Robot hand device

Abstract

To provide a robot hand that can execute grip-motion of fingers that is suitable for an object, by using a new control element referred to as sliding resistance, and a robot hand operating method.SOLUTION: The robot hand device comprises bending / driving means 51 that bends fingers (a-e) of a joint mechanism 50 and rotation range adjusting means 52, provided in rotation places of the fingers (a-e), which adjusts respective ranges of rotation of the fingers (a-e) by the bending / driving means 51. The rotation range adjusting means 52 is constituted of variable load mechanisms 53 that adjust individually rotational sliding resistance of the rotation places of the fingers (a-e) by applying voltages.SELECTED DRAWING: Figure 1

Description

Technical Field

[0004] ,

[0001] The present invention relates to a humanoid robot hand device and a robot hand operation method capable of gradually bending the finger joints constituting five fingers according to the shape and state (hard, soft, brittle, etc.) of an object.

Background Art

[0002] In a general five-finger robot hand, it is often operated in an integrated environment attached to a multi-joint robot arm so that the same operations as those of a human can be performed. And in such a robot hand, it is necessary to appropriately bend the finger joints according to the shape and state (hard, soft, brittle, etc.) of the object to be grasped.

[0003] As this type of robot, the techniques described in Patent Documents 1 and 2 are disclosed. The robot hand shown in Patent Document 1 includes a finger portion whose outer shape is formed by a group of wires in which a plurality of wires having a loop-shaped elasticity are arranged at a predetermined interval in a knuckle portion, a motor for driving a joint portion (for example, a servo motor, a stepping motor, a combination of a motor and a gear, etc.), and a displacement sensor installed around the tip of the wire group for detecting a load when contacting an object. And in the control unit of this robot hand, according to the load around the tip of the wire group detected by the displacement sensor, the motor is made to perform the bending operation of the knuckle.

[0004] The robot hand shown in Patent Document 2 includes an elastic portion provided on a finger body portion where a gripping force acts when gripping an object to be gripped, and a tactile sensor provided for each joint for sensing a reaction force when the joint is bent. And in this robot hand, by sequentially energizing a plurality of motors for each joint in the finger body from the base side of the finger, the joints of the finger body are sequentially bent. In this robotic hand, the fingers are bent sequentially from the base joint to grasp the object being grasped, thereby preventing strong localized stimulation to the object being grasped and enabling a soft and reliable grasping motion. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-160022 [Patent Document 2] Japanese Patent Publication No. 2018-001359 [Overview of the project] [Problems that the invention aims to solve]

[0006] By the way, in the robot hands shown in Patent Documents 1 and 2, the flexion of the phalanges / joints is performed by controlling the drive of the motor, but there is a problem in that it is difficult to finely control the sequence of movement of the phalanges / joints and the degree of flexion, making it impossible to perform a gripping operation suitable for the object.

[0007] This invention has been made in view of the above circumstances, and provides a robot hand device and a robot hand operation method that can perform a finger joint gripping operation suitable for an object by using a new control element called sliding resistance. [Means for solving the problem]

[0008] To solve the above problems, this invention proposes the following means. A robot hand device according to a first aspect of the present invention comprises a joint mechanism having a plurality of rotatably connected joints, each joint constituting a finger part, and the finger part being rotatably connected to the hand body; a bending drive means for bending the joints of the joint mechanism; and a rotation range adjustment means provided at the rotation points of the joints for adjusting the rotation range of each joint by the bending drive means, wherein the rotation range adjustment means consists of a variable load mechanism that individually adjusts the rotation sliding resistance of the rotation points of the joints by applying a voltage.

