Device for a steering device and steering device for a vehicle

Abstract

The utility model relates to a device for a steering system and a steering system of a vehicle, comprising a sensor device (S) and a control device (10) and an electrically conductive functional conductor (13) connected to the control device as a heating wire for heating a surface (2), the control device (10) comprising a heating circuit (11) and a sensor circuit (12), the utility model relates to a sensor device (S) for detecting the position of a hand (H), comprising a heating circuit (12) for heating a surface (2) by means of a heating wire (13), and a sensor circuit (12) which is designed to detect a touch of the hand on the surface (2), the sensor device (S) being formed from a plurality of capacitive sensors connected to the sensor circuit (12) for capacitive detection of the position of the hand (H), the capacitive sensors being arranged along the surface (2), each sensor has at least one sensor electrode.

Description

Technical Field

[0001] The present invention relates to a device configured to alternately heat a surface or implement the recognition of surface touch. Background Art

[0002] A variety of devices for heating a touched surface at a steering device are known from the prior art. Such devices are typically integrated in a steering device (e.g., a steering gear or a steering wheel) or in a seat.

[0003] Heating the steering device is primarily a comfort function that should provide the operator with a temperature-appropriate operating element.

[0004] In contrast, touch recognition at the steering device is mainly used to improve driving safety, because by touch recognition, the driver's hand or the driver himself / herself is recognized, so as to ensure, for example, that the driver grasps the steering device with at least one hand.

[0005] In addition, information about the touch or presence of the driver and / or hand can also be used in a large number of other systems of a vehicle.

[0006] In a vehicle, it may be necessary to detect whether the driver places his / her hand on the steering wheel (e.g., to determine whether the driver is ready to perform a steering operation). The steering assistance device may include the possibility of active correction for the driver that can be used in certain situations. However, there may be other reasons to recognize whether the driver places his / her hand on the steering wheel. Therefore, for example, it can be stipulated that the steering assistance system is enabled only when the driver places his / her hand on the steering wheel. In most countries, it is stipulated that even when modern assistance systems can safely and autonomously control a vehicle in certain situations, the vehicle should be under the control of the driver during driving.

[0007] However, in order to determine whether at least one hand is placed on the steering wheel, a variety of concepts have been developed. A known concept is based on the EPS system, which senses low-amplitude vibrations in the steering wheel. When the driver places his / her hand on the steering wheel, this generates a detectable damping effect. However, this vibration may distract or interfere with the driver. Other systems use special sensors. One system uses a resistive sensor element, in which two conductors are arranged spaced apart from each other under the surface of the steering wheel. When a certain pressure is applied on the surface, the conductors come into contact. However, the pressure required to activate the sensor makes the reliability of this method relatively low.

[0008] An alternative method uses a capacitive sensor that identifies a hand by the hand's influence on the electric field generated by the sensor, thereby identifying a capacitance change. In particular, document US2012 / 326735 A1 discloses the use of a capacitive sensor that is arranged and configured such that it identifies contacts with the front right, front left, and rear surfaces of a steering wheel, respectively. The sensors are enabled simultaneously, and when the impedance of a sensor is greater than or equal to a threshold value of the impedance, the sensor records the contact. Although capacitive sensors are more reliable than resistive sensors, the detection result of one hand of a user may be distorted due to the grounding state of the other hand.

[0009] Ultimately, this is a complex network of capacitive units that are subject to the dynamic influence of a ground terminal or ground, resulting in undesirable results.

[0010] If, due to the driver's contact with a grounded component of the vehicle, the other hand is grounded or connected to ground, the overall impedance will be significantly different from the case where the other hand is not grounded. Generally, if the other hand or the driver is always grounded somewhere, the detected signal will be more significant or higher in its signal strength. However, it is very difficult to detect the grounding state of the other hand, let alone evaluate its influence on the detected signal. Other factors may also affect the detected signal, such as the driver's sitting position, thereby making the reliability of the measurement result lower. Therefore, it is necessary to make the measurement result more reliable.

[0011] Another influence is crosstalk or general electromagnetic interaction between sensors and between the sensors and the surrounding environment. Although solutions and shielding concepts are known in the prior art to suppress or at least reduce this influence, these solutions and shielding concepts, even if technically fully compatible, usually can only be implemented at a relatively high additional cost.

