Tactile feedback method and apparatus

Abstract

According to one embodiment, a method is provided for reducing strain and improving the mechanical displacement response of a haptic feedback device (100). The method includes the steps of: generating an input signal (200) for an actuator (105) of the haptic feedback device (100), wherein the signal level of the input signal is configured to change at a higher frequency in the downward or upward direction of the waveform of the input signal between two consecutive amplitudes of the input signal, compared to the change in signal level in the opposite direction of the waveform before and after the two consecutive amplitudes; and providing the input signal to the haptic feedback device. A device and method are disclosed.

Description

Technical Field

[0001] This disclosure relates to tactile feedback. In particular, this disclosure relates to methods and devices for improved tactile feedback.

Background Art

[0002] Tactile feedback technology is widely used in modern devices such as telephones, virtual reality (VR) devices, automobiles, etc. Tactile feedback means the experience of touch by applying force, vibration or movement to the user. Using tactile feedback technology, for example, virtual objects can be created or controlled in computer simulations, or the remote control of machines and / or devices can be improved.

Summary of the Invention

[0003] This summary is provided to introduce, in a simplified form, a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The scope of protection sought in various embodiments of this disclosure is indicated by the independent claims.

[0004] Exemplary embodiments of this disclosure may enable a method and apparatus for generating a tactile feedback input signal having improved characteristics. The tactile feedback input signal may be capable of reducing distortion in a tactile feedback device or providing an improved tactile feedback experience to a user of the tactile feedback device. Exemplary embodiments may be capable of maximizing the displacement of a tactile feedback element that provides tactile feedback when actuated by a tactile feedback signal.

[0005] According to a first embodiment, a method is provided. The method may include the steps of: generating an input signal for an actuator of a haptic feedback device, wherein the signal level of the input signal is configured to change at a higher frequency in the downward or upward direction of the waveform of the input signal between two consecutive amplitudes of the input signal, compared to the signal level change in the opposite direction of the waveform before and after two consecutive amplitudes; and providing the input signal to a haptic feedback device.

[0006] According to the implementation of the first embodiment, the signal level changes at a first frequency before reaching a first amplitude of a series of amplitudes, changes at a second frequency during the series of amplitudes, and changes at a third frequency after reaching a second amplitude of the series of amplitudes, the second frequency being higher than the first and third frequencies.

[0007] According to the implementation of the first embodiment, the first frequency and the third frequency include the same frequency.

[0008] According to the implementation of the first embodiment, the higher-order frequencies are configured to be substantially equal to the natural frequencies of the haptic interaction elements of a haptic feedback device configured to be actuated using an input signal.

[0009] According to the implementation of the first embodiment, the higher-order frequencies are configured to be substantially equal to the first or second natural frequencies of the haptic interaction element of a haptic feedback device configured to be actuated using an input signal.

[0010] According to the implementation of the first embodiment, the second frequency is configured to be substantially equal to the natural frequency of the haptic interaction element of the haptic feedback device being operated, and at least one of the first frequency or the third frequency is configured to be substantially equal to a lower-order natural frequency of the haptic interaction element than the second frequency.

[0011] According to the implementation of the first embodiment, at least one of the first frequency or the third frequency is configured to be substantially equal to the first natural frequency of the tactile interaction element, and the second frequency is configured to be substantially equal to the second natural frequency of the tactile interaction element.

[0012] According to the implementation of the first embodiment, the method may further include the steps of acquiring data indicating one or more natural frequencies of tactile interaction elements, and constructing at least one of the frequencies based on the data.

[0013] According to the implementation of the first embodiment, the data includes one or more measurements of the displacement of a tactile interaction element with respect to an operating frequency, and the method includes the step of configuring at least one of the frequencies to be the frequency that yields the near maximum displacement.

[0014] According to the implementation of the first embodiment, the method may include the step of performing smoothing of the input signal in the opposite direction to the waveform.

[0015] According to a second embodiment, an apparatus is provided. The apparatus may include an input signal generating circuit, the input signal generating circuit is configured to perform the steps of: generating an input signal for an actuator of a haptic feedback device, wherein the signal level of the input signal is configured to change at a higher frequency in the downward or upward direction of the waveform of the input signal between two consecutive amplitudes of the input signal, compared to the change in signal level in the opposite direction of the waveform before and after the two consecutive amplitudes; and providing the input signal to the actuator of the haptic feedback device.

[0016] According to the implementation of the second embodiment, the signal level is configured to change at a first frequency before reaching a first amplitude of a series of amplitudes, change at a second frequency during the series of amplitudes, and change at a third frequency after reaching a second amplitude of the series of amplitudes, wherein the second frequency is higher than the first and third frequencies.

[0017] According to the implementation of the second embodiment, the first frequency and the third frequency include the same frequency.

[0018] According to the implementation of the second embodiment, the higher-order frequencies are configured to be substantially equal to the natural frequencies of the haptic interaction elements of a haptic feedback device configured to be actuated using an input signal.

[0019] According to the implementation of the second embodiment, the higher-order frequencies are configured to be substantially equal to the first or second natural frequencies of the haptic interaction element of a haptic feedback device configured to be actuated using an input signal.

[0020] According to the implementation of the second embodiment, the second frequency is configured to be substantially equal to the natural frequency of the haptic interaction element of the haptic feedback device being operated, and at least one of the first frequency or the third frequency is configured to be substantially equal to a lower-order natural frequency of the haptic interaction element than the second frequency.

[0021] According to the implementation of the second embodiment, at least one of the first frequency or the third frequency is configured to be substantially equal to the first natural frequency of the tactile interaction element, and the second frequency is configured to be substantially equal to the second natural frequency of the tactile interaction element.