[0009] A joint motion method according to a second aspect of the present invention is a robot hand device having a joint mechanism having a plurality of rotatably connected phalanges, wherein each finger part is composed of these plurality of phalanges, and these finger parts are also rotatably connected to the hand body, wherein the joint mechanism comprises a bending drive step for bending the phalanges of the joint mechanism, and a rotation range adjustment step for adjusting the rotation range of each of the phalanges by the bending drive step, and the rotation range adjustment step is characterized in that it comprises a resistance variable step for individually adjusting the rotational sliding resistance of the rotational parts of the phalanges by applying a voltage. [Effects of the Invention]

[0010] According to the present invention, by providing a dedicated variable load mechanism that individually adjusts the rotational sliding resistance of the phalangeal joints, it becomes possible to perform fine gripping movements of the phalangeal joints that are suitable for the shape and condition of the object (hard, soft, brittle, etc.). [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows the minimum configuration of the robot hand device according to the present invention, where (A) is a schematic diagram of the overall configuration and (B) is a diagram showing the variable load mechanism. [Figure 2] This is a schematic diagram showing the finger parts of a robot hand device according to an embodiment. [Figure 3] This diagram shows the internal structure of the finger parts. [Figure 4]FIG. 3 is a diagram showing an operation example of the variable load mechanism represented by reference numeral IV, where (A) shows a state in which no voltage is applied to the coil, and (B) shows a state in which a voltage is applied to the coil. [Figure 5] (A) to (D) are diagrams showing a continuous operation example 1 of the robot hand device according to the embodiment. [Figure 6] (A) to (C) are diagrams showing a continuous operation example 2 of the robot hand device according to the embodiment. [Figure 7] (A) to (D) are diagrams showing a continuous operation example 3 of the robot hand device according to the embodiment. [Figure 8] FIG. showing a modification example 1 of the embodiment. [Figure 9] FIG. showing a modification example 2 of the embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0012] [[ID=ID=23]]The minimum configuration of the robot hand device 100 according to the present invention will be described with reference to FIGS. 1(A) and (B). As shown in FIG. 1(A), this robot hand device 1 is mainly composed of a joint mechanism 50, a bending drive means 51, and a rotation range adjustment means 52. The joint mechanism 50 has a plurality of finger joints a to c and finger joints d and e rotatably connected via finger joint rotation shafts (m1, m2, and m3), and a plurality of finger parts 1 to 5 (five in the drawing, but can be appropriately changed) are constituted by these plurality of finger joints a to c and finger joints d and e. In addition, in this joint mechanism 50, these five finger parts 1 to 5 are configured to be rotatably connected to the hand main body part 6 via rotation support shafts (n1, n2, and n3).

[0013] The bending drive means 51 is for bending the finger joints a to e of the joint mechanism from a reference position, and is constituted by, for example, a motor, a wire, or the like.

[0014] The rotation range adjustment means 52 is provided at the rotation points of the finger joints a to e of the joint mechanism 50, and adjusts the respective rotation ranges of the finger joints a to e by the bending drive means 51, and varies the rotational resistance at each rotation point of the finger joints a to e by adjusting the voltage or the like. Specifically, as shown in FIG. 1(B), the rotation range adjustment means 52 includes a variable load mechanism 53 that individually adjusts the rotational sliding resistance at the rotation points of the finger joints a to e by applying a voltage.

[0015] According to the robot hand device 100 according to the present invention described above, separately from the bending drive means 51 that bends the finger joints a to e of the joint mechanism 50, at the rotation points of the finger joints a to e, a variable load mechanism 53 that individually adjusts the rotational sliding resistance at the rotation points of the finger joints a to e by applying a voltage and adjusts the respective rotation ranges of the finger joints a to e is provided. That is, in the robot hand device 100 of the present invention, by providing a dedicated variable load mechanism 53 that individually adjusts the rotational sliding resistance at the rotation points of the finger joints a to e, it becomes possible to execute a fine gripping operation of the finger joints a to e suitable for the shape and state (hard, soft, brittle, etc.) of the object.

[0016] (Embodiment) ​​​​​​​​​​​​In finger part 11, the phalangeal rotation axis M1 corresponds to the "first joint," the phalangeal rotation axis M2 corresponds to the "second joint," and the rotation support axis N1 corresponds to the "third joint." Specifically, in the joint mechanism 20 of the finger part 11, the phalangeal rotation axes M1, M2 and rotation support axis N1 of the three phalanges A to C are arranged in a positional relationship that is parallel or nearly parallel to each other, and are rotatably provided on the flat side which is in the positive (+) direction (direction of arrow P1) or the back of the hand which is in the negative (-) direction (direction of arrow R1) from the initial reference position O shown in Figure 2.

