Method for authorizing access to a motor vehicle by means of a mobile electronic identification device

Description

[0001] The invention relates to a method for authorizing access to a motor vehicle by means of a mobile electronic identification transmitter and to an arrangement comprising a motor vehicle and an identification transmitter which is set up / programmed to carry out this method.

[0002] Mobile electronic identification transmitters are used to authorize access to a motor vehicle as an alternative to a mechanical vehicle key. Low-frequency radio systems are typically used to communicate between the identification transmitter and the vehicle. This allows authentication data to be transmitted wirelessly. In this context, the use of a radio connection according to the UWB standard is well known. Using such a communication connection according to the UWB standard, it is not only possible to transmit data between the identification transmitter and the vehicle. Such UWB transmission also allows the current distance between the identification transmitter and the vehicle to be determined with relatively high accuracy and transmitted to the vehicle.

[0003] Methods such as the "ping-pong" method or the so-called "polling" method can be used for this purpose. These methods are based on determining the required signal transmission time for signals transmitted between the identification transmitter and the vehicle and using this transmission time to calculate the desired distance between the vehicle and the identification transmitter.

[0004] However, the disadvantage of such a UWB connection is its relatively high electrical power consumption and relatively short range.

[0005] In this context, it is known from conventional motor vehicles, whose access can be authorized using mobile identification transmitters, to implement the wireless transmission of authorization information in addition to the UWB connection using an additional radio connection according to the so-called BLE standard ("Bluetooth Low Energy Standard"). A communication connection according to the BLE standard has the advantage of a longer range and lower electrical power requirements compared to a communication connection according to the UWB standard. However, unlike the UWB connection, the BLE connection does not allow for precise determination of the position or distance of the identification transmitters relative to the vehicle.

[0006] These properties of the BLE connection are exploited in the authorization process described in US 2019 0263356 A1. Accordingly, when the identification transmitter approaches the motor vehicle, the UWB communication connection is activated using the BTE communication connection. For this purpose, the signal strength of the BLE connection between the motor vehicle and the identification transmitter is evaluated, and if a certain signal strength threshold is exceeded, the UWB connection is activated. Using said UWB connection, the distance between the motor vehicle and the identification transmitter is then calculated, so that certain actions can be triggered in the motor vehicle if a certain minimum distance is exceeded.

[0007] In practice, however, determining a suitable reference value for the signal strength of the BLE connection proves to be problematic with this method, since this signal strength can depend heavily on a variety of different environmental conditions.

[0008] A passive access system for a vehicle is known from US 2020 / 198580 A1. The passive access system comprises a wearable key fob and a communication and control unit arranged on the vehicle, wherein the communication and control unit is configured to control a function of the vehicle. The wearable fob and the communication and control unit are configured to communicate with each other via ultra-wideband (UWB) signals. When the vehicle function is triggered, the communication and control unit initiates a two-way UWB ranging session with the wearable fob, wherein the portable pendant determines a first distance between the portable pendant and the communication and control unit, and the communication and control unit determines a second distance between the portable pendant and the communication and control unit.

[0009] The communication and control unit is designed to prevent control of the function of the vehicle if a final distance determined from the first and second distances is greater than the predetermined distance.

[0010] Furthermore, a vehicle control device is known from US 2021 / 179014 A1. The vehicle control device comprises a vehicle communication control unit that communicates with a mobile terminal located in a communication area outside the vehicle. Furthermore, the vehicle control device comprises a distance measuring unit that measures a distance between a vehicle and the mobile terminal.Furthermore, the vehicle control device includes a distance measuring control unit that measures the distance between the vehicle and the mobile terminal by switching, based on a predetermined condition, between a first distance measuring mode in which the distance between the vehicle and the mobile terminal is repeatedly measured by the distance measuring unit without depending on the reception of measurement instruction information transmitted from the mobile terminal, and a second distance measuring mode in which the distance between the vehicle and the mobile terminal is measured by the distance measuring unit in response to the reception of the measurement instruction information when communication is established between the vehicle communication control unit and the mobile terminal.

[0011] It is therefore an object of the present invention to provide an improved method for authorizing access to a motor vehicle by means of a mobile electronic identification transmitter, which takes into account the problems explained above.

[0012] This object is achieved by the subject matter of the independent patent claims. Preferred embodiments are the subject matter of the dependent patent claims.

[0013] The basic idea of the invention is therefore to monitor the decrease in signal strength of the BLE connection while the identification transmitter is moved away from the vehicle and to store the currently measured signal strength as a reference value. When the UWB connection exceeds the maximum range, the UWB connection is interrupted, i.e., deactivated. Due to the increased range, the BLE connection remains active.

