LU100720B1

LU100720B1 - Sensor arrangement for capacitive position detection of an object

Info

Publication number: LU100720B1
Application number: LU100720A
Authority: LU
Inventors: Laurent Lamesch
Original assignee: Iee Sa
Priority date: 2018-03-05
Filing date: 2018-03-05
Publication date: 2019-10-01

Abstract

The invention relates to a sensor arrangement (1) for capacitive position detection of an object (20). In order to provide means for hand detection on a steering wheel which are reliable and have a low complexity, the invention provides that the sensor arrangement comprises: a first electrode (2) and a second electrode (3) extending along a first direction (X) and being disposed proximate each other in a second direction (Y) perpendicular to the first direction (X), wherein a width of the first electrode (2) in the second direction (Y) increases along the first direction (X), while a width of the second electrode (3) decreases; and a plurality of conducting elements (4), isolated from each other and from the first (2) and second electrode (3) and being disposed over the first (2) and second electrode (3) so that each conducting element (4) overlaps with the first (2) and second electrode (3).

Description

Sensor arrangement for capacitive position detection of an object

Technical field [0001] The invention relates to a sensor arrangement for capacitive positiondetection of an object.

Background of the Invention [0002] In modern vehicles, it can be necessary to detect whether the driver hashis hands on the steering wheel (e.g. in order to determine whether the driver isready to carry out a steering action). Steering assistants may include an activecorrection possibility for the driver to be used in certain circumstances. Forexample, a provision may be made for a steering assistance system to beactivated only when the driver has his hands on the steering wheel. In mostcountries, it is mandatory that the vehicle when moving is under the control of thedriver, even if modern assistance systems would be able to safely operate thevehicle autonomously in certain situations.

[0003] In order to identify whether or not at least one hand is positioned on thesteering wheel, several concepts have been developed. One concept relies on theEPS system and induces a low-amplitude vibration in the steering wheel. If thehands of the driver are on the steering wheel, this has a dampening effect whichcan be detected. However, the vibration can be distracting or disturbing to thedriver. Other systems use dedicated sensors. One such system uses resistivesensor elements where two conductors are disposed spaced apart under thesurface of the steering wheel. If a certain pressure is exerted on the surface, theconductors are brought into contact. However, the amount of pressure required toactivate the sensor makes this approach less reliable. Another approach usescapacitive sensors, which detect a hand by its influence on an electric fieldgenerated by the sensor. While these sensors are more reliable, they considerablyincrease the complexity of the steering wheel, in particular if the position of thehand is to be detected, which makes it necessary to provide a plurality of sensors,i.e. one for each surface position, along with detection circuitry for each individualsensor. This complexity increases the costs and makes the system more prone tofailure.

[0004] DE 10 2014 016 422 A1 discloses an apparatus for detecting a steeringwheel contact, with at least one first electrode arranged in a steering wheel, which,together with a human body functioning as a second electrode and anintermediate dielectric, forms a sensor capacitor. The apparatus further comprisesan evaluation circuit with a reference capacitor of known capacity, which can beconnected parallel to the sensor capacitor, a DC voltage source that can beconnected to the reference capacitor, and a measuring means for measuring thevoltage across the reference capacitor.

[0005] US 2011/0133919 A1 relates to a system for the detection of user handposition on a steering wheel. The system comprises a sensor array disposed onthe circumference of said wheel configured to detect contact of first and seconduser hands with said sensor array, a processor whereby data from said sensorarray is received and processed generating user hand size, location andmovement data and a feedback device whereby a user is alerted to an unsafehand position. Embodiments show a plurality of sensors disposed around thecircumference of the steering wheel [0006] WO 2016/087231 A1 discloses a sensor system for a steering wheel withat least one capacitive sensor means and control means for controlling the sensormeans, wherein said capacitive sensor means includes at least two electricallyconductive sensor structures. The at least two sensor structures are at leastpartially disposed in meshing, and are intended to be arranged in the grippingrange of a steering wheel, wherein the sensor system is configured such that aposition of a human hand can be determined from the ratio of the detectedchanges of the the capacitive coupling associated with the individual sensorstructures.

