A device for a motor vehicle for detecting an activation operation of an activated vehicle function

Abstract

The invention relates to a device for detecting an activation action for activating a function of a vehicle. Furthermore, the invention relates to a method and to a use. A device for detecting an activation action for activating a function of a vehicle has at least one sensor element (21) for sensing a change in the surroundings of the sensor element (21), a control device for electrically actuating the sensor element (21), and a calculation and analysis device (90). A filter device in a signal path (SP) has at least one high-pass filter (41, 43) for reducing the frequency of a detection signal to at least below the at least one detection frequency. The filter device according to the invention has at least or exactly a second-order or third-order or higher-order high-pass filter.

Description

TECHNICAL FIELD

[0001] The invention relates to a device for detecting an activation action for activating a function of a vehicle. Furthermore the invention relates to a method and to a use. BACKGROUND

[0002] Capacitive sensors are known from the prior art for detecting activation actions on a motor vehicle. Capacitive sensors are used, for example, for detecting the approach of a user or a complex activation action by a user. As a reaction to the detection, for example, a flap can be activated and / or an authentication with the user can be initiated.

[0003] However, a problem that can occur with conventional sensors is that the detection is influenced by electronic interference effects, such as static electricity carried by a user. SUMMARY

[0004] It is therefore the task of the invention to at least partially solve the aforementioned disadvantages. In particular, it is the task of the invention to provide an improved possibility for detecting activation actions.

[0005] The aforementioned task will be solved by a device having the technical features of the invention and by a method having the technical features of the invention. Further features and details are apparent from the description and the drawings.

[0006] The task will in particular be solved by a device, in particular a switch device for a vehicle, in particular a motor vehicle, for detecting an activation action for activating a function on the vehicle. The activation action, such as an approach action or a movement, can serve the purpose of activating a function on the vehicle. The function can be, for example, the opening and / or unlocking of a flap on the vehicle. The device can be used, for example, to carry out an activation action in front of, beside and / or behind the vehicle, which activation action serves to activate the opening and / or unlocking of a flap (of a similar function). For carrying out the activation action, the user can serve as an activation tool himself or the user can use an activation tool, for example a foot. The activation action can be, for example, a movement of the foot under the bumper of the vehicle. The activation action comprises, for example, a forward movement in one direction under the bumper and a subsequent backward movement.

[0007] The device according to the invention can have at least one of the following components:

[0008] - at least one (in particular electrically conductive) sensor element for (in particular capacitive) sensing a change in the surroundings of the sensor element, preferably for sensing an approach and / or a movement by an activation tool (such as the user himself).

[0009] - a control device, in particular electronic, for electrically operating the sensor element, in particular with a control signal, in order to generate a (in particular for sensing) detection signal, the frequency of which comprises at least one predefined detection frequency, in particular the detection signal depending on the sensed change.

[0010] - a calculation and analysis device, in particular electronic, which is connected to the sensor element via a signal path in order to repeatedly acquire at least one parameter of the sensor element which is special for sensing, in particular the parameter of the changing sensor capacitance, from the detection signal in order to detect the activation operation.

[0011] - a filter device, in particular electronic, in the signal path, in particular having a high-pass filter, in order to reduce the frequency of the detection signal so that it is below the detection frequency, that is to say to partially or completely suppress the frequency of the detection signal, and / or in order to at least pass the detection frequency.

[0012] This makes it possible to filter out disturbing frequencies which influence the detection. It is particularly advantageous when the filter device filters the detection signal which is received in the signal path by the calculation and analysis device of the sensor for processing in order to obtain the parameter. That is to say, the filter device can filter the charge carrier which is transmitted from the sensor element to the calculation and analysis device according to the frequency. The transmission can be amplified or adjusted in the signal path, for example with an amplifier, as the case can be. The detection signal is therefore not necessarily a uniquely defined current, but can also be an information carrier, since there can also be components in the signal path which amplify.

[0013] The control device and the calculation and analysis device can each be an electronic circuit device or can jointly have electronic components. That is to say, a processing device, for example a microcontroller, can be part of both the control device and the calculation and analysis device. There can furthermore be a circuit board on which at least some of the components of the inventive device are arranged. In particular, at least the calculation and analysis device and the control device can be arranged on the circuit board.

[0014] The device according to the invention is fixed on or in a part of a vehicle (form-fit or force-fit or material connection). By way of example, this means that the device according to the invention can be integrated into a bumper or a door handle. The part of the vehicle can be formed together with the device according to the invention as a separately mountable mounting unit which can be mounted as an integral part. The sensor element can be arranged on the inside of the bumper and be fixed there form-fit or force-fit or material connection.

[0015] The signal path can comprise at least one or exactly one power path, in which the same current (same current strength) flows and / or in which the same potential energy is present. In addition or additionally, the signal path can intersect with one such path, which leads from the sensor element to the calculation and analysis device and / or in which the signal is detected from the sensor element to the calculation and analysis element. Alternatively, the potential energy and the current strength can also change in the signal path, or there can be impedance changes, current breaks or the like in the signal path, in particular as long as the transmission of the detection signal can be ensured.

