Control device with active haptic feedback for a vehicle

Abstract

Described is an operating device (10) with active haptic feedback for a vehicle, which has a two-mass oscillation system, namely a first oscillation system with a first resonant frequency comprising a housing (12) and a control panel (14) spring-elastically mounted thereon, and a second oscillation system with a second resonant frequency comprising a moving-coil actuator (18) which has a stator (20) and a translator (26) with a magnet spring-elastically connected to it. The moving-coil actuator (18) is controlled by a control signal which has signal components at a first excitation frequency and a second excitation frequency that are above and below the first resonant frequency or the second resonant frequency, or below the first resonant frequency and above the second resonant frequency.

Description

[0001] The invention relates to an operating device for a vehicle, wherein the operating device has active haptic feedback.

[0002] Touch-sensitive controls for vehicles, particularly touchscreens or touchpads, are very popular. With touch-sensitive controls, it is advantageous to provide the user with tactile feedback that the desired command has been recognized and accepted. This haptic feedback can be passive or active. In the former case, the control panel is coupled with a conventional switch, which, due to its design and force-displacement characteristic, triggers haptic feedback. However, the subjective perception for the user can be insufficient, especially with larger and therefore heavier control panels.

[0003] Known haptic feedback systems with active triggering of tactile feedback are based on vibration systems excited by a typically electromagnetic actuator. Corresponding systems and methods for outputting active haptic feedback to an operator are disclosed in DE 10 2023 122 631 A1 and DE 10 2022 108 877 A1, which each disclose an input method and an input device with active haptic feedback and vibration suppression. An input device with active haptic feedback and vibration suppression is also disclosed in DE 10 2019 112 461 A1. To convey the typical "click" sensation of a classic switch or button to the operator, as with a passive haptic feedback system, it is advantageous if the actively excited systems exhibit minimal vibration.For this purpose, for example, the actuator is controlled again with a stop pulse shortly after the initial excitation in order to suppress further oscillation or at least to dampen it significantly.

[0004] The object of the invention is to simplify the control of the actuator of an operating device with active haptic feedback for a vehicle, whereby the operating panel of the operating device hardly vibrates.

[0005] To solve this problem, the invention proposes an operating device with active haptic feedback for a vehicle, wherein the operating device is provided with - a case, - a control panel with a touch-sensitive user interface for manual operation by touching an object, such as a person's finger, - wherein the control panel is spring-loaded on and / or in the housing and together with the housing forms a first vibration system with a first resonant frequency, - a moving coil actuator for mechanical excitation of the control panel upon detection of valid manual operation of the control panel's user interface, - wherein the moving coil actuator has a stator comprising an electrical coil and a translator comprising a magnet, connected to it by a spring elasticity, and forms a second oscillation system with a second resonant frequency, - wherein the translator is rigidly mechanically connected to the control panel and the stator is free from any mechanical connection to both the control panel and the housing, or wherein the stator is rigidly mechanically connected to the control panel and the translator is free from any mechanical connection to both the control panel and the housing and - wherein the translator or the stator is mechanically movable when the moving coil actuator is activated, and thus the control panel can be mechanically excited, and - an evaluation and control unit that receives signals from the touch sensors of the operator panel and evaluates them for valid operation and, upon detection of valid operation of the operator panel's user interface, outputs a control signal to the stator for pulse-like mechanical movement of the translator or stator, - wherein the control signal has signal components at a first excitation frequency and at a second excitation frequency, and - wherein the first excitation frequency is below the smaller of the two resonance frequencies by a predefinable first value and the second excitation frequency is above the larger of the two resonance frequencies by a predefinable second value or - wherein the first excitation frequency is below the first resonance frequency by a predefinable first value and the second excitation frequency is above the first resonance frequency by a predefinable second value, or the first excitation frequency is below the second resonance frequency by a predefinable first value and the second excitation frequency is above the second resonance frequency by a predefinable second value.

