Control unit of double arm device, and robot system

Abstract

To enable changing a posture of an object on a mounting surface so as to make usefulness.SOLUTION: A control unit 90 controls the operation of a double arm device 1 which is constituted so as to change positions of a first arm 10 and a second arm 20 by a power source 80. The control unit 90 includes: a first control section for bringing the first arm 10 into contact with a first side part 901 of an object 900 in a state where the first arm 10 and the second arm 20 are arranged so as to hold therebetween the box-shaped object 900 arranged by bringing a bottom 905 into contact with a mounting surface, in a first direction in parallel to the mounting surface 911; and a second control section for moving the first arm 10 so as to approach the second arm 20 in a state where the first arm 10 contacts the first side part 901, and changing a posture of the object 900 so that the object 900 is inclined.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control device for a dual-arm device having two arms and a robot system.

Background Art

[0002] Conventionally, devices using a dual-arm device having two arms for acting on an object such as a box body have been used. Such devices include, for example, robot systems used for transporting objects in a manufacturing site, a warehouse, etc., and devices such as robots for handling objects on a production line.

[0003] The following Patent Document 1 describes a hand device having a clamping claw that can protrude and retract from one vertical arm toward the other vertical arm and is operated by the biasing force of a coil spring. Thereby, stacking and unstacking of parts boxes can be easily performed.

[0004] The following Patent Document 2 describes a robot hand having a first claw portion and a second clamping portion for clamping an article, and a driving device for approaching or separating them, and capable of being inserted into the gap between articles. Thereby, it becomes possible to easily take out adjacent arranged articles.

[0005] The following Patent Document 3 describes a device for adsorbing the upper surface and side surface of a load and moving them, and a processor for controlling them, and a unloading device for moving the adsorption portion upward in a state where the upper surface and side surface of the load are adsorbed. Thereby, efficient unloading of the load becomes possible.

[0006] The following Patent Document 4 describes a linear motion expansion and contraction mechanism having a plurality of arranged structures, a member for rotatably connecting them, and a member for performing fixing and releasing, and performing expansion and contraction of the structures through these. Thereby, an increase in the number of parts can be suppressed, and miniaturization and weight reduction are possible.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-200806 [Patent Document 2] Japanese Patent Application Laid-Open No. 2020-172358 [Patent Document 3] Japanese Patent Application Laid-Open No. 2021-066578 [Patent Document 4] Japanese Patent Application Laid-Open No. 2017-057929 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] There are various scenarios where dual-arm devices are used and scenarios where they are expected to be utilized in the future. Among such various scenarios, it would be useful if the dual-arm device could be effectively utilized in a specific one or multiple scenarios.

[0009] An object of this invention is to provide a control device for a dual-arm device and a robot system that enable effective utilization of the dual-arm device. [Means for Solving the Problems]

[0010] The control device for a dual-arm device according to the first aspect of the present invention is a control device for a dual-arm device configured to be able to change the positions of a first arm and a second arm by a power source, and is configured such that the first arm and the second arm are respectively arranged so as to sandwich and line up in a first direction parallel to the mounting surface a box-shaped object having its bottom in contact with the mounting surface. The control device for a dual-arm device includes a first control unit that causes the first arm to contact a first side portion of the object that is closer to the first arm than the second arm, and a second control unit that changes the posture of the object so that the object tilts while a part of the bottom of the object that is closer to the second arm than the first arm in the first direction remains in contact with the mounting surface by moving the first arm closer to the second arm in the first direction while the first arm is in contact with the first side portion.

[0011] With such a configuration, the posture of the object on the placement surface can be changed, and the dual-arm device can be effectively utilized. Since the second arm is located on the opposite side of the first arm in the first direction, it can be provided so that the object with the changed posture can be supported using the second arm.

[0012] Further, the control device of the dual-arm device of the second invention, with respect to the first invention, the first control unit arranges the second arm so that the second arm contacts the second side portion of the object closer to the second arm than the first arm or the second arm is positioned in the vicinity of the second side portion, and the second control unit moves the second arm so that the second arm remains in contact with the second side portion or the second arm is positioned in the vicinity of the second side portion as the first arm moves. It is a control device for a dual-arm device.

[0013] With such a configuration, the posture of the object can be stably changed.

[0014] Further, the control device of the dual-arm device of the third invention, with respect to the first or second invention, the second control unit moves the first arm so that the locus of the first arm draws an arc centered on a part of the bottom that contacts the placement surface when viewed from the second direction parallel to the placement surface and orthogonal to the first direction. It is a control device for a dual-arm device.

[0015] With such a configuration, the posture of the object can be changed so that the position where the first arm contacts the first side portion does not change.

[0016] Further, the control device of the dual-arm device of the fourth invention, with respect to any one of the first to third inventions, the second control unit ends the movement of the first arm when it is determined based on the detection result of a force sensor capable of detecting the force applied to at least one of the first arm and the second arm that the detection result satisfies a predetermined stop condition. It is a control device for a dual-arm device.

[0017] With such a configuration, the posture of the object can be changed so as to satisfy the stop condition. For example, it is possible to prevent excessive force from being applied to the object whose posture has changed.

[0018] Further, the control device of the dual-arm device of the fifth invention includes, with respect to the fourth invention, a third control unit that moves the first arm between the bottom and the placement surface after the movement of the first arm by the second control unit is completed, and is a control device of the dual-arm device.

[0019] With such a configuration, the object can be supported by the first arm in a state where the posture of the object is changed.

[0020] Further, the robot system of the sixth invention includes a power source and a dual-arm device configured to be able to change the positions of the first arm and the second arm by the power source, and any one of the above control devices, and is configured to be able to change the posture of a box-shaped object placed on the placement surface with its bottom in contact therewith, and is a robot system.

[0021] With such a configuration, the posture of the object on the placement surface can be changed, and a robot system that can effectively utilize the dual-arm device can be configured.

Effect of the Invention

[0022] According to the present invention, it is possible to provide a control device and a robot system of a dual-arm device that enable effective utilization of the dual-arm device.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0024] Hereinafter, embodiments of a dual-arm device, its control device, and a robot system including them will be described with reference to the drawings.

