JP6867211B2 - Wrist rotation structure in humanoid hand, wrist rotation structure in hand and hand - Google Patents

Description

The present invention relates to a wrist rotation structure in a humanoid hand provided with a plurality of finger mechanisms, particularly in a humanoid hand that reduces the burden of gripping an object.

FIG. 4 is a diagram illustrating the joints of the human hand. The thumb flexes and rotates to some extent around the CM joint, MP joint, and IP joint, and the index finger, middle finger, ring finger, and little finger are MP joint and PIP joint. And flexes and rotates to some extent around the DIP joint.

Patent Document 1 and Patent Document 2 disclose a humanoid hand that grips an object (part, etc.) by a plurality of finger mechanisms that imitate the human hand, and transfers or rotates the object.

FIG. 5A illustrates the outline of the humanoid hand disclosed in Patent Document 1, and a portion corresponding to a CM joint of each finger mechanism is connected to a palm substrate via a universal joint. .. There is no disclosure of details about the connecting portion between the palm substrate and the arm.

FIG. 5B illustrates the outline of the humanoid hand disclosed in Patent Document 2, and in this humanoid hand, the portion corresponding to the CM joint of each thumb mechanism is rotatably connected to the palm substrate. The portion corresponding to the MP joint of the finger mechanism other than the thumb is rotatably connected to the palm substrate. This prior art also does not disclose details about the connection between the palm substrate and the arm.

When connecting the palm substrate to the tip of the arm portion corresponding to the human arm, not limited to the above patent documents, generally, the relationship between the thumb mechanism and the CM joint is not considered, and the rotation center of the palm substrate and the thumb It is far from the CM joint of the mechanism.

Japanese Patent No. 4462742 Japanese Unexamined Patent Publication No. 2010-264548

When an object is gripped, lifted, moved, or rotated by a conventional humanoid hand, a large moment acts on the wrist portion of the hand, which requires a high-power actuator (drive source).

In addition, when a large moment acts on the wrist portion, the other portion must also be structurally structured to overcome the moment, resulting in an overall increase in size or weight.

As a result of faithfully verifying the structure of the human hand, the present inventors have found that when the object is gripped, the palm is curved inward, and the center of rotation of the wrist portion is relatively the center of gravity of the object. It was found that it approaches.

The present invention is based on the above findings, and the present invention is a rotating structure of a wrist in a humanoid hand in which a plurality of finger mechanisms including a thumb mechanism are attached to a palm substrate connected to the tip of an arm. The palm substrate is rotatably supported around an axis substantially orthogonal to the plane including the palm substrate, and the rotation center of the palm substrate is the CM joint of the thumb mechanism orthogonal to the inward / outward axis of the wrist. The CM joint of the little finger is closer to the fingertip than the horizontal axis through which it passes, closer to the hand side than the line connecting the CM joints of the thumb, middle finger, ring finger and little finger, and closer to the center than the vertical axis passing through the CM joint of the thumb mechanism. It was set in the area closer to the center than the vertical axis through which it passes.

It is most preferable that the rotation center of the palm substrate is located in the region where the moment acting on the rotation center when the object is gripped by a plurality of finger mechanisms including the thumb mechanism is the smallest.

When the tip of the arm is rotatable with respect to the arm body, it is preferable to arrange the tip of the arm so that the rotation axis of the tip and the rotation axis of the palm substrate are substantially orthogonal to each other.

According to the humanoid hand according to the present invention, even a heavy object can be lifted, moved, or rotated by an actuator (drive source) having a lower output than before.

In addition, no unreasonable force acts on each joint or the like, the movement of the robot becomes smooth, and weight reduction can be achieved.