[0016] The at least one detected frequency can be depicted as a frequency range in a frequency spectrum (i.e. a plurality of frequencies), which is set for the detection signal. The detection signal can thus be defined as a sinusoidal signal and (in actual operation) essentially prepared as sinusoidal. Depending on the setting of the detection signal, it can thus only occupy a small part of the frequency spectrum. Frequencies of the detection signal that occur outside the set frequency range in actual operation are thus considered to be interfering frequency portions. One cause of the interfering frequencies can occur in the charge carrier displacement due to electrostatic induction. The charge carrier displacement occurs as, for example, a direct current and is marked as a low frequency in the detection signal frequency spectrum. Filter means can be used to filter out the low frequency and other interfering frequencies, if applicable. The actual (disturbed) detection signal is thus converted into a filtered signal by the filter means, in which the interfering frequencies are reduced, and which can be analyzed by the calculation and analysis device. The filtered detection signal can thus be more in line with the set frequency range from the frequency point of view than the disturbed detection signal. The advantage is that the interfering factors are filtered out and the analysis by the calculation and analysis device can be less adversely affected.

[0017] The detected frequency can advantageously be predetermined such that an improved signal transmission according to EMV (electromagnetic compatibility) requirements is possible. That is, the detected frequency can be predefined as 333 kHz, i.e. as a center frequency of the detection signal frequency range. The filter means can thus be designed to pass this frequency, but to suppress other frequencies. In addition, the detected frequency can have an amplitude that alternates between two extreme values of -1 volt to 1 volt.

[0018] Advantageously, the vehicle is a motor vehicle, in particular a hybrid or electric vehicle, with a high-voltage electrical system (Hochvolt-Bordnetz) and / or an electric motor. In addition, the vehicle can also be a fuel vehicle and / or a passenger vehicle and / or a semi- or fully-automated vehicle. Advantageously, the vehicle has a security system which can communicate an authentication with an identity information encoder (ID-Geber). Depending on the communication and / or authentication, a function on the vehicle can be activated. If the identity information encoder must be authenticated for this, the function can be a safety-relevant function, such as the authorization of the unlocking and / or starting of the vehicle. The security system can thus also be a passive access system, which initiates the authentication and / or the function when the identity information encoder is sensed in the proximity without the active manual operation of the passive access system by the identity information encoder. For this purpose, the security system repeatedly sends a wake-up signal, which is received by the identity information encoder when it is in the proximity, and then initiates the authentication. The function can also be the activation of a vehicle light and / or the operation (opening and / or closing) of a flap (such as a front, rear, side door or flap). That is, the vehicle light is automatically switched on when the proximity is detected and / or the flap is automatically operated when the user's movement is detected.

[0019] In addition, it is also conceivable that an activation operation will be used to activate a function on the vehicle by means of the device according to the application. In particular, an activation operation which is located outside the vehicle. That is, the sensor element which senses the change is located outside the vehicle (i.e. no longer in the interior space of the vehicle). When the activation operation is successfully detected by the device according to the application, the function can be activated by the device (in particular by the processing device) and / or the authentication procedure is initiated. The activation operation can be the movement of a proximity and / or activation tool. When the activation tool is a non-electrified object (so that the activation tool does not refer to the identity information encoder), the activation tool and the activation operation can be detected. The activation tool can be a non-electrified and / or non-metallic and / or biological entity, such as a body part of the user. It is therefore particularly advantageous to detect the activation operation using inductive detection, since no special equipment is required on the activation tool.

[0020] An example of a device according to the application can advantageously be an electronic switch (switching device) and have a plurality of electronic components which are arranged at least on a circuit board and are connected to one another by means of an electrical circuit. At least one of the electronic components can be an integrated circuit (for example a processing device as a microprocessor). Several of the electronic components can also be surface-mounted-device components. The sensor can be embodied as a conductive circuit or as a flat electrode on the circuit board, or be connected to the circuit board by means of a lead (for example an electrical lead). In the latter case a part of the sensor element, i.e. the lead (for example a coaxial lead), can be embodied as a flat electrode or as a length-extended conductor. The sensor element can also be embodied as a capacitive electrode, since a change in capacitance occurs by means of the sensor element. Alternatively, a plurality of sensor elements can also be provided, which can be operated simultaneously or alternately, in order to produce a change in capacitance. The circuit board and / or the sensor element can be integrated, for example, into a door handle and / or a bumper. The sensor element can be arranged in such a way that it defines a detection region for the activation operation.

