WO2018212190A1

WO2018212190A1 - Grasping system

Info

Publication number: WO2018212190A1
Application number: PCT/JP2018/018781
Authority: WO
Inventors: 聖也渡邉; 松尾　芳一
Original assignee: Thk株式会社
Priority date: 2017-05-15
Filing date: 2018-05-15
Publication date: 2018-11-22
Also published as: JP7149267B2; JPWO2018212190A1

Abstract

The present invention allows an object to be grasped without being affected, to the degree possible, by the conditions in which the object is disposed. The present invention relates to a grasping system for grasping an object by way of a hand mechanism having at least two finger units and for performing tilting-and-grasping to grasp the object after tilting same. In order to perform this tilting-and-grasping: a first action determination unit is used to determine a prescribed direction and a first action contact face to bring a first finger unit into contact with an object to be grasped in order to perform a first action for tilting the object to be grasped in the prescribed direction; and a second action determination unit is used to determine a second action contact face to bring a second finger unit, from among the at least two finger units but different from the first finger unit, into contact with the object to be grasped in order to perform a second action for grasping said object in the tilted state.

Description

Gripping system

The present invention relates to a gripping system for gripping an object by a hand mechanism having at least two fingers.

Many technologies have been developed for gripping objects using end effectors and hand mechanisms that mimic the structure of human hands. For example, Patent Document 1 discloses a technique related to an end effector using an adsorption device that adsorbs an object by suction. The end effector has three fingers. Each finger rotates by a plurality of actuators, and the proximal phalanx, the first middle phalanx, the second middle phalanx, and the distal phalanx rotate. Driven or driven by relative refraction. In this way, each finger part is driven with multiple degrees of freedom, so that the suction device provided on each finger part is brought close to the target object along the normal direction of the surface of the target object. The suction effect can be applied to the object.

Further, Patent Document 2 discloses an end effector having three fingers, in which an object is gripped using two or three fingers. For example, FIG. 24 of Patent Document 2 shows a gripping form in which a key is sandwiched between two fingers, and FIG. 29 shows a gripping form in which a ball is gripped by three fingers. Patent Document 2 also discloses a technique in which two fingers cooperate to hold a relatively flat object. For example, in the gripping configuration shown in FIGS. 30A and 30B, the side edge of the key placed on a plane is sandwiched, and the key is pivoted while one side edge is captured between the plate member and the pad. The gripping is performed by starting up and sandwiching the key between the end faces of the two fingers.

Japanese Patent No. 5525587 Special table 2015-533669

When an object is to be gripped by the hand mechanism, it is necessary to place the finger part of the hand mechanism with respect to the object so that the object is sandwiched. Therefore, when there is no space for placing the finger part around the object, or when the predetermined surface of the object that the finger part contacts to hold with the finger part is not exposed, the hand mechanism It becomes difficult to grip the object. For example, in a state where a plurality of objects of the same type are placed side by side in a container or the like, if an object is to be gripped one by one, the adjacent object or container is obstructed by the hand mechanism. Grasping the object can be difficult.

In such a case, conventionally, a gripping device including a suction device that sucks a target object widely is used. However, when using such a suction device, it is necessary to prepare the suction device according to the shape, structure, etc. of the target in order to appropriately apply the suction force to the target. As a result, the versatility is greatly hindered. Also, depending on the surface material and shape of the object, the suction force by the suction device may be difficult to act or the trace of the suction may remain, and it has not yet been possible to provide a highly versatile gripping system. Currently.

The present invention has been made in view of the above-described problems, and is a highly versatile gripping that enables gripping of an object without being affected as much as possible by the situation where the object is arranged. The purpose is to provide a system.

In the present invention, in order to solve the above-described problems, a configuration is adopted in which the grasped object is tilted so that the grasped object can be grasped. Then, the operation content related to the tilting of the gripping object and the gripping of the tilted gripping object is determined. With such a configuration, it is possible to realize gripping that is not easily affected by the arrangement state of the object.

Specifically, the present invention is a gripping system for taking out an object stored by a hand mechanism having at least two fingers from a storage container in which a plurality of objects are stored, A gripping object determining unit that determines a gripping object to be gripped among a plurality of objects based on an exposed area or an exposure ratio of each of the objects in a state of being stored in the storage container; For a first operation of tilting the grasped object in a predetermined direction, a first operation contact surface that makes contact with the first finger portion of the at least two finger portions and the predetermined direction are determined. A second motion different from the first finger portion among the at least two finger portions for a second motion for gripping the gripping object in a state tilted by the first motion and the first motion determining portion. For the second movement, touching the finger Comprising a second operation determining unit that determines the Sawamen, the.

Further, the present invention is a gripping system for taking out a stored object from a storage container in which a plurality of objects are stored by a hand mechanism having at least two fingers. An acquisition unit for acquiring environmental information including at least information on the position of the target object and the arrangement of the target objects in the storage container, and the target stored in the storage container based on the environmental information A determination unit that determines whether or not a predetermined gripping surface for holding the object sandwiched between the fingers of the hand mechanism from a pairing direction is exposed when gripping an object; and the plurality of objects A gripping object determining unit that determines a gripping target object to be gripped may be provided. The gripping object determination unit calculates each of the states stored in the storage container calculated from the environment information when the determination unit determines that the predetermined gripping surface is not exposed. The gripping object may be determined based on the exposed area of the object. Furthermore, the gripping system is configured such that a part of the bottom surface of the gripping object is a part of the storage container based on an exposed area of the gripping object that is stored in the storage container calculated from the environment information. A first operation contact surface for contacting a first finger part of the at least two finger parts, for a first action of tilting the grasped object in a predetermined direction in contact with the floor surface; For a second operation for gripping the object in a state of being tilted by the first operation based on an exposed area of the object to be gripped, and a first operation determining unit that determines a predetermined direction, A second operation determining unit that determines a second operation contact surface that contacts a second finger unit different from the first finger unit among the at least two finger units.

* The object can be gripped without being affected as much as possible by the situation where the object is arranged.

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 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 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 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-sensitive sensor in the front end side of the 1st finger 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 control apparatus which concerns on an Example. It is a flowchart of the grip control performed with the grip system which concerns on an Example. It is a figure which shows an example of the arrangement | positioning state of the several target object in a storage container. It is a figure which shows a part of environmental information regarding the target object arrange | positioned at a storage container. It is a figure which shows the direct holding | grip performed with the hand mechanism which concerns on an Example. It is a 1st figure for demonstrating the tilting grip performed with the hand mechanism which concerns on an Example. It is a 2nd figure for demonstrating the tilting grip performed with the hand mechanism which concerns on an Example. It is a 3rd figure for demonstrating the tilting grip performed with the hand mechanism which concerns on an Example. It is a 4th figure for demonstrating the tilting grip performed with the hand mechanism which concerns on an Example. It is a 5th figure for demonstrating the tilting grip performed with the hand mechanism which concerns on an Example. It is a flowchart of the process for determining the holding | grip target object performed by the holding | grip control shown in FIG. 13 is a flowchart of processing for determining an operation parameter for tilting gripping of a gripping object performed by gripping control illustrated in FIG. 12. It is a 1st figure which shows the state which inclined the holding | grip target object in a storage container. It is a figure which shows the arrangement pattern of the finger at the time of holding | grip a holding target object by a hand mechanism. It is a figure which shows a part of environmental information regarding the target object arrange | positioned in the storage container updated after the tilting holding | grip of the holding target object was completed. It is a 2nd figure which shows the state which inclined the holding | grip target object in a storage container. It is a figure which shows an example of the arrangement | positioning state of the several target object in a storage container. 13 is a flowchart of processing for repeatedly performing tilt gripping, which is additionally performed with respect to the grip control illustrated in FIG. 12.

