METHOD FOR CONTROLLING A HEATED STEERING HANDLE AND TOUCH DETECTION ON THE STEERING HANDLE AND STEERING HANDLE WITH HEATED STEERING AND TOUCH DETECTION

Description

[0001] The invention relates to a method for controlling the heating of a steering handle and for touch detection on the steering handle.

[0002] A variety of steering handles, such as steering wheels, are known from the prior art, in which a heating element or a touch detection element, or both, are integrated. Corresponding methods for controlling these elements are also known.

[0003] The heating of the steering handle is primarily a comfort function, intended to provide the operator with a pleasantly tempered control element.

[0004] In contrast, touch detection primarily serves to increase driving safety, as it aims to ensure that the driver is gripping the handle with at least one hand. Additionally, information about the touch or presence of the driver and / or hand can also be used by numerous other vehicle systems.

[0005] Such touch detection is particularly relevant in the context of automated driving or autonomous vehicles, where the driver is still required to grip the steering wheel for safety reasons. Alternatively, a touch could signal to the vehicle that the driver wishes to regain control. To provide both a heated steering wheel or heated steering grips and touch detection, current technology typically involves equipping the steering wheel with both a heating element and a separate touch detection sensor. However, this results in a space-consuming and costly design.

[0006] Furthermore, a combination of heating and touch detection and associated methods are known from both EP 2 028 078 A1 and DE 11 2018 005 213 T5. According to both variants, a sensor with several sensor lines is provided, one of which is also used as a heating wire, so that they are integrally formed.

[0007] However, the problem is that the control methods, or the methods for control using a sensor control circuit, must be coordinated with the heating system, or with the method for control using the heating control circuit, since the control of the sensor must not affect the heating system and the control of the heating system must not affect the sensor.

[0008] Accordingly, the evaluation of the sensor or the circuitry required for it, as well as the associated procedure, is complex, expensive and prone to errors.

[0009] Further state of the art in this field is given in particular by documents DE 10 2019 124 293 A1 and WO 2018 / 213 344 A1. Aspects of controlling the heating of a steering handle and touch detection on the steering handle are also described in document DE 10 2018 222551 A1.

[0010] The invention is therefore based on the objective of overcoming the aforementioned disadvantages and providing a simple method for controlling the heating of a steering handle as well as touch detection on the steering handle and a steering handle with integrated heating and touch detection, which can be implemented both cost-effectively and, in particular, simply with regard to the control.

[0011] This problem is solved by the combination of features according to claim 1.

[0012] According to the invention, a method for controlling the heating of a steering handle and for touch detection on the steering handle is proposed. The steering handle has at least one electrically conductive functional conductor as a heating wire for heating the steering handle, which is a sensor element of a sensor for touch detection on the steering handle. Furthermore, the steering handle has a control device electrically connected to at least one functional conductor, which includes a heating control circuit for heating the steering handle via the functional conductor and a sensor control circuit for touch detection on the steering handle via the functional conductor.

[0013] The procedure stipulates that where at least one functional conductor is electrically connected to the heating control circuit and simultaneously or previously disconnected from the sensor control circuit; where at least one functional conductor electrically connected to the heating control circuit is controlled by the heating control circuit to heat the steering handle; where at least one functional conductor is electrically connected to the sensor control circuit and simultaneously or previously disconnected from the heating control circuit; where at least one functional conductor electrically connected to the sensor control circuit is controlled by the sensor control circuit to detect a touch of the steering handle.

[0014] An advantageous further development of the method also provides that, after or before connecting the at least one functional conductor to the sensor control circuit, a higher-level control system or an operating interface queries whether touch detection is to be carried out by means of the sensor control circuit by controlling the at least one functional conductor, by which a touch of the steering handle can be detected.

[0015] Furthermore, it can be advantageously provided that, when the sensor control circuit detects contact with the steering handle, the configuration of the at least one functional conductor and the sensor control circuit is recorded as an actual value and compared with a target value. The target value can, for example, be stored in a memory unit of the control device. The actual value can, for example, be an ohmic resistance or a temperature of the at least one functional conductor.

