WO2016144057A1 - Space-adaptive finger module and gripper having same - Google Patents

Abstract

A finger module comprises: a frame; a finger structure capable of rotating in two directions with respect to the frame around a bending rotary shaft and an opening rotary shaft, which extend in different directions; and a motor for operating the finger structure, wherein the finger structure can perform a bending motion of rotating around the bending rotary shaft and an opening motion of rotating around the opening rotary shaft, and is configured so as to first perform the bending motion by the driving of the motor and to perform the opening motion by the driving power of the motor when the bending motion is restricted. A gripper comprises the finger module.

Description

Space-compliant finger module and gripper with same

The present invention relates to a finger module and a gripper having the same, and more particularly, to a finger module and a gripper having the same capable of responding to a space.

In the past, the tasks required by the industrial sector were mostly those requiring relatively simple sequences. In this work environment, the robot was able to perform the desired task with a simple structure.

However, as the industrial fields are diversified and robots are used for services and medical purposes, the structure of the robots is also diversifying.

Due to the development of the robot, the end-effector provided at the end of the arm of the robot has also changed functionally.

End effectors for robotic arms are being devised that can perform gripping operations to perform more diverse and sophisticated functions.

As a form capable of performing the gripping operation, a gripper using a finger structure is used. However, the finger motion of the conventional gripper is constrained on the one-dimensional plane, and thus the gripping function is limited.

To compensate for this, anthropomorphic robotic hands are being developed that mimic the structure of human hands. However, in the case of anthropomorphic robot hands, too many actuators and systems are required for gripping, which is more complicated and expensive than necessary.

There is a need for an end effector of a type that can compensate for the disadvantages of the conventional gripper and anthropomorphic robot hand.

According to an embodiment of the present invention, a finger module operating in compliance with a space is applied to a gripper to provide an end effector that can make a maximum grip shape with a minimum driver when the gripper grabs an actual object.

According to an aspect of the present invention includes a frame, a finger structure rotatable in two directions with respect to the frame relative to the bending axis and the open axis of rotation extending in different directions, and a motor for operating the finger structure, the finger The structure may perform a bending operation that rotates with respect to the bending rotation axis and an opening operation that rotates with respect to the opening rotation axis, and a bending operation is first performed by driving the motor, and when the bending operation is limited, There is provided a finger module configured to perform the opening operation by a driving force.

According to an embodiment, when the finger structure comes into contact with an object, the opening operation and the bending operation may be simultaneously performed, such that the finger structure moves along the curved surface of the object and maintains contact with the object.

According to one embodiment, the finger module is a joint structure for applying a force to receive the driving force of the motor so that the finger structure is rotated simultaneously with respect to the bending rotation axis and the open rotation axis, and the finger structure is the opening axis of rotation Further comprising an opening stiffness imparting device for imparting rigidity to restrain rotation about the center, wherein the finger module contacts the object, and the motor provides a driving force to overcome the rigidity imparted by the open stiffness imparting device. The finger structure rotates about the open axis of rotation.

According to one embodiment, the joint structure is a spherical link structure comprising a plurality of links rotatably connected about a plurality of spherical link axis of rotation, the plurality of spherical link axis of rotation meet at one intersection, and is connected to the motor The input shaft of the joint structure is arranged in line with the opening axis of rotation.

According to one embodiment, the bending rotation axis and the open axis of rotation are perpendicular to each other.

According to one embodiment, the finger structure includes a plurality of nodes connected in a row, the plurality of nodes are connected relative to the node axis of rotation rotatably.

According to an embodiment, in the state where the bending of the finger structure is not limited, the entire finger structure rotates about the bending rotation axis without relative rotation between the plurality of nodes, and the first node of the nodes of the finger structure. When the bending operation of is limited, a second node subsequent to the first node rotates about the first node rotation axis formed at the connection portion between the first node and the second node.

According to an embodiment of the present disclosure, the spreading operation may be performed when the rotation of the node is limited at the end of the finger structure.

According to one embodiment, the finger structure is a crank rotatably connected about the first node rotation axis, the first crank rotation axis about the crank is rotatably connected, and receives the driving force of the motor A first node link for applying a force to rotate the crank about the first node axis of rotation, a first bending rigidity imparting device for constraining the crank to freely rotate with respect to the first node; When a force is applied to rotate the crank about the first node rotation axis, the crank applies a force to the first node and the first node rotates about the bending axis of rotation.

According to one embodiment, the finger structure has a second node link, one end of which is freely rotatable with respect to the crank on the second crank rotation axis, and the other end of which is connected to apply a force to the second node. When the first node is in contact with the object and the bending motion of the first node is restricted, the crank rotates about the first node rotation axis and overcomes the first bending stiffness imparted by the first bending stiffness applying device. The second node link exerts a force on the second node by the rotation of the crank, so that the second node rotates about the first node about the first node rotation axis.

