JP2006079191A - Vibration presentation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration presentation apparatus capable of presenting a user with vibration with as little attenuation as possible by means of a film-shaped piezoelectric sensor, and of providing the desired vibration through feedback control regardless of how a vibrator is worn. <P>SOLUTION: The vibration presentation apparatus 10 includes a PC 12. A microcomputer 14 creates a drive signal proportional to a command signal including a desired vibrational frequency provided by the PC 12, and imparts the drive signal to an eccentric motor type vibrator 18 via a power amplifier 16. The eccentric motor type vibrator 18 is worn on the user's body with the film-shaped piezoelectric sensor 20 therebetween and produces vibration when driven under control of the microcomputer 14. The vibration is applied to the user and detected by the piezoelectric sensor 20. The microcomputer 14 compares the detected vibrational frequency with the desired vibrational frequency and adjusts the vibrational frequency so that the frequencies match. This allows feedback control of the eccentric motor type vibrator 18. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vibration presenting apparatus, and more particularly to a vibration presenting apparatus that presents vibration to a user using a vibrator attached to the user's body.

  Information presentation using vibrotactile sensation can be used in situations where information presentation by audiovisual sense is not good, and is not affected by the direction in which the wearer is facing, and can present information only to the wearer. . A widely known example is a vibrator function of a mobile phone. Non-patent literature 1 and non-patent literature 2 disclose research examples of information presentation using vibrotactile sensations. According to Non-Patent Document 1, a vibrator is attached to a predetermined position of the whole body tactile suit, and a virtual object can be recognized based on tactile information by vibration of each vibrator. According to Non-Patent Document 2, the vibrator is mounted on the sole, and the sensory position due to the vibration of the vibrator is controlled by a so-called phantom sensation technique.

An example of the prior art is disclosed in Patent Document 1. In the vibration monitoring device disclosed in Patent Document 1, the vibration sensor is installed in a vibration measurement object, and a vibration detection unit and a vibration generation unit are incorporated in the case of the vibration sensor. In the vibration monitoring apparatus having such a configuration, the soundness of the vibration sensor is confirmed by generating vibration with respect to the vibration generating means and detecting the vibration with the vibration detecting means.
Hiroaki Yano, Tetsuro Ogi, Michitaka Hirose, Development of whole body tactile presentation device using vibrator, Transactions of the Virtual Reality Society of Japan, Vol.3, No.3, pp141-148,1998 Yuichiro Kume, Yasuhiko Shirai, Motohisa Tsuda, Toyohiko Hatada: Transmission of information by skin vibration stimulation to the sole, Japan Virtual Reality Academic Journal, Vol.3, No.3, pp.83-88,1998 JP-A-8-159862

  However, in Non-Patent Document 1, since tactile information is presented only by turning on / off vibration without applying vibration strength, simple information such as contact / non-contact with a virtual object is presented. It was only done. In other words, the amount of information that can be presented is small because only the on / off of the vibrator is controlled like the vibrator function of the mobile phone.

  In Non-Patent Document 2, it is difficult to accurately determine a physical quantity that stimulates a sensory receptor because it is difficult to maintain the contact pressure between the vibrator and the skin surface precisely and constantly. Assuming that the vibration intensity changes in proportion to the drive voltage output from the PC, the amount of stimulation is changed for convenience. For this reason, it is difficult to accurately reproduce a desired vibration frequency and amplitude. That is, even if the vibration frequency or the vibration amplitude changes due to factors such as the state of attachment of the vibrator or the state of the skin, it has not been possible to cope with this.

  Furthermore, the vibration monitoring device disclosed in Patent Document 1 sends a vibration control signal and a frequency control signal according to a calibration table, thereby vibrating the vibrator, detecting the vibration with a piezoelectric element, and detecting the sound of the vibration sensor. I try to check the sex. However, since this vibration sensor is provided with a vibrator and a piezoelectric element inside the case, when it is used as it is as a device for presenting vibration to the human body, it depends on the thickness and material of the case. There is a problem that the presented vibration is attenuated (reduced). Further, it is difficult to accurately reproduce a desired vibration frequency and amplitude due to factors such as the mounting position and the mounting state, as in the case of Non-Patent Document 1 and Non-Patent Document 2 described above. That is, it is not suitable for a device that presents vibration to the body.