The whole view of the humanoid hand to which the rotation structure of the wrist which concerns on this invention is applied. (A) is a diagram showing a flexor carpi ulnaris state of the humanoid hand, and (b) is a diagram showing a flexor carpi ulnaris state. (A) is a diagram showing another embodiment in which the inward / outward axis of the wrist and the rotation center of the palm substrate are offset, and (b) is given 2 or 3 degrees of freedom to the rotation center of the palm substrate. The figure which shows another embodiment. A diagram illustrating the joints of a human hand. (A) is a diagram showing a humanoid hand proposed in Patent Document 1, and (b) is a diagram showing a humanoid hand proposed in Patent Document 2.

In the rotating structure of the wrist in the humanoid hand according to the present invention, a chevron-shaped tip 2 is rotatably attached to the main body of the arm 1 about a shaft 3, and a palm substrate 4 is placed in the center of the tip 2. It is rotatably attached around a shaft 5 in a direction orthogonal to the shaft 3. The axis 3 is a rotation center axis in the vertical plane of the wrist and is orthogonal to the supination / supination axis L0 of the wrist.

Since the shape of the tip portion 2 has a chevron shape with the left and right sides curved inward, it can be expanded or contracted when a force in the length direction of the arm is applied to the humanoid hand, whereby, for example, the fingertip portion. Effectively prevents damage to the fingertips when the hand hits an obstacle.

The rotation center axis 5 of the palm substrate 4 in the horizontal plane passes through the CM joint portion 15 of the thumb mechanism and is orthogonal to the inward / outward axis L0, the horizontal axis L1, the index finger mechanism 7, and the middle finger mechanism 8. The line L2 connecting the CM joint portion 25 of the ring finger mechanism 9 and the little finger mechanism 10, the vertical axis L3 parallel to the axis L0 passing through the CM joint portion 15 of the thumb mechanism, and the CM joint portion 25 of the little finger mechanism 10. It is set in the area surrounded by the vertical axis L4 parallel to the axis L0 passing through. By setting in this way, the rotation center shaft 5 results in being relatively close to the CM joint portion 15 of the thumb mechanism, and the moment acting on the rotation center shaft 5 becomes small.

As described above, the thumb mechanism 6, the index finger mechanism 7, the middle finger mechanism 8, the ring finger mechanism 9, and the little finger mechanism 10 are attached to the palm substrate 4.
The thumb mechanism 6 includes a first bone member 11 corresponding to the middle hand bone, a second bone member 12 corresponding to the base segment bone, and a third bone member 13 corresponding to the distal segment bone, and the first bone member 11 The base end portion is rotatably connected to the back surface side of the palm substrate 4 via the CM joint portion 15, and the base end portion of the second bone member 12 is connected to the tip end portion of the first bone member 11 with the MP joint portion 16. The base end portion of the third bone member 13 is rotatably connected to the tip end portion of the second bone member 12 via the IP joint portion 17.

A link mechanism 20 is arranged along the first bone member 11 to the third bone member 13, and by causing the link mechanism 20 to perform a pulling operation or a pulling operation, the first bone member 11 to the fourth bone member 14 performs a rotation (flexion) operation around each of the joint portions 15, 16 and 17.

Since the index finger mechanism 7, the middle finger mechanism 8, the ring finger mechanism 9, and the little finger mechanism 10 have the same structure, the little finger mechanism 10 will be described with a drawing number.
Each finger mechanism has a first bone member 21 corresponding to the middle hand bone, a second bone member 22 corresponding to the proximal phalanx, a third bone member 23 corresponding to the middle phalanx, and a fourth bone member corresponding to the distal phalanx. A bone member 24 is provided, and a base end portion of the first bone member 21 is rotatably connected to the surface side of the palm substrate 4 via a CM joint portion 25 formed of a universal joint.

Further, the base end portion of the second bone member 22 is rotatably connected to the tip end portion of the first bone member 21 via the MP joint portion 26, and the base end portion of the third bone member 23 is the second bone. It is rotatably connected to the tip of the member 22 via the PIP joint 27, and the base end of the fourth bone member 24 is rotatably connected to the tip of the third bone member 23 via the DIP joint 28. Is connected to.

