Tactile presentation device and tactile presentation method

Abstract

To provide a tactile sensation presentation device capable of presenting a good tactile sensation when a vibration system including an actuator has a plurality of resonant frequencies.SOLUTION: A tactile sensation presentation device (100) includes: an actuator (140) that vibrates in response to an input signal; a vibration target (130) that is connected to the actuator and is vibrated in response to the vibration of the actuator; and a controller (150) that performs drive control of the actuator. A vibration system including the actuator and the vibration target has a plurality of resonant frequencies. The controller corrects an input drive signal using a correction model (152) generated in advance based on the plurality of resonant frequencies and outputs it to the actuator as the input signal, or outputs a signal generated in advance using the correction model to the actuator as the input signal.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to a tactile presentation device and a tactile presentation method.

Background Art

[0002] Conventionally, there has been a tactile operable device including a tactile actuator, a motion sensor, and a control circuit. The control circuit determines a drive signal for the tactile actuator based on a desired motion for a tactile effect and a model representing the transient behavior of the tactile actuator. The control circuit further measures the motion output by the tactile actuator based on the drive signal applied to the tactile actuator. The control circuit determines a motion error indicating the difference between the measured motion and the desired motion, and adjusts the drive signal based on the motion error to generate an adjusted drive signal. The adjusted drive signal is applied to the tactile actuator to generate a tactile effect (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a vibration system including an actuator has a plurality of resonance frequencies, it is not easy to present good tactile sensation because the influence of vibrations at each resonance frequency occurs. However, in conventional tactile operable devices, the case where a vibration system including an actuator has a plurality of resonance frequencies has not been sufficiently considered.

[0005] Therefore, an object is to provide a tactile presentation device and a tactile presentation method capable of presenting good tactile sensation when a vibration system including an actuator has a plurality of resonance frequencies. [Means for solving the problem]

[0006] The tactile presentation device of the embodiment of the present disclosure comprises an actuator that vibrates in response to an input signal, an excitation target connected to the actuator and excited in response to the vibration of the actuator, and a controller that controls the drive of the actuator. The vibration system including the actuator and the excitation target has a plurality of resonant frequencies, and the controller corrects the input drive signal using a correction model that has been generated in advance based on the plurality of resonant frequencies and outputs it to the actuator as the input signal, or outputs a signal that has been generated in advance using the correction model as the input signal to the actuator.

[0007] A tactile presentation method according to an embodiment of the present disclosure is a method for controlling a device comprising an actuator and an object to be vibrated in accordance with the vibration of the actuator, wherein the vibration system including the actuator and the object to be vibrated has a plurality of resonant frequencies, wherein the drive signal is corrected and output to the actuator using a correction model that has been generated in advance based on the plurality of resonant frequencies, or the signal that has been generated in advance using the correction model is output to the actuator as the input signal. [Effects of the Invention]

[0008] This invention provides a tactile presentation device and a tactile presentation method that can provide good tactile sensations when a vibration system including an actuator has multiple resonant frequencies. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example of the configuration of the tactile presentation device according to the embodiment. [Figure 2A] This figure shows a simulation model that represents the mechanical system configuration of a haptic feedback device using springs and dampers as equivalent components. [Figure 2B] This diagram shows a real-world example of the mechanical system configuration of a haptic feedback device, represented equivalently by springs and dampers. [Figure 3] This figure shows an example of the frequency characteristics of gain and phase in an ideal haptic presentation device and a real-world haptic presentation device. [Figure 4] This figure shows an example of the frequency characteristics of vibration acceleration in an actuator alone and in a tactile feedback device. [Figure 5] This diagram illustrates a method for constructing a pseudo-inverse transfer function. [Figure 6] This figure shows the frequency characteristics of the minimum displacement (solid line) and the minimum acceleration (dashed line) that can be detected by Pacinian corpuscles on the surface of the human hand. [Figure 7] This is a block diagram showing an example of the configuration of a haptic feedback device. [Figure 8A] This figure shows an example of a pseudo-inverse filter characteristic obtained from the pseudo-inverse transfer function of a haptic feedback device. [Figure 8B] This figure shows an example of the pseudo-inverse filter characteristics of a pseudo-inverse filter. [Figure 9] This figure shows an example of panel vibration immediately after the actuator of a haptic presentation device starts vibrating. [Figure 10] This figure shows an example of the gain and phase of the system to be stabilized. [Figure 11A] This figure shows the frequency characteristics of the output gain and phase of an ideal haptic feedback device. [Figure 11B] This figure shows the time evolution of the drive signal (upper side) input to the ideal haptic presentation device described above and the acceleration of the vibration generated by the ideal haptic presentation device (lower side). [Figure 11C] This figure shows an example of panel vibration immediately after the actuator of the tactile presentation device of the embodiment starts vibrating. [Modes for carrying out the invention]

[0010] The following describes embodiments to which the tactile presentation device and tactile presentation method of this disclosure are applied.

[0011] Hereinafter, an explanation will be given by defining an XYZ coordinate system. The direction parallel to the X-axis (X direction), the direction parallel to the Y-axis (Y direction), and the direction parallel to the Z-axis (Z direction) are orthogonal to each other. Also, hereinafter, for convenience of explanation, the -Z direction side may be referred to as the lower side or bottom, and the +Z direction side may be referred to as the upper side or top, but this does not represent a universal up-down relationship. Also, a plan view means a view from the XY plane.

