Processing device, suction mechanism control unit, program, processing system, and suction mechanism

Abstract

This processing device comprises a suction force determination unit which determines, on the basis of first object information pertaining to an object, a suction force of a suction mechanism which suctions the object.

Description

Processing device, adsorption mechanism control unit, program, processing system, and adsorption mechanism

[0001] The present disclosure relates to a technique for adsorbing an object.

[0002] Patent Document 1 describes a technology for adsorbing an object.

[0003] Japanese Patent Application Laid-Open No. 2021-130188

[0004] A processing device, a suction mechanism control unit, a program, a processing system, and a suction mechanism are disclosed. In one embodiment, the processing device includes an suction force determination unit that determines an suction force when the suction mechanism suctions an object based on first object information about the object.

[0005] In one embodiment, the suction mechanism control unit controls the suction mechanism based on the suction force determination result of the suction force determination unit.

[0006] In one embodiment, the program is a program for causing a computer device to function as the processing device.

[0007] In one embodiment, the program is a program for causing a computer device to function as the above-mentioned suction mechanism control unit.

[0008] In one embodiment, a processing system includes a suction mechanism that suctions an object, and the processing device described above that determines the suction force when the suction mechanism suctions the object.

[0009] In one embodiment, the suction mechanism is a suction mechanism that suctions an object. The suction mechanism includes a first suction portion, a second suction portion, and a drive mechanism. The first suction portion has a first suction opening. The second suction portion has a second suction opening that is smaller than the first suction opening and is movable relative to the first suction portion within the first suction portion. The drive mechanism moves the second suction portion relative to the first suction portion within the first suction portion so that the second suction opening moves in and out of the first suction portion relatively. The drive mechanism is capable of switching between a first state in which the first suction portion suctions the object and a second state in which the second suction portion suctions the object.

[0010] 1 is a schematic diagram showing an example of a system. FIG. 1 is a schematic diagram showing an example of a robot control device. FIG. 1 is a schematic diagram showing an example of a hand control device (processing device). FIG. 1 is a schematic diagram showing an example of a robot hand. FIG. 1 is a schematic diagram showing an example of a robot hand. FIG. 1 is a schematic diagram showing an example of a robot hand. FIG. 1 is a schematic diagram showing an example of a robot hand. FIG. 1 is a schematic diagram showing an example of a configuration of a part of a system. FIG. 1 is a schematic diagram showing an example of an object. FIG. 1 is a schematic diagram showing an example of an operation of a robot control device and a hand control device. FIG. 1 is a schematic diagram showing an example of a positional relationship between a plurality of suction units. FIG. 1 is a schematic diagram showing an example of a positional relationship between a plurality of suction units. FIG. 1 is a schematic diagram showing an example of an operation of a robot control device and a hand control device. FIG. 1 is a schematic diagram showing an example of a configuration of a part of a system. FIG. 1 is a schematic diagram showing an example of a robot hand. FIG. 1 is a schematic diagram showing an example of an suction unit. FIG. 1 is a schematic diagram showing an example of an suction unit and a switching unit. FIG. 1 is a schematic diagram showing an example of an operation of a robot control device and a hand control device. FIG. 1 is a schematic diagram showing an example of an operation of a robot control device and a hand control device. FIG. 1 is a schematic diagram showing an example of a robot hand. FIG. 1 is a schematic diagram showing an example of a sensor unit. FIG. 1 is a schematic diagram showing an example of a memory unit. FIG. 1 is a schematic diagram showing an example of a memory unit.

[0011] FIG. 1 is a schematic diagram showing an example of a system 1 including a suction mechanism 50. The suction mechanism 50 is capable of suctioning an object 8 and changing the suction force when suctioning the object 8. The system 1 is, for example, a robot system including a robot 2 having the suction mechanism 50. Hereinafter, an example will be described in which the system 1 is a robot system, but the system 1 may be a system other than a robot system. The system 1 that is a robot system may be referred to as a robot system 1.

[0012] The robot system 1 includes, for example, a robot 2 and a robot control system 10 that controls the robot 2. The robot control system 10 (also referred to as a control system 10 or a processing system 10) includes, for example, a system control device 11, a robot control device 12, a hand control device 13, a terminal device 14, and a camera sensor 15.

[0013] The robot 2 performs a task of, for example, moving an object 8 from a work start platform to a work target platform. The robot 2 includes, for example, an arm 3 and a robot hand 4 connected to the arm 3. The robot hand 4 includes, for example, an adsorption mechanism 50 capable of adsorbing and holding one object 8. The adsorption mechanism 50 includes, for example, an adsorption structure 40 having at least one adsorption portion 41 that adsorbs one object 8, and a negative pressure generating unit 51 (see FIG. 9 described later) that generates negative pressure in the at least one adsorption portion 41. The adsorption mechanism 50 also includes, for example, a drive mechanism 52 (see FIG. 9 described later) that changes the position of the at least one adsorption portion 41. The robot 2 adsorbs, for example, the object 8 on the work start platform with the adsorption structure 40. Then, the robot 2 moves the arm 3 with the object 8 adsorbed by the adsorption structure 40 to move the object 8 to the work target platform. The object 8 is also referred to as a workpiece. Note that the task performed by the robot 2 is not limited to this. In the following, an example will be described in which the suction structure 40 has a plurality of suction portions 41, but the number of suction portions 41 that the suction structure 40 has may be one.

