Patent Publication Number: US-2022236803-A1

Title: Actuator device, method for generating voltage waveform, method for driving field-responsiveness polymer actuator, and program

Description:
TECHNICAL FIELD 
     The present disclosure relates to an actuator device, a method for generating a voltage waveform, a method for driving an electroactive polymer actuator, and a program. 
     BACKGROUND ART 
     Patent Document 1 discloses a tactile sense presentation device that causes a user to recognize, as a tactile sense, an operation (such as vibration) that is based on the expansion and contraction of an electroactive polymer actuator. The tactile sense presentation device changes the waveform of a voltage applied to the electroactive polymer actuator so as to change operation patterns of the electroactive polymer actuator, thereby presenting the user with various tactile senses that correspond to operation patterns. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     Patent Document 1: Japanese Laid-Open Patent Publication No. 2014-510346 
     SUMMARY OF THE INVENTION 
     Problems that the Invention is to Solve 
     To present the user with a particular tactile sense using the tactile sense presentation device, a voltage waveform that operates the electroactive polymer actuator first needs to be generated such that the particular tactile sense is presented. The voltage waveform is generated by, for example, preparing a basic voltage waveform, repeating an editing task that changes the voltage waveform and an operation test of the electroactive polymer actuator using the edited voltage waveform, and causing the tactile sense presented from the electroactive polymer actuator to become close to the particular tactile sense. 
     It is an object of the present disclosure to improve the efficiency of generating a voltage waveform that produces a particular motion of an electroactive polymer actuator. 
     Means for Solving the Problem 
     An actuator device that solves the above-described problem includes: an electroactive polymer actuator that includes two electrodes; a drive unit configured to drive the electroactive polymer actuator by repeatedly applying, to a section between the two electrodes, a voltage that changes in correspondence with drive waveform data that indicates voltage changes corresponding to one cycle; and a waveform editing section configured to change edit waveform data in correspondence with an operation performed by a user. When the edit waveform data is changed during driving of the electroactive polymer actuator, the actuator device is configured to update the drive waveform data such that the changed edit waveform data becomes new drive waveform data and drive the electroactive polymer actuator using the updated drive waveform data. 
     In the configuration, when the edit waveform data is changed during driving of the electroactive polymer actuator, the operation of the electroactive polymer actuator is switched to an operation that is based on the changed edit waveform data without performing an operation such as saving or sending the changed edit waveform data. This allows the user to smoothly search for a voltage waveform that produces a particular motion of the electroactive polymer actuator while editing the edit waveform data. As a result, the voltage waveform is generated efficiently. 
     It is preferred that the actuator device include a change determination section configured to regularly determine whether the edit waveform data has been changed and the actuator device be configured to update the drive waveform data when the change determination section determines that the edit waveform data has been changed 
     The configuration reduces the frequency of updating the drive waveform data used to drive the electroactive polymer actuator. 
     It is preferred that the actuator device include an image processor configured to cause a display to display an image that corresponds to the edit waveform data and that the waveform editing section be configured to change the edit waveform data through an operation performed by the user, the operation changing the image displayed on the display using a pointing device. 
     The configuration allows the user to edit a waveform intuitively. Thus, even a user who has a small amount of knowledge related to machine or information processing easily generates a voltage waveform that produces a particular motion of the electroactive polymer actuator. 
     It is preferred that the actuator device be employed as a tactile sense presentation device that causes the user to recognize, as a tactile sense, an operation that is based on expansion and contraction of the electroactive polymer actuator. 
     In the actuator device, it is preferred that the tactile sense presentation device be a pulsation generating apparatus that causes the user to recognize, as a tactile sense of pulsation, vibration that is based on the expansion and contraction of the electroactive polymer actuator. 
     In the actuator device, it is preferred that when an operation is performed to invoke voltage waveform data stored in advance during driving of the electroactive polymer actuator, the actuator device be configured to change the edit waveform data to the voltage waveform data. 
     The configuration easily changes the operation of the electroactive polymer actuator during driving to an operation that is based on the voltage waveform data stored in advance. 
     A method for generating a voltage waveform that solves the above-described problem includes producing a waveform of applied voltage that produces a particular motion of the electroactive polymer actuator using the actuator device. 