[0025] The coordinates shown in the following drawings indicate directions and are common to each drawing. The Z direction of the coordinates is the direction perpendicular to the horizontal plane. The X direction is the direction perpendicular to the Z direction, and the Y direction is the direction perpendicular to the Z direction and perpendicular to the X direction. Note that the Z direction may be referred to as the vertical direction (the direction that is positive on the Z axis when viewed from the origin of the illustrated coordinates is upward), the Y direction may be referred to as the left-right direction (the direction that is positive on the Y axis when viewed from the origin of the illustrated coordinates is right), and the X direction may be referred to as the front-back direction (the direction that is positive on the X axis when viewed from the origin of the illustrated coordinates is rear or front). The left-right direction may be referred to as the first direction, and the front-back direction may be referred to as the second direction. That is, the first direction and the second direction are directions parallel to the horizontal plane.

[0026] In the following description, the shapes and positional relationships of each part may be described by indicating each direction in this way, but the indication of the direction is only for the convenience of explanation and does not limit the orientation and posture during the use of each device according to the present invention. In addition, the expressions indicating the direction and the expressions indicating the states such as horizontal, vertical, and orthogonal only show that they can be roughly understood in that way, and it is not always necessary to be strictly understood as being exactly as the expression.

[0027] (Embodiment)

[0028] The outline of this embodiment is as follows. The dual-arm device includes a first arm and a second arm that can be arranged apart in the left-right direction. The first arm and the second arm can each change their positions using a power source. The control device of the dual-arm device is configured to be able to change the posture of a box-shaped object placed on the placement surface by controlling the operation of the dual-arm device.

[0029] Hereinafter, the configuration of the dual-arm device and its control device configured as described above, and the configuration of a robot system which is one example of their usage will be described.

[0030] FIG. 1 is a perspective view showing a robot system 100 using the dual-arm device 1 according to this embodiment.

[0031] The robot system 100 includes a dual-arm device 1, a first moving unit 110, a second moving unit 120, a third moving unit 130, and a carriage 140.

[0032] In this embodiment, the dual-arm device 1 has two arms 10, 20 (a first arm 10 and a second arm 20). The two arms 10, 20 are arranged apart in a first direction in the horizontal plane. Hereinafter, the left-right direction will be described as the first direction. The two arms 10, 20 are arranged so as to be separated from each other in the left-right direction. The two arms 10, 20 are arranged side by side in the left-right direction. In the following description, the first arm 10 is arranged to the right of the second arm 20. The second arm 20 is arranged to the left of the first arm 10. That is, the first arm 10 is on the right side and the second arm 20 is on the left side. Note that the left-right positional relationship between the two arms 10, 20 is not limited to this, and it may be the opposite, or it may be configured to be changeable as appropriate. As will be described later, the dual-arm device 1 is configured to support a conveyance object by the two arms 10, 20 and be able to lift the conveyance object from the placement surface on which the conveyance object is placed.

[0033] The double-arm device 1 is attached, for example, by moving parts 110, 120, 130 so as to be movable with respect to the carriage 140. The double-arm device 1 is movable in a first direction and a second direction in a horizontal plane and is movable in a vertical direction. Note that the second direction is a direction perpendicular to the first direction, that is, the X direction. The double-arm device 1 will be moved in the directions of the three axes in a rectangular coordinate system. Note that, as any one of the moving parts 110, 120, 130 is included in the double-arm device 1, the configuration of the double-arm device 1 may be grasped. At least one of the moving parts 110, 120, 130 may not be provided.

[0034] The first moving part 110 supports the double-arm device 1. The first moving part 110 displaces the double-arm device 1 in the first direction. Also, the robot system 100 can move an object to be transported supported by the double-arm device 1 in the first direction by moving the double-arm device 1 by the first moving part 110. The first moving part 110 has, as an example, a first support part 111 that supports the double-arm device 1 and a linear actuator that moves the double-arm device 1 in the first direction with respect to the first support part 111. More specifically, for example, a guide along the first direction may be provided on the bottom surface of the first support part 111 extending in the first direction, and a slider may be assembled to the guide so as to be slidable in the first direction. And the double-arm device 1 may be fixed to the slider.

[0035] The second moving part 120 supports the first moving part 110 and moves the first moving part 110 in the second direction. Therefore, the double-arm device 1 will be moved in the second direction by the second moving part 120. The second moving part 120 has, as an example, a second support part 121 that supports the first support part 111 of the first moving part 110 and a linear actuator that moves the first support part 111 in the second direction with respect to the second support part 121. More specifically, for example, a guide along the second direction may be provided on the bottom surface of the second support part 121 extending in the second direction, and a slider may be assembled to the guide so as to be slidable in the second direction. And the upper surface of the first support part 111 may be fixed to the slider.

[0036] The third moving part 130 supports the second moving part 120 and moves the second moving part 120 in the vertical direction. Therefore, the double-arm device 1 is moved in the vertical direction by the third moving part 130. The third moving part 130 includes, as an example, a pair of columns 131 and 132 spaced apart in a first direction, an upper surface plate 133 connecting upper ends of the columns 131 and 132, a lifting part 134 whose ends are supported by the pair of columns 131 and 132 and which supports a second support part 121 of the second moving part 120, and a pair of linear actuators that move the lifting part 134 synchronously in the vertical direction with respect to the pair of columns 131 and 132. More specifically, guides along the vertical direction may be provided on surfaces of the columns 131 and 132 extending in the vertical direction on the side of the lifting part 134, and sliders may be assembled to the guides so as to be slidable in the vertical direction. And both ends of the lifting part 134 in the first direction may be fixed to the sliders, respectively.

[0037] In the moving parts 110, 120, and 130, for example, the slider may be assembled to two or more guides provided in parallel. Also, the linear actuators included in the moving parts 110, 120, and 130 may each independently have, for example, a rack and pinion mechanism and a driving means for rotating the pinion, or a ball screw mechanism and a driving means for rotating a screw shaft of the ball screw mechanism, or a pair of pulleys, an endless belt wound around the pair of pulleys, and a driving means for rotating the pulleys, or a sprocket and a chain may be used instead of the pulleys and the belt, or other configurations may be used. Note that mechanisms for moving a supported object in a linear direction using guides, sliders, linear actuators, etc. are already known, and detailed descriptions thereof are omitted. In FIG. 1, illustrations of guides, sliders, and linear actuators are omitted.