[0006] According to the invention, the operating device comprises a control panel with a touch-sensitive user interface for manual operation by touching it with an object, such as a finger, a writing instrument, a pen, or the like. The control panel, which can be a touchscreen, for example, is spring-loaded and mounted on or within a housing, forming a first oscillation system with a first resonant frequency. The control panel is mechanically excited by a moving-coil actuator. This mechanical excitation occurs when valid manual operation of the control panel's user interface is detected. This is the case when the control panel is subjected to a minimum pressing force or a minimum depressing movement, as is typically the case when the control panel is actuated. The moving-coil actuator comprises a stator and a translator connected to it by a spring.The stator is equipped with an electrical coil, while the translator has a magnet. According to the invention, either the stator or the translator is mechanically fixed to the control panel. When the translator is activated, it vibrates and thus mechanically excites the control panel. An evaluation and control unit detects both a valid activation of the control panel and controls the moving-coil actuator to produce a pulsed mechanical movement of the translator or stator, by means of an electrical control signal.

[0007] According to the invention, this control signal has signal components at a first excitation frequency and at a second excitation frequency. The control signal preferably does not have any other frequencies.

[0008] According to the invention, the magnitudes of these two excitation frequencies are selected such that the first excitation frequency is below the smaller of the two resonance frequencies by a predefinable first value, and the second excitation frequency is above the larger of the two resonance frequencies by a predefinable second value. However, it is advantageous if the first excitation frequency is below the first resonance frequency by a predefinable first value, i.e., below the resonance frequency of the first vibration system comprising the housing and the control panel, while the second excitation frequency is above the first resonance frequency by a predefinable second value.Alternatively, the first excitation frequency can be below the second resonant frequency by a predefinable first value, i.e., below the resonant frequency of the moving coil actuator, while the second excitation frequency is above the second resonant frequency by a predefinable second value.

[0009] Experiments have shown that the selection of the control signal according to the invention, with the two excitation frequencies which, as described above, are related to the resonance frequencies, results in an extremely short decay time. Furthermore, it has been shown that it is advantageous if the control signal is a superposition of two time-limited and amplitude-modulated sine waves. Finally, experiments have also shown that the amplitude of the sine wave with the second excitation frequency should be smaller than the amplitude of the sine wave with the first excitation frequency.

[0010] The concept according to the invention makes it possible to excite the overall system in such a way that sufficient energy can be introduced into the system. However, the invention avoids exciting the overall system at the typically dominant first resonant frequency, which is defined by the vibration system consisting of the housing and control panel. Because the excitation frequencies of the control signal are located close to this first resonant frequency, namely above and below it, sufficient energy is introduced into the overall system without it oscillating at the first resonant frequency. The difference between the two excitation frequencies defines the width of a frequency band with the excitation frequencies as the corner frequencies, which is advantageous with regard to the decay phase.

[0011] In an advantageous embodiment of the invention, it can be provided that the first resonant frequency and the second resonant frequency are essentially identical, i.e., that one of the two resonant frequencies deviates from the other of the two resonant frequencies by less than 40%, or less than 30%, or less than 20%, or less than 10%, or less than 5%, or that the two resonant frequencies are identical and thus both vibration systems have the same common resonant frequency, wherein the first excitation frequency of the control signal is below the common resonant frequency by the predefinable first value and the second excitation frequency of the control signal is above the common resonant frequency by the predefinable second value.

[0012] Furthermore, it can be advantageous if the first value and the second value are each between 10% and 70%, or between 10% and 60%, or between 10% and 50%, or between 10% and 30%, or between 10% and 20% of the first resonant frequency and / or the second resonant frequency.

[0013] Typically, the resonant frequencies of a spring-coupled housing and control panel lie between 90 and 200 Hz. The resonant frequency of a commonly used moving-coil actuator also lies within this frequency range. Therefore, the first excitation frequency of the control signal should be between 50 Hz and 150 Hz, and the second excitation frequency between 160 Hz and 250 Hz.

