WO2015049020A1

WO2015049020A1 - Motor vehicle touchscreen with haptic feedback

Info

Publication number: WO2015049020A1
Application number: PCT/EP2014/002145
Authority: WO
Inventors: Ulrich Müller; Manuel Kühner; Manfred Mittermeier; Michael Wachinger
Original assignee: Audi Ag
Priority date: 2013-10-02
Filing date: 2014-08-05
Publication date: 2015-04-09
Also published as: DE102013016491B4; DE102013016491A1

Abstract

The invention relates to an operator control apparatus (16) for a motor vehicle (10), having a plate (26) that a user can touch with a finger (34) and that has a sensor matrix (28), and having a control device (32) that is designed to take sensor signals (S) from the sensor matrix (28) as a basis for emitting an excitation signal (U), and having an actuator (42, 42') that is designed to take the excitation signal (U) as a basis for moving the plate (26), so that the plate (26) executes a deflection movement (44) that can be felt by the finger (34). The actuator (42, 42') is designed to produce only a force (F) that acts in one direction and thereby to apply a predetermined pulse energy to the plate (26), the control device (32) being designed to control the deflection movement (44) by means of the excitation signal (U) and thereby to transmit a predominant portion of the pulse energy to the finger (34) in a first half-cycle (48) of the deflection movement (44).

Description

Motor vehicle touch screen with haptic feedback

DESCRIPTION: The invention relates to an operating device for a motor vehicle. The operating device has a touchpad or touchscreen or generally a disk with a sensor matrix comprising a plurality of sensors for sensing a touch and / or a pressure force. To operate the operating device, a user has to press the pane with a finger. In this case, it is provided that an actuator moves the disk so that the disk carries out a deflection movement to be felt with the finger from an initial position, as a result of which a haptic feedback for the user is generated on the disk. An operating device of the type described is known for example from US 2005/0225539 A1. Thereafter, the disc of a touch screen is resiliently mounted and is shaken to generate the haptic feedback by means of a motor. The disc thus performs a periodic, damped vibration. In connection with a deflection of the disc in the disc plane a unique jerky deflection movement is described.

DE 103 15 841 A1 likewise discloses an operating device with haptic feedback. In this operating device, the push-buttons for pressing and for generating the haptic feedback are spatially separated from a display device.

From DE 10 2005 048 230 A1 a touch screen is known, which is moved to generate a haptic feedback in the disk plane of the touch screen. Here, a shaking movement is provided with several periods of vibration.

From DE 10 2009 034 871 A1 an operating system for detecting user inputs in a motor vehicle with haptic operating feedback is disclosed. known. The feedback is a vibration with continuously increasing frequency but constant vibration amplitude.

In DE 10 2007 005 889 A1 an operating unit for a motor vehicle is described in which a haptic feedback is generated by an electromagnetic, electrostatic or piezoelectric actuator. Here, a touch screen is put into a periodic oscillation with a frequency of 100 Hertz to 400 Hertz. In the known from the prior art controls with touch screen and haptic feedback, it has been found to be disadvantageous that the disc of the touch screen is set in a vibration lasting several periods. However, this is usually necessary in order to achieve a resonance effect, by means of which a noticeable oscillation is generated in the pane of the touchscreen even with a relatively low-power actuator.

In contrast, a haptic feedback is not provided as a periodic vibration in the push-buttons also usually present in motor vehicles, but the passive, translational control element is pressed in an operating direction and the resulting triggered by the push-button controlled function is often the user abrupt drop (click), which is caused by a path-dependent actuation force (force-displacement curve). The drop in force can be coupled with an impulsive sound, ie a clicking sound. The technical realization of the force-displacement curve is usually done by Gummischaltmatten, snap discs, which are also referred to as crackpot frog, or microswitch. By pressing a push-button and then pressing a touchscreen with haptic feedback, the user clearly senses an inhomogeneity of the haptic feedback.

The object of the invention is to ensure the homogeneity of the operating haptics in a motor vehicle.