[0038] The third moving unit 130 is fixed to the carriage 140. Note that the proximal end side of the third moving unit 130, that is, the lower end portion may be fixed to the carriage 140. The carriage 140 may have, as an example, a base 141 to which the proximal end side of the third moving unit 130 is fixed, and a plurality of traveling means 142 fixed to the base 141 and capable of traveling on a traveling surface such as a floor surface. The base 141 may be, as an example, a plate-shaped member. The traveling means 142 is usually a wheel, but may be a roller other than a wheel, an endless track, a ball caster having a ball, or the like. Further, the carriage 140 may or may not have a driving means for driving the traveling means 142. In the latter case, the carriage 140 may be moved manually. Also, the carriage 140 that is moved manually may have a fixing means for fixing the traveling means 142 so that the carriage 140 does not move when the moving units 110, 120, 130 perform local conveyance of the object to be conveyed. The fixing means may be, for example, a wheel stopper. While the moving units 110, 120, 130 locally convey the object to be conveyed, the carriage 140 will convey the object to be conveyed more globally.

[0039] Note that the robot system 100 has a reception unit (not shown) for receiving operations and instructions from a user, and a system control unit (not shown) for controlling the operations of the moving units 110, 120, 130.

[0040] The reception unit may receive, for example, operations and instructions regarding the moving units 110, 120, 130, or operations and instructions regarding the carriage 140. Further, it may receive operations and instructions regarding the dual-arm device 1. The reception may be, for example, reception of information input from an input device (for example, a keyboard, a mouse, a touch panel, etc.), or reception of information transmitted via a wired or wireless communication line. Note that the reception unit may or may not include a device (for example, an input device, a communication device, etc.) for performing the reception. Also, the reception unit may be realized by hardware, or may be realized by software such as a driver for driving a predetermined device.

[0041] The system control unit controls the first moving unit 110, the second moving unit 120, and the third moving unit 130 respectively. By the control of this system control unit, for example, local conveyance such as moving or positioning an object to be conveyed supported by the dual-arm device 1 is performed. Also, for example, when the carriage 140 has a driving means, the system control unit may also perform movement control of the carriage 140. These controls may be performed, for example, according to operations or instructions received by the reception unit. The movement control of the carriage 140 may be, for example, movement control regarding the movement direction and movement speed according to an operation received by the reception unit, or autonomous movement control from a predetermined starting point to a destination. Note that the system control unit may be configured to function as a control device 90 as described later.

[0042] Next, the configuration of the dual-arm device 1 will be described.

[0043] In the present embodiment, the dual-arm device 1 has a first arm 10, a second arm 20, a base 50, a power source 80, and a control device 90.

[0044] The base 50 supports the first arm 10 and the second arm 20. The base 50 is attached to the first support portion 111. Note that the base 50 may be a portion grasped as the first support portion 111.

[0045] The first arm 10 and the second arm 20 are each attached to the base 50 such that the second direction is the longitudinal direction. In other words, the first arm 10 and the second arm 20 are provided so as to protrude forward from the base 50. The first arm 10 and the second arm 20 are each formed in a rod shape extending forward (inward) from the base end portion attached to the base 50. It can be said that the first arm 10 and the second arm 20 are each configured to form a beam shape as a whole. Note that the shapes of the first arm 10 and the second arm 20 are not limited to this, and other shapes such as columnar and plate-like shapes may be used. The first arm 10 and the second arm 20 may be configured such that, for example, the main portion protruding forward from the base 50 is formed using a single member, or the portion may be configured by combining a plurality of members.

[0046] The first arm 10 and the second arm 20 can be arranged so as to be spaced apart in the left-right direction. The double-arm device 1 is configured such that, by displacing the first arm 10 and the second arm 20 with respect to the object to be conveyed, the posture of the object to be conveyed can be changed or supported as will be described later.

[0047] In the present embodiment, the first arm 10 has a rod-shaped rod portion 11 and an insertion portion 13 located at the front end portion of the rod portion 11. Further, the second arm 20 has a rod-shaped rod portion 21 and an insertion portion 23 located at the front end portion of the rod portion 21. In the present embodiment, the rod portions 11 and 21 each have a substantially circular cross-sectional shape. Note that the cross-sectional shapes of the rod portions 11 and 21 are not limited to this, and may be any of an ellipse, a polygon, a semi-circle, etc. Further, the cross-sectional shapes of the rod portions 11 and 21 may be different from each other at different positions in the front-rear direction.

[0048] The insertion portions 13 and 23 are formed in a tapered shape such that the thickness in one direction (for example, the left - right direction) decreases as it approaches the front end portion. It can be said that the insertion portions 13 and 23 are formed to be tapered in plan view. Note that the insertion portions 13 and 23 are not limited to being formed in a tapered shape, and may be portions formed to be tapered. It can be said that the insertion portions 13 and 23 are formed so that the respective arms 10 and 20 can be inserted between the side surface of the object and the surface of another member facing the side surface.

[0049] In the present embodiment, the first arm 10 and the second arm 20 have shapes that are symmetric with each other about the left - right direction. In other words, the second arm 20 has a shape symmetric to the first arm 10 with respect to a plane parallel to the XZ plane. Note that the shapes of the first arm 10 and the second arm 20 are not limited to this. The shape of the first arm 10 and the shape of the second arm 20 may not be symmetric with each other about the left - right direction, or may be the same shape. Also, for example, in each of the first arm 10 and the second arm 20, the insertion portions 13 and 23 may not be provided.

[0050] Here, in the present embodiment, the double - arm device 1 includes force sensors 5 capable of detecting the forces applied to the first arm 10 and the second arm 20 respectively. The force sensors 5 are arranged, for example, at the base end portions of the first arm 10 that are supported by the base 50. Also, the force sensors 5 are arranged, for example, at the base end portions of the second arm 20 that are supported by the base 50. That is, in the present embodiment, the force sensors 5 are provided, for example, between each of the first arm 10 and the second arm 20 and the base 50. Each force sensor 5 is, for example, a sensor for detecting an external force, but is not limited to this. The sensor for detecting an external force may be, for example, a 3 - axis or 6 - axis force - sensing sensor. Each force sensor 5 is preferably configured and arranged so that the sensor can detect the direction and magnitude of the force applied to each of the first arm 10 and the second arm 20.

