Method for operating an actuation system for a motor vehicle and actuation system

Abstract

The proposed solution concerns a method for operating an actuation system for a motor vehicle, which includes the following steps: - Connect, with a switch assembly, a first receive path arrangement with a first antenna, - Connect, with the switch assembly, a transmission path arrangement with a second antenna, - Sending a first transmission signal from the transmission path arrangement via the second antenna, - Receiving a first received signal caused by the first transmitted signal via the first antenna, - Receiving a second received signal caused by the first transmitted signal via a second receiving path arrangement, which can be connected to the two antennas via the switch assembly, and - Calibrating the first received signal with a calibration unit, whereby the calibration is carried out using the second received signal. The proposed solution also concerns an actuation system for a motor vehicle.

Description

[0001] The proposed solution relates to a method for operating an actuation system according to claim 1, an actuation system according to claim 13, a motor vehicle according to claim 18 and a computer program product according to claim 19.

[0002] The actuation system can be used to access the vehicle. For example, the actuation system can trigger the adjustment of a control element. This control element could be, for example, a vehicle flap such as a door or tailgate. The actuation system can be installed inside the vehicle door and detect a gesture to trigger the adjustment using radio waves.

[0003] It is known that gesture recognition via radio waves is unreliable. To improve reliability, the actuation system can receive information about the environmental conditions at the actuating element (for example, snow on the vehicle door). This information can be provided to the actuation system by a sensor device (often already present on a motor vehicle), which could include, for example, a snow sensor, a rain sensor, and / or a temperature sensor. However, it is generally desirable for the actuation system to become active before the sensor device when the vehicle is not in operation. If the actuation system is used as part of vehicle access, the vehicle is typically not in operation before access is authorized.If the sensor device becomes active at a time when it is unclear whether a user wishes to adjust the adjustment element, there is a risk that a great deal of electrical energy will be consumed in its operation, thus depleting a vehicle battery without the user being able to prevent the depletion.

[0004] It is therefore still desirable to determine environmental conditions using the actuation system (without the sensor device). However, the radio waves transmitted by the actuation system and received due to signal reflection can be subject to interference not solely attributable to environmental conditions, making it difficult to differentiate between them. This includes, for example, distinguishing between snow and rain, different snow consistencies, or varying snow water content. Accurate detection of environmental conditions can prevent errors in gesture recognition.

[0005] Against this background, the proposed solution is based on the task of providing a method for operating an actuation system with which gestures can be recognized more reliably.

[0006] According to a first aspect of the proposed solution, the problem is solved by a method for operating an actuation system for a motor vehicle, which includes the following steps: - Connect, with a switch assembly, a first receive path arrangement with a first antenna, - Connect, with the switch assembly, a transmission path arrangement with a second antenna, - Sending a first transmission signal from the transmission path arrangement via the second antenna, - Receiving a first received signal caused by the first transmitted signal via the first antenna, - Receiving a second received signal caused by the first transmitted signal via a second receiving path arrangement, which can be connected to the two antennas via the switch assembly, and - Calibrating the first received signal with a calibration unit, whereby the calibration is carried out using the second received signal.

[0007] The actuating system can therefore have two receive path arrangements and one transmit path arrangement. Each receive path arrangement can have an analog-to-digital converter. The transmit path arrangement can have a digital-to-analog converter. Transmit signals can be sent from the transmit path arrangement via one of at least two antennas. The receive path arrangements can receive signals via the at least two antennas. The switch assembly can connect the transmit path arrangement to one of the at least two antennas. Furthermore, the switch assembly can connect one of the two receive path arrangements to the other of the at least two antennas. Thus, one of the receive path arrangements is typically not connected to any antenna.

[0008] To connect the transmit path arrangement and / or one of the receive path arrangements to the antennas, the switch assembly can establish an electrically conductive connection to the antennas. The electrically conductive connection can, for example, comprise an electrical conductor. In particular, the electrical conductor can comprise a metal layer printed on a printed circuit board.

[0009] Regardless of whether the second receive path is connected to an antenna, the second receive signal can be received. The second receive signal can therefore be received even if there is no electrically conductive connection to either antenna. In particular, the second receive signal can be received simultaneously with the first receive signal.

[0010] The transmit signal can be a signal pulse sent for a limited duration (e.g., 0.5 ms). Alternatively, the transmit signal can be sent continuously over a longer period (e.g., more than 0.5 ms). The receive signals can each be signals received over a predetermined period (e.g., 0.5 ms). The receive signals can be generated by the transmit signal or by reflections of the transmit signal from objects in the vicinity of the actuation system (e.g., a user's hand or a layer of snow). It is conceivable and possible that within a given calibration period, a large number of initial transmit signals are sent and, correspondingly, a large number of initial and secondary receive signals are received.

[0011] In one embodiment, the transmit path arrangement, the first receive path arrangement, and the second receive path arrangement are each connected to the switch assembly via an interface. The first transmit signal can thus be transmitted from the transmit path arrangement through the interface and the switch assembly to the second antenna. The first receive signal can be transmitted from the first antenna through the switch assembly and the interface to the first receive path arrangement.

[0012] In one embodiment, the second received signal is received via the interface of the second receive path arrangement. The second received signal can, for example, originate from electromagnetic waves and / or surface currents emanating from the transmit path arrangement and / or the associated switching assembly, which may propagate across a printed circuit board on which the interfaces of the receive path arrangements (and the interface of the transmit path arrangement) are located.

[0013] In one embodiment, the second received signal results from crosstalk between the transmit path arrangement and / or the associated switch assembly when the first transmit signal is sent to the interface of the second received path arrangement. The second received signal can thus, in particular, reflect the received first transmit signal. A first signal component, reflecting the first transmit signal, can be more prominent than a second signal component, which is caused by signal reflection from objects in the vicinity of the actuating system. For example, the first signal component can have an amplitude greater (e.g., more than twice as large) than the second signal component.