[0007] US 7,019,623 B2 discloses a steering wheel for detecting the position ofthe hands of a driver. The steering wheel comprises a steering ring with a pluralityof sensors distributed over the periphery of the steering ring and extending overthe entire length of the steering ring. The sensors comprise a plurality of sensorsegments arranged in a row in the longitudinal direction of the steering ring, eachsaid sensor segment separated from another sensor segment by a distance whichis smaller than the width of a finger, the lengths of said sensor segments beingless than the width of a finger.

[0008] US 6,768,962 B2 relates to a method for sensing a readiness to steer or asteering behavior of a motor vehicle driver. An electrical signal is provided whenthe driver touches or exerts pressure on at least one sensor on the steering wheel.The sensor is provided with a multiplicity of sensor elements or sensor segmentsarranged along a circumference of the steering wheel. A detection is performedregarding at least where the driver's hand grasps the steering wheel at apredetermined position from inside, outside, top or bottom thereof.

[0009] US 2012/0296528 A1 discloses a steering wheel for a vehicle, whichcomprises a steering-wheel rim having a grasping area thereon, at which thesteering wheel is able to be grasped by the hands of a driver for steering thevehicle, and a plurality of touch-sensitive sensors distributed over the graspingarea. The sensors may be arranged in matrix form along the surface of thesteering wheel.

Object of the invention [0010] It is thus an object of the present invention to provide means for handdetection on a steering wheel which are reliable and have a low complexity. Thisproblem is solved by a sensor arrangement according to claim 1.

General Description of the Invention [0011] The invention provides a sensor arrangement for capacitive positiondetection of an object. The sensor arrangement is designed to detect the presenceof an object, in particular a hand or a finger of a user, and, more specifically, todetect a position of the object. The sensor arrangement is designed for capacitivedetection, which means that the detection of the object is based on measuring acapacitance or, respectively, a quantity that depends on a capacitance. Thesensor arrangement may be disposed along a detection surface in order to detectan object adjacent the detection surface. The detection surface may correspond tothe outer surface of some device. The shape of the detection surface is not limitedwithin the scope of the invention and may e.g. be plain, curved, angled or the like.

[0012] The sensor arrangement comprises a first electrode and a secondelectrode extending along a first direction and being disposed proximate eachother in a second direction perpendicular to the first direction, wherein a width of the first electrode in the second direction increases along the first direction, while awidth of the second electrode decreases. The first and second electrode are atleast partially made of conductive material, e.g. metal sheet, conductive foil or thelike. Normally, they are flat or sheet-shaped. The electrodes are electricallyisolated from each other and may be disposed on an isolating substrate. Bothelectrodes extend along a first direction and are disposed proximate each other ina second direction perpendicular to the first direction. The first and seconddirection are normally directions along the detection surface. It should be notedthat the two directions do not have to be straight with respect to a Cartesiancoordinate system. This may depend on the shape of the detection surface. Forexample, if the detection surface was spherical, both the first and the seconddirection normally would be curved, e.g. corresponding to the polar and azimuthaldirection. However, even if the detection surface is plain, the first and seconddirection could e.g. correspond to a radial and tangential direction.

[0013] Both electrodes can be characterised by a width along the seconddirection, i.e. the width of the respective electrode is its dimension along thesecond direction. Along the first direction, the width of the first electrode increases,while the width of the second electrode decreases. Therefore, at each positionalong the first direction, the ratio of the width of the first electrode and the width ofthe second electrode has a value that increases along the first direction. The widthof each electrode preferably changes (increases or decreases, respectively)strictly monotonously along the first direction so that the width of each electrodehas a unique value for each position along the first direction. However, it isconceivable that the width remains constant for a small interval along the firstdirection or that there is a small interval where the change is reversed. Forexample, the width of the first electrode could remain constant or even decreaseover a small interval corresponding to e.g. 5% or 10% of its entire length.