A link mechanism 30 is arranged along the first bone member 21 to the fourth bone member 24, and by causing the link mechanism 30 to perform a pulling operation or a pulling operation, the first bone member 21 to the fourth bone member 24 performs a rotation (flexion) operation around each joint portion 25, 26, 27, 28.

Here, the link mechanism 20 and the link mechanism 30 are interlocked with each other, and by driving an actuator or the like, the thumb mechanism 6, the index finger mechanism 7, the middle finger mechanism 8, the ring finger mechanism 9, and the little finger mechanism 10 operate at the same time. Do.

FIG. 2A shows a flexor carpi ulnaris rotated counterclockwise in the horizontal plane with the rotation center axis 5 of the palm substrate 4 as the center, and FIG. 2B shows a clockwise direction in the horizontal plane with the axis L0 as the center. Indicates a flexed state rotated in.

In the case of the present invention, the palm substrate 4 is not curved, but from the beginning, the rotation center axis 5 of the palm substrate 4 in the horizontal plane is within the region surrounded by the line segments L1, L2, L3 and L4 as described above. Since it is set, the distance between the thumb mechanism 6 and the CM joint portion 15 is relatively small, and even if the thumb mechanism 6 is rotated around the rotation center axis 5, the distance from the wrist does not fluctuate significantly, and the distance to the wrist does not change significantly. The fluctuation of the acting moment is also small.

In an actual human hand, the part corresponding to the palm substrate 4 is composed of a plurality of bones, and when grasping an object, the above-mentioned plurality of bones are changed by changing between the above-mentioned plurality of bones. And get the proper shape.

When a human hand holds an object so as to come into contact with a portion corresponding to a palm substrate 4 composed of a plurality of bones, the center of gravity of this object and the CM joint of the thumb come close to each other, so that the moment acting on the center of rotation of the wrist is generated. It becomes smaller.

3 (a) and 3 (b) are views showing another embodiment, and in the embodiment shown in (a), the rotation center axis of the wrist inward / outward rotation axis L0 and the palm substrate 4 is shown. In the embodiment shown in (b), the degree of freedom is increased by adopting a multi-degree-of-freedom mechanism as the rotation center axis 5 of the palm substrate 4. The figure shows an embodiment realized by the gimbal mechanism, but other methods may be used as long as 2 degrees of freedom or 3 degrees of freedom can be imparted.

In either case, the horizontal axis L1 that passes the rotation center axis 5 of the palm substrate 4 through the CM joint portion 15 of the thumb mechanism, and the CM joint portion 25 of the index finger mechanism 7, the middle finger mechanism 8, the ring finger mechanism 9, and the little finger mechanism 10. By setting it in the area surrounded by the line L2 connecting the two, the vertical axis L3 passing through the CM joint portion 15 of the thumb mechanism, and the vertical axis L4 passing through the CM joint portion 25 of the little finger mechanism 10, the wrist can be set. The fluctuation of the acting moment is made small.

In the illustrated example, the distance between the shaft 5 which is the center of rotation of the palm substrate 4 and the CM joint portion 15 of the thumb mechanism 6 is narrow and the two are separated from each other, but the shaft 5 and the CM joint portion 15 are thick. It may be arranged so as to overlap in the direction.

The rotation structure of the wrist in the humanoid hand according to the present invention is not necessarily limited to the five-fingered humanoid hand, and can be applied as long as it has two or more finger mechanisms and has a structure for gripping an object.

