WO2018212205A1

WO2018212205A1 - Hand mechanism, gripping system, and gripping program

Info

Publication number: WO2018212205A1
Application number: PCT/JP2018/018821
Authority: WO
Inventors: 晋治川畑; 嘉将遠藤; 文哉小泉; 松尾　芳一; 野村　祐樹; 聖也渡邉; 健児日高
Original assignee: Thk株式会社
Priority date: 2017-05-15
Filing date: 2018-05-15
Publication date: 2018-11-22

Abstract

Provided is a hand mechanism, wherein, regardless of the attitude and the surrounding circumstances of a target object, the target object is more desirably gripped. In this hand mechanism having three or more finger parts, when gripping a target object, at least one finger part among the three of more finger parts functions as a state changeable finger part which contacts the target object and then changes the attitude or position of the target object. In addition, at least two of finger parts other than the finger part functioning as the state changeable finger part function as gripping finger parts which grip the target object, the position or attitude of which has been changed by the state changeable finger part.

Description

Hand mechanism, gripping system, and gripping program

The present invention relates to a hand mechanism for gripping an object with a plurality of fingers, a gripping system, and a gripping program.

Conventionally, a hand mechanism that is attached to a robot arm or the like and grips an object with a plurality of fingers has been developed. For example, Patent Document 1 discloses a hand mechanism including three fingers (finger). In the hand mechanism disclosed in Patent Document 1, the three fingers have the same structure. Furthermore, in the hand mechanism of Patent Document 1, a plate member with a free end protruding from the tip is provided at the tip of the finger. By configuring the finger portion in such a manner, when the object placed on the plane is gripped by the hand mechanism, the finger member plate member is pushed between the plane and the object. The object can be held by the finger.

Special table 2015-533669

Generally, when a target object is gripped by a hand mechanism, it is necessary to set the target object in advance so that the posture of the target object and its surroundings are suitable for gripping by the hand mechanism. However, considering the use of the hand mechanism for various objects and under various circumstances, it is desirable to reduce the restrictions due to the installation state and the installation state of the object as much as possible.

The present invention has been made in view of the above problems, and provides a technique capable of more suitably gripping an object in a hand mechanism regardless of the posture of the object and its surroundings. With the goal.

The hand mechanism according to the present invention includes three or more fingers, and when gripping an object, at least one of the three or more fingers touches the object. While functioning as a state changing finger unit that changes the posture and / or position of the object above, at least two of the finger units other than the finger unit functioning as the state changing finger unit are: It functions as a gripping finger unit that grips the object in a state in which the posture and / or position has been changed by the state changing finger unit.

According to the present invention, in the hand mechanism, the object can be more appropriately gripped regardless of the posture of the object and the surrounding situation.

It is a figure which shows schematic structure of the robot arm which concerns on an Example. It is a perspective view of the hand mechanism which concerns on an Example. It is a top view of the hand mechanism which concerns on an Example. It is a side view of the finger | toe part of the hand mechanism which concerns on an Example. It is the figure which looked at the front-end | tip part side of the finger | toe part of the hand mechanism which concerns on an Example from the direction of the arrow A of FIG. It is a figure which shows the internal structure of the connection part vicinity of the finger part in a base part, and the internal structure of the base end part in a finger part, and a 2nd joint part of the hand mechanism which concerns on an Example. It is a figure which shows the internal structure of the 1st joint part in a finger part, and the 2nd finger link part of the hand mechanism which concerns on an Example. It is a figure which shows the movable range of the 2nd joint part in the finger | toe part of the hand mechanism which concerns on an Example. It is a figure which shows the movable range of the 1st joint part in the finger | toe part of the hand mechanism which concerns on an Example. It is a figure which shows arrangement | positioning of the pressure sensor in the 1st link part of the finger | toe part of the hand mechanism which concerns on an Example. It is a block diagram which shows each function part contained in the arm control apparatus and hand control apparatus which concern on an Example. It is a figure which shows an example of the shape of the target object hold | gripped by a hand mechanism. It is a figure showing the state where a plurality of objects were arranged and arranged. It is a 1st figure which shows the operation | movement at the time of changing the attitude | position of a target object with the 1st finger | toe part of the hand mechanism which concerns on an Example. It is a 2nd figure which shows the operation | movement at the time of changing the attitude | position of a target object with the 1st finger | toe part of the hand mechanism which concerns on an Example. It is a 1st figure which shows the state which hold | gripped the target object with the 2nd finger part, the 3rd finger part, and the 4th finger part of the hand mechanism which concerns on an Example. It is a 2nd figure which shows the state which hold | gripped the target object with the 2nd finger part, the 3rd finger part, and the 4th finger part of the hand mechanism which concerns on an Example. It is a 1st figure which shows the 1st other example of operation | movement of the hand mechanism which concerns on an Example. It is a 2nd figure which shows the 1st other example of operation | movement of the hand mechanism which concerns on an Example. It is a 1st figure which shows the 2nd other example of operation | movement of the hand mechanism which concerns on an Example. It is a 2nd figure which shows the 2nd other example of operation | movement of the hand mechanism which concerns on an Example. The flowchart which shows the control flow at the time of hold | gripping a target object with the hand mechanism which concerns on an Example. It is the figure which showed schematic structure of the stopper which concerns on an Example. It is sectional drawing of the 2nd joint part vicinity when the 2nd joint part which concerns on an Example extends most. It is sectional drawing of the 2nd joint part vicinity when the 2nd joint part which concerns on an Example is bent most.

The hand mechanism according to the present invention includes three or more fingers. Here, when the object is gripped by the hand mechanism, a predetermined gripping portion, which is a portion where the finger is brought into contact with the object in order to sandwich the object with the finger, can be contacted with the finger. It must be exposed in the state. However, an object that becomes an obstacle when grasping an object, such as a wall surface of a container that stores the object or other objects when a plurality of objects are arranged in contact with each other In a situation where the object is installed in a state where the objects are close to each other, a predetermined gripping position on the object may not be exposed in a state where the finger part can be contacted. In such a case, it is difficult to hold the object by the hand mechanism when the object is left as it is. However, even in such a case, if the interval between the object and the obstacle is increased by changing the posture or position of the object, a predetermined gripping position on the object can be exposed. Then, in a state where a predetermined gripping portion of the object is exposed in this way, a finger is brought into contact with the gripping portion and the object is sandwiched between the finger portions, whereby the object is gripped by the hand mechanism. be able to.

Therefore, in the hand mechanism according to the present invention, when gripping an object, the posture or position of the object after at least one of the three or more fingers touches the object. It functions as a state change finger part for changing Even when the predetermined gripping portion of the object is not exposed in a state where the finger part can be contacted, the state changing finger part can be brought into contact with the object. Furthermore, if the state change finger part is brought into contact with the object, the posture or position of the object can be changed by the state finger part. Then, by changing the posture or position of the object so that the distance between the object and the obstacle is increased, a predetermined gripping portion of the object can be exposed as described above.

