Control of a safety function of a motor vehicle

Abstract

The invention relates to a method (200) for controlling a safety function of a motor vehicle, comprising the following steps: initiating (205) a wireless connection between a handheld device (110) and the motor vehicle (105); determining (210) an expected data traffic that should be transmitted over the interface (145); determining (245) a time interval from the expected data traffic; and periodically activating (255) the connection at the time interval.

Description

Technical Field

[0001] The present invention relates to the control of a motor vehicle. In particular, the present invention relates to the control of a safety function of a motor vehicle. Background Art

[0002] Motor vehicles can be equipped with safety devices to protect safety functions from unauthorized use. Safety functions can include, for example, unlocking or closing anti-theft locks, locking doors, hoods or windows of the motor vehicle. The safety functions can be controlled by means of a mobile device, which is in particular designed as a smartphone. A wireless connection can be established between the mobile device and the motor vehicle. The mobile device and the motor vehicle can each authenticate each other via the connection, and predetermined safety functions of the motor vehicle can be controlled by means of the mobile device. The safety function, for example, the opening of a locking system, can be explicitly requested by the user of the mobile device or can be automatically triggered, for example, when the mobile device is sufficiently close to the motor vehicle.

[0003] Security functions can be controlled, for example, by means of a technology known as digital car keys. The corresponding specification, known as Digital Key Release 3, is available, for example, in version 1.1.0 as of July 20, 2022.

[0004] A wireless connection is required to control safety functions of a motor vehicle. Starting the connection may consume much more energy than maintaining it. Therefore, the connection is usually activated at regular time intervals after it has been started. For this purpose, the mobile device and the motor vehicle can negotiate a time interval. The shorter the time interval, the faster the data traffic that occurs can be transmitted via the connection. The longer the time interval, the less energy is required to maintain the connection. This conflict of objectives is usually resolved by a compromise. For example, the time interval can be approximately 30 ms.

[0005] In order not to restrict the use of the safety functions of the motor vehicle to mobile devices, a dedicated handheld device can be used instead, which provides the corresponding functions. In order to make the handheld device as small and light as possible, the size of the internal power supply can be very small. Therefore, it is advantageous to use as little electrical energy as possible to operate the handheld device. Summary of the invention

[0006] The object of the present invention is to provide an improved technique for controlling safety functions of a motor vehicle by means of a handheld device. The present invention achieves this object by means of the technical solution of the independent claim. The dependent claims provide preferred embodiments.

[0007] A method for controlling a safety function of a motor vehicle comprises the following steps: initiating a wireless connection between a handheld device and a motor vehicle; determining an expected data flow to be transmitted via the connection; determining a time interval based on the expected data flow; and regularly activating the connection at the time interval.

[0008] In contrast to known techniques in which the time interval is determined only once for a connection, the conflict between the goals of fast transmission and energy-efficient transmission can be better resolved by dynamically adjusting the time interval. If no significant data traffic is expected, the time interval can be selected to be longer, so that the energy required to maintain the connection can be saved. Conversely, if significant data traffic is expected, the time interval can be shortened, so that the waiting time until the incoming data is transmitted can be short. The reaction speed of the motor vehicle to the data to be transmitted can be very high.

[0009] Preferably, the periodic activation is performed on the handheld device side. This can reduce the energy consumption of the handheld device to maintain the connection. Unlike on the vehicle side, the handheld device may only have a small amount of energy available. Optionally, the periodic activation can also be performed on the vehicle side. The determination of the time interval and the prior determination of the expected data flow are preferably also performed on the handheld device side.

[0010] Safety functions on motor vehicles cannot be controlled without further auxiliary devices. In particular, safety functions may require the use of the handheld device described herein. Direct control of the safety functions is usually not provided. The operation of the safety function can be controlled manually or automatically by using the handheld device. The safety function can be provided in particular for preventing unauthorized use of the motor vehicle. The safety function can include unlocking or closing anti-theft locks, opening or closing doors, windows or lids of the motor vehicle. In addition, child safety devices can be controlled with the help of the safety function. Other safety functions can also be controlled in this way.

[0011] Generally, it is preferred to protect the safety functions of the motor vehicle by means of a digital vehicle key, in particular a digital vehicle key specified by the Car Connectivity Consortium. In order to comply with the established standards for protecting the safety functions, further steps may need to be taken.