[0012] Also, hereinafter, for the sake of clarity of the configuration, the lengths, thicknesses, thicknesses, etc. of each part may be exaggerated and shown. Also, terms such as parallel and up-down allow a deviation that does not impair the effects of the embodiments.

[0013] <Embodiment> FIG. 1 is a diagram showing an example of the configuration of the tactile presentation device 100 of the embodiment. The tactile presentation device 100 includes a fixing part 110, an elastic member 120, a panel 130, an actuator 140, and a controller 150.

[0014] The panel 130 is an example of an object to be vibrated. The vibration system including the actuator 140 and the panel 130 is an example of a first vibration system. The vibration system including the panel 130 and the fixing part 110 is an example of a second vibration system. The vibration system of the entire tactile presentation device 100 includes a vibration system including the actuator 140 and the panel 130 (an example of a first vibration system) and a vibration system including the panel 130 and the fixing part 110 (an example of a second vibration system). The resonance frequencies of the vibration system including the actuator 140 and the panel 130 (an example of a first vibration system) and the vibration system including the panel 130 and the fixing part 110 (an example of a second vibration system) are different. That is, the vibration system of the entire tactile presentation device 100 has at least two resonance frequencies.

[0015] The haptic presentation device 100 may be installed in electronic devices such as tablet computers, smartphones, and game consoles used by individuals, and may be provided on the operating section of the electronic device. Alternatively, the haptic presentation device 100 may be provided on the operating section of electronic devices installed in mobile vehicles such as cars, trains, or aircraft. Furthermore, the haptic presentation device 100 may be provided on the input section of electronic devices such as tablet-type input devices or ATMs (Automatic Teller Machines) that are placed in stores or facilities and used by an unspecified number of users.

[0016] The fixing portion 110 is the part that is fixed to the electronic device on which the tactile presentation device 100 is installed. The panel 130 is attached to the fixing portion 110 via an elastic member 120. An actuator 140 may also be attached to the fixing portion 110.

[0017] The elastic member 120 is a member that elastically holds the panel 130 relative to the fixing part 110, and includes an elastic material such as rubber. The elastic member 120 may also be a suspension device that mitigates vibrations between the fixing part 110 and the panel 130.

[0018] Panel 130 is, for example, a part that receives touch input from the operator, and its upper surface is the operating surface 130A. Figure 1 shows the operating positions A to D on the operating surface 130A. Panel 130 may be integrally configured with a touch panel. The operating surface 130A is, for example, the upper surface of a plate-shaped member made of resin or glass.

[0019] The actuator 140 has a lower end fixed to the fixed part 110 and an upper end fixed to the lower surface of the panel 130 by adhesive or the like. The actuator 140 is, for example, an LRA (Linear Resonant Actuator), but it may also be a vibration-accumulating type vibration element other than an LRA. Alternatively, the actuator 140 may be a linear actuator such as a voice coil motor, which is not a vibration-accumulating type. That is, the first vibration system may not have a resonant frequency, and the second vibration system may have multiple different resonant frequencies. The actuator 140 is driven and controlled by the controller 150 to vibrate the panel 130. The actuator 140 does not have to be fixed to the fixed part 110, in which case it can be suspended from the lower surface of the panel 130.

[0020] The controller 150 is implemented by a computer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), input / output interface, and internal bus. As an example, the controller 150 is composed of an MCU (Micro Controller Unit). The controller 150 controls the drive of the actuator 140. If the panel 130 includes a touch panel, the controller 150 can, for example, control the drive of the actuator 140 according to the detection result of the touch panel, and can control the drive of the actuator 140 according to which of the operation positions A to D on the operation surface 130A is operated on.

[0021] Figure 2A is a simulation model that shows the mechanical system configuration of the haptic presentation device 100 shown in Figure 1 equivalently represented by springs and dampers.

[0022] In the simulation model shown in Figure 2A, the panel is coupled to the fixed part by spring K1 and damper C1, and the actuator is coupled to the panel via spring K2 and damper C2. Springs K1 and K2 are springs with spring constants K1 and K2, respectively. Dampers C1 and C2 are dampers with damping ratios C1 and C2, respectively. The panel and actuator have masses m1 and m2, respectively. The simulation model shown in Figure 2A has two resonant frequencies: a resonant frequency of the first vibration system including the actuator and the panel, and a resonant frequency of the second vibration system including the panel and the fixed part.

[0023] Figure 2B is a diagram that shows an equivalent representation of the actual configuration of the mechanical system of the haptic presentation device 100 shown in Figure 1, using springs and dampers. The actual configuration shown in Figure 2B is a more realistic configuration than the simplified simulation model shown in Figure 2A. However, in reality, the haptic presentation device 100 may have an even more complex configuration than the actual configuration shown in Figure 2B.

[0024] In the real-world configuration example shown in Figure 2B, the panel is coupled to the fixed part by spring K1 and damper C1, and the actuator is coupled to the panel via spring K2 and damper C2. Furthermore, member A is coupled to the actuator via spring K3 and damper C3, and member A is coupled to the fixed part via spring K4 and damper C4. Springs K1 to K4 have spring constants K1 to K4, respectively. Dampers C1 to C4 have damping ratios C1 to C4, respectively. In the configuration example shown in Figure 2B, multiple resonances occur in the vibration system including springs K1 to K4, dampers C1 to C4, the panel (mass m1'), the actuator (mass m2'), and member A (mass m3), resulting in the vibrations occurring in the panel having three or more resonant frequencies. The tactile presentation device 100 can also be described in more complex configuration examples with an even greater number of resonant frequencies. Here, member A is one of the components of the tactile presentation device 100, and may be part of the fixing part 110, the elastic member 120, the panel 130, or the actuator 140. In other words, among the components of the tactile presentation device 100, each component other than the elastic member 120 may also have viscoelastic properties.

