JP2013180366A - Robot and robot hand - Google Patents

Abstract

A robot and a robot hand for reliably grasping an object are provided.
A first finger part and a second finger part that move in a first direction parallel to a predetermined plane and grip an object, and a base part that supports the first finger part and the second finger part. The first finger part and the second finger part each have a first part and a second part connected in a second direction orthogonal to the predetermined plane, and the first part is the first finger part And a contact surface that contacts the object in a state where the second finger portion grips the object, and the contact surface is different from the second part in the second direction from the second part. It is inclined in the second direction with respect to the predetermined plane so as to protrude in the opposite direction of the first finger portion and the second finger portion toward the opposite end side.
[Selection] Figure 23

Description

  The present invention relates to a robot and a robot hand.

  In recent years, SCARA robots, multi-axis robots, and the like are used for assembly and inspection of products at manufacturing sites and the like. When an object is transported when a product is assembled or inspected, the robot sucks the object or holds it by an arm.

  In such an industrial robot, it is required to efficiently grasp an object having various and various postures in a predetermined posture in automatic assembly and other work processes. For example, in the robot of Patent Document 1, a chuck mechanism that grips an object can be rotated forward and backward around a central axis that supports the chuck itself by a rotation mechanism, and the rotation mechanism itself is rotated downward by a predetermined angle by a swing mechanism. It is possible to rotate within the range.

JP 2009-78312 A

  However, in the invention described in Patent Document 1, if the object is small and light, for example, it is difficult to accurately detect the position and orientation of the object using a camera, and the chuck mechanism for gripping the object is difficult. In some cases, accurate positioning cannot be performed. If the chuck mechanism cannot be accurately positioned, the object and the chuck mechanism may come into contact with each other at an unintended location during the gripping operation. In that case, since the object is lightweight, the object moves in an unintended direction, and the object may not be held at a desired position, or the object may jump out of the gripping space.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a robot and a robot hand that reliably hold an object.

  The robot according to the present invention supports a first finger part and a second finger part that move in a first direction parallel to a predetermined plane and grip an object, and the first finger part and the second finger part. A first portion and a second portion connected in a second direction orthogonal to the predetermined plane, and the first portion includes the first portion and the second portion. The one finger part and the second finger part have an abutting surface that abuts on the object in a state of gripping the object, and the abutting surface extends from the second part to the second part in the second direction. It is inclined in the second direction with respect to the predetermined plane so as to protrude in the opposite direction of the first finger portion and the second finger portion toward the end opposite to the portion.

  According to the present invention, the first finger part and the second finger part respectively have a first part and a second part connected in a direction orthogonal to a predetermined plane, and the pair of finger parts is an object in the first part. A contact surface that contacts the object in a state of gripping the first finger portion and the second finger from the second portion to the end opposite to the second portion in the second direction. Since it is inclined in the second direction with respect to a predetermined plane so as to protrude in the opposing direction of the part, when the pair of finger parts grips the object, the object in the second direction Can be captured inside. Thereby, a target object can be grasped reliably.

In the robot described above, it is preferable that the second portion has a flange portion that protrudes in a moving direction of the object in a direction opposite to the first finger portion and the second finger portion.
ADVANTAGE OF THE INVENTION According to this invention, when holding a target object with a pair of finger part, it can control that a target object moves to a 2nd direction. Thereby, it can suppress that a target object jumps out in a 2nd direction.

In the robot described above, it is preferable that the flange portion has a plane portion parallel to the predetermined plane on the first portion side.
According to the present invention, since the collar portion has the flat portion parallel to the predetermined plane on the first portion side, the object can be supported on the plane parallel to the predetermined plane.

In the robot described above, it is preferable that the flange portion has a cutout portion on a surface facing each other in the first direction.
According to the present invention, since the flanges have the notches on the surfaces facing each other in the first direction, a part of the object can be sandwiched in the notches. Thereby, the width | variety of the holding | grip aspect of a pair of finger part spreads.

In the above robot, it is preferable that at least one of the first part and the second part has a plate shape.
According to the present invention, since at least one of the first part and the second part is plate-shaped, it is possible to efficiently perform the gripping operation of the pair of finger parts even in a narrow space.

In the robot described above, it is preferable that the plate-like portions of the first portion and the second portion have the same thickness.
According to the present invention, since the plate-like portion of the first portion and the second portion has the same thickness, the gripping operation of the pair of finger portions can be performed efficiently even in a narrow space.

In the robot described above, it is preferable that the first part and the second part are fixed to be separable from each other.
According to the present invention, since the first portion and the second portion are separably fixed to each other, the first portion and the second portion can be manufactured separately. Thereby, a manufacturing cost can be reduced compared with the case where the 1st part and the 2nd part are manufactured integrally.

In the robot described above, the second portion has a second contact surface that contacts the object in a state where the pair of finger portions grips the object, and the contact surface and the second contact It is preferable that the surface has a recess provided so that both end portions in a third direction that is parallel to the predetermined plane and orthogonal to the first direction protrude from the center portion.
According to the present invention, the contact surface and the second contact surface are provided so that both end portions in the third direction that are parallel to the predetermined plane and orthogonal to the first direction protrude from the center portion. Since it has a recessed part, an object can be taken in a pair of finger part about a 2nd direction and a 3rd direction. Thereby, a target object can be grasped reliably.

  A robot hand according to the present invention includes a first finger part and a second finger part that move in a first direction parallel to a predetermined plane and grip an object, wherein the first finger part and the second finger part are , Each having a first part and a second part connected in a second direction orthogonal to the predetermined plane, wherein the first part is a state in which the first finger part and the second finger part grip the object A contact surface that contacts the object, and the contact surface extends from the second portion to an end opposite to the second portion in the second direction. It is inclined in the second direction with respect to the predetermined plane so as to protrude in the opposing direction of the two fingers.

  According to the present invention, the first finger part and the second finger part respectively have a first part and a second part connected in a direction orthogonal to a predetermined plane, and the pair of finger parts is an object in the first part. A contact surface that contacts the object in a state of gripping the first finger portion and the second finger from the second portion to the end opposite to the second portion in the second direction. Since it is inclined in the second direction with respect to a predetermined plane so as to protrude in the opposing direction of the part, when the pair of finger parts grips the object, the object in the second direction Can be captured inside. Thereby, a target object can be grasped reliably.

1 is a perspective view showing a schematic configuration of a robot 1 according to the present embodiment. It is a top view which shows the structure of the holding part which concerns on the same embodiment. It is a figure explaining the opening-closing mechanism of the nail | claw part which concerns on the same embodiment. It is a figure explaining the procedure which computes parameter alpha, beta, and d of a claw part shape concerning the embodiment. It is a figure explaining the components which the nail | claw part which concerns on the same embodiment can hold | grip. It is a figure explaining the relationship between the largest magnitude | size which can be hold | gripped and the parameters (alpha), (beta), and d of a nail | claw part shape which concern on the embodiment. It is a figure explaining the magnitude | size of the component which can be hold | gripped by the relationship between the vertex of the nail | claw part which concerns on the embodiment, and components. It is a figure explaining the relationship between the vertex of the nail | claw part which concerns on the embodiment, and components. It is a figure explaining the magnitude | size of the component which can be hold | gripped when the nail | claw part which concerns on this embodiment is closed. It is a figure explaining calculation of the minimum size of the component which can be grasped by the claw part concerning the embodiment. It is a figure explaining the parameter of the caging area | region which concerns on the same embodiment. It is a figure explaining the shape of a caging area | region and each parameter concerning the embodiment. It is a figure explaining the case where the distance of the x direction of the caging area | region which concerns on the embodiment is c21. It is a figure explaining the case where the distance of the x direction of the caging area | region which concerns on the embodiment is c22. It is a figure explaining the case where the distance of the x direction of the caging area | region which concerns on the embodiment is c23. It is a figure explaining the case where the distance of the x direction of the caging area | region which concerns on the embodiment is c24. It is a figure explaining the relationship between the largest magnitude | size rmax2 which can be caged, and distance c1, c2, clim concerning the embodiment. It is a figure explaining the conditions of self-alignment concerning the embodiment. It is a figure explaining the force added to components from the nail | claw part which concerns on the same embodiment. It is a figure explaining the relationship between r and the vertex a2 which concern on the same embodiment. It is a figure explaining the conditions used when attaching the component M which concerns on the embodiment. It is a figure explaining the example which is interfering with the components M2 which the nail | claw part tip which concerns on the embodiment attaches. It is sectional drawing which shows the structure of the finger part which concerns on the same embodiment. It is a perspective view which shows the structure of the robot hand which concerns on the same embodiment. It is sectional drawing which shows operation | movement of the robot hand which concerns on the embodiment. It is a figure showing other composition of the robot hand concerning the embodiment. It is a figure showing other composition of the robot hand concerning the embodiment. It is a figure showing other composition of the robot hand concerning the embodiment. It is a figure showing other composition of the robot hand concerning the embodiment. It is the figure which showed a mode that a cylindrical object and a plate-shaped object were hold | gripped with the robot hand which concerns on the same embodiment. It is a general | schematic external view which shows a mode that the robot system to which the robot apparatus which is 2nd embodiment of this invention is applied performs a work. It is a general | schematic external view of the robot system in 3rd embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, an actual structure and a scale, a number, and the like in each structure are different.