According to another aspect of the present invention, a base includes a first finger module fixed to the base, wherein the first finger module is the finger module, and the frame of the first finger module is gripper fixed to the base. Is provided.

According to one embodiment, the gripper further comprises a second finger module fixed to the base, the second finger module and the first finger module and the mirror so that the opening direction of the first finger module and the opposite direction is made in the opposite direction It is formed in a symmetrical structure.

According to one embodiment, the gripper further comprises a third finger module fixed to the base, the third finger module and the second finger module and the second finger module and the bending operation direction is made in the opposite direction and It is formed in a mirror symmetrical structure.

According to an embodiment of the present invention, the open axis of rotation of the third finger module may be fixed so that the open operation is not performed.

1 to 5 illustrate a finger module according to an embodiment of the present invention from different angles.

6 is a conceptual view illustrating the configuration of a finger structure according to an embodiment of the present invention.

7 illustrates a five-section spherical link structure according to an example.

8 illustrates a joint structure according to an embodiment of the present invention.

9 is a conceptual diagram illustrating the configuration of a finger module according to an embodiment of the present invention.

10 is a perspective view of a gripper according to an embodiment of the present invention.

FIG. 11 is a diagram illustrating an opening operation of a first finger module and a second finger module of the gripper of FIG. 10.

FIG. 12 is a view illustrating a bending operation of a second finger module and a third finger module of the gripper of FIG. 10.

FIG. 13 illustrates a state in which a cylindrical object is gripped using the gripper of FIG. 10.

FIG. 14 illustrates a gripper of a spherical object using the gripper of FIG. 10.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described. Although the present invention has been described with reference to the embodiments shown in the drawings, this is described as one embodiment, whereby the technical spirit of the present invention and its core configuration and operation are not limited.

1 to 5 show the finger module 1 according to an embodiment of the invention from different angles.

As shown in FIGS. 1-5, the finger module 1 includes a frame 40, a finger structure 10 fixed to the frame 40, a motor and a joint structure 30.

The frame 40 is formed of an upper frame 41, a side frame 42 and a lower frame 43 in a substantially "C" shape.

The motor 20 is inserted into the lower frame 43 of the frame 40, and the motor 20 is fixed to extend in the same direction as the side frame 42.

The side frame 42 of the frame 40 extends vertically at one end of the top frame 41 and the bottom frame 43, so that the joint structure 30 is connected to the top frame 41 and the bottom frame 43. Provides an operating space in which it can operate.

The rotary connector 120 is coupled to the middle of the upper frame 41. Rotating connector 120 is a connection bundle 121 extending in the longitudinal direction of the upper frame 41 from the top of the upper frame 41, and the connection through the upper frame 41 perpendicular to the upper frame 41 A shaft 122.

The connecting shaft 122 is rotatably connected with respect to the top frame 41 at the open joint 114. An opening axis S ₁ (see FIG. 8) is defined extending through the center of the opening joint 114 and extending in the longitudinal direction of the connecting shaft 122, and the rotation connector 120 is an opening axis S _1. Is rotated about the upper frame 41.

6 is a conceptual diagram illustrating the configuration of a finger structure 10 according to an embodiment of the present invention.

1 to 6, at one end of the first node 101 of the finger structure 10, a first flange 161 is formed to surround the side of the connection bundle 121, and the joint structure 30 may be formed. The fourth link 34 penetrates through the first flange 161 and the connecting bundle 121 to connect the two members.

The first node 101 is freely rotatable with respect to the fourth link 34 at the bending joint 111. A bending axis of rotation S ₅ (see FIG. 8) is defined extending through the center of the bending joint 111 and extending in the longitudinal direction of the fourth link 34, and the first node 101 defines the bending axis of rotation S ₅ . It is rotatable about the rotational connector 120 to the center.

Since the rotary connector 120 is connected to the frame 40, the first node 101 may be said to be rotatable about the frame 40 about the bending rotation axis S ₅ . In addition, when the rotation connector 120 rotates about the frame 40 about the opening axis of rotation S ₁ , the first node 101 is also about the frame 40 about the opening axis of rotation S ₁ . Rotate

The second flange 162 is formed at the other end of the first node 101, and the first node shaft 135 is formed to pass through the two second flanges 162. The first node shaft 135 is fixedly connected to the first node 101 at the first node joint 112.

A third flange 163 extending inwardly of the second flange 162 is formed at one end of the second node 102 connected in series with the first node 101, and the third flange 163 is formed of a third flange 163. It is connected freely rotatable with respect to one node shaft 135.