[0025] <Frequency characteristics of gain and phase in an ideal haptic presentation device and a real-world haptic presentation device> Figure 3 shows an example of the frequency characteristics of gain and phase in an ideal haptic presentation device and a real haptic presentation device. An ideal haptic presentation device is one that has the ideal characteristics shown in Figure 3. Furthermore, unless otherwise specified, the simulation model shown in Figure 2A will be used as the real haptic presentation device below. The upper part of Figure 3 shows the frequency characteristics of the acceleration gain, and the lower part of Figure 3 shows the frequency characteristics of the phase in an ideal haptic presentation device and a real haptic presentation device. Also, in Figure 3, the characteristics of the ideal haptic presentation device are shown with a dashed line, and the characteristics of a real haptic presentation device are shown with a solid line. The characteristics of the real haptic presentation device here can be realized by the simulation model shown in Figure 2A. Figure 3 shows the characteristics when the drive signal input to actuator 140 is constant regardless of frequency.

[0026] As shown by the dashed line in the upper part of Figure 3, the acceleration of an ideal haptic presentation device has the characteristic of changing smoothly with respect to frequency changes. On the other hand, as shown by the solid line in the upper part of Figure 3, the acceleration of a real haptic presentation device has peaks at multiple frequencies (two in Figure 3 as an example). In other words, there are multiple resonant frequencies in a real haptic presentation device.

[0027] Furthermore, as shown by the dashed line at the bottom of Figure 3, the phase of an ideal haptic presentation device has the characteristic of changing smoothly with respect to frequency changes. On the other hand, as shown by the solid line at the bottom of Figure 3, the phase of a real haptic presentation device fluctuates significantly around the resonant frequency.

[0028] <Inverse filter> To correct the acceleration frequency characteristics of a real-world haptic feedback device to ideal acceleration frequency characteristics, an inverse filter having the inverse characteristics of the acceleration frequency characteristics of the real-world haptic feedback device, as shown in Figure 3, can be used. This makes the output of the inverse filter flat. Furthermore, by using an inverse filter having the inverse characteristics of the phase frequency characteristics of the real-world haptic feedback device, as shown in Figure 3, the output of the inverse filter can also be made flat for phase.

[0029] However, the frequency response of the acceleration of a real haptic feedback device shown in Figure 3 has a very low gain on the low-frequency side. Therefore, the inverse response would require an infinitely large gain on the low-frequency side. Thus, there is a problem in that an inverse filter with an infinitely large gain on the low-frequency side is difficult to realize.

[0030] <Transfer function of a real-world haptic feedback device> Figure 4 shows an example of the frequency characteristics of vibration acceleration for the actuator 140 alone and for the haptic presentation device 100. The haptic presentation device 100 has a more complex mechanical system configuration, as shown in Figure 2B, rather than the configuration shown in the simulation model in Figure 2A. In Figure 4, the frequency characteristics of vibration acceleration for the actuator 140 alone are shown by a dashed line, and the frequency characteristics of vibration acceleration for the panel 130 of the haptic presentation device 100 are shown by a solid line.

[0031] In the example shown in Figure 4, the vibration acceleration of the actuator 140 alone peaks at approximately 120 Hz, which is the resonant frequency, and decreases smoothly at frequencies lower and higher than the resonant frequency. In contrast, as shown in Figure 4, the panel 130 can actually have multiple resonant frequencies, and the vibration acceleration of the panel 130 of the haptic presentation device 100 has a complex characteristic with peaks at each of the more than 10 resonant frequencies.

[0032] In such a tactile presentation device 100, when the drive signal input to the actuator 140 is used as input and the vibration of the panel 130 is used as output, the transfer function is, for example, represented by equation (1) below, a function in which both the numerator and denominator are multiplied by multiple terms.

number

[0033] Here, let's consider deriving the inverse transfer function of the generalized transfer function shown in equation (1), and assume a transfer function of the form shown in Figure 5. The value of s that makes the (s-a3) term in the numerator of equation (1) zero is s=a3 (a3>0), which is an unstable zero. When we find the inverse filter from a transfer function with such an unstable zero, the (s-a3) term will be present in the denominator, resulting in an inverse filter that includes an unstable pole. Since a system containing an unstable pole oscillates, it becomes difficult to drive the actuator 140 stably and smoothly.

[0034] Therefore, the tactile presentation device 100 of this embodiment uses a pseudo-inverse filter (hereinafter referred to as "pseudo-inverse filter") which is a modified inverse filter, in order to achieve ideal response characteristics. The pseudo-inverse filter is an example of a correction model that corrects the drive signal input to the actuator 140.

[0035] <Pseudo-inverse filter> Figure 5 illustrates a method for constructing a pseudo-inverse transfer function. On the left side of Figure 5, the minimum transfer function including the unstable zeros and stable poles of the tactile presentation device 100, the transfer function, and the time evolution characteristics of the transfer function are shown. Such a transfer function has unstable zeros because the numerator (-2s+2) becomes zero when s is 1.