  In the following description, the XYZ rectangular coordinate system shown in FIG. 1 is set, and each member will be described with reference to this XYZ rectangular coordinate system. In the XYZ orthogonal coordinate system, the X axis and the Y axis are set in a direction parallel to the horizontal plane and orthogonal to each other, and the Z axis is set in a direction (vertical direction) orthogonal to each of the X axis and the Y axis.

[First embodiment]
FIG. 1 is a perspective view showing a schematic configuration of a robot 1 according to the first embodiment of the present invention. In FIG. 1, the code | symbol W1 is a 1st target object, and the code | symbol W2 is a 2nd target object. Reference numeral L1A is a rotation axis of the first arm 21A, reference numeral L2A is a rotation axis of the second arm 22A, reference numeral L3A is a rotation axis of the third arm 23A, and reference numeral L4A is a rotation axis of the grip portion 10A. Reference numeral L1B denotes a rotation axis of the first arm 21B, reference numeral L2B denotes a rotation axis of the second arm 22B, reference numeral L3B denotes a rotation axis of the third arm 23B, and reference numeral L4B denotes a rotation axis of the grip portion 10B.

  Here, a small and lightweight gear is illustrated and described as the first object W1, and an electronic device including a support shaft (pin) that rotatably supports the gear is illustrated as the second object W2. I will explain. The first object W1 has a substantially cylindrical shape having a curved surface on the side in contact with the grip portion.

  As shown in FIG. 1, the robot 1 according to this embodiment includes a robot hand RH. The robot hand RH includes gripping portions 10A and 10B provided on the main body portion 11. The grip portion 10A has a pair of finger portions 41 and 42 that are provided so as to be openable and closable and grip an object. The gripping part 10B has a pair of finger parts 43 and 44 that are provided so as to be openable and closable and grip an object.

  In addition, the robot 1 includes arms (moving devices) 20A and 20B that relatively move the object and the gripping units 10A and 10B, belt conveyors 33 and 34 that convey the first object W1, and the first object W1. A first belt conveyor (moving device) 33, a stage 37 serving as a delivery base for the first object W1, a stage (moving device) 30 on which the objects W1, W2 are placed, and an arm 20A, 20B and a base 50 for supporting the stage 30, cameras 40A, 40B attached to the arms 20A, 20B, a control device 60 for controlling the operation of the robot 1 itself, and input instructions to the control device 60, respectively. And an input device 70 for performing.

  The grip portion 10A is connected to the distal end portion of the third arm 23A. The gripping unit 10 </ b> A grips the first object W <b> 1 disposed on the first belt conveyor 33. The gripping unit 10A transports the gripped first object W1 to the stage 37. The gripper 10A includes a detection device 41A that detects a force for gripping the first object W1. As the detection device 41A, for example, a pressure sensor or a sensor that detects a change in torque of the motor (change in current flowing through the motor) can be used.

  The grip 10B is connected to the tip of the third arm 23B. The gripping unit 10 </ b> B grips the first object W <b> 1 arranged on the stage 37. The gripping unit 10B transports the gripped first object W1 to the stage 30. The gripping unit 10B transports the gripped first object W1 (or disposed on the stage 37) to the second target object W2. Specifically, the gear W1 is inserted through the pin of the electronic device W2 by the grip portion 10B. The gripping part 10B includes a detection device 41B that detects a force for gripping the first object W1. As the detection device 41B, for example, a pressure sensor or a sensor that detects a change in torque of the motor (change in current flowing through the motor) can be used.

  In the arm 20A, a first arm 21A, a second arm 22A, and a third arm 23A are connected in this order. The first arm 21A has a main shaft 24 having a rotation axis in the Z-axis direction and a base portion 25 having a substantially rectangular shape in plan view. It is connected to the base 50 via. The first arm 21 </ b> A is provided so as to be able to rotate forward and backward around the rotation axis L <b> 1 </ b> A in the horizontal direction (direction parallel to the XY plane) at the connection point with the main shaft 24. The second arm 22A is provided so as to be able to rotate forward and backward around the rotation axis L2A in the horizontal direction at the connection point with the first arm 21A. The third arm 23A is provided so as to be able to rotate forward and backward about the rotation axis L3A in the horizontal direction and to be vertically movable in the vertical direction (Z-axis direction) at the connection point with the second arm 22A. The grip portion 10A is provided so as to be able to rotate forward and backward around the rotation axis L4A in a direction orthogonal to the horizontal direction at a connection point with the third arm 23A.

  In the arm 20B, a first arm 21B, a second arm 22B, and a third arm 23B are connected in this order. The first arm 21B has a main shaft 24 having a rotation axis in the Z-axis direction and a base portion 25 having a substantially rectangular shape in plan view. It is connected to the base 50 via. The first arm 21 </ b> B is provided so as to be able to rotate forward and backward around the rotation axis L <b> 1 </ b> B in the horizontal direction (direction parallel to the XY plane) at the connection point with the main shaft 24. The second arm 22B is provided so as to be able to rotate forward and backward around the rotation axis L2B in the horizontal direction at the connection point with the first arm 21B. The third arm 23B is provided so as to be able to rotate forward and backward around the rotation axis L3B in the horizontal direction and to be vertically movable in the vertical direction (Z-axis direction) at the connection point with the second arm 22B. The grip portion 10B is provided so as to be able to rotate forward and backward around the rotation axis L4B in a direction orthogonal to the horizontal direction at a connection point with the third arm 23B.

  The first belt conveyor 33 and the second belt conveyor 34 are spaced apart in this order from the side on which the arm 20A is provided. The feeder 36 is disposed on the upstream side (+ Y direction side) of the first belt conveyor 33. The second belt conveyor 34 is larger than the first belt conveyor 33 in plan view so as to protrude downstream (−Y direction side) of the first belt conveyor 33. The first object W1 dropped from the first belt conveyor 33 is transported to the second belt conveyor 34 and put into the opening 36a of the feeder 36 by an inclined belt conveyor (not shown). In this way, the first object W1 that has not been gripped by the gripping portion 10A circulates through the first belt conveyor 33, the second belt conveyor 34, and the feeder 36.

  The stage 30 includes a top plate 31 on which an object is placed and a base portion 35 that supports the top plate 31. For example, the base unit 35 includes a moving mechanism that horizontally moves the top plate 31 in the X direction and a moving mechanism that moves the top plate 31 in the Y direction. It is provided to be movable.

  The camera 40A is attached to the tip of the second arm 22A that constitutes the arm 20A. For example, a CCD camera is used as the camera 40A. The camera 40A images the first object W1 placed on the first belt conveyor 33. The captured image of the camera 40A is transmitted to the control device 60.

  The camera 40B is attached to the tip of the second arm 22B that constitutes the arm 20B. For example, a CCD camera is used as the camera 40B. The camera 40B images the first object W1 and the second object W2 placed on the top board 31. The captured image of the camera 40B is transmitted to the control device 60.

  The control device 60 includes a memory, a CPU, a power supply circuit, and the like. The control device 60 stores an operation program that defines the operation content of the robot 1 input from the input device 70, and activates various programs stored in the memory by the CPU to control the robot 1 in an integrated manner.

  FIG. 2 is a perspective view and a plan view showing the configuration of the finger unit according to the present embodiment. Here, the finger parts 41 and 42 of the gripping part 10A out of the gripping part 10A and the gripping part 10B will be exemplified to describe the configuration of the finger parts. Since the finger portions 43 and 44 of the grip portion 10B have the same configuration as the finger portions 41 and 42 of the grip portion 10A, detailed description thereof is omitted.

As shown in FIG. 2A, the finger part 41 and the finger part 42 open and close, for example, in the X direction (first direction) along a plane parallel to the XY plane (predetermined plane).
The finger part 41 includes a first member (first part) 51, a second member (second part) 52, and a fixing member 53. The finger part 41 has a first end face 41a on the −Z side and a second end face 41b on the + Z side in the Z direction (second direction) orthogonal to the XY plane.

  The first member 51 is disposed on the first end surface 41 a side of the finger portion 41. The first member 51 has a slope 71, a slope 72, and a folded portion 73. The slope 71 and the slope 72 are formed in a planar shape so as to face the finger portion 42. Therefore, the inclined surface 71 and the inclined surface 72 of the finger part 41 are opposing surfaces that face different finger parts 42. The inclined surface 71 and the inclined surface 72 are formed so as to be inclined toward the −X side with respect to the YZ plane as going toward the + Z side. In addition, the inclined surface 71 and the inclined surface 72 are inclined in the −X direction so that the end of the first member 51 in the Y direction protrudes from the central portion.

  The second member 52 is disposed on the second end face 41b side in the Z direction. The second member 52 has a claw portion 101. The nail | claw part 101 is a part contact | abutted to a target object. The second member 52 is formed with a notch 52a. The fixing member 53 fixes the first member 51 and the second member 52. As the fixing member 53, for example, a mechanical part such as a screw is used.

  Similarly, the finger portion 42 includes a first member (first portion) 61, a second member (second portion) 62, and a fixing member 63. The finger part 42 has a first end face 42 a on the −Z side and a second end face 42 b on the + Z side in the Z direction (second direction) orthogonal to the XY plane.

