Robot hand control device and robot hand control system

Abstract

A robot hand control device according to one aspect of the present disclosure comprises: an acquisition unit that acquires, from a detection unit for recognizing a space in which a workpiece to be gripped by a robot hand having at least two finger parts is present, information pertaining to the workpiece; a configuration unit that sets up an operation plan on the basis of the information pertaining to the workpiece, the operation plan including at least a travel path to be taken by the robot hand before gripping the workpiece, and an action of the robot hand for achieving a gripping pose in which the robot hand grips the workpiece; and a control unit that controls actions of the robot hand in accordance with the operation plan.

Description

Robot hand control device and robot hand control system

[0001] The present disclosure relates to a robot hand control device and a robot hand control system.

[0002] Robot systems in which a robot grips a workpiece and moves the workpiece have been proposed for various work sites.

[0003] For example, as disclosed in Patent Document 1, there is a technique that collates a reference three-dimensional shape of a gripping target object with a three-dimensional shape of a predetermined target object measured by a measuring device, and proposes information related to gripping if the collation result falls within a predetermined range.

[0004] Japanese Patent No. 6746140

[0005] Patent Document 1 does not consider switching the nipping operation or the like depending on the object to be gripped.

[0006] An object of the present disclosure is to provide a robot hand control device and a robot hand control system capable of performing appropriate operations for gripping a workpiece.

[0007] A robot hand control device according to an aspect of the present disclosure includes: an acquisition unit that acquires information about a workpiece from a detection unit that recognizes a space where the workpiece to be gripped by a robot hand having at least two or more fingers exists; a setting unit that sets an action plan including at least a movement path of the robot hand until the workpiece is gripped and an operation of the robot hand for bringing the robot hand into a gripping pose for gripping the workpiece, based on the information about the workpiece; and a control unit that controls the operation of the robot hand according to the action plan.

[0008] The present disclosure enables appropriate operations to be performed for gripping a workpiece.

[0009] This is a schematic diagram showing an example configuration of a robot system including a robot hand according to an embodiment of the present disclosure. This is a perspective view of the robot hand. This is a top view of the main part of the robot hand. This is a left side view of the main part of the robot hand. This is a rear view of the main part of the robot hand. This is a schematic perspective view of the members constituting the fingers and the wires for moving the fingers. This is a diagram showing the arrangement of some of the components of the first finger and the first wire. This is a diagram showing the arrangement of some of the components of the first finger and the first wire. This is a diagram showing the arrangement of some of the components of the first finger and the first wire. This is a diagram showing some of the components of the second finger and the second wire. This is a diagram showing some of the components of the second finger and the second wire. This is a diagram showing some of the components of the second finger and the second wire. This is a diagram showing an example of the positional relationship between the worm shaft and the rotation axis of the motor. This is a diagram showing another example of the positional relationship between the worm shaft and the rotation axis of the motor. This is a diagram showing yet another example of the positional relationship between the worm shaft and the rotation axis of the motor. This is a perspective view of the positioning device. This is a perspective view of the members constituting the positioning device. This is a top view of the palm, the gripping device, and the fixed pulley and movable pulley on which the gripping wire is attached. This is a left side view of a movable positioning worm and a movable positioning worm wheel. This is a perspective view of a robot hand including a palm that is moved by a rocking device. This is a top view, rear view, and bottom view of the palm and rocking device. This is a left side view of a robot hand rocked by a rocking device. This is a rear view of a robot hand rocked by a rocking device. This is a rear view of a fixed pulley, a gripping device, a relaxation suppression mechanism, a palm, a rocking shaft, and a rocking worm wheel. This is a perspective view of a relaxation suppression mechanism provided on the palm. This is a rear view of a fixed pulley, a rocking pulley, a rocking shaft, a palm, and a gripping wire. This is a block diagram illustrating the configuration of a control device according to the first embodiment. This is a diagram illustrating the configuration of a category database according to the first embodiment. This is a diagram illustrating the configuration of a category-grasping pose corresponding database according to the first embodiment. This is a diagram explaining the concept up to determining the gripping pose in the robot controller according to the first embodiment. This is a conceptual diagram explaining the setting of approach points by the approach point setting unit according to the first embodiment.This is a conceptual diagram showing an example of an auxiliary operation set by the auxiliary operation setting unit according to the first embodiment. This is a diagram showing a list of auxiliary operations that can be set by the auxiliary operation setting unit according to the first embodiment. This is a diagram showing an example of a gripping pose database according to the first embodiment. This is a diagram showing gripping pose HP1 according to the first embodiment. This is a diagram showing gripping pose HP1 according to the first embodiment. This is a diagram showing gripping pose HP2 according to the first embodiment. This is a diagram showing gripping pose HP2 according to the first embodiment. This is a diagram showing gripping pose HP3 according to the first embodiment. This is a diagram showing gripping pose HP4 according to the first embodiment. This is a diagram showing gripping pose HP4 according to the first embodiment. This is a diagram showing gripping pose HP5 according to the first embodiment. This is a diagram showing gripping pose HP6 according to the first embodiment. This is a diagram showing gripping pose HP6 according to the first embodiment. This is a diagram showing gripping pose HP7 according to the first embodiment. This is a diagram showing gripping pose HP7 according to the first embodiment. This is a diagram showing gripping pose HP8 according to the first embodiment. This is a diagram showing gripping pose HP8 according to the first embodiment. This is a diagram showing gripping pose HP8 according to the first embodiment. This is a diagram showing the gripping pose HP9 according to the first embodiment. This is a diagram showing the gripping pose HP9 according to the first embodiment. This is a diagram showing the gripping pose HP9 according to the first embodiment. This is a diagram showing the gripping pose HP10 according to the first embodiment. This is a diagram showing the gripping pose HP11 according to the first embodiment. This is a diagram showing the gripping pose HP12 according to the first embodiment. This is a diagram showing the gripping pose HP13 according to the first embodiment. This is a flowchart showing the processing procedure for moving a workpiece in the control device according to the first embodiment. This is a flowchart showing the processing procedure for gripping operation in the hand controller according to the first embodiment. This is a flowchart showing the procedure for diagnosing the degree of fatigue of the robot hand in the control device according to the first embodiment. This is a diagram showing the change in speed of the positioning motor and gripping motor when a gripping operation of the robot hand is performed by the hand controller according to the first embodiment.This figure shows the changes in speed of the positioning motor and the gripping motor when the robot hand performs a gripping operation using the hand controller according to the first embodiment. This figure shows the changes in the detection results based on the workpiece falling, as measured by the detection sensor according to the first embodiment. This figure shows the changes in the detection results until the wire lifespan is detected, as measured by the detection sensor according to the first embodiment.

[0010] The embodiments for carrying out the invention will be described below with reference to the drawings. In each drawing, the same reference numerals are used for identical components, and redundant explanations may be omitted.

[0011] Hereinafter, a robot hand 100 according to an embodiment of this disclosure will be described with reference to the drawings. Figure 1 is a schematic diagram showing an example configuration of a robot system 600 including the robot hand 100. The robot system 600 is an example of a control system for a robot hand and comprises a robot hand 100, a robot 110, a camera 120, and a control device 610. The robot 110 has a plurality of joints, a plurality of arms, and a plurality of actuators 110A. The robot hand 100 is attached to the tip of the arm of the robot 110.

[0012] The control device 610 includes a picking robot controller 620 and a hand controller 630. The picking robot controller 620 is a controller for controlling the robot 110. The hand controller 630 is a controller for controlling the robot hand 100.

[0013] Camera 120 captures images of the work area where the workpiece 700 is located. The work area where the workpiece 700 is located includes at least the workpiece 700 to be gripped and the destination of the workpiece 700 moved by the robot hand 100. Therefore, the image information captured by camera 120 shows the position of the workpiece 700 in the work area, as well as the surrounding environment of the workpiece 700.

[0014] The camera 120 is electrically connected to the control device 610 (picking robot controller 620). Image information captured by the camera 120 is output to the picking robot controller 620.

[0015] Camera 120 is a monocular camera having an image sensor such as a CCD or CMOS, and is an example of a detection unit that recognizes the space in which the workpiece to be grasped exists. This embodiment does not limit the detection unit that recognizes the space in which the workpiece to be grasped exists to camera 120, and other detection units may be used. Other detection units may be, for example, stereo cameras, millimeter-wave radar, LIDAR, infrared sensors, etc., or other detection units may be combined with camera 120.

[0016] The control device 610 is, for example, a device equipped with a microcomputer, and includes a CPU, a volatile memory device, a non-volatile memory device, and an input / output interface. The same applies to the picking robot controller 620 and the hand controller 630. In the illustrated example, the picking robot controller 620 and the hand controller 630 are separate and independent devices, but they may be configured as an integrated unit. The hand controller 630 may be mounted on the robot hand 100 or on the robot 110.

[0017] The picking robot controller 620 can perform various processes based on information about the workpiece 700 acquired by the camera 120, for example. The picking robot controller 620 is also electrically connected to the robot 110. The picking robot controller 620 can control the operation of multiple joints, multiple arms, and multiple actuators 110A of the robot 110.

[0018] The picking robot controller 620 according to this embodiment recognizes the three-dimensional space representing the work area as captured in the image information of the camera 120 in a three-dimensional coordinate system. The three-dimensional coordinate system recognized by the picking robot controller 620 is, for example, defined as having the center of the work area as the origin, with a predetermined direction passing through the origin that is included in a predetermined plane as the X-axis, a direction that is included in the predetermined plane and perpendicular to the X-axis as the Y-axis, and a height direction perpendicular to the predetermined plane as the Z-coordinate.

[0019] The picking robot controller 620 stores the target position (in a three-dimensional coordinate system) to which the workpiece 700 will be moved. Furthermore, the picking robot controller 620 can recognize the position coordinates (in a three-dimensional coordinate system) of the robot 110's reference position from the signals from the motor encoders used to operate the robot 110's arm. The reference position may be called, for example, the robot 110's center point. Therefore, the picking robot controller 620 can generate a movement path that the center point passes through in order to operate the robot 110 within the work area.

[0020] The hand controller 630 can output various commands, such as positioning commands and gripping commands, to the robot hand 100. The robot hand 100 sets the position (orientation) of each of the multiple fingers that make up the robot hand 100 to a predetermined position (orientation) according to the positioning command output from the hand controller 630. The robot hand 100 also closes the multiple fingers that are in the predetermined orientation according to the gripping command output from the hand controller 630 to perform a gripping operation on the workpiece 700. The hand controller 630 is also configured to provide feedback control of the movement of various actuators mounted on the robot hand 100 based on the output of various sensors mounted on the robot hand 100. The various sensors include, for example, a force detection sensor that detects the force acting on the robot hand 100, and a rotation angle sensor that detects the rotation angle of various rotating members. The various actuators include a positioning motor for positioning the fingers, and a gripping motor for performing the gripping operation.

[0021] In the illustrated example, the hand controller 630 is configured to output 13 types of positioning commands and controls the movement of the robot hand 100 so that the position of the multiple finger parts constituting the robot hand 100 becomes one of the 13 types of positions. In this embodiment, the position of the finger parts for grasping is also called the grasping pose.

[0022] The picking robot controller 620 can determine which of the 13 gripping poses is suitable for gripping the workpiece 700 based on information about the workpiece 700 acquired by the camera 120. The robot system 600 can grip the workpiece 700 using the robot hand 100 by controlling the movements of the robot hand 100 and the robot 110 in this manner.

[0023] The robot hand 100 according to this embodiment is a robot hand used for industrial purposes and has four finger portions FP (see Figure 2), but it is sufficient to have at least three or more finger portions. Each of the multiple finger portions FP of the robot hand 100 has one or more joints, and it is possible to make the degree of bending of the joints different for each of the 13 types of grasping poses stored in the grasping pose database 631A (see Figure 23).

[0024] Next, the robot hand 100 will be described in detail with reference to Figures 2 to 5. Figure 2 is a perspective view of the robot hand 100, Figure 3 is a top view of the main part of the robot hand 100 (excluding the finger portions FP), Figure 4 is a left side view of the main part of the robot hand 100, and Figure 5 is a rear view of the main part of the robot hand 100. In Figures 3 to 5, the finger portions FP that make up the robot hand 100 are omitted from the illustration for clarity.

[0025] In Figure 2, X1 represents one direction of the X-axis in the three-dimensional Cartesian coordinate system, and X2 represents the other direction of the X-axis. Similarly, Y1 represents one direction of the Y-axis in the three-dimensional Cartesian coordinate system, and Y2 represents the other direction of the Y-axis. Likewise, Z1 represents one direction of the Z-axis in the three-dimensional Cartesian coordinate system, and Z2 represents the other direction of the Z-axis. In Figure 2, the X1 side of the robot hand 100 corresponds to the front side of the robot hand 100, and the X2 side of the robot hand 100 corresponds to the rear side of the robot hand 100. Also, the Y1 side of the robot hand 100 corresponds to the left side of the robot hand 100, and the Y2 side of the robot hand 100 corresponds to the right side of the robot hand 100. Furthermore, the Z1 side of the robot hand 100 corresponds to the top side of the robot hand 100, and the Z2 side of the robot hand 100 corresponds to the bottom side of the robot hand 100. The same applies to other figures.

[0026] In the illustrated example, the robot hand 100 is a device corresponding to a human right hand and has finger portions FP and palm portions PM. The robot hand 100 may also be configured to correspond to a human left hand.

[0027] The finger portion FP includes the first finger portion FP1 corresponding to the thumb, the second finger portion FP2 corresponding to the index finger, the third finger portion FP3 corresponding to the middle finger, and the fourth finger portion FP4 corresponding to the ring finger. The finger portion FP may also include the fifth finger portion corresponding to the little finger. In addition, the number of finger portions other than the first finger portion FP1 may be one, two, three, four, or five or more.

[0028] Specifically, as shown in Figure 2, the first finger portion FP1 has a first distal phalanx DP1 and a first proximal phalanx BP1. The first distal phalanx DP1 and the first proximal phalanx BP1 are connected via joint DJ1, and the first proximal phalanx BP1 and the palm portion PM are connected via joint BJ1. The second finger portion FP2 has a second distal phalanx DP2, a second middle phalanx CP2, and a second proximal phalanx BP2. The second distal phalanx DP2 and the second middle phalanx CP2 are connected via joint DJ2, the second middle phalanx CP2 and the second proximal phalanx BP2 are connected via joint CJ2, and the second proximal phalanx BP2 and the palm portion PM are connected via joint BJ2. The third finger portion FP3 and the fourth finger portion FP4 have the same configuration as the second finger portion FP2.

[0029] The palm portion PM corresponds to the palm of a human hand. In the illustrated example, the palm portion PM includes a first palm portion PM1 to which the first finger portion FP1 is attached, and a second palm portion PM2 to which the second finger portion FP2 to the fourth finger portion FP4 are attached. The first palm portion PM1 and the second palm portion PM2 are connected so that they can swing relative to each other around the pivot axis PX (see Figure 5), as indicated by the arrow AR1.

[0030] Furthermore, the robot hand 100 includes a positioning device PD (see Figure 2), a gripping device GD (see Figure 2), and a rocking device SD (see Figure 5).

[0031] The positioning device PD is a device that positions the finger portion FP (a device that controls the posture of the finger portion FP). In the illustrated example, the positioning device PD includes a first positioning device PD1 that controls the posture of the first finger portion FP1, a second positioning device PD2 that controls the posture of the second finger portion FP2, a third positioning device PD3 that controls the posture of the third finger portion FP3, and a fourth positioning device PD4 that controls the posture of the fourth finger portion FP4.

[0032] The first positioning device PD1 includes a first fixed positioning device PD1F that is not movable in the X-axis direction relative to the palm portion PM, and a first movable positioning device PD1M that is movable in the X-axis direction relative to the palm portion PM. As shown in Figure 4, the first fixed positioning device PD1F has a first fixed positioning worm gear WG1F as a first fixed positioning power transmission mechanism, a first fixed wire WR1F as a first fixed positioning power transmission member, and a first fixed motor MT1F as a first fixed positioning actuator. The first fixed positioning worm gear WG1F has a first fixed positioning worm WM1F and a first fixed positioning worm wheel WH1F. The first movable positioning device PD1M has a first movable positioning worm gear WG1M as a first movable positioning power transmission mechanism, a first movable wire WR1M as a first movable positioning power transmission member, and a first movable motor MT1M as a first movable positioning actuator. The first movable positioning worm gear WG1M includes a first movable positioning worm WM1M and a first movable positioning worm wheel WH1M. The first fixed positioning power transmission member and the first movable positioning power transmission member may be a link mechanism instead of a wire.

[0033] The second positioning device PD2 includes a second fixed positioning device PD2F that is not movable in the X-axis direction relative to the palm portion PM, and a second movable positioning device PD2M that is movable in the X-axis direction relative to the palm portion PM. As shown in Figure 3, the second fixed positioning device PD2F has a second fixed positioning worm gear WG2F as a second fixed positioning power transmission mechanism, a second fixed wire WR2F as a second fixed positioning power transmission member, and a second fixed motor MT2F as a second fixed positioning actuator. The second fixed positioning worm gear WG2F has a second fixed positioning worm WM2F and a second fixed positioning worm wheel WH2F. The second movable positioning device PD2M has a second movable positioning worm gear WG2M as a second movable positioning power transmission mechanism, a second movable wire WR2M as a second movable positioning power transmission member, and a second movable motor MT2M as a second movable positioning actuator. The second movable positioning worm gear WG2M includes a second movable positioning worm WM2M and a second movable positioning worm wheel WH2M. The second fixed positioning power transmission member and the second movable positioning power transmission member may be a link mechanism instead of a wire.

[0034] The third positioning device PD3 and the fourth positioning device PD4 have the same configuration as the second positioning device PD2. Specifically, the third positioning device PD3 includes a third fixed positioning device PD3F which includes a third fixed positioning worm gear WG3F (third fixed positioning worm WM3F and third fixed positioning worm wheel WH3F), a third fixed wire WR3F, and a third fixed motor MT3F, and a third movable positioning device PD3M which includes a third movable positioning worm gear WG3M (third movable positioning worm WM3M and third movable positioning worm wheel WH3M), a third movable wire WR3M, and a third movable motor MT3M. Furthermore, the fourth positioning device PD4 includes a fourth fixed positioning device PD4F which includes a fourth fixed positioning worm gear WG4F (fourth fixed positioning worm WM4F and fourth fixed positioning worm wheel WH4F), a fourth fixed wire WR4F, and a fourth fixed motor MT4F, and a fourth movable positioning device PD4M which includes a fourth movable positioning worm gear WG4M (fourth movable positioning worm WM4M and fourth movable positioning worm wheel WH4M), a fourth movable wire WR4M, and a fourth movable motor MT4M.

