Hybrid actuator

Abstract

The present invention relates to a hybrid actuator which induces an operation of a target body part through electrical stimulation and enables a posture of a corresponding body part to be maintained using electrostatic force and tension. The hybrid actuator includes: a first frame fixed to a target body part; a second frame fixed to a body part different from the target body part; a stimulator which generates an electrical stimulation signal for stimulating muscles moving the target body part during a predetermined time; an electrostatic clutch which includes a first electrode and a second electrode and applies static electricity after the electrical stimulation signal is generated, to generate an electrostatic force between the first electrode and the second electrode; a first tension part which connects the first electrode and the first frame and enables a posture of the target body part to be maintained through tension; and a second tension part which connects the first electrode and the second frame and applies tension to the first electrode.

Description

Hybrid actuator

[0001] The present invention relates to an actuator structure for causing a movement of a specific body part and maintaining a posture after the movement is performed.

[0002] The number of patients with motor neuron disorders continues to increase due to congenital, genetic, and accidental injuries, falls and functional decline in the elderly, spinal cord injuries, cerebrovascular diseases, and strokes. The number of patients with motor neuron disorders in Korea increased from 1.8 million in 2004 to 3.4 million in 2020, and the number of patients with complete paralysis in Korea reached 458,000 in 2020.

[0003] According to research results from the University of Irvine in the United States (study by Kim D. Anderson), the physical function that quadriplegic patients most want restored is the ability to move their hands and arms.

[0004] Therefore, it is urgent to develop motor assistive devices or rehabilitation equipment that can help patients with motor neuron disorders or complete paralysis move their hands or arms according to their intentions or assist their movements.

[0005] However, conventional exercise assist devices and rehabilitation equipment lack portability, such as requiring a stationary robotic arm, or are limited to hospitals, so there is a need to develop exercise assist devices and rehabilitation equipment that are easy to carry and can be used indoors and outdoors.

[0006] In addition, in the above-described exercise assistive device or rehabilitation equipment, a function is required to recognize the patient's intention to move, precisely control the movement, and maintain the posture of the arm or hand for a certain period of time after the control.

[0007] The purpose of the present invention is to provide a hybrid actuator using electrostatic force and a loop, which maintains the posture of an arm or hand of a wearer of a motion assist device or rehabilitation device by utilizing the electrostatic effect, frictional force, and loop tension that appear when a high voltage is applied between two electrodes.

[0008] The purpose of the present invention is not limited to the purposes mentioned above, and other purposes not mentioned will be clearly understood by those skilled in the art from the description below.

[0009] According to one embodiment of the present invention, a hybrid actuator comprises: a first frame fixed to a target body part; a second frame fixed to a body part different from the target body part; a stimulator generating an electrical stimulation signal for stimulating a muscle moving the target body part for a predetermined period of time; an electrostatic clutch including a first electrode and a second electrode facing the first electrode, and applying static electricity for a predetermined period of time after generation of the electrical stimulation signal to generate an electrostatic force between the first electrode and the second electrode; a first tensile member connecting the first electrode and the first frame and maintaining a posture of the target body part through tension between the first electrode and the first frame; and a second tensile member connecting the first electrode and the second frame and applying tension to the first electrode.

[0010] In one embodiment of the present invention, the second electrode is characterized in that it is composed of a conductive fiber.

[0011] In one embodiment of the present invention, the second electrode corresponds to a part of clothing worn by the user.

[0012] In one embodiment of the present invention, the second tensile member includes a strain sensor.

[0013] In one embodiment of the present invention, the second tensile member measures the horizontal position of the first electrode with respect to the second electrode.

[0014] In one embodiment of the present invention, the electrostatic clutch changes the charge amount of the electrostatic electricity depending on the horizontal position of the first electrode with respect to the second electrode.

[0015] In one embodiment of the present invention, the hybrid actuator further includes a restoration unit that restores the target body part to a posture prior to the generation of the electrical stimulation signal when the application of the static electricity is released.

[0016] In one embodiment of the present invention, the first frame, the second frame, and the second electrode are characterized in that they are fixed to clothing worn by a user of the hybrid actuator.

[0017]

[0018] A method of operating a hybrid actuator according to one embodiment of the present invention includes: a step in which the hybrid actuator applies an electric stimulation signal to a muscle of a target body part to move the target body part; a step in which the hybrid actuator maintains a posture of the target body part using an electrostatic force and a tension; and a step in which the hybrid actuator releases the electrostatic force and reduces the tension to restore the posture of the target body part to a state prior to applying the electric stimulation signal.