  The first member 61 is disposed on the first end surface 42 a side of the finger portion 42. The first member 61 has a slope 81, a slope 82, and a folded portion 83. The slope 81 and the slope 82 are formed in a planar shape so as to face the finger portion 41. Therefore, the inclined surface 81 and the inclined surface 82 of the finger part 42 are opposed surfaces that face the different finger parts 41. The inclined surface 81 and the inclined surface 82 are formed so as to be inclined toward the + X side with respect to the YZ plane as going toward the + Z side. Further, the slope 81 and the slope 82 are inclined in the + X direction so that the end of the first member 61 in the Y direction protrudes with respect to the center.

  The second member 62 is disposed on the second end face 42b side in the Z direction. The second member 62 has a claw portion 102. The nail | claw part 102 is a part contact | abutted to a target object. The second member 62 has a notch 62a. The fixing member 63 fixes the first member 61 and the second member 62. As the fixing member 63, for example, a mechanical part such as a screw is used.

[Configuration of finger part in XY plan view]
Next, the structure in the XY plane view of the finger part 41 and the finger part 42 is demonstrated.
As shown in FIG. 2B, the first member 51 of the finger part 41 has a claw part 101, and the first member 61 of the finger part 42 has a claw part 102. As shown in FIG. 2B, the claw portion 101 and the claw portion 102 are in a line symmetric relationship with the reference line 202. In addition, the claw portion 101 and the claw portion 102 are first inclined surfaces (also referred to as front end surfaces) 111 and 112 that gradually incline away from each other as they go from the front end toward the rear end (also referred to as a base end or base portion). And second inclined surfaces (also referred to as a base-side surface or a base-side surface) 121 and 122 that are gradually inclined in directions close to each other. Further, the claw portion 101 and the claw portion 102 can be formed by, for example, bending a metal (flat plate) such as aluminum or cutting the metal (cuboid).

  With such a configuration, the first object W1 is gripped near the tips of the claw portion 101 and the claw portion 102. For this reason, since the nail | claw part 101 and the nail | claw part 102 hold | grip and convey the 1st target object W1, it can implement | achieve three functions, caging, self-alignment, and friction grip. The control device 60 performs control so that the claw portion 101 and the claw portion 102 grip the first object W1 at four or more contact points.

  “Caging” refers to a space in which the first object W1 is closed by the pair of claws 101 and 102 when the object (first object W1) is in a certain position and posture. It means that there is. In the caging, the position or posture of the first object W1 is not restricted by the claw portion 101 and the claw portion 102 and is free.

  “Self-alignment” refers to the shape of the nail 101 and the nail 102, the nail 101 and the nail 102, and the first object W1 when the nail 101 and the nail 102 sandwich the first object W1. This means that the first object W1 is moved to a predetermined position in the closed space by the frictional force.

  “Friction grip” means that the claw part 101 and the claw part 102 contact the first object W1 at four or more contact points to restrain the first object W1, and the first object W1 by frictional force. Is restrained in a direction perpendicular to the surface 33a on which the first object W1 is arranged.

As shown in FIG. 2C, the tip of the claw portion 101 has a triangular shape (also referred to as a concave portion) surrounded by vertices a ₁ , a ₂ , and a ₃ (hereinafter referred to as a claw shape). . This nail shape is represented by three parameters α, β, and d. The symbol β represents an angle formed by the line segment a ₁ a ₂ and the line segment a ₁ a _3, and the symbol α represents a case where a perpendicular (also referred to as a base line) is dropped from the vertex a ₂ to the line segment a ₁ a ₃ . It represents the angle between the line segment a ₂ a ₃ and the perpendicular. The symbol d represents the height (= a ₂ a ₃ cos α) to the base a ₂ of the triangle a ₁ a ₂ a ₃ . Further, the point a ₂ that is the intersection of the first inclined surface 111 and the second inclined surface 121 is also referred to as a base point.

  In the nail portion 101, the range that the nail shape parameters α, β, and d can take is expressed by the following equation (1).

Hereinafter, a method for calculating the parameters α, β, d of the nail shape will be described. FIG. 3A and FIG. 3B are diagrams illustrating the opening / closing mechanism of the claw portion according to the present embodiment.
As shown in FIG. 3 (a), the control device 60, the claw portion 101 and the claw portion 102, the center point Q of intersection by extending the side connecting the respective vertices a ₁ and a _3, and another side It opens and closes by controlling an angle φ formed by lines extending a ₁ a ₃ . Further, the claw portion 101 and the claw portion 102 are represented by three parameters (hereinafter referred to as opening / closing parameters) θ, γ, and l (el) in opening and closing the claw portion 101. The point P represents the center of rotation, and the symbol l (el) is from the point P to the lower end a ₁ of the triangle a ₁ a ₂ a ₃ of the claw portion 101 (point B; also referred to as the end of the base side surface). Represents distance. The symbol γ represents the angle formed by the BP when the claw portion 101 is closed and the x axis, and the symbol θ is the BP when the claw portion 101 is closed and B′P when the claw portion 101 is open. Represents the angle formed by.

Next, a procedure for calculating the parameters α, β, d of the nail shape will be described with reference to the drawings. FIG. 4 is a view for explaining the procedure for calculating the parameters α, β, d of the claw shape according to the present embodiment.
First, an outline of a procedure for calculating the parameters α, β, and d of the nail shape will be described with reference to FIG.

  The claw design device (not shown) calculates a range that can be gripped by the claw 101 and the claw 102 (step S1). In this embodiment, an example in which the claw part design apparatus calculates the parameters α, β, and d of the claw part shape of the claw part 101 and the claw part 102 will be described. For example, the calculation is performed according to these calculation procedures. You may make it perform the calculation apparatus and the designer of a nail | claw part.

  Next, the nail | claw part design apparatus narrows down the range which can hold | grip the nail | claw part 101 and the nail | claw part 102 using the constraint conditions containing the caging conditions and self-alignment conditions mentioned later (step S2).

  Next, the nail design device narrows down the range of the nail shape of the nail 101 and the nail 102 from the constraint conditions (step S3).

  Next, the nail design apparatus calculates the toe shapes of the nail 101 and the nail 102, that is, calculates the parameters α, β, and d of the nail shape (step S4).

[Conditions for friction gripping]
Next, the calculation method of the range that can be gripped by the claw portion 101 and the claw portion 102 performed in step S1 will be described in detail. The condition for the claw part 101 and the claw part 102 to grip the object W1 is that the claw parts 101, 102 and the object W1 are in contact with each other with at least three contact points and are restrained ( Friction grip conditions).

  First, the claw design device obtains the maximum size of the object W1 (part) that can be gripped by the claw 101 and the claw 102.

  FIG. 5 is a diagram illustrating components that can be gripped by the claw portion according to the present embodiment. In this figure, the shape of the object M gripped by the claw portion 101 and the claw portion 102 is circular (for example, a columnar shape) when viewed from the xy plane. Further, in the following description, the triangular shapes at the tips of the above-described claw part 101 and claw part 102 will be described in order to calculate the claw part shape parameters α, β, and d. In the following description, even if the gripping parts have different claw part shape parameters α, β, and d, they are referred to as claw parts 101 and 102 by using common reference numerals 101 and 102. In addition, the object W1 gripped by the claw portion 101 and the claw portion 102 is hereinafter referred to as a component M using a common reference M even if the sizes are different.

Further, as shown in FIGS. 5A to 5C, the contact point between the first inclined surface 111 of the claw portion 101 and the object M is a point p ₁ , the second inclined surface 121 of the claw portion 101 and the component M. Is a point p ₂ , a contact between the first inclined surface 112 of the claw 102 and the part M is a point p ₄ , and a contact between the second inclined surface 122 of the claw 102 and the part M is a point p ₃ . A center point o of the object M is on the reference line 202, passes through the center point o, and a line segment perpendicular to the reference line 202 is referred to as a center line 201.

  FIG. 5A is a diagram illustrating components that can be gripped by the claw portion 101 and the claw portion 102, and FIG. 5B is a component of the maximum size that can be gripped by the claw portion 101 and the claw portion 102. FIG. 5C is a diagram illustrating parts that the claw portion 101 and the claw portion 102 cannot grip.

As shown in FIG. 5 (a), the center line 201, a line segment connecting the contact point _{p 1} and _{p 4,} it is positioned between the line connecting the contact point _{p 2} and _{p 3.} In such a state, since the claw part 101 and the claw part 102 can be gripped so as to surround the part M by the four contact points, the part M is stably gripped by frictional gripping.

As shown in FIG. 5 (c), the center line 201 is positioned in the positive direction of the y-direction than the line segment connecting the contact point p ₁ and p _4. In such a state, since the claw part 101 and the claw part 102 cannot be gripped so as to surround the part M by the four contact points, the part M may not be gripped stably by frictional gripping. For example, when the friction coefficient between the object M and the claw part 101 and the claw part 102 is smaller than a predetermined value, the part M may come off in the positive direction in the y direction from the frictionally gripped state.

Therefore, the maximum size of the component M to the claw portion 101 and the claw portion 102 is gripped, as shown in FIG. 5 (b), if it matches the line connecting the center line 201 and the contact p ₁ and p ₄ It is. The maximum radius of the component M that can be gripped by the surfaces of the claw portion 101 and the claw portion 102 (the first inclined surfaces 111 and 112, the second inclined surfaces 121 and 122) is r _max1 (hereinafter referred to as the maximum size that can be gripped). Represented by

FIG. 6 is a diagram for explaining the relationship between the maximum grippable size and the parameters α, β, and d of the claw shape according to the present embodiment. As shown in FIG. 6, the component M surrounds the component M with _four contacts p _{1 to} p ₄ . That is, all the contacts p _{1 to} p ₄ and the component M are on the surfaces of the claw portion 101 and the claw portion 102 (first inclined surfaces 111 and 112, second inclined surfaces 121 and 122). In this way, the maximum _grippable size that can surround the part M with the four contact points is represented by r _max11 .