[0019] The flexion driving means 21 is used to drive the phalanges A to C of the joint mechanism 20 to palmar flexion toward the palm side in the positive direction (direction of arrow P1) from the reference position O, or to dorsiflexion toward the back of the hand in the negative direction (direction of arrow R1) from the reference position O, and is composed of, for example, a wire 30. The wires 30 are installed for each finger part 11, and two wires are connected to the phalanges A located at the tip of each finger part 11. Furthermore, the wires 30 of each finger part 11 are positioned slightly offset towards the flat side / back side from the rotation centers of the phalangeal rotation axes (M1, M2) and the rotation support axis (N1) in order to apply bending force to each finger part 11. Furthermore, the wires 30 of each finger part 11 are pulled or pulled out by actuators 41 installed at any part of the structure that makes up the hand, wrist, or arm.

[0020] The rotation range adjustment means 22 is provided at the rotation points of phalanges A to C and adjusts the rotation range of each phalange A to C by the bending drive means 21, thereby varying the rotation resistance at each rotation point of phalanges A to C by adjusting the voltage, etc. Specifically, the rotation range adjustment means 22 consists of a variable load mechanism 24 that individually adjusts the rotational sliding resistance of the rotation points of phalanges A to C by applying a voltage.

[0021] Furthermore, this variable load mechanism 24 controls the sequence of movement of each joint by changing the sliding load by varying the rotational resistance at each rotation point of phalanges A to C through voltage adjustment, etc. The variable load mechanism 24 of the rotation range adjustment means 22 is provided on the phalangeal rotation axis M1 which becomes the "first joint", the phalangeal rotation axis M2 which becomes the "second joint", and the rotation support axis N1 which becomes the "third joint" in the finger part 11.

[0022] The specific configuration of the variable load mechanism 24 will be explained with reference to Figures 3 to 9. Figures 3 and 4 show an example of a variable load mechanism 24 located between phalanges A and B of the finger part 11. As shown in Figure 4(A), the variable load mechanism 24 is an electromagnetic brake comprising a shaft 25 which serves as a phalangeal rotation axis M1 that rotatably connects phalangeal A and phalangeal B, a coil 26 fixed to the shaft 25 via a coil holder 26A, a rod 27 made of a magnetic material to which the magnetic field generated by energizing the coil 26 acts, and an outer ring 28 to which the rod 27 is fixed. The energizing of the coil 26 is performed by turning a switch 29 ON / OFF.

[0023] In this configuration, the shaft 25 and coil 26 are fixed to the phalangeal A side, while the rod 27 and outer ring 28 are installed to be movable axially relative to the shaft 25. A bearing (not shown) is also installed between the shaft 25 and the phalangeal B. In this variable load mechanism 24, as shown in Figure 4(B), by energizing the coil 26, the rod 27 moves along the shaft 25 in the left-right direction in the figure, and the outer ring 28, which is integrated with the rod 27, contacts and slides against the phalangeal B (the contact and sliding point is indicated by reference numeral 28A in Figure 4(B)). This allows the variable load mechanism 24 to apply a sliding load to the relative rotation of phalanges A and B.

[0024] As a result, the rotation range adjustment means 22 selectively energizes each coil 26 of the variable load mechanism 24 provided on the phalangeal rotation axes M1, M2 and the phalangeal support axis N1 of phalangeal segments A to C, thereby allowing for free rotation / stopping of the rotation of the rotating parts of phalangeal segments A to C. Furthermore, in this case, the variable load mechanism 24 can adjust the magnitude of the current / voltage supplied to each coil 26, thereby freely adjusting not only whether or not the phalanges A to C rotate, but also the amount of rotation, i.e., the rotation angle.