[0035] The gripping device GD is a device that controls the gripping force, which is the force used to grip an object such as a workpiece 700 with the finger portion FP. In the illustrated example, as shown in Figure 3, the gripping device GD has a gripping worm gear WG10 as a gripping power transmission mechanism, a gripping wire WR10 as a gripping power transmission member, and a gripping motor MT10 as a gripping actuator. As shown in Figure 5, the gripping worm gear WG10 has a gripping worm WM10 and a gripping worm wheel WH10.

[0036] The control device 610 (hand controller 630) can, for example, determine the orientation of the finger portion FP by the positioning device PD (after the finger portion FP is in contact with an object), and then generate a desired gripping force using the gripping device GD.

[0037] The oscillating device SD is a device that causes the first palm portion PM1 and the second palm portion PM2 to oscillate relative to each other. In the illustrated example, as shown in Figure 5, the oscillating device SD has an oscillating worm gear WG20, a first gear GR21, a second gear GR22, an oscillating shaft SH20 as an oscillating power transmission mechanism, and an oscillating motor MT20 as an oscillating actuator. The oscillating worm gear WG20 has an oscillating worm WM20 and an oscillating worm wheel WH20.

[0038] In the following, the first fixed wire WR1F and the first movable wire WR1M may be collectively referred to as "first wire WR1." The same applies to the second wire WR2 (second fixed wire WR2F and second movable wire WR2M), the third wire WR3 (third fixed wire WR3F and third movable wire WR3M), and the fourth wire WR4 (fourth fixed wire WR4F and fourth movable wire WR4M). Furthermore, the first movable wires WR1M to the fourth movable wires WR4M may be collectively referred to as "movable wires," and the first fixed wires WR1F to the fourth fixed wires WR4F may be collectively referred to as "fixed wires." In addition, "movable wires" and "fixed wires" may be collectively referred to as "wires."

[0039] Furthermore, the first fixed-position worm gear WG1F and the first movable-position worm gear WG1M may be collectively referred to as "first-position worm gear WG1". The same applies to the second-position worm gear WG2 (second fixed-position worm gear WG2F and second movable-position worm gear WG2M), the third-position worm gear WG3 (third fixed-position worm gear WG3F and third movable-position worm gear WG3M), and the fourth-position worm gear WG4 (fourth fixed-position worm gear WG4F and fourth movable-position worm gear WG4M). In addition, the first to fourth-position worm gears WG1 to WG4 may be collectively referred to as "worm gear WG".

[0040] Furthermore, the first fixed-positioning worm WM1F and the first movable-positioning worm WM1M may be collectively referred to as "first-positioning worm WM1". The same applies to the second-positioning worm WM2 (second fixed-positioning worm WM2F and second movable-positioning worm WM2M), the third-positioning worm WM3 (third fixed-positioning worm WM3F and third movable-positioning worm WM3M), and the fourth-positioning worm WM4 (fourth fixed-positioning worm WM4F and fourth movable-positioning worm WM4M). In addition, the first to fourth-positioning worms WM1 to WM4, the gripping worm WM10, and the oscillating worm WM20 may be collectively referred to as "worm WM", and the axis of the worm WM may be referred to as "worm axis WX". Note that "worm" may also be called a "screw gear" or "worm shaft".

[0041] Furthermore, the first fixed-positioning worm wheel WH1F and the first movable-positioning worm wheel WH1M may be collectively referred to as "first-positioning worm wheel WH1". The same applies to the second-positioning worm wheel WH2 (second fixed-positioning worm wheel WH2F and second movable-positioning worm wheel WH2M), the third-positioning worm wheel WH3 (third fixed-positioning worm wheel WH3F and third movable-positioning worm wheel WH3M), and the fourth-positioning worm wheel WH4 (fourth fixed-positioning worm wheel WH4F and fourth movable-positioning worm wheel WH4M). In addition, the first to fourth-positioning worm wheels WH1 to WH4, the gripping worm wheel WH10, and the oscillating worm wheel WH20 may be collectively referred to as "worm wheel".

[0042] Furthermore, the first fixed motor MT1F and the first movable motor MT1M may be collectively referred to as "first motor MT1". The same applies to the second motor MT2 (second fixed motor MT2F and second movable motor MT2M), the third motor MT3 (third fixed motor MT3F and third movable motor MT3M), and the fourth motor MT4 (fourth fixed motor MT4F and fourth movable motor MT4M). In addition, the first motors MT1 to the fourth motors MT4, the gripping motor MT10, and the oscillating motor MT20 may be collectively referred to as "motor MT", and the rotation axis of motor MT may be referred to as "rotation axis RX".

[0043] Next, with reference to Figure 6, an example of the movement of the finger portion FP by the positioning device PD will be described. Figure 6 is a schematic perspective view of some of the components constituting the second finger portion FP2 and the second wire WR2. Specifically, the top image of Figure 6 (the uppermost image) shows the state when the second finger portion FP2 is extended straight. The second image from the top of Figure 6 shows the movement of the second distal phalanx DP2, the second middle phalanx CP2, and the second proximal phalanx BP2, each oscillating around their respective joints. The third image from the top of Figure 6 shows the movement of the second distal phalanx DP2 and the second middle phalanx CP2, each oscillating around their respective joints without oscillating the second proximal phalanx BP2. The bottom image of Figure 6 shows the movement of only the second proximal phalanx BP2 oscillating around its corresponding joint without oscillating either the second distal phalanx DP2 or the second middle phalanx CP2. The following explanation, with reference to Figure 6, pertains to the movement of the second finger portion FP2 by the second positioning device PD2, but it also applies similarly to the movement of the first finger portion FP1 by the first positioning device PD1, the movement of the third finger portion FP3 by the third positioning device PD3, and the movement of the fourth finger portion FP4 by the fourth positioning device PD4.

[0044] In the example shown in Fig. 6, the second distal phalanx DP2 is swingably connected to the second middle phalanx CP2 via the joint DJ2. A fixing pin PN1 and a fixed drum FD1 are fixed to the second distal phalanx DP2. The second middle phalanx CP2 is swingably connected to the second proximal phalanx BP2 via the joint CJ2. A fixing pin PN2 and a fixed pulley FYa are attached to the second middle phalanx CP2. The second proximal phalanx BP2 is swingably connected to the second palm part PM2 via the joint BJ2. A fixed drum FD2 and a fixed drum FD3 are fixed to the second proximal phalanx BP2. A fixed pulley FYb is attached to the second palm part PM2. One end (distal end) of the second movable wire WR2M is fixed to the fixing pin PN1, the other end (proximal end) thereof is fixed to the second movable positioning worm wheel WH2M, and the second movable wire WR2M is arranged so as to be wound around the second movable positioning worm wheel WH2M or fed out from the second movable positioning worm wheel WH2M. One end (distal end) of the second fixed wire WR2F is fixed to the fixing pin PN2, the other end (proximal end) thereof is fixed to the second fixed positioning worm wheel WH2F, and the second fixed wire WR2F is arranged so as to be wound around the second fixed positioning worm wheel WH2F or fed out from the second fixed positioning worm wheel WH2F. For clarity, in Fig. 6, the second movable wire WR2M is represented by a broken line, the second fixed wire WR2F is represented by a solid line, and in drawings other than the top drawing of Fig. 6, illustration of most of the second wire WR2 (the portion along the second finger part FP2) is omitted.

[0045] As shown in the second drawing from the top in Fig. 6, when the second fixed wire WR2F is held (without being wound or fed out) and the second movable wire WR2M is wound as indicated by arrow AR2, the posture of the second finger part FP2 changes as indicated by arrow AR3. Specifically, the second finger part FP2 is configured to uniformly swing each of the second distal phalanx DP2, the second middle phalanx CP2, and the second proximal phalanx BP2 around the corresponding joints.

[0046] Further, as shown in the third diagram from the top of FIG. 6, when the second movable wire WR2M is held (without being wound or fed out), and the second fixed wire WR2F is wound as indicated by arrow AR4, the posture of the second finger portion FP2 changes as indicated by arrow AR5. Specifically, the second finger portion FP2 is configured such that without swinging the second proximal phalanx portion BP2, each of the second distal phalanx portion DP2 and the second middle phalanx portion CP2 is evenly swung around the corresponding joint.

[0047] Further, as shown in the bottommost diagram of FIG. 6, when the second fixed wire WR2F is wound as indicated by arrow AR6 and the second fixed wire WR2F is fed out as indicated by arrow AR7, the posture of the second finger portion FP2 changes as indicated by arrow AR8. Specifically, the second finger portion FP2 is configured such that without swinging each of the second distal phalanx portion DP2 and the second middle phalanx portion CP2, only the second proximal phalanx portion BP2 is swung around the corresponding joint.

[0048] As described above, the second positioning device PD2 can achieve a desired posture of the second finger portion FP2 by appropriately combining the winding, holding, and feeding out of the second fixed wire WR2F with the winding, holding, and feeding out of the second movable wire WR2M. For example, the second positioning device PD2 can also move the fingertip of the second finger portion FP2 along a linear trajectory. In the example shown in FIG. 6, when the force applied by the second positioning device PD2 to change the posture of the second finger portion FP2 disappears, the second finger portion FP2 is configured to return to the initial state (the state shown in the topmost diagram of FIG. 6) by a torsion spring (not shown) attached to each joint. However, the second finger portion FP2 may be configured to return to the initial state by winding or feeding out another wire.

[0049] Next, another configuration example of the finger portion FP will be described with reference to FIGS. 7A to 7C. FIGS. 7A to 7C are diagrams showing a part of the constituent elements of the first finger portion FP1 mounted on the robot hand 100 shown in FIG. 2 and the arrangement of the first wire WR1. Specifically, FIG. 7A is a left side view, FIG. 7B is a bottom view, and FIG. 7C is a top view.

[0050] In the example shown in Figures 7A to 7C, the first finger portion FP1 includes tensioners TS1 to TS3, fixed drums FD1 to FD5, and a fixed pulley FYa. The first wire WR1 includes the first fixed wire WR1F and the first movable wire WR1M. The first fixed wire WR1F includes the first fixed wire WR1F1 and the first fixed wire WR1F2. The tensioner TS1 is a member to which one end (distal end) of the first movable wire WR1M is fixed, and is fixed to the first distal phalanx portion DP1 (see Figure 2) of the first finger portion FP1. The fixed drum FD1 is a fixed drum on which the first movable wire WR1M is hung, and is fixed to the first distal phalanx portion DP1 (see Figure 2). Tensioner TS2 is a member to which one end (distal end) of the first fixed wire WR1F1 is fixed, and is fixed to the first proximal phalange BP1 (see Figure 2) of the first finger portion FP1. Tensioner TS3 is a member to which one end (distal end) of the first fixed wire WR1F2 is fixed, and is fixed to the first proximal phalange BP1 (see Figure 2). Fixed drum FD2 is a fixed drum on which the first fixed wire WR1F (first fixed wire WR1F1 and first fixed wire WR1F2) is hung, and is fixed to the first proximal phalange BP1 (see Figure 2). Fixed pulley FYa is a fixed pulley on which the first movable wire WR1M is hung, and is attached to the first proximal phalange BP1 (see Figure 2). Fixed drum FD3 is a fixed drum on which the first fixed wire WR1F2 is hung, and is fixed to the first palm portion PM1 (see Figure 2). Fixed drum FD4 is a fixed drum on which the first fixed wire WR1F1 is attached, and is fixed to the first palm portion PM1 (see Figure 2). Fixed drum FD5 is a fixed drum on which the first movable wire WR1M is attached, and is fixed to the first palm portion PM1 (see Figure 2).

[0051] With this configuration, the first positioning device PD1 can achieve the desired position of the first finger portion FP1 by appropriately combining the winding, holding, and unwinding of the first fixed wire WR1F with the winding, holding, and unwinding of the first movable wire WR1M, similar to the configuration shown in Figure 6.

[0052] Next, with reference to Figures 8A to 8C, yet another example of the configuration of the finger portion FP will be described. Figures 8A to 8C show some of the components of the second finger portion FP2 mounted on the robot hand 100 shown in Figure 2 and the arrangement of the second wire WR2. Specifically, Figure 8A is a top view, Figure 8B is a left side view, and Figure 8C is a right side view.

[0053] In the example shown in Figures 8A to 8C, the second finger portion FP2 includes tensioners TS1 to TS4, fixed drums FD1 to FD6, and fixed pulleys FYa to FYb. The second wire WR2 includes the second fixed wire WR2F and the second movable wire WR2M. The second fixed wire WR2F includes the second fixed wire WR2F11, the second fixed wire WR2F12, the second fixed wire WR2F21, and the second fixed wire WR2F22. The fixed drum FD1 is a fixed drum on which the second fixed wire WR2F (second fixed wire WR2F12 and second fixed wire WR2F22) is attached, and is fixed to the second distal phalanx portion DP2 of the second finger portion FP2 (see Figure 2). The fixed drum FD2 is a fixed drum on which the second fixed wires WR2F12 and WR2F22 are hung, and is fixed to the second base node BP2 (see Figure 2) of the second finger section FP2. The fixed pulley FYa is a fixed pulley on which the second movable wire WR2M is hung, and is attached to the second middle node CP2 (see Figure 2). The tensioner TS1 is a member on which the other end (proximal end) of the second fixed wire WR2F12 is fixed, and is fixed to the second base node BP2 (see Figure 2) of the second finger section FP2. The tensioner TS2 is a member on which the other end (proximal end) of the second fixed wire WR2F22 is fixed, and is fixed to the second base node BP2 (see Figure 2) of the second finger section FP2. Tensioner TS3 is a member to which one end (distal end) of the second fixing wire WR2F11 is fixed, and is fixed to the second proximal phalange BP2 (see Figure 2) of the second finger portion FP2. Tensioner TS4 is a member to which one end (distal end) of the second fixing wire WR2F21 is fixed, and is fixed to the second proximal phalange BP2 (see Figure 2) of the second finger portion FP2. Fixing drum FD3 is a fixing drum on which the second fixing wire WR2F (second fixing wire WR2F1 and second fixing wire WR2F2) is hung, and is fixed to the second proximal phalange BP2 (see Figure 2). Fixing drum FD4 is a fixing drum on which the second fixing wire WR2F21 is hung, and is fixed to the second palm portion PM2 (see Figure 2). Fixed drum FD5 is a fixed drum on which the second fixed wire WR2F11 is attached, and is fixed to the second palm portion PM2 (see Figure 2). Fixed drum FD6 is a fixed drum on which the second movable wire WR2M is attached, and is fixed to the second palm portion PM2 (see Figure 2).

[0054] With this configuration, the second positioning device PD2 can achieve the desired posture of the second finger portion FP2 by appropriately combining the winding, holding, and unwinding of the second fixed wire WR2F with the winding, holding, and unwinding of the second movable wire WR2M, similar to the configuration shown in Figure 6. The same applies to the third positioning device PD3 and the fourth positioning device PD4 mounted on the robot hand 100 shown in Figure 2.

[0055] Next, with reference to Figure 9, an example of the positional relationship between the worm axis WX and the rotary axis RX will be described. Figure 9 is a diagram showing the positional relationship between the worm axis WX and the rotary axis RX. Specifically, the left side of Figure 9 is a front view of the worm WM and motor MT mounted on the robot hand 100 shown in Figure 2, the upper right side of Figure 9 is a top view of the worm WM and motor MT, and the lower right side of Figure 9 is a left side view of the worm WM and motor MT.

[0056] In the illustrated example, as shown in the upper right of Figure 9, in a top view along the Z-axis, the six positioning worms are arranged such that each of the six worm axes (worm axis WX2 of the second positioning worm WM2 (worm axis WX2F and worm axis WX2M), worm axis WX3 of the third positioning worm WM3 (worm axis WX3F and worm axis WX3M), and worm axis WX4 of the fourth positioning worm WM4 (worm axis WX4F and worm axis WX4M)) is parallel to the X-axis (parallel to each other). In other words, as shown in the left of Figure 9, the six positioning worms are arranged such that each worm axis lies on the first plane VL1 in a front view along the X-axis. Furthermore, the six positioning motors are arranged such that, in a top view, each of the six rotation axes (the rotation axis RX2 of the second motor MT2 (rotation axis RX2F and rotation axis RX2M), the rotation axis RX3 of the third motor MT3 (rotation axis RX3F and rotation axis RX3M), and the rotation axis RX4 of the fourth motor MT4 (rotation axis RX4F and rotation axis RX4M)) and each of the six worm axes WX are aligned in the same straight line. In addition, the gripping worm WM10 is arranged such that, in a top view, the worm axis WX10 and the rotation axis RX10 of the gripping motor MT10 are aligned in the same straight line. Furthermore, in a top view, the gripping worm WM10 is arranged such that the worm axis WX10 is perpendicular to the worm axis of each of the six positioning worms. In other words, the gripping worm WM10 is positioned such that, in a top view, its worm axis WX10 is parallel to the second plane VL2, which is perpendicular to the worm axis of each of the six positioning worms. The oscillating worm WM20 is positioned such that, in a top view, its worm axis WX20 (see the lower right diagram in Figure 9) and the rotation axis RX10 of the gripping motor MT10 overlap (are parallel). The oscillating motor MT20 is also positioned such that, in a top view, its rotation axis RX20 and the rotation axis RX10 of the gripping motor MT10 are parallel to the Y-axis (parallel to each other).

[0057] Furthermore, as shown in the left diagram of Figure 9, in a front view along the X-axis, the 10 positioning worms are arranged such that each of the 10 worm axes (worm axis WX1 (worm axis WX1F and worm axis WX1M), worm axis WX2 (worm axis WX2F and worm axis WX2M), worm axis WX3 (worm axis WX3F and worm axis WX3M), worm axis WX4 (worm axis WX4F and worm axis WX4M), worm axis WX10, and worm axis WX20) is parallel to the XY plane.

[0058] This arrangement, as shown in the lower right diagram of Figure 9, has the effect of preventing the distance between the lower end of the positioning device PD and the upper end of the gripping device GD (height dimension HT, value HT1) from becoming excessively large in a left side view along the Y-axis. In other words, this arrangement has the effect of allowing the positioning device PD and the gripping device GD to be housed within the height dimension HT.

[0059] Furthermore, this arrangement has the effect of preventing the distance between the front end of the positioning device PD and the rear end of the gripping device GD (depth dimension DT, value DT1) from becoming excessively large when viewed from the left side. In other words, this arrangement has the effect of allowing the positioning device PD and the gripping device GD to be housed within the depth dimension DT.

[0060] Next, with reference to Figure 10, another example of the positional relationship between the worm shaft WX and the rotation shaft RX will be described. Figure 10 is a diagram showing another example of the positional relationship between the worm shaft WX and the rotation shaft RX, and corresponds to Figure 9. Note that in Figure 10, the oscillating motor MT20 and the oscillating worm WM20 are omitted from the illustration for clarity.