The above-described gripping system of the present invention is a system that grips an object using a hand mechanism having at least two fingers. Here, about the finger part which a hand mechanism has, the structure (position and number of joints, the shape and number of link mechanisms, etc. constituting the finger part) of each finger part may be formed differently. Or the structure of all the finger | toe parts may be formed identically. Moreover, the actuator which drives each finger | toe part can employ | adopt the actuator of a well-known form.

Here, in the above-described gripping system, the gripping object determination unit has an exposed area or an exposure ratio of each target object in a state where the gripping target object to be gripped among the plurality of target objects is stored in the storage container. Determine based on. Furthermore, in the above gripping system, the first motion determination unit determines the first motion contact surface, which is a motion parameter necessary for the first motion for tilting the gripping object, and the tilt direction (predetermined direction). To do. Further, the second motion determining unit determines a second motion contact surface that is a motion parameter necessary for the second motion of gripping the gripping target object that is tilted by the first motion.

According to such a gripping system of the present invention, it is possible to select a gripping object from a plurality of objects stored in a storage container, and to grip the gripping object after tilting the gripping object by a hand mechanism. It becomes possible. Therefore, the object can be gripped without being affected as much as possible by the situation where the object is arranged.

In the gripping system, a gripping target is determined from a plurality of targets by the gripping target determination unit, and the presence or absence of the predetermined gripping surface is determined by the determination unit based on environment information acquired by the acquisition unit. It may be determined. The environmental information is information necessary for gripping a plurality of objects stored in the storage container for each target object, and at least relates to the position of the target object and the arrangement of the objects in the storage container. Contains information. These pieces of information may be collected as environmental information in a form including each information as it is so that each information can be individually identified, or collected as environmental information in a form in which each information is associated and processed. May be. The environment information may be provided to the gripping system in advance, or may be obtained using an imaging result obtained by an imaging device such as a camera.

Further, the predetermined gripping surface is a surface of a gripping object that can be gripped from a pairing direction by a finger portion of the hand mechanism. Therefore, if a predetermined gripping surface is exposed on the gripping object, the fingers of the hand mechanism come into contact with the gripping object from the pairing direction and come into contact with the predetermined gripping surface. This means that the object to be grasped can be grasped. Such gripping using the predetermined gripping surface is hereinafter referred to as “direct gripping”. Therefore, in such a case, the hand mechanism can grasp the grasped object by the finger portion without changing the position or posture of the grasped object. The paired directions are two directions in which the directions in contact with the object to be grasped are preferably 180 degrees opposite to each other in order to stably grasp the object. As long as the object can be gripped, the direction in contact with the object may be appropriately shifted.

On the other hand, if it is determined that the predetermined gripping surface is not exposed in the gripping object, it means that it is difficult for the hand mechanism to perform the direct gripping on the gripping object. Therefore, in such a case, a first operation for tilting the gripping target is performed so that the gripping target can be gripped by the hand mechanism, and the tilted state is achieved by the first motion. A second operation for gripping the gripping object may be performed. And about the contact surface for 1st operation | movement which is an operation parameter required for the said 1st operation | movement, and an inclination direction (predetermined direction), the exposure of the holding | grip target object calculated from environmental information by the 1st operation | movement determination part. It may be determined based on the area. The second operation contact surface, which is an operation parameter necessary for the second operation, may also be determined by the second operation determination unit based on the exposed area of the grasped object.

As described above, in the gripping system of the present invention, when the state in which the object is arranged is a state in which direct gripping is difficult, according to the motion parameters determined by the first motion determination unit and the second motion determination unit. Thus, it is possible to realize gripping of a gripping object in a form different from direct gripping by the hand mechanism. That is, the first operation and the second operation are suitably reflected by accurately reflecting the arrangement state of the object in the storage container, in particular, the arrangement state regarding the gripping object while a plurality of objects are disposed in the storage container. Thus, the object to be grasped can be grasped stably. By adopting such a configuration, it becomes possible to virtually eliminate the influence of the arrangement state of the object placed before gripping and stably grip the gripping object. The versatility can be very high.

Hereinafter, specific embodiments of the present invention will be described 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 gripping system according to the present invention is applied to a robot arm will be described. The gripping system is a system for gripping an object to be gripped using a hand mechanism 2 provided at the tip of the robot arm 1. FIG. 1 is a diagram illustrating a schematic configuration of a robot arm 1 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. Next, 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 30 c, and the third joint portion 30 c is connected to the third arm link portion 33. A motor (not shown) for relatively rotating the second arm link portion 32 is provided.

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 by the fourth joint portion 30d, and the other end side of the fourth arm link portion 34 is connected to the fifth joint portion. The part 30e is connected to the fifth arm link part 35. 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. By configuring the arm mechanism 3 as described above, the arm mechanism 3 can be a mechanism having five 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. 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 (the direction perpendicular to the paper surface in FIG. 3). 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.

The finger part 21 has a first finger link part 211, a second finger link part 212, and a base end part 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.

And the drive mechanism of the base end part 213 and the drive mechanism of the 2nd joint part 23 are demonstrated based on 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, the base portion 20 is connected to the gear 65 connected to the rotation shaft of the base end portion 213 and the rotation shaft of the third motor 53, which rotates the entire finger portion 21. A gear 66 is provided. 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. That is, the entire finger portion 21 can be rotationally driven by the third motor 53.

Also, 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, and the second finger link portion 212 has a base end portion. It is driven to rotate relative to 213. At this time, the driving force by the second motor 52 and the driving force by the third motor 53 are configured to be independently transmitted to the operation target. FIG. 7 is a diagram illustrating 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.

Next, in the finger part 21, one end of the first finger link part 211 is connected to the other end of the second finger link part 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. Based on FIG. 8, the drive mechanism of the 1st joint part 22 is demonstrated. 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 that are fitted to 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, and the first finger link portion 211 is It is driven to rotate relative to the finger link unit 212. 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.

As shown in FIGS. 2 and 4, in this embodiment, the finger portion 21 has a base more than the first joint portion 22 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.

Further, 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 sensor 70 is a sensor that detects an external force (pressure) acting on the distal end side of the first finger link portion 211. Further, as shown in FIG. 4, the pressure-sensitive sensors 70 are provided on both surfaces of the wall surface 215 on the bending direction side and the wall surface 216 on the extension direction side of the first joint portion 22 on the distal end side of the first finger link portion 211. ing. Here, in this embodiment, the wall surface 215 on the bending direction side of the first joint portion 22 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 are arranged side by side along the curved surface shape on the wall surface 215 on the bending direction side of the first joint portion 22 on the distal end side of the first finger link portion 211. May be.

<Pedestal part>
Next, configurations of an arm control device 42 that is a control device of the robot arm 1 and a hand control device 43 that is a control device of the hand mechanism 2 arranged inside the pedestal portion 4 will be described with reference to FIG. The arm control device 42 and the hand control device 43 form a control device for the gripping system of this embodiment. FIG. 11 is a block diagram showing each functional unit included in the arm control device 42 and the hand control device 43. The arm control device 42 includes drivers that generate drive signals for driving the motors mounted on the arm mechanism 3 of the robot arm 1, and the drive signals from the drivers are supplied to the corresponding motors. Configured as follows. The arm control device 42 is a computer having an arithmetic processing unit and a memory, and includes an arm control unit 420 and a motor state quantity acquisition unit 421 as functional units. Each functional unit is formed by executing a predetermined control program in the arm control device 42.

