US20240030914A1 - Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method - Google Patents
Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method Download PDFInfo
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- US20240030914A1 US20240030914A1 US18/376,557 US202318376557A US2024030914A1 US 20240030914 A1 US20240030914 A1 US 20240030914A1 US 202318376557 A US202318376557 A US 202318376557A US 2024030914 A1 US2024030914 A1 US 2024030914A1
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- steering wheel
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- capacitance
- steering
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- 238000000034 method Methods 0.000 title claims abstract description 22
- 239000004020 conductor Substances 0.000 claims abstract description 106
- 230000008859 change Effects 0.000 claims abstract description 10
- 230000010363 phase shift Effects 0.000 claims abstract description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 6
- 238000011156 evaluation Methods 0.000 abstract description 23
- 238000001514 detection method Methods 0.000 description 12
- 239000003990 capacitor Substances 0.000 description 8
- 230000010355 oscillation Effects 0.000 description 6
- 230000008878 coupling Effects 0.000 description 4
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D1/00—Steering controls, i.e. means for initiating a change of direction of the vehicle
- B62D1/02—Steering controls, i.e. means for initiating a change of direction of the vehicle vehicle-mounted
- B62D1/04—Hand wheels
- B62D1/046—Adaptations on rotatable parts of the steering wheel for accommodation of switches
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
- H03K17/96—Touch switches
- H03K17/962—Capacitive touch switches
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D1/00—Steering controls, i.e. means for initiating a change of direction of the vehicle
- B62D1/02—Steering controls, i.e. means for initiating a change of direction of the vehicle vehicle-mounted
- B62D1/04—Hand wheels
- B62D1/06—Rims, e.g. with heating means; Rim covers
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
- H03K2217/94—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated
- H03K2217/96—Touch switches
- H03K2217/9607—Capacitive touch switches
- H03K2217/96071—Capacitive touch switches characterised by the detection principle
- H03K2217/96072—Phase comparison, i.e. where a phase comparator receives at one input the signal directly from the oscillator, at a second input the same signal but delayed, with a delay depending on a sensing capacitance
Definitions
- the invention relates to a method for detecting contact with a manually activated steering or control device, in particular a vehicle steering wheel.
- the invention also relates to a device for carrying out the method.
- Knowing whether the driver of a vehicle is currently touching the steering wheel or not is information that is essential or at least useful for various safety and driver assistance systems.
- devices are known to date in which capacitive or resistive sensors are integrated into the steering wheel.
- DE 10 2014 016 422 A1 discloses a device and a method for detecting steering wheel contact which are based on the fact that a first electrode arranged in the steering wheel forms a sensor capacitor together with the human body functioning as a second electrode and an intermediate dielectric.
- An evaluation circuit having a charged reference capacitor of a known capacitance can be connected in parallel to said sensor capacitor such that part of the charge of the reference capacitor is transferred to the sensor capacitor.
- the determination of the change in capacitance of the sensor capacitor required for detection is carried out while taking into account the known capacitance of the reference capacitor and the measured voltage on the reference capacitor before and after the parallel connection of the evaluation circuit. If a plurality of first electrodes, which are distributed over the steering wheel rim and are electrically isolated from one another, are provided, conclusions may be drawn about the specific point of steering wheel contact.
- the object of the invention is to be able to precisely detect the position of contact with a steering or control device using simple means.
- the method according to the invention for detecting contact with a manually activated steering or control device, in particular a vehicle steering wheel comprises the following steps:
- determining should include measuring, calculating, otherwise determining or knowing a variable.
- the invention is based on the knowledge that there are already established, effective methods for detecting a change in capacitance in capacitive measurement technology.
- a first basic method is based on the change in the capacitive coupling of a sensor structure with respect to a reference electrode as a result of an action.
- a second basic method is based on the change in the capacitive coupling of a sensor structure with respect to the environment as a result of an action.
- the invention extends these methods by including a significant resistance of a conductor line of the conductor arrangement.
- at least one conductor line of the conductor arrangement has an appreciable ohmic resistance in comparison to, for example, a conventional copper wire line.
- an evaluable RC element is formed that can be changed by an action such as manual contact.
- the total resistance (impedance) of the conductor arrangement is determined by measuring the current profile.
- the term “alternating voltage” is intended to include all voltage profiles based on oscillations, in particular sinusoidal, square, triangular and sawtooth oscillations, but also pulse voltages with successive voltage pulses. Because the total resistance of the conductor arrangement is made up of a real component that is determined by the ohmic resistance of the conductor line, and a virtual component that is determined by the capacitance that develops between another conductor line (reference electrode) or the environment, the position of the contact of the steering or control device can be inferred from the phase angle.