[0014] If the ID transmitter approaches the vehicle again at a later time, the BLE connection with a longer range is activated first, so that the increasing signal strength of the BLE connection – due to the decreasing distance between the ID transmitter and the vehicle – is monitored. If the signal strength reaches or exceeds the previously stored reference value, the first communication connection, i.e., the UWB connection, is reactivated in order to determine the current distance of the ID transmitter from the vehicle as part of the authorization process.

[0015] The method according to the invention is used to authorize access to a motor vehicle using a mobile electronic identification transmitter, which can be unlocked using this identification transmitter. The identification transmitter is connected to the motor vehicle both via a first wireless communication connection operating with the UWB standard and via a second wireless communication connection operating with the BLE standard, for data transmission or data transmission. The first wireless communication connection is designed such that it can be used to determine the current distance between the identification transmitter and the motor vehicle. Common methods known to those skilled in the art, such as so-called "ping-poing" methods or a so-called polling method, can be used for this purpose.These methods are based on the fact that by determining the signal propagation time of a signal transmitted from the identification transmitter to the motor vehicle or vice versa from the motor vehicle to the identification transmitter, a current distance between the identification transmitter and the motor vehicle is calculated.

[0016] A maximum range of the first communication connection measured from the motor vehicle is less than a maximum range of the second communication connection also measured from the motor vehicle.

[0017] The method according to the invention comprises three measures a), b), and c). According to measure a), a decrease in the signal strength of the second communication connection is monitored, preferably by the motor vehicle, while the identification transmitter is moved away from the motor vehicle, so that the distance between the motor vehicle and the identification transmitter increases. In practice, this is the case when the person carrying the identification transmitter - for example, the driver of the motor vehicle - has left the vehicle after parking it and is moving away from the vehicle. The signal strength can be monitored in the vehicle or in the identification transmitter. According to a further measure b), the current signal strength of the second communication connection is stored as a reference value as soon as the first communication connection between the motor vehicle and the identification transmitter is deactivated or interrupted.This typically occurs when the distance between the vehicle and the identification transmitter has exceeded the maximum range of the first communication connection. Due to the greater maximum range of the second communication connection, it typically remains intact at the time of deactivation or interruption of the first communication connection, so the signal strength of the second communication connection can be easily measured at this time.

[0018] If the identification transmitter is moved back toward the motor vehicle at a later time—this typically occurs when the driver of the parked motor vehicle wishes to drive away—the invention reactivates the deactivated first communication connection as soon as the signal strength of the second communication connection exceeds the stored reference value due to the decreasing distance between the motor vehicle and the identification transmitter when the identification transmitter is moved toward the motor vehicle again. Such an exceedance of the reference value signals that the identification transmitter is within range of the first communication connection, so that it is again available for determining the distance between the motor vehicle and the identification transmitter—as part of the access authorization to the motor vehicle.

[0019] The first communication connection is expediently deactivated when the maximum range of the first communication connection is exceeded when the identification transmitter is moved away from the motor vehicle. However, it is also conceivable that the first communication connection is deactivated at an earlier point in time, for example due to the very high electrical power consumption of the identification transmitter, which is required to operate the first communication connection. To prevent an electrical energy storage device present in the identification transmitter - typically a rechargeable electric battery - from becoming completely discharged, it may therefore be advisable to deactivate the first communication connection before its maximum range has been reached. In this case, however, measures b) and c) can also be applied.

[0020] Particularly preferably, after the reactivation of the first communication connection performed in step c), in step d) following step c), the current distance of the identification transmitter from the vehicle is determined using the first communication connection – as part of the authorization of access to the vehicle for the person carrying the identification transmitter. This makes it possible to trigger various actions in the vehicle depending on the determined distance.

[0021] According to an advantageous further development, authorization data can be transmitted from the identification transmitter to the motor vehicle by means of the second communication connection as soon as the distance determined in measure d) falls below a predetermined minimum value.

[0022] Particularly preferably, a predetermined action can be executed in or on the motor vehicle as soon as the distance determined in measure d) falls below or has fallen below a predetermined minimum value. In further developments of this variant, two or more such actions can also be executed, whereby it is conceivable that each individual action is assigned an individual minimum distance value. This opens up a wide range of design possibilities.