[0014] The system control device 11, the robot control device 12, the terminal device 14, and the camera sensor 15 are connected to a network 16 including, for example, the Internet. The system control device 11, the robot control device 12, the terminal device 14, and the camera sensor 15 can communicate with each other through the network 16. The hand control device 13 may also be connected to the network 16. Furthermore, at least two of the system control device 11, the robot control device 12, the hand control device 13, the terminal device 14, and the camera sensor 15 may communicate with each other directly without going through the network 16. Each of the system control device 11, the robot control device 12, the hand control device 13, and the terminal device 14 can also be considered a processing device.

[0015] The camera sensor 15 is capable of, for example, capturing an image of the work area of ​​the robot 2. The camera sensor 15 is capable of, for example, capturing an image of the object 8. The camera sensor 15 is capable of, for example, generating a distance image including distance information to each measurement point within the work area, and a color image showing the object 8. The camera sensor 15 is also called a three-dimensional camera. The camera sensor 15 is capable of outputting the generated distance image and color image to the network 16.

[0016] The system control device 11 manages the overall operation of the robot control system 10. The system control device 11 is, for example, a type of computer device. The system control device 11 may be, for example, configured as a cloud server.

[0017] The terminal device 14 is capable of receiving input from a user and sending notifications to the user. The terminal device 14 is, for example, a type of computer device. The terminal device 14 may be, for example, a desktop or notebook personal computer, a tablet terminal, a mobile phone such as a smartphone, or other device. The user can input, for example, information required for controlling the robot 2 to the terminal device 14.

[0018] The terminal device 14 includes, for example, an input unit that accepts input from a user and a notification unit that notifies the user. The input unit may include, for example, a mouse and a keyboard. The input unit may also include a touch sensor that accepts touch operations by the user. The notification unit may also include a display unit that can display various information. The display unit may be, for example, a liquid crystal display, an organic electroluminescence (EL) display, or a plasma display. Furthermore, when the input unit includes a touch sensor, the touch sensor and the display unit may constitute a touch panel display having a display function and a touch detection function. The touch panel display can detect touch operations on the display surface of the display unit. The notification unit may also include a speaker. The input unit and the notification unit constitute a user interface.

[0019] The robot controller 12 manages the overall operation of the robot 2. The robot controller 12 can control, for example, the arm 3. The position and posture of the arm 3 are controlled by the robot controller 12, so that the object 8 held by the robot hand 4 moves from the work start table to the work target table.

[0020] Fig. 2 is a schematic diagram showing an example of the configuration of the robot control device 12. As shown in Fig. 2, the robot control device 12 includes, for example, a control unit 120, a storage unit 121, an interface 122, and an interface 123. The robot control device 12 can also be called, for example, a control circuit. The robot control device 12 is, for example, a type of computer device.

[0021] The interface 122 is capable of communicating with the network 16 based on a communication standard such as Wi-Fi. The interface 122 can also be referred to as, for example, an interface circuit. The interface 122 can also be referred to as, for example, a communication unit or a communication circuit. The interface 122 may be connected to the network 16 by wire or wirelessly. The interface 122 inputs information received from the network 16 to the control unit 120. The interface 122 also outputs information from the control unit 120 to the network 16.

[0022] The interface 123 is capable of exchanging information with the hand control device 13. The control unit 120 is capable of exchanging information with the hand control device 13 through the interface 123. The interface 123 can also be referred to as, for example, an interface circuit.

[0023] The control unit 120 can generally manage the operation of the robot control unit 12 by controlling the other components of the robot control unit 12. The control unit 120 can also be referred to as a control circuit, for example. The control unit 120 includes at least one processor to provide control and processing power for performing various functions, as described in more detail below.

[0024] According to various embodiments, the at least one processor may be implemented as a single integrated circuit (IC) or as multiple communicatively connected integrated circuits ICs and / or discrete circuits. The at least one processor may be implemented according to various known techniques.

[0025] In one embodiment, a processor includes one or more circuits or units configured to perform one or more data-computing procedures or processes, e.g., by executing instructions stored in associated memory. In other embodiments, a processor may be firmware (e.g., discrete logic components) configured to perform one or more data-computing procedures or processes.

[0026] According to various embodiments, the processor may include one or more processors, controllers, microprocessors, microcontrollers, application specific integrated circuits (ASICs), digital signal processors, programmable logic devices, field programmable gate arrays, or any combination of these devices or configurations, or other known devices and configurations, to perform the functions described below.

[0027] The control unit 120 may include, for example, a central processing unit (CPU) as a processor. The storage unit 121 may include a non-transitory recording medium readable by the CPU of the control unit 120, such as a read-only memory (ROM) and a random access memory (RAM). The storage unit 121 may include, for example, a non-volatile memory such as a non-volatile random access memory (NVRAM). The storage unit 121 stores, for example, a program 121a for controlling the robot control device 12. Various functions of the control unit 120 are realized, for example, by the CPU of the control unit 120 executing the program 121a in the storage unit 121.

[0028] The configuration of the control unit 120 is not limited to the above example. For example, the control unit 120 may include multiple CPUs. The control unit 120 may also include at least one DSP (Digital Signal Processor). All or some of the functions of the control unit 120 may be implemented by a hardware circuit that does not require software to implement the function. The storage unit 121 may also include a computer-readable non-transitory recording medium other than ROM and RAM. The storage unit 121 may also include, for example, a small hard disk drive or SSD (Solid State Drive).

[0029] The hand control device 13 as a processing device is capable of controlling the robot hand 4. The hand control device 13 may be provided inside the robot hand 4 or outside the robot hand 4. The hand control device 13 acquires information addressed to the hand control device 13 from the network 16 via the robot control device 12. The hand control device 13 also outputs information addressed to the network 16 to the network 16 via the robot control device 12. Figure 3 is a schematic diagram showing an example of the configuration of the hand control device 13.