A first node axis of rotation S ₆ is defined that passes through the center of the first node joint 112 and extends in the longitudinal direction of the first node shaft 135, and the second node 102 is the first node axis of rotation S _6. It can be rotated about the first node (101) around.

A fourth flange 164 is formed at the other end of the second node 102, and a second node shaft 136 is formed to pass through the two fourth flanges 164. The second node shaft 136 is fixedly connected to the second node 102 at the second node joint 113.

A fifth flange 165 extending inwardly of the fourth flange 164 is formed at one end of the third node 103 connected in series with the second node 102, and the fifth flange 165 is formed of a fifth flange 165. It is connected freely rotatable with respect to the two node shaft 136.

The second node axis of rotation S ₇ is defined to extend through the center of the second node joint 113 in the longitudinal direction of the second node shaft 136, and the third node 103 is the second node axis of rotation S _7. Rotatable about the second node 102 with respect to).

The upper surface of the first node 101 to the third node 103 is formed with a gripping surface (104, 105, 106) is formed flat, each of the gripping surface (104, 105, 106) is a first node 101 ) To the third node 103 is arranged to form the same plane when straight.

The first node 101 to the third node 103 are operated by a plurality of node links and cranks connected to the lower end, and rotate by moving from the lower end to the upper end with respect to the associated rotation axis to perform the gripping operation.

As shown, one corner portion of the crank 142 having a substantially triangular shape is connected to the first node shaft 135. A second torsion spring 132 is connected between the crank 142 and the first node shaft 135 as a first bending rigidity imparting device.

The crank 142 is freely rotatable with respect to the first node shaft 135, but is freely constrained by the stiffness provided by the second torsion spring 132.

The rigidity provided by the torsion spring refers to the force that the torsion spring can maintain its shape without elastic deformation.

When a force exceeding the rigidity provided by the second torsion spring 132 is applied to the crank 142, the crank 142 may rotate about the first node shaft 135 about the first node axis of rotation S ₆ . Can be.

One end of the first node link 141 is connected to the first crank joint 152 corresponding to the other edge of the triangular edge of the crank 142.

A first crank rotation axis S ₉ is defined at the center of the first crank joint 152 and extends in parallel with the first node rotation axis S ₆ , and the first node link 141 is the first crank rotation axis S _9. It can be freely rotated about the crank 142 around.

The other end of the first node link 141 is connected to the end of the third link 33 of the joint structure 30 at the first node link joint 151. A first node link rotation axis S ₈ is defined at the center of the first node link joint 151 and extends in parallel with the first node axis of rotation S ₆ , and the first node link 141 is a first node link axis of rotation. It is freely rotatable about the third link 33 about (S ₈ ).

One end of the second node link 142 is connected to the second crank joint 153 corresponding to another corner of the triangular edge of the crank 142.

A second crank rotation shaft S ₁₀ is defined at the center of the second crank joint 153 and extends in parallel with the first node rotation shaft S ₆ , and the second node link 142 is the second crank rotation shaft S _10. It can be freely rotated about the crank 142 around.

The other end of the second node link 143 is rotatably connected to the second node link joint 154 formed on the rear surface of the third node 103.

In the center of the second node link joint 154, a second node link axis of rotation S ₁₁ extending in parallel with the first node axis of rotation S ₆ is defined, and the second node link 142 is a second node link axis of rotation. It is possible to freely rotate about the third node 103 about S ₁₁ .

As shown, the third torsion spring 133 is connected to the second node shaft 136 as a second bending rigidity imparting device.

The third node 103 is freely rotatable with respect to the second node shaft 136, but free rotation is constrained by the rigidity provided by the third torsion spring 133.

When a force exceeding the rigidity provided by the third torsion spring 133 is applied to the third node 103, the third node 103 is applied to the second node 102 about the second node rotation axis S ₇ . Can rotate relative to

Referring to FIG. 6, when the third link 33 rotates counterclockwise around the bending rotation axis S ₅ , the first node link 141 moves to the right side of the drawing to push the crank 142.

At this time, since the free rotation of the crank 142 with respect to the first node rotation axis S ₆ is constrained by the second torsion spring 132, the relative movement of the crank 142 with respect to the first node 101. Will not occur. When the first node link 141 pushes the crank 142, the crank 142 pushes the second node link 143, and the second node link 143 exerts a force on the third node 103. .

Since the free rotation of the third node 103 with respect to the second node axis of rotation S ₇ is constrained by the third torsion spring 133, the third node 103 of the third node 103 with respect to the second node 102 of the third node 103 is restricted. Relative motion does not occur.

The force applied by the first node link 141 to the third node 103 is also applied to the second node 102 as it is.

As described above, the finger structure 10 according to the present embodiment has links that are constrained to each other so that relative rotation between components does not occur due to the restraining force of the second torsion spring 132 and the third torsion spring 133. It is in an integral state of movement.

