Vibration display device, vibration generation system, vibration display program, recording medium storing the vibration display program, and vibration generation method

Abstract

For low frequency vibrations that are far from the resonance frequency band of an actuator and are difficult to be presented, the actuator is used to present the vibrations that humans can easily perceive (misperceive) as being at a low frequency.　A vibration presentation device (1) presents vibrations in a first frequency band using an actuator (31) having the resonance frequency at a second frequency band, which is greater than the first frequency band, the vibration presentation device (1) comprising at least: an acquisition unit (101) that acquires a signal including the vibrations in the first frequency band in which the resonance frequency is lower than the second frequency band; a calculation unit (102) that determines a maximum value of the vibrations in the first frequency band acquired by the acquisition unit (101), and determines, from the maximum value, a maximum value time, which is the time when said vibrations reach the maximum value; and a control unit (103) that generates a single wave by controlling, on the basis of the maximum value time calculated by the calculation unit (102), the actuator during a transition time, which is the time before and after the maximum value time and includes the maximum value time.

Description

Technical Field

[0001] The technology described in this specification relates to a vibration presentation device, a vibration generation system, a vibration presentation program, a recording medium storing the vibration presentation program, and a vibration generation method.

Background Art

[0002] In recent years, in the fields of smartphones, game consoles, Virtual Reality (VR) devices, robot operation support, etc., the sophistication of vibration feedback has been progressing in order to enhance the sense of physical presence and realism (for example, see Patent Document 1). Since the vibration perception sensitivity of humans is maximized around 200 Hz for vibration feedback, the vibrators mounted on mobile terminals such as smartphones are often small Linear Resonant Actuator (LRA) type vibrators with a resonant frequency around 200 Hz that can represent a frequency band of about 100 to 300 Hz (for example, see Patent Document 2).

[0003] Also, in recent years, the broadband of LRA has been progressing, and those that can present a resonance frequency of about 50 to 400 Hz have been developed, and there are also devices such as controllers of game consoles that set the resonance frequency of the vibrator at 60 Hz to 100 Hz (for example, see Patent Document 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the aforementioned LRA with a resonant frequency of around 50Hz to 400Hz, it is difficult to present vibrations in the low-frequency range of several tens of Hz, which are far from the resonant frequency. In order to further enhance the perception of the low-frequency band and lower the resonant frequency to below 50Hz, it is necessary to increase the mass of the resonant system or to install another oscillator for that purpose, which results in a larger volume being occupied by the oscillator.

[0006] Patent Document 4 discloses an invention in which the size of a movable body can be suppressed by adjusting the amplitude of a movable body, which moves between biasing means such as springs, by applying controlled accumulation and attenuation signals to coils around the movable body, thereby causing the pseudo-vibration formed by the envelope connecting the peaks of the amplitude to be at a frequency that a person can perceive. However, this depends on the structure of the oscillator, the input of multiple signals is complex, and it is unclear whether it can reproduce frequencies below 50 Hz.

[0007] Above all, the movements required to reproduce game consoles, VR devices, etc., are currently complex, and there is a need to provide low frequencies simply. However, the technology disclosed in Patent Document 4 makes this extremely difficult, and in particular, it cannot be used when reproduction of online real-time signals is required.

[0008] Therefore, there is a challenge in that it is not easy to express the sensation of low-frequency vibrations of several tens of Hz in small information terminals such as smartphones that are equipped only with LRAs with a resonant frequency of around 100Hz to 300Hz.

[0009] The technology described herein aims to present vibrations at low frequencies that are difficult to present due to their distance from the resonant frequency band of the installed actuator, without using additional actuators, by devising the control of the actuator, etc., so that humans are more likely to perceive (perceive as having an illusion of) those low frequencies. [Means for solving the problem]

[0010] The vibration presentation device of the present invention presents vibrations in a first frequency band using an actuator having a resonant frequency in a second frequency band larger than the first frequency band, comprising: an acquisition unit that acquires a signal including vibrations in the first frequency band having a resonant frequency lower than the second frequency band; and the vibrations in the first frequency band acquired by the acquisition unit multiple Find the local maximum, From the plurality of local maximums, select a local maximum that is separated from adjacent local maximums by a predetermined time interval or more, or if adjacent local maximums are not separated by a predetermined time interval or more, select only the largest local maximum among the adjacent local maximums. From the aforementioned maximum value, The aforementioned The system includes a calculation unit that determines the maximum value time, which is the time when the maximum value occurs, and a control unit that controls the actuator within a transition time, which is the time before and after the maximum value time calculated by the calculation unit, to generate a single wave. [Effects of the Invention]

[0011] In this invention, vibrations with frequencies lower than the resonant frequency band that can be presented by the actuator can be converted into vibrations that humans are more likely to perceive (perceive as having) those frequencies and presented accordingly. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram showing an example configuration of a vibration generation system as an embodiment. [Figure 2] Figure 1 shows a graph illustrating the principle of alternative vibration presentation processing for low-frequency vibrations using the vibration generation system shown. (a) is a graph representing an example of the low-frequency signal to be presented and the single waveform (short-time pulse waveform) to be controlled, and (b) is a graph representing an example of reverberation vibration generated in the enclosure (measured by a laser displacement meter). [Figure 3] Figure 1 shows the results of a subject experiment on the presentation of alternative vibrations for low-frequency vibrations using the vibration generation system shown in Figure 1. (a) is a table showing the response options given by the subjects, and (b) to (e) are graphs showing the response results when the original (target signal) low-frequency waveform was 10Hz, 20Hz, 30Hz, and 40Hz, respectively. [Figure 4](a) is a graph for explaining a first example of amplitude and timing calculation processing by the vibration generation system shown in FIG. 1, and (b) is a graph for explaining a second example of amplitude and timing calculation processing by the vibration generation system shown in FIG. 1. [Figure 5] It is a graph for explaining the online calculation processing of the amplitude and timing of low-frequency vibration. [Figure 6] It is a block diagram for explaining the generation processing of the first vibration waveform and the second vibration waveform by the vibration generation system shown in FIG. 1. [Figure 7] (a) is a block diagram for explaining vibration generation processing when using an actuator with an oscillator, and (b) is a block diagram for explaining vibration generation processing when using a mobile terminal.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments will be described with reference to the drawings. However, the embodiments shown below are merely examples, and there is no intention to exclude various modifications and applications of technologies not explicitly shown in the embodiments. That is, the present embodiment can be variously modified and implemented without departing from its gist.

