DE102023102185A1 - Method for operating a capacitive sensor device - Google Patents

Abstract

The invention relates to a method for operating a capacitive sensor device (100) for a functional device (101), in particular in the form of a door handle, of a vehicle (F), wherein the sensor device (100) has at least one sensor element (10) for detecting an actuation of a user (B) on the functional device (101), a control unit (20) for controlling and/or reading the sensor element (10), a shielding element (11) for aligning a detection area of the sensor element (10), and at least one edge element (12) for adapting environmental influences to the sensor element (10), the method comprising:- operating the sensor device (100) for detecting the actuation of the user on the functional device (101) and/or- operating the sensor device (100) for detecting an exposure of an outer surface (102) of the functional device (101) to moisture, in particular water droplets.

Description

The invention relates to a method for operating a capacitive sensor device for a functional device, in particular in the form of a door handle, of a vehicle. The invention also relates to a corresponding computer program product for carrying out a corresponding method. The invention also relates to a corresponding control unit for carrying out a corresponding method. The invention also relates to a corresponding sensor device with a corresponding control unit. The invention also relates to a corresponding functional device with a corresponding sensor device.

Sensor devices for functional devices in vehicles are generally known. Known sensor devices are used to operate moving parts in vehicles, such as a door or a tailgate. Known sensor devices usually have sensors that can exchange information with the environment in order to detect a user approaching and/or touching the functional device. Capacitive sensors are often used as sensors. However, the operation of such sensors does not always prove to be reliable, since the capacitive field can easily be distorted by environmental influences, in particular by moisture.

The object of the invention is therefore to at least partially overcome the disadvantages described above. In particular, the object of the invention is to provide an improved method for operating a capacitive sensor device for a functional device, in particular in the form of a door handle, of a vehicle. Preferably, the object of the invention is to provide a method for operating a capacitive sensor device for a functional device, in particular in the form of a door handle, of a vehicle, which enables safe and reliable operation of the sensor device and expanded functionality in the sensor device, preferably with regard to improved sensor functions and/or detection of moisture, such as in the case of rain. Furthermore, the object of the present invention is to provide a corresponding computer program product for carrying out a corresponding method. Furthermore, the object of the present invention is to provide a corresponding control unit for carrying out a corresponding method. Furthermore, the object of the present invention is to provide a corresponding sensor device with a corresponding control unit. In addition, the object of the present invention is to provide a corresponding functional device with a corresponding sensor device.

The above object is achieved by: a method for operating a capacitive sensor device for a functional device, in particular in the form of a door handle, of a vehicle with the features of the independent method claim, a corresponding computer program product with the features of the independent product claim, a corresponding control unit, a corresponding sensor device and a corresponding functional device with the features of the independent device claims. Features, advantages and details that are described in connection with different aspects of the invention naturally also apply in connection with the other aspects of 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 mutually.

• - mindestens ein Sensorelement zum Erfassen einer Betätigungshandlung, bspw. in Form einer Annäherung und/oder einer Berührung, eines Benutzers an der Funktionsvorrichtung und/oder zum Erfassen einer Beaufschlagung einer Außenfläche der Funktionsvorrichtung mit Feuchtigkeit, insbesondere mit Wassertröpfchen, wobei vorzugsweise das mindestens eine Sensorelement mindestens eine, bevorzugt kapazitive, Sensorelektrode aufweist und/oder bildet,
• - eine Steuereinheit zum Ansteuern (bspw. Laden und Entladen) und/oder zum Auslesen des Sensorelementes (bspw. durch analoges und/oder digitales Verarbeiten von Sensorsignalen und/oder Auswerten der Ergebnisse der Verarbeitung).

The invention provides: a method for operating a capacitive sensor device (100) for a functional device (101), in particular in the form of an access device, preferably a door handle, of a vehicle (F), wherein the sensor device (100)

• - at least one sensor element for detecting an actuation action, for example in the form of an approach and/or a touch, of a user on the functional device and/or for detecting an exposure of an outer surface of the functional device to moisture, in particular water droplets, wherein preferably the at least one sensor element has and/or forms at least one, preferably capacitive, sensor electrode,
• - a control unit for controlling (e.g. charging and discharging) and/or reading the sensor element (e.g. by analog and/or digital processing of sensor signals and/or evaluating the results of the processing).

• - ein Abschirmelement zum Ausrichten eines Detektionsbereiches des Sensorelementes, wobei die Steuereinheit zum Ansteuern und/oder zum Auslesen des Abschirmelementes dienen kann, wobei vorzugsweise das Abschirmelement mindestens eine, insbesondere flächige, Schirmelektrode aufweist und/oder bildet, und
• - ein Randelement zum Anpassen von Umgebungseinflüssen (insbesondre durch Feuchtigkeit) auf das Sensorelement, wobei die Steuereinheit zum Ansteuern und/oder zum Auslesen des Randelementes dienen kann, wobei insbesondere das Randelement separat zum Abschirmelement ausgebildet und/oder beabstandet zum Abschirmelement angeordnet ist, wobei vorzugsweise das Randelement mindestens eine, insbesondere kapazitive, vorzugsweise flächige, Elektrode aufweist und/oder bildet, aufweist.

Furthermore, the sensor device can comprise;

• - a shielding element for aligning a detection area of the sensor element, wherein the control unit can serve to control and/or read the shielding element, wherein preferably the shielding element has at least one, in particular flat, shield electrode and/or forms, and
• - an edge element for adapting environmental influences (in particular moisture) to the sensor element, wherein the control unit can serve to control and/or read the edge element, wherein in particular the edge element is formed separately from the shielding element and/or arranged at a distance from the shielding element, wherein preferably the edge element has and/or forms at least one, in particular capacitive, preferably flat, electrode.

• - Betreiben der Sensorvorrichtung zum Erfassen der Betätigungshandlung des Benutzers an der Funktionsvorrichtung, (sog. Modus 1, wobei insbesondere die Umgebungseinflüsse, bspw. durch Feuchtigkeit, auf das Sensorelement zumindest reduziert (F1+F2) bis gar eliminiert sind (F1)), und/oder
• - Betreiben der Sensorvorrichtung zum Erfassen einer Beaufschlagung einer Außenfläche der Funktionsvorrichtung mit Feuchtigkeit, insbesondere mit Wassertröpfchen, (sog. Modus 2, wobei insbesondere die Umgebungseinflüsse, bspw. durch Feuchtigkeit, auf das Sensorelement erfassbar (F1+F2) bis dominierend sind (F2)).

The procedure comprises the following procedural steps/procedural modes:

• - Operating the sensor device to detect the user's actuation of the functional device (so-called mode 1, whereby in particular the environmental influences, e.g. due to moisture, on the sensor element are at least reduced (F1+F2) or even eliminated (F1)), and/or
• - Operating the sensor device to detect an exposure of an outer surface of the functional device to moisture, in particular to water droplets (so-called mode 2, wherein in particular the environmental influences, e.g. due to moisture, on the sensor element are detectable (F1+F2) to dominant (F2)).

As already mentioned above, the functional device can be designed in the form of a door handle of the vehicle, which can be designed to be extendable or fixed, for example, in order to operate a movable part of the vehicle. The operation can include locking, unlocking, opening and/or closing.

It is also conceivable that the functional device can be designed in the form of a module or chip, which can be arranged at different positions on or in the vehicle in order to actuate a movable part of the vehicle. The actuation can include locking, unlocking, opening and/or closing. It is conceivable that the functional device can be arranged in the form of a module or chip on or next to the movable part of the vehicle to be actuated. A door, a tailgate, a fuel filler flap, a loading flap, a folding mirror, a sunroof, a window pane, or similar can be conceivable as a movable part. In the case of a side door of the vehicle as a movable part, the functional device can be arranged in the form of a module or chip on the door itself or on the B-pillar of the vehicle.

The sensor device can preferably be designed for convenient operation of a movable part of the vehicle. The operation can preferably require a specific operation sequence. Firstly, during a specific operation sequence, the sensor element can detect an approach of the user to the functional device. In addition, the user can be authenticated, for example after detecting an approach of the user into the detection area of the sensor element. The authentication can be used to check whether the user is authorized to operate the movable part and/or to gain access to the vehicle and/or to a functional area of the vehicle. Furthermore, during a specific operation sequence, the sensor element can detect a touch by the user on an outer surface of the functional device.

The sensor device can have one or more sensor elements. Different sensor elements can be designed for different actuation functions, such as locking or unlocking, opening or closing the movable part of the vehicle. Different actuation functions can provide different actuation sequences. Different sensor elements can preferably have different detection ranges.

Furthermore, it is conceivable that different sensor elements can have a (common) shielding element and/or a (common) edge element.