[0021] According to a further possibility, the sensor element can be embodied as an electrically conductive sensor electrode, which acquires a specific parameter which varies as a sensor capacitance, and / or the evaluation device has an electronic processing device for evaluating the varying sensor capacitance value on the basis of the detection signal. The sensor can be dependent on the sensor capacitance value in terms of the amplitude. This effect will be described below (in some places in simplified form). The sensor capacitance is embodied as a capacitance between the sensor electrode and at least one further electrically conductive conductor (for example a ground). The ground can be, for example, the vehicle body. There can be a dielectric between the sensor electrode and the further electrically conductive conductor, for example the surroundings of the vehicle in which the activation operation takes place. The activation operation can therefore influence the sensor capacitance value. The detection signal can be sensed as a repeated charge carrier transfer, in which the charge carriers are transferred from the sensor electrode to the evaluation device or vice versa. The amount of charge carriers transferred is dependent on the sensor capacitance value. The amplitude of the detection signal, in particular the current strength, is therefore also dependent on the sensor capacitance value.

[0022] The sensor element can be embodied as an electrode of a capacitor which has a varying capacitance value (i.e. the sensor capacitance value). When the sensor element is controlled by means of the control device, a displacement of a charge can occur, which is dependent on the sensor capacitance value. A displacement current can also occur as a result of interference. Both can essentially be measured by means of the evaluation device. However, the displacement current can be attenuated or completely eliminated by means of a filter device.

[0023] A further advantage is that the evaluation device has an integrator for evaluating the charge carriers carried by the detection signal and / or caused by the change in the surroundings. The integrator device can also have an operational amplifier, for example, to form an electronic integrator, for example, by means of a frequency-dependent negative feedback. The integrator device of the evaluation device can accumulate the amount of charge carriers and use this to evaluate the change. The output signal of the integrator device can thus be formed specifically for the activation operation such that an output signal that exceeds a threshold value is recognized as a detection of the activation operation. This exceeding of the threshold value can be detected by the processing device, for example, and use this to evaluate the change in the sensor capacitance value by means of the detection signal. The processing device can be a microprocessor and have, as the case can be, at least one further component of a control device, such as a digital-to-analog converter. The control device can be a signal generator to generate a control signal, such as a sinusoidal signal, to define the signal form of the detection signal.

[0024] It is also conceivable that there is a transfer device in the signal path between the sensor element and the filter element, which has a voltage outputter to prepare the detection signal for the filter depending on a change in the surroundings and / or depending on a change in the sensor capacitance value. The transfer device can thus have, for example, an operational amplifier and at least one filter element, for example, a capacitor and a resistor. The filtering of the control signal and / or the detection signal can additionally be provided by means of at least one filter element, for example, by means of a bandpass behavior and / or a frequency-dependent negative feedback. The detection signal can be prepared depending on the sensor capacitance value, since the amount of charge carriers transferred by means of the detection signal depends on the capacitance present on the sensor element. The detection signal can be prepared by means of a periodic control signal, which is particularly a periodically varying voltage and / or current, in particular a sinusoidal voltage or current, by means of the control device. The controller element can be controlled by means of a control signal by the control device, such that the transfer of charge carriers to the sensor element is initiated. For this purpose, the control device can be designed as a signal generator, which is electrically connected to the transfer device, such that the control signal is converted into the detection signal on the sensor element from the transfer device. To this end, the transfer device performs a transformation of the impedance, as the case can be.

[0025] The transfer device can also be configured for a frequency-dependent and / or phase-dependent transfer, in particular for a frequency-dependent and / or phase-dependent change of a frequency-dependent and / or phase-dependent transfer of an electrical input signal, in particular of a control signal, in particular for a frequency-dependent and / or phase-dependent change. The transfer device can additionally be used to output an electrical output signal which is related to the input signal, i.e. the control signal, which is transferred (and / or changed) in terms of frequency and / or phase, and which is preferentially defined in terms of signal form by the input signal. The output signal can be understood as a sensor voltage or a sensor current. The output of the transfer device and the sensor element are electrically connected directly or indirectly to output the output signal electrically to the sensor element. The transfer device has an input at which the input signal is prepared. The input can be electrically connected to the control device.

[0026] In particular, the transfer device has a controllable source device, in particular an electrical source, such as a voltage or current source, to generate an output signal which is dependent on the input signal and / or dependent on a frequency-dependent and / or phase-dependent transfer, in particular a frequency- and / or phase-dependent change of the input signal, i.e. in particular controlled by the input signal which is transferred / changed, and which preferentially outputs the output signal as a guided electrical signal to the sensor element. This can have the advantage that the frequency spectrum of the input signal is adapted by the transfer device, for example that (unwanted) interference frequencies of the input signal are filtered out and / or circumvented when outputting the output signal to the sensor. The use of a source device which is also controllable can additionally ensure that the output signal on the sensor element still has (approximately, for example within a specified error range) the frequency spectrum which has been adapted by the transfer device.

[0027] The use of a controllable source device of a transfer device can have the particular advantage of preparing a signal which is guided to the sensor element. In particular, by actively generating the output signal and guiding the output signal to the sensor element, it can be advantageous to output an output signal which is reduced in terms of interference.

