CAPACITIVE SENSOR ARRANGEMENT FOR A VEHICLE

Description

[0001] The present invention relates to an arrangement for evaluating a capacitive sensor device in a vehicle. Furthermore, the invention relates to a method for operating a sensor element, a computer program product, and a computer-readable medium.

[0002] It is known from the prior art that capacitive sensors can be provided in vehicles to detect an activation action. Such an activation action can be implemented as a simple approach or as a complex gesture. In any case, the activation action serves to activate a vehicle function, e.g., to initiate authentication in the vehicle and / or to open a tailgate. For this purpose, the capacitive sensor can be arranged in the rear area of ​​the vehicle, e.g., near a bumper, so that it can be activated by a foot movement or the like of a vehicle user.

[0003] The evaluation of a capacitive sensor can be performed using a so-called charge transfer method. Such charge transfer methods are known, for example, from DE 10 2012 102 422 A1, DE 10 2012 105 266 A1, DE 10 2013 112 909 A1, and DE 10 2013 112 910 A1.

[0004] It is often a technical challenge to prevent sensor interference from the sensor's or vehicle's environment. Environmental moisture (e.g., rain) is known to cause interference. However, due to the sensor's electronic evaluation, electromagnetic signals can also be a source of interference. For example, external transmitters, such as medium-wave radio or the like, may have a negative influence. In practice, signals from these transmitters that interact at an evaluation frequency of the capacitive sensor, e.g., in the range from 510 kHz to 1.71 MHz, are particularly relevant. In other words, the electronic evaluation can exhibit a (particularly frequency-dependent) interference signal sensitivity, preferably frequency sensitivity, so that certain frequencies can represent a particular interference influence.If these signals from external transmitters interfere with the evaluation, they are considered external interference signals, which represent a disruptive immission for the vehicle's sensor. Measures to reduce and / or compensate for the influence of these interference signals are technically complex and costly. A similar capacitive sensor is known from DE29721213 U1.

[0005] It is therefore an object of the present invention to at least partially remedy the disadvantages described above. In particular, it is an object of the present invention to provide an improved evaluation option for a capacitive sensor device, in particular for a capacitive sensor.

[0006] The above object is achieved by an arrangement having the features of the independent device claim, a method having the features of the independent method claim, a computer program product having the features of the co-ordinate device claim, and by a computer-readable medium having the features of the further co-ordinate device claim. Further features and details of the invention emerge from the respective sub-claims, the description, and the drawings. Features and details described in connection with the arrangement according to the invention naturally also apply in connection with the method according to the invention, the computer program product according to the invention, and the computer-readable medium according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made reciprocally.

[0007] The object is achieved in particular by an arrangement, preferably an electronic device and / or circuit arrangement, for evaluation in a capacitive sensor device (preferably as a proximity sensor) of a vehicle. In particular, the arrangement according to the invention serves to detect an activation action in the vehicle.

[0008] The vehicle can be designed, for example, as a motor vehicle, preferably a passenger car and / or a truck. For example, the vehicle is designed as an electric vehicle and / or a hybrid vehicle and / or an autonomous (self-driving) vehicle. The vehicle can have a security system designed to communicate with a mobile identification transmitter (ID transmitter). Via the communication, for example, at least one piece of authentication information, such as an authentication code or the like, is transmitted from the ID transmitter to the vehicle. When the security system evaluates this authentication information, it can authenticate the ID transmitter and, for example, authorize it to release and / or activate at least one vehicle function.With a passive access system, it may be possible for a vehicle function, such as unlocking the vehicle, to be activated automatically - without manual operation of the ID transmitter - upon successful authentication and / or appropriate authorization.

[0009] Possible vehicle functions include, for example, unlocking the vehicle and / or opening a tailgate and / or opening a side door of the vehicle and / or opening a front and / or hood and / or enabling an engine start.

[0010] To increase convenience, at least one proximity sensor is provided on the vehicle, for example, to initiate communication for authentication and / or activation of at least one vehicle function upon detection of the approach of an object and / or user (possibly with the ID transmitter) to the vehicle. This at least one proximity sensor is attached, for example, to the rear and / or side and / or front area of ​​the vehicle. In the rear area, detection of approach and / or successful authentication can, for example, initiate the opening of the tailgate. In the front area, detection of approach and / or successful authentication can, for example, initiate the opening of the front and / or hood. In the side area, detection of approach and / or successful authentication can, for example, initiate the unlocking and / or opening of a side door.

[0011] According to a further advantage of the arrangement according to the invention, the at least one proximity sensor is at least partially arranged in the rear and / or front area in a bumper and / or in the side area of ​​the vehicle in an (outside) door handle. It can be provided that at least one sensor element of the proximity sensor is arranged in the bumper or door handle and is directed toward an exterior area of ​​the vehicle in order to detect an approach and / or gesture in a monitoring area outside the vehicle. Alternatively or additionally, the proximity sensor can also monitor the interior of the vehicle.

[0012] In embodiment variants of the arrangement according to the invention, it may be possible for the at least one proximity sensor to at least partially comprise the capacitive sensor device or to be designed as such. The proximity sensor, i.e. in particular the capacitive sensor device, can comprise at least one sensor element as a sensitive element. This can be designed, for example, as a sensor electrode and attached to the vehicle and / or aligned in such a way that a monitoring area outside the vehicle can be detected. The detection of the approach can, if necessary, also be used to detect gestures or the like on the vehicle. For example, several sensor elements can also be used for a common monitoring area in the arrangement according to the invention.