[0025] Furthermore, a contact sensor 31 is provided on the surface of the finger part 11, as shown in Figures 2 and 7. The contact sensor 31 detects whether or not an object is being grasped, and is installed on both the palm side and the back side of the finger part 11 (only one side is shown in the figure). These contact sensors 31 are placed on the elastic sheet 42 (see Figure 2) that covers the finger part 11.

[0026] Next, the operation of the variable load mechanism 24 of the rotation range adjustment means 22 will be explained with reference to Figures 4 and 5 to 7. As shown in Figures 4(A) to 4(B), when a voltage is first applied to the variable load mechanism 24 of the phalanges A to C where a sliding load is to be generated, the magnetic force generated in the coil 26 pulls the magnetic rod 27 into the coil 26, causing the outer ring 28 to come into contact with the phalanges A to C (phalanges B in this example), and generating a rotational load between the shaft 25, which serves as the axis of rotation, and the phalanges A to C.

[0027] Subsequently, when the wire 30 is pulled, flexion of phalanges A to C begins. At this time, phalanges A to C, which are under light load, start moving quickly and rotate widely, while phalanges A to C, which are under heavy load, begin to rotate only after phalanges A to C, which are under light load, have finished bending. In other words, the rotation range adjustment means 22 maximizes the load of the variable load mechanism 24, locking the targeted phalanges A to C in place. This prevents phalanges A to C from moving simultaneously, and instead enables control to bend each phalange A to C individually.

[0028] Figures 5(A) to (D) show examples of movements for grasping relatively small objects using phalanges A to C of finger part 11. First, in the variable load mechanism 24 of the rotation range adjustment means 22, the sliding load is set to "first phalangeal A (phalangeal rotation axis M1) < second phalangeal B (phalangeal rotation axis M2) < third phalangeal C (phalangeal support axis N1)". Then, the actuator 41 (see Figure 2) of the bending drive means 21 pulls the wire 30 on the predetermined side.

[0029] As a result, once the first phalangeal segment A bends and finishes flexing, the second phalangeal segment B slowly begins to bend, followed by the third phalangeal segment C. At this point, when the flexed state of phalangeal segments A and B reaches an angle where they can grip an object, the sliding load on the third phalangeal segment C is reduced to control the degree of bending. As a result, the robot hand device 101 can grasp relatively small objects by bending the five-finger part 11.

[0030] Figures 6(A) to (C) show examples of movements for grasping thin objects such as paper or cards using phalanges A to C of finger part 11. First, in the variable load mechanism 24 of the rotation range adjustment means 22, the sliding load is set so that "first phalangeal A (phalangeal rotation axis M1) = second phalangeal B (phalangeal rotation axis M2) > third phalangeal C (phalangeal support axis N1)". Then, the actuator 41 (see Figure 2) of the bending drive means 21 pulls the wire 30 on the predetermined side. As a result, once the third phalangeal segment C bends and completes its flexion, the first phalangeal segment A and the second phalangeal segment B begin to bend slowly. This allows the robotic hand device 101 to grasp thin objects such as paper or cards by bending the five-finger part 11.

[0031] Figure 7 shows an example of the operation of finger joints A to C of the finger part 11 using the detection signal from the contact sensor 31. In the variable load mechanism 24 of the rotation range adjustment means 22, when the contact sensor 31 detects that the object to be gripped S1 has been pinched or caught, the operation of the actuator 41 is stopped in stages, thereby enabling gripping without crushing.

[0032] For example, in the variable load mechanism 24 of the rotation range adjustment means 22, when gripping a fragile object S1 such as an egg, the sliding resistance of only the third phalangeal C (phalangeal support axis N1) is first reduced to allow movement. Subsequently, when the variable load mechanism 24 detects that the contact sensor 31 of the third phalangeal segment C has come into contact with the object S1, it maximizes the sliding resistance of the third phalangeal segment C to stop its movement, as shown in Figures 7(A) to (B), and reduces the sliding resistance of the second phalangeal segment B (phalangeal segment rotation axis M2) to allow the second phalangeal segment B to move. Subsequently, when the variable load mechanism 24 detects that the contact sensor 31 of the second phalangeal B has come into contact with the object S1, it maximizes the sliding resistance of the second phalangeal B to stop its movement, as shown in Figures 7(B) to 7(C), and reduces the sliding resistance of the first phalangeal A (phalangeal rotation axis M1) to allow the first phalangeal A to move.