[0014] Furthermore, the sensor arrangement comprises a plurality of conductingelements, isolated from each other and from the first and second electrode andbeing disposed over the first and second electrode so that each conductingelement overlaps with the first and second electrode. The conducting elementscan be made of the same materials as the first and second electrode, e.g. metalsheet or conductive foil. Each of the conducting elements is electrically isolated from the above-mentioned electrodes and from other conducting elements. It isdisposed over the first and second electrode, which means that it is spaced fromthese electrodes along a (third) direction perpendicular to the first and seconddirection. In other words, the first and second electrode may be disposed in alower layer of the sensor arrangement, while the conducting elements may bedisposed in an upper layer of the sensor arrangement. To this respect, the sensorarrangement may also be regarded as a multi-layer arrangement.

[0015] During operation, the first and second electrode can be coupled to ameasurement device which is configured to electrically charge both electrodes andto measure a quantity that is representative of the capacitance of each electrode.For example, both electrodes could be charged with the same voltage and themeasurement device could detect the charge in each electrode by measuring thecurrent flowing in and out of this electrode. However, there are other possibilitiesto determine the capacitance of an electrode and the invention is not limited to anyspecific method. In general, each electrode can have a capacitance with respect toground, which is changed when an object is in the proximity of the electrode. Dueto its conducting property, each conducting element has the same electricalpotential over its entire surface or volume. Therefore, if an object is disposed overonly a part of the respective conducting element, this changes the electricalpotential of the entire conducting element. Since the conducting element overlapswith both the first and second electrode, the electric field of both electrodes isaffected, which in turn influences the capacitance of both electrodes. In otherwords, even if the object is disposed over only one electrode, the presence of theconducting element ensures that the capacitance of the other electrode isinfluenced as well.

[0016] It should be noted that the conducting elements, although they mayphysically resemble electrodes, do not require any wiring. Also, they are simple toproduce and can be realised e.g. by a single layer of conducting material.Therefore, the inventive sensor arrangement can be realised in a relatively simpleand cheap way compared to a sensor arrangement with a multitude of individualelectrodes, each of which requires wiring. Also, with a large number of individualelectrodes, signals from each electrode need to be evaluated separately. With the inventive sensor arrangement, there is only need for two electrodes that requirewiring and signal evaluation.

[0017] The basic idea of the invention is that the presence of an object changesthe capacitance of both electrodes locally, i.e. in the area where the object isdisposed adjacent the respective electrode. This may also be described aschanging the electric field over the electrode. Since the capacitance of a specificportion of an electrode is (more or less) proportional to the area of this portion, thechange in capacitance depends on the width of the respective electrode this area.For example, in a position along the first direction where the width of the firstelectrode is relatively large while the width of the second electrode is relativelysmall, the proximity of an object gives rise to a greater capacitance change for thefirst electrode than for the second electrode. Thus, by evaluating the ratio ofcapacitance changes for both electrodes, the position of the object along the firstdirection can be determined or estimated. The function of the conducting elementsis to provide a proper coupling with both electrodes even if the object is positioned(mostly) over only one of the electrodes.

[0018] As pointed out before, the conducting elements are electrically isolatedfrom the first and second electrode, e.g. by an layer of isolating material. Theconducting elements could be disposed on an outer surface of a device so that theobject can actually touch a conducting element. Alternatively, the conductingelements could be covered by another layer of isolating material which in turnforms the outer surface.

[0019] There are various conceivable applications for the inventive sensorarrangement. According to one preferred embodiment, the sensor arrangement isadapted to for hand detection in a steering wheel of a vehicle, normally a landvehicle like a car. However, application to other vehicles like sea or air vehicles isalso conceivable. In such an embodiment, the first and second electrode and theconducting elements are disposed along a surface of the steering wheel, wherebya position of a hand of a user can be detected. In other words, the detectionsurface is an outer surface of the steering wheel. The sensor arrangement may inthis context also be characterised as a sensor arrangement for hand positiondetection, since the main purpose is to detect the position of at least one hand of auser (driver) on the steering wheel. It should be noted that a steering wheel could be provided with more than one inventive sensor arrangement, if this is consideredadvantageous.