[0014] Also, each figure does not mean that it only includes the components shown in the figure, and can include other components. Hereinafter, in the figures, parts with the same reference numerals indicate the same or similar parts unless otherwise specified.

[0015] 〔A〕Embodiment A-1. Configuration of the System FIG. 1 is a diagram schematically showing a configuration example of a vibration generation system 100 as an embodiment.

[0016] The vibration generation system 100 consists of a vibration presentation device 1 and a vibration somatic sensation device 3.

[0017] The vibration presentation device 1 includes a CPU 11, a memory 12, a storage device 13, an input unit 41, an output unit 42, and a transmission unit 43, and each is connected by a bus 15.

[0018] The vibration sensation device 3 comprises an actuator 31, a drive unit 32, and a receiver unit 33, and is housed in a housing 34.

[0019] The vibration display device 1 and the vibration sensation device 3 may be provided as separate units or as a single unit. Furthermore, a part of the vibration display device 1 may be provided in the vibration sensation device 3. Also, when the vibration display device 1 and the vibration sensation device 3 are integrated, the housing 34 may house the entire vibration display device 1.

[0020] The vibration generating system 100 in this embodiment is mainly used in smartphones, game consoles, virtual reality (VR) devices, robots, etc., but it may also be applied to chairs, suits, headsets, etc. that include a vibration device.

[0021] The vibration presentation device 1 includes a Central Processing Unit (CPU) 11 for control and driving, a memory 12 for storing programs and the like, a storage device 13, an input unit 41 for acquiring information including signals to be reproduced such as the original signal, an output unit 42 for outputting information other than tactile sensations such as vibration to the user, a transmission unit 43 for communicating information with the vibration sensation device 3, and a bus 15 connecting them.

[0022] The CPU 11 is a processing unit that performs various control and calculations, and realizes various functions by executing the Operating System (OS) and vibration presentation program stored in the memory 12. That is, as shown in Figure 1, the CPU 11 may function as an acquisition unit 101, a calculation unit 102, and a control unit 103.

[0023] The CPU 11 is an example of a computer and, exemplarily, controls the operation of the entire vibration presentation device 1. The device for controlling the operation of the entire vibration presentation device 1 is not limited to the CPU 11, but may be, for example, one of the following: MPU, DSP, ASIC, PLD, FPGA, or dedicated processor. Alternatively, the device for controlling the operation of the entire vibration presentation device 1 may be a combination of two or more of the following: CPU, MPU, DSP, ASIC, PLD, FPGA, and dedicated processor. Note that MPU is an abbreviation for Micro Processing Unit, DSP is an abbreviation for Digital Signal Processor, and ASIC is an abbreviation for Application Specific Integrated Circuit. Also, PLD is an abbreviation for Programmable Logic Device, and FPGA is an abbreviation for Field Programmable Gate Array.

[0024] Memory 12 is a recording medium that stores the Operating System (OS) and vibration presentation programs, and consists of Read Only Memory (ROM) and Random Access Memory (RAM), among others.

[0025] The storage device 13 is a device that stores data in a read-write manner, and may be a Hard Disk Drive (HDD), Solid State Drive (SSD), or Storage Class Memory (SCM). The storage device 13 stores information acquired by the input unit 41, signals and tactile signals related to vibrations to be reproduced, and various data calculated by the calculation unit 102 using a vibration presentation program.

[0026] The input unit 41 is a vibration presentation device 1 that acquires various types of information online, including acoustic information such as music, movies, and games, as well as impact, sensations during operation, and vibrations generated when the robot comes into contact with an object. The input unit 41 does not need to be provided if information intended to reproduce tactile sensations is already stored in the memory device 13 or the like.

[0027] The output unit 42 generates video and audio sources that present information other than the vibration experience device 3 to the user via the vibration presentation device 1. The output unit 42 does not need to be provided if it does not present video, audio, or other information to the user. Alternatively, the vibration experience device 3 may also be equipped with the output unit 42.

[0028] The transmitting unit 43 is the part that transmits control signals via wired or wireless means through the receiving unit 33 of the vibration sensory device 3.

[0029] When the vibration presentation device 1 and the vibration sensation device 3 are integrated, the transmitting unit 43 may utilize communication methods such as SPI, I2C, or I2S, or analog signals such as voltage. The transmitting unit 43 may also be built into the CPU 11 as a function.

[0030] For wired connections, communication methods such as USB, Thunderbolt®, Ethernet®, and HDMI® may be used.

[0031] In the case of wireless communication, for example, it may be a communication unit for Bluetooth®, WiFi, or ZigBee®, or a communication unit for wireless LAN (Local Area Network).

[0032] The acquisition unit 101, calculation unit 102, and control unit 103 of the CPU 11 will be explained in detail.

[0033] The acquisition unit 101 acquires audio information such as music, movies, and games, as well as signals such as impact, sensations during operation, and vibrations generated when the robot comes into contact with an object, obtained from the input unit 41.