[0013] Furthermore, a control device is provided for operating, in particular for evaluating, the at least one sensor element with (using) at least one (in particular electrical) evaluation sequence. A (in particular electronic) control device of the control device is used to provide the evaluation sequence by adapting it (e.g., adapting the evaluation sequence and / or the evaluation) to influence an interference signal sensitivity of the evaluation in the capacitive sensor device, preferably to influence the spectrum of the evaluation sequence. In other words, the evaluation sequence can be adapted due to the adaptation in such a way that the interference signal sensitivity is influenced. For this purpose, the evaluation sequence can optionally have at least one adaptation feature that is specific to the adaptation (e.g., phase jumps or the like).This has the advantage that the evaluation sequence can be adapted to reduce the influence of external interference signals during the evaluation of the capacitive sensor device and thus increase the reliability of the evaluation.

[0014] According to one advantage of the invention, in the arrangement according to the invention, the adaptation and / or provision of the evaluation sequence can be achieved by generating the evaluation sequence using an adaptation means, preferably according to a specification (such as a specification for the temporal introduction of phase jumps) and / or a predetermined adaptation routine (e.g., a specific modulation type, such as phase-shift keying). For this purpose, for example, the electronic control device, such as a microcontroller or the like, can be provided, which carries out the generation, possibly also signal shaping, of the evaluation sequence using the adaptation means. The adaptation means has, for example, pre-stored information (e.g., in a data memory) and / or a computer program and / or a configuration of the control device.

[0015] The evaluation in the capacitive sensor device is used, for example, to detect the approach of the object and / or the user. If the evaluation determines, for example, a certain change in a property of the sensor element, such as a changing capacitance, this can be interpreted as an approach. For this purpose, the change in capacitance determined by the evaluation is compared with a threshold value in order to positively detect the approach if the threshold value is exceeded. However, it is possible that external transmitters (i.e. transmitters outside the vehicle) emit external interference signals, in particular radio signals, which interfere with the evaluation. This interference may be frequency-dependent, so that the interference signal sensitivity - i.e. in particular the sensitivity for interference signals - is only present for certain frequencies or frequency ranges. In order to reduce the interference signal sensitivity, for example,The spectrum of the evaluation sequence can be modified. For example, particularly dominant or specific frequencies that are also present in the interference signal (i.e., interference frequencies), e.g., in an original signal for the evaluation sequence, can be attenuated. In other words, the adaptation can be implemented as an amplitude adaptation, which attenuates the amplitudes for certain interference frequencies in the original signal and / or redistributes them in the spectrum to obtain the evaluation sequence.

[0016] The original signal can, for example, be generated electrically in real and / or analog form as an intermediate product, and the evaluation sequence can be formed from this by adaptation. However, it can also be a fictitious (i.e. imaginary and / or not electrically real and / or generated in analog form and / or only provided digitally) original signal, which is used during signal generation, for example within the processor, to provide the evaluation sequence. The (fictitious) original signal can also only serve as a simplified illustration within the scope of this invention in order to specify the adaptation. Accordingly, the evaluation sequence can also be generated directly in such a way that it is influenced by the adaptation, without the original signal as such having to be used digitally and / or analogically. For this purpose, for example.The evaluation sequence is predefined by the adaptation means and / or even pre-stored as a temporal sequence (with the sequence components). Therefore, it does not necessarily have to be regenerated, but can simply be output electrically based on the pre-stored information (e.g., by a digital-to-analog converter). However, it can be advantageous if the evaluation sequence is generated by the adaptation means and / or the control device, for example, to reduce costs for a data storage device.

[0017] The evaluation sequence can be specified by the adaptation (possibly regardless of the type of production and / or generation and / or whether the original signal is actually used or used analogously) and in particular can have the adaptation features as brought about by the adaptation and described below. The adaptation can therefore always be provided, even with a completely pre-stored evaluation sequence which merely needs to be output. The use of the adaptation in the arrangement according to the invention is preferably understood to mean that it specifies the evaluation sequence, in particular the adaptation features of the evaluation sequence. The adaptation is to be understood in particular as the production and / or generation of the evaluation sequence with a specific signal shape.

[0018] The adaptation can be designed to have the advantage of redistributing energy in the frequency domain during the evaluation sequence, preferably resulting in a type of "defined noise." Without the use of adaptation, such as phase shifts, the sensor element is operated, for example, with an original evaluation sequence (the original signal), which may have an original evaluation frequency (at its center of gravity or as the strongest frequency component). A source of interference in the vicinity of the sensor device, e.g., a radio transmitter with a radio frequency at least similar to the original evaluation frequency, can then disrupt the evaluation as an interference signal, e.g., by transferring energy to the sensor element. The goal can therefore be to attenuate the original evaluation frequency in favor of redistribution in the spectrum.This can also be interpreted as using not just a single original evaluation frequency, but instead a frequency range. This means that the individual radio frequency no longer has the same disruptive influence, and the evaluation can be improved.