[0012] Preferably, the time intervals are coordinated between the handheld device and the motor vehicle. The coordination may include a determination on the handheld device side or a negotiation between the handheld device and the motor vehicle. The negotiation may include a suggestion of one or more time intervals by the handheld device and confirmation of one of the time intervals by the motor vehicle. The data transmission may be performed regularly after the end of a time interval in each case. The transmitting device and / or the receiving device may only be operated at these time points. If the connection cannot be activated several times in sequence, the connection may be canceled unilaterally. In this case, the safety function may no longer be controlled. The connection must be restarted to establish the connection.

[0013] Particularly preferably, the probability that data traffic should be transmitted is determined; the time interval is shortened as the probability increases. As the probability decreases, the time interval can be extended. In other words, the greater the probability that data is to be transmitted, the more frequently the connection activation can occur. The probability of the data traffic can be determined in different ways.

[0014] In one embodiment, the probability is determined based on the movement of the handheld device relative to the motor vehicle. If movement occurs, the probability may be higher. If no or only small movement occurs, the probability may be lower. The probability may be determined in one or more discrete levels or continuously with respect to the movement of the handheld device.

[0015] In another embodiment, the probability is determined based on the movement of the motor vehicle. If the motor vehicle is moving, the probability of data to be transmitted can be lower. If the motor vehicle is stationary, the probability increases. The probability can also be determined in one or more discrete levels or continuously based on the speed of movement.

[0016] It may be determined whether the handheld device is moved by a walking person. The probability may be determined based on the determination. If the handheld device is moved by a walking person, a higher probability may be used, otherwise a lower probability may be used. The speed of movement of the person may be taken into account when determining the probability value.

[0017] In another embodiment, the probability is determined based on the distance between the handheld device and the motor vehicle. If the distance is small, the probability may be higher. If the distance is large, the probability may be lower.

[0018] The distance can be determined in different ways. In one embodiment, the connection parameters of the interface on which the connection is made can be used. Such parameters may include, for example, signal strength (RSSI) or signal-to-noise ratio (SNR). If the signal strength is small or the signal-to-noise ratio is high, it can be considered that the distance is far. Alternatively, the distance can also be determined by means of a transmission method through the interface. The connection is preferably established by means of Bluetooth Low Energy (BLE) between the handheld device and the motor vehicle. The current BLE specification stipulates the distance determination between two communication partners. The handheld device and the motor vehicle can also establish another connection, which is preferably implemented by means of ultra-wideband technology (UWB). The distance and direction of the handheld device relative to the motor vehicle can be further improved by the other connection. The distance determination can be controlled by means of data transmission through the BLE interface.

[0019] The probability can also be determined according to the state of the motor vehicle. If the motor vehicle is parked or stopped, for example, a higher probability can be used. If the vehicle is in motion or driving, a lower probability applies.

[0020] In addition to the probability, the power capacity of the energy storage device of the handheld device can be used to determine the time interval. The higher the power capacity of the energy storage device, the smaller the time interval can be selected. The energy storage device can include a storage battery or a battery in particular. The power capacity of such an electrochemical energy storage device can be determined based on the open circuit voltage, the internal resistance, the ambient temperature or a model. The model can determine the remaining energy based on the energy initially present in the energy storage device and the energy consumption that occurs. In addition, it can be determined whether the voltage of the electrical energy storage device is observed to drop below a predetermined threshold value during the operation of the predetermined load. In this case, it can be determined that the power capacity of the energy storage device is low.

[0021] A handheld device for controlling safety functions of a motor vehicle comprises a wireless interface for transmitting data and a processing device. The processing device is configured to initiate a connection with the motor vehicle via the interface and to periodically activate the connection. The time intervals between activations are determined in this case based on the expected data flow to be transmitted via the interface.

[0022] The handheld device and in particular its processing device can be configured to partially or completely perform the method described herein. For this purpose, the processing device can be electronically constructed and, for example, include 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.