The arm control unit 420 is provided in each

joint unit

30a, 30b, 30c, 30d, and 30e of the arm mechanism 3 based on environment information acquired by an environment information acquisition unit 432 described later that the hand control device 43 has. By controlling the motor, the arm mechanism 3 is moved, 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, and 30e of the arm mechanism 3 are encoders that detect state quantities (such as the rotational position and rotational speed of the rotation shaft of the motor) related to the respective rotational states. (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 the predetermined grippable position based on the state quantity of each motor input to the motor state quantity acquisition unit 421. To do.

Next, the hand control device 43 includes drivers that generate drive signals for driving the motors mounted on the hand mechanism 2, and the drive signals from the drivers are supplied to the corresponding motors. Configured. The hand control device 43 is a computer having an arithmetic processing unit and a memory. As functional units, a motor state quantity acquisition unit 430, a sensor information acquisition unit 431, an environment information acquisition unit 432, a direct grip control unit 433, a determination unit 434, A gripping object determination unit 435, a first motion determination unit 436, a second motion determination unit 437, a motion control unit 438, and a grip determination unit 439 are provided. Each functional unit is formed by executing a predetermined control program in the hand control device 43.

The hand control device 43 is configured to control the hand mechanism 2 moved to a predetermined grippable position based on the environment information acquired by the environment information acquisition unit 432. The environment information acquisition unit 432 acquires environment information that is information related to an object to be gripped by the hand mechanism 2 and a storage container. Here, the environmental information includes at least information regarding the position of the object and the arrangement of the objects in the container. This environmental information may be included so that each of these pieces of information can be individually identified, or alternatively, may be included as complex information formed by associating each piece of information. Furthermore, information on the shape and dimensions of the object and the storage container, and information on objects other than the object existing around the object may be included. The environment information acquisition unit 432 may acquire environment information input by the user. When a visual sensor that captures an image including an object is provided, the environment information acquisition unit 432 may acquire environment information by performing known image processing on the image captured by the visual sensor. Good.

The direct grip control unit 433 is a functional unit that causes the hand mechanism 2 to perform direct gripping, which is one of the gripping forms of the object. Direct gripping means that at least two finger portions of the finger portions 21 of the hand mechanism 2 are left in the state in which the target object is placed before gripping, that is, without changing the position or posture of the target object. It is the form of the holding | grip performed by making it contact and pinch | interpose with respect to the said target object. Details of the direct gripping executed by the direct gripping control unit 433 will be described later.

Next, the determination unit 434 is a functional unit that determines whether the arrangement state of the object to be grasped is a state in which the direct grasping is possible based on the environment information of the object. The gripping object determination unit 435 is a functional unit that determines a target object (grip target object) to be gripped from among a plurality of target objects arranged in the storage container. The determination process by the gripping object determination unit 435 is also performed based on the environmental information of the object stored in the storage container. In addition, the first motion determination unit 436 performs the first motion for tilting gripping, which is a gripping form different from direct gripping, when the gripping target object is arranged in a state where the gripping cannot be performed directly by the determination unit 434. It is a functional unit that determines related operation parameters (first operation contact surface and tilt direction), and the second operation determination unit 437 performs a second operation performed following the first operation for the tilt gripping. It is a function part which determines the operation parameter (2nd operation contact surface) relevant to this. As shown in FIGS. 16 to 18C, which will be described later, the tilt gripping is performed with the side surface exposed so that the target object 10 can be gripped by tilting the target object 10 and changing its posture. It is a gripping form. In order to realize this tilting gripping, the first operation and the second operation described above are required. Details of the first operation and the second operation and details of operation parameters related to each operation will be described later. The motion control unit 438 is a functional unit that causes the hand mechanism 2 to perform tilt gripping based on the above-described motion parameters, and the grip determination unit 439 determines whether the tilt gripping performed is successful. It is a function part to determine.

In the hand control device 43, the first motor 51 and the second motor for driving each finger portion 21 of the hand mechanism 2 for gripping the object, whether the direct gripping or the tilt gripping different from the direct gripping. The motor 52 and the third motor 53 are controlled based on the environmental information. Each first motor 51, each second motor 52, and each third motor 53 of the hand mechanism 2 includes encoders (such as a rotational position and a rotational speed of the rotation shaft of the motor) that detect state quantities relating to the respective rotational states. (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 430. Then, the hand control device 43 servo-controls each

motor

52, 52, 53 in each finger 21 based on the state quantity of each

motor

51, 52, 53 input to the motor state quantity acquisition unit 430. Hold it.

Furthermore, in the hand control device 43, the detection value of the pressure-sensitive sensor 70 provided on the tip side of each finger portion 21 of the hand mechanism 2 is input to the sensor information acquisition unit 431. And the hand control apparatus 43 can detect the contact to the target object of the finger | toe part 21 based on the detected value of the pressure-sensitive sensor 70 of each finger | toe part 21 acquired by the sensor information acquisition part 431, and it becomes the detection signal. Based on this, it is possible to control the

motors

51, 52, 53 in each finger 21.

In FIG. 11, the arm control device 42 and the hand control device 43 are shown separately as control devices included in the gripping system. However, as an alternative, each functional unit is integrated with both devices. A configuration formed in one control device can also be adopted. Further, even when the control devices included in the gripping system are classified into the arm control device 42 and the hand control device 43, each functional unit shown in FIG. As long as it is formed in the control device, appropriate information can be exchanged between the arm control device 42 and the hand control device 43 as necessary. In addition, a configuration in which a part of each functional unit in the arm control device 42 or the hand control device 43 is formed in a control device separate from the arm control device 42 and the hand control device 43 may be employed. .

<Gripping control>
Here, based on FIG. 12, the grip control of the object by the grip system using the hand mechanism 2 mounted on the robot arm 1 will be described. The grip control is realized by executing a predetermined control program in the arm control device 42 and the hand control device 43. In the present embodiment, as shown in the upper part (a) of FIG. 13, each object 10 is moved by the hand mechanism 2 by grip control in a state where the plurality of objects 10 are arranged in the storage container 80. It shall be gripped. In a state before the grip control is started, a plurality of objects 10 are accommodated in the horizontal three rows and the vertical three rows in the container 80, and each of the objects 10 has the same rectangular parallelepiped shape. Have. In this embodiment, when identifying the arrangement position of the target object 10 in the container 80 for each target object 10, a reference number “10” is used to identify the arrangement position. It shall be added. As shown in the lower part (b) of FIG. 13, the notation represents the row position and the column position in the container 80 in the form of a matrix. For example, the reference numbers of the objects 10 in the front horizontal row of the storage container 80 can be described as 10 (1_1), 10 (1_2), and 10 (1_3) in order from the left. In addition, when it is not necessary to represent the arrangement position of the target object 10 in the storage container 80 for every target object 10, the said description may be abbreviate | omitted.

