JP2023119278A - Robot hand device and robot hand operating method - Google Patents

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

The present invention provides a humanoid robot hand device and robot hand operation method that can bend phalanges that make up five fingers step by step according to the shape and condition of an object (hard, soft, fragile, etc.). Regarding.

A typical five-fingered robot hand is often attached to an articulated robot arm and operated in an integrated environment so that it can perform the same motion as a human being.
In such a robot hand, it is necessary to appropriately bend the phalanges according to the shape and state (hard, soft, fragile, etc.) of the object to be gripped.

Techniques described in Patent Documents 1 and 2 are disclosed as this type of robot.
The robot hand disclosed in Japanese Patent Laid-Open No. 2002-200003 has a finger portion whose outer shape is formed by a wire rod group in which a plurality of loop-shaped elastic wire rods are arranged at predetermined intervals in the phalanx portion, and a joint portion. (for example, a servo motor, a stepping motor, a combination of a motor and a gear, etc.), and a displacement sensor that is installed around the tip of the wire rod group and detects the load when it comes into contact with the object.
Then, in the control unit of the robot hand, the bending motion of the phalanx is performed by the motor according to the load around the tip of the wire group detected by the displacement sensor.

In the robot hand disclosed in Patent Document 2, an elastic portion provided in a finger body portion where a gripping force acts when an object to be gripped by fingers acts, and a reaction force provided for each joint when the joint is bent. and a tactile sensor that senses receiving a
In this robot hand, the joints of the finger body are sequentially bent by energizing a plurality of motors for each joint of the finger body in order from the finger root side.
At that time, since the robot hand sequentially bends the finger bodies from the joints on the root side to grip the grasped object so as to wrap it, it is expected that strong local stimulation is applied to the grasped object by the movement. In addition to preventing this, a soft and reliable gripping operation can be performed.

Japanese Patent Application Laid-Open No. 2021-160022 JP 2018-001359 A

By the way, in the robot hands disclosed in Patent Documents 1 and 2, the phalanges/joints are flexed by controlling the driving of the motors, but it is difficult to finely control the movement order of the phalanges/joints, the degree of flexion, and the like. There is a problem that a gripping operation suitable for the object cannot be performed.

The present invention has been made in view of the circumstances described above, and a robot hand device capable of executing a gripping motion of the phalanx suitable for an object by using a new control element called sliding resistance. and a robot hand motion method.

In order to solve the above problems, the present invention proposes the following means.
The robot hand apparatus according to the first aspect of the present invention has a plurality of phalanxes that are rotatably connected, and each finger part is composed of the plurality of phalanxes, and the finger part is attached to the hand main body. a joint mechanism rotatably connected to the joint mechanism; bending drive means for bending the phalanx of the joint mechanism; rotating range adjusting means for adjusting the rotating range, wherein the rotating range adjusting means comprises a variable load mechanism that individually adjusts the rotational sliding resistance of the rotating parts of the phalanx by voltage application.

In the joint operation method according to the second aspect of the present invention, each finger part has a plurality of phalanges that are rotatably connected, and each finger part is configured by the plurality of phalanxes, and these finger parts are attached to the hand main body. A robot hand device comprising joint mechanisms rotatably connected to each other, a bending drive step for bending the phalanx of the joint mechanism, and a rotation range for adjusting the rotation range of each of the phalanges by the bending drive step and a step of adjusting the rotation range, wherein the step of adjusting the rotation range comprises a variable resistance step of individually adjusting the rotational sliding resistance of the rotating portions of the phalanx by applying voltage.

According to the present invention, by providing a dedicated variable load mechanism that individually adjusts the rotational sliding resistance of the rotating parts of the phalanx, the phalanx suitable for the shape and state of the object (hard, soft, brittle, etc.) It is possible to perform a fine grasping motion.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the minimum structure of the robot hand apparatus which concerns on this invention, Comprising: (A) is a schematic block diagram of whole, (B) is a figure which shows a variable load mechanism. 1 is a schematic configuration diagram showing finger parts of a robot hand device according to an embodiment; FIG. It is a figure which shows the internal structure of finger parts. FIG. 4 is a diagram showing an operation example of the variable load mechanism indicated by symbol IV in FIG. 3, where (A) shows a state in which voltage is not applied to the coil, and (B) shows a state in which voltage is applied to the coil. (A) to (D) are diagrams showing a continuous operation example 1 of the robot hand device according to the embodiment. (A) to (C) are diagrams showing a continuous operation example 2 of the robot hand device according to the embodiment. (A) to (D) are diagrams showing a continuous operation example 3 of the robot hand device according to the embodiment. It is a figure which shows the modification 1 of embodiment. It is a figure which shows the modification 2 of embodiment.