1 ... arm, 2 ... arm tip, 3 ... shaft, 4 ... palm substrate, 5 ... palm substrate rotation center axis, 6 ... thumb mechanism, 7 ... finger mechanism, 8 ... middle finger mechanism, 9 ... ring finger mechanism 10, 10 ... Small finger mechanism, 11 ... 1st bone member, 12 ... 2nd bone member, 13 ... 3rd bone member, 15 ... CM joint part, 16 ... MP joint part, 17 ... IP joint part, 20 ... Link mechanism, 21 ... 1st bone member, 22 ... 2nd bone member, 23 ... 3rd bone member, 24 ... 4th bone member, 25 ... CM joint part, 26 ... MP joint part, 27 ... PIP joint part, 28 ... DIP joint Part, 30 ... Link mechanism.
L0 ... Wrist inward / outward axis L1 ... Horizontal axis L2 that passes through the CM joint of the thumb mechanism and is orthogonal to the inward / outward axis L0 ... CM joint of the finger display mechanism, middle finger mechanism, ring finger mechanism, and little finger mechanism Line connecting the parts L3 ... Vertical axis passing through the CM joint of the thumb mechanism L4 ... Vertical axis passing through the CM joint of the little finger mechanism

Claims (8)

It is a rotating structure of the wrist in a humanoid hand in which a plurality of finger mechanisms including a thumb mechanism are attached to a palm substrate connected to the tip of the arm.
The palm substrate is rotatably supported around an axis substantially orthogonal to the plane including the palm substrate.
The center of rotation of the palm substrate is orthogonal to the inward and outward axes of the wrist when viewed from the axial direction in a neutral state that is neither in a flexed state nor in a flexed state, and is a CM joint of the thumb mechanism. A straight line passing through the portion, a straight line connecting the CM joint part of the finger indicating mechanism and the CM joint part of the middle finger mechanism, a straight line connecting the CM joint part of the middle finger mechanism and the CM joint part of the ring finger mechanism, and the ring finger mechanism. A straight line connecting the CM joint portion of the small finger mechanism and the CM joint portion of the small finger mechanism, a straight line passing through the CM joint portion of the thumb mechanism and parallel to the inward / outward axis, and the CM joint portion of the small finger mechanism. A rotating structure of a wrist in a humanoid hand, characterized in that it is set in a region including the palm substrate formed by a straight line parallel to the inner / outer axis. In the humanoid hand according to claim 1, the rotation center of the palm substrate is a moment acting on the rotation center when an object is gripped by a plurality of finger mechanisms including the thumb mechanism in the region. The rotating structure of the wrist in a humanoid hand, which is characterized by being in the smallest position. The tip of the arm is characterized in that it is supported by a shaft that is orthogonal to the inward and outward axes and enables swinging toward the inner surface side of the grip and the back side of the hand when viewed from the axial direction. The rotating structure of the wrist in the humanoid hand according to claim 1 or 2. A humanoid hand having a rotating structure according to any one of claims 1 to 3. It is a rotating structure of the wrist in a hand in which a plurality of finger mechanisms are attached to a palm board connected to the tip of the arm.
The palm substrate is rotatably supported around an axis substantially orthogonal to the plane including the palm substrate.
The center of rotation of the palm substrate is orthogonal to the inward and outward axes of the wrist when viewed from the axial direction in a neutral state that is neither in the flexed state nor in the flexed state, and is a finger mechanism corresponding to the thumb. The straight line passing through the CM joint portion of the above, the straight line connecting the CM joint portion of the finger mechanism corresponding to the indicator finger and the CM joint portion of the finger mechanism corresponding to the small finger, and the CM joint portion of the finger mechanism corresponding to the thumb. Set in the region including the palm substrate formed by a straight line parallel to the inward / outward axis and a straight line parallel to the inward / outward axis passing through the CM joint of the finger mechanism corresponding to the thumb. Has been
Rotating structure of the wrist in the hand. The rotation center of the palm substrate is a position where the moment acting on the rotation center when the object is gripped by the plurality of finger mechanisms in the region is the smallest.
The rotating structure of the wrist in the hand according to claim 5. The tip of the arm is supported by a shaft that is orthogonal to the inward and outward axes and enables swinging toward the inner surface side of the grip and the back side of the hand when viewed from the axial direction.
The rotating structure of the wrist in the hand according to claim 5 or 6. A hand having a rotating structure according to any one of claims 5 to 7.

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