[0061] The example shown in Figure 10 differs from the example shown in Figure 9 in that, as shown in the left diagram of Figure 10, the worm axis WX10 of the gripping worm WM10 is inclined with respect to the first plane VL1 in a front view along the X-axis. In the example shown in Figure 9, the worm axis WX10 is parallel to the first plane VL1. Specifically, in the example shown in Figure 10, the gripping worm WM10 is positioned such that a first angle α is formed between the worm axis WX10 and the first plane VL1. The first angle α is, for example, less than 20 degrees. In addition, the gripping motor MT10 is positioned such that the rotation axis RX10 and the worm axis WX10 are on the same straight line.

[0062] In this configuration, the height dimension HT between the lower end of the positioning device PD and the upper end of the gripping device GD (gripping motor MT10) is HT2, which is slightly larger than the value HT1 in the example shown in Figure 9, but smaller than when the first angle α is 20 degrees or more. Also, in the example shown in the left diagram of Figure 10, the gripping motor MT10 and the gripping worm WM10 are positioned at an angle such that the upper end of the left end of the gripping motor MT10 is higher than the upper end of the right end of the gripping worm WM10. However, the gripping motor MT10 and the gripping worm WM10 may also be positioned at an angle such that the upper end of the left end of the gripping motor MT10 is lower than the upper end of the right end of the gripping worm WM10. In this case, the height dimension HT between the lower end of the positioning device PD and the upper end of the gripping device GD (gripping worm WM10) may be smaller than the value HT1 in the example shown in Figure 9.

[0063] Next, with reference to Figure 11, another example of the positional relationship between the worm shaft WX and the rotation shaft RX will be described. Figure 11 is a diagram showing yet another example of the positional relationship between the worm shaft WX and the rotation shaft RX, and corresponds to Figures 9 and 10. Note that in Figure 11, for clarity, the oscillating motor MT20 and the oscillating worm WM20 are omitted from the illustration.

[0064] The example shown in Figure 11 differs from the examples shown in Figures 9 and 10 in that, as shown in the upper right view of Figure 11, the worm axis WX10 of the gripping worm WM10 is inclined with respect to the second plane VL2 in a top view along the Z-axis direction. In the examples shown in Figures 9 and 10, the worm axis WX10 is parallel to the second plane VL2. Specifically, in the example shown in Figure 11, the gripping worm WM10 is positioned such that a second angle β is formed between the worm axis WX10 and the second plane VL2. The second angle β is, for example, less than 20 degrees. In addition, the gripping motor MT10 is positioned such that the rotation axis RX10 and the worm axis WX10 are on the same straight line.

[0065] In this configuration, the depth dimension DT between the front end of the positioning device PD and the rear end of the gripping device GD (gripping motor MT10) is DT2, which is slightly larger than the value DT1 in the example shown in Figure 9, but smaller than when the second angle β is 20 degrees or more. Also, in the example shown in the upper right diagram of Figure 11, the gripping motor MT10 and the gripping worm WM10 are positioned at an angle such that the rear end of the left end of the gripping motor MT10 is located behind the rear end of the right end of the gripping worm WM10. However, the gripping motor MT10 and the gripping worm WM10 may also be positioned at an angle such that the rear end of the left end of the gripping motor MT10 is located in front of the rear end of the right end of the gripping worm WM10. In this case, the depth dimension DT between the front end of the positioning device PD and the rear end of the gripping device GD (gripping worm WM10) may be smaller than the value DT1 in the example shown in Figure 9.

[0066] Next, the details of the gripping device GD will be described with reference to Figures 12 to 15. Figure 12 is a perspective view of the positioning device PD, in which a part of the components (movable assembly MA) is moved by the gripping device GD. Specifically, the upper part of Figure 12 is a perspective view of the second positioning device PD2, and the lower part of Figure 12 is a perspective view of the frame FM (second frame FM2) that constitutes the second positioning device PD2. Figure 13 is a perspective view of the components that constitute the second positioning device PD2. Specifically, the upper part of Figure 13 is a perspective view of a part of the second frame FM2, the movable assembly MA (second movable assembly MA2), and the second movable positioning worm WM2M that constitute the second positioning device PD2, the middle part of Figure 13 is a perspective view of the second movable assembly MA2, and the lower part of Figure 13 is a perspective view of a part of the second frame FM2, the second movable positioning worm WM2M, and the biasing spring SP (second biasing spring SP2). Figure 14 is a top view of the palm section PM, the gripping device GD, and the fixed pulley FY and movable pulley MP on which the gripping wire WR10 is attached. Specifically, the left side of Figure 14 shows the state before the gripping operation is performed (initial state), and the right side of Figure 14 shows the state after the gripping operation is performed (gripping state). Figure 15 is a left side view of the second movable positioning worm gear WG2M (second movable positioning worm WM2M and second movable positioning worm wheel WH2M). Specifically, the upper side of Figure 15 shows the state before the gripping operation is performed, and the lower side of Figure 15 shows the state after the gripping operation is performed. The following explanation, referring to Figures 12 to 15, mainly concerns the second positioning device PD2, but also applies similarly to the first positioning device PD1, the third positioning device PD3, and the fourth positioning device PD4.

[0067] As shown in Figure 12, the second positioning device PD2 includes a second frame FM2. The second fixed positioning worm WM2F, the second movable positioning worm WM2M, the second fixed positioning worm wheel WH2F, the second movable positioning worm wheel WH2M, the second fixed motor MT2F, and the second movable motor MT2M are mounted on the second frame FM2. In other words, the second positioning device PD2 is unitized (modularized) including the second motor MT2, the second positioning worm gear WG2, and the second frame FM2.

[0068] The second frame FM2 includes frame members FM21 to FM26. Frame members FM21 to FM23 are plate-shaped members extending along the XZ plane. Frame member FM21 has a circular hole RH1 and a rectangular opening RA1, frame member FM22 has a circular hole RH2 and a rectangular opening RA2, and frame member FM23 has a circular hole RH3 and a rectangular opening RA3.

[0069] The second fixed-position worm wheel WH2F has its shaft inserted through the circular hole RH1 of frame member FM21 and the circular hole RH2 of frame member FM22, respectively. The second fixed-position worm wheel WH2F is supported by frame members FM21 and FM22 so as to be rotatable around a rotation axis parallel to the Y axis and immovable in the X axis direction. A rotation angle sensor, such as a potentiometer, is attached near the rotation axis of the second fixed-position worm wheel WH2F. The rotation angle sensor may also be attached to the motor shaft.

[0070] The second movable positioning worm wheel WH2M has its shaft inserted through slide blocks SB (second slide block SB2), which are fitted into rectangular openings RA2 of frame member FM22 and RA3 of frame member FM23, respectively. The second slide block SB2 is supported by frame members FM22 and FM23 so as to be movable in the X-axis direction. The second movable positioning worm wheel WH2M is also supported by the second slide block SB2 so as to be rotatable around a rotation axis parallel to the Y-axis. A rotation angle sensor, such as a potentiometer, is attached near the rotation axis of the second movable positioning worm wheel WH2M. The rotation angle sensor may also be attached to the motor shaft.

[0071] In the illustrated example, the rotation axis of the second fixed-positioning worm wheel WH2F and the rotation axis of the second movable-positioning worm wheel WH2M are arranged parallel to the Y-axis and offset in the X-axis direction. This arrangement has the effect of facilitating the installation of rotation angle sensors corresponding to each rotation axis.

[0072] Frame member FM24 is fixed to the rear ends of each of frame members FM21 to FM23, and is also fixed to the upper end surface of the rear wall portion of frame member FM26. Frame member FM25 is positioned to support the lower surfaces of the central portions of each of frame members FM21 to FM23, and is fixed to the inner bottom surface of frame member FM26. Frame member FM26 is a member having a front wall portion and a rear wall portion. The front ends of each of frame members FM21 to FM23 are fixed to the upper end surface of the front wall portion of frame member FM26.

[0073] A force detection sensor SG (second force detection sensor SG2) is attached to the frame portion surrounding the rectangular opening RA1 of the frame member FM21. The force detection sensor SG is a device for detecting the force acting on the robot hand 100. In the illustrated example, as shown in Figure 2, the force detection sensor SG includes a first force detection sensor SG1 for detecting the force acting on the first finger portion FP1, a second force detection sensor SG2 for detecting the force acting on the second finger portion FP2, a third force detection sensor SG3 for detecting the force acting on the third finger portion FP3, and a fourth force detection sensor SG4 for detecting the force acting on the fourth finger portion FP4. As shown in the lower diagram of Figure 12, the second force detection sensor SG2 consists of at least one (four in the illustrated example) strain gauge sensors attached to the frame portion (elongated portion) of the frame member FM21. That is, each strain gauge sensor is attached to a part (strain-generating body) that is easily expanded or contracted when subjected to force. The same applies to the first force detection sensor SG1, the third force detection sensor SG3, and the fourth force detection sensor SG4. However, the force detection sensors SG (first force detection sensor SG11 to fourth force detection sensor SG14) may be attached to the palm part PM as shown in Figure 16, or to other parts of the robot hand 100. Furthermore, the force detection sensors SG may be piezoelectric sensors, capacitive sensors, or sensors of other types.

[0074] This arrangement of the force detection sensor SG has the effect of simplifying the structure of the robot hand 100. This is because there is no need to route cables for electrically connecting the force detection sensor SG and the control device 610 (hand controller 630) within the finger portion FP. Furthermore, this arrangement has the effect of improving the waterproofness and water resistance of the robot hand 100. This is because the electronic equipment, including the force detection sensor SG, can be placed (housed) in the palm portion PM instead of the finger portion FP. Additionally, attaching (sticking) the force detection sensor SG to the frame portion (elongated part) of the frame member FM21 also has the effect of simplifying the structure of the robot hand 100. This is because there is no need to provide special structures such as structures suitable for sensing the force detection sensor SG, and consequently, the number of parts can be reduced.

[0075] The control device 610 (hand controller 630) detects the change in tension of the wire (especially the fixed wire) when the finger portion FP of the robot hand 100 comes into contact with an object such as a workpiece 700, based on the output of the force detection sensor SG. By detecting this change in tension, the control device 610 (hand controller 630) can detect that the finger portion FP has come into contact with the object.

[0076] Furthermore, the second positioning device PD2 includes a second movable assembly MA2, as shown in Figure 13. Specifically, the second movable assembly MA2 includes a second movable positioning worm wheel WH2M, a second slide block SB2, and a movable pulley MP (second movable pulley MP2), as shown in the center view of Figure 13. The second slide block SB2 includes a central part CB, protrusions PT (left protrusion PTL and right protrusion PTR), and a movable pulley support block BK. The left protrusion PTL, which has a substantially rectangular end face, is fitted into a rectangular opening RA2 of the frame member FM22 so as to be slidable in the X-axis direction, and the right protrusion PTR, which has a substantially rectangular end face, is fitted into a rectangular opening RA3 of the frame member FM23 so as to be slidable in the X-axis direction. The central part CB is configured so that its rear surface is in contact with four biasing springs SP (second biasing spring SP2, see the lower view of Figure 13). The second biasing spring SP2 is compressed by the rear surface of the central part CB when the second movable assembly MA2 moves to the rear (X2 side), generating a restoring force.

[0077] As shown in Figure 14, the gripping device GD is configured to wind up or unwind the gripping wire WR10. Specifically, the gripping device GD includes a gripping motor MT10, a gripping worm gear WG10 (gripping worm WM10 and gripping worm wheel WH10), and a gripping wire WR10. The gripping device GD is configured to wind up the gripping wire WR10 by rotating the gripping motor MT10 in one direction (forward) and to unwind the gripping wire WR10 by rotating the gripping motor MT10 in the other direction (reverse). The gripping motor MT10 is configured to output a force greater than that generated by the positioning motor. This is to enable the generation of a tension greater than the wire tension generated by the positioning motor.

[0078] The gripping wire WR10 has one end (distal end) fixed to a fixing pin PN10 (see Figure 5) provided on the first palm portion PM1, and the other end (proximal end) fixed to a gripping worm wheel WH10 (see Figure 5). The gripping wire WR10 has its intermediate portion hooked onto a plurality of fixed wire attachment members (fixed pulleys FY (fixed pulleys FY1 to FY15, see Figures 3 and 4)) and a plurality of movable wire attachment members (movable pulleys MP (first movable pulley MP1 to fourth movable pulley MP4)). The plurality of movable pulleys MP include the first movable pulley MP1 provided on the first positioning device PD1, the second movable pulley MP2 provided on the second movable positioning device PD2M, the third movable pulley MP3 provided on the third movable positioning device PD3M, and the fourth movable pulley MP4 provided on the fourth movable positioning device PD4M.

[0079] With this configuration, the gripping device GD can move the movable pulley MP from its initial position (see left diagram in Figure 14) to its gripping position (see right diagram in Figure 14) by winding the gripping wire WR10 onto the gripping worm wheel WH10. Specifically, as shown in the right diagram in Figure 14, the gripping device GD can move the first movable pulley MP1 in the direction indicated by arrow AR11, the second movable pulley MP2 in the direction indicated by arrow AR12, the third movable pulley MP3 in the direction indicated by arrow AR13, and the fourth movable pulley MP4 in the direction indicated by arrow AR14. As a result, in the illustrated example, the first movable positioning device PD1M, equipped with the first movable pulley MP1, moves backward (towards X2) by a distance DS1, the second movable positioning device PD2M, equipped with the second movable pulley MP2, moves backward (towards X2) by a distance DS2, the third movable positioning device PD3M, equipped with the third movable pulley MP3, moves backward (towards X2) by a distance DS3, and the fourth movable positioning device PD4M, equipped with the fourth movable pulley MP4, moves backward (towards X2) by a distance DS4. This movement can achieve an action (gripping action) similar to the action (positioning action) of the finger portion FP caused by winding up the movable wire. The gripping action can also be described as an action that brings the tip of the first finger portion FP1 closer to the tips of the second finger portion FP2 to the fourth finger portion FP4.

[0080] Specifically, as shown by arrow AR12 in the right-hand diagram of Figure 14, when the second movable pulley MP2 moves backward, the entire second movable assembly MA2 (see the center diagram in Figure 13) moves backward. Then, as shown by arrow AR16, the second movable positioning worm wheel WH2M moves backward (towards X2) while rolling clockwise on the second movable positioning worm WM2M, as indicated by arrow AR15 in the upper diagram of Figure 15, and winds up the second movable wire WR2M. As a result, the tension of the second movable wire WR2M increases. In the illustrated example, the second movable positioning worm WM2M does not rotate around the worm shaft WX2M during the gripping operation, but it may rotate around the worm shaft WX2M. That is, the positioning operation and the gripping operation may be performed simultaneously.

[0081] In the example shown in Figure 15, the second movable positioning worm wheel WH2M rolls on the second movable positioning worm WM2M so as to rotate by an angle γ around its central axis (worm wheel axis). The central axis of the second movable positioning worm wheel WH2M then moves backward (towards X2) by a distance DS10.

[0082] In this way, the gripping device GD can bring the tip of the first finger FP1 closer to the tips of the second finger FP2 to the fourth finger FP4 by winding up each of the movable wires (first movable wire WR1M to fourth movable wire WR4M). That is, the robot hand 100 can grip an object such as a workpiece 700.

[0083] Furthermore, this configuration using a movable pulley MP has the effect of increasing the gripping force of each finger FP with a single gripping motor MT10. Additionally, this configuration has the effect of equalizing the gripping force of each finger FP.

[0084] Furthermore, when the gripping motor MT10 rotates in reverse and the gripping force provided by the gripping motor MT10 weakens, the second movable assembly MA2 moves forward while rolling in the reverse direction (counterclockwise) on the second movable positioning worm WM2M due to the restoring force of the second biasing spring SP2. In other words, the second movable assembly MA2 moves toward its original position (the position before the gripping operation began). Note that when the gripping motor MT10 is stopped, the second movable positioning worm WM2M functions as a stopper, so the second movable assembly MA2 does not move in the front-rear direction (X-axis direction). Also, when the positioning operation by the second movable motor MT2M is performed without increasing or decreasing the gripping force provided by the gripping motor MT10, the movement of the second movable assembly MA2 toward the rear is restricted by the second biasing spring SP2. Therefore, the second movable positioning worm wheel WH2M rotates without rolling on the second movable positioning worm WM2M which is rotating around the worm shaft WX2, and can wind up the second movable wire WR2M.

[0085] Next, the details of the rocking device SD will be explained with reference to Figures 16 to 19. Figure 16 is a perspective view of the robot hand 100, including the palm section PM, which is moved by the rocking device SD. In Figure 16, the palm section PM is in its initial state (the plate surface of the base PM1B of the first palm section PM1 and the plate surface of the second palm section PM2 are parallel). Also, for clarity, the positioning device PD, which is actually mounted on the palm section PM, is not shown in Figure 16. Figure 17 is a diagram of the palm section PM and the rocking device SD. Specifically, the top, middle, and bottom views of Figure 17 are the top, rear, and bottom views of the rocking device SD mounted on the palm section PM. Figure 18 is a left side view of the robot hand 100 being rocked by the rocking device SD. Specifically, the upper part of Figure 18 shows the robot hand 100 when the palm portion PM is in its initial state, and the lower part of Figure 18 shows the robot hand 100 when the palm portion PM is in a swinging state (the plate surface of the base PM1B of the first palm portion PM1 and the plate surface of the second palm portion PM2 are not parallel). Figure 19 is a rear view of the robot hand 100 being oscillated by the swinging device SD. Specifically, the upper part of Figure 19 shows the robot hand 100 when the palm portion PM is in its initial state, and the lower part of Figure 18 shows the robot hand 100 when the palm portion PM is in a swinging state.

[0086] The oscillating device SD is a device that causes the first palm portion PM1 and the second palm portion PM2 to oscillate relative to each other. In the illustrated example, as shown in Figure 17, the oscillating device SD has an oscillating worm gear WG20, a first gear GR21, a second gear GR22, an oscillating shaft SH20 as an oscillating power transmission mechanism, and an oscillating motor MT20 as an oscillating actuator. The oscillating worm gear WG20 has an oscillating worm WM20 and an oscillating worm wheel WH20.

[0087] The first palm section PM1 is supported by the second palm section PM2 so that it can oscillate around the pivot axis PX of the pivot shaft SH20 and the pivot worm wheel WH20 as they rotate around the pivot axis PX. The pivot motor MT20, the first gear GR21, the second gear GR22, and the pivot worm WM20 are mounted on the second palm section PM2.

[0088] The oscillating motor MT20 rotates the first gear GR21, the second gear GR22, and the oscillating worm WM20 in sequence, thereby rotating the oscillating worm wheel WH20 and the oscillating shaft SH20 around the oscillating shaft PX, and consequently causing the first palm portion PM1 to oscillate. Note that the first gear GR21 and the second gear GR22 may be replaced with other rotational transmission mechanisms using belts and pulleys, etc.

