Device, vibration presentation device, method, vibration presentation method, and program

Abstract

This apparatus includes a control unit for outputting, on the basis of target data that is time-series data of a wave containing at least a low-frequency component of 100 Hz or less, a first wave that is an amplitude-modulated wave satisfying: a condition wherein the envelope has a maximum value at the timing at which a low-frequency component local-maximum value, which is a local maximum value in the waveform of the low-frequency component, appears; and a condition wherein the waveform of the envelope is a single-peak mountain shape having a predetermined time width.

Description

Apparatus, vibration presentation apparatus, method, vibration presentation method and program

[0001] The present invention relates to a device, a vibration presentation device, a method, a vibration presentation method, and a program. This application claims priority to Japanese Patent Application No. 2023-207653, filed on December 8, 2023, the contents of which are incorporated herein by reference.

[0002] In recent years, with the popularity of e-sports and virtual reality (VR), video games such as online games and social games have become increasingly popular. Accordingly, there has been growing interest in technology that generates various vibrations, ranging from low to high frequencies according to the content of the game, using portable game consoles, game controllers, VR controllers, etc., and allows users to experience these vibrations.

[0003] Furthermore, the demand for such vibration-experiencing technology is increasing not only in games and VR but also in other fields such as movies and music. For example, in the case of movies, the use of vibration-experiencing technology makes it possible to provide viewers with vibrations according to the content of the movie (see, for example, Patent Documents 1 and 2). For example, in the case of orchestral music, the use of vibrations makes it possible to simulate the experience of watching in a theater.

[0004] JP 2021-65872 A International Patent Publication No. 2022 / 254732

[0005] Yuya Hoshi et al., “Alternative presentation method of low-frequency vibration sensation using a voice coil type vibrator”, Proceedings of the JSME Robotics and Mechatronics Conference (CD-ROM), Vol.2022 Page.ROMBUNNO.2P2-B12 (2022)

[0006] Such vibrations are generated by vibrators such as piezoelectric vibrators and linear resonant actuator (LRA) vibrators. However, according to Newtonian mechanics, the natural frequency of a vibrator decreases as the vibrator's mass increases. Therefore, in order to generate low-frequency vibrations, the vibrator may need to be large.

[0007] In view of the above circumstances, an object of the present invention is to provide a technique for suppressing an increase in the size of a vibrator.

[0008] One aspect of the present invention is an apparatus that includes a control unit that outputs a first wave, which is an amplitude-modulated wave that satisfies the following conditions: an envelope has a maximum value at the timing of the appearance of a low-frequency component maximum value, which is a maximum value in the waveform of the low-frequency component, based on target data that is time-series data of a wave that includes low-frequency components of at least 100 Hz or less; and the waveform of the envelope has a single-peaked mountain shape with a predetermined time width.

[0009] One aspect of the present invention is a vibration presentation device including the above device and a vibrator that vibrates in response to waves output from the control unit.

[0010] One aspect of the present invention is a method executed by the above-described apparatus, the method including an output step of outputting the first wave.

[0011] One aspect of the present invention is a vibration presentation method executed by the above-mentioned vibration presentation device, which includes a vibration step of vibrating the vibrator using waves output from the control unit of the vibration presentation device.

[0012] One aspect of the present invention is a program for causing a computer to function as the above-described device.

[0013] One aspect of the present invention is a program for causing a computer to function as the vibration presentation device.

[0014] According to the present invention, it is possible to prevent the vibrator from becoming large.

[0015] 1 is an explanatory diagram illustrating an overview of a vibration presentation device according to an embodiment. FIG. 2 is an explanatory diagram illustrating an example of a process for obtaining a mountain-shaped waveform by spline interpolation according to an embodiment. FIG. 1 is a first diagram illustrating an example of a result of a first experiment according to an embodiment. FIG. 2 is a second diagram illustrating an example of a result of the first experiment according to an embodiment. FIG. 1 is a first diagram illustrating an example of a waveform of an excitation wave used in a second experiment according to an embodiment. FIG. 2 is a second diagram illustrating an example of a waveform of an excitation wave used in a second experiment according to an embodiment. FIG. 1 is a first diagram illustrating an example of a result of the second experiment according to an embodiment. FIG. 2 is a second diagram illustrating an example of a result of the second experiment according to an embodiment. A diagram illustrating an example of a hardware configuration of a vibration presentation device according to an embodiment. A flowchart illustrating an example of a flow of processing executed by a vibration presentation device according to an embodiment.

[0016] 1 is an explanatory diagram illustrating an overview of a vibration presentation system 100 according to an embodiment. The vibration presentation system 100 includes a device 1 and a vibrator 2. The vibrator 2 is a vibrator that vibrates in response to a wave output from the device 1. More specifically, the vibrator 2 is a vibrator that vibrates in response to a wave such as a first wave or a third wave (to be described later) that is output from a control unit 11 (to be described later) included in the device 1.

[0017] The vibrator 2 may be, for example, a piezoelectric vibrator or a Linear Resonant Actuator (LRA) vibrator. Note that many commonly used piezoelectric vibrators vibrate at frequencies between 80 Hz and 400 Hz, but have small amplitudes in the low-frequency range of 100 Hz or less.