For example, two sensor elements can be provided for a door handle. A first sensor element can, for example, have a detection area that is directed outwards away from the vehicle in order to detect a user approaching the detection area and then touching an outer surface of the functional device. The first sensor element can, for example, be used to unlock and, if necessary, directly open the movable part. A second sensor element can, for example, have a detection area that is directed inwards towards the vehicle, in particular into a handle recess, in order to detect a user reaching behind the door handle. The second sensor element can, for example, be used to lock the movable part.

In the previous example, a shielding element can be provided for both sensor elements and separate the detection area of the first sensor element from the detection area of the second sensor element or align it on the one hand outwards away from the vehicle and on the other hand inwards towards the vehicle, in particular into a handle recess.

In the previous example, an edge element can be provided for both sensor elements in order to control the environmental influences, in particular moisture, on the sensor element according to the desired function (reducing the moisture influence for the purpose of cleaning the sensor signal and/or increasing the moisture influence for the purpose of moisture or rain detection), preferably with the aid of the control unit, which preferably applies field control to the edge element.

The invention recognizes that sensor devices, in particular capacitive sensor devices, react sensitively to environmental influences, in particular humidity. High humidity in the ambient air can trigger an undesired detection at the sensor element. Humidity fluctuations can also impair the sensor functions.

In addition, the invention recognizes that the sensor device reacts differently to moisture, such as a drop of water on an outer surface of the functional device, which is usually poorly conductive, and to a human body, such as a human finger, which touches the outer surface of the functional device and which is usually highly conductive.

• - eine Funktion, um das Wasser, bspw. in Form von Regen, an einer Außenfläche der Funktionsvorrichtung zu detektieren (bzw. Regendetektion),
• - eine andere Funktion, um die Erfassung einer Betätigungshandlung, insbesondere einer Berührung, des Benutzers an einer Außenfläche der Funktionsvorrichtung von Feuchtigkeitseinflüssen zu bereinigen, und/oder um den Unterschied zwischen der Erfassung einer Betätigungshandlung, insbesondere einer Berührung, des Benutzers und der Erfassung einer Feuchtigkeitsbeaufschlagung an einer Außenfläche der Funktionsvorrichtung (zumindest) zu vergrößern.

The invention uses this difference in the reaction of the sensor device to enable different functions in the sensor device. The following functions are conceivable:

• - a function to detect water, e.g. in the form of rain, on an external surface of the functional device (or rain detection),
• - another function to clear the detection of an actuation action, in particular a touch, of the user on an outer surface of the functional device from moisture influences, and/or to (at least) increase the difference between the detection of an actuation action, in particular a touch, of the user and the detection of moisture exposure on an outer surface of the functional device.

To establish good rain suppression and/or rain detection, two different physical approaches and a combination of them are used. Here, the differences between a human body and a raindrop are used.

A human body is well grounded due to its dimensions. Its electrical potential is not noticeably changed by a local influence near the body. In contrast, a raindrop, dirty water or something similar changes its electrical potential depending on the local conditions.

A second difference between a raindrop and a human body is the resistance of the material. The conductivity of the human body is greater than 50000µS/cm, while the conductivity of clear water is only 0.05 µS/cm.

Combined with the shape of free water as opposed to the human body, the resulting resistance of a human body is significantly different than the resistance of any type of water.

The idea is to use a single voltage pulse or a sequence of voltage pulses of any frequency to measure the capacitance in such a way that it is less sensitive to rain or intentionally extremely sensitive to rain.

There is a wide variety of capacitive sensor systems. What they all have in common is the approach of charging a sensor element, e.g. in the form of a capacitive sensor electrode, according to the external capacitance and then measuring this charge, e.g. by discharging the sensor element and measuring the discharge time.

Depending on the external capacitance, the amount of charge that can be charged on the sensor element varies. This difference is now evaluated according to the invention.

The charge on the capacitive sensor electrode can be positive or negative. Several voltage pulses or just one voltage pulse may be required to enable rain suppression and/or rain detection. The pulses can have a single frequency or a mixture of frequencies. A combination of voltage pulse sequences and frequencies is also conceivable.

In order to charge and/or discharge the sensor element, a certain voltage is applied to the sensor element in several voltage pulses or just one voltage pulse. The charge of the charged sensor element is transferred to a comparison electrode, which can be measured.

If a raindrop or water is near the sensor electrode, the water does not significantly affect the detection of a user's action, especially a touch.

In the absence of the user, a raindrop can cause an unwanted charge to flow to the sensor electrode. This allows the sensor element to also detect something, but at a much slower rate than detecting a touch by the user.

If a human body causes a capacitance at the sensor electrode, there is almost no resistance involved. This means that there is hardly any voltage drop in the internal resistance of the finger when touched and the charge is completely dissipated relatively quickly.

When a raindrop causes a different capacitance at the sensor electrode, a large internal resistance is involved. The charge is moved more slowly and there is a voltage drop across the internal resistance.

When a finger causes a change in capacitance, no significant difference can be seen between a short and a long measuring pulse.

If a raindrop causes a change in capacitance, the difference between a short and a long measuring pulse is significant.

The sensor signal therefore differs when detecting the user and when detecting water. The invention uses these differences to detect or eliminate rain influences on the sensor device.

The advantage is that it is not necessary to work with different frequencies. The frequencies used only need to be selected depending on the needs of the capacitive system.

The edge element can generally be used to prevent unwanted charge from flowing to the sensor electrode via a raindrop (reduction of the moisture influence in order to clean up the sensor signal).

Advantageously, the edge element can be subjected to the same or a similar potential as the sensor electrode in order to prevent charge from flowing to the sensor electrode via the water droplet.

In addition, the influence of moisture can be reduced and the difference between user detection and water detection can be increased by targeted control, e.g. synchronous and/or concurrent control, of the edge element (cleaning of the sensor signal and/or improved differentiation between rain detection and user detection).

In addition, the moisture influence can be increased by targeted control, e.g. asynchronous and/or counter-rotating control, of the edge element in such a way that moisture or rain detection is possible (increasing the moisture influence for the purpose of moisture or rain detection).

Thus, an improved sensor device for a functional device of a vehicle can be provided which is safe and reliable in operation and which has an extended functionality, preferably with regard to improved sensor functions and/or detection of moisture, such as in the case of rain. In this way, an improved functional device for a vehicle can also be provided.

Furthermore, it can be provided that the sensor element has and/or forms at least one, in particular capacitive, sensor electrode (preferably made of metal). In this way, the sensor element can be used for a capacitive measurement. With the help of such a sensor element, not only the approach of the user into the detection area can be detected, but also the user touching an outer surface of the functional device.

Furthermore, it can be provided that the detection area of the sensor element is essentially horizontal when installed on the vehicle. In this way, the approach of the user to the vehicle can be detected over relatively large ranges. An authentication query can then be started in an advantageous manner, preferably before the user reaches the vehicle and touches the functional device, which can also be detected using the sensor element with the horizontal detection area.

Furthermore, it can be provided that the detection area of the sensor element is designed to be essentially vertical when installed on the vehicle. In this way, further actuation functions can be provided by the sensor device, such as locking a movable part of the vehicle.

In addition, the sensor element can be designed to detect a user approaching the detection area. In addition, the sensor element can be designed to detect a user touching an outer surface of the functional device. In this way, certain processes for activating the functional device can be provided.

Advantageously, the sensor element can be designed to detect exposure of an outer surface of the functional device to moisture, in particular water droplets.

Furthermore, it can be provided that the shielding element has and/or forms at least one, in particular capacitive, preferably flat, shielding electrode (preferably made of metal). In this way, the shielding element can align the detection area of the sensor element in the desired direction.

Furthermore, it can be provided that the edge element has at least one, in particular capacitive, preferably flat, electrode section (preferably made of metal). In this way, the edge element can reduce the influence of water from different directions for various functionally essential components of the sensor device, such as the at least one sensor element, possibly another sensor element, the control unit, a communication unit, etc.

Furthermore, it can be provided that the sensor element is arranged and/or attached to the control unit. In this way, a compact design of the sensor device can be made possible.

In addition, it can be provided that the sensor element can be arranged and/or fastened to the functional device. In this way, improved detection areas can be created on the functional device.

It can also be provided that the control unit has at least one circuit board. The sensor element can advantageously be arranged and/or fastened to the circuit board. The shielding element can preferably be arranged and/or fastened to the circuit board.