[0089] Next, with reference to Figures 20 and 21, the slack suppression mechanism LP, which suppresses the slack of the gripping wire WR10 when the first palm portion PM1 is oscillated by the oscillating device SD, will be described. Figure 20 is a rear view of the fixed pulley FY, gripping device GD, slack suppression mechanism LP, palm portion PM, oscillating shaft SH20, and oscillating worm wheel WH20. Figure 21 is a perspective view of the slack suppression mechanism LP provided on the palm portion PM. Specifically, the left view of Figure 21 (upper left and lower left views) is a perspective view of the slack suppression mechanism LP provided on the palm portion PM viewed from the front left diagonally from above, and the right view of Figure 21 (upper right and lower right views) is a perspective view of the slack suppression mechanism LP provided on the palm portion PM viewed from the rear right diagonally from above. Furthermore, the upper diagrams of Figure 21 (upper left and upper right) are perspective views of the palm area PM in its initial state, while the lower diagrams of Figure 21 (lower left and lower right) are perspective views of the palm area PM in a oscillating state.

[0090] The slack suppression mechanism LP includes an oscillating pulley MP30 as an oscillating wire hanging member, and a pulley support block BK30. As shown in Figure 20, the oscillating pulley MP30 is a member on which a portion of the gripping wire WR10 is hung between the fixed pulleys FY9 and FY10, and is positioned so that its rotation axis RX30 extends parallel to the oscillating axis PX. The pulley support block BK30 is a member that rotatably supports the oscillating pulley MP30, and is positioned so that it can oscillate around the oscillating axis PX independently of the rotation of the oscillating worm wheel WH20 and the oscillating shaft SH20. In other words, the pulley support block BK30 is configured to oscillate around the oscillating axis PX while maintaining a state in which the rotation axis RX30 of the oscillating pulley MP30 and the oscillating axis PX are parallel, even when the oscillating worm wheel WH20 and the oscillating shaft SH20 are not rotating.

[0091] The rotation axes of fixed pulley FY9, fixed pulley FY10, and oscillating pulley MP30 are parallel to the oscillating axis PX and perpendicular to the rotation axis of fixed pulley FY8 in a top view as shown in Figure 3. In addition, the rotation axis of fixed pulley FY8 is perpendicular to the rotation axes of fixed pulleys FY4 to FY7 in a front view.

[0092] With this configuration, the relaxation suppression mechanism LP can prevent the gripping wire WR10 from becoming loose between the fixed pulley FY9 and the fixed pulley FY10, even when the palm portion PM changes from the initial state (see upper diagram in Figure 22) to the oscillating state (see lower diagram in Figure 22) by the oscillating device SD.

[0093] Figure 22 is a rear view of the fixed pulley FY9, fixed pulley FY10, oscillating pulley MP30, oscillating shaft SH20, palm section PM, and gripping wire WR10. Specifically, the upper part of Figure 22 shows the arrangement of each component when the palm section PM is in its initial state, and the lower part of Figure 22 shows the arrangement of each component when the palm section PM is in the oscillating state. In the lower part of Figure 22, for the sake of clarity, the positions of the fixed pulley FY10 and oscillating pulley MP30 in the initial state are shown with dashed lines.

[0094] As shown in Figure 22, when the first palm portion PM1 is oscillated relative to the second palm portion PM2 by the oscillating device SD, the center of the fixed pulley FY10 fixed to the first palm portion PM1 oscillates downward along the circumference of a circle with radius RD1 centered on the oscillating axis PX, when viewed from the rear along the X-axis. The center of the oscillating pulley MP30, which is pivotably mounted relative to the oscillating axis PX, oscillates downward along the circumference of a circle with radius RD2 centered on the oscillating axis PX due to the tension of the gripping wire WR10. The oscillating angle θ1 of the fixed pulley FY10 is greater than the oscillating angle θ2 of the oscillating pulley MP30. The oscillating angle θ1 of the fixed pulley FY10 corresponds to the oscillating angle of the first palm portion PM1. Furthermore, the length of the portion between point CT1 (a point on the gripping wire WR10 that is in contact with the fixed pulley FY9) and point CT2 (a point on the gripping wire WR10 that is in contact with the fixed pulley FY10) on the gripping wire WR10 remains constant whether the palm portion PM is in its initial state or in a swinging state.

[0095] If the oscillating pulley MP30 were a fixed pulley (non-oscillating pulley) with the oscillating axis PX as its axis of rotation, then when the first palm portion PM1 (fixed pulley FY10) oscillates around the oscillating axis PX, the gripping wire WR10 would slacken between the fixed pulley (non-oscillating pulley) and the fixed pulley FY10. This is because the length of the portion of the gripping wire WR10 that was in contact with the fixed pulley (non-oscillating pulley) (the wrapped portion) would shorten. The slackening suppression mechanism LP can suppress such slack by allowing the pulley support block BK30, which supports the oscillating pulley MP30, to oscillate freely around the oscillating axis PX. Specifically, when the palm portion PM is in a swinging state (as shown in the lower diagram of Figure 22), the distance between the rotation axis of the fixed pulley FY10 and the rotation axis of the swinging pulley MP30 increases as the swing angle θ1 is greater than the swing angle θ2, compared to when the palm portion PM is in its initial state (as shown in the upper diagram of Figure 22). The slack suppression mechanism LP can then absorb the slack in the gripping wire WR10 due to this increase.

[0096] Thus, the slack suppression mechanism LP is configured such that the pulley support block BK30, which supports the swing pulley MP30, swings around the swing axis PX due to the tension of the gripping wire WR10. Therefore, the slack suppression mechanism LP can suppress the gripping wire WR10 from slackening even when the palm portion PM changes from an initial state to a swinging state. Therefore, the slack suppression mechanism LP can prevent the movement of the robot hand 100 from being hindered by the slack of the gripping wire WR10. In addition, the slack suppression mechanism LP can prevent the swing angle of the first finger portion FP1 from being limited by the slack of the gripping wire WR10, and prevent the amount of winding of the gripping wire WR10 by the gripping device GD from increasing due to the slack of the gripping wire WR10.

[0097] As shown in the lower part of Figure 22, the oscillating pulley MP30 is configured to oscillate on the side closer to the fixed pulley FY10 (Y1 side) than the oscillating axis PX in the Y-axis direction. However, it may also be configured to oscillate on the side further from the fixed pulley FY10 (Y2 side) than the oscillating axis PX. Furthermore, as shown in the upper part of Figure 22, the oscillating pulley MP30 is positioned such that the distance between the rotation axis RX30 of the oscillating pulley MP30 and the oscillating axis PX (radius RD2) is smaller than the distance between the rotation axis of the fixed pulley FY10 and the oscillating axis PX (radius RD1). However, if the oscillating pulley MP30 is configured to oscillate on the side further from the fixed pulley FY10 (Y2 side) than the oscillating axis PX, it may be positioned such that the radius RD2 is larger than the radius RD1.

[0098] As described above, the robot hand 100 according to the embodiment of this disclosure, as shown in Figure 2, includes a first finger portion FP1, a second finger portion FP2, a palm portion PM, a plurality of first positioning worm gears WG1 (see Figure 4) arranged in the palm portion PM and transmitting a force to control the posture of the first finger portion FP1, a plurality of second positioning worm gears WG2 (see Figure 3) arranged in the palm portion PM and transmitting a force to control the posture of the second finger portion FP2, and a gripping worm gear WG10 arranged in the palm portion PM and transmitting a force to grip an object (workpiece 700, see Figure 1) by the first finger portion FP1 and the second finger portion FP2. As shown in Figure 10, the gripping worm gear WG10 is positioned in the palm portion PM such that the first angle α formed between the first plane VL1, which includes the worm shafts WX2 (worm shafts WX2F and WX2M) of each of the multiple second positioning worm gears WG2 (second fixed positioning worm WM2F and second movable positioning worm WM2M), and the worm shaft WX10 of the gripping worm gear WG10 (gripping worm WM10) is less than a predetermined angle. The predetermined angle is preferably 20 degrees, more preferably 10 degrees, and even more preferably 5 degrees.

[0099] This configuration has the effect of allowing multiple worm gears WG to be arranged with greater space efficiency. Furthermore, as shown in Figure 10, this configuration has the effect of allowing the second positioning worm WM2, the second motor MT2, the gripping worm WM10, and the gripping motor MT10 to be arranged (housed) within the limited height dimension HT of the palm portion PM.

[0100] Furthermore, the gripping worm gear WG10 may be positioned in the palm portion PM such that, as shown in Figure 11, the second angle β formed between the second plane VL2 perpendicular to the worm axis WX2 of the second positioning worm gear WG2 and the worm axis WX10 of the gripping worm gear WG10 (gripping worm WM10) is less than a predetermined angle. The predetermined angle is preferably 20 degrees, more preferably 10 degrees, and even more preferably 5 degrees.

[0101] As shown in Figure 11, this configuration has the advantage of allowing the second positioning worm WM2, the second motor MT2, the gripping worm WM10, and the gripping motor MT10 to be arranged (housed) within the limited depth dimension DT of the palm portion PM.

[0102] Furthermore, the gripping worm gear WG10 may be arranged such that the worm axis WX10 of the gripping worm gear WG10 (gripping worm WM10) is parallel to the first plane VL1, as shown in Figure 9. Alternatively, the gripping worm gear WG10 may be arranged such that the first angle α and the second angle β are zero degrees, as shown in Figure 9. The robot hand 100 may also have a gripping motor MT10 as a gripping rotary actuator that drives the gripping worm gear WG10, as shown in Figure 9. In this case, the gripping worm gear WG10 may be arranged such that the rotation axis RX10 of the gripping motor MT10 and the worm axis WX10 of the gripping worm gear WG10 (gripping worm WM10) are on the same straight line. Furthermore, as shown in Figure 9, the robot hand 100 may have a second motor MT2 as a second positioning rotary actuator that drives the second positioning worm gear WG2. In this case, the second positioning worm gear WG2 may be arranged such that the rotation axis RX2 of the second motor MT2 and the worm axis WX2 of the second positioning worm gear WG2 (second positioning worm WM2) are located on the same straight line.

[0103] As shown in Figure 9, this configuration has the advantage of allowing the second positioning worm WM2, the second motor MT2, the gripping worm WM10, and the gripping motor MT10 to be arranged (housed) within the limited height dimension HT of the palm portion PM and within the limited depth dimension DT of the palm portion PM.

[0104] Furthermore, as shown in Figure 2, the robot hand 100 according to the embodiment of this disclosure has a plurality of finger portions FP, a palm portion PM, and a force detection sensor SG that detects when at least one of the plurality of finger portions FP touches an object (workpiece 700). The force detection sensor SG is located on the palm portion PM.

[0105] This configuration has the effect of realizing a function (contact detection function) that detects contact between the finger portion FP and an object such as the workpiece 700 with a simpler structure. Furthermore, this configuration allows for the detection of contact between the finger portion FP and the workpiece 700 without delay, enabling the robot hand 100 to stably grip the workpiece 700. This configuration also simplifies the structure of the robot hand 100 because it eliminates the need to route cables for electrically connecting the force detection sensor SG and the control device 610 (hand controller 630) within the finger portion FP. Additionally, this configuration enhances the waterproof and water-resistant properties of the robot hand 100 because the electronic equipment, including the force detection sensor SG, can be housed in the palm portion PM instead of the finger portion FP.

[0106] Furthermore, the force detection sensor SG may be arranged to correspond to at least one of the multiple finger portions FP.

[0107] This configuration has the effect of being able to determine that at least one of the multiple finger portions FP has come into contact with an object. With this configuration, the hand controller 630 can determine, for example, that at least one of the four finger portions FP has come into contact with an object.

[0108] Furthermore, as shown in Figure 2, multiple force detection sensors SG may be arranged to correspond to each of the multiple finger portions FP.

[0109] This configuration has the effect of being able to identify which of the multiple finger portions FP has made contact with the object. With this configuration, the hand controller 630 can determine, for example, that all four finger portions FP have made contact with the object. Alternatively, the hand controller 630 can determine, for example, that only the third finger portion FP3 of the four finger portions FP has not made contact with the object.

[0110] Furthermore, as shown in Figure 2, the multiple finger portions FP may have a first finger portion FP1 and a second finger portion FP2, and may be arranged so that the first finger portion FP1 and the second finger portion FP2 can grip an object (workpiece 700). The force detection sensor SG may be arranged to correspond to the second finger portion FP2.

[0111] This configuration has the effect of being able to determine with high accuracy whether or not the second finger portion FP2 has come into contact with an object. Furthermore, compared to a configuration in which force detection sensors SG are attached to the palm portion PM corresponding to each of the multiple finger portions FP, this configuration has the effects of reducing the manufacturing cost of the robot hand 100, reducing the number of parts, improving space efficiency in the parts constituting the palm portion PM, and saving space for the robot hand 100.

[0112] Furthermore, as shown in Figure 2, the force detection sensor SG may include at least one of a strain gauge sensor, a piezoelectric sensor, and a capacitive sensor for detecting the magnitude of deformation of the palm portion PM when at least one of the first finger portion FP1 and the second finger portion FP2 touches an object (workpiece 700). The robot hand 100 may also have a control device for processing the signal output by the force detection sensor SG. The control device may be a control device 610, a picking robot controller 620, or a hand controller 630.

[0113] Furthermore, as shown in Figure 2, the robot hand 100 according to the embodiment of this disclosure includes a finger portion FP including a first finger portion FP1 and a second finger portion FP2, a palm portion PM, a positioning device PD including a first movable positioning device PD1M (see Figure 4) disposed on the palm portion PM and controlling the posture of the first finger portion FP1, and a second movable positioning device PD2M disposed on the palm portion PM and controlling the posture of the second finger portion FP2, and a gripping device GD disposed on the palm portion PM and controlling the force with which the first finger portion FP1 and the second finger portion FP2 grip an object (workpiece 700, see Figure 1). The first movable positioning device PD1M includes a first movable positioning worm gear WG1M as a first movable positioning power transmission mechanism disposed on the palm portion PM, as shown in Figure 4. Furthermore, as shown in Figure 3, the second movable positioning device PD2M has a second movable positioning worm gear WG2M as a second movable positioning power transmission mechanism located in the palm portion PM. Also, as shown in Figure 3, the gripping device GD has a gripping worm gear WG10 as a gripping power transmission mechanism located in the palm portion PM, and a gripping wire WR10, one end of which is fixed to the palm portion PM and the other end of which is fixed to the gripping worm gear WG10 (gripping worm wheel WH10, see Figure 5) and wound up. Furthermore, the middle portion of the gripping wire WR10 is attached to a first movable wire attachment member (first movable pulley MP1) provided on the first movable positioning worm gear WG1M, a second movable wire attachment member (second movable pulley MP2) provided on the second movable positioning worm gear WG2M, and a plurality of fixed wire attachment members (fixed pulleys FY) provided on the palm portion PM. As shown in Figure 14, the robot hand 100 increases the gripping force on the object (workpiece 700) by causing the gripping device GD to wind the gripping wire WR10, thereby moving the first movable positioning worm gear WG1M and the second movable positioning worm gear WG2M away from the finger portion FP.

[0114] This configuration allows for the implementation of a gripping device GD using a simple machine such as a pulley system (a combination of a fixed pulley FY and a movable pulley MP), resulting in a space-saving design for the robot hand 100. Furthermore, this configuration allows for the increased gripping force provided by the first finger portion FP1 and the second finger portion FP2 to be achieved with a single wire (gripping wire WR10).

[0115] Furthermore, the finger portion FP may include a third finger portion FP3, as shown in Figure 2. In this case, the positioning device PD may include a third movable positioning device PD3M, which is positioned on the palm portion PM and controls the posture of the third finger portion FP3. The third movable positioning device PD3M may also have a third movable positioning worm gear WG3M, which is a third movable positioning power transmission mechanism positioned on the palm portion PM, as shown in Figure 3. Furthermore, the intermediate portion of the gripping wire WR10 may be attached to a first movable wire attachment member (first movable pulley MP1) provided on the first movable positioning worm gear WG1M, a second movable wire attachment member (second movable pulley MP2) provided on the second movable positioning worm gear WG2M, a third movable wire attachment member (third movable pulley MP3) provided on the third movable positioning worm gear WG3M, and a plurality of fixed wire attachment members (fixed pulleys FY) provided on the palm portion PM. By winding the gripping wire WR10 onto the gripping device GD, the first movable positioning worm gear WG1M, the second movable positioning worm gear WG2M, and the third movable positioning worm gear WG3M may be moved away from the finger portion FP, thereby increasing the gripping force on the object (workpiece 700).

[0116] This configuration has the effect of increasing the gripping force provided by the first finger portion FP1, the second finger portion FP2, and the third finger portion FP3 using a single wire (gripping wire WR10).

[0117] Furthermore, the finger portion FP may further include a fourth finger portion FP4, as shown in Figure 2. In this case, the positioning device PD may include a fourth movable positioning device PD4M, which is positioned on the palm portion PM and controls the posture of the fourth finger portion FP4. The fourth movable positioning device PD4M may also have a fourth movable positioning worm gear WG4M, which is a fourth movable positioning power transmission mechanism positioned on the palm portion PM, as shown in Figure 3. Furthermore, the intermediate portion of the gripping wire WR10 may be attached to a first movable wire attachment member (first movable pulley MP1) provided on the first movable positioning worm gear WG1M, a second movable wire attachment member (second movable pulley MP2) provided on the second movable positioning worm gear WG2M, a third movable wire attachment member (third movable pulley MP3) provided on the third movable positioning worm gear WG3M, a fourth movable wire attachment member (fourth movable pulley MP4) provided on the fourth movable positioning worm gear WG4M, and a plurality of fixed wire attachment members (fixed pulleys FY) provided on the palm portion PM. Furthermore, by winding the gripping wire WR10 onto the gripping device GD, the first movable positioning worm gear WG1M, the second movable positioning worm gear WG2M, the third movable positioning worm gear WG3M, and the fourth movable positioning worm gear WG4M may be moved away from the finger portion FP, thereby increasing the gripping force on the object (workpiece 700).

[0118] This configuration has the effect of increasing the gripping force provided by the first finger portion FP1 and the second to fourth finger portions FP2 to FP4 using a single wire (gripping wire WR10).

[0119] Furthermore, the worm gear (movable positioning worm gear) may include a worm (movable positioning worm) and a worm wheel (movable positioning worm wheel). In this case, the robot hand 100 may increase the gripping force on the object (workpiece 700) by having the gripping device GD wind the gripping wire WR10, thereby causing the (movable positioning worm wheel) to roll on the worm (movable positioning worm) in a direction away from the finger portion FP. Also, the movable wire attachment member may be a pulley, pin, or ring, etc. Similarly, the fixed wire attachment member may be a pulley, pin, or ring, etc.