In addition, the container 80 has a peripheral wall portion 82 having a height similar to that of the target object 10 on the left and right sides and the rear side, but the front side takes out the target object 10 inside. The front wall 81 has a shape that is cut out to facilitate the operation. Specifically, in the front wall portion 81, the left and right

end wall portions

81 a and 81 c connected to the peripheral wall portion 82 have the same height as the peripheral wall portion 82. A low wall portion 81b having a height of about 10% is provided. Therefore, for the three objects 10 in the front horizontal row in the container 80 shown in FIG. 13, the front surfaces of the objects 10 (1_1) and 10 (1_3) at the left and right ends are the

end walls

81a and 81c. Although it is covered along the height direction, the front surface of the central object 10 (1_2) is covered only by the low wall portion 81b and is relatively exposed.

The details of the grip control will be described below. First, in S101, the hand mechanism 2 is moved to a predetermined grippable position. This process is executed by the arm control unit 420 of the arm control device 42. Specifically, the environment information acquired by the environment information acquisition unit 432 is delivered from the hand control device 43 to the arm control device 42. Then, based on the delivered environment information, the hand mechanism 2 acts on a predetermined grippable position where the hand mechanism 2 should be positioned, that is, each of the plurality of objects 10 arranged in the storage container 80. By doing so, a position where each object can be gripped is calculated. For example, on the basis of the position information of the storage container 80 included in the environment information, a predetermined distance and a position away from the storage container 80 may be calculated as a predetermined grippable position so that the storage container 80 can be gripped. When the process of S101 ends, the process proceeds to S102.

In S102, it is determined whether or not the object can be directly gripped by the hand mechanism 2 moved to a predetermined grippable position. The determination is performed by the determination unit 434 based on the environment information. Here, the information regarding the arrangement of the objects 10 in the storage container 80 corresponding to the arrangement state shown in FIG. 13A, which is included in the environment information when the grip control is started, will be described with reference to FIG. . In addition to the information regarding the arrangement, the positional information of the container 80 and each object 10 is included in the environment information. In the information regarding the arrangement shown in FIG. 14, a grip completion flag, a left side exposure ratio, a front surface exposure ratio, and a right side exposure ratio are associated with each object 10. Each of the objects 10 is identified by using the object ID as a notation for identifying the arrangement position. Further, when the grip completion flag is set to “1”, it means that the object 10 has already been taken out of the storage container 80 by gripping the hand mechanism 2 and is set to “0”. In this case, the object 10 still remains in the storage container 80. The left side exposure ratio is such that the left side surface of the object 10 (the left side surface toward the object 10 in FIG. 13) is covered with another object (such as the container 80 or the object 10 other than itself). It is an index indicating the degree to which the left side is completely exposed when the value is 100%, and the left side is completely covered when the value is 0%. To do. Further, the front surface exposure ratio and the right side surface exposure ratio are indexes indicating the extent to which the front surface and the right side surface of the object 10 are not covered with other objects, as with the left side surface exposure ratio. In addition, in FIG. 14, the information regarding the exposure ratio of the back surface of the target object 10 is not tied to each target object. In the arrangement state shown in FIG. 13, the target object 10 is always gripped from the front, This is because the back surface of the object 10 is always left unexposed.

As described above, in the arrangement state illustrated in FIG. 13A, the side surfaces of the objects 10 other than the three objects 10 in the front horizontal row are covered with the peripheral wall portion 82 and the three objects 10 in front thereof. . Therefore, for the six objects 10 with the object IDs 2_1 to 3_3, the exposure ratio of each surface is 0%. On the other hand, among the three objects 10 in the front horizontal row, the effects of the end wall part 81a and the end wall part 81c are considered for the object 10 (1_1) and the object 10 (1_3) on both left and right ends. The front surface exposure ratio is 70%, but the left side surface and right side exposure ratios are 0%. For the central object 10 (1_2), the front surface exposure ratio is set to 90% in consideration of the influence of the low wall portion 81b, and the left side surface and right side surface exposure ratio is set to 0%. The “exposure” referred to in the present application is such that a space where the finger portion 21 can enter is formed near the surface of the object 10 so that the finger portion 21 of the hand mechanism 2 can contact the exposed surface of the object 10. Say it is exposed.

<Direct grip>
Here, details of direct gripping by the hand mechanism 2 will be described based on FIG. The object 10 shown in FIG. 15 is placed on the floor in a state where it can be directly gripped. In a state where direct gripping is possible, as shown in FIG. 15, the end surface 10 a of the object 10 and the end surface 10 b facing the object 10 are both exposed to the extent that the finger portion 21 of the hand mechanism 2 can be contacted. ing. In the present application, when the four finger parts 21 included in the hand mechanism 2 and the first finger link part 211 constituting the four finger parts 21 are distinguished and identified for each finger part, reference numerals “21” and “211” are used. "A" to "D", which are subscripts for identification, are added, and the description of the subscripts may be omitted if there is no need to distinguish and identify them. Further, the subscripts “A” to “D” are assigned to the respective finger parts in the clockwise order in the state of the arrangement of the finger parts 21 shown in FIG. Here, since the end surface 10a and the end surface 10b are exposed in the object 10, the object 10 is moved from the paired direction indicated by the white arrow in the drawing by the finger part 21A and the finger part 21C of the hand mechanism 2. It becomes possible to sandwich and hold. At this time, since the object 10 can be grasped without changing the posture or position of the object 10, the object arranged as shown in FIG. 15 is in a state where it can be directly grasped.

Considering the movement of the finger part 21 of the hand mechanism 2 in such direct gripping, the determination of whether or not direct gripping is possible by the determination unit 434 in S102 grips the target object 10 from the paired direction as described above. This is a determination process performed as to whether the surface of the object 10 (which corresponds to the predetermined gripping surface of the present invention and an example thereof is the end surfaces 10a and 10b shown in FIG. 15) is exposed. . Therefore, the object 10 in a state where both the left side surface and the right side surface, which are the opposite side surfaces of the object 10, are exposed to the extent that they can be directly gripped (for example, the exposure ratio is 60% or more) is the container 80. It is possible to determine whether or not direct gripping is possible based on whether or not it is present inside. In the information regarding the arrangement shown in FIG. 14, since the exposure ratio of the left and right side surfaces of any object is 0%, it is determined that direct gripping cannot be performed.

If an affirmative determination is made in S102, the process proceeds to S103, and if a negative determination is made, the process proceeds to S104. Here, in S103, direct gripping by the hand mechanism 2 is performed with an affirmative determination in S102. For example, as shown in FIG. 15, the first finger link portion 211A of the finger portion 21A is in contact with the end surface 10a, and the first finger link portion 211C of the finger portion 21C is in contact with the end surface 10b, whereby the object 10 is directly gripped. Is done. In the direct gripping, it is sufficient that the target object 10 is gripped by at least two finger parts 21. However, even if the target object 10 is gripped more stably by bringing more finger parts 21 into contact with the target object 10 Good. For example, in the state shown in FIG. 15, the first finger link portion 211B of the finger portion 21B or the first finger link portion 211D of the finger portion 21D (not shown) comes into contact with the object 10 to directly hold the object. May be. After the process of S103, this control ends.

Next, in S104, in order to realize gripping of the target object 10 by performing tilted grip in a form different from direct gripping with a negative determination in S102, the target object to be tilted gripped (grip target object) Ten decisions are made.