[0018] The device 1 includes a control unit 11 having a processor 91 such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit) or an NPU (Neural Network Processing Unit) and a memory 92 connected by a bus, and executes a program.

[0019] The control unit 11 executes a program to perform, for example, a first wave output process, which is a process of outputting a first wave based on target data, which is time-series data of a wave containing low-frequency components of at least 100 Hz or less (hereinafter referred to as the "target wave").

[0020] The first wave is presented at the timing of the appearance of a maximum value (hereinafter referred to as the "low-frequency component maximum value") in the waveform of the above-mentioned low-frequency component (hereinafter referred to as the "target low-frequency component") contained in the target wave, and is an amplitude-modulated wave that satisfies the conditions that the envelope has a maximum value (hereinafter referred to as the "envelope maximum value") and that the waveform of the envelope is a single-peaked mountain shape of a predetermined time width.

[0021] The reason why the frequency of the low frequency component is 100 Hz or less is that, as mentioned above, many commonly used vibrators can drive vibrations at 80 Hz or more and 400 Hz or less, but the amplitude is low below 100 Hz and it is difficult to perceive, and it is desired to improve the ease of perception in the range where it is difficult to perceive with vibrations from commonly used vibrators.

[0022] The predetermined time width is, for example, 5 ms or more and less than 50 ms. When the time width is 5 ms or more and less than 50 ms, it is easy to transmit a low-frequency sensation to the person receiving the vibration of the vibrator 2, as will be described later.

[0023] The above-mentioned peak-shaped waveform is a waveform represented by, for example, a sine function. The above-mentioned peak-shaped waveform may also be a waveform represented by, for example, a Gaussian function. More specifically, a waveform represented by a Gaussian function is a waveform in which the peak width is set to a predetermined width using a parameter representing the standard deviation of the Gaussian function. The above-mentioned peak-shaped waveform may also be a waveform represented by, for example, a polynomial function. The above-mentioned peak-shaped waveform may also be a square wave waveform. The above-mentioned peak-shaped waveform may also be a triangular wave waveform. The above-mentioned peak-shaped waveform may also be a sawtooth wave waveform. In this way, the peak-shaped waveform may be, for example, any of a waveform represented by a sine function, a waveform represented by a Gaussian function, a waveform represented by a polynomial function, a square wave waveform, a triangular wave waveform, or a sawtooth wave waveform.

[0024] The above-mentioned "peak-shaped waveform" means that the approximate shape is a single-peaked peak. Therefore, the above-mentioned examples of peak-shaped waveforms, such as waveforms expressed by sine functions, are merely examples, and the peak-shaped waveform may be a waveform expressed by another function as long as it is roughly a peak. For example, the peak-shaped waveform may be a waveform that has a depression in one part but has a single-peaked peak shape in its approximate shape.

[0025] The peak-shaped waveform may be the result of spline interpolation, for example, of a waveform that connects a sample at the start position of the spline target period, a sample at the end position of the spline target period, and a sample at the position of a low-frequency component maximum value included in the spline target period. The spline target period is a period that includes one low-frequency component maximum value obtained from the waveform of the target low-frequency component. Examples of peak-shaped waveforms obtained by spline interpolation will be described later.

[0026] In spline interpolation, for example, additional sample points may be added in addition to the above three points so as to satisfy the above-mentioned condition that the envelope waveform is a single-peaked mountain shape with a predetermined time width.

[0027] The low-frequency component maximum value may be spaced apart from the adjacent low-frequency component maximum value by 10 ms or more. By setting the maximum value in this manner, unnecessary maximum values ​​that are not involved in the low-frequency sensation can be eliminated.

[0028] The frequency of the first carrier wave is, for example, 80 Hz or more and 400 Hz or less.

[0029] The target low frequency component has a frequency of, for example, 100 Hz or less.

[0030] If the target wave further includes a high-frequency component greater than 100 Hz, the control unit 11 may execute a program to perform a third wave output process. The third wave output process is a process of outputting a composite wave (hereinafter referred to as the "third wave"), which is a wave obtained by synthesizing the second wave and the first wave in phase, instead of the first wave. The first wave is a wave obtained by the first wave output process.

[0031] The second wave is an amplitude-modulated wave obtained by a predetermined signal conversion based on the high-frequency components contained in the target wave (hereinafter referred to as the "target high-frequency components"). It is desirable that the carrier wave of the second wave and the carrier wave of the first wave have the same frequency and phase. This allows the waveforms of the first and second waves to be combined without canceling each other out.

[0032] The predetermined signal transformation may be, for example, amplitude modulation based on the effective value of the signal, amplitude modulation based on the energy of the signal, amplitude modulation based on a pre-identified perceptual quantity, or a combination thereof. The predetermined signal transformation may be, for example, Intensity Segment Modulation (ISM; see Patent Document 1).