[0030] 3, the hand control device 13 includes, for example, a control unit 130, a storage unit 131, and an interface 132. The hand control device 13 can also be called, for example, a control circuit. The hand control device 13 is, for example, a type of computer device.

[0031] The interface 132 is capable of exchanging information with the interface 123 of the robot control device 12. The control unit 130 is capable of exchanging information with the robot control device 12 through the interface 132. The interface 132 can also be referred to as, for example, an interface circuit.

[0032] The control unit 130 is capable of overall management of the operation of the hand control device 13 by controlling the other components of the hand control device 13. The control unit 130 may also be referred to as, for example, a control circuit. The control unit 130 includes at least one processor to provide control and processing capabilities for executing various functions, as will be described in more detail below. The above description of the processor included in the control unit 120 of the robot control device 12 also applies to the processor included in the control unit 130.

[0033] The control unit 130 may include, for example, a CPU as a processor. The storage unit 131 may include a non-transitory recording medium readable by the CPU of the control unit 130, such as a ROM or a RAM. The storage unit 131 may include, for example, an NVRAM as a non-volatile memory. The storage unit 131 stores, for example, a program 131a for controlling the hand control device 13. The various functions of the control unit 130 are realized, for example, by the CPU of the control unit 130 executing the program 131a in the storage unit 131.

[0034] The configuration of the control unit 130 is not limited to the above example. For example, the control unit 130 may include multiple CPUs. The control unit 130 may also include at least one DSP. All or some of the functions of the control unit 130 may be realized by a hardware circuit that does not require software to realize the function. Similarly to the storage unit 121, the storage unit 131 may include a computer-readable non-transitory recording medium other than ROM and RAM.

[0035] In the processing system 10 having the above configuration, when information output by the terminal device 14 is input to the robot control device 12 or the hand control device 13, the information is input to the robot control device 12 or the hand control device 13, for example, via the system control device 11. Also, when information output by the robot control device 12 or the hand control device 13 is input to the terminal device 14, the information is input to the terminal device 14, for example, via the system control device 11. Also, when the distance image and color image output by the camera sensor 15 are input to the robot control device 12 or the hand control device 13, the distance image and color image are input to the robot control device 12 or the hand control device 13, for example, via the system control device 11.

[0036] The information output by the terminal device 14 may be input to the robot control device 12 or the hand control device 13 without passing through the system control device 11. The information output by the robot control device 12 or the hand control device 13 may be input to the terminal device 14 without passing through the system control device 11. The distance image and color image output by the camera sensor 15 may be input to the robot control device 12 or the hand control device 13 without passing through the system control device 11.

[0037] The robot control system 10 may include a plurality of system control devices 11. The robot control system 10 may also include a plurality of robot control devices 12. The robot control system 10 may also include a plurality of hand control devices 13. The robot control system 10 may also include a plurality of terminal devices 14. The robot system 1 may also include a plurality of robots 2. In this case, each robot 2 may be controlled by at least one robot control device 12. The robot hand 4 included in each robot 2 may also be controlled by at least one hand control device 13.

[0038] 4 to 8 are schematic diagrams showing an example of a robot hand 4. As shown in FIGS. 4 to 8, the robot hand 4 includes, for example, an outer case 45 that houses multiple components, and an adsorption structure 40 that protrudes from the outer case 45. The outer case 45 includes, for example, a main body 46 and a connection portion 47 that connects to the arm 3. The connection portion 47 forms the wrist portion of the robot hand 4. Hereinafter, the connection portion 47 will also be referred to as the wrist portion 47. The main body 46 houses, for example, a negative pressure generator 51, a drive mechanism 52, and the like. The robot hand 4 includes an adsorption mechanism 50 that has the adsorption structure 40, the negative pressure generator 51, and the drive mechanism 52.

[0039] The suction structure 40 includes, for example, four suction portions 41. Each suction portion 41 protrudes from the bottom surface 46a of the main body portion 46. Each suction portion 41 is movable along the bottom surface 46a. Each suction portion 41 is movable in a planar direction within the bottom surface 46a. Each suction portion 41 is movable individually, in other words, individually movable. The positional relationship between the multiple suction portions 41 is changeable in a planar direction along the bottom surface 46a. In the robot hand 4, the positional relationship between the multiple suction portions 41 is changeable. The suction portions 41 are also called suction nozzles, for example. The bottom surface 46a of the main body portion 46 is rectangular, for example.

[0040] Each suction portion 41 has a suction pad 410 at its tip. The suction pad 410 is made of an elastic material such as synthetic rubber. The suction pad 410 is hollow and has a suction opening 411. The suction openings 411 of the multiple suction pads 410 are, for example, the same size as one another. The suction openings 411 of the multiple suction pads 410 are, for example, the same shape as one another. When the suction portion 41 suctions the object 8, an opening edge 412 of the suction opening 411 in the suction pad 410 abuts against the object 8, and the suction opening 411 is blocked by the object 8. Then, the negative pressure generator 51 (described later) reduces the pressure inside the suction pad 410, causing the opening edge 412 of the suction pad 410 to tightly contact the object 8. As a result, the object 8 is suctioned by the suction pad 410. When the suction pad 410 suctions the object 8, the reduced pressure inside the suction pad 410 causes the suction pad 410 to elastically deform and shrink. This reduces the height of the suction pad 410 and the diameter of the suction opening 411. The suction pad 410 may be flat as in the examples of FIGS. 4 to 8, or may be bellows-shaped. The suction pad 410 is also called a vacuum pad. The multiple suction pads 410 are located, for example, on the same plane. The multiple suction pads 410 are arranged along the bottom surface 46a of the main body portion 46. Hereinafter, the imaginary arrangement plane on which the multiple suction pads 410 are arranged is referred to as the pad arrangement plane. The pad arrangement plane is, for example, parallel to the bottom surface 46a.