[0034] If the memory device 13 or other storage device already contains signals related to vibrations or tactile signals that are to be reproduced, these signals are read from the memory device 13 and acquired by the acquisition unit 101.

[0035] The calculation unit 102 analyzes the tactile signals acquired by the acquisition unit 101, separates and extracts them into a first frequency band and a second frequency band, or calculates the maximum value of the vibration in the first frequency band, the time (timing) of the maximum value, and the amplitude. The specific calculation process will be described later.

[0036] The control unit 103 is the part that generates control signals to control the actuator. While reproducing the second frequency band calculated by the calculation unit 102 by controlling the actuator 31, it generates a pulse wave such as a sine wave or a square wave having at least a predetermined period (hereinafter also referred to as the "single-pulse period time") within a predetermined time including the maximum value in the first frequency band, by controlling the actuator 31, thereby reproducing a simulated first frequency band. Within the predetermined time for generation, the period may be a half-period, 1.5 periods, or 2 periods, or waveforms with several periods of different amplitudes may be output. By using waveforms with several periods of different amplitudes, it may be possible to effectively generate reverberation in the housing 34.

[0037] These generated sine waves and pulse waves may be collectively referred to as single-shot waveforms. The single-shot period time for generating the single-shot waveform is preferably 0.002 seconds or more and 0.02 seconds or less, considering the vibration frequency that can be generated by the current actuator and is large enough for the user to feel. Alternatively, it may be determined according to the ratio of the periods of the vibration waveforms acquired by the acquisition unit 101.

[0038] Next, I will explain the vibration sensation device 3. The vibration sensation device 3 of this embodiment is a part that reproduces and provides to the user acoustic information such as music, movies, and games, as well as tactile signals such as shocks, sensations when operating, and vibrations generated when a robot comes into contact with an object. The vibration sensation device 3 has an actuator 31 that generates vibrations, a drive unit 32, and a receiver unit 33. In order to make the reproduced tactile signals closer to reality, the actuator 31 is equipped with a resonance system in a frequency band of approximately 50 to 350 Hz, which is a high frequency band (second frequency band) in which humans have high vibration perception sensitivity. In this invention, for example, the high frequency band is reproduced using an actuator 31 of 200 Hz ± 150 Hz, and furthermore, the actuator 31 is used to convert and present simulated vibrations in the low frequency band (first frequency band) of 100 Hz or less (10 Hz to 100 Hz, especially 10 Hz to 50 Hz) in a way that humans can experience.

[0039] In this embodiment, the actuator 31 is a voice coil type actuator using a magnet and a coil, such as an LRA (linear resonant actuator). The actuator 31 may be provided inside the housing 34. In this case, the actuator 31 and the housing 34 constitute a resonant system. The resonant frequency of the actuator 31's resonant system may be, for example, 200 Hz ± 150 Hz. The upper limit of the actuator 31's resonant system may be, for example, 350 Hz, and the lower limit may be 50 Hz.

[0040] The actuator 31 is not limited to a voice coil type actuator; it may also be constructed by a weight supported and connected to an elastic body within the housing 34. In this case, the actuator 31, elastic body, weight, and housing 34 constitute a resonant system. The weight may be a battery or various components within the housing 34.

[0041] The drive unit 32 is the part that drives the actuator 31 based on a digital or analog signal that controls the actuator 31, which is generated by the control unit 103 and received by the receiving unit 33. The drive unit 32 may include an amplifier (not shown), a feedback circuit, etc., for driving the actuator 31.

[0042] The receiving unit 33 is the part that receives the control signal transmitted from the transmitting unit 43 of the vibration presentation device 1. The receiving unit 33 may be omitted if the signal from the transmitting unit 43 is sent directly to the driving unit 32.

[0043] A-2. Presentation of alternative vibrations The following describes a specific method of the present invention for reproducing a simulated first frequency band using alternative vibrations.

[0044] Figure 2 is a graph illustrating the principle of the alternative vibration presentation process for low-frequency vibrations by the vibration generation system 100 shown in Figure 1. Figure 2(a) is a graph showing an example of the low-frequency signal to be presented and the short-duration single waveform to be controlled, and Figure 2(b) is a graph showing an example of reverberation vibration generated in the housing 34 (measured by a laser displacement meter).

[0045] In the graph shown in Figure 2(a), the horizontal axis represents time (Time [s]) and the vertical axis represents amplitude. The dotted line graph represents the waveform of the original signal to be reproduced at 10 Hz (the target signal to be reproduced by the alternative vibration (hereinafter sometimes referred to as the "target signal")), and the solid line graph represents the pulse signal, which is a single waveform generated by controlling the actuator 31. A short-duration pulse signal is generated as the input waveform by controlling the actuator 31, in sync with the timing of the peak of the low-frequency signal of the continuous target signal. In the example shown in Figure 2(a), the pulse signal input by the actuator 31 uses a 1-period sine wave. By generating the pulse signal in sync with the peak of the low-frequency signal, a characteristic low-frequency period is expressed.

[0046] The control pulse signal (in other words, the alternative waveform) is generated by the following equation: where A is the amplitude of the original low frequency, f is the frequency of the alternative stimulus, and t' is the time when the original low frequency reaches its maximum value.

number

[0047] In the graph shown in Figure 2(b), the horizontal axis represents time (Time [s]), the left vertical axis represents the voltage of the original signal and control signal (Original / Control signal [V]), and the right vertical axis represents the measured vibration displacement (Measured vibration [μm]). The dotted line graph represents the original signal (target signal), the thick line graph represents the pulse signal generated by controlling the actuator 31 (Control pulse signal), and the thin line graph represents the displacement (Measured vibration) generated in the housing 34 of the vibration generation system 100 and measured. A short pulse input to the actuator 31 generates reverberant vibration due to the natural vibration of the housing 34, which includes the actuator 31. It takes time for the reverberant vibration to decay. This decayed waveform is thought to generate the low-frequency sensation that is difficult to reproduce with the actuator 31.