[0019] In one embodiment of the present invention, the step of maintaining the posture includes a step of the hybrid actuator generating the electrostatic force using an electrostatic clutch including a first electrode and a second electrode opposite to the first electrode.

[0020] In one embodiment of the present invention, the step of maintaining the posture includes the step of applying tension to the target body part by using the hybrid actuator, a first tensile member connecting the first frame fixed to the target body part and the electrostatic clutch, and a second tensile member connecting the electrostatic clutch and a second frame fixed to a body part other than the target body part.

[0021] In one embodiment of the present invention, the second tensile member includes a strain sensor.

[0022] According to one embodiment of the present invention, the motion of the arm or hand of the wearer of the assistive device is controlled through muscle stimulation, and then the posture and shape of the corresponding part of the wearer are maintained using electrostatic force and a loop, thereby effectively operating the motion assistance function of the wearer.

[0023] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0024] Fig. 1 is a block diagram showing the configuration of a hybrid actuator according to one embodiment of the present invention.

[0025] FIG. 2 is a drawing showing the configuration of a hybrid actuator according to one embodiment of the present invention.

[0026] FIG. 3 is a reference diagram showing an example of controlling hand movements using a hybrid actuator according to the present invention.

[0027] Fig. 4 is a reference diagram showing an example of controlling the movement of an arm using a hybrid actuator according to the present invention.

[0028] Figure 5 is a block diagram showing a detailed configuration of a hybrid actuator according to one embodiment of the present invention.

[0029] Figure 6 is a flowchart for explaining an operating method of a hybrid actuator according to one embodiment of the present invention.

[0030] The advantages and features of the present invention, and the methods for achieving them, will become clear with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Meanwhile, the terminology used in this specification is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated in the phrase. The terms "comprises" and / or "comprising" as used in the specification do not exclude the presence or addition of one or more other components, steps, operations, and / or elements mentioned.

[0031] While terms like "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms may be used to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0032]

[0033] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components in between. Conversely, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "directly between" or "adjacent to" and "directly adjacent to", should be interpreted similarly.

[0034] In describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description is omitted.

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In order to facilitate an overall understanding in describing the present invention, the same reference numbers will be used for the same means regardless of the drawing numbers.

[0036]

[0037] Fig. 1 is a block diagram showing the configuration of a hybrid actuator according to one embodiment of the present invention.

[0038] A hybrid actuator (100) according to one embodiment of the present invention induces movement of a target body part through electrical stimulation and maintains the posture of the body part using electrostatic force and loop tension.

[0039]

[0040] A hybrid actuator (100) according to one embodiment of the present invention includes a first frame (110), a second frame (120), a stimulator (130), an electrostatic clutch (140), a first tensile part (150), a second tensile part (160), and a control part (170), and may further include a restoration part (180).

[0041] The first frame (110) is fixed to a body part (hereinafter, abbreviated as "target body part") that is the target of the operation and posture maintenance of the hybrid actuator (100). Specifically, the first frame (110) is fixed to the skin or clothing of the target body part. Since the first frame (110) is fixed to the target body part, it is possible to maintain the posture of the target body part by applying tension to the target body part through the first tensile member (150) connected to the first frame (110).

[0042] The second frame (120) is fixed to a body part (skin or clothing) different from the target body part. The second frame (120) serves to secure the hybrid actuator (100) to a specific part of the wearer's body and prevent it from shaking. Therefore, the hybrid actuator (100) can accurately operate the target body part and stably maintain the posture of the target body part.

[0043] The stimulator (130) includes a muscle stimulation electrode (131), and generates an electrical stimulation signal for stimulating a muscle that moves a target body part through the muscle stimulation electrode (131) according to a control command of the control unit (170) for a predetermined period of time, thereby causing the target body part to perform a specific movement. That is, the stimulator (130) causes the target body part to perform a specific movement by stimulating muscle nerves by applying current to the skin through the muscle stimulation electrode (131), thereby causing the muscle to contract. The number of muscle stimulation electrodes (131) included in the stimulator (130) may be plural (in case of n, they are indicated as 131-1, 131-2, ..., 131-n). For example, the stimulator (130) applies an electrical stimulation signal (current) to an arm part through the muscle stimulation electrode (131) to contract the flexor muscles, thereby causing a specific finger to bend.