[0041] As shown in FIGS. 5 to 8 , the bottom surface 46a of the main body portion 46 of the exterior case 45 is provided with a plurality of grooves 460 corresponding to the plurality of suction portions 41. The grooves 460 are spaced apart from one another. The corresponding suction portions 41 partially protrude from the grooves 460. The suction portions 41 are movable along the corresponding grooves 460. This allows the suction pads 410 of the suction portions 41 to move along the grooves 460 corresponding to the suction portions 41. Note that one groove may be provided for the plurality of suction portions 41. As in the examples of FIGS. 5 to 8 , by providing individual grooves 460 for each of the plurality of suction portions 41, interference between the plurality of suction portions 41 can be reduced when controlling the positions of the plurality of suction portions 41.

[0042] Each groove 460 is, for example, L-shaped. Each groove 460 has a first groove 461 and a second groove 462 that extends from one longitudinal end of the first groove 461 in a direction different from the first groove 461. The second groove 462 extends, for example, perpendicularly from the first groove 461. The first groove 461 extends from one corner of the bottom surface 46a along a short side of the bottom surface 46a and reaches near the center of the short side. The second groove 462 extends from one end of the first groove 461 in the longitudinal direction, which is closer to the center of the short side of the bottom surface 46a, along the long side of the bottom surface 46a and reaches near the center of the long side.

[0043] 6 to 8 show how the positional relationship of the multiple suction portions 41 changes. In the example of FIG. 6 , each suction portion 41 is located at the end of the first groove 461 of the corresponding groove 460, on the corner side of the bottom surface 46 a. As a result, the four suction portions 41 of the suction structure 40 are located at the four corners of the bottom surface 46 a. When each suction portion 41 moves along the first groove 461 from the state shown in FIG. 6 , the positional relationship of the multiple suction portions 41 becomes, for example, as shown in FIG. 7 . In the example of FIG. 7 , each suction portion 41 is located at the corner of the corresponding groove 460 (i.e., the boundary between the first groove 461 and the second groove 462). When each suction portion 41 moves along the second groove 462 from the state shown in FIG. 7 , the positional relationship of the multiple suction portions 41 becomes, for example, as shown in FIG. 8 . In the example of FIG. 8 , each suction portion 41 is located at the end of the second groove 462 of the corresponding groove 460, opposite the first groove 461. As a result, the plurality of suction portions 41 are positioned at the center of the bottom surface 46a.

[0044] As described above, each groove 460 includes the first groove 461 and the second groove 462 extending in different directions, so that each suction portion 41 is movable in two directions in the planar direction along the bottom surface 46 a. This allows the positional relationship of the multiple suction portions 41 to be changed in two directions in the planar direction along the bottom surface 46 a.

[0045] The shape of the grooves 460 is not limited to the above example. In the examples of FIGS. 5 to 8 , each groove 460 is L-shaped. However, for example, each groove 460 may be U-shaped, having one first groove 461 and two opposing second grooves 462, or may be U-shaped, having one second groove 462 and two opposing first grooves 461. Furthermore, each groove 460 may be square-shaped, having two opposing first grooves 461 and two opposing second grooves 462. Furthermore, each groove 460 may be linear, having one first groove 461 or one second groove 462. Furthermore, although the multiple grooves 460 have similar shapes in the examples of FIGS. 5 to 8 , the multiple grooves 460 may have different shapes. Furthermore, some of the multiple grooves 460 may have shapes different from the other parts. When each groove 460 has at least two grooves extending in different directions, each suction portion 41 can move in at least two directions in a plane along the bottom surface 46 a. In this case, the positional relationship between the multiple suction portions 41 can be changed in at least two directions in a plane along the bottom surface 46 a.

[0046] Furthermore, the degree of freedom of movement of the suction units 41 is not limited to the above example. The positional relationship between the multiple suction units 41 is set based on object information related to the object 8, as will be described later. The degree of freedom of movement of each suction unit 41 may be set appropriately so that examples of setting the positional relationship between the multiple suction units 41 (for example, the examples in Figures 12 to 14) described later can be realized.

[0047] 9 is a schematic diagram showing an example of a configuration related to control of the robot hand 4 in the robot system 1. As shown in Fig. 9, the robot 2 includes, for example, a negative pressure generating unit 51, a driving mechanism 52, and a sensor unit 59 for acquiring various information related to the robot 2.

[0048] The negative pressure generator 51 included in the suction mechanism 50 is connected to the multiple suction units 41 and can generate negative pressure in each suction pad 410 to reduce the pressure inside each suction pad 410. The negative pressure generator 51 is controlled by the hand control device 13. The negative pressure generator 51 can also release the generation of negative pressure in each suction pad 410. When a suction pad 410 is suctioning an object 8, if the generation of negative pressure in the suction pad 410 is released, the suction pad 410 releases the suction of the object 8. The smaller the negative pressure in the suction pad 410, the greater the suction force of the suction pad 410 (in other words, the suction force of the suction unit 41 that includes the suction pad 410).