[0036] The center of Figure 5 shows the inverse transfer function of the haptic presentation device 100 and its time-varying characteristics. The inverse transfer function is the inverse of the transfer function of the haptic presentation device 100 shown on the left side of Figure 5, and is therefore (-s-2) / (-2s+2). Such a transfer function has an unstable pole because the denominator (2s-2) becomes zero when s is 1. Using an inverse transfer function that includes an unstable pole will cause oscillation, making it difficult to drive the actuator 140 stably and smoothly.

[0037] The right side of Figure 5 shows the pseudo-inverse transfer function that forms the basis of the pseudo-inverse filter of the haptic presentation device 100, and the time-varying characteristics of the pseudo-inverse transfer function. The pseudo-inverse transfer function has a configuration in which the sign of the real part of the denominator of the inverse transfer function in the center of Figure 5 is reversed. Therefore, the pseudo-inverse transfer function is (-s-2) / (2s+2). Such a pseudo-inverse transfer function has a stable pole because the denominator (2s+2) becomes zero when s is -1.

[0038] The pseudo-inverse filter of the haptic presentation device 100 is created based on this method of constructing a pseudo-inverse transfer function. In other words, the pseudo-inverse filter of the haptic presentation device 100 is a model based on a pseudo-inverse transfer function in which unstable poles included in the inverse transfer function are replaced with stable poles.

[0039] Furthermore, the pseudo-inverse filter of the tactile presentation device 100 may be a model based on an inverse transfer function for a pseudo-transfer function obtained by replacing unstable zeros in the transfer function with stable zeros. In this case, the stable zeros may be realized as the result of inverting the sign of the real part of the unstable zeros.

[0040] The pseudo-inverse filter obtained in this manner is a correction model that reduces the influence of multiple resonant frequencies on the response characteristics.

[0041] Figure 6 shows the frequency characteristics of the minimum displacement (solid line) and the minimum acceleration (dashed line) that can be detected by Pacinian corpuscles on the surface of the human hand.

[0042] The displacement that Pacinian corpuscles can sense represents the displacement of an object being touched by hand. Therefore, the frequency characteristic of the minimum displacement that Pacinian corpuscles can sense (solid line) represents the vibration sensation that Pacinian corpuscles can perceive. As can be seen from the characteristics of the solid line, the lower limit of the frequency of displacement that Pacinian corpuscles can sense is known to be below 30 Hz, as shown in Figure 6. Furthermore, it is known that the sensitivity of displacement that Pacinian corpuscles can sense peaks at 250 Hz and then decreases, and the vibration perception band is known to extend down to about 1 kHz.

[0043] Furthermore, the frequency characteristics of acceleration shown by the dashed line are derived from the frequency characteristics of displacement shown by the solid line. The acceleration that can be perceived by Pacinian corpuscles represents the vibration of an object being touched by hand. As shown in Figure 6, below 250 Hz, the minimum acceleration required to perceive vibration is almost constant. From this characteristic, it is known that Pacinian corpuscles have acceleration perception characteristics. On the other hand, at frequencies higher than 250 Hz, the required acceleration increases rapidly. Using 100 Hz as a reference, the required acceleration is about 20 times greater at 600 Hz and about 70 times greater at 800 Hz. Therefore, it is known that the upper limit of the effective vibration perception band is approximately 500 Hz to 700 Hz.

[0044] Furthermore, since other tactile receptors are activated at frequencies below 100 Hz, it is understood that the frequency range in which Pacinian corpuscles effectively function as vibration receptors is approximately 100 to 700 Hz. Therefore, in order to secure the vibration band of 100 to 500 Hz that is effective for vibration receptors, as an example, frequencies below 30 Hz and frequencies above 700 Hz will be blocked.

[0045] <Configuration of the tactile presentation device 100> Figure 7 is a block diagram showing an example of the configuration of the haptic presentation device 100. As shown in Figure 7, the controller 150 includes a target drive signal output unit 151, a pseudo-inverse filter 152, an LPF (Low Pass Filter) 153, and a DAC (Digital to Analog Converter) 154.

[0046] The target drive signal output unit 151 reads and outputs the target drive signal stored in memory. The target drive signal is a signal that has a target value for the drive signal that the controller 150 outputs to the actuator 140 when driving the actuator 140.

[0047] The pseudo-inverse filter 152 is a pseudo-inverse filter based on a pseudo-inverse transfer function configured by inverting the sign of the real part of the denominator of the inverse transfer function, as explained using Figure 5, and has a stable pole. The pseudo-inverse filter 152 also incorporates a High Pass Filter (HPF), which corrects the gain with the pseudo-inverse filter characteristics and blocks the low-frequency component of the gain with the HPF. The cutoff frequency of the HPF included in the pseudo-inverse filter 152 is an example of the first frequency.

[0048] The cutoff frequency of the HPF included in the pseudo-inverse filter 152 is preferably set to a frequency in the range of 20Hz to 100Hz, and in this example, it is 30Hz. Furthermore, since the upper limit of the gain below the cutoff frequency of the HPF of the pseudo-inverse filter 152 is between 20dB and 30dB, the gain on the low-frequency side can be reliably reduced.

[0049] The LPF153 is provided to block high-frequency components of the signal that has passed through the pseudo-inverse filter 152. The cutoff frequency of the LPF153 is an example of a second frequency. The cutoff frequency of the LPF153 is preferably 500Hz or higher, and in this example it is 700Hz.