[0014] In one embodiment, calibrating the first received signal involves removing or minimizing a signal component resulting from crosstalk between the first and second antennas. The first component of the second received signal can be used to calculate the signal component to be removed or minimized. Calibration can thus help to isolate a signal component in the first received signal caused by environmental conditions from a signal component caused by direct reception of the transmitted signal. This allows for more reliable detection of environmental conditions based on the first received signal after calibration.

[0015] In one embodiment, a classification unit, to which the calibrated first received signal is fed, determines at least one environmental condition of the actuation system based on this calibrated first received signal. For example, the classification unit can compare the calibrated first received signal with classified received signals stored in a memory unit of the actuation system. Depending on which classified received signal the calibrated first received signal matches, the classification unit can determine at least one environmental condition. As a result of this determination, the classification unit can, for example, specify a scenario consisting of one or more environmental conditions. Examples of such scenarios are snow cover (one environmental condition) or snow cover with heavy snowfall (two environmental conditions).The at least one environmental condition can generally represent a state of an environment and / or a configuration of objects around the actuation system. An area around the actuation system of up to 10 m, in particular 1 m, and most especially 0.5 m, can be characterized by the at least one environmental condition.

[0016] In one embodiment, an electronic control unit that controls the actuation system specifies at least one operating parameter of the actuation system based on the determined at least one environmental condition. This specification can be based, in particular, on the scenario provided by the classification unit. The at least one operating parameter may be particularly suitable for reliably enabling gesture recognition when the at least one environmental condition is present. For example, the at least one operating parameter of the storage unit may be assigned to the classified received signal that is most similar to the calibrated first received signal.

[0017] The at least one operating parameter can relate to physical properties of the transmitted signal (for example, transmission power, amplitude, pulse duration) and / or parameters used for evaluating a third received signal (for example, tolerance values ​​in gesture recognition).

[0018] In one configuration, the following steps are performed after calibration: - Connect, with the switch assembly, the first receive path arrangement to the second antenna, and - Connect, to the switch assembly, the transmit path arrangement with the first antenna, and - Sending another transmission signal from the transmission path arrangement via the first antenna.

[0019] Following these steps, the first receive path assembly is switched from the first antenna to the second antenna, and the transmit path assembly is switched from the second antenna to the first antenna. Alternatively, the second receive path assembly can be connected to the second antenna (the first receive path assembly is then not connected to either antenna). The antennas used to calibrate the actuation system can be exchanged in this way, particularly for gesture recognition. For example, such a change can be advantageous if the first antenna has different physical properties than the second antenna.

[0020] For example, the first antenna may have a different radiation pattern than the second antenna. The radiation pattern of the second antenna may be better suited for calibration, while the radiation pattern of the first antenna may be better suited for gesture recognition. In particular, one of the antennas, such as the first antenna connected to the transmit path array for gesture recognition, may have a directional radiation pattern. Additionally or alternatively, one of the antennas, such as the second antenna connected to the transmit path array for calibration, may have a unidirectional radiation pattern.

[0021] The directional radiation pattern of the first antenna allows it to focus the transmitted signal into a detection area where the gesture is expected. This detection area could, for example, encompass a volume of less than 0.5 cubic meters, directly adjacent to the actuation system. Within this volume, the directional radiation pattern enables a higher transmission power than outside of it. Conversely, the second antenna can achieve a uniform transmission power within and adjacent to the detection area, allowing for reliable determination of environmental conditions.

[0022] In one embodiment, a gesture by a user of the control system is recognized based on a third received signal, which is received after the first received signal via the first or second antenna. This gesture can then trigger a command to actuate a control element of the vehicle. The third received signal can be generated by a further transmitted signal. It can be characterized by signal reflections of the further transmitted signal from objects (such as the user's hand and / or a layer of snow). In principle, a multitude of additional transmitted signals can be sent and a corresponding number of third received signals received to reliably recognize a user gesture.

[0023] The third received signal can be evaluated by an evaluation unit, which may be part of the electronic control unit. This evaluation allows the user's gesture that triggers the activation to be recognized.

[0024] To increase the reliability of the detection, the third received signal can be calibrated using a fourth received signal. For example, if the third received signal was received via the second antenna and the associated first receive path arrangement, the fourth received signal can be received via the second receive path arrangement, which is not connected to any antenna. This calibration allows a signal component caused by at least one environmental condition (including, for example, the user's hand) to be isolated from the evaluation.

[0025] Reliable recognition can also be improved by specifying at least one operating parameter. For example, the electronic control unit can specify an operating parameter in the form of higher transmission power if the determination of at least one environmental condition based on the first received signal indicates the presence of snow cover. In such a case, there is a risk that the subsequent transmission signal, which is sent to recognize the gesture, will be attenuated by the snow. This could result in the third received signal, which is received due to signal reflection from the subsequent transmission signal off a part of the user's body, such as their hand, having an insufficient signal-to-noise ratio to reliably recognize a gesture. Increasing the transmission power can compensate for the attenuation caused by the snow cover.Furthermore, if snow is present, the electronic control unit can specify a longer transmission duration for the subsequent signal if the user first wipes away the snow before performing the gesture to be recognized (and thus only then executes a gesture to activate the system). Alternatively or additionally, a waiting period can be specified for evaluating the third received signal if it is expected that the user will first wipe away the snow (for example, due to the thickness of the snow cover) before executing a gesture to activate the system.

[0026] The specification of at least one operating parameter can additionally or alternatively include the specification of a threshold value for gesture recognition. For example, the threshold value can have a default value that characterizes the degree of correspondence between a gesture recognized based on the third received signal (or a multitude of third received signals) and a gesture stored in an electronic storage unit of the actuation system. In rainy conditions, there is a risk that a user might execute the gesture imprecisely because they want to trigger the actuation quickly. This can be particularly relevant for an actuation system that provides access to a motor vehicle, where the user wants to get out of the rain quickly.In such a case, the threshold can be reduced below the standard value to ensure that the evaluation unit triggers the action even with a low degree of similarity between the user's gesture and a gesture stored in the memory unit.