[0048] A-3. Subjective evaluation of alternative vibrations In fact, we investigated to what extent the aforementioned method of presenting alternative vibrations can convey the sensation of low frequencies.

[0049] Figure 3 shows the results of a subject experiment on the presentation of alternative vibrations for low-frequency vibrations by the vibration generation system 100. (a) is a table showing the response options given by the subjects. (b) is a graph showing the average of three responses from the subjects when the low-frequency waveform of the target signal is 10 Hz. (c) is a graph showing the average of three responses from the subjects when the low-frequency waveform of the target signal is 20 Hz. (d) is a graph showing the average of three responses from the subjects when the low-frequency waveform of the target signal is 30 Hz. (e) is a graph showing the average of three responses from the subjects when the low-frequency waveform of the target signal is 40 Hz. Figures (b) to (e) also show the maximum, minimum, interquartile range, and median of the response options.

[0050] In the subject experiment shown in Figure 3, sine waves of 10Hz, 20Hz, 30Hz, and 40Hz were set as target low-frequency vibrations, and sine waves of 60Hz, 80Hz, and 100Hz were used as substitute vibration stimuli for each. The subject evaluated whether the target low-frequency vibrations could be presented using the aforementioned substitute vibration presentation processing method based on their subjective sensory experience. In the sensory experiment, to prevent subjects from selecting answers based on information other than the vibrations they felt, they were made to experience the vibrations by holding a voice coil type vibrator capable of presenting approximately 10Hz to 100Hz in one hand. The subjects were seven men and women in their 20s.

[0051] To begin, in order to teach the subjects the difference between low frequency and high frequency, a 10 Hz sine wave was repeatedly presented as low frequency and an 80 Hz sine wave as high frequency until the subjects could distinguish the difference.

[0052] The stimuli used for subjective evaluation included four types: the target signal, the low-frequency vibration itself (Raw Wave); substitute vibrations created using a 60Hz sine wave; substitute vibrations created using an 80Hz sine wave; and substitute vibrations created using a 100Hz sine wave. These were administered for target low-frequency vibrations of 10Hz, 20Hz, 30Hz, and 40Hz, respectively.

[0053] In the sensory experiment, a voice coil type oscillator was used to present a stimulus for 5 seconds, and participants were asked to indicate whether they perceived the stimulus as low frequency or high frequency using the 7-point Likert scale shown in Figure 3(a). A score closer to 1 on the scale indicates a high frequency (a sensory experience closer to the 80Hz instructed to the participant), while a score closer to 7 on the scale indicates a low frequency (a sensory experience closer to the 10Hz instructed to the participant).

[0054] The stimuli were presented repeatedly as many times as the subjects were able to respond. Each type of stimulus was presented randomly to avoid order effects. The subjects conducted the experiment with their hearing blocked by white noise and soundproof earmuffs. The stimuli in the experiment were output from a voice coil oscillator (VP4, Acouve Laboratory, Inc.) held by the subject, via a USB audio interface (ASUS, XONAR U7 MK II) and an audio amplifier (SMSL SA-36A PRO).

[0055] As shown in Figure 3(b), when targeting a 10Hz low-frequency vibration, the subjective experience was similarly strong for both the 10Hz low-frequency vibration itself (raw wave) and single waveforms of 60Hz, 80Hz, and 100Hz. In the case of 20Hz, the subjective experience of low frequency, including the 20Hz low-frequency vibration itself (raw wave), was slightly weaker than in the case of 10Hz.

[0056] Regarding 30Hz and 40Hz, I often felt a sensation similar to high frequencies, including the low-frequency vibrations themselves (raw waves) at 30Hz and 40Hz.

[0057] On the other hand, for 10Hz, 20Hz, 30Hz, and 40Hz, the median values ​​of the response scales tended to be close to the values ​​that subjects responded to when the low-frequency vibrations themselves were 10Hz, 20Hz, 30Hz, and 40Hz, and to the values ​​that subjects responded to when the substitute vibrations were created at 60Hz, 80Hz, and 100Hz. This suggests that, for all 10Hz, 20Hz, 30Hz, and 40Hz frequencies, subjects obtained a sensation similar to the low-frequency vibrations themselves (raw waves) when using the substitute vibrations created at 60Hz, 80Hz, and 100Hz.

[0058] As described above, even with vibrations of 60Hz, 80Hz, and 100Hz, the method of presenting alternative vibrations according to the present invention can be used to present subjects with a sensation close to that of the target low-frequency vibration.

[0059] In the experiment shown in Figure 3, a voice coil type vibrator capable of presenting vibrations in the range of approximately 10 Hz to 100 Hz was used to strictly prevent subjects from selecting answers based on information other than vibration. However, it has been confirmed that even with a voice coil type vibrator that cannot present vibrations in the range of 10 Hz to 50 Hz, the method of the present invention can be used to present subjects with a sensation similar to low-frequency vibrations that cannot be presented otherwise.

[0060] A-4. Method for determining the amplitude and timing of alternative oscillations from the target signal. The above describes a method for creating alternative vibrations from an ideal original signal (target signal). However, in reality, the original signals (target signals) reproduced in music, games, etc., have complex vibrations. Below, we will describe how to create the alternative vibrations of the present invention in such complex vibrations.

[0061] Figure 4(a) is a graph illustrating a first example of the timing calculation process for generating a single waveform by using an example of a signal such as vibration generated by music, which has been previously acquired by the acquisition unit 101 of the vibration generation system 100 shown in Figure 1, or has been previously stored in the memory device 13, etc., and the calculation unit 102 controls the amplitude and the control unit 103 controls the actuator 31. Figure 4(b) is a graph illustrating a second example.