[0050] The vibrations presented by the tactile presentation device 100 on the operating surface 130A are primarily perceived by Pacinian corpuscles on the surface of the human hand. The upper limit of the frequency range that Pacinian corpuscles can perceive is approximately 500 Hz to 1 kHz. Therefore, the LPF 153 is provided to block high-frequency components of the drive signal that cannot be perceived by Pacinian corpuscles.

[0051] The DAC154 is located on the output side of the LPF153 and converts the drive signal that has passed through the LPF153 into an analog signal and outputs it to the drive amplifier141. As a result, the actuator140 is driven by the drive signal supplied via the drive amplifier141, causing the vibration mechanism 142, including the panel 130, to vibrate. Figure 7 shows an acceleration sensor 10 for detecting the vibration of the vibration mechanism 142.

[0052] In this description, we have explained a configuration in which the pseudo-inverse filter 152 has a high-pass filter (HPF) and an low-pass filter (LPF) 153 is provided after the pseudo-inverse filter 152. However, the pseudo-inverse filter 152 may also have an LPF equivalent to the LPF 153 in addition to the HPF. Furthermore, the HPF may be provided outside the pseudo-inverse filter 152 (before or after the pseudo-inverse filter 152). Also, the LPF 153 may be provided before the pseudo-inverse filter 152.

[0053] Furthermore, instead of the pseudo-inverse filter 152 having a built-in HPF, the pseudo-inverse filter characteristics of the pseudo-inverse filter 152 may have low-frequency component cutoff characteristics similar to those of an HPF. In other words, the pseudo-inverse filter 152 may be a correction model limited by a high-pass filter that sets an upper limit on the gain below the first frequency.

[0054] Furthermore, the pseudo-inverse filter characteristics of the pseudo-inverse filter 152 may have a high-frequency component blocking function, such as an LPF. In other words, it may be a correction model limited by a low-pass filter with a second frequency as the cutoff frequency.

[0055] Alternatively, the input signal to the DAC154 generated when the target drive signal is input may be stored in memory or the like by pre-calculating it using an electronic computer or the like, without having to calculate it in real time. In this case, the controller 150 does not need to have a target drive signal output unit 151, a pseudo-inverse filter 152, and an LPF 153. Instead, it may have a memory to store the input signal calculated in advance as described above, and read the input signal from the memory and output it to the DAC154. In this case as well, the same effects as when the controller 150 has a target drive signal output unit 151, a pseudo-inverse filter 152, and an LPF 153 can be obtained.

[0056] <Pseudo-inverse filter characteristics of pseudo-inverse filter 152> Figure 8A shows an example of the pseudo-inverse filter characteristics obtained from the pseudo-inverse transfer function of the haptic presentation device 100. Figure 8B shows an example of the pseudo-inverse filter characteristics of the pseudo-inverse filter 152.

[0057] By performing the processing shown in Figure 5, the inverse transfer function can be obtained from the transfer function of the haptic presentation device 100, and a pseudo-inverse transfer function can be obtained by further performing a sign processing to eliminate the unstable poles of the inverse transfer function. The pseudo-inverse filter characteristics of the haptic presentation device 100 shown in Figure 8A are derived from the pseudo-inverse transfer function obtained in this way. One example of the sign processing to eliminate unstable poles is to invert the sign of the real part of the denominator of the inverse transfer function in the center of Figure 5, as shown in the denominator of the pseudo-inverse transfer function on the right side of Figure 5.

[0058] The pseudo-inverse filter characteristics of the pseudo-inverse filter 152 shown in Figure 8B were obtained by suppressing the gain on the low-frequency side with a high-pass filter and blocking the high-frequency components with a low-pass filter, relative to the gain of the pseudo-inverse transfer function shown in Figure 8A.

[0059] Note that the operating positions A to D on the operating surface 130A of the panel 130 shown in Figure 1 have different positional relationships with the actuator 140, the fixing part 110, and the elastic member 120. Therefore, the vibration characteristics of the panel 130 at operating positions A to D may differ to a degree that cannot be ignored. A difference in vibration characteristics that cannot be ignored means, for example, that the gain of the pseudo-inverse filter characteristics shown in Figure 8A or Figure 8B differs to a degree that the user can perceive as a difference in the tactile sensation presented by operating positions A to D.

[0060] In such cases, the controller 150 may have multiple pseudo-inverse filters 152 corresponding to multiple operation positions A to D, and may select and use the pseudo-inverse filter 152 corresponding to the operation position where the operation was performed from among the multiple operation positions A to D based on the output of the touch panel of the panel 130.

[0061] <Time change of acceleration of panel 130> Figure 9 shows an example of the vibration of the panel 130 immediately after the actuator 140 of the haptic presentation device 100 starts vibrating. In Figure 9, the horizontal axis represents time (seconds), and the vertical axis represents the vibration acceleration (m / s²). 2 ) represents.

[0062] Figure 9 shows the time evolution of the acceleration of panel 130 with a solid line. For comparison, Figure 9 also shows the time evolution of the panel's acceleration in an ideal haptic presentation device with a dashed line, and the time evolution of the panel's acceleration without the pseudo-inverse filter 152 with a dashed-dotted line. The actuator 140 starts driving at time 0 (seconds).

[0063] The time change in acceleration of the panel 130 of the haptic presentation device 100, shown by the solid line, is in close agreement with the time change in acceleration of the panel in the ideal haptic presentation device, shown by the dashed line, and the vibration subsides in about 0.015 seconds immediately after the start of operation of the actuator 140. Furthermore, the time change in acceleration of the panel 130 when the pseudo-inverse filter 152, shown by the dashed line, is larger in amplitude than the acceleration of the panel 130 of the haptic presentation device 100, shown by the solid line, and the vibration does not subside even after about 0.1 seconds.