[0027] Additionally or alternatively, the specification of at least one operating parameter can include a number of further transmission signals per unit of time (transmission frequency). This allows for adjustment of the temporal resolution for gesture recognition. The transmission frequency can generally have a standard value, determined to ensure reliable gesture recognition while simultaneously minimizing the electrical energy consumption of the activation system. In rainy conditions, there is a risk that a user will execute the gesture very quickly, thus requiring a higher temporal resolution for reliable gesture recognition. In such cases, a transmission frequency higher than the standard value can be specified to ensure reliable gesture recognition even during rapid execution.

[0028] The calibration of the initial received signal (and, if necessary, the determination of at least one environmental condition) can take place at a time when the user is at a distance from the operating system. In particular, the distance can be greater than the distance required for gesture recognition. The distance can, for example, be more than 1 m, especially more than 6 m.

[0029] In one embodiment, the third received signal is triggered by a further transmitted signal with a lower signal strength than the first transmitted signal. The signal strength of this additional transmitted signal can be lower because the user is closer to the control system when recognizing the gesture than during the calibration of the first received signal (and, if applicable, during the determination of the at least one environmental condition). Thus, gesture recognition can occur without the time delay that would otherwise be necessary for determining the environmental conditions. Furthermore, this allows the determination of the environmental conditions to take place at a time when the user is not significantly influencing the first received signal through their physical presence, which can complicate the determination of the at least one environmental condition.

[0030] In one embodiment, the first transmission signal is sent as part of a communication process with a mobile device belonging to the user of the actuating system and / or as part of determining the user's distance to the actuating system. The first transmission signal can thus fulfill at least one further function (in addition to generating a signal reflection to trigger the first received signal).

[0031] In particular, the initial transmission signal can be used to transmit data. The communication process with the user's mobile device can be used, specifically, to identify the user based on the mobile device. This may require the transmission of data relating to the user's identity. The mobile device could, for example, be a smartphone or a key fob. Triggering the adjustment of the control element by the operating system can be contingent upon the user being identified through the communication process as being authorized to make the adjustment (so-called "Phone as a Key"). The operating system can act as an anchor for such a Phone-as-a-Key system. Accordingly, a user-specific gesture can be defined, which the identified user can use to operate the operating system.

[0032] Furthermore, the communication process can be used to determine the user's position relative to the control system (user localization). For this purpose, localization data, obtained from the mobile device via a global navigation satellite system such as GPS, can be transmitted to the control system. The control system can then compare this data with its own position (possibly also determined via a global navigation satellite system such as GPS) to calculate the user's distance.

[0033] Furthermore, the user's distance from the activation system can be determined, for example, by measuring the time of flight of the signal transmitted by the first transmission signal. Distance determination using signal reflection can provide more accurate values ​​for the user's position than localization. In particular, it allows for the determination of the user's approach (determining user approach).

[0034] In one embodiment, the evaluation unit recognizes the user's gesture based on the third received signal, whereby the evaluation unit is in standby mode during the communication process and / or while determining the user's distance. To recognize the user's gesture, the evaluation unit can switch from standby mode to an operating mode. This prevents the evaluation unit from evaluating received signals at a time when no user gesture is expected because the user is too far away. This saves electrical energy for operating the evaluation unit. In particular, using the communication process to locate and / or determine the user's approach allows for a prediction of when the evaluation unit should switch to operating mode ("wake-up" strategy). For example, the communication process might indicate that the user has moved beyond a measurement threshold (e.g.,The user is located at a distance of over 6 m from the actuation system, where the measurement threshold corresponds to a distance at which the user's approach can be measured by signal reflection from their body. Determining the user's approach can involve a stepwise approach from a distance below the measurement threshold (e.g., below 6 m) down to a detection threshold (e.g., 1 m) from the actuation system. The detection threshold can correspond to a distance at which the evaluation unit can recognize a gesture in received signals (i.e., when the signal-to-noise ratio is sufficiently good). If the electronic control unit determines that the user is less than the detection threshold from the actuation system, it can switch the evaluation unit to operating mode to process received signals, such as the third gesture recognition signal.The actuation system can be designed and configured in such a way that a recognized gesture only triggers an adjustment of the adjusting element if the gesture corresponds to a gesture assigned to the identified user.

[0035] It is conceivable and possible that the communication process is carried out with the first transmission signal (or a multitude of first transmission signals) and / or that the determination of the user's distance is carried out with a second transmission signal (or a multitude of second transmission signals). Gesture recognition can be carried out with a further transmission signal (or a multitude of further transmission signals).

[0036] According to a second aspect of the claimed solution, the problem is solved by an actuation system for a motor vehicle. The actuation system has at least two antennas. Furthermore, the actuation system has a transmit path arrangement and two receive path arrangements that can be connected to the at least two antennas. The actuation system can be designed and configured such that at any given time only one transmit path arrangement or one receive path arrangement can be connected to an antenna. Preferably, at least the transmit path arrangement and one of the receive path arrangements are connected to one of the antennas. One of the receive path arrangements can be disconnected from both antennas.

[0037] The actuating system further comprises a switch assembly designed and configured to establish a connection between the transmit path arrangement and a first of the at least two antennas, and between a first of the receive path arrangements and a second of the at least two antennas. A calibration unit of the actuating system is designed and configured to calibrate a first receive signal, received via the first antenna and generated by a first transmit signal sent by the transmit path arrangement via the second antenna, using a second receive signal, received via a second receive path arrangement and generated by the first transmit signal. In particular, the two receive signals can be received simultaneously or with at least a temporal overlap.