[0049] The negative pressure generating unit 51 is controlled by the hand control device 13 to change the suction force of the suction mechanism 50 when the suction mechanism 50 suctions the object 8. Here, when the suction mechanism 50 includes multiple suction units 41, as in the examples of FIGS. 4 to 8 , changing the suction force of the suction mechanism 50 means changing the suction force of at least one of the multiple suction units 41. Furthermore, when the suction mechanism 50 releases its suction of the object 8, the suction force of the suction mechanism 50 can also be considered to be changed to zero. This suction force of the suction mechanism 50 when the suction mechanism 50 releases its suction of the object 8 (i.e., zero suction force) is not included in the suction force of the suction mechanism 50 when it suctions the object 8.

[0050] The negative pressure generator 51 includes, for example, a vacuum pump. The negative pressure generator 51 may be able to individually change the suction force of each suction unit 41. In this case, the negative pressure generator 51 may include multiple vacuum pumps that generate negative pressure in each of the multiple suction units 41. Alternatively, the negative pressure generator 51 may be able to collectively change the suction force of the multiple suction units 41. In this case, the negative pressure generator 51 may include a single vacuum pump that generates negative pressure in the multiple suction units 41. The suction force of the suction unit 41 is determined based on the negative pressure in the suction pad 410 of the suction unit 41 and the size (more specifically, the area) of the suction opening 411 of the suction pad 410. The negative pressure generator 51 can change the suction force of the suction unit 41 by changing the negative pressure generated in the suction pad 410 of the suction unit 41. The negative pressure generator 51 is provided, for example, in the main body 46 of the exterior case 45 of the robot hand 4. The negative pressure generating unit 51 may include an ejector that generates a vacuum from compressed air.

[0051] The drive mechanism 52 included in the suction mechanism 50 is capable of, for example, moving each suction unit 41. In other words, the drive mechanism 52 is capable of changing the position of each suction unit 41. It can also be said that the drive mechanism 52 is capable of changing the positional relationship between the multiple suction units 41. The drive mechanism 52 is controlled by the hand control device 13.

[0052] The drive mechanism 52 may be configured, for example, by an electric actuator including a motor. The drive mechanism 52 may be able to move each suction unit 41 individually. In other words, the drive mechanism 52 may be able to change the position of each suction unit 41 individually. In this case, the drive mechanism 52 may include a plurality of electric actuators that move the plurality of suction units 41, respectively. The drive mechanism 52 may also be able to move the plurality of suction units 41 collectively. In other words, the drive mechanism 52 may be able to change the positions of the plurality of suction units 41 collectively. In this case, the drive mechanism 52 may include a single electric actuator that moves the plurality of suction units 41 collectively. The drive mechanism 52 is provided, for example, in the main body portion 46 of the exterior case 45 of the robot hand 4.

[0053] The sensor unit 59 includes multiple types of sensors, such as a position sensor 53, a negative pressure detection sensor 54, a pressure sensor 55, a force sensor 56, and a distance sensor 57. The detection results of the position sensor 53, the negative pressure detection sensor 54, the pressure sensor 55, the force sensor 56, and the distance sensor 57 are input to the hand control device 13.

[0054] The position sensor 53 can detect the rotational position of the motor included in the drive mechanism 52. The position sensor 53 is, for example, a rotary encoder. If the drive mechanism 52 includes multiple motors, the sensor unit 59 may include multiple position sensors 53 that detect the rotational positions of the multiple motors. The suction mechanism control unit 137 (described below) included in the hand control device 13 identifies the position of each suction unit 41 based on the detection result of at least one position sensor 53 included in the sensor unit 59. The suction mechanism control unit 137 then controls the drive mechanism 52 based on the identification result to set each suction unit 41 to a desired position. In other words, the suction mechanism control unit 137 controls the drive mechanism 52 based on the identification result to set the positional relationship between the multiple suction units 41 to a desired positional relationship. The position sensor 53 is provided, for example, in the main body portion 46 of the exterior case 45.

[0055] The sensor unit 59 includes a plurality of negative pressure detection sensors 54 corresponding to the plurality of suction units 41, respectively. Each negative pressure detection sensor 54 is capable of detecting the negative pressure within the suction pad 410 of the corresponding suction unit 41. The negative pressure detection sensors 54 may be semiconductor-type, metal thin film-type, or other types. The negative pressure detection sensors 54 are provided, for example, within the main body portion 46 of the exterior case 45.

[0056] The sensor unit 59 includes a plurality of pressure sensors 55 corresponding to the plurality of suction units 41, respectively. Each pressure sensor 55 detects the contact pressure of the suction pad 410 of the corresponding suction unit 41 against the object 8. For example, if the suction pad 410 is made of pressure-sensitive conductive rubber, the suction pad 410 may constitute part of the pressure sensor 55. Pressure-sensitive conductive rubber is rubber whose electrical resistance changes depending on the pressure applied thereto. If the suction pad 410 is made of pressure-sensitive conductive rubber, the electrical resistance of the suction pad 410 changes depending on the contact pressure of the suction pad 410 against the object 8. The pressure sensor 55 may detect the electrical resistance of the suction pad 410 made of pressure-sensitive conductive rubber and output the detection result as the detection result of the contact pressure of the suction pad 410 against the object 8. Note that the pressure sensor 55 may be a semiconductor-type pressure sensor or a metal thin-film-type pressure sensor. In this case, the suction pad 410 may include the pressure sensor 55 at its opening edge 412.

