WO2022118457A1

WO2022118457A1 - Haptic device

Info

Publication number: WO2022118457A1
Application number: PCT/JP2020/045194
Authority: WO
Inventors: 敏輝和田
Original assignee: 日本電信電話株式会社
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2022-06-09

Abstract

This haptic device (10) of the present invention stores a compensation model (12A) relating to a tactile presentation device (13) in a storage circuit (12) in advance, and when generating a drive signal (Sd), a control circuit (11) generates a drive signal (Sd) which compensates for the input/output characteristics (G) of the tactile presentation device (13), on the basis of the compensation model (12A) stored in the storage circuit (12). This makes it possible to present a highly realistic virtual tactile sensation.

Description

Tactile device

The present invention relates to a tactile presentation technique for presenting a virtual tactile sensation by driving a tactile presentation device.

In recent years, research on virtual reality (VR), which allows people to experience a virtual world generated by a computer as if it were real, is progressing. In addition, a virtual reality reproduction device that can realistically reproduce the visual sense, auditory sense, and tactile sense by images and sounds is being developed. For example, there is a head-mounted display (HMD: Head Mounted Display) as a device that can reproduce three-dimensional video and audio. On the other hand, tactile devices are attracting attention as devices that can reproduce human tactile sensations. The tactile device is configured to present skin sensory feedback, that is, virtual tactile sensation, to a person by tactile sensation such as force, vibration, and temperature by driving a tactile presentation device such as a vibration device or a Peltier Device. (See, for example, Non-Patent Document 1 and the like).

Yasuyuki Inoue et al., "Tactile presentation system based on the principle of tactile primary colors", TVRSJ Vol.25 No.1 pp.86-94, 2020

In order to give various virtual tactile sensations to humans using tactile devices, it is necessary to drive the tactile presentation devices with various intensities and frequencies. On the other hand, the tactile presentation device has individual input / output characteristics for each element type and model, and the virtual tactile presentation efficiency differs depending on the strength and frequency of the applied drive signal. Here, the presentation efficiency is a presentation amount with respect to the drive signal strength, and when the tactile presentation device is a vibration device, the presentation amount corresponds to the vibration amount. Therefore, the tactile intensity of the tactile sensation actually output from the actuator may be different from the applied drive signal intensity. Therefore, there is a problem that it is not possible to present a highly realistic virtual tactile sensation, and the experience of the user who uses the haptic device is impaired.

The present invention is for solving such a problem, and an object of the present invention is to provide a tactile presentation technique capable of presenting a highly realistic virtual tactile sensation.

In order to achieve such an object, the tactile device according to the present invention is configured to present a tactile sensation corresponding to an applied drive signal, and generates the drive signal based on the input signal. A control circuit configured to be applied to the tactile presentation device and a storage circuit are provided, and the storage circuit provides a compensation model for compensating the input / output characteristics of the tactile presentation device for each of a plurality of frequency regions. The control circuit is stored individually in advance, and when the drive signal is generated, the control circuit is based on the compensation model in the frequency region corresponding to the frequency specified by the input signal among the compensation models stored in the storage circuit. It is configured to generate the drive signal that compensates for the input / output characteristics of the tactile presentation device.

According to the present invention, it is possible to present a highly realistic virtual tactile sensation.

FIG. 1 is a block diagram showing a configuration of a tactile device. FIG. 2 is a graph showing the frequency characteristics of the tactile presentation device. FIG. 3 is a graph showing the frequency characteristics (by designated intensity) of the tactile presentation device. FIG. 4 is a graph showing the input / output characteristics of the entire tactile device. FIG. 5 is a graph showing the input / output characteristics of the tactile presentation device. FIG. 6 is a graph showing an example of generating a compensation model (unified model). FIG. 7 is a graph showing a generation example (individual model) of a compensation model. FIG. 8 is a graph showing the frequency characteristics (after compensation) of the drive signal. FIG. 9 is a graph showing the frequency characteristics (with compensation) of the tactile presentation device.

Next, an embodiment of the present invention will be described with reference to the drawings.
[Tactile device]
First, the tactile device 10 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a tactile device.