Furthermore, it is conceivable that the edge element is arranged and/or attached to the circuit board at least in sections. In this way, the edge element can also be used to shield a communication unit (23), in particular an NFC unit. The edge element can be used with several sections offset and/or spaced from the NFC coil in order to prevent direct kappa coupling into the NFC coil. The NFC coil has two sensor sections on average, which can be symmetrically surrounded by edge element sections. This can also compensate for the differences in thickness between the layers of the PCB.

It is also conceivable that the edge element can be arranged and/or attached to the functional device at least in sections at a distance from the circuit board. In this way, the edge element can be used to specifically determine the direction from which the influence of water is to be prevented. This can be advantageous in particular in the edge area of the sensor element in order to prevent unwanted charge from flowing to the sensor electrode via conductive parts of the vehicle and via a raindrop.

Furthermore, it can be provided that in order to detect the actuation and/or to detect the exposure of an outer surface of the functional device to moisture, in particular water droplets, the sensor element is charged and/or discharged, in particular by the control unit, preferably with the aid of control electronics of the control unit. When the sensor element is discharged, an electrical potential on the charged sensor element can advantageously be measured and/or a discharge time of the charged sensor element can be determined, in particular by the control unit, preferably with the aid of control electronics of the control unit. An electrical potential on the charged sensor element and/or a discharge time of the charged sensor element can be specific to the actuation, preferably an approach and/or a touch, of the user to the functional device and/or an exposure of an outer surface of the functional device to moisture, in particular water droplets. In this way, a capacitive measurement with a sensor electrode can be enabled.

Furthermore, it can be provided that the charge of the sensor element is transferred to a comparison capacitance, in particular by the control unit, preferably with the help of control electronics of the control unit, in order to measure an electrical potential on the charged sensor element and/or to determine a discharge time of the charged sensor element. In this way, a simple and reliable evaluation can be provided to measure an electrical potential at the charged sensor element and/or to determine a discharge time of the charged sensor element.

Advantageously, the sensor element can be charged and/or discharged using one or more voltage pulses, preferably voltage pulse sequences, in particular by the control unit, preferably using control electronics of the control unit. In particular, an electrical potential at the charged sensor element and/or a discharge time of the charged sensor element can be specific to the actuation, preferably an approach and/or a touch, of the user to the functional device and/or an exposure of an outer surface of the functional device to moisture, in particular water droplets. In this way, a simple and reliable measuring method can be provided to measure an electrical potential at the charged sensor element and/or to determine a discharge time of the charged sensor element.

Furthermore, it can be provided that the exposure of an outer surface of the functional device to moisture, in particular to water droplets, is detected as a function of one, in particular exclusively one, detection signal of the sensor element, in particular by the control unit, preferably with the aid of control electronics of the control unit. For this purpose, in particular a form of the detection signal of the sensor element can be evaluated. Since a drop of water causes a slow load shift, a detection signal with a slowly falling and/or rising edge can be a sign of a drop of water. In contrast, a finger touch causes almost no voltage drop, so that a steeply falling and/or rising edge can be recognized in the detection signal. In this way, it can be determined from just one detection signal of the sensor element whether the sensor element is sensing a drop of water or a human finger.

Furthermore, it can be provided that the exposure of an outer surface of the functional device to moisture, in particular to water droplets, is detected as a function of a comparison between two detection signals of the sensor element, in particular by the control unit, preferably with the aid of control electronics of the control unit. In particular, the amplitudes of the detection signals of the sensor element can be compared, preferably if the detection signals have different voltage pulse sequences with different pulse/pause ratios and/or different voltage levels. This makes it possible to exploit the effect that a raindrop causes a slow load shift and a measurable voltage drop, for example in the range of a few mV to a few V, so that the difference between a short and a long measurement pulse in the detection signals is noticeably large. Corresponding voltage pulse sequences can each form a point in the corresponding detection signal, which is now higher or lower.

In addition, exposure of an outer surface of the functional device to moisture, in particular water droplets, can be detected as a function of one, in particular exclusively one, voltage pulse of the sensor element of the sensor element, in particular as a function of a transient, in particular a gradient, of the voltage pulse of the sensor element. For example, two points in time for reading the voltage can be determined in order to determine the transient. In addition, the transient can be determined from the entire voltage pulse. In this way, rapid and reliable rain detection can be made possible.

In addition, exposure of an outer surface of the functional device to moisture, in particular water droplets, can be detected depending on a comparison between two voltage pulses of the sensor element, in particular depending on a comparison of the amplitudes of the voltage pulses of the sensor element, preferably when the voltage pulses have different lengths. In this way, reliable rain detection can be made possible. Pulses of different lengths cause load shifts of different sizes. The voltage drop can be in a measurable range, for example in the range of a few mV to a few V, so that the difference between a short and a long measurement pulse is noticeably large. Such rain detection is fast. Two voltage pulses are sufficient to enable reliable rain detection.

Furthermore, it can be provided that the control unit has control electronics which are designed to detect the exposure of an outer surface of the functional device to moisture, in particular to water droplets, depending on a comparison between two voltage pulse sequences of the sensor element. In particular, the amplitudes of the voltage pulse sequences of the sensor element can be compared, preferably if the voltage pulse sequences have different pulse/pause ratios. Different Long pulses cause load shifts of varying magnitudes. The voltage drop can be in a measurable range, for example in the range of a few mV to a few V, so that the difference between a voltage pulse sequence with a short and a voltage pulse sequence with a long measuring pulse can be seen from the side. Such rain detection is quick and reliable. Two points in the voltage pulse sequences are sufficient to enable reliable rain detection.

Furthermore, it can be provided that the shielding element is subjected to a specific voltage and/or to specific voltage profiles, preferably voltage pulse sequences, or is connected to a ground potential, in particular by the control unit, preferably with the aid of control electronics of the control unit. In this way, extended functions can be provided for the shielding element. The shielding element can thus be switched on or off in a targeted manner. For the sake of simplicity, the shielding element can be connected to a ground potential.

In addition, the shielding element can be charged and/or discharged using one or more voltage pulses, preferably voltage pulse sequences. Using the shielding element, the sensor device can provide different functionalities and/or different methods for detecting moisture. It is also conceivable that the voltage pulses, preferably voltage pulse sequences, on the sensor element and the voltage pulses, preferably voltage pulse sequences, on the shielding element are coordinated with one another and/or correspond. Preferably, the voltage pulses, preferably voltage pulse sequences, on the sensor element and the voltage pulses, preferably voltage pulse sequences, on the shielding element can be carried out with a time offset and/or phase shift. In this advantageous manner, a measurable influence on a transient of the voltage pulses on the sensor element can be generated.

• - eine erste Funktion, die Erfassung einer Betätigungshandlung, insbesondere einer Berührung, des Benutzers an einer Außenfläche der Funktionsvorrichtung von Feuchtigkeitseinflüssen zu bereinigen, und/oder
• - eine zweite Funktion, um die Erfassung einer Beaufschlagung einer Außenfläche der Funktionsvorrichtung mit Feuchtigkeit, insbesondere mit Wassertröpfchen, zu verstärken. Auf diese Weise können verbesserte Effekte durch das Randelement erzielt werden. Auf diese Weise kann das Randelement mithilfe einer Feldsteuerung angesteuert werden, um unterschiedliche Funktion(en) bereitzustellen (gezielte Regenunterdrückung und/oder verstärkte Regendetektion).

Advantageously, it can be provided that the edge element is subjected to a specific voltage and/or to specific voltage profiles, preferably voltage pulse sequences, in particular by the control unit, preferably with the aid of control electronics of the control unit, in order to provide at least one or more different function(s) with regard to the environmental influences, in particular moisture, on the sensor element:

• - a first function to clean the detection of an actuation, in particular a touch, of the user on an outer surface of the functional device from moisture influences, and/or
• - a second function to enhance the detection of exposure of an outer surface of the functional device to moisture, in particular water droplets. In this way, improved effects can be achieved by the edge element. In this way, the edge element can be controlled using a field control to provide different function(s) (targeted rain suppression and/or enhanced rain detection).

Furthermore, it can be provided that the edge element is subjected to a certain voltage and/or certain voltage profiles, preferably voltage pulse sequences, in particular by the control unit, preferably with the aid of control electronics of the control unit, in order to reduce the environmental influences, in particular moisture, on the sensor element. In this way, the detection signal of the sensor element can be specifically cleaned of the environmental influences on the sensor element.

Furthermore, it can be provided that the edge element is subjected to a specific voltage and/or to specific voltage profiles, preferably voltage pulse sequences, in particular by the control unit, preferably with the aid of control electronics of the control unit, in order to amplify the environmental influences, in particular moisture, on the sensor element, in particular to detect the exposure of an outer surface of the functional device to moisture, in particular water droplets. In this way, increased rain detection can be made possible in the sensor device.