- a skillful arrangement and design of the conductor arrangement not only enables precise position determination, but in principle movement patterns (gestures) may also be detected and analyzed. After a successful interpretation, a function assigned to the respective identified gesture may be triggered.
- the core of the invention lies in the evaluation of variables that are easy to measure or determine and, in comparison to other contact detection devices, only one line segment with significant ohmic resistance is required as the only special component aside from a few normal lines, the invention has the advantage that it is inexpensive overall and may be installed without great effort.
- the steps of the method according to the invention are preferably carried out continuously. That means that the steering or control device is continuously monitored without major breaks. This is a prerequisite for reliable detection of gestures.
- the evaluation of the determined values additionally comprises in particular at least one of the following steps:
- the method according to the invention may be used to trigger certain functions as a function of the evaluation.
- the invention also provides a device for carrying out the method according to the invention.
- the device comprises a steering or control device, in particular a vehicle steering wheel, a conductor arrangement which is arranged on the steering or control device and has at least one conductor line with a significant ohmic resistance, and a control and evaluation device arranged in the vicinity.
- the control and evaluation device is configured to apply an alternating voltage to the conductor arrangement, to measure the current profile in the conductor arrangement and to evaluate the determined values.
- this control and evaluation device is networked with the vehicle, in particular with a higher-order control unit of the on-board electronics.
- an “alternating voltage” should again generally be understood as a voltage profile based on oscillations, in particular a sinusoidal, square, triangular, sawtooth oscillation, but also a pulse voltage with successive voltage pulses.
- the provision of a plurality of conductor arrangements distributed over the steering or control device enables, on the one hand, greater reliability and/or accuracy (resolution) when it comes to contact detection. On the other hand, this also enables the detection of multi-touch inputs, similar to a touch-sensitive display.
- the conductor arrangement provided according to the invention is preferably arranged below a surface of the steering or control device. In the case of a vehicle steering wheel, this would be, for example, below a casing of the steering wheel rim. In principle, the conductor arrangement should be placed as close as possible to the surface to ensure high sensitivity.
- the conductor arrangement has two substantially parallel electrical conductors, of which at least one has a significant ohmic resistance which is significantly higher compared to a copper wire, preferably within a range of 10 ⁇ /m to 1 ⁇ /m.
- the capacitive coupling of the two conductors changes in the presence of a hand. Thanks to the inclusion of the determined total resistance, the position of the hand may then be determined.
- the electrical conductors should each be insulated to prevent undesired coupling with neighboring components or interference.
- the conductor arrangement has a plurality of sensor fields in the form of electrically conductive surfaces or regions and connected in series by electrical conductors, the electrical conductors having a significant ohmic resistance between the sensor surfaces or regions.
- the conductor arrangement is thus formed by a series of resistors and conductor surfaces or regions arranged in a row.
- a characteristic RC element is created, the behavior of which may be evaluated by the control and evaluation device in such a way that the position of the hand may be determined.
- the reliability and accuracy of the contact detection may be optimized through the number, shape, size and arrangement of the sensor fields or regions.
- a skillful arrangement and design of the conductor arrangement is preferred such that as few sensor surfaces or regions as possible have to be installed and as few cables or conductor tracks as possible have to be laid.
- the conductor line has one or more elongated electrical conductors with a significant ohmic resistance which is or are laid in a specific manner such that RC elements are formed which can be evaluated in sequence.
- control and evaluation device in such a way that certain functions can be triggered as a function of the evaluation.
- the device serves as a complex command input device with which the operator may selectively call up certain functions.
- FIG. 1 shows a first embodiment of a conductor arrangement for a device according to the invention for detecting contact with a manually activated steering or control device;
- FIG. 2 shows a second embodiment of a conductor arrangement for a device according to the invention for detecting contact with a manually activated steering or control device;
- FIG. 3 shows a third embodiment of a conductor arrangement for a device according to the invention for detecting contact with a manually activated steering or control device
- FIG. 4 shows a fourth embodiment of a conductor arrangement for a device according to the invention for detecting contact with a manually activated steering or control device.
- a first conductor arrangement 10 having two parallel electrical conductors 12 , 14 is arranged in the rim of the steering wheel, as shown symbolically in FIG. 1 . More specifically, the conductor arrangement 10 is arranged under a decorative surface of the steering wheel, for example under a leather covering.
- the conductor arrangement runs along the entire circumference or at least a substantial part of the steering wheel rim.
- a plurality of such conductor arrangements 10 are provided, each of which is arranged in a partial region of the steering wheel rim.
- a plurality of conductor arrangements 10 may be distributed over the toroidal circumference of the steering wheel rim.