The object is solved by the subject matters of the independent claims. Advantageous developments of the invention will become apparent from the features of the dependent claims. Accordingly, an operating device for a motor vehicle is provided by the invention. In the known manner, the operating device has a touch-sensitive disk to be touched by a user with a finger for an operating action, which has a sensor matrix with a plurality of sensors, as is known from a touchscreen and a touchpad. For detecting whether the user presses the disc, a control device is provided which receives the sensor signals of the sensor matrix and detects a touch of the disc and / or a release of the disc on the basis of the sensor signals. The latter is the case when the user lifts his finger off the disc again, so the pressure subsides. Upon detection of the touch and / or release, the control device in each case sends out an excitation signal which serves to activate an actuator. This actuator is designed to move and / or deform the disk as a function of the excitation signal, so that the disk carries out a deflection movement to be felt with the finger from a starting position. The starting position may be different from the rest position of the disk assumed at un actuated state, so that the user should first press the disk with a predetermined actuating force and thus deform or deflect it before the haptic feedback is generated. The excitation signal can also be generated if a change of state of the operating device is to be signaled as haptic feedback, ie, for example, whenever a new menu item has been reached when scrolling through an operating menu.

In the operating device according to the invention, the actuator is now designed to perform no multiple periods comprehensive vibration, but only to produce a unidirectional force acting on the disc and thereby act on the disc with a predetermined pulse energy. The actuator ruptures or thus abuts only the disc with a single jerk. However, the disk itself could then vibrate and, corresponding to a mass-spring system, execute a vibration that spans several periods. In order to prevent this, in the operating device according to the invention the deflection movement is controlled by the control device by means of the excitation signal. The deflection signal is in this case designed in such a way that a predominant part of the pulse energy is transmitted to the disc and / or the finger in a first half-wave of the deflection movement. The invention has the advantage that the user feels the snaps or tapping or clicking also known from push buttons when pressing the disc. At the same time, the operating device according to the invention can be provided with very simple means, since only one actuator is necessary, which must be able to generate a force only in one direction. In this case, the actuator can transmit the force with a force direction vector to the disk, which lies in the disk plane or is oriented transversely or perpendicular to the disk plane. As already stated, the disk can be provided as part of a touchscreen or a touchpad.

Since the actuator exerts its force in one direction only, it is provided according to a development of the invention that the disc and / or a holding device of the disc is designed to generate a restoring force in the direction of the rest position. It is particularly preferred that even the restoring force is formed by a mechanical tension of the disc, so their elastic deformation. Then no additional mechanical components are needed.

According to one embodiment of the invention, in the deflection movement, the maximum deflection of the disc from the starting position is less than 0.7 mm, in particular less than 0.5 mm. As a result, the material of the disc is protected and only one actuator with relatively low drive power is required. However, by concentrating the pulse energy in the first half cycle of the deflection movement, this small deflection is perfectly sufficient to produce a feedback noticeable to the user. The excitation signal for controlling the force generated by the actuator is preferably non-periodic. As a result, vibrations are avoided in the disc. In this case, the excitation signal is preferably embodied as an impulse, that is to say it has a chronological progression which starts from zero starting in an amplitude direction, in order then to fall back to the zero line and to remain there. In this case, the rise is preferably configured as a jump, that is, as a rising edge, through which the amplitude increases in a period of, for example, less than one or two or five milliseconds from the zero line to the maximum amplitude. According to an advantageous embodiment of the invention it is provided that the excitation signal has a sloping ramp and / or a multi-stage sloping course. This results in the advantage that the disc is braked after the maximum deflection when swinging back into the starting position, so that overshoots are damped.

The described course of the excitation signal can be designed as an analog signal, that is to say as a continuous signal. Another development of the invention provides that the excitation signal is formed by a pulse width modulation, that is, the course described above represents an average value of the output signal generated by pulse width modulation. A pulse width modulation has the advantage that the excitation signal without digital-to-analog converter can be generated by simply switching between two switching states.

Another advantage of the operating device according to the invention is that numerous different types of actuators can be used. Actuators with a PT1 behavior are preferably provided, ie actuators which, based on the output quantity force, at least approximately function according to a PT1 element, ie have a proportional transmission behavior with a first-order delay. This results in the advantage that the excitation signal does not have to be determined expensively via an inversion of the system model, as is usual, for example, in the context of control technology in the context of feedforward control. In particular, an actuator with PT1 behavior can also reliably generate step-like excitation. An example of such an actuator is, apart from the known non-linearities of this actuator class, an electrodynamic actuator with the input voltage and the output force. Another, particularly suitable class of actuators are electroactive polymers. These have the advantage that the falling edge of the activation signal can be implemented as a sliding and thus particularly good damping movement. An actuator based on a piezoelectric crystal is also suitable for generating mechanical excitation pulses.