[0033] 1 shows example C0 (sine wave) and example C1 (amplitude-modulated wave with an envelope narrower than that of a sine wave) superimposed on each other. Example C0 shows the waveform of an amplitude-modulated wave with a sine wave envelope superimposed on a carrier wave waveform. Example C1 shows the waveform of an amplitude-modulated wave with an envelope narrower than that of example C0 and the same carrier wave as that of example C0 superimposed on a carrier wave waveform.

[0034] The envelope waveform of Example C1 is a mountain shape. The envelope wave of Example C1 is an example of a first wave. The carrier wave shown in Example C0 can present a low-frequency feeling by expressing low frequencies with the envelope component of the amplitude-modulated wave. However, the high-frequency feeling of the carrier wave also remains strong at the same time. On the other hand, the envelope shown in Example C1 can convey a low-frequency feeling while suppressing the high-frequency feeling. The width of the envelope shown in Example C1 (corresponding to the above-mentioned specified time width) is preferably 5 ms or more and less than 50 ms, and more preferably in the range of 25 ms ± 10 ms. In this way, by narrowing the width of the envelope shape of the amplitude-modulated wave, a low-frequency feeling can be presented while suppressing the high-frequency feeling.

[0035] In particular, this method is highly versatile and can be used even with piezoelectric vibrators that have small reverberation vibrations. Furthermore, even with LRA vibrators, the method described in Non-Patent Document 1, which presents proxy vibrations, can be made more effective by keeping the reverberation vibrations within the envelope range that gives the feeling of low frequencies such as the first and second waves.

[0036] 2 is an explanatory diagram illustrating an example of a process for obtaining a mountain-shaped waveform using spline interpolation in an embodiment. Fig. 2 shows images G1, G2, and G3. Image G1 shows an example of a time series W1 (i.e., a waveform (target wave)) in the low-frequency band (100 Hz or less) of the amplitude of the waveform to be reproduced.

[0037] The waveform W1 has a sample P1 indicating a first minimum value, a sample P2 indicating a first maximum value, a sample P3 indicating a second minimum value, a sample P4 indicating a second maximum value, and a sample P5 indicating a third minimum value. The amplitude values ​​of the samples P2 and P4 in the waveform W1 are each an example of a low-frequency component maximum value.

[0038] As for the maximum value between sample P2 and adjacent sample P3, the time interval between sample P2 and sample P3 is less than 10 ms, so sample P2, which has the largest maximum value (amplitude), is selected.

[0039] The time of sample P1 is t1, the time of sample P2 is t2, the time of sample P3 is t3, the time of sample P4 is t4, and the time of sample P5 is t5. t1 to t5 have the relationship t1<t2<t3<t4<t5. t3-t1 is equal to or greater than a predetermined time greater than 10 ms. t4-t2 is equal to or greater than a predetermined time greater than 10 ms. t5-t3 is equal to or greater than a predetermined time greater than 10 ms.

[0040] Furthermore, image G1 shows that when waveform W1 is considered as a two-dimensional figure spanned by a time axis and an axis perpendicular to the time axis (i.e., an axis in the amplitude direction), the length of a perpendicular line drawn from sample P2 to a line segment connecting samples P1 and P3 is A1. Image G1 also shows that the length of a perpendicular line drawn from sample P4 to a line segment connecting samples P3 and P5 is A2.

[0041] Image G2 shows waveforms W2 and W3 as examples of single-peaked mountain-shaped waveforms obtained based on waveform W1. Waveform W2 is a waveform obtained from samples P1, P2, and P3 of waveform W1, and is expressed as a Gaussian function having a peak at time t2 (the same as time t2 in image G1), with a peak height of A1. Waveform W3 is a waveform obtained from samples P3, P4, and P5 of waveform W1, and is expressed as a Gaussian function having a peak at time t4 (the same as time t4 in image G1), with a peak height of A2.

[0042] Thus, the waveforms W2 and W3 are examples of the waveform of the first wave. The peak values ​​of the waveforms W2 and W3 are each examples of envelope maximum values.

[0043] Image G3 shows waveforms W4 and W5 as examples of single-peaked mountain-shaped waveforms obtained by spline interpolation of waveform W1 shown in image G1. Waveform W4 is the result of adding samples Q1 and Q2 before and after sample P2 based on the time of sample P2 and the magnitude of A1 obtained from waveform W1 so as to form a single-peaked mountain-shaped waveform of a predetermined time width, and then spline interpolating sample Q1, sample P2, and sample Q2 including the added samples Q1 and Q2.

[0044] Waveform W5 is the result of adding samples Q3 and Q4 before and after sample P4 so as to form a single-peaked, mountain-shaped waveform of a predetermined time width based on the time of sample P4 and the magnitude of A2 obtained from waveform W1, and then spline interpolating sample Q3, sample P4, and sample Q4, including the added samples Q3 and Q4. Both waveforms W4 and W5 are mountain-shaped waveforms.

[0045] The peak values ​​of waveform W4 and waveform W5 are examples of envelope maximum values. Sample Q1 is an example of a sample at the start position of the spline target period, and sample Q2 is an example of a sample at the end position of the spline target period.

[0046] It should be noted that the spline interpolation does not necessarily have to be performed for three points, and may be performed under more constraints.