In addition, it can be provided that the edge element is charged and/or discharged using one or more voltage pulses, preferably voltage pulse sequences, in particular by the control unit, preferably using control electronics of the control unit. In this way, field control of the edge element and also coordinated control of the sensor element and the edge element can be made possible. Advantageously, the voltage pulses, preferably voltage pulse sequences, on the sensor element and the voltage pulses, preferably voltage pulse sequences, on the edge element can be coordinated with one another.

In addition, it can be provided that the edge element and the sensor element are synchronously and/or concurrently with an equal or different specific voltage(s) and/or identical or different specific voltage profiles, preferably voltage pulse sequences, are applied, in particular by the control unit, preferably with the aid of control electronics of the control unit, in order to reduce the environmental influences, in particular moisture, on the sensor element. In this way, the differences between a detection of a water droplet and a detection of a human finger can be increased and/or the sensor signal can be cleaned up.

Furthermore, it can be provided that the edge element and the sensor element are asynchronously and/or oppositely subjected to the same or different specific voltage(s) and/or the same or different specific voltage profiles, preferably voltage pulse sequences, in particular by the control unit, preferably with the aid of control electronics of the control unit, in order to amplify the environmental influences, in particular moisture, on the sensor element, in particular to detect the exposure of an outer surface of the functional device to moisture, in particular water droplets. In this way, the effect of the water on the sensor element can be amplified, so that simple, quick and reliable rain detection can be provided in the sensor device.

Different checking methods for detecting exposure of an outer surface of the functional device to moisture, in particular water droplets, can be provided by controlling a sensor element, a shielding element and/or an edge element, each individually or in combination.

In principle, it is conceivable that different inspection procedures for detecting exposure of an outer surface of the functional device to moisture, in particular to water droplets, are carried out individually or in combination.

It is also conceivable that at least one checking method can provide a first indication of exposure of an outer surface of the functional device to moisture, in particular water droplets. At least one further checking method or several further checking methods can then be carried out to confirm the detection. In this way, a multi-checking method can be provided.

It is also conceivable that the edge element has a 3D shape. In this way, the edge element can be designed with different sections that can protect different functional components in the sensor device from environmental influences.

It is also conceivable that the edge element is designed to be frame-shaped, at least in sections. In this way, the edge element can in particular surround the narrow long sides of the sensor element and protect a side area of the sensor element from environmental influences.

Furthermore, it is conceivable that the edge element is made of a, in particular planar, metal sheet, preferably by punching and bending the metal sheet. In this way, a simple and cost-effective edge element can be provided.

It is also conceivable that the edge element is used to adapt environmental influences to at least one side area of the sensor element, wherein in particular the edge element has at least one, in particular two, legs for adapting environmental influences to at least one side area of the sensor element. In this way, the environmental influences on the sensor element can be reliably reduced, which cause charge to flow from the sensor element to conductive parts of the vehicle via the water.

It is also conceivable that the edge element is used to shield control electronics of the control unit, wherein in particular the edge element has at least one, in particular two, shield sections for shielding control electronics of the control unit. In this way, the edge element can fulfill a further advantageous function in order to protect the control electronics from influences caused by electromagnetic fields and/or undesirable capacitive couplings.

In order to provide advantageous sections of the edge element, such as the legs and/or the shield sections, the edge element can be arranged at least in sections outside the circuit board of the control unit, in particular on the functional device.

Advantageously, it can be provided that the edge element can serve as a fastening element and/or positioning element and/or spacer element for the control unit on the functional device. Furthermore, the edge element can have at least one or more have special angled fastening sections which can be used to fasten and/or position the control unit on the functional device and/or to arrange it at a distance from an outer surface of the functional device. In this way, the edge element can develop further advantages with regard to the assembly of the sensor device.

It is also conceivable that the edge element is used to shield a communication unit, in particular an NFC unit, of the control unit, wherein in particular the edge element has at least one, in particular several, shield sections for shielding a communication unit, in particular an NFC unit, of the control unit. The edge element can be integrated at least in sections within a circuit board of the control unit. An NFC coil has on average two sensor sections, which can be symmetrically surrounded by edge element sections, which in turn can be arranged offset and/or spaced from the sensor sections of the NFC coil. In this way, direct kappa coupling into the NFC coil can be prevented. In addition, the thickness differences between the layers of the PCB can be compensated for.

The invention further provides: a computer program product comprising instructions which, when the computer program product is executed by a computer, cause the computer to carry out the method, which can run as described above. The same advantages are achieved as described above in connection with the method.

The invention further provides: a control unit, having a memory unit in which a code is stored, and a computing unit, wherein when the code is executed by the computing unit, the method can be carried out, which can run as described above. The same advantages are achieved as described above in connection with the method.

In addition, the invention provides: a sensor device for a functional device, in particular in the form of a door handle, of a vehicle, having a control unit as described above. The same advantages are achieved as described above in connection with the method.

The invention also provides a functional device, in particular in the form of a door handle, for a vehicle, with a sensor device as described above. The same advantages are achieved as described above in connection with the method.

• 1 eine beispielhafte Darstellung einer Sensorvorrichtung,
• 2 eine beispielhafte Darstellung einer Sensorvorrichtung im Rahmen der vorliegenden Offenbarung,
• 3 eine beispielhafte Darstellung einer Sensorvorrichtung im Rahmen der vorliegenden Offenbarung,
• 4 eine beispielhafte Darstellung einer Sensorvorrichtung im Rahmen der vorliegenden Offenbarung,
• 5 eine beispielhafte Darstellung von Spannungs-Pulsabfolgen beim Entladen eines Sensorelementes bei einem Wasserstropfen,
• 6 eine beispielhafte Darstellung von Spannungs-Pulsabfolgen beim Entladen eines Sensorelementes bei einem menschlichen Finger,
• 7 eine beispielhafte Darstellung von Detektionssignalen eines Sensorelementes beim Entladen eines Sensorelementes, links bei einem Wasserstropfen und rechts bei einem menschlichen Finger,
• 8 eine beispielhafte Darstellung von Spannungs-Pulsabfolgen beim Entladen eines Sensorelementes bei einem Wasserstropfen, oben: ohne eine Ansteuerung des Randelementes, mittig: mit einer mitläufigen Ansteuerung des Randelementes zum Reduzieren des Feuchtigkeitseinflusses und untern: mit einer gegenläufigen Ansteuerung des Randelementes zum Verstärken des Feuchtigkeitseinflusses,
• 9 eine beispielhafte Darstellung einer Sensorvorrichtung mit einem möglichen Randelement,
• 10 eine beispielhafte Darstellung einer Sensorvorrichtung mit einem möglichen Randelement, und
• 11 eine beispielhafte Darstellung einer Sensorvorrichtung mit einem möglichen Randelement.

Further advantages, features and details of the invention emerge from the following description, in which embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. It shows:

• 1 an exemplary representation of a sensor device,
• 2 an exemplary representation of a sensor device within the scope of the present disclosure,
• 3 an exemplary representation of a sensor device within the scope of the present disclosure,
• 4 an exemplary representation of a sensor device within the scope of the present disclosure,
• 5 an example of voltage pulse sequences when discharging a sensor element in a drop of water,
• 6 an example of voltage pulse sequences when discharging a sensor element in a human finger,
• 7 an exemplary representation of detection signals of a sensor element when discharging a sensor element, on the left with a drop of water and on the right with a human finger,
• 8th an example of voltage pulse sequences when discharging a sensor element with a drop of water, top: without control of the edge element, middle: with a concurrent control of the edge element to reduce the moisture influence and bottom: with a counter-current control of the edge element to increase the moisture influence,
• 9 an exemplary representation of a sensor device with a possible edge element,
• 10 an exemplary representation of a sensor device with a possible edge element, and
• 11 an exemplary representation of a sensor device with a possible edge element.

• - mindestens ein Sensorelement 10 zum Erfassen einer Betätigungshandlung, bspw. in Form einer Annäherung und/oder einer Berührung, eines Benutzers an der Funktionsvorrichtung 101 und/oder zum Erfassen einer Beaufschlagung einer Außenfläche der Funktionsvorrichtung mit Feuchtigkeit, insbesondere mit Wassertröpfchen, wobei vorzugsweise das mindestens eine Sensorelement 10 mindestens eine, bevorzugt kapazitive, Sensorelektrode aufweist und/oder bildet,
• - eine Steuereinheit 20 zum Ansteuern (bspw. Laden und Entladen) und/oder zum Auslesen des Sensorelementes 10 (bspw. durch analoges und/oder digitales Verarbeiten von Sensorsignalen und/oder Auswerten der Ergebnisse der Verarbeitung).