[0038] In one embodiment, the switch assembly has two antenna ports for connecting antennas. A multi-switch element is connected to the first of these antenna ports, and at least two antennas are connected to this multi-switch element. One of these antennas can be selected for connection to the first antenna port via the multi-switch element. In principle, the actuation system can have two antennas, one connected to the first antenna port and the other to the second antenna port. Gesture recognition can be performed even more reliably if more antennas are used. The multi-switch element can be used to increase the number of antennas (with a fixed number of antenna ports). The multi-switch element can, for example, include an RF switch (high-frequency switch). This allows the additional antennas connected to the multi-switch element to be selected, if necessary.The antennas can be switched to the first antenna port in rapid succession. For example, it is conceivable and possible that the additional antennas connected to the first antenna port via the multi-switch element differ in their physical properties. This allows the reception of the received signals to be adapted to at least one environmental condition or a reception scenario (user localization, determination of user approach, gesture recognition) by selecting a suitable additional antenna. Furthermore, by using different antennas, and especially more than two, as receiving antennas, the at least one environmental condition can be determined more reliably.

[0039] In one embodiment, the transmit path arrangement and the two receive path arrangements each have an interface via which the transmit and receive path arrangements can be connected to the at least two antennas. The interfaces are arranged on a common electronic carrier element, such that a transmit signal sent from the transmit path arrangement via one of the at least two antennas generates a receive signal in both receive path arrangements by crosstalk. The electronic carrier element can, for example, be a printed circuit board. The transmit path arrangement, the two receive path arrangements, the switch assembly, the antennas, and / or the calibration unit can be arranged on the printed circuit board. Regardless of which of the receive path arrangements is connected to an antenna, both receive path arrangements can receive a receive signal based on crosstalk.Using the received signal from the receiving path arrangement not connected to an antenna, the calibration unit can isolate a signal component attributable to at least one environmental condition from the received signal of the receiving path arrangement connected to an antenna. This can facilitate the differentiation between a signal component caused by a gesture to be recognized and a signal component attributable to the at least one environmental condition.

[0040] In one embodiment, the transmit path arrangement and the two receive path arrangements are part of a chip assembly that includes an electronic control unit with a calibration unit, a classification unit for determining at least one environmental condition based on the calibrated first received signal, and an evaluation unit for recognizing a user gesture based on a third received signal. Integrating these components into the chip assembly allows for a space-saving design of the actuation system. The chip assembly can, in particular, comprise a single (square) chip.

[0041] The chip assembly can have a communication interface for communication with a vehicle system. For example, the communication interface can be connected to a CAN bus.

[0042] In one embodiment, the transmission path arrangement is provided and configured for generating ultra-wideband signals. An ultra-wideband signal can, for example, be a signal with a bandwidth of at least 500 MHz. Additionally or alternatively, the actuating system can include at least one transmission device for communication with another wireless transmission technology. This other wireless transmission technology can, for example, be Bluetooth or NFC. The electronic control unit of the actuating system can also be provided and configured for controlling a lighting arrangement. The lighting arrangement can include at least one LED.

[0043] The actuation system according to the second aspect of the proposed solution can exhibit the features and advantages of the method according to the first aspect of the proposed solution.

[0044] The proposed solution further relates to a motor vehicle with an adjusting element and at least one actuation system as described in the second aspect of the proposed solution, wherein the adjusting element can be adjusted by a user through (contactless and wireless) actuation of the at least one actuation system. Actuation can be performed, for example, with a gesture. The motor vehicle may, for instance, have an opening that can be closed by the adjusting element. A gesture used to actuate the at least one actuation system can thus indicate a user's desire to open the opening. The opening may, in particular, be an opening that provides access to the motor vehicle. The adjusting element may, for example, be a vehicle door, a tailgate, or a frunk door.

[0045] The at least one actuation system can be concealed from the user by a body component of the vehicle. This body component can be non-metallic, such as a decorative element. For example, the at least one actuation system could be located in the vehicle door or tailgate. In principle, it is conceivable and possible to provide multiple actuation systems that are interconnected to recognize a user gesture.

[0046] The proposed solution also relates to a computer program product comprising instructions which, when executed by at least one processor of an electronic control unit of an actuation system for a motor vehicle, cause the at least one processor to execute a procedure according to the first aspect of the proposed solution. The at least one processor may be part of a processor unit of the electronic control unit.

[0047] The underlying concept of the proposed solution will be explained in more detail below using the exemplary embodiments shown in the figures. These show: Fig. 1 a schematic view of an actuation system; Fig. 2A a schematic view of an actuation system with a switch assembly in a first state; Fig. 2B a schematic view of an actuation system with a switch assembly in a second state; Fig. 2C a schematic view of an actuation system of a switch assembly in a third state; Fig. 3 a schematic view of an actuation system with a multiple switch assembly; Fig. 4 a view of an actuation system arranged on a motor vehicle; Fig. 5 a graphical representation of the signal strength of a received signal in relation to a distance from the actuating system; Fig. 6. A further graphical representation of the signal strength of a received signal in relation to a distance from the actuating system; Fig. 7 Views of a user in different positions while approaching a motor vehicle; and Fig. 8 A flow chart of steps performed by the actuation system during the user's approach to the motor vehicle.

[0048] Fig. Figure 1 shows a schematic view of an actuation system A. The actuation system A comprises a chip assembly with an electrical circuit board 1 on which an electronic control unit 2 (for example, in the form of a chip) is arranged. The electronic control unit 2 generates (digital) transmit signals S1, which can be sent via a transmit path arrangement 33 on the electrical circuit board 1. The electronic control unit 2 receives receive signals S2, S3 via a first and a second receive path arrangement 31, 32, which are also arranged on the electrical circuit board 1. The actuation system A does not necessarily include a circuit board 1. If it does include a circuit board 1, the aforementioned components do not necessarily all have to be arranged on this circuit board 1. It is also conceivable and possible that individual components are arranged on one or more separate circuit boards 1 or that other carrier elements are used.

[0049] The chip assembly is connected to antennas 4 in the form of a first and a second antenna 41, 42. The transmit path arrangement 33 and the receive path arrangements 31, 32 can be connected to the antennas 4 via a switch assembly 5. For connection to the switch assembly 5, the transmit path arrangement 33 and the receive path arrangements 31, 32 each have an interface 310, 320, 330.