[0047] Furthermore, the alternative waveform used for spline interpolation is not limited to a Gaussian function, and any narrow, mountain-shaped waveform (such as the waveform shown in FIG. 6, which will be described later) may be used. In this case, the waveform may be expressed by AM (amplitude modulation).

[0048] The horizontal axis in image G2 represents the time axis of the waveform to be reproduced. The vertical axis in image G3 represents the magnitude of the amplitude to be reproduced. The horizontal axis in image G3 represents the time axis of the waveform to be reproduced. The vertical axis in image G3 represents the magnitude of the amplitude to be reproduced.

[0049] The amplitude-modulated wave (i.e., the first wave) having an envelope narrower than that of a sine wave in the vibration presentation system 100 may be integrated with the high-frequency component generated by the ISM and presented. However, in this case, there is a risk that the waveforms may be canceled out due to a phase shift between the first wave and the high-frequency component.

[0050] To prevent this, it is desirable to combine the high-frequency and low-frequency intensities and generate an AM wave at the same time. Specifically, the intensity to be used at low frequencies is calculated, and the calculated low-frequency intensity is added to the high-frequency intensity of the original waveform to generate an AM wave. This makes it possible to present a waveform in which both high-frequency and low-frequency components can be perceived.

[0051] <Technical Significance of Outputting the First Wave> As described above, it is difficult for vibrators such as piezoelectric vibrators and LRA vibrators to excite large amplitude vibrations when excited at low frequencies. Or, even if they can be excited, they cannot obtain an amplitude large enough to perceive the vibration. This is because the sensitivity with which humans perceive vibration has frequency characteristics. In other words, there are frequencies at which vibration is easily perceived and frequencies at which it is difficult to perceive.

[0052] Commonly used vibrators are designed with these circumstances in mind. For example, in the case of an LRA type vibrator, the closer the vibration frequency of an LPA type vibrator is to the resonant frequency, the larger the amplitude. Therefore, taking into consideration this and the frequency characteristics of human perception (sensitivity peaks at around 200 Hz), the resonant frequency of an LRA type vibrator is often set to around 200 Hz.

[0053] For example, in the case of a piezoelectric vibrator, low and high frequencies have roughly the same amplitude. However, humans have a higher sensitivity to high frequencies. Therefore, when it comes to perceiving vibrations from a piezoelectric vibrator, people feel a stronger stimulus when the vibrator vibrates at a high frequency.

[0054] Taking these circumstances into consideration, the vibration presentation system 100 excites the vibrator 2 with, for example, an amplitude-modulated wave in which the carrier wave has a frequency that can drive the vibrator with a vibration large enough for a human to perceive, and the envelope has a low frequency.

[0055] In this way, while the vibrator 2 is excited at the frequency of the carrier wave, the perceived strength of the excitation changes at low frequencies, so that a low-frequency sensation can be presented by the vibration of the vibrator 2. Since the perceived strength of the excitation changes at low frequencies, and the excitation frequency is not a low frequency, there is no need to enlarge the vibrator 2.

[0056] In this way, the vibration presentation system 100 can allow the user to experience low-frequency vibrations without increasing the size of the vibrator. This is the technical significance of outputting the first wave. In fact, this effect of allowing the user to experience low-frequency vibrations without increasing the size of the vibrator 2 has been demonstrated in experiments. An example of the experimental results will now be described.

[0057] <About the Experiments> Experiment 1 was conducted using a waveform represented by a Gaussian function as the mountain-shaped waveform, and Experiment 2 was conducted using a waveform obtained by the above-mentioned spline interpolation as the mountain-shaped waveform. In both Experiment 1 and Experiment 2, the wave that excited the vibrator (hereinafter referred to as "excitation wave") was a wave output from the control unit 11. In both Experiment 1 and Experiment 2, a questionnaire was conducted on 10 subjects regarding how they felt about the vibration.

[0058] In both Experiments 1 and 2, the subjects were trained in advance to distinguish between the tactile sensations of low and high frequencies generated by a general-purpose vibrator (VP4), and the training was continued until the subjects were able to distinguish between the tactile sensations of low and high frequencies generated by the VP4.

[0059] <<First Experiment>> A description will be given of the waveform of the excitation wave used in the first experiment. In the first experiment, an ISM wave (hereinafter referred to as "experimental high frequency wave") and an experimental hybrid wave were used.

[0060] The high frequency wave used in the experiment was a wave expressed by the following formula (1) converted by ISM, with a = 0.5, ft = 2 Hz, fe = 150 Hz, and fc = 400 Hz.

[0061]

[0062] The experimental hybrid wave was a wave obtained by combining the first experimental low-frequency wave and the experimental high-frequency wave so that they met the conditions that they were in phase and had the same peak position. The first experimental low-frequency wave was a first wave whose mountain-shaped waveform was represented by a Gaussian function. Four widths of the Gaussian function of the first experimental low-frequency wave were used: 100 ms, 50 ms, 25 ms, and 12.5 ms. In the first experiment, the width of the Gaussian function was defined as 6σ (i.e., six times the standard deviation). The frequency and phase of the carrier wave of the first experimental low-frequency wave and the carrier wave of the experimental high-frequency wave were identical.