  Therefore, a main object of the present invention is to provide a vibration presentation device that can reliably present a desired vibration.

  The invention of claim 1 is a vibration presentation device that includes a vibrator to be mounted on a user's body and presents vibration to the user by driving the vibrator, and a driving unit that drives the vibrator. A vibration sensor that is provided integrally with the vibrator and detects vibration of the vibrator, and a detection means that detects an output of the vibration sensor when the vibrator is driven by the driving means, and the driving means detects Based on the detection result of the means, at least one of the vibration frequency and amplitude of the vibrator is feedback-controlled.

  According to the first aspect of the present invention, the vibration presentation device includes a vibrator to be worn on the user's body, and presents vibration (stimulation) to the user by driving the vibrator. The driving means drives the vibrator according to a command signal, for example. This vibrator is provided integrally with the piezoelectric sensor and is worn on the user's body. The detection means detects the output of the piezoelectric sensor when the vibrator is driven, that is, when vibration occurs. For example, the piezoelectric sensor outputs a voltage (alternating voltage) corresponding to the actual vibration frequency and vibration amplitude of the vibrator. The drive means feedback-controls at least one of the vibration frequency and amplitude of the vibrator based on the detection result of the detection means. In other words, the vibration frequency of the vibrator is controlled to match the target vibration frequency, the vibration amplitude of the vibrator is controlled to match the target amplitude, or both of them are controlled. To do.

  According to the first aspect of the present invention, since at least one of the vibration frequency and amplitude of the vibrator is feedback-controlled, the vibrator can be vibrated at a desired vibration frequency and / or a desired amplitude. That is, a desired vibration can be presented to the user.

  The invention of claim 2 is dependent on claim 1, and the vibration sensor includes a piezoelectric film, and the piezoelectric film is disposed on a side that can face the body of the user.

  In the invention of claim 2, a piezoelectric film is used as the vibration sensor. The piezoelectric film outputs the vibration of the vibrator as an electric signal according to the displacement of the film. This piezoelectric film is arrange | positioned at the side which can oppose (facing) a user's body. For example, the piezoelectric film is disposed so as to be sandwiched between the vibrator and the user's body, and detects the vibration of the vibrator.

  According to the second aspect of the present invention, since the piezoelectric film is used as the vibration sensor, it is a side that can face the user's body, and can be disposed so as to be sandwiched between the vibrator and the user's body. Since it is a film, attenuation of the vibration amount of the vibrator can be minimized. That is, a desired vibration can be reliably presented to the user, and the actual vibration of the vibrator can be accurately detected.

  The invention of claim 3 is dependent on claim 1 or 2, and the vibrator includes an eccentric motor type vibrator.

  In the invention of claim 3, an eccentric motor type vibrator is used as the vibrator. The drive means feedback-controls at least one of the vibration frequency and vibration amplitude of the eccentric motor type vibrator based on the detection result (actual vibration frequency and actual amplitude of the vibrator). That is, the eccentric motor type vibrator is driven so that the actual vibration frequency matches the target frequency and the actual amplitude matches the target amplitude. Alternatively, feedback control is performed on either the vibration frequency or the vibration amplitude.

  According to the invention of claim 3, since the eccentric motor type vibrator is feedback-controlled, the vibrator can be vibrated at a desired vibration frequency and / or a desired vibration amplitude. Therefore, different types of vibrations can be presented by changing the target vibration frequency and target amplitude.

  The invention of claim 4 is dependent on claim 1 or 2, wherein the vibrator includes a voice coil type vibrator, and the driving means is based on the detection result of the detection means and the target amplitude. Feedback control of vibration amplitude.

  In the invention of claim 4, a voice coil type vibrator is used as the vibrator. The drive means feedback-controls the vibration amplitude of the voice coil type vibrator based on the detection result of the detection means, that is, the actual amplitude and the target amplitude of the vibrator. That is, the voice coil type vibrator is driven so that the actual amplitude matches the target amplitude.