A minimum configuration of a robot hand device 100 according to the present invention will be described with reference to FIGS. 1(A) and 1(B).
This robot hand device 100 has, as main components, a joint mechanism 50, a bending driving means 51, and a rotation range adjusting means 52, as shown in FIG. 1(A).
The joint mechanism 50 has a plurality of phalanges a to c and phalanges d and e rotatably connected via phalanx rotation shafts (m1, m2 and m3), and these phalanges a to A plurality of finger parts 1 to 5 (five in the drawing, but can be changed as appropriate) are composed of c and phalanges d and e.
Further, in this joint mechanism 50, these five finger parts 1 to 5 are rotatably connected to the hand main body 6 via rotation support shafts (n1, n2, n3).

The bending driving means 51 is for bending the phalanxes a to e of the joint mechanism 50 from the reference position, and is composed of, for example, a motor and a wire.

The rotation range adjustment means 52 is provided at the rotation positions of the phalanges a to e of the joint mechanism 50, and adjusts the respective rotation ranges of the phalanges a to e by the bending drive means 51. etc., to vary the rotation resistance at each rotation point of the phalanges a to e.
Specifically, as shown in FIG. 1(B), the rotation range adjusting means 52 is composed of a variable load mechanism 53 that individually adjusts the rotational sliding resistance of the rotating portions of the phalanges a to e by applying a voltage.

According to the robot hand device 100 according to the present invention described above, apart from the bending drive means 51 for bending the phalanges a to e of the joint mechanism 50, the phalanges a to e are rotated by applying a voltage to the phalanges a to e. It is a configuration in which a variable load mechanism 53 is provided to individually adjust the rotational sliding resistance of the rotational portions a to e to adjust the respective rotational ranges of the phalanges a to e.
That is, in the robot hand device 100 of the present invention, by providing the dedicated variable load mechanism 53 for individually adjusting the rotational sliding resistance of the rotational portions of the phalanges a to e, the shape and state of the object (hard, soft, , fragile, etc.).

(embodiment)
A robot hand device 101 according to an embodiment of the present invention will be described with reference to FIGS. 2 to 9. FIG.
As shown in FIG. 2, the robot hand device 101 is mainly composed of a joint mechanism 20, bending driving means 21, and rotation range adjusting means 22, and is a multi-joint robot arm (not shown). is installed at the tip of the

The joint mechanism 20 has a plurality of phalanges A to C rotatably connected via the phalanx rotation shafts (M1, M2), and the plurality of phalanges A to C, for example, each of five A finger part 11 is constructed.
Further, in the joint mechanism 20, the finger part 11 is rotatably connected to the hand main body 16 via the rotation support shaft N1.

In the finger part 11, the phalanx rotation axis M1 corresponds to the "first joint", the phalange rotation axis M2 to the "second joint", and the rotation support axis N1 to the "third joint".
Specifically, in the joint mechanism 20 of the finger part 11, the phalanx rotation axes M1 and M2 and the rotation support axis N1 of the three phalanges A to C are arranged in a parallel or substantially parallel positional relationship, It is rotatably provided from the reference position O in the initial state shown in FIG. .

The flexion drive means 21 causes the phalanges A to C of the joint mechanism 20 to flex their palms to the flat side in the plus direction (arrow P1 direction) from the reference position O, or in the minus direction (arrow R1 direction) from the reference position O. ), and is composed of a wire 30, for example.
Two wires 30 are installed for each finger part 11 and connected to the phalanx A located at the tip of each finger part 11 .
In addition, in order to apply a bending force to each finger part 11, the wire 30 of each finger part 11 is slightly flat side/back side from the rotation center of the phalanx rotation shafts (M1, M2) and the rotation support shaft (N1). It is installed in a misaligned position.
Also, the wire 30 of each finger part 11 is pulled or pulled out by an actuator 41 installed at an arbitrary portion of the structure constituting the hand, wrist, or arm.

The rotation range adjustment means 22 is provided at the rotation positions of the phalanges A to C, and adjusts the respective rotation ranges of the phalanges A to C by the bending drive means 21. Rotation resistance at each rotation point of ∼C is variable.
Specifically, the rotation range adjusting means 22 is composed of a variable load mechanism 24 that individually adjusts the rotational sliding resistance of the rotating portions of the phalanxes A to C by applying voltage.