     A method for driving an electroactive polymer actuator that solves the above-described problem includes the steps of: driving the electroactive polymer actuator by repeatedly applying a voltage that changes in correspondence with drive waveform data that indicates voltage changes corresponding to one cycle; changing edit waveform data in correspondence with an operation performed by a user; and when the edit waveform data is changed during driving of the electroactive polymer actuator, updating the drive waveform data such that the changed edit waveform data becomes new drive waveform data. The driving includes driving the electroactive polymer actuator using the drive waveform data updated in the updating. 
     A program that controls an actuator device that solves the above-described problem includes: an electroactive polymer actuator that includes two electrodes; a drive unit configured to drive the electroactive polymer actuator by repeatedly applying, to a section between the two electrodes, a voltage that changes in correspondence with drive waveform data that indicates voltage changes corresponding to one cycle; and a waveform editing section configured to change edit waveform data in correspondence with an operation performed by a user. When the edit waveform data is changed during driving of the electroactive polymer actuator, the program causes the actuator device to execute a process that updates the drive waveform data such that the changed edit waveform data becomes new drive waveform data and drives the electroactive polymer actuator using the updated drive waveform data. 
     Effects of the Invention 
     The present disclosure improves the efficiency of generating a voltage waveform that produces a particular motion of an electroactive polymer actuator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing a pulsation generating apparatus. 
         FIG. 2  is a cross-sectional view showing a dummy. 
         FIG. 3  is a cross-sectional view showing the cross-sectional structure of a dielectric elastomer actuator. 
         FIG. 4  is a block diagram showing the pulsation generating apparatus. 
         FIG. 5  is a diagram illustrating waveform editing screens. 
         FIG. 6  is a diagram illustrating the waveform editing screens during operation. 
         FIG. 7  is a flowchart showing the control executed by the waveform editing device while the dielectric elastomer actuator is driven. 
         FIG. 8  is a flowchart showing the control executed by the drive unit while the dielectric elastomer actuator is driven. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     An embodiment in which an actuator device of the present disclosure applied to a pulsation generating apparatus will now be described. The pulsation generating apparatus causes a user to recognize, as a tactile sense of the pulsation of a human body, the vibration generated in correspondence with applied voltage. 
     As shown in  FIGS. 1 and 2 , the pulsation generating apparatus includes a dummy  10 . The dummy  10  imitates the outer shape of a front arm and a hand of a human body and is made of flexible material. Examples of the flexible material of the dummy  10  include elastomers, such as silicone or urethane. 
     The dummy  10  internally includes a first core  11 , a second core  12 , and a sheet-shaped dielectric elastomer actuator (DEA)  13 . The first core  11  and the second core  12  imitate the radius and the ulna of a human body, respectively. The DEA  13  imitates a radial artery. 
     As shown in  FIG. 3 , the DEA  13  is a multi-layer structure formed by laminating sets of a dielectric layer  20 , a positive electrode  21 , and a negative electrode  22 . The dielectric layer  20  is made of dielectric elastomer and has a sheet shape. The positive electrode  21  and the negative electrode  22  are electrode layers on the opposite sides of the dielectric layer  20  in the thickness direction. An insulating layer  23  is laminated on each of the outermost layers of the DEA  13 . When a direct-current voltage is applied to a section between the positive electrode  21  and the negative electrode  22 , the DEA  13  deforms in correspondence with the magnitude of the applied voltage such that the dielectric layer  20  is compressed in the thickness direction and extended in a surface direction of the DEA  13 . The surface direction of the DEA  13  extends along the surface of each dielectric layer  20 . 
     The dielectric elastomer of the dielectric layer  20  is not particularly limited and may be a dielectric elastomer used for a typical DEA. Examples of the dielectric elastomer include crosslinked polyrotaxane, silicone elastomer, and urethane elastomer. One of these types of dielectric elastomer may be used alone, or two or more of these may be used in combination. The thickness of the dielectric layer  20  is, for example, 20 to 200 μm. 
     Examples of the materials of the positive electrode  21  and the negative electrode  22  include conductive elastomer, carbon nanotube, Ketjenblackack®, and metal vapor deposition film. Examples of the conductive elastomer include a conductive elastomer that contains an insulating polymer and a conductive filler. 