This tactile device 10 is a device that presents skin sensory feedback, that is, a virtual tactile sensation, to a person by tactile sensation such as force, vibration, and temperature. As shown in FIG. 1, the tactile device 10 includes a control circuit 11, a storage circuit 12, and a tactile presentation device 13 as main circuit configurations.

[Control circuit]
The control circuit 11 comprises a signal processing circuit that processes and outputs the input signal as a whole, and is driven based on the input signal Si input from a host device (not shown) such as a PC, a smartphone, or a tablet. Compensation for the frequency region corresponding to the frequency f specified by the input signal Si in the compensation model 12A stored in the storage circuit 12 when the signal Sd is generated and applied to the tactile presentation device 13 to generate the drive signal Sd. Based on the model, it is configured to generate a drive signal Sd that compensates for the input / output characteristics of the tactile presentation device 13.

Specifically, the control circuit 11 inputs / outputs the entire tactile device 10 in which the relationship between the designated intensity i specified by the input signal Si and the tactile intensity presented by the tactile presentation device 13 is defined in advance. It has a signal strength v that compensates for the input / output characteristic G of the tactile presentation device 13 based on the individual model of the frequency region corresponding to the frequency f specified by the input signal in the compensation model 12A so as to match the characteristic F. It is configured to generate a drive signal Sd.

Further, when the tactile presentation device 13 is composed of a vibration device that presents a tactile sensation by vibration, the compensation model 12A includes a model that compensates for the frequency characteristics of the tactile presentation device 13, and the control circuit 11 is designated by the input signal Si. The input signal in the compensation model 12A so that the relationship between the specified designated intensity i and the tactile intensity presented by the tactile presentation device 13 matches the input / output characteristic F of the entire tactile device 10 defined in advance. Based on the individual model of the frequency domain corresponding to the frequency f specified by Si, it is configured to generate the drive signal Sd having the signal strength v compensated for the frequency characteristic (input / output characteristic G) of the tactile presentation device 13. ing.

Specifically, the input / output characteristics of the entire tactile device 10 showing the relationship between the designated intensity i specified by the input signal Si and the tactile intensity a of the tactile sensation presented by the tactile presenting device 13 in the compensation model 12A. It consists of F and the inverse characteristics of the input / output characteristic G of the tactile presentation device 13, which shows the relationship between the signal strength v of the drive signal Sd and the tactile strength a of the tactile sensation presented by the tactile presentation device 13 in each frequency domain. , May be configured to include a plurality of individual models. Further, the inverse characteristic of the input / output characteristic G of the tactile presentation device 13 may be configured to include the frequency f specified by the input signal Si as a variable.

[Memory circuit]
The storage circuit 12 is composed of a semiconductor memory, and is configured to store in advance a compensation model 12A that compensates for the input / output characteristics of the tactile presentation device 13. In the compensation model 12A, the relationship between the designated intensity i specified by the input signal Si and the tactile intensity a of the tactile sensation presented by the tactile presenting device 13 matches the input / output characteristics of the entire tactile device 10 defined in advance. As such, it is a model for compensation.

The compensation model 12A shows the relationship between the designated intensity i specified by the input signal Si and the tactile intensity a of the tactile sensation presented by the tactile presenting device 13, and the input / output characteristics F of the entire tactile device 10 and their respective frequencies. With a plurality of individual models consisting of inverse characteristics regarding the input / output characteristic G of the tactile presentation device 13 showing the relationship between the signal strength v of the drive signal Sd and the tactile strength a of the tactile sensation presented by the tactile presentation device 13 in the region. It is composed of. As the compensation model 12A, a function expression showing the correspondence between the input value and the output value and its parameters may be stored. A table showing the correspondence between the input value and the output value may be stored.

[Tactile presentation device]
The tactile presentation device 13 is a general element that presents skin sensory feedback, that is, virtual tactile St., to a human by tactile sensations such as force, vibration, and temperature. As one of the tactile presentation devices 13 that present a sensation by force or vibration, there is a vibration device such as a vibration actuator. Further, as one of the tactile presentation devices 13 that present a sensation by temperature, there is a Peltier Device made of a plate-shaped semiconductor thermoelectric element using the Peltier Effect.