[0012] In order to be able to provide heating and touch recognition simultaneously, it is generally stipulated in the prior art that for the application of such a device (i.e., a steering device or a seat), it should be equipped with both a heater and a separate or individual sensor for touch recognition. However, this results in a large and costly structure.

[0013] Furthermore, the combination of heating and touch recognition is known from document EP 2 028 078 A1 and document DE 11 2018 005 213 T5. According to these two variants, the sensors are each provided with a plurality of sensor lines, and one of the sensor lines is simultaneously used as a heating line, such that these sensor lines are configured to be integrated with each other. Summary of the Utility Model

[0014] The object of the present invention is to overcome the above-mentioned drawbacks and to provide a device for heating a surface and for capacitively recognizing a surface touch, which device enables the simultaneous execution of functions and in which the reliability and accuracy of capacitive hand detection at the steering wheel are improved.

[0015] According to the present invention, there is thus provided a device for heating a surface and for recognizing a surface touch.

[0016] The device can in particular be integrated in the steering device or in the seat of a vehicle. Correspondingly, the surface can for example be the handle surface or the gripping surface of the steering device, or the seat surface or the backrest surface of the seat.

[0017] According to the present invention, there is provided a device for a steering device, which device is for heating the (at the steering device) surface and for recognizing a touch of this surface, which device has a sensor device and a control device and a conductive functional conductor, which is connected to the control device and which serves as a heating wire for heating the surface, wherein the control device has a heating circuit and a sensor circuit (preferably having a measuring circuit), the heating circuit being for heating the surface by means of the functional conductor and the sensor circuit being configured to recognize a touch of the hand on the surface.

[0018] According to the present invention, the sensor device consists of a plurality of capacitive sensors connected to a measuring device for capacitive hand position detection, these capacitive sensors being arranged along the surface, wherein each sensor has at least one sensor electrode, wherein the measuring device is configured to selectively perform a series of detection processes at a plurality of sensors and preferably to enable at least one sensor in each detection process by applying a detection signal at its at least one sensor electrode, wherein the sensors respectively enabled for measurement can be temporarily connected directly or via a resistor to ground or to the vehicle ground by means of a switching element, while the other sensors not enabled during the detection process are separated from ground or from the ground as usual.

[0019] It is particularly advantageous that the measuring device is an integrated component of the sensor circuit, such that the enabling and subsequent measurement of the individual sensors can be controlled by a unit.

[0020] In a preferred design of the present invention, it is also provided that the high-resistance resistor has a resistance of at least 5 kΩ.

[0021] The concept of the present invention is that, firstly, the sensors to be currently measured are temporarily grounded directly or with a high resistance (e.g., exceeding 5 kΩ) in sequence, and then the measurement is carried out. All other sensors (which are not being measured) are simultaneously disconnected via switching elements and not grounded. After the measurement process of the sensor that has just been enabled ends, this scheme is carried out step by step in sequence for the other sensors until the measurement sequence restarts or ends at the first sensor after reaching the last sensor. The disabling of the sensor that has just been enabled and the enabling of the next respective additional sensor can be carried out one after another in close temporal proximity, such that the measurement intervals are very short. It is conceivable that other measurement sequences are also controlled by the control device, where, for example, one or more sensors are not enabled, grounded with a high resistance, and disabled in sequence in the measurement sequence, but are skipped. This can be done during the first run or afterwards.

[0022] According to the present invention, it is thus provided that the control device is configured to first temporarily connect the sensors that are respectively enabled for measurement to ground or earth via a switching element, and then (after disconnecting from earth or ground again) start the capacitance measurement process.

[0023] The following design is further advantageous, wherein the control device is configured to, at the end of each detection process, ground at least one additional sensor that is enabled for the next detection process, and further continue to separate all other sensors that are not enabled during the detection process from ground or earth in the conventional manner, in particular such that the switching elements that are set to connect to ground or earth for these sensors remain disconnected.

[0024] Therefore, the detection process includes temporary grounding and subsequent measurement process.