[0050] A first switch element 51, which is assigned to the first antenna 41, is switchable between a first and a second switch position. In the first switch position, shown here, the first switch element 51 connects the first antenna 41 to the interface 310 of the first receive path arrangement 31. In the second switch position, the first switch element 51 can be connected to a third switch element 53.

[0051] The third switch element 53 is assigned to the transmit path arrangement 33. In the first switch position, the third switch element 53 can be connected to the first switch element 51, provided the latter is in the second switch position. The transmit path arrangement 33 can therefore be connected to the first antenna 41 by switching the first switch element 51 to the second switch position and the third switch element 53 to the first switch position. In the second switch position, shown here, the third switch element 53 can be connected to a second switch element 52.

[0052] The second switch element 52 is assigned to the second antenna 42. In the first switch position of the second switch element 52, as shown here, the second switch element 52 can be connected to the third switch element 53. Since the second switch element 52 is in the first switch position and the third switch element 53 is in the second position, the transmit path arrangement 33 is connected to the second antenna 42 in this illustration. In the second switch position, the second switch element 52 can be connected to the second receive path arrangement 32.

[0053] In principle, the switch assembly 5 can be configured in any way. Regardless of the configuration of the switch assembly 5, in the configuration shown with one transmit path arrangement 33 and two receive path arrangements 31, 32 as well as two antennas 4, there is at least one receive path arrangement 31, 32 that is not connected to an antenna. It is conceivable and possible that a plurality of receive path arrangements 31, 32 are provided, of which at least some or all but one are not connected to an antenna 4.

[0054] The transmit path arrangement 33 transmits a first transmit signal S1 via the second antenna 42. A first receive signal S2 is received via the first antenna 41, which is connected to the first receive path arrangement 31. Simultaneously, or at least with a temporal overlap, a second receive signal S2 is received by the second receive path arrangement 32. The second receive signal S2 is received via the interface 320 of the second receive path arrangement 32.

[0055] The electronic control unit 2 includes a calibration unit 21, which is configured and designed to calibrate the first received signal S2 using the second received signal S3. The electronic control unit 2 also includes a classification unit 22, to which the calibrated first received signal S2 is fed. Based on the calibrated first received signal S2, the classification unit 22 determines at least one environmental condition of the actuating system A. The calibration has the advantage that it can remove or at least minimize a signal component in the first received signal S2 that is due to crosstalk between the second antenna 42 and the first antenna 41. The calibrated first received signal S2 can therefore be characterized primarily by a detuning of the first antenna 41 caused by the at least one environmental condition.

[0056] A key concept of the proposed solution is to utilize internal crosstalk between the transmit path arrangement 33 and the second receive path arrangement 32 for calibrating the first received signal S2, in order to determine the signal component of the first received signal S2 that is attributable to crosstalk. This signal component can be made available to an evaluation unit 23 and / or stored in a storage unit 25 for later use. Furthermore, the signal component can be removed from the first received signal S2, or at least minimized, to generate the calibrated first received signal S2. Therefore, the calibrated first received signal S2 contains only a signal component that is induced by the at least one environmental condition. This allows the classification unit 22 to determine the at least one environmental condition more reliably.The calibrated first received signal S2 can be made available to the evaluation unit 23 and / or stored in a storage unit 25 for later use.

[0057] Based on the determined environmental condition (at least one), the electronic control unit 2 specifies at least one operating parameter of the actuation system A. This specification can be more optimal the more accurately the environmental condition (at least one) has been determined.

[0058] The electronic control unit 2 also has an evaluation unit 23, with which, on the basis of a received signal (for example, a third received signal S2', which is received after the first received signal S2 via the first or the second antenna 41, 42), a gesture G of a user N of the actuation system A, with which a command to actuate an adjusting element K of the motor vehicle F can be triggered, can be recognized.

[0059] The evaluation unit 23 can receive a signal component determined by the calibration unit 21, which is based on crosstalk between the transmit signal S1 and the antenna 41, 42, which is connected to one of the receive path arrangements 31, 32. Alternatively or additionally, the evaluation unit 23 can receive a signal component determined by the calibration unit 21, which is based on at least one environmental condition. The evaluation unit 23 can also be designed and configured to remove or minimize signal components based on crosstalk and / or at least one environmental condition from the received signal (e.g., the third received signal S2') that forms the basis for recognizing the gesture G of the user N.

[0060] The electronic control unit 2 further comprises an electronic storage unit 25, which serves, for example, to store the calibrated first received signal S2. The electronic control unit 2 also comprises a processor unit 24, which can process the transmitted signal S1 and / or the received signal S2, S2', S3. In particular, the processor unit 24 can comprise at least one processor with which the actuation system A can be operated.

[0061] Fig. Figure 2A shows a schematic view of the actuating system A with a switch assembly 5 in a first state. In the first state, none of the transmit path arrangements 33 and receive path arrangements 31, 32 are connected to any of the antennas. Such a state can occur, for example, when switching between the second and third states described below.

[0062] The transmit path arrangement 33 includes a digital-to-analog converter 331. The two receive path arrangements 31 and 32 each include an analog-to-digital converter 311 and 321, respectively. The electronic control unit 2 provides the digital transmit signals S1, which are converted into analog transmit signals S1 by the digital-to-analog converter 331 of the transmit path arrangement 33. Furthermore, the electronic control unit 2 processes digital receive signals S2 and S3, which are generated from analog receive signals S2 and S3 by the respective analog-to-digital converters 311 and 321.

[0063] Fig. Figure 2B shows a schematic view of the actuating system A in the second state. In the second state, the transmit path arrangement 33 is connected to the first antenna 41. The first receive path arrangement 31 receives a first receive signal S2 through crosstalk between the transmit path arrangement 33 and / or the switch assembly 5 (in particular its first and third switch elements 51, 53) and the first receive path arrangement 31 (in particular its associated interface 310). The second receive path arrangement 32 is connected to the second antenna 42.