In addition, the variable load mechanism 24 controls the order of movement of each joint by adjusting the voltage or the like to vary the rotational resistance at each rotational position of the phalanxes A to C to change the sliding load.
In addition, the variable load mechanism 24 of the rotation range adjusting means 22 includes, in the finger part 11, the phalanx rotation axis M1 as the "first joint", the phalange rotation axis M2 as the "second joint", and the "third joint". is provided on the rotation support shaft N1.

A specific configuration of the variable load mechanism 24 will be described with reference to FIGS. 3 to 9. FIG.
FIGS. 3 and 4 show an example of the variable load mechanism 24 positioned between the phalanx A and the phalanx B of the finger part 11. FIG.
As shown in FIG. 4A, the variable load mechanism 24 includes a shaft 25 serving as a phalanx rotation axis M1 that rotatably connects the phalanx A and the phalanx B, and a coil holder 26A attached to the shaft 25. It is an electromagnetic brake having a coil 26 fixed via a coil 26, a rod 27 made of a magnetic material to which a magnetic field generated by energization of the coil 26 is applied, and an outer ring 28 to which the rod 27 is fixed. It should be noted that the coil 26 is energized by turning the switch 29 ON/OFF.

In these structures, the shaft 25 and the coil 26 are fixed on the phalanx A side, and the rod 27 and the outer ring 28 are installed so as to be axially movable with respect to the shaft 25 . A bearing (not shown) is installed between the shaft 25 and the phalanx B. As shown in FIG.
In such a variable load mechanism 24, by energizing the coil 26 as shown in FIG. The outer ring 28 contacts and slides on the phalanx B (the contact-sliding portion is indicated by reference numeral 28A in FIG. 4(B)).
As a result, the variable load mechanism 24 can apply a sliding load to the relative rotation of the phalanx A and the phalanx B. As shown in FIG.

As a result, in the rotation range adjusting means 22, each coil 26 of the variable load mechanism 24 provided on each of the phalanx rotating shafts M1 and M2 and the phalanx supporting shaft N1 of the phalanges A to C is selectively By energizing the phalanxes A to C, it is possible to freely rotate/stop the rotation at the rotating portions.
At this time, by adjusting the magnitude of the current/voltage supplied to each coil 26 in the variable load mechanism 24, the presence or absence of rotation of the phalanxes A to C, as well as the amount of rotation, that is, the rotation angle, can be freely adjusted. be able to.

A contact sensor 31 is provided on the surface of the finger part 11 as shown in FIGS.
The contact sensor 31 detects whether or not an object is gripped, and is installed on both the flat side and the back side of the finger part 11 (only one side is shown in the figure). These contact sensors 31 are arranged on an elastic sheet 42 (see FIG. 2) that covers the finger part 11. As shown in FIG.

Next, the operation of the variable load mechanism 24 of the rotation range adjusting means 22 will be described with reference to FIGS. 4 and 5 to 7. FIG.
As shown in FIGS. 4A and 4B, first, when a voltage is applied to the variable load mechanisms 24 of the phalanges A to C for which a sliding load is to be generated, the magnetic force generated in the coil 26 causes a magnetic The rod 27, which is the body, is drawn into the coil 26, the outer ring 28 contacts the phalanges A to C (the phalanx B in this example), and rotates between the shaft 25, which is the rotation axis, and the phalanges A to C. generate a load.

After that, when the wire 30 is pulled, the phalanges A to C start to bend. In A to C, rotation starts after the lightly loaded phalanges A to C have fully bent.
That is, the rotation range adjusting means 22 raises the load of the variable load mechanism 24 to the maximum to lock the target phalanges A to C, thereby preventing the phalanges A to C from moving in the same manner. Individual flexion control of phalanges A-C can be achieved.

FIGS. 5A to 5D show an operation example for grasping a relatively small object with the phalanges A to C of the finger part 11. FIG.
First, in the variable load mechanism 24 of the rotation range adjusting means 22, the sliding load is set to "first phalanx A (phalanx rotation axis M1)<second phalanx B (phalanx rotation axis M2)<third phalanx C. (phalange support axis N1)", the wire 30 on the predetermined side is pulled by the actuator 41 (see FIG. 2) of the bending drive means 21. As shown in FIG.