[0022] According to the implementation of the second embodiment, the device further comprises a control circuit configured to perform the steps of: acquiring data indicating one or more natural frequencies of tactile interaction elements; and configuring at least one of the frequencies based on the data.

[0023] According to the implementation of the second embodiment, the data includes one or more measurements of the displacement of a tactile interaction element with respect to an operating frequency, at least one of which is the frequency that produces the near maximum displacement.

[0024] According to the implementation form of the second aspect, the input signal generation circuit is configured to perform smoothing of the input signal in the reverse direction of the waveform.

[0025] According to the implementation form of the second aspect, the device includes a tactile feedback device.

[0026] According to the implementation form of the second aspect, the tactile interaction element includes a knob, a display, or a panel.

Brief Description of the Drawings

[0027] The accompanying drawings are included to provide a further understanding of the charging device, form part of this specification, show examples, and together with the description, serve to explain the principle of the charging device.

[0028] [Figure 1] An example of a tactile feedback device according to an exemplary embodiment is shown. [Figure 2] An example of a tactile feedback input signal according to an exemplary embodiment is shown. [Figure 3A] An example of a measured response to a sine wave tactile feedback input signal and a sine wave excitation is shown. [Figure 3B] An example of a measured response to a square wave tactile feedback input signal and a square wave excitation is shown. [Figure 3C] A sine wave tactile feedback input signal having a high descent gradient according to an exemplary embodiment and the measured responses of the respective signals are shown. [Figure 3D] A sine wave tactile feedback input signal having a sharp descent gradient and smoothed at the start and end of the signal according to an exemplary embodiment and the measured responses of the respective signals are shown. [Figure 4] An example of two tactile feedback input signals including different frequencies according to an exemplary embodiment is shown. [Figure 5] An exemplary embodiment of a device configured to implement one or more exemplary embodiments is shown. [Figure 6]An example of measurement data showing the resonance of the measured components according to an exemplary embodiment is shown. [Figure 7A] This shows an example of measurement results for a haptic feedback device when excited by a single-cycle square wave impulse at 165 Hz. [Figure 7B] This shows an example of measurement results for a haptic feedback device when excited by a single-cycle sinusoidal impulse at 165 Hz. [Figure 7C] An example of measurement results for a haptic feedback device when excited with a 165 Hz haptic feedback input signal modified according to an exemplary embodiment is shown. [Figure 8] An example of a method for reducing distortion in a haptic feedback device according to an exemplary embodiment is shown.

[0029] In the attached drawings, similar reference numbers are used to indicate similar parts. [Modes for carrying out the invention]

[0030] Embodiments are described in detail here, and their examples are shown in the accompanying drawings. The detailed description provided below in relation to the accompanying drawings is intended to describe these embodiments and is not intended to represent the only form in which these embodiments may be constructed or utilized. The description describes the function of the embodiments and the sequence of steps for constructing and operating them. However, the same or equivalent functions and sequences may also be achieved by different embodiments.

[0031] Haptic technology, or simply haptics, is a technology that can provide users of associated devices that utilize haptics with a simulated touch experience as a notification, such as a response to an action or function. This is called haptic feedback. Haptic feedback may be generated by a haptic feedback device and may generally provide haptic feedback to the enclosure of the associated device. For example, a haptic feedback device may provide a haptic feedback signal that may consist of a very rapidly dissipating vibration signal generated by a voltage signal, as a result the user recognizes a press on a touchscreen, which is also used by the associated device.

[0032] Haptic feedback devices, due to their nature, may also be used to generate sound. For example, the enclosure of a haptic-based device may be designed to also transmit audio signals. This means that the signal quality of the haptic input signal driving the haptic feedback device must be maintained, and the haptic feedback device itself must be able to efficiently convert the input signal into mechanical energy.

[0033] When driving haptic feedback devices, distortion, ringing, and undesirable undertones or overtones may be generated due to an unoptimized signal format or excessively low or high signal power.

[0034] The object of this disclosure is to provide an improved input signal for haptic feedback. The input signal may be modified so that distortion and ringing can be reduced. A more accurate and faster feedback input signal may be provided to enhance the haptic feedback provided to the user of the haptic feedback device.

[0035] Exemplary embodiments provide a method for generating an input signal to be provided to a haptic feedback device, an apparatus configured to perform the exemplary method, and a haptic feedback device configured to receive an input signal from the apparatus.

[0036] Figure 1 shows an example of a haptic feedback device 100 according to an exemplary embodiment. The haptic feedback device 100 may include at least one support unit 103, 104 (suspension unit) for the haptic interaction element 101. The support units 103, 104 may include, for example, a spring. The support units 103, 104 may be made of an elastic material. The haptic interaction element is sometimes also referred to as a haptic interface element. The haptic interaction element 101 may include a surface. The haptic interaction element 101 may include, for example, a knob, panel, display, etc., configured to transmit haptic feedback to the user. The haptic interaction element 101 may be configured to be mechanically displaced when actuated. For example, the surface may be mechanically biased or bent when actuated by an actuator. Mechanical bending may be measured as the (mechanical) displacement of the surface with respect to a reference plane. For example, the haptic interaction element 101 may be configured to move between a first position and a second position when an actuator coupled to the haptic interaction element is triggered by an input signal. The input signal for the haptic feedback device is sometimes called the haptic feedback input signal. The haptic feedback device 100 may also include a base element 102. The base element 102 may act as a mechanical reference plane for the haptic interaction element 101. For example, the haptic interaction element 101 may be configured to mechanically bend downward toward the base element 102 when in operation. One or more support units 103, 104 may be configured between the haptic interaction element and the base element such that there is at least sufficient space for displacement toward the base element.