[0028] According to the application, the transmission device is connected to the sensor element via a first interface, and / or to the evaluation device and / or to the filter device via a second interface, and / or to the control device via a third interface. The transmission device can have a voltage output and / or a voltage multiplier in order to keep the potential at the third interface constant or to amplify it for the generation of a potential at the first interface for the sensor element. Preferably, the potential at the sensor element and / or the potential at the second interface follow the potential at the third interface (amplified or constant). In this way, the transmission device can have a "decoupling" in which the transmission device is used as a controllable voltage source. A voltage can be generated at the sensor element in order to influence the charge carrier transmission in accordance with a control signal at the third interface. In accordance with the control signal and in particular the charge carrier transmission, a detection signal can be generated at the second interface in order to evaluate parameters in accordance with the detection signal. The amount of the transmitted charge carriers, i.e. the current, of the detection signal is evaluated. By means of the "decoupling", the load on the sensor element can be reduced.

[0029] In addition, a rectifier device can be provided, which has one or more rectifiers. The rectifier device can be designed without diodes or similar components, so that substantially no voltage drop occurs at the rectifier device, or at least only a very small voltage drop occurs. This can be achieved in that the rectifying function is performed by at least one electronic switch of the rectifier device, which switch switches on and off in a clocked manner.

[0030] The rectifying function of the rectifier device can be a "coherent" rectification by means of the at least one rectifier. This can be understood in that the at least one rectifier has a predetermined period, which transmits the electronic signal (detection signal) from the filter device to the integrator device, preferably in synchronization with the electronic control of the control device or in relation to the control signal. In this way, the detection signal is rectified coherently in relation to the control signal. For this purpose, each rectifier has at least one electronic switch. The period can be predetermined in such a way that only the positive half-wave (or the negative half-wave), for example, of the respective predetermined fundamental wave, i.e. of a harmonic of the electronic signal (for example, the first harmonic, the frequency of which is passed through as a center frequency by the filter device, and, if appropriate, further harmonics), is transmitted. Thus, each period can be synchronized with the control device in such a way that the period is adapted in accordance with the waveform of the electronic signal, i.e. of the signal of the sensor element, of the electronic control. Alternatively, the rectifying function can also be implemented incoherently, if appropriate, using diodes.

[0031] The filter device has at least or exactly one partial device for high-pass filtering. The high-pass filter of the filter device can be the only high-pass filter and / or a first-order high-pass filter. The filter device can thus filter overall only with first order, so that the complexity of the filter device is reduced. In addition, the filter device can have a further partial device in addition to the partial device for first-order filtering, which is also used for first-order high-pass filtering. Together, a second-order high-pass filter function can be obtained, so that the filtering function is further improved. It is also conceivable to realize higher-order filter device high-pass filter functions, i.e. third- or fourth-order, by using more corresponding partial devices.

[0032] It can be advantageous within the scope of the application if the filter device has at least or exactly a second- or third- or higher-order high-pass filter. For example, a second-order high-pass filter can be realized in that the filter device knows two partial devices with high-order filtering. That is, the filter device uses two capacitors, or a capacitor is supplemented by an inductor for a first-order high-pass filter. This has the advantage that frequencies below the detected frequency can be filtered out particularly reliably. The filter's slew rate can be increased, and when the high-pass filter is part of a bandpass filter, the passband has a flatter course of the absolute frequency response.

[0033] In addition, it is also conceivable within the scope of the application that the filter device has a first partial device with a high-pass filter and a second partial device with a low-pass filter. In this way, the filtering function of the detected signal can be further improved. The filter device can provide a bandpass filter in this way. To this end, the filter device knows a capacitor and / or at least one resistor and / or only analog electronic components.

[0034] Alternatively, it is conceivable that the filter device can also have a third partial device with a high-pass filter. A bandpass filter consisting of an at least or exactly first-order low-pass filter and an at least or exactly second-order high-pass filter is thus obtained. Interference frequencies above the detected frequency can thus also be filtered out.

[0035] Alternatively, it is also possible for the filter device to form a bandpass filter. This makes it possible for both interference frequencies below the detected frequency and interference frequencies above the detected frequency to be suppressed.

[0036] It is also conceivable within the scope of the application that the filter device serves to reduce the influence of electrostatic induction at the sensor element, in particular to reduce the displacement of charge carriers (in particular by the influence of the electric field at the sensor element). The application can be directed in particular to disturbances caused by electrostatics and / or electrostatic induction. The displacement of charge carriers caused by the disturbance (also referred to as displacement current) can be understood, for example, as the use of cat hair. This disturbing effect has been known for centuries, for example, static electricity generated by rubbing against cat hair. This effect of charging results in the displacement of charge carriers in the conductor around an electrical conductor. This effect can cause a displacement of charge carriers in the sensor element, i.e. a displacement current, in particular due to the alternating action of adjacent conductors, for example of additional conductors as will be described further below. This can be evaluated by the evaluation device, i.e. the measuring machine, as a change in the sensor capacitance which is incorrectly measured or which is compensated for a change in the sensor capacitance which is actually present. The latter can result in the activation of an operation not being detected. Surprisingly, it can be determined within the scope of the application that the use of the filter device at least partially reduces this disturbing detection.

