JP2008006558A - Power assist device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power assist device, easily attached and detached to and from an operator. <P>SOLUTION: This power assist device includes: a first sheathing part 46 to which an upper arm can be inserted;a second sheathing part 48 connected to the first sheathing part 46 through a joint part, to which a forearm can be inserted; a third sheathing part 50 connected to the second sheathing part 48 through a joint part, to which the hand can be inserted; a plurality of actuators 38a, 38b, 38c for turning the first sheathing part, the second sheathing part and the third sheathing part around the joint part; a plurality of sensors 52 provided on the inner wall surface of each sheathing part not to constrain the arm and hand; and a control part 78 for controlling the sheathing part 44 to follow up the movement of the arm or the hand when the sensor 52 detects that the arm or the hand of the operator is moved in the sheathing part 44. The respective sheathing parts 44 is formed U-shaped in section with one side opened, so that the arm and hand of the operator can be inserted and pulled out through the opening part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power assist device that can be attached to an operator to assist the movement following the movement of the operator, and a sensor that is used in the apparatus and detects the movement of the operator.

There is a power assist device as a device that is attached to an operator and assists the operation of the operator (see, for example, Patent Document 1).
The power assist device is being developed for use when a heavy burden is placed on the arms and legs, such as when a caregiver wakes up a bedridden caregiver or when loading or unloading luggage in a warehouse. Has been.

Since the power assist device assists the operation of the operator, it is necessary to provide a sensor for detecting the operation of the operator and to control the motor of the joint portion so as to follow the operation detected by the sensor. Come.
A bioelectric potential sensor, a pressure sensor, a strain gauge, or the like can be considered as a sensor for detecting the operation of the operator.
In the power assist device disclosed in Patent Document 1, a pressure sensor, an acceleration sensor, a speed sensor, a position sensor, or the like is used as a sensor.

JP 2004-105261 A

In many cases, a power assist device worn by an operator is very troublesome to attach to and remove from the operator. In particular, when a biopotential sensor or a pressure sensor is used as the sensor, the sensor needs to be restrained by the operator.
However, if the operator restrains the sensor, if the power assist device is likely to fall out of balance and fall, the operator cannot be instantly escaped from the power assist device and there is a risk of being involved in a fall There is.
In addition, there is a problem that it takes time and effort to attach and detach the operator to and from the power assist device even during normal times when there is no risk of falling.

  Accordingly, the present invention is made to solve the above-described problems, and an object thereof is to provide a power assist device that can be easily attached to and detached from an operator.

  According to the power assist device of the present invention, in the power assist device that operates to follow the movement of the operator and assists the movement of the operator, a base provided with freely rotating wheels, and a base A leg portion projecting upward from the upper end of the leg portion, a first exterior portion that is pivotally connected to the upper end of the leg portion via a joint portion, and an operator's upper arm can be inserted; A second exterior portion that is rotatably connected to the other end side of the exterior portion through a joint portion, and into which an operator's forearm can be inserted, and one end side is connected to the other end side of the second exterior portion and the joint portion A third exterior part that is pivotally connected to each other and can be inserted by an operator's hand, and is provided at each joint part, and includes a first exterior part, a second exterior part, and a third exterior part. A plurality of actuators, each of which rotates around the joint, and the arm wall of the operator on the inner wall of each exterior part. Multiple sensors that detect movement of the operator's arm and hand within the exterior, and one of the sensors detects that the operator's arm or hand has moved within the exterior. A control unit that controls each actuator so that any one of the exterior parts provided with the corresponding sensor is moved following the movement of the arm or the hand, It is formed in a U-shaped cross section having an opening on the side, and is characterized in that it is formed so that the operator's arm and hand can be inserted and extracted from the opening.

The effect | action by employ | adopting this structure is as follows.
The sensor in the power assist device does not restrain the operator, and the exterior part is formed in a U shape with an opening on one side, so when wearing the power assist device, the arm and hand are placed inside the exterior part from the opening side of the exterior part. It can be installed simply by inserting it into When the sensor detects the movement of the operator's arm or hand inserted into the exterior part, the control unit controls the exterior part to move following the movement of the arm or hand. When removing the power assist device, simply remove the arm from the opening side of the exterior to complete the removal. For this reason, when there is a risk of falling, it can be removed instantly, and the risk of the operator can be reduced. Moreover, since it becomes easy to attach or detach as described above, the power assist device can be easily used.