[0037] The displacement 107 of the tactile interaction element (i.e., the distance between the first position and the second position) may be such that the user can perceive the movement of the tactile interaction element between the two positions when the user is in contact with the tactile interaction element 101. For example, when the user grasps their finger on the tactile interaction element 101, the displacement 120 may be perceived by the user as a vibration or bump.

[0038] For example, the haptic feedback device 100 may be included in or coupled to any suitable device, such as a mobile phone, television, computer, music player, or any other type of user device. For example, the base element 102 may form at least part of the frame of the device. For example, the haptic interaction element 101 may be the screen or display of the device (e.g., an electronic device), or may be included therein. The haptic feedback device 100 may be applicable to vehicles (e.g., automobiles or ships). For example, the haptic feedback device 100 may include car panels, such as interior car panels (e.g., door panels, ceiling or roof panels, wall panels, frame panels, or any other parts of the interior of the vehicle). The haptic interaction element 101 may include a car display. Alternatively, the haptic feedback device 100 may be included in a wearable device, such as a wearable electronic device. For example, the haptic feedback device 100 may be included in a portable electronic device, such as a wristwatch.

[0039] Furthermore, the haptic feedback device 100 may include an actuator 105. The actuator 105 may be excited by driving the actuator 105 with an input signal supplied to the input port 106. The haptic feedback device 100 is configured to be excited (actuated) to obtain sufficient movement (displacement 120) between the haptic interaction element 101 and the base element 102, and as a result, the user may detect the excitation caused by driving the input signal to the input port 106. The input signal may be configured to operate in the haptic frequency band. The haptic frequency band may refer to frequencies between 10 and 300 Hz, preferably between 20 and 250 Hz, or more preferably between 150 and 180 Hz.

[0040] The actuator 105 of the exemplary haptic feedback device 100 shown in Figure 1 may comprise, for example, a first magnetic element coupled to a haptic interaction element 101. The first magnetic element may be configured to move along the displacement 120 of the haptic interaction element 101. The haptic feedback device 100 may further comprise a second magnetic element coupled to a base element 102. At least one of the first or second magnetic element may comprise a permanent magnet. The second magnetic element may be positioned to face the first magnetic element. The haptic feedback device 100 may also comprise a coil positioned between the first and second magnetic elements. For example, the coil may be coupled to the second magnetic element. The coil may be configured to be electrically excited by an input signal via an input port 106. The coil may be configured to cause movement of the haptic interaction element based on a magnetic field configured to be generated by the coil when the input signal is activated. The displacement of the haptic interaction element 101 caused by the movement may occur in a direction perpendicular to the surface plane 108 of the base element 102. The displacement 120 of the tactile interaction element 101 may be proportional to the input signal supplied to the coil. The coil may also be called a tactile coil or feedback coil. However, the actuator design shown in Figure 1 is an example, and the actuator may be implemented differently. For example, the actuator 105 may comprise a voice coil actuator or a piezo tactile actuator. The actuator 105 may further comprise any other type of tactile actuator that may be applicable to actuating the tactile interaction element 101.

[0041] The haptic feedback device 100 may include, or be configured to be coupled with, a device 109 configured to provide an input signal to an actuator 105. The device 109 may include at least an input signal generation circuit 110. The input signal generation circuit 110 may be configured to generate an input signal for the haptic feedback device, for example, in response to a trigger. The input signal generation circuit 110 may be configured to excite power to actuate the movement (e.g., mechanical bending) of a haptic interaction element. The input signal may be generated based on one or more parameters obtained by the input signal generation circuit 110. The parameters may include, for example, the maximum voltage or current level (i.e., amplitude) of the input signal, one or more frequencies to be applied to the input signal, or at least one of one or more smoothing operations to be performed. One or more smoothing operations may include, for example, the least squares method. For example, when the signal changes from a first frequency to a second frequency, or from a second frequency to a third frequency, a discontinuity or abrupt undesirable change in the signal may occur near the region where the signal changes direction. The least squares method may be used to mitigate / minimize the problems that may arise from the discontinuity (e.g., a "pop" sound).

[0042] The device may further include a control circuit 111. The control circuit 111 may be configured to provide one or more parameters to the input signal generation circuit 110. For example, the control circuit 111 may be configured to determine one or more frequencies used when generating the input signal. The control circuit 111 may be further configured, for example, to provide a trigger to the input signal generation circuit 110.

[0043] The input generation circuit 110 and the control circuit 111 may be implemented using analog or digital circuits, or a combination thereof. In the analog domain, these circuits may be implemented based on, for example, comparator, differentiator, or integrator circuits. In the digital domain, the circuits may include digital components such as logic gates, other digital logic, or processor circuits such as a microcontroller unit (MCU) associated with at least one memory. The input signal generation circuit configuration and / or control circuit configuration may be applicable to any user device configured to receive input signals for the operation of haptic feedback.

[0044] A haptic feedback device, particularly a haptic interaction element, may have at least one natural frequency, and usually more than one. A natural frequency refers to the natural frequency or resonant frequency of a haptic feedback device that tends to produce vibration in the absence of any driving force. The natural frequency may depend on the dimensions, components, materials, etc., of the haptic feedback device. Therefore, a signal introduced as an input signal to the haptic feedback device, including one or more of these natural frequencies, can increase the displacement energy of the haptic interaction element and prolong ringing.