[0014] It is advantageous if the control signal is designed as a superposition of two time-limited and amplitude-modulated sine waves, where the frequency of one sine wave is equal to the first excitation frequency and the frequency of the other sine wave is equal to the second excitation frequency. In particular, the control signal consists exclusively of the two aforementioned sine waves.

[0015] According to a further embodiment of the invention, it is advantageous if the ratio of the amplitude of the signal component of the control signal at the second excitation frequency to the amplitude of the signal component of the control signal at the first excitation frequency is less than or equal to 1, or less than or equal to 0.9, or less than or equal to 0.8, or less than or equal to 0.7, or less than or equal to 0.6, or less than or equal to 0.5.

[0016] The invention is described in more detail below with reference to several exemplary embodiments. Specifically, the following are shown: Fig. 1 schematically the main components of an embodiment of the operating device, which forms a two-mass total vibration system and Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6 diagrams under different assumptions of the resonance frequencies of both oscillation systems and for different control signals for the moving coil actuator in the frequency domain (see the respective figures (a)) and in the time domain (see the respective figures (b)).

[0017] In Fig. Figure 1 schematically shows the operating device 10, which comprises a housing 12 and an operating panel 14, which can, for example, be electro-optical and, in particular, implemented as a touchscreen. As shown in Figure 16, the operating panel 14 is spring-loaded on the housing 12.

[0018] Mechanically coupled to the control panel 14 is a moving coil actuator 18, which has a stator 20 with an electrical coil 22 and a translator 26 with a magnet, which is spring-elastically connected to the stator (indicated at 24).

[0019] As in Fig. As shown in Figure 1, in this embodiment the stator 20 is rigidly connected to the underside of the control panel 14. The translator is suspended from the stator 20 via the spring-loaded connection 24.

[0020] The operating device 10 also includes an evaluation and control unit 28, which is typically electronic and includes a microprocessor as well as the associated peripherals such as RAM, ROM memory, I / O ports, etc.

[0021] The control panel 14 has a touch sensor 30 that can detect where the operating surface 32 of the control panel 14 is touched, for example, by a finger 34 of a hand. The touch sensor 30 sends signals to the evaluation and control unit 28, which also receives a signal from, for example, a distance sensor 36 and recognizes a valid actuation of the control panel 14. In such a case, the evaluation and control unit 28 uses a control signal to activate the electrical coil 22 of the stator 20, whereupon the translator 26 of the moving-coil actuator 16 begins to oscillate. According to the invention, the control signal is selected such that the actuation itself is sharp and short-term, and the decay phase is largely suppressed, so that the person operating the control device 10 experiences tactile feedback similar to that of a mechanical button or switch.

[0022] In principle, the design of the overall vibration system is governed by the fact that the system properties of the control device, such as stiffness, are specified by the vehicle manufacturer. Unfortunately, the moving-coil actuators used according to the invention are not always freely configurable. The natural frequencies of the actuator and the vibration system consisting of the control panel and housing (operating device) determine the overall system behavior. A small difference between the two natural frequencies is advantageous with regard to improved efficiency and robustness under changes. Furthermore, a small difference in the natural frequencies leads to improved damping of the overall system if the device itself tends to oscillate freely, as is the case, for example, when the movement of the control panel is enabled by metal springs.

[0023] The idea according to the invention is to select the control frequency of the moving-coil actuator that lies beside the device's natural frequency, i.e., besides the first resonant frequency of the oscillating system consisting of the control panel 14 and the housing 16, specifically both above and below the first resonant frequency. It has been found that excitation frequencies approximately 20% to 60% below and 20% to 60% above the first resonant frequency are advantageous. A so-called fundamental pulse has proven advantageous as the control signal. This pulse is the superposition of two exponentially enveloped sine waves, one of which has a frequency equal to the first excitation frequency below the first resonant frequency, and the other of which has a frequency equal to the second excitation frequency above the first resonant frequency.Such exponentially enveloping sine waves can be easily described and defined analytically, without poles and also without divergence / convergence problems.

