Haptic feedback device, haptic feedback method, and program

Abstract

To properly provide, when haptic sensation with electric stimulus is provided, the haptic sensation without causing pain.SOLUTION: A haptic feedback device includes: a waveform processing unit 12 which processes haptic signals generated from haptic vibration sampled at a predetermined frequency to form pulse voltages of a predetermined short intervals, for each sampling signal; and a pulse application unit 22 which applies the pulse voltages of the predetermined short intervals obtained in the waveform processing unit 12 to electrodes 23a, 23b, 23c that are brought into contact with skin. Accordingly, haptic sensation can be provided to a fingertip, or the like, properly without causing pain.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tactile presentation device, a tactile presentation method, and a program that present a sense of touch to a finger or the like of a subject.

Background Art

[0002] In recent years, tactile presentation devices that present a pseudo-tactile sensation to the skin of a finger or the like have been developed. For example, there has been developed a tactile presentation device that reproduces various tactile sensations by vibration of a vibration member, such as the tactile sensation when a finger rubs a smooth portion or the tactile sensation when a finger rubs a rough portion. Such a tactile presentation device can present, for example, a tactile sensation linked to an image and give a subject a feeling as if they actually touched what is shown in the image.

[0003] As a method of presenting a tactile sensation, in addition to a method of physically vibrating a vibration member, there is a method of applying a stimulus with an electrode. The electrode is suitable because it can be configured relatively small. Patent Document 1 describes a technique of performing tactile presentation by bringing minute electrodes arranged on a substrate into contact with a finger and applying an electrical stimulus.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, when presenting a tactile sensation by an electrical stimulus, there has been a problem that it is difficult to give an appropriate stimulus when applying an electrical signal to the skin of a finger or the like. That is, even when an electrical stimulus of the same voltage is applied to the skin, there are differences in the degree felt by each individual. If the electrical stimulus is too strong, it will be felt as painful, and if it is too weak, it will be difficult to feel the tactile sensation, so there has been a problem that appropriate adjustment is difficult.

[0006] In view of this point, an object of the present invention is to provide a tactile presentation device, a tactile presentation method, and a program capable of appropriate tactile presentation when presenting a sense of touch by electrical stimulation.

Means for Solving the Problems

[0007] The tactile presentation device of the present invention includes a waveform processing unit that converts a tactile signal capturing a vibration of touch sampled at a predetermined frequency into a pulse voltage at a constant short time interval for each sampling signal, and a pulse application unit that applies the pulse voltage at the constant short time interval obtained by the waveform processing unit to an electrode in contact with the skin.

[0008] Further, the tactile presentation method of the present invention includes waveform processing in which an information processing device converts a tactile signal capturing a vibration of touch sampled at a predetermined frequency into a pulse voltage at a constant short time interval for each sampling signal, and pulse application processing in which the pulse voltage at the constant short time interval obtained by the waveform processing is applied from the information processing device to an electrode in contact with the skin.

[0009] Further, the program of the present invention causes a computer to execute procedures for executing each process of the above-described tactile presentation method.

Effects of the Invention

[0010] According to the present invention, it is possible to appropriately present a sense of touch by electrical stimulation to the wearer of the electrode without causing pain.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0012] Hereinafter, an embodiment of the present invention (hereinafter referred to as "this example") will be described with reference to the accompanying drawings. As shown in FIG. 1, this example is composed of a tactile presentation device 10 and its peripheral devices, a tactile detection sensor 1 and a pulse application device 20. That is, in this example, the touch detected by the tactile detection sensor 1 worn by the tactile detector is reproduced by the finger of the tactile presenter.

[0013] [Configuration of Tactile Presentation Device] The tactile presentation device 10 is composed of, for example, a computer which is an information processing device, and includes an acquisition unit 11, a waveform processing unit 12, a storage unit 13, and a transmission unit 14. The acquisition unit 11 acquires the tactile signal detected by the tactile detection sensor 1. The tactile detection sensor 1 is, for example, a sensor worn on the finger of the tactile detector. That is, the tactile detection sensor 1 detects the vibration of the finger when the finger of the tactile detector touches the surface of an object, and obtains a tactile signal corresponding to the vibration.