The invention also includes a motor vehicle, which includes an embodiment of the operating device according to the invention and at least one. mechanical actuator, such as a push button or a rocker switch has. The actuator is characterized from that it has a snap mechanism, which has the sudden drop in the force-displacement curve described above, that produces a noticeable click when pressing. In the motor vehicle according to the invention, it is now provided that the operating device with its disk (touchscreen or touchpad) and the actuator is designed to imitate by means of the actuator a haptic impression caused by the snap mechanism when the actuating element (pushbutton) is triggered by means of the disk. In other words, the user feels when pressing the disc, so for example, a touchpad, the same click effect, as when pressing the actuator, such as, for example, the push button. This results in the advantage that in the motor vehicle according to the invention the Bedienhaptik is homogeneous.

The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car.

The invention is also realized by a method in which upon detection of contact of the disc described by means of an actuator, a deflection force is generated only in a predetermined direction and thereby dje disc is subjected to a unidirectional deflection pulse.

Developments of the method according to the invention which have features which have already been described in connection with the operating device according to the invention also belong to the invention. For this reason, the corresponding developments of the method according to the invention will not be explained again here.

The sensor matrix of the disk can be touch sensors and / or pressure sensors or else proximity sensors, by means of which, for example, a change in an electrical capacitance by making the finger approach can be measured.

In the following an embodiment of the invention is described. This shows:

1 is a schematic representation of an embodiment of the motor vehicle according to the invention, 2 shows a diagram with a schematic progression of a deflection movement of a contact-sensitive pane of the motor vehicle of FIG. 1, FIG.

Fig. 3 to

Fig. 6 are each a diagram with a schematic course of a

Excitation signal of a control device of the motor vehicle of FIG. 1.

The exemplary embodiment explained below is a preferred embodiment of the invention. In the exemplary embodiment, however, the described components of the embodiment each represent individual features of the invention, which are to be considered independently of one another and which also develop the invention independently of one another and thus also individually or in a different combination than the one shown as part of the invention are. Furthermore, the described embodiment can also be supplemented by further features of the invention already described.

In Fig. 1 of a motor vehicle 10 of the vehicle interior 12 is shown. Shown is a dashboard 14, in which a touchpad 16 and a push button 18 can be installed. For the following explanations, a deflection direction X is defined for better orientation.

The pushbutton 18 represents an actuating element, which yields when pressed on a touch surface 20, for example, with the finger and moves in the direction of deflection X in the dashboard 14. In this case acts on the pushing finger a restoring force R 'to the rest position shown in Fig. 1 of the push button 18 back. The course of the restoring force R 'as a function of the deflection X is shown in FIG. 1 below the pushbutton 8. The push-button 18 may have a snap-action disc 22, by means of which the restoring force R 'initially increases with increasing deflection X, in order to abruptly drop off at a snap point 24, so that the user feels a click with his finger.

The touchpad 16 represents an embodiment of the operating device according to the invention. The touchpad 16 may have a disk 26 with a sensor matrix 28. The sensor matrix 28 can in a known manner a Have a plurality of individual sensors 30, of which in Fig. 1 for the sake of clarity, only a few are provided with a reference numeral. The sensors 30 of the sensor matrix 28 are coupled to a control device 32, which may be, for example, a microcontroller or a control device. The control device 32 recognizes from the sensor signals S of the sensors 30 when a user presses with his finger 34 on the disk 26. On the basis of the sensor signals S can be detected in particular, where on the disk 26, the point of contact of the finger 34 with the disk 26. The touchpad 16 can also be designed as a touchscreen.