[0019] The interference signal sensitivity is in particular a sensitivity for interference signals of certain frequencies, whereby the interference signals are preferably emitted externally by the vehicle, i.e. are emissions for the sensor device.

[0020] The evaluation sequence can be any electrical signal, preferably a rectangular and / or rectangular-like and / or rectangular-based signal (hereinafter also referred to as a rectangular signal for short) or a sinusoidal and / or sinusoidal and / or sine-based signal (hereinafter also referred to as a sinusoidal signal for short), preferably with at least one frequency. For example, the sinusoidal signal has a narrow frequency spectrum, whereas the rectangular signal has non-negligible components in a very broad spectral range. The rectangular signal can consist (at least partially or predominantly or essentially) of odd-numbered harmonics. Since these are obviously not ideal signal shapes, there may also be deviations from the aforementioned in the evaluation sequence.

[0021] Since the evaluation sequence may have at least one dominant frequency and / or at least one dominant frequency range when viewed spectrally, external interference signals can, for example, have an interfering effect on the evaluation if they also have this frequency and / or frequency components in this frequency range. The evaluation therefore has an interference signal sensitivity for this frequency and / or the frequency range. The higher the amplitude of the evaluation sequence for this frequency or the frequency range, the higher the interference signal sensitivity may be. One solution may be to influence the interference signal sensitivity of the evaluation by the control device by means of adaptation, preferably frequency- and / or phase-dependent adaptation, preferably frequency and / or amplitude and / or phase adaptation, preferably by modulation. In other words, the evaluation sequence can be provided by this adaptation. For this purpose, for example,the amplitude of an original signal of the evaluation sequence can be reduced for at least one frequency component that corresponds to a frequency component in the interference signal. In other words, those frequencies that are also present in the interference signal (i.e. at least one frequency in common with the interference signal) can be provided in an attenuated form in the evaluation sequence. The original signal is, for example, a fictitious signal (e.g. used only for processing and not generated in analog form) or a signal initially generated in analog form by the control device and used to form the evaluation sequence. For example, the original signal can be a square wave signal or sine wave signal with a first frequency spectrum that is changed by the adaptation, so that the adapted original signal forms the evaluation sequence with a second frequency spectrum.Due to the adaptation, the second frequency spectrum may contain a smaller and / or attenuated portion of the at least one frequency common to the interference signal than the first frequency spectrum. The external interference signal is generated, for example, by external transmitters, preferably radio and / or wireless transmitters. "External" refers to the vehicle with the arrangement according to the invention; thus, the external interference signal is generated and / or emitted outside the vehicle.

[0022] It is further conceivable that the adaptation is implemented as an adaptation, in particular a temporal adaptation, of sequence components of the evaluation sequence, preferably a sequence component width and / or a sequence component spacing. For this purpose, for example, the sequence component width and / or the sequence component spacing are varied over time in order to adapt a spectrum of the evaluation sequence, in particular to an interference signal. In this way, the interference signal sensitivity can be reliably reduced.

[0023] Furthermore, it is conceivable that the adaptation is carried out as a modulation, in particular frequency or phase modulation, so that the evaluation sequence is provided with repeated phase jumps as provided according to the invention.

[0024] For example, at least one original frequency, preferably a sampling frequency, can be assigned to the evaluation sequence. The original frequency or sampling frequency is, for example, a frequency of the original signal (which can be a simple square wave or sine wave). The original frequency is, for example, the strongest frequency component of the original signal, i.e. the non-modulated signal. It may now be possible that this at least one original frequency corresponds to an interference frequency in an interference signal. Therefore, the evaluation can easily be impaired by interference signals if the evaluation sequence were to correspond to the original signal. According to the invention, it is therefore possible that the original signal is not used for the evaluation, but rather an evaluation sequence (possibly based thereon), in particular an evaluation signal. This preferably has (e.g. due to the modulation, if necessary).alternatively or additionally due to further adaptation measures) a spectrum in which at least one interference frequency of the interference signal is attenuated (with respect to the amplitude in the frequency domain). This improves the interference signal sensitivity and thus also the reliability of the evaluation.

[0025] According to the invention, the control device is designed to generate the evaluation sequence with repeated phase jumps, preferably to attenuate at least one predetermined frequency, preferably an original sampling frequency for the sensor element, during the evaluation sequence. The phase jumps are a simple and reliable means of redistributing the energy in the spectrum, i.e., distributing the amplitudes more evenly across different frequencies in the frequency range. Therefore, the interference signal sensitivity for the interference frequencies is reduced in favor of sensitivity for other frequencies.

[0026] It is also conceivable for the adaptation to be implemented as frequency modulation, frequency shift keying, or phase shift keying, preferably as binary phase shift keying, quadrature phase shift keying, or phase shift keying with at least two or at least four phase states. These methods are particularly suitable for the adaptation described.

[0027] Furthermore, the invention provides that at least one switch element is connected to the control device, in particular electrically, in order to be switched, preferably switched over, repeatedly and as a function of the adaptation, preferably as a function of phase jumps, by the control device, preferably in order to carry out charge transport between the sensor element, preferably a sensor electrode, and the control device according to the evaluation sequence, wherein in particular the evaluation sequence can be provided at least partially by switching the switch element. The switching has the advantage that the sensor element can be electrically charged in a first step and electrically evaluated in a second step, e.g., by charge transport from the sensor element to a holding arrangement.Since switching can influence the evaluation sequence, it is conceivable that the control of the switch element is adapted for the adaptation according to the invention.