  According to the invention of claim 4, even when a voice coil type vibrator is used as the vibrator, vibration having a desired amplitude can be presented.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

<First embodiment>
Referring to FIG. 1, the vibration presentation device 10 of the first embodiment includes a PC 12 and is attached to the user's body, although not shown. The PC 12 functions as a host computer. However, it is possible to provide a workstation instead of the PC 12. A microcomputer 14 is connected to the PC 12, and the microcomputer 14 controls the driving of the eccentric motor type vibrator 18 under the instruction of the PC 12. Specifically, the PC 12 gives a drive instruction (command signal) including a target vibration frequency (target vibration frequency) to the microcomputer 14. The microcomputer 14 generates and outputs a drive signal (PWM signal) according to the command signal. This drive signal is amplified by the power amplifier 16 and then applied to the eccentric motor type vibrator 18. That is, the drive voltage according to the command signal from the PC 12 is given to the eccentric motor type vibrator 18.

  The eccentric motor type vibrator 18 is a vibrator for wearing on the body, and although not shown, the vibration sensor 20 (“piezoelectric sensor” in the first embodiment) 20 provided integrally therewith is used by the user. The piezoelectric sensor 20 is attached (attached) so that the piezoelectric sensor 20 is brought into contact with a desired part (location) of the body, that is, the vibration part. Specifically, the eccentric motor type vibrator 18 and the piezoelectric sensor 20 are attached to the user's body so that the piezoelectric sensor 20 is sandwiched between the eccentric motor type vibrator 18 and the user's body. That is, the piezoelectric sensor 20 is disposed on the side that can face (face to) the user's body.

  Here, as can be seen with reference to FIG. 2, the eccentric motor type vibrator 18 is disposed on the piezoelectric sensor 20, and the eccentric motor type vibrator 18 and the piezoelectric sensor 20 are, for example, a double-sided tape or an adhesive. Are integrally provided. FIG. 2 shows a state in which the lid of the casing 18a is opened in order to show the inside of the eccentric motor type vibrator 18 in an easily understandable manner. A rotation shaft 18b is provided inside the housing 18a, and a weight 18c for making the rotation shaft 18b left-right asymmetric is fixed to the rotation shaft 18b. Therefore, when the rotary shaft 18b rotates, the weight 18c also rotates, and as shown in FIG. 3, the eccentric motor type vibrator 18 vibrates in the horizontal direction, and thereby vibrates in the vertical direction. Such vibration is transmitted to the user's body via the piezoelectric sensor 20. That is, vibration is presented to the user.

  Although omitted in FIG. 2, the coils, magnets, and the like of the eccentric motor are provided inside the casing 18a and below the weight 18c.

  As shown in FIG. 2, the piezoelectric sensor 20 includes a piezoelectric film 20a, and an eccentric motor type vibrator 18 is fixedly provided on the piezoelectric film 20a. As the piezoelectric sensor 20, for example, a vibration sensor “SDT1-028K (product number)” manufactured by Tokyo Sensor Co., Ltd. can be used. This vibration sensor converts the displacement of the surface of the piezoelectric film into an electrical signal and outputs it. In the first embodiment, an electric signal corresponding to a change in deformation caused by vibration of the eccentric motor type vibrator 18 is output. The electric signal output from the vibration sensor reflects the vibration frequency and vibration amplitude of the eccentric motor type vibrator 18. Thus, since the film-like piezoelectric sensor 20 is used, as described above, even if the piezoelectric sensor 20 is provided so as to be sandwiched between the eccentric motor type vibrator 18 and the user's body, the eccentric motor type vibrator 18 is provided. Can be presented to the user's body with almost no damping. In addition, the eccentric motor type vibrator 18 attached to the body is affected by the load depending on the mounting position, the mounting method, the wearing state, and the like. Can be accurately detected by the piezoelectric sensor 20.

  Returning to FIG. 1, when the piezoelectric sensor 20 detects the vibration of the eccentric motor type vibrator 18, the piezoelectric sensor 20 outputs a voltage corresponding to the vibration. That is, an AC voltage corresponding to the actual vibration frequency of the eccentric motor type vibrator 18 (hereinafter referred to as “detected vibration frequency” for convenience of description) and the amplitude of vibration is output. The output (output voltage) from the piezoelectric sensor 20 is amplified by the preamplifier 22 and input to the comparator 24. The comparator 24 shapes the amplified output voltage and outputs a rectangular wave voltage to the microcomputer 14. That is, the comparator 24 shapes the analog waveform that changes in a sine wave shape into a digital on / off waveform.