[0045] The input signal provided to the haptic feedback device may be divided into three separate, distinguishable regions. In the first region, the input signal may be configured to transition a haptic interaction element to a first position. For example, the haptic interaction element 101 may be driven to a first position (e.g., upward or downward relative to the base element 102) in response to an input voltage or current connected to an actuator. The input voltage may be selected based on a desired displacement value, i.e., a first or second position relative to a reference plane. In the second region, the displacement (tension) may be relaxed by driving the input signal to a maximum value opposite to that in the first region, further transitioning the haptic interaction element 101 to a second position. The second region may be driven at a higher frequency than the first region. Therefore, the transition between the first and second positions may be fast (i.e., the signal level changes faster from peak to peak compared to when using lower frequencies). The higher frequencies may preferably correspond to the natural frequencies of the haptic interaction element 101. Therefore, higher displacement values ​​may be achieved. Finally, in the third domain, the input signal may be driven to cause the haptic interaction element to transition from an opposite displacement value back to its original (zero) displacement value at a frequency slower than the second domain frequency. The displacement value may depend on the power or energy under which the device is operated. For example, a 1-volt peak-to-peak input signal may have a higher displacement value than a 0.5-volt peak-to-peak input signal, provided that the haptic feedback device in question has not already saturated between these voltage values.

[0046] Figure 2 shows an exemplary embodiment of an input signal 200 for a haptic feedback device on a time-amplitude axis. The time axis (x) is divided into milliseconds (ms), and the amplitude axis (y) is normalized between -1 and 1. The input signal 200 may be configured to control a haptic feedback device, such as the exemplary haptic feedback device 100 in Figure 1. The input signal may be input to the haptic feedback device 100 to actuate an actuator, thereby causing a mechanical displacement of the haptic interaction element 101. Thus, haptic feedback may be provided for a user interacting with the haptic feedback device 100. For example, a user may feel a mechanical displacement with their finger when they place their finger on the haptic interaction element 101.

[0047] In Figure 2, the input signal 200 comprises three regions: a first region 201 in which the input signal 200 starts at 0 and reaches a normalized input amplitude value of 1; a second region 202 in which the input signal 200 decreases to a normalized input amplitude value of -1; and a third region 203 in which the input signal 200 returns to its original value of 0 ("resting value").

[0048] The purpose behind dividing the haptic input signal into three regions is to improve the quality of the haptic feedback response by allowing the device to manipulate the signal behavior between these regions. For example, to reduce strain and ringing, or to increase power efficiency and maximize the feedback amplitude, which may be considered as the displacement of the surface (i.e., the haptic feedback element).

[0049] An exemplary embodiment of the input signal 200 may be generated, for example, by an input signal generation circuit. The input signal generation circuit may comprise at least one processing unit, such as a microcontroller unit (MCU), an ARM processor, an x86 processor, a field-programmable gate array (FPGA), a coprocessor, a controller, a digital signal processor (DSP), a processing circuit with or without an associated DSP, an application-specific integrated circuit (ASIC), a hardware accelerator, or a dedicated computer chip. The input signal 200 may be configured to control an actuator 105 of an exemplary haptic feedback device 100. The input signal 200 may be configured to change the signal level in a first direction toward a first amplitude within the wave period of the input signal at a first frequency. This may be considered equivalent to the first region 201 described above.

[0050] Furthermore, the input signal 200 may be further configured to change the signal level in a second direction from a first amplitude to a second amplitude within the wave period of the input signal at a second frequency. This may be considered equivalent to the second region 202 described above.

[0051] Finally, the input signal 200 may be further configured to change the signal level from the second amplitude to the first direction within the wave period of the input signal at a frequency lower than the second frequency. This may be considered equivalent to the third region 203 described above. The lower frequencies in the third region 203 may correspond to the first frequency or to a third frequency having a different value.

[0052] In addition, the second frequency may be configured to be substantially equal to the natural frequency of the tactile interaction element of the haptic feedback device configured to be actuated using the input signal 200. Furthermore, the first and / or third frequencies may be configured to be lower than the second frequency. For example, the second frequency may be substantially equal to the second natural frequency of the haptic interaction element. The first and / or third frequencies may be substantially equal to the first natural frequency of the haptic interaction element, which is a lower frequency than the second natural frequency. However, the first, second, and third frequencies may be any frequencies within the desired haptic frequency band. Preferably, the second frequency is approximately the first or second natural frequency. The frequencies may also correspond to higher-order natural frequencies (3 to N) than the first or second natural frequency. However, the first and third frequencies are lower frequencies than the second frequency, for example, having lower-order natural frequencies than the second frequency. One or more higher-order natural frequencies may be selected, for example, when the lower-order natural frequencies of the tactile interaction element to be activated fall below the tactile frequency band.

[0053] The natural frequencies used may be determined based on a given value to the input generation circuit. Alternatively, at least one of the first, second, or third frequencies may be tuned based on the characteristics of the tactile interaction element and / or tactile feedback device. Characteristics may include, for example, size and / or material used. For example, if the natural frequencies are not readily available, they may be estimated based on one or more measurements of the tactile interaction element. The measurements may indicate one or more frequencies at which resonance occurs. Thus, the input signal may be tuned to a tactile interaction element with unknown characteristics. Tuning may be performed, for example, by the input generation circuit or by a coupled control circuit configured to perform tuning. For example, displacement values ​​may be measured at different (operating) frequencies of the input signal. From the measurements, one or more resonances may be detected based on the peak values ​​of the displacement and used to estimate the natural frequencies. The selected frequencies may be specific to the implementation.

[0054] The direction selected for the input signal 200 may not affect the displacement of the haptic feedback device, depending on the design of the haptic feedback device itself. However, the second direction is opposite to the first direction. For example, the input signal may be configured to rise in the first direction (towards the positive maximum) and fall in the second direction (towards the negative maximum), or vice versa. The frequency at which the rate of change of the input signal waveform is determined may be modified so that it changes when it reaches the amplitude of the input signal level.