[0028] It is also optionally conceivable for the control device to be designed to provide the evaluation sequence with sequence components, preferably pulses, preferably rectangular pulses, that are at least partially output with different widths and / or different spacings. This adaptation in the time domain has a direct influence on the spectrum, which may be broadened and / or redistributed.

[0029] Furthermore, it is optionally possible within the scope of the invention for at least one switch element to be connected, in particular electrically, to a transmission path to the sensor element in order to repeatedly connect the sensor element via the transmission path alternately to a transmit path (in particular for charging the sensor element) and to a receive path (in particular for transferring a charge from the sensor element), wherein preferably at least the transfer and / or the charging can be carried out with the evaluation sequence. For transferring the charge, the receive path is connected, for example, to a holding arrangement. For charging, the transmit path is connected, for example, to a digital-to-analog converter. This enables simple and reliable evaluation.

[0030] It is further conceivable for the control device to have a holding arrangement which is connected, in particular electrically, to a transmission path to the sensor element via a receive path and / or via a switch element, in order to carry out a charge transfer of the charge stored in the sensor element to the holding arrangement, preferably by means of the evaluation sequence, and preferably to evaluate a variable capacitance of the sensor element based on the charge transfer. For this purpose, a (in particular fixed) capacitance of the holding arrangement can be used to store a charge transferred from the sensor element to the holding arrangement during the charge transfer. To further improve the evaluation, the holding arrangement can be designed as an integrator and / or have such an integrator.

[0031] According to an advantageous development of the invention, it can be provided that the control device is designed to carry out the operation, in particular the evaluation, of the sensor element, in particular a charge transfer by the evaluation sequence, in a frequency-sensitive manner (in particular for external interference frequencies of the external interference signal). The interference signal sensitivity can be reduced by the adaptation, and preferably a bandwidth of the frequency sensitivity can be increased at the same time. The interference signal sensitivity preferably determines a frequency-dependent susceptibility to external (interference) signals. For example, the interference signal sensitivity is reduced by attenuating particularly dominant frequencies of an (analog or digital or fictitious, i.e., imaginary) original signal and / or by reducing the amplitudes of these frequencies.This makes it possible to reduce the influence of individual particularly dominant frequencies, so that the interference signal has a reduced influence on the evaluation.

[0032] Furthermore, it is optionally provided that the control device has an adaptation means for generating the evaluation sequence as a signal with temporally successive sequence components, in particular pulses, preferably in a rectangular or sinusoidal form. Preferably, through the adaptation, preferably through repeated phase jumps, a pulse width of individual pulses or, in some cases, a spacing between the pulses is increased, preferably doubled, in particular through switching between at least or exactly two phase positions of the signal at each phase jump. This represents a simple and cost-effective solution for implementing the described adaptation.

[0033] Furthermore, within the scope of the invention, it can be provided that the evaluation sequence can be provided in a phase-modulated manner during operation by means of phase jumps, preferably by means of binary phase-shift keying or quadrature phase-shift keying or phase-shift keying with at least two or at least four phase states. With four phase states, quadrature phase-shift keying, for example, can be used. This enables the use of reliable and cost-effective modulation methods. The modulation can be carried out for adaptation, for example, by the control device, such as a microcontroller, using a computer program (e.g., the adaptation means).The computer program can then be designed to form the evaluation sequence, which has adaptation features characteristic of the modulation (such as phase jumps and / or sequence component spacing and / or pulse spacing and / or sequence component widths and / or pulse widths and / or sequence component amplitudes and / or pulse amplitudes). This formed evaluation sequence—present only digitally as information and therefore not as an analog signal—can then be converted into the analog evaluation sequence using a digital-to-analog converter.

[0034] Within the scope of this invention, the use of modulation as adaptation can refer to the fact that modulation techniques are used accordingly and / or at least partially to provide or generate the evaluation sequence. For example, the use of phase-shift keying means that phase jumps corresponding to the phase-shift keying are recognizable in the evaluation sequence. Modulation therefore does not have to be understood to mean that data transmission (e.g. via radio) must take place. An (analog or digital) original signal can also be modulated as an intermediate step - only optionally - in order to obtain the evaluation sequence, or this intermediate step can be omitted and the evaluation sequence can be formed directly in order to provide the evaluation sequence through modulation as adaptation.

[0035] It may further be possible to provide an adaptation means, such as a computer program and / or a configuration and / or data, which comprises information about the adaptation and preferably comprises information about intervals between the phase jumps, in particular to carry out the phase jumps equidistantly at predefined intervals. This can provide a simple way of configuring or programming the adaptation. The information can be implemented in such a way that the evaluation sequence is generated as a fixed, predetermined sequence (i.e., a sequence of subsequences, such as pulses). Alternatively, it is conceivable for the evaluation sequence to comprise a random or pseudo-random sequence of sequence components. For example, the sequence can be generated by the control device using stochastic methods.Accordingly, it may be possible to provide an adaptation means that contains information about the intervals between phase jumps during the adaptation, in order to perform the phase jumps at irregular and / or pseudo-random, predefined intervals. This can be made possible, for example, by appropriate programming of the control device and / or a random number generator.