[0062] In the first example shown in Figure 4(a), the vibration to be reproduced is shown as the low-frequency signal (original signal (target signal)) after being separated into high-frequency and low-frequency signals, as described later. The low-frequency signal is a signal below a predetermined frequency, for example, 100 Hz or less, preferably 80 Hz or less, and more preferably 60 Hz or less. It may be appropriately determined to match the region that is difficult to reproduce with the mounted actuator 31. The low-frequency signal may be processed as the entire low-frequency signal after separation, or it may be further separated into predetermined low-frequency regions (for example, if a low-frequency signal of 10 Hz or more below 80 Hz is acquired, it may be further separated into 10 Hz to 50 Hz and 50 Hz to 80 Hz, and the processing of the calculation unit 102 may be applied to each low-frequency signal). In that case, by controlling various drive parameters of the actuator 31, such as the waveform of a single wave, the period time of a single wave, and the amplitude, for each separated frequency band, multiple alternative vibrations that are closer to human perception may be presented in combination for each frequency band.

[0063] The calculation unit 102 calculates multiple maximum and minimum values ​​contained in the signal waveform in the low-frequency band. The inventor's experiments revealed that when the substitute vibration is created at a very short time interval before the reverberation vibration has sufficiently decayed, the subject no longer perceives it as the target low-frequency vibration, but rather as the original high-frequency vibration of the actuator 31. Therefore, in order to create a substitute vibration for the low-frequency vibration, adjacent maximum values ​​are selected from the calculated multiple maximum values ​​that are separated by a predetermined time interval (hereinafter sometimes referred to as the "interval time") (for example, 0.1 seconds or more). If adjacent maximum values ​​are not separated by a predetermined time interval, only the most characteristic (largest) maximum value among the adjacent maximum values ​​is selected. In the illustrated example, the point marked "X" is not selected as a maximum value because it is not separated by a predetermined time interval. The position of the maximum value selected in this way (hereinafter also referred to as the "maximum value time") is calculated as the timing time for presenting the substitute vibration.

[0064] On the other hand, regarding the amplitude, in the first example, the distance from the maximum value to the intersection point of a line connecting multiple local minima is calculated as the amplitude of the alternative oscillation (see double arrow) (hereinafter sometimes referred to as the "maximum amplitude").

[0065] In this manner, the timing and amplitude for presenting the alternative vibration are determined.

[0066] In the second example shown in Figure 4(b), the calculation unit 102 calculates only the multiple maximum values ​​contained within the low-frequency waveform. The selection of the maximum values ​​is the same as in the first example, and the position of the selected maximum value (maximum time) is calculated as the timing time for presenting the alternative oscillation.

[0067] On the other hand, in the second example, the maximum amplitude is calculated as the distance from a predetermined reference value to the maximum value, which is the amplitude of the substituted oscillation (see double arrow).

[0068] The first example is effective when the background noise is large and the target low-frequency signal waveform is small compared to the noise. On the other hand, the second example is effective when the target low-frequency signal waveform is sufficiently large compared to the noise.

[0069] The timing at which a single waveform is output does not necessarily have to be exactly at the time of the maximum value; it may be generated at a time before or after the time of the maximum value, that is, by a predetermined time transition (hereinafter also referred to as the "transition time") from the time of the maximum value. The predetermined time transition (transition time) may be set so that the timing at which the enclosure vibration (reverberation vibration) controlled by the single waveform is at its maximum coincides with, or is approximately the same as, the time of the maximum value obtained from the target signal, and it is sufficient if it does not cause discomfort to the human eye.

[0070] The transition time is determined by the degree of lag that a person can tolerate between the visual and auditory information presented by the output unit 42 and the actual information. Existing research has shown that humans have a threshold for noticing a lag of about 0.04 seconds for repetitive sensory experiences and about 0.03 seconds for single sensory experiences. Therefore, the transition time can be set within a range of, for example, ±0.04 seconds, but it is desirable to set it within a range of about ±0.02 seconds to avoid causing discomfort to sensitive individuals.

[0071] Furthermore, it is desirable that the timing of single-waveform generation maintains the interval time between the calculated maximum values.

[0072] The reason why the timing does not need to be precisely at the time of the maximum value is that even if the timing of outputting a single waveform is shifted by a certain amount, people who experience vibrations will hardly notice. Therefore, it is considered important to reproduce the time between the main maximum values ​​of the target signal that is being reproduced in order to present the user with alternative vibrations in the low-frequency range.

[0073] Note that in Figures 4(a) and (b), the maximum value and maximum time are determined from the waveform, amplitude height, etc., but this is not the only method. For example, they may be determined from the mean square, RMS value, change rate, etc. Any method that can determine the maximum value and maximum time, which are characteristic points of the signal, is acceptable.

[0074] The amplitude of the substituted vibration does not need to be exactly the magnitude of the maximum amplitude obtained in Figures 4(a) and (b), but may be determined by multiplying the obtained maximum amplitude by a predetermined ratio. The predetermined ratio may be adjusted to match the characteristics of the housing and actuator used so as to approach the low-frequency sensation of the original signal (target signal). The calculated amplitude may be adjusted using an exponential function or the like to match the nonlinear subjective intensity perceived by humans. The predetermined ratio may be, for example, 80% to 120% of the obtained maximum amplitude.

[0075] Furthermore, the amplitude of the substituted vibration may be presented as a predetermined constant amplitude, for example, when the maximum amplitude of the signal to be reproduced does not fluctuate significantly. In this case, it is not necessary to determine the maximum amplitude.