- the two conductors 12 , 14 are provided with insulation, i.e. they are insulated from each other and from their environment.
- the two conductors 12 , 14 form a capacitance with respect to one another.
- the capacitance C would be calculated as follows:
- a special feature of the first conductor arrangement 10 provided for the device described here is that at least one line segment, i.e. at least one of the two conductors 12 , 14 has a significant ohmic resistance compared to a copper wire, in particular within a range of 10 ⁇ /m to 1 ⁇ /m.
- the total ohmic resistance or the specific resistance of the conductors 12 , 14 is known to a control and evaluation device.
- the total resistance consists of a real component and a virtual component.
- the real component is determined by the resistive conductor 12 or 14 and the virtual component by the capacitance that develops between the conductors 12 , 14 .
- a certain phase angle is set for the total resistance.
- both contact per se and movement patterns may be recognized in this way.
- the control and evaluation device may interpret certain gestures and trigger functions that are assigned to the gestures.
- a plurality of separate conductor arrangements 10 are distributed over the steering wheel, a plurality of simultaneous steering wheel contacts (two hands on the steering wheel) may be distinguished.
- the arrangement of the conductor arrangement(s) 10 is not limited to the steering wheel rim, but can also extend to the spokes and the central part of the steering wheel.
- any course of the parallel conductors 12 , 14 that is advantageous for the evaluation may be provided, for example a regular or irregular meandering course.
- FIG. 2 symbolically shows a second conductor arrangement 10 that is provided for a second embodiment of the device for detecting contact with a manually activated steering or control device.
- the second embodiment is also described below using the example of a vehicle steering wheel.
- the second conductor arrangement 10 consists substantially of a conductor line having a plurality of sensor fields 16 that are connected to one another in an electrically conductive manner.
- the sensor fields 16 are electrically conductive surfaces or regions that, for example may be formed from foils, conductive varnishes, wire meshes, wire mats or other wire structures. It is crucial for the sensor fields 16 to be electrically conductive and to be able to generate a significant capacitive field in relation to a hand.
- the electrical conductors 18 between the sensor fields 16 in turn have an ohmic resistance that is significantly higher than the resistance, for example, of a copper wire or the like.
- Either the conductors 16 themselves may be resistive, or electrical components 20 , conductor portions or the like with a significant ohmic resistance are connected in series.
- the second conductor arrangement 10 is also arranged under a decorative surface of the steering wheel, for example under a leather covering.
- the conductor arrangement 10 runs along the entire circumference or at least a substantial part of the steering wheel.
- a plurality of such conductor arrangements 10 are provided, each of which is arranged in a partial region of the steering wheel rim.
- a capacitance is formed or the capacitance (Gland) changes with respect to the capacitance between the conductor arrangement 10 and the environment without a hand in the immediate vicinity.
- the presence of the hand determines or changes the virtual component of the total resistance of the conductor arrangement 10 .
- a certain phase angle is set depending on the position of the hand. Similar to the first embodiment, if the applied alternating voltage is known, an evaluation in the control and evaluation device is possible by measuring the current profile, which allows a precise conclusion to be drawn about the position of the hand on the steering wheel.
- the accuracy of the position determination (resolution) in the second embodiment depends in particular on the number, shape, size and arrangement of the sensor fields 16 .
- the sensor fields 16 may be generated and sampled (measured) not only capacitively, but also inductively, resistively, digitally (switch), magnetically and optically. Combinations are also possible, such as capacitive-resistive sensor fields 16 .
- the sampling of the sensor fields 16 may take place sequentially or in parallel, it being possible for the sensor fields 16 to be sampled individually or in groups.
- FIGS. 3 and 4 symbolically show two further conductor arrangements 10 that are provided for a third or fourth embodiment of the device for detecting contact with a manually activated steering or control device.
- the sensor fields 16 are formed by elongated electrical conductors 18 that are tightly curved or twisted in certain regions or have some other very strongly curved course that deviates significantly from a straight course. Because the electrical conductors 18 have such a specific course, the sensor surfaces 16 , together with the intermediate (straight) conductor portions that have a significant ohmic resistance and/or with interposed components 20 (electrical resistance elements or the like), form individual RC elements. Said RC elements are evaluated in sequence.
- the conductor arrangement 10 shown in FIG. 4 largely corresponds to that of FIG. 3 . However, no resistors in the form of components or the like are inserted between the sensor fields 16 . Instead, when the measured current profile is evaluated in the control and evaluation device, the known total resistance R of the electrical conductor 18 is taken into account.
- the invention was explained using the example of a vehicle steering wheel, but is not restricted to this application.
- the contact detection according to the invention may in principle be used with any manually activated steering or control devices of motor vehicles, trains, machines, etc.