[0057] The force sensor 56 is provided, for example, in the wrist portion 47 of the exterior case 45. The force sensor 56 can detect, for example, forces and moments acting on the robot hand 4. The force sensor 56 is, for example, a six-axis force sensor. The force sensor 56 can detect forces acting on the robot hand 4 in the x-axis direction, forces acting on the robot hand 4 in the y-axis direction, and forces acting on the robot hand 4 in the z-axis direction. The force sensor 56 can also detect moments acting on the robot hand 4 about the x-axis, moments acting on the robot hand 4 about the y-axis, and moments acting on the robot hand 4 about the z-axis. The z-axis is set, for example, in a direction perpendicular to the bottom surface 46a of the main body portion 46 of the exterior case 45. The x-axis is set in a direction perpendicular to the z-axis, and the y-axis is set in a direction perpendicular to the z-axis and x-axis. The x-axis and y-axis are parallel to the bottom surface 46a. The force sensor 56 may be, for example, an electrical resistance type, a capacitance type, a piezoelectric type, or an optical type.

[0058] The sensor unit 59 includes a plurality of distance sensors 57 corresponding to the plurality of suction units 41, respectively. Each distance sensor 57 detects the distance between the corresponding suction unit 41 and the object 8. The distance sensor 57 is also called a distance measurement sensor. The distance sensor 57 may be, for example, an optical type using a laser or the like, a radio wave type using millimeter waves or the like, or an ultrasonic type using ultrasonic waves. The distance sensor 57 is provided, for example, at a location other than the suction pad 410 in the suction unit 41. When the suction pad 410 is pressed against the object 8 and deforms, the distance detected by the distance sensor 57 becomes smaller. The distance detected by the distance sensor 57 indicates the degree of pressing of the suction pad 410 against the object 8, in other words, the degree of contact of the suction pad 410 with the object 8. The distance detected by the distance sensor 57 also indicates the degree of adhesion of the suction pad 410 to the object 8.

[0059] The control unit 130 of the hand control device 13 can control the robot hand 4 based on the detection results of the sensor unit 59. The control unit 130 can control the suction force of the suction structure 40 by controlling the negative pressure generating unit 51. The control unit 130 can control the position of each suction unit 41 of the suction structure 40 by controlling the drive mechanism 52.

[0060] The CPU of the control unit 130 executes the program 131a in the storage unit 131, whereby the control unit 130 forms an attractive force determination unit 135, a position determination unit 136, an attractive mechanism control unit 137, and a determination unit 138 as functional blocks. Note that all or some of the functions of the attractive force determination unit 135 may be realized by a hardware circuit that does not require software to realize the function. The same applies to the position determination unit 136, the attractive mechanism control unit 137, and the determination unit 138.

[0061] The suction force determination unit 135 determines the suction force with which the suction mechanism 50 suctions the object 8, based on the first object information related to the object 8. Hereinafter, unless otherwise specified, the suction force refers to the suction force with which the object 8 is suctioned. When the suction mechanism 50 includes a plurality of suction units 41, determining the suction force of the suction mechanism 50 means determining the suction force of at least one of the plurality of suction units 41.

[0062] The adhesive force determination unit 135 determines the adhesive force of each adhesive unit 41 based on, for example, the first object information. The adhesive force determination unit 135 can determine the adhesive force of the adhesive unit 41 for each object 8 by using the first object information. For example, the adhesive force determination unit 135 can determine the adhesive force of the adhesive unit 41 depending on the type of object 8. Note that as a result of the adhesive force determination unit 135 determining the adhesive force of the adhesive unit 41 based on each piece of first object information for multiple objects 8 of different types, the adhesive unit 41 may adhesively attach multiple objects 8 of different types with the same adhesive force.

[0063] The position determination unit 136 determines the position of each suction unit 41 based on the second object information related to the object 8. It can also be said that the position determination unit 136 determines the positional relationship of the multiple suction units 41 based on the second object information. The position determination unit 136 can determine the position of the suction unit 41 for each object 8 by using the second object information. For example, the position determination unit 136 can determine the position of the suction unit 41 according to the type of object 8. It can also be said that the position determination unit 136 can determine the positional relationship of the multiple suction units 41 for each object 8. Note that as a result of the position determination unit 136 determining the positions of the suction units 41 based on each of the second object information for multiple objects 8 of different types, the positions of the suction units 41 may end up being the same.

[0064] The suction mechanism control unit 137 controls the negative pressure generating unit 51 based on the suction force determination result of the suction force determination unit 135. The suction mechanism control unit 137 can cause the negative pressure generating unit 51 to change the suction force of the suction mechanism 50. The suction mechanism control unit 137 controls the negative pressure generating unit 51 so that, for each suction unit 41, a negative pressure is generated in the suction pad 410 of the suction unit 41 such that the suction force of the suction unit 41 becomes the suction force determined by the suction force determination unit 135. Here, the control unit 130 can control the suction force of each suction unit 41 based on the first object information, but may also be able to control the suction forces of only some of the multiple suction units 41.

[0065] Furthermore, the suction mechanism control unit 137 controls the drive mechanism 52 based on the determination result of the position determination unit 136. The suction mechanism control unit 137 can cause the drive mechanism 52 to change the position of each suction unit 41. The suction mechanism control unit 137 controls the drive mechanism 52 so that the position of each suction unit 41 becomes the position determined by the position determination unit 136. Here, the control unit 130 can control the position of each suction unit 41, but may also be able to control the positions of only some of the multiple suction units 41. In this case, grooves 460 corresponding to suction units 41 whose positions are not controlled may not be provided.