[0023] Particularly preferably, the predetermined action can include or be the unlocking of at least one vehicle door of the motor vehicle. This leads to a significant increase in convenience when the person carrying the identification transmitter wishes to enter the still-locked vehicle, since the vehicle can thus be automatically unlocked, increasing convenience, before the person reaches the vehicle door.

[0024] In measure b), the reference value can be determined by averaging the signal strength over a predetermined period of time. This can prove advantageous for compensating for local fluctuations in the measured signal strength over time or space, similar to a low-pass filter.

[0025] A value for this predetermined period of time of between 1 second and 5 seconds, preferably approximately 4.5 seconds, has proven particularly suitable.

[0026] Particularly preferably, the electronic identification transmitter can be part of a smartphone. Since a modern smartphone is often already configured to transmit data using both the BLE standard and the UWB standard, a commercially available smartphone can be used to implement the method according to the invention without any hardware upgrades.

[0027] The invention further relates to an arrangement comprising a motor vehicle and a mobile electronic identification transmitter, which can communicate or communicates with the motor vehicle by means of a first wireless communication connection according to the UWB standard and by means of a second wireless communication connection according to the BLE standard.

[0028] The first wireless communication connection is designed such that it can be used to determine the current distance between the identification transmitter and the motor vehicle. Common methods, such as the so-called polling method, can be used for this purpose. This method is based on calculating the current distance between the identification transmitter and the motor vehicle by determining the signal propagation time of a signal sent from the identification transmitter to the motor vehicle, or vice versa, from the motor vehicle to the identification transmitter. The arrangement further comprises a control / regulation device present in the motor vehicle, which is configured / programmed to carry out the method according to the invention explained above. The advantages of the method according to the invention explained above are therefore also transferred to the arrangement according to the invention.

[0029] According to a preferred embodiment of the arrangement, the electronic identification transmitter is part of a smartphone or is formed by such a smartphone. Since a modern smartphone is often configured for data transmission using both BLE and UWB standards, a commercially available smartphone can be used to implement the method according to the invention without any hardware upgrades.

[0030] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawing.

[0031] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0032] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0033] The only Figure 1Illustrates an example of an arrangement 20 according to the invention in a plan view. The arrangement 20 comprises a motor vehicle 1 with vehicle doors 4, through which access to a vehicle interior of the motor vehicle 1 is possible. The motor vehicle 1 comprises a control / regulation device 10 that is configured / programmed to carry out the method according to the invention. The control / regulation device 10 can be a control unit connected to a fieldbus present in the motor vehicle 1, such as a LIN or CAN bus. The arrangement 20 further comprises a mobile electronic identification transmitter 2. The electronic identification transmitter 2 can be part of a smartphone 11 or be formed by a smartphone 11. The identification transmitter 2 enables automatic authorization of access to the motor vehicle 1 as the identification transmitter 2 approaches the motor vehicle 1.

[0034] The mobile identification transmitter 2 can communicate with the control / regulation device 10 of the motor vehicle 1 via a first wireless communication connection 3a according to the UWB standard and via a second wireless communication connection 3b according to the BLE standard. For this purpose, a corresponding first transmitting and receiving device 6a can be provided in the motor vehicle 1, which is connected to the control / regulation device 10 for data transmission. This first transmitting and receiving device 6a can communicate via the first communication connection 3a with a corresponding first transmitting and receiving device 7a present in the identification transmitter 2.Accordingly, a second transmitting and receiving device 6b can be provided in the motor vehicle 1, which is connected to the control / regulation device for data transmission and can communicate via the second communication connection 3b with a corresponding second transmitting and receiving device 7b present in the identification transmitter 2. A first maximum range RM1 of the first communication connection 3a from the motor vehicle 1 to the identification transmitter 2, measured from the motor vehicle 1, is less than a second maximum range RM2 of the second communication connection 3b from the motor vehicle 1, also measured from the motor vehicle 1. The first maximum range RM1 and the second maximum range RM2 are shown in FIG. Figure 1 indicated by dashed lines. The ranges RM1 and RM2 shown are not drawn to scale.

[0035] In the following, the Figure 1the method according to the invention is explained by way of example.

[0036] The procedure comprises three measures a), b) and c).