[0016] According to the invention, it is provided that when the sensor control circuit detects a touch of the steering handle, a change in a capacitive field detected by the at least one functional conductor is evaluated by the sensor control circuit, and that when the sensor control circuit detects a touch of the steering handle, a change in the impedance of at least one functional conductor is detected and evaluated by the sensor control circuit.

[0017] Another advantageous refinement of the method provides that when connecting at least one functional conductor to the sensor control circuit, several functional conductors are connected to the sensor control circuit, so that the functional conductors together with the sensor control circuit form multiple sensors. Alternatively or additionally, multiple sensor control circuits can be provided, and when connecting at least one functional conductor to the sensor control circuit, one or more functional conductors can be connected to each sensor control circuit, so that the functional conductors together with the sensor control circuits form multiple sensors.

[0018] If multiple sensors are present, it is preferably provided that, when at least one functional conductor is activated to detect a touch of the steering handle, each sensor is queried to determine whether a touch of the steering handle has been detected. Furthermore, it can also be checked whether each sensor has been queried.

[0019] According to the invention, when detecting a change in the impedance of at least one functional conductor, it is also verified whether this change is due to contact with the steering handle. When detecting a change in the capacitive field of at least one functional conductor, it is additionally verified whether this change is due to contact with the steering handle. This verification can be achieved, for example, by requiring the capacitive change or the change in impedance to follow a predetermined profile, which may be stored in the control device. Minimum and maximum values ​​for the change in the capacitive field or impedance can also be used for this verification.

[0020] Furthermore, another advantageous variant of the method can provide that, before or after connecting at least one functional conductor to the heating control circuit, a query is performed to determine whether the heating control circuit should activate the at least one functional conductor to heat the steering handle. This query can also be performed, for example, via a higher-level control system to which the control device is connected via a signal connection. Alternatively, an operator interface can also be queried.

[0021] Furthermore, it may be provided that, when the steering handle is heated, at least one functional conductor is controlled by the heating control circuit, a target value for the temperature of the steering handle is queried and / or an actual value of the temperature of the steering handle is recorded and compared with the target value.

[0022] Another aspect, not part of the invention, relates to a steering handle with heating and touch detection for a vehicle. The steering handle can be a steering wheel, a steering rod, a control stick, or a steering yoke. The steering handle has a core element, which can be, for example, the core of a steering wheel rim that surrounds a steering axis. Furthermore, the core element can be, in particular, a core located in an area of ​​the steering handle where the operator can grip it. In addition to the core element, the steering handle has a control device and at least one functional layer arranged on the core element, and in particular on the surface of the core element.The functional layer includes at least one electrically conductive functional conductor running within the functional layer, serving as a heating wire for heating the steering handle. This conductor also functions as a sensor element, sensor line, or sensor electrode for detecting contact with the steering handle. To control or energize the functional conductor, the control device is electrically connected to at least one of the functional conductors and comprises a heating control circuit for heating the steering handle via the functional conductor, as well as a sensor control circuit for detecting contact with the steering handle via the functional conductor. Preferably, the sensor control circuit and the functional conductor together form the sensor, and more specifically, a capacitive sensor and / or a sensor for detecting a change in the impedance of the functional conductor, particularly one caused by contact.Furthermore, preferably no additional sensor line is provided, so that the sensor is designed to detect contact with the steering handle solely from the approach of a body (e.g., the hand or knee of an operator or driver) to the functional conductor acting as a sensor electrode. It is particularly advantageous that the control device is designed to alternately control the functional conductor—using the heating control circuit to heat the steering handle—and, using the sensor control circuit, to detect contact with the steering handle. Due to this alternate control, it is not necessary to precisely coordinate the two control circuits, since the functional conductor does not act simultaneously, but exclusively sequentially, i.e., one after the other, as a heating wire and as a sensor element. Nevertheless, the sensor control circuit and the heating control circuit can be coordinated to reduce the signal-to-noise ratio.An alternating control can also include a middle position or a neutral state in which the functional conductor is neither connected to the heating control circuit nor to the sensor control circuit.