Further, at least two legs are provided, and the first exterior part, the second exterior part, and the third exterior part are each paired so as to correspond to both the left and right arms of the operator. It may be characterized by being provided.
Thereby, the operator's arms and hands can be assisted.

Further, each of the exterior portions corresponding to the right arm and the right hand of the operator and each of the exterior portions corresponding to the left arm and the left hand of the operator are such that the openings face each other and face the inside of the operator's body. It may be characterized by being arranged.
By adopting this configuration, in order for the operator to pull out both arms and both hands from the exterior when falling, it is only necessary to shrink the arms and hands to the inside of the body, and from the power assist device instantly. It can be withdrawn, and danger avoidance can be reliably performed.

  According to the power assist device of the present invention, it is very easy to attach and detach, and since it is possible to instantly perform the removal when it is likely to fall, the risk of the operator can be reduced.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments according to the invention will be described with reference to the accompanying drawings.
The power assist device 30 of the present embodiment is used for the purpose of carrying heavy objects by hand in a warehouse or the like, and follows the movement of the arm and hand with respect to the arm portion and hand ahead of the operator's shoulder. However, instead of the arm and hand of the operator, the load on the arm and hand is borne by a heavy object.

First, the overall configuration of the power assist device 30 will be described.
The power assist device 30 includes a base 32, arm portions 34, and leg portions 35 for attaching and supporting the arm portions 34 to the base 32.
In the power assist device 30 of the present embodiment, a plurality of actuators 38a, 38b, and 38c are attached so that each of the plurality of exterior portions 46, 48, and 50 constituting the arm portion 34 can be rotated. By rotating each other, the movement of the mounted operator's shoulder, elbow and wrist is followed.

  The base 32 is provided with freely rotating wheels 39, 39,... So that the arm portion 34 can be moved to a predetermined position. The base 32 moves on the ground along with the movement of the operator's foot.

The base 32 is formed in a U shape with an opening at the rear when viewed in a plan view. The base 32 is configured by connecting three members of a front part 32a, a right part 32b, and a left part 32c, and the above-described wheels 39, 39,.
The operator enters the inside of the base 32 from the position where the rear is opened, and wears the operator's arm on the arm portion 34.

Leg portions 35 and 35 for supporting the arm portion 34 on the base 32 are provided on the right portion 32b and the left portion 32c of the base 32 so as to protrude upward.
Each leg portion 35 is a rod-like member as a whole, and is configured by connecting two upper leg portions 35a and lower leg portions 35b via hinges 40 so that they can be bent in the middle. The hinge 40 is provided so as to have a frictional force that rotates only when a certain force or more is applied to the upper leg 35a and the lower leg 35b in the direction in which the hinge 40 is rotated. The upper leg portion 35a and the lower leg portion 35b are held so as not to rotate.

  Moreover, the lower end part of each lower leg part 35b is attached to the right part 32b and the left part 32c of the base 32 via the hinge 42 so that it can be bent with respect to the base 32. The hinge 42 is provided so as to have a frictional force that rotates only when a certain force or more is applied to the lower leg 35b in the direction in which the hinge 42 is rotated. In normal times, the lower leg 35b is based on the lower leg 35b. The base 32 is held so as not to rotate.

Next, the arm part 34 will be described.
The arm portions 34 are provided on the left and right sides for the right hand and the left hand, respectively, and the rear end portions of the arm portions 34 are rotatably connected to the upper leg portions 35a by actuators 38a provided at the upper end portions of the leg portions 35. ing.
The arm portion 34 is provided so as to be worn on the arm and hand ahead of the operator's shoulder. A portion where the rear end portion of the arm portion 34 is connected to the upper end portion of the upper leg portion 35a corresponds to the position of the operator's shoulder.

The arm part 34 has an exterior part 44 that covers the surface of the operator. The exterior portion 44 is formed so as to cover the surface of the operator's arm from three directions so that a thin plate made of metal or synthetic resin has a U-shaped cross section.
The exterior portions 44 of the left and right arm portions 34 are provided so as to open inside the arms (on the body side of the operator), and the operator simply inserts the arms and hands into the exterior portion 44 from the inside. Thus, the power assist device 30 can be mounted. After the operator's arm and hand are inserted into the arm portion 34, the arm and hand are not restrained by the exterior portion 44, and can be detached from the arm portion 34 simply by extracting the arm from the opening side.