[0023] The handheld device may include an electrical energy storage device for providing a predetermined amount of energy. The energy storage device may be designed as a rechargeable or non-renewable energy source. The energy storage device is preferably electrochemically constructed and may include a storage battery or a battery, for example. The battery may be designed in particular as a button cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will now be described in more detail with reference to the accompanying drawings. The accompanying drawings are as follows:

[0025] Figure 1 showing the system; and

[0026] Figure 2 A flow chart showing the method is shown. DETAILED DESCRIPTION

[0027] Figure 1 The system 100 is shown, which includes a motor vehicle 105 and a handheld device 110. A control device 115 is installed on the motor vehicle 105, which is provided for communicating with the handheld device 110 on the one hand and for controlling safety functions of the motor vehicle 105 on the other hand. The control device 115 comprises a processing device 120, a first interface 125 and a second interface 130 in the present case.

[0028] Both interfaces 125, 130 are wirelessly designed. The first interface 125 is provided for transmitting data between the control unit 115 and the handheld device 110. The first interface 125 preferably operates according to the Bluetooth Low Energy standard.

[0029] The second interface 130 is also provided for communicating with the handheld device 110. However, in this case, essentially no data is transmitted, but rather a radiometric distance determination is performed. The second interface 130 preferably operates with the aid of an ultra-wideband. A plurality of antennas can be provided on the motor vehicle 105, which are included in the second interface 130. By transmitting a series of pulses between the different antennas and the handheld device 110, the relative distance can be determined. Based on the relative distance, it can be determined in which direction and at what distance the handheld device 110 is located.

[0030] A connection 135 may be provided for communicating with another device on the motor vehicle 105. Communication can take place in both directions. Thus, the processing device 120 can control the safety function via the other device. In turn, the other device can provide the state of the motor vehicle 105 to the control device 115.

[0031] The handheld device 110 comprises a processing device 140, a first wireless interface 145 corresponding to the first wireless interface 125 of the motor vehicle 105 and an optional second wireless interface 150 corresponding to the second wireless interface 130 of the motor vehicle 105. In addition, an energy source 155 is preferably provided. An optional keypad 160 is provided for actuation by a user in order to request execution of a predetermined safety function of the motor vehicle 105.

[0032] Energy source 155 is usually designed as an energy storage device, which is provided for receiving a predetermined amount of energy and providing it to handheld device 110. Energy storage device 155 can include a storage battery or a battery in particular. Energy storage device 155 can be fixedly installed in handheld device 110 or can be designed to be replaceable.

[0033] Figure 2 The flowchart of method 200 for controlling a safety function of motor vehicle 105 is shown. In step 205 , a wireless connection between handheld device 110 and motor vehicle 105 may be initiated. The connection is preferably made via first interface 125 , 145 .

[0034] In step 210, the probability that data traffic should be transmitted via the started connection can be determined. The probability can be determined in different ways. Optionally, different heuristics can be applied, which can be combined with each other to determine the probability.

[0035] For example, a movement of handheld device 110 may be determined in step 215. This movement may be determined by means of corresponding sensors on the handheld device 110, such as inertial sensors.

[0036] In step 220 , the movement of motor vehicle 105 can be determined. A dedicated sensor can also be used for this purpose. Alternatively, the movement of motor vehicle 105 can be determined based on a speed signal or a series of determined geographical locations of motor vehicle 105 , for example.

[0037] In step 225, it can be determined whether handheld device 110 is carried by a walking person. For this purpose, a movement pattern of handheld device 110 relative to its environment can be determined. The movement pattern is preferably determined using an acceleration sensor.

[0038] In step 230 , the distance from handheld device 110 to motor vehicle 105 can be determined. The distance can be determined based on connection parameters of the connection via first interface 125 , 145 or by means of a determination method via second interface 130 , 150 .

[0039] In step 235 , the state of motor vehicle 105 may be determined. The state may indicate, in particular, whether motor vehicle 105 is parked, whether the motor vehicle is ready to drive, and / or whether the motor vehicle is driving.

[0040] By examining one or more of the indications of steps 215 to 235, the probability of impending data traffic may be determined.

[0041] In step 240 , the power capability of energy source 155 of handheld device 110 may be determined. The power capability indicates how much energy can be drawn from energy source 155 . In particular, the power capability may relate to the remaining energy that can be drawn from energy source 155 .