[0064] Thus, it was confirmed that the tactile presentation device 100 can obtain good vibration characteristics equivalent to those of an ideal tactile presentation device by using the pseudo-inverse filter 152.

[0065] <Gain and Phase> Figure 10 shows an example of the gain and phase of the system to be stabilized. The upper part of Figure 10 shows the frequency characteristics of the gain, and the lower part shows the frequency characteristics of the phase. In the frequency characteristics of the gain, the solid line represents the frequency characteristics of the gain of the system to be stabilized, the dashed line represents the frequency characteristics of the gain of the pseudo-inverse filter 152, and the dashed line represents the frequency characteristics of the output gain when the pseudo-inverse filter 152 and the system to be stabilized are connected in series.

[0066] As shown in the upper part of Figure 10, the output when the pseudo-inverse filter 152 (shown by the dashed line) and the system to be stabilized are connected in series is flat at 0 dB from the low frequency side to the high frequency side. This is because it is obtained by multiplying the frequency characteristics of the system to be stabilized (shown by the solid line) and the pseudo-inverse filter characteristics of the pseudo-inverse filter 152 (shown by the dashed line). Since the pseudo-inverse filter characteristics of the pseudo-inverse filter 152 (shown by the dashed line) are the inverse characteristics of the frequency characteristics of the system to be stabilized (shown by the solid line), the gain of the output (dashed line) when the system to be stabilized and the pseudo-inverse filter 152 are connected in series is flat.

[0067] Furthermore, in the lower part of Figure 10, the solid line represents the frequency characteristics of the phase of the system to be stabilized, the dashed line represents the pseudo-inverse filter characteristics of the phase of the pseudo-inverse filter 152, and the dashed line represents the frequency characteristics of the phase when the unstable zeros of the system to be stabilized are stabilized. The dashed line in the lower part of Figure 10 shows the phase characteristics when the system to be stabilized and the pseudo-inverse filter 152 are connected in series, and it was confirmed that even with the use of a pseudo-inverse filter, the phase fluctuation is not large and all phases are stable. In this example, a pseudo-inverse filter with stabilized unstable zeros was proposed, but slight phase fluctuations occur as shown by the dashed line. To stabilize the phase fluctuations, optimization may be performed using a nonlinear optimization method or the like based on the configuration of this pseudo-inverse filter.

[0068] <Effects> The tactile presentation device 100 comprises an actuator 140 that vibrates in response to an input signal, a panel 130 connected to the actuator 140 and excited in response to the vibration of the actuator 140, and a controller 150 that controls the drive of the actuator 140. The vibration system, including the actuator 140 and the panel 130, has multiple resonant frequencies. The controller 150 corrects the input drive signal using a correction model (pseudo-inverse filter 152) that has been pre-generated based on the multiple resonant frequencies and outputs it to the actuator 140 as an input signal, or outputs a signal that has been pre-generated using the correction model (pseudo-inverse filter 152) to the actuator 140 as an input signal. Therefore, the drive signal input to the actuator 140 is corrected by a correction model that has been pre-generated based on the multiple resonant frequencies.

[0069] Therefore, when the vibration system including the actuator 140 has multiple resonant frequencies, a tactile presentation device 100 capable of providing good tactile sensation can be provided. Furthermore, since the pseudo-inverse filter 152 is a correction model pre-generated based on multiple resonant frequencies, and there is no need to generate a correction model through feedback control, a tactile presentation device 100 with good responsiveness can be provided.

[0070] Furthermore, the correction model is based on an inverse transfer function of a transfer function that takes the input signal as the input and the response characteristics of panel 130 as the output. Therefore, by using a correction model based on an inverse transfer function of a transfer function that takes the vibration of panel 130 as the output in response to the input of actuator 140, the gain of a vibration system having multiple resonant frequencies can be appropriately corrected.

[0071] Furthermore, the correction model is a model based on a pseudo-inverse transfer function in which unstable poles included in the inverse transfer function are replaced with stable poles, or a model based on the inverse transfer function for a pseudo-transfer function in which unstable zeros included in the transfer function are replaced with stable zeros. As a result, it is possible to suppress system oscillation, obtain a stable gain with respect to frequency changes, and provide a tactile presentation device 100 that can provide good tactile feedback.

[0072] Furthermore, the stable pole is the inverse of the positive and negative signs of the real part of the unstable pole, and the stable zero is the inverse of the positive and negative signs of the real part of the unstable zero. Therefore, by using an easily implementable correction model, oscillation of the system (for example, the vibration system of the entire tactile presentation device 100) can be suppressed, a stable gain with respect to frequency changes can be obtained, and a tactile presentation device 100 capable of presenting good tactile sensations can be provided.

[0073] Furthermore, the pseudo-inverse filter 152 is a correction model that reduces the influence of multiple resonant frequencies on the response characteristics. As a result, the actuator 140 can be driven smoothly, and a tactile presentation device 100 that can provide better tactile feedback can be provided.

[0074] Furthermore, the pseudo-inverse filter 152 is a correction model that includes a high-pass filter that sets an upper limit on the gain below the first frequency, or is limited by a high-pass filter that sets an upper limit on the gain below the first frequency. Therefore, it is possible to block the portion of the pseudo-inverse filter characteristic where the gain is infinitely large at low frequencies, making it easier to realize the pseudo-inverse filter 152.