[0020] In particular, the first direction may correspond to a circumferentialdirection of the steering wheel. In such a case, the position of a hand around thecircumference of the steering wheel can be detected with a single sensorarrangement that requires only a limited amount of wiring, e.g. one wire for eachelectrode, while the conducting elements required no wiring.

[0021] In order to allow for a simple determination of the position of the object, itmay be advantageous if there is a simple relation between this position and thecapacitance of the respective electrode. According to one preferred embodiment,the width of at least one electrode changes monotonically along the first direction.The width of at least one electrode may e.g. change linearly along the firstdirection. Therefore, the capacitance normally changes in a monotonous way withrespect to the position of the object along the first direction. If the width of therespective electrode changes in a non-monotonous way, this normally means thatthere are some areas where the position of the object can be detected with higheraccuracy and some areas where it can be detected with less accuracy. Dependingon the application, this could even be desirable, but for many applications theaccuracy should be the same along the entire length of the first and/or secondelectrode. It is also preferred that the width of both the first and second electrodechanges monotonously along the first direction.

[0022] It should be noted that even if the width of the respective electrodechanges in a monotonous or linear way, this does not mean that the edges of thiselectrode have to be straight lines. However, in a preferred embodiment, at leastone electrode is triangular or trapezoidal. Of course, either of these configurationscorresponds to a linear change of the width of the respective electrode. Inparticular, both the first and second electrode can be triangular or trapezoidal.Also, both electrodes may have an identical shape, differing only by a rotation of180°.

[0023] In order to achieve a detection over a long distance along the first directionwith a single pair of (first and second) electrodes, it is desirable that the respectiveelectrode has a more or less elongate shape. It is therefore preferred that a lengthof at least one electrode along the first direction is at least three times the maximum width of this electrode. Depending on the embodiment, the ratio can beeven higher, e.g. 5 times or even 10 times. The only practical limit is that thelonger the electrode becomes with respect to its maximum width, the less thechange or "gradient" of the width along the first direction becomes, therebyreducing the possible detection accuracy for the position of the object.

[0024] Detection accuracy can also be optimised if the conducting elements aredisposed sequentially along the first direction. In other words, there is a distinctsequence of the conducting elements along the first direction, with eachconducting element followed by another one. In this configuration, where no twoconducting elements are disposed in the same position with the respect to the firstdirection, there is a clear correspondence between each conducting element and aregion of the first or second electrode having a certain width.

[0025] If the conducting elements are disposed sequentially, their individualshapes could be chosen in various ways. According to one embodiment, at leastone conducting element has edges that are parallel to the second direction. Inother words, the respective conducting element is limited by edges that areperpendicular to the first direction.

[0026] With the inventive sensor arrangement, the capacitance of the first orsecond electrode largely depends on whether an object to be detected is disposedadjacent a specific conducting element (or a group of conducting elements).However, the capacitance normally does not depend on e.g. over which part of aspecific conducting element the object is placed. Therefore, since detection of theposition of the object depends on the capacitance, the accuracy of the detection isnormally limited by the size of the respective conducting element. In other words,the sensitivity of the sensor arrangement can be increased if a relatively highnumber of conducting elements is employed. Preferably, the sensor arrangementcomprises at least 4, preferably at least 6, more preferably at least 8 conductingelements. Normally, the number of distinguishable object positions along the firstdirection corresponds at least to the number of conducting elements. That is, if 4conducting elements are used, at least 4 object positions can be distinguished. Inaddition, implicit interpolation between two adjacent conducting elements allows acontinuous position detection. The accuracy then depends on the size of theconducting elements relative to the size of the object.