[0076] Next, we will describe a method for determining the amplitude and timing of low-frequency vibrations with respect to the target signal acquired online in real time by the input unit 41.

[0077] Figure 5 is a graph illustrating the process of determining the amplitude and timing of alternative vibrations after information acquired in real time by the input unit 41 is acquired as a signal by the acquisition unit 101, separated into high-frequency vibrations and low-frequency vibrations, and the target low-frequency vibrations are extracted. The horizontal axis represents the passage of time.

[0078] The extracted original low-frequency vibration signal (target signal) is divided into segments of a fixed time, and the maximum value within each segment is calculated. The fixed segment may coincide with the segments necessary for processing the separated high-frequency vibrations. The segment may be 0.02 seconds or less, and may be intervals of 0.01 seconds, 0.005 seconds, etc. Within the segment, the segment where the maximum value changes from increasing to decreasing is detected, and the maximum value immediately before the decrease is calculated as the maximum value time of the original signal. Time differentiation may be used when calculating the maximum value. After the maximum value (peak value) is detected, the next peak may be excluded for a predetermined time T (for example, within 0.1 seconds) determined from the aforementioned interval time, according to a predetermined rule (for example, not being 20% ​​or more greater than the previous maximum value). In Figure 5, circles indicate segments with maximum values ​​that were detected and not excluded within the predetermined time, and crosses indicate segments with maximum values ​​that were excluded.

[0079] Case #1 represents the case where no next maximum value is detected within a predetermined time T. In this case #1, the maximum value detected is determined as the single-wave output timing (maximum value time), as usual. Case #2 represents the case where a next maximum value is detected within a predetermined time, but it is not excluded because it is larger than the previous maximum value by a predetermined value. The predetermined value is, for example, 20% or more larger than the previous maximum value. In this case #2, both the first detected maximum value and the next maximum value which is 20% or more larger than the previous maximum value are determined as the single-wave output timing (maximum value time). However, the elapsed time of the predetermined time T may be prioritized, and the next maximum value for which the predetermined time T has not elapsed may be excluded from the single-wave output timing. Case #3 represents the case where a next maximum value is detected within a predetermined time T, but it is excluded because it is smaller than the previous maximum value. In this case #3, only the first detected maximum value is determined as the output timing, and the next smaller maximum value is excluded from the single-wave output timing. However, if the elapsed time of a predetermined time T is prioritized, and the next maximum value (the first maximum value used as the output timing in case #3) for which the predetermined time T has not elapsed in case #2 is excluded from the single-wave output timing, then the next smaller maximum value in case #3 may be used as the single-wave output timing (maximum value time).

[0080] Whether to prioritize points where the previous maximum value is greater than a predetermined value, or to prioritize the elapsed time T, is determined based on the characteristics of the signal being reproduced and the situation being presented.

[0081] The method for calculating the maximum value can also be adapted to calculate the minimum value by finding the minimum value within an interval and determining the interval where the value changes from decreasing to increasing. By applying the calculated maximum and minimum values ​​to the method shown in Figure 4(a), the amplitude of a short-duration single-waveform can be calculated. When processing online, the output timing of the single-waveform is set to be as quickly as possible after the amplitude of the single-waveform is calculated using the method shown in Figures 4(a) and (b). Regarding the amplitude, the amplitude of the single-waveform may be calculated in advance by buffering signals for a predetermined time T or longer.

[0082] The original signal acquired online, as described above, may be reproduced again after going online by resetting the output timing and amplitude according to the method shown in Figures 4(a) and (b) as a previously acquired signal. Alternatively, in order to reproduce the feel of the online state, the output timing and amplitude at the time of online operation may be stored in the memory device 13, and the signal may be reproduced using those output timing and amplitude settings.

[0083] In Figures 4(a), (b), and 5, the maximum value time and maximum value amplitude calculated by the calculation unit 102 are stored in the memory device 13 as time-series data for reproduction, linked with other visual and auditory information. By reading the time-series data for reproduction stored in the memory device 13, the control unit 103 can control the drive timing of the actuator 31 along with the visual and auditory information at any time, providing the user with an immersive experience.

[0084] A-5. Processing of the calculation unit Next, the processing of the calculation unit 102 of the vibration generation system 100 will be described in detail.

[0085] Figure 6 is a block diagram illustrating the process of generating vibration waveforms in a first frequency band, which is in the low-frequency range, and vibration waveforms in a second frequency band, which is in the high-frequency range, from the original signals such as vibrations generated in music, movies, games, etc., acquired by the acquisition unit 101 by the calculation unit 102, or from the original signals that are pre-stored in the memory device 13, etc.

[0086] Step 201 is the step of separating signals below a predetermined frequency from a signal X(t) acquired by the acquisition unit 101 or previously stored in the memory device 13, etc. (in other words, the signal to be reproduced before conversion) into a high-frequency band signal H(t) and a low-frequency band signal L(t).

[0087] The high-frequency band signal H(t) is filtered using a high-frequency band-pass filter, such as a high-pass filter, to remove signals below a predetermined frequency. Known methods are used for separation and removal. The separated high-frequency band signal H(t) is then used in a second vibration waveform generation step 202, which generates a second vibration waveform S2(t), which is a high-frequency band waveform.

[0088] On the other hand, for low-frequency band signals, a low-frequency band-pass filter such as a low-pass filter is used to filter out low-frequency band signals L(t) below a predetermined frequency from the signal X(t). Next, in the calculation step 203 of the calculation unit 102, the amplitude (maximum amplitude) of a single wave A is calculated from the extracted low-frequency band signal L(t) using the method described in Figures 4 and 5. i (i represents the number of the single wave to be generated.) and output time (maximum time) t i The first vibration generation step 204 calculates the amplitude A calculated in step 203 for a single wave. i and output time t i A first vibration waveform (alternative vibration) S1(t), which is a waveform in the low frequency band, is generated. At this time, the first vibration generation step 204 determines the shape of the single-pulse wave by referring to single-pulse wave parameters for determining the single-pulse waveform. The single-pulse wave parameters may include numerical values ​​such as the single-pulse wave period time, transition time, interval time, or amplitude ratio of the single-pulse wave.