[0051] Note that the mounting position of the force sensor 5 is not limited to the above. For example, in each of the first arm 10 and the second arm 20, it may be embedded inside the rod-shaped portions 11, 21 so as to be able to detect the force applied to the rod-shaped portions 11, 21. Further, the force sensor 5 may be a sensor (for example, a strain gauge or the like) attached to the rod-shaped portions 11, 21 of the first arm 10 and the second arm 20 and capable of detecting the distortion or the like of the rod-shaped portions 11, 21. Further, one of the first arm 10 and the second arm 20 may not have the force sensor 5.

[0052] FIG. 2 is a perspective view for explaining the configuration of the dual-arm device 1. FIG. 3 is a front view for explaining the configuration of the dual-arm device 1.

[0053] In the present embodiment, the robot system 100 is used to change the posture of the object 900 placed on the placement surface (shown in FIG. 5 and the like) by using the dual-arm device 1 as described later. Further, in the present embodiment, the robot system 100 is configured to be able to support the object 900 whose posture has been changed by the dual-arm device 1 by the dual-arm device 1, lift the object 900 supported by the dual-arm device 1 from the placement surface, or convey it.

[0054] In FIGS. 2 and 3, as an example, a state in which a substantially rectangular parallelepiped box-shaped object 900 is supported by the dual-arm device 1 is shown.

[0055] The object 900 is not particularly limited as long as it is box-shaped. Here, the box shape refers to a three-dimensional shape whose surface is composed of several flat or curved surfaces. The box shape may further be limited to a shape that does not have a recess that occupies most of a certain surface as a whole. For example, a package to be transported having an outer box such as a cardboard box can be the object 900. Note that the object 900 does not necessarily have to have a box that constitutes the surface, such as a box-shaped workpiece or jig used at a manufacturing site or the like. The weight of the object 900 is not particularly limited, but it may be a weight that is difficult for a human to carry, for example, 30 kg or more, or 50 kg or more. The shape of the object 900 is not limited to a rectangular parallelepiped shape, and may be a columnar shape, a conical shape, or the like.

[0056] The object 900 has a first side portion 901 that is the right side surface, a second side portion 902 that is the opposite left side surface, and a bottom portion 905 that is the bottom surface. In the present embodiment, when the posture of the object 900 is changed by the dual-arm device 1, the first hand 10 and the second hand 20 are first arranged so as to sandwich and line up the object 900 in the left-right direction. In a state where the first hand 10, the object 900, and the second hand 20 are lined up in the left-right direction in this way, it can be said that the first side portion 901 is the side portion of the object 900 that is closer to the first arm 10 than the second arm 20. Also, it can be said that the second side portion 902 is the side portion of the object 900 that is closer to the first arm 10 than the second arm 20.

[0057] In the present embodiment, the first arm 10 and the second arm 20 are each independently movable in the first direction with respect to the base 50. Further, the first arm 10 and the second arm 20 are each independently movable in the vertical direction with respect to the base 50. That is, the dual-arm device 1 can change the posture of the object 900, for example, as will be described later, by moving the first arm 10 and the second arm 20. Further, the dual-arm device 1 is configured such that by moving the first arm 10 and the second arm 20, it can support or release the support of the object 900 by the first arm 10 and the second arm 20. Further, the dual-arm device 1 can also move the object 900 supported by the first arm 10 and the second arm 20 in the first direction, for example, by moving the first arm 10 and the second arm 20 simultaneously in the same direction. Note that either one of the first arm 10 and the second arm 20 may be movable in the vertical direction with respect to the base 50. Further, either one of the first arm 10 and the second arm 20 may be movable in the first direction with respect to the base 50. In this case, since the dual-arm device 1 can be moved by the moving parts 110, 130, etc. of the robot system 100, the relative positional relationship between the first arm 10 and the second arm 20 in the first direction or the vertical direction may be appropriately changed.

[0058] In the present embodiment, in order to move the first arm 10 and the second arm 20 independently in the first direction and the vertical direction, the dual-arm device 1 is provided with, for example, a linear actuator for moving the first arm 10 and a linear actuator for moving the second arm 20. The number of linear actuators is not limited. Each actuator is driven by a power source 80. Each linear actuator may independently have, for example, a rack and pinion mechanism and a driving means for rotating the pinion, or may have a ball screw mechanism and a driving means for rotating the screw shaft of the ball screw mechanism, or may have a pair of pulleys, an endless belt wound around the pair of pulleys, and a driving means for rotating the pulleys, or may use a sprocket and a chain instead of the pulleys and the belt, or may have other configurations. Note that mechanisms for moving a supported object in a linear direction using guides, sliders, linear actuators, etc. are already known, and detailed descriptions thereof are omitted. In FIG. 1, illustration of linear actuators and the like is omitted.

[0059] FIG. 4 is a block diagram showing the configuration of the control system of the dual-arm device 1.

[0060] As shown in FIG. 4, the dual-arm device 1 is provided with a power source 80, a control device 90, and a force sensor 5. The control device 90 is configured to be able to acquire information output from the force sensor 5. Further, the control device 90 is configured to be able to output a control signal for driving the power source 80 or supply power to the power source 80 to drive the power source 80.

[0061] The power source 80 may be said to be a driving part. The power source 80 is, for example, a motor, but is not limited thereto. The type of the motor is not limited. The power source 80 may be one or two or more. The power source 80 is configured to be driven based on the control by the control device 90. The power source 80 is used as the power source when moving the first arm 10 and the second arm 20 in the left-right direction or in the up-down direction.

[0062] In the present embodiment, a transmission mechanism for transmitting the force from the power source 80 to the first arm 10 and the second arm 20 is used together with the power source 80 in the linear actuator. The transmission mechanism is configured using, for example, gears, but the type of the mechanism is not limited. For example, as the transmission mechanism, a mechanism using a belt or a mechanism using a ball screw or the like may be used.

[0063] The control device 90 is configured to control the operation of the power source 80. By the control by the control device 90, for example, the posture of the object 900 is changed by the first arm 10 or the second arm 20, or the object 900 is supported by the arms 10, 20. Further, by this control, local conveyance such as positioning of the object 900 is performed. The control device 90 may be configured to perform control according to an operation received by, for example, a reception unit, or may be configured to perform autonomous control so as to execute a predetermined task.