[0027] A simple and yet effective way to provide for a reliable position detectionof an object is to provide that a plurality of conducting elements are identicallyshaped. In particular, all conducting elements can be identically shaped. At theone hand, this can help to simplify the design and the production of the sensorarrangement, while on the other hand, the relation between the position of anobject and the capacitance of the first and second electrode, respectively, isnormally simpler if a plurality of conducting elements have the same shape.

[0028] For the sensor arrangement to work in the inventive way, it is notimperative that the conducting elements have a certain shape. However, it ispreferred that at least one conducting element is rectangular. Normally, the edgesof the rectangular conducting element are aligned along the first and seconddirection, respectively.

[0029] Although the conducting elements need to be electrically isolated fromeach other and therefore need to be disposed spaced-apart, the detectionaccuracy is normally improved if the spacing between two conducting elements isnot too great. According to one embodiment, a distance between two conductingelements along the first direction is smaller than a length of either conductingelement along the first direction. For example, the distance may correspond to lessthan 50% or less than 25% of the length of either conducting element.

[0030] The effectiveness of the sensor arrangement can be increased if at leastone conducting element extends over the entire width of at least one of the firstand second electrode along the second direction. Preferably, the respectiveconducting element extends over the entire width of both the first and secondelectrode along the second direction. In other words, with regard to a(mathematical) surface extending along the first and second direction, therespective conducting element fully overlaps with the respective electrode alongthe second direction.

[0031] According to one embodiment, the sensor arrangement comprises a thirdelectrode which is disposed next to the first electrode opposite the secondelectrode. The third electrode may also be disposed along the detection surface.The purpose of this third electrode is to capacitively detect an object next to thefirst electrode. If an object is simultaneously detected by the first, second and thirdelectrode, it may be assumed that this is the same object, which extends beyond the first and second electrode. If, for example, the first and second electrode aredisposed around the circumference of a steering wheel on the outer side, while thethird electrode is disposed on the inner side, the first and second electrode may beused to detect the position of a finger or hand of the user around the steeringwheel, while a simultaneous detection by the third electrode may be used toconclude that the user grips around the steering wheel with his hand. In order toavoid any false detections by the third electrode, no conducting element shouldoverlap the third electrode. In other words, every conducting element should bespaced from the third electrode along the second direction.

[0032] While there could be a plurality of third electrodes for a single firstelectrode, it is preferred that there is only one third electrode corresponding to thefirst electrode. This design helps to keep the sensor arrangement simple andcheap to produce and also reduces the required circuitry. In order to allow for amore or less complete coverage, it is preferred that the third electrode extendsalong at least 80% of the length of the first electrode. Depending on the length ofthe first electrode compared to the size of a typical object to be detected, e.g. afinger or a hand of a user, a larger ratio may be necessary to assure a safedetection of an object in the proximity of the third electrode. For instance, it mayextend along at least 90% or at least 95% of the length of the first electrode.

[0033] The sensor arrangement may further comprise a measurement device,which is electrically connected to the first and second electrode and is adapted todetermine a position of the object along the first direction based on a capacitanceof the first electrode and a capacitance of the second electrode. As alreadyexplained above, the capacitances of the two electrodes are affected differentlydepending on where the object is positioned along the first direction. Therefore, acertain capacitance ratio or a ratio of capacitance change can be associated with aposition of the object. The respective relation can be determined experimentallyand the measurement device may be programmed with a look-up table containingcorresponding values. Alternatively, the measurement device could calculate theposition based on some mathematical model. As already mentioned above, thereare different possibilities how the measurement device could determine thecapacitance or a value representative of the capacitance. E.g. each electrodecould be charged with the same voltage and the measurement device could monitor the current flowing into or out of the respective electrode to determine itscharge. If a third electrode is present, the measurement device is also electricallyconnected to this third electrode and is adapted to detect an object adjacent thethird electrode based on a capacitance of the third electrode.