[0063] The reason for the in-phase nature of the signals is the same as that of matter waves and photons in quantum physics such as quantum optics: the higher the coherency of the two waves, the stronger the signal that can be obtained. Therefore, the signals do not necessarily need to be in-phase, depending on the strength of the required signal.

[0064] Thus, the first experimental low frequency wave is an example of a first wave, the experimental high frequency wave is an example of a second wave, and the experimental hybrid wave is an example of a third wave.

[0065] <<<Relationship Between Waves and Questionnaire in First Experiment>>> The relationship between the vibrations felt by the subjects and the questionnaire will be explained. In the first experiment, the piezoelectric vibrator was repeatedly excited by either the experimental hybrid wave or the first de-emphasized wave, which was randomly selected once every four times. Note that the first de-emphasized wave was not a composite wave of the experimental high frequency wave and the first experimental low frequency wave, but a wave obtained by simply combining a Gaussian function wave with the experimental high frequency wave.

[0066] To explain these four excitation repetitions more specifically, the fourth excitation wave that excited the piezoelectric transducer was actually a wave randomly selected from eight types and synthesized into the experimental high-frequency wave. The reason is that the width 6σ (σ represents the standard deviation) of the Gaussian functions of both the experimental hybrid wave and the first de-emphasized wave was not constant and independent of the repetition, but was a width randomly selected from four candidates.

[0067] The four candidate frequencies were 100 ms, 50 ms, 25 ms, and 12.5 ms. Therefore, in each of four excitation sets, the first three excitations were performed using the experimental high-frequency wave, and the fourth excitation was performed using one of the eight frequencies randomly selected from the eight frequencies. The eight frequencies were: an experimental hybrid wave with a Gaussian function width of 100 ms, an experimental hybrid wave with a Gaussian function width of 50 ms, an experimental hybrid wave with a Gaussian function width of 25 ms, an experimental hybrid wave with a Gaussian function width of 12.5 ms, a first de-emphasized frequency wave with a Gaussian function width of 100 ms, a first de-emphasized frequency wave with a Gaussian function width of 50 ms, a first de-emphasized frequency wave with a Gaussian function width of 25 ms, and a first de-emphasized frequency wave with a Gaussian function width of 12.5 ms.

[0068] For each of the four sets, each subject evaluated the tactile sensation of the piezoelectric vibrator vibration induced by the first three excitation waves and the tactile sensation of the piezoelectric vibrator vibration induced by the fourth excitation wave. The four-time set was repeated five times, and the subjects were allowed to repeat the experience until they were satisfied. Therefore, each subject experienced all eight types of vibration at least once.

[0069] Specifically, the subjects' evaluation consisted of their answers to the following two questions. The subjects were asked to answer each question on a 7-point Likert scale. Question 1, one of the questions, asked, "Is there a low-frequency tactile sensation separate from the high-frequency tactile sensation?" Question 2, the other of the questions, asked, "Is there a change in the high-frequency tactile sensation due to the low-frequency sensation?" Question 2 was to be answered if the subjects answered "I felt a low-frequency sensation" to question 1.

[0070] More specifically, the first question was, "When you felt the vibrations caused by the fourth excitation wave, did you feel a low-frequency tactile sensation in addition to a high-frequency tactile sensation?" The second question was asked after the answer to the first question was, "You said you felt a low-frequency tactile sensation with the fourth vibration, but did the high-frequency tactile sensation you felt with the fourth vibration change from the high-frequency tactile sensations you felt with the first to third vibrations?"

[0071] The seven possible answers on the 7-point Likert scale were: "1: Not at all," "2: Not at all," "3: Not really," "4: Neither," "5: Somewhat," "6: Somewhat," and "7: Very much."

[0072] <<<Experimental Results of First Experiment>>> Fig. 3 is a first diagram showing an example of the results of the first experiment in the embodiment. Fig. 4 is a second diagram showing an example of the results of the first experiment in the embodiment. More specifically, Fig. 3 is a diagram showing the results of the subjects' answers to the first question. Fig. 4 is a diagram showing the results of the subjects' answers to the second question.

[0073] The graphs in Figures 3 and 4 are box plots showing the range from the first quartile to the third quartile, the median, the maximum value, and the minimum value, which are indicated by the top and bottom ends of the whiskers, respectively.

[0074] In Fig. 3, the results in area D1 show the responses of the subjects to the first question when the first emphasis wave appeared as the fourth wave. In Fig. 3, the results in area D2 show the responses of the subjects to the first question when the experimental hybrid wave appeared as the fourth wave.

[0075] The results for area D2 in Figure 3 show that when the experimental hybrid wave appeared as the fourth wave, the subjects responded that they felt a low-frequency tactile sensation, regardless of the Gaussian function width of 6σ. When the Gaussian function width was 12.5 ms, the number of subjects who responded that they did not feel a low-frequency tactile sensation increased compared to the other cases, but only three out of ten subjects received a score of four or less. Therefore, the majority of subjects responded that they felt a low-frequency tactile sensation.

