STEERING HANDLE WITH HEATING AND TOUCH DETECTION

Description

[0001] The invention relates to a steering handle with integrated heating and touch detection.

[0002] A variety of steering handles, such as steering wheels, are known from the prior art, in which a heater or a touch detection system or both a heater and a touch detection system are integrated.

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

[0004] In contrast, touch detection primarily serves to increase driving safety, as it detects the driver's hand or the driver himself and thus ensures, for example, that the driver is grasping the handle with at least one hand. In addition, the 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 required to maintain a firm grip on the steering wheel for safety reasons. Alternatively, a touch could also signal to the vehicle that the driver wishes to regain control of the vehicle.

[0006] In order to provide both a heated steering wheel or handle and touch detection, the state of the art usually provides for a steering wheel to be equipped with both a heater and a separate or separate sensor for touch detection. However, this results in a space-intensive and cost-intensive design.

[0007] Furthermore, a combination of heating and touch detection is known from both EP 2 028 078 A1 and DE 11 2018 005 213 T5. According to both variants, a sensor with multiple sensor lines is provided, one of which is also used as a heating wire, so that the two are integrally formed.

[0008] However, the problem is that the control or a sensor control circuit must be precisely matched to the heater or the heater control circuit, since the control of the sensor must not influence the heater and the control of the heater must not influence the sensor.

[0009] Accordingly, the evaluation of the sensor or a necessary circuit is complex, expensive and prone to errors.

[0010] Further prior art in this field is provided in particular by the documents DE 10 2019 124 293 A1 and WO 2018 / 213 344 A1.

[0011] The invention is therefore based on the object of overcoming the aforementioned disadvantages and providing a steering handle with integrated heating and touch detection that can be implemented both cost-effectively and, in particular, with simple control. This object is achieved by the combination of features according to claim 1.

[0012] According to the invention, a steering handle with heating and touch detection for a vehicle is therefore proposed. The steering handle can be a steering wheel or, for example, a handlebar, a joystick, or a control horn. The steering handle has a core element, which can be, for example, the core of a steering rim of a steering wheel that surrounds a steering axle. Furthermore, the core element can in particular be a core in a region of the steering handle at which the steering handle can be gripped by an operator as intended. In addition to the core element, the steering handle according to the invention 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 has at least one electrically conductive functional conductor running within the functional layer as a heating wire for heating the steering handle, which is simultaneously a sensor element or a sensor line or sensor electrode of a sensor for detecting touches of 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 has a heating control circuit for heating the steering handle via the functional conductor and a sensor control circuit for detecting touches of the steering handle via the functional conductor. Preferably, the sensor control circuit and the functional conductor together form the sensor and furthermore in particular a capacitive sensor and / or a sensor for detecting a change in the impedance of the functional conductor, in particular caused by touch.In addition, preferably no further 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. hand or knee of an operator or driver) to the functional conductor acting as a sensor electrode. According to the invention, it is particularly advantageous that the control device is designed to control the functional conductor alternately with the heating control circuit to heat the steering handle and with the sensor control circuit to detect contact with the steering handle. Due to the alternate control, it is not necessary to coordinate the two control circuits exactly with one another, since the functional conductor does not function 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 with one another to reduce the signal to noise ratio.Alternating control may also include a center position or a neutral state in which the function conductor is connected neither to the heating control circuit nor to the sensor control circuit.

[0013] In order 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, which are each electrically contacted with the control device.

[0014] In order to enable both the most complete heating of the steering handle and the most complete touch detection over the entire intended grippable area of ​​the steering handle, it is preferably provided that the functional conductor runs according to a predetermined pattern in substantially the entire functional layer.

[0015] If multiple functional conductors are provided, a control device can be provided for each functional conductor. Furthermore, a common control device can be provided for multiple functional conductors, which has 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 has a heating control circuit and a sensor control circuit for each of the multiple functional conductors.

[0016] A further advantageous development is one in which the functional layer completely surrounds the core element in the circumferential direction. The circumferential direction is understood to be the circumferential direction around a main extension axis or main extension curve of the steering handle, particularly in the intended grippable area of ​​the steering handle.