[0055] The input signal 200, when operating in the first region 201, may generally be understood as part of a sinusoidal signal (1 / 2π wavelength). The rate of change of the input signal in the first region 201 may be at least partially slower than that of each sine wave operating at the first frequency. Furthermore, the rate of change of the input signal in the first region is slower than the rate of change of the input signal in the second region.

[0056] For example, a pure sine wave with an amplitude of 1 takes 3.5 ms to reach its peak amplitude (one-quarter of the entire period) and has a frequency of approximately 71 Hz. However, the input signal 200 during the first region 201 may have a slightly gentler slope compared to a normal (pure) sine wave with a frequency of 71 Hz, when the signal starts at the addressed position 210 in Figure 2 (a time between 0 and 1 ms) and when the signal reaches an amplitude of 1 at the addressed position 211 in approximately 3.5 ms.

[0057] The input signal 200 may be smoothed in the first region. With respect to the frequency components of the signal, the smoothing operation may act as a low-pass filter, reducing high-frequency components and allowing low-frequency components to pass through with little change. For example, the input signal generation circuit may include a filter, such as a low-pass filter, to filter out at least the sinusoidal components in the first region 201. The filter may be implemented with any suitable circuit.

[0058] For example, in the first region 201, the sinusoidal portion may include a sine wave, which is modified by the input signal generation circuit to have a gentler slope at the addressed positions 210 and 211. This may be done by signal editor software, mathematically (e.g., based on appropriate code), or by an AI algorithm trained to optimize the signal for a particular behavior.

[0059] Alternatively or additionally, the input signal 200 between the first region 201 may be generated purely mathematically, for example, as a combination of a sine wave and / or a constant factor, a multiplication of a sine wave and / or a constant, a division of a sine wave and / or a constant factor, etc.

[0060] The input signal 200 in the second region 202 is then configured with a second frequency and a second direction. The input signal 200 in the second region 202 may include a sinusoidal portion having a faster rate of change than the input signal 200 in the first region 201. In other words, the input signal may have a steeper slope in the waveform in the second region. The second frequency may be approximately equal to the natural frequency of the haptic interaction element being manipulated. The sinusoidal portion in the second region 202 may include a pure sinusoidal portion and does not necessarily need to be modified, for example, as in the example of the input signal 200 in the first region 201.

[0061] The input signal 200 in the third region 203 may be configured to the first frequency, or, similar to the first region 201, to be configured to the third frequency and in the first direction. For example, the input signal may include a sinusoidal portion having a rate of change that is at least partially slower than the rate of change of the input signal in the second region. Similarly, with respect to the first region 201, the addressed positions 230 and 231 may include a smoothed sinusoidal portion. The third frequency may or may not correspond to the first frequency, but is configured to be lower than the second frequency.

[0062] As described above, the input signal may be configured to have a slower rate of change between the first and third regions compared to the rate of change of the input signal between the second region. In other words, the voltage level of the input signal may change more slowly between the first and third regions in the same amount of time than in the second region. The first, second, and third regions may be distinguished by the change in the direction of the signal with respect to the change in voltage level. The first, second, and third regions may also be called the first, second, and third parts of the wavelength of the input signal, respectively. Alternatively, the first, second, and third regions may be called the first, second, and third parts of the (wave) period of the input signal, respectively. The second part of the wave period may be shorter than the first and third parts of the wave period.

[0063] The input signal 200 may be used to reduce distortion and / or ringing. Next, the input signal 200 is compared to an alternative input signal of the haptic feedback device to demonstrate the reduction of distortion and / or ringing that can be achieved with the proposed configuration. Figure 3A shows two measured signals: i) an input signal 301 consisting of a pure sine wave (e.g., sin(2πft), f=frequency, t=time) that drives the haptic feedback device, and ii) the displacement response 302 in the haptic interaction element caused thereby. In Figure 3A, the displacement response 302 shows significant ringing at 310 after the input signal 301 becomes 0. Each division on the x-axis has a length of 5 ms.

[0064] Figure 3B shows the same measurement setup as in Figure 3A, but in this case, the square wave input signal 303 drives the same haptic feedback device. The displacement response 304 shows significant distortion in the peak displacement region and undesirable ringing at 311, which can be unpleasant for operators using devices that utilize haptic feedback. This is generally due to the harmonic characteristics of the square wave signal.

[0065] Figure 3C shows a measurement setup in which an input signal 305 is generated according to an exemplary embodiment. The input signal 305 may include sinusoidal components at slower frequencies than in Figure 3A in the first region 201 and the third region 203, and sinusoidal components at higher frequencies in the second region. Due to the gentler slopes in the first region 201 and the third region 203, the displacement response 306 exhibits significantly reduced ringing at 312 compared to the case of Figure 3A or Figure 3B.

[0066] Finally, Figure 3D shows a measurement setup in which the same haptic feedback device (as in Figures 3A-C) is driven by an exemplary embodiment of input signal 307. Input signal 307, like input signal 200, may be configured by smoothing the beginning and end of the input signal. The displacement response 308 may have a reduced ringing response compared to any previous example. Furthermore, the displacement response 308 in Figure 3D is better than the displacement response 306 in Figure 3C, but input signal 306 in Figure 3D is also faster (totaling about 7.5 ms) compared to the total time (about 10 ms) of input signal 305 in Figure 3C. This reduction in the total time required to generate the signal may improve power efficiency and allow the operator of the associated haptic feedback device to experience the haptic feedback signal faster.