     Examples of the insulating polymer include crosslinked polyrotaxane, silicone elastomer, and urethane elastomer. One of these types of insulating polymer may be used alone, or two or more of these may be used in combination. Examples of the conductive filler include Ketjenblack®, carbon black, and metal particle such as copper or silver. One of these types of conductive filler may be used alone, or two or more of these may be used in combination. The thickness of each of the positive electrode  21  and the negative electrode  22  is, for example, 0.01 to 100 μm. 
     The dielectric elastomer of the insulating layer  23  is not particularly limited and may be a dielectric elastomer used for an insulating portion of a typical DEA. Examples of the insulating elastomer include crosslinked polyrotaxane, silicone elastomer, acrylic elastomer, and urethane elastomer. One of these types of insulating elastomer may be used alone, or two or more of these may be used in combination. The thickness of the insulating layer  23  is, for example, 3 to 100 μm. 
     As shown in  FIGS. 1 and 4 , the pulsation generating apparatus includes a drive unit  30  and a waveform editing device  40 . The drive unit  30  is configured to apply a cyclically-changing voltage to a section between two electrodes (the positive electrode  21  and the negative electrode  22  of the DEA  13 ). The waveform editing device  40  is configured to edit the waveform of a voltage applied to the DEA  13  by the drive unit  30 . The drive unit  30  includes a drive-side memory  31  and a controller  32 . The drive unit  30  may he circuitry including: 1) one or more processors that operate according to a computer program (software); 2) one or more dedicated hardware circuits such as application specific integrated circuits (ASICs) that execute at least part of various processes; or 3) a combination thereof. The processor includes a CPU and a memory such as a RAM and a ROM. The memory stores program codes or commands configured to cause the CPU to execute processes. The memory, or a computer readable medium, includes any type of media that are accessible by general-purpose computers and dedicated computers. The drive-side memory  31  stores drive waveform data that indicates changes in voltage corresponding to one cycle sent from the waveform editing device  40 . The controller  32  repeatedly applies, from a power supply (not shown) to the DEA  13 , a voltage having a waveform that is based on the drive waveform data stored in the drive-side memory  31 . 
     The waveform editing device  40  is a computer that includes a pointing device  41  (input device), a display  42 . a first memory  43 , a second memory  44 , a third memory  45 , a waveform editing section  46 , a change determination section  47 , a condition changing section  48 , and an image processor  49 . That is, the waveform editing section  46 , the change determination section  47 , the condition changing section  48 , and the image processor  49  may be circuitry including: 1) one or more processors that operate according to a computer program (software); 2) one or more dedicated hardware circuits such as application specific integrated circuits (ASICs) that execute at least part of various processes; or 3) a combination thereof. The processor includes a CPU and a memory such as a RAM and a ROM. The memory stores program codes or commands configured to cause the CPU to execute processes. The memory, or a computer readable medium, includes any type of media that are accessible by general-purpose computers and dedicated computers. 
     The pointing device  41  is, for example, a keyboard, a touch panel, or a mouse. The pointing device  41  receives, for example, an operation command from an operator. The display  42  is, for example, a display device such as a liquid crystal display or an organic EL display. 
     As shown in  FIG. 5 , the upper section of the display  42  displays an output button  51  used to switch the application of a voltage to the DEA  13  between on and off. The left section of the display  42  displays invocation buttons  52  used to invoke registered voltage waveform data and a save button  53  used to register new voltage waveform data. 
     The middle section of the display  42  displays anchor point buttons  54  that are respectively used to add and delete an anchor point P (described later) and a first waveform editing screen  55  that indicates a waveform subject to editing. The right upper section of the display  42  displays a driving situation screen  56  that indicates the voltage applied to the DEA  13 . The middle lower section of the display  42  indicates a second waveform editing screen  57 . The second waveform editing screen  57  includes a slider that changes the amplitude of an output (Amp), the magnitude of an offset voltage (Offset), and a maximum voltage (Max voltage). The right lower section of the display  42  displays a condition setting screen  58 . The condition setting screen  58  includes a slider that sets a driving condition in the case of applying a voltage having a waveform based on the drive waveform data in the drive unit  30 . Examples of the driving condition include the speed of one cycle (BeatCount) and the length of a standby time arranged between cycles (Interval). 