[0089] A-6. Processing of the control unit Figure 7(a) is a block diagram illustrating the vibration generation process when the actuator 31 is controlled by the control unit 103 of a typical device, and Figure 7(b) is a block diagram illustrating the vibration generation process when using a device with a device-specific parameter conversion function, such as a mobile terminal like a smartphone.

[0090] In Figure 7(a), the high-frequency gain adjustment step 302 adjusts the high-frequency gain of the second vibration waveform S2(t) of the high-frequency band signal generated in the second vibration waveform generation step 202 in Figure 6 using a high-frequency band gain adjuster. On the other hand, in the low-frequency gain adjustment step 303, the low-frequency gain of the first vibration waveform (alternative vibration) S1(t) of the low-frequency band signal generated in the first vibration generation step 204 in Figure 6 is adjusted using a low-frequency band gain adjuster.

[0091] In the synthesis step 304, the first vibration waveform S1(t) and the second vibration waveform S2(t), whose gains have been adjusted, are combined to form a composite wave. In the driving step 305, a signal is generated from the control unit 103 of the vibration generation system 100 based on the composite wave from the synthesis step 304 to drive the actuator 31.

[0092] In Figure 7(b), if the vibration generation system 100 has a parameter conversion function specific to the device such as a mobile terminal, the high-frequency band signal is converted in the high-frequency conversion step 402. The second vibration waveform S2(t) of the high-frequency band signal generated in the second vibration waveform generation step 202 in Figure 6 is converted as a high-frequency parameter sequence based on the conversion defined by the operating system (OS) of the mobile terminal. The signal converted as a high-frequency parameter sequence in step 402 is converted into a time series and an amplitude series in step 403. Then, in step 404, the control unit 103 drives the actuator 31 to create and reproduce the tactile pattern.

[0093] On the other hand, for low-frequency band signals, in calculation step 203 of Figure 6, the amplitude A of a single wave calculated by the calculation unit 102 is... i and output time (timing) ti In step 502, the data is converted into parameters specific to the mobile device. In step 503, the signal converted as a parameter sequence is converted into a time series and an amplitude series. Then, in step 504, the control unit 103 drives the actuator 31 to create and reproduce the tactile pattern.

[0094] [B] Torture In the vibration presentation device 1 of the embodiment described above, vibrations in the low frequency range of several tens of Hz, which is lower than the resonant frequency range that can be presented by the actuator, are converted into vibrations that are easily perceptible to humans.

[0095] This invention utilizes an LRA with a resonant frequency of approximately 100Hz to 300Hz, which is commonly installed in mobile devices and the like, and can be used in combination with various technologies.

[0096] For example, the inventors of this application disclose in Patent Document 2, cited below, a technique that uses an energy control unit to maintain the energy of a signal at high frequencies, thereby converting it to approximately 200 Hz while maintaining the high-frequency tactile sensation. This technique can be used in conjunction with the presentation method of this application using alternative vibrations for low-bandwidth vibrations. Even when using an LRA with a narrow frequency band, combining the present invention with the technique disclosed in Patent Document 2 makes it possible to present a wide frequency band of several tens of Hz to approximately 400 Hz, increasing the design flexibility of the equipment and enabling miniaturization and cost reduction.

[0097] [C] Effect According to the vibration presentation device, vibration presentation program, computer-readable recording medium storing the vibration presentation program, and vibration presentation method of the embodiment, the following effects can be achieved, for example.

[0098] This invention makes it possible to convert vibrations with frequencies lower than the resonant frequency band of the actuator 31 into vibrations that are easily perceived by humans, by creating alternative vibrations using the actuator 31. In particular, in portable devices such as smartphones that use LRA as an oscillator, it has conventionally been difficult to represent low frequencies of about 10Hz to 50Hz with LRA, but by using this invention, it is possible to present the sensation of low frequencies.

[0099] This enables the expression of low-frequency vibrations in portable devices and game controllers, resulting in more immersive vibration experiences. It also allows for the presentation of tactile vibrations in music, movies, and videos on portable devices.

[0100] This invention acquires a signal from the original signal, which is the target of reproduction, that includes vibrations in a first frequency band, which are vibrations in the low frequency band. It determines the maximum value of the acquired vibrations in the first frequency band, calculates the maximum value time using a calculation unit 102, and based on the calculated maximum value time, drives the actuator 31 within a transition time that does not affect human perception around the maximum value time to generate a single wave. As a result, even if the actuator 31 cannot generate vibrations in the low frequency band, it is possible to present a simulated low-frequency vibration to the user, thereby presenting a low-frequency sensation, eliminating the need for additional actuators and leading to miniaturization of the device.

[0101] Furthermore, by determining the maximum amplitude at the maximum time, it is possible to present low-frequency oscillations with greater accuracy.

[0102] Furthermore, by determining the single-wave period time and transition time for generating single waves based on human perception, the sensation of high-frequency vibration can be reduced.

[0103] When the calculation unit 102 calculates the maximum value time from a signal having multiple maximum values, it sets the interval time, which is the time interval between adjacent maximum values, to 0.1 seconds or more, so that the alternative waveform presented does not give the human sense of high-frequency vibration.