Abstract
A method for detecting contact with a manually activated steering or control device, in particular a vehicle steering wheel, comprises the following steps: applying an alternating voltage to at least one conductor arrangement (10) which is arranged on the steering or control device, and has at least one conductor line with a significant ohmic resistance; determining the current profile in the conductor arrangement (10); determining the real component and the virtual component of the instantaneous alternating current resistance of the conductor arrangement (10); determining the capacitance or the change in capacitance of the conductor arrangement (10); determining the phase shift; and evaluating the determined values. A device for carrying out the method comprises a steering or control device, in particular a vehicle steering wheel, a conductor arrangement (10) which is arranged on the steering or control device and which has at least one conductor line with a significant ohmic resistance, and a control and evaluation device which is configured to apply an alternating voltage to the conductor arrangement (10), to measure the current profile in the conductor arrangement (10) and to evaluate the determined values.
Description
- This application is a continuation of U.S. patent application Ser. No. 17/059,608 filed Nov. 30, 2020, which corresponds to PCT/EP2019/064603, filed Jun. 5, 2019, which claims the benefit of German Application No. 10 2018 113 879.2, filed Jun. 11, 2018, the subject matter of which are incorporated herein by reference in their entirety.
- The invention relates to a method for detecting contact with a manually activated steering or control device, in particular a vehicle steering wheel. The invention also relates to a device for carrying out the method.
- Knowing whether the driver of a vehicle is currently touching the steering wheel or not is information that is essential or at least useful for various safety and driver assistance systems. In principle, there are various technical options for detecting steering wheel contact. In particular, devices are known to date in which capacitive or resistive sensors are integrated into the steering wheel.
- For certain demanding applications, however, it is necessary, beyond mere contact detection, to locate the contact, i.e. not only a steering wheel contact per se, but also the location of the contact on the steering wheel must be determined. However, such a location determination is technically difficult to implement. Additional lines and components are usually required for this, and the installation effort increases considerably.
- DE 10 2014 016 422 A1 discloses a device and a method for detecting steering wheel contact which are based on the fact that a first electrode arranged in the steering wheel forms a sensor capacitor together with the human body functioning as a second electrode and an intermediate dielectric. An evaluation circuit having a charged reference capacitor of a known capacitance can be connected in parallel to said sensor capacitor such that part of the charge of the reference capacitor is transferred to the sensor capacitor. The determination of the change in capacitance of the sensor capacitor required for detection is carried out while taking into account the known capacitance of the reference capacitor and the measured voltage on the reference capacitor before and after the parallel connection of the evaluation circuit. If a plurality of first electrodes, which are distributed over the steering wheel rim and are electrically isolated from one another, are provided, conclusions may be drawn about the specific point of steering wheel contact.
- The object of the invention is to be able to precisely detect the position of contact with a steering or control device using simple means.
- This object is achieved by a method for detecting contact with a manually activated steering or control device having the features of claim 1 and by a device for carrying out the method having the features of claim 5. Advantageous and expedient embodiments of the method according to the invention and the device according to the invention are specified in the associated subclaims.
- The method according to the invention for detecting contact with a manually activated steering or control device, in particular a vehicle steering wheel, comprises the following steps:
-
- applying an alternating voltage to at least one conductor arrangement which is arranged on the steering or control device, and has at least one conductor line with a significant ohmic resistance;
- determining the current profile in the conductor arrangement;
- determining the real component and the virtual component of the alternating current resistance of the conductor arrangement;
- determining the capacitance or the change in capacitance of the conductor arrangement;
- determining the phase shift (phase angle); and
- evaluating the determined values.
- In general, “determining” should include measuring, calculating, otherwise determining or knowing a variable.
- The invention is based on the knowledge that there are already established, effective methods for detecting a change in capacitance in capacitive measurement technology. A first basic method is based on the change in the capacitive coupling of a sensor structure with respect to a reference electrode as a result of an action. A second basic method is based on the change in the capacitive coupling of a sensor structure with respect to the environment as a result of an action. The invention extends these methods by including a significant resistance of a conductor line of the conductor arrangement. According to the invention, at least one conductor line of the conductor arrangement has an appreciable ohmic resistance in comparison to, for example, a conventional copper wire line. In this way, an evaluable RC element is formed that can be changed by an action such as manual contact. If the applied alternating voltage is known, the total resistance (impedance) of the conductor arrangement is determined by measuring the current profile. The term “alternating voltage” is intended to include all voltage profiles based on oscillations, in particular sinusoidal, square, triangular and sawtooth oscillations, but also pulse voltages with successive voltage pulses. Because the total resistance of the conductor arrangement is made up of a real component that is determined by the ohmic resistance of the conductor line, and a virtual component that is determined by the capacitance that develops between another conductor line (reference electrode) or the environment, the position of the contact of the steering or control device can be inferred from the phase angle.