[0064] In the present embodiment, the control device 90 is configured to be able to control the positions of the first arm 10 and the second arm 20 in conjunction with the system control unit. Note that the control of these positions may be regarded as being performed by the control device 90 or may be regarded as being performed by the system control unit.

[0065] In this embodiment, the control device 90 is configured to control the power source 80 based on the detection result of the force sensor 5. That is, based on the detection result of the force sensor 5, it is possible to determine that the object 900 is in contact with the first arm 10 or the second arm 20, and the force acting on the object 900 by the first arm 10 or the second arm 20, etc.

[0066] For example, when the object 900 is lifted and supported from the placement surface by the first arm 10 and the second arm 20, the control device 90 moves at least one of the first arm 10 and the second arm 20, and determines the force applied to each of the arms 10, 20 based on the detection results of the force sensors 5 of the first arm 10 and the second arm 20 respectively. Then, the control device 90 can determine whether the object 900 has been lifted based on the determination result and the transition of the determination result, etc.

[0067] Note that the force sensor 5 of one or both of the first arm 10 and the second arm 20 does not necessarily have to be used for the control by the control device 90. For example, when handling an object 900 having a predetermined shape and dimensions, control may be performed so that the positional relationship between the first arm 10 and the second arm 20 becomes a preset positional relationship according to the dimensions of the object 900, etc. Also, a sensor using a camera, laser light, etc. provided in the dual-arm device 1 or the robot system 100 may be provided, and control may be performed so that the positional relationship between the first arm 10 and the second arm 20 becomes appropriate according to the detection result. By performing such control, it is possible to surely change the posture of the object 900 or support the object 900. Such control may be performed by the control device 90. Also, the control device 90 may be configured to perform control regarding the operations of the first arm 10 and the second arm 20 using both the detection result of a sensor using a camera, laser light, etc. and the detection result of the force sensor 5.

[0068] Here, in the present embodiment, the control device 90 is configured to be able to change the posture of the object 900 so that the object 900 changes from the first state where the bottom 905 is in contact with the placement surface to the second state where the object 900 is tilted while a part 906 of the bottom 905 is in contact with the placement surface, by the first arm 10 and the second arm 20. Further, the control device 90 is configured to be able to support the object 900 in the second state by the first arm 10 and the second arm 20.

[0069] Such a thing is realized by sequentially performing the following control by the control device 90. It can be said that the following control is performed by the first control unit 91, the second control unit 92, and the third control unit 93 provided in the control device 90, respectively. Note that the control operations of the respective control units 91, 92, 93 do not need to be distinguished from each other, and it may be considered that the control device 90 performs the control operation.

[0070] That is, in the present embodiment, the first control unit 91 causes the first arm 10 to contact the first side portion 901 of the object 900 in a state where the first arm 10 and the second arm 20 are respectively arranged so as to sandwich the object 900 in the first direction in the posture of the first state. That is, the first control unit 91 moves the first arm 10 in the first direction with respect to the placed object 900 and detects that the first arm 10 has come into contact with the object 900. When the first control unit 91 detects that the first arm 10 has come into contact with the object 900 based on, for example, the detection result of the force sensor 5, the first control unit 91 can stop the movement of the first arm 10. As a result, the first arm 10 is in contact with the first side portion 901 of the object 900.

[0071] After the above-described operation by the first control unit 91, the second control unit 92 is configured to perform a control operation as follows. That is, in a state where the first arm 10 is in contact with the first side portion 901, the first control unit 91 moves the first arm 10 closer to the second arm 20 in the first direction. For example, when the first arm 10 is to the right of the second arm 20, it can be said that the first control unit 91 moves the first arm 10 so as to be displaced at least somewhat to the left. With a part of the bottom portion 905 of the object 900 that is closer to the second arm 20 than the first arm 10 in the first direction, that is, a part closer to the second side portion 902, remaining in contact with the placement surface, when the object 900 tilts, the first arm 10 approaches the second arm 20 in the first direction. Thereby, the second control unit 92 changes the posture of the object 900 to the second state. That is, the second control unit 92 causes a force in the first direction to act on a part of the first side portion 901 (a part above the placement surface) by the first arm 10 in a state where the object 900 does not move on the placement surface in the first direction, so that a moment is generated in the object 900 with the portion in contact with the placement surface as a fulcrum. When the object 900 rotates about the fulcrum, the object 900 becomes the second state.

[0072] When the control by the second control unit 92 is performed in this way, it is preferable that the second control unit 92 is configured to move the first arm 10 so that the locus of the first arm 10 draws an arc centered on a part of the bottom portion 905 (that is, the fulcrum) in contact with the placement surface when viewed from the second direction. Thereby, when the object 900 tilts about the fulcrum, the change in the position of the portion where the first arm 10 and the first side portion 901 are in contact becomes small. The influence of the friction between the first arm 10 and the first side portion 901 can be reduced.

[0073] In the present embodiment, when such control by the second control unit 92 is performed, the second control unit 92 determines whether the detection result of the force sensor 5 capable of detecting the forces applied to the first arm 10 and the second arm 20 satisfies a predetermined stop condition based on the detection result. When the second control unit 92 determines that the stop condition is satisfied, it ends the movement of the first arm 10.

[0074] That is, when the inclination of the object 900 in the second state increases and the center of gravity of the object 900 exceeds the fulcrum, a moment due to gravity acts on the object 900, and the object 900 rotates. Then, the second control unit 92 ends the movement of the first arm 10. In this case, since the second arm 20 is located on the opposite side of the first arm 10 across the object 900 in the first direction, the object that changes its posture and rotates due to gravity can be supported using the second arm 20. In this case, the object 900 moves away from the first arm 10, contacts the second arm 20 on the second side portion 902 side, and is in a state where the object 900 is supported by the second arm 20. When such a phenomenon occurs, the magnitude of the force applied to the first arm 10 suddenly decreases, and the magnitude of the force applied to the second arm 20 suddenly increases.