[0033] Subsequently, when the variable load mechanism 24 detects that the contact sensor 31 of the first phalangeal A has come into contact with the object S1, it stops pulling the wire 30 as shown in Figures 7(C) to (D). Furthermore, by equipping the robot hand device 101 with contact sensors 31 on both the palm side and the back side, the phalanges A to C of the finger parts 11 can be bent to either the palm side or the back side, making it possible to freely grasp fragile objects S1.

[0034] In the robot hand device 101 according to the embodiment described above, in addition to the bending drive means 21 that bends the phalanges A to C of the joint mechanism 20, a variable load mechanism 24 is provided at the rotation points of phalanges A to C to adjust the rotation range of each phalange A to C by individually adjusting the rotational sliding resistance of the rotation points of phalanges A to C by applying a voltage. In other words, the robot hand device 101 of this embodiment is equipped with a dedicated variable load mechanism 24 that individually adjusts the rotational sliding resistance of the rotating parts of the finger joints A to C, making it possible to perform fine gripping operations of finger joints A to C that are suitable for the shape and condition of the object (hard, soft, brittle, etc.).

[0035] (Variation 1) In the variable load mechanism 24 of the above embodiment, the relative rotation of phalanges A to C (phalanges B in the example of Figure 4) is restricted by sliding the outer ring 28 on phalanges A to C. However, the mechanism is not limited to this, and as shown in Figure 8, the relative rotation of phalanges A to C may be restricted by using a shape memory shaft 32 made of shape memory alloy instead of using the coil 26, rod 27, and outer ring 28.

[0036] This shape-memory shaft 32 is installed in place of the shaft 25 shown in Figure 4, and by applying voltage to both sides of it and changing its shape, rotational sliding resistance is generated in the adjacent phalanges A to C. Figure 8 shows an example in which shape memory shafts 32 are used for the shafts of the phalangeal rotation axes M1 and M2. The phalangeal rotation axis M1, which is not deformed because no voltage is applied, is shown as a "solid line," while the phalangeal rotation axis M2, which is deformed because voltage is applied, is shown as a "dashed line."

[0037] (Modification 2) Furthermore, in the variable load mechanism 24 of the above embodiment, the relative rotation of phalanges A to C (phalanges B in the example of Figure 4) is restricted by sliding the outer ring 28 on phalanges A to C. However, the mechanism is not limited to this, and as shown in Figure 9, the relative rotation of phalanges A to C may be restricted by using a shape memory spring 33 made of a shape memory alloy instead of the coil 26, rod 27, and outer ring 28.

[0038] This shape-memory spring 33 changes its shape by applying voltage to both sides, thereby tightening the shaft 25 and generating rotational sliding resistance in the adjacent phalanges A to C.

[0039] Furthermore, this invention can be applied to a wide range of objects that perform bending and stretching movements. Furthermore, although this invention focuses on the "hand," when considering bending and extending movements, it can be replaced with the elbow, knee, or foot, and can also be applied to machines that model themselves after the structure of the human body. Furthermore, prosthetic arms and legs, used as medical devices, are devices that reproduce the movements of various human body parts and serve as second limbs. The technology of this invention can also be applied to this field.

[0040] Although embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design modifications and the like are also included within the scope of the gist of the present invention. [Industrial applicability]

[0041] The present invention relates to a humanoid robot hand device and a robot hand operation method that can flex the phalanges constituting the five fingers in stages according to the shape and condition of the object (hard, soft, brittle, etc.). [Explanation of symbols]