[0037] It is also conceivable within the scope of the application that the sensor device has a sensor element which has an additional electrical conductor which extends at least partially or predominantly parallel to the sensor element. The additional conductor can also be mutually arched with the sensor element. The additional conductor and the sensor element can each be designed as a conductor which is stretched in the length direction, i.e. the length direction is stretched significantly more than the other directions (for example at least 10 times or at least 20 times or at least 50 times). The sensor element and / or the entire sensor device can be designed as a wire. This can make the installation of the sensor element on a vehicle particularly simple. This design is particularly advantageous for the application of the sensor device in a vehicle bumper, in order to observe the area outside the bumper with the sensor element.

[0038] It is also possible that the sensor device has a sensor element and at least one additional conductor. The additional conductor can be designed like the sensor element as an electrical conductor and have a material with electrical conductivity. The additional conductor can have substantially the same length as the sensor element and / or extend parallel to the sensor element. An electrically capacitive coupling, i.e. in the range of picofarad (pF), can be formed between the additional conductor and the sensor element. The sensor element can be connected to the additional conductor galvanically isolated. In addition, the additional conductor and the sensor element can also have an electronic connection. The additional conductor and the sensor element can thus be connected to each other galvanically, i.e. directly or via a resistor. The connection can also be located outside the sensor device, i.e. via an interface device. In addition, the sensor element and the additional conductor can also be connected to ground, in each case also via an interface device. The interface device is located, for example, between the sensor device and a processing device (to be described further below). The (at least) one sensor element and the (at least one) additional conductor can each be designed as an electrical conductor, in particular as a twisted wire, or the like.

[0039] The sensor element can surround the additional conductor at a fixed distance. The sensor element can itself act as a shield for the additional conductor. An insulator can be present between the additional conductor and the sensor element. The sensor device can have an outer diameter of 1 to 50 mm. In addition, the sensor device and in particular the sensor element can have a circular cross-section or be designed as a flat wire. The sensor element as a flat wire can have a height which is 2, 5 or 10 times smaller than its width and / or a length which is 2, 5 or 10 times greater than its width. The sensor element and in particular the additional conductor can be used contrary to their original purpose according to the application. In particular, the sensor element can be used as a sensor electrode and the additional conductor as a functional element. In addition, the sensor element can be electrically floating, i.e. be electrically connected only at one point. This can prevent the sensor element from being part of a closed electrical circuit.

[0040] It is also conceivable for the or an additional conductor and the sensor element to be electrically coupled together by means of an interface coupling. This coupling can be effected by means of the electrical resistance of the interface coupling, but can alternatively or additionally also be effected by means of further components, such as capacitors and / or inductors. The interface coupling can thus be formed as an electrical circuit arrangement having at least one component, and in particular has two interfaces for connecting the sensor element on the one hand and the additional conductor on the other hand. In particular, the interface coupling can have a connection device, such as a plug, for connecting the sensor element to a processing device. This makes it possible for the sensor element to be simply installed on the processing device. It also makes it possible for the sensor element to be replaced flexibly while retaining the same processing device. The interface coupling can also be designed in such a way that, in operation, displacement currents (arising as a result of interference) can be passed through the device according to the application. To this end, the interface coupling can comply with the requirements for an electrically conductive, and if appropriate low-resistance, connection between the additional conductor and the sensor element.

[0041] The device according to the application can have the or a processing device, which has a control device and / or a calculation and analysis device and / or a processing device, and is configured, for example, as a controller of a vehicle. The processing device, in particular the processing device, can also be electrically connected to the vehicle electronics, in particular by means of an additional plug. By means of this connection, functions on the vehicle can be activated, such as opening a flap or the like. The processing device can also be part of an assembly which comprises an electronic system which the device according to the application can itself have for analyzing and controlling the sensor element and / or detecting activation operations. It is thus possible to dispense with the vehicle electronics having to control and / or analyze the sensor element itself. The device according to the application can thus be used in a multiplicity of ways.

[0042] According to an advantageous embodiment of the application, the additional conductor in the sensor device is inactive, i.e. for detection, its influence on the electrostatic induction at the sensor element is particular. The additional conductor can be, for example, an unused conductor, in particular a wire, of the sensor device. The use of the sensor element and the wire offers the advantage of simple installation and lower production costs. The retention of the additional conductor also reduces the complexity of the device. Of course, the electrostatic induction which forms the interference effect is also to be taken into account, which can be purposefully solved by using filter devices. The filter devices can be designed in particular to counteract the electrostatic induction which arises as a result of the additional conductor. To this end, the filter devices can be designed by means of a plurality of tests and / or corrections in such a way that the interference frequencies which arise as a result of the electrostatic induction are largely reduced. In other words, the filter function of the filter devices makes it possible to suppress the displacement currents.

[0043] It is also conceivable that the or a sensor device has the form of a coaxial line, which has the sensor element as outer conductor of the coaxial line and an additional conductor as inner conductor, i.e. core, of the coaxial line.