[0066] The first object information and the second object information are stored in the storage unit 131. Each of the first object information and the second object information is updated, for example, whenever the type of the object 8 is changed. The first object information may be the same as the second object information or may be different from the second object information. In the former case, instead of the first object information and the second object information being prepared separately, common object information may be prepared for the attraction force determination unit 135 and the position determination unit 136, and the object information may be used as both the first object information and the second object information.

[0067] The first object information may include, for example, weight information indicating the weight of the object 8 (also referred to as object weight). The first object information may also include first range information indicating a range on the surface of the object 8 where the suction mechanism 50 cannot suction (non-suction range). For example, as shown in Fig. 10 , if there is a narrow range 800 (also referred to as area 800) on the surface of the object 8 that is one level lower than the surrounding area, and the suction pads 410 cannot suction the range 800, the range 800 is determined to be the non-suction range 800. Fig. 10 shows an example of how the object 8 and the multiple suction pads 410 appear when viewed from a direction along the pad arrangement plane.

[0068] The first object information may also include second range information indicating a range (adsorption prohibited range) in which adsorption by the adsorption mechanism 50 is prohibited. The adsorption prohibited range may include, for example, a range on the surface of the object 8 in which the object 8 may be damaged by being adsorbed by the adsorption pad 410. The adsorption prohibited range may also include, for example, a range on the surface of the object 8 in which the object 8 may be deformed by being adsorbed by the adsorption pad 410.

[0069] The first object information may also include tilt constraint information indicating a constraint on the tilt of the object 8 (also referred to as a tilt constraint). The tilt constraint may include, for example, an allowable tilt range indicating the allowable tilt of the object 8 when the object 8 is being held and moved by the suction mechanism 50. The allowable tilt range may be expressed, for example, in degrees.

[0070] The second object information may include, for example, shape information representing the shape of the object 8 (also referred to as the object shape). The shape information may be, for example, three-dimensional point cloud data representing the object shape, or three-dimensional CAD data of the object 8. The second object information may also include center of gravity position information representing the center of gravity position of the object 8 (also referred to as the object center of gravity position). The second object information may also include first range information. The second object information may also include second range information.

[0071] At least one of the weight information, first range information, second range information, tilt constraint information, shape information, and center of gravity position information may be input by a user to the robot control system 10. In this case, for example, the user may input at least one of the weight information, first range information, second range information, tilt constraint information, shape information, and center of gravity position information to the terminal device 14. At least one of the weight information, first range information, second range information, tilt constraint information, shape information, and center of gravity position information input to the terminal device 14 is input to the hand control device 13 and stored in the memory unit 131.

[0072] The shape information may be generated by the control unit 130 of the hand control device 13. In this case, for example, the position determination unit 136 that uses the shape information may generate the shape information based on, for example, a distance image and a color image acquired by the camera sensor 15. In this case, the distance image and the color image output by the camera sensor 15 are input to the hand control device 13 and stored in the memory unit 131. The position determination unit 136 generates three-dimensional point cloud data indicating the shape of an object based on, for example, the distance image and the color image in the memory unit 131. The three-dimensional point cloud data generated by the position determination unit 136 is stored in the memory unit 131 as shape information. Note that the shape information may also be generated by the control unit 120 of the robot control device 12.

[0073] The center of gravity position information may be generated by the control unit 130. In this case, for example, the position determination unit 136 using the center of gravity position information may generate the center of gravity position information based on, for example, a distance image and a color image acquired by the camera sensor 15. In this case, the position determination unit 136 generates three-dimensional point cloud data indicating the object shape based on, for example, a distance image and a color image, similar to when generating shape information. Then, the position determination unit 136 identifies the object center of gravity position based on the generated three-dimensional point cloud data. The position determination unit 136 generates center of gravity position information indicating the identified object center of gravity position and stores it in the storage unit 131. Furthermore, when three-dimensional CAD data of the object 8 is stored in the storage unit 131, the position determination unit 136 may identify the object center of gravity position based on the CAD data and generate center of gravity position information indicating the identified object center of gravity position. Note that the center of gravity position information may be generated by the control unit 120 of the robot control device 12.

[0074] The determination unit 138 determines the suction state of the object 8 in the suction mechanism 50 based on the detection result of at least one sensor in the sensor unit 59. The determination unit 138 determines the suction state of the object 8 in the suction mechanism 50 based on the detection result of at least one sensor, for example, the negative pressure detection sensor 54, the pressure sensor 55, the force sensor 56, and the distance sensor 57. Hereinafter, the term "suction state" simply refers to the suction state of the object 8 in the suction mechanism 50 (in other words, the suction state of the object 8 in the suction structure 40).

[0075] The hand control device 13 may notify an alert to a device outside the hand control device 13, depending on the determination result of the determination unit 138. For example, the interface 132 of the hand control device 13 may notify the robot control device 12 of the alert. In this case, the interface 132 functions as a notification unit that notifies the alert.

[0076] 11 is a schematic diagram showing an example of the operation of the robot control device 12 and the hand control device 13 when the robot 2 moves the object 8 from the work start platform to the work target platform. For example, the terminal device 14 accepts a work start instruction from a user instructing the robot 2 to start work. The work start instruction accepted by the terminal device 14 is input to the robot control device 12 and the hand control device 13.

[0077] In step s1, the control unit 120 of the robot control device 12 to which the work start command has been input recognizes the object 8 on the work start table based on the range image and color image output from the camera sensor 15. Then, based on the recognition result of the object 8, the control unit 120 controls the position and posture of the arm 3 so that the robot hand 4 is positioned above the object 8. When the robot hand 4 is positioned above the object 8, the pad placement plane is, for example, parallel to the work start table. When the control unit 120 has moved the robot hand 4 above the object 8, it outputs placement completion information indicating that the placement of the robot hand 4 above the object 8 has been completed to the hand control device 13 via the interface 123.