[0025] The following concept is also advantageous, wherein the control device or the measuring device is configured to enable more than one individual sensor respectively.

[0026] In a preferred design of the present invention, it is provided that a heating wire is used to heat the surface (touch surface), while the sensor device is used to identify the touch of the surface.

[0027] Another advantageous design is to arrange the heating wire in a planar and meandering manner.

[0028] In a preferred configuration, it is provided that the switching element for connecting and disconnecting the sensor from ground or earth is configured as a semiconductor switching element or an electronically controllable switching element.

[0029] The following configuration is further preferred, wherein an optional additional wiring harness Lr connected to the voltage source and ground or earth is arranged parallel to the sensor connection device (wiring harness L1), in which sensor device is arranged between the power supply and ground or earth, the additional wiring harness having at least two switching elements, between which a fixed reference capacitor C ref is connected to ground / earth. Further advantageously, two parallel wiring harnesses are each connected to the measuring device via separate measuring channels, and for this purpose the measuring device has a measuring input for sensor measurement and an input for a reference measuring line for the wiring harness having the reference capacitor C ref .

[0030] Another aspect of the invention also relates to a steering control device for a vehicle, the steering control device having the above-described device, wherein the surface is a gripping surface for gripping the steering control device, such that the gripping surface can be heated and the touch on the gripping surface can be detected.

[0031] As long as technically feasible and not mutually contradictory, the features disclosed above can be combined arbitrarily even without being explicitly described in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other advantageous refinements of the invention are explained in detail below in connection with the preferred embodiments of the invention described with reference to the drawings. Shown are:

[0033] Figure 1 The device according to the invention is shown;

[0034] Figure 2 A schematic diagram for explaining the sensor device is shown;

[0035] Figure 3 The steering control device having the functional conductors of the device is shown.

[0036] The drawings are schematic diagrams. The same reference signs in the drawings indicate identical functional and / or structural features. DETAILED DESCRIPTION

[0037] Figure 1 The device 1 according to the invention is schematically shown. The device has a control device 10 and functional conductors 13 connected to the control device 10, by means of which the surface 2 can be heated and the touch on the surface 2 can be detected.

[0038] In order to heat the surface 2 via the heating line 13, a heating circuit 11 is provided in the control device 10, which heating circuit currently includes a control device 11C and a switching element 11V. In order to be able to detect the touch on the surface 2, the sensor circuit 12 evaluates the capacitance change detected via the functional conductors 13.

[0039] The control device 11C of the heating circuit 11 and the sensor circuit 12 are currently arranged on a common microcontroller 15. However, the control device and the sensor circuit can also be arranged on separate microcontrollers or can generally be arranged separately from each other.

[0040] As part of the device 1 or as part of the control device 10, a voltage supply unit 14 is also provided. However, alternatively, the voltage supply unit does not necessarily have to be understood as part of the device 1 or the control device 10. The sensor circuit 12 and the heating circuit 11 are supplied with a power supply voltage or an operating voltage by the voltage supply unit 14.

[0041] The switching element 11V can be implemented by different circuits.

[0042] Figure 2 A function for heating the surface 2 at the steering device 3 (see Figure 3 ) of the device 1 and for recognizing a touch on the surface 2 at the steering device 3 is shown.

[0043] The sensor device S is connected to the sensor circuit 12. In addition, a conductive functional conductor 13 is provided as a heating wire for heating the surface 2. The control device 10 also has a Figure 1 heating circuit 11 as shown in. The sensor circuit 12 is configured to recognize a touch of a hand on the surface 2. The sensor device S consists of capacitive sensors arranged along the surface 2, and each sensor has at least one sensor electrode.

[0044] Figure 2 It is also shown that an optional wiring harness Lr is arranged in parallel with the sensor connection means L1. The sensor device S is arranged between the voltage source U and the ground E or the ground M.

[0045] The wiring harness Lr is also connected to the voltage source and the ground or the ground, and is equipped with two switching elements SL1 and SL2. Between these two switching elements, a fixed reference capacitor C ref is connected to the ground / ground.