[0023] To contact the functional conductor with the control device, it is preferably provided that the functional conductor has a first end and a second end opposite along the longitudinal direction of the functional conductor, each of which is electrically contacted with the control device.

[0024] In order to enable both the most complete possible heating of the steering handle and the most complete possible touch detection over the entire intended reachable area of ​​the steering handle, it is preferably provided that the functional conductor runs according to a predetermined pattern in the substantially entire functional layer.

[0025] If multiple functional conductors are provided, a control device can be provided for each functional conductor. Alternatively, a common control device can be provided for multiple functional conductors, which includes a heating control circuit and a sensor control circuit for each functional conductor. Furthermore, a common control device can be provided for multiple functional conductors, which includes a heating control circuit and a sensor control circuit for multiple functional conductors.

[0026] Furthermore, a further development is advantageous in which the functional layer completely surrounds the core element in the circumferential direction. Here, the circumferential direction is to be understood as the circumferential direction around a principal extension axis or principal extension curve of the steering handle, particularly in the area of ​​the steering handle that is intended to be gripped.

[0027] Furthermore, the functional layer can be arranged on the core element, essentially covering its entire lateral surface, or generally covering the entire lateral surface of the core element. Areas for connecting the core element to other elements of the steering handle, such as struts connecting the core element to the steering axle, can remain free of the functional layer. For this purpose, the functional layer, and in particular a support layer described later, can be flexible and / or elastic, so that the shape of the functional layer can adapt to the shape of the core element. Furthermore, the functional layer can preferably be a developed version of the core element's lateral surface, which in turn can have recesses or cutouts in which connecting elements, such as struts leading to a central element, can be provided.

[0028] The functional layer can be arranged directly on the core element, and further layers, such as a soft layer that improves the feel of the steering handle, can also be arranged between the core element and the functional layer.

[0029] To ensure a uniform arrangement of the functional conductor across the substantially entire functional layer, it is further preferably provided that the at least one functional conductor is uniformly arranged within the functional layer and, in particular, follows a predetermined path and is further preferably arranged in a meandering pattern within or on the functional layer. Preferably, the functional conductor(s) are divided into a plurality of sections, between each of which the functional conductor is deflected, wherein the distance between immediately adjacent sections of the functional conductor remains constant and the distances are equal.

[0030] If not just one functional conductor but a multitude of functional conductors are provided, the distances between the sections of different functional conductors are preferably also constant and equal.

[0031] To enable both targeted heating of different zones of the steering handle and zone-dependent touch detection, a further advantageous embodiment provides that the functional layer, in particular corresponding to a surface of the core element and, furthermore, in a designated gripping area of ​​the steering handle, is divided into at least two zones, with each zone having a functional conductor that covers the respective zone completely. The zones can be arranged side by side and / or consecutively along the main extent (main extent axis or main extent curve) of the core element or the designated gripping area of ​​the steering handle. If the zones are arranged both side by side and consecutively, this results in a grid-like or matrix-like arrangement of the zones.

[0032] The zones can be arranged transversely to the main axis or curve of the functional layer, which may correspond to the main axis or curve of the steering handle, and / or adjacent to or alternating along it, so that a distinction can be made between contacts along the main axis or curve of the steering handle and / or contacts on the front and / or back of the steering handle. In a region of the functional layer defining the front of the steering handle, more zones may be provided than in a region defining the back of the steering handle.

[0033] Furthermore, the zones can also be nested within each other or arranged to surround one another. For example, a first inner zone can be surrounded by a second outer zone in a frame-like manner, with the two zones extending as a unit or together across the entire extent of the functional layer in the transverse and / or longitudinal direction.