The 2 to 4 and 9 to 11 show a sensor device 100 for a functional device 101, in particular in the form of an access device, preferably a door handle, of a vehicle F, comprising:

• - at least one sensor element 10 for detecting an actuation action, for example in the form of an approach and/or a touch, of a user on the functional device 101 and/or for detecting an exposure of an outer surface of the functional device to moisture, in particular to water droplets, wherein preferably the at least one sensor element 10 has and/or forms at least one, preferably capacitive, sensor electrode,
• - a control unit 20 for controlling (e.g. charging and discharging) and/or reading the sensor element 10 (e.g. by analog and/or digital processing of sensor signals and/or evaluating the results of the processing).

• - ein Abschirmelement 11 zum Ausrichten eines Detektionsbereiches des Sensorelementes 10, wobei die Steuereinheit 20 zum Ansteuern (bspw. Laden und Entladen) und/oder zum Auslesen des Abschirmelementes 11 ausgebildet sein und dienen kann, wobei vorzugsweise das Abschirmelement 11 mindestens eine, insbesondere flächige, Schirmelektrode aufweist und/oder bildet, und/oder
• - ein Randelement 12 zum Anpassen von Umgebungseinflüssen (insbesondre durch Feuchtigkeit) auf das Sensorelement 10, wobei die Steuereinheit 20 zum Ansteuern (bspw. Laden und Entladen) und/oder zum Auslesen des Randelementes 12 ausgebildet sein und dienen kann, wobei insbesondere das Randelement 12 separat zum Abschirmelement 11 ausgebildet und/oder beabstandet zum Abschirmelement 11 angeordnet ist, wobei vorzugsweise das Randelement 12 mindestens eine, insbesondere kapazitive, vorzugsweise flächige, Elektrode aufweist und/oder bildet.

In addition, the sensor device 100 may comprise the following elements:

• - a shielding element 11 for aligning a detection area of the sensor element 10, wherein the control unit 20 can be designed and used to control (e.g. charge and discharge) and/or read the shielding element 11, wherein the shielding element 11 preferably has and/or forms at least one, in particular flat, shielding electrode, and/or
• - an edge element 12 for adapting environmental influences (in particular moisture) to the sensor element 10, wherein the control unit 20 can be designed and used to control (e.g. charging and discharging) and/or to read the edge element 12, wherein in particular the edge element 12 is designed separately from the shielding element 11 and/or is arranged at a distance from the shielding element 11, wherein preferably the edge element 12 has and/or forms at least one, in particular capacitive, preferably flat, electrode.

• Modus 1 Betreiben der Sensorvorrichtung 100 zum Erfassen der Betätigungshandlung des Benutzers an der Funktionsvorrichtung 101 und/oder
• Modus 2 Betreiben der Sensorvorrichtung 100 zum Erfassen einer Beaufschlagung einer Außenfläche 102 der Funktionsvorrichtung 101 mit Feuchtigkeit, insbesondere mit Wassertröpfchen.

The method according to the invention serves to operate such a sensor device, in particular a capacitive one. The method has the following method steps/method modes:

• Mode 1 Operating the sensor device 100 to detect the user’s actuation of the functional device 101 and/or
• Mode 2 Operating the sensor device 100 to detect an exposure of an outer surface 102 of the functional device 101 to moisture, in particular water droplets.

In mode 1, the environmental influences, e.g. moisture, on the sensor element 10 are at least reduced (functions of the edge element 12: F1+F2, cf. 5 to 7 and the 8th above) or even eliminated (function of the edge element 12: F1, cf. 8th in the middle).

In mode 2, in particular the environmental influences, e.g. moisture, on the sensor element 10 are made detectable (functions of the edge element 12: F1+F2) to dominant (function of the edge element 12: F2, cf. 8th below).

Like it 4 As suggested, the functional device 101 can be designed, for example, in the form of a door handle of the vehicle F, which can be designed, for example, to be extendable or fixed.

Like it 9 to 11 As indicated, the functional device 101 can be designed in the form of a module or chip, which can be arranged at different positions on or in the vehicle F in order to actuate a movable part of the vehicle F. The actuation can include locking, unlocking, opening and/or closing the movable part of the vehicle F. It is conceivable that the functional device 101 can be arranged on (e.g. on the door handle) or next to (e.g. on a B-pillar) the movable part of the vehicle F to be actuated. A door, a tailgate, a fuel filler flap, a loading flap, a hinged mirror, a sunroof, a window pane, or the like is conceivable as a movable part.

The sensor device 100 can enable a comfortable operation of the movable part of the vehicle F. The operation can advantageously require a specific operation sequence, which can be detected by the at least one sensor element 10. First, in a specific operation sequence, a presence or approach of the user B to the functional device 101 can be detected by the sensor element 10. Then, an authentication of the user B can be initiated to check whether the user B is authorized to operate the movable part and/or to gain access to the vehicle F. Thereupon During a specific actuation sequence, a touch by the user B on an outer surface 102 of the functional device 101 can be detected by the sensor element 10. Only when the specific actuation sequence has been detected by the at least one sensor element 10 can the control unit 20 generate a signal according to which the movable part is actuated.

Like it 9 to 11 As indicated, the sensor device 100 can have one or more sensor elements 10. Different sensor elements 10 can be designed for different actuation functions or types, such as unlocking and possibly opening or locking the movable part of the vehicle F. Different actuation functions can provide for different actuation sequences. Different sensor elements 10 can preferably have different detection ranges.

Furthermore, 9 to 11 that different sensor elements 10 can have a (common, e.g. planar) shielding element 11 and/or a (common, e.g. 3D-shaped) edge element 12.

For example, two sensor elements 10 can be provided for a door handle. A first sensor element 10 can, for example, have a detection area which is directed outwards away from the vehicle F in order to detect a user B approaching the detection area and then touching an outer surface 102 of the functional device 101. The first sensor element can, for example, be used to unlock and, if necessary, to open the movable part directly, depending on whether the door handle is movable and stationary. A second sensor element 10 can, for example, have a detection area which is directed inwards towards the vehicle F, in particular into a recessed grip, in order to detect a reaching behind the door handle, for example when closing the vehicle door. The second sensor element 10 can, for example, be used to lock the movable part. This example is shown schematically in the 1 to 4 and 9 to 11 shown.

Like it 9 to 11 show, a shielding element 11, in particular a planar one, can be provided for both sensor elements 10 and separate the detection area of the first sensor element 10 from the detection area of the second sensor element 10 or align it on the one hand outwards away from the vehicle F and on the other hand inwards towards the vehicle F, in particular into a recessed grip.

Like it 9 to 11 show, a particularly 3D-shaped edge element 12 can be provided for both sensor elements. As 5 to 8 As can be seen, the edge element 12 is designed to control the environmental influences, in particular moisture, on the sensor element 10 according to the desired function F1, F2 (reduction of the moisture influence for the purpose of cleaning the sensor signal F1 and/or increase of the moisture influence for the purpose of moisture or rain detection F2). 8th also suggests, the edge element 12 can be controlled by means of the control unit 20, preferably by means of a field control, in order to specifically reduce the influence of moisture (function F1, see the middle graphic in 8th ) or to amplify (function F2, see the lower graphic in 8th ).

Like it 1 As illustrated, sensor devices 100, in particular capacitive sensor devices, react sensitively to environmental influences, in particular humidity. High humidity in the ambient air can trigger an undesired detection at the sensor element. Humidity fluctuations can also impair the sensor functions.

Like it 1 As further illustrated, the sensor device 100 reacts differently to moisture, such as a drop of water W on an outer surface 102 of the functional device 101, which is usually poorly conductive (resistance R _W ), and to a user B, such as a human finger, which touches the outer surface of the functional device and which is usually well conductive (resistance R _B ).

• - eine Funktion F2 (vgl. die untere Grafik in 8), um das Wasser, bspw. in Form von Regen, zu detektieren (bzw. Regendetektion),
• - eine andere Funktion F1 (vgl. die obere und mittlere Grafik in 8), um die Erfassung einer Betätigungshandlung, insbesondere einer Berührung, des Benutzers B an einer Außenfläche 102 der Funktionsvorrichtung 101 von Feuchtigkeitseinflüssen zu bereinigen (vgl. mittlere Grafik in 8), und/oder um den Unterschied zwischen der Erfassung einer Betätigungshandlung, insbesondere einer Berührung, des Benutzers B und der Erfassung einer Feuchtigkeitsbeaufschlagung an einer Außenfläche 102 der Funktionsvorrichtung 101 (zumindest) zu vergrößern (vgl. obere Grafik in 8 sowie 5 bis 7).