[0037] According to measure a), a decrease in the signal strength of the second communication connection 3b is monitored while the identification transmitter 2 is moved away from the motor vehicle 1, so that the distance A between the motor vehicle 1 and the identification transmitter 2 increases. In measure b), the current signal strength of the second communication connection 3b is stored as a reference value as soon as the maximum range RM1 of the first communication connection 3a is exceeded when the identification transmitter 2 is moved away from the motor vehicle 1. In this case, the first communication connection 3a between the motor vehicle 1 and the identification transmitter 2 is deactivated, whereas the second communication connection 3b remains active. The reference value can be determined by averaging the signal strength over a predetermined period of time. This predetermined period of time can, for example, be between 1 second and 5 seconds, in particular approximately 4.5 seconds.According to measure c), the deactivated first communication connection 3a is reactivated as soon as the signal strength of the second communication connection exceeds the stored reference value again due to the decreasing distance between the motor vehicle and the identification transmitter when the identification transmitter 2 is moved again towards the motor vehicle.

[0038] After the reactivation of the first communication connection 3a carried out in measure c), the current distance A of the identification transmitter 2 from the motor vehicle 1 can be determined by means of the first communication connection 3a in a measure d) following measure c). Authorization data can be transmitted from the identification transmitter 3 to the motor vehicle 1 via the second communication connection 3b, preferably in encrypted form, as soon as the distance A determined in measure d) falls below a predetermined minimum value (AMIN). Likewise, a predetermined action can be carried out in the motor vehicle 1 as soon as the distance A determined in measure d) falls below the predetermined minimum value AMIN (cf. Figure 1 ). This predetermined action can, for example, be the unlocking of one of the vehicle doors 4 of the motor vehicle 1.

Claims

1. Method for authorizing access to a motor vehicle (1) by means of a mobile electronic identification transmitter (2), which motor vehicle can be unlocked by means of this identification transmitter (2), wherein the identification transmitter (2) can communicate with the motor vehicle (1) for data transmission, both via a first wireless communication connection (3a) operating according to the UWB standard and via a second wireless communication connection (3b) operating according to the BLE standard, wherein a maximum transmission range (RM1) of the first communication connection (3a) is less than a maximum transmission range (RM2) of the second communication connection (3b), wherein the method comprises the following measures: a) monitoring a decrease in the signal strength (S) of the second communication connection (3b) while the identification transmitter (2) is moved away from the motor vehicle (1), such that the distance (A) between the motor vehicle (1) and the identification transmitter (2) increases, b) storing the current signal strength (S) of the second communication connection (3b) as a reference value as soon as the first communication connection (3a) between the motor vehicle (1) and the identification transmitter (2) is deactivated / interrupted, c) reactivating the first communication connection (3a) when the identification transmitter (2) is moved back toward the motor vehicle (1), as soon as the signal strength (S) of the second communication connection (3b) exceeds the stored reference value due to the decreasing distance (A) between the motor vehicle (1) and the identification transmitter (2).

2. Method according to claim 1, characterized in that the first communication connection is deactivated if the maximum transmission range (RM1) of the first communication connection (3a) is exceeded when the identification transmitter (2) is moved away from the motor vehicle (1).

3. Method according to either claim 1 or claim 2, characterized in that, after the reactivation of the first communication connection (3a) carried out in measure c), in a measure d) following measure c), the current distance (A) from the identification transmitter (2) to the motor vehicle (1) is determined by means of the first communication connection (3a).

4. Method according to claim 3, characterized in that authorization data are transmitted from the identification transmitter (3) to the motor vehicle (11) by means of the second communication connection (3b) as soon as the distance (A) determined in measure d) falls below a predetermined minimum value (AMIN).

5. Method according to either claim 3 or claim 4, characterized in that at least one predetermined action is carried out by the motor vehicle (1) as soon as the distance (A) determined in measure d) falls below the predetermined minimum value (AMIN), wherein preferably the at least one predetermined action comprises or is the unlocking of at least one vehicle door (4) of the motor vehicle (1).

6. Method according to any of the preceding claims, characterized in that, in measure b), the reference value is determined by averaging the signal strength (S) over a predetermined period of time.

7. Method according to claim 6, characterized in that the predetermined period of time is between 1 second and 5 seconds, preferably approximately 4.5 seconds.

8. Method according to any of the preceding claims, characterized in that the electronic identification transmitter (2) is part of a smartphone (11).

9. Arrangement (20) comprising - a motor vehicle (1), - a mobile electronic identification transmitter (2) which can communicate or communicates with the motor vehicle by means of a first wireless communication connection (3a) in accordance with the UWB standard and by means of a second wireless communication connection (3b) in accordance with the BLE standard, - an open / closed-loop control device (10) which is present in the motor vehicle (1) and is configured / programmed to carry out the method according to any of the preceding claims.

10. Arrangement according to claim 9, characterized in that the electronic identification transmitter (2) is part of a smartphone (11) or is formed by a smartphone (11).