  FIG. 7 is a diagram illustrating the size of a component that can be gripped by the relationship between the apex of the claw portion and the component according to the present embodiment. FIG. 8 is a diagram illustrating the relationship between the apex of the claw portion and the component according to the present embodiment.

  FIG. 7A is a diagram illustrating a case where gripping is possible, and FIG. 7B is a diagram illustrating a case where gripping is impossible. In the following description, the case where the component M is a resin softer than the material of the claw portion 101 and the claw portion 102 will be described.

As shown in FIG. 7 (a), component M is in contact with the second inclined surface 122 and the contact _{p 3} in contact with the second inclined surface 121 and the contact _{p 2} of the claw portion 101, and the claw portion 102 . The component M is not in contact with the first inclined surface 111 of the claw portion 101 and is in contact with the vertex a ₃ (contact point p ₃ ) of the triangle a ₁ a ₂ a ₃ at the tip of the claw portion 101. At the contact point p ₁ , the side a ₂ a ₃ of the triangle a ₁ a ₂ a ₃ of the claw portion 101 is a tangent line of the component M. For this reason, the apex a ₃ of the claw portion 101 does not pierce the part M.

On the other hand, as shown in FIG. 7 (b), similarly to FIG. 7 (a), the component M is in contact with the second inclined surface 121 and the contact _{p 2} of the claw portion 101, and a second inclination of the pawl portion 102 We are in contact with the surface 122 and the contact _{p 3.} However, the apex a ₁ of the claw portion 101 and the part M are in contact with each other at the contact point p ₁ . In this case, at the contact point p ₁ , the side a ₂ a ₃ of the triangle a ₁ a ₂ a ₃ of the claw portion 101 is not a tangent line of the component M. For this reason, the apex a ₃ of the claw portion 101 is stuck into the part M.
That is, as a condition of the maximum size that can be gripped, the vertex a ₃ or the vertex a ₁ of the claw portion 101 needs not to pierce the part M.

Hereinafter, the apex a ₃ of the nail part 101 and the nail part 102 and the apex a _{1 of the} nail part 101 and the nail part 102 are referred to as nail tips.

8 (a) is a diagram vertex _{a 3} claw portion 101 and pawl portion 102 will be described conditions that do not Tsukisasara the component M. FIG. 8B is a diagram for explaining a condition in which the claw part 101 and the apex a ₁ of the claw part 102 do not pierce the part M. 8 (a) and FIG. 8 (b) is whether the nail shape parameter α is less than π / 2-β or more than π / 2-β. In this way, the maximum _grippable size that takes into account the condition that the tip is not _pierced is expressed by _rmax12 .

As a result, as shown in FIG. 6 and FIG. 8, the maximum _grippable size r _max1 is determined from geometrical relations by the nail shape parameters α, β, d and open / close parameters θ, γ, l (el ), The following equations (2) to (4) are obtained.

In formula (2), whether r _max1 is selected as r _max11 or r _max12 depends on the shape of the toe. Moreover, in Formula (4), if represents a case classification, when α is less than π / 2−β, r _max12 = d / cos (α) × tan ((π / 2−β + α) / 2) When α is π / 2−β or more, r _max12 = d / sin (β) × tan ((π / 2−β + α) / 2).

  Next, a state where the claw portion 101 and the claw portion 102 are closed will be described. FIG. 9 is a diagram illustrating the size of a component that can be gripped when the claw portion according to the present embodiment is closed.

As shown in FIG. 9B, when the claw portion 101 and the claw portion 102 are closed, the first inclined surfaces 111 and 112 and the second inclined surfaces 121 and 122 of the claw portion 101 and the claw portion 102 are respectively , The component M and the contacts p _{1 to} p ₄ , respectively. The component M in this state has a minimum size r _min1 that can be gripped by the claw portion 101 and the claw portion 102.

On the other hand, as shown in FIG. 9A, when the component M is small, when the claw portion 101 and the claw portion 102 are closed, the component M cannot contact with all the _four contacts p _{1 to} p ₄ . Such a state is assumed that the claw part 101 and the claw part 102 cannot grip the part M (cannot be gripped).

Further, as shown in FIG. 9 (c), the rear end of the part M is in contact with the contact _{p 2} and _{p 3} in the second inclined surfaces 121 and 122 of the claws 101 and the claw portion 102. The contacts p ₁ and p ₄ of the tip of the part M and the claw portion 101 and the claw portion 102 are the tips a ₃ of the claw portion 101 and the claw portion 102. A line segment a ₂ a ₃ is a tangent to the part M. Such a state is a state where the claw portion 101 and the claw portion 102 do not pierce the component M as described with reference to FIG.

FIG. 10 is a diagram for explaining the calculation of the minimum size of a component that can be gripped by the claw portion according to the present embodiment. In this state, as in FIG. 9B, when the claw portion 101 and the claw portion 102 are closed, the component M is a surface of the claw portion 101 and the claw portion 102 (first inclined surfaces 111 and 112, second inclined surface). 121 and 122) in a state in contact with four contacts _p 1 ~p _4. Since the part M is a circle, the minimum size r _min1 of the part M that can be gripped by the claw part 101 and the claw part 102 is the radius of the inscribed circle when the claw is closed. Therefore, the minimum size of the grippable parts can be obtained from the geometric relationship shown in FIG.

  Above, description of the calculation performed at step S1 is complete | finished.

  Next, the process performed in step S2 will be described in detail. In step S2, the caging condition and the self-alignment condition are used as constraint conditions to narrow down the range in which the claw part 101 and the claw part 102 can be gripped.

FIG. 11 is a diagram for explaining parameters of the caging area according to the present embodiment. As shown in FIG. 11A, the symbol r represents the radius of the part M. The space S in which the center point o of the part M can move freely is represented by c _{2 in} the x direction and c ₁ in the y direction. Further, as shown in FIG. 11B, the symbol H represents the vertex on the positive direction side in the y direction of the caging region S, and the symbol J represents the vertex on the negative direction side in the y direction. Further, the symbol I represents the vertex in the x direction on the negative direction side with respect to the line segment HJ of the caging region S, and the symbol K represents the vertex in the x direction on the positive direction side with respect to the line segment HJ. That is, the length c ₁ in the y direction is the distance between the vertices H and J, and the length c ₂ in the x direction is the distance between the vertices I and K.

  FIG. 12 is a diagram for explaining the shape of the caging region and each parameter according to the present embodiment.

First, the code is defined. As shown in FIGS. 12A and 12B, in the triangles a ₁ a ₂ a ₃ of the claw portion 101 and the claw portion 102, the symbol 1 (el) ₂ is the y between the vertices a ₃ and a ₁ Represents the distance in the direction. Further, the length c ₁ in the y direction described with reference to FIG. 11 is represented by reference numerals c ₁₁ and c ₁₂ according to the shape of the caging region. Moreover, the x-direction length _{c 2} described in FIG. 11, according to the shape of the caging region, represented by reference numeral _{c 21, c 22, c 23} , c 24. Further, reference numeral l _{(el) 1} represents the apex _{a 1} of the triangle _a 1 _a 2 _{a 3} by symbol B, represents the x-direction distance between the point B and the vertex J.

First, as shown in FIGS. 12A and 12B, the lengths c ₁₁ and c ₁₂ in the y direction are divided according to the shape of the area surrounded by the vertex IJK of the caging area S. The distance between the tip positions of the left and right claw portions 101 and the claw portions 102 is equal to or less than the diameter of the component M. That is, the upper end of the distance c ₁₁ is the midpoint of the toe tip position of the left and right claw portions 101 and the claw portion 102.

As shown in FIG. 12A, the line segment of the caging region S is a straight line between the vertices I and J and a straight line between the vertices J and K. The line segment of the caging region S is not a straight line between the vertices H and I and is not a straight line between the vertices H and K. Further, as shown in FIG. 12A, the distance between the point B and the vertex J is not r. The y-direction length of the caging region S in such a state and c _11.

As shown in FIG. 12B, the line segment of the caging region S is not only a straight line between the vertices I and J but also a straight line between the vertices J and K. That is, the line segment between the vertices I and J has a straight line and a curved line as shown in FIG. The line segment of the caging region S has a straight line and a curved line between the vertices H and I and between the vertices H and K, respectively. Further, as shown in FIG. 12B, the distance between the point B and the vertex J is r. The y-direction length of the caging region S in such a state and c _12.

As shown in FIGS. 12A and 12B, the distance c _{1 in} the y direction of the caging region S is classified according to the following equation (6).

From geometrical relationship shown in FIG. 12 (b) 12 and (a), _{c 11} and _{c 12} in the y direction of the length of the caging region S, like the following equation (7) to the following equation (8) become.

In the expressions (7) and (8), the distance l (el) ₁ and the distance l (el) ₂ are the following expressions (9) to (10).

  Moreover, in Formula (7) and Formula (8), angle (theta) is following Formula (11).