[0075] Therefore, for example, that the force applied to the second arm 20 suddenly increases and that the magnitude of the force applied to the first arm 10 suddenly decreases are set as the predetermined stop conditions. For each of the arms 10 and 20, instead of the condition that the force applied to the arm 10 or 20 suddenly increases, conditions such as that the magnitude of the detected force exceeds a predetermined threshold value, that the increase amount of the detected force per unit time exceeds a predetermined threshold value, or that the magnitude of the acceleration caused by the force applied to the arm 10 or 20 exceeds a predetermined threshold value may be used. Also, it may be set that a detection result indicating that the state of contact and separation between the arms 10 and 20 and the object 900 has changed is used as the stop condition. After changing the posture of the object 900 so as to satisfy the stop condition, it is possible to prevent an excessive force from being applied to the object 900 whose posture has changed.

[0076] Note that the stop condition may be related to the detection result of the force sensor 5 of the force applied to either the first arm 10 or the second arm 20. That is, the second control unit 92 may be configured to determine whether the stop condition is satisfied based on the detection result of the force sensor 5 of the force applied to either the first arm 10 or the second arm 20. For example, it is possible to set as the stop condition that the magnitude of the force applied to the first arm 10 suddenly decreases, or that the force applied to the second arm 20 suddenly increases.

[0077] Note that in the present embodiment, when the object 900 is brought into the second state by the first control unit 91 and the second control unit 92 in this way, the first control unit 91 and the second control unit 92 may be configured to also control the operation of the second arm 20. Such control can be performed, for example, as follows.

[0078] For example, the first control unit 91 arranges the second arm 20 so that the second arm 20 contacts the second side portion 902 of the object 900. Thereby, the first arm 10 and the second arm 20 are in a state of contacting the object 900. Further, as the second control unit 92 moves the first arm 10 in a direction approaching the second arm 20, the second control unit 92 moves the second arm 20 so that the second arm 20 remains in contact with the second side portion 20. Since the second arm 20 is attached to the object 900, an effect may be obtained such that the object 900 can be tilted so as not to be displaced on the placement surface in the first direction. Note that even when the second arm 20 is moved in this way, at each time point, the first arm 10 may be moved so as to approach the second arm 20 at that time point in the first direction.

[0079] By operating the second arm 20 in this way, the object 900 can be tilted more stably. Further, when the inclination of the object 900 increases and the object 900 rotates due to gravity, since the object 900 is immediately supported by the second arm 20, the displacement amount due to the gravity of the object 900 becomes small, and it is possible to prevent an impact from being applied to the object 900.

[0080] In addition, the control by the first control unit 91 and the second control unit 92 regarding the operation of the second arm 20 can be performed based on, for example, the detection result of the force sensor 5 that detects the force applied to the second arm 20. That is, for example, the first control unit 91 moves the second arm 20 closer to the second side portion 902 until it is determined that the second arm 20 has contacted the second side portion 902 based on the detection result of the force sensor 5. Further, the second control unit 92 may displace the second arm 20 based on the detection result of the force sensor 5 so that the force applied to the second arm 20 is within a predetermined range. Note that this is not limited thereto, and the first control unit 91 and the second control unit 92 may be configured to change the position of the second arm 20 so as to be located at a position specified in advance according to the position of the first arm 10, or to move along a predetermined locus. For example, the second control unit 92 may be configured to move the second arm 20 so that, when viewed from the second direction, the locus of the second arm 20 draws an arc centered on a part (that is, the fulcrum) of the bottom portion 905 that contacts the placement surface. Thereby, when the object 900 tilts about the fulcrum, the change in the position of the portion where the second arm 20 contacts the second side portion 902 becomes small. The influence of the friction between the second arm 20 and the second side portion 902 can be reduced.

[0081] In addition, when the first control unit 91 and the second control unit 92 control the operation of the second arm 20, the second arm 20 does not necessarily have to be moved so as to contact the second side portion 902. For example, first, with the second arm 20 moved so that it is positioned in the vicinity of the second side portion 902 by the first control unit 91, the second control unit 92 may move the first arm 10 closer to the second arm 20 in the first direction. In this case, the second control unit 92 may be configured to move the second arm 20 so that the second arm 20 continues to be positioned in the vicinity of the second side portion 902 as the first arm 10 moves. In this case, for example, the second arm 20 may be positioned at a predetermined position corresponding to the position of the first arm 10, or the second arm 20 may be positioned at a position corresponding to the position and state of the object 900 detected by a sensor such as a camera.

[0082] After the above-described operation by the second control unit 92 is performed, the third control unit 93 is configured to perform a control operation as follows. That is, when the movement of the first arm 10 by the second control unit 92 is completed, the object 900 is supported mainly by the placement surface and the second arm 20 in the second state. In this case, the third control unit 93 moves the first arm 10 and moves it between the bottom portion 905 and the placement surface. That is, the third control unit 93 moves the first arm 10 so that the first arm 10 is positioned below the bottom portion 905 in the vertical direction.

[0083] Note that the control operation by the third control unit 93 may be performed so that the first arm 10 contacts the bottom portion 905, or the first arm 10 may be moved to a position close to the bottom portion 905. For such control, similar to the movement of the second arm 20 by the first control unit 91 and the like described above, the detection result of the force sensor 5 that detects the force applied to the first arm 10 or the detection result of a sensor such as a camera may be used. Further, the first arm 10 may be moved to a predetermined position. By doing so, in the second state, the first arm 10 and the second arm 20 are respectively arranged below the bottom portion 905 exposed on the lower side of the object 900 and the second control unit 902. Therefore, the posture of the object 900 is surely maintained in the second state.

[0084] Note that in the present embodiment, in a state where the control operation by the third control unit 93 is performed in this way, the control device 90 may perform an operation of supporting the object 900 and lifting it from the placement surface. That is, by moving the first arm 10 and the second arm 20 upward, the object 900 can be lifted from the placement surface in a state where the first arm 10 contacts the bottom portion 905 and the second arm 20 contacts the second side portion 902. The object 900 is lifted from the placement surface while being inclined from the first state as shown in, for example, FIG. 2 or FIG. 3. The robot system 1 may be able to convey the object 900 lifted in this way to another place.

[0085] As described above, in the present embodiment, the postures of the objects 900 on the placement surface can be changed by the first arm 10 and the second arm 20, and the dual-arm device 1 can be effectively utilized. Since the second arm 20 is located on the opposite side of the first arm 10 in the first direction, it can be provided so that the object 900 with a changed posture can be supported using the second arm 20.