Thus, when the first phalanx A bends first and finishes bending, the second phalanx B begins to bend slowly, and then the third phalanx C begins to bend. At this time, when the bending state of the phalanxes A and B reaches an angle at which the object can be sandwiched between the phalanxes A and B, the sliding load on the third phalanx C is reduced to control the degree of bending.
As a result, in the robot hand device 101, it is possible to pinch a relatively small object by bending the five-finger part 11. As shown in FIG.

FIGS. 6A to 6C show examples of operations for gripping a thin object such as paper or a card with the phalanges A to C of the finger part 11. FIG.
First, in the variable load mechanism 24 of the rotation range adjusting means 22, the sliding load is set to "first phalanx A (phalanx rotation axis M1)=second phalanx B (phalanx rotation axis M2)>third phalanx C. (phalange support axis N1)", the wire 30 on the predetermined side is pulled by the actuator 41 (see FIG. 2) of the bending drive means 21. As shown in FIG.
Thereby, when the third phalanx C bends first and finishes bending, the first phalanx A and the second phalanx B begin to bend slowly. As a result, the robot hand device 101 can pinch a thin object such as paper or a card by bending the five-finger part 11 .

FIG. 7 shows an operation example of the phalanges A to C of the finger part 11 using the detection signal of the contact sensor 31. As shown in FIG.
In the variable load mechanism 24 of the rotation range adjusting means 22, when the contact sensor 31 detects that the object to be grasped S1 is pinched or pinched, the operation of the actuator 41 is stopped in stages so that the object can be grasped without being crushed. enable

For example, in the variable load mechanism 24 of the rotation range adjusting means 22, when gripping a fragile object S1 such as an egg, first, the sliding resistance of only the third phalanx C (phalange support axis N1) is reduced. make it movable.
After that, in the variable load mechanism 24, when the contact sensor 31 of the third phalanx C detects contact with the object S1, as shown in FIGS. The sliding resistance is maximized to stop the movement, and the sliding resistance of the second phalanx B (phalanx rotation axis M2) is lightened to move the second phalanx B.
After that, in the variable load mechanism 24, when the contact sensor 31 of the second phalanx B detects contact with the object S1, as shown in FIGS. The sliding resistance is maximized to stop the movement, and the sliding resistance of the first phalanx A (phalange rotation axis M1) is lightened to move the first phalanx A.

After that, when the contact sensor 31 of the first phalanx A has detected contact with the object S1, the variable load mechanism 24 stops pulling the wire 30 as shown in FIGS. Let
By providing the contact sensors 31 on both the flat side and the back side of the robot hand device 101, the phalanges A to C of the finger part 11 can be bent to either the flat side or the back side. , the fragile object S1 can be freely grasped.

According to the robot hand device 101 according to the present embodiment described above, apart from the bending drive means 21 for bending the phalanges A to C of the joint mechanism 20, the phalanxes A to C are rotated by voltage application. A variable load mechanism 24 is provided for adjusting the rotation range of each of the phalanxes A to C by individually adjusting the rotational sliding resistance of the rotational portions of the phalanxes A to C.
That is, in the robot hand device 101 of the present embodiment, by providing the dedicated variable load mechanism 24 that individually adjusts the rotational sliding resistance of the rotational portions of the phalanxes A to C, the shape and state of the object (hard, hard, (soft, fragile, etc.).

(Modification 1)
In the variable load mechanism 24 of the above embodiment, the relative rotation of the phalanxes A to C is regulated by sliding the outer ring 28 on the phalanxes A to C (the phalanx B in the example of FIG. 4). Not limited to this, as shown in FIG. 8, without using the coil 26, the rod 27 and the outer ring 28, the shape memory shaft 32 formed of a shape memory alloy is used to regulate the relative rotation of the phalanxes A to C. Also good.

This shape-memory shaft 32 is provided in place of the shaft 25 shown in FIG. generate dynamic resistance.
Note that FIG. 8 shows an example in which the shape-memory shaft 32 is used for the shafts of the phalanx rotation axes M1 and M2, and the phalanx rotation axis M1 to which no voltage is applied and no deformation occurs is indicated by the "solid line". , and the phalanx rotation axis M2 to which the voltage was applied and the deformation occurred is indicated by the "dashed line".

(Modification 2)
In addition, in the variable load mechanism 24 of the above embodiment, the relative rotation of the phalanxes A to C is regulated by sliding the outer ring 28 on the phalanxes A to C (the phalanx B in the example of FIG. 4). Not limited to this, as shown in FIG. 9, instead of the coil 26, the rod 27 and the outer ring 28, a shape memory spring 33 made of a shape memory alloy is used to restrict the relative rotation of the phalanges A to C. Also good.