<About tilting grip>
Here, before explaining the processing after S104, details of the tilting gripping by the hand mechanism 2 will be described based on FIGS. 16 to 18C. In tilting gripping, first, the tilting operation of the gripping target object 10 is performed using the first operation contact surface. This tilting operation corresponds to the first operation of the present invention, and is an operation for exposing the side surface of the grasped object 10 to such an extent that the finger unit 21 of the hand mechanism 2 can be contacted. The first operation determining unit 436 The first operation contact surface and the tilt direction, which are operation parameters related to the tilt operation, are determined. The first operation contact surface is a surface of the gripping target object 10 with which the finger portion 21 comes into contact in order to tilt the gripping target object 10 by the hand mechanism 2, and the tilting direction is a finger on the first motion contact surface. This is the tilting direction when the gripping object 10 is tilted by bringing the part 21 into contact therewith. The operation parameter determination process will be described later. Then, when the operation control unit 438 controls the hand mechanism 2 according to these operation parameters, the tilting operation is realized.

The tilting operation will be specifically described with reference to FIGS. 16 and 17. The motion control unit 438 uses the first finger link portion 211 </ b> A of the finger portion 21 </ b> A as the upper surface of the grasped object 10 that is the first operation contact surface. 101 is contacted. Therefore, the finger part 21A that contacts the upper surface 101 corresponds to the first finger part of the present invention. At this time, the other finger portions 21B to 21D are not in contact with the object 10. Then, while maintaining the contact state between the finger portion 21A and the upper surface 101, the motion control unit 438 controls the driving of the finger portion 21A and pulls the force to pull the gripping target object 10 in the tilting direction (front side). To act on. Therefore, as shown in FIG. 17, the grasped object 10 is tilted so that the upper part approaches the floor surface side with a part of the bottom surface in contact with the floor surface as the center.

As a result of the tilting operation, the back surface (side surface on the back side) 102 of the gripping target object 10 that has been in contact with the target object 10 ′ that is not the gripping target in the arrangement state before gripping is exposed, and the back surface is exposed. A space is formed between the object 102 and the object 10 ′. The space becomes larger as the tilt of the grasped object 10 progresses. The tilting operation is continued until the space is large enough to allow the finger part 21B and the finger part 21D different from the finger part 21A of the hand mechanism 2 to enter. The space that is sufficient for the entry of the finger part 21B and the finger part 21D in this way is hereinafter referred to as an entry space.

And when a sufficiently large entrance space is formed, the tilting operation is stopped. At this time, the state in which the finger portion 21A is in contact with the upper surface 101 is maintained, and the grasped object 10 is maintained in a tilted state. Thereafter, a gripping operation, that is, the second operation of the present invention is performed on the gripping target object 10 in the tilted state. Note that the second motion determination unit 437 determines a second motion contact surface that is a motion parameter related to the gripping motion. The second operation contact surface is a surface of the gripping object 10 for touching and gripping the gripping target object 10 tilted by the hand mechanism 2 with the finger portion 21. The operation parameter determination process will be described later. Then, the operation control unit 438 controls the hand mechanism 2 according to the operation parameter, whereby the gripping operation after the tilting operation is realized.

This gripping operation is a gripping of the gripping target object 10 performed in a state where the gripping target object 10 is tilted and its back surface 102 is exposed. The gripping operation will be specifically described based on FIGS. 18A to 18C. FIGS. 18A to 18C show the same state where the hand mechanism 2 is gripping the gripping object 10 by gripping operation from different viewpoints. 18A is a view from the direction in which the back surface 102 of the object 10 can be seen, FIG. 18B is a view from the side of the object 10, and FIG. 18C is a view from the direction in which the front surface 103 of the object 10 can be seen. FIG.

In the gripping operation of tilted gripping, the first finger link part 211B of the finger part 21B and the first finger link part 211D of the finger part 21D are entered in the entry space formed between the gripping target object 10 and the adjacent target object 10 ′. The two finger link portions are brought into contact with the back surface 102, and the first finger link portion 211C of the finger portion 21C is brought into contact with the front surface 103 of the object 10. That is, in the gripping forms shown in FIGS. 18A to 18C, the back surface 102 and the front surface 103 of the gripping target object 10 are the second operation contact surfaces. In the tilting gripping, the gripping target object 10 is used by using a finger part other than the finger part 21A used for supporting the gripping target object 10 in the tilted state from the front and back in the tilted state. Stable gripping is realized. Therefore, in this case, the finger portion 21B, the finger portion 21C, and the finger portion 21D that are in contact with the back surface 102 and the front surface 103, which are the second operation contact surfaces, correspond to the second finger portion or the third finger portion of the present invention. Note that the contact pattern of the finger portion 21 in the gripping operation is not limited to the form shown in FIGS. 18A to 18C. For example, as an alternative, the number of finger portions 21 used for the gripping operation may be two instead of three. In this case, one finger part 21 contacts each of the back surface 102 and the front surface 103.

Further, in order to hold the object more stably in the tilting holding, as shown in FIG. 18B, when the holding object 10 is viewed from the side, the first link finger of the finger portion 21 on the back surface 102 side. It is preferable that the first link finger portion of the finger portion 21 on the front surface 103 side is generally opposed. Also, as shown in FIGS. 18A to 18C, when the tilting gripping is performed with the three finger portions 21, when viewed from the back surface 102 or the front surface 103, the action point of the one finger portion 21C is two fingers. It is preferable that each finger part 21 contacts an object so that it may be located between each action point of the part 21B and the finger part 21D.

As described above, the tilt gripping is used for the gripping operation by tilting the object 10 to expose the side surface (back surface) that was not exposed before the tilting. For this reason, the gripping object 10 needs to be tilted from the state where it is currently disposed for gripping. Accordingly, the determination processing of the gripping object in S104 of the grip control is performed according to the flow shown in FIG. 19 based on this point. The determination process is executed by the gripping object determination unit 435.

<Handling object determination processing>
First, in S201, environmental information regarding all the objects 10 currently stored in the storage container 80, in particular, information regarding the arrangement shown in FIG. 14 is acquired. Next, in S202, the exposed areas of the side surfaces of all the objects 10 are calculated. Specifically, the exposed area of the side surface of each object 10 is obtained by multiplying the area of the side surface obtained from the dimensions of the object 10 included in the environmental information by the numerical value related to the exposure ratio included in the information related to the alignment. Is calculated. In the present embodiment, the front, back, left, and right side surfaces of the object 10 have the same area.

Next, in S203, the gripping object 10 is determined based on the exposed area of the side surface calculated in S202. When the object 10 is tilted and gripped, taking into account that the object in the tilted state is gripped using the side surface located in the tilting direction, when the object 10 is tilted, the exposed area is as much as possible. It is conceivable that the object 10 can be gripped more stably when tilted so that the large side faces the floor. Therefore, in the present embodiment, the target object 10 having the largest exposed area on the side surface is determined as the gripping target object from among the plurality of target objects 10 stored in the storage container 80. In the arrangement state of FIG. 13A, the exposure ratio of the left and right side surfaces is 0% in all the objects 10, but the exposure ratio of the front surface of the object 10 (1_2) is the largest, 90%. 10 (1_2) is determined as the gripping object.

<Operation parameter determination processing>
Here, the control returns to the grip control in FIG. When the gripping object is determined by the gripping object determination process, the process proceeds to S105 and S106. In S105, operation parameters (first operation contact surface and tilt direction) for the first movement for tilting are determined, and in S106, operation parameters (second operation) for the second operation following the first operation. Contact surface) is determined. The determination processing in S105 and S106 is performed by the first operation determination unit 436 and the second operation determination unit 437 according to the flow shown in FIG.