In the motor vehicle 10 is ensured at an actuation of the touchpad 16 that the user perceives the perceived as a generally high-quality haptic impression that he feels when triggering the pushbutton 18 due to the click effect, even with the touchpad 16. The touchpad 16 is thereby designed according to the invention as an active, translational, ie to be pressed, control. The user feels at the fingertip of the finger 34 in spite of the closed surface of the disc 26 when pressing the disc 26 a click, as he feels it at the push button 18. If the user presses with the finger 34 on the disk 16 with a pressing movement 36, then acts on the finger 34, a restoring force R, the course of which is also shown in Fig. 1 as a function of the deflection X. The force-displacement curve 38 shows that likewise the restoring force R increases with increasing deflection X, in order then to abruptly drop at a snap-action point 40.

In the case of the disk 26, no snap disk is used here, but an actuator 42 which is mechanically coupled to the disk, e.g. is glued, and upon reaching the snap point 40 a deflection force F exerts on the disc. As a result, the disc 26 is deflected jerkily in the deflection direction X, which the user feels with the finger 34 as a click on the disc surface.

The actuator 42 is controlled by the control device 32 by means of a deflection signal U, which may be a voltage signal, for example. The control device 32 recognizes on the basis of the sensor signals S that the finger 34 presses the disk 26 and generates the deflection signal U when the snap point 40 is reached. The actuator 42 pulls on the disk 26 in the example shown so that it continues in the direction of deflection X. emotional. An amplitude of the deflection signal U may correspond to an amplitude of a deflection of the disk 26 caused by the actuator 42. It may also be a pressure on the disc 26 are exerted by the actuator 42. Alternatively, a lateral movement for pressing movement 36 can be generated by an actuator 42 'acting in a disk plane of the disk 26.

The activation of the actuator 42 by means of the deflection signal U effected active deflection of the disc 26 at the snap point 40 is shown in Fig. 2 again in more detail. Shown is the course of the deflection X over the time t. Upon reaching the snap point 40 of the actuator 42 pulls with the deflection force F on the disc 26 so that the deflection X, starting from their current starting position at the snap point 40 further increases. The inertia of the disc 26 and the actuator components of the actuator 42 results in a curved course of the deflection movement 44. The actuator 42 deflects the disc 26 with a single pulse, that is, the deflection force F acts unidirectionally for a predetermined period of time 46. A maximum additional Deflection 52, which is caused by the actuator 42 after reaching the snap point 40, may be in a range up to 7 mm, preferably up to 5 mm.

Thereafter, it can be provided that the disc 26 oscillates automatically by their mechanical deformation back to the starting position. In this case, however, it is ensured that the predominant part of the pulse energy transmitted by the actuator to the disk 26 is concentrated in a first half-wave 46 and transmitted to the finger 34. A swinging 50 of the disc 26 is strongly attenuated in the touchpad 6.

For this purpose, the deflection signal U is generated by the control device 32 in a manner adapted to the disc 26 and its mechanical suspension. Possible signal curves of the triggering signal U are explained in FIGS. 3 to 6.

In the excitation signal U according to FIG. 3, the rising edge 54 is formed according to a step function. This will create the click effect. The sloping region 56 has two steps 58. As a result of this multistage drop of the excitation signal U, the disk 26 is guided or decelerated during its movement. FIG. 4 shows an excitation signal U with a total of three stages 58 as a multi-stage profile. This avoids that the user with the finger 34 notes the gradual return as further clicks. In Fig. 5, an excitation signal U is shown with a sloping ramp 60 through which a particularly smooth and jerk-free provision of the disc 26 is reached in the starting position.

FIG. 6 shows how such a ramp can be achieved by means of a pulse-width-modulated excitation signal 62. For illustration, an effective value 64 of the pulse-width-modulated signal 62 is also shown.

The haptic feedback provided at the touchpad 16 can be used to inform the user quite generally of a function triggering or to give him feedback about the state of the operated system. An example of the second aspect would be a haptic feedback on the selection or marking of a new item in a list, for example, when the user strokes or wipes his finger 16 over the touchpad 16.

In conventional push buttons, the movement of the surface 20 is parallel or normal to the actuation direction. In the case of an active translatory operating part, such as the touchpad 16, a comparable haptic impression can also be generated by a lateral movement of the surface of the pane 26 relative to the actuation direction 36, without the user consciously perceiving this. This is possible as long as the deflection amplitude is small enough. Active controls are activated by actuators. The actuators are energy converters that convert, for example, electrical, pneumatic or hydraulic energy into mechanical energy, in particular force and movement. Aside from an actuator, active control elements can generally be described as an approximate mechanical mass-damper-spring system. In addition, they usually have dissipation due to non-linear friction components, which also have to be taken into account. In the operating device according to the invention is now moved in such a way that as a rule perceived high quality haptic feedback is generated with an active control. The method relates both to a lateral and parallel direction of movement with respect to the actuation direction 36.