[0044] The electrostatic clutch (140) includes a first electrode (141) and a second electrode (142). The first electrode (141) faces the second electrode (142). After the stimulator (130) generates an electrical stimulation signal, the electrostatic clutch (140) applies electrostatic electricity to the first electrode (141) and the second electrode (142) under the control of the control unit (180), thereby generating an electrostatic force between the two electrodes. The second electrode (142) may be made of conductive fiber and may be fixed to clothing worn by a user or may be a part of clothing worn by the user.

[0045] The first tensile member (150) connects the first frame (110) and the first electrode (141), and applies tension to the first frame (110) to maintain the posture of the target body part. For example, the first tensile member (150) may be any one of various elastic materials having tension, such as a loop, wire, spring, rubber band, or flexible ribbon.

[0046] The second tensile member (160) connects the second frame (120) and the first electrode (141), and applies tension to the first electrode (141) so that the area of ​​the first electrode (141) facing the second electrode (142) becomes greater than or equal to a reference value. Therefore, the second tensile member (160) plays a role in supporting the maintenance of the electrostatic force between the first electrode (141) and the second electrode (142) when the posture of the target body part must be maintained. The second tensile member (160), like the first tensile member (150), may also be any one of elastic materials having tension.

[0047] In particular, the second tensile member (160) may include a strain sensor. In this case, the strain sensor functions to apply tension to the first electrode (141) and to measure the position. That is, when the second tensile member (160) includes a strain sensor, in addition to the function of applying tension to the first electrode (141), the second tensile member (160) measures the distance between the second frame (120) and the first electrode (141), in other words, the horizontal position of the first electrode (141) with respect to the second electrode (142), and transmits the measured result to the control unit (170). The control unit (170) controls the amount of electrostatic charge applied to the electrostatic clutch (140) according to the horizontal position of the first electrode (141) with respect to the second electrode (142), so that the tension required to maintain the posture of the target body part is maintained. That is, the electrostatic clutch (140) has a characteristic in which the amount of electrostatic charge changes depending on the horizontal position of the first electrode (141).

[0048] As another example, the first tensile member (150) or the second tensile member (160) may be a shape memory alloy (e.g., a nickel-titanium alloy). In this case, the control unit (170) may apply electricity to the shape memory alloy to increase its temperature, thereby causing the shape memory alloy to contract. When a shape memory alloy is introduced into the first tensile member (150) or the second tensile member (160), the stimulator (130) may be omitted from the hybrid actuator (100).

[0049] The control unit (170) controls the stimulator (130) and the electrostatic clutch (140) according to a signal received from an external device. The control unit (170) transmits a control command to the stimulator (130) so that the stimulator (130) generates an electric stimulation signal for a predetermined period of time, and controls the electrostatic clutch (140) after the generation of the electric stimulation signal so that an electrostatic force is generated between the first electrode (141) and the second electrode (142) for a predetermined period of time so that the posture of the target body part is maintained. For example, the control unit (170) includes a brain neural signal interface, receives a brain neural signal or a converted signal thereof, and transmits a control command to the stimulator (130) according to the received signal so that the stimulator (130) generates an electric stimulation signal for a predetermined period of time so that the finger, which is the target body part, can be bent.

[0050] The restoration unit (180) restores the target body part to the posture prior to the generation of the electric stimulation signal when the static electricity of the static clutch (140) is released. The restoration unit (180) connects the first frame (110) and the third frame (190) and applies tension to the first frame (110) so that the target body part restores to the posture prior to the generation of the electric stimulation signal. The restoration unit (180) may be any one of various elastic materials having tension, such as a loop, a wire, a spring, a rubber band, or a flexible ribbon. The third frame (190) is fixed to a specific part of the body or clothing. The third frame (190) is arranged so as to apply tension to the first frame (110) in the opposite direction to the direction of tension between the first frame (110) and the first electrode (141).

[0051] Meanwhile, the specific forms of the first frame (110), the second frame (120), and the third frame (190) may vary. For example, when the target body part is a finger, the first frame (110) may be a thimble worn by the user on the tip of the finger, the second frame (120) may be a fixing device included in an exoskeleton or wearable suit worn by the user, and the third frame (130) may be a fixing device mounted on a glove worn by the user.