In the description of the operation parameter determination process shown in FIG. 20, it is assumed that the gripping target is the target 10 (1_2) among the plurality of targets 10 stored in the storage container 80 as shown in FIG. To do. The grasped object 10 (1_2) is a cubic object having a front surface S1, a back surface S5, a left side surface S2, a right side surface S3, an upper surface S4, and a bottom surface. First, in S301, environmental information of the grasped object 10 (1_2) is acquired. That is, the left side exposure ratio of the gripping object 10 (1_2) is 0%, the front surface exposure ratio is 90%, the right side surface exposure ratio is 0%, and the dimensions of the gripping object 10 (1_2) are recognized. . In S302, based on these exposure ratios, the exposed area of each side surface (left side, front, right side) of the grasped object 10 (1_2) is calculated. At this time, the dimension information of the grasped object 10 (1_2) is used as the environment information.

As described in the determination processing of the gripping object, the tilting operation of the gripping object 10 (1_2) and the subsequent gripping operation are more easily performed as the exposed area is larger. Therefore, in S303, the direction in which the side surface having the maximum exposed area among the side surfaces of the grasped object 10 (1_2) calculated in S302 is tilted so as to approach the floor surface is determined as the tilt direction. In the present embodiment, since the exposed area of the front surface S1 is maximized in the gripping target object 10 (1_2), the direction in which the front surface S1 of the gripping target object 10 (1_2) tilts toward the front side as shown in FIG. It is determined as the tilt direction. As another method, since the tilting operation of the grasping object 10 (1_2) and the subsequent grasping operation may be performed more stably as the exposure ratio is larger, of the side surfaces of the grasping object 10 (1_2). The direction of tilting so that the side surface with the maximum exposure ratio approaches the floor surface may be determined as the tilting direction.

Further, in S304, in order to realize the tilt of the grasped object 10 (1_2) in the determined tilt direction, the surface (first operation contact surface) with which the finger portion 21 of the hand mechanism 2 contacts is determined. Done. For the determination, environmental information regarding the gripping object 10 (1_2), particularly information such as the shape of the gripping object 10 (1_2) and the exposed surface is used. Specifically, the grasped object 10 (1_2) has a rectangular parallelepiped shape, and its upper surface S4 is exposed. Therefore, the upper surface S4 is determined as the first operation contact surface based on the structure condition of the grasped object 10 (1_2) and the like.

Next, in S305, in order to grip the gripping target object 10 (1_2) that has been tilted by the tilting operation, the surface (second operation contact surface) with which the finger portion 21 of the hand mechanism 2 comes into contact is determined. Is called. Also in this determination, environmental information regarding the gripping object 10 (1_2), particularly information such as the shape of the gripping object 10 (1_2) and the exposed surface is used. Specifically, as a result of the calculation in S302, the front surface S1 in which the exposure area is maximized and the back surface S5 that faces the surface S1 and is exposed by the tilting operation are determined as the second operation contact surface. Thereby, the gripping object 10 (1_2) can be gripped stably. As another method, depending on the size and shape of the grasped object 10 (1_2), the upper surface S4 that is the first operation contact surface used for the tilting operation and the back surface S5 that is exposed by the tilting operation may be It can also be determined as a contact surface for two operations.

Next, in S306, the number of finger parts 21 of the hand mechanism 2 used for the gripping operation of the tilting grip is determined. Since the hand mechanism 2 is provided with the four finger portions 21, it is most preferable to use the four finger portions 21 for stable grasping of the grasped object 10 (1_2). However, the four finger portions 21 are not necessarily used for the gripping operation for reasons such as the shape of the gripping target object 10 (1_2) and the correlation between the dimensions of the gripping target object 10 (1_2) and the finger portion 21. For example, when the widths of the front surface S1 and the back surface S5 that are the second operation contact surfaces are wide enough to arrange the two finger portions 21 side by side, as shown in FIGS. 22 (a) and 22 (b), By arranging the two finger portions 21 on at least one surface, three or four finger portions 21 can be used for the gripping operation. In tilting gripping, the gripping object 10 (1_2) is tilted by bringing at least one finger portion 21 into contact with the first motion contact surface. Therefore, in order to perform the gripping operation using the four finger parts 21 as shown in FIG. 22A, the gripping object 10 (1_2) in the tilted state is first gripped by the three finger parts 21. Thereafter, the at least one finger portion 21 used for the tilting operation is additionally caused to perform a gripping operation. As a result, the time required for the gripping operation of the gripping object 10 (1_2) becomes long, or when the finger part 21 used for the tilting operation is separated from the gripping object 10 (1_2) for the gripping operation. There is a possibility that the balance of the object 10 (1_2) may be lost. Therefore, in such a case, as shown in FIG. 22B, the use of the three finger portions 21 for the gripping operation can stabilize gripping and shorten the gripping time.

If the width of the front surface S1 and the back surface S5 is not wide enough to arrange the two finger portions 21 side by side, the two finger portions 21 are used for the gripping operation as shown in FIG. . Note that in this case, it may be difficult to hold the gripping object 10 (1_2) with sufficient stability depending on the contact position of the finger 21 with the gripping object 10 (1_2), the weight of the gripping object 10 (1_2), and the like. possible. In such a case, as shown in FIG. 22 (d), the object 10 (1_2) held by the two fingers 21 is taken out of the storage container 80, and the left side S2 and the right side S3 are exposed. When the state is reached, each side surface may be additionally gripped by the remaining fingers. The processing related to the change of the number of finger portions 21 used for the gripping operation performed based on the environmental information such as the dimension of the gripping object 10 (1_2) in this way is the processing performed by the use finger changing portion of the present invention. It corresponds to.

As described above, the operation parameters for the first operation and the second operation are determined by the operation parameter determination processing (processing of S105 and S106 of grip control). Then, when returning to the grip control again, in S107, the finger portion 21A of the hand mechanism 2 is brought into contact with the first operation contact surface (upper surface S4) determined in S105, and the object to be gripped is also determined according to the determined tilt direction. 10 (1_2) tilting operation is started (see also FIGS. 16, 17, and 21). As a result of this tilting operation, the back surface S5 of the grasped object 10 (1_2) is exposed, and a space is formed between the back surface S5 and the object 10 (2_2) behind it. Accordingly, in S108, it is determined whether or not the space has become large enough to allow the finger portion 21 of the hand mechanism 2 to enter and the tilting operation has been completed. Note that this determination is made based on the movement amount of the finger portion 21A related to the pulling amount of the grasped object 10 (1_2). If an affirmative determination is made in S108, the process proceeds to S109, and if a negative determination is made, the tilting operation of the grasped object 10 (1_2) is continued.

Next, in S109, the tilting operation is stopped with an affirmative determination in S108. At this time, the state where the finger portion 21A is in contact with the first operation contact surface (upper surface) S4 is maintained. In S110, the finger portion 21 of the hand mechanism 2 is brought into contact with the second operation contact surfaces (front surface S1 and back surface S5) determined in S106, and the gripping operation of the gripping object 10 (1_2) is performed. In the present embodiment, as shown in FIG. 22B, the gripping operation is realized by the three finger portions 21. When the gripping operation of the object is performed in S110, the hand mechanism 2 can move the gripping object 10 (1_2) to a desired target position while gripping the gripping object 10 (1_2).