  In the formula (11), a, b, and c are the following formulas (12) to (14).

[Caging conditions]
Next, according to the shape of the caging region S, the distance c ₂ in the x direction of the caging region S is divided into c _{21 to} c _{24 as shown} in FIGS.

Figure 13 is a diagram distance x direction caging region according to the present embodiment will be described the case of c _21. Figure 14 is a diagram distance x direction caging region according to the present embodiment will be described the case of c _22. Figure 15 is a diagram distance x direction caging region according to the present embodiment will be described the case of c _23. Figure 16 is a diagram distance x direction caging region according to the present embodiment will be described the case of c _24.

First, symbols used in FIGS. 13 to 16 are defined. The symbol T represents the vertex a ₃ of the triangle a ₁ a ₂ a ₃ of the claw portion 101, and the symbol B represents the vertex a ₁ . A symbol C represents the vertex J of the caging region S. A symbol L1 represents a straight line passing through a line segment connecting the vertex J and the vertex I of the caging region S. A symbol A represents an end point of a straight line range between the vertex I and the vertex H. That is, in FIG. 13, the line segment IA is a straight line, and the line segment AH is a curve.

The straight line L2 is a straight line passing through the straight line range IA between the vertex I and the vertex H of the caging region S. Code l _{(el) 3} represents the vertex J of the caging region S, the x-direction distance between the vertex _{a 2} of the triangle _a 1 _a 2 _{a 3} a claw portion 101. Reference numeral 1 (el) ₄ represents a distance between the point A (boundary between the arc and the straight line (upper side)) and the straight line L1, and reference numeral 1 (el) ₅ represents a point C (boundary between the arc and the straight line (lower side). )) And the distance between the straight line L2. Reference symbol l (el) ₆ represents the distance between point A and point B (tip tip), and l (el) ₇ represents the distance between point C and point T (tip tip).

As shown in FIGS. 13 to 16, the distance _{c 2} vertices IK caging region S is case analysis as follows (15).

In Expression (15), for example, l ₄ greater than 0 (zero) means that there is a straight line region between the vertex I and the vertex H of the caging region S. Further, l ₄ less than 0 (zero) means that there is no straight line region between the vertex I and the vertex H of the caging region S, that is, there is a curved region. When l ₄ is equal to or greater than 0 (zero), it means that there is a straight line region between the vertex I and the vertex H of the caging region S and a curved region is included.

As shown in FIG. 13, the caging region S having a distance c ₂₁ is the section of the vertex H and vertex I is formed by straight lines and curves, sections of the apex I and the apex J is formed only in a straight line. As shown in FIG. 14, the caging region S having a distance c ₂₂ is the section of the vertex H and vertex I is formed only by a curved line, the section of the apex I and the apex J is formed only in a straight line. As shown in FIG. 15, the caging region S having a distance c ₂₃ is the section of the vertex H and vertex I is formed by straight lines and curves, sections of the apex I and the apex J is formed only by a curved line. As shown in FIG. 16, in the caging region S having the distance c ₂₄ , the section between the vertex H and the vertex I is formed by only a curve, and the section between the vertex I and the vertex J is formed by only a curve.

From the geometric relationships shown in FIGS. 13 to 16, _c 21 _{to c 24} in the x-direction of the length of the caging region S, the following equation (16) to equation (19).

In the equations (16) to (19), l (el) _{3 to} l (el) ₇ and the angle θ are the following equations (20) to (25).

  In the formula (25), a, b, and c are the following formulas (26) to (28).

The larger the caging area S, the more robust the component M can be with respect to the position error. Further, the value of the distance c ₁ and c ₂ of the larger component M caging region S becomes small. Therefore set the minimum value _{c lim} allowable position error, the distance _{c 1} or _{c 2} is the minimum value _c magnitude of _lim below component M caging possible maximum size _{r max2.} The claw design device obtains r _max2 by numerical calculation from Equation (6) and Equation (15).

FIG. 17 is a diagram for explaining the relationship between the maximum caging possible size r _max2 and the distances c ₁ , c ₂ , c _{lim according to} the present embodiment. In FIG. 17, the vertical axis represents the lengths of distances c ₁ , c ₂ , and c _lim , and the horizontal axis represents the radius of the component M. As shown in FIG. 17, as the maximum size r _max2 that can be caging, a value having a small r at the intersection of the curve of the distance c ₁ or c ₂ and the minimum value c _lim is selected. For example, the _{c 12} is selected in the divided case of formula (6), _{if c 21} is selected in the selection of the formula (15), maximum size _{r max2} capable caging the curve of the distance _{c 12} or _{c 21} And a value with a small r at the intersection of the minimum value c _lim is selected.

Further, the minimum value c _lim is an allowable position error. The allowable position error is a range (caging region S) in which the part M can freely move in a state where caging is established. For example, if the minimum value c _lim = 2.0 [mm], the distance c ₁ or c ₂ is 2.0 [mm].

This value is, for example, recognizes an object at the camera, in the case of gripping the object by the gripping unit 10A, the positioning error of the camera of the recognition errors and grip portion 10A is, c _1, c ₂ to 2.0 [mm as long as it is within the range of the area S to be formed at], which means that it is caging the part M of r _max2.

[Self-alignment conditions]
Next, a method for calculating the maximum size of the part M that can be self-aligned by the claw design apparatus will be described.

FIG. 18 is a diagram for explaining self-alignment conditions according to the present embodiment. As shown in FIG. 18 (a), component M is in contact with the contact _{p 2} and p ₃ of the second inclined surface 121 of the pawl 101 and the pawl portion 102 and 122. In this state, when the claw portion 101 and the claw portion 102 move in a direction approaching each other, that is, close, the component M is moved in the positive direction of the y direction. Thereby, self-alignment is performed (also referred to as upward self-alignment). In FIG. 18A, symbol φ represents an angle formed by the line segment a ₁ a ₂ of the claw portion 101 and the line segment 401 that starts from the vertex a ₁ and is parallel to the y direction.

Further, as shown in FIG. 18 (b), component M is in contact with the contact _{p 1} and _{p 4} of the first inclined surface 111 of the pawl 101 and the pawl portion 102 and 112. In this state, when the claw portion 101 and the claw portion 102 move in a direction approaching each other, that is, close, the component M is moved in the negative direction of the y direction. Thereby, self-alignment is performed (also referred to as downward self-alignment). Further, in FIG. 18B, symbol φ represents an angle formed by the line segment a ₃ a ₂ of the claw portion 101 and the line segment 411 parallel to the y direction starting from the vertex a ₃ .
This angle φ is the contact angle between the claw portion 101 and the part M.

FIG. 19 is a diagram illustrating the force applied to the component from the claw portion according to the present embodiment. FIG. 19A is a diagram for explaining the force applied to the component from the claw portion during the self-alignment in the upward direction as in FIG. 18A. FIG. 19B is a diagram for explaining the force applied to the component from the claw portion during the self-alignment in the upward direction as in FIG. 18B. Further, in FIG. 19 (b), the reference numeral xb is the distance from the vertex _{a 3} claw portion 101 to the line segment 421 passing through the center point o of the component M. FIG. 20 is a diagram illustrating the relationship between r and the vertex a _{2 according to} the present embodiment.

As shown in FIG. 19A and FIG. 19B, the force F applied to the part M from the claw portion 101 and the claw portion 102 is applied to the claw portion direction (line segment a ₂ a ₁ direction or line segment a ₃ a ₂ (Direction) force f _s and x-direction force f _x are expressed by the following equation (29).

Furthermore, frictional force f _f acting on the component M is, when the friction coefficient is mu, is expressed by the following equation (30).

  From the equations (29) and (30), the condition for moving the component M by closing the claw portion 101 and the claw portion 102 is expressed by the following equation (31).

  In the formula (31), the following formula (32) is set.

  Next, self-alignment conditions for upward self-alignment will be described. As shown in FIG. 19B, the contact angle φ is represented by the following equation (33).

As the claw portion 101 and the claw portion 102 are closed as in the expression (33), the contact angle φ becomes smaller. Therefore, in the range where β is less than (tan ⁻¹ μ), the component M stops in the middle of self-alignment. May end up. For this reason, the minimum size r _min2 of the part M that can be self-aligned in the upward direction is expressed by the following equation (34) from the geometrical relationship shown in FIG.

  Substituting equation (33) into equation (34) results in the following equation (35).

  Next, self-alignment conditions in the case of downward self-alignment will be described. As shown in FIG. 19B, the contact angle φ is expressed by the following equation (36).

As the nail part 101 and the nail part 102 are closed as shown in the equation (36), the contact angle φ becomes larger. Therefore, in the range where (π / 2−α) is (tan ⁻¹ μ) or more, the nail part 101 is the most. When the claw portion 102 is opened, self-alignment is possible. For this reason, the maximum size r _max3 of the component M that can be self-aligned in the downward direction is expressed by the following equation (37) from the geometrical relationship shown in FIG.

  Substituting equation (36) into equation (37) yields the following equation (38).

As described above, in step S2, the claw design device calculates the maximum size r _max2 of the part M that can be _cage from the equations (6) and (15) based on the caging conditions. Further, the claw design apparatus calculates the minimum size r _min2 of the component M that can be self-aligned in the upward direction based on the self-alignment condition from the equation (35), and the component M that can be self-aligned in the downward direction. _Is calculated from the equation (38).

