STEERING WHEEL WITH ADAPTIVE-CAPACITIVE TOUCH RECOGNITION, AN ASSOCIATED ASSEMBLY AND MOTOR VEHICLE

Abstract

A steering wheel for a motor vehicle is presented. The steering wheel includes a steering wheel hub configured for the detachable attachment to a steering shaft of the motor vehicle; a steering wheel rim fixed to the steering wheel hub; at least one electrode, which is integrated into the steering wheel rim, for the capacitive detection of a touch on the steering wheel rim; an electrically conductive connection disposed outside the steering wheel to apply an electrical measuring potential for touch detection to the electrode, and to detect the touch on the steering wheel rim; a non-volatile data storage unit on or in the steering wheel, wherein the non-volatile data storage unit is in each case configured or developed to be read out by a reading unit disposed outside the steering wheel and connected to the electronic evaluation unit in a data-transmitting manner.

Claims

1. A steering wheel for a motor vehicle, comprising: a steering wheel hub configured as a detachable attachment to a steering shaft of the motor vehicle; a steering wheel rim fixed to the steering wheel hub; at least one electrode, which is integrated into the steering wheel rim, wherein the at least one electrode is configured for a capacitive detection of a touch on the steering wheel rim; an electrically conductive connection between the at least one electrode and an electronic evaluation unit disposed outside the steering wheel, to apply an electrical measuring potential for touch detection to the at least one electrode via the electrically conductive connection, and to detect, based on an associated change in measuring capacitance, the touch on the steering wheel rim, depending on at least one predetermined parameter; a non-volatile data storage unit, which is disposed on or in the steering wheel and in which the at least one predetermined parameter is stored; a reading unit, which is disposed outside the steering wheel, is connected in a data-transmitting manner to the electronic evaluation unit, and which is configured for reading out the non-volatile data storage unit and transmit the at least one predetermined parameter to the electronic evaluation unit.

2. The steering wheel according to claim 1, wherein the at least one electrode and the non-volatile data storage unit are disposed on a common substrate.

3. The steering wheel according to claim 2, wherein the common substrate is any one of: a film and a fabric.

4. The steering wheel according to claim 1, wherein the at least one electrode is formed by a heating wire of a steering wheel heating.

5. The steering wheel according to claim 1, wherein the non-volatile data storage unit is wirelessly read out by the reading unit via a transponder disposed on the steering wheel.

6. The steering wheel according to claim 5, wherein the transponder is disposed on the common substrate.

7. The steering wheel according to claim 5, wherein the transponder and the non-volatile data storage unit are disposed in the steering wheel rim.

8. The steering wheel according to claim 1, wherein the steering wheel is included in an assembly, wherein the assembly further comprises an electronic evaluation unit disposed outside the steering wheel and a reading unit disposed outside the steering wheel.

9. The steering wheel according to claim 8, wherein a motor vehicle comprises the assembly.

10. An assembly, comprising: a steering wheel hub configured as a detachable attachment to a steering shaft of the motor vehicle; a steering wheel rim fixed to the steering wheel hub; at least one electrode, which is integrated into the steering wheel rim, wherein the at least one electrode is configured for a capacitive detection of a touch on the steering wheel rim; an electrically conductive connection between the at least one electrode and an electronic evaluation unit disposed outside the steering wheel, to apply an electrical measuring potential for touch detection to the at least one electrode via the electrically conductive connection, and to detect, based on an associated change in measuring capacitance, the touch on the steering wheel rim, depending on at least one predetermined parameter; a non-volatile data storage unit, which is disposed on or in the steering wheel and in which the at least one predetermined parameter is stored; a reading unit, which is disposed outside the steering wheel, is connected in a data-transmitting manner to the electronic evaluation unit, and which is configured for reading out the non-volatile data storage unit and transmit the at least one predetermined parameter to the electronic evaluation unit; an electronic evaluation unit disposed outside the steering wheel; and a reading unit disposed outside the steering wheel.

11. A motor vehicle, comprising: an assembly, wherein the assembly further comprises: a steering wheel hub configured as a detachable attachment to a steering shaft of the motor vehicle; a steering wheel rim fixed to the steering wheel hub; at least one electrode, which is integrated into the steering wheel rim, wherein the at least one electrode is configured for a capacitive detection of a touch on the steering wheel rim; an electrically conductive connection between the at least one electrode and an electronic evaluation unit disposed outside the steering wheel, to apply an electrical measuring potential for touch detection to the at least one electrode via the electrically conductive connection, and to detect, based on an associated change in measuring capacitance, the touch on the steering wheel rim, depending on at least one predetermined parameter; a non-volatile data storage unit, which is disposed on or in the steering wheel and in which the at least one predetermined parameter is stored; a reading unit, which is disposed outside the steering wheel, is connected in a data-transmitting manner to the electronic evaluation unit, and which is configured for reading out the non-volatile data storage unit and transmit the at least one predetermined parameter to the electronic evaluation unit; an electronic evaluation unit disposed outside the steering wheel; and a reading unit disposed outside the steering wheel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The various disclosed embodiments explained in more detail with reference to the following Figure. The Figure is to be understood only as an example and merely represents a preferred embodiment. In the drawing:

[0013] FIG. 1 shows a schematic illustration of an embodiment of the assembly according to an embodiment.