[0024] The schematic in Fig. The two-mass oscillation system shown was simulated assuming different resonant frequencies for both oscillation systems and for control signals based on superpositions of two time-limited and amplitude-modulated sine waves with different frequencies above and below the device's natural frequency (first resonant frequency of the oscillation system consisting of the control panel 14 and the housing 12). The control panel 14 was assumed to weigh 100 g, while the weights for the moving-coil actuator elements 16 were assumed to be 5 g for the stator 20 and 5 g for the translator 22. The stiffness of the elastic mounting 16 and the elastic connection 24 were assumed to be between 4 kN / m and 15 kN / m, and their damping values ​​2 kg / s. Example 1 - First resonant frequency 100 Hz (device natural frequency) - Second resonant frequency 100 Hz (actuator natural frequency) - Control signal A(t)* (Sine (60 Hz) + Sine (160 Hz)) - Frequency domain - Combination of excitations below and above the device's natural frequency (first resonant frequency) - significant broadening of the spectrum without reduction on one side - Time domain - very short wave packet with a non-continuous amplitude profile (beats) - rapid decay of the oscillations - short interval between oscillations at the beginning of the control signal, resulting in a very distinct haptic feel overall.

[0025] In Fig. 2a shows the transfer function (system function) in the frequency domain, while in Fig. 2b the control signal (input signal) and the oscillation behavior (motion signal) of the two-mass oscillation system are shown in the time domain. Example 2 - First resonant frequency 100 Hz (device natural frequency) - Second resonant frequency 130 Hz (actuator natural frequency) - Control signal A(t)* (Sine (50 Hz) + Sine (180 Hz)) - Frequency domain - Broadening of the spectrum in the range of the device's natural frequency - Time domain - short wave packet with strong damping during decay - An additional frequency below the device's natural frequency reduces oscillation.

[0026] In Fig. Figure 3a shows the transfer function (system function) in the frequency domain, while in Fig. 3b the control signal (input signal) and the oscillation behavior (motion signal) of the two-mass oscillation system are shown in the time domain. Example 3 - First resonant frequency 130 Hz (device natural frequency) - Second resonant frequency 100 Hz (actuator natural frequency) - Control signal A(t)* (Sine (60 Hz) + Sine (160 Hz)) - Frequency domain - Factor F ≤ 1 to adjust the ratio of the amplitudes of the frequency components - The high-frequency component must not become too high to avoid free oscillation of the system. - Time domain - short, concise signal - rapid drop in signal strength - greatly reduced amplitude / inefficient control, therefore only applicable if sufficient reserve is available

[0027] In Fig. 4a shows the transfer function (system function) in the frequency domain, while in Fig. 4b the control signal (input signal) and the oscillation behavior (motion signal) of the two-mass oscillation system are shown in the time domain. Example 4 - First resonant frequency 180 Hz (device natural frequency) - Second resonant frequency 100 Hz (actuator natural frequency) - Control signal A(t)* (sine wave (150 Hz) + sine wave (220 Hz)) - Excitation pulse with a lower and higher frequency than the device's natural frequency - Frequency domain - Broadening of the spectrum with amplification of the ranges above and below the device's natural frequency (180 Hz) - Time domain - short wave packet with slow decay (but with low amplitude)

[0028] In Fig. 5a shows the transfer function (system function) in the frequency domain, while in Fig. 5b the control signal (input signal) and the oscillation behavior (motion signal) of the two-mass oscillation system are shown in the time domain. Example 5 - First resonant frequency 100 Hz (device natural frequency) - Second resonant frequency 180 Hz (actuator natural frequency) - Control signal A(t)* (Sine (60 Hz) + Sine (140 Hz)) - Excitation pulses with lower and higher frequencies than the device's natural frequency (100 Hz) - Frequency domain - Broadening of the spectrum with amplification of the areas above and below the device's natural frequency (100 Hz) - Time domain - short wave packet with slow decay (but with low amplitude)