     The operator can operate the DEA  13  and edit the waveform of a voltage applied to the DEA  13  by operating the pointing device  41  so as to operate various buttons displayed on the display  42  and by changing the displayed contents of the first waveform editing screen  55  and the second waveform editing screen  57 , Further, the operator can set the driving condition by operating the pointing device  41  so as to change the displayed content of the condition setting screen  58 . 
     The first memory  43  stores registered voltage waveform data in association with the invocation buttons  52 . The registered voltage waveform data includes voltage waveform data. corresponding to one cycle that reproduces a known pulsation pattern, such as normal pulse or smooth pulse, and voltage waveform data corresponding to one cycle created by the user. The normal pulse is a vibration pattern of artery in a case where a person is normal and healthy. The smooth pulse is a vibration pattern of an artery that occurs, for example, during pregnancy. The voltage waveform data that reproduces a known pulsation pattern is associated with the invocation button  52  that is named a pulse name such as “normal pulse.” The voltage waveform data created by the user is associated with the invocation button  52  that is named “User.” 
     The second memory  44  stores the drive waveform data that was sent to the drive unit  30  most recently (hereinafter referred to as the previous waveform data) and edit waveform data, which will be described below. 
     The third memory  45  stores programs that cause the waveform editing device  40  and the drive unit  30  to execute the processes of steps S 13  to S 13  and steps S 21  to S 24 . The waveform editing device  40  and the drive unit  30  execute the processes of steps S 11  to S 13  and steps S 21  to S 24  in accordance with the programs. 
     The waveform editing section  46  creates edit waveform data corresponding to one cycle that is based on the previous waveform data sent to the drive unit  30 , and causes the second memory  44  to store the edit waveform data. The edit waveform data stored in the second memory  44  is changed through an operation performed by the user. At a specific point in time, the waveform editing section  46  sends the current edit waveform data to the drive unit  30  as drive waveform data and updates the previous drive waveform data stored in the second memory  44 . 
     The change determination section  47  refers to the comparison between the previous waveform data and the edit waveform data that are stored in the second memory  44  to determine whether the edit waveform data has been changed. 
     The condition changing section  48  sends, to the drive unit  30 , the driving condition that has been set through an operation performed by the user. 
     The image processor  49  creates an image that indicates a waveform corresponding to edit waveform data and displays the image on the first waveform editing screen  55  of the display  42 . The first waveform editing screen  55  displays a waveform that includes several anchor points P and Bezier curves. The anchor points P correspond to a start point, an end point, and inflection points of a waveform that corresponds to one cycle. Each of the Bezier curves connects adjacent ones of the anchor points P. The image processor  49  creates an image indicating a waveform in which the current driving condition is reflected on the previous drive waveform data stored in the second memory  44  and displays the image on the driving situation screen  56  of the display  42 . 
     Various types of the voltage waveform data in the present embodiment include, as parameters that define a waveform, information related to the coordinates of all the anchor points P of a waveform corresponding to one cycle, the Bezier curves that each connect adjacent ones of the anchor points P, the magnitude of an output, the magnitude of an offset voltage, and the maximum voltage. The anchor point P corresponding to the start point and the anchor point P corresponding to the end point have the same value. 
     Referring to  FIG. 7 , while the DEA  13  is driven, the waveform editing device  40  repeatedly executes the following processes of steps S 11  to S 13  in a cycle of several milliseconds to several tens of milliseconds. 
     In step S 11 , the change determination section  47  compares the previous waveform data with the edit waveform data stored in the second memory  44  to determine whether the previous waveform data is different from the current edit waveform data. The determination of the difference between the previous waveform data and the current edit waveform data is based on whether the parameters included in the previous waveform data all match the parameters included in the current edit waveform data. 
     When determining in step S 11  that the previous waveform data. is different from the current edit waveform data (YES), the waveform editing section  46  executes step S 12  to send the current edit waveform data to the drive unit  30  as the drive waveform data. Next, in step S 13 , the waveform editing section  46  updates the previous waveform data stored in the second memory  44  and then ends the process. When determining in step S 11  that the previous waveform data is not different from the current edit waveform data (NO), the change determination section  47  ends the process. 
     Referring to  FIG. 8 , while the DEA  13  is driven, the controller  32  of the drive unit  30  repeatedly executes the following processes of steps S 21  to S 24  in a cycle of several milliseconds to several tens of milliseconds. 