Brief Description of the Drawings [0034] Further details and advantages of the present invention will be apparentfrom the following detailed description of not limiting embodiments with referenceto the attached drawing, wherein:

Fig. 1 is a schematic view of a first embodiment of an inventive sensorarrangement; and

Fig. 2 is a schematic view of a second embodiment of an inventive sensorarrangement.

Description of Preferred Embodiments [0035] Fig.1 schematically shows a first embodiment of an inventive sensorarrangement 1, which may be used for hand position detection on a steeringwheel. The sensor arrangement 1 comprises a first electrode 2 and a secondelectrode 3, both of which are trapezoidal and extend along a first direction X. Thesensor arrangement 1 may be disposed around the circumference of the steeringwheel, where the first direction X corresponds to the circumferential direction ofthe steering wheel. Both electrodes 2, 3 are separate and electrically isolated fromeach other and an isolating substrate 6. However, they are disposed proximateeach other in a second direction Y that is perpendicular to the first direction X. Awidth of the first electrode 2 in the second direction Y increases along the firstdirection X, while a width of the second electrode 3 decreases. A length of eachelectrode 2, 3 along the first direction X is about 10 times its maximum width alongthe second direction Y. Both electrodes 2, 3 are disposed along a detectionsurface 7, which corresponds to the surface of the steering wheel. For ease ofdisplay, the detection surface 7, which is in fact curved, is projected onto thedrawing plane.

[0036] A plurality of conducting elements 4 are disposed over the first and secondelectrode 2, 3 so that each conducting element 4 overlaps with both electrodes 2, 3. The conducting elements 4 are electrically isolated from each other and fromthe first and second electrodes 2, 3, e.g. by a layer of electrically isolating materialdisposed in between. All conducting elements 4 are rectangular, identically shapedand have edges 4.1 that are parallel to the second direction Y. The distancebetween 2 conducting elements 4 along the first direction X is about 20% of thelength of each conducting element 4 along the first direction X. In thisembodiment, ten conducting elements 4 are sequentially disposed along the firstdirection X. Alternatively, a smaller or greater number of conducting elements 4could be employed. Along the second direction Y, each conducting element 4 isdisposed over the entire width of the first electrode 2 and the second electrode 3.While the first and second electrode 2, 3 are connected to a measurement device10 by first and second wires (or, more generally, conducting lines) 11, 12, no suchwiring is required for the conducting elements 4.

[0037] The measurement device 10 is adapted to apply a voltage to each of theelectrodes 2, 3 and to detect the capacitance of each electrode 2, 3. For instance,the measurement device 10 could monitor the currents flowing through the wires11, 12, whereby the electric charge and thus the capacitance of each electrode 2,3 can be determined. In general, when an electrode 2, 3 is charged, an electricfield forms between the electrode 2, 3 and ground, which may be represented bysome vehicle component. If an object 20, like the hand of a user, is placedadjacent the steering wheel, this has an influence on the electric field, andtherefore on the capacitance of the electrodes 2, 3. Among others, thecapacitance change depends on the area of the respective electrode 2, 3 that isadjacent the object 20. Therefore, if the object 20 is placed in a first position Aalong the first direction X where the width of the first electrode 2 is smaller than thewidth of the second electrode 3, the capacitance change is greater for the secondelectrode 3 than for the first electrode 2. If the object 20 is placed in a secondposition B where the width of the first electrode 2 is greater than the width of thesecond electrode 3, the capacitance change is greater for the first electrode 2.Therefore, by evaluating the ratio of the capacitance change, a position of theobject 20 along the first direction X can be determined. This may be performed bythe measurement device 10 using a look-up table in which experimentallydetermined values are stored.

[0038] In the first and second position A, B, the object 20 is shown to fully overlapwith the first electrode 2 and the second electrode 3 along the second direction Y.In a third position C, the object 20 overlaps only with the second electrode 3.Without the presence of the conducting elements 4, there would be a measurablecapacitance change for the second electrode 3 but little or no capacitance changefor the first electrode 2. This could lead to a false detection and the assumptionthat the object 20 is in a position where the width of the second electrode 3 isconsiderably greater than the width of the first electrode 2. However, such falsedetection is avoided by the presence of the conducting elements 4. Since they aremade of conductive material, each of them has a single electrical potential over itsentire surface or volume. Therefore, even though the object 20 itself does notoverlap with the first electrode 2, the electric field of the first electrode 2 isconsiderably affected, which leads to a measurable capacitance change.