Therefore, when the third link 33 rotates in the counterclockwise direction about the bending rotation axis S ₅ , the entire finger structure 10 is bent rotation axis S with the nodes 101, 102, 103 unfolded in a straight line. ₅ ) it is rotated counterclockwise around (see FIG. 11).

This bending operation enables a so-called "pinch grip" operation of picking up a small, thin object such as a needle into the third segment 103 at the far end.

However, the bending operation of the finger structure 10 according to the present embodiment is not limited to being performed with the nodes 101, 102, 103 unfolded in a straight line.

Simple relative rotation of the nodes 101, 102, 103 enables bending operation very much like a human finger.

While the entire finger structure 10 is rotated counterclockwise about the bending rotation axis S ₅ , when the first node 101 contacts the object to be gripped or reaches the rotation limit allowed by the structure 10, The first node 101 can no longer rotate and the movement is constrained.

At this time, if the third link 33 continues to rotate in the counterclockwise direction with a rotational force greater than the torsion of the second torsion spring 132, the first node link 141 pushes the crank 142 with the crank 142. ) Overcomes the rigidity of the second torsion spring 132 and rotates about the first node rotation axis S ₆ .

Accordingly, the crank 142 pushes the second node link 143 to the right, and the second node link 143 exerts a force on the third node 103.

Since the free rotation of the third node 103 with respect to the second node axis of rotation S ₇ is constrained by the third torsion spring 133, the third node 103 of the third node 103 with respect to the second node 102 of the third node 103 is restricted. Relative motion does not occur.

The force applied by the first node link 141 to the third node 103 is also applied to the second node 102 as it is.

By this operation, while the rotation of the first node 101 is constrained, the second node 102 is rotated counterclockwise with respect to the first node 101. At this time, the third node 103 is maintained in a state arranged in a date with the second node 102 and moves together with the second node 102.

If second node 102 also contacts an object or reaches an acceptable rotational limit, second node 102 can no longer rotate and constrain its movement.

At this time, when the third link 33 continues to rotate counterclockwise with a rotational force greater than or equal to the rigid force provided by the second torsion spring 132 and the third torsion spring 133, the first node link 141 is rotated. By the force pushing the crank 142, the crank 142 overcomes the rigidity of the second torsion spring 132 and rotates about the first node rotation axis S ₆ , and the second node link 143 is moved to the right. Push to apply force to the third node 103.

The third node 103 overcomes the rigidity of the third torsion spring 133 by the force pushed by the second node link 143 and rotates about the second node rotation axis S ₇ . This third node 103 is rotated until the third node 103 contacts the object or reaches an acceptable limit.

As described above, the first link 101 to the third node 103 are rotated relative to each other by simply rotating the third link about the bending rotation axis S ₅ , so as to sequentially wrap and grip the object. ("power grip") or "hook grip", which allows hooks to be rotated to the limit of rotation to form hooks to support objects.

On the other hand, the finger structure 10 of the finger module 1 according to the present embodiment is to perform the opening operation to rotate based on the opening rotation axis (S ₁ ) in addition to the bending operation based on the above-described bending rotation axis (S ₅ ). Can be.

The bending operation and / or the opening operation are all made by one motor 20. For this purpose, the finger module 1 according to the present embodiment includes a joint structure 30 formed of a five-section spherical link structure.

Unlike the planar link mechanism, the spherical link structure is characterized by the movement of links along a spherical surface rather than a plane. Thus, determining the size of the link is determined by the angle on the circumference of the link and not by the length of the link. This spherical link structure is characterized in that all of the rotating shafts provided at one point ("center point") meet.

When the spherical link structure becomes a five-section link, it becomes a two-degree-of-freedom mechanism like a five-plane link.

However, since the spherical link structure of Section 5 is operated by three rotational movements, it can be moved about two axes like the end node of a real human finger, and the object to be gripped by controlling the motion of one of them by a spring According to the size and shape of the deformable motion can be formed.

7 illustrates a five-section spherical link structure in accordance with one embodiment.

As shown in FIG. 7, the first link 31 ′ of the five-section spherical link structure is configured to rotate about the rotation axis S ₂ by the rotation of the motor, and the remaining links freely rotate about the associated rotation axis. It is configured to. The rotating shafts S ₁ to S ₅ of the spherical link structure are formed to meet at one point.

According to the present embodiment, the rotating shaft S ₂ is an input shaft of the motor 20, the rotating shaft S ₁ is an open rotation shaft, and the rotating shaft S ₅ is a bending rotation shaft.