  The microcomputer 14 measures the frequency (detected vibration frequency) from the input rectangular wave voltage, compares the target vibration frequency with the detected vibration frequency, calculates the duty ratio of the PWM waveform (PWM signal), and detects the detected vibration. The frequency and the duty ratio of the PWM signal are transmitted to the PC 12. Thereby, those values can be monitored on the PC 12. Although illustration is omitted, if a display (LCD or CRT monitor) is connected to the PC 12, these values can be visually displayed by a numerical value or a line graph according to time series.

  Further, the microcomputer 14 executes feedback control on the calculated duty ratio of the PWM signal. That is, the duty ratio of the PWM signal generated and output by the microcomputer 14 is adjusted so that the detected vibration frequency matches the target vibration frequency. Here, the duty ratio can be expressed by 0 to 100%, and in the first embodiment, 0 to 100% corresponds to a value of 0 to 1023 and is adjusted with a resolution of 10 bits.

  For example, when the detected vibration frequency is lower than the target vibration frequency, the microcomputer 14 adds “1” to the duty ratio value represented by 10 bits. On the other hand, when the detected vibration frequency is higher than the target vibration frequency, “1” is subtracted from the value of the duty ratio represented by 10 bits. That is, the duty ratio (D) is adjusted according to Equation 1. In Equation 1, f1 is a target vibration frequency, and f2 is a detected vibration frequency (vibration frequency of the eccentric motor type vibrator 18 detected by the piezoelectric sensor 20).

<Equation 1>
D = D + 1 (f1> f2)
D = D-1 (f1 <f2)
0 ≦ D ≦ 1023
An operation verification experiment was performed on the vibration presentation device 10 having such a configuration. Specifically, a verification experiment was performed to determine whether the piezoelectric sensor 20 is operating normally and whether feedback control is normally performed.

  As described above, the piezoelectric sensor 20 outputs an electrical signal corresponding to a change in deformation of the surface thereof, that is, the surface of the piezoelectric film 20a due to the vibration of the eccentric motor type vibrator 18. Further, since the eccentric motor type vibrator 18 is not a simple vertical vibration but gives a complex vibration (horizontal and vertical vibration) to the surface of the piezoelectric film 20a, can the frequency be measured accurately? It is necessary to verify whether.

  Therefore, an experiment was conducted in which the vibration frequency was physically read using a laser type distance reading meter and compared with the vibration frequency (detection vibration frequency) read by the piezoelectric sensor 20 (vibration sensor). As the laser type distance reading meter, a CCD laser displacement sensor “LK-030 / LK-2000 (product number)” manufactured by Keyence Corporation was used.

  However, when the eccentric motor type vibrator 18 and the piezoelectric sensor 20 are attached to the user (human) in consideration of the actual wearing state, a laser type distance reading meter (hereinafter referred to as “laser sensor”) is sensitive to humans. The movement is also measured. For this reason, in the verification experiment, a model simulating human skin was used, and the eccentric motor type vibrator 18 and the piezoelectric sensor 20 were attached to this model. Specifically, a rectangular parallelepiped sponge having the same elastic coefficient as that of the skin, for example, is placed on the table, a piezoelectric sensor 20 is placed thereon, and an eccentric motor type vibrator 18 is placed thereon. Each was fixed with double-sided tape. In this state, the displacement in the lateral direction of the eccentric motor type vibrator 18 which can take vibration most accurately is measured by the laser sensor.

  Measurement was performed when the duty ratio of the drive voltage (PWM signal) applied to the eccentric motor type vibrator 18 was 98%, 78%, 58%, and 39%. The result is shown in FIG. FIG. 4 shows the relationship between the output frequency of the piezoelectric sensor 20 (vibration sensor) and the output frequency of the laser sensor. Here, the dotted line shown in FIG. 4 is a straight line having an inclination of 1, and the output frequency of the piezoelectric sensor 20 and the output frequency of the laser sensor coincide on this straight line. As can be seen from FIG. 4, since the deviation between the output frequency of the piezoelectric sensor 20 and the output frequency of the laser sensor is small regardless of the duty ratio, the vibration frequency of the vibration motor 18 detected by the piezoelectric sensor 20 is almost the same. It is considered accurate. That is, it can be said that the piezoelectric sensor 20 is operating normally.