By applying a voltage to both sides of the shape memory spring 33 and changing its shape, the shaft 25 is tightened and rotational sliding resistance is generated in the adjacent phalanges A to C. FIG.

It should be noted that the present invention can be applied and applied to objects that bend and stretch in general.
In addition, although the present invention focuses on the "hand", it can be replaced with elbows, knees, feet, etc. when bending and stretching motions are considered, and can also be applied to machines modeled on the structure of the human body.
In addition, as a medical device, an artificial arm or artificial leg is a device that reproduces the motion of each part of a human being, and plays the role of a second limb. The technology of the present invention can also be applied to this field.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are included within the scope of the present invention.

The present invention provides a humanoid robot hand device and a robot hand operating method that can bend phalanges that make up five fingers step by step according to the shape and condition of an object (hard, soft, fragile, etc.). Regarding.

1 finger part 2 finger part 3 finger part 4 finger part 5 finger part 6 hand main body 11 finger part 16 hand main body 20 joint mechanism 21 bending driving means 22 rotation range adjusting means 24 variable load mechanism 25 shaft 26 coil 27 rod 28 outer ring 29 switch 30 wire 31 contact sensor 32 shape memory shaft 33 shape memory spring 41 actuator 42 elastic sheet 50 joint mechanism 51 bending drive means 52 rotation range adjusting means 53 variable load mechanism a phalanx b phalanx c phalanx d phalanx e finger phalanx A phalanx B phalanx C phalanx m1 phalanx rotation axis m2 phalanx rotation axis m3 phalanx rotation axis n1 rotation support axis n2 rotation support axis n3 rotation support axis M1 phalanx rotation axis M2 phalanx rotation axis N1 rotation support Axis P1 Flat side R1 Instep side S1 Object 100 Robot hand device 101 Robot hand device

Claims (9)

a joint mechanism having a plurality of phalanxes that are rotatably connected, each finger part being composed of the plurality of phalanxes, and the finger part being rotatably connected to the hand main body;
bending driving means for bending the phalanges of the joint mechanism;
a rotation range adjustment means provided at a rotation location of the phalanx for adjusting the rotation range of each of the phalanges by the bending drive means;
The robot hand device according to claim 1, wherein the rotation range adjusting means comprises a variable load mechanism that individually adjusts the rotational sliding resistance of the rotating portions of the phalanx by applying a voltage. 2. The robot hand device according to claim 1, wherein the rotation range adjusting means bends the phalanx step by step by sequentially adjusting the rotational sliding resistance of the variable load mechanism. The variable load mechanism includes a shaft connected to one phalanx, a coil fixed to the shaft, a magnetic body provided on the outer periphery of the shaft so as to be movable along the axis of the shaft, and the An outer ring provided integrally with a magnetic body, and a switch for applying a voltage to the coil,
The coil is characterized in that when a voltage is applied by turning on the switch, the outer ring is brought into contact with the phalanx on the other side via the magnetic material, thereby generating sliding resistance between the two phalanxes. 3. The robot hand device according to claim 1 or 2. 2. The variable load mechanism is characterized in that the rotary shaft/support shaft of the joint mechanism is configured by a shape memory shaft, and the shape memory shaft is deformed by applying a voltage to generate rotational sliding resistance. 3. The robot hand device according to any one of 2. 3. The variable load mechanism has a shape memory spring that constrains the rotating part of the joint mechanism, and the shape memory spring is deformed by applying voltage to generate rotational sliding resistance. The robot hand device according to any one of 1. 4. The bending driving means is characterized in that the phalanges of the joint mechanism are palm-flexed from the reference position to the flat side, which is the positive direction, and dorsiflexed from the reference position to the dorsal side, which is the negative direction. The robot hand device according to any one of 1 to 5. The robot hand device according to any one of claims 1 to 6, wherein said bending driving means comprises a wire for pulling/loosening the phalanx of said joint mechanism. 8. The robot hand device according to claim 7, wherein the wire is connected to the first phalanx of the finger part. The hand has a plurality of phalanxes that are rotatably connected to form each finger part, and a joint mechanism in which these finger parts are also rotatably connected to the hand main body. In the robot hand device,
a flexion driving step for flexing the phalanges of the articulation mechanism;
a rotation range adjustment step of adjusting the rotation range of each of the phalanges by the flexion drive step;
The method for operating a joint in a robot hand device, wherein the rotational range adjusting step individually adjusts the rotational sliding resistance of the rotational portions of the phalanx by applying a voltage.

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