[0052]

[0053] FIG. 2 is a diagram showing the configuration of a hybrid actuator according to one embodiment of the present invention. As shown in FIG. 2, a first frame (110) and a first electrode (141) are connected by a first tensile member (150), and the first electrode (141) is connected by a second frame (120) and a second tensile member (160). The second tensile member (160) may be a strain sensor or include a strain sensor. The first electrode (141) faces the second electrode (142) and is preferably parallel to it. In FIG. 2, the second electrode (142) is made of a conductive fiber material and is fixed to clothing (51). When the posture of a target body part must be maintained, it is preferable that the first electrode (141) have an area facing the second electrode (142) as large as possible. The control unit (170) controls the amount of electrostatic charge between the first electrode (141) and the second electrode (142) based on the measured position of the first electrode (141) so that the tension of the first tension member (150) is maintained constant.

[0054]

[0055] Fig. 3 is a reference diagram illustrating an example of controlling hand movements using a hybrid actuator according to the present invention. In Fig. 3, the body part controlled by the hybrid actuator (100) is a finger, and the first frame (110) is fixed to the tip of the finger.

[0056] The first tensile member (150) connects the first frame (110) and the first electrode (141), and a specific point of the first tensile member (150) is fixed to a fixture worn by the user. For example, the first tensile member (150) connects the first frame (110) and the first electrode (141) by penetrating a hole in a glove worn by the user. The hole serves to prevent the middle point of the first tensile member (150) from deviating from the user's body by a certain range.

[0057] In order to bend the user's fingers according to the user's intention (e.g., brain nerve signals), the control unit (170) applies an electrical stimulation signal to the flexor muscle (digitorum flexor) through the stimulator (130) attached to the user's forearm. In addition, the control unit (170) controls the electrostatic clutch (140) to generate an electrostatic force between the first electrode (141) and the second electrode (142). Since the stimulator (130) cannot continuously generate the electrical stimulation signal due to factors such as the user's safety, fatigue, and battery capacity, the posture of the target body part is maintained through the tension of the first tensile unit (150) and the second tensile unit (160) and the electrostatic force of the electrostatic clutch (140).

[0058] The restoration unit (180) connects the first frame (110) and the third frame (190), and when the tension between the first electrode (141) and the first frame (110) is relieved by the release of the electrostatic force, tension is applied in the opposite direction so that the target body part, the finger, is restored to the position before the electrical stimulation signal was generated.

[0059]

[0060] FIG. 4 is a reference diagram illustrating an example of controlling arm motion using a hybrid actuator according to the present invention. Unlike FIG. 3, where the first frame (110) is positioned at the fingertips, the first frame (110) illustrated in FIG. 4 is positioned on the forearm to control arm motion. The second frame (120) is positioned closer to the hand. In this way, the hybrid actuator (100) can vary the positions of its components depending on the target body part to be controlled.

[0061]

[0062] Fig. 5 is a block diagram showing a detailed configuration of a hybrid actuator according to one embodiment of the present invention.

[0063] In the embodiment of FIG. 5, the control unit (170) includes an MCU (171) and a switch (172). The MCU (171) can receive signals from the outside through a separate communication module. The MCU (171) can generate a control command based on the external signal. The MCU (171) transmits the control command to the stimulator (130) so that the stimulator (130) generates an electric stimulation signal, and applies static electricity to the electrodes (141, 142) of the electrostatic clutch (140) through the switch (172) to generate an electrostatic force between the two electrodes (141, 142). In addition, the MCU (171) determines the relative position of the first electrode (141) with respect to the second electrode (142) based on the sensing signal transmitted by the strain sensor (160), and controls the amount of electrostatic charge applied to the electrostatic clutch (140) according to the determined position.

[0064]

[0065] Fig. 6 is a flowchart illustrating an operating method of a hybrid actuator according to one embodiment of the present invention. It is assumed that the operating method of the hybrid actuator is performed by a hybrid actuator (100).

[0066] As illustrated in FIG. 6, the operating method of a hybrid actuator according to one embodiment of the present invention includes steps S210 to S230.

[0067] Step S210 is a step for moving a target body part. The control unit (170) generates a control command based on a signal received from an external device and transmits it to the stimulator (130). The stimulator (130) includes a muscle stimulation electrode (131), and according to the control command of the control unit (170), generates an electrical stimulation signal for stimulating the muscles that move the target body part through the muscle stimulation electrode (131) for a predetermined period of time, thereby causing the target body part to perform a specific movement.