The exterior portion 44 of the arm portion 34 includes an upper arm portion 46 that covers from the shoulder to the elbow of the operator, a forearm portion 48 that covers from the elbow to the wrist, and a hand portion 50 that covers from the wrist to the fingertip. The upper arm portion 46 and the forearm portion 48 are rotatably connected by an actuator 38b, and the forearm portion 48 and the hand portion 50 are rotatably connected by an actuator 38c.
In the present embodiment, the arm portion 34 is arranged such that the elbow joint and wrist of the operator bend upward. Therefore, when the operator wears the arm portion 34 on his / her arm, the arm and hand are caused to enter the exterior portion 44 so that the inside of the upper arm and the forearm and the palm of the user face upward. As described above, it is assumed that the arm portion 34 of the present embodiment is mainly used when a heavy object is supported and carried by the inner surface of the operator's forearm portion and the palm.

  The upper arm 46 includes an upper surface 46a that covers the inner side of the operator's upper arm (the elbow joint facing upward when worn) and the outer side of the operator's upper arm (the elbow joint facing downward when worn) It comprises a lower surface portion 46b that covers the outside of the wrist) and a side surface portion 46c that connects the upper surface portion 46a and the lower surface portion 46b to cover the side surface of the upper arm of the operator, and the upper surface portion 46a and the lower surface portion 46b are in contact with each other. It is formed in a U-shaped cross section so that it does not.

  The forearm portion 48 includes an upper surface portion 48a that covers the inside of the operator's forearm (the elbow joint facing upward when worn) and the outside of the operator's forearm (the elbow joint facing downward when worn) A lower surface portion 48b covering the outer side of the wrist), and a side surface portion 48c that connects the upper surface portion 48a and the lower surface portion 48b to cover the side surface of the operator's forearm, and the upper surface portion 48a and the lower surface portion 48b are in contact with each other. It is formed in a U-shaped cross section so that it does not.

  The hand portion 50 includes an upper surface portion 50a that covers the palm of the operator, a lower surface portion 50b that covers the back of the operator's hand, and a side surface portion 50c that covers the side surface of the operator's hand by connecting the upper surface portion 50a and the lower surface portion 50b. The upper surface portion 50a and the lower surface portion 50b are in contact with each other at their tips, and are formed in a U-shaped cross section.

A rotation shaft (not shown) of the actuator 38a is attached to one end side (rear end side) of the side surface portion 46c of the upper arm portion 46, and the housing of the actuator 38a is attached to the upper end portion of the upper leg portion 35a. It has been. For this reason, when the rotation shaft of the actuator 38a is driven, the upper arm portion 46 rotates with respect to the upper leg portion 35a.
The housing of the actuator 38 b is attached to the other end side (tip side) of the side surface portion 46 c of the upper arm portion 46, and the rotation shaft (not shown) of the actuator 38 b is the side surface portion of the forearm portion 48. It is attached to the rear end of 48c. For this reason, when the rotation shaft of the actuator 38 b is driven, the forearm portion 48 rotates with respect to the upper arm portion 46.
The housing of the actuator 38c is attached to the tip of the side surface portion 48c of the forearm portion 48, and the rotation shaft (not shown) of the actuator 38c is attached to the rear end portion of the side surface portion 50c of the hand portion 50. It has been. For this reason, when the rotation shaft of the actuator 38 c is driven, the hand portion 50 rotates with respect to the forearm portion 48.

A plurality of press detection sensors 52 (hereinafter sometimes simply referred to as sensors) for detecting the movement of the operator are provided on the inner wall surfaces of the exterior portions 46, 48, and 50 of the arm portion 34. The sensor 52 is provided inside the exterior portion 44 of the arm portion 34, and is deformed in the pressing direction when the operator's arm or hand contacts and presses.
The sensor 52 detects a change in distance due to deformation when the operator's arm or hand is pressed and deformed.

As described above, in the power assist device 30 of the present embodiment, the inner wall surface of the exterior portion 44 does not need to be in contact with the operator, but rather is not in contact with the operator when the operator is not moving. It is possible to make contact between the operator and the inner wall surface (sensor 52) of the exterior portion 44 for the first time when is operated.
Thus, since the exterior portion 44 has a U-shaped cross section and the sensor 52 is normally configured to be non-contact with the operator, the power assist device 30 does not restrain the operator and can be easily attached and detached. It is. Further, since the power assist device 30 does not restrain the operator, if there is a risk of falling, the operator can immediately pull out his arm from the opening side of the exterior portion 44, and the operator can It is not necessary to be involved in the fall of the device 30.