Hereinafter, the case where the tactile presentation device 13 is composed of a vibration device will be described as an example, but the present invention is not limited to this. As long as it is an element that presents a virtual tactile sensation, another device such as a Pelche element may be used as the tactile sensation presenting device 13. At this time, the vibration and the vibration intensity of the vibration device in the following description correspond to the tactile sensation (virtual tactile sensation) and the tactile sensation of another device used as the tactile presentation device 13.

[Principle of the present invention]
Next, the principle of the present invention will be described with reference to FIG.
In general, an element such as a vibration actuator that converts an input drive signal into a tactile sense and presents it has a frequency characteristic in which the intensity of the tactile sense presented changes depending on the frequency. Therefore, even if the strength of the drive signal is the same, if the frequency is different, the tactile strength of the presented tactile sensation may be different.

FIG. 2 is a graph showing the frequency characteristics of the vibrating device. Taking the case where the tactile presentation device 13 is made of a vibration device as an example, as shown in FIG. 2, even if the strength of the drive signal is constant, the presented vibration strength (acceleration) may be different when the frequency is different. be. In FIG. 2, the frequency fp indicates the frequency at which the vibration intensity is maximized, and the general usage method is to drive the vibration device at a single frequency in the vicinity of this frequency fp.

However, fixing the driving frequency limits the expression of virtual tactile sensation. This is because it is necessary to drive the vibration device with various intensities and frequencies in order to give various virtual tactile sensations to humans. Therefore, when a frequency far from the frequency fp is used in an attempt to drive at a different frequency, the vibration intensity presented by the vibration device is significantly reduced, and as a result, a correct intensity design cannot be performed.

A developer who creates content, an application, or the like using the tactile device 10 specifies the tactile sensation to be presented by the tactile device 10 with a plurality of parameters by an input signal Si input from the host device to the tactile device 10. At this time, the parameter for designating the tactile intensity a of the tactile sensation to be presented is the specified intensity i (N / A: no unit), and the vibration frequency of the tactile sensation to be presented is f (Hz). When the designated intensities i are set to 25, 50, 75, 100 and the frequency f is changed, a graph as shown in FIG. 3 can be obtained as the frequency characteristics. FIG. 3 is a graph showing the frequency characteristics (by designated intensity) of the vibration device.

On the other hand, the vibration intensity a of the vibration device is represented by a function g having the signal intensity v of the drive signal Sd and the frequency f as variables, that is, a = g (f, v). This function g is a frequency-dependent input / output characteristic of the vibration device (tactile presentation device 13).
Therefore, even if the designated intensity i is set, the vibration intensity a differs depending on the frequency f of the drive signal Sd. Therefore, the vibration intensity at the frequencies f = f1 and i = 50 is set to a (f1, 50), and the frequency f = f2. If (≠ f1) and the vibration intensity of i = 50 is a (f2,50), then a (f1,50) ≠ a (f2,50). As a result, it can be seen that the vibration strength a corresponding to the designated designated strength i cannot be obtained.

The present invention focuses on the fact that the reason why the vibration intensity a corresponding to the designated intensity i specified by the input signal Si is not presented by the vibration device is the frequency characteristic of the vibration device 13 here. Then, even if the frequencies f are different, the vibration intensity a corresponding to the specified intensity i specified by the input signal Si can be obtained, that is, a (f1, i) = a (f2, i). In addition, the control circuit 11 corrects the drive signal Sd.

As shown in FIG. 1, when the input / output characteristic of the control circuit 11 is H and the input / output characteristic of the tactile presentation device 13 is G, the input / output characteristic F of the entire tactile device 10 is represented by F = HG. Will be done. Of these, the input / output characteristic H corresponds to the compensation model 12A for performing frequency compensation of the tactile presentation device 13. At this time, the input / output characteristic F is defined at the time of designing the tactile device 10. Further, the input / output characteristic G can be obtained by simulation or measurement of the tactile presentation device 13. Therefore, assuming that the inverse function of G is G ^-1 , the input / output characteristic H is represented by H = F · G ^-1 , and the input / output characteristic H can be specified from these input / output characteristics G and F.