The haptic feedback is generated by a brief, impulsive stimulation of the surface in contact with the user. In particular, the excitation does not occur periodically, which distinguishes it from the haptic feedback systems known from the prior art. The excitation takes place, as already described, in such a way that the deflection of the disc preferably has the time profile shown in FIG. Key features of this deflection are that the course has a strongly damped characteristic. The movement consists of a few periods of oscillation, ideally one or a half period. The movement is preferably completed after 10 to 30 milliseconds. The maximum deflection is preferably less than 0.5 mm.

The diagrams in FIGS. 3 to 6 show the basic profile of the triggering signal, that is to say the control voltage, for achieving the haptic impression described in FIG. 2, wherein the voltage can also be pulse width modulated, as illustrated in FIG is.

The actuator 42, as a particular advantage, must only be able to generate a force in one direction only.

The invention thus advantageously makes it possible to imitate a haptic impression of a pushbutton or another actuating element generating a clicking effect, even when an active control element, such as a touchpad or touchscreen, is actuated.

Claims

CLAIMS:

First operating device (16) for a motor vehicle (10), with

a touch-sensitive disc (26) to be touched by a user with a finger (34) for an operating action and having a sensor matrix (28) comprising a plurality of sensors (30),

- A control device (32) which is adapted to receive sensor signals (S) of the sensor matrix (28) and at a detected based on the sensor signals (S) touching the disc (26) and / or one of the sensor signals (S) detected Releasing the disc (26) and / or for signaling a change in state of the operating device in each case an excitation signal (U) to send, and

an actuator (42, 42 ') which is designed to move and / or deform the disc (26) in dependence on the excitation signal (U) so that the disc (26) moves out of a starting position performs deflection movement (44) to be felt with the finger (34),

characterized in that

the actuator (42, 42 ') is adapted to generate only a unidirectionally acting force (F) on the disc (26) and thereby to act on the disc (26) with a predetermined pulse energy, the control means (32) adapted thereto is to control the deflection movement (44) by means of the excitation signal (U) and thereby to transmit a predominant part of the pulse energy in a first half-wave (48) of the deflection movement (44) on the finger (34).

2. Control device (16) according to claim 1, wherein the disc (26) in a touch screen or a touchpad (16) is provided.

3. Operating device (16) according to any one of the preceding claims, wherein the disc (26) and / or a holding device of the disc (26) is adapted to generate a restoring force in the direction of a rest position of the disc.

4. Operating device (16) according to any one of the preceding claims, wherein in the deflection movement (44) a maximum deflection (52) of the disc (26) from the initial position is less than 0.7 mm, in particular less than 0.5 mm.

5. Operating device (16) according to one of the preceding claims, wherein the excitation signal (U) is non-periodic.

6. Operating device (16) according to one of the preceding claims, wherein the excitation signal (U) has a sloping ramp (60) and / or a multi-stage sloping course (56).

7. Operating device (16) according to one of the preceding claims, wherein the excitation signal (U) by a pulse width modulation (62) is formed.

8. Operating device (16) according to one of the preceding claims, wherein the actuator (42, 42 ') has a PT1 behavior.

9. Motor vehicle (10) with an operating device (16) according to one of the preceding claims and at least one mechanical actuating element (18) which has a snap-action mechanism (22), wherein the operating device (16) is designed, by means of the actuator (16). 42, 42 ') imitate a haptic impression caused by the snap mechanism (22) when the actuating element (18) is triggered by means of the disc (26).

10. A method for operating a motor vehicle operating device (16) having a proximity and / or touch-sensitive disc (26), wherein upon detection of a touch of the disc (26) and / or a release of the disc (26) and / or for signaling a change in state of the operating device, a deflection force (F) is generated by means of an actuator (42, 42 ') only in a predetermined direction (X) and thereby a unidirectional deflection pulse (48) is applied to the disc (26).