Further, in the hand mechanism according to the present invention, when gripping an object, at least two finger parts other than the finger parts functioning as the state change finger parts have the state change fingers. It functions as a gripping finger unit that grips an object whose posture or position has been changed by the unit. That is, when gripping the target object, the gripping finger part comes into contact with a predetermined gripping position of the target object exposed by changing the posture or position of the target object by the state changing finger part. Then, the object is gripped by the gripping fingers.

Since the hand mechanism includes the state changing finger part and the gripping finger part as described above, the object can be gripped by the hand mechanism regardless of the posture of the object and its surroundings. Become.

<Example>
Specific embodiments of the present invention will be described below with reference to the drawings. The dimensions, materials, shapes, relative arrangements, and the like of the components described in the present embodiment are not intended to limit the technical scope of the invention to those unless otherwise specified.

Here, a case where the hand mechanism and the gripping system according to the present invention are applied to a robot arm will be described. FIG. 1 is a diagram illustrating a schematic configuration of a robot arm according to the present embodiment. The robot arm 1 includes a hand mechanism 2, an arm mechanism 3, and a pedestal portion 4. A hand mechanism 2 is attached to one end of the arm mechanism 3. The other end of the arm mechanism 3 is attached to the pedestal portion 4. The hand mechanism 2 includes a base portion 20 connected to the arm mechanism 3 and four finger portions 21 provided on the base portion 20. The detailed configuration of the hand mechanism 2 will be described later.

<Arm mechanism>
The arm mechanism 3 includes a first arm link portion 31, a second arm link portion 32, a third arm link portion 33, a fourth arm link portion 34, a fifth arm link portion 35, and a connection member 36. The base portion 20 of the hand mechanism 2 is connected to a first joint portion 30 a formed on one end side of the first arm link portion 31 of the arm mechanism 3. The first joint portion 30 a is provided with a motor (not shown) for rotating the hand mechanism 2 around the axis of the first arm link portion 31 with respect to the first arm link portion 31. The other end side of the first arm link portion 31 is connected to one end side of the second arm link portion 32 at the second joint portion 30b. The first arm link part 31 and the second arm link part 32 are connected so that their central axes intersect perpendicularly. A motor for rotating the first arm link part 31 around the axis of the second arm link part 32 around the other end side with respect to the second arm link part 32 is provided in the second joint part 30b. (Not shown) is provided. Further, the other end side of the second arm link portion 32 is connected to one end side of the third arm link portion 33 at the third joint portion 30c. The third joint part 30 c is provided with a motor (not shown) for rotating the second arm link part 32 relative to the third arm link part 33.

Similarly, the other end side of the third arm link portion 33 is connected to one end side of the fourth arm link portion 34 at the fourth joint portion 30d. Further, the other end side of the fourth arm link portion 34 is connected to the fifth arm link portion 35 by a fifth joint portion 30e. The fourth joint portion 30d is provided with a motor (not shown) for rotating the third arm link portion 33 relative to the fourth arm link portion 34. Further, the fifth joint portion 30e is provided with a motor (not shown) for rotating the fourth arm link portion 34 relative to the fifth arm link portion 35. Further, the fifth arm link portion 35 is connected to a connection member 36 disposed vertically from the pedestal portion 4 by a sixth joint portion 30f. The fifth arm link portion 35 and the connection member 36 are connected so that their central axes are coaxial. The sixth joint portion 30f is provided with a motor (not shown) for rotating the fifth arm link portion 35 around the axes of the fifth arm link portion 35 and the connection member 36. With the arm mechanism 3 having such a configuration, for example, the arm mechanism 3 can be a mechanism having six degrees of freedom.

<Hand mechanism>
Next, the configuration of the hand mechanism 2 will be described with reference to FIGS. FIG. 2 is a perspective view of the hand mechanism 2. FIG. 3 is a top view of the hand mechanism 2. In FIG. 3, the arrows indicate the rotation movable ranges of the finger portions 21. As shown in FIGS. 2 and 3, in the hand mechanism 2, the four fingers 21 on the base 20 are centered on the axis in the longitudinal direction of the hand mechanism 2 (direction perpendicular to the paper surface in FIG. 3). On the circumference, they are arranged at equiangular intervals (ie, 90 deg intervals). The four finger portions 21 all have the same structure and the same length. However, the operation of each finger 21 is controlled independently.

4 to 10 are diagrams for explaining the configuration of the finger portion 21 of the hand mechanism 2 and its driving mechanism. FIG. 4 is a side view of the finger part 21. In FIG. 4, the base portion 20 is shown in a transparent state, and a part of the internal structure of the finger portion 21 located inside the base portion 20 is also shown. FIG. 5 is a view of the distal end side of the finger portion 21 as viewed from the direction of arrow A in FIG. 4 and 5, a part of a second finger link part 212 of the finger part 21 to be described later is shown in a transparent state, and the internal structure of the second finger link part 212 is also shown. Yes.

2 and 4, each finger portion 21 has a first finger link portion 211, a second finger link portion 212, and a base end portion 213. The base end portion 213 of the finger portion 21 is connected to the base portion 20. Here, the base end portion 213 is connected to the base portion 20 so as to be rotatable about the longitudinal axis of the finger portion 21 (direction perpendicular to the paper surface in FIG. 3) with respect to the base portion 20, as indicated by an arrow in FIG. Yes. In the finger part 21, one end of the second finger link part 212 is connected to the base end part 213. A second joint portion 23 is formed at a connection portion between the second finger link portion 212 and the base end portion 213.

Here, the drive mechanism of the base end portion 213 and the drive mechanism of the second joint portion 23 will be described with reference to FIG. FIG. 6 is a diagram illustrating an internal structure of the base portion 20 in the vicinity of the connection portion of the finger portion 21 and an internal structure of the proximal end portion 213 and the second joint portion 23 in the finger portion 21. As shown in FIG. 6, a gear 65, a gear 66, a second motor 52, and a third motor 53 are provided inside the base portion 20. The gear 65 is a gear for rotating the entire finger portion 21, and is connected to the rotation shaft of the base end portion 213. The gear 66 is connected to the rotation shaft of the third motor 53. The gear 65 and the gear 66 are engaged with each other. With such a configuration, when the third motor 53 rotates, the rotational force is transmitted to the rotation shaft of the base end portion 213 via the two

gears

65 and 66. As a result, the base end portion 213 is rotationally driven, and accordingly, the entire finger portion 21 is rotationally driven within a range indicated by an arrow in FIG.

Further, a worm wheel 63 and a worm 64 meshed with the worm wheel 63 are provided inside the second joint portion 23. The worm wheel 63 is connected to the rotation shaft of the second finger link part 212 in the second joint part 23. A worm 64 is connected to the rotating shaft of the second motor 52 provided in the base portion 20. With such a configuration, when the second motor 52 is rotationally driven, the rotational force is transmitted to the rotation shaft of the second finger link portion 212 by the worm 64 and the worm wheel 63. As a result, the second finger link part 212 is rotationally driven relative to the base end part 213. Here, FIG. 7 is a diagram showing a movable range of the second joint portion 23 in the finger portion 21 realized by the driving force of the second motor 52. As shown in FIG. 7, the second joint portion 23 is formed to be able to bend and extend. The driving force by the second motor 52 and the driving force by the third motor 53 are configured to be transmitted independently to the operation target.