[I / O characteristics F]
The input / output characteristic F of the entire tactile device 10 will be described.
Assuming that the specified intensity specified by the input signal Si is i and the vibration intensity of the vibrating device is a (m / s ² ), the vibration intensity a depends on the specified intensity i, a = c · i, as shown in FIG. (C is a constant) is controlled linearly. FIG. 4 is a graph showing the input / output characteristics of the entire tactile device. As shown in FIG. 4, the constant c indicating the slope of the graph corresponds to the linear gain of the entire tactile device 10, and can be freely defined by the designer within a range that can be perceived by the user of the tactile device 10 and is not unpleasant. Just do it. As a result, for example, when the designated intensity i = 50 is specified in the input signal Si, the vibration intensity a = 3 [m / s ² ] is defined as c = 3/50. As a result, when the designated intensity i = 100 is specified in the input signal Si, the vibration intensity a = 6 [m / s ² ] is output.

[I / O characteristics G]
The input / output characteristic G of the tactile presentation device 13 will be described.
FIG. 5 is a graph showing the input / output characteristics of the vibration device. When the above-mentioned a = g (f, v) is generated for each frequency f (f1, f2, f3) and the obtained a = g _f (v) is graphed, the drive signals at each frequency f1, f2, f3 are obtained. The input / output characteristic G as shown in FIG. 5, which shows the relationship between the signal strength v of Sd and the vibration strength a, can be obtained.
These input / output characteristics G can be derived from the simulation result of the vibration device or the actual measurement result. When using actual measurement results, it is desirable to consider individual differences and use multiple measurement results obtained from different individuals.

[I / O characteristics H]
The input / output characteristic H of the control circuit 11, that is, the compensation model 12A will be described.
The input / output characteristics G of the vibration device at frequencies f1, f2, and f3 shown in FIG. 5 described above are
a _f1 = g _f1 (v) at f = f1
a _f2 = g _f2 (v) at f = f2
a _f3 = g _f3 (v) at f = f3
Then, these inverse functions are
v = g ^f1-1 ( _{a f1} ₎
v = g _f2-1 ( _{a f2} ⁾
v = g _f3-1 ( _{a f3} ⁾
It is expressed as. By these inverse functions, the signal strength v of the drive signal Sd to be actually applied can be specified for the vibration strength a to be presented for each of the frequencies f1, f2, and f3.

Therefore, based on the input / output characteristic F of the entire tactile device 10, the vibration intensity a presented by the tactile presentation device 13 is specified from the intensity i specified by the input signal Si, and the input / output characteristic G of the tactile presentation device 13 is specified. If the signal strength v of the drive signal Sd to be actually applied at the frequency f specified by the input signal Si is specified based on the inverse function, the input / output characteristic H of the control circuit 11, that is, the compensation model 12A is specified. It will be.
As described above, in the input / output characteristic H of the control circuit 11, that is, the compensation model 12A, a = c · i corresponding to the input / output characteristic F and v = g _f ^-1 (a) corresponding to the inverse function of the input / output characteristic G. It is composed of _f ). Therefore, the input / output characteristic H may be expressed as a compensation function v = g _f ^-1 (c · i) by combining them.

For the model construction of the compensation model 12A, the simulation result may be used or the measurement result may be used. In the case of measurement data, increasing the number of frequencies makes it easier to compensate for individual differences. In particular, when constructing the compensation model 12A based on the measurement results, an approximate model may be generated from the measurement results of a specific frequency and intensity, and the compensation model 12A may be constructed by complementing this for all combinations.

Further, the compensation model 12A is composed of individual models generated for each of a plurality of frequency domains. When generating an approximate model from the measurement results of a specific frequency and intensity, it is difficult to approximate with one unified model over all frequency domains, as shown in FIG. 6, depending on the input / output characteristic G of the tactile presentation device 13. In some cases. FIG. 6 is a graph showing an example of generating a compensation model (unified model). FIG. 6 shows a compensation model for each specified intensity i. For example, in the vicinity of frequencies fa and fb, the discrepancy between the actual measurement result and the unified model becomes relatively large, and the correlation between the two decreases. As a result, the compensation accuracy is lowered.