The first link 31 'to change the position of the rotation shaft when the rotation (S _2), the first link 31' to the other rotation axis (S ₃₎ associated with the. Accordingly, each link is rotated about the associated axis of rotation to satisfy the condition that all axes of rotation must meet at the center point.

According to the present embodiment, in accordance with the shape of the object, the rotation of the fourth link 34 'with respect to the rotation axis (S ₁ ) of the fourth link 34' as necessary, so that the bending and / or opening operation of the finger structure 10 can be made. Constrain or release.

When the rotation of the fourth link 34 ′ about the rotational axis S ₁ is constrained, only a bending operation is performed based on the rotation axis S ₅ , and the fourth link 34 ′ is rotated about the rotational axis S ₁ . When the rotation restraint is released, a bending operation based on the rotation axis S ₅ and an opening operation based on the rotation axis S ₁ occur simultaneously.

In addition, when the rotation restraint about the rotation shaft S ₁ of the fourth link 34 'is released and the rotation restraint about the rotation shaft S ₅ of the third link 33' is referred to the rotation shaft S ₁ . Only one open action can occur.

In order to form a five-section spherical link structure having such a configuration, the angle formed by the rotation axis must be designed.

According to the present embodiment, in order to form the finger module 1 which performs an operation similar to a human finger, α ₁₂ = 0 ° and α ₅₁ = 90 °, so that the opening axis of rotation S ₁ and the motor are separated. The angle of the rotating shaft S ₂ was 0 degrees, and the angle of the bending rotating shaft S ₅ and the spreading rotation shaft S ₁ was 90 degrees.

8 shows a joint structure 30 according to the present embodiment. In FIG. 8, only the third link 33 is partially illustrated to describe the structure of the joint structure 30, which is a spherical joint structure.

As best shown in FIG. 2, the third link 33 includes a spherical link portion 331 extending from the fourth spherical link joint 314 to the third spherical link joint 313, and a third spherical link joint. The node link portion 332 extends from 313 to the first node link joint 151. In FIG. 8, only the spherical link portion of the third link 33 is shown.

As shown in FIG. 6, when the rotation angle θ ₅ of the third link 33 based on the bending rotation axis S ₅ is an output value of the joint structure 30, the rotation angle θ ₅ is The angle between the axes of rotation was calculated to be the maximum.

At this time, when a human finger was modeled, the length of each link of the finger structure 10 was determined as shown in Table 1 below.

link l ₁ l ₂ l ₃ l ₄ l ₅ l ₆ l ₇ l ₈ l ₉ l ₁₀ Length (mm) 57 28 54 15 38 15 22 38 9 35

The results obtained by optimizing using the pattern search method using the nonlinear constraint interpolation, boundary conditions and the like of the finger module 1 are shown in Table 2 below.

α ₂₃ α ₃₄ α ₄₅ 49 ° 63 ° 38.94 °

1 to 5 and 8, the motor 20 has a first link 31 and a first axis such that its axis extends in the direction of the first spherical link rotation axis S ₂ , which is an input shaft of the joint structure 30. It is connected at the spherical link joint 311.

The other end of the first link 31 is rotatably connected to the second link 32 and the second spherical link joint 312. The second spherical link rotation axis S ₃ extends beyond the center of the second spherical link joint 312 and meets at the center point with the first spherical link rotation axis S ₂ .

The other end of the second link 32 is rotatably connected to the third link 33 at the third spherical link joint 313 formed in the middle of the third link 33. The third spherical link rotary shaft S ₄ extends beyond the center of the third spherical link joint 313 and meets at the center point with the first spherical link rotary shaft S ₂ and the second spherical link rotary shaft S ₃ .

The spherical link portion 331 of the third link 33 extending from the third spherical link joint 313 extends to the fourth spherical link joint 314 and is rotatably connected to the fourth link 34.

The fourth spherical link joint 314 is concentric with the bending joint 111 defining the bending rotation axis S ₅ .

The bending rotating shaft S ₅ meets at one point with the first spherical link rotating shaft S ₂ , the second spherical link rotating shaft S ₃ , and the third spherical link rotating shaft S ₄ .

The fourth link 34 may be rotatably inserted into the rotation bundle 121 of the rotation connector 120, or may be rotatably connected to the fourth link 34. According to the present embodiment, the rotating bundle 121 may be viewed as a fourth link of the joint structure 30 in a large sense.

The bending rotation axis S ₅ is perpendicular to the opening rotation axis S ₁ defined by the connection shaft 122 of the rotation connector 120, and forms the same axis as the first spherical link rotation axis S ₂ .

Therefore, the opening rotation axis S ₁ meets at one point with the first spherical link rotation axis S ₂ , the second spherical link rotation axis S ₃ , the third spherical link rotation axis S ₄ , and the bending rotation axis S ₅ . .