[0017] In addition, the functional layer can be arranged on the core element so as to substantially completely cover a lateral surface of the core element or generally substantially completely cover the 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 carrier layer explained 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, a shape of the functional layer can preferably be a development of the lateral surface of the core element, wherein in turn recesses or gaps can be provided in which connecting elements, such as struts leading to a central element, can be provided.

[0018] The functional layer can be arranged directly on the core element, and further layers, such as a soft layer that improves the haptics of the steering grip, can also be arranged between the core element and the functional layer.

[0019] To ensure a uniform arrangement of the functional conductor over substantially the entire functional layer, it is further preferably provided that the at least one functional conductor is uniformly arranged in the functional layer and in particular follows a predetermined course and more particularly is arranged meandering in or on the functional layer. Preferably, the functional conductor or the functional conductors are divided into a plurality of sections, between which there is a deflection of the functional conductor in each case, the distance between directly adjacent sections of the functional conductor remaining constant and the distances being equal.

[0020] If not just one functional conductor but a plurality of functional conductors is provided, the distances between the sections of different functional conductors are preferably consistent and equal.

[0021] In order to enable both targeted heating of different zones of the steering handle and zone-dependent touch detection, a further advantageous variant provides for the functional layer, in particular corresponding to a surface of the core element and further in particular the functional layer in a normally graspable area of ​​the steering handle, to be divided into at least two zones, and for each zone to be provided with a functional conductor that, in particular, completely covers the respective zone. The zones can be arranged next to one another and / or consecutively along the main extension (main extension axis or main extension curve) of the core element or the normally graspable area of ​​the steering handle. If the zones are arranged both next to one another and consecutively, this results in a grid-like or matrix-like arrangement of the zones.

[0022] The zones can be arranged transversely to the main extension axis or curve of the functional layer, which can correspond to the main extension 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 extension axis or curve of the steering handle and / or contacts on a front and / or rear side of the steering handle. More zones can be provided in a region of the functional layer defining the front side of the steering handle than in a region of the functional layer defining the rear side of the steering handle.

[0023] Furthermore, the zones can also be nested within one another or arranged so as to surround one another. For example, a first inner zone can be framed by a second outer zone, whereby the two zones can extend transversely and / or longitudinally as a unit or jointly over the entire extent of the functional layer.

[0024] Furthermore, it is preferably provided that the functional layer has a flexible carrier layer, which can also be referred to or designed as a carrier mat. The at least one functional conductor is arranged on the carrier layer. Alternatively or additionally, the at least one functional conductor is embedded in the carrier layer. Furthermore, the functional layer can also have two carrier layers or carrier mats, between which the at least one functional conductor is arranged or embedded. With the carrier layer, the functional layer can be arranged in a simple manner on the core element or a material surrounding the core element. Accordingly, the functional conductor can first be arranged and fixed on a flat carrier layer and then arranged with the carrier layer on the core element, wherein the carrier layer is usually curved with the functional conductor arranged on it.takes on a curved shape corresponding to the core element.

[0025] Advantageously, the control device can also be provided with a switching element configured to alternately electrically connect the functional conductor to the heating control circuit and the sensor control circuit. Accordingly, the functional conductor is never simultaneously electrically connected to the heating control circuit and the sensor control circuit, so that the functional conductor can never be energized or controlled by both the heating control circuit and the sensor control circuit at the same time.

[0026] Furthermore, the switching element can also have a middle position in which the at least one functional conductor is connected neither to the heating control circuit nor to the sensor control circuit.

[0027] In addition to a physically present switching element in the control device, it can also be provided alternatively or for safety reasons that mutual locking 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 contact with the steering handle.

[0028] Furthermore, the functional conductor is made up of a large number of individual wires or strands.

[0029] The individual wires are arranged at least in sections, separated from one another, spaced apart, or fanned out. Several sections can also be provided over which the individual wires run separately, with sections in between each section in which the individual wires run as bundles or in bundles.