[0067] Figure 4 shows an example of two haptic feedback input signals (S1 401 and S2 402) according to an exemplary embodiment. S1 401 includes a second region 202 tuned to approximately 210 Hz, and S2 402 includes a second region 202 tuned to approximately 156 Hz. In other words, Figure 4A shows input signals tuned to different haptic feedback devices (different natural frequencies). Here, tuning may mean modifying one or more frequencies of one or more input signal components. For example, the input signal may include a composite signal. The input signal may include, for example, three sinusoidal components. The first sinusoidal component may be configured to a first frequency. The second sinusoidal component may be configured to a second frequency. The third sinusoidal component may be configured to a first frequency. Alternatively, a third frequency having a different value from the first and second frequencies may be used for the third sinusoidal component, as described above. At least the first and third sinusoidal components may be smoothed. The input signal may be obtained by adding the three sinusoidal components together in three phases. Thus, the input signals 401 and 402 have steeper descending slopes than ascending slopes, resulting in less distortion and improved haptic feedback. For example, by increasing the rate of change between amplitudes of the signal level, the haptic interaction element may produce faster and greater displacements relative to its initial position at the start of each region compared to the displacements caused by the input signal before reaching the first amplitude and after the second amplitude.

[0068] Figure 5 shows an exemplary embodiment of the apparatus 500 configured to carry out one or more exemplary embodiments.

[0069] The device 500 may include at least one processor 502 which can be configured to generate exemplary embodiments of the input signal 200. Furthermore, the device 500 may include at least one memory 504 which contains computer program code 506. The at least one memory 504 may contain signal data such as exemplary embodiments of the input signal 200 for haptic feedback. Alternatively, the computer program code 506 may include computer code instructions (ARM- or x86, etc.) which instruct the at least one processor 502 to generate an output signal. The device 500 may also include an I / O module 508 which can be used to provide exemplary embodiments to a haptic feedback device. The I / O module 508 may include a DAC (digital-to-analog converter) which takes the haptic feedback input signal 200 provided by the at least one processor 502 in digital form and converts it into an analog signal for a haptic feedback device such as the haptic feedback device 100.

[0070] The apparatus 500 may include, for example, apparatus 109. The apparatus 500 may also include means for generating input signals to a haptic feedback device. The means may include, for example, an input signal generation circuit 110. The means may further include a control circuit 111. In one embodiment, the apparatus 500 includes a haptic feedback device. In an exemplary embodiment, the apparatus 500 may include a haptic feedback device 100 and apparatus 109. Furthermore, the apparatus 500 may include a user device such as a mobile phone, tablet, television, vehicle, wearable device, screen, or display configured to interact with the user using haptic feedback.

[0071] For example, the device 500 may include a cellphone, for example, the cellphone's main processor may process the generation of the input signal 200, or the cellphone may include a small DSP, which may include an optimized instruction set and / or instructions for generating the input signal 200, or may include the input signal 200 itself, thereby achieving low latency (fast response).

[0072] According to exemplary embodiments, the apparatus 500 may be configured to tune the input signal 200 for haptic feedback based on the characteristics of the haptic feedback device. For example, the apparatus 500 may be configured to tune the input signal 200 approximately to the first natural frequency of each haptic feedback device between the first region 201 and the third region 203. This may reduce the energy required to drive the haptic feedback device to a desired displacement value between the first region 201 and / or the third region 203. Furthermore, the apparatus 500 may be configured to tune the input signal 200 to the second natural frequency of the haptic feedback device during the second region 202. Thus, a clearly defined haptic feedback signal may be achieved to improve haptic feedback to the user. The first and second natural frequencies may yield more optimal results (e.g., a maximized displacement response), but the frequencies may be freely selected and may include higher-order natural frequencies without losing the effects of reduced strain and improved haptic feedback.

[0073] In one embodiment, the device 500 may be configured to acquire data indicating one or more natural frequencies of a tactile interaction element. The data may include, for example, measurement data including the displacement response of the tactile interaction element to an operating frequency. Based on the measurement data, the device 500 may be configured to determine at least one of a first frequency or a second frequency. For example, the device 500 may select one or more frequencies corresponding to the highest displacement value in order to tune the input signal.

[0074] Figure 6 shows an example of measurement data indicating the resonance / natural frequencies of the measured components according to an exemplary embodiment. The measurement data may include the measured frequency response of a haptic feedback device, showing the displacement response of the haptic interaction elements of the haptic feedback device when operated at one or more frequencies. Measurements may be taken at one or more locations on the haptic interaction element, such as a panel. In this example, measurements are taken at three different locations on the device. The uppermost frequency response is measured at the center of the panel and shows one natural frequency 610 at 110 Hz and a second natural frequency 612 at 165 Hz. Thus, regions 201 and the third region 203 may be tuned to 110 Hz, and the second region 202 may be tuned to 165 Hz. The selected frequencies do not need to be exactly the same as the natural frequencies; an approximation is sufficient.

[0075] However, not all haptic feedback devices have a natural frequency in the so-called "tactile region" or tactile frequency band, which is generally a frequency band that includes frequencies that provide a good tactile response to the user. The tactile region is sometimes defined as 150–180 Hz, in which case human skin is most sensitive, and the frequency is low enough not to produce an audible sound due to the dimensions of the haptic feedback device. However, the first natural frequency in this example may be used to reduce the required input power of the exemplary embodiment, because the haptic feedback device may use natural resonance to increase displacement. The tactile frequency band may also be defined more broadly, such as 20–250 Hz, depending on the use case. A device configured to generate an input signal may be provided with a tactile frequency band parameter for frequency selection. When the natural frequency does not lie within the desired tactile frequency band, the first and second frequencies may be selected to have any value within the tactile frequency band, as long as the second frequency is substantially higher than the first frequency. For example, frequencies may be selected based on provided displacement response data so that the frequency with the greatest displacement is selected, even if they are not resonant frequencies. If frequencies other than natural frequencies are used, the displacement achieved may be lower, but the accuracy and speed of haptic feedback may still be improved.