[0029] In Fig. 6a shows the transfer function (system function) in the frequency domain, while in Fig. 6b the control signal (input signal) and the oscillation behavior (motion signal) of the two-mass oscillation system are shown in the time domain. REFERENCE MARK LIST 10 Operating device 12 cases 14 Control panel 16 spring-elastic bearings 18 Moving coil actuator 20 Stator 22 electrical coil 24 spring-elastic connection 26 Translator 28 Evaluation and control unit 30 Touch sensors 32 User interface 34 fingers 36 Distance sensor

Claims

Operating device with active haptic feedback for a vehicle, comprising: a housing (12); an operating panel (14) with a touch-sensitive user interface (32) for manual operation by touching an object, such as a person's finger (34); the operating panel (14) being spring-loaded on and / or in the housing (12) and forming a first oscillation system with a first resonant frequency together with the housing (12); a moving-coil actuator (18) for mechanically exciting the operating panel (14) upon detection of valid manual operation of the user interface (32) of the operating panel (14); the moving-coil actuator (18) comprising a stator (20) having an electrical coil (22) and a translator (26) having a magnet and spring-loaded to the stator, forming a second oscillation system with a second resonant frequency.- wherein the translator (26) is mechanically connected to the control panel (14) and the stator (20) is free from any mechanical connection to both the control panel (14) and the housing (12), or wherein the stator (20) is mechanically connected to the control panel (14) and the translator (26) is free from any mechanical connection to both the control panel (14) and the housing (12), and- wherein the translator (26) or the stator (20) is mechanically movable when the moving coil actuator (18) is actuated, and thus the control panel (14) can be mechanically excited, and- an evaluation and control unit (28) which receives signals from the touch sensors of the control panel (14) and evaluates these for valid operation, and upon detection of valid operation of the user interface (32) of the control panel (14) sends a control signal to the stator (20) for the pulse-like mechanical movement of the translator (26) or stators (20), characterized by- that the control signal has signal components at a first excitation frequency and at a second excitation frequency, and- that the first excitation frequency is below the smaller of the two resonance frequencies by a predefinable first value and the second excitation frequency is above the larger of the two resonance frequencies by a predefinable second value, or- that the first excitation frequency is below the first resonance frequency by a predefinable first value and the second excitation frequency is above the first resonance frequency by a predefinable second value, or the first excitation frequency is below the second resonance frequency by a predefinable first value and the second excitation frequency is above the second resonance frequency by a predefinable second value. Control device according to claim 1, characterized in that: - the first resonant frequency and the second resonant frequency are essentially identical, i.e., that one of the two resonant frequencies deviates from the other of the two resonant frequencies by less than 40%, or less than 30%, or less than 20%, or less than 10%, or less than 5%; or - the two resonant frequencies are identical, and thus both vibration systems have the same common resonant frequency, wherein the first excitation frequency of the control signal is below the common resonant frequency by the predefinable first value, and the second excitation frequency of the control signal is above the common resonant frequency by the predefinable second value. Operating device according to claim 1 or 2, characterized in that the first value and the second value are each between 10% and 70% or between 10% and 60% or between 10% and 50% or between 10% and 30% or between 10% and 20% of the first resonant frequency and / or the second resonant frequency. Control device according to one of claims 1 to 3, characterized in that each of the two resonant frequencies is in the range between 90 Hz and 200 Hz and / or that the first excitation frequency of the control signal is between 50 Hz and 150 Hz and the second excitation frequency of the control signal is between 160 Hz and 250 Hz. Control device according to one of claims 1 to 4, characterized in that the control signal is designed as a superposition of two time-limited and amplitude-modulated sine waves, of which the frequency of one sine wave is equal to the first excitation frequency and the frequency of the other sine wave is equal to the second excitation frequency. Control device according to any one of claims 1 to 5, characterized in that the ratio of the amplitude of the signal component of the control signal at the second excitation frequency to the amplitude of the signal component of the control signal at the first excitation frequency is less than or equal to 1, or less than or equal to 0.9, or less than or equal to 0.8, or less than or equal to 0.7, or less than or equal to 0.6, or less than or equal to 0.5.

Images