Control device for a motor vehicle, method for operating a control device and motor vehicle

Abstract

Operating device for a motor vehicle, comprising an operating element (32) which has an operating surface (34) to be touched by a user with a finger for an operating action, a sensor device (40) by which a contact point (BS) of the operating surface (34) of the operating element (32) and the actuating force (F) acting on the operating surface (34) during local contact by the user can be detected, and a control unit (50) which is connected to the sensor device (40) by means of a signal and is configured to compare the actuating force (F) with a release force threshold, wherein the release force threshold is variable, and wherein the control unit (50) is configured to adjust the variable release force threshold depending on the contact point (BS).

Description

[0001] The invention relates to an operating device for a motor vehicle, comprising an operating element which has an operating surface to be touched by a user with a finger for an operating action, a sensor device by which a contact point of the operating surface of the operating element and the actuating force acting on the operating surface during local contact by the user can be detected, and a control unit which is connected to the sensor device by means of a signal and is designed to compare the actuating force with a trigger force threshold.

[0002] Such operating devices are generally known from the prior art and are usually arranged in the vehicle interior, particularly on an instrument panel or center console. The operating device serves to adjust various functions of the vehicle. It comprises a control element, which is typically a touch element, and thus detects contact by a finger. To detect actual activation at a contact point, a trigger force threshold is defined, whereby the actuating force applied by a person at the contact point must be higher than the trigger force threshold for actual activation to be detected. Users perceive such operating elements with a flat operating surface as high-quality if the operating element, or the surface touched by the user, exhibits high, homogeneous stiffness across its entire operating area.Such operating devices are known, for example, from DE 10 2014 018 350 A1, from DE 10 2013 016 491 B4 and from DE 10 2016 123 559 A1, wherein in the embodiment described in DE 10 2014 018 350 A1 the release force threshold is variable such that a force function is stored behind all areas marked with symbols, simulating a button press. The problem is that the stiffness of the operating element, or the stiffness of the operating surface perceptible to the user, differs from one another at different contact points due to various reasons, for example, due to the suspension or bearing of the operating element and / or due to different devices acting on the operating element. As a result, the distance traveled when the control element is actuated in order to apply an actuating force above the trigger force threshold varies depending on the local stiffness at the contact points.The path increases with the reduction in stiffness. As a result, the control element has not only touch points perceived as high-quality by the user, but also touch points perceived as low-quality, i.e., with lower local stiffness.

[0003] Furthermore, DE 10 2015 219 039 A1 discloses a touch sensor for a vehicle interior, which is designed as a capacitive or resistive touch sensor.

[0004] The object of the invention is to provide an operating device which has a control element that is perceived homogeneously when actuated.

[0005] The object of the invention is solved by the features of claim 1.

[0006] According to the invention, the release force threshold is variable, and the control unit is configured to adjust the variable release force threshold depending on the point of contact and thus depending on the local stiffness of the operating element. The release force threshold can increase or decrease with the local stiffness of the operating element.

[0007] Preferably, a predefined release force threshold characteristic curve or a predefined release force threshold characteristic map is stored in the control unit, whereby the release force threshold is defined location-specifically depending on the point of contact. The release force threshold characteristic curve defines the release force threshold in one direction depending on the point of contact. The release force threshold characteristic map defines the release force threshold for the entire two-dimensional, planar operating surface. When determining the release force threshold characteristic curve and the release force threshold characteristic map, all factors influencing the stiffness of the operating element are taken into account, such that the release force threshold is directly related to the local stiffness of the operating element.

[0008] Due to the variable release force threshold, the distance required to trigger a function is the same at every point of contact, thus providing the user with a consistent operating sensation regardless of where the control element is touched. In this simple and cost-effective way, the user perceives the control device as high-quality, irrespective of the point of contact.

[0009] In a preferred embodiment, the control element is a touchscreen or a touchpad. The key difference between a touchpad and a touchscreen is that the touchscreen additionally displays a dynamic image. In both versions, a touch on the control element is detected, and a predefined function is triggered depending on the point of contact. In a preferred embodiment, the touchscreen or touchpad has a resistive or capacitive touch sensor. Resistive touchscreen technology uses a pressure-sensitive layer that responds to touch. This layer consists of two conductive layers separated by a spacer. When the screen is touched, the two layers come into contact and register the touch as an electrical signal.In contrast, capacitive touchscreen technology uses a layer of conductive material, such as indium tin oxide, which stores electrical charge. When the user touches the screen with their finger, some of the charge is transferred, and the touch is registered as a change in capacitance. Both technologies can detect the point of contact.