[0076] Figure 7A shows an example of surface measurement results for a haptic feedback device when excited with a single-cycle square wave impulse at 165 Hz, as shown in 701. The measured acceleration of the surface displacement is shown in 702, and the final displacement response is shown in 703. Due to the high-frequency components of the square wave, the surface attempts to respond to the high-frequency components of the square wave edges, resulting in a highly non-uniform acceleration response, as shown in 704. This can lead to high-frequency mechanical noise (F=ma, where acceleration has high values ​​and high frequencies). Consequently, the force F becomes large and can overwhelm the mechanical clearance present in real-world configurations.

[0077] Figure 7B shows an example of measurement results for the same haptic feedback device as in Figure 7A, when excited with a single-cycle sinusoidal impulse at 165 Hz, as shown in 711. The measured acceleration of surface displacement is shown in 712, and the displacement response is shown in 713. The acceleration response is clearer than in the square wave example in Figure 7A, but a non-uniform acceleration response still exists at the beginning and end of the sinusoidal impulse because the abrupt start and stop of the signal introduce undesirable high-frequency components and noise.

[0078] Figure 7C shows an example of measurement results for the haptic feedback device shown in Figures 7A and 7B when excited with a haptic feedback input signal 200 according to an exemplary embodiment shown in 721, in which case the input signal 200 between the first region 201 and the third region 203 is tuned to approximately 110 Hz, and the input signal 200 between the second region 202 is tuned to approximately 165 Hz. The acceleration response is shown in 722, and the displacement response is shown in 723. The acceleration response shows a clearer response at both the beginning and end of the impulse (compared to Figures 7A and 7B) because unwanted frequency components are removed (filtered) from the impulse, and the working surface of the haptic feedback device does not have to follow rapid changes.

[0079] Figure 8 shows an example of a method for reducing distortion in a haptic feedback device according to an exemplary embodiment. The method may further allow for an increase in the displacement of the haptic feedback element of the haptic feedback device. Thus, the haptic feedback may be improved when activated by the input signal generated by this method. For example, the method may be performed by apparatus 109 or apparatus 500.

[0080] In 800, the method may include the step of generating an input signal for an actuator of a haptic feedback device, wherein the signal level of the input signal is configured to change at a higher frequency in the downward or upward direction of the waveform of the input signal between two consecutive amplitudes of the input signal, compared to the change in signal level in the opposite direction of the waveform before and after the two consecutive amplitudes. The signal level may be configured to change in the downward or upward direction of the waveform of the input signal at a first frequency. The first frequency may be configured to be substantially lower than a second frequency. The second frequency may be configured in the opposite direction to the downward or upward direction. The second frequency may be configured to be substantially equal to the natural frequency of a haptic interaction element of a haptic feedback device configured to be actuated using the input signal. The waveform may be configured to return to a baseline (e.g., the waveform starts at a zero level of the signal level) at a third frequency, the third frequency being lower than the second frequency. The third frequency may correspond to the second frequency. The first / third frequencies may be substantially equal to the natural frequencies of the tactile interaction element, where the natural frequency corresponding to the first frequency is lower than the natural frequency of the second frequency. The method may further include filtering the input signal in at least the first / third frequency portion to, for example, smooth the input signal at the beginning and end of the waveform.

[0081] In 802, the method may include the step of providing an input signal to a haptic feedback device. The input signal may be configured to activate a haptic interaction element of the haptic feedback device. This may provide an improved haptic feedback to the user of the haptic feedback device.

[0082] Further features of the method arise directly from the functions and parameters of devices 100, 109, or 500, as described, for example, in the appended claims and throughout the specification, and are therefore not repeated here. Different variations of the method may be applied, as described in relation to various exemplary embodiments.

[0083] Those skilled in the art will see that, with advances in the technology, exemplary embodiments can be implemented in a variety of ways. Therefore, exemplary embodiments are not limited to the examples described above, but can instead be modified within the scope of the claims.

[0084] The apparatus may be configured to perform, or cause to perform, any aspect of the method described herein. Furthermore, a computer program or computer program product may, when executed, provide instructions to cause the apparatus to perform any aspect of the method described herein. Furthermore, the apparatus may provide means for performing any aspect of the method described herein. According to an exemplary embodiment, the means comprises at least one processor and at least one memory containing program code, the at least one processor containing program code configured, when executed by the at least one processor, to cause the execution of any aspect of the method. The means may include structural elements described herein.

[0085] Any range or device value given herein may be extended or modified without loss of the desired effect. Furthermore, unless expressly denied, any embodiment may be combined with another embodiment.

[0086] While the subject matter is described using language specific to structural features and / or actions, it should be understood that the subject matter defined in the attached claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as examples of implementing the claims, and other equivalent features and actions are intended to be within the scope of the claims.

[0087] It should be understood that the above benefits and advantages may relate to one embodiment or to multiple embodiments. Embodiments are not limited to those that solve any or all of the described problems, or that have any or all of the described benefits and advantages. It should be further understood that a reference to "one" item may refer to one or more of these items.