The invention uses this difference in the reaction of the sensor device 100 to enable different functions in the sensor device 100, such as 5 to 8 The following functions are conceivable:

• - a function F2 (see the lower graphic in 8th ) to detect water, e.g. in the form of rain (or rain detection),
• - another function F1 (see the upper and middle graphics in 8th ) in order to remove moisture influences from the detection of an actuation, in particular a touch, of the user B on an outer surface 102 of the functional device 101 (see middle graphic in 8th ), and/or the difference between the detection of an actuation, in particular a touch, of the user B and the detection of moisture on an outer surface 102 of the functional device 101 (at least) to increase (see upper graphic in 8th as well as 5 to 7 ).

According to the invention, the differences between the human body of a user B and a drop of water W are mainly exploited.

A human body of a user B is well grounded due to its dimensions. Its electrical potential is not noticeably changed by a local influence near the body. In contrast, a raindrop or water drop W, especially including dirty water or similar, changes its electrical potential depending on the local conditions.

A second difference between a drop of water W and a human body of a user B is the resistance of the material. The conductivity of the human body is greater than 50000µS/cm, while the conductivity of extremely clear water is only 0.05 µS/cm.

Combined with the shape of the water droplet W in contrast to the human body, the resulting resistance R _B of a human body is significantly lower than the resistance R _W of the water droplet W.

Like it 5 , especially compared to 6 , and 8th As can be seen, a sequence of voltage pulses (or a single voltage pulse, preferably of any frequency) can be used to measure the capacitance in a way that makes it less sensitive to rain ( 5 to 7 and 8th above), almost insensitive to rain ( 8th centered) or intentionally extremely sensitive to rain ( 8th below). Several voltage pulses or just one voltage pulse may be required to enable rain suppression and/or rain detection. The pulses can have a single frequency or a mixture of frequencies. A combination of voltage pulse sequences and frequencies is also conceivable.

The sensor device 100 can be operated in such a way that the sensor element 10 is initially charged according to the external capacitance. The charge on the capacitive sensor electrode 10 can be positive or negative. This charge is then measured, for example by discharging the sensor element 10 and measuring the discharge time.

Depending on the external capacitance, the amount of charge that can be charged on the sensor element 10 varies. This difference (illustrated as ΔU in the 5 , 6 and 8th and A1-A2 in 7 ) is now evaluated according to the invention.

5 and 6 show long discharge pulses at the top and short discharge pulses at the bottom. To discharge the sensor element, the sensor element 10 is connected to a comparison capacitance Load.

In 8th discharge pulses of equal length are shown. In the middle and lower graph in 8th the edge element 12 is additionally controlled to provide the function F1 (reduction of the moisture influence) or function F2 (strengthening of the moisture influence), which will be referred to in more detail below.

Like it 6 shows, the water does not significantly affect the detection of a touch by user B, even if a raindrop or water is near the sensor electrode. If a human body causes a capacitance at the sensor electrode, almost no resistance is involved. This means that there is hardly any voltage drop in the internal resistance of the finger when touched and the load is completely shifted relatively quickly.

Like it 5 shows (see also 1 ), in the absence of the user B, an unwanted charge can flow to the sensor electrode via a water droplet W. The sensor element 10 can thus also carry out a detection, but much more slowly than a detection of a touch by the user (see the lower graphic in 5 ). If a raindrop or water drop W causes a different capacitance at the sensor electrode 10, a large internal resistance is involved. The load is moved more slowly and there is a voltage drop ΔU at the internal resistance.

In 5 a voltage drop ΔU of approx. 46 mV can be detected (above the detection occurs at approx. 71.89 mV, below the detection occurs at approx. 25.55 mV).

In order to charge the sensor element 10 more quickly under the influence of water, the voltage pulses could either last longer and/or the level of the voltage U could be increased.

If a finger causes a change in capacitance, no great difference can be seen between a short and a long measuring pulse (cf. 6 ).

If a drop of water causes a change in capacitance, the difference between a short and a long measuring pulse is large (cf. the voltage drop ΔU of approx. 46 mV in 5 ).

The detection signal S1 or S2 is therefore different when user B is detected (right in 7 ) and a detection of the water drop W (left in 7 ).

Like it 7 As illustrated (slow discharge pulses above, fast discharge pulses below), the sensor element 10 cannot be discharged as quickly with fast discharge pulses as with slow discharge pulses. The detection signal S1 above has a higher amplitude than the detection signal S2 below.

In this way, a water droplet W can be detected, especially when two detection signals S1 and S2 with different pulse/pause ratios are compared.

In contrast, when a user is detected on the right in 7 There is almost no difference between the amplitudes of the detection signals S1 and S2.

But even with just one detection signal S1 or S2, a water drop W can be detected. 7 As indicated, the edges of the detection signals S1, S2 on the left are relatively gently falling. In contrast, the edges of the detection signals S1, S2 on the right are relatively steeply falling.

Thus, a detection signal S1 or S2 can be assigned by its shape to a water droplet W (flatly rising and/or falling) or to a user B (steeply rising and/or falling).

Like it 4 and 9 to 11 indicate, the control unit 20 can have at least one circuit board 21. Advantageously, the sensor element 10 can be arranged and/or fastened to the circuit board 21. Preferably, the shielding element 11 can be arranged and/or fastened to the circuit board 21.

In addition, the edge element 12 can be arranged and/or fastened to the circuit board 21 at least in sections (cf. 11 ). In this way, the edge element 12 can be used to shield a communication unit 23, in particular an NFC unit. The edge element 12 can be used with several sections offset and/or spaced from the NFC coil in order to prevent direct kappa coupling into the NFC coil. The NFC coil has two sensor sections on average, which can be symmetrically surrounded by shield sections 12e, 12f, 12g. This also makes it possible to compensate for the differences in thickness between the layers of the PCB.

Furthermore, the edge element 12 can be arranged and/or fastened to the functional device 101 at least partially spaced apart from the circuit board 21 (cf. 2 to 4 and 9 and 10). In this way, the direction from which the water influence is to be prevented can be determined with the aid of the edge element 12. This can be advantageous in particular in the side area 10s of the sensor element 10 in order to prevent unwanted charge from flowing to the sensor electrode via conductive parts of the vehicle F and via a water droplet W, as is the case 1 and 3 indicate.

As already mentioned above, the control unit 20 can have control electronics 22 which are designed to charge and/or discharge the sensor element 10. The control unit 20 can advantageously be designed to measure an electrical potential on the charged sensor element 10 and/or to determine a discharge time of the charged sensor element 10. An electrical potential on the charged sensor element 10 and/or a discharge time of the charged sensor element 10 can be specific to the actuation action, preferably an approach and/or a touch, of the user on the functional device 101.

Like it 4 shows, the control unit 20 can have a comparison capacitance Load, which is designed to absorb the charge of the sensor element 10 in order to measure an electrical potential at the charged sensor element 10 and/or to determine a discharge time of the charged sensor element 10.

As already mentioned above, the control unit 20 can have control electronics 22 which are designed to charge and/or discharge the sensor element 10 using one or more voltage pulses, preferably voltage pulse sequences, as 5 , 6 and 8th In particular, an electrical potential at the charged sensor element 10 and/or a discharge time of the charged sensor element 10 can be specific to the actuation action, preferably an approach and/or a touch, of the user to the functional device 100 and/or an exposure of an outer surface 102 of the functional device 100 to moisture, in particular to water droplets.

Furthermore, the control unit 20 can have control electronics 22 which are designed to detect an exposure of an outer surface 102 of the functional device 101 to moisture, in particular to water droplets, depending on one, in particular exclusively one, detection signal S1 of the sensor element 10, as 7 This can be done in particular by a form of the detection signal S1 of the sensor element 10 can be evaluated. Since a water drop W causes a slow load shift, a detection signal S1, S2 with a slowly falling edge can be a sign of a water drop W (see left in 7 ). In contrast, a finger touch causes almost no voltage drop, so that a strong falling edge can be seen in the detection signal S1, S2 (see right in 7 ). In this way, it can be determined from just one detection signal S1 of the sensor element 10 whether the sensor element senses a water drop W or a human finger.

Furthermore, the control unit 20 can have control electronics 22 which are designed to detect the exposure of an outer surface 102 of the functional device 101 to moisture, in particular to water droplets, depending on a comparison between two detection signals S1, S2 of the sensor element 10. In particular, the amplitudes A1, A2 of the detection signals S1, S2 of the sensor element 10 can be compared, preferably if the detection signals S1, S2 have different voltage pulse sequences with different pulse/pause ratios and/or different voltage levels.