[0034] It is further preferably provided that the functional layer has a flexible support layer, which can also be referred to as a support mat. The at least one functional conductor is arranged on the support layer. Alternatively or additionally, the at least one functional conductor is embedded in the support layer. Furthermore, the functional layer can also have two support layers or support mats, between which the at least one functional conductor is arranged or embedded. The functional layer can be easily arranged on the core element or a material surrounding the core element using the support layer. Accordingly, the functional conductor can first be arranged and fixed on a flat support layer and then arranged on the core element together with the support layer, whereby the support layer is usually curved along with the functional conductor arranged on it.assumes a curved shape corresponding to the core element.

[0035] It can also be advantageous to provide the control device with a switching element designed to alternately connect the functional conductor electrically to the heating control circuit and the sensor control circuit. Accordingly, the functional conductor is never simultaneously electrically connected to both the heating control circuit and the sensor control circuit, so that the functional conductor can never be energized or controlled by both at the same time.

[0036] Furthermore, the switching element can also have a middle position in which at least one functional conductor is not connected to either the heating control circuit or the sensor control circuit.

[0037] In addition to a physically present switching element in the control device, it can alternatively or for safety reasons also be provided that mutual interlocking is achieved by programming the heating control circuit and the sensor control circuit and / or switching elements in the heating control circuit and the sensor control circuit, whereby a functional conductor can be controlled not simultaneously but exclusively alternately to heat the steering handle and to detect a touch of the steering handle.

[0038] Furthermore, the functional conductor can be a single wire or be formed from a multitude of single wires or strands.

[0039] If the functional conductor is formed from a multitude of individual wires, the individual wires can be separated from one another, spaced apart, or fanned out, at least in sections. Several sections can also be provided over which the individual wires run separately, with sections in between in which the individual wires run as bundles.

[0040] Although the heating control circuit and the sensor control circuit do not need to be coordinated, it is advantageous to design the functional conductor in such a way that both a sufficiently high heating output and a sufficiently high sensor output or sensitivity can be achieved. Accordingly, it is preferably provided that the ohmic resistance of at least one functional conductor, and in the case of multiple functional conductors, is selected depending on the length of the functional conductor and / or its path within the functional layer, such that a predetermined heating output and a predetermined sensor sensitivity can be achieved with the respective functional conductor.

[0041] In other words, the predetermined path of the functional conductor, as well as the material properties and especially the ohmic resistance of the functional conductor, are chosen so that both a desired heating power and a desired sensor power or sensor sensitivity can be achieved.

[0042] To achieve a desired or predetermined heating power, the total resistance (ohmic resistance) of a functional conductor is preferably between 0.5 and 5 ohms.

[0043] In such a range of total resistance, it is further preferably provided that the ratio of the total length I of the functional conductor to the cross-sectional area of ​​the functional conductor is in the range of 30 to 300 m / mm². The following applies accordingly to an embodiment of the functional conductor as a single wire with a cross-sectional area A₁ and an embodiment of the functional conductor as several single wires of the number n and a respective cross-sectional area A₂: l A 1 = l n ∗ A 2 = 30 … 300 m mm 2

[0044] If the steering handle is designed as a steering wheel with a steering wheel diameter d L, it is further preferably provided that for a total length I as the sum of all lengths of all functional lines, the following applies: l ≥ 50 ∗ d L

[0045] Starting from a functional conductor formed from a single wire with a cross-sectional area A 1 of the single wire or a functional conductor formed from several individual wires of the number n with a cross-sectional area A 2 of the individual wires, the following preferably applies with regard to the ratio to the steering wheel diameter d L: A 1 = n ∗ A 2 ≥ 0 , 66 … 1 , 66 ∗ d L

[0046] If the functional conductor is arranged in a meandering pattern, as described above, or according to another predetermined pattern, sections of the functional conductor, or even sections of different functional conductors, may run adjacent to one another. To ensure that every intended contact is detected, an advantageous embodiment provides that the distance between two adjacent and parallel sections of the at least one functional conductor, or of different functional conductors, is less than or equal to a predetermined minimum contact distance, which is particularly 10 mm. This contact distance corresponds to the smallest detectable contact, which, corresponding to the approximate width of a small finger, can be 10 mm. This allows even slight touches of the handlebar, such as those made by just one finger, to be detected.