[0044] It is furthermore possible that not only the sensor element(s) but also the additional conductor(s) are electrically connected with the signal path, in particular via an interface coupler. The current between the sensor and the additional conductor can thus also influence the analysis function of the calculation analysis device.

[0045] Likewise a further subject of the application is a method for detecting an activation operation for activating a function on a vehicle, in particular for detecting an activation operation in front of, beside and / or behind a vehicle for activating the opening and / or unlocking of a cover on the vehicle.

[0046] To this end the following steps are carried out, preferably successively or in any order, wherein individual or multiple steps can be repeated and / or at least partially occur in time parallel, if desired all steps are carried out repeatedly:

[0047] - sensing a change, in particular the approach of an activation tool, in the vicinity of the sensor element, in particular with a (in particular electrically conductive) sensor element, wherein preferably the vicinity extends between a vehicle part, such as a bumper, and a piece of ground on which the vehicle is located,

[0048] - controlling the sensor element with a (in particular electronic) control device to prepare a (in particular for detecting changes) detection signal, which has a frequency which includes at least one predefined detected frequency,

[0049] - obtaining at least one parameter, such as a sensor capacitance value, which is special for detecting the activation operation by a (in particular electronic) calculation analysis device, wherein the calculation analysis device is connected with the sensor element via a signal path, to repeatedly obtain the parameter from the detection signal,

[0050] - reducing at least the frequency of the detection signal below the at least one detected frequency by filter means in the signal path, which at least have a high-pass filter.

[0051] The method according to the application thus has the same advantages as specifically described for the device according to the application. It is alternatively conceivable to carry out the method with a device according to the application.

[0052] Likewise, another subject of the present application is the use of a filter device according to the present application for reducing electronic induction disturbances on a sensor element of a device according to the present application. Such a use according to the present application has the same advantages as described for the device and the method according to the present application.

[0053] Further advantages, features and details of the present application are apparent from the following description, in which embodiments of the present application are described in detail with reference to the drawings. The features mentioned in the claims and the specification can each be essential for the invention in its own individual combination or in any desired combination of the features. The following is shown. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 is a detail view of a component of a device according to the present application,

[0055] Figure 2 is another detail view of a component of a device according to the present application for visualizing the use and the method according to the present application,

[0056] Figure 3 is a detail view of a filter device,

[0057] Figure 4 is another detail view of a filter device,

[0058] Figure 5 is a detail side view of a vehicle with a device according to the present application,

[0059] Figure 6 is a detail rear view of a vehicle with a device according to the present application,

[0060] Figure 7 is another detail view of a component of a device according to the present application. DETAILED DESCRIPTION

[0061] Figure 1 A device 10 according to the present application for a vehicle 1 for detecting an activation operation for activating a function on the vehicle is shown. As shown in Figure 5 The device 10 according to the present application can also be used for detecting an activation operation in front, at the side and / or at the rear of the vehicle 1 for activating the opening and / or unlocking of a cover 2 on the vehicle 1, as shown in Fig. 6. For this purpose, the device 10 according to the present application can be installed in the respective position on the vehicle 1, as the case can be, in particular in front, at the side or at the rear. The device 10 according to the present application can therefore comprise a housing with a positioning element which allows the device to be installed in a position specifically provided for on the vehicle. In addition to the installation of the device 10 according to the present application in the bumper 4, other positions, such as in the door handle 5 or in another vehicle component, are conceivable.

[0062] For example in Figure 6 The device 10 according to the application is shown mounted in the bumper 4, in this mounting position a sensor arrangement 20 (and thus correspondingly a sensor element 21 and / or an additional conductor 22) of the device 10 according to the application extends in the vehicle transverse direction (in this direction more than half the length of the bumper 4 extends) and is electrically connected to a processing device 200. The sensor element 21 can thus be used to sense a change in its surroundings, in particular the approach of an activation means such as a user's foot. That is to say, the back and forth movement of the foot under the bumper 4 is detected as an activation operation.

[0063] Figure 1 As shown, the sensor arrangement 2 (for example in the form of a coaxial conductor) can have a sensor element 21 in the form of an outer conductor 21 and an additional conductor 22 in the form of an inner conductor 22. The sensor element 21 thus surrounds the additional conductor 22 in space. Between the sensor element 21 and the additional conductor 22, the sensor arrangement 22 can also have an isolating element. The sensor element 21 and the additional conductor 22 can be electrically connected by their respective interfaces A2, Al by the electrical connection point 28 to the interface device 25. The interface device 25 has a connection device such as a plug 26 and comprises a first electrical interface Al for the additional conductor 22 and a second electrical interface A2 for the sensor element 21. In addition, the interface device 25 can have an interface coupling 27, which can optionally be outside the interface device 25. By means of the interface coupling, in particular at least one or exactly one electrical resistor, the sensor element 21 can be electrically connected to the additional conductor 22. Both the sensor element 21 and the additional conductor 22 can be electrically coupled to the signal path SP by means of the interface coupling 27. The signal path SP can be used to transfer the electrical charge carriers between the sensor element 21 and, if appropriate, the additional conductor 22 and the processing device 200.