[0014] For example, when the tactile detection sensor 1 performs an operation of rubbing an object with a rough (minutely uneven) surface at the belly of the finger of the tactile detector, the tactile detection sensor 1 obtains a tactile signal that detects the vibration of the finger corresponding to the roughness (minute unevenness). The tactile signal output by the tactile detection sensor 1 is an analog signal having a waveform (such as a voltage waveform) corresponding to vibration. The acquisition unit 11 performs an acquisition process of digitizing and capturing the analog signal that is the tactile signal. The tactile detection signal obtained by the acquisition unit 11 is supplied to the waveform processing unit 12.

[0015] The waveform processing unit 12 performs waveform processing to sample the supplied digitized tactile signal at a relatively low frequency for tactile presentation (for example, a frequency within the range of 20 Hz to 300 Hz). Note that the sampling frequency at the time of digitization by the acquisition unit 11 is set to a higher frequency than the sampling frequency at the time of conversion to a burst wave by the waveform processing unit 12, or is set to the same frequency as the sampling frequency at the time of conversion to a burst wave by the waveform processing unit 12.

[0016] Furthermore, the waveform processing unit 12 causes each sampling value of the sampled data to be maintained for a relatively short time. The short time during which voltage is applied here, that is, the on-pulse width, is, for example, 0.1 milliseconds to 0.3 milliseconds. Also, the interval between each sampling signal (pulse signal) between the on-pulse width and the next on-pulse width, that is, the off-pulse width, is 0.2 milliseconds or more. Thereby, processing is performed to make pulses at a constant short time interval for each sampling signal.

[0017] The tactile signal (tactile presentation data) obtained by the processing of the waveform processing unit 12 is stored in the storage unit 13 and transmitted from the transmission unit 14 to the pulse application device 20 by wire or wirelessly. Note that instead of transmitting the output of the tactile detection sensor 1 processed by the waveform processing unit 12 in real time, the transmission unit 14 may transmit the past tactile signal stored in the storage unit 13.

[0018] Also, as shown in FIG. 1, the pulse application device 20 includes a reception unit 21 and a pulse application unit 22. The reception unit 21 receives the tactile signal (tactile presentation data) transmitted from the tactile presentation device 10. When performing wireless transmission between the transmission unit 14 of the tactile presentation device 10 and the reception unit 21 of the pulse application device 20, for example, wireless communication is performed according to the Bluetooth (registered trademark) standard. The tactile signal received by the reception unit 21 is supplied to the pulse application unit 22.

[0019] The pulse application unit 22 applies a pulse voltage to the electrodes 23a, 23b, and 23c attached to the fingers of the hand H of the tactile presenter. For example, in the example of FIG. 1, the electrodes 23a, 23b, and 23c formed in a finger ring shape are attached to the three fingertips of the hand H. Then, the surfaces of the skin of the three fingertips are brought into contact with the electrodes 23a, 23b, and 23c. Although not shown, the ground potential unit is also brought into contact with the surface of the skin of the same finger. Note that attaching the electrodes 23a, 23b, and 23c to the three fingers is just an example. For example, only one electrode may be attached to one finger. Alternatively, electrodes may be attached to all five fingers.

[0020] Then, the pulse application unit 22 applies the tactile signal received by the reception unit 21 to each of the electrodes 23a, 23b, and 23c. Here, the received tactile signal is a pulse signal with a pulse width of on from 0.1 ms to 0.3 ms at a frequency within the range of 20 Hz to 300 Hz. Note that the off pulse signal is set to 0.2 ms or more.