[0064] Fig. Figure 2C shows a schematic view of the actuating system A in the third state. In the third state, the transmit path arrangement 33 is connected to the second antenna 42. The second receive path arrangement 32 receives a second receive signal S3 through crosstalk between the transmit path arrangement 33 and / or the switch assembly 5 (in particular its second and third switch elements 52, 53) and the second receive path arrangement 32 (in particular its associated interface 320). The first receive path arrangement 31 is connected to the first antenna 41.

[0065] Fig. Figure 3 shows a schematic view of an actuation system A with a multi-switch element 6. The multi-switch element 6 is connected to a second of two antenna ports 502 of the switch assembly 5. The first antenna 41 is connected to the chip assembly via a first antenna port 501 of the switch assembly 5. A second and a third antenna 42, 43 can be connected to the chip assembly via a second antenna port 502. Alternatively, the multi-switch element 6 can be arranged at the first antenna port 501.

[0066] The multi-switch element 6 allows selection of which of the second and third antennas 42, 43 can be connected to the second antenna port 502. In principle, any number of antennas can be connected to the second antenna port 502 via the multi-switch element 6. The second and third antennas 42, 43 can differ from each other and, if applicable, from the first antenna 41 with regard to their physical properties, in particular their radiation pattern.

[0067] The switching of the plurality of antennas 42, 43 connected to the multiple switch element 6 can be controlled by the electronic control unit 2. For this purpose, the multiple switch element 6 is coupled to the electronic control unit 2.

[0068] Fig. Figure 4 shows a view of an actuation system A arranged on a motor vehicle F. The actuation system A is shown by way of example on an adjustment element in the form of a vehicle door K. In principle, it can be arranged at any position on the motor vehicle F, possibly even at a distance from the adjustment element.

[0069] In this case, the actuation system A can be arranged behind a decorative element on the vehicle door K, thus concealing it from a user N. A transmitted signal S1 emitted by the first antenna 41 can be reflected by an object O (for example, snow covering the vehicle door K) and a hand H (or any other body part) of a user N. The travel time between the object O and the second antenna 42, which receives the reflected signal as part of a received signal S2, S2', is shorter than the travel time between the hand H and the second antenna 42, so the reflected signal is received by the object O before the reflected signal is received by the hand H. Based on this time offset, the distance at which the signal reflection occurred can be determined.

[0070] If the transmitted signal S1 passes through object O on its way to hand H, it may change. The signal reflected by hand H may pass through object O again on its way to the second antenna 42, which may also cause it to change. The presence of object O thus has a dual impact on the reliability of gesture G recognition. Therefore, it is desirable for the evaluation unit 23 to be able to consider at least one environmental condition when evaluating the received signal S2, S3 and / or to remove or at least minimize a signal component caused by crosstalk in order to increase the reliability of gesture G recognition.

[0071] In the example shown, gesture recognition takes place within a detection area D. User N is located outside this detection area D. In such a situation, the actuation system A can be designed and configured to perform a first operating mode to locate user N via a mobile device E and / or to determine user N's ​​approach (e.g., by measuring the time of flight of radio waves reflected from user N's ​​body) in a second operating mode. Once user N has entered detection area D, gesture recognition G can be performed in a third operating mode. The actuation system's energy consumption in the third operating mode can be higher than in the first and second operating modes.

[0072] Actuating system A comprises a first assembly with a printed circuit board 1 (or any alternative carrier element) on which at least the switch assembly 5, the transmit path arrangement 33, and the two receive path arrangements 31, 32 are arranged. Actuating system A further comprises a second assembly in the form of the electronic control unit 2. The electronic control unit 2 is connected to the first assembly at least for the exchange of control data. In principle, the second assembly can be arranged on the printed circuit board 1 of the first assembly. Actuating system A comprises a third assembly, which is coupled to the electronic control unit 2. The third assembly includes a bus interface 7. Actuating system A can be connected to an automotive bus system (e.g., CAN bus) via this interface. The first, second, and third assemblies can be arranged on a common carrier element such as a printed circuit board 1.The antennas 4 can also be arranged on the support element.

[0073] Fig. Figure 5 shows a graphical representation of the signal strength of a received signal S2, S2' in relation to a distance from the actuating system A. The representation is idealized so that the individual signal components (here in the form of local maxima) are distinguishable. A first local maximum P1, which is received first after the transmission of the transmit signal S1, represents crosstalk between the first antenna 41, which is used to transmit the transmit signal S1, and the second antenna 42, which is used to receive the received signal S2, S2', whose signal strength is shown here. The two second local maxima P2 represent signal reflections caused by objects O in the immediate and near vicinity (e.g., 0.5 m) of the actuating system A. These second maxima P2 allow conclusions to be drawn about at least one environmental condition.However, they can also contribute to obscuring or masking a third maximum P3, which represents signal reflections caused by a user N of the operating system A. A gesture G of user N may be detected less reliably if the corresponding signal reflection has too low a signal-to-noise ratio. Furthermore, the signal strength of the received signal S2, S2' caused by a signal reflection from user N is lowest because user N is farther away than objects O that cause the second maxima P2 (e.g., snow cover on the operating system A).

[0074] Fig. Figure 6 shows a further graphical representation of the signal strength of a calibrated received signal S2, S2' in relation to a distance from the actuating system A. In the calibrated received signal S2, S2', the first local maximum P1 has been minimized. This makes it easier to identify a second local maximum P2 caused by at least one environmental condition. An example threshold T represents a decision threshold. If the decision threshold is exceeded by a signal strength of the received signal S2, S2', this can be recognized as a gesture G. By predetermining at least one environmental condition, the signal component caused by this condition in the received signal S2, S2' can be reduced. The reduction is significant enough that the signal component falls below the threshold T.The third local maximum P3, which is caused by the signal reflection at the user N, thus remains as the only relevant signal component above the threshold T, so that it can be used to recognize the gesture G.

[0075] In this illustration, a left-pointing arrow at the third local maximum P3 clarifies that this maximum moves to the left within a sequence of numerous received signals S2, S2'. This means that the user N performs a gesture G representing an approach to the actuation system A. This could, for example, represent a forward movement of the hand H. The arrow also illustrates that the signal reflection received by the actuation system A as the received signal S2, S2' is time-varying. This time variability is due to the gesture G performed by the user N. Thus, the gesture G can be recognized, among other things, by the time-varying of the received signal S2, S2'.