[0010] In a preferred embodiment, the sensor device comprises a touch-sensitive sensor matrix arranged on the control element. The touch-sensitive sensor matrix is, for example, a resistive or capacitive touch sensor. The touch-sensitive sensor matrix detects the point of contact on the control element's operating surface. The sensor matrix can also be configured to additionally detect the actuating force applied to the operating surface by the user.

[0011] Preferably, the sensor device includes a separate force sensor that can detect the actuating force acting on the operating surface when the user touches it, regardless of the point of contact. For example, the operating element can be supported against the housing-mounted force sensor, thus detecting the actuating force independently of the point of contact.

[0012] In a preferred embodiment, a haptic actuator is provided which is electrically connected to the control unit. The control unit is configured to activate the haptic actuator when the trigger force threshold is exceeded. For example, the actuation force is detected by the force sensor, and if the detected actuation force exceeds the trigger force threshold, the haptic actuator is activated by the control unit, thereby providing the user with feedback about the actuation. The haptic actuator can, for example, be configured to exert a pulsed counterforce or a vibration on the control element, causing the user to feel a brief feedback on their finger.

[0013] Additionally or alternatively, if the trigger force threshold is exceeded, an actuation of the control element can be detected and a function of a vehicle system can be controlled based on this.

[0014] The problem is further solved by a motor vehicle with an operating device according to any one of claims 1 to 7 and by a method for operating an operating device according to any one of claims 1 to 7, wherein the contact point on the operating surface of the control element is first determined and, based on this, the trigger force threshold, which varies across the operating surface, is determined as a function of the contact point. Finally, the actuating force on the operating surface of the control element is determined and compared with the determined, contact-point-specific trigger force threshold, wherein, if the actuating force exceeds the trigger force threshold, a trigger signal, in particular for a haptic actuator or a vehicle system, is generated.

[0015] An embodiment of the invention is explained in more detail with reference to the drawings. Fig. Figure 1 schematically shows a motor vehicle in a perspective view, and Fig. Figure 2 shows an operating device of a motor vehicle. Fig. 1 in a cross-section.

[0016] Fig. Figure 1 shows a section of a motor vehicle 10 with a vehicle interior 12. In the vehicle interior 12, a steering wheel 14, two vehicle seats 161, 162, i.e., two front seats, an instrument panel 18, and a center console 20 are arranged, the center console 20 dividing the vehicle interior 12 into a driver's side, in which one vehicle seat 161 is arranged, and a passenger side, in which the other vehicle seat 162 is arranged.

[0017] A control device 30 is arranged on the center console 20, which is also in Fig. 2 is shown. The operating device 30 comprises a control element 32, which is arranged in an opening of the center console 20 and has a control surface 34 on a side facing the vehicle interior 12.

[0018] The operating device 30 also includes a sensor device 40, which has a touch-sensitive sensor matrix 42 that is connected to a control unit 50 via a signal. The sensor device 40 is located on the side of the operating element 32 facing the vehicle interior 12 and is designed to detect touch, and in particular the exact point of contact BS, of a finger 2 acting on the operating surface 34. The sensor device 40 also includes a force sensor 44, which is connected to the control unit 50 via a signal. The force sensor 44 is attached to the center console 20 and supports the operating element 32 on the side facing away from the vehicle interior 12. The operating element 32 is guided laterally on the center console 20 by several guides 341, 342.

[0019] To provide feedback to the person when operating the control device 30, a haptic actuator 48 is provided, which is electrically coupled to the control unit 50 and can be controlled by the control unit 50. The haptic actuator 48 is arranged on the side of the control element 32 facing away from the vehicle interior 12 and is designed to generate haptic feedback, for example a vibration, to the person touching the control surface.

[0020] When a person applies force to the control element 32 with their finger 2, the force F applied by the person is detected by the force sensor 44, the point of contact BS is detected by the touch-sensitive sensor matrix 42, and the sensor signals are transmitted to the control unit 50. The control unit 50 evaluates the point of contact BS and compares the actuation force K with a trigger force threshold. If the actuation force K exceeds the trigger force threshold, a control signal is generated for a function of a vehicle system (not shown) associated with the point of contact BS. In this way, the control device 30 functions as a touchscreen. Additionally, if the trigger force K exceeds the trigger force threshold, the haptic actuator 48 is activated by the control unit 50, providing the person with feedback about the actuation.