[0042] In step 245 , a time interval for activating the connection between first interfaces 125 , 145 may be determined. The time interval is preferably determined on the handheld device 110 side and based on the probability determined in step 210 and / or the power capability of energy source 155 determined in step 240 .

[0043] In step 250, the determined time intervals can be coordinated between handheld device 110 and motor vehicle 105. For this purpose, the time intervals can be transmitted from handheld device 110 to motor vehicle 105 or its control unit 115. The time intervals can be provided as binding regulations or the time intervals can be negotiated between handheld device 110 and motor vehicle 105, wherein handheld device 110 preferably attempts to bring the time intervals as close as possible to the previously determined time intervals.

[0044] In step 255, the connection existing between the first interfaces 125, 145 can be activated periodically based on the negotiated time interval. When the connection is activated, the prepared data can be transmitted. In one embodiment, a predetermined amount of data can be transmitted each time the connection is activated. In another embodiment, after the connection is activated, as much data as the data prepared for transmission can be transmitted. Only after this can the connection be periodically activated again. In the phase where the connection is not activated, the interfaces 125, 145 can be deactivated.

[0045] Reference numerals list

[0046] 100 systems

[0047] 105 Motor Vehicles

[0048] 110 Handheld Devices

[0049] 115 Control Equipment

[0050] 120 Processing device

[0051] 125 First Interface

[0052] 130 Second interface

[0053] 135 connection

[0054] 140 Processing device

[0055] 145 First Interface

[0056] 150 Second interface

[0057] 155 Energy Source

[0058] 160 key area

[0059] 200 Methods

[0060] 205 Connection started

[0061] 210 Determine the probability of data flow

[0062] 215 Determine the movement of the handheld device

[0063] 220 Determining the movement of motor vehicles

[0064] 225 Identify the person walking

[0065] 230 Determine the distance from the handheld device to the motor vehicle

[0066] 235 Determining the status of a motor vehicle

[0067] 240 Determine the power capability of the energy source

[0068] 245 Determine the time interval

[0069] 250 Coordinated Time Interval

[0070] 255 Periodically activate the connection

Claims

1. A method (200) for controlling a safety function of a motor vehicle (105), wherein: The method (200) comprises the following steps: - initiating (205) a wireless connection between the handheld device (110) and the motor vehicle (105); - determining (210) an expected amount of data traffic to be transmitted via said connection; - determine (245) the time interval based on expected data traffic; and - regularly activating (255) said connection at said time interval.

2. The method (200) according to claim 1, wherein: The periodic activation (255) is performed on the handheld device (110) side.

3. The method (200) according to claim 1 or 2, wherein: Safety functions on the motor vehicle (105) can only be controlled by using a handheld device (110).

4. The method (200) according to any one of the preceding claims, wherein: A time interval is coordinated (250) between the handheld device (110) and the vehicle (105).

5. The method (200) according to any one of the preceding claims, further comprising determining (210) a probability that the data traffic should be transmitted; the time interval shortening as the probability increases.

6. The method (200) according to claim 5, wherein: The probability is determined (215) based on movement of the handheld device (110) relative to the motor vehicle (105).

7. The method (200) according to claim 5 or 6, wherein: The probability is determined (220) based on the movement of the motor vehicle (105).

8. The method (200) according to any one of claims 5 to 7, wherein: It is determined (225) whether the handheld device (110) is moved by a walking person; and the probability is determined based on this.

9. The method (200) according to any one of claims 5 to 8, wherein: The probability is determined (230) based on a distance between the handheld device (110) and the motor vehicle (105).

10. The method (200) according to any one of claims 5 to 9, wherein: The probability is determined (235) as a function of a state of the motor vehicle (105).

11. The method (200) according to any of the preceding claims, wherein: The time interval is determined (245) based on a power capability (240) of an energy storage device of the handheld device (110).

12. A handheld device (110) for controlling a safety function of a motor vehicle (105), wherein: The handheld device (110) includes the following elements: - a wireless interface (145) for transmitting data; and - a processing device (140) which is configured to initiate a connection with the motor vehicle (105) via the interface (145) and to regularly activate the connection; It is characterized in that The time interval between activations is determined as a function of the expected data flow to be transmitted via the interface (145).

13. The handheld device (110) according to claim 12, further comprising an electrical energy accumulator (155) for providing a predetermined amount of energy.

Images