate in particular according to the NFC standard. The third wireless interface 225 can play a role in authentication between the wireless key 110 and the motor vehicle 105.

[0036] The wireless key 110 can be used to control a predetermined function of the motor vehicle 105, in particular a security function that can enable or authorize access to or use of the motor vehicle 105. If the wireless key 110 is integrated with the mobile phone 115, a vehicle function can be controlled via a corresponding application; operation can be performed via an input / output device. To control the hands-free system 125, the control device 205 can, in particular, access a specific position of the wireless key 110.

[0037] To evaluate further information on board the motor vehicle 105 that may indicate the location of the wireless key 110, a further interface 230 may be provided, which is typically wired and may be connected to a data bus of the motor vehicle 105. A further signal on board the motor vehicle 105 may be received via the interface 230, which may, for example, relate to the opening or closing of a vehicle door or a vehicle hatch. Another exemplary signal may indicate a driving speed or whether the motor vehicle 105 is stationary or moving. Another possible signal may indicate whether the motor vehicle 105 is parked or ready to drive.

[0038] Fig.3 shows a flowchart of an exemplary method 300. In a step 305, the motor vehicle 105 is parked. A corresponding signal can be provided for this purpose. It can also be determined that the motor vehicle 105 is stationary.

[0039] If the person 120 carrying the wireless key 110 and the mobile phone 115 approaches the motor vehicle 105, the wireless key 110 comes within communication range of the motor vehicle 105 at a given time, so that a communication connection can be established via the first interface 210 in a step 310. The communication connection can, in particular, comprise a BLE connection.

[0040] In a step 315, an approach of the person 120 can be determined, for example, based on a signal strength curve of a signal via the first wireless interface 210. Other indicators can also be evaluated to determine that the person 120 is approaching the motor vehicle 105 and that there is a probability that the person 120 wants to enter the motor vehicle 105.

[0041] Typically, the range of the second wireless interface 215 is shorter than that of the first wireless interface 210, so that communication via the second wireless interface 215 can only take place at a later time. The result of this communication can include enabling a predetermined function of the motor vehicle 105. The function can be controlled automatically or at the request of the person 120.

[0042] In a step 320, it can be determined that a vehicle door of the motor vehicle 105 has been opened. For this determination, for example, a door contact, an image from an interior camera, or a request for automatic door opening can be evaluated.

[0043] In a step 325, a distance or position of the wireless key 110 relative to the motor vehicle 105 can be determined. The distance determination can be time-controlled or triggered by an event. The event can, in particular, include the opening of a door or flap, which was determined in step 320.

[0044] Based on the determined distance or position, it can be determined in a step 330 whether the wireless key 110 is located in the interior 140 of the motor vehicle 105 or not.

[0045] If it is determined that the wireless key 110 is not located in the interior 140 of the motor vehicle 105, the hands-free device 125 may be deactivated in a step 335. Otherwise, if it is determined that the wireless key 110 is present in the interior 140 of the motor vehicle 105, the hands-free device 125 may be activated in a step 340.

[0046] After completing one of steps 335, 340, the method 300 may return to step 320 and run through it again. This run may be interrupted if the motor vehicle 105 is parked and the person 120 has left the motor vehicle 105. Reference symbol 100 systems 105 Motor vehicle 110 wireless key 115 Mobile phone 120 people 125 Hands-free system 130 microphone 135 speakers 140 interior 205 Control device 210 first wireless interface 215 second wireless interface 220 transceivers 225 third interface 230 interface 300 procedures 305 Motor vehicle is parked 310 Establish BLE connection 315 Determine approach to the motor vehicle 320 Determine door opening 325 Determine distance or position 330 wireless key in the interior? 335 Deactivate hands-free system 340 Activate hands-free system

Claims

[1] Method (300) for controlling a hands-free device (125) on board a motor vehicle (105), the method (300) comprising the following steps: - determining (325) a distance of a wireless key (110) from the motor vehicle (105); - establishing (310) a wireless communication connection between the motor vehicle (105) and a mobile phone (115); and - Controlling (335, 340) the hands-free device (125) depending on the determined distance. [2] The method (300) of claim 1, wherein a position of the wireless key (110) is determined (325); and wherein the hands-free device (125) is controlled in dependence on the determined position. [3] The method (300) of claim 1 or 2, wherein it is determined whether the wireless key (110) is located in an interior (140) of the motor vehicle (105); and the hands-free device (125) is activated if the wireless key (110) is located in the interior (140); or deactivated if it is located outside the interior (140). [4] Method (300) according to one of the preceding claims, wherein the communication connection is established (310) as a function of the determined distance. [5] Method (300) according to one of the preceding claims, wherein the distance to the wireless key (110) is determined when a door or flap of the motor vehicle (105) is opened or closed (320). [6] Method (300) according to one of the preceding claims, wherein activation or deactivation of the hands-free device (125) is controlled only when a standstill of the motor vehicle (105) has been determined. [7] Motor vehicle (105) with the following elements: - a first wireless interface (210) for communication with a mobile phone (115); - a hands-free device (125); - a second wireless interface (215) for determining a distance of a wireless key (110) from the motor vehicle (105); and - a control device (205) which is designed to control the hands-free device (125) as a function of the determined distance of the wireless key (110). [8] Motor vehicle (105) according to claim 7, wherein the second wireless interface (215) is configured to determine a position of the wireless key (110); and wherein the control device (205) is configured to control the hands-free device (125) depending on the determined position. [9] Motor vehicle (105) according to one of claims 7 or 8, wherein the first interface (210) operates with Bluetooth Low Energy. [10] Motor vehicle (105) according to claim 9, wherein the first (210) and the second interface (215) are identical to each other. [11] Motor vehicle (105) according to one of claims 7 to 10, wherein the second wireless interface (215) operates with UWB. [12] System (100) comprising a motor vehicle (105) according to any one of claims 7 to 11, a mobile phone (115) and a wireless key (110). [13] The system (100) of claim 12, wherein the mobile phone (115) is integrated with the wireless key (110).

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