As shown in FIGS. 4 and 5, in the finger portion 21, one end of the first finger link portion 211 is connected to the other end of the second finger link portion 212. A first joint portion 22 is formed at a connection portion between the first finger link portion 211 and the second finger link portion 212. Here, the drive mechanism of the 1st joint part 22 is demonstrated based on FIG. FIG. 8 is a diagram illustrating an internal structure of the first joint portion 22 and the second finger link portion 212 in the finger portion 21. Two

bevel gears

61 and 62 meshing with each other are provided inside the first joint portion 22. One bevel gear 61 is connected to the rotation shaft of the first finger link portion 211 in the first joint portion 22. The other bevel gear 62 is connected to the rotation shaft of the first motor 51 provided inside the second finger link portion 212. With such a configuration, when the first motor 51 is rotationally driven, the rotational force is transmitted to the rotation shaft of the first finger link portion 211 by the two

bevel gears

61 and 62. As a result, the first finger link portion 211 is rotationally driven relative to the second finger link portion 212. Here, FIG. 9 is a diagram illustrating a movable range of the first joint portion 22 in the finger portion 21 realized by the driving force of the first motor 51. As shown in FIG. 9, the first joint portion 22 is formed to be able to bend and extend.

Further, as shown in FIGS. 2 and 4, in the present embodiment, the finger portion 21 is based on the first joint portion 22 rather than the first finger link portion 211 on the distal end side of the first joint portion 22. The second finger link part 212 on the part 20 side (base end part 213 side) is longer.

In addition, as shown in FIGS. 2, 4, 5, and 10, in this embodiment, a pressure-sensitive sensor 70 is provided on the distal end side of the first finger link portion 211 of the finger portion 21. The pressure-sensitive sensor 70 is a sensor that detects an external force (pressure) acting on the distal end portion of the first finger link portion 211. Further, as shown in FIG. 4, the pressure-sensitive sensor 70 is a wall surface on the bending direction side of the first joint portion 22 in the first finger link portion 211 (hereinafter also referred to as “bending sidewall surface”) 215. Further, it is provided on both surfaces of the wall surface 216 on the extension direction side (hereinafter also referred to as “extension side wall surface”) 216. Here, in this embodiment, the bent side wall surface 215 on the distal end side of the first finger link portion 211 is formed in a curved surface shape. Therefore, as shown in FIG. 10, a plurality of pressure-sensitive sensors 70 may be arranged side by side along the curved shape on the bent side wall surface 215 on the distal end side of the first finger link portion 211. As the pressure sensor 70, any known type of sensor such as a piezoelectric type, a strain gauge type, or a capacitance type may be used. In this embodiment, the pressure-sensitive sensor 70 corresponds to “contact pressure detecting means” according to the present invention.

<Pedestal part>
Next, configurations of the arm control device 42 and the hand control device 43 built in the pedestal portion 4 will be described with reference to FIG. The arm control device 42 is a control device for controlling the arm mechanism 3 of the robot arm 1. The hand control device 43 is a control device for controlling the hand mechanism 2 of the robot arm 1. FIG. 11 is a block diagram illustrating each functional unit included in the arm control device 42 and the hand control device 43.

The arm control device 42 includes a plurality of drivers that generate drive signals for driving the motors provided at the joints of the arm mechanism 3 so that the drive signals from the drivers are supplied to the corresponding motors. Configured. The arm control device 42 includes a computer having an arithmetic processing device and a memory. The arm control device 42 includes an arm control unit 420 and a motor state quantity acquisition unit 421 as functional units. These functional units are formed by executing a predetermined control program in a computer included in the arm control device 42.

The arm control unit 420 supplies each driver of the arm mechanism 3 by supplying a drive signal from each driver based on target information acquired by a target information acquisition unit 430 described later, which is a functional unit of the hand control device 43. The motors provided in the

joint portions

30a, 30b, 30c, 30d, 30e, and 30f are controlled. The arm controller 420 moves the arm mechanism 3 by controlling each motor, thereby moving the hand mechanism 2 to a predetermined grippable position suitable for gripping the object. In addition, the motors provided in the

joint portions

30a, 30b, 30c, 30d, 30e, and 30f of the arm mechanism 3 detect state quantities (such as the rotational position and rotational speed of the rotation shaft of the motor) related to the respective rotational states. An encoder (not shown) is provided. Then, the state quantity of each motor detected by the encoder of each motor is input to the motor state quantity acquisition unit 421 of the arm control device 42. Then, the arm control unit 420 servo-controls each motor so that, for example, the hand mechanism 2 moves to a predetermined grippable position based on the motor state quantity input to the motor state quantity acquisition unit 421.

The hand control device 43 includes a plurality of drivers that generate drive signals for driving the motors provided in the hand mechanism 2 so that the drive signals from the drivers are supplied to the corresponding motors. Composed. The hand control device 43 includes a computer having an arithmetic processing device and a memory. And the hand control apparatus 43 has the target object information acquisition part 430, the hand control part 431, the motor state quantity acquisition part 432, and the sensor information acquisition part 433 as a function part. These functional units are formed by executing a predetermined control program in a computer included in the hand control device 43.

The object information acquisition unit 430 acquires object information that is information regarding an object to be gripped by the hand mechanism 2. Here, the object information includes information on the shape, dimensions, and position of the object, and environmental information around the object (information on objects other than the object existing around the object, for example, , Information on the shape of the container in which the object is stored and the arrangement of the objects in the container). The object information acquisition unit 430 may acquire object information input by the user. When a visual sensor that captures an image including an object is provided, the object information acquisition unit 430 may acquire object information from an image captured by the visual sensor.

In addition, the hand control unit 431 supplies the driving signal from each driver based on the object information acquired by the object information acquiring unit 430, thereby driving each finger unit 21 of the hand mechanism 2. 51, each 2nd motor 52, and each 3rd motor 53 are controlled. For example, the hand control unit 431 controls each of the first mechanisms of the hand mechanism 2 in order to grip the object by the hand mechanism 2 that has been moved to a predetermined grippable position by controlling the arm mechanism 3 by the arm control unit 420. The motor 51, each second motor 52, and each third motor 53 are controlled. In addition, the first motor 51, the second motor 52, and the third motor 53 of the hand mechanism 2 detect state quantities (such as the rotational position and rotational speed of the rotation shaft of the motor) related to the respective rotational states. An encoder (not shown) is provided. Then, the state quantities of the

motors

51, 52, 53 detected by the encoders of the

motors

51, 52, 53 are input to the motor state quantity acquisition unit 432 of the hand control device 43. Then, based on the state quantities of the

motors

51, 52, 53 input to the motor state quantity acquisition unit 432, the hand control unit 431, for example, moves each finger so as to hold the object with the plurality of finger parts 21. Servo-control each

motor

51,52,53 in the part 21. FIG.