[0064] It is recalled here that other interface couplings 27 can also be envisaged, or that the additional conductor 22 is completely isolated from the sensor 21. That is to say, there can be a capacitive coupling between the additional conductor 22 and the sensor 21. The occurrence of a displacement current, which interferes, can be causally related to the interface coupling 27, or else or additionally to other factors. It is therefore

[0065] The application is not limited to the type of interface coupling 27 shown.

[0066] Figure 2The device 10 according to the application and further details are shown. It can be seen that the sensor element 21 (and, if appropriate, the additional conductor 22) is connected via a signal path first to 30 and then to a filter device 40 of a processing device 200. In this way the detection signal S can be passed via the signal path SP to Figure 7 the calculation and analysis device 90 shown. The calculation and analysis device 90 can have a rectifier and / or an integrator 60 and / or a converter 70 for the calculation and analysis of the detection signal S. The converter 70 can convert the output signal of the integrator 60 into a digital signal which can be further analysed by a processing device 95, for example compared with a threshold value for the detection of an activation operation.

[0067] A specific embodiment of the device 10 according to the application for the control of the sensor element 21 and the analysis of the detection signal S is shown by way of example in Figure 7 Fig. 3. There is an electronic control device 80 for the electronic control of the sensor element 21 for the production of the detection signal S, the frequency of which includes a predefined detection frequency. In addition, a calculation and analysis device 90 is connected via a signal path SP to the sensor element 21 for the repeated determination of at least one sensor element-specific parameter of the sensor element 21 for the detection of an activation operation from the detection signal S. This parameter is in particular a varying sensor CS. As shown in Figure 7 Fig. 3, the sensor 21 can thus be designed as a sensor electrode 21 of a capacitor having a capacitance value CS, the capacitor being formed with respect to the ground potential to form the sensor capacitance value CS.

[0068] In addition, a filter device 40 can be incorporated in the signal path SP, the filter device having at least a high-pass filter 41, 43 for reducing the frequency of the detection signal S to below the at least one detection frequency mentioned.

[0069] In addition, a transfer device 30 can be present in the signal path between the sensor element 21 and the filter device 40, the transfer device 30 comprising in particular an electronic voltage output for the production of the detection signal S for the filter 40 from the varying sensor capacitance value CS of the sensor 21. The transfer device 30 can comprise at least one filter element 32, for example a capacitor C and / or a resistor R, for the improved production of the detection signal S. In addition, the transfer device 30 can have an operational amplifier 31 for the provision of the voltage output.

[0070] Figure 3 The filter device 40 and further details are shown in 4 Fig. 4. The filter device 40 can have a first partial device 41 with a high-pass filter 41 and a second partial device 42 with a low-pass filter 42. According to Figure 4The filter device can have a high-pass filter 41, 43 in the form of a second-order high-pass filter 41, 43 and have a third partial device with a further high-pass filter 43. Each partial device 41, 42, 43 can in turn have a filter circuit of an RC circuit. The filter device 40 can thus constitute a band-pass filter.

[0071] The kind of filter device 40 shown can be used in such a way that the electrostatic induction at the sensor element 21, in particular the charge carrier displacement caused by the electric field acting on the sensor 21, is reduced. The filter device 40 can thus also be referred to as an interference filter. The filter device 40 can be a band-pass filter with a center frequency f0, wherein the center frequency f0 of the operating frequency of the device according to the application, i.e. the frequency to be detected, is in particular 333 kHz.

[0072] Figure 2 A step diagram of the method according to the application is shown. According to a first method step a sensor 21 can detect a change in its surroundings, in particular the approach of an activation means 3. According to a second method step a control device 80 controls the sensor element 21 to prepare a detection signal S, the frequency of which includes at least one predefined frequency to be detected. Thereafter according to a third method step at least one parameter of the sensor element 21 specific to the detection is acquired by a calculation and analysis device 90, which is connected to the sensor element 21 via a signal path SP to repeatedly acquire the parameter from the detection signal. Thereafter according to a fourth method step a filter device 40 via the signal path SP filters out frequencies of the detection signal S which are lower than the at least one frequency to be detected. The filter device 40 can thus be used to reduce the influence of electrostatic induction at the sensor element 21 in the device 10 according to the application.

[0073] The foregoing embodiments merely describe the application in an exemplary framework. The details of the embodiments can naturally be freely combined, as far as technically meaningful, without departing from the scope of the application.