[0047] Other advantageous embodiments of the invention are characterized in the dependent claims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. The figures show: Fig. 1 a steering handle; Fig. 2 a first variant of a functional layer; Fig. 3 a second variant of a functional layer; Fig. 4 a third variant of a functional layer; Fig. 5 a fourth variant of a functional layer; Fig. 6 a fifth variant of a functional layer; Fig. 7 a section of a functional conductor; Fig. 8 procedure for controlling a steering handle.

[0048] The figures are schematic examples. Identical reference symbols in the figures indicate identical functional and / or structural features.

[0049] In Figure 1Figure 1 is a schematic representation of a steering handle 1, and more precisely, a steering wheel as a steering handle 1, which is essentially formed by a steering rim as the core element 10, a central element 14, and three struts 13 connecting the central element 14 to the core element 10. The core element 10 is rotatable around the axis of rotation R as the steering axis for steering the vehicle and is, in this case, round or torus-shaped, although the shape of the core element 10 is not limited to a torus-shaped form. Rather, the principal axis of extension X, or in this case the principal extension curve X, of the core element 10 can follow almost any predetermined path, so that the core element 10 can, for example, also be oval, cylindrical, or polygonal.

[0050] According to the illustrated embodiment of the steering handle 1, a functional layer 11 is provided on the core element 10, completely covering the surface or lateral surface of the core element, with the exception of the connection points for the struts 13 and optionally existing other elements, such as switches, display or design elements, which surrounds the main extension curve X, which itself revolves around the axis of rotation R, in the circumferential direction U.

[0051] In the Figures 2 to 6Various variants of functional layers 11 are shown, which differ essentially only in the number of their zones 11A, 11B, 11C, 11D and, accordingly, in the number of functional conductors 12A, 12B, 12C, 12D arranged or present in the functional layers 11. Furthermore, the functional layers 11 are each shown in a simplified form, so that the representation of the functional layers 11 does not correspond to a development of a lateral surface of a torus according to the core element 10 and does not take into account the connection areas of the struts 13.

[0052] From a in Figure 1The first diameter d K of the torus or core element 10 and a second diameter d L of the torus or core element 10 result in the length IK in the circumferential direction U and the length IL along the principal extension curve X, which is formed as a circle, as well as the area A of the lateral surface of the torus or core element 10 and the area A of the functional layer 11 as follows: l K = πd K l L = πd L A = πd K ∗ πd L

[0053] As per the variant of functional layer 11 in Figure 2As shown, a steering handle 1 equipped with this functional layer 11 has two electrically conductive functional conductors 12A, 12B running within the functional layer 11 and arranged in a meandering pattern. Two zones 11A and 11B are provided on the functional layer, which adjoin each other along the development of the main extension axis X and are thus adjacent to each other in the circumferential direction U. Each zone 11A, 11B has one functional conductor 12A, 12B, whereby the functional conductors 12A, 12B can also run through the other zone 11A, 11B, particularly for contacting the functional conductors 12A, 12B, as shown here for the first functional conductor 12A of the first zone 11A.

[0054] The functional conductors 12A and 12B are each electrically contacted with a control device 20, whereby only the control device 20 of the first functional conductor 12A is shown. The control devices 20 each have a heating control circuit 21 and a sensor control circuit 22, as well as a switching element 23, which is configured to alternately connect the respective functional conductor 12A or 12B to the heating control circuit 21 and the sensor control circuit 22, such that in a first switching position of the switching element 23, the respective functional conductor 12A or 12B acts as a heating wire for heating the steering handle 1 and is controllable, and in a second switching position of the switching element 23, it acts as a sensor element, and in particular as a sensor electrode of a sensor formed by the respective functional conductor 12A or 12B with the respective sensor control circuit for touch detection of the steering handle 1 and is controllable.