Furthermore, the hand control device 43 has a sensor information acquisition unit 433. The sensor information acquisition unit 433 receives a detection value of the pressure sensor 70 provided in the first finger link unit 211 of each finger unit 21 of the hand mechanism 2. And the hand control part 431 can detect the contact to the target object of each finger | toe part 21 based on the detection value of each pressure sensor 70 acquired by the sensor information acquisition part 433, and each based on the detection signal Each

motor

51, 52, 53 in the finger part 21 can also be controlled.

<Finger functions>
Next, the function of each finger part 21 when the object is gripped by the hand mechanism 2 will be described. Here, FIG. 12 is a diagram illustrating an example of the shape of the object 10 held by the hand mechanism 2. FIG. 13 is a diagram showing a state in which a plurality of objects 10 (10 ′) are arranged and arranged. As shown in FIGS. 12 and 13, the object 10 is a rectangular parallelepiped having six surfaces (S1 to S6). However, the shape of the object 10 shown in FIG. 12 is merely an example, and the shape of the object gripped by the hand mechanism 2 is not limited to a rectangular parallelepiped.

Here, when the object 10 is gripped by the hand mechanism 2, at least two of the six surfaces of the object 10 are defined as predetermined gripping surfaces (corresponding to predetermined gripping locations), and the predetermined gripping is performed. One of the fingers 21 of the hand mechanism 2 needs to be brought into contact with each surface, and the object 10 needs to be sandwiched between the fingers 21. In the following, a case will be described in which the object 10 is gripped using the two surfaces S5 and S6 having the largest area among the six surfaces of the object 10 as predetermined gripping surfaces.

When the object 10 is to be gripped by the hand mechanism 2 with the surfaces S5 and S6 of the object 10 as predetermined gripping surfaces, both of the surfaces S5 and S6 are connected to any of the finger portions 21 of the hand mechanism 2. It must be exposed so that it can be touched. However, as shown in FIG. 13, in a state where a plurality of objects 10 (10 ′) to be grasped sequentially by the hand mechanism 2 are arranged and arranged in contact with each other, a predetermined grasping of the object 10 is performed. The surface may be placed in contact with the adjacent object 10 '. In the case of FIG. 13, one of the two predetermined gripping surfaces S5 and S6 of the object 10 is in a state of being in contact with the adjacent object 10 ′. In such a case, the gripping surface S6 of the object 10 is not exposed. Therefore, if the target object 10 remains in the state shown in FIG. 13, the finger part 21 of the hand mechanism 2 cannot be brought into contact with the gripping surface S6 of the target object 10, so that the target object 10 is gripped by the hand mechanism 2. Can not do it.

Thus, in this embodiment, when the hand mechanism 2 grips the target object 10 in the above-described situation, first, it functions as a state changing finger portion of the four finger portions 21 in the hand mechanism 2. The posture of the object 10 is changed by one finger part. After that, among the four finger portions 21 in the hand mechanism 2, the three finger portions other than the finger portions functioning as state changing finger portions and the finger portions functioning as gripping finger portions are targeted. Hold the object 10.

Hereinafter, in the present embodiment, details of a procedure for gripping the object 10 placed in the state shown in FIG. 13 by the hand mechanism 2 will be described based on FIGS. 14 to 17. Here, each finger part 21 of the hand mechanism 2 is referred to as a first finger part 21A, a second finger part 21B, a third finger part 21C, and a fourth finger part 21D, respectively. In the following description, the first finger portion 21A is used as a finger portion functioning as a state changing finger portion, and the second to

fourth finger portions

21B, 21C, and 21C are used as finger portions functioning as gripping finger portions. explain. 14 and 15 are diagrams illustrating an operation when the posture of the target object 10 is changed by the first finger portion 21A of the hand mechanism 2. FIG. 16 and 17 are diagrams showing a state in which the object 10 is held by the second finger part 21B, the third finger part 21C, and the fourth finger part 21D of the hand mechanism 2. The procedure of gripping the object 10 by the hand mechanism 2 as described below is performed after the hand mechanism 2 is moved to a predetermined grippable position by the arm mechanism 3 being controlled by the arm control device 42. This is realized by controlling the hand mechanism 2 by the control device 43.

As shown in FIG. 13, even when the object 10 is placed in a state where it is in contact with an adjacent object 10 ′ with one gripping surface S 6 as a contact surface, the upper surface S 4 is exposed. . Therefore, the finger part 21 of the hand mechanism 2 can be brought into contact with the upper surface S4 of the object 10. Therefore, in the present embodiment, as shown in FIG. 14, first, the first finger link portion 211 A of the first finger portion 21 A that functions as a state change finger portion in the current gripping of the target object 10 is used as the upper surface of the target object 10. Contact S4. Note that the contact of the first finger link portion 211A to the object 10 of the first finger link portion 211A can be detected by the pressure-sensitive sensor 70 provided on the first finger link portion 211A. At this time, in a state where the first finger part 21 A is in contact with the upper surface S 4 of the object 10, the other finger parts 21 B, 21 C, 21 D in the hand mechanism 2 are not in contact with the object 10.

Then, as shown in FIG. 15, the object 10 is tilted forward by the first finger part 21 A in a state where the first finger link part 211 A is in contact with the upper surface S 4 of the object 10. That is, the object 10 is tilted in a direction in which the gripping surface S6 of the object 10 is separated from the adjacent object 10 ′. Thus, by changing the posture of the object 10 by the first finger part 21A functioning as the state changing finger part, the interval between the object 10 and the adjacent object 10 ′ can be increased. . Thereby, the gripping surface S6 of the object 10 can be exposed. As a result, not only the other gripping surface S5 of the object 10 but also the one gripping surface S6 can be brought into contact with fingers other than the first finger 21A in the hand mechanism 2. In this way, the state of the object 10 in which the finger portion 21 of the hand mechanism 2 can be brought into contact with both of the predetermined gripping surfaces S5 and S6 of the object 10 in the following is referred to as “predetermined This is referred to as a “gripable state”.

Then, as shown in FIGS. 16 and 17, the object 10 of this time is set after the object 10 is tilted by the first finger portion 21 A so that the posture of the object 10 becomes a predetermined grippable state. The object 10 is grasped by the second finger part 21B, the third finger part 21C, and the fourth finger part 21D that function as a grasping finger part. At this time, in FIGS. 16 and 17, the first finger link portion 211 B and the fourth finger portion 21 B of the second finger portion 21 B are formed on one gripping surface S 6 of the target object 10 exposed by changing the posture of the target object 10. The first finger link portion 211D of the finger portion 21D is brought into contact. Further, the first finger link portion 211C of the third finger portion 21C is brought into contact with the other gripping surface S5 of the object 10. However, it is not always necessary to bring two fingers into contact with one gripping surface S6 of the object 10. That is, one finger part is brought into contact with one gripping surface S6 of the object 10, and the two objects are brought into contact with the other gripping surface S5 of the object 10, It may be gripped. The contact of the first finger link part 211B of the second finger part 21B, the first finger link part 211C of the third finger part 21C, and the first finger link part 211D of the fourth finger part 21D to the object 10 is as follows. , And can be detected by the pressure sensitive sensor 70 provided in each first

finger link portion

211B, 211C, 211D.