[0075] Also, since the cut-off frequency of the HPF is 30 Hz or more and 100 Hz or less, it is possible to cut off a portion where the gain is infinitely large on the low-frequency side of 30 Hz or more and 100 Hz or less, making it easier to implement the pseudo inverse filter 152.

[0076] Also, since the upper limit value of the gain is 20 dB or more and 30 dB or less, it is possible to reliably reduce the gain on the low-frequency side.

[0077] Also, the correction model includes a low-pass filter having the second frequency as the cut-off frequency, or is a correction model restricted by a low-pass filter having the second frequency as the cut-off frequency. Therefore, on the high-frequency side of the pseudo inverse filter characteristics, it is possible to reduce the gain of high-frequency components that cannot be perceived by the Pacinian corpuscles of the human body, and it is possible to more easily implement the pseudo inverse filter 152.

[0078] Since the second frequency is 500 Hz or more and 1 kHz or less, it is possible to effectively reduce the gain of high-frequency components that cannot be perceived by the Pacinian corpuscles of the human body.

[0079] The tactile display device 100 further includes a fixing portion 110 connected to the panel 130, and the plurality of resonance frequencies include the resonance frequency of the first vibration system including the actuator 140 and the panel 130, and the resonance frequency of the second vibration system including the panel 130 and the fixing portion 110. In the vibration system of the entire tactile display device 100 having such resonance frequencies of the first vibration system and the second vibration system, it is possible to provide a tactile display device 100 that can present a good tactile sensation.

[0080] Also, the panel 130 includes an operation surface 130A having a plurality of operation positions A to D, the controller 150 has a plurality of correction models corresponding to the plurality of operation positions A to D, and selects and uses the correction model corresponding to the operation position where the operation is performed among the plurality of operation positions. Therefore, it is possible to provide a tactile display device 100 that can present a good tactile sensation set corresponding to the plurality of operation positions A to D.

[0081] <Differences in characteristics due to Q value> Figure 11A shows the frequency characteristics of the output gain and phase of the ideal haptic presentation device shown in Figure 3. Figure 11A shows the frequency characteristics of the output gain and phase of the ideal haptic presentation device when the Q value is set to one of five levels from 1 to 5.

[0082] Figure 11B shows the time evolution of the drive signal (upper) input to the ideal haptic presentation device and the acceleration of the vibration generated by the ideal haptic presentation device (lower). The characteristics of the acceleration generated by the ideal haptic presentation device are shown when the Q value is set to one of five levels from 1 to 5.

[0083] Figure 11C shows an example of the vibration of the panel 130 immediately after the actuator 140 of the haptic presentation device 100 starts vibrating. Figure 11C shows the time-dependent characteristics of the vibration of the panel 130 when the Q value is set to one of five levels from 1 to 5. In Figure 11C, the horizontal axis represents time (seconds), and the vertical axis represents the vibration acceleration (m / s²). 2 ) represents.

[0084] The larger the Q value, the greater the change in the gain and phase of the output of the pseudo-inverse filter 152 (see Figure 11A), the larger the amplitude of the vibration acceleration of the actuator 140 (see Figure 11B), and the larger the vibration acceleration of the panel 130 (see Figure 11C). When the Q value was set to 6 or higher, the vibration acceleration of the panel 130 (see Figure 11C) became even larger, but it took a longer time for the vibration of the panel 130 to dampen.

[0085] Focusing on the vibration acceleration of panel 130 (see Figure 11C), the damping time from the start of vibration until it subsides is preferably within 2 to 3 cycles. From this viewpoint, a Q value of 5 or less is preferable.

[0086] Although exemplary embodiments of the tactile presentation device and tactile presentation method of this disclosure have been described above, this disclosure is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims.

[0087] The following additional information is disclosed regarding the embodiments described above. (Note 1) An actuator that vibrates in response to an input signal, A vibration target connected to the actuator and excited in accordance with the vibration of the actuator, A controller that controls the drive of the actuator and Equipped with, The vibration system, which includes the actuator and the object to be excited, has a plurality of resonant frequencies. The controller is a tactile presentation device that corrects the drive signal using a correction model pre-generated based on the plurality of resonant frequencies and outputs it to the actuator as the input signal, or outputs a signal pre-generated using the correction model to the actuator as the input signal. (Note 2) The correction model is a model based on an inverse transfer function for a transfer function that takes the input signal as input and the response characteristics of the vibration target as output, as described in Appendix 1, for the tactile presentation device. (Note 3) The tactile presentation device as described in Appendix 2, wherein the correction model is a model based on a pseudo-inverse transfer function obtained by replacing unstable poles in the inverse transfer function with stable poles, or a model based on an inverse transfer function for a pseudo-transfer function obtained by replacing unstable zeros in the transfer function with stable zeros. (Note 4) The stable electrode is obtained by inverting the positive and negative signs of the real part of the unstable electrode. The tactile presentation device described in Appendix 3, wherein the stable zero is obtained by inverting the sign of the real part of the unstable zero. (Note 5) The tactile presentation device according to any one of the appendices 1 to 4, wherein the correction model is a correction model that reduces the influence of the plurality of resonant frequencies on the response characteristics. (Note 6) The tactile presentation device according to any one of the appendices 1 to 5, wherein the correction model includes a filter that sets an upper limit on the gain of a first frequency or less, or is a correction model limited by a filter that sets an upper limit on the gain of a first frequency or less. (Note 7) The tactile presentation device described in Appendix 6, wherein the first frequency is 30 Hz or more and 100 Hz or less. (Note 8) The tactile presentation device described in Appendix 6, wherein the upper limit of the gain is 20 dB or more and 30 dB or less. (Note 9) The haptic presentation device according to any one of the appendices 1 to 8, wherein the correction model includes a low-pass filter with a second frequency as the cutoff frequency, or is a correction model limited by a low-pass filter with a second frequency as the cutoff frequency. (Note 10) The tactile presentation device described in Appendix 9, wherein the second frequency is 500 Hz or more and 1 kHz or less. (Note 11) The system further comprises a fixed part connected to the object to be vibrated, The tactile presentation device according to any one of the appendices 1 to 10, wherein the plurality of resonant frequencies include the resonant frequency of a first vibration system including the actuator and the vibration target, and the resonant frequency of a second vibration system including the vibration target and the fixed part. (Note 12) The vibration target includes an operating surface having multiple operating positions, The tactile presentation device according to any one of the appendices 1 to 11, wherein the controller has a plurality of correction models corresponding to the plurality of operation positions, and a correction model corresponding to the operation position in which the operation was performed is selected and used. (Note 13) A method for controlling a device comprising an actuator and an object to be vibrated in response to the vibration of the actuator, wherein the vibration system including the actuator and the object to be vibrated has a plurality of resonant frequencies, A tactile presentation method comprising correcting a drive signal using a correction model pre-generated based on the aforementioned plurality of resonant frequencies and outputting it to the actuator, or outputting a signal pre-generated using the correction model as the input signal to the actuator. [Explanation of Symbols]