[0120] Furthermore, as shown in Figure 2, the robot hand 100 according to the embodiment of this disclosure includes a finger portion FP including a first finger portion FP1 and a second finger portion FP2, a palm portion PM including a first palm portion PM1 on which the first finger portion FP1 is located and a second palm portion PM2 on which the second finger portion FP2 is located, and a swing mechanism that swings the first palm portion PM1 and the second palm portion PM2 relative to each other around a swing axis PX (see Figure 5) located between the first palm portion PM1 and the second palm portion PM2. The device SD (see Figure 5) includes a positioning device PD which includes a first movable positioning device PD1M positioned on the palm PM and controlling the posture of the first finger portion FP1, and a second movable positioning device PD2M positioned on the palm PM and controlling the posture of the second finger portion FP2, and a gripping device GD positioned on the palm PM and controlling the force with which the first finger portion FP1 and the second finger portion FP2 grip an object (workpiece 700). The gripping device GD includes a gripping worm gear WG10 as a gripping power transmission mechanism positioned on the palm PM, and a gripping wire WR10 which has one end fixed to the palm PM and the other end fixed to the gripping worm gear WG10 (gripping worm wheel WH10) and wound up. As shown in Figure 20, the middle portion of the gripping wire WR10 is attached to a first fixed wire attachment member (fixed pulley FY10) that is immovably mounted on the first palm part PM1, a second fixed wire attachment member (fixed pulley FY9) that is immovably mounted on the second palm part PM2, and a swinging wire attachment member (swinging pulley MP30) that is swingable around the swing axis PX. The robot hand 100 then increases the gripping force on the object (workpiece 700) by having the gripping device GD wind the gripping wire WR10, thereby moving the first finger part FP1 and the second finger part FP2 so that the tips of the first finger part FP1 and the second finger part FP2 move closer to each other.

[0121] This configuration has the effect of enabling the gripping device GD and the rocking device SD to operate appropriately. Furthermore, this configuration has the effect of enabling the gripping device GD, which increases the gripping force of multiple finger parts FP including the first finger part FP1 using a single gripping wire WR10, and the rocking device SD, which rocks the first palm part PM1 (first finger part FP1), to operate appropriately. As a result, with this configuration, the robot hand 100 can assume a gripping posture with a greater degree of freedom.

[0122] Furthermore, as shown in Figure 22, the gripping wire WR10 may be arranged such that a third wire portion WP3, located between a first wire portion WP1 that contacts the first fixed wire hanging member (fixed pulley FY10) and a second wire portion WP2 that contacts the second fixed wire hanging member (fixed pulley FY9), contacts the oscillating wire hanging member (oscillating pulley MP30). Also, as shown in Figure 22, the oscillating wire hanging member (oscillating pulley MP30) may be positioned closer to the oscillating axis PX than the first fixed wire hanging member (fixed pulley FY10) and the second fixed wire hanging member (fixed pulley FY9).

[0123] Furthermore, as shown in Figure 4, the first movable positioning device PD1M may include a first movable positioning worm gear WG1M positioned on the first palm portion PM1, and a first movable wire WR1M, one end of which is fixed to the first finger portion FP1 and the other end of which is fixed to and wound up by the first movable positioning worm gear WG1M (first movable positioning worm wheel WH1M). Furthermore, as shown in Figure 3, the second movable positioning device PD2M may include a second movable positioning worm gear WG2M positioned on the second palm portion PM2, and a second movable wire WR2M, one end of which is fixed to the second finger portion FP2 and the other end of which is fixed to and wound up by the second movable positioning worm gear WG2M (second movable positioning worm wheel WH2M). Furthermore, the intermediate portion of the gripping wire WR10 may be attached to a first fixed wire attachment member (fixed pulley FY10), a second fixed wire attachment member (fixed pulley FY9), a first movable wire attachment member (first movable pulley MP1, see Figure 14) provided on the first movable positioning worm gear WG1M, a second movable wire attachment member (second movable pulley MP2, see Figure 14) provided on the second movable positioning worm gear WG2M, and a swinging wire attachment member (swinging pulley MP30), as shown in Figure 22. The robot hand 100 may increase the gripping force on the object (workpiece 700) by having the gripping device GD wind the gripping wire WR10, thereby moving the first movable positioning worm gear WG1M and the second movable positioning worm gear WG2M away from the finger portion FP. Furthermore, the swinging wire hanger, the movable wire hanger, and the fixed wire hanger may each be a pulley, a pin, or a ring, etc.

[0124] This configuration has the effect of suppressing the slack in the gripping wire WR10 when the first palm portion PM1 is swung by the swinging device SD.

[0125] [Control Device] Figure 23 is a block diagram illustrating the configuration of the control device 610 according to this embodiment. In the example shown in Figure 23, the control device 610 includes a picking robot controller 620 and a hand controller 630. This embodiment shows an example in which the picking robot controller 620 and the hand controller 630 are provided as separate controllers, but the functions of the picking robot controller 620 and the hand controller 630 may also be implemented with a single controller that combines them.

[0126] The picking robot controller 620 has the configuration of a computer, for example, having a CPU, ROM, RAM, and a storage unit 621. In the picking robot controller 620, the CPU executes a program stored in the ROM to realize the acquisition unit 622, the workpiece recognition unit 623, the category classification unit 624, the action plan setting unit 625, the gripping pose processing unit 626, the arm control unit 627, the output control unit 628, and the communication unit 629. The storage unit 621 of the picking robot controller 620 stores a category database 621A and a category-grasping pose corresponding database 621B.

[0127] In this embodiment, the picking robot controller 620 controls the robot 110 to move the workpiece to be grasped based on image information acquired from the camera 120. To this end, the picking robot controller 620 classifies the workpiece to be grasped into a category based on the image information and controls the robot hand 100 to grasp the workpiece in a grasping pose corresponding to that category.

[0128] Figure 24 is a diagram illustrating the configuration of the category database 621A according to this embodiment. As shown in Figure 24, the category database 621A stores categories, category record models, and attributes in association with each other. The category database 621A according to this embodiment has eight types of categories for classifying workpieces: rectangular parallelepiped CA1, cylindrical CA2, bag CA3, thin object CA4, complex shape CA5, blister pack CA6, cloth and mesh CA7, and rod CA8. This embodiment does not limit the number of categories for classifying workpieces to eight types; there may be nine or more types, or seven or fewer types.

[0129] Furthermore, in this embodiment, the workpieces may be classified even more finely than categories. For example, the workpieces contained in cylinder CA2 may be classified into one of the following: "wet wipes, canned beverages", "PET bottle beverages, detergent bottles", or "instant noodles". Another example is that the workpieces contained in bag CA3 may be classified into one of the following: "packaged snacks, bread", "retort curry", "packaged beverages, refill packs", "wet wipes", "packaged clothing", or "packaged stationery".

[0130] The category database 621A stores a category record model for each category, used to compare the workpiece with its shape. The category record model represents the general shape of a workpiece classified into that category. The category record model is used to compare the workpiece's shape with the model when classifying the workpiece into a category.

[0131] The category database 621A may store attributes for each category. Attributes are information indicating the properties of the workpieces included in the category, such as "liquid inside," "hollow + solid," or "easily changeable shape."

[0132] Furthermore, the category attributes may also include information regarding the softness of the workpiece, the hardness of the workpiece, the coefficient of friction of the workpiece surface (dynamic friction coefficient, static friction coefficient), information indicating whether the workpiece is easily brought into contact with the finger portion FP of the robot hand 100, and information regarding the fragility of the workpiece.

[0133] The attributes for each category are used, for example, to determine at least one of the following when the robot hand 100 grips a workpiece: gripping pose, gripping position, and gripping force.

[0134] The control device 610 according to this embodiment includes a category database 621A, which allows the workpiece to be gripped to be classified into one of several categories CA1 to CA8. Although there are countless types of workpieces, the control device 610 according to this embodiment can simplify subsequent processing by classifying the workpiece to be gripped into, for example, eight categories CA1 to CA8.

[0135] Figure 25 is a diagram illustrating the configuration of the category-grasp pose database 621B according to this embodiment. As shown in Figure 25, the category-grasp pose database 621B stores the correspondence between categories and grasp poses. In the example shown in Figure 25, for each combination of eight categories and thirteen grasp poses, it indicates whether the workpiece included in that category can be grasped with that grasp pose. Specifically, if a grasp pose can grasp a workpiece included in a category, a "○" is shown in the frame. In other words, the category-grasp pose database 621B makes it possible to select the optimal grasp poses HP1 to HP13 for a workpiece by configuring an 8x13 matrix. This embodiment does not limit the number of grasp poses to 13; there may be 14 or more, or 12 or fewer.

[0136] For example, if the category is a rectangular prism CA1, the robot hand 100 can grasp the workpiece if it is in grasping poses HP3, HP4, HP7, or HP9.

[0137] Furthermore, the category-grasping pose correspondence database 621B makes it possible to associate grasping poses with classifications more detailed than categories. For example, among the cylindrical CA2, "wet wipes, canned beverages" can be grasped if the grasping pose is HP1, HP6-HP8, HP3. Among the cylindrical CA2, "PET bottle beverages, detergent bottles" can be grasped if the grasping pose is HP1, HP7, HP9, HP13. Among the cylindrical CA2, "instant noodles" can be grasped if the grasping pose is HP1, HP7, HP8.

[0138] Similarly, for each category from bag CA3 to rod CA8, we will omit further explanation, assuming that a gripping pose capable of gripping a workpiece is already defined.

[0139] Figure 25 shows an example where there are multiple grasping poses associated with each category, but there may also be an example where there is only one grasping pose associated with a category.

[0140] Furthermore, the control device 610 according to this embodiment includes a category-grasping pose database 621B, which allows for the selection of gripping poses HP1 to HP13 associated with categories CA1 to CA8. Therefore, the control device 610 can appropriately select a gripping pose according to the workpiece classification, or in other words, the shape of the workpiece. Consequently, the control device 610 can reduce the workload required to determine a gripping pose corresponding to the shape of the workpiece.

[0141] The robot hand 100 may add, change, or delete categories CA1 to CA8 stored in the category database 621A. The control device 610 may add, change, or delete grasping poses HP1 to HP13 stored in the grasping pose database 631A. There is no particular limit to the number of categories stored in the category database 621A. Similarly, there is no particular limit to the number of categories stored in the category-grasping pose correspondence database 621B.

[0142] In this embodiment, the case in which the picking robot controller 620 holds a category database 621A and a category-grasp pose database 621B is described, but the embodiment is not limited to this. For example, an external device that can communicate with the picking robot controller 620 may hold the category database 621A and the category-grasp pose database 621B. In this case, the picking robot controller 620 can obtain the category for classifying the workpiece, the grip pose, etc., by querying the external device.

[0143] Returning to Figure 23, the acquisition unit 622 acquires detection results from sensors provided in the robot system 600. For example, the acquisition unit 622 acquires image information from the camera 120 showing the workpiece 700 to be gripped. In this embodiment, the acquisition unit 622 acquires image information showing the workpiece 700 to be gripped as information about the workpiece, but any information that can identify the shape of the workpiece 700 is acceptable. For example, the acquisition unit 622 may acquire LIDAR detection results, etc.

[0144] The workpiece recognition unit 623 recognizes the shape of the workpiece, the position coordinates of the workpiece within the work area, the size of the workpiece, and the orientation of the workpiece from the image information acquired by the acquisition unit 622. Furthermore, the workpiece recognition unit 623 recognizes the surrounding environment of the workpiece.

[0145] By the way, the image information captured by camera 120 is referenced from a single viewpoint, which can make it difficult to grasp the overall shape of the workpiece 700 to be gripped. On the other hand, if there are multiple workpieces of the same type in the work area, the image information captured of the work area often shows the same type of workpiece from different angles.

[0146] Therefore, in this embodiment, when the workpiece recognition unit 623 recognizes that multiple workpieces of the same type are depicted in the image information, it combines the shapes of the multiple workpieces shown in the image information to recognize the overall shape of the workpiece. In this embodiment, the accuracy of workpiece shape recognition by the workpiece recognition unit 623 is improved, and thus the classification accuracy of the category corresponding to the workpiece can be improved. Furthermore, the workpiece recognition unit 623 is not limited to cases where it recognizes that multiple workpieces of the same type are depicted in a single image, but may also perform the same processing when it recognizes that multiple workpieces of the same type are depicted in multiple images. For example, the workpiece recognition unit 623 may perform the same processing when the same type of workpiece is depicted in the previously captured image information and the currently captured image information.

[0147] The category classification unit 624 classifies the workpiece to be gripped into one of eight categories based on the information about the workpiece to be gripped recognized by the workpiece recognition unit 623. The category classification unit 624 may also further classify the workpiece if the category to which the workpiece belongs is further subdivided. For example, when the category classification unit 624 classifies the workpiece into cylindrical CA2, it may classify it into "wet wipes, canned beverages," "PET bottle beverages, detergent bottles," or "instant noodles."

[0148] The category classification unit 624 may use any method to classify a workpiece into a category. In this embodiment, the category classification unit 624 compares the shape of the workpiece recognized by the workpiece recognition unit 623 with the category record model for each category stored in the category database 621A. Then, the category classification unit 624 classifies the workpiece into the category corresponding to the category record model that is closest to the shape of the workpiece based on the comparison results.

[0149] The action plan setting unit 625 includes an approach point setting unit 625A and an auxiliary operation setting unit 625B. The action plan setting unit 625 sets an action plan for moving the workpiece based on information about the workpiece recognized by the workpiece recognition unit 623 and the category classified by the category classification unit.

[0150] The action plan is a plan for having the robot hand 100 perform a task, and includes, for example, a movement path for the robot hand 100 and the actions of the robot hand 100 to assume a gripping position for grasping a workpiece. The movement path for the robot hand 100 includes a path for moving the robot hand 100 to the position for grasping the workpiece, and a path for moving the robot hand 100 to the target position (destination) after grasping the workpiece. In this embodiment, the movement path included in the action plan is the path for moving the workpiece to the target position, but it is not limited to this path. For example, the movement path included in the action plan may be limited to the path for moving the robot hand 100 to the position for grasping the workpiece.

[0151] The action plan setting unit 625 outputs a request to the gripping pose processing unit 626 to determine the movement of the robot hand 100 to assume a gripping pose. The action plan setting unit 625 also outputs information necessary for the gripping pose processing unit 626 to determine the gripping pose. For example, the action plan setting unit 625 outputs the category to which the workpiece is classified, the posture of the workpiece, the position of the workpiece, and the size of the workpiece to the gripping pose processing unit 626. Furthermore, the action plan setting unit 625 outputs surrounding environment information to the gripping pose processing unit 626, which indicates at least one of the areas in which the robot hand 100 can move and areas in which other objects exist, based on the information about the workpiece. Other objects include, for example, at least one of the obstacles present around the workpiece and the walls surrounding the work area.

[0152] The gripping pose processing unit 626 comprises a selection unit 626A and a determination unit 626B, and performs processing to determine the gripping pose of the robot hand 100.

[0153] The selection unit 626A selects a grasping pose corresponding to a classified category based on the correspondence relationships held in the category-grasping pose database 621B. In this embodiment, the selection unit 626A selects one or more grasping poses from the 13 types of grasping poses defined in the category-grasping pose database 621B.

[0154] When multiple gripping poses are selected by the selection unit 626A, the determination unit 626B determines a gripping pose for gripping the workpiece based on at least one of the following: the posture of the workpiece, the position of the workpiece, and the size of the workpiece, from among the gripping poses selected by the selection unit 626A.

[0155] Furthermore, if the gripping pose processing unit 626 has received surrounding environment information from the action plan setting unit 625, the determination unit 626B determines the gripping pose based on the surrounding environment information. For example, if the surrounding environment information indicates that the area in which the robot hand 100 can move is limited by obstacles present around the workpiece, the determination unit 626B determines a gripping pose that allows the workpiece to be gripped even within the limited movable area.

[0156] The method used by the determination unit 626B to determine the grasping pose may be any method, not limited to well-known methods. For example, the grasping pose may be determined using a pre-trained model.

[0157] A trained model, for example, will output one of several grasping poses when given input information such as multiple grasping poses, workpiece orientation, workpiece position, workpiece size, and surrounding environment information. The trained model is trained using machine learning with training data that associates such input information with the grasping pose best suited for grasping. For example, backpropagation training using a neural network may be applied as a machine learning method.

[0158] In this embodiment, the method for determining the gripping pose corresponding to the position of gripping the workpiece and the posture of the workpiece may be any method, not limited to well-known methods.

[0159] Figure 26 is a diagram illustrating the concept of determining the gripping pose in the picking robot controller 620 according to this embodiment.

[0160] As shown in Figure 26, the workpiece recognition unit 623 generates information about the workpiece from the image information acquired by the acquisition unit 622 and outputs it to the category classification unit 624. The information about the workpiece includes, for example, the shape of the workpiece, the position coordinates of the workpiece, the size of the workpiece, the orientation of the workpiece, and information about the surrounding environment.

[0161] The category classification unit 624 then classifies the workpiece into one of eight categories based on the information about the workpiece input from the workpiece recognition unit 623. In the example shown in Figure 26, the workpiece is classified as a "rectangular prism".

[0162] The classification result from the category classification unit 624 is then input to the gripping pose processing unit 626 via the action plan setting unit 625. The selection unit 626A, included in the gripping pose processing unit 626, then refers to the category-grasping pose correspondence database 621B and selects a gripping pose corresponding to "cuboid". Figure 26 shows an example in which gripping poses 2011, 2012, and 2013 corresponding to the "cuboid" workpiece 2001 are selected.

[0163] The determination unit 626B then determines a gripping pose 2012 as the gripping pose for gripping the workpiece 2001, taking into consideration the orientation of the workpiece and surrounding environment information. In the example shown in Figure 26, since the orientation of the "rectangular parallelepiped" is "vertical," a gripping pose 2012 suitable for gripping a "vertical" workpiece is determined.

[0164] Furthermore, the determination unit 626B, taking into account information about the current workpiece and the surrounding environment, determines a gripping pose according to the priority order determined for each gripping pose if there are multiple gripping poses in which the robot hand 100 can grip the workpiece. In this embodiment, since an appropriate gripping pose is determined for the workpiece by taking into account information about the current workpiece and the surrounding environment, the success rate of gripping the workpiece can be improved.

[0165] Returning to Figure 23, the gripping pose processing unit 626 outputs the gripping pose determined by the determination unit 626B to the action plan setting unit 625.

[0166] The action plan setting unit 625 then sets the action plan to include the action of gripping the workpiece in a gripping pose. By setting the action plan in this way, the operation can be set to grip the workpiece in a gripping pose selected from 13 types of gripping poses.

[0167] The approach point setting unit 625A of the action plan setting unit 625 sets the approach point for gripping the workpiece with the gripping pose input by the gripping pose processing unit 626, and the posture of the robot hand 100 at the approach point.