- A skillful arrangement and design of the conductor arrangement not only enables precise position determination, but in principle movement patterns (gestures) may also be detected and analyzed. After a successful interpretation, a function assigned to the respective identified gesture may be triggered.
- Because the core of the invention lies in the evaluation of variables that are easy to measure or determine and, in comparison to other contact detection devices, only one line segment with significant ohmic resistance is required as the only special component aside from a few normal lines, the invention has the advantage that it is inexpensive overall and may be installed without great effort.
- The steps of the method according to the invention are preferably carried out continuously. That means that the steering or control device is continuously monitored without major breaks. This is a prerequisite for reliable detection of gestures.
- In the method according to the invention, the evaluation of the determined values additionally comprises in particular at least one of the following steps:
-
- detecting whether the steering or control device is contacted over a large area;
- detecting whether the steering or control device is contacted at certain points;
- grip detection (type of grip);
- detecting the number of simultaneous contacts;
- locating the positions of a plurality of contacts;
- determining the duration of a contact;
- identifying gestures.
- The more of these steps that are carried out, the more versatile the method according to the invention is.
- Thanks to the possibility of a versatile evaluation of the determined values, the method according to the invention may be used to trigger certain functions as a function of the evaluation.
- The invention also provides a device for carrying out the method according to the invention. The device comprises a steering or control device, in particular a vehicle steering wheel, a conductor arrangement which is arranged on the steering or control device and has at least one conductor line with a significant ohmic resistance, and a control and evaluation device arranged in the vicinity. The control and evaluation device is configured to apply an alternating voltage to the conductor arrangement, to measure the current profile in the conductor arrangement and to evaluate the determined values. Furthermore, this control and evaluation device is networked with the vehicle, in particular with a higher-order control unit of the on-board electronics.
- In this case, an “alternating voltage” should again generally be understood as a voltage profile based on oscillations, in particular a sinusoidal, square, triangular, sawtooth oscillation, but also a pulse voltage with successive voltage pulses.
- The provision of a plurality of conductor arrangements distributed over the steering or control device enables, on the one hand, greater reliability and/or accuracy (resolution) when it comes to contact detection. On the other hand, this also enables the detection of multi-touch inputs, similar to a touch-sensitive display.
- The conductor arrangement provided according to the invention is preferably arranged below a surface of the steering or control device. In the case of a vehicle steering wheel, this would be, for example, below a casing of the steering wheel rim. In principle, the conductor arrangement should be placed as close as possible to the surface to ensure high sensitivity.
- According to a first preferred embodiment of the device according to the invention, the conductor arrangement has two substantially parallel electrical conductors, of which at least one has a significant ohmic resistance which is significantly higher compared to a copper wire, preferably within a range of 10 Ω/m to 1 Ω/m. In this embodiment, the capacitive coupling of the two conductors changes in the presence of a hand. Thanks to the inclusion of the determined total resistance, the position of the hand may then be determined.
- The electrical conductors should each be insulated to prevent undesired coupling with neighboring components or interference.
- According to a second preferred embodiment of the device according to the invention, the conductor arrangement has a plurality of sensor fields in the form of electrically conductive surfaces or regions and connected in series by electrical conductors, the electrical conductors having a significant ohmic resistance between the sensor surfaces or regions. The conductor arrangement is thus formed by a series of resistors and conductor surfaces or regions arranged in a row. In combination with a hand, a characteristic RC element is created, the behavior of which may be evaluated by the control and evaluation device in such a way that the position of the hand may be determined. The reliability and accuracy of the contact detection may be optimized through the number, shape, size and arrangement of the sensor fields or regions. In order to keep the costs for the device low, a skillful arrangement and design of the conductor arrangement is preferred such that as few sensor surfaces or regions as possible have to be installed and as few cables or conductor tracks as possible have to be laid.
- According to another preferred aspect of the invention, the conductor line has one or more elongated electrical conductors with a significant ohmic resistance which is or are laid in a specific manner such that RC elements are formed which can be evaluated in sequence.
- In general, thanks to the versatile evaluation options already mentioned, it is possible to configure the control and evaluation device in such a way that certain functions can be triggered as a function of the evaluation. In this case, the device serves as a complex command input device with which the operator may selectively call up certain functions.