Moreover, the opening side of the exterior part 44 in the left and right arms 34, 34 is provided so as to face the inside of the operator's body. In other words, the openings of the exterior portions 44 of the arms 34 and 34 are arranged so as to face each other.
For this reason, in order for the operator to pull out both arms and both hands from the exterior portion 44 in the event of a fall or the like, it is only necessary to retract the arms and hands to the inside of the body, and the power assist device 30 can be detached instantaneously. .

Hereinafter, the sensor will be described with reference to FIGS.
The sensor 52 in the present embodiment is an optical sensor that detects an operator's movement by detecting a change in the optical path length.
The sensor 52 is formed in a substantially cubic shape, and a plate-like member provided on the side in contact with the operator is a pressing portion 54, and a plate-like member provided so as to face the pressing portion 54 is provided. Reference unit 55. And the connection part 56 is provided so that the press part 54 and the reference | standard part 55 may be connected, and the circumference | surroundings of the space between the press part 54 and the reference | standard part 55 may be enclosed.
The connecting portion 56 is formed by an elastic member that easily deforms when the operator's arm or hand abuts against and presses against the pressing portion 54 and returns immediately when no force is applied. Yes. The connecting portion 56 is preferably made of an elastic material such as rubber sponge.
On the other hand, the pressing portion 54 and the reference portion 55 are formed in a plate shape from a material such as a metal or a synthetic resin that is not easily deformed by the force that the operator contacts and presses.

The back side of the surface of the pressing portion 54 that contacts the operator, that is, the surface side of the pressing portion 54 that faces the reference portion 55 is formed on the reflecting surface 54a so that light is reflected.
The reference portion 55 is provided with a laser diode 58 that irradiates the reflecting surface 54a with laser light, and a photodetector 60 that receives the laser light reflected from the reflecting surface 54a. The laser diode 58 corresponds to the light emitting portion referred to in the claims, and the photodetector 60 corresponds to the light receiving portion referred to in the claims.

  When the operator contacts the pressing portion 54 of the sensor 52, the connecting portion 56 is deformed in a compressing direction. Due to the compression of the connecting portion 56, the pressing portion 54 approaches the reference portion 55. When the pressing portion 54 approaches the reference portion 55, the optical path length until the laser light irradiated by the laser diode 58 reaches the photodetector 60 becomes shorter than before the connection portion 56 is compressed. The photodetector 60 can detect a change in received light intensity based on a change in the optical path length. Specifically, the output current value of the photodetector 60 increases as the received light intensity increases as the optical path length decreases.

  As described above, the sensor 52 includes a rectangular parallelepiped or a cubic box by the pressing portion 54, the reference portion 55, and the connecting portion 56. The inside of the box composed of the pressing portion 54, the reference portion 55, and the connecting portion 56 is shielded so as not to be affected by light from the outside. Therefore, each of the pressing portion 54, the reference portion 55, and the connecting portion 56 is formed of a light-shielding material, and the members are joined so as not to generate a gap.

As shown in FIG. 6 to FIG. 7, the optical sensor 52 constitutes a sensor unit 62 in which two optical sensors 52, 52 are combined, and the sensor unit 62 is attached to the inner wall surface of the exterior portion 44.
The sensor unit 62 is configured such that the sensor 52 is embedded in each of the opposing mounting portions 64a and 64b of the elastic member 64 formed in a U-shaped cross section.
As the elastic member 64, a rubber sponge or the like can be adopted as in the connection portion 56 of the sensor 52.
The sensor 52 is embedded in each of the attachment portions 64a and 64b of the elastic member 64 so that the pressing portion 54 of the sensor 52 is located on the surface side. At this time, the surface of the pressing portion 54 of the sensor 52 and the surfaces of the attachment portions 64a and 64b of the elastic member 64 may be provided so as to be the same surface (level).

  In this way, by attaching the sensor unit 62 as a pair of sensors 52 to the inside of the exterior portion 44 of the arm portion 34 so that the opening side of the sensor unit 62 coincides with the opening side of the exterior portion 44. The sensor 52 can be easily attached and the arms and hands can be taken in and out. Further, it becomes easy to detect the movement direction of the operator's arm and hand and to detect movement in the direction opposite to the movement direction.