As described above, according to the hand mechanism 2 according to the present embodiment, the predetermined gripping surface of the target object 10 is exposed because the target object 10 is arranged in contact with the other target object 10 '. Even if the finger part 21 of the hand mechanism 2 cannot be brought into contact with the predetermined gripping surface of the object 10 in the state as it is, one of the four finger parts 21 , The posture of the object 10 can be changed to a predetermined grippable state. Then, the predetermined gripping surface of the target object 10 that has been in contact with the other target object 10 ′ is changed by changing the posture of the target object 10 to a predetermined grippable state by the finger part functioning as the state changing finger part. Can be exposed. As a result, on the predetermined gripping surface of the target object 10, a finger unit other than the finger unit functioning as the state changing finger unit in the hand mechanism 2 and functioning as the gripping finger unit (in the above example, The second finger 21B, the third finger 21C, and the fourth finger 21D) can be brought into contact with each other. Therefore, the object 10 can be sandwiched between the three finger portions that function as the gripping finger portions in the hand mechanism 2, and thus the object 10 can be gripped.

Furthermore, the hand mechanism 2 according to the present embodiment includes four finger portions 21, and the posture of the object 10 is changed by one finger portion functioning as a state changing finger portion. Also, the object 10 can be gripped by causing the other three fingers to function as gripping fingers. Note that the hand mechanism 2 according to the present embodiment does not necessarily include the four finger portions 21. In other words, if the hand mechanism 2 includes at least three finger portions 21, two fingers other than the one finger that functions as a state change finger can function as gripping fingers. The object 10 can be gripped. However, as described above, if the hand mechanism 2 includes the four finger portions 21, even if one finger portion 21 functions as a state change finger portion, The part 21 can function as a gripping finger part. And as shown in FIG.16 and FIG.17, it can suppress that a moment acts on the target object 10 of the hold | gripped state by pinching the target object 10 with the three finger | toe parts 21. FIG. That is, the object 10 can be gripped in a more stable state by causing the three finger portions 21 to function as gripping finger portions.

Further, in the hand mechanism 2 according to the present embodiment, the four finger portions 21 are arranged at equiangular intervals in the circumferential direction in the base portion 20. And all of the four finger | toe parts 21 are the same structures, Furthermore, the length is also the same. Therefore, any of the four finger portions 21 can perform the same operation, and the effect on the target object 10 when the same operation is performed on the target object 10 is the same. Therefore, in the hand mechanism 2, any of the four finger portions 21 can function as both a state change finger portion and a gripping finger portion. That is, in the above example, the first finger 21A functions as the state change finger, but any one of the second finger 21B, the third finger 21C, and the fourth finger 21D is used as the state change finger. The other finger parts including the first finger part 21A can also function as gripping finger parts. For this reason, when the object 10 is gripped by the gripping finger part after the posture of the object 10 is changed to a predetermined grippable state by the state changing finger part, the hand mechanism 2 with respect to the object 10 is It is possible to suppress as much as possible the restriction on the position and posture.

Also, according to the hand mechanism 2 according to the present embodiment, the single object mechanism 10 can be used to hold the object 10 while changing the posture of the object 10 to a predetermined holdable state. Therefore, unlike this embodiment, the posture of the object is changed to a predetermined gripping state using a device separate from the hand mechanism for gripping the object, and then the object is gripped by the hand mechanism. Compared to such a case, the tact time can be shortened.

Note that, among the four finger portions 21 in the hand mechanism 2, which finger portion functions as the state change finger portion and which finger portion functions as the gripping finger portion may be appropriately selected by the user. In addition, the hand control unit 431 may select based on the object information acquired by the object information acquisition unit 430.

Moreover, in the hand mechanism 2 according to the present embodiment, a configuration having five or more finger portions 21 may be adopted. Even in such a case, five or more finger parts 21 may be arranged at equiangular intervals in the circumferential direction in the base part 20, and any of the finger parts 21 may have the same structure. And any of the five or more finger parts 21 is good also as a structure which can function as a finger part for a state change, and a finger part for a holding | grip.

Further, in this embodiment, each finger unit is used both when the posture of the object 10 is changed to a predetermined grippable state by the state changing finger unit and when the object 10 is held by the gripping finger unit. It is necessary to detect the contact of the tip portion of 21 with the object 10 by the pressure sensor 70 provided on the first finger link portion 211 of each finger portion 21. For that purpose, the pressure-sensitive sensor 70 needs to be surely brought into contact with the object 10. Here, in the hand mechanism 2, as described above, each finger portion 21 is attached to the base portion 20 so as to be rotatable around the axis of the finger portion 21. Each finger portion 21 is formed with two

joint portions

22 and 23. Furthermore, the two

joint portions

22 and 23 are both formed to be able to bend and extend. By configuring the finger portion 21 in this way, the finger portion 21 as a whole has a relatively high degree of freedom of movement and a relatively large movable range. Therefore, when the tip part of the finger part 21 is brought into contact with the object 10, the contact angle (contact direction) can be appropriately adjusted. Therefore, the pressure-sensitive sensor 70 provided in the first finger link portion 211 of the finger portion 21 can be brought into contact with the object 10 more reliably.

In addition, the joint part formed in the finger | toe part 21 does not necessarily need to be two places, and may be one place. However, by providing the joint portion at two locations in the finger portion 21, as compared with the case where the joint portion is only one location, the finger portion 21 as a whole can have a higher degree of freedom of movement and its movable range. Can be made larger. Further, the joint portion may be provided at three or more locations in the finger portion 21.

Furthermore, in the hand mechanism 2 according to the present embodiment, pressure-sensitive sensors 70 are provided on both the bent side wall surface 215 and the extended side wall surface 216 of the first finger link portion 211 of each finger portion 21. With such a configuration, even when the bent side wall surface 215 of the first finger link portion 211 is in contact with the object 10, even when the extended side wall surface 216 of the first finger link portion 211 is in contact with the object 10, the contact is made. Can be detected by the pressure-sensitive sensor 70. Accordingly, the posture of the object 10 can be changed by the finger 21 regardless of which of the bent side wall surface 215 and the extended side wall surface 216 of the first finger link portion 211 of the finger portion 21 is in contact with the object 10. Or the object 10 can be gripped.