As best shown in FIG. 2, the first torsion spring 131 is connected to the connecting shaft 122 forming the opening rotation shaft S ₁ as a device for providing opening stiffness.

The connecting shaft 122 is freely rotatable with respect to the frame 40, but the free rotation is constrained by the rigidity provided by the first torsion spring 131.

If a force exceeding the rigidity provided by the first torsion spring 131 is not applied to the rotary connector 120, the rotary connector 120 does not rotate about the open rotation axis S ₁ and is fixed. . When a force equal to or greater than the rigidity provided by the first torsion spring 131 is applied to the rotary connector 120, the rotary connector 120 is rotated about an opening axis of rotation S ₁ to perform an opening operation.

9 is a conceptual diagram of the configuration of the finger module 1 according to the present embodiment.

When the motor 20 rotates so that the first link 31 rotates about the first spherical link rotation axis S ₂ , the position of the second spherical link rotation axis S ₃ associated with the first link 31 changes. Done.

Since the joint structure 30 operates so that the rotation axis formed by the constituent links always meets at the center point, the second link so that the second spherical link rotation axis S ₃ and the third spherical link rotation axis S ₄ may meet at one point. 31 rotates about the center point.

As a result, the position of the third spherical link rotation axis S ₄ is changed, and the third link 33 is centered on the center point so that the third spherical link rotation axis S ₄ and the bending rotation axis S ₅ meet at one point. Will rotate.

At this time, since the fourth spherical link joint 314 defining the bending rotation axis S ₅ is fixed to the fourth link 34 constrained to the frame 40 and its height is fixed, the third link 33 Is rotated about the bending axis (S ₅ ).

The rotation of the third link 33 causes the bending structure of the finger structure 10 as described above.

Due to the structural feature of the spherical link joint, if there is no restraint by the first torsion spring 131, the fourth link 34 is rotated about the open rotation axis (S ₁ ).

When the fourth link 34 rotates, the rotation connector 120 rotates with respect to the frame 40, and the entire finger structure 10 rotates about the open rotation axis S ₁ to perform the open operation.

That is, the bending motion and the opening motion may be simultaneously performed by the rotation of one motor 20 by the joint structure 30, which is a spherical link structure of five sections that generates two degrees of freedom motion.

However, if the finger structure 10 is always performed with the bending operation and the opening operation, the object that can be gripped will be limited, and the holding force will not be high.

Therefore, the finger module 1 according to the present embodiment is guided so that the bending operation is first performed by the driving of the motor 20 by the action of the first torsion spring 131, and the bending operation is performed when the bending operation is stopped. It is configured to be.

In more detail, the free rotation about the spreading axis S ₁ of the fourth link 34 is restricted by the rigidity of the first torsion spring 131.

Therefore, the fourth link 34 is fixed to the open rotation axis S ₁ of the fourth link 34, and the third link 33 is rotated about the bending rotation axis S ₅ . Only the bending operation of the finger structure 10 is made.

However, if the bending movement is restricted because the finger structure 10 comes into contact with an object or reaches an allowable bending rotational threshold, the third link 33 can no longer rotate about the bending rotation axis S ₅ .

When the bending motion of the finger structure 10 is restricted, not only the first node 101 to the third node 103 contact with an object while sequentially rotating, the third node 103 may be pinched through a pinch grip or the like. There may be a case where the bending motion of h) is limited.

If the bending motion of the third node 103 is not limited due to the structure of the finger structure 10, the bending motion of the finger structure 10 is not completely limited. The bending motions of the first and second nodes are also limited, thereby limiting the bending motion of the finger structure 10.

When the movement of the third link 33 is constrained, the movement of the first link 31 and the second link 32 is also constrained.

In this state, when the motor 20 increases the rotational force to such a degree that the first torsion spring 131 does not elastically deform, the force is transmitted to the finger structure 10 through the third link 33 to allow the finger structure ( The grip force of 10 (ie, the pressure exerted by the finger structure 10 against the object) increases.

When the rotational force of the motor 20 is increased so as to overcome the rigidity of the first torsion spring 131, when the elastic deformation of the first torsion spring 131 is made, the fourth link 34 is the first torsion spring 131. Overcoming the rigidity is to rotate about the bending axis (S ₅ ).

When the fourth link 34 is rotated about the bending axis of rotation (S ₅ ), while the rotary connector 120 rotates about the bending axis of rotation (S ₅ ), the finger structure 10 connected thereto is opened.

If the finger structure 10 pushes on a flat surface such as a wall and the bending operation of the finger structure 10 is impossible, only the spreading operation is performed (see FIG. 11).

However, if the finger structure 10 is in contact with a curved surface of a spherical body such as a ball, a space for bending motion is secured when the spreading operation is performed, so that the bending motion and the spreading motion are simultaneously performed along the curved surface of the object. As the finger structure moves, it is possible to maintain contact with the object (see FIG. 14).