In addition, 5 , 6 and 8th that the control unit 20 can have control electronics 22 which are designed to detect the exposure of an outer surface 102 of the functional device 101 to moisture, in particular to water droplets, as a function of one, in particular exclusively one, voltage pulse of the sensor element 10 of the sensor element 10, in particular as a function of a transient, in particular a gradient, of the voltage pulse of the sensor element 10. For example, two points in time on the x-axis can be determined for reading voltage U10 on the sensor element 10 in order to determine the transient of the voltage pulse. In addition, the transient can be calculated from the entire voltage pulse. In this way, rapid and reliable rain detection can be made possible.

In addition, 5 , 6 and 8th that the control unit 20 can have control electronics 22 which are designed to detect an exposure of an outer surface 102 of the functional device 101 to moisture, in particular to water droplets, depending on a comparison between two voltage pulses of the sensor element 10, in particular depending on a comparison of the amplitudes of the voltage pulses of the sensor element 10, preferably when the voltage pulses have different lengths. In this way, reliable rain detection can be made possible. Pulses of different lengths cause load shifts of different sizes, as 5 left shows a comparison between an upper and a lower graphic. The voltage drop can be in a measurable range, for example in the range of a few mV to a few V, so that the difference between a short and a long measurement pulse is noticeably large. Such rain detection is fast. Two voltage pulses are sufficient to enable reliable rain detection.

Furthermore, 5 , 6 and 8th that the control unit 20 can have control electronics 22 which are designed to detect the exposure of an outer surface 102 of the functional device 101 to moisture, in particular to water droplets, depending on a comparison between two voltage pulse sequences of the sensor element 10. In particular, the amplitudes of the voltage pulse sequences of the sensor element 10 can be compared, preferably if the voltage pulse sequences have different pulse/pause ratios. Pulses of different lengths cause different load shifts, as 5 left shows a comparison between an upper and a lower graphic. The voltage drop ΔU can be in a measurable range, for example in the range of a few mV to a few V, so that the difference between a short and a long measurement pulse is noticeably large. Such rain detection is very fast. Two points in the voltage pulse sequences are enough to enable reliable rain detection.

Furthermore, the control electronics 22 can be designed to apply a specific voltage and/or specific voltage profiles, preferably voltage pulse sequences, to the shielding element 11. The shielding element 11 can thus be switched on or off in a targeted manner. For the sake of simplicity, the control unit 20 can be designed to connect the shielding element 11 to a ground potential.

An embodiment not shown in the figures for reasons of simplicity can provide that the control electronics 22 can be designed to charge and/or discharge the shielding element 11 using one or more voltage pulses, preferably voltage pulse sequences. With the help of the shielding element 11, the sensor device 100 can provide different functionalities and/or different methods for detecting moisture. It is also conceivable that the voltage pulses, preferably voltage pulse sequences, are applied to the sensor element 10 and the voltage pulses, preferably voltage pulse sequences, on the shielding element 11 are coordinated with one another and/or correspond. Preferably, the voltage pulses, preferably voltage pulse sequences, on the sensor element 10 and the voltage pulses, preferably voltage pulse sequences, on the shielding element 11 can be carried out with a time offset and/or phase shift. In this advantageous manner, a measurable influence on a transient of the voltage pulses on the sensor element 10 can be generated.

Furthermore, 8th that the control unit 20 can have control electronics 22 which are designed to apply a specific voltage and/or specific voltage profiles, preferably voltage pulse sequences, to the edge element 12 in order to provide at least one or more different function(s) F1, F2 with regard to the environmental influences, in particular moisture, on the sensor element 10. The edge element 12 can be controlled using a field control in order to achieve different effects (targeted rain suppression F1 and/or increased rain detection F2). The voltage pulses, preferably voltage pulse sequences, on the sensor element 10 and the voltage pulses, preferably voltage pulse sequences, on the edge element 12 can also be coordinated with one another.

Like it 8th in the middle, the control unit 20 can have control electronics 22 which are designed to apply the same or different specific voltage(s) and/or the same or different specific voltage curves, preferably voltage pulse sequences, to the edge element 12 and the sensor element 10 synchronously or concurrently in order to reduce the environmental influences, in particular moisture, on the sensor element 10.

Like it 8th As indicated below, the control unit 20 can have control electronics 22 which are designed to apply the same or different specific voltage(s) and/or the same or different specific voltage profiles, preferably voltage pulse sequences, to the edge element 12 and the sensor element 10 asynchronously or in opposite directions in order to amplify the environmental influences, in particular moisture, on the sensor element 10, in particular to detect the exposure of an outer surface 102 of the functional device 101 to moisture, in particular water droplets. In this way, the effect of the water on the sensor element 10 can be amplified, so that simple, quick and reliable rain detection can be provided in the sensor device 100.

Different checking methods for detecting exposure of an outer surface 102 of the functional device 101 to moisture, in particular to water droplets, can be provided by controlling a sensor element 10, a shielding element 11 and/or an edge element 12, each individually or in combination.

In principle, it is conceivable that different checking methods for detecting exposure of an outer surface 102 of the functional device 101 to moisture, in particular to water droplets, are carried out individually or in combination.

It is also conceivable that at least one checking method (e.g. transient of a voltage pulse on the sensor element 10 shows a typical gradient for a water drop) can provide a first indication of an external surface 102 of the functional device 101 being exposed to moisture, in particular water droplets. At least one further checking method (e.g. comparison of amplitudes of two voltage pulses on the sensor element 10) or several further checking methods (e.g. with additional control of the shielding element 11 and/or the edge element 12) can then be carried out in order to confirm the first indication. In this way, a multi-checking method can be provided.

Like it 9 to 11 show, the edge element 12 can have a 3D shape. In this way, the edge element 12 can form different sections with extended functions, in particular in order to be able to protect various functional components 10s, 22, NFC in the sensor device 100 from environmental influences.

The edge element 12 can be made of a, in particular planar, metal sheet, preferably by punching and bending the metal sheet.

Like it 9 and 10 show, the edge element 12 can be designed in a frame-like manner at least in sections. In this way, the edge element can in particular surround the narrow long sides of the sensor element and protect a side area 10s of the sensor element 10 from environmental influences.

Like it 10 shows, the edge element 12 can have at least one, in particular two, legs 12a, 12b for adapting to environmental influences on at least one side area 10s of the sensor element 10. In this way, the environmental influences that cause charge to flow from the sensor element to conductive parts of the vehicle via the water droplet W can be reliably reduced.

In addition, it is conceivable that the edge element 12 has at least one, in particular two, shield sections 12c, 12d for shielding a control electronics 22 of the control unit 20. In this way, the edge element 12 can fulfill a further advantageous function in order to protect the control electronics 22 from influences by electromagnetic fields and/or capacitive couplings.

In order to provide advantageous sections 12a, 12b, 12c, 12d of the edge element 12, such as the legs 12a, 12b and/or the shield sections 12c, 12d, the edge element 12 can be arranged at least in sections outside the circuit board 21 of the control unit 20, in particular on the functional device 101.

Furthermore, 9 and 10 that the edge element 12 can be designed as a fastening element and/or positioning element and/or spacer element for the control unit 20 on the functional device 101. For this purpose, the edge element 12 can have at least one or more, in particular angled, fastening sections 12i, 12h, which are designed to fasten the control unit 20 on the functional device 101 and/or to position it and/or to arrange it at a distance from an outer surface 102 of the functional device 101. In this way, the edge element 12 can develop further advantages with regard to the assembly of the sensor device 100 on the functional device 101.

Furthermore, 11 that the edge element 12 can have at least one, in particular several, shield sections 12e, 12f, 12g for shielding a communication unit 23, in particular an NFC unit, of the control unit 20. The edge element 12 can be integrated at least in sections within a circuit board 21 of the control unit 20. An NFC coil has on average two sensor sections that can be symmetrically surrounded by shield sections 12e, 12f, 12g, which in turn can be arranged offset and/or spaced from the sensor sections of the NFC coil. In this way, direct kappa coupling into the NFC coil can be prevented. In addition, the thickness differences between the layers of the circuit board 21 can be compensated for.

A corresponding computer program product, a corresponding control unit 20, a corresponding sensor device 100 and a functional device 101 also represent an aspect of the invention.

The above explanation of the embodiments describes the present invention exclusively in the context of examples. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically expedient, without departing from the scope of the present invention.