  Above, description of the calculation performed at step S2 is complete | finished.

[Conditions for assembling target parts]
Next, the process performed in step S3 will be described in detail. In step S3, the conditions used when considering the case of attaching the component M will be described.

  FIG. 21 is a diagram for explaining conditions used when the component M according to the present embodiment is attached. As shown in FIG. 21 (a), the claw portion 101 and the claw portion 102 attach the gripped component M1 so that the gears of the attachment destination component M2 are assembled. That is, the parts M1 and M2 are gears having gears, for example. FIG. 21B is a diagram for explaining conditions under which the claw tip can be assembled without interference with the component M2 to be attached. Moreover, FIG. 22 is a figure explaining the example which is interfering with the components M2 which the nail | claw part tip which concerns on this embodiment attaches.

In FIG. 21B, the symbol o ₁ is the center point of the component M1, and the symbol o ₂ is the center point of the component M2 to be attached. Reference numeral l (el) ₈ represents a distance in the x direction between the vertex a1 of the triangle a ₁ a ₂ a ₃ of the claw portion 101 and the center point o ₁ of the part M1, and reference numeral l (el) ₉ represents the nail. represents the distance between the vertex a1 and the vertex _{a 3} parts 101, reference numeral l _{(el) 10} represents the y component of the distance between the apex _{a 1} of the center point _{o 2} and the claw portion 101 of the attached part M2.

  As shown in FIG. 22, when the claw portion 101 and the claw portion 102 are attached to the gear component M2 when the gear part M1 is attached to the gear part M2, if the claw part tip shape wraps the part M1 too much, the other gear and the claw tip Will interfere. That is, the nail | claw part 101 and the nail | claw part 102 need to satisfy | fill following Formula (39) as conditions which can be assembled | attached without interference.

In the equation (39), the distances l (el) ₈ , l (el) ₉ and l (el) ₁₀ are the following equations (40) to (42).

In equation (42), as shown in FIG. 21 (b), r ₁ represents the radius of the gear to be grasped, r ₂ represents the radius of the gear to be assembled, and d ₁ represents the gear. Represents the inter-axis distance.

  As described above, in step S3, the claw design device calculates the conditions of the claw part 101 and the claw part 102 according to the equation (39) based on the conditions under which components can be assembled.

  Note that step S3 needs to be considered when attaching the gears as shown in FIG. 21A, but may not be considered when attaching the gripped component M to the shaft, for example. In this case, the calculation process in step S3 may not be performed.

  In the present embodiment, an example in which a condition that does not interfere with the attachment destination component M2 has been described. However, the claw portion 101 and the claw portion 102 interfere with the attachment component M2 depending on the size of the component M to be gripped. You may make it delete a part. Even in this case, the interference portion is deleted so as to satisfy the above-described friction gripping conditions, self-alignment conditions, and caging conditions.

  Above, description of the calculation performed at step S3 is complete | finished.

  Next, the process performed in step S4 will be described in detail. In step S4, the toe shapes of the nail portion 101 and the nail portion 102 are calculated using the results calculated in steps S1 to S3.

The claw design apparatus uses the allowable position error c _lim and the friction coefficient μ to calculate the minimum size r _min of the component M that can be gripped in the toe shape by the following equation (43) and the following equation (44): The maximum size r _max that can be gripped is calculated.

In other words, the claw design device can perform self-alignment from the tip to the base end with the minimum size r _min1 of the component M that can be frictionally gripped as the minimum size r _min of the component M by the equation (43). A large value is selected from the minimum sizes r _min2 of the parts M. Further, the claw portion design device, by the equation (44), the maximum size r _max of the part M, the maximum size r _max1 friction grippable part M, the area around which the movable part M is The smallest value is selected from among the maximum size r _max2 of the maximum component M and the maximum size r _max3 of the component M that can be self-aligned from the distal end to the proximal end. The minimum size r _min of the component M and the maximum size r _{max of} the component M selected in this way are the range of the size of the component M that can be gripped by the claw portion 101 and the claw portion 102.

Incidentally, the tip portion of the claw portions 101 and 102, rather than necessarily shows only end in a strict sense, for example, as shown in FIG. 3 (a), a straight line passing through the point a ₁ and the point a ₃ It also includes the side of the tip including, and similar parts. Similarly, the base portions of the claw portions 101 and 102 do not necessarily show only the end portions in a strict sense. For example, as shown in FIG. 3A, a straight line passing through the points a ₁ and a ₃ It also includes the side of the rear end that contains and similar parts.

  In addition, although the formulas in the specification are shown on the assumption that the object is a circle, even a gear can be sufficiently established by treating it as a circumscribed circle approximately.

[Configuration of finger part in ZX sectional view]
Next, the configuration of the finger part 41 and the finger part 42 shown in FIG.
FIG. 23 is a diagram illustrating a ZX cross section of the finger part 41 and the finger part 42.
As shown in FIG. 23, the finger part 41 and the finger part 42 have a line-symmetric relationship with respect to the reference line 203.

  The inclined surface 71 is inclined in the Z direction with respect to the XY plane so as to protrude in the + X direction from the + Z side end of the first member 51 to the −Z side end of the first member 51. Similarly, the inclined surface 81 is inclined in the Z direction with respect to the XY plane so as to protrude in the −X direction from the + Z side end of the first member 61 to the −Z side end of the first member 61.

  The inclined surface 71 is inclined in the Z direction with respect to the XY plane so as to protrude in the + X direction from the + Z side end of the first member 51 to the −Z side end of the first member 51. Similarly, the inclined surface 81 is inclined in the Z direction with respect to the XY plane so as to protrude in the −X direction from the + Z side end of the first member 61 to the −Z side end of the first member 61.

  In addition, regarding the second member 52 of the finger part 41 and the second member 62 of the finger part 42, the nail part 101 and the nail part 102 have the object gripped by the finger part 41 and the finger part 42, and the second end face 41 b and the second part 62. It functions as a collar part that suppresses it from jumping out from the two end faces 42b. The nail | claw part 101 and the nail | claw part 102 have the movement control surface 101a and the movement control surface 102a which respectively control the movement of a target object at the 1st member 51 side and the 1st member 61 side. The movement restricting surface 101a and the movement restricting surface 102a are each formed in a plane parallel to the XY plane.

  Further, as shown in FIG. 24, the first member 51 and the second member 52 can be separated by removing the fixing member 53. Similarly, the first member 61 and the second member 62 can be separated by removing the fixing member 63. Since the first member 51 and the second member 52 and the first member 61 and the second member 62 can be separated from each other, the finger part 41 and the finger part 42 are integrally formed. Compared with the case, the manufacturing cost of each member is reduced. Further, the first member 51 and the second member 52 of the finger portion 41, the first member 61 and the second member of the finger portion 42, depending on the size and shape of the object gripped by the finger portion 41 and the finger portion 42. There is an advantage that 62 can be appropriately replaced.

  25 (a) to 25 (c) are cross-sectional views showing the operation of the gripping portion 10A. FIG. 25D is a perspective view showing a gripping state of an object by the gripping unit 10A. Hereinafter, with reference to FIG. 25A to FIG. 25D, an operation of gripping an object using the finger part 41 and the finger part 42 configured as described above will be described.

  First, the first object W1 is carried into the first belt conveyor 33 by the feeder 36 (see FIG. 1). Next, the first object W1 is imaged by the camera 40A. The control device 60 detects the position of the first object W1 placed on the first belt conveyor 33 (placement surface 33a) based on the imaging result of the camera 40A.

  Next, the arm 20A is controlled and relatively moved so that the gripping portion 10A approaches the first object W1. Next, the gripping unit 10A is controlled to cause the gripping unit 10A to grip the first object W1. Here, the gripping part 10A (the finger part 41 and the finger part 42) realizes three functions of caging, self-alignment, and frictional gripping in the Z direction of the first object W1.

  Specifically, as shown in FIG. 25A, after the finger part 41 and the finger part 42 are arranged around the first object W1, the grip part 10A is controlled to control the finger part 41 and the finger part 42. Is opened and closed on a surface parallel to the surface 33a (see FIG. 1) on which the first object W1 is placed, and the finger 41 and the finger 42 surround the periphery of the first object W1. Thereby, the first object W1 is prevented from jumping out of the region surrounded by the finger part 41 and the finger part 42 (caging).

  Next, as shown in FIG. 25B, the first object W1 is sandwiched between the finger part 41 and the finger part 42 from the side of the first object W1. Thus, the first object W1 is first supported by the slope 71, the slope 72, the slope 81, and the slope 82, respectively. Thereafter, the first object W1 moves in the + Z direction along the inclined surface 71, the inclined surface 72, the inclined surface 81, and the inclined surface 82 according to the pinching of the finger portion 41 and the finger portion 42, and the position in the Z direction is adjusted (self alignment).

  And as shown in FIG.25 (c), it is the 1st object by the finger part 41 and the finger part 42 by three or more contact points and contact surfaces (contact point G1, contact point G2, contact surface G3, and contact surface G4). The object W1 is gripped. Since the second member 52 of the finger part 41 and the second member 62 of the finger part 42 function as a buttocks, movement of the first object W1 in the + Z direction is restricted. At the same time, the movement of the finger part 41 and the finger part 42 in the closing direction is restricted. At this time, since the first object W1 is in contact with the movement restriction surface 101a and the movement restriction surface 102a, the first object W1 is gripped in a state parallel to the movement restriction surface 101a and the movement restriction surface 102a. In this way, the first object W1 is restrained at a predetermined position (friction gripping) as shown in FIG. At this time, the force with which the gripping part 10A grips the first object W1 is detected by a detection device (see FIG. 1) provided in the gripping part 10A. Thereafter, the gripper 10A transports the gripped first object W1 to the stage 30 (see FIG. 1).