Further, as described above, in the hand mechanism 2 according to the present embodiment, the second finger link portion 212 is longer than the first finger link portion 211 in each finger portion 21. According to such a configuration, as shown in FIGS. 16 and 17, the space between the target object 10 and the adjacent target object 10 ′ formed by changing the posture of the target object 10 ( The first finger link part 211 of the finger part that functions as the gripping finger part when the object 10 is to be gripped by the gripping finger part after the tip part of the gripping finger part is inserted into the gap) It becomes easier to put the in the space. Further, when the object 10 is sandwiched between the three finger parts 21 in the hand mechanism 2, the object is compared with the configuration in which the first finger link part 211 is longer than the second finger link part 212. 10, the pressing force of each finger 21 can be applied more stably. Therefore, the object 10 can be gripped more stably by the hand mechanism 2.

In addition, in the above, since the target object 10 was arrange | positioned in the state which contacted other target object 10 ', the case where the predetermined holding surface of the target object 10 was not exposed was demonstrated as an example. However, an object that can be an obstacle when the finger portion 21 of the hand mechanism 2 is brought into contact with a predetermined gripping surface of the object 10 is not limited to the other object 10 ′. For example, when the predetermined gripping surface of the object 10 is not exposed because the object 10 is arranged in contact with the wall surface of the container that stores the object 10, the wall surface of the container 10 is obstructed. It becomes. Even in such a case, the object 10 can be grasped by applying the same grasping procedure as described above when grasping the object 10 by the hand mechanism 2.

<Other examples of object state change>
Here, when gripping an object using the hand mechanism 2 according to the present embodiment, the operation of the hand mechanism 2 when the state of the object is set to a predetermined grippable state is shown in FIGS. 14 and 15. It is not limited to such an operation. Hereinafter, another example of the operation of the hand mechanism 2 when the state of the object is set to a predetermined grippable state will be described with reference to FIGS. 18 and 19 are diagrams illustrating a first other example of the operation of the hand mechanism 2. 20 and 21 are diagrams illustrating a second other example of the operation of the hand mechanism 2.

In FIG. 18, the rectangular parallelepiped objects 11 are arranged side by side in contact with the other objects 11 ′. In the object 11, a surface S5 that is in contact with the other object 11 ′ and a surface S6 opposite to the surface S5 are set as predetermined gripping surfaces. That is, one gripping surface S5 of the object 11 is not exposed. Therefore, in the state shown in FIG. 18, the finger part 21 of the hand mechanism 2 cannot be brought into contact with one gripping surface S5 of the object 11.

Even in the case shown in FIG. 18, in order to grip the object 11 by the hand mechanism 2, it is necessary to first set the state of the object 11 to a predetermined grippable state. Therefore, even in this case, the posture of the object 11 is changed using the first finger portion 21A as the state changing finger portion among the four finger portions 21 of the hand mechanism 2. 18 and 19, illustration of the hand mechanism 2 other than the first finger portion 21A is omitted.

In FIG. 18, the first finger link portion 211A of the first finger portion 21A is brought into contact with the vicinity of the end portion on the other gripping surface S6 side of the upper surface S4 of the object 11. Then, by pressing the upper surface S4 of the object 11 with the first finger portion 21A as it is, the object 11 is turned in the direction indicated by the white arrow. By doing so, as shown in FIG. 19, the one gripping surface S5 side of the object 11 is lifted, and the object 11 is inclined. As a result, not only the other gripping surface S6 of the object 11 but also the one gripping surface S5 can be brought into contact with a finger portion that functions as a gripping finger portion in the hand mechanism 2. That is, the state of the object 11 becomes a predetermined grippable state. 18 and 19, even when the posture of the object 11 is changed, the finger portions other than the first finger portion 21A among the four finger portions 21 of the hand mechanism 2 are used as the state changing finger portions. Can also be used.

In FIG. 20, the rectangular parallelepiped objects 12 are arranged side by side in contact with the other objects 12 ′. And in the target object 12, surface S5 which is contacting other target object 12 ', and surface S6 on the opposite side to this surface S5 are set as a predetermined | prescribed holding surface. That is, in the state shown in FIG. 20, the finger part 21 of the hand mechanism 2 cannot be brought into contact with one gripping surface S5 of the object 12.

Therefore, in this case, the position of the object 12 is changed using the first finger 21A among the four fingers 21 of the hand mechanism 2 as the state changing finger. 20 and 21, illustration of the hand mechanism 2 other than the first finger portion 21A is omitted.

In FIG. 20, the first finger link portion 211 A of the first finger portion 21 A is brought into contact with the upper portion of the other gripping surface S 6 of the object 12. Then, the first finger 21A presses the other gripping surface S6 of the object 12 to press the object 12 against the object 12 ′, and the first finger 21A presses the object 12 ′. Shift the position in the direction indicated by the white arrow. By doing so, as shown in FIG. 21, the position of the object 12 moves upward, and as a result, the object 12 protrudes above the height of the upper surface S4 of the object 12 ′. . That is, the upper part of one gripping surface S5 of the object 12 is exposed. Thereby, not only the other gripping surface S6 of the object 12 but also the one gripping surface S5 can be brought into contact with the finger portion functioning as the gripping finger portion in the hand mechanism 2. That is, the state of the object 12 becomes a predetermined grippable state. 20 and 21, finger portions other than the first finger portion 21A among the four finger portions 21 of the hand mechanism 2 can also be used as the state change finger portions.

As shown in FIGS. 18 to 21 described above, according to the hand mechanism 2 according to the present embodiment, the four fingers 21 have a relatively high degree of freedom of movement and a relatively large movable range. Therefore, the state of the object can be changed to a predetermined grippable state by various operations using the finger part functioning as the state changing finger part. Furthermore, an object that has become a predetermined grippable state by each operation can be gripped by using a finger part that functions as a gripping finger part.

<Control flow>
Next, a control flow for gripping an object by the hand mechanism 2 will be described based on a flowchart shown in FIG. This control flow is realized by executing a predetermined control program in the arm control device 42 and the hand control device 43. In this flow, first, in S101, object information about the object to be grasped this time is acquired by the object information acquisition unit 430.

Next, in S102, the finger part selected as the state changing finger part among the four finger parts 21 in the hand mechanism 2 is brought into contact with the object. At this time, based on the object information acquired by the object information acquisition unit 430 in S101, a wall surface that can be touched with the finger part in the current object is selected, and the wall surface of the selected object is selected. Touch the state change finger. Next, in S103, the state and / or position of the object is changed by the state change finger unit brought into contact with the object, thereby changing the state of the object to a predetermined grippable state. Next, in S104, an object that has become a predetermined grippable state by executing the process of S103 is a finger part other than the state change finger part among the four finger parts 21 in the hand mechanism 2. And gripping with the finger selected as the gripping finger. At this time, the gripping finger portion of the hand mechanism 2 is brought into contact with a predetermined gripping surface of the target object, and then the target finger is gripped by the gripping finger portion.

Each step in the control flow is executed by the arm control device 42 and the hand control device 43, so that the object can be gripped by the hand mechanism 2 regardless of the posture of the object and its surroundings. .