     In step S 21 , the controller  32  refers to the drive waveform data stored in the drive-side memory  31  and the driving condition received from the condition changing section  48  of the waveform editing device  40  to calculate a voltage Vn that should be applied next. Next, in step S 22 , the controller  32  applies the calculated voltage Vn to the DEA  13 . 
     Subsequently, in step S 23 , the controller  32  determines whether new drive waveform data has been received from the waveform editing section  46  of the waveform editing device  40 . When determining in step S 23  that new drive waveform data has been received (YES), the controller  32  executes step S 24  to update the drive waveform data stored in the drive-side memory  31  to the received new drive waveform data. Then, the controller  32  ends the process. When determining in step S 23  that new drive waveform data has not been received (NO), the controller  32  ends the process. 
     Description will now be made for a method in which the pulsation generating apparatus of the present embodiment is used to generate a voltage waveform that operates the DEA  13  so as to present a particular tactile sense. The following description provides an example in which registered voltage waveform data corresponding to a normal pulse is edited to generate a voltage waveform that operates the DEA  13  so as to present a tactile sense that is closer to the pulsation pattern of a normal pulse felt by a skilled person during actual palpation. 
     First, a preparatory step is executed to drive the DEA  13  so as to operate the dummy  10  in a pulsation pattern that is based on registered voltage waveform data corresponding to a normal pulse. 
     More specifically, in a state in which the output button  51  is turned off, that is, when voltage is not applied to the DEA  13  from the drive unit  30  and the DEA  13  is deactivated, the pointing device  41  is operated to click the invocation button  52  corresponding to a normal pulse. In the waveform editing device  40 , this operation causes the registered voltage waveform data corresponding to a normal pulse to be sent to the drive unit  30  as drive waveform data and updates the previous waveform data stored in the second memory  44 . In the drive unit  30 , the drive waveform data stored in the drive-side memory  31  is updated using the drive waveform data sent from the waveform editing device  40 . 
     The waveform editing section  46  of the waveform editing device  40  creates new edit waveform data in which the registered voltage waveform data corresponding to a normal pulse is duplicated and updates the edit waveform data stored in the second memory  44 . The image processor  49  creates an image that indicates a waveform corresponding to the edit waveform data and displays the image on the first waveform editing screen  55  of the display  42 . The position of each slider displayed on the second waveform editing screen  57  is adjusted to the value of the registered voltage waveform data corresponding to a normal pulse. 
     Then, after the pointing device  41  is operated to turn the output button  51  on, the processes shown in  FIG. 8  are repeatedly executed in the drive unit  30 . This causes the voltage that changes in correspondence with the drive waveform data stored in the drive-side memory  31  (i.e., the registered voltage waveform data corresponding to a normal pulse) to be applied to the DEA  13  so as to operate the DEA  13 . Further, the processes shown in  FIG. 7  are repeatedly executed in the waveform editing device  40 . 
     Next, an editing step is executed to edit a waveform. In the editing step, the user is a skilled person at palpation. In the editing step, the user uses one hand to touch the dummy  10  so as to experience the pulsation presented from the dummy  10  in correspondence with the operation of the DEA  13  while the user uses the other hand to operate the pointing device  41  so as to edit the edit waveform data. 
     Referring to  FIG. 6 , the user changes the waveform displayed on the first waveform editing screen  55  by moving the anchor points P onto the image of the waveform displayed on the first waveform editing screen  55  and by adding or deleting the anchor points P. The anchor points P are moved through a general operation using a pointing device, for example, by moving a pointer  59  displayed on the first waveform editing screen  55  onto a target anchor point P (i.e., performing drag and drop) or by operating an arrow key on the keyboard with the target anchor point P selected. The sections between the anchor points P are automatically complemented by the Bezier curves. Further, the user operates the pointing device  41  to change the position of each slider displayed on the second waveform editing screen  57 . For example, to return to the registered voltage waveform data corresponding to a normal pulse or to use another registered voltage waveform data as a basis, the invocation button  52  corresponding to target registered voltage waveform data is clicked so as to change the waveform displayed on the first waveform editing screen  55 . 