- Further features and advantages of the invention will become apparent from the following description and from the accompanying drawings, to which reference is made. In the drawings:
-
FIG. 1 shows a first embodiment of a conductor arrangement for a device according to the invention for detecting contact with a manually activated steering or control device; -
FIG. 2 shows a second embodiment of a conductor arrangement for a device according to the invention for detecting contact with a manually activated steering or control device; -
FIG. 3 shows a third embodiment of a conductor arrangement for a device according to the invention for detecting contact with a manually activated steering or control device; and -
FIG. 4 shows a fourth embodiment of a conductor arrangement for a device according to the invention for detecting contact with a manually activated steering or control device. - In the following, a device for detecting contact with a manually activated steering or control device is described using the example of a vehicle steering wheel.
- According to a first embodiment of the device, a
first conductor arrangement 10 having two parallelelectrical conductors FIG. 1 . More specifically, theconductor arrangement 10 is arranged under a decorative surface of the steering wheel, for example under a leather covering. - The conductor arrangement runs along the entire circumference or at least a substantial part of the steering wheel rim. Alternatively, a plurality of
such conductor arrangements 10 are provided, each of which is arranged in a partial region of the steering wheel rim. In addition, a plurality ofconductor arrangements 10 may be distributed over the toroidal circumference of the steering wheel rim. - The two
conductors - The two
conductors -
-
- where ε: dielectric constant between the conductors
- l: length of the conductors
- d: distance between the conductor central axes
- R: radius of the conductor cross sections
- A special feature of the
first conductor arrangement 10 provided for the device described here is that at least one line segment, i.e. at least one of the twoconductors conductors - If an alternating voltage, i.e. a voltage having a profile based on an oscillation (such as a sinusoidal, square, triangular, or sawtooth oscillation) or a pulse voltage having successive voltage pulses is applied to the
conductor arrangement 10, the total resistance consists of a real component and a virtual component. The real component is determined by theresistive conductor conductors - If a hand comes very close to the conductors, as is the case when contacting the steering wheel rim, the capacitance of the conductor arrangement changes significantly (Chand). This means that the virtual component of the total resistance changes and, as a result, so does the phase angle. If the alternating voltage is known, this detuning may be recognized and registered by measuring the current profile. In addition, a precise conclusion about the position of the hand on the steering wheel may be drawn in the control and evaluation device based on the change in the real component and the virtual component or the change in the phase angle.
- In the context of permanent monitoring by the control and evaluation device, both contact per se and movement patterns (gestures) may be recognized in this way. The control and evaluation device may interpret certain gestures and trigger functions that are assigned to the gestures.
- If a plurality of
separate conductor arrangements 10 are distributed over the steering wheel, a plurality of simultaneous steering wheel contacts (two hands on the steering wheel) may be distinguished. - The arrangement of the conductor arrangement(s) 10 is not limited to the steering wheel rim, but can also extend to the spokes and the central part of the steering wheel. In addition, any course of the
parallel conductors -
FIG. 2 symbolically shows asecond conductor arrangement 10 that is provided for a second embodiment of the device for detecting contact with a manually activated steering or control device. The second embodiment is also described below using the example of a vehicle steering wheel. - The
second conductor arrangement 10 consists substantially of a conductor line having a plurality ofsensor fields 16 that are connected to one another in an electrically conductive manner. The sensor fields 16 are electrically conductive surfaces or regions that, for example may be formed from foils, conductive varnishes, wire meshes, wire mats or other wire structures. It is crucial for the sensor fields 16 to be electrically conductive and to be able to generate a significant capacitive field in relation to a hand. - The
electrical conductors 18 between the sensor fields 16 in turn have an ohmic resistance that is significantly higher than the resistance, for example, of a copper wire or the like. Either theconductors 16 themselves may be resistive, orelectrical components 20, conductor portions or the like with a significant ohmic resistance are connected in series. - As in the first embodiment, the
second conductor arrangement 10 is also arranged under a decorative surface of the steering wheel, for example under a leather covering. Theconductor arrangement 10 runs along the entire circumference or at least a substantial part of the steering wheel. Alternatively, a plurality ofsuch conductor arrangements 10 are provided, each of which is arranged in a partial region of the steering wheel rim. - If a hand comes very close to a sensor field of the
second conductor arrangement 10, as is the case when the steering wheel rim is contacted, a capacitance is formed or the capacitance (Gland) changes with respect to the capacitance between theconductor arrangement 10 and the environment without a hand in the immediate vicinity. The presence of the hand in turn determines or changes the virtual component of the total resistance of theconductor arrangement 10. A certain phase angle is set depending on the position of the hand. Similar to the first embodiment, if the applied alternating voltage is known, an evaluation in the control and evaluation device is possible by measuring the current profile, which allows a precise conclusion to be drawn about the position of the hand on the steering wheel. - The accuracy of the position determination (resolution) in the second embodiment depends in particular on the number, shape, size and arrangement of the sensor fields 16.