[0076] Furthermore, the difference between the results in region D1 and region D2 in FIG. 3 indicates that, in order to obtain a low-frequency tactile sensation, the appearance of the experimental hybrid wave as the fourth wave is preferable to the appearance of the first de-emphasized wave as the fourth wave.

[0077] The results in Figure 4 show that when the width of the Gaussian function is 12.5 ms or 25 ms, low-frequency tactile sensations are presented without affecting high-frequency tactile sensations more than in the other cases. In particular, the results in Figure 4 show that when the width of the Gaussian function is 25 ms, low-frequency tactile sensations are presented with less impact on high-frequency tactile sensations than in the other cases.

[0078] The experimental results illustrated in Figures 3 and 4 show that by using device 1, it is possible to provide a low-frequency tactile sensation to a subject, and further, it is possible to provide not only a low-frequency sensation but also a low-frequency sensation without substantially changing the high-frequency tactile sensation.

[0079] A technology that can provide low-frequency tactile sensations without substantially changing high-frequency tactile sensations is particularly useful for providing tactile sensations that match music. Because music uses a wide range of sounds, being able to provide tactile sensations that match high and low frequencies can enrich the listener's experience.

[0080] <Example of more preferable conditions> Here, taking into consideration the experimental results illustrated in Figures 3 and 4 and the <technical significance of outputting the first wave>, a more preferable condition than others will be shown. It is more preferable that the width 6σ of the Gaussian function is 5 ms or more and less than 50 ms. Note that 5 ms is a condition in which a 200 Hz wave fits within the width of the Gaussian function.

[0081] Note that 200 Hz is a value between 80 Hz and 400 Hz, and is the carrier wave frequency used in the experiments to obtain the experimental results shown in Figures 3 and 4, as described above. Furthermore, approximately 25 ms is more preferable. Considering that the envelope frequency should be lower than the carrier wave frequency, it is preferable that the frequency of the first wave be between 10 Hz and 100 Hz.

[0082] Furthermore, in the experimental example that obtained the experimental results shown in Figures 3 and 4, the frequency of the carrier wave of the experimental high frequency was 200 Hz, as described above. The experimental high frequency is an example of the second wave, as described above. Therefore, although the carrier wave of the second wave is, for example, 200 Hz, the frequency of the carrier wave of the second wave does not necessarily have to be 200 Hz or higher. As described above, since the frequency at which commonly used vibrators vibrate is 80 Hz or higher, the frequency of the carrier wave of the second wave is not limited to 200 Hz, as long as it is, for example, 80 Hz or higher.

[0083] <<Second Experiment>> The waveform of the excitation wave used in the second experiment will be described.

[0084] 5A and 5B are diagrams illustrating an example of a waveform of an excitation wave that has not been subjected to low-frequency bodily sensation enhancement processing and that has been used in a second experiment according to the embodiment. FIG. 6A and 6B are diagrams illustrating an example of a waveform of an excitation wave that has been subjected to low-frequency bodily sensation enhancement processing and that has been used in a second experiment according to the embodiment.

[0085] The low-frequency bodily sensation enhancement process is a process for obtaining a first wave from a target wave. Therefore, the excitation wave that has not undergone low-frequency bodily sensation enhancement process is the target wave. The excitation wave that has undergone low-frequency bodily sensation enhancement process is the first wave.

[0086] The horizontal axis of the graph in Fig. 5 represents time, and the vertical axis represents amplitude. The horizontal axis of the graph in Fig. 6 represents time, and the vertical axis represents amplitude. There is a significant difference in the waveforms shown in Fig. 5 and Fig. 6 around time 1.34 s.

[0087] The waveform shown in FIG. 5 is a wave obtained by applying ISM to the target high frequency component to convert it into a 200 Hz amplitude modulated wave, and combining the target low frequency component with the ISM amplitude modulated wave without performing modulation processing.

[0088] The waveform shown in Figure 6 is an example of a waveform in which a 200 Hz amplitude-modulated wave obtained by applying ISM to the target high-frequency component and a second experimental low-frequency wave are superimposed so that they are in phase. The second experimental low-frequency wave is a first wave in which the waveform obtained by the spline interpolation described above is used as a mountain-shaped waveform, and the carrier wave is 200 Hz. Therefore, the second experimental low-frequency wave is an example of the first wave.

[0089] More specifically, the first wave, in which the waveform obtained by the above-mentioned spline interpolation based on the waveform shown in Figure 5 was used as a mountain-shaped waveform, was the second experimental low frequency, and the waveform of this second experimental low frequency is the waveform shown in Figure 6. More specifically, the spline interpolation was spline interpolation in which zero points were inserted at the midpoints between the maximum values ​​in the waveform in Figure 5.

[0090] Hereinafter, the wave used in the second experiment that has not undergone low-frequency somatic sensation enhancement processing will be referred to as a “second non-enhanced wave.” Therefore, the wave shown in FIG. 5 is an example of a second non-enhanced wave.

[0091] <<<<Relationship between waves and questionnaire in the second experiment>>> In the second experiment, each subject experienced the vibration of a vibrator using the second non-emphasized wave as the excitation wave and the vibration of a vibrator using the second experimental low frequency as the excitation wave, and was asked to answer the third and fourth questions for each.