The finger module 1 according to the present embodiment is a lack driving finger module for controlling a multi-degree of freedom finger structure composed of a plurality of joints by one motor 20. First to third torsion springs were used for control of the underdrive module.

The second torsion spring 132 and the third torsion spring 133 are sufficient if the spring constant is determined so as to have a rigidity enough to overcome the weight of the finger structure 10.

However, the rigidity of the first torsion spring 131 is related to the gripping force of the finger structure 10. If the first torsion spring 131 is not elastically deformed, the opening operation is not performed. Therefore, the larger the rigidity of the first torsion spring 131 is, the greater the holding force due to the bending operation of the finger structure 10 is.

However, when the stiffness of the first torsion spring 131 is large enough that the output of the motor 20 cannot win, the opening operation cannot be performed, so that the maximum output of the motor 20 should not be reached.

Since the torque transmitted by the rotational force of the motor 20 to each part of the finger structure 10 can be calculated using the kinematic relationship of the finger module 1, the motor control corresponding to the stiffness of the first to third torsion springs can be calculated. This will allow for smooth and precise gripping control.

The gripper 500 may be formed using the finger module 1 according to the present embodiment.

10 is a perspective view of a gripper 500 according to an embodiment of the present invention.

The gripper 500 includes a base 511 in the form of a wide plate, a fixed shaft 512 extending vertically from the base, and a fixed frame in the shape of a "c" shape coupled to an upper end of the fixed shaft 512. .

The stationary frame includes side frames 514 and 515 spaced vertically apart from each other and a palm frame 516 disposed to cross the two side frames 514 and 515.

The frame 40 of the finger module (first finger module 1) corresponding to the above-described embodiment is fixed to the side frame 514 on one side.

The palm frame 516 is disposed perpendicular to the axial direction of the motor 20 of the first finger module 1.

The second finger module 1 'and the third finger module 1 "are coupled to the side frame 514 of the other side, respectively. The second finger module 1' and the third finger module 1" Frames 40 ′, 40 ″ are coupled to the side frame 514.

The second finger module 1 ′ has the same configuration as the first finger module 1, but the first finger module 1 is placed in a longitudinal mirror of the finger structure 10 of the first finger module 1. In the open view, it has the same mirror symmetry as reflected in the mirror.

FIG. 11 is a diagram illustrating an opening direction of the first finger module 1 and the second finger module 1 ′.

FIG. 11 illustrates a case in which the gripper 500 performs an operation of attaching a finger module to a wall and pushing a wall (not shown).

In the state where the first finger module 1 and the second finger module 1 'are in close contact with the wall, the finger structures of the two finger modules are not bent.

When the motor 20 of the first finger module 1 and the motor 20 'of the second finger module 1' are rotated in opposite directions, the first finger module 1 moves to the right. 1 ″) is a state in which the finger module of the gripper 500 is opened while the opening operation is performed to the left side. Through this, the contact area of the gripper 500 with respect to the wall can be extended.

The gripper 500 is pushed forward by pushing the wall in a state where the finger module is open to both sides, so that more stable force transmission is possible.

The third finger module 1 "is mirror symmetrical as reflected in the mirror when the second finger module 1 'is reflected in a mirror placed in a direction perpendicular to the longitudinal direction of the finger structure of the second finger module 1'. Has a structure.

However, according to the present embodiment, the connecting shaft is fixed to the frame so that the third finger module 1 "is not opened. That is, the third finger module 1" is capable of bending only.

12 illustrates a pinch operation using the gripper 500.

As shown in FIG. 12, the second finger module 1 ′ and the third finger module 1 ″ are configured such that the spreading operation is performed in the opposite direction, such that the third nodes at the ends may contact each other.

The gripper 500 according to the present exemplary embodiment may include a first finger module 1 and a second finger module 1 ′ that perform an opening operation in the opposite direction, and may perform a stable gripping operation on various objects. .

FIG. 13 illustrates a gripping operation on the cylindrical object M. Referring to FIG.

Each motor of the first to third finger modules 1, 1 ', and 1 "is driven to bend each finger module simultaneously (Fig. 13 (a)).

When the first to third finger modules 1, 1 ′ and 1 ″ contact the object M, the bending motion of the finger structure of each finger module is restrained (FIG. 13B).

 In this state, when the motor outputs of the first and second finger modules 1 and 1 'are generated to the extent that each finger module overcomes the rigidity of the first torsion spring, the first and second finger modules 1 and 1' are generated. ) Opens in the opposite direction.

This operation is useful for stably holding a relatively long cylindrical object (M), and even when holding a thin cylindrical object with a hook grip to hold the distance between the finger module to enable a more stable grip.