In addition, according to the hand mechanism 2 which concerns on a present Example, when the target object is arrange | positioned in the state in which all the predetermined holding surfaces were exposed so that the finger | toe part 21 of this hand mechanism 2 could contact, it is natural. Without changing the state of the object, the object can be gripped by bringing the finger portion 21 into contact with a predetermined gripping surface. Further, in this case, all the four finger portions 21 can be used as gripping finger portions, and the object can be gripped by sandwiching the object with the four finger portions 21.

<Modification of hand mechanism>
As described above, the worm wheel 63 and the worm 64 meshed with the worm wheel 63 are provided in the second joint portion 23 as a screw mechanism. The worm wheel 63 is connected to the rotation shaft of the second finger link part 212 in the second joint part 23. A worm 64 is connected to the rotating shaft of the second motor 52 provided in the base portion 20. With such a configuration, when the second motor 52 is rotationally driven, the rotational force is transmitted to the rotation shaft of the second finger link portion 212 by the worm 64 and the worm wheel 63. As a result, the second finger link part 212 is rotationally driven relative to the base end part 213.

The rotation of the second finger link portion 212 is physically limited at both end positions of the movable range when the second joint portion 23 bends and extends within the movable range shown in FIG. 7 by the driving force of the second motor 52. A stopper is provided. FIG. 23 is a diagram showing a schematic configuration of the stopper 230. The stopper 230 includes a first stopper 231 provided at the base end portion 213, a second stopper 232 provided at the second finger link portion 212, and a third stopper 233 provided at the base end portion 213. ing.

The first stopper 231 is an outer peripheral surface 631 that covers the outer side of the worm wheel 63 at the base end portion 213, and the outer peripheral surface 631 is formed on the outer peripheral surface 631 formed around the rotation axis of the second finger link portion 212. It is provided so as to protrude from. The central axis of the outer peripheral surface 631 coincides with the central axis of the worm wheel 63. Further, the second stopper 232 is provided on a side surface of the second finger link portion 212 that faces the traveling direction when the second joint portion 23 extends. Further, the second stopper 232 is provided at a location that rotates along the outer peripheral surface 631 while being separated from the outer peripheral surface 631 of the base end portion 213 when the second joint portion 23 extends. The distance between the second stopper 232 and the outer peripheral surface 631 is smaller than the protruding amount of the first stopper 231 from the outer peripheral surface 631. The second stopper 232 is fixed to the second finger link portion 212 using bolts 234. The first stopper 231 may be fixed to the outer peripheral surface 631 of the base end portion 213 by welding or bolts, or the first stopper 231 may be formed on the outer peripheral surface 631.

FIG. 24 is a cross-sectional view of the vicinity of the second joint portion 23 when the second joint portion 23 is most extended. Since the distance between the second stopper 232 and the outer peripheral surface 631 is smaller than the protruding amount of the first stopper 231 from the outer peripheral surface 631, when the second joint portion 23 extends most, the first of the second stopper 232 The abutting portion 2321 abuts on the first stopper 231. The first contact portion 2321 is a surface formed at the end portion of the second stopper 232 on the proximal end portion 213 side in the axial direction of the second finger link portion 212, and the axial direction of the second finger link portion 212. It is an orthogonal plane. The shape of the first contact portion 2321 is formed in accordance with the shape of the first stopper 231, and when the second joint portion 23 is extended most, the first contact portion 2321 has a flat surface and the first stopper 231. It forms so that the plane concerned may become parallel and contact. Thus, the first stopper 231 imposes a physical restriction so that the second joint portion 23 does not extend any further. With the second stopper 232 in contact with the first stopper 231, the second stopper 232 can be moved in the axial direction of the bolt 234 by removing the bolt 234.

On the other hand, FIG. 25 is a cross-sectional view of the vicinity of the second joint portion 23 when the second joint portion 23 is bent most. When the second joint portion 23 is bent most, a second contact portion 2322 different from the first contact portion 2321 of the second stopper 232 contacts the outer surface 632 of the base end portion 213. The outer surface 632 is a top surface of the base end portion 213 protruding from the base portion 20, is formed so as to be parallel to the top surface of the base portion 20, and is formed on a tangent line of the outer peripheral surface 631. . The outer surface 632 with which the second stopper 232 comes into contact is referred to as a third stopper 233. When the second joint portion 23 is extended, the distance between the second stopper 232 and the outer peripheral surface 631 is maintained constant. However, when the second joint portion 23 is bent, the bending angle is large. The distance between the second stopper 232 and the outer surface 632 becomes shorter. Then, when the second joint portion 23 is bent most, the second contact portion 2322 of the second stopper 232 contacts the third stopper 233. The second contact portion 2322 is a surface formed so as to face the central axis side of the second finger link portion 212, and is a surface inclined with respect to the axial direction of the second finger link portion 212. The shape of the second contact portion 2322 is formed in accordance with the shape of the third stopper 233. When the second joint portion 23 is bent most, the second contact portion 2322 has a flat surface and the third stopper 233. It forms so that the plane concerned may become parallel and contact. Thus, the third stopper 233 imposes physical restrictions so that the second joint portion 23 does not bend any more. The second stopper 232 can be moved in the axial direction of the bolt 234 by removing the bolt 234 while the second stopper 232 is in contact with the third stopper 233.

As described above, when the second joint portion 23 extends the most, the second stopper 232 contacts the first stopper 231, and when the second joint portion 23 is bent most, the second stopper 232 becomes the third stopper 233. A stopper 230 is formed so as to abut against. These stoppers 230 can limit the movable range of bending and extension of the second joint portion 23. In the hand mechanism 2, the second stopper 232 is normally controlled by the hand control device 43 so as not to contact the first stopper 231 and the third stopper 233. The hand control device 43 stores a reference position that is a position in which the second joint portion 23 is not bent or extended, and the rotation angle of the second finger link portion 212 from the reference position is determined by the second stopper. The second motor 52 is controlled so that the rotation angle 232 does not contact the first stopper 231 and the third stopper 233.

However, the reference position of the second finger link unit 212 is erased from the memory, for example, when the power of the hand control device 43 is turned off, or the actual use position of the hand mechanism 2 is stored in the memory as the usage time of the hand mechanism 2 increases. There may be a deviation from the reference position. In such a case, the second stopper 232 may come into contact with the first stopper 231 or the third stopper 233. When driving force is supplied to the worm 64 with the second stopper 232 in contact with the first stopper 231 or the third stopper 233, the load at the contact portion between the worm 64 and the worm wheel 63 increases. This increases the frictional force. Therefore, it becomes difficult to rotate the worm 64 in the reverse direction, and the second joint portion 23 may be locked and it may be difficult to bend and extend the second joint portion 23.

In contrast, the second stopper 232 according to the present embodiment is configured to be movable. In other words, by removing the bolt 234 that fixes the second stopper 232, the second stopper 232 can be attached and detached (that is, movable). By moving the second stopper 232 when the second joint portion 23 is locked, the second stopper 232 is not in contact with the first stopper 231 or the third stopper 233. As a result, the load at the contact portion between the worm 64 and the worm wheel 63 is reduced and the frictional force is reduced, so that the worm 64 can be rotated in the direction of releasing the lock. In this way, the lock of the second joint portion 23 can be released. After releasing the lock, the second stopper 232 is reattached to the second finger link portion 212 using the bolt 234.