  As described above, according to the present embodiment, the finger portion 41 and the finger portion 42 are provided on the side of the first end member 41a and end surface 42a side in the Z direction and the other end surface 41b and end surface 42b side in the Z direction. The first object W1 moves to the second member 52 side in response to the first object W1 being sandwiched between the finger part 41 and the finger part 42 in the first member 51. The first member 51 and the first member 61 are inclined in the Z direction with respect to the XY plane so that the first member 51 and the first member 61 protrude from the + Z side edge to the −Z side edge in the opposing direction of the finger part 41 and the finger part 42. Therefore, the first object W1 can be taken into the finger part 41 and the finger part 42 in the Z direction. Thereby, the 1st target object W1 can be hold | gripped reliably.

  Further, according to the robot 1 of the present embodiment, the finger unit 41 and the finger unit 42 move to the periphery of the first object W1 and then open and close on a plane parallel to the placement surface 33a under the control of the control device 60. Therefore, the periphery of the first object W1 is surrounded by the finger part 41 and the finger part 42. Thereby, the first object W1 is prevented from jumping out of the region surrounded by the finger part 41 and the finger part 42 (caging). Moreover, since the finger part 41 and the finger part 42 pinch | interpose the 1st target object W1 from the both sides of a Z direction, the 1st target object W1 moves according to the finger part 41 and the finger part 42, and this adjusts a position (self alignment). In addition, since the gripping unit 10A grips the first object at three or more contact points and contact surfaces, the position of the first object W1 in the Z direction is constrained, and the first object is caused by friction between the contact points and the contact surface. The object W1 can be stably gripped (friction gripping). The first object W1 can be held at a predetermined position in the Z direction by such an operation of the holding unit 10A.

  Therefore, the robot 1 according to this embodiment can realize caging, self-alignment, and frictional gripping of the first object W1 in each of the X direction, the Y direction, and the Z direction, that is, in a three-dimensional space. Therefore, it is possible to provide the robot 1 that can hold the first object W1 at a predetermined position without escaping.

  In the said embodiment, the 1st member 51 and the 2nd member 52 are separable, and the 1st member 61 and the 2nd member 62 are separable. For this reason, for example, as shown in Drawing 26 (a)-Drawing 26 (c), the 1st member 51 of finger part 41 and the 1st member 61 of finger part 42 are exchangeable. In FIG. 26A to FIG. 26C, for example, an angle α1 between the inclined surface 71 (or inclined surface 72) and the movement restricting surface 101a and an angle α2 between the inclined surface 81 (or inclined surface 82) and the movement restricting surface 102a are as follows. The first member 51 and the first member 61 formed in a predetermined shape can be used so as to change. Here, as an example, α1 and α2 = 30 ° in FIG. 26A, α1 and α2 = 45 ° in FIG. 26B, and α1 and α2 = 60 ° in FIG. . Of course, α1 and α2 may be other angles.

  In addition, as shown in FIG. 27A, the second member 52 of the finger part 41 and the second member 62 of the finger part 42 can be exchanged so that the dimensions of the notch part 52a and the notch part 62a are different. it can. In the configuration shown in FIG. 27A, the dimensions of the notch 52a and the notch 62a are smaller than those of the above embodiment. In this configuration, the first object W1 is less likely to jump out than the configuration of the above embodiment. For this reason, even if the dimension of the 1st target object W1 is small, it can prevent reliably popping out from the 2nd end surface 41b and the 2nd end surface 42b side.

  Further, as shown in FIG. 27B, the first member 51 and the second member 52 of the finger 41 and the first of the finger 42 so that the dimensions of the nail 101 and the nail 102 in the Y direction are different. The member 61 and the second member 62 can be exchanged. In this case, the first object W1 having a small size can be gripped.

  As shown in FIG. 28, the first member 51 of the finger part 41 and the first member 61 of the finger part 42 may be formed in a plate shape. According to this configuration, even in a narrow space, the finger 41 and the finger 42 can be efficiently gripped around the periphery. Further, the second member 52 of the finger part 41 and the second member 62 of the finger part 42 may be formed in a plate shape. The first member 51 and the first member 61, and the second member 52 and the second member 62 may both be formed in a plate shape. Furthermore, in the above case, it is preferable that the plate-like portions of the first member 51, the first member 61, the second member 52, and the second member 62 have the same thickness.

  In the above embodiment, the configuration in which the movement restricting surface 101a and the movement restricting surface 102a are formed in parallel to the XY plane has been described as an example. However, the present invention is not limited to this. For example, as shown in FIG. 29A, the movement restricting surface 101a and the movement restricting surface 102a may be inclined with respect to the XY plane. FIG. 29A shows a configuration in which the finger part 41 and the finger part 42 are inclined toward the + Z side so as to face each other, but the present invention is not limited to this, and the finger part 41 and the finger part 42 are not limited thereto. The structure may be inclined to the −Z side so as to face the opposite surface side.

  Further, in the finger portion 41, the angle formed by the inclined surface 71 and the inclined surface 72 may be different in the Z direction. 29B, the angle α3 between the slope 71 and the slope 72 at the −Z side end of the first member 51 and the slope 71 and the slope 72 at the + Z side end of the first member 51 will be described. And the angle α4 may be different. Thereby, the burden in terms of machining accuracy is reduced.

  In addition, the robot 1 according to the embodiment is not limited to the case where caging, self-alignment, and frictional gripping are performed using, for example, the finger 41 and the finger 42, and can be used in other cases. For example, as shown in FIG. 30A, when gripping a cylindrical object W3 whose dimension in the Z direction is larger than the dimension of the finger part 41 and the finger part 42, caging and self-direction in the X direction and the Y direction. Although alignment and frictional gripping can be realized, they are not realized in the Z direction. Even in such a usage mode, the object W3 can be reliably gripped.

  In addition, as shown in FIG. 30B, when gripping an object W4 whose dimension in the Y direction is larger than that of the finger part 41 and the finger part 42, caging, self-alignment and frictional gripping in the Z direction are performed. Although it can be realized, it is not realized in the X direction and the Y direction. Even in such a usage mode, the object W4 can be reliably gripped.

[Second Embodiment]
Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  In the robot system according to the second embodiment of the present invention, the assembly part to which the first part is attached is attached in combination with the second part conveyed by the robot body without applying a physical load to the first part. It is an assembly system. In the present embodiment, an example in which the first component and the second component are spur gears (hereinafter referred to as gears) will be described.

  FIG. 31 is a schematic external view showing a state in which a robot system to which the robot apparatus according to the second embodiment is applied performs work.

  In the figure, the robot system 801 includes a robot body 810, a gripping unit 811, a robot control device 820, a photographing device 830, a cable 840, and a cable 841.

  The robot body 810, the robot control device 820, and the cable 841 are included in the robot device.

  Specifically, the robot body 810 includes a support base 810a fixed to the ground, an arm part 810b connected to the support base 810a so as to be capable of turning and bending, and an arm part 810b capable of swinging and swinging. And a hand portion 10c connected to the head. The robot body 810 is, for example, a seven-axis vertical articulated robot, and has a degree of freedom of seven axes by the operation in which the support base 810a, the arm unit 810b, and the hand unit 10c are linked. That is, the seven degrees of freedom are a six-axis degree of freedom by the support base 810a and the arm part 810b and a one-axis degree of freedom by the hand part 10c.

  The robot body 810 includes a gripping portion 811 that is movable. The grip part 811 includes the claw part of the present invention. In FIG. 31, the gripping portion 811 is schematically shown to show its function.

  The robot body 810 takes in a robot control command supplied from the robot control device 820, changes the position and orientation of the gripper 811 as desired in the three-dimensional space by drive control based on the robot control command, and also holds the gripper 811. Open and close the nails.

  Note that the robot body 810 is not limited to one having seven degrees of freedom, and may be one having six degrees of freedom, for example. Moreover, you may install the support stand 810a in the place fixed with respect to the grounds, such as a wall and a ceiling.

  As shown in FIG. 31, an assembly component 805 is installed within the movable range of the grip portion 811 by the operation of the robot body 810. In addition, in the same figure, illustration of the support stand (desk) of the assembly component 805 is abbreviate | omitted. The assembly component 805 includes a plate-like base 850, a shaft 851 standing upright (including vertical) with respect to the base 850, and a shaft 852. The assembly component 805 is configured by attaching a gear 853 (first component) to the shaft 851 and attaching a gear 854 (second component) to the shaft 852. However, the assembly component 805 is completed by attaching the gear 854 to the shaft 852 after the gear 853 is attached to the shaft 851.

  It should be noted that the scales of parts, structures, etc. in the figure are different from actual ones in order to make the figure clear.

  The imaging device 830 captures the assembly component 805 to acquire a captured image that is a still image or a moving image, and supplies the captured image to the robot control device 820 via the cable 840.