The sensor unit 62 is attached to a plurality of locations of the exterior part 44. In this embodiment, the sensor unit 62 is attached to the rear end side of the upper arm portion 46, and the sensor 52 is disposed on the inner wall surface of the upper surface portion 46a and the inner wall surface of the lower surface portion 46b.
Further, the sensor unit 62 is also attached to the rear end side of the forearm portion 48, and the sensor 52 is disposed on the inner wall surface of the upper surface portion 48a and the inner wall surface of the lower surface portion 48b.
Furthermore, the sensor unit 62 is also attached to the rear end side of the hand portion 50, and the sensor 52 is disposed on the inner wall surface of the upper surface portion 50a and the inner wall surface of the lower surface portion 50b.

The sensor 52 provided on the upper surface portion 46a of the upper arm portion 46 is configured such that when the upper arm of the operator moves upward, the connecting portion 56 is deformed by the upper arm of the operator coming into contact with the pressing portion 54 and the reference portion 55. Therefore, an output current having a value corresponding to the approached distance is output.
When the upper arm of the operator moves downward, the sensor 52 provided on the lower surface portion 46b of the upper arm portion 46 is deformed by the contact of the upper arm of the operator so that the connecting portion 56 is deformed. Therefore, an output current having a value corresponding to the approached distance is output.

The sensor 52 provided on the upper surface 48 a of the forearm 48 is configured such that when the operator's forearm moves upward, the operator's forearm abuts to deform the connecting portion 56, so that the connection between the pressing portion 54 and the reference portion 55. Therefore, an output current having a value corresponding to the approached distance is output.
When the forearm of the operator moves downward, the sensor 52 provided on the lower surface 48b of the forearm 48 is deformed by the contact of the forearm of the operator and the connecting portion 56 is deformed between the pressing portion 54 and the reference portion 55. Therefore, an output current having a value corresponding to the approached distance is output.

When the operator's hand moves upward, the sensor 52 provided on the upper surface part 50a of the hand part 50 is deformed by the contact of the operator's hand so that the connecting part 56 is deformed and the gap between the pressing part 54 and the reference part 55 is reached. Therefore, an output current having a value corresponding to the approached distance is output.
When the operator's hand moves downward, the sensor 52 provided on the lower surface part 50b of the hand part 50 is deformed by the contact of the operator's hand, so that the connecting part 56 is deformed and the gap between the pressing part 54 and the reference part 55 is reached. Therefore, an output current having a value corresponding to the approached distance is output.

Next, a block diagram of a control system of the power assist device is shown in FIGS. 8 and 9, and a circuit configuration for performing control based on this will be described. Note that the block diagram shown in FIG. 8 shows only the circuit configuration for one arm, and the power assist device 30 as a whole having the two arm portions 34 is provided with two circuit configurations similar to this diagram. .
Servo motors are used as the actuators 38a, 38b, 38c of this embodiment, and servo drivers 70, 70,... For controlling the servo motors are connected to the respective servo motors. Each servo motor is provided with encoders 72, 72..., And a position signal in each servo motor detected by each encoder 72 is input to the servo driver 70.

  The servo driver 70 incorporates a CPU 74, a ROM 75, and a bridge circuit 76 composed of a plurality of transistors. The servo driver 70 controls the rotation angle of the servo motor based on the position signal input from the encoder 72.

  The sensors 52, 52,... Are connected to a control unit 78, and an output current output from the photodetector of each sensor 52, 52,. The control unit 78 includes a CPU 80 that reads a control program stored in the memory and executes a control operation, and a ROM 81 and a RAM 82 that are memories.

The control part 78 receives the output current from each sensor 52, 52 ... provided in each exterior part 44, 44 ... as an operator movement signal.
When the controller 78 receives the operator movement signal from each sensor 52, the exterior part 44 provided with the sensor 52 that outputs the operator movement signal moves by a distance based on the magnitude of the operator movement signal. Thus, the servo motor provided in the corresponding exterior portion 44 is calculated to rotate by a predetermined number of rotations. The controller 78 outputs a control signal to the servo driver 70 of the corresponding servo motor so that the servo motor is driven based on the calculated result.

  Note that the control unit 78 does not control to drive only one servo motor when receiving an operator movement signal from any one of the sensors 52, but from one sensor 52. The exterior portion 44 may be moved by driving a plurality of servo motors in response to the operator movement signal. In such a case, the control unit 78 calculates the rotation angle of each servo motor to determine how much the plurality of servo motors are rotated with respect to the input operator movement signal, and each servo motor is driven at the calculated rotation angle. In this manner, a control signal is output to each servo driver 70.