  Next, in order to verify whether the feedback control is normally performed, an external factor is given to the vibrator (eccentric motor type vibrator 18) using the model as described above to change the vibration frequency. Measured. Specifically, the eccentric motor type vibrator 18 is placed with the piezoelectric sensor 20 in contact with the sponge so as to be in a horizontal state, and the vibration frequency is changed by placing a weight on the sponge. In this model, the eccentric motor type transducer 18 is suddenly pushed from above with the eccentric motor type transducer 18 attached to the human arm (the eccentric motor type transducer 18 is suddenly applied to the human arm. It is imitated). The verification experiment is performed with and without feedback control, and the respective results are shown in FIG.

  FIG. 5 is a graph showing temporal changes in the vibration frequency (detected vibration frequency). However, the weight was placed on the eccentric motor type vibrator 18 when 600 ms had elapsed since the start of the verification experiment. As can be seen from FIG. 5, in the case where feedback control is not performed, when the weight is placed on the eccentric motor type vibrator 18, only the vibration frequency fluctuates and does not converge to the target frequency. On the other hand, when feedback control is performed, the vibration frequency starts to converge to the target frequency gradually from the start of the verification experiment, and becomes almost stable at the target frequency when about 200 ms elapses. Thereafter, when the weight is placed on the eccentric motor type vibrator 18, the vibration frequency deviates from the target frequency, but when about 850 ms has passed since the start of the verification experiment (when about 250 ms has passed since the weight was placed). ), It becomes almost stable again at the target frequency. Thus, in the vibration presentation device 10, it can be seen that the feedback control is also performed normally.

  According to the first embodiment, since the vibrator is feedback-controlled, vibration with a desired frequency can be presented even if the attachment state of the vibrator changes.

  In addition, since the vibrator is attached to the user's body via a film-like piezoelectric sensor, the vibration by the vibrator can be presented to the user with almost no attenuation.

  In the first embodiment, detailed description is omitted. However, if the target vibration frequency is changed, the vibration frequency of the vibrator can be changed according to the target vibration frequency, and the strength is not simply on / off of vibration. Of different vibrations (of different frequencies). That is, the amount of information to be presented can be increased.

  In the first embodiment, the case where one vibrator is provided has been described. However, two or more vibrators may be provided. In such a case, the same number of piezoelectric sensors as the number of vibrators are provided, and the vibration frequency of each vibrator is feedback-controlled. In this way, various information can be presented by changing the vibrator to vibrate according to the time series or changing the vibration frequency of each vibrator. For example, if two vibrators are arranged at a predetermined interval and the vibrators are vibrated simultaneously with the same strength, the user is on a straight line of the two vibrators and the vibration is applied to the center thereof. Perceive. In this case, the position of the vibration perceived by the user can be changed by making the vibration intensity of each vibrator different. Furthermore, by devising the arrangement of a plurality of transducers and sequentially driving the transducers in a time-series pattern, it is possible to present direction information and analog quantity information.

  Thus, when presenting information to the user, switching of vibration (on / off) is also an important factor. In general, the drive voltage of the eccentric motor type vibrator is represented by a rectangular wave as shown in FIG. When such a drive voltage is applied to the eccentric motor type vibrator, the response characteristic of the eccentric motor (the eccentric motor type vibrator 18) as shown in FIG. 6B can be obtained. As can be seen with reference to FIG. 6B, when a drive voltage as shown in FIG. 6A is applied, the displacement of the eccentric motor type vibrator, that is, vibration, rises and falls of the drive voltage. It will change slowly. That is, the response characteristic of the eccentric motor type vibrator 18 is dull. Therefore, in order to sharpen (improve) the response characteristics of the eccentric motor type vibrator 18 at the rise and fall, it is conceivable to change the waveform of the drive voltage. For example, as shown in FIG. 7A, the voltage at the time of rising of the drive voltage is set higher than that at the steady state, and the voltage at the time of falling of the drive voltage is made smaller than the 0 level (giving back electromotive force) By doing so, it is possible to give a vibration (stimulation) for a short time to the user. However, actually, when the eccentric motor, that is, the eccentric motor type vibrator 18 is stopped, the terminal of the motor is short-circuited. When the drive voltage as shown in FIG. 7A is applied to the eccentric motor type vibrator 18, the response characteristic is improved, and the time until the target amplitude is reached as shown in FIG. 7B. And the time until the motor stops can be shortened. However, in FIG. 7B, the time variation of the amplitude is shown for easy understanding of the response characteristics.