Then, when the gripping of the gripping object 10 (1_2) is completed, the information regarding the arrangement of the environmental information regarding the object 10 stored in the storage container 80 is updated in S111. The information regarding the alignment is as shown in FIG. 14 before the holding of the holding object 10 (1_2), but after being updated in S111, the state is as shown in FIG. Specifically, “1” is set in the grip completion flag of the gripping object 10 (1_2). At the same time, the right side exposure ratio of the gripping object 10 (1_1), the left side exposure ratio of the gripping object 10 (1_3), the gripping object when the gripping object 10 (1_2) is taken out from the storage container 80. The value of the front exposure ratio of 10 (2_2) is updated to 100%. Thereby, the grip control shown in FIG. 12 is completed.

As described above, in the grip control, when the object 10 is arranged so as to be directly gripped, the direct grip is executed. As a result, the time required for gripping the object 10 can be shortened. On the other hand, even if the object 10 is disposed in the container 80 in a state where direct grip is not possible, the object 10 is tilted by bringing the finger portion 21A of the hand mechanism 2 into contact with the first operation contact surface. Thus, the tilting gripping of the object 10 is realized by the remaining finger portions 21B to 21D. In this tilting gripping, the object 10 is gripped while the finger part 21A is in contact with it, so that the time required to form a state in which the object 10 can be tilted gripping can be shortened as much as possible. it can. As described above, in the above grip control, it is possible to realize gripping of the target object 10 without being affected as much as possible by the situation where the target object 10 is arranged. Therefore, extremely efficient gripping of the object and movement of the object after gripping are possible.

In the grip control performed after the grip target 10 (1_2) is taken out from the storage container 80, environmental information including information on the arrangement shown in FIG. 23 is used. In this case, the exposed area of the right side surface of the object 10 (1_1), the left side surface of the object 10 (1_3), or the front surface of the object 10 (2_2) is maximized. It will be. If the gripping target object 10 (1_1) is determined to be the gripping target object, since the exposed area of the right side surface of the side surface is larger than the front surface, the gripping target object 10 (1_1) is shown in FIG. Is tilted to the right as the tilting direction in the first motion, and the upper surface of the grasped object 10 (1_1) is determined as the first motion contact surface with which the finger portion 21 comes into contact. Further, in consideration of the tilting motion of the gripping target object 10 (1_1) in the tilting direction, the gripping target object that is exposed to the right side surface and the right side surface of the gripping target object 10 (1_1) by the tilting motion. The left side surface of the object 10 (1_1) is determined as the second operation contact surface.

<Modification>
Based on FIG. 25, the modification of a present Example is demonstrated. FIG. 25 shows a state in which the objects 10 are arranged in the storage container 80 side by side in four rows and three rows. In addition, the description for the specification of each target object in the storage container 80 shall be based on said Example. Regarding the plurality of objects 10 placed in such an arrangement state, the object 10 (1_2) or the object (1_3) having a relatively large exposed area on the front surface is set as the first gripping object. If the object (1_3) is taken as the object to be grasped by the grasping control and taken out from the storage container 80 (see FIG. 25B), the object to be grasped in the next grasping control is the object 10 ( 1_2).

At this time, since the right side surface of the object 10 (1_2) is completely exposed, the side surface of the object 10 (1_2) having the maximum exposed area is the right side surface. Therefore, by the operation parameter determination process of FIG. 20, the tilt direction of the object 10 (1_2) is set to the direction in which the right side surface approaches the floor surface (see FIG. 25C). However, when the object 10 (1_2) is tilted in the tilt direction, the space between the object 10 (1_2) and the object (1_4) is narrowed. Therefore, it is difficult to bring the finger portion 21 of the hand mechanism 2 into contact with the right side surface of the object 10 (1_2) serving as the second operation contact surface for the gripping operation performed after the tilt operation in the tilt direction. In this case, another direction may be adopted as the tilt direction.

In this case, when the tilt direction is determined in S303 of the operation parameter determination process of FIG. 20, the tilt direction is determined based on the exposed area of the side surface and the size of the space necessary for the gripping operation of the tilted gripping target object. Is done. In the case of the present embodiment, the front surface of the object 10 (1_2) is also greatly exposed next to the right side surface, and the container 80 and other objects 10 are not present in the vicinity thereof. Therefore, when it is difficult to hold the object 10 (1_2) after being tilted as shown in FIG. 25C, the front surface of the object 10 (1_2) is brought closer to the floor surface. The direction of tilting is determined as the tilting direction for the first operation. Thus, by taking into consideration the size of the space necessary for the gripping operation of the tilt gripping, it is possible to realize smoother gripping of the object 10.

In the above grip control, whether or not direct gripping is possible is determined, and if it is determined that direct gripping is not possible, the gripping target is tilted and gripped. The tilted gripping of the gripping object may be performed without performing it. In this case, the gripping system is a gripping system for taking out the stored object from a storage container storing a plurality of objects by a hand mechanism having at least two fingers. A gripping object determining unit that determines a gripping target object to be gripped among the target objects based on an exposed area or an exposure ratio of each of the objects in a state of being stored in the storage container; and the gripping A first motion contact surface for contacting the first finger portion of the at least two finger portions and a predetermined direction for the first motion for tilting the object in the predetermined direction is determined. A second action different from the first finger part among the at least two finger parts for a second action of gripping the grasped object in a state of being tilted by the first action; Part contact, second Comprising a second operation determining unit that determines the active contact surface.

A grip retry process that can additionally be executed in the grip control according to the first embodiment will be described with reference to FIG. FIG. 26 is a flowchart of the grip retry process. This process determines whether or not the tilt grip is successful when the tilt grip is performed in S104 to S111 of the grip control. This is a process of changing the conditions related to tilt gripping, that is, the operation parameters of the first motion and the second motion and trying tilt grip again. Specifically, this grip retry process is performed after gripping the gripping object in S110 of grip control.

Specifically, in S401, it is determined whether or not the tilting gripping of the gripping object has succeeded in S110. The determination process is executed by the grip determination unit 439. Specifically, among the finger portions 21 of the hand mechanism 2 used for tilting gripping, pressure sensors provided on each of the finger portions 21 that are in contact with the second operation contact surface of the grasped object. 70, when the detected value at the timing of contact with the second operation contact surface is a detection value in a range that is assumed (that is, a value corresponding to a pressure that is generated when the object to be grasped is suitably grasped). In this case, it is determined that the tilt gripping is successful. On the other hand, when the detected value of the pressure-sensitive sensor 70 deviates from the assumed range, it can be determined that the tilt gripping has not been successful. If an affirmative determination is made in S401, the gripping retry process is terminated, and if a negative determination is made, the process proceeds to S402.

In S402, it is determined whether or not another tilting operation can be applied to the gripping object when the tilting gripping is not successful due to the negative determination in S401. For example, as shown in FIG. 25 (c), it is assumed that when the tilting operation is performed in the direction in which the right side surface of the gripping object 10 (1_2) is brought close to the floor surface, the tilting gripping is not successful. . In this case, the gripping object 10 (1_2) may adopt a tilting operation in a direction in which the front surface thereof is brought close to the floor surface instead of a tilting operation in a direction in which the right side surface is brought close to the floor surface. As described above, this is because the entire surface of the grasped object 10 (1_2) is sufficiently exposed to perform the tilting operation. In such a case, a positive determination is made in S402, and the process proceeds to S403.