     When the user performs an operation to change the displayed contents of the first waveform editing screen  55  and the second waveform editing screen  57 , the waveform editing section  46  changes the edit waveform data stored in the second memory  44  to edit waveform data that is based on the displayed contents of the first waveform editing screen  55  and the second waveform editing screen  57 . 
     As shown in the flowchart of  FIG. 7 , while the DEA  13  is driven, the waveform editing device  40  performs step S 11  to regularly execute the process that determines whether the previous waveform data stored in the second memory  44  is different from the edit waveform data. Thus, when the edit waveform data is changed, the previous waveform data is determined as being different from the current edit waveform data in step S 11  of the current or next cycle. Then, in step S 12 , the current edit waveform data is sent to the drive unit  30  as the drive waveform data. 
     As shown in the flowchart of  FIG. 8 , while the DEA  13  is driven, the drive unit  30  performs step S 23  to regularly execute the process that determines whether new drive waveform data has been received from the waveform editing section  46 . Thus, after new drive waveform data is received, the new drive waveform data is determined as having been received in step S 23  of the current or next cycle. In step S 24 , the drive waveform data stored in the drive-side memory  31  is updated to the received new drive waveform data. Then, in steps S 21  and S 22  of the next cycle or the cycle after the next, the received new drive waveform data is used to calculate the voltage Vn that should be applied next and apply the calculated voltage Vn to the DEA  13 . This changes the operation of the DEA  13  to an operation that is based on the received new drive waveform data (i.e., the edit waveform data that has been edited by the user). 
     The processes shown in  FIGS. 7 and 8  are repeatedly executed in a cycle of several milliseconds to several tens of milliseconds. Thus, immediately after the user performs an operation to change the displayed contents of the first waveform editing screen  55  and the second waveform editing screen  57 , the operation of the DEA  13  is changed to an operation based on the changed edit waveform data. This changes the vibration pattern transmitted to the hand of the user that touches the dummy  10 . 
     As shown in the flowchart of  FIG. 7 , after the current edit waveform data is sent to the drive unit  30  as the drive waveform data in step S 12 , the previous waveform data stored in the second memory  44  is updated in step S 13 . Then, in step S 11  of the next cycle, the determination based on the updated previous waveform data is executed. 
     For the vibration pattern of the pulsation transmitted from the dummy  10  to one hand of the user to become close to the pulsation pattern of a normal pulse based on his or her experience, the user operates the other hand to operate the pointing device  41  so as to change the displayed contents of the first waveform editing screen  55  and the second waveform editing screen  57  and edit the edit waveform data. This changes the vibration pattern of the pulsation transmitted from the dummy  10  every time the edit waveform data is edited. When the vibration pattern transmitted from the dummy  10  matches the vibration pattern of the normal pulse based on his or her experience, the user clicks the save button  53  to update the registered voltage waveform data corresponding to a normal pulse to the current edit waveform data or register the current edit waveform data as new voltage waveform data created by the user. This provides a voltage waveform that operates the DEA  13  so as to present a tactile sense that is closer to the pulsation pattern of a normal pulse felt by a skilled person during actual palpation. 
     The advantages of the present embodiment will now be described. 
     (1) The pulsation generating apparatus includes the DEA  13 , the drive unit  30 , and the waveform editing section  46 . The DEA  13  includes two electrodes. The drive unit  30  is configured to drive the DEA  13  by repeatedly applying, to a section between the two electrodes, a voltage that changes in correspondence with the drive waveform data that indicates voltage changes corresponding to one cycle. The waveform editing section  46  is configured to change the edit waveform data in correspondence with an operation performed by the user. When the edit waveform data is changed during driving of the DEA  13 , the pulsation generating apparatus is configured to update the drive waveform data. such that the changed edit waveform data becomes new drive waveform data and drive the DEA  13  using the updated drive waveform data. 
     In the configuration, when the edit waveform data is changed during driving of the DEA  13 , the operation of the DEA  13  is switched to an operation that is based on the changed edit waveform data without performing an operation such as saving or sending the changed edit waveform data. This allows the user to smoothly search for a voltage waveform that produces a particular motion of the DEA  13  while editing the edit waveform data. As a result, the voltage waveform is generated efficiently. 
     (2) The pulsation generating apparatus includes the change determination section  47  configured to regularly determine whether the edit waveform data has been changed. The pulsation generating apparatus is configured to update the drive waveform data when the change determination section  47  determines that the edit waveform data has been changed. 