[0074] 1 vehicle

[0075] 2 cover panel

[0076] 3 activation means

[0077] 4 bumper

[0078] 5 door handle

[0079] 10 device

[0080] 20 sensor device, coaxial conductor

[0081] 21 sensor element, outer conductor, shield

[0082] 22 additional conductor, inner conductor, core

[0083] 25 interface means

[0084] 26 plug

[0085] 27 interface coupler

[0086] 28 connection point

[0087] 30 transfer means, CVF

[0088] 31 operational amplifier

[0089] 32 filter element

[0090] 40 filter means, BP

[0091] 41 first means part, high-pass filter

[0092] 42 second means part, low-pass filter

[0093] 43 third means part, high-pass filter

[0094] 50 rectifier

[0095] 60 integrator, CR

[0096] 70 converter, analog-digital converter

[0097] 80 control means

[0098] 90 calculation and analysis means

[0099] 95 processing device

[0100] 200 processing means

[0101] 41, 43 high-pass filter

[0102] A1 first interface

[0103] A2 second interface

[0104] C capacitor

[0105] CS sensor capacitance value

[0106] R resistance

[0107] S detection signal

[0108] SP signal path.

Claims

1. A device for detecting an activation operation for activating a function on a vehicle, having: - at least one sensor element (21) for capacitively sensing a change in the surroundings of the sensor element (21); - a control device (80) for electrically actuating the sensor element (21) to prepare a detection signal (S) which is prepared by the control device (80) by means of a periodic control signal with a periodic change in voltage and / or current, the detection signal (S) having at least one predefined detection frequency included in the frequency; - a calculation and analysis device (90) which is connected to the sensor element (21) by means of a signal path (SP) for repeatedly acquiring a parameter specific to the detection of the sensor element (21) from the detection signal (S) for detecting the activation operation; - a filter device (40) in the signal path (SP), the filter device (40) having at least one high-pass filter (41, 43) for reducing the frequency of the detection signal to at least below the at least one detection frequency, - a transfer device (30) in the signal path (SP) between the sensor element (21) and the filter device (40), the transfer device (30) having a voltage output for preparing the detection signal (S) from the sensor element (21) in dependence on a change in the sensor capacitance (CS) of the sensor element (21) for the filter device (40). The sensor element (21) is an electrically conductive sensor electrode for detecting the parameter specific to the detection in the form of a change in the sensor capacitance (CS), wherein the calculation and analysis device (90) has an electronic processing device (95) for calculating and analyzing the change in the sensor capacitance (CS) from the detection signal. The calculation and analysis device (90) has an integrator (60) for analyzing the charge quantity transferred by the detection signal (S) and associated with the change. The filter device (40) has a high-pass filter (41, 43) in the form of a second-order high-pass filter (41, 43). The filter device (40) has a first partial device (41) with a high-pass filter (41) and a second partial device (42) with a low-pass filter (42). wherein The filter device (40) has a third partial device (43) with a further high-pass filter (43).

2. A device according to claim 1, characterised in that The filter device (40) is a band-pass filter.

3. An apparatus according to claim 1 or 2, characterised in that The filter device (40) is used to reduce the influence of electrostatic induction at the sensor element (21), in particular a displacement of the charge quantity caused by an electric field acting on the sensor element (21).

4. An apparatus according to claim 1, characterized in that There is a sensor device (20) having the sensor element (21) and an additional electrical conductor (22), wherein the additional conductor (22) is arranged at least partially or predominantly parallel to the sensor element (21).

5. The apparatus of claim 1, wherein The additional conductor (22) is electrically coupled to the sensor element (21) by means of an interface coupling (27).

6. An apparatus according to claim 5, characterized in that ​ 7. An apparatus according to claim 1, characterized in that ​ 8. An apparatus according to claim 1, characterized in that ​ 9. An apparatus according to claim 1, characterized in that ​ 10. An apparatus according to claim 1, characterized in that ​ 11. An apparatus according to claim 1, characterized in that There is an additional conductor (22) which is not functional for the detection, which is of particular interest for the influence of electrostatic induction at the sensor element (21).

12. An apparatus according to claim 1, characterized in that A sensor device (20) is a coaxial line (20) which has the sensor element (21) as outer conductor of the coaxial line (20) and an additional conductor (22) as inner conductor of the coaxial line (20).

13. A method for detecting an activation operation which activates a function on a vehicle, which is carried out in the following steps: - sensing a change capacitively with the sensor element (21) in the vicinity of the sensor element (21), - controlling the sensor element (21) with a control device (80) to prepare a detection signal (S), which is prepared by the control device (80) by a periodic control signal with a periodic change of voltage and / or current, which signal comprises at least one predefined detection frequency in the frequency, - obtaining at least one parameter which is of particular interest for detecting the activation operation by a calculation analysis device (90), which is connected together with the sensor element (21) by a signal path (SP) to repeatedly obtain the parameter from the detection signal (S), - reducing at least the frequency of the detection signal (S) below the at least one detection frequency by filter means (40) in the signal path, which filter means have at least one high-pass filter (41, 43), wherein - there being a transfer device (30) in the signal path (SP) between the sensor element (21) and the filter means (40), which transfer device (30) has a voltage output for preparing the detection signal (S) for the filter means (40) depending on a change in the sensor capacitance (CS) of the sensor element (21).

14. Method for detecting an activation operation for activating a function on a vehicle according to claim 13, characterized in that The method is carried out by the device for detecting an activation operation which activates a function on a vehicle according to any one of claims 1 to 12.

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