  Furthermore, in the first embodiment, the piezoelectric film 20a is used in an exposed state, but a protective film can be provided on the outer side, that is, on the side facing (facing) the human body. As the protective film, considering the contact of the user (human) with the body, the protective film has an elastic modulus approximating the average elastic modulus of human skin, and the elastic modulus approximating the elastic modulus of the piezoelectric film (20a). For example, a thin film having high rigidity or a thin film having high rigidity can be used.

In the first embodiment, a piezoelectric sensor is used as the vibration sensor, but a strain detection element can also be used. The strain detection element is, for example, a strain gauge (a film-like material having a resistance wire).
<Second embodiment>
The vibration presentation device 10 'of the second embodiment shown in FIG. 8 is the same as the first embodiment except that the vibration amplitude of the eccentric motor type vibrator 18 is feedback-controlled in addition to the vibration frequency. Therefore, the overlapping contents will be explained briefly.

  As can be seen with reference to FIG. 8, the vibration presentation device 10 ′ is further provided with a peak meter 26 between the preamplifier 22 and the microcomputer 14 in the vibration presentation device 10 of the first embodiment. In the vibration presentation device 10 ′ of the third embodiment, a command signal including a target vibration frequency and a target amplitude (target amplitude) is given from the PC 12 to the microcomputer 14. The microcomputer 14 generates a drive signal in response to the command signal and outputs it to the power amplifier 16. Therefore, the drive voltage according to the command signal is given to the eccentric motor type vibrator 18.

  Then, the eccentric motor type vibrator 18 vibrates, and the vibration is detected by the piezoelectric sensor 20. The piezoelectric sensor 20 outputs a voltage corresponding to the detected vibration. This voltage (output voltage) is amplified by the preamplifier 22, input to the comparator 24, and input to the peak meter 26.

  Here, the point that the vibration frequency of the eccentric motor type vibrator 18 is feedback-controlled based on the output from the comparator 24 is the same as in the first embodiment, and therefore, the duplicated explanation is omitted.

  The peak meter 26 detects the maximum value (peak value) of the amplitude of the amplified output voltage, and inputs the detected peak value to the microcomputer 14. That is, the actual amplitude (hereinafter referred to as “detected amplitude”) of the eccentric motor type vibrator 18 is input to the microcomputer 14. The microcomputer 14 compares the detected amplitude with the target amplitude, and adjusts (controls) the amplitude of the command signal (drive signal) given to the power amplifier 16 so that the detected amplitude matches the target amplitude. In this way, the amplitude of the eccentric motor type vibrator 58 is feedback-controlled. Note that the amplitude feedback control method is the same as in the first embodiment, and a detailed description thereof will be omitted.

  Here, for example, when feedback control is not performed, if the eccentric motor type vibrator 18 is pressed (pressed), the rotational speed of the eccentric motor increases. At this time, the user feels that the vibration has increased. On the other hand, when feedback control is performed so that only the frequency is constant as in the first embodiment, when the eccentric motor type vibrator 18 is pressed down, the rotational speed is controlled to be constant. The current flowing through the eccentric motor is reduced from the initial state, and the amplitude of vibration of the eccentric motor type vibrator 18 is significantly reduced. For this reason, as a user's sensation, the user feels that the vibration is weakened. Therefore, as shown in the second embodiment, when both the vibration frequency and amplitude of the eccentric motor type vibrator 18 are feedback controlled, the vibration frequency is not kept constant and the initial amplitude is maintained. By controlling so as not to decrease more than the set value from the state, it becomes possible to keep the vibration intensity constant in the sense of the user.

  According to the second embodiment, since the vibrator is feedback-controlled, it is possible to present vibration having a desired frequency and a desired amplitude even when the mounting state of the vibrator is changed. For this reason, the types of vibrations can be further increased as compared with the case shown in the first embodiment, and a wealth of types of information can be presented.

  In the second embodiment, since both the frequency and amplitude of the vibration are feedback-controlled, it is possible to present the user with a stable vibration, that is, a vibration whose intensity is kept constant.

In the second embodiment, both the frequency and amplitude of vibration are feedback controlled, but only the amplitude of vibration may be fed back.
<Third embodiment>
The vibration presenting device of the third embodiment presents vibration to the user using a voice coil type vibrator, and can feedback control the amplitude of vibration of the voice coil type vibrator. In the third embodiment, the same contents as those in the first embodiment or the second embodiment will be briefly described.