[0055] The switching element 23 is shown here with a switching actuator, but can also, for example, have a switching actuator for each end of the respective functional conductor 12A, 12B.

[0056] In order to be able to detect touches with a predetermined or desired sensor sensitivity and to heat the steering wheel or steering handle 1 as predetermined or desired, the material properties or the material chosen for the functional line 12A, 12B and the routing of the functional line 12A, 12B are selected in such a way that both requirements can be met.

[0057] For example, if a touch in different areas or zones of the steering handle 1 is to be distinguishable, the functional layer 11 is divided into different or multiple layers and according to the variant in Figure 2divided into two zones 11A and 11B, so that a touch in the first zone 11A can be distinguished from a touch in the second zone 11B. For example, in Figure 2 The contact on the front and on the back of the steering handle 1 can be distinguished.

[0058] In order to detect even slight touches, and in particular touches by a single finger, the distance 15 between parallel sections of the functional conductors 12A, 12B or of a functional conductor 12A, 12B is less than or equal to a predetermined touch distance, which is, for example, 10 mm and corresponds to the approximate width of a finger.

[0059] As an example, a steering wheel with a first diameter dK of 35 mm and a second diameter dL of 350 mm is assumed. To differentiate the contact zones, the functional layer 11 is used according to Figure 2The steering handle 1 is divided into two zones 11A and 11B, each equipped with a functional conductor 12A and 12B. The two zones 11A and 11B are arranged side-by-side along the circumferential direction U, or orthogonally to the principal extension curve X, so that contact can be distinguished between the rear side of the handle 1 facing away from the driver and the front side facing the driver. The functional conductors 12A and 12B each consist of a 7-core stranded wire (seven individual wires per functional conductor 12A and 12B) made of 0.08 mm² copper wire, which differs from the simplified representation of the Figure 2 It is laid in a meandering pattern 6 times along the entire length of the main extension axis X, so that the total length (of all functional conductors 12A, 12B) resulting from the individual lengths of the functional conductors 12A, 12B is approximately 8 m.

[0060] With such a design of the functional conductors 12A, 12B, an ohmic resistance of approximately 4 ohms per zone 11A, 11B or per functional conductor 12A, 12B results.

[0061] As long as the respective functional conductor 12A, 12B is contacted with the respective heating control circuit 21, the functional layer 11 or the entire steering handle 1 can be heated evenly and with a predetermined power output, without the heating control circuit 21 needing to consider the sensor functionality. By switching the respective switching element 23 accordingly, and thereby disconnecting the respective functional conductor 12A, 12B from the respective heating control circuit 21 and connecting it electrically to the respective sensor control circuit 22, the respective functional conductor 12A, 12B together with the respective sensor control circuit 22 forms a sensor that can detect a touch in the respective zone 11A, 11B without needing to be controlled by the heating control circuit 21.

[0062] Accordingly, heating control circuit 21 and sensor control circuit 22 can be independent of each other and comparatively simple in design.

[0063] In functional layer 11 according to the Figure 3 Two zones 11A and 11B are also provided, which, however, are not arranged adjacent to each other in the circumferential direction U, but are arranged consecutively along the principal extension curve X and thus adjacent to each other, thereby deviating from the variant according to Figure 2 It is not possible to distinguish between a contact on the front and a contact on the back of the steering handle 1, but rather between contacts along the principal extension curve X. With regard to a system rotating with the steering handle, a distinction can thus be made between a contact on the left side of the steering handle 1 and a contact on the right side of the steering handle 1.

[0064] The functional layer 11 according to Figure 4Furthermore, it features a grid- or matrix-like arrangement of a total of four zones 11A, 11B, 11C, 11D, each with a functional conductor 12A, 12B, 12C, 12D, such that two zones (11A to 11C and 11B to 11D) are adjacent to each other in the circumferential direction U, and two zones (11A to 11B and 11C to 11D) are adjacent to each other along the principal extension curve X. This allows for differentiation between contacts on the front and back of the steering handle 1 and between contacts along the principal extension curve X of the steering handle 1.