[0021] When data for designating the finger that gives the tactile sensation is added to the tactile signal (tactile presentation data) supplied from the pulse application unit 22 to each of the electrodes 23a, 23b, and 23c, among the three electrodes 23a, 23b, and 23c, a pulse signal is applied to any one of the electrodes 23a, 23b, and 23c attached to the corresponding finger.

[0022] Note that the tactile presentation device 10 shown in FIG. 1 is composed of a computer, which is a so-called information processing device. That is, when the hardware configuration of the computer as the tactile presentation device 10 is shown below FIG. 1, it is composed of a CPU (Central Processing Unit) 10a, a work memory 10b, a storage 10c, an input unit 10d, and a communication interface 10e.

[0023] The CPU 10a is an arithmetic processing unit that reads the program code of the software that realizes the functions performed by the tactile presentation device 10 from the storage 10c and causes the work memory 10b to execute it. The CPU 10a reads the program code from the storage 10c and executes arithmetic processing in the work memory 10b, whereby various processing functional units are configured in the work memory 10b. For example, the acquisition unit 11 and the waveform processing unit 12 described above are configured in the work memory 10b.

[0024] The storage 10c stores program data and also stores tactile signals. The input unit 10d performs input processing of tactile signals from the tactile detection sensor 1. The communication interface 10e communicates with the pulse application device 20.

[0025] [Example of Transmission Processing of Tactile Signals] FIG. 2 is a flowchart showing an example of processing between the tactile presentation device 10 and the pulse application device 20. First, the tactile presentation device 10 samples the input tactile signal as pulse data sampled at a low frequency (a frequency within the range of 20 Hz to 300 Hz) for tactile presentation, and performs waveform processing such that the pulse width of each on is from 0.1 msec to 0.3 msec (step S11). The off pulse width is 0.2 msec or more. Then, the transmission unit 14 transmits the tactile presentation data obtained in step S11 to the pulse application device 20 (step S12). The tactile presentation device 10 repeatedly executes the processing of steps S11 and S12.

[0026] The pulse application device 20 receives the tactile presentation data transmitted in step S12 (step S21). Then, the pulse application unit 22 applies a pulse voltage corresponding to the tactile presentation data received in step S21 to any one of the finger electrodes 23a, 23b, 23c (step S22). The pulse application device 20 repeatedly executes the processing of steps S21 and S22.

[0027] [Examples of Sensor Detection Signals and Electrode Application Signals] Next, examples of the sensor detection signal supplied to the tactile presentation device 10 in this example and the tactile presentation signal obtained by processing the sensor detection signal will be described. Figure 3 shows an enlarged view of a part of the tactile signal (analog signal) supplied from the tactile detection sensor 1 to the acquisition unit 11 of the tactile presentation device 10. The horizontal axis in Figure 3 represents time, and the vertical axis represents the physical quantity of the vibration state corresponding to the touch. The physical quantity on the vertical axis is, for example, voltage.

[0028] As shown in Figure 3, the tactile signal supplied to the acquisition unit 11 has the characteristic α of a curve corresponding to the vibration state indicating the touch. The variation in the physical quantity of this characteristic α corresponds to the touch obtained from the portion touched by the tactile detection sensor 1.

[0029] Figure 4 shows the time change of the tactile presentation data obtained when the tactile presentation device 10 of this example processes the tactile signal shown in Figure 3. The horizontal axis in Figure 4 represents time, and the vertical axis represents the physical quantity (voltage) applied to the electrodes. As already described, the waveform processing unit 12 of the tactile presentation device 10 performs processing to obtain a pulse signal with a pulse width between 0.1 ms and 0.3 ms at a specific frequency (period) within the range of 20 Hz to 300 Hz. As a result, pulse signals P1, P2, P3,... are obtained, where the signal values at each timing of the tactile signal shown in Figure 3 are sampled.