[0030] Although the heating control circuit and the sensor control circuit do not have to be coordinated with one another, it is advantageous to design the functional conductor in such a way that both a sufficiently high heating output and a sufficiently high sensor performance or sensor sensitivity can be achieved. Accordingly, it is preferably provided that an ohmic resistance of at least one functional conductor, and in the case of multiple functional conductors, is selected depending on a length of the functional conductor and / or a course of the functional conductor in the functional layer in such a way that both a predetermined heating output and a predetermined sensor sensitivity can be achieved with the respective functional conductor.

[0031] In other words, in particular the predetermined course of the functional conductor as well as the material properties and in particular the ohmic resistance of the functional conductor are selected such that both a desired heating power and a desired sensor power or sensor sensitivity can be achieved.

[0032] To achieve a desired or predetermined heating output, the total resistance (ohmic resistance) of a functional conductor is preferably between 0.5 and 5 ohms.

[0033] 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-section of the functional conductor is in the range of 30 to 300 m / mm 2 . For a design of the functional conductor as a single wire with a cross-sectional area A 1 and a design of the functional conductor as several individual wires of the number n and a respective cross-sectional area A 2 , the following applies accordingly: l A 1 = l n ∗ A 2 = 30 … 300 m mm 2

[0034] 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 the sum of all lengths of all functional lines is: l ≥ 50 ∗ d L

[0035] Starting from a functional conductor formed from a single individual wire with a cross-sectional area A 1 of the individual 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 relationship to the steering wheel diameter d L: A 1 = n ∗ A 2 ≥ 0 , 66 … 1 , 66 ∗ d L

[0036] If the functional conductor is arranged as described above, for example in a meandering manner or according to another predetermined pattern, it may result that sections of the functional conductor or sections of different functional conductors run adjacent to one another. In order to ensure that every intended contact is detected, an advantageous variant provides that a 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 in particular 10 mm. The contact distance corresponds to the smallest contact to be detected, which can be 10 mm, corresponding to the approximate width of a little finger. This means that even slight contact with the steering handle, for example by just one finger, can be detected.

[0037] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. They 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.

[0038] The figures are schematic examples. Like reference numerals in the figures indicate like functional and / or structural features.

[0039] In Figure 11 shows a schematic steering handle 1, and more precisely a steering wheel as the 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 about the rotation axis R as the steering axis for steering the vehicle and is round or torus-shaped in this case, whereby the shape of the core element 10 is not limited to a torus-shaped configuration. Rather, the main extension axis X, or here the main extension curve X, of the core element 10 can follow almost any predetermined course, so that the core element 10 can also be oval, cylindrical, or polygonal, for example.

[0040] According to the illustrated embodiment of the steering handle 1, a functional layer 11 is provided on the core element 10, which completely covers the surface or lateral surface of the core element, with the exception of the connection points for the struts 13 and optionally present further elements, such as switches, display or design elements, and which surrounds the main extension curve X, which itself revolves around the rotation axis R, in the circumferential direction U.

[0041] In the Figures 2 to 6Various variants of functional layers 11 are shown, which essentially only differ 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 manner, so that the illustration 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.

[0042] From a Figure 1From the first diameter d K of the torus or core element 10 and a second diameter d L of the torus or core element 10, the length IK in the circumferential direction U and the length IL along the main extension curve X formed as a circular line 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 are as follows: l K = πd K l L = πd L A = πd K ∗ πd L

[0043] 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 in the functional layer 11 and each arranged in a meandering shape. Two zones 11A and 11B are provided on the functional layer, which adjoin one another along the development of the main extension axis X and are thus adjacent to one another in the circumferential direction U. One functional conductor 12A, 12B is provided for each zone 11A, 11B, wherein the functional conductors 12A, 12B can also run through the respective other zone 11A, 11B, in particular for contacting the functional conductors 12A, 12B, as is shown here for the first functional conductor 12A of the first zone 11A.