In the present embodiment, in order to reduce such a discrepancy between the actual measurement result and the unified model, the operating region of the tactile presentation device 13 is divided into a plurality of frequency regions, and the actual measurement results are obtained for each of these frequency regions. It is designed to generate an individual model. Thereby, it is possible to switch to the individual model of the frequency domain corresponding to the designated intensity i and compensate the input / output characteristic G of the tactile presentation device 13. At this time, in some frequency regions, the discrepancy between the measurement result and the unified model may not be reduced, so the switching frequency fx for switching the individual model is important.

For example, when a switching frequency fx is provided between frequencies fa and fb and divided into two frequency domains Ra and Rb and individual models are switched and used, the measurement result shown in FIG. 6 has a low density of measurement data. , It is not possible to generate an individual model with high accuracy. Therefore, as shown in FIG. 7, the frequency points to be measured are increased between the frequencies fa and fb, individual models are generated using each of these frequency points as the switching frequency, and these are evaluated to be individual with the measurement result. The individual model at the switching frequency with the smallest deviation from the model may be selected.

In addition, these individual models may be connected to one model for each designated intensity i. Further, when evaluating the model, it is possible to evaluate whether the individual model correctly expresses the behavior of the tactile presentation device 13 by measuring at a frequency outside the operating region of the tactile presentation device 13.
Further, the combination of individual models for each frequency domain is not limited to the two divisions shown in FIG. 7, but is divided into low frequency, medium frequency (including resonance point), and high frequency band, or near the resonance point. It may be divided in the distance. For example, when the operating region of the tactile presentation device 13 is 40-100 Hz, the former is composed of three individual models: a low frequency band: 40 Hz or less, a medium frequency band: 40-80 Hz, and a high frequency band: 80 Hz or more. To. The latter is composed of two individual models: near the resonance point: 40-80 Hz, far from the resonance point: 40 Hz or less and 80 Hz or more.

[Operation of this embodiment]
Next, the operation of the tactile device 10 according to the present embodiment will be described.
First, the control circuit 11 has a vibration intensity to be presented from the vibration device based on the function a = c · i (input / output characteristic H) of the compensation model 12A from the value of the designated intensity i of the input signal Si. Identify a.
Next, the control circuit 11 selects an individual model corresponding to the frequency f of the input signal Si from the compensation model 12A, and the function of the individual model v = g _f ^-1 (a _f ) (input). Based on the inverse characteristic of the output characteristic G), the signal strength v required to present the vibration strength af of the frequency _f from the vibration device is specified, and the drive signal having this signal strength v, that is, the vibration at the frequency f is specified. A drive signal Sd that compensates for the input / output characteristics of the device is generated.

FIG. 8 is a graph showing the frequency characteristics (after compensation) of the drive signal. FIG. 9 is a graph showing the frequency characteristics (with compensation) of the vibration device. As a result, it is possible to generate a drive signal Sd that compensates for the frequency characteristics of the vibrating device as shown in FIG. Therefore, by performing such compensation in the control circuit 11, when the same specified intensity i is specified in the input signal Si, as shown in FIG. 9, a constant vibration intensity a is obtained over a wide range of frequencies f. It will be possible to present.

[Effect of this embodiment]
As described above, in the present embodiment, the storage circuit 12 stores the compensation model 12A relating to the tactile presentation device 13 individually in advance for each of a plurality of frequency domains, and the control circuit 11 generates the drive signal Sd. At this time, among the compensation models 12A stored in the storage circuit 12, the drive signal Sd that compensates for the input / output characteristic G of the tactile presentation device 13 based on the individual model of the frequency domain corresponding to the frequency f specified by the input signal Si. Is configured to generate.
Specifically, the control circuit 11 inputs / outputs the entire tactile device 10 in which the relationship between the designated intensity i specified by the input signal Si and the tactile intensity presented by the tactile presentation device 13 is defined in advance. It has a signal strength v that compensates for the input / output characteristic G of the tactile presentation device 13 based on the individual model of the frequency region corresponding to the frequency f specified by the input signal in the compensation model 12A so as to match the characteristic F. It is configured to generate a drive signal Sd.