  Referring to FIG. 9, the vibration presentation device 50 of the third embodiment includes a PC 52. The PC 52 functions as a host computer, and also has a function of controlling a vibrator, similar to the microcomputer 14 shown in the first embodiment. Have. A PC 52 is connected with a sine wave generator 54 and a power amplifier 56. The PC 52 gives a frequency command value to the Sin wave generator 54 and gives an amplitude command value to the power amplifier 56. The sine wave generator 54 generates a sine wave (sine wave) having a predetermined amplitude at the frequency according to the frequency command value from the PC 52 and inputs the sine wave to the power amplifier 56.

  The predetermined amplitude of the sine wave generated by the sine wave generator 54 is an arbitrary value set before shipment such as when the vibration presentation device 50 is manufactured.

  The power amplifier 56 adjusts the amplitude of the sine wave input from the sine wave generator 54 in accordance with the amplitude command value given from the PC 52, and the sine wave (drive signal) with the adjusted amplitude is converted into the voice coil type vibrator 58. To give. That is, an alternating drive voltage having an amplitude and frequency indicated by the PC 52 is applied to the voice coil type vibrator 58.

  As shown in FIG. 10, the voice coil type vibrator 58 is disposed on the piezoelectric film 60 a of the piezoelectric sensor 60. However, in FIG. 10, a cross section is shown for easy understanding of the configuration of the voice coil type vibrator 58. For example, a multi-actor (trade name) manufactured by NEC TOKIN Corporation can be used as the voice coil type vibrator 58, and its detailed configuration and operation are disclosed in Japanese Patent Application Laid-Open No. 2003-300017. Since the piezoelectric sensor 60 is the same as the piezoelectric sensor 20 shown in the first embodiment, detailed description thereof will be omitted.

  The configuration and operation of the voice coil type vibrator 58 will be briefly described with reference to FIG. The voice coil type vibrator 58 includes a casing 58a as a vibration transmitting portion, and two suspensions 58b are provided inside the casing 58a. A yoke 58c is connected to the suspension 58b and is flexibly supported in the housing 58a. A permanent magnet 58d is connected to the yoke 58c. A voice coil 58e is provided in a gap formed by the yoke 58c and the permanent magnet 58d. The voice coil 58e is fixedly provided on a vibrating body 58f fixed to the casing 58a. Although illustration is omitted, the drive voltage (AC voltage) from the power amplifier 56 is applied to the voice coil 58e. Then, the permanent magnet 58d (and the yoke 58c) or the voice coil 58e repeats moving up and down. Accordingly, the vertical movement of the permanent magnet 58d and the yoke 58c is transmitted to the casing 58a via the suspension 58b, and the casing 58a vibrates. In addition, due to the movement of the voice coil 58e in the vertical direction, the vibrating body 58f moves in the vertical direction, and the casing 58a vibrates. However, the permanent magnet 58d and the voice coil 58e act on each other to operate in opposite phases and transmit vibration to the outside. In this case, when the vibrating body 58f is formed so as to be easily deformed, the vibration of the vibrating body 58f can be presented to the user's body via the piezoelectric film 20a.

  Although not expressed in FIG. 10, the moving speed and acceleration of the permanent magnet 58d are determined by the drive voltage of the voice coil type vibrator 58, and consequently affect the strength of vibration (magnitude of amplitude).

  Returning to FIG. 9, the vibration of the voice coil type vibrator 58 is detected by the piezoelectric sensor 60. When detecting the vibration of the voice coil type vibrator 58, the piezoelectric sensor 60 outputs a voltage corresponding to the vibration. That is, an AC voltage corresponding to the actual vibration frequency (hereinafter referred to as “detection vibration frequency”) and the actual vibration amplitude (hereinafter referred to as “detection amplitude”) of the voice coil type vibrator 58 is output. The output voltage from the piezoelectric sensor 60 is amplified by the preamplifier 62, noise is removed by the filter (LPF in this first embodiment) 64, and then given to the f / V converter 66 and the peak meter 68.

  The f / V converter 66 detects the frequency of the output voltage of the piezoelectric sensor 60 subjected to amplification and noise removal, converts the detected frequency, that is, the detected vibration frequency, into a voltage value (DC voltage), and inputs the voltage value (DC voltage) to the PC 52. The peak meter 68 detects the peak value of the amplitude of the output voltage of the piezoelectric sensor 60 that has been amplified and noise-eliminated, that is, the detected amplitude, and inputs the detected peak value to the PC 52.