[0036] Thus, it can be provided that an adaptation means, preferably a random number generator, is designed to perform phase jumps during the adaptation at random intervals. For example, the adaptation means randomly determines whether and / or when the phase jump is performed during the evaluation sequence. For this purpose, there are, for example, boundary conditions, e.g., that the phase jump may only be performed at certain time intervals or at and / or with certain phase positions. Synchronization can also be provided.

[0037] The invention also relates to a method according to claim 9 for operating a sensor element for an evaluation in a capacitive sensor device of a vehicle, for detecting an activation action in the vehicle.

[0038] Advantageously, in a method according to the invention, at least one of the following steps can be carried out, wherein the steps are preferably carried out one after the other in the specified order or in any order, and if necessary, individual steps can also be repeated: Carrying out several recharging processes on the sensor element, Carrying out an evaluation, in particular of a variable capacity of the sensor element, based on the recharging processes in order to monitor an environment of the sensor element, The charge transfer processes are carried out using an evaluation sequence that features an adaptation, namely repeated phase jumps, to influence the sensitivity of the evaluation to interference signals. Thus, the method according to the invention provides the same advantages as those described in detail with reference to an arrangement according to the invention. Furthermore, the method can be suitable for operating an arrangement according to the invention.

[0039] Within the scope of the invention, it can preferably be provided that, to provide the evaluation sequence, an original signal, preferably a square-wave or sine-wave signal, is adapted by the adaptation, preferably modulated, preferably frequency- and / or phase-modulated, particularly preferably by a control device of a control device. The original signal can actually be generated (e.g., via a digital-to-analog converter) and then adapted, or it can simply be processed internally as information by the control device to generate the evaluation sequence. The latter has the advantage of enabling rapid and reliable generation of the evaluation sequence. Accordingly, the original signal can also be regarded as "original signal information."

[0040] Furthermore, the invention provides that the charge transfer processes each comprise a transmission process for charging the sensor element and / or a reception process for transferring a charge from the sensor element to a holding arrangement, namely an integrator arrangement. Through the adaptation, namely through the phase jumps, the transmission and / or reception processes are carried out at different intervals from one another. The different intervals, e.g., of sequence components for charging the sensor element and / or transferring the charge, enable the interference signal sensitivity and / or the spectrum of the evaluation sequence to be influenced. The integrator arrangement is designed, for example, as an integrator using an operational amplifier.

[0041] The invention also relates to a computer program product comprising instructions which, when executed by a control device, cause the device to perform the steps of a method according to the invention. Thus, the computer program product according to the invention provides the same advantages as those described in detail with reference to a method according to the invention. To carry out the reloading processes, the computer program product can, for example, initiate a switching of a switching element by the control device.

[0042] The invention also relates to a computer-readable medium on which the computer program product according to the invention is stored. Thus, the computer-readable medium according to the invention offers the same advantages as those described in detail with reference to a method according to the invention.

[0043] Also protected is a further computer program product for providing and / or forming and / or generating an evaluation sequence according to a method according to the invention and / or for a control device of an arrangement according to the invention. Also protected is a further computer-readable medium on which this further computer program product according to the invention is stored.

[0044] Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. They show schematically: Figure 1 shows a perspective view of a vehicle rear, Figure 2 shows a schematic diagram of an arrangement according to the invention, and Figure 3 shows an exemplary evaluation sequence.

[0045] In the following figures, identical reference numerals are used for the same technical features, even in different embodiments.

[0046] In Figure 1A vehicle 1 with an arrangement 10 according to the invention is shown. The arrangement 10 is designed for evaluation by a capacitive sensor device 20 of the vehicle 1, in particular for detecting an activation action in the vehicle 1, e.g., in the front and / or side and / or rear area. As an example of these areas, detection in the rear area is shown, in which at least one sensor element 20.1, preferably at least one sensor electrode 20.1, of the arrangement 10 according to the invention can be arranged in a bumper 3 of the vehicle 1. In this way, the sensor device 20 can be used to detect an outer area of ​​the vehicle 1 in front of the tailgate 2 in order to activate a vehicle function upon detection of an approach of an object (such as a user 8), such as communication with an identification transmitter and / or opening of the tailgate 2. For example, the at least one sensor element 20.1 is arranged and directed toward the exterior area such that a movement of a body part 9 as the activation means 9 of the user 8 is detected below the tailgate 2 or below the bumper 3. Alternatively or additionally, the sensor element 20.1 can also be arranged in other components of the vehicle 1, such as in at least one door handle 4, preferably the exterior door handle 4, and / or in a sill and / or the like.