[0168] Figure 27 is a conceptual diagram illustrating the setting of the approach point by the approach point setting unit 625A according to this embodiment. In the example shown in Figure 27, two embodiments are shown: one in which the center point of the robot hand 100 is at a first position 2111 and the workpiece 2101 is grasped from a first posture, and another in which the center point of the robot hand 100 is at a second position 2112 and the workpiece 2101 is grasped from a second posture.

[0169] The first position 2111 is set to be above the workpiece 2101. The posture of the robot hand 100 is set to (θa, θb, θc). In this embodiment, the first posture (θa, θb, θc) is indicated by the rotation angle for each axis of the three-dimensional coordinate system, representing the direction in which the robot hand 100 moves (for example, the direction from the center point at the base of the robot hand 100 to where the third finger portion FP3 is located).

[0170] When the picking robot controller 620 moves the robot hand 100 in direction 2121 from the first position 2111 in orientation (θa, θb, θc), the robot hand 100 makes contact with the workpiece 2101 at position 2122 while tilted relative to it. As shown in Figure 27, it is difficult for the robot hand 100 to stably grasp the workpiece 2101 at position 2122 and orientation (θa, θb, θc).

[0171] In contrast, the second position 2112 is at the same height as the workpiece 2101, and in the second posture (θa1, θb1, θc1), the robot hand 100 is positioned directly in front of the workpiece 2101.

[0172] When the picking robot controller 620 moves the robot hand 100 in direction 2131 from a second position (x1, y1, z1) 2112 to a posture (θa1, θb1, θc1), the robot hand 100 is facing the workpiece 2101 and is able to grasp the workpiece 2101 at a third position (x2, y2, z3) 2132. At the third position 2132 and posture (θa1, θb1, θc1), the robot hand 100 can grasp the workpiece 2101 in a stable state.

[0173] In other words, for the robot hand 100 to grip the workpiece in a stable state, the approach points that the robot hand 100 passes through before gripping the workpiece are important. Therefore, the approach point setting unit 625A according to this embodiment sets an approach point for gripping the workpiece in a determined gripping pose, and the posture of the robot hand 100 at the approach point, based on the posture and position of the workpiece. Any known method can be used for setting the approach point and posture, as long as it can be set to a position where it is easy to grip the workpiece in the determined gripping pose.

[0174] Furthermore, the approach point setting unit 625A sets the approach point based on surrounding environment information, taking into account the area in which the robot hand 100 can move so as to avoid objects present around the workpiece.

[0175] Returning to Figure 23, the auxiliary action setting unit 625B of the action plan setting unit 625 sets an auxiliary action based on at least one of the workpiece's posture and the workpiece's position when the robot hand 100 requires a prior action to grasp the workpiece. The setting of the auxiliary action is not limited to at least one of the workpiece's posture and the workpiece's position, and whether or not to perform the auxiliary action may be determined based on at least one of the workpiece's category, grasping pose, workpiece position, workpiece posture, and the workpiece's surrounding environment.

[0176] Auxiliary actions are actions performed before the robot hand grasps the workpiece, and include, for example, actions to move the workpiece to a position that makes it easier to grasp, actions to move the workpiece to change its orientation to make it easier to grasp, and actions to change the position of obstacles (including workpieces that are not the target of grasping) that would hinder the grasping of the workpiece.

[0177] Figure 28 is a conceptual diagram showing an example of an auxiliary operation set by the auxiliary operation setting unit 625B according to this embodiment. In the example shown in Figure 28, the workpiece 2211 is located at adjacent positions 2211A on walls 2202 and 2203 of the work area 2201. In this case, it is difficult for the robot hand 100 to grasp the workpiece 2211.

[0178] Therefore, the auxiliary operation setting unit 625B sets an auxiliary operation to shift the workpiece 2211 from position 2211A to position 2211B. Each finger FP of the robot hand 100 is provided with a suction mechanism. Thus, with any finger FP of the robot hand 100 in contact with the upper part of the workpiece 2211, the picking robot controller 620 controls the movement of the robot hand 100 to pull out the workpiece 2211, thereby shifting the workpiece 2211 to position 2211B. After that, the picking robot controller 620 and the hand controller 630 are controlled to grasp the workpiece in the grasping pose determined by the grasping pose processing unit 626.

[0179] Next, the types of auxiliary operations will be explained. Figure 29 is a diagram showing a list of auxiliary operations that can be set by the auxiliary operation setting unit 625B according to this embodiment. In the example shown in Figure 29, the auxiliary operation setting unit 625B sets an auxiliary operation when the information regarding the workpiece recognized by the workpiece recognition unit 623 satisfies the conditions for the auxiliary operation.

[0180] In the example shown in Figure 29, the type of auxiliary operation, the change in the workpiece, and the operation are associated with each auxiliary operation condition. The auxiliary operation setting unit 625B sets the operation associated with the auxiliary operation condition as an auxiliary operation when the auxiliary operation condition is met. In the example shown in Figure 29, the conditions for executing the auxiliary operation are "when picking up a thin workpiece," "when picking up densely packed workpieces," and "when there is a workpiece at the edge of the container," but other conditions may also be used as conditions for executing the auxiliary operation.

[0181] Auxiliary actions are movements performed by the robot hand 100 to facilitate gripping the workpiece. When the robot hand 100 performs a set auxiliary action, at least one of the following changes occurs: the position of the workpiece or the orientation of the workpiece. Examples of workpiece changes include the workpiece changing from a horizontal to a vertical position, being shifted, or being tilted.

[0182] In this way, the action plan setting unit 625 sets an action plan based on information about the workpiece, including, if necessary, auxiliary actions to move the robot hand 100 to a position where it can grasp the workpiece before grasping it.

[0183] Furthermore, the action plan setting unit 625 sets the action plan so as to grip the workpiece after at least one of the workpiece's position or orientation has changed due to an auxiliary operation. Therefore, the control device 610 according to this embodiment can easily grip a workpiece by performing an auxiliary operation, even in situations where it is difficult to grip the workpiece.

[0184] Returning to Figure 23, the action plan setting unit 625 sets an action plan based on the gripping pose input by the gripping pose processing unit 626 and the category attributes. For example, the action plan setting unit 625 takes the category attributes into consideration and sets the actions of the robot hand 100 when it grips. The settings related to the actions include the target gripping force when gripping the workpiece. Note that various settings are possible for setting the action plan based on the category attributes, depending on the embodiment. If the attribute is "hollow + solid", the action plan setting unit 625 may set the gripping position of the robot hand 100 so as to grip the center of gravity of the solid inside the workpiece.

[0185] The arm control unit 627 controls the movement of the robot 110 according to the action plan set in the action plan setting unit 625. For example, the arm control unit 627 is an example of a control unit that controls the actuator 110A that drives the arm of the robot 110 so that the robot hand 100 moves along the movement path included in the action plan.

[0186] In this way, the arm control unit 627 drives the arm of the robot 110. Since the arm of the robot 110 is connected to the robot hand 100, the workpiece can be moved when the robot hand 100 is gripping the workpiece.

[0187] The output control unit 628 controls the output of information to the external device 650. The external device 650 can be any device located outside the control unit 610, such as a lamp to indicate an abnormality, or a communication terminal owned by the operator controlling the robot 110. For example, if the external device 650 is a lamp, the output control unit 628 controls the lamp to turn on when it detects an abnormality.

[0188] The communication unit 629 transmits and receives information to and from the hand controller 630. For example, the communication unit 629 transmits an instruction to the hand controller 630 to move the robot hand 100 into a gripping pose according to the action plan set in the action plan setting unit 625. The instruction to be transmitted may include, for example, the gripping pose and the target gripping force when gripping in that gripping pose.

[0189] Furthermore, the communication unit 629 receives a notification that an abnormality has occurred when the hand controller 630 detects an abnormality. In this case, the output control unit 628 outputs a notification that an abnormality has occurred to the external device 650.

[0190] The hand controller 630 controls the robot hand 100 according to instructions from the picking robot controller 620. The hand controller 630 has the configuration of a computer, for example, having a CPU, ROM, RAM, and a storage unit 631. In the hand controller 630, the CPU executes a program stored in the ROM to realize the communication unit 632, the hand control unit 633, the acquisition unit 634, and the determination unit 635. The storage unit 631 of the hand controller 630 stores the grasping pose database 631A.

[0191] As described above, the hand controller 630 is electrically connected to a plurality of force detection sensors SG. The plurality of force detection sensors SG include force detection sensors SG1 to SG4. The first force detection sensor SG1 detects the force (strain) acting on the first finger portion FP1. The second force detection sensor SG2 detects the force (strain) acting on the second finger portion FP2. The third force detection sensor SG3 detects the force (strain) acting on the third finger portion FP3. The fourth force detection sensor SG4 detects the force (strain) acting on the fourth finger portion FP4. When force detection sensors SG1 to SG4 are not distinguished, they are referred to simply as force detection sensors SG. The signals output from the force detection sensors SG are input to the hand controller 630. An amplifier to amplify the signals may also be provided between the hand controller 630 and the force detection sensors SG.

[0192] The hand controller 630 is electrically connected to a plurality of positioning motors MT1 to MT4, an oscillating motor MT20, and a gripping motor MT10. The plurality of positioning motors MT1 to MT4 include positioning motors MT1F, MT1M, MT2F, MT2M, MT3F, MT3M, MT4F, and MT4M. Positioning motors MT1F and MT1M are drive sources for driving the first finger portion FP1. Positioning motors MT2F and MT2M are drive sources for driving the second finger portion FP2. Positioning motors MT3F and MT3M are drive sources for driving the third finger portion FP3. Positioning motors MT4F and MT4M are drive sources for driving the fourth finger portion FP4. The oscillating motor MT20 oscillates the first palm portion PM1 that supports the first finger portion FP1. The gripping motor MT10 is a power source for increasing the gripping force provided by the first finger portion FP1 to the fourth finger portion FP4.

[0193] The hand controller 630 may incorporate motor drivers for driving a plurality of positioning motors MT1 to MT4, a swing motor MT20, and a gripping motor MT10. A motor driver may be provided for each of the positioning motors MT1 to MT4, the swing motor MT20, and the gripping motor MT10. The motor driver may be implemented, for example, by executing a program stored in the memory unit 631.

[0194] Figure 30 shows an example of the gripping pose database 631A according to this embodiment. As shown in Figure 30, the gripping pose database 631A stores parameters for gripping in each of the 13 types of gripping poses that the robot hand 100 can grip. In the example shown in Figure 30, the parameters for performing a gripping pose are stored in association with the gripping position (for gripping the workpiece in the gripping pose), the arrangement of the first finger (thumb), the number of fingers required (to perform the gripping pose), the action (for taking the gripping pose), and the degree of flexion of each joint (for taking the gripping pose). The gripping position is, for example, the position coordinates of the center point when gripping the workpiece. The arrangement of the first finger (thumb) is, for example, the arrangement of the first palm part PM1 that is oscillated by the oscillating motor MT20. Note that this embodiment shows an example of parameters for performing an action to take a gripping pose, and any parameters that enable taking a gripping pose may be used. Next, the gripping poses will be described.

[0195] Figures 31A to 31D, 32A to 32D, 33A to 33C, 34A to 34B, 35A to 35C, 36A to 36D, and 37A to 37C are explanatory diagrams showing the grasping pose of the robot hand 100 controlled by the hand controller 630 according to this embodiment.

[0196] Figures 31A and 31B show the gripping pose HP1. The gripping pose HP1 may be, for example, a pose in which the first finger portion FP1 does not reach the other finger portions (second finger portion FP2, third finger portion FP3, and fourth finger portion FP4). The gripping pose HP1 is used, for example, when gripping a workpiece having a cylindrical shape.

[0197] In the gripping pose HP1 shown in Figure 31A, the workpiece to be gripped is a plastic bottle. The robot hand 100 grips the cylindrical body of the workpiece 701 from the side.

[0198] In the gripping pose HP1 shown in Figure 31B, the workpiece to be gripped is an example where the workpiece is a spray bottle. The robot hand 100 grips the cylindrical body of the workpiece 702 from the side. In gripping pose HP1, the body of the workpiece 702 with the larger outer diameter may also be gripped.

[0199] Figures 31C and 31D show the grasping pose HP2. The grasping pose HP2 may be, for example, a pose in which the first finger FP1 reaches one or more of the other second finger FP2, third finger FP3, and fourth finger FP4, but does not make contact with them.

[0200] In the gripping pose HP2 shown in Figure 31C, the workpiece to be gripped is a spray bottle. The robot hand 100 grips the upper part of the body and the shoulder of the workpiece 702 from the side. The shoulder of the workpiece 702 is positioned above the body and may be a part with a smaller outer diameter than the body. In the gripping pose HP2, the first finger portion FP1 and the second finger portion FP2 may be positioned so as to rest on the shoulder, which has a smaller outer diameter than the body.

[0201] In the gripping pose HP2 shown in Figure 31D, the workpiece to be gripped is an example where it is a brush. The robot hand 100 grips the rod-shaped portion of the workpiece 703 from the side.

[0202] Figures 32A, 32B, and 32C show gripping poses HP3 and HP4. Grasping poses HP3 and HP4 may be, for example, gripping poses with the first finger portion FP1 and two or more of the other second finger portion FP2, third finger portion FP3, and fourth finger portion FP4. The difference between gripping poses HP3 and HP4 is, for example, whether the finger portion FP that contacts the workpiece is the tip or the pad. Grasping poses HP3 and HP4 include, for example, forms for gripping workpieces 704 to 706 which are boxes, blister packs, or bags.

[0203] In the gripping pose HP3 shown in Figure 32A, the workpiece 704 to be gripped is an example where it is a box. In gripping pose HP3, the robot hand 100 grips the body of the workpiece 704 from the side.

[0204] In the gripping pose HP4 shown in Figure 32B, the workpiece 705 to be gripped is an example where it is in a blister pack. A blister pack is used to package, for example, a rod-shaped stationery item, and includes a backing card, the rod-shaped product contained within, and a transparent packaging material to enclose them. The blister has protruding parts that correspond to the shape of the contained item.

[0205] In the gripping pose HP4 shown in Figure 32C, the workpiece 706 to be gripped is an example where the workpiece is a bag. The bag is a bag that contains contents such as liquid, powder, or solid material. The bag has a part that contains the contents and a sheet-like part with a closed opening. In gripping pose HP4, the robot hand 100 grips the sheet-like part of the workpiece 706 with its protruding portion.

[0206] Figure 32D shows a gripping pose HP5. The gripping pose HP5 may be, for example, a pose in which a circular workpiece is gripped by multiple finger portions FP along the circle, and the base body 10 corresponding to the palm contacts the workpiece. The gripping pose HP5 includes, for example, a form for gripping a workpiece 707 which is a cup noodle.

[0207] In the gripping pose HP5 shown in Figure 32D, the workpiece 707 to be gripped is an example of instant cup noodles. The workpiece 707 has a cylindrical body, and the outer diameter of the upper part of the body may be larger than the outer diameter of the lower part. The workpiece 707, which is instant cup noodles, has a cup-shaped container for holding the noodles and a sheet-like lid for closing the opening of the container.

[0208] In gripping pose HP5, the robot hand 100 grips the body of the workpiece 707 from above.

[0209] Figures 33A, 33B, and 33C show the gripping pose HP6. The gripping pose HP6 may be, for example, a pose in which the four finger portions FP conform to the shape of the workpiece, and the palm portion PM corresponding to the palm of the hand makes contact with the workpiece. The gripping pose HP6 includes, for example, a form for gripping workpieces 708, 701, and 709, which are spray bottles, PET bottles, cans, or towels.

[0210] In the gripping pose HP6 shown in Figure 33A, the workpiece 708 to be gripped is an example where the workpiece is a spray bottle. In gripping pose HP6, the robot hand 100 grips the upper part of the workpiece 708 from above. The spray bottle includes a cylindrical body that contains liquid and a handle attached to the top of the body. In gripping pose HP6, the robot hand may also grip the handle on the top of the workpiece 708 from above. The handle may include, for example, a grip, a nozzle, or a lever.

[0211] In the gripping pose HP6 shown in Figure 33B, the workpiece 708 to be gripped is an example where the workpiece is a plastic bottle. In the plastic bottle shown in Figure 33B, the cap is positioned at the bottom and the bottom of the cylindrical container is positioned at the top. In gripping pose HP6, the robot hand 100 grips the bottom of the body of the workpiece 701 from above. The bottom of the workpiece 701 may be in contact with the palm portion PM of the robot hand 100, which corresponds to the palm of the hand.

[0212] In the gripping pose HP6 shown in Figure 33C, the workpiece 709 to be gripped is an example where it is a towel. The towel shown in Figure 33C is in a folded state and may be a three-layered stack. In gripping pose HP6, the robot hand 100 grips the workpiece 709 from above.

[0213] Figures 34A and 34B show the gripping pose HP7. The gripping pose HP7 may be, for example, a pose in which a circular workpiece is gripped by multiple finger portions FP along the circle, while the palm portion PM corresponding to the palm does not come into contact with the workpiece. The gripping pose HP7 includes forms for gripping workpieces 701 and 707, which are PET bottles or instant noodle cups.

[0214] In the gripping pose HP7 shown in Figure 34A, the workpiece 701 to be gripped is an example where the workpiece is a plastic bottle. In the plastic bottle shown in Figure 34A, the cap is positioned at the bottom and the bottom of the cylindrical container is positioned at the top. In gripping pose HP7, the robot hand 100 grips the bottom of the body of the workpiece 701 from above. The bottom of the workpiece 701 is not in contact with the palm portion PM of the robot hand 100, which corresponds to the palm of the hand. In gripping pose HP7, a gap is formed between the palm portion PM and the workpiece 701.

[0215] In the gripping pose HP7 shown in Figure 34B, the workpiece 707 to be gripped is an example where it is a cup noodle. In gripping pose HP7, the robot hand 100 grips the body of the workpiece 707 from above. The lid of the workpiece 707 is not in contact with the palm portion PM corresponding to the palm of the robot hand 100. In gripping pose HP7, a gap is formed between the palm portion PM and the workpiece 701.

[0216] Figures 35A, 35B, and 35C show the gripping pose HP8. The gripping pose HP8 may be, for example, a pose in which the four finger portions FP conform to the shape of the workpiece, and the palm portion PM corresponding to the palm does not come into contact with the workpiece. The gripping pose HP8 includes, for example, a form for gripping workpieces 710, 705, and 709, which are thin plate-shaped boxes, blister packs, or towels.

[0217] In the gripping pose HP8 shown in Figure 35A, the workpiece 710 to be gripped is an example where it is a thin plate-shaped box. In gripping pose HP8, the robot hand 100 grips the workpiece 710 from above.

[0218] In the gripping pose HP8 shown in Figure 35B, the workpiece 705 to be gripped is an example where it is in a blister pack. In gripping pose HP8, the robot hand 100 grips the workpiece 705 from above. In Figure 35B, the blister pack is positioned so that the thickness direction of the cardboard backing is aligned with the vertical direction.