[0042] 1 Finger part 2 Finger parts 3 Finger parts 4 finger parts 5 Finger parts 6. Hand Body 11 finger parts 16. Hand Body 20 Joint Mechanisms 21 Bending drive means 22 Rotation range adjustment means 24 Variable load mechanism 25 shaft 26 coils 27 Rods 28 Outer ring 29 switches 30 wires 31 Contact Sensor 32 Shape memory shaft 33 Shape memory spring 41 Actuator 42 Elastic Sheets 50 Joint Mechanisms 51 Bending drive means 52 Rotation range adjustment means 53 Variable Load Mechanism a phalanx b phalanx c phalanx d phalanx e phalanx A phalanx B phalanx C phalanx m1 phalangeal axis m2 phalangeal rotation axis m3 phalangeal axis n1 Rotation support shaft n2 Rotating support shaft n3 Rotating support shaft M1 phalangeal rotation axis M2 Phalangeal rotation axis N1 Rotating support shaft P1 Flat side R1 Top of hand S1 Object 100 Robot Hand Devices 101 Robot Hand Device

Claims

1. A joint mechanism having multiple joints that are rotatably connected, with these joints forming each finger part, and the finger part being rotatably connected to the hand body, A bending drive means for bending the phalanges of the aforementioned joint mechanism, The device comprises a rotation range adjusting means provided at the rotation point of the phalangeal joint for adjusting the rotation range of each phalangeal joint by the bending drive means, The rotation range adjustment means consists of a variable load mechanism that individually adjusts the rotational sliding resistance of the rotating parts of the joint by applying a voltage. The variable load mechanism comprises a shaft connected to one of the joints, a coil fixed to the shaft, a magnetic body provided on the outer circumference of the shaft so as to be movable along the axis of the shaft, an outer ring provided integrally with the magnetic body, and a switch for applying voltage to the coil. The robot hand device is characterized in that, when a voltage is applied by turning on the switch, the coil brings its outer ring into contact with the other finger joint via the magnetic material, thereby generating sliding resistance between the two finger joints.

2. A joint mechanism having a plurality of joints that are rotatably connected, wherein each finger part is formed by these plurality of joints, and the finger part is rotatably connected to the hand body, A bending drive means for bending the phalanges of the aforementioned joint mechanism, The device comprises a rotation range adjusting means provided at the rotation point of the phalangeal joint for adjusting the rotation range of each phalangeal joint by the bending drive means, The rotation range adjustment means consists of a variable load mechanism that individually adjusts the rotational sliding resistance of the rotating parts of the joint by applying a voltage. The variable load mechanism uses a shape memory shaft for the rotation axis / support axis of the joint mechanism, and generates rotational sliding resistance by deforming the shape memory shaft so as to change the magnitude of the curvature of the rotational part of the shape memory shaft relative to the center of rotation when a voltage is applied. A robotic hand device characterized by the following features.

3. A joint mechanism having a plurality of joints that are rotatably connected, wherein each finger part is formed by these plurality of joints, and the finger part is rotatably connected to the hand body, A bending drive means for bending the phalanges of the aforementioned joint mechanism, The device comprises a rotation range adjusting means provided at the rotation point of the phalangeal joint for adjusting the rotation range of each phalangeal joint by the bending drive means, The rotation range adjustment means consists of a variable load mechanism that individually adjusts the rotational sliding resistance of the rotating parts of the joint by applying a voltage. The variable load mechanism has a shape memory spring that restrains the rotating part of the joint mechanism, and the shape memory spring is provided around the axis of the rotating part and generates rotational sliding resistance by deforming when a voltage is applied and tightening the axis.

4. The robot hand device according to any one of claims 1 to 3, characterized in that the rotation range adjustment means sequentially adjusts the rotational sliding resistance of the variable load mechanism to bend the finger joint in stages.

5. The robot hand device according to any one of claims 1 to 4, characterized in that the bending drive means causes the phalanges of the joint mechanism to palmar flexion toward the palm side in a positive direction from the reference position, and dorsiflexion toward the dorsal side in a negative direction from the reference position.

6. The robot hand device according to any one of claims 1 to 5, characterized in that the bending drive means consists of a wire for pulling / releasing the phalanges of the joint mechanism.

7. The robot hand device according to claim 6, characterized in that the wire is connected to the first phalangeal segment of the finger part.

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