     The configuration reduces the frequency of updating the drive waveform data used to drive the DEA  13 . 
     (3) The pulsation generating apparatus includes the image processor  49  configured to cause the display  42  to display an image that corresponds to the edit waveform data. The waveform editing section  46  is configured to change the edit waveform data in correspondence with the user&#39;s operation that changes the image displayed on the display  42  using the pointing device  41 . 
     The configuration allows the user to edit a waveform intuitively. Thus, even a user who has a small amount of knowledge related to machine or information processing easily generates a voltage waveform that produces a particular motion of the DEA  13 . 
     (4) When an operation is performed to invoke registered voltage waveform data during driving of the DEA  13 , the edit waveform data is changed to the registered voltage waveform data. 
     The configuration easily changes the operation of the DEA  13  during driving to an operation that is based on the registered voltage waveform data. 
     The present embodiment may he modified as follows. The present embodiment and the following modifications can be combined as long as they remain technically consistent with each other. 
     The parameters that define waveforms included in various types of voltage waveform data are not limited to the parameters of the above-described embodiment. For example, some of the parameters of the above-described embodiment may be omitted. Alternatively, another parameter may be added. 
     The processes of steps S 23  and S 24  in the processes shown in the flowchart of  FIG. 8 , that is, the processes that determine whether new drive waveform data has been received from the waveform editing section  46  and update the drive waveform data in a case where the new drive waveform data has been received, do not have to be executed every time. In other words, the frequency and the point in time at which the processes of steps S 23  and S 24  may be changed. For example, the processes of steps S 23  and S 24  are executed at a specific point in time that is the end of changes in voltage corresponding to one cycle based on the drive waveform data, and the processes of steps S 23  and S 24  are not executed at other points in time. in this case, the processes of steps S 23  and S 24  are executed only one time while the voltage corresponding to one cycle based on the drive waveform data is changing. 
     The change determination section  47  may be omitted. In this case, the process of step S 11  in the flowchart of  FIG. 7  is omitted so that the processes of steps S 12  and S 13  are executed every time, and the process of step S 23  in the flowchart of  FIG. 8  is omitted so that the process of S 24  is executed every time. 
     The pointing device  41  and the display  42  may be external devices that are prepared separately from the actuator device of the present disclosure. 
     The number of the DEAs  13  arranged in the dummy  10  is not particularly limited. 
     The DEAs  13  may be replaced with other electroactive polymer actuators (EPA) such as ionic polymer metal composites (IPMC). 
     The actuator device of the present disclosure may be employed as a tactile sense presentation device other than the pulsation generating apparatus that causes the user to recognize, as a tactile sense, an operation such as vibration generated in correspondence with applied voltage. The actuator device of the present disclosure can be employed not only in the tactile sense presentation device but also in most types of devices that change applied voltage so as to produce a particular motion in electroactive polymer actuator. 
     Some or all of the electroactive polymer actuator such as the DEA  13 , the drive unit  30 , and the waveform editing device  40 , which form the actuator device, may be integrally formed. For example, the electroactive polymer actuator may be formed integrally with the drive unit  30 . Alternatively, the drive unit  30  may be formed integrally with the waveform editing device  40 . Instead, the electroactive polymer actuator, the drive unit  30 , and the waveform editing device  40  may be integrally formed. 
     The programs that cause the actuator device to execute the processes of steps S 11  to S 13  and steps S 21  to S 24  may be stored in a memory device incorporated in the actuator device or may be stored in an external memory device such as removable media. The programs may be stored in a WEB server and executed in the WEB server. 
     DESCRIPTION OF THE REFERENCE NUMERALS 
     P) Anchor Point;  10 ) Dummy;  13 ) Dielectric Elastomer Actuator (DEA);  30 ) Drive Unit;  31 ) Drive-side Memory;  32 ) Controller;  40 ) Waveform Editing Device;  41 ) Pointing Device;  42 ) Display;  43 ) First Memory;  44 ) Second Memory;  45 ) Third Memory;  46 ) Waveform Editing Section;  47 ) Change Determination Section;  48 ) Condition Changing Section;  49 ) Image Processor;  55 ) First Waveform Editing Screen;  56 ) Second Waveform Editing Screen