  The PC 52 calculates a vibration frequency (detected vibration frequency) from the voltage value input from the f / V converter 66 and compares it with a frequency command value. Here, the voice coil vibrator 58 vibrates at the same frequency as the drive voltage (alternating voltage) as long as it operates normally. Accordingly, the PC 52 determines that the system is abnormal when the detected vibration frequency is significantly deviated from the frequency command value. Although illustration is omitted, an output device such as a display or a speaker is connected to the PC 52, and when it is determined that the system is abnormal, the system abnormality is notified to the user by a warning message and / or a warning sound. It may be. The PC 52 compares the peak value (detected amplitude) input from the peak meter 68 with the target amplitude, and adjusts (controls) the amplitude command value to be given to the power amplifier 56 so that the detected amplitude matches the target amplitude. )

  In this way, the amplitude of the voice coil type vibrator 58 is feedback controlled. Note that the amplitude feedback control method is the same as in the first embodiment, and a detailed description thereof will be omitted.

  According to the third embodiment, vibration with a desired amplitude can be reliably presented, so that desired information can be presented to the user.

  In the third embodiment, as shown in FIG. 10, the voice coil type vibrator 58 is arranged so that the vibrating body 58f is in contact with the piezoelectric film 60a, but the state shown in FIG. Even if they are arranged in reverse, vibrations can be presented to the user's body.

It is a block diagram which shows the electrical constitution of the vibration presentation apparatus of 1st Example of this invention. FIG. 2 is an illustrative view showing a configuration of a eccentric motor type vibrator and a piezoelectric sensor shown in FIG. 1. It is an illustration figure which shows a mode that the eccentric motor type | mold vibrator | oscillator shown in FIG. 1 vibrates. A drive voltage having a different duty ratio is applied to the eccentric motor type vibrator shown in FIG. 1, and the output frequency when the vibration of the eccentric motor type vibrator is detected by the piezoelectric sensor and the output frequency when detected by the laser sensor. It is a graph which shows a relationship. It is a graph which shows the time-sequential change of the vibration frequency with the case where feedback control of the vibration of an eccentric motor type | mold vibrator is not performed using the vibration presentation apparatus shown in FIG. FIG. 2 is an illustrative view showing an example of a drive voltage applied to an eccentric motor type vibrator by the power amplifier shown in FIG. 1 and response characteristics of the eccentric motor type vibrator. FIG. 5 is an illustrative view showing another example of drive voltage applied to the eccentric motor type vibrator by the power amplifier shown in FIG. 1 and response characteristics of the eccentric motor type vibrator in that case. It is a block diagram which shows the electrical constitution of the vibration presentation apparatus of 2nd Example of this invention. It is a block diagram which shows the electric constitution of the vibration presentation apparatus of 3rd Example of this invention. FIG. 10 is an illustrative view showing a configuration of a voice coil type vibrator and a piezoelectric sensor shown in FIG. 9.

Explanation of symbols

10, 50 ... vibration presenting device 12, 52 ... PC
DESCRIPTION OF SYMBOLS 14 ... Microcomputer 16, 56 ... Power amplifier 18, 58 ... Vibrator 20, 60 ... Piezo sensor 22, 62 ... Preamplifier 24 ... Comparator 26, 68 ... Peak meter 66 ... f / V converter

Claims (4)

A vibration presentation device that includes a vibrator to be worn on a user's body and presents vibration to the user by driving the vibrator,
Driving means for driving the vibrator;
A vibration sensor provided integrally with the vibrator and detecting vibration of the vibrator; and a detection means for detecting an output of the vibration sensor when the vibrator is driven by the driving means;
The drive means is a vibration presentation device that feedback-controls at least one of frequency and amplitude of vibration of the vibrator based on a detection result of the detection means. The vibration sensor includes a piezoelectric film,
The vibration presentation apparatus according to claim 1, wherein the piezoelectric film is disposed on a side that can face the body of the user.   The vibration presentation device according to claim 1, wherein the vibrator includes an eccentric motor type vibrator. The vibrator includes a voice coil type vibrator,
The vibration presenting device according to claim 1, wherein the driving unit feedback-controls the amplitude of vibration of the voice coil type vibrator based on a detection result of the detecting unit and a target amplitude.

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