[0092] The third question was, "Is there a low-frequency tactile sensation separate from the high-frequency tactile sensation?" As illustrated in Figures 5 and 6, the second experiment differed from the first experiment in that it did not include the four concepts in the set of four used in the first experiment. Therefore, subjects were first presented with a high-frequency tactile sensation using the amplitude-modulated ISM wave, followed by the second unmodulated wave or the second experimental low-frequency wave. More specifically, the third question was, "Does the vibration experienced the second time provide a low-frequency tactile sensation separate from the high-frequency tactile sensation experienced the first time?"

[0093] The fourth question was asked if the answer to the third question was "I felt a low-frequency tactile sensation." The fourth question asked, "Has the feeling of high-frequency tactile sensation changed after experiencing low-frequency tactile sensation?"

[0094] The subjects were asked to respond to each question on a 7-point Likert scale. In the second experiment, the seven possible answers on the 7-point Likert scale were "1: Not at all," "2: Not at all," "3: Not really," "4: Neutral," "5: Somewhat," "6: Some," and "7: Very much."

[0095] <<<<Experimental Results of Second Experiment>>> Fig. 7 is a first diagram showing an example of the results of the second experiment in the embodiment. Fig. 8 is a second diagram showing an example of the results of the second experiment in the embodiment. More specifically, Fig. 7 is a diagram showing the results of the subjects' answers to the third question. Fig. 8 is a diagram showing the results of the subjects' answers to the fourth question.

[0096] The graphs in Figures 7 and 8 are box plots showing the range from the first quartile to the third quartile, the median, the maximum value, and the minimum value, which are indicated by the top and bottom ends of the whiskers, respectively.

[0097] The results in area D3 in Fig. 7 show the responses to the third question obtained from the subjects when they experienced the vibration of the vibrator excited by the second non-emphasized wave. The results in area D4 in Fig. 7 show the responses to the third question obtained from the subjects when they experienced the vibration of the vibrator excited by the second experimental low frequency wave.

[0098] The results in Figure 7 show that more people responded that they felt a low-frequency tactile sensation when the excitation wave was the second experimental low frequency than when the excitation wave was the second non-emphasized wave. Also, the results in Figure 8 show that even when a low-frequency tactile sensation is obtained, it tends not to affect the high-frequency tactile sensation.

[0099] The experimental results shown in Figures 7 and 8 show that even when spline interpolation is used, it is possible to provide a low-frequency tactile sensation to the subject, and furthermore, it is possible to provide not only a low-frequency sensation but also a low-frequency sensation without substantially changing the high-frequency sensation.

[0100] 9 is a diagram showing an example of the hardware configuration of the device 1 according to the embodiment. As described above, the device 1 includes a control unit 11 including a processor 91 such as a CPU and a memory 92 connected by a bus, and executes a program. By executing the program, the device 1 functions as a device including the control unit 11, an interface unit 12, and a storage unit 13.

[0101] More specifically, the processor 91 reads out a program stored in the storage unit 13 and stores the read out program in the memory 92. The processor 91 executes the program stored in the memory 92, whereby the device 1 functions as a device including the control unit 11, the interface unit 12, and the storage unit 13.

[0102] The control unit 11 controls the operation of various functional units included in the device 1. The control unit 11 executes, for example, a first wave output process. The control unit 11 may execute, for example, a third wave output process. The vibrator 2 vibrates due to the first wave or the third wave output by the control unit 11.

[0103] The control unit 11, for example, acquires target data input via the interface unit 12. The control unit 11, for example, acquires target data previously stored in the storage unit 13. The control unit 11 may, for example, perform a Fourier transform on the target wave indicated by the target data, and then perform an inverse Fourier transform on data in a predetermined frequency range of 100 Hz or less from the spectrum indicated by the result of the Fourier transform, thereby obtaining target low-frequency components. The control unit 11 may, for example, perform a Fourier transform on the target wave indicated by the target data, and then perform an inverse Fourier transform on data in a predetermined frequency range of more than 100 Hz from the spectrum indicated by the result of the Fourier transform, thereby obtaining target high-frequency components.

[0104] The control unit 11 may, for example, acquire information stored in the storage unit 13. Specifically, the process of acquiring information stored in the storage unit 13 is a read process.

[0105] The interface unit 12 includes a communication interface for connecting the device 1 to an external device. The interface unit 12 communicates with the external device via a wired or wireless connection. The external device is, for example, the vibrator 2. In such a case, the interface unit 12 outputs the first wave and the third wave to the vibrator 2 through communication with the vibrator 2. The external device may be, for example, a device that is a source of the target data. In such a case, the interface unit 12 acquires the target data through communication with the device that is the source of the target data.

[0106] The interface unit 12 includes input devices such as a mouse, keyboard, touch panel, and microphone. The interface unit 12 may be configured as an interface that connects these input devices to the apparatus 1. In this way, the interface unit 12 accepts input of various information to the apparatus 1 via the input device, either wired or wireless. Note that the target data does not necessarily need to be input to a communication interface, but may be input to an input device.