FIG. 14 illustrates a gripping operation of the spherical object M '.

Each motor of the first to third finger modules 1, 1 ', 1 "is driven to simultaneously bend each finger module.

When the first to third finger modules 1, 1 ', 1 "contact the object M', the bending motion of the finger structure of each finger module is restrained (FIG. 14 (a)).

 In this state, when the motor outputs of the first and second finger modules 1 and 1 'are generated to the extent that each finger module overcomes the rigidity of the first torsion spring, the first and second finger modules 1 and 1' are generated. ) Opens in the opposite direction.

At this time, a space for the finger structures of the first and second finger modules 1 and 1 'to be bent by the surface curve of the spherical object M' is secured, and the bend operation occurs simultaneously with the opening operation. (FIG. 14 (b)).

Accordingly, the finger structures 10 and 10 'of the two finger modules 1 and 1' of the gripper 500 move in conformity with the curved surface while maintaining contact with the object M ', thereby enabling a stable grip. .

Claims (14)

frame; A finger structure rotatable in two directions with respect to the frame with respect to the bending rotation axis and the opening rotation axis extending in different directions; A motor for operating the finger structure, The finger structure may perform a bending operation of rotating based on the bending rotation axis and an opening operation of rotating based on the opening rotation axis, A bending module is first performed by the driving of the motor, and when the bending operation is limited, the finger module is configured to perform the opening operation by the driving force of the motor. The method of claim 1, When the finger structure is in contact with an object, the opening operation and the bending operation are simultaneously performed. And the finger structure moves along a curved surface of the object to maintain contact with the object. The method of claim 1, A joint structure configured to receive a driving force of the motor and apply a force to simultaneously rotate the finger structure about the bending rotation axis and the opening rotation axis; A stiffness imparting device for imparting rigidity that constrains the finger structure to rotate about the fold axis of rotation; And the finger structure rotates about the open axis of rotation when the finger module contacts the object and the motor provides a driving force to overcome the rigidity imparted by the openness stiffness imparting device. The method of claim 3, The joint structure, A plurality of links rotatably connected about a plurality of spherical link rotation axes, A spherical link structure in which the plurality of spherical link rotation axes meet at one intersection; The input module of the joint structure connected to the motor is a finger module, characterized in that arranged in a straight line with the open axis of rotation. The method of claim 4, wherein The bending rotation axis and the open rotation axis of the finger module, characterized in that orthogonal to each other. The method of claim 1, The finger structure includes a plurality of nodes connected in line, The plurality of nodes are finger module, characterized in that connected relative to the rotation axis around the node. The method of claim 6, When the finger structure is not limited to the bending rotation, the entire finger structure rotates about the bending rotation axis without relative rotation between the plurality of nodes, When the bending motion of the first node of the node of the finger structure is limited, a second node connected to the first node subsequent to the first node is centered on a first node rotation axis formed at the connection portion between the first node and the second node. Finger module, characterized in that rotating. The method of claim 7, wherein The spreading operation is a finger module, characterized in that configured to be performed if the rotational movement of the node at the end of the finger structure is limited. The method of claim 7, wherein The finger structure, A crank rotatably connected about the first node axis of rotation, A first node link that is freely rotatable with respect to the crank about a first crank rotation axis, and receives a driving force of the motor to apply a force to rotate the crank about the first node rotation axis; A first bending stiffness imparting device for restraining the crank free rotation about the first node, A first node linking the crank with a force to rotate the first axis of rotation about the axis, the crank applies a force to the first node, characterized in that the first node rotates about the bending axis of rotation module. The method of claim 9, The finger structure is One end of which is freely rotatable with respect to the crank at a second crank axis of rotation, the other end of which comprises a second node link connected to exert a force on the second node, When the first node is in contact with the object and the bending motion of the first node is limited, the crank overcomes the first bending rigidity imparted by the first bending stiffness applying device and rotates about the first node rotation axis. and, And the second node link exerts a force on the second node by rotation of the crank so that the second node rotates about the first node about the first node axis of rotation. Base; A first finger module fixed relative to the base, The first finger module is a finger module according to any one of claims 1 to 10, And a frame of the first finger module is fixed to the base. The method of claim 11, Further comprising a second finger module fixed to the base, And the second finger module is formed in a mirror symmetrical structure with the first finger module such that the first finger module and the opening operation direction are opposite to each other. The method of claim 12, Further comprising a third finger module fixed to the base, And the third finger module is formed in a mirror symmetrical structure with the second finger module such that the bending direction of the second finger module and the second finger module are formed in opposite directions. The method of claim 13, The third finger module gripper, characterized in that the separation axis of rotation is fixed so that the separation operation is not made.

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