[0021] Due to the connection and mounting of the control element 32, as well as the components mechanically coupled to the control element 32, such as the force sensor 44 and the haptic actuator 48, the stiffness of the control element 32 and the stiffness of the operating surface 34, as perceived by the user, vary. This results in variations in the haptic feedback when the control element 32 is actuated, depending on the contact point BS. In particular, the distance traveled when the control element 32 is actuated to reach the trigger force threshold varies depending on its local stiffness. This distance increases as the stiffness decreases.

[0022] To provide a consistent feel across the entire operating surface 34, the trigger force threshold is adjusted depending on the point of contact BS. The trigger force threshold thus varies depending on which point BS the user applies pressure to the operating surface BS. For example, the trigger force threshold can be relatively high at a point of contact BS where the operating element 32 has relatively high stiffness, such as where the operating element 32 is supported by the force sensor 44, and relatively low at a point of contact BS where the stiffness is relatively low, such as at the edge of the operating element 32. The trigger force threshold varies across the operating surface in such a way that the actuation path is identical at every point of contact BS, i.e., homogeneous across the entire operating surface 34.

[0023] To set the trigger force threshold depending on the contact point BS, a trigger force threshold characteristic map is stored in the control unit 50, so that a corresponding trigger force threshold exists for each contact point BS. All stiffness changes, such as the coupling with the force sensor 44, are taken into account in the trigger force threshold characteristic map.

[0024] When the control element 32 is actuated, i.e., when a person applies pressure to the control surface 34 with a finger 2, the contact point BS on the control surface 34 of the control element 32 is first detected by the sensor matrix 42. The control unit 50 then determines the corresponding trigger force threshold for contact point BS based on the trigger force threshold characteristic map. Subsequently, the actuation force F detected by the force sensor 44 and transmitted to the control unit 50 is compared with the determined trigger force threshold. If the actuation force F exceeds the determined trigger force threshold, the control unit 50 generates a trigger signal, which activates the haptic actuator 48 and transmits it to the vehicle system (not shown).

Claims

[1] Control device for a motor vehicle, with a control element (32) which has a control surface (34) that a user can touch with a finger for an operating action, a sensor device (40) by which a contact point (BS) of the control surface (34) of the control element (32) and the actuating force (F) acting on the control surface (34) during local contact by the user can be detected, and a control unit (50) which is connected to the sensor device (40) by means of a signal and is designed to adjust the actuating force (F) with a release force threshold, wherein the release force threshold is variable, wherein the control unit (50) is designed to adjust the variable release force threshold depending on the point of contact (BS), characterized by , that the control element (32) has a stiffness that varies over the control surface (34), wherein the control element (32) has an associated local stiffness at each contact point (BS), and the release force threshold increases or decreases with the local stiffness of the control element (34). [2] Operating device according to one of the preceding claims, characterized by that the tripping force threshold is determined using a tripping force threshold characteristic curve or a tripping force threshold characteristic map. [3] Operating device according to one of the preceding claims, characterized by , that the control element (32) is a touchscreen or a touchpad. [4] Operating device according to one of the preceding claims, characterized by , that the sensor device (40) has a touch-sensitive sensor matrix (42) which is arranged on the control element (32). [5] Operating device according to any one of the preceding claims, characterized by , that the sensor device (40) has a force sensor by which the actuating force (K) acting on the operating surface (34) when touched by the user, independent of the point of contact (BS), can be detected. [6] Operating device according to one of the preceding claims, characterized by , that a haptic actuator (48) is provided which is electrically connected to the control unit (50), wherein the control unit (50) is designed to control the haptic actuator (48) when the trigger force threshold is exceeded. [7] Operating device according to one of the preceding claims, characterized by , that the control unit (50) is designed to detect an actuation of the control element (32) when the trigger force threshold is exceeded. [8] Method for operating an operating device according to any one of claims 1 to 7, comprising the following steps: - Detection of a touch point (BS) on the operating surface (34) of the control element (32), - Determining a trigger force threshold that varies across the operating surface (34) depending on the point of contact (BS), - Detecting an actuating force (F) on the operating surface (34) of the control element (32), - Comparison of the actuation force (F) with the release force threshold, whereby a release signal is determined if the actuation force (F) exceeds the release force threshold. [9] Motor vehicle with an operating device (30) according to any one of claims 1 to 7.

Images