[0047] Furthermore, a control device 50 can be provided for operating the at least one sensor element 20.1. For this purpose, the control device 50 can use at least one evaluation sequence S', as in Figure 2is shown schematically in the circuit diagram. Specifically, a control device 50.1 of the control device 50 is provided in order to provide the evaluation sequence S' by an adaptation for influencing an interference signal sensitivity of the evaluation, preferably for influencing the spectrum of the evaluation sequence S'. The control device 50.1 is designed, for example, as a microcontroller and / or integrated circuit and / or processor and / or the like. The control device 50.1 and / or further parts of the control device 50 are preferably fastened to a circuit board of the sensor device 20 (not explicitly shown). The control device 50, in particular the control device 50.1, can be electrically connected to the sensor element 20.1 via conductor tracks of this circuit board. However, if necessary (at least partly)) Other connection variants for signal transport, such as galvanically isolated and / or optical signal transmission. In this way, the evaluation sequence S' can be transmitted as a (e.g., electrical) signal between the control device 50 and the sensor element 20.1 in order to operate the sensor element 20.1 and thus the sensor device 20, in particular to evaluate and / or provide detection of the sensor device 20.

[0048] For signal transport, a transmission path u is preferably used (at least partially), which connects the control device 50 with the at least one sensor element 20.1. Figure 2shown that at least one switch element S can be connected (in particular electrically) to the transmission path u to the sensor element 20.1 in order to repeatedly connect the sensor element 20.1 via the transmission path u alternately to a transmit path t for charging the sensor element 20.1 and to a receive path r for transferring a charge from the sensor element 20.1, wherein at least the transfer can be carried out using the evaluation sequence S'. For example, the charging can also be carried out using the evaluation sequence S'. The charging relates in particular to an (electrical) charge transport from the control device 50 to the sensor element 20.1 and the transfer relates to an (electrical) charge transport from the sensor element 20.1 to the control device 50, preferably to a holding arrangement 50.4 with a holding capacity CH. Optionally, several (at least two) sensor elements 20.1 can also be provided, which (e.g.alternately and / or clocked) to the transmission path u via a switching device 60. This makes it possible to carry out the evaluation with a single control device 50 (and / or also a single holding arrangement 50.4) but several sensor elements 20.1.

[0049] The holding arrangement 50.4 can be connected (optionally electrically) via the switch element S to the transmission path u to the sensor element 20.1 (i.e., can also be connected repeatedly) in order to carry out a charge transfer (in particular a transport) of the charge stored in the sensor element 20.1 to the holding arrangement 50.4 by means of the evaluation sequence S', and preferably to evaluate a variable capacitance (sensor capacitance CS) of the sensor element 20.1 based on the charge transfer. The evaluation principle can be understood such that the variable capacitance CS is provided by the sensor element 20.1 and is changed due to external influences (such as approaching the sensor element 20.1). For example, the variable capacitance CS is measured by the control device 50 against a ground potential 20.2, so that the sensor element 20.1 can be designed as a single electrode (the sensor electrode 20.1).In other words, a counter electrode to the sensor electrode 20.1 does not necessarily have to be provided structurally (e.g. as a discrete component) in order to enable the evaluation of the sensor device 20. For example, the sensor element 20.1 can be designed as a single electrical line (and, for example, extend elongatedly in the form of a cable), which is connected to the transmission path u via a single electrical connection. It is evident here that with such a construction, the capacitance CS is formed by the sensor element 20.1 in such a way that the environment of the vehicle influences the capacitance CS and thus the evaluation, in particular forming a dielectric for this capacitance CS. In particular, if the sensor element 20.1 can be understood as an electrode, it becomes clear that electrical and / or electromagnetic influences outside the vehicle 1 can influence the evaluation. It is thus conceivable that external (ieTransmitters located outside the vehicle 1) can emit at least one interference signal that influences the evaluation. For example, the interference signal has at least one frequency that is also used in the evaluation sequence S'. Such interference frequencies can have a non-negligible influence on the evaluation and change the capacitance and / or charge transport measured during the evaluation (and therefore possibly lead to incorrect detection by the sensor device 20). As a solution, the invention can therefore provide for the use of an adaptation that takes the at least one interference signal into account when providing, in particular generating, the evaluation sequence S'. In other words, an imaginary or real first signal, hereinafter also referred to as an original signal, on which the evaluation sequence S' is based, can be adapted if necessary.

[0050] The evaluation sequence S' has, for example, at least one original frequency, preferably a sampling frequency, for the sensor element 20.1, which corresponds (at least nearly or approximately) to at least one frequency in the interference signal. Depending on the adaptation, the evaluation sequence S' may no longer have this original frequency, but may merely be based on it (e.g., the frequency was eliminated by the adaptation). The original sampling frequency is therefore, for example, a frequency of the original signal (which can be a simple square-wave or sine-wave signal). The original signal is, for example, a signal that can be generated by a simple clock generator. If fixed frequencies are provided for the original signal, the evaluation can easily be impaired by interference signals if the evaluation sequence S' were to correspond to the original signal. Therefore, the original signal can be adapted to obtain the evaluation sequence S' with a modified spectrum.In this way, the spectrum can be adjusted to be less sensitive to the interference signal. Thus, the interference sensitivity of the evaluation can be reduced.

[0051] The adaptation is implemented, for example, as a modulation, in particular frequency or phase modulation (in particular of the original signal). A method known for implementing modulation can therefore be used to provide the adapted evaluation sequence S'. Such methods include, for example, frequency modulation and / or frequency-shift keying and / or phase modulation and / or phase-shift keying. The use of such methods has the advantage that the immunity of the evaluation to the interference signal can be increased, since the frequency components of the evaluation sequence S' that are also present in the interference signal can be attenuated. The principle is explained in more detail below using examples.