DETAILED DESCRIPTION

[0014] FIG. 1 shows an embodiment of the assembly according to the embodiment. The assembly according to the embodiment comprises a steering wheel 1 and a reading unit 7 disposed outside the steering wheel 1 and an electronic evaluation unit 6 disposed outside the steering wheel 1. The reading unit 7 is connected in a data-transmitting manner to the electronic evaluation unit 6. A data line, which is not specified in any more detail, is provided in FIG. 1 for this purpose. However, this transmission may also be configured in a wireless manner.

[0015] The steering wheel 1 comprises a steering wheel hub 3 for the detachable attachment of the steering wheel 1 to a steering shaft 12 of a motor vehicle, which is not shown in any more detail. The steering wheel 1 further comprises an annular steering wheel rim 2, which is supported on the steering wheel hub 3 via several spokes 11. The surface of the steering wheel rim 2 serves as a grip surface for a motor vehicle operator, which is also referred to as a driver in short, to perform steering inputs. An electrode 4, which extends along the steering wheel rim 2 in the circumferential direction corresponding to the direction of rotation of the steering wheel 1, is disposed underneath the surface of the steering wheel rim 2, and thus integrated into the steering wheel rim 2. A measuring potential is applied to the electrode 4 by the electronic evaluation unit 6 via an electrically conductive connection 5. The electrically conductive connection 5 contains a slide contact provided in the region of the steering wheel hub 3, for example.

[0016] In this embodiment, the electrode 4 is formed by a heating wire of a steering wheel heating, which is not shown and which applies a pulse-width modulated heating current to the heating wire, while the electrode 4 is available for touch detection during the dead time of this heating current. Thus, a touch on the steering wheel rim 2 is detected by the electronic evaluation unit 6 based on an associated change in measuring capacitance and depending on a predetermined parameter. The function of the capacitive touch detection is based, for instance, on the change of the electrical field in the vicinity in front of the electrode 4, more specifically in the region of the surface of the steering wheel rim 2. For example, the electronic evaluation unit 6 includes an RC oscillator circuit. The capacitance between the electrode 4 and the electric ground potential is measured while the measuring potential is applied. As an alternative, a counter-electrode with an associated ground or counter-potential may also be provided instead of a ground potential. Due to a hand of the driver approaching the electrode 4, particularly when the steering wheel rim 2 is touched, the capacitance increases and thus affects the oscillation amplitude of the RC oscillator. This change causes a downstream trigger stage, which is associated with the electronic evaluation unit 6, to “tilt” and change its initial state, whereby a touch is positively detected, Generally, the sensitivity of the electronic evaluation unit 6 can be adjusted by selecting the switching distance, The switching distance of the capacitive touch detection varies with the permittivity constant and the conductivity of the approaching material, as well as with the effective surface of the approaching body compared with the electrode surface which, however, is the case only to a limited extent in the steering wheel situation. However, the switching distance is also dependent on the installation conditions, i.e. the materials of the steering wheel rim 2 surrounding the electrode 4, i.e. on whether the former includes genuine leather, imitation leather, wood or the Ike. For example, the switching distance is determined by a parameter associated with the permittivity of the material of the steering wheel rim 2 and/or a parameter associated with the geometry and the position of the electrode within the steering wheel rim 2.

[0017] Thus, according to the disclosed embodiments, there is also provided a non-volatile data storage unit 10, which is disposed on or in the steering wheel 1, here also in the steering wheel rim 2, and in which, in each case, at least one of the parameters, such as the parameter associated with the electric permittivity constant of the steering wheel rim material, for example, is stored. This non-volatile data storage unit 10 is read out by the reading unit 7, which is disposed outside the steering wheel 1 and connected in a data-transmitting manner to the electronic evaluation unit 6, in order to transmit the at least one parameter to the electronic evaluation unit 6, so that the latter is able, for example in the evaluation steps subsequent to the read-out, to carry out the detection in an adjusted manner using the stored and read-out parameter. In this embodiment, a wireless read-out of the non-volatile data storage unit 10 by means of a transponder 9 is provided, which is disposed on or in the steering wheel 1 and which is electrically conductively connected to the non-volatile data storage unit 10, and wherein the transponder 9 communicates wirelessly with the reading unit 7. For example, the wireless communication between the transponder 9 and the reading unit 7 makes use of Radio Frequency Identification (RFD) technology in an active or passive configuration, Near Field Communication (NFC) technology, Bluetooth® technology or WiFi technology. For example, the electrode 4, the non-volatile storage unit 10 and the transponder 9 are disposed on a common substrate, which is not shown in FIG. 1.