[0219] In the gripping pose HP8 shown in Figure 35C, the workpiece 709 to be gripped is an example where the workpiece is a towel. The towel shown in Figure 35C is in a folded state and may be a three-layer laminate. In gripping pose HP8, the robot hand 100 grips the workpiece 709 by sandwiching it in the thickness direction. The first finger portion FP1 is positioned on the underside of the workpiece 709, while the remaining second finger portion FP2, third finger portion FP3, and fourth finger portion FP4 are positioned on the upper side of the workpiece 709.

[0220] Figures 36A, 36B, and 36C show the gripping pose HP9. The gripping pose HP9 may be, for example, a pose in which the workpiece is gripped with three finger portions FP. The gripping pose HP9 includes, for example, a form for gripping workpieces 711, 701, and 708 which are vertically oriented boxes, PET bottles, or spray bottles.

[0221] In the gripping pose HP9 shown in Figure 36A, the workpiece 711 to be gripped is an example where the workpiece is a vertically elongated box. In gripping pose HP9, the robot hand 100 grips the workpiece 711 from above. In gripping pose HP9, the workpiece 711 is gripped using three fingers: the first finger FP1, the second finger FP2, and the third finger FP3.

[0222] In the gripping pose HP9 shown in Figure 36B, the workpiece 701 to be gripped is an example where the workpiece is a plastic bottle. In gripping pose HP9, the robot hand 100 grips the cap portion of the plastic bottle from above. In gripping pose HP9, the workpiece 701 is gripped using the three fingers: the first finger FP1, the second finger FP2, and the third finger FP3.

[0223] In the gripping pose HP9 shown in Figure 36C, the workpiece 701 to be gripped is an example where it is a spray bottle. In gripping pose HP9, the robot hand 100 may grip the handle on the top of the workpiece 708 from above. In gripping pose HP9, the workpiece 708 is gripped using the three fingers: the first finger FP1, the second finger FP2, and the third finger FP3.

[0224] Figure 36D shows a gripping pose HP10. The gripping pose HP10 may be, for example, a gripping pose in which the side surface of the second finger portion FP2 is in contact with the workpiece. The gripping pose HP10 includes, for example, a form for gripping a workpiece 712 which is a bag or film. The bag may be, for example, a pouch container for retort food or detergent. The bag may also be, for example, a bag-shaped container for containing multiple products.

[0225] In the gripping pose HP10 shown in Figure 36D, the workpiece 712 to be gripped is an example where it is a bag. In gripping pose HP10, the robot hand 100 grips the workpiece 712 from above. In gripping pose HP9, the workpiece 711 is gripped by the first finger portion FP1 and the second finger portion FP2. The side surface of the second finger portion FP2 may be in contact with the workpiece 712.

[0226] Figure 37A shows a gripping pose HP11. The gripping pose HP11 may be, for example, a pose in which the workpiece is gripped with the tips of multiple finger portions FP. The gripping pose HP11 includes, for example, a form in which a workpiece 710, which is a thin plate-shaped box, is gripped.

[0227] In the gripping pose HP11 shown in Figure 37A, the workpiece 710 to be gripped is an example where the workpiece is a thin plate-shaped box. In gripping pose HP11, the robot hand 100 grips the workpiece 710 in the thickness direction. The first finger portion FP1 is positioned on the upper side of the workpiece 710, while the remaining second finger portion FP2, third finger portion FP3, and fourth finger portion FP4 are positioned on the lower side of the workpiece 710. In gripping pose HP11, the tip of the finger portion FP grips the workpiece 710.

[0228] Figure 37B shows a gripping pose HP12. The gripping pose HP12 may be, for example, a pose in which the workpiece is gripped so that each of the four finger portions FP is aligned with the surface of the workpiece. The gripping pose HP12 includes a form for gripping a workpiece 712 which is a bag.

[0229] In the gripping pose HP12 shown in Figure 37B, the workpiece 712 to be gripped is an example where it is a bag. In gripping pose HP12, the robot hand 100 grips the workpiece 712 from above. In gripping pose HP12, all the fingers may be arranged, for example, along the vertical direction. The first finger FP1 may be arranged along the back of the workpiece 712, while the remaining second finger FP2, third finger FP3, and fourth finger FP4 may be arranged along the front of the workpiece 712.

[0230] Figure 37C shows a gripping pose HP13. The gripping pose HP13 may be, for example, a pose in which the workpiece is gripped so that the side surface of the third finger portion FP3 is in contact with the workpiece. The gripping pose HP13 includes, for example, a form in which a workpiece 701, which is a PET bottle, is gripped.

[0231] In the gripping pose HP13 shown in Figure 37C, the workpiece 701 to be gripped is an example where the workpiece is a plastic bottle. In gripping pose HP13, the robot hand 100 grips the cap portion of the plastic bottle from above. In gripping pose HP13, the workpiece 701 is gripped using the three fingers: the first finger FP1, the second finger FP2, and the third finger FP3. In gripping pose HP13, the side surface of the third finger FP3 is in contact with the workpiece 701.

[0232] Returning to Figure 23, the communication unit 632 sends and receives information with the picking robot controller 620. For example, the communication unit 632 receives an instruction from the picking robot controller 620 to move the robot hand 100 into a gripping position. The received instruction may include, for example, the gripping position and the target gripping force when gripping in that gripping position.

[0233] The hand control unit 633 controls the robot hand 100 to operate according to the instructions received by the communication unit 632. This enables the hand control unit 633 to control the robot hand 100 in accordance with the action plan.

[0234] The robot hand 100 according to this embodiment operates using positioning motors MT1 to MT4, a gripping motor MT10, and a rocking motor MT20. Therefore, the hand control unit 633 controls the positioning motors MT1 to MT4 (including the first fixed motor MT1 and the first movable motor MT1M) as first fixed positioning actuators, the gripping motor MT10, and the rocking motor MT20.

[0235] The acquisition unit 634 acquires detection results from sensors provided on the robot hand 100, which has wires WR1 to WR4 that drive each of the multiple finger parts FP by transmitting power generated from each of the positioning motors MT1 to MT4 and the gripping motor MT10. For example, the acquisition unit 634 is an example of a second acquisition unit, and acquires a signal indicating the detection result of the force applied to the robot hand 100 from a force detection sensor SG attached to the robot hand 100.

[0236] The determination unit 635 determines the current state of the robot hand 100 based on the force detection result from the force detection sensor SG.

[0237] The force detection sensor SG is a sensor capable of detecting force when a force is applied to the finger portion FP of the robot hand 100. Therefore, the determination unit 635 can determine the state of the finger portion FP based on the signal from the force detection sensor SG. Based on the signal from the force detection sensor SG, the determination unit 635 can determine the state of the finger portion FP, such as contact with the workpiece at any part of the finger portion FP, the gripping force generated by the finger portion FP, or whether the gripped workpiece has fallen.

[0238] For example, the hand control unit 633 is an example of a second control unit, and in order to grasp a workpiece, it starts control to move at least one of the multiple finger portions FP of the robot hand 100 so that it can grasp the workpiece in a grasping pose indicated by an instruction received by the communication unit 632, using positioning motors MT1 to MT4.

[0239] Then, after control by the hand control unit 633 is initiated, the determination unit 635 determines whether or not the robot hand 100 has come into contact with the workpiece based on the change in the signal (force detection result) obtained from the force detection sensor SG.

[0240] When the determination unit 635 determines that the finger portion FP of the robot hand 100 has come into contact with the workpiece, the hand control unit 633 starts control to change the gripping force output from the actuator compared to before the contact was determined. In this embodiment, when the hand control unit 633 determines that the finger portion FP of the robot hand 100 has come into contact with the workpiece, it starts control of the gripping motor MT10 to increase the gripping force.

[0241] As described above, the hand control unit 633 in this embodiment uses positioning motors MT1 to MT4 to control the operation of at least one of the multiple finger portions FP corresponding to the gripping pose until it is determined that the finger portions FP of the robot hand 100 have made contact with the workpiece. The hand control unit 633 also uses the oscillating motor MT20 to control the relative oscillating of the first palm portion PM1 and the second palm portion PM2 in advance to achieve the gripping pose. When the determination unit 635 determines that the finger portions FP of the robot hand 100 have made contact with the workpiece, the hand control unit 633 starts driving the gripping motor MT10 and starts control to increase the gripping force on the workpiece. Although this embodiment describes an example in which control is performed to increase the gripping force on the workpiece after the robot hand 100 has made contact with the workpiece, the control is not limited to increasing the gripping force on the workpiece. Depending on the shape or material of the workpiece, it is also possible that the hand control unit 633 may perform control to reduce the gripping force of the workpiece after the robot hand 100 has made contact with the workpiece.

[0242] After control of the gripping motor MT10 is started, the determination unit 635 determines whether the gripping force of the robot hand 100 has reached the target gripping force based on the change in the signal (force detection result) obtained from the force detection sensor SG.

[0243] In this embodiment, the hand control unit 633 stops controlling the gripping motor MT10 after starting control of the gripping force motor, if the determination unit 635 determines that the gripping force of the robot hand 100 has reached the target gripping force. In other words, when the change in the signal acquired from the force detection sensor SG satisfies the condition that the target gripping force has been reached, the hand control unit 633 stops controlling the force that grips the workpiece. Note that in this embodiment, the condition for stopping the control that changes the force that grips the workpiece is not limited to when the target gripping force has been reached, but any condition that allows the robot hand 100 to determine that it has gripped the workpiece is acceptable.

[0244] The control by the hand controller 630 according to this embodiment is not limited to operating the positioning motors MT1 to MT4 before operating the gripping motor MT10. For example, if the workpiece is a light object such as an envelope, the robot hand 100 can grip the workpiece without operating the gripping motor MT10.

[0245] For example, if the determination unit 635 determines that the finger portion FP of the robot hand 100 has come into contact with the workpiece, the hand control unit 633 considers the workpiece to be grasped and stops the control of the finger portion FP of the robot hand. Subsequently, the picking robot controller 620 controls the robot 110 to move the workpiece. Whether or not the hand control unit 633 operates the gripping motor MT10 is switched according to instructions from the picking robot controller 620. For example, the hand control unit 633 may switch whether or not to operate the gripping motor MT10 according to the target gripping force input from the picking robot controller 620.

[0246] Furthermore, the determination unit 635 also determines whether or not the workpiece has fallen from the robot hand 100 after the robot hand 100 has started moving the workpiece. While the arm control unit 627 is moving the workpiece with the robot 110, the determination unit 635 determines whether or not the force detected by the force detection sensor SG has fallen below a drop threshold (an example of a predetermined standard). If the determination unit 635 determines that the force detected by the force detection sensor SG has fallen below the drop threshold, the communication unit 632 notifies the picking robot controller 620 that the force has fallen below the drop threshold. In this embodiment, the case in which a drop threshold is used as a predetermined standard for determining whether or not the workpiece has fallen will be described. However, this embodiment is not limited to the example in which a drop threshold is used as a predetermined standard, and any standard that can detect a change in gripping force may be used.

[0247] Then, when the communication unit 629 of the picking robot controller 620 receives a signal that the weight has fallen below a fall threshold, the arm control unit 627 stops the movement of the robot arm 110. In this embodiment, an example of stopping the movement of the arm is described, but it is not limited to stopping the movement of the arm; it may also be reduced in the movement speed of the arm, etc. In other words, in this embodiment, when the robot 110 is gripping a workpiece, if the force indicated by the signal acquired by the acquisition unit 634 changes by more than a predetermined standard, the arm control unit 627 suppresses the movement of the robot arm 110, assuming that the workpiece has fallen.

[0248] Furthermore, the determination unit 635 determines whether or not the mechanisms within the robot hand 100 are deteriorating. For example, the wires WR1 to WR4, which drive each of the multiple finger parts FP by transmitting power generated from the positioning motors MT1 to MT4 within the robot hand 100, tend to stretch when they deteriorate. Also, if the torsion springs provided in the joints to return each of the multiple finger parts FP to its open state deteriorate, they will no longer return to their original state, a phenomenon known as "sagging."

[0249] The determination unit 635 then compares the signal acquired from the force detection sensor SG with a predetermined value for diagnosing deterioration while the robot hand 100 is in a predetermined pose, thereby determining whether or not the components of the robot hand 100 (for example, at least one of the wires WR1 to WR4 and the torsion spring) have deteriorated. The communication unit 632 then transmits the determination result to the picking robot controller 620. The predetermined pose is a pose determined for diagnosing deterioration. For example, the pose for detecting deterioration of wires WR1 to WR4 is a state in which all of the multiple finger parts FP of the robot hand 100 are open, and the pose for detecting deterioration of the torsion spring may include the movement from a state in which all of the finger parts FP of the robot hand 100 are gripped to a state in which all of the finger parts FP are open. The predetermined value for diagnosing deterioration is a value determined according to the respective characteristics of the wires WR1 to WR4 and the torsion spring to be diagnosed.

[0250] The output control unit 628 of the picking robot controller 620 then outputs information to the external device 650 indicating the degree of fatigue of at least one of the wires WR1 to WR4 and the torsion spring, based on the determination result.

[0251] Furthermore, if the determination unit 635 determines that the workpiece has fallen from the robot hand 100, it may store the position where the robot hand 100 was gripping the workpiece at the time of the fall, the gripping pose, the workpiece category, the target gripping force, and image information of the workpiece in the storage unit 621 as history.

[0252] Furthermore, machine learning may be performed using the information stored as history as training data. For example, the trained model used by the decision unit 626B to determine the grasping pose may be retrained using the training data. Retraining of the trained model may be performed by the picking robot controller 620, or by a cloud server connected to the picking robot controller 620. By retraining the trained model used to determine the grasping pose, the accuracy of determining the grasping pose can be improved.

[0253] [Processing Procedure] Next, the processing procedure for the control device 610 according to this embodiment to move the workpiece will be described. Figure 38 is a flowchart showing the processing procedure for moving the workpiece in the control device 610 according to this embodiment.

[0254] First, the acquisition unit 622 acquires image information of the work area from the camera 120 (S2301).

[0255] Next, the workpiece recognition unit 623 recognizes information about the workpiece captured in the acquired image information (S2302). This information includes, for example, the shape of the workpiece, the position coordinates of the workpiece within the work area, the size of the workpiece, the orientation of the workpiece, and information about the surrounding environment of the workpiece.

[0256] Then, the category classification unit 624 classifies the workpiece to be gripped into a category based on the information about the workpiece (S2303).

[0257] The action plan setting unit 625 instructs the gripping pose processing unit 626 to determine the gripping pose, and the selection unit 626A of the gripping pose processing unit 626 refers to the category-grasping pose correspondence database 621B and selects a gripping pose corresponding to the category (S2304).

[0258] The determination unit 626B of the gripping pose processing unit 626 determines a gripping pose based on one of the following: the posture of the workpiece or information about the surrounding environment (S2305).

[0259] Then, the approach point setting unit 625A of the action plan setting unit 625 sets the approach point and the posture of the robot hand 100 corresponding to the grasping pose, and the auxiliary action setting unit 625B sets auxiliary actions as needed (S2306).

[0260] The action plan setting unit 625 sets an action plan to move the workpiece to the target position based on at least one of the following: the gripping pose, the approach point, the posture of the robot hand 100 at the approach point, and auxiliary movements (S2307).

[0261] The arm control unit 627 and the hand control unit 633 control the robot 110 (including the arm) and the robot hand 100 respectively according to the action plan (S2308).

[0262] The arm control unit 627 determines whether the robot 110 has reached a designated position specified in the action plan (S2309). If it determines that the robot has not reached a designated position specified in the action plan (S2309: NO), the determination unit 635 determines whether the detection result of the force detection sensor SG is below the fall threshold (S2310).

[0263] If the determination unit 635 determines that the detection result is greater than the fall threshold (S2310: NO), it determines whether or not an abnormality has occurred in the system control (S2312). If the determination unit 635 determines that an abnormality has occurred in the system control (S2312: YES), the communication unit 632 of the hand controller 630 notifies the picking robot controller 620 that an abnormality has occurred in the system control. Then, the arm control unit 627 of the picking robot controller 620 stops the movement of the robot 110 (S2311), and the process ends.

[0264] On the other hand, if the determination unit 635 determines that no abnormality has occurred in the system control (S2312: NO), it estimates the current situation to be due to external factors such as the surrounding environment and proceeds with processing again from S2308. The predetermined position of the robot 110 is a position predetermined as a reference for recognizing the current position of the robot 110.

[0265] On the other hand, if the determination unit 635 determines that the detection result of the force detection sensor SG is below the fall threshold (S2310: YES), the communication unit 632 of the hand controller 630 notifies the picking robot controller 620 that the fall threshold has been exceeded. Then, the arm control unit 627 of the picking robot controller 620 stops the movement of the robot 110 (S2311), and the process ends.

[0266] In S2309, if the arm control unit 627 determines that the robot 110 has reached a designated position specified in the action plan (S2309: YES), it determines whether the designated position is the target position to which the robot 110 will move (S2313). If the arm control unit 627 determines that it is the target position (S2313: YES), it terminates the process.

[0267] If the arm control unit 627 determines that the specified position is not the target position to which the robot 110 will move (S2313: NO), it determines whether or not it is the starting position for the auxiliary operation (S2314). If it determines that it is the starting position for the auxiliary operation (S2314: YES), the arm control unit 627 and the hand control unit 633 control the robot 110 and the robot hand 100 according to the set auxiliary operation (S2315), and then process again from S2308.

[0268] On the other hand, if the arm control unit 627 determines that it is not the starting position for the auxiliary movement (S2314: NO), it determines whether it is an approach point or not (S2316). If it determines that it is an approach point (S2316: YES), the arm control unit 627 and the hand control unit 633 control the robot 110 and the robot hand 100 so that the robot hand 100 moves in a position where it can grasp the workpiece, according to the set auxiliary movement (S2317), and the process resumes from S2308.

[0269] On the other hand, if the arm control unit 627 determines that it is not an approach point (S2316: NO), it determines whether it is the starting position for the gripping operation (S2318). If it determines that it is the starting position for the gripping operation (S2318: YES), the arm control unit 627 and the hand control unit 633 perform a gripping operation to grip the workpiece (S2319), and the process resumes from S2308. The specific gripping operation will be described later.

[0270] On the other hand, if the arm control unit 627 determines that it is not the starting position for the gripping operation (S2318: NO), it performs the processing corresponding to that position (S2320) and then resumes processing from S2308.

[0271] The control device 610 according to this embodiment can move the workpiece to the target position by performing the above-described process. Next, the gripping operation in S2319 will be described.

[0272] Figure 39 is a flowchart showing the processing procedure for a gripping operation in the hand controller 630 according to this embodiment. Figure 39 shows an example of a two-stage gripping operation in which the positioning motors MT1 to MT4 are operated first, followed by the operation of the gripping motor MT10.