[0052] The adaptation is preferably carried out in such a way that the evaluation sequence S' can be provided with repeated phase jumps P. Accordingly, the control device 50.1 can be designed to generate the evaluation sequence S', in particular with repeated phase jumps P, in order to attenuate at least one predetermined frequency, preferably an original sampling frequency for the sensor element 20.1, in the evaluation sequence S'. Modulation can be used for this purpose, e.g., phase-shift keying, which is preferably implemented as binary phase-shift keying or quadrature phase-shift keying or phase-shift keying with at least two or at least four phase states.

[0053] To implement the adaptation, the at least one switch element S can be electrically connected to the control device 50.1 so that the switch element S is switched, preferably switched, repeatedly and as a function of the adaptation, preferably as a function of phase jumps P, by the control device 50.1. In this way, charge transport between the sensor element 20.1 and the control device 50 can be carried out according to the evaluation sequence S', wherein the evaluation sequence S' can be provided at least partially by switching the switch element S. For example, the switch element S is switched irregularly to carry out the adaptation in order to reduce the interference signal sensitivity during the evaluation. The switching can be a switching between the receive path r and the transmit path t, which are hereby alternately connected to the transmission path u.

[0054] As in Figure 3As shown, the control device 50.1 can be designed to provide the evaluation sequence S' with sequence components S'.1, preferably pulses, preferably rectangular and / or signal-shaped pulses, which are at least partially output with different widths and / or different spacings. The sequence components S'.1 are present in the original signal, for example, at regular intervals, and the original signal therefore has a spectrum with at least one dominant frequency. This potentially makes the evaluation susceptible to interference signals which also have this frequency as an interference frequency. Since, according to the invention, not the original signal but (for example exclusively) the evaluation sequence S' is used for the evaluation (the original signal is, for example, not generated at all or merely internally as a digital "intermediate product" in the control device 50.1), the interference signal sensitivity can be influenced as desired. By using the adaptation, for example,Distances and / or widths of the sequence components S'.1 can be changed. Examples include sequence component widths S'.2 and sequence component distances S'.3, which are varied by phase jumps P over time t'. A phase position is also shown as an example for clarification. For example, the first phase jump P can occur at 180° and increase the sequence component distance S'.3. Furthermore, the next second phase jump P can increase the sequence component width S'.2. In this way, by adjusting the sequence components S'.1 (if necessary with the amplitude A not changed) in the time domain (as in . Figure 3shown) the spectrum of the evaluation sequence S' and thus the amplitude A (in the frequency domain) for certain frequency components are adapted to the interference signal (changed with regard to the interference signal). For this purpose, an adaptation means 50.3, such as a computer program and / or a random number generator, of the control device 50.1 can be used. The adaptation can, for example, also use pre-stored information and / or sequence for the evaluation sequence S', which is stored, for example, in a data memory 50.8 of the control device 50.1. Alternatively or additionally, a data memory 50.8 of the control device 50.1 can also be used as a computer-readable medium for the computer program. For outputting the evaluation sequence S', in particular the Figure 3shown evaluation signal S', a digital-to-analog converter 50.2 can be used, which can be integrated, for example, in the control device 50.1. In this way, the control device 50.1 and / or the adaptation means 50.3 can be used reliably to generate the evaluation sequence S' as a signal S' with temporally successive pulses (i.e., the sequence components S'.1), in particular in rectangular or sinusoidal form, wherein, through the adaptation, preferably through repeated phase jumps P, a pulse width (i.e., sequence component width S'.2) of individual pulses or, in individual cases, a distance (i.e., sequence component distance S'.3) between the pulses is increased, preferably doubled, in particular through switching between at least or exactly two phase positions of the signal S' at each phase jump P.

[0055] The above explanation of the embodiments describes the present invention exclusively by way of examples. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically feasible, without departing from the scope of the present invention. List of reference symbols

[0056] 1Vehicle 2Tailgate 3Bumper 4Door handle 8User 9Body part, activation means 10Arrangement, circuit arrangement 20Sensor device 20.1Sensor element, sensor electrode 20.2Ground potential 50Control device 50.1Control device, microcontroller 50.2Digital-to-analog converter 50.3Adaptation means 50.4Holding arrangement 50.8Data memory 60Switching device rReceive path tTransmit path t`Time uTransmission path AAmplitude CHHolding capacitance CSSensor capacitance PPhase shift SSwitch element S'Evaluation sequence, signal S'.1Sequence component S'.2Sequence component width S'.3Sequence component spacing

Claims

1. Arrangement (10) for an evaluation in a capacitive sensor device (20) of a vehicle (1) for detecting an activation action in the vehicle (1), the capacitive sensor device being a proximity sensor, having a control device (50) for operating at least one sensor element (20.1) with at least one evaluation sequence (S'), wherein an actuation device (50.1) of the control device (50) is provided in order to provide the evaluation sequence (S') by means of an adaptation for influencing an interference signal sensitivity of the evaluation, preferably for influencing the spectrum of the evaluation sequence (S'), wherein the actuation device (50.1) is designed to generate the evaluation sequence (S') with repeated phase jumps (P) in order to attenuate at least one predetermined frequency, preferably an original sampling frequency for the sensor element (20.1), in the evaluation sequence (S'), wherein at least one switch element (S) is connected to the actuation device (50.1) to be switched repeatedly and in dependence on the adaptation, namely in dependence on phase jumps (P), by the actuation device (50.1) so as to perform a charge transport between the sensor element (20.1) and the control device (50) in accordance with the evaluation sequence (S'), whereby the evaluation sequence (S') can be provided at least in part by switching the switch element (S), wherein the control device (50) has a holding arrangement (50.4) which is connected via the switch element (S) to a transmission path (u) to the sensor element (20.1) in order to carry out a recharging of the charge stored in the sensor element (20.1) to the holding arrangement (50.4) by means of the evaluation sequence (S'), and in order to evaluate a variable capacitance of the sensor element (20.1) on the basis of the recharging, wherein the holding arrangement (50.4) comprises an integrator.