The shape of the stopper 230 is not limited to the above shape, and the relative rotation of the second finger link portion 212 with respect to the proximal end portion 213 is physically limited on each of the bent side and the extended side of the second joint portion 23. Any shape can be used. In this embodiment, one second stopper 232 physically restricts the rotation of the second finger link portion 212 on each of the bending side and the extension side of the second joint portion 23. Instead, two stoppers that restrict the rotation of the second finger link part 212 separately on the bending side and the extension side may be provided on the second finger link part 212, and each may be configured to be movable. In other words, different stoppers may contact the first stopper 231 and the third stopper 233. In the present embodiment, the second stopper 232 is configured to be movable. Alternatively, the first stopper 231 and the third stopper 233 may be configured to be movable. Further, all the stoppers 230 may be configured to be movable. In the above description, the rotation of the second finger link portion 212 is physically limited on each of the bent side and the extended side. However, the rotation of the second finger link portion 212 is limited only on one of the bent side and the extended side. May be configured to physically limit the above. That is, one of the first stopper 231 or the third stopper 233 may be omitted.

In the present embodiment, the second stopper 232 can be moved by removing the bolt 234 that fixes the second stopper 232. However, the structure that allows the second stopper 232 to move is not limited thereto. For example, the second stopper 232 may move as the second stopper 232 rotates or advances and retreats. Further, the second stopper 232 is not limited to the bolt 234, and other known fixing means can be used.

Note that the above-described stopper 230 can also be applied to a hand mechanism in the case where the posture and / or position of the object is not changed when the object is gripped. The stopper 230 is provided at the second joint portion 23. However, when rotation using a worm and a worm wheel is performed at another joint portion, a stopper can be provided at the indirect portion. Further, the worm wheel 63 and the worm 64 have been described as examples of the screw mechanism, but the screw mechanism can be applied to other than the worm wheel 63 and the worm 64 as long as the screw mechanism can be self-locked.

DESCRIPTION OF SYMBOLS 1 ... Robot arm, 2 ... Hand mechanism, 20 ... Base part, 21 ... Finger part, 22 ... 1st joint part, 23 ... 2nd joint part, 211 ... 1st finger link part, 212 ... 2nd finger link part, 213 ... Base end part, 3 ... Arm mechanism, 30a ... 1st joint part, 30b ... 2nd joint part, 30c ... 3rd joint part, 30d ... 4th joint part, 30e ... 5th joint part, 30f ... 6th joint part, 31 ... 1st arm link part, 32 ... 1st 2 arm link part, 33 ... 3rd arm link part, 34 ... 4th arm link part, 35 ... 5th arm link part, 36 ... connecting member, 4 ... pedestal part, 42 ... Arm control device, 420 ... Arm control unit, 421 ... Motor state quantity acquisition unit, 43 ... Hand control device, 430 ..Object information acquisition unit, 431... Hand control unit, 432... Motor state quantity acquisition unit, 433 .. sensor information acquisition unit, 51... First motor, 52. 53 ... 3rd motor, 61, 62 ... Bevel gear, 63 ... Worm wheel, 64 ... Worm, 65, 66 ... Gear, 70 ... Pressure sensor

Claims

With 3 or more fingers,
When gripping an object, for changing the state in which at least one of the three or more fingers touches the object and changes the posture and / or position of the object A state in which the posture and / or the position of at least two finger parts other than the finger parts functioning as the state change finger parts are changed by the state change finger parts while functioning as the finger parts A hand mechanism that functions as a gripping finger for gripping the object.
2. The hand mechanism according to claim 1, wherein any of the three or more fingers can function as both the state changing finger and the gripping finger.
A base portion,
3. The hand mechanism according to claim 2, wherein the three or more finger parts are arranged at equal angular intervals in the circumferential direction in the base part, and the three or more finger parts all have the same structure.
The hand mechanism according to claim 3, wherein the lengths of all the three or more fingers are substantially the same.
Comprising four or more fingers
5. The device according to claim 1, wherein when gripping the object, at least three finger portions other than the finger portions functioning as the state changing finger portions function as the gripping finger portions. The hand mechanism according to claim 1.
The finger portion is provided to be rotatable around an axis of the finger portion; and
The finger has a joint that can bend and extend;
The hand mechanism according to any one of claims 1 to 5, wherein a contact pressure detection unit is provided at a distal end portion of the finger portion.
The hand mechanism according to claim 6, wherein the contact pressure detecting means is provided on a plurality of wall surfaces or surrounding wall surfaces at a tip portion of the finger portion.
The hand mechanism according to claim 6 or 7, wherein the finger portion has two or more joint portions.
The finger portion is provided to be rotatable around an axis of the finger portion; and
The finger has a joint that can bend and extend;
The second finger link part on the base part side is longer than the first finger link part on the tip part side of the joint part in the finger part than the joint part of the finger part. The hand mechanism according to one item.
In a hand mechanism having a finger part,
The finger is
A joint that can be bent and extended by a screw mechanism;
A stopper for limiting the range in which the bending or extension is possible;
Have
A hand mechanism in which the stopper is movable.
The screw mechanism includes a worm and a worm wheel;
The finger is
A proximal end;
A finger link portion connected to the base end portion in the joint portion and rotating relative to the base end portion around the axis of the worm wheel according to bending and extension of the joint portion;
Have
The stopper includes a first stopper provided at the base end portion, a second stopper provided at the finger link portion, and a third stopper provided at the base end portion,
When the joint portion is extended most, the first stopper and the second stopper are in contact with each other, thereby limiting the range in which the joint portion can be extended,
When the joint portion is bent most, the third stopper and the second stopper are in contact with each other, thereby limiting the range in which the joint portion can be bent,
In the second stopper, a location that contacts the first stopper is different from a location that contacts the third stopper.
The hand mechanism according to claim 10.
The hand mechanism according to any one of claims 1 to 11,
A gripping system comprising: a control device that controls the hand mechanism when gripping the object by the hand mechanism;
When gripping the object by the hand mechanism, the control device causes the finger part selected as the state changing finger part among the three or more finger parts of the hand mechanism to contact the object. The posture of the object is changed by the finger selected as the state changing finger to change the state of the object to a predetermined grippable state, and the predetermined grippable state is obtained. A gripping system in which the object is gripped by a finger portion selected as the gripping finger portion among the three or more finger portions of the hand mechanism.
A control device for controlling the hand mechanism according to any one of claims 1 to 11,
Contacting the object with a finger selected as the state changing finger among the three or more fingers of the hand mechanism;
Changing the posture and / or position of the object by the state changing finger brought into contact with the object to make the state of the object a predetermined grippable state;
A gripping program for executing the step of gripping the object in the predetermined grippable state by a finger part selected as the gripping finger part among the three or more finger parts of the hand mechanism.