[0044] The functional conductors 12A, 12B are each electrically contacted with a control device 20, wherein 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 designed to alternately connect the respective functional conductor 12A, 12B to the heating control circuit 21 and the sensor control circuit 22, so that the respective functional conductor 12A, 12B acts and can be controlled as a heating wire for heating the steering handle 1 in a first switching position of the switching element 23 and acts and can be controlled as a sensor element and in particular as a sensor electrode of a sensor formed by the respective functional conductor 12A, 12B with the respective sensor control circuit for detecting contact with the steering handle 1.

[0045] The switching element 23 is shown here with a switching actuator, but can also have, for example, a switching actuator for each line end of the respective functional conductor 12A, 12B.

[0046] In order to be able to detect contacts with a predetermined or desired sensor sensitivity as well as to heat the steering wheel or steering handle 1 as predetermined or desired, both the material properties or the material selected for the functional line 12A, 12B and the course of the functional lines 12A, 12B are selected such that both requirements can be met.

[0047] If, for example, 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 several and, according to the variant, into Figure 2divided into two zones 11A, 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 a front and on a back of the steering handle 1 can be distinguished.

[0048] In order to be able 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.

[0049] As an example, we assume a steering wheel with a first diameter d K of 35 mm and a second diameter d L of 350 mm. To distinguish the contact zones, the functional layer 11 is Figure 2divided into two zones 11A, 11B and each provided with a functional conductor 12A, 12B. The two zones 11A, 11B are arranged next to each other along the circumferential direction U or orthogonally to the main extension curve X, so that a distinction can be made between a contact on the rear side facing away from the driver and a contact on the front side of the steering handle 1 facing the driver. The functional conductors 12A, 12B are each formed from a 7-core stranded wire (seven individual wires per functional conductor 12A, 12B) made of 0.08 mm 2< copper wire, which, in contrast to the simplified representation of the Figure 2 6 times meandering over the entire course 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.

[0050] With such a design of the functional conductors 12A, 12B, an ohmic resistance of approximately 4 ohms results per zone 11A, 11B or per functional conductor 12A, 12B.

[0051] As long as the respective functional conductor 12A, 12B is in contact 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, whereby the heating control circuit 21 does not have to take the sensor functionality into account. By appropriately switching the respective switching element 23 and the associated separation of the respective functional conductor 12A, 12B from the respective heating control circuit 21 as well as the electrical connection 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 contact in the respective zone 11A, 11B without having to take into account control by the heating control circuit 21.

[0052] Accordingly, heating control circuit 21 and sensor control circuit 22 can be constructed independently of each other and comparatively simply.

[0053] In the functional layer 11 according to the Figure 3 two zones 11A, 11B are also provided, which, however, are not arranged adjacent to one another in the circumferential direction U, but are arranged one after the other along the main extension curve X and thus adjacent to one another, whereby, in contrast to the variant according to Figure 2 not between a contact on a front side and a contact on a back side of the steering handle 1, but rather between contacts along the main extension curve X. With respect 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.

[0054] The functional layer 11 according to Figure 4also has 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, so that two zones (11A to 11C and 11B to 11D) are adjacent to one another in the circumferential direction U and two zones (11A to 11B and 11C to 11D) are adjacent to one another along the main extension curve X. This makes it possible to distinguish between contacts on the front and back of the steering handle 1 and between contacts along the main extension curve X of the steering handle 1.

[0055] In Figure 5 a further 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.

[0056] With Figure 61 illustrates a further advantageous variant of the functional layer 11, in which three zones 11A, 11B, 11C are provided, each with a functional conductor 12A, 12B, 12C. The first zone 11A is provided to define a rear side of the steering handle 1. The second and third zones 11B, 11C are provided 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 main extension curve X, but in the transverse direction to the main extension curve X, it is only provided on one side of the main extension curve X. The remaining area is occupied by the second and third zones 11B, 11C, which are arranged successively along the main extension curve X.As a result, a touch on the rear side of the steering handle 1 can be detected by means of the first zone 11A and a distinction can be made at the front between touches on a left and right side of the steering handle 1, wherein, for example, the second zone 11B is assigned to a touch on the left side and the third zone 11C is assigned to a touch on the right side of the steering handle 1. In . Figure 7 a functional conductor is shown in sections, which can correspond to one of the functional conductors 12A, 12B, 12C, 12D, as it is used in one of the Figures 2 to 6 shown variants can be used. The Figure 7The functional conductor shown is formed from several individual wires, and in this case, by way of example, three individual wires 121, 122, 123, which are fanned out or separated in the illustrated section into the two sections 120A, 120B, so that a wider area of ​​the functional layer and thus of the upper or outer surface of the core element 10 can be covered by one functional conductor. Between the fanned out sections 120A, 120B, the functional conductor can also run in a bundle, as shown.