2. Arrangement (10) according to claim 1, characterized in that the adaptation is implemented as phase modulation, so that the evaluation sequence (S') can preferably be provided with repeated phase jumps (P).

3. Arrangement (10) according to one of the preceding claims, characterized in that the adaptation is implemented as an adaptation, in particular a temporal adaptation, of sequence components (S'.1) of the evaluation sequence (S'), preferably a sequence component width (S'.2) and / or a sequence component spacing (S'.3), and / or that the adaptation is implemented as a phase shift keying, preferably as a binary phase shift keying or a quadrature phase shift keying or a phase shift keying with at least two or at least four phase states.

4. Arrangement (10) according to one of the preceding claims, characterized in that the actuation device (50.1) is designed to provide the evaluation sequence (S') with sequence components (S'.1), preferably pulses, preferably rectangular pulses, which are at least partially output with different widths and / or different spacing.

5. Arrangement (10) according to one of the preceding claims, characterized in that at least one switch element (S) is connected to a transmission path (u) to the sensor element (20.1) in order to repeatedly connect the sensor element (20.1) via the transmission path (u) alternately to a transmit path (t) for charging the sensor element (20.1) and to a receive path (r) for recharging a charge from the sensor element (20.1), it being possible to carry out at least the recharging with the evaluation sequence (S').

6. Arrangement (10) according to one of the preceding claims, characterized in that the control device (50) is designed to perform the operation, in particular the evaluation, of the sensor element (20.1) in a frequency-sensitive manner, wherein the interference signal sensitivity can be reduced by the adaptation, and preferably a bandwidth of the frequency sensitivity can be increased at the same time, wherein preferably the interference signal sensitivity determines a frequency-dependent susceptibility to interference for external signals, and / or that the actuation device (50.1) has a matching means (50.3) in order to generate the evaluation sequence (S') as a signal (S') with pulses following one another in time, in particular in rectangular or sinusoidal form, a pulse width of individual pulses or an interval between the pulses being increased, preferably doubled, by the adaptation, preferably by repeated phase jumps (P), in particular by a switchover between at least or exactly two phase positions of the signal (S') with each phase jump (P).

7. Arrangement (10) according to one of the preceding claims, characterized in that the evaluation sequence (S') can be provided continuously phase-modulated during operation by means of phase jumps (P), preferably by means of binary phase shift keying or quadrature phase shift keying or phase shift keying with at least two or at least four phase states.

8. Arrangement (10) according to one of the preceding claims, characterized in that a matching means (50.3) is provided, which has information about the matching, and preferably has information about the intervals between the phase jumps (P), in order to carry out the phase jumps (P) equidistantly at predefined intervals, and / or in that a matching means (50.3) is provided, which has information about intervals of phase jumps (P) during the matching in order to carry out the phase jumps (P) at irregular and / or pseudo-random, predefined intervals, and / or in that a matching means (50.3) is provided, preferably a random number generator, in order to carry out phase jumps (P) during the matching at random intervals.

9. Method for operating a sensor element (20.1) for an evaluation in a capacitive sensor device (20) of a vehicle (1) for detecting an activation action in the vehicle (1), wherein the capacitive sensor device is a proximity sensor, whereby the following steps are carried out: - Carry out several recharging processes at the sensor element (20.1), - Performing an evaluation, in particular of a variable capacitance of the sensor element (20.1), on the basis of the recharging processes in order to monitor an environment of the sensor element (20.1), whereby the recharging processes are carried out with an evaluation sequence (S') which has an adaptation, namely repeated phase jumps (P), for influencing an interference signal sensitivity of the evaluation, the recharging processes each having a transmission process for charging the sensor element (20.1) and a reception process for transmitting a charge of the sensor element (20.1) to a holding arrangement (50.4), namely an integrator arrangement (50.4), the transmission and / or reception processes being carried out at different distances from one another as a result of the adaptation, namely as a result of the phase jumps (P).

10. Method according to the preceding claim, characterized in that to provide the evaluation sequence (S'), an original signal, preferably a square-wave or sinusoidal signal, is adapted by the adaptation, preferably phase-modulated, particularly preferably by an actuation device (50.1) of a control device (50).

11. A method according to any one of the preceding claims, characterized in that an arrangement (10) according to one of the preceding claims is operated.

12. A computer program product comprising instructions which, when executed by an actuation device (50.1), cause it to perform the steps of a method according to any one of the preceding claims.

13. A computer-readable medium on which the computer program product according to the preceding claim is stored.