[0088] 100 Tactile presentation devices 110 Fixed part 120 Elastic member 130 panels 130A operation surface 140 Actuators 141 Drive Amplifier 142 Vibration mechanism 150 controllers 151 Target drive signal output section 152 Pseudo-inverse filter 153 LPF 154 DAC

Claims

1. An actuator that vibrates in response to an input signal, A vibration target connected to the actuator and excited in accordance with the vibration of the actuator, A controller that controls the drive of the actuator and Equipped with, The vibration system, which includes the actuator and the object to be excited, has a plurality of resonant frequencies. The controller corrects the drive signal using a correction model pre-generated based on the plurality of resonant frequencies and outputs it to the actuator as the input signal, or outputs a signal pre-generated using the correction model to the actuator as the input signal. The correction model is a model based on an inverse transfer function for a transfer function that takes the input signal as input and the response characteristics of the vibrating object as output, in a tactile presentation device.

2. The tactile presentation device according to claim 1, wherein the correction model is a model based on a pseudo-inverse transfer function obtained by replacing unstable poles included in the inverse transfer function with stable poles, or a model based on an inverse transfer function for a pseudo-transfer function obtained by replacing unstable zeros included in the transfer function with stable zeros.

3. The stable electrode is obtained by inverting the positive and negative signs of the real part of the unstable electrode. The tactile presentation device according to claim 2, wherein the stable zero is obtained by inverting the sign of the real part of the unstable zero.

4. The tactile presentation device according to claim 1, wherein the correction model is a correction model that reduces the influence of the plurality of resonant frequencies on the response characteristics.

5. The haptic presentation device according to claim 1, wherein the correction model includes a filter that sets an upper limit on the gain of a first frequency or less, or is a correction model limited by a filter that sets an upper limit on the gain of a first frequency or less.

6. The tactile presentation device according to claim 5, wherein the first frequency is 30 Hz or more and 100 Hz or less.

7. The tactile presentation device according to claim 5, wherein the upper limit of the gain is 20 dB or more and 30 dB or less.

8. The haptic presentation device according to claim 1, wherein the correction model includes a low-pass filter with a second frequency as the cutoff frequency, or is a correction model limited by a low-pass filter with a second frequency as the cutoff frequency.

9. The tactile presentation device according to claim 8, wherein the second frequency is 500 Hz or more and 1 kHz or less.

10. The system further comprises a fixed part connected to the object to be vibrated, The tactile presentation device according to claim 1, wherein the plurality of resonant frequencies include the resonant frequencies of a first vibration system including the actuator and the vibration target, and the resonant frequencies of a second vibration system including the vibration target and the fixed part.

11. An actuator that vibrates in response to an input signal, A vibration target connected to the actuator and excited in accordance with the vibration of the actuator, A controller that controls the drive of the actuator and Equipped with, The vibration system, which includes the actuator and the object to be excited, has a plurality of resonant frequencies. The controller corrects the drive signal using a correction model pre-generated based on the plurality of resonant frequencies and outputs it to the actuator as the input signal, or outputs a signal pre-generated using the correction model to the actuator as the input signal. The vibration target includes an operating surface having multiple operating positions, The controller is a haptic presentation device that selects and uses a correction model from among a plurality of correction models corresponding to each of the plurality of operation positions, the correction model corresponding to the operation position in which the operation was performed.

12. A method for controlling a device comprising an actuator that vibrates in response to an input signal and an object that is excited in response to the vibration of the actuator, wherein the vibration system including the actuator and the object has a plurality of resonant frequencies, Using a correction model pre-generated based on the plurality of resonant frequencies, the drive signal is corrected and output to the actuator, or a signal pre-generated using the correction model is output to the actuator as the input signal. The correction model is a model based on an inverse transfer function for a transfer function that takes the input signal as input and the response characteristics of the vibrating object as output, in a tactile presentation method.

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