[0039] Fig. 2 shows a second embodiment of an inventive sensor arrangement 1,which differs from the embodiment shown in fig. 1 in that a rectangular thirdelectrode 5 is disposed next to the first electrode 2 opposite the second electrode3. The third electrode 5 is connected to the measurement device 10 by a third wire13. The measurement device 10 is adapted to apply a voltage to the thirdelectrode 5 and to detect a capacitance of the third electrode 5. If an object 20 is ina fourth position D, where it is placed not only over the first and second electrode2, 3 but also over the third electrode 5, the electric field of the third electrode 5 isaffected, thus leading to a capacitance change. In a steering wheel, the first andsecond electrode 2, 3 can be disposed on an outer side of a ring of the steeringwheel, while the third electrode 5 is disposed on an inner side of the ring.Therefore, if a capacitance change for all 3 electrodes 2, 3, 5 is detected by themeasurement device 10, this can be interpreted as a hand of the user grippingaround the ring of the steering wheel. Therefore, by providing the third electrode 5,it is possible to distinguish between a hand which is only loosely placed on thesteering wheel and a hand that actually grips the steering wheel. In order to avoidany false detections by the third electrode 5, no conducting element 4 overlaps thethird electrode 5. In other words, each conducting element 4 is spaced from thethird electrode 5 along the second direction Y.

List of Reference Symbols 1 sensor arrangement 2, 3, 5 electrode 4 conducting element 4.1 edge 6 isolating substrate 7 detection plane 10 measurement device 11, 12, 13 wire 20 object A, B, C, D position X first direction Y second direction

Claims

1. Sensoranordnung (1) zur kapazitiven Positionserkennung einesGegenstands (20), umfassend: - eine erste Elektrode (2) und eine zweite Elektrode (3), die sich entlangeiner ersten Richtung (X) erstrecken und in einer zweiten Richtung (Y)senkrecht zur ersten Richtung (X) nahe beieinander angeordnet sind,wobei eine Breite der ersten Elektrode (2) in der zweiten Richtung (Y)entlang der ersten Richtung (X) zunimmt, während eine Breite derzweiten Elektrode (3) abnimmt; und - mehrere leitfähige Elemente (4), die voneinander und von der ersten (2)und der zweiten Elektrode (3) isoliert sind, und die über der ersten (2)und der zweiten Elektrode (3) derart angeordnet sind, dass jedesleitfähige Element (4) die erste (2) und die zweite Elektrode (3)überlappt.A sensor arrangement (1) for capacitive position detection of an object (20), comprising: - a first electrode (2) and a second electrode (3) extending along a first direction (X) and in a second direction (Y) perpendicular to first direction (X) are arranged close to each other, wherein a width of the first electrode (2) in the second direction (Y) increases along the first direction (X) while a width of the second electrode (3) decreases; and a plurality of conductive elements (4) insulated from each other and from the first (2) and second electrodes (3) and disposed above the first (2) and second electrodes (3) such that each conductive element (4) the first (2) and the second electrode (3) overlap.

2. Sensoranordnung gemäß Anspruch 1, dadurch gekennzeichnet, dass siefürdie Handerkennung in einem Lenkrad eines Fahrzeugs angepasst ist.Sensor arrangement according to claim 1, characterized in that it is adapted for hand recognition in a steering wheel of a vehicle.

3. Sensoranordnung gemäß Anspruch 2, dadurch gekennzeichnet, dass dieerste Richtung (X) einer Umfangsrichtung des Lenkrads entspricht.3. Sensor arrangement according to claim 2, characterized in that the first direction (X) corresponds to a circumferential direction of the steering wheel.

4. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass sich die Breite von mindestens einer Elektrode (2,3) entlang der ersten Richtung (X) monoton ändert.4. Sensor arrangement according to one of the preceding claims, characterized in that the width of at least one electrode (2,3) along the first direction (X) changes monotonically.

5. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass mindestens eine Elektrode (2, 3) dreieckig odertrapezförmig ist.5. Sensor arrangement according to one of the preceding claims, characterized in that at least one electrode (2, 3) is triangular or trapezoidal.

6. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass eine Lange von mindestens einer Elektrode (2, 3) entlang der ersten Richtung (X) mindestens das Dreifache dermaximalen Breite dieser Elektrode (2, 3) beträgt.6. Sensor arrangement according to one of the preceding claims, characterized in that a length of at least one electrode (2, 3) along the first direction (X) is at least three times the maximum width of this electrode (2, 3).

7. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass die leitfähigen Elemente (4) sequentiell entlangder ersten Richtung (X) angeordnet sind.Sensor arrangement according to one of the preceding claims, characterized in that the conductive elements (4) are arranged sequentially along the first direction (X).

8. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass mindestens ein leitfähiges Element (4) Kanten(4.1) aufweist, die parallel zur zweiten Richtung (Y) sind.8. Sensor arrangement according to one of the preceding claims, characterized in that at least one conductive element (4) edges (4.1) which are parallel to the second direction (Y).

9. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass mehrere leitfähige Elemente (4) identisch geformtsind.Sensor arrangement according to one of the preceding claims, characterized in that a plurality of conductive elements (4) are identically shaped.

10. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass mindestens ein leitfähiges Element (4) rechteckigist.Sensor arrangement according to one of the preceding claims, characterized in that at least one conductive element (4) is rectangular.

11 Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass ein Abstand zwischen zwei leitfähigen Elementen(4) entlang der ersten Richtung (X) kleiner ist als eine Länge eines derleitfähigen Elemente (4) entlang der ersten Richtung (X).11. Sensor arrangement according to one of the preceding claims, characterized in that a distance between two conductive elements (4) along the first direction (X) is smaller than a length of one of the conductive elements (4) along the first direction (X).

12. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass sich mindestens ein leitfähiges Element (4) überdie gesamte Breite von mindestens einer von der ersten (2) und derzweiten Elektrode (3) entlang der zweiten Richtung (Y) erstreckt.Sensor arrangement according to one of the preceding claims, characterized in that at least one conductive element (4) extends across the entire width of at least one of the first (2) and second electrodes (3) along the second direction (Y).

13. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass sie eine dritte Elektrode (5) umfasst, die neben derersten Elektrode (2) gegenüber der zweiten Elektrode (3) angeordnet ist.Sensor arrangement according to one of the preceding claims, characterized in that it comprises a third electrode (5) arranged next to the first electrode (2) opposite the second electrode (3).

14. Sensoranordnung gemäß einem der vorstehenden Ansprüche, dadurchgekennzeichnet, dass sich die dritte Elektrode (5) über mindestens 80 %der Länge der ersten Elektrode (2) erstreckt.Sensor arrangement according to one of the preceding claims, characterized in that the third electrode (5) extends over at least 80% of the length of the first electrode (2).

15.Sensoranordnung gemäß einem der vorstehenden Ansprüche, fernerumfassend eine Messvorrichtung (10), die elektrisch mit der ersten (2)und der zweiten Elektrode (3) verbunden und dazu geeignet ist, einePosition des Gegenstands (20) entlang der ersten Richtung (X)basierend auf einer Kapazität der ersten Elektrode (2) und einerKapazität der zweiten Elektrode (3) zu bestimmen.A sensor assembly according to any one of the preceding claims, further comprising a measuring device (10) electrically connected to the first (2) and second electrodes (3) and adapted to position the article (20) along the first direction (X). based on a capacitance of the first electrode (2) and a capacitance of the second electrode (3).