Further, when the tactile presentation device 13 is composed of a vibration device that presents a tactile sensation by vibration, the compensation model 12A includes a model that compensates for the frequency characteristics of the tactile presentation device 13, and the control circuit 11 is designated by the input signal Si. The input signal in the compensation model 12A so that the relationship between the specified specified intensity i and the tactile intensity presented by the tactile presentation device 13 matches the input / output characteristic F of the entire tactile device 10 defined in advance. Based on the individual model of the frequency domain corresponding to the frequency f specified by Si, it is configured to generate the drive signal Sd having the signal strength v compensated for the input / output characteristic G of the tactile presentation device 13.

Therefore, according to the present embodiment, the drive signal Sd compensated for the input / output characteristic G of the tactile presentation device 13 is transmitted from the control circuit 11 to the tactile presentation device 13 based on the designated intensity i specified by the input signal Si. It will be applied. Therefore, for example, even when the tactile presentation device 13 has a frequency characteristic such as a vibration device, when the same designated intensity i is specified by the input signal Si, a constant tactile sensation is given over a wide range of frequencies f. The intensity a can be presented. Further, since the drive signal Sd in which the input / output characteristic G is compensated is generated based on the individual model of the frequency domain corresponding to the frequency f specified by the input signal in the compensation model 12A, the input / output characteristic is highly accurate. G will be compensated. As a result, the tactile device 10 can present a highly realistic virtual tactile sensation.

[Extension of embodiment]
Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the structure and details of the present invention within the scope of the present invention.

10 ... tactile device, 11 ... control circuit, 12 ... storage circuit, 12A ... compensation model, 13 ... tactile presentation device, Si ... input signal, f, f1, f2, f3, fp, fx ... frequency, Sd ... drive signal, v ... signal strength, St ... tactile (vibration), a ... tactile strength (vibration strength), F, G, H ... input / output characteristics.

Claims

A tactile presentation device configured to present a tactile sensation in response to an applied drive signal, and a tactile presentation device.
A control circuit configured to generate the drive signal based on the input signal and apply it to the tactile presentation device.
Equipped with a storage circuit
The storage circuit stores a plurality of individual models constituting a compensation model that compensates for the input / output characteristics of the tactile presentation device individually in advance for each frequency domain.
When the control circuit generates the drive signal, the tactile presentation device is input based on an individual model in the frequency domain corresponding to the frequency specified by the input signal among the compensation models stored in the storage circuit. A tactile device characterized by generating the drive signal with compensated output characteristics.
In the tactile device according to claim 1,
In the control circuit, the relationship between the specified intensity specified by the input signal and the tactile intensity of the tactile sensation presented by the tactile presenting device matches the predefined input / output characteristics of the entire tactile device. , The drive signal having a signal strength compensated for the input / output characteristics of the tactile presentation device is configured based on an individual model of the frequency region corresponding to the frequency specified by the input signal. Tactile device featuring.
In the tactile device according to claim 1,
The tactile presentation device comprises a vibration device that presents a tactile sensation by vibration.
The individual model includes a model that compensates for the frequency characteristics of the vibration device.
The control circuit said that the relationship between the specified intensity specified by the input signal and the tactile intensity of the tactile sensation presented by the vibrating device matches the predefined input / output characteristics of the tactile device. It is configured to generate the drive signal having the signal strength of the drive signal compensated for the frequency characteristics of the vibration device, based on an individual model of the frequency domain corresponding to the frequency specified by the input signal. Tactile device featuring.
In the tactile device according to claim 1,
The compensation model describes the input / output characteristics of the entire tactile device, which shows the relationship between the specified intensity specified by the input signal and the tactile intensity of the tactile sensation presented by the tactile presenting device, and the above-mentioned in each frequency domain. It is characterized by including a plurality of individual models having inverse characteristics regarding the input / output characteristics of the tactile presentation device, which show the relationship between the signal strength of the drive signal and the tactile strength of the tactile sensation presented by the tactile presentation device. Tactile device.
In the tactile device according to claim 4,
A tactile device characterized in that the inverse characteristic relating to the input / output characteristics of the tactile presentation device includes a frequency specified by the input signal as a variable.