- In principle, the same applies to the second embodiment with regard to the arrangement of the second conductor arrangement 10 (steering wheel rim, steering wheel spokes, steering wheel center part), to the provision and distribution of a plurality of
second conductor arrangements 10 and to gesture detection as in the first embodiment. - The sensor fields 16 may be generated and sampled (measured) not only capacitively, but also inductively, resistively, digitally (switch), magnetically and optically. Combinations are also possible, such as capacitive-resistive sensor fields 16.
- The sampling of the sensor fields 16 may take place sequentially or in parallel, it being possible for the sensor fields 16 to be sampled individually or in groups.
-
FIGS. 3 and 4 symbolically show twofurther conductor arrangements 10 that are provided for a third or fourth embodiment of the device for detecting contact with a manually activated steering or control device. - In the
conductor arrangement 10 shown inFIG. 3 , the sensor fields 16 are formed by elongatedelectrical conductors 18 that are tightly curved or twisted in certain regions or have some other very strongly curved course that deviates significantly from a straight course. Because theelectrical conductors 18 have such a specific course, the sensor surfaces 16, together with the intermediate (straight) conductor portions that have a significant ohmic resistance and/or with interposed components 20 (electrical resistance elements or the like), form individual RC elements. Said RC elements are evaluated in sequence. - The
conductor arrangement 10 shown inFIG. 4 largely corresponds to that ofFIG. 3 . However, no resistors in the form of components or the like are inserted between the sensor fields 16. Instead, when the measured current profile is evaluated in the control and evaluation device, the known total resistance R of theelectrical conductor 18 is taken into account. - With all embodiments, it is possible to distinguish between different types of contact, such as prolonged contact at a localizable point, knocking movements, stroking movements (including the direction), etc. by means of a suitable evaluation algorithm. This makes it possible to carry out functions that go beyond the detection of steering wheel contact per se in the context of safety and driver assistance systems and possibly the knowledge of whether the steering wheel is being gripped safely. In particular, grip detection is possible, i.e. the type of grip with which the driver grips or grasps the steering wheel may be recognized.
- The most important differentiation possibilities and some of the functions that are introduced with them (assuming suitable placement and design of the conductor arrangements 10) are listed again as examples below:
-
- generally recognizing whether the steering wheel is fully grasped manually or whether the steering wheel is only touched selectively with a finger, etc.;
- detecting a contact at certain points (e.g. knocking) interpretation as a keystroke;
- detecting the positions of contacts at certain points interpretation as different keystrokes;
- detecting the number of simultaneous contacts conclusion about one-handed or two-handed steering wheel contact and/or multi-touch inputs;
- detecting the duration of a certain contact use for stepless setting of parameters;
- detecting certain gestures triggering assigned functions such as setting turn signals (left, right), turning on windshield wipers, radio control, in general within applications: “forward,” “back” etc.
- The two embodiments described or certain aspects thereof can of course also be combined with one another.
- The invention was explained using the example of a vehicle steering wheel, but is not restricted to this application. The contact detection according to the invention may in principle be used with any manually activated steering or control devices of motor vehicles, trains, machines, etc.
Claims (3)
1. A device for detecting contact with a manually activated steering wheel of a vehicle, the device comprising:
the steering wheel;
a conductor arrangement (10) which is arranged on the steering wheel, the conductor arrangement (10) having two substantially parallel electrical conductor lines (12, 14) extending on the steering wheel, a first one of the two parallel electrical conductor lines (12, 14) having a significant ohmic resistance that is significantly higher compared to a copper wire and within a range of 10 Ω/m to 1 Ω/m, a second one of the two parallel electrical conductor lines (12, 14) having an ohmic resistance that is equal to or lower than that of a copper wire, the two electrical conductor lines (12, 14) forming a capacitance with respect to one another that changes when the steering wheel is contacted; and
a control unit which is configured
to apply an alternating voltage to the conductor arrangement (10),
to determine the capacitance or the change in the capacitance;
to determine a current in the conductor arrangement (10), and
to evaluate the determined values.