[0046] The capacitance C Sen of the measuring sensor of the sensor device is shown as being adjacent to the capacitance C Fin of the user's hand. Advantageously, the reference capacitor C ref is substantially the same as or in the same order of magnitude as the capacitance C Sen of the measuring sensor. However, if necessary, it can also be different due to the configuration.

[0047] The parallel wire harnesses L1, L2, …, Lr are respectively connected to the measuring device 10 through separate measuring channels. For this purpose, the measuring device 10 respectively has measuring inputs CH1, …, CH for sensor measurement R and an input CH2 for the reference measurement line of the wire harness having the reference capacitance C ref .

[0048] In addition, the sensor circuit 1 is configured to selectively perform a series of detection processes at multiple sensors.

[0049] The surface 2 to be heated (the touch of which should also be detected) so that the device 1 can be set in various applications, where Figure 3 the steering wheel is exemplarily shown as the steering control device 3, which should be heated and the touch of which should be detected.

Claims

1. An apparatus (1) for a steering control device (3), the apparatus being adapted to heat a surface (2) at the steering control device (3) and to recognize a touch of the surface (2) at the steering control device (3), The apparatus has a sensor device (S) and a control device (10) and a conductive functional conductor, which is a heating wire (13), connected to the control device for heating the surface (2). Wherein, The control device (10) has a heating circuit (11) and a sensor circuit (12), the heating circuit being adapted to heat the surface (2) via the heating wire (13), and the sensor circuit being configured to recognize a touch of the surface (2) by a hand. Wherein the sensor device (S) is formed by a plurality of capacitive sensors connected to the sensor circuit (12) for capacitive position detection of a hand (H), the plurality of capacitive sensors being arranged along the surface (2). Wherein each sensor has at least one sensor electrode. Wherein the sensor circuit (12) is configured to selectively perform a series of detection processes at a plurality of sensors and to enable at least one sensor by applying a detection signal at at least one of its sensor electrodes in each detection process. Wherein the control device (10) has a switching element for each sensor, and the control device (10) is configured to temporarily connect the sensors respectively enabled for measurement directly or via a resistor to ground or to the vehicle ground through the respective switching element, while separating the other sensors not enabled during the detection process from ground or the ground connection.

2. The apparatus (1) according to claim 1, Characterized in that, The control device (10) is configured such that the sensors respectively enabled for measurement are temporarily connected to ground or the ground connection through the switching element first, and then the capacitance measurement process is started.

3. The apparatus (1) according to claim 1 or 2, Characterized in that, The control device (10) is configured to enable at least one further sensor and to ground the at least one further sensor at the end of each detection process, and to further keep all other sensors not enabled during the detection process separated from ground or the ground connection.

4. The apparatus (1) according to claim 1 or 2, Characterized in that, The sensor circuit (12) is configured to enable more than one individual sensor respectively.

5. The apparatus (1) according to claim 1 or 2, Characterized in that, The heating wire (13) is used to heat the surface (2), while the sensor device is used to recognize a touch of the surface (2).

6. The apparatus (1) according to claim 1 or 2, Wherein, The heating wire (13) is arranged in a planar and meandering manner.

7. The apparatus (1) according to claim 1 or 2, Wherein, The switching element is configured as a semiconductor switching element or an electronically controllable switching element.

8. The apparatus (1) according to claim 1 or 2, Characterized in that, A wiring harness (L2) connected to a voltage source and ground or earth is arranged in parallel with a sensor connection device (L1), in which a sensor device (S) is arranged between the voltage source (U) and ground or earth. The wiring harness has at least two switching elements (SL1, SL2), between which a fixed reference capacitor C is provided. ref Connected to ground / earth.

9. The apparatus according to claim 8, characterized in that Parallel wire harnesses (L1, L2, …, Lr) are respectively connected to the sensor circuit (12) via separate measurement channels, and to this end, the sensor circuit (12) respectively has a measurement input for sensor measurement and an input for a reference measurement line of the wire harness having a reference capacitance C ref of the wire harness.

10. A steering control device (3) for a vehicle, said steering control device having a device (1) according to one of claims 1 to 9, wherein the surface is a gripping surface for gripping the steering control device, such that the gripping surface can be heated and the touch on the gripping surface can be detected.

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