[0030] The pulse values (peak values) of the respective pulse signals P1, P2, P3,... are the values obtained by sampling the tactile signal shown in Figure 4 and change according to the detection state of the touch. Here, the on-pulse width PW is a value set between 0.1 ms and 0.3 ms, and all the pulse signals P1, P2, P3,... have the same on-pulse width value. Also, the interval between each pulse signal set to 0.2 ms or more is the same for all the pulse signals P1, P2, P3,.... The tactile presentation device 10 outputs such pulse signals P1, P2, P3,... with the pulse width PW, which are applied from the pulse application device 20 to the electrodes 23a, 23b, 23c.

[0031] As a result, the tactile display device 10 can present the same tactile sensation as that detected by the tactile detection sensor 1 to the finger of the tactile presenter wearing the electrodes 23a, 23b, and 23c. In this case, each of the pulse signals P1, P2, P3, ··· is an off-pulse signal set for 0.2 msec or more. Then, the tactile presenter wearing the electrodes 23a, 23b, and 23c can appropriately feel the electrical stimulation from the tactile display device 10 as the tactile sensation of the finger.

[0032] Note that when not using a pulse signal with a relatively large interval as in this example, there is a possibility that the tactile presenter may feel pain when applying a voltage signal. However, in the case of this example, it is possible to avoid giving such pain and only give a good tactile sensation.

[0033] [Examples of sensor signals when rubbing the surfaces of various objects] Note that in the examples of FIGS. 3 and 4, very simple tactile signals are shown. However, in the tactile display device 10 of this example, it is possible to present various tactile sensations corresponding to tactile detection signals. FIG. 5 shows an example of a tactile detection signal output by the tactile detection sensor 1 when a tactile detector rubs the surfaces of five types of objects. The horizontal axis in FIG. 5 is time (seconds), and the vertical axis is a physical quantity (voltage: mV). Here, an example of acquiring data for 2 seconds is shown.

[0034] As each of the data d1, d2, d3, d4, and d5 shown in FIG. 5, the following are examples of data when rubbing with a finger. Data d1 is a tactile detection signal when rubbing the surface of a plastic corrugated board (so-called plastic danbo) having the same structure as cardboard with a finger. Data d2 is a tactile detection signal when rubbing the surface of relatively smooth wallpaper with a finger. Data d3 is a tactile detection signal when rubbing the surface of a hook-and-loop fastener (trade name Magic Tape: registered trademark) with a finger. Data d4 is a tactile detection signal when rubbing the surface of a silicone sheet with a finger. Data d5 is a tactile detection signal when rubbing the surface of an aluminum sheet with a finger.

[0035] As can be seen by comparing the data d1 to d5 shown in FIG. 5, the vibration state detected by the tactile detection sensor 1 changes according to the surface state of each material. Although each of the data d1 to d5 shown in FIG. 5 is an analog waveform, the waveform processing unit 12 of the tactile presentation device 10 in this example samples each of the data d1 to d5 at a specific period (for example, sampling at 200 Hz) and applies it to the electrodes as an off pulse signal set for 0.2 msec or more, similar to the example of FIG. 4. Thereby, it is possible to give a tactile sensation similar to that when rubbing the surface of each material to the finger of the tactile presenter who is not touching the object.

[0036] [Another Example of Electrodes] As shown in FIG. 1, when the ring-shaped electrodes 23a, 23b, and 23c are attached to the finger, since the electrodes are present on the fingertips of the finger to which the electrodes 23a, 23b, and 23c are attached, the electrodes may get in the way when the tactile presenter rubs the surface of an object with a finger. For this reason, each of the electrodes 23a, 23b, and 23c may have a mounting state different from that in the example of FIG. 1. For example, as shown in FIG. 6, electrodes 23x and 23y may be attached to locations close to the nails of the fingers F1 and F2 (the base side of the nails).

[0037] The locations where the electrodes 23x and 23y are attached are the fingertips of the fingers F1 and F2 (the locations opposite to the nails), and it is possible to feel the tactile sensation by touching the surface of the object with the fingertips of each of F1 and F2. Also, even when the electrodes 23x and 23y are attached in the state shown in FIG. 6, the tactile presenter can feel the tactile sensation at the fingertips in the same manner as in the case of the ring electrodes shown in FIG. 1 by the applied pulse signal.