2. The device according to claim 1 , wherein the electrical conductor lines (12, 14) are each insulated.
3. A method for detecting contact with a manually activated steering wheel of a vehicle, the method comprising:
providing the device according to claim 1 ;
applying an alternating voltage to the conductor arrangement (10);
determining a current in the conductor arrangement (10);
determining a real component and an imaginary component of a resistance of the conductor arrangement (10);
determining a capacitance or a change in capacitance of the conductor arrangement (10);
determining a phase shift; and
evaluating the determined values.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US18/376,557 US20240030914A1 (en) | 2018-06-11 | 2023-10-04 | Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
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DE102018113879.2 | 2018-06-11 | ||
DE102018113879.2A DE102018113879A1 (en) | 2018-06-11 | 2018-06-11 | Method for detecting a touch of a hand-operated steering device, in particular a vehicle steering wheel, and device for carrying out the method |
PCT/EP2019/064603 WO2019238486A1 (en) | 2018-06-11 | 2019-06-05 | Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method |
US202017059608A | 2020-11-30 | 2020-11-30 | |
US18/376,557 US20240030914A1 (en) | 2018-06-11 | 2023-10-04 | Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method |
Related Parent Applications (2)
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PCT/EP2019/064603 Continuation WO2019238486A1 (en) | 2018-06-11 | 2019-06-05 | Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method |
US17/059,608 Continuation US11894841B2 (en) | 2018-06-11 | 2019-06-05 | Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method |
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US20240030914A1 true US20240030914A1 (en) | 2024-01-25 |
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US17/059,608 Active US11894841B2 (en) | 2018-06-11 | 2019-06-05 | Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method |
US18/376,557 Pending US20240030914A1 (en) | 2018-06-11 | 2023-10-04 | Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method |
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US17/059,608 Active US11894841B2 (en) | 2018-06-11 | 2019-06-05 | Method for detecting contact with a manually activated steering device, in particular a vehicle steering wheel, and a device for carrying out the method |
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EP (1) | EP3802274B1 (en) |
CN (1) | CN112236350A (en) |
DE (1) | DE102018113879A1 (en) |
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DE10113661A1 (en) * | 2001-03-21 | 2002-09-26 | Philips Corp Intellectual Pty | Catheter for magnetic resonance imaging has an excitation transmitter at its distal end which excites vibration within the area surrounding it that is readily imaged by the MR imaging device |
CN1767784A (en) | 2003-04-03 | 2006-05-03 | 日本先锋公司 | Living body information detecting device, contact member used therefor, and living body information detecting member-use paint |
TW201008118A (en) | 2008-04-10 | 2010-02-16 | Atmel Corp | Capacitive touch screen with noise suppression |
DE102009055424A1 (en) * | 2009-12-30 | 2011-07-07 | Takata-Petri Ag, 63743 | Capacitive sensor module |
DE102009055426A1 (en) * | 2009-12-30 | 2011-07-07 | Takata-Petri Ag, 63743 | Capacitive sensor module |
JP2012195290A (en) * | 2011-03-02 | 2012-10-11 | Hitachi Cable Ltd | Insulated wire |
CN107054374B (en) * | 2011-06-22 | 2019-10-18 | Tk控股公司 | The sensing system of steering wheel for vehicle |
DE102011084903A1 (en) * | 2011-10-20 | 2013-04-25 | TAKATA Aktiengesellschaft | Sensor systems for a motor vehicle |
JP5447496B2 (en) * | 2011-12-19 | 2014-03-19 | 株式会社デンソー | Capacitive touch sensor controller |
US9346480B2 (en) * | 2012-11-30 | 2016-05-24 | Tk Holdings Inc. | Hand sensing on steering wheel using heater element |
US9248851B2 (en) * | 2013-02-13 | 2016-02-02 | Tk Holdings Inc. | Steering wheel hand detection systems |
JP2014190856A (en) * | 2013-03-27 | 2014-10-06 | Nidec Elesys Corp | Apparatus for detecting driver's letting go of steering wheel |
WO2014184743A1 (en) * | 2013-05-15 | 2014-11-20 | Gentherm Canada Ltd. | Conductive heater having sensing capabilities |
WO2015187647A1 (en) * | 2014-06-02 | 2015-12-10 | Tk Holdings Inc. | Systems and methods for printing sensor circuits on a sensor mat for a steering wheel |
DE102014016422A1 (en) | 2014-11-07 | 2016-05-12 | Trw Automotive Safety Systems Gmbh | Device and method for detecting a steering wheel touch |
DE102015216095B4 (en) * | 2015-08-24 | 2023-08-03 | Joyson Safety Systems Germany Gmbh | Method and device for determining a system status of an electronic measuring system |
US10293783B2 (en) * | 2016-05-19 | 2019-05-21 | Ford Global Technologies, Llc | Driver detection steering wheel |
US10302794B2 (en) * | 2016-10-17 | 2019-05-28 | Joyson Safety Systems Japan K. K. | Detection system for detecting a person on a seat |
LU100490B1 (en) * | 2017-10-19 | 2019-04-25 | Iee Sa | Capacitive Sensor System |
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EP3802274A1 (en) | 2021-04-14 |
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US11894841B2 (en) | 2024-02-06 |
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