Claims

1. A steering handle (1) with heating and contact detection for a vehicle, wherein the steering handle (1) has a core element (10), a control device (20), and at least one functional layer (11) arranged on the core element (10), wherein the functional layer (11) has at least one electrically conductive functional conductor (12A, 12B, 12C, 12D) running in the functional layer (11) as a heating wire for heating the steering handle (1), which functional conductor (12A, 12B, 12C, 12D) is a sensor element of a sensor for detecting contact with the steering handle (1), wherein the control device (20) is electrically connected to at least one functional conductor (12A, 12B, 12C, 12D), has a heating control circuit (21) for heating the steering handle (1) via the functional conductor (12A, 12B, 12C, 12D) as well as a sensor control circuit (22) for detecting contact with the steering handle (1) via the functional conductor (12A, 12B, 12C, 12D), and is designed to control the functional conductor (12A, 12B, 12C, 12D) alternately with the heating control circuit (21) in order to heat the steering handle (1) and with the sensor control circuit (22) in order to detect contact with the steering handle (1), characterized in that the functional conductor (12A, 12B, 12C, 12D) is formed from a plurality of individual wires (121, 122, 123), and the individual wires (121, 122, 123) are arranged so as to run at least partially separately from one another.

2. The steering handle according to claim 1, wherein the functional layer (11) completely surrounds the core element (10) in the circumferential direction (U).

3. The steering handle according to claim 1 or 2, wherein the functional layer (11) can be arranged on the core element (10) so as to substantially completely cover a lateral surface of the core element (10) and / or a shape of the functional layer (11) is in particular a progression of the lateral surface of the core element (10).

4. The steering handle according to any one of the preceding claims, wherein the at least one functional conductor (12A, 12B, 12C, 12D) is arranged uniformly in the functional layer (11) and is arranged in particular following a predetermined course and furthermore in particular in a meandering shape in the functional layer (11).

5. The steering handle according to any one of the preceding claims, wherein the functional layer (11) is divided into at least two zones (11A, 11B, 11C, 11D), and a functional conductor (12A, 12B, 12C, 12D) covering the respective zone (11A, 11B, 11C, 11D) is provided for each zone (11A, 11B, 11C, 11D).

6. The steering handle according to any one of the preceding claims, wherein the functional layer (11) has a flexible carrier layer on which the at least one functional conductor (12A, 12B, 12C, 12D) is arranged and / or in which the functional conductor (12A, 12B, 12C, 12D) is embedded.

7. The steering handle according to any one of the preceding claims, wherein the control device (20) has a switching element (23) which is designed to alternately electrically connect the functional conductor (12A, 12B, 12C, 12D) to the heating control circuit (21) and to the sensor control circuit (22).

8. The steering handle according to any one of the preceding claims, wherein the functional conductor (12A, 12B, 12C, 12D) is a single wire or is formed from a plurality of single wires (121, 122, 123).

9. The steering handle according to any one of the preceding claims, wherein an ohmic resistance of the at least one functional conductor (12A, 12B, 12C, 12D) is selected as a function of a length of the functional conductor and / or a course of the respective functional conductor (12A, 12B, 12C, 12D) in the functional layer (11), thus enabling a predetermined heating output and a predetermined sensor sensitivity to be achieved.

10. The steering handle according to any one of the preceding claims, wherein a distance (15) between two mutually adjacent and parallel sections of the at least one functional conductor (12A, 12B, 12C, 12D) is less than or equal to a predetermined minimum contact distance, which is in particular 10 mm.