[0076] Fig. Figure 7 shows views of a user N in different positions while approaching a motor vehicle F. In the first position, the actuation system A is in its first operating mode. In this mode, it communicates with the user N's ​​mobile device E by transmitting a signal S1. For example, the actuation system A could be part of a digital key vehicle access system. The user N's ​​mobile device E could then serve as a key to unlock the motor vehicle F. If the key (e.g., a transmitted code) is deemed valid by the actuation system A, the user N can adjust the control element K using the actuation system A. In this first operating mode, the actuation system A can exchange data with the mobile device E. This data could enable the user N to be located.

[0077] In a second position, the user N is closer (e.g., 1 m to 6 m) to the actuation system A (e.g., less than a measurement threshold, which is, for example, between 3 m and 6 m). The actuation system A can then switch to a second operating mode. The second operating mode may require more electrical energy than the first operating mode. Therefore, the operation of the actuation system A in the second operating mode can be delayed by using the first operating mode, thus saving electrical energy. In the second operating mode, the distance between the user N and the actuation system A can be determined, for example, by measuring the time of flight of the transmitted signal S1.

[0078] In the third position, the user N is even closer to the actuating system A (for example, less than a detection threshold of, say, 1 m). The actuating system A can then switch to a third operating mode. The third operating mode may require more electrical energy than the second and / or the first operating mode. Therefore, the operation of the actuating system A in the third operating mode can be delayed by using the first two operating modes, thus saving electrical energy. In the second operating mode, a gesture G by the user N, with which the user activates the actuating system A to adjust the adjusting element K, can be detected.

[0079] The actuating system A is arranged on an adjustment element in the form of a vehicle door K of a motor vehicle F. It is concealed within the vehicle door K and is not visible to a user N. The actuating system A has a first and a second antenna 41, 42. In principle, the actuating system A can have any number of antennas, and it can be designed and configured to use an assigned antenna 4 for transmitting and receiving in each operating mode. In the third operating mode, the actuating system A transmits a further signal S1' (if applicable) via the second antenna 42.with a lower signal strength than the transmit signal S1 for communication with the mobile device E or for determining the approach of the user N), with which a gesture G is recognized on the basis of a signal reflection that causes a signal component of a received signal S2', which is received by the actuation system via the first antenna 41.

[0080] Fig.Figure 8 shows a flowchart of steps performed by the actuation system A as user N approaches the vehicle F. In a first step, B1, the actuation system A starts from a standby mode into an initial operating mode. In this initial operating mode, in a second step, B2, the actuation system A checks whether a mobile device E is detected. For this purpose, the actuation system A can transmit a signal S1 via an antenna, upon receipt of which the mobile device E communicates with the actuation system A. If no device E is detected, the actuation system A returns to standby mode and can, for example, switch back to the initial operating mode after a predetermined time interval.

[0081] When a mobile device E is detected, user N is located in a third step B3. For user N location, a multitude of transmitted signals S1 are sent to the mobile device E to communicate with it. Signal reflections of the transmitted signals S1 from objects O in the vicinity of the actuation system A can be used in a fourth step B4 to calibrate a received signal S2 and determine at least one environmental condition.

[0082] In a fifth step, B5, the actuation system A checks whether the user is approaching N. This check can be based on the user's location. If the user is not approaching N, the actuation system A can continue locating the user at defined time intervals.

[0083] If the actuation system A determines that the user N is approaching, it can determine the user N's ​​distance in a sixth step B6. This can be done, for example, by transmitting a signal S1 in a second operating mode. The signal S1 can have a different signal strength and / or frequency than the signal S1 transmitted in the first operating mode. The signal S1 transmitted to determine the user N's ​​distance can be reflected back to the actuation system A due to signal reflection off the user N's ​​body, allowing the system to determine the user N's ​​distance from the system by measuring the time of flight. For this determination of the user N's ​​distance, the user N can be at a distance from the actuation system A that is less than a measurement threshold.For example, in the first operating mode, the localization of user N can be used to determine whether user N is below the measurement threshold to the actuation system A.

[0084] During the determination of the user's distance N, the actuation system A can perform a further calibration of the received signal S2 and a further determination of at least one environmental condition in a seven-step process B7. This allows the received signal S2 to be calibrated even better and the at least one environmental condition to be determined even more accurately.

[0085] In the eighth step, B8, the actuation system A determines whether the user N has entered a detection zone D. If not, the actuation system A continues determining the user N's ​​distance. The detection zone D is reached when the user N's ​​distance is less than a detection threshold. Within the detection zone D, a gesture G can be recognized in a ninth step, B9. The actuation system A thus switches to a third operating mode in which gestures G are recognized when the user N has entered the detection zone D.

[0086] In a tenth step, B10, the actuation system A checks whether the gesture G matches a gesture G stored in an electronic storage unit 25. The actuation system A takes at least one environmental condition into account. If the gesture G does not match a stored gesture G, the actuation system A continues with gesture recognition. If the gesture G matches a stored gesture G, an actuation command is triggered in an eleventh step, B11, which adjusts an adjusting element. Reference symbol list 1 circuit board 2 electronic control units 21 Calibration unit 22 Classification unit 23 Evaluation unit 24 processor units 25 storage units 31, 32 Receive path arrangement 33 Transmission path arrangement 310, 320, 330 interfaces 311, 321 Analog-to-Digital Converter 331 Digital-to-Analog Converter 4, 41, 42, 43 antennas 5 Switch assembly 501, 502 Antenna Port 51, 52, 53 Switch elements 6 Multi-switch element 7 Bus interface A control system D Detection range E mobile device F motor vehicle G gesture H Hand K vehicle door N users O object P1, P2, P3 local maxima S1, S1' transmit signal S2, S2', S3 Receive signal T threshold