[0086] FIG. 5 is a first diagram showing a usage example of the dual-arm device 1. FIG. 6 is a second diagram showing a usage example of the dual-arm device 1.

[0087] The applicable scenarios of such a dual-arm device 1 are, for example, scenarios where an object 900 is placed on a placement surface 911 such as a pallet 910 or a shelf, and the operation of lifting the object 900 from the pallet 910 is performed.

[0088] That is, in FIGS. 5 and 6, the transition of the operations of the first arm 10 and the second arm 20 in the state where the object 900 is placed on the pallet 910 is schematically shown in a front view (viewpoint from the back side). The object 900 is, for example, a rectangular parallelepiped. The object 900 has a first side portion 901 which is the right side surface (the left side surface in the figure), a second side portion 902 which is the left side surface, and a bottom portion 905 which is the bottom surface. In the front view, the front of the object 900 faces the front. In the figure, the marks shown in circular white and black schematically indicate the position of the center of gravity COG of the object 900.

[0089] The following operations can be executed, for example, by the control device 90 performing control according to a predetermined control method as described above. The control for moving the arms 10 and 20 to an appropriate position while remaining non-contact with the object 900 and the like can be performed, for example, by previously storing setting values regarding the position and the like in the control device 90 and the like, or by using the detection results of sensors such as cameras.

[0090] (Step S11) It is the first state where the object 900 is placed on the placement surface 911. First, the first arm 10 is arranged on the right side of the object 900, and the second arm 20 is arranged on the left side of the object 900. In this state, the control device 90 causes the first arm 10 to contact the first side portion 901. Then, the control device 90 moves the first arm 10 to the left, that is, in the direction approaching the second arm 20 in the left-right direction.

[0091] Here, in the present embodiment, it is preferable that the control device 90 brings the first arm 10 into contact with a position above the center of gravity COG in the vertical direction of the first side portion 901. Further, it is preferable that the control device 90 brings the first arm 10 into contact with the vicinity of the upper part of the object 900. Thereby, a larger moment can be generated so that the control device 90 rotates about the fulcrum 906, which is a part of the bottom portion 905 located relatively far from the first side portion 901.

[0092] (Step S12) As the first arm 10 moves as described above, the object 900 rotates about the fulcrum 906, and the portion of the bottom surface 905 other than the fulcrum 906 moves away from the placement surface 911. That is, the object 900 enters the second state. Further, as the first arm 10 moves to the left, the inclination of the object 900 increases. As shown by the dashed line in the figure, it is preferable that the first arm 10 is configured to move along a locus that draws an arc centered on the fulcrum 906.

[0093] Here, in this example, the second arm 20 moves while maintaining a state of being in contact with or close to the second side portion 902 as the first arm 10 moves. It is preferable that the second arm 20 is also configured to move along a locus that draws an arc centered on the fulcrum 906. Thereby, the object 900 can be stably tilted while maintaining the state where the fulcrum 906 is in contact with the placement surface 911.

[0094] (Step S13) When the inclination of the object 900 increases and the position of the center of gravity COG is located to the left of the fulcrum 906 in the left - right direction, the object 900 rotates due to gravity. Then, due to gravity, the weight of the object 900 acts on the second arm 20, and the force acting on the first arm 10 becomes smaller. Then, as described above, the control device 90 stops the movement of the first arm 10.

[0095] (Step S14) The object 900 is supported by the fulcrum 906 and the second arm 20. In this state, the control device 90 moves the first arm 10 from above the first side portion 901 to below the bottom portion 905. As a result, even if an external force or the like is applied to the object 900, the second state can be maintained because it is supported by the first arm 10 and the second arm 20.

[0096] (Step S15) Thereafter, the control device 90 displaces the first arm 10 and the second arm 20 upward. Then, the bottom portion 905 and the second side portion 902 come into contact with the first arm 10 and the second arm 20, and the object 900 is lifted while maintaining the posture in the second state. When the fulcrum 906 is separated from the mounting surface 911, the object 900 can be transported by the robot system 1 in a state where it is supported by the dual-arm device 1.

[0097] By performing the control as described above, the posture of the object 900 can be changed from the first state to the second state. Also, the state in which the object 900 is tilted can be surely maintained and held, or the object 900 can be lifted from the mounting surface 911 and made movable.

[0098] FIG. 7 is a third diagram showing an example of use of the dual-arm device 1.

[0099] Even when handling an object 900B in the shape of a box that is not a rectangular parallelepiped, the dual-arm device 1 can be used, for example, as described below. That is, in the figure, for example, a box-shaped object 900B having a shape that is triangular in a front view is shown. The object 900B has a first side portion 901, a second side portion 902, and a bottom portion 905 in a front view. The object 900B is triangular prism-shaped, but may be, for example, quadrangular pyramid-shaped.

[0100] Even when handling such an object 900B, the first arm 10 can be used to rotate the object 900B about the fulcrum 906 to a second state (step S21). Further, by supporting the second side portion 902 with the second arm 20 and supporting the bottom portion 905 with the moved first arm 10, it is possible to maintain the object 900B in an inclined state or lift the object 900B from the placement surface 911 (step S22).

[0101] As described above, according to the present embodiment, the dual-arm device 1 can be effectively utilized, and the convenience of the dual-arm device 1 can be enhanced.

[0102] FIG. 8 is a diagram showing a usage example of the first arm 310 and the second arm 320 according to a modified example of the present embodiment.

[0103] As shown in the figure, the dual-arm device 1 may be configured to include a first arm 310 and a second arm 320 configured to have movable parts 315 and 325 that come into contact with the object 900.

[0104] For example, the first arm 310 has a plate-shaped movable part 315 rotatably attached to a rod-shaped part 311 with the rod-shaped part 311 extending in the second direction as a rotation axis. The movable part 315 can contact the first side portion 901 with an area wider than that of the rod-shaped part 311. Similarly, the second arm 320 has a plate-shaped movable part 325 rotatably attached to a rod-shaped part 321 with the rod-shaped part 321 extending in the second direction as a rotation axis. The movable part 325 can contact the second side portion 902 with an area wider than that of the rod-shaped part 321.