[0068] Step S220 is a step for maintaining the posture of the target body part. After the electrical stimulation signal is generated, the electrostatic clutch (140) applies electrostatic electricity to the first electrode (141) and the second electrode (142) under the control of the control unit (170), thereby generating an electrostatic force between the two electrodes. In addition,

[0069] The second tensile member (160) is fixed to the second frame (120) and applies tension to the first electrode (141), and the first tensile member (150) connected to the first electrode (141) and the first frame (110) applies tension to the first frame (110) fixed to the target body part. The hybrid actuator (100) uses the electrostatic force generated from the electrostatic clutch (140) and the tension of the first tensile member (150) and the second tensile member (160) to maintain the posture of the target body part.

[0070] Step S230 is a step for restoring the posture of the target body part. After a predetermined time has elapsed, the static electricity of the electrostatic clutch (140) is released under the control of the control unit (170). As the static electricity is released, the restraint state of the first electrode (141) is released, and the tension of the first tensile part (150) and the second tensile part (160) is reduced. When the application of the static electricity of the electrostatic clutch (140) is released, the restoration unit (180) restores the target body part to the posture before the generation of the electric stimulation signal. The restoration unit (180), whose both ends are fixed to the first frame (110) and the third frame (190), applies tension to the first frame (110) so that the target body part is restored to the posture before the generation of the electric stimulation signal.

[0071]

[0072] Meanwhile, even if the content is omitted in the description referring to Fig. 6, the content described with reference to Figs. 1 to 5 may be applied to Fig. 6. And the content described with reference to Fig. 6 may be applied to Figs. 1 to 5.

[0073]

[0074] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. A first frame fixed to a target body part; A second frame fixed to a body part other than the above target body part; A stimulator that generates an electrical stimulation signal that stimulates a muscle that moves the target body part for a predetermined period of time; An electrostatic clutch comprising a first electrode and a second electrode facing the first electrode, and applying electrostatic electricity for a predetermined time after generation of the electrical stimulation signal to generate an electrostatic force between the first electrode and the second electrode; A first tensile member connecting the first electrode and the first frame and maintaining the posture of the target body part through tension between the first electrode and the first frame; and A second tensile member connecting the first electrode and the second frame and applying tension to the first electrode; A hybrid actuator comprising:

2. In paragraph 1, The second electrode is characterized in that it is composed of conductive fibers. In hybrid drive.

3. In paragraph 1, The above second electrode corresponds to a part of clothing worn by the user. In hybrid drive.

4. In the first paragraph, the second tensile member, Including a strain sensor In hybrid drive.

5. In the first paragraph, the second tensile member, Measuring the horizontal position of the first electrode based on the second electrode In hybrid drive.

6. In the first paragraph, the electrostatic clutch, The charge amount of the static electricity changes depending on the horizontal position of the first electrode relative to the second electrode. In hybrid drive.

7. In paragraph 1, A hybrid actuator further comprising a restoration unit that restores the target body part to the posture before the electrical stimulation signal is generated when the static electricity is removed.

8. In the first paragraph, the first frame, the second frame and the second electrode, characterized in that the hybrid actuator is fixed to the clothing worn by the user. Hybrid actuator.

9. A step in which a hybrid actuator applies an electrical stimulation signal to a muscle of a target body part to move the target body part; The step of the hybrid actuator maintaining the posture of the target body part by using electrostatic force and tension; and A step in which the hybrid actuator releases the electrostatic force and reduces the tension to restore the posture of the target body part to the state prior to applying the electrical stimulation signal; A method of operating a hybrid actuator comprising:

10. In the 9th paragraph, the step of maintaining the posture is: The hybrid actuator comprises a step of generating the electrostatic force by using an electrostatic clutch including a first electrode and a second electrode opposite to the first electrode. Method of operation of a hybrid actuator.

11. In the 10th paragraph, the step of maintaining the posture is: The hybrid actuator includes a step of applying tension to the target body part by using a first tensile member connecting the first frame fixed to the target body part and the electrostatic clutch, and a second tensile member connecting the electrostatic clutch and the second frame fixed to the target body part and another body part. Method of operation of a hybrid actuator.

12. In the 11th paragraph, the second tensile member, Including a strain sensor Method of operation of a hybrid actuator.

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