Claims

[1] Method for operating an actuation system (A) for a motor vehicle (F) comprising the following steps: - Connect, with a switch assembly (5), a first receive path arrangement (31) to a first antenna (41), - Connect, with the switch assembly (5), a transmit path arrangement (33) to a second antenna (42), - Sending a first transmit signal (S1) from the transmit path arrangement (33) via the second antenna (42), - Receiving a first received signal (S2) caused by the first transmitted signal (S1) via the first antenna (41), - Receiving a second received signal (S3) caused by the first transmitted signal (S1) via a second received path arrangement (32) which can be connected to the two antennas (41, 42) via the switch assembly (5), and - Calibrating the first received signal (S2) with a calibration unit (21), whereby the calibration is carried out using the second received signal (S3). [2] Method according to claim 1, characterized by , that the transmit path arrangement (33), the first receive path arrangement (31) and the second receive path arrangement (32) are each connected to the switch assembly (5) via an interface (310, 320, 330). [3] Method according to claim 2, characterized by , that the second receive signal (S3) is received via the interface (320) of the second receive path arrangement (32). [4] Method according to claim 3, characterized by , that the second received signal (S3) results from crosstalk between the transmit path arrangement (33) and / or the associated switch assembly (5) when transmitting the first transmit signal (S1) with the interface of the second received path arrangement (32). [5] Method according to any of the preceding claims, characterized by, that the calibration of the first received signal (S2) includes removing or minimizing a signal component resulting from crosstalk between the first antenna (41) and the second antenna (42). [6] Method according to any of the preceding claims, characterized by , that a classification unit (22), to which the calibrated first received signal (S2) is supplied, determines at least one environmental condition of the actuation system (A) on the basis of the calibrated first received signal (S2). [7] Method according to claim 6, characterized by , that an electronic control unit (2) with which the actuation system (A) is controlled specifies at least one operating parameter of the actuation system (A) on the basis of the determined at least one environmental condition. [8] Method according to any of the preceding claims, characterized by , after calibration, - Connect, with the switch assembly (5), the first receive path arrangement (31) to the second antenna (42), and - Connect, with the switch assembly (5), the transmit path arrangement (33) to the first antenna (41), and - Sending another transmit signal (S1') from the transmit path arrangement (33) via the first antenna (41). [9] Method according to any of the preceding claims, characterized by Detect, on the basis of a third received signal (S2') received after the first received signal (S2) via the first antenna (41) or the second antenna (42), a gesture (G) of a user (N) of the actuation system (A) with which a command to actuate an adjustment element (K) of the motor vehicle (F) can be triggered. [10] Method according to claim 9, characterized by , that the third received signal (S2') is caused by another transmitted signal (S1') which has a lower signal strength than the first transmitted signal (S1). [11] Method according to any of the preceding claims, characterized by , that the first transmission signal (S1) is sent as part of a communication process with a mobile device (E) of a user (N) of the actuation system (A) and / or as part of determining a distance of the user (N) to the actuation system (A). [12] Method according to claim 11, characterized by , that the recognition of the gesture (G) of the user (N) by an evaluation unit (23) is based on a third received signal (S2'), wherein the evaluation unit (23) is in standby mode during the communication process and / or during the determination of the distance of the user (N). [13] Actuation system (A) for a motor vehicle (F), with - at least two antennas (4, 41, 42, 43), - a transmit path arrangement (33) and two receive path arrangements (31, 32) which can be connected to the at least two antennas (4, 41, 42, 43), - a switch assembly (5) which is designed and configured to establish a connection between the transmit path arrangement (33) and a first of the at least two antennas (41) and between a first of the receive path arrangements (31) and a second of the at least two antennas (42), and - a calibration unit (21) which is designed and configured to calibrate a first received signal (S2) received via the first antenna (41) and generated by a first transmitted signal (S1) sent by the transmit path arrangement (33) via the second antenna (42), using a second received signal (S3) received via a second received path arrangement (32) and generated by the first transmitted signal (S1). [14] Actuating system (A) according to claim 13, characterized by, that the switch assembly (5) has two antenna ports (501, 502) for connecting antennas (4, 41, 42, 43), wherein a multi-switch element (6) is connected to a first of the antenna ports (501), to which at least two antennas (42, 43) are connected, one of which can be selected via the multi-switch element (6) for connection to the first antenna port (501). [15] Actuating system (A) according to one of claims 13 and 14, characterized by, that the transmit path arrangement (33) and the two receive path arrangements (31, 32) each have an interface (310, 320, 330) via which the transmit and receive path arrangements (31, 32, 33) can be connected to the at least two antennas (4, 41, 42, 43), wherein the interfaces (310, 320, 330) are arranged on a common electronic carrier element (1), such that a transmit signal (S1, S1') sent by the transmit path arrangement (33) via one of the at least two antennas (4, 41, 42, 43) generates a receive signal (S2, S2', S3) in both receive path arrangements (31, 32) by crosstalk. [16] Actuating system (A) according to any one of claims 13 to 15, characterized by, that the transmit path arrangement (33) and the two receive path arrangements (31, 32) are part of a chip assembly comprising an electronic control unit (2) with the calibration unit (21), a classification unit (22) for determining at least one environmental condition based on the calibrated first received signal (S2) and an evaluation unit (23) for recognizing a gesture (G) of a user (N) based on a third received signal (S2'). [17] Actuating system (A) according to any one of claims 13 to 16, characterized by , that the transmit path arrangement (33) is designed and configured to generate ultra-wideband signals and / or that the actuating system (A) has at least one transmission device for communication with another wireless transmission technology. [18] Motor vehicle (F) with an adjusting element (K) and at least one actuating system (A) according to one of claims 13 to 17, wherein the adjusting element (K) is adjustable by actuating the at least one actuating system (A) by a user (N). [19] Computer program product comprising instructions which, when executed by at least one processor of an electronic control unit (2) of an actuation system (A) for a motor vehicle, cause the at least one processor to execute a method according to any one of claims 1 to 12.

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