[0105] By using the arms 310 and 320 configured in this way, when a force is applied to the object 900 by the first arm 310 or the second arm 320, the maximum value of the pressure on the surface of the object 900 can be reduced. Further, since the movable parts 315 and 325 are rotatable with respect to the rod-shaped parts 311 and 321, the above-described effects can be obtained without the need to rotate the arms 310 and 320 according to the inclination of the object 900.

[0106] Note that the processing in this embodiment may be realized by software. And this software may be distributed by software download or the like. Also, this software may be recorded on a recording medium such as an optical disk and distributed. Note that the software for executing the control method by the control device or the like in this embodiment is the following program. That is, this program is a program executed by a computer used together with a robot system or a dual-arm device, and in a state where the first arm and the second arm are respectively arranged so as to sandwich and line up in a first direction parallel to the mounting surface a box-shaped object placed with its bottom in contact with the mounting surface, the computer is made to execute a first step of bringing the first arm into contact with a first side portion of the object on the side closer to the first arm than the second arm, and a second step of changing the posture of the object so that the object tilts while a part of the bottom of the object closer to the second arm than the first arm in the first direction remains in contact with the mounting surface by moving the first arm closer to the second arm in the first direction in a state where the first arm is in contact with the first side portion.

[0107] (Others)

[0108] Also, in the above embodiment, two or more components existing in one device may be physically realized by one medium.

[0109] In the above-described embodiment, the components of the control device 90 that controls the dual-arm device 1 may be configured by dedicated hardware, or for components that can be realized by software, they may be realized by executing a program. For example, each component can be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. At the time of its execution, the program execution unit may execute the program while accessing a storage unit or a recording medium. Also, the program may be executed by being downloaded from a server or the like, or may be executed by reading a program recorded on a predetermined recording medium (for example, an optical disk, a magnetic disk, a semiconductor memory, etc.). Further, this program may be used as a program constituting a program product. Also, the computer that executes the program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

[0110] Also, in the above-described embodiment, each process (each function) may be realized by being centrally processed by a single device (system), or may be realized by being distributedly processed by a plurality of devices (in this case, the entire system composed of a plurality of devices performing distributed processing can be grasped as one "device").

[0111] Also, in the above-described embodiment, the transfer of information performed between each component may be, for example, when the two components that transfer the information are physically different, by the output of information by one component and the reception of information by the other component, or when the two components that transfer the information are physically the same, by moving from the processing phase corresponding to one component to the processing phase corresponding to the other component.

[0112] Also, in the above-described embodiments, information related to the processing executed by each component, for example, information received, acquired, selected, generated, transmitted, or received by each component, and information such as thresholds, mathematical formulas, addresses, etc. used by each component in the processing may be temporarily or permanently stored in a recording medium not shown even if not specified in the above description. Also, the accumulation of information in the recording medium not shown may be performed by each component or an accumulation unit not shown. Also, the reading of information from the recording medium not shown may be performed by each component or a reading unit not shown.

[0113] Also, in the above-described embodiments, when information used by each component or the like, for example, information such as thresholds, addresses, and various setting values used by each component in the processing may be changed by the user, even if not specified in the above description, the user may appropriately be able to change such information, or not. When the user can change such information, the change may be realized, for example, by a reception unit not shown that receives a change instruction from the user and a change unit not shown that changes the information in response to the change instruction. The reception of the change instruction by the reception unit not shown may be, for example, reception from an input device, reception of information transmitted via a communication line, or reception of information read from a predetermined recording medium.

[0114] The present invention is not limited to the above-described embodiments and various modifications are possible, and these are also included within the scope of the present invention.

[0115] The components of the above-described embodiments and modifications may be appropriately replaced or combined with other elements. Also, some components and functions in the above-described embodiments and modifications may be omitted.

[0116] The robot system is not limited to the conveyance device as described above. The robot system may not have a cart. For example, the robot system may be fixed to a fixed pedestal or the like.

Industrial Applicability

[0117] As described above, the control device for the dual-arm device according to the present invention can change the posture of an object on the placement surface by the dual-arm device, and is useful for dual-arm devices and the like.

Explanation of Signs

[0118] 1 Dual-arm device, 5 Force sensor, 10,310 First arm, 20,320 Second arm, 80 Power source, 90 Control device, 91 First control unit, 92 Second control unit, 93 Third control unit, 100 Robot system, 900,900B Object, 901 First side part, 902 Second side part, 905 Bottom part, 906 Fulcrum (a part of the bottom), 911 Placement surface

Claims

1. A control device for a dual-arm device that controls an operation of a dual-arm device configured to be able to change the positions of a first arm and a second arm by a power source, a first control unit that brings the first arm into contact with a first side portion of a box-shaped object that is placed on a placement surface with its bottom portion in contact with the placement surface, the first arm and the second arm being arranged side by side to sandwich the box-shaped object in a first direction parallel to the placement surface; and a second control unit that changes a posture of the object so that the object tilts while a portion of the bottom of the object that is closer to the second arm than the first arm in the first direction remains in contact with the placement surface by moving the first arm in a first direction toward the second arm while the first arm is in contact with the first side portion.

2. the first control unit disposes the second arm so that the second arm contacts a second side portion of the object that is closer to the second arm than the first arm or is located in the vicinity of the second side portion; The control device for a dual-arm device according to claim 1, wherein the second control unit moves the second arm in association with the movement of the first arm so that the second arm remains in contact with the second side portion or so that the second arm is positioned in the vicinity of the second side portion.

3. The control device for a dual-arm device described in claim 1, wherein the second control unit moves the first arm so that a trajectory of the first arm describes an arc centered on a part of the bottom that contacts the placement surface when viewed from a second direction that is parallel to the placement surface and perpendicular to the first direction.

4. a force sensor capable of detecting a force applied to at least one of the first arm and the second arm, The control device for a dual-arm device according to claim 1 , wherein the second control unit terminates the movement of the first arm when it determines that the detection result of the force sensor satisfies a predetermined stop condition.

5. The control device for a dual-arm device according to claim 4 , further comprising a third control unit that moves the first arm between the bottom portion and the placement surface after the second control unit has finished moving the first arm.

6. a dual-arm device configured to change positions of a first arm and a second arm by a power source; A robot system comprising the control device according to claim 1, configured to be able to change the posture of a box-shaped object placed with its bottom in contact with a placement surface.

Images