List of reference symbols

100

Sensor device

10

Sensor element

10s

Page area

Load

Comparative capacity

11

Shielding element

12

Edge element

12a, 12b

leg

12c, 12d

Shield sections

12e, 12f, 12g

Shield sections

12h, 12i

Fastening sections

20

Control unit

21

Circuit board

22

Control electronics

23

Communication unit

101

Functional device

102

Exterior surface

B

user

Rb

Resistance from the user

W

Waterdrop

Rw

Resistance of water drop

F

Vehicle

S1

Detection signal

A1

amplitude

S2

Detection signal

A2

amplitude

I

Electricity

U

Tension

U10

Voltage at the sensor element

ULoad

Voltage at comparison capacity

ΔU

Voltage drop

Claims (25)

Method for operating a capacitive sensor device (100) for a functional device (101), in particular in the form of an access device, preferably a door handle, of a vehicle (F), wherein the sensor device (100) has at least one sensor element (10), preferably in the form of a, preferably capacitive, sensor electrode, for detecting an actuation, in particular in the form of an approach and/or a touch, of a user (B) on the functional device (101) and/or for detecting an exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets, and a control unit (20) for controlling and/or reading the sensor element (10), the method comprising: - operating the sensor device (100) for detecting the actuation of the user on the functional device (101) and/or - operating the sensor device (100) for detecting the exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets. Procedure according to Claim 1 , characterized in that the sensor device (100) is provided with a shielding element (11) for aligning a detection area of the sensor element (10), wherein the control unit (20) serves to control and/or read out the shielding element (11), and/or that the sensor device (100) is provided with at least one edge element (12), in particular formed separately from the shielding element (11) and/or arranged at a distance from the shielding element (11), for adapting environmental influences to the sensor element (10), wherein the control unit (20) serves to control and/or read out the edge element (12). Method according to one of the preceding claims, characterized in that in order to detect the actuation action and/or to detect an application of moisture, in particular water droplets, to an outer surface (102) of the functional device (101), the sensor element (10) is charged and/or discharged, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), and/or when discharging the sensor element (10), an electrical potential on the charged sensor element (10) is measured and/or a discharge time of the charged sensor element (10) is determined, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), wherein in particular an electrical potential on the charged sensor element (10) and/or a discharge time of the charged sensor element (10) for the actuation action, preferably an approach and/or a touch, of the user (B) on the functional device (101) and/or a Exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets, is specific. Method according to one of the preceding claims, characterized in that the charge of the sensor element (10) is transferred to a comparison capacitance (load), in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), in order to measure an electrical potential at the charged sensor element (10) and/or to determine a discharge time of the charged sensor element (10). Method according to one of the preceding claims, characterized in that the sensor element (10) is charged and/or discharged with the aid of one or more voltage pulses, preferably voltage pulse sequences, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), wherein in particular an electrical potential at the charged sensor element (10) and/or a discharge time of the charged sensor element (10) are specific for the actuation action, preferably an approach and/or a touch, of the user (B) to the functional device (101) and/or an exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets. Method according to one of the preceding claims, characterized in that an exposure of an outer surface (102) of the functional device (101) to moisture, in particular water droplets, is carried out as a function of one, in particular exclusively one, Detection signal (S1) of the sensor element (10) is detected, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), preferably depending on a form of the detection signal (S1) of the sensor element (10). Method according to one of the preceding claims, characterized in that an exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets, is detected as a function of a comparison between two detection signals (S1, S2) of the sensor element (10), in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), preferably as a function of a comparison of the amplitudes of the detection signals (S1, S2) of the sensor element (10), preferably when the detection signals (S1, S2) have different voltage pulse sequences with different pulse/pause ratios and/or different voltage levels. Method according to one of the preceding claims, characterized in that an exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets, is detected as a function of one, in particular exclusively one, voltage pulse of the sensor element (10) of the sensor element (10), in particular as a function of a transient, in particular a slope, of the voltage pulse of the sensor element (10). Method according to one of the preceding claims, characterized in that an exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets, is detected as a function of a comparison of two voltage pulses of the sensor element (10), in particular as a function of a comparison of the amplitudes of the voltage pulses of the sensor element (10), preferably when the voltage pulses have different lengths. Method according to one of the preceding claims, characterized in that an exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets, is detected as a function of a comparison between two voltage pulse sequences of the sensor element (10), in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), preferably as a function of a comparison of the amplitudes of the voltage pulse sequences of the sensor element (10), preferably when the voltage pulse sequences have different pulse/pause ratios. Method according to one of the preceding claims, characterized in that the shielding element (11) is subjected to a specific voltage and/or to specific voltage curves, preferably voltage pulse sequences, or is connected to a ground potential, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20). Sensor device (100) according to one of the preceding claims, characterized in that the shielding element (11) is charged and/or discharged using one or more voltage pulses, preferably voltage pulse sequences, wherein in particular the voltage pulses, preferably voltage pulse sequences, on the sensor element (10) and the voltage pulses, preferably voltage pulse sequences, on the shielding element (11) are coordinated with one another and/or correspond, wherein preferably the voltage pulses, preferably voltage pulse sequences, on the sensor element (10) and the voltage pulses, preferably voltage pulse sequences, on the shielding element (11) are carried out with a temporal offset and/or phase-shifted in order to preferably generate a measurable influence on a transient of the voltage pulses on the sensor element (10). Method according to one of the preceding claims, characterized in that the edge element (12) is subjected to a specific voltage and/or to specific voltage profiles, preferably voltage pulse sequences, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), in order to provide at least one or more different function(s) (F1, F2) with regard to the environmental influences, in particular moisture, on the sensor element (10): - a first function (F1), to clean the detection of an actuation action, in particular a touch, of the user on an outer surface (102) of the functional device (101) from moisture influences, and/or - a second function (F2) to enhance the detection of exposure of an outer surface (102) of the functional device (101) to moisture, in particular water droplets. Method according to one of the preceding claims, characterized in that the edge element (12) is subjected to a specific voltage and/or to specific voltage curves, preferably voltage pulse sequences, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), in order to reduce the environmental influences, in particular due to moisture, on the sensor element (10). Method according to one of the preceding claims, characterized in that the edge element (12) is subjected to a specific voltage and/or to specific voltage profiles, preferably voltage pulse sequences, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), in order to amplify the environmental influences, in particular moisture, on the sensor element (10), in order in particular to detect the exposure of an outer surface (102) of the functional device (101) to moisture, in particular water droplets. Method according to one of the preceding claims, characterized in that the edge element (12) is charged and/or discharged with the aid of one or more voltage pulses, preferably voltage pulse sequences, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), wherein in particular the voltage pulses, preferably voltage pulse sequences, on the sensor element (10) and the voltage pulses, preferably voltage pulse sequences, on the edge element (12) are coordinated with one another. Method according to one of the preceding claims, characterized in that the edge element (12) and the sensor element (10) are synchronously and/or concurrently subjected to an identical or different specific voltage(s) and/or identical or different specific voltage profiles, preferably voltage pulse sequences, in particular by the control unit (20), preferably with the aid of control electronics (22) of the control unit (20), in order to reduce the environmental influences, in particular due to moisture, on the sensor element (10). Method according to one of the preceding claims, characterized in that the edge element (12) and the sensor element (10) are asynchronously and/or oppositely subjected to an identical or different specific voltage(s) and/or identical or different specific voltage profiles, preferably voltage pulse sequences, in order to amplify the environmental influences, in particular due to moisture, on the sensor element (10), in particular in order to detect an exposure of an outer surface (102) of the functional device (101) to moisture, in particular to water droplets. Method according to one of the preceding claims, characterized in that the edge element (12) is used for adapting environmental influences to at least one side region (10s) of the sensor element (10), wherein in particular the edge element (12) has at least one, in particular two, legs (12a, 12b) for adapting environmental influences to at least one side region (10s) of the sensor element (10). Method according to one of the preceding claims, characterized in that the edge element (12) is used for shielding a control electronics (22) of the control unit (20), wherein in particular the edge element (12) has at least one, in particular two, shield sections (12c, 12d) for shielding a control electronics (22) of the control unit (20). Method according to one of the preceding claims, characterized in that the edge element (12) is used for shielding a communication unit (23), in particular an NFC unit, of the control unit (20), wherein in particular the edge element (12) has at least one, in particular several, shield sections (12e, 12f, 12g) for shielding a communication unit (23), in particular an NFC unit, of the control unit (20). Computer program product comprising instructions which, when the computer program product is executed by a computer, ter to carry out the method according to one of the preceding claims. Control unit (20), comprising a memory unit in which a code is stored, and a computing unit, wherein when the code is executed by the computing unit, the method according to one of the preceding claims is carried out. Sensor device (100) for a functional device (101), in particular in the form of a door handle, of a vehicle (F), comprising a control unit (20) according to the preceding claim. Functional device (101), in particular in the form of a door handle, for a vehicle (F), with a sensor device (100) according to the preceding claim.

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