  The photographing device 830 is realized by, for example, a digital camera device or a digital video camera device. The photographing direction is substantially vertical (including vertical) above the assembly component 805 and the photographing direction is substantially vertical (including vertical) below. Fixed installation in position. However, in FIG. 31, the distance between the shaft 851 and the shaft 852 and the imaging device 830 is sufficiently longer than the distance between the shaft 851 and the shaft 852.

  The cable 840 supplies control data for the imaging device 830 output from the robot control device 820 to the imaging device 830, and supplies response data and a captured image output from the imaging device 830 to the robot control device 820. The control data includes, for example, control commands such as a shooting start command and a shooting stop command that the robot control device 820 notifies the shooting device 830. The response data includes, for example, a response to the control data that the imaging device 830 notifies the robot control device 820.

  The cable 841 supplies a robot control command output from the robot control device 820 to the robot main body 810, and supplies a robot control response output from the robot main body 810 to the robot control device 820. The robot control command is a control command for driving and controlling each movable part of the robot body 810. The robot control response includes, for example, a response to the robot control command that the robot body 810 notifies the robot control device 820 of. The cable 841 is, for example, a cable such as a serial communication line or a computer network.

  The robot controller 820 captures a tracking image of the assembly component 805 supplied from the imaging device 830, controls the operation of each movable part of the robot body 810 based on the tracking image, and passes the gear 854 through the shaft 852. Attach to assembly part 805.

[Third embodiment]
In the robot system according to the third embodiment of the present invention, the robot body includes two arms. In this embodiment, a hand is attached to each arm. In this robot system, a captured image of an assembly part is acquired by an imaging device attached to the hand of one arm of the robot body, and the part is conveyed by a gripping part attached to the hand of the other arm.

  FIG. 32 is a schematic external view of a robot system according to the third embodiment.

  In the figure, the robot system 802 includes a robot body 860, a photographing device 861, a gripping unit 862, a robot control device 820, and a cable 863.

  The robot body 860, the robot control device 820, and the cable 863 are included in the robot device.

  Since the robot control device 820 has the same configuration as that of the second embodiment, detailed description of the robot control device 820 is omitted.

  Specifically, the robot main body 860 includes a main body 860a that is movably installed on the ground, a neck 860b that is connected to the main body 860a so as to be rotatable, a head 860c that is fixed to the neck 860b, A first arm portion 860d connected to the head portion 860c so as to be able to bend and extend, a second arm portion 860e connected to the head portion 860c so as to be able to turn and bend and extend, and the robot body with respect to the installation surface of the robot body 860 860f is attached to the main body 860a so as to be movable.

  A gripping part 862 is attached to the hand that is the open end of the first arm part 860d. In addition, a photographing device 861 is attached to the hand that is the open end of the second arm portion 860e.

  The transfer unit 860f supports the robot body 860 so that the robot body 860 can move in a certain direction or in a freely movable direction with respect to the installation surface of the robot body 860. The transport unit 860f is realized by four sets of wheels, four sets of casters, a pair of endless tracks, and the like.

  The robot body 860 is, for example, a vertical articulated robot (double-arm robot) having two arms. The robot body 860 takes in the robot control command supplied from the robot control device 820, and changes the positions and postures of the imaging device 861 and the gripper 862 in the three-dimensional space as desired by drive control based on the robot control command. Further, the claw portion of the grip portion 862 is opened and closed.

  The imaging device 861 captures a subject to acquire a captured image that is a still image or a moving image, and supplies the captured image to the robot control device 820. The photographing device 861 is realized by, for example, a digital camera device or a digital video camera device.

  The grip portion 862 includes the claw portion of the present invention. In FIG. 32, the gripping portion 862 is schematically shown to show its function.

  The cable 863 supplies a robot control command output from the robot control device 820 to the robot main body 860, and supplies a robot control response output from the robot main body 860 to the robot control device 820. The robot control command is a control command for driving and controlling each movable part of the robot body 860. The robot control response includes, for example, a response to a robot control command that the robot body 860 notifies the robot control device 820 of. The cable 863 is, for example, a cable such as a serial communication line or a computer network.

  The robot control device 820 controls the operations of the neck 860b, the head 860c, and the second arm 860e of the robot main body 860, and changes the position and posture of the imaging device 861. Specifically, the robot control device 820 installs the imaging device 861 at a position where the imaging direction is substantially vertically downward and substantially vertically above an assembly component (not shown).

  Further, the robot control device 820 takes in a photographed image of the assembly part supplied from the photographing device 861, and based on the photographed image, the neck 860b, the head 860c, and the first arm of the robot main body 860 are captured. The operation with the part 860d is controlled, and the gear is passed through the shaft and attached to the assembly part as in the second embodiment.

The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention.
In the present embodiment, the example in which the claw portion grips the component and is transported or assembled to the second object has been described. However, for example, the claw portion is attached using an image captured by a camera provided on the arm. May be. The camera may take an image of the part or the second object under the control of the control device 60 and recognize the attachment position based on the captured image. And based on the recognized result, you may make it a control apparatus control so that components may be moved to the attachment position of a 2nd target object.

  As described above, by designing the claw portion, it is possible to obtain a shape in which the range of the diameter size of the grippable part of the hand that can grip a small and lightweight part is widest. Further, since the robot includes the claw portion designed in this way, it is possible to grip a small and light component, and further widen the range of the size of the component that can be gripped. In addition, since the range of the size of the parts that can be gripped is wide, the frequency of replacing the claw portion mounted on the robot for each part is reduced, and the robot can grip a wide range of parts.

In the present embodiment, an example in which the present invention is applied to an assembly robot including the claw portions 101 and 102 has been described. However, for example, the robot 1 of the present embodiment may be applied to a transfer device or the like.
Further, in the present embodiment, an example in which the object is grasped, conveyed, or incorporated has been described. However, for example, a predetermined operation such as disassembly or inspection of an object may be performed.

  Note that a program for realizing the functions of the control unit in FIG. 1 of the embodiment and each unit of the claw design device (not shown) is recorded on a computer-readable recording medium, and the program recorded on the recording medium is stored in the computer system. The processing of each unit may be performed by reading and executing. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if the WWW system is used.

  “Computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM (Read Only Memory), a portable medium such as a CD-ROM, and a USB (Universal Serial Bus) I / F (interface). A storage device such as a USB memory or a hard disk built in a computer system. Further, the “computer-readable recording medium” includes a medium that holds a program for a certain period of time, such as a volatile memory inside a computer system serving as a server or a client. The program may be a program for realizing a part of the above-described functions, or may be a program that can realize the above-described functions in combination with a program already recorded in a computer system.

DESCRIPTION OF SYMBOLS 1 ... Robot 10A, 10B ... Gripping part 20A, 20B arm (moving device)
W1, M, M1 ... first object (parts) W2, M2 ... second object 30 ... stage (moving device) 33 ... first belt conveyor, 34 ... second belt conveyor, 37 ... stage 50 ... base 40A , 40B ... Camera 60 ... Control device 70 ... Input devices 41A, 41B, 101, 102 ... Claw RH ... Robot hand CN ... Link mechanism EC ... Encoder 51 ... First member, 52 ... Second member, 52a ... Notch 53 ... Fixing member, 71 ... Slope, 72 ... Slope, 73 ... Folded portion 61 ... First member, 62 ... Second member, 62a ... Notch, 63 ... Fixing member, 81 ... Slope, 82 ... Slope, 83 ... Folded part

Claims (9)

A first finger part and a second finger part that move in a first direction parallel to a predetermined plane and grip an object;
A base for supporting the first finger and the second finger,
The first finger part and the second finger part respectively have a first part and a second part connected in a second direction orthogonal to the predetermined plane,
The first portion has an abutment surface that abuts on the object in a state where the first finger part and the second finger part grip the object,
In the second direction, the predetermined contact surface protrudes in the opposing direction of the first finger portion and the second finger portion from the second portion to the end opposite to the second portion in the second direction. The robot is inclined in the second direction with respect to the plane of the robot. 2. The robot according to claim 1, wherein the second portion has a collar portion that protrudes in a moving direction of the object in a direction opposite to the first finger portion and the second finger portion. The robot according to claim 2, wherein the flange portion has a plane portion parallel to the predetermined plane on the first portion side. The robot according to any one of claims 1 to 3, wherein the flange portion has a cutout portion on a surface facing each other in the first direction. The robot according to any one of claims 1 to 4, wherein at least one of the first part and the second part has a plate shape. The robot according to claim 5, wherein a plate-like portion of the first portion and the second portion has the same thickness. The robot according to any one of claims 1 to 6, wherein the first part and the second part are fixed to be separable from each other. The second portion has a second abutting surface that abuts against the object in a state where the pair of finger parts grips the object,
The abutting surface and the second abutting surface are concave portions provided so that both end portions in a third direction that are parallel to the predetermined plane and orthogonal to the first direction protrude from the central portion. The robot according to any one of claims 1 to 7. A first finger part and a second finger part that move in a first direction parallel to a predetermined plane and grip an object,
The first finger part and the second finger part respectively have a first part and a second part connected in a second direction orthogonal to the predetermined plane,
The first portion has an abutment surface that abuts on the object in a state where the first finger part and the second finger part grip the object,
In the second direction, the predetermined contact surface protrudes in the opposing direction of the first finger portion and the second finger portion from the second portion to the end opposite to the second portion in the second direction. The robot hand is inclined in the second direction with respect to the plane of the robot.

Images