In the embodiment described above, the sensor is an optical sensor. However, the sensor may be a capacitance sensor (not shown) instead of an optical sensor.
In the capacitance sensor, the pressing portion 54 and the reference portion 55 are each formed of a metal plate and have a function as an electrode of a capacitor. When the operator's arm or hand comes into contact with the pressing portion 54, the connecting portion is deformed, and the distance between the pressing portion 54 and the reference portion 55 is shortened. As the distance between the pressing portion 54 and the reference portion 55 becomes shorter, the capacitance increases. By detecting this change in capacitance, the movement distance of the operator's arm or hand can be detected.

Further, in the embodiment described above, the hinge 40 is provided at a portion connecting the upper leg portion 35a and the lower leg portion 35b constituting each leg portion 35, and further, the portion connecting each lower leg portion 35b and the base 32 is provided. The hinge 42 is provided.
Therefore, the drive of the leg portion 35 is not driven by the actuator but moves by the operator's force.
However, an actuator is provided in each of the part connecting the upper leg part 35a and the lower leg part 35b and the part connecting the lower leg part 35b and the base 32 in the leg part 35, and a plurality of sensors provided in the arm part 34 are provided. Based on the operator movement signal output from 52, the actuators provided in the arm portion 34 and the actuators provided in the leg portion 35 distribute the operating distance of each actuator, and the operation of the leg portion 35 is also controlled by the control portion 78. It may be controlled by

  While the present invention has been described in detail with reference to a preferred embodiment, the present invention is not limited to this embodiment, and it goes without saying that many modifications can be made without departing from the spirit of the invention. .

It is explanatory drawing which shows the place which looked at the power assist apparatus of this invention from diagonally backward. It is the side view which looked at the power assist device from the inside. It is explanatory drawing which shows the place which looked at the arm part from diagonally backward inside. It is explanatory drawing of a sensor. It is a side view of a sensor. It is explanatory drawing of a sensor unit. It is a side view of a sensor unit. It is a block diagram of a control circuit. It is a block diagram which shows the internal structure of a servo driver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 Power assist apparatus 32 Base 32a Front part 32b Right part 32c Left part 34 Arm part 35 Leg part 35a Upper leg part 35b Lower leg part 38a Actuator 38b Actuator 38c Actuator 39 Wheel 40 Hinge 42 Hinge 44 Exterior part 46 Upper arm part 46a Upper surface part 46b Lower surface portion 46c Side surface portion 48 Forearm portion 48a Upper surface portion 48b Lower surface portion 48c Side surface portion 50 Hand side portion 50a Upper surface portion 50b Lower surface portion 50c Side surface portion 52 Sensor 54 Pressing portion 54a Reflecting surface 55 Reference portion 56 Connecting portion 58 Laser diode 60 Photodetector 62 Sensor unit 64 Elastic member 64a, 64b Mounting portion 70 Servo driver 72 Encoder 74 CPU
75 ROM
76 Bridge circuit 78 Control unit 80 CPU
81 ROM
82 RAM

Claims (3)

In the power assist device that operates to follow the movement of the operator and assists the movement of the operator,
A base with freely rotating wheels;
Legs projecting upward from the base,
A first exterior part that is pivotally connected to the upper end of the leg part via a joint part and into which the upper arm of the operator can be inserted;
One end side is rotatably connected to the other end side of the first exterior part via a joint part, and a second exterior part into which an operator's forearm can be inserted;
One end side is rotatably connected to the other end side of the second exterior part via a joint part, and a third exterior part into which an operator's hand can be inserted;
A plurality of actuators provided in each joint portion, each of which rotates the first exterior portion, the second exterior portion, and the third exterior portion around the joint portion;
A plurality of sensors provided on the inner wall surface of each exterior portion so as not to restrain the operator's arm and hand, and detecting movement of the operator's arm and hand within the exterior portion;
If any of the sensors detects that the operator's arm or hand has moved within the exterior part, the exterior part provided with the corresponding sensor is moved following the movement of the arm or hand. And a control unit for controlling each actuator,
Each exterior part is formed in a U-shaped cross-section with one side open, and is formed so that the operator's arm and hand can be inserted and extracted from the opening. Assist device. At least two legs are provided,
The first exterior part, the second exterior part, and the third exterior part are provided in pairs so as to correspond to both the left and right arms and hands of the operator. Item 4. The power assist device according to Item 1.   The exterior parts corresponding to the right arm and the right hand of the operator and the exterior parts corresponding to the left arm and the left hand of the operator are arranged so that the openings face each other and face the inside of the operator's body. The power assist device according to claim 2, wherein the power assist device is a power assist device.

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