[0273] The communication unit 632 of the hand controller 630 receives a gripping instruction from the picking robot controller 620 (S2401). The gripping instruction includes the gripping pose and target gripping force, etc.

[0274] The hand control unit 633 operates the positioning motors MT1 to MT4 to assume a gripping pose, causing the robot hand 100 to perform a gripping operation (S2402).

[0275] The acquisition unit 634 acquires a signal indicating the detection result from the force detection sensor SG (S2403). The determination unit 635 determines whether the force detected by the force detection sensor SG is greater than or equal to the contact detection threshold (S2404). If it is determined that the force detected by the force detection sensor SG is less than the contact detection threshold (S2404: NO), the hand controller 630 processes again from S2402.

[0276] On the other hand, if the determination unit 635 determines that the force detected by the force detection sensor SG is equal to or greater than the contact detection threshold (S2404: YES), the hand control unit 633 stops the driving of the positioning motors MT1 to MT4 (S2405).

[0277] On the other hand, if the determination unit 635 determines that the force detected by the force detection sensor SG is equal to or greater than the contact detection threshold (S2404: YES), the hand control unit 633 stops the driving of the positioning motors MT1 to MT4 (S2405).

[0278] Subsequently, the hand control unit 633 drives the gripping motor MT10 to increase the gripping force of the robot hand 100 (S2406).

[0279] The acquisition unit 634 acquires a signal indicating the detection result from the force detection sensor SG (S2407). The determination unit 635 determines whether the force detected by the force detection sensor SG is equal to or greater than the target gripping force (S2408). If it is determined that the force detected by the force detection sensor SG is less than the target gripping force (S2408: NO), the hand controller 630 processes again from S2406.

[0280] On the other hand, if the determination unit 635 determines that the force detected by the force detection sensor SG is equal to or greater than the target gripping force (S2408: YES), the hand control unit 633 stops driving the gripping motor MT10 (S2409).

[0281] The hand controller 630 according to this embodiment can perform the above-described control to achieve two-stage control using positioning motors MT1 to MT4 and gripping motor MT10, thereby enabling the robot hand 100 to grip in a determined gripping pose and to grip the workpiece with a target gripping force.

[0282] Furthermore, the control device 610 according to this embodiment also diagnoses the degree of fatigue of the robot hand 100.

[0283] Figure 40 is a flowchart showing the procedure for diagnosing the fatigue level of the robot hand 100 by the control device 610 according to this embodiment. The timing of diagnosing the fatigue level can be any timing, for example, at predetermined intervals when the robot hand 100 is not performing any work.

[0284] The hand control unit 633 controls the robot hand 100 to return to its initial pose (S2501). The pose of the robot hand 100 can be any pose, as long as it is a pose determined for diagnosing the degree of fatigue.

[0285] The acquisition unit 634 acquires a signal indicating the detection result by the force detection sensor SG in the initial pose state (S2502).

[0286] The determination unit 635 determines whether the force indicated by the detection result acquired by the acquisition unit 634 is below the wire failure threshold (S2503). If the determination unit 635 determines that it is below the wire failure threshold (S2503: YES), the communication unit 632 notifies the picking robot controller 620 that the wire failure threshold has been exceeded. Then, the output control unit 628 outputs to the external device 650 that wires WR1 to WR4 have reached the end of their lifespan according to the received notification (S2504).

[0287] On the other hand, if the determination unit 635 determines that the value is greater than the wire failure threshold (S2503: NO), it is considered normal and the process proceeds to S2505.

[0288] Furthermore, the hand control unit 633 controls the robot hand 100 so that all of its finger FPs are open after they have been in a gripping position (S2505).

[0289] The acquisition unit 634 acquires a signal (S2506) that shows the detection result by the force detection sensor SG from the state in which all finger portions FP are gripping to the state in which all finger portions FP are open.

[0290] The determination unit 635 determines whether the force indicated by the detection result acquired by the acquisition unit 634 is below the spring failure threshold (S2507). If the determination unit 635 determines that it is below the spring failure threshold (S2507: YES), the communication unit 632 notifies the picking robot controller 620 that the force has fallen below the spring failure threshold. Then, the output control unit 628 outputs to the external device 650 that the torsion spring has reached the end of its lifespan according to the received notification (S2508), and terminates the process.

[0291] On the other hand, if the determination unit 635 determines that the value is greater than the spring failure threshold (S2507: NO), the process is terminated, and the condition is considered normal.

[0292] Next, the gripping control using the positioning motors MT1 to MT4 and the gripping motor MT10 in the hand controller 630 will be described.

[0293] Figure 41 shows the changes in speed of the positioning motors MT1 to MT4 and the gripping motor MT10 when the robot hand 100 performs a gripping operation using the hand controller 630 according to this embodiment.

[0294] In Figure 41, reference numeral 4101 indicates the change in speed of the positioning motors MT1 to MT4, reference numeral 4102 indicates the change in speed of the gripping motor MT10, and reference numeral 4103 indicates the change in force detected by the force detection sensor SG.

[0295] As shown by line 2601 of reference numeral 4101 in Figure 41, the positioning motors MT1 to MT4 increase their speed until they reach speed v11, under control from the hand control unit 633. After that, the positioning motors MT1 to MT4 maintain speed v11.

[0296] In Figure 41, reference numeral 4103 indicates the contact detection threshold Th1 and the target gripping force Th2. In Figure 41, reference numeral 4103 indicates that the determination unit 635 determines that at time t1, the force detected by the force detection sensor SG is greater than or equal to the contact detection threshold Th1.

[0297] Then, the hand control unit 633 controls the positioning motors MT1 to MT4 to stop. Therefore, as shown by line 2601 of reference numeral 4101 in Figure 41, the speed of the positioning motors MT1 to MT4 decreases from time t1 until they stop.

[0298] Furthermore, the hand control unit 633 controls the gripping motor MT10 to be driven from time t1.

[0299] As shown by line 2602 of reference numeral 4102 in Figure 41, the gripping motor MT10 increases its speed to v21 under control from the hand control unit 633. After that, the gripping motor MT10 maintains its speed v12.

[0300] As a result of the control described above, as shown by line 2603 of reference numeral 4103 in Figure 41, the force detected by the force detection sensor SG increases up to time t1, then its increase is temporarily suppressed, but then it increases again.

[0301] Then, the determination unit 635 determines that the force detected by the force detection sensor SG at time t2 is equal to or greater than the target gripping force Th2.

[0302] Then, the hand control unit 633 controls the gripping motor MT10 to stop. Consequently, as shown by line 2602 of reference numeral 4102 in Figure 41, the speed of the positioning motors MT1 to MT4 decreases from time t2 until they stop.

[0303] As shown by line 2603 of reference numeral 4103 in Figure 41, from time t2 onward, the force detected by the force detection sensor SG remains at or above the target gripping force Th2.

[0304] Therefore, the hand control unit 633 can move the workpiece while maintaining a state where the gripping force Th2 is greater than or equal to the target gripping force.

[0305] The control device 610 according to this embodiment is not limited to two-stage control using positioning motors MT1 to MT4 and gripping motor MT10.

[0306] Next, we will explain the gripping control using the positioning motors MT1 to MT4 in the hand controller 630. In the example shown in Figure 42, we will assume that a light object such as an envelope is being gripped.

[0307] Figure 42 shows the change in speed of the positioning motors MT1 to MT4 when the robot hand 100 performs a gripping operation using the hand controller 630 according to this embodiment.

[0308] In Figure 42, reference numeral 4201 indicates the change in speed of the positioning motors MT1 to MT4, reference numeral 4202 indicates the change in speed of the gripping motor MT10, and reference numeral 4203 indicates the change in force detected by the force detection sensor SG. In Figure 42, for comparison with Figure 41, reference numeral 4202 indicates the change in speed of the gripping motor MT10, but the gripping motor MT10 remains stopped.

[0309] As shown by line 2701 of reference numeral 4201 in Figure 42, the positioning motors MT1 to MT4 increase their speed until they reach speed v11, under control from the hand control unit 633. After that, the positioning motors MT1 to MT4 maintain speed v11.

[0310] In Figure 42, reference numeral 4203 indicates the contact detection threshold Th1. In Figure 42, reference numeral 4203 indicates that the determination unit 635 determines that at time t11, the force detected by the force detection sensor SG is greater than or equal to the contact detection threshold Th1.

[0311] Then, the hand control unit 633 controls the positioning motors MT1 to MT4 to stop. Therefore, as shown by line 2701 of reference numeral 4201 in Figure 42, the speed of the positioning motors MT1 to MT4 decreases from time t1 until they stop.

[0312] As a result of the control described above, the force detected by the force detection sensor SG increases until time t11, as shown by line 2703 of reference numeral 4203 in Figure 42. After time t11, the force detected by the force detection sensor SG remains above the contact detection threshold Th1.

[0313] Therefore, the hand control unit 633 can move the workpiece while maintaining a state where the contact detection threshold Th1 is above the threshold.

[0314] Furthermore, the hand controller 630 can detect the workpiece falling based on the detection results from the force detection sensor SG.

[0315] Figure 43 shows the change in detection results based on the dropping of a workpiece, as measured by the force detection sensor SG according to this embodiment.

[0316] In the example shown in Figure 43, the hand controller 630 performs the same control as shown up to time t2 in Figure x12 until time t22. Therefore, as shown by line 2801, at time t22, the force detected by the force detection sensor SG reaches the target gripping force Th2.

[0317] From time t22 onward, the determination unit 635 repeatedly determines whether the force detected by the force detection sensor SG is less than or equal to the fall threshold Th3.

[0318] At time t23, the workpiece falls. Consequently, at time t24, the determination unit 635 determines that the force detected by the force detection sensor SG has fallen to or below the fall threshold Th3. From this point onward, the control device 610 processes the data assuming that the workpiece has fallen. The specific processing is as described above and will not be explained further.

[0319] As shown in Figure 43, the determination unit 635 can detect the workpiece falling by repeatedly determining whether the force detected by the force detection sensor SG has fallen below the fall threshold Th3.

[0320] Furthermore, the hand controller 630 can detect the lifespan of components such as wires WR1 to WR4 based on the detection results from the force detection sensor SG.

[0321] Figure 44 shows the changes in the detection results of the force detection sensor SG according to this embodiment until the lifespan of wires WR1 to WR4 is detected.

[0322] The determination unit 635 of the hand controller 630 periodically determines whether the force detected by the force detection sensor SG is less than or equal to the failure threshold Th4 while the robot hand 100 is in a predetermined pose. As shown by line 2901 in Figure 44, initially the force detection sensor SG detects an initial value Pini, but as the robot hand 100 is used, the force detected by the force detection sensor SG gradually decreases.

[0323] Then, the determination unit 635 of the hand controller 630 determines that the force detected by the force detection sensor SG at time t31 is less than or equal to the failure threshold Th4. In this case, the output control unit 628 outputs to the external device 650 that wires WR1 to WR4 have reached the end of their lifespan. Therefore, the operator using the robot system 600 can recognize the end of the lifespan of wires WR1 to WR4 and take appropriate action, such as replacing wires WR1 to WR4.

[0324] In the embodiments described above, an example using wires WR1 to WR4 as an example of a power transmission member was explained. However, the power transmission member is not limited to wires WR1 to WR4; any power transmission member capable of transmitting power is acceptable, and other power transmission members such as belts may be used.

[0325] In the embodiments described above, an example using a torsion spring was explained as an example of an elastic member. However, the elastic member is not limited to a torsion spring, and other elastic members such as rubber may be used.

[0326] The control device 610 according to the above embodiment can easily determine the gripping pose corresponding to the workpiece, thereby reducing the processing burden.

[0327] Furthermore, the control device 610 according to the above embodiment sets an action plan based on information about the workpiece, in other words, according to the current state of the workpiece, and controls the movement of the robot hand according to the action plan. Therefore, the control device 610 can perform control according to the state of the workpiece, thereby improving the accuracy of the robot hand's movements when moving the workpiece.

[0328] Furthermore, the control device 610 according to the above embodiment recognizes the current status of the robot hand based on the signal acquired from the force detection sensor and performs control according to the current status, thereby suppressing actions that are not suitable for the current status. Therefore, the control device 610 according to the above embodiment can improve the work efficiency of the robot hand and improve the safety of the robot hand or the workpiece.

[0329] Preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described above. Various modifications, substitutions, etc., can be applied to the embodiments described above without departing from the scope of the present invention. Furthermore, features described separately can be combined as long as no technical inconsistencies arise.

[0330] This application claims priority based on Japanese Patent Application No. 2025-032339 and Japanese Patent Application No. 2025-032340, filed on 28 February 2025, and the entire contents of these Japanese Patent Applications are incorporated herein by reference.

[0331]

Claims

An acquisition unit that acquires information about a workpiece from a detection unit that recognizes the space in which a workpiece to be grasped by a robot hand having at least two or more fingers exists, A setting unit sets an action plan that includes, based on information about the workpiece, at least the movement path of the robot hand until it grasps the workpiece, and the movement of the robot hand to assume a grasping pose for grasping the workpiece. A control unit that controls the movement of the robot hand according to the aforementioned action plan, A control device for a robot hand, equipped with the following features. 　 The actions included in the action plan are actions to assume a gripping pose, selected from a plurality of predetermined gripping poses based on information about the workpiece, for the robot hand to grasp the workpiece. A control device for a robot hand according to claim 1. 　 The system further includes a classification unit that, based on the information relating to the workpiece, classifies the workpiece to be gripped into a category corresponding to the workpiece from a plurality of predetermined categories for classifying the shape of the workpiece, The actions included in the aforementioned action plan are actions to achieve the grasping pose corresponding to the aforementioned category. The control device for a robot hand according to claim 2. 　 The information about the workpiece acquired by the acquisition unit includes at least one of the following: the shape of the workpiece, the orientation of the workpiece, the position of the workpiece, and information about the surrounding environment of the workpiece. A control device for a robot hand according to claim 1. 　 The aforementioned movement path is a position that the robot hand passes through before grasping the workpiece, and includes a first position determined based on the orientation and position of the workpiece in order to grasp the workpiece in the grasping pose. A control device for a robot hand according to claim 1. 　 The first position is further determined based on the surrounding environment of the workpiece, so as to avoid objects present in the vicinity of the workpiece. The control device for a robot hand according to claim 5. 　 The setting unit sets the action plan, which includes auxiliary actions to move the robot hand to a position where the workpiece can be grasped, based on information about the workpiece. A control device for a robot hand according to claim 1. 　 The robot hand whose movement is controlled by the control unit has at least three or more fingers, each of which has one or more joints, and is capable of varying the degree of bending of the joints of each finger for each pose for grasping the workpiece. A control device for a robot hand according to claim 1. 　 A second acquisition unit acquires a signal from a force detection sensor attached to the robot hand, which has a power transmission member that drives each of the multiple finger parts by transmitting power generated from an actuator. A second control unit initiates control to move at least one of the plurality of fingers of the robot hand in order to grasp the workpiece, After control by the second control unit is initiated, a determination unit determines whether or not the robot hand has come into contact with the workpiece based on the change in the signal acquired by the second acquisition unit, A control device for a robot hand according to claim 1, further comprising: 　 The second control unit stops the control of the finger portion of the robot hand when the determination unit determines that the finger portion of the robot hand has come into contact with the workpiece. The control device for a robot hand according to claim 9. 　 The second control unit, when the determination unit determines that the finger portion of the robot hand has come into contact with the workpiece, starts control to change the gripping force of the workpiece output from the actuator compared to before the contact was determined. The control device for a robot hand according to claim 9. 　 The actuator is It includes a positioning motor for moving the finger portion and a gripping motor capable of being driven with a larger torque than the positioning motor for gripping the workpiece, The second control unit controls the operation of at least one of the plurality of fingers using the positioning motor until it is determined that the fingers of the robot hand have come into contact with the workpiece. The second control unit, when the determination unit determines that the fingers of the robot hand have come into contact with the workpiece, starts driving the gripping motor and initiates control to increase the gripping force of the workpiece. The control device for a robot hand according to claim 11. 　 The second control unit starts controlling the gripping force of the workpiece output from the actuator, and then stops the control of changing the gripping force of the workpiece when the change in the signal acquired by the second acquisition unit satisfies a predetermined condition. The control device for a robot hand according to claim 11. 　 The system further includes an arm control unit that drives an arm connected to the robot hand in a state where it is gripping the workpiece, The arm control unit suppresses the driving of the arm when the second acquisition unit determines that the signal acquired by the second acquisition unit while the workpiece is being gripped has changed by the determination unit to a predetermined standard or more. The control device for a robot hand according to claim 9. 　 The second acquisition unit acquires the signal from the force detection sensor attached to the robot hand, which further has an elastic member for driving each of the plurality of fingers in addition to the power transmission member. The system further includes an output control unit that outputs information indicating the degree of fatigue of the power transmission member or elastic member, based on a comparison result between the signal acquired from the force detection sensor and a predetermined value, while the robot hand is in a predetermined pose. The control device for a robot hand according to claim 9. Furthermore, a second acquisition unit acquires a signal from a force detection sensor attached to the robot hand, which has a power transmission member that drives each of the multiple finger parts by transmitting power generated from an actuator. The system includes an arm control unit that drives an arm connected to the robot hand in a state where it is gripping the workpiece, The arm control unit suppresses the driving of the arm when the signal acquired by the second acquisition unit changes by more than a predetermined standard while the workpiece is being gripped. A control device for a robot hand according to claim 1. 　 A second acquisition unit acquires signals from force detection sensors attached to a robot hand having a power transmission member and an elastic member in order to drive each of the multiple finger parts, The system further includes an output control unit that outputs information indicating the fatigue level of the power transmission member or elastic member, based on a comparison result between the signal obtained from the force detection sensor and a predetermined value, while the robot hand is in a predetermined pose. A control device for a robot hand according to claim 1. 　 An industrial robot hand having at least two or more fingers, A detection unit that recognizes the space in which the workpiece to be grasped by the robot hand exists, An acquisition unit that acquires information about the workpiece from the detection unit, A setting unit sets an action plan that includes, based on information about the workpiece, at least the movement path of the robot hand until it grasps the workpiece, and the movement of the robot hand to assume a grasping pose for grasping the workpiece. A control unit that controls the movement of the robot hand according to the aforementioned action plan, A control system for a robot hand, equipped with the following features. 　 The robot hand has a power transmission member that drives each of its multiple finger parts by transmitting power generated from an actuator. A force detection sensor attached to the robot hand, A second acquisition unit acquires a signal from the force detection sensor, A second control unit initiates control to operate at least one of the multiple finger portions of the robot hand in order to grasp the workpiece, After control by the second control unit is initiated, a determination unit determines whether or not the robot hand has come into contact with the workpiece based on the change in the signal acquired by the second acquisition unit, The robot hand control system according to claim 18, further comprising:

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