[0038] Also, the point of presenting the tactile sensation at the fingertips as shown in FIGS. 1 and 6 is merely an example, and electrodes may be arranged at other locations on the skin to present the tactile sensation. In the configuration shown in FIG. 1, the tactile presentation device 10 and the pulse application device 20 are configured as separate devices. In contrast, for example, the tactile presentation device 10 and the pulse application device 20 may be integrated. In this case, for example, by miniaturizing the integrated tactile presentation device so that it can be worn on the wrist of the tactile presenter, etc., it becomes possible to more easily present tactile sensations to the fingertips.

[0039] Also, in the configuration shown in FIG. 1, the tactile presentation device 10 is configured to process the tactile signal output by the tactile detection sensor 1, but it may also process the past tactile signals stored in the storage unit 13 and apply a similar pulse signal to the electrodes. Thereby, for example, the storage unit 13 stores the tactile sensations when rubbing the surfaces of a plurality of types of objects as shown in FIG. 5, and it becomes possible to freely present the selected tactile sensation to the fingertips of the tactile presenter according to the situation at that time.

[0040] Note that as the signal stored in the storage unit 13, it is preferable to store a pulse signal subjected to waveform processing as shown in FIG. 4, for example. Thereby, the tactile presentation device 10 can read out the stored data in the storage unit 13 and apply it to the electrodes as it is without performing waveform processing.

[0041] Also, in FIG. 1, the tactile presentation device 10 is exemplified as being configured by a computer which is an information processing device. In contrast, the tactile presentation device 10 and the pulse application device 20 may be configured as devices equipped with dedicated hardware for performing their respective signal processing. When configuring the tactile presentation device 10 as a computer, a program for executing the processing procedure described in the flowchart of FIG. 2 is prepared, installed in the tactile presentation device 10 which is a computer, and executed by the tactile presentation device 10.

Explanation of Reference Numerals

[0042] 1... Tactile detection sensor, 10... Tactile presentation device, 10a... CPU, 10b... Work memory, 10c... Storage, 10d... Input unit, 10e... Communication interface, 11... Acquisition unit, 12... Waveform processing unit, 13... Memory unit, 14... Transmission unit, 20... Pulse application device, 21... Reception unit, 22... Pulse application unit, 23a, 23b, 23c, 23x, 23y... Electrodes

Claims

1. A waveform processing unit that converts a tactile signal capturing a tactile vibration sampled at a predetermined frequency into a pulse voltage with a constant short time interval for each sampling signal, and a pulse application unit that applies the pulse voltage with the constant short time interval obtained by the waveform processing unit to an electrode in contact with the skin. A tactile presentation device.

2. The predetermined frequency is a frequency between 20 Hz and 300 Hz, the on-pulse width of the pulse voltage with a short time width is set between 0.1 ms and 0.3 ms, and the off-pulse width of each pulse voltage is 0.2 ms or more. The tactile presentation device according to Claim 1.

3. The electrode is attached to a finger. The tactile presentation device according to Claim 2.

4. The electrode is attached to a location other than the fingertip. The tactile presentation device according to Claim 3.

5. An information processing device performs waveform processing that converts a tactile signal capturing a tactile vibration sampled at a predetermined frequency into a pulse voltage with a constant short time interval for each sampling signal, and includes pulse application processing that applies the pulse voltage with the constant short time interval obtained by the waveform processing to an electrode in contact with the skin from the information processing device. A tactile presentation method.

6. A program implemented on a computer that performs a process of applying a voltage to an electrode, a waveform processing procedure that converts a tactile signal capturing a tactile vibration sampled at a predetermined frequency into a pulse voltage with a constant short time interval for each sampling signal, and causes the computer to execute a pulse application procedure that applies the pulse voltage with the constant short time interval obtained by the waveform processing procedure to an electrode in contact with the skin. A program.

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