[0065] In Figure 5 Another configuration of the functional layer 11 with two zones 11A, 11B is shown, wherein the first zone 11A surrounds the second zone 11B in a frame-like manner, or the first functional conductor 12A of the first zone 11A surrounds the second functional conductor 12B of the second zone 11B in a frame-like manner.

[0066] With Figure 6Figure 1 illustrates a further advantageous variant of the functional layer 11, in which three zones 11A, 11B, 11C, each with a functional conductor 12A, 12B, 12C, are provided. The first zone 11A is designed to define the rear side of the steering handle 1. The second and third zones 11B, 11C are designed to jointly define the front side of the steering handle 1. Accordingly, the first zone 11A extends over the entire extent of the functional layer 11 along the principal extension curve X, but only on one side of the principal extension curve X in the transverse direction. The remaining area is occupied by the second and third zones 11B, 11C, which are arranged consecutively along the principal extension curve X.This allows a touch on the back of the steering handle 1 to be detected by means of the first zone 11A and a distinction to be made on the front between touches on a left and right side of the steering handle 1, whereby, for example, the second zone 11B is assigned to a touch on the left side and the third zone 11C to a touch on the right side of the steering handle 1.

[0067] In Figure 7 A functional conductor is shown section by section, which can correspond to one of the functional conductors 12A, 12B, 12C, 12D, as it appears in one of the diagrams in the Figures 2 to 6 The variants shown may be used. The one in Figure 7The functional conductor shown is formed from several individual wires, and in this example, three individual wires 121, 122, 123, which are fanned out or separated in the two sections 120A, 120B shown in the section shown, so that a functional conductor can cover a wider area of ​​the functional layer and thus of the top or outer surface of the core element 10. Between the fanned-out sections 120A, 120B, the functional conductor can also run bundled as shown.

[0068] In Figure 8 The diagram shows a procedural flow based on a flowchart, where numbers 1 arranged at decision nodes (diamonds) are equivalent to a "yes" and numbers 0 to a "no".

[0069] The procedure, once initiated, involves the following steps and decisions: A. Deactivate the heating of the steering handle 1, disconnect at least one functional conductor 12A, 12B, 12C, 12D from the heating control circuit 21 and connect at least one functional conductor 12A, 12B, 12C, 12D to the sensor control circuit 22. B. Should touch detection and, in particular, hand detection be performed on the steering handle 1? C. Have all sensors formed by at least one functional conductor 12A, 12B, 12C, 12D and one control device 20 each been measured or detected? D. Perform sensor configuration. E. Detect a capacitive change detected by the sensors. F. Perform sensor configuration. G. Evaluate the detected and recorded capacitive change to determine whether the capacitive change was caused by a touch, preferably by a touch detection algorithm stored in the sensor control circuit 22. H.Was the evaluation reliable and was a touch or no touch reliably detected? I. Should the steering handle 1 be heated? J. Activate heating of the steering handle 1, disconnect at least one functional conductor 12A, 12B, 12C, 12D from the sensor control circuit 22 and connect at least one functional conductor 12A, 12B, 12C, 12D to the heating control circuit 21. K. Query a target temperature and / or an electrical power corresponding to a heating power with which the at least one functional conductor 12A, 12B, 12C, 12D is to be energized. L. Was the target temperature and / or the electrical power reached?