Note that if a negative determination is made in S402, the process proceeds to S408, and the tilting gripping of the gripping target object 10 is stopped in S408. In this case, the gripping system stops the gripping object 10 without taking out the gripping object 10 from the storage container 80. Thus, about the operation | movement of the robot arm 1 and the hand mechanism 2 when the holding process of the target object 10 is stopped, operations other than the predetermined holding operation may be performed. For example, after returning the robot arm 1 and the hand mechanism 2 to predetermined positions and states, an alarm may be issued to inform the user that the object 10 has not been gripped, or the gripping may be performed. The gripping control may be advanced by switching the target object to another object.

Here, the process of S403 will be described. In S403, the side surface of the object to be gripped that is the reference for determining the tilt direction when tilt gripping is not successful (the side surface whose exposure area is maximized in S303 of the operation parameter determination process, or S403 before one round) The direction of tilting so that the side surface having the next largest exposed area near the floor surface is determined as the tilting direction. In the example shown in FIG. 25C, the front surface of the grasped object 10 (1_2) is the side having the largest exposed area next to the right side surface. Therefore, the direction in which the front surface approaches the floor surface is determined as a new tilting direction of the grasped object 10 (1_2). When the process of S403 is completed, the first operation contact surface for realizing the tilting operation is determined in S404, the second operation contact surface for the gripping operation is determined in S405, and the gripping operation is performed in S406. The number of finger parts 21 to be used is determined. Since these processes are substantially the same as S304, S305, and S306 in the above-described operation parameter determination process, detailed description thereof is omitted.

Then, after the gripping object is tilted and gripped according to the operation parameters for tilting gripping newly determined in S403 to S406, whether or not the tilting gripping is successful is determined in S407. Note that this determination is substantially the same as the determination processing in S401, and therefore detailed description thereof is omitted. Note that even if the tilting operation is performed in the direction in which the front surface of the gripping target object 10 (1_2) approaches the floor surface and then the gripping operation is performed, if the tilting gripping is not successful, the gripping target object 10 (1_2) is detected. ), There are no other tilting motion options, so a negative determination is made in S402 and the processing in S408 is performed.

As described above, the gripping retry process is additionally performed on the gripping control, so that the gripping target can be tilted and gripped as much as possible. Also, in the grip retry process, if the tilt grip is not successful, the tilt operation is changed, but in combination with or separate from it, the tilt operation remains the same and only the conditions related to the grip operation are changed. May be. For example, the number of fingers of the hand mechanism 2 used for the gripping operation may be changed. As another method, the selection of the second operation contact surface for the gripping operation may be changed. For example, if the tilt gripping is not successful with the side surface with the largest exposure area and the side surface facing it exposed as a second motion contact surface, the tilting operation is used in the next tilting gripping. The gripping operation may be performed again using the first contact surface for operation and the side surface exposed by the tilting operation as the second operation contact surface.

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, 43 ... Hand control device, 51 ... First motor, 52 ... Second motor, 53 ...

Third motor

61, 62 ... bevel gear, 63 ... worm wheel, 64 ... worm, 65, 66 ... gear, 70 ... pressure sensor, 10 ... object, 10 '... Non-object, 80 ... container, 101 ... first operation contact surface, 102 ... second operation contact surface

Claims

A gripping system for taking out an object stored by a hand mechanism having at least two fingers from a storage container in which a plurality of objects are stored,
A gripping object determination unit that determines a gripping object to be gripped among the plurality of objects based on an exposed area or an exposure ratio of each of the objects in a state of being stored in the storage container;
For a first operation of tilting the grasped object in a predetermined direction, a first operation contact surface for contacting the first finger portion of the at least two finger portions and the predetermined direction are determined. A first action determining unit that
A second finger part different from the first finger part of the at least two finger parts is brought into contact for a second action of gripping the grasped object in a state of being tilted by the first action; A second motion determining unit that determines a contact surface for two motions;
A gripping system comprising:
The first operation determining unit determines the predetermined direction based on an exposed area or an exposure ratio of each side surface of the grasped object in a state of being accommodated in the accommodating container.
The gripping system according to claim 1.
A determination unit for determining whether or not the object in which a predetermined gripping surface for holding and gripping by the finger part of the hand mechanism is exposed exists in the storage container;
When the determination unit determines that the object with the predetermined gripping surface exposed is not present in the storage container, the gripping object determination unit is stored in the storage container. Determining the gripping object based on an exposed area or an exposure ratio of each of the objects in a state of being
The gripping system according to claim 1 or 2.
An acquisition unit for acquiring environmental information including at least information on the position of the object and the arrangement of the objects in the container;
The gripping object determination unit calculates an exposed area or an exposure ratio of each object in a state of being accommodated in the container, based on the environment information,
The first motion determining unit determines the first motion contact surface and the predetermined direction based on the environment information,
The second motion determining unit determines the second motion contact surface based on the environment information.
The gripping system according to claim 1 or 2.
An acquisition unit for acquiring environmental information including at least information on the position of the object and the arrangement of the objects in the container;
The determination unit determines whether or not the object from which the predetermined gripping surface is exposed is present in the storage container based on the environmental information.
The gripping system according to claim 3.
The hand mechanism has at least three fingers.
The second motion determining unit determines the second motion contact surface that contacts the second finger portion and a third finger portion different from the first finger portion among the at least three finger portions.
The gripping system according to any one of claims 1 to 3.
An acquisition unit for acquiring environmental information including at least information on the position of the object and the arrangement of the objects in the container;
Based on the environment information, a use finger changing unit that changes the number of the finger units used for the second operation,
The gripping system according to claim 6, further comprising:
The gripping object determination unit uses, as the gripping object, an object having the maximum exposed area or exposure ratio of a side surface that is not hidden by the storage container or another adjacent object among the plurality of objects. decide,
The gripping system according to any one of claims 1 to 7.
In the case where the gripping object has a plurality of side surfaces, the first motion determining unit is configured to determine a portion of the plurality of side surfaces of the gripping target object that is not hidden by the storage container or other adjacent objects. A direction in which the exposed maximum side surface with the maximum exposed area or exposure ratio is tilted so as to approach the floor surface of the container is determined as the predetermined direction, and a predetermined object of the gripping object different from the exposed maximum side surface is determined. Determining a surface as the first operating contact surface;
The gripping system according to any one of claims 1 to 8.
The second operation determining unit determines, as the second operation contact surface, the maximum exposed side surface and a side surface facing the maximum exposed side surface among the plurality of side surfaces of the gripping object.
The gripping system according to claim 9.
The exposed maximum side surface is a side surface where all surfaces of the plurality of side surfaces are exposed in a state where the gripping object is stored in the storage container.
The gripping system according to claim 9 or 10.
In addition to the exposed area or exposure ratio of each side surface of the gripping target object in the state of being accommodated in the storage container, the first motion determining unit is configured to detect the gripping target object that has been tilted by the first motion. And determining the predetermined direction based on the size of the space required for contacting the second finger.
The gripping system according to claim 2.
Based on the first operation contact surface and the predetermined direction determined by the first operation determination unit, and the second operation contact surface determined by the second operation determination unit, the hand mechanism is moved to the hand mechanism. A control unit for executing the first operation and the second operation;
A gripping determination unit that determines whether the gripping of the gripping object by the hand mechanism is successful;
Further comprising
When the grip determining unit determines that the gripping object is not successfully gripped, the first motion determining unit tilts the gripping object different from the predetermined direction when the gripping is not successful. Determining the direction as a new predetermined direction and determining the first operation contact surface corresponding to the new predetermined direction;
The second motion determining unit determines the second motion contact surface corresponding to the new predetermined direction;
The gripping system according to any one of claims 1 to 12.