[0107] The interface unit 12 outputs various types of information. The interface unit 12 includes a display device such as a CRT (Cathode Ray Tube) display, a liquid crystal display, or an organic EL (Electro-Luminescence) display. The interface unit 12 may be configured as an interface that connects these display devices to the device 1. The interface unit 12 outputs information input to, for example, a communication interface or an input device of the interface unit 12.

[0108] The storage unit 13 is configured using a computer-readable storage medium device (non-transitory computer-readable recording medium) such as a magnetic hard disk device or a semiconductor storage device. The storage unit 13 stores various information related to the device 1. The storage unit 13 stores, for example, various information generated by the operation of the control unit 11. The storage unit 13 stores, for example, information input to the interface unit 12.

[0109] <Example of Processing Flow> Fig. 10 is a flowchart showing an example of the processing flow executed by the device 1 of the embodiment. In the example of Fig. 10, a case where a first wave output process is executed will be described as an example. The control unit 11 acquires target data (step S101). Next, the control unit 11 executes the first wave output process (step S102). As a result of the execution of the first wave output process, for example, the vibrator 2 vibrates due to the first wave obtained by the execution of the first wave output process.

[0110] The device 1 configured in this manner executes a first wave output process. As a result, if the obtained first wave is used, the vibrator 2 can be excited with the first wave. Therefore, the vibrator 2 excited in this manner can present a low frequency. Here, the vibrator 2 may be a general-purpose one. Therefore, if the first wave is obtained in the first wave output process, the vibrator 2 can present a low frequency without being enlarged. Therefore, the device 1 can suppress the enlargement of the vibrator 2.

[0111] (Modification) The vibration presentation system 100 may be implemented as a vibration presentation device. Therefore, the vibration presentation system 100 is an example of a vibration presentation device. The vibration of the vibrator 2 by the first wave or the third wave output by the control unit 11 may be excited by any known technology.

[0112] The control unit 11 may be implemented using a plurality of information processing devices connected to each other via a network so as to be able to communicate with each other. In this case, the respective functional units of the control unit 11 may be distributed and implemented in the plurality of information processing devices.

[0113] All or part of the functions of the device 1 and the vibration presentation system 100 may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The program may be recorded on a computer-readable recording medium. Examples of computer-readable recording media include portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into computer systems. The program may be transmitted via a telecommunications line.

[0114] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0115] REFERENCE SIGNS LIST 100... vibration presentation system, 1... device, 11... control unit, 12... interface unit, 13... storage unit, 2... vibrator, 91... processor, 92... memory

Claims

1. An apparatus comprising: a control unit that outputs a first wave, which is an amplitude modulated wave that satisfies the following conditions based on target data that is time series data of a wave including low-frequency components of at least 100 Hz or less, the envelope having a maximum value at the timing of the appearance of a low-frequency component maximum value that is a maximum value in the waveform of the low-frequency component, and the envelope waveform having a single-peaked mountain shape of a predetermined time width.

2. The device according to claim 1, wherein the predetermined time width is equal to or greater than 5 ms and less than 50 ms.

3. The device according to claim 1, wherein the mountain-shaped waveform is any one of a waveform represented by a sine function, a waveform represented by a Gaussian function, a waveform represented by a polynomial function, a square wave waveform, a triangular wave waveform, and a sawtooth wave waveform.

4. The device of claim 1, wherein the mountain-shaped waveform is the result of spline interpolation of a waveform that connects a sample at the start of a period including one of the low-frequency component maximum values ​​obtained from the low-frequency component waveform, a sample at the end of the period, and a sample at the position of the low-frequency component maximum value.

5. The device according to claim 1, wherein the low-frequency component maximum value is spaced from an adjacent low-frequency component maximum value by an interval of 10 ms or more.

6. The device according to claim 1, wherein the frequency of the first carrier wave is between 80 Hz and 400 Hz.

7. The device of claim 1, wherein the low frequency component has a frequency of 100 Hz or less.

8. The device described in claim 1, wherein the target data further includes high-frequency components greater than 100 Hz, and the control unit outputs, in place of the first wave, a composite wave that is a wave obtained by synthesizing in phase the first wave and a second wave, the second wave being an amplitude-modulated wave obtained by a predetermined signal conversion based on the high-frequency components and having a carrier wave period equal to the carrier wave period of the first wave.

9. The device according to claim 8, wherein the signal conversion is either amplitude modulation based on the effective value of the signal, amplitude modulation based on the energy of the signal, or amplitude modulation based on a pre-identified perceptual quantity, or a combination thereof.

10. A vibration presentation device comprising: the device according to claim 1; and a vibrator that vibrates in response to waves output from the control unit.

11. A method performed by the apparatus of claim 1, comprising: an output step of outputting said first wave.

12. A vibration presentation method executed by the vibration presentation device according to claim 10, comprising: a vibration step of vibrating the vibrator by a wave output from the control unit of the vibration presentation device.

13. A program for causing a computer to function as the device according to any one of claims 1 to 9.

14. A program for causing a computer to function as the vibration presentation device according to claim 10.

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