Claims

1. A method for controlling a heating of a steering handle (1) and touch detection at the steering handle (1), the steering handle (1) having at least one electrically conductive functional conductor (12A, 12B, 12C, 12D) as heating wire for heating the steering handle (1), which is a sensor element of a sensor for touch detection of the steering handle (1), and a control device (20) being electrically connected to at least one functional conductor (12A, 12B, 12C, 12D), which has a heating control circuit (21) for heating the steering handle (1) via the functional conductor (12A, 12B, 12C, 12D) and a sensor control circuit (22) for touch detection at the steering handle (1) via the functional conductor (12A, 12B, 12C, 12D), wherein, according to the method, it is provided that the at least one functional conductor (12A, 12B, 12C, 12D) is electrically connected to the heating control circuit (21) and is simultaneously or beforehand disconnected from the sensor control circuit (22), the at least one functional conductor (12A, 12B, 12C, 12D), electrically connected to the heating control circuit (21), is addressed by the heating control circuit (21) in a manner heating the steering handle (1), the at least one functional conductor (12A, 12B, 12C, 12D) is electrically connected to the sensor control circuit (22) and is simultaneously or beforehand disconnected from the heating control circuit (21), the at least one functional conductor (12A, 12B, 12C, 12D), electrically connected to the sensor control circuit (22), is addressed by the sensor control circuit (22) in a manner detecting a touch of the steering handle (1), characterised in that, upon the addressing of the at least one functional conductor (12A, 12B, 12C, 12D) by the sensor control circuit (22) in a manner detecting a touch of the steering handle (1), a change of a capacitive field detected by the at least one functional conductor (12A, 12B, 12C, 12D) and a change of an impedance of at least one functional conductor (12A, 12B, 12C, 12D) are detected and evaluated by the sensor control circuit (22) and wherein, upon detection of the change of the capacitive field and the change of the impedance of at least one functional conductor (12A, 12B, 12C, 12D), it is plausibilised whether this is a touch of the steering handle (1).

2. The method according to claim 1, wherein, after or before the connecting of the at least one functional conductor (12A, 12B, 12C, 12D) to the sensor control circuit (22), it is queried whether a touch detection through the addressing of the at least one functional conductor (12A, 12B, 12C, 12D) by the sensor control circuit (22) in a manner detecting a touch of the steering handle (1) is to be performed.

3. The method according to claim 1 or 2, wherein, upon the addressing of the at least one functional conductor (12A, 12B, 12C, 12D) by the sensor control circuit (22) in a manner detecting a touch of the steering handle (1), a configuration of the at least one functional conductor (12A, 12B, 12C, 12D) and the sensor control circuit (22) is detected as an actual value and is compared to a target value.

4. The method according to any one of the preceding claims, wherein, upon the connecting of the at least one functional conductor (12A, 12B, 12C, 12D) to the sensor control circuit (22), multiple functional conductors (12A, 12B, 12C, 12D) are connected to the sensor control circuit (22), so that the functional conductors (12A, 12B, 12C, 12D) form multiple sensors with the sensor control circuit (22), and / or multiple sensor control circuits (22) are provided and, upon the connecting of the at least one functional conductor (12A, 12B, 12C, 12D) to the sensor control circuit (22), one functional conductor (12A, 12B, 12C, 12D) or multiple functional conductors (12A, 12B, 12C, 12D) are connected to each sensor control circuit (22), so that the functional conductors (12A, 12B, 12C, 12D) form multiple sensors with the sensor control circuits (22).

5. The method according to the preceding claim, wherein, upon an addressing of the at least one functional conductor (12A, 12B, 12C, 12D) in a manner detecting a touch of the steering handle (1), each sensor is queried whether a touch of the steering handle (1) was detected.

6. The method according to any one of the preceding claims, wherein, after or before the connecting of the at least one functional conductor (12A, 12B, 12C, 12D) to the heating control circuit (21), it is queried by the sensor control circuit (22) whether an addressing of the at least one functional conductor (12A, 12B, 12C, 12D) by the heating control circuit (21) in a manner heating the steering handle (1) is to be performed.

7. The method according to any one of the preceding claims, wherein, upon an addressing of the at least one functional conductor (12A, 12B, 12C, 12D) by the heating control circuit (22) in a manner heating the steering handle (1), a target value for the temperature of the steering handle is queried, and / or an actual value of the temperature of the steering handle is detected and compared to the target value.