[0088] The steps or operations of the methods described herein may be performed in any preferred order, or, where appropriate, simultaneously. Furthermore, individual blocks may be removed from any of the methods without departing from the scope of the subject matter described herein. Any aspect of the embodiments described above may be combined with any aspect of any of the other embodiments described without losing the desired effect to form further embodiments.

[0089] In this specification, the term “comprising” is used to mean including the specified methods, blocks, or elements, but such blocks or elements do not constitute an exclusive list, and the methods or apparatus may include additional blocks or elements.

[0090] The objects may sometimes be called the "first" object or the "second" object, but this does not necessarily indicate the order or importance of the objects. Rather, such attributes may be used solely for the purpose of distinguishing the objects from one another.

[0091] As used in this application, the term "circuit" may mean one or more hardware circuits and processors, such as (1) a hardware-only circuit implementation (e.g., an implementation of analog and / or digital circuits only), (2) a combination of hardware circuits and software, such as (i) a combination of analog and / or digital hardware circuits and software / firmware, and (ii) any part of a hardware processor and software (e.g., a digital signal processor), software, and memory that cooperate to enable the device to perform various exemplary embodiments, and (3) a microprocessor or part of a microprocessor that requires software (e.g., firmware) for operation, but may not be present when not required for operation.

[0092] The above description is given merely as an example, and it should be understood that various modifications can be made by those skilled in the art. Although various embodiments have been described above in some detail or by reference to one or more individual embodiments, those skilled in the art can make numerous modifications to the disclosed embodiments without departing from the scope of this specification.

Claims

1. It is a method, A step of generating an input signal (200) for an actuator of a haptic feedback device (100), wherein the input signal (200) is composed of the sum of three sinusoidal components in three phases, the first and third sinusoidal components are configured to have lower frequencies than the second sinusoidal component, and at least the second sinusoidal component is configured to be approximately equal to the natural frequency of a haptic interaction element (101) of the haptic feedback device (100) configured to be actuated using the input signal (200), and as a result, the signal level of the input signal within a wave period is configured such that the rate of change between two consecutive amplitudes of the signal level of the input signal is faster than the rate of change of the signal level before and after the two consecutive amplitudes. The steps include providing the input signal to the haptic feedback device, Methods that include...

2. The method according to claim 1, wherein the signal level changes at a first frequency configured for the first sinusoidal component before reaching the first amplitude of the continuous amplitude, changes at a second frequency configured for the second sinusoidal component during the continuous amplitude, and changes at a third frequency configured for the third sinusoidal component after reaching the second amplitude of the continuous amplitude, wherein the second frequency is higher than the first frequency and the third frequency.

3. The method according to claim 2, wherein the second frequency is configured to be substantially equal to the natural frequency of the tactile interaction element (101) of the haptic feedback device being operated, and at least one of the first frequency or the third frequency is configured to be substantially equal to a lower-order natural frequency of the tactile interaction element (101) than the second frequency.

4. The steps include obtaining data indicating one or more natural frequencies of the aforementioned tactile interaction elements, Based on the above data, the step of configuring at least one of the above frequencies, The method according to any one of claims 1 to 3, further comprising:

5. The method according to claim 4, wherein the data includes one or more measurements of the displacement of the tactile interaction element with respect to an operating frequency, and the method includes the step of configuring at least one of the frequencies to be a frequency that yields the approximate maximum displacement.

6. The step of performing smoothing of at least the first sinusoidal component and the third sinusoidal component. The method according to any one of claims 1 to 5, including the method described in any one of claims 1 to 5.

7. A device (500) equipped with an input signal generation circuit, wherein the input signal generation circuit is A step of generating an input signal (200) for an actuator (105) of a haptic feedback device (100), wherein the input signal (200) is composed of the sum of three sinusoidal components in three phases, the first and third sinusoidal components are configured to have lower frequencies than the second sinusoidal component, and at least the second sinusoidal component is configured to be approximately equal to the natural frequency of the haptic interaction element (101) of the haptic feedback device (100), and as a result, the signal level of the input signal within the wave period is configured such that the rate of change between two consecutive amplitudes of the signal level of the input signal is faster than the rate of change of the signal level before and after the two consecutive amplitudes. The steps include providing the input signal to the actuator of the haptic feedback device, A device (500) configured to perform the following.

8. The apparatus according to claim 7, wherein the signal level is configured to change at a first frequency configured for the first sinusoidal component before reaching the first amplitude of the continuous amplitude, at a second frequency configured for the second sinusoidal component during the continuous amplitude, and at a third frequency configured for the third sinusoidal component after reaching the second amplitude of the continuous amplitude, wherein the second frequency is higher than the first frequency and the third frequency.

9. The apparatus (500) according to claim 8, wherein the second frequency is configured to be substantially equal to the natural frequency of the tactile interaction element of the haptic feedback device being operated, and at least one of the first frequency or the third frequency is configured to be substantially equal to a lower-order natural frequency of the tactile interaction element than the second frequency.

10. The aforementioned device is The steps include obtaining data indicating one or more natural frequencies of the aforementioned tactile interaction elements, Based on the above data, the step of configuring at least one of the above frequencies, The apparatus (500) according to any one of claims 7 to 9, further comprising a control circuit configured to perform the following.

11. The apparatus (500) according to claim 10, wherein the data includes one or more measurements of the displacement of the tactile interaction element (101) with respect to an operating frequency, and at least one of the frequencies is configured to produce a frequency that yields approximately the maximum displacement.

12. The apparatus (500) according to any one of claims 7 to 9, wherein the input signal generation circuit is configured to perform smoothing of at least the first sinusoidal component and the third sinusoidal component.

13. The apparatus (500) comprises the haptic feedback device (100) according to any one of claims 7 to 9.

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