[0104] When providing vibrations online, the calculation unit 102 may calculate a second maximum value if the intensity of the second maximum value immediately following the first maximum value is greater than the intensity of the first maximum value by a predetermined percentage or more, even if the interval between the first and second maximum values ​​is less than or equal to a predetermined interval. This allows for real-time reflection of low-frequency sensations in real time, such as in online applications, by providing the user with an alternative waveform at characteristic points in the original waveform.

[0105] The control unit 103 generates a sine wave or pulse wave with an intensity of 80% to 120% of the intensity of the maximum amplitude. This allows for appropriate control of the intensity of the alternative waveform, resulting in a more realistic sound.

[0106] The actuator of the present invention uses a housing that generates reverberation vibrations, and by utilizing these reverberations, it can present the user with more realistic low-frequency alternative vibrations.

[0107] [D] Other The disclosed technology is not limited to the embodiments described above, and can be implemented in various ways without departing from the spirit of each embodiment. Each configuration and each process of each embodiment can be selected or combined as needed.

[0108] The vibration generating system 100 shown in Figure 1 is equipped with one actuator 31, but it is not limited to this. The number of actuators 31 provided in the vibration generating system 100 can be varied. [Explanation of Symbols]

[0109] 1: Vibration presentation device 3: Vibration sensation device 11: CPU 12: Memory 13:Storage device 15: Bus 31: Actuator 32: Drive unit 33: Receiving unit 34: Cabinet 41: Input section 42: Output section 43: Transmitter 100: Vibration generation system 101: Acquisition Department 102: Calculation Unit 103: Control Unit

Claims

1. A vibration presentation device that presents vibrations in a first frequency band using an actuator having a resonant frequency in a second frequency band larger than the first frequency band, An acquisition unit that acquires a signal including vibrations in the first frequency band, which have a resonant frequency lower than the second frequency band, A calculation unit that obtains a plurality of maximum values ​​of the vibration in the first frequency band obtained by the acquisition unit, selects a maximum value from the plurality of maximum values ​​that is separated from adjacent maximum values ​​by a predetermined time interval or more, or, if adjacent maximum values ​​are not separated by a predetermined time interval or more, selects only the largest maximum value from the adjacent maximum values, and calculates the maximum value time, which is the time at which the maximum value occurs, from the selected maximum value, A control unit that generates a single wave by controlling the actuator within a transition time which is the time before and after the maximum value time calculated by the calculation unit, A vibration display device equipped with the following features.

2. The calculation unit determines the maximum value amplitude, which is the amplitude of the maximum value at the maximum value time. The vibration display device according to claim 1.

3. The single-wave period time for generating the aforementioned single wave is 0.002 seconds or more and 0.02 seconds or less. The vibration display device according to claim 1.

4. The transition time is 0.04 seconds or less. The vibration display device according to claim 1.

5. The calculation unit calculates a plurality of the maximum values ​​and calculates the maximum value time for intervals of 0.1 seconds or more, which are the time intervals between adjacent maximum values. The vibration display device according to claim 1.

6. The calculation unit calculates a plurality of maximum values, and if the intensity of the second maximum value immediately following the first maximum value is greater than or equal to a predetermined percentage than the intensity of the first maximum value, it calculates the maximum value time even if the interval time between the first maximum value and the second maximum value is less than or equal to the interval time. The vibration display device according to claim 5.

7. The control unit generates the single wave having an amplitude of 80% to 120% of the maximum amplitude. The vibration presentation device according to claim 2.

8. The first frequency band is between 10 Hz and 100 Hz. The vibration display device according to claim 1.

9. The calculation unit calculates the maximum value of the vibration based on the waveform or amplitude of the vibration. The vibration display device according to claim 1.

10. The vibration presentation device according to claim 1, The device comprises an actuator having a resonant frequency in the second frequency band, and a vibration sensation device having a housing that generates reverberant vibrations by controlling the actuator. Vibration generation system.

11. The transition time is set to the time when the reverberation vibration of the enclosure is at its maximum during the time including the maximum value time. The vibration generating system according to claim 9.

12. On the computer, A step of acquiring a signal that includes vibrations in a first frequency band, which has a resonant frequency lower than the second frequency band, A calculation step in which a plurality of maximum values ​​of the vibration in the first frequency band obtained by the acquisition step are determined, a maximum value is selected from the plurality of maximum values ​​in which adjacent maximum values ​​are separated by a predetermined time interval or more, or if adjacent maximum values ​​are not separated by a predetermined time interval or more, only the largest maximum value among the adjacent maximum values ​​is selected, and the maximum value time, which is the time at which the maximum value occurs, is determined from the selected maximum value, A vibration presentation program that causes the program to perform a drive step of generating a single wave by controlling an actuator having a resonant frequency in the second frequency band within a transition time which is the time before and after the maximum value time calculated by the calculation step.

13. A recording medium storing the vibration notification program described in claim 12.

14. A vibration presentation method comprising presenting vibrations in a first frequency band using an actuator having a resonant frequency in a second frequency band larger than the first frequency band, The steps include acquiring a signal that includes vibrations in the first frequency band, which have a resonant frequency lower than at least the second frequency band, A calculation step in which a plurality of maximum values ​​of the vibration in the first frequency band obtained by the acquisition step are determined, a maximum value is selected from the plurality of maximum values ​​in which adjacent maximum values ​​are separated by a predetermined time interval or more, or if adjacent maximum values ​​are not separated by a predetermined time interval or more, only the largest maximum value among the adjacent maximum values ​​is selected, and the maximum value time, which is the time at which the maximum value occurs, is determined from the selected maximum value, A drive step in which, based on the maximum value time calculated by the calculation step, controls an actuator having a resonant frequency in the second frequency band within a transition time which is the time before and after the maximum value time to generate a single wave; A method for generating vibration, including the method described above.

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