[0078] In step s2, the position determination unit 136 of the hand control device 13 to which the placement completion information has been input determines the position of each suction unit 41 based on the second object information in the storage unit 131. Next, in step s3, the suction mechanism control unit 137 controls the drive mechanism 52 so that the position of each suction unit 41 becomes the position determined in step s2. Once the position of each suction unit 41 is determined, the positional relationship between the multiple suction units 41 is determined. In other words, the suction mechanism control unit 137 controls the drive mechanism 52 so that the positional relationship between the multiple suction units 41 becomes the positional relationship determined in step s2. This allows the position of each suction unit 41 to be set to a position corresponding to the object 8, allowing the multiple suction units 41 to appropriately suction the object 8. Once the position of each suction unit 41 has been set, the suction mechanism control unit 137 outputs setting completion information indicating that setting of the position of each suction unit 41 has been completed to the robot control device 12 via the interface 132. A specific example of a method for determining the position of the suction unit 41 will be described in detail later.

[0079] Step s4 is executed in the robot control device 12 to which the setting completion information has been input. In step s4, the control unit 120 of the robot control device 12 controls the attitude of the arm 3 to move the robot hand 4 downward until the suction pads 410 contact the object 8. At this time, the robot hand 4 moves in a direction perpendicular to the pad arrangement plane (also referred to as the arrangement plane perpendicular direction). The control unit 120 appropriately contacts the suction pads 410 with the object 8 so that the robot hand 4 can appropriately adsorb the object 8. The control unit 120 controls the attitude of the arm 3 so that the opening edges 412 of the suction pads 410 appropriately contact the object 8. For example, the control unit 120 controls the attitude of the arm 3 to control the movement speed of the robot hand 4 in the direction perpendicular to the arrangement plane. The control unit 120 controls the movement speed of the robot hand 4 based on the detection results of the pressure sensors 55 included in the robot hand 4, for example. The detection results of the pressure sensors 55 are input from the hand control device 13 to the robot control device 12. By controlling the movement speed of the robot hand 4, the position of each suction portion 41 of the robot hand 4 in the direction perpendicular to the arrangement plane is controlled. The control unit 120 identifies the contact pressure of each of the suction pads 410 against the object 8 from the detection results of the multiple pressure sensors 55. The control unit 120 then controls the movement speed of the robot hand 4 so that the contact pressure of each suction pad 410 against the object 8 is appropriate. In other words, the control unit 120 controls the position of the robot hand 4 in the direction perpendicular to the arrangement plane so that the contact pressure of each suction pad 410 against the object 8 falls within a predetermined range. This allows each suction pad 410 to appropriately abut against the object 8, i.e., each suction pad 410 is appropriately pressed against the object 8, and each suction portion 41 of the robot hand 4 to appropriately adsorb the object 8. When the contact of the plurality of suction parts 41 with the object 8 is completed, the control part 120 outputs preparation completion information indicating that preparation for starting suction is completed to the hand control device 13 via the interface 123 .

[0080] The control unit 120 may control the movement speed of the robot hand 4 based on the detection results of the multiple distance sensors 57 included in the robot hand 4, thereby bringing each suction pad 410 into contact with the object 8. The detection results of each distance sensor 57 are input from the hand control unit 13 to the robot control unit 12. The control unit 120 determines the distance between each of the multiple suction units 41 and the object 8 based on the detection results of the multiple distance sensors 57. The control unit 120 then controls the movement speed of the robot hand 4 so that the distance between each suction unit 41 and the object 8 is appropriate for each suction unit 41. In other words, the control unit 120 controls the position of the robot hand 4 in the direction perpendicular to the arrangement plane so that the distance between each suction unit 41 and the object 8 falls within a predetermined range for each suction unit 41. This allows each suction pad 410 to appropriately come into contact with the object 8, and each suction unit 41 of the robot hand 4 to appropriately adsorb the object 8.

[0081] Furthermore, the control unit 120 may control the moving speed of the robot hand 4 based on the detection results of the multiple pressure sensors 55 and the detection results of the multiple distance sensors 57 to bring each suction pad 410 into contact with the object 8. In this case, the control unit 120 determines the contact pressure of each of the multiple suction pads 410 against the object 8 from the detection results of the multiple pressure sensors 55. The control unit 120 also determines the distance between each of the multiple suction units 41 and the object 8 from the detection results of the multiple distance sensors 57. The control unit 120 then controls the moving speed of the robot hand 4 so that, for each suction unit 41, the contact pressure of the suction pad 410 of that suction unit 41 against the object 8 is appropriate and the distance between that suction unit 41 and the object 8 is appropriate. This allows each suction pad 410 to appropriately come into contact with the object 8.

[0082] Upon receiving the preparation completion information, the hand control device 13 executes step s5. In step s5, the suction force determination unit 135 determines the suction force of the suction mechanism 50. The suction force determination unit 135 determines the suction force of each suction unit 41 based on the first object information in the memory unit 131. Determining the suction force can also be considered as determining the set value of the suction force. Then, in step s6, the suction mechanism control unit 137 controls the suction mechanism 50 based on the suction force determination result of the suction force determination unit 135. Specifically, the suction mechanism control unit 137 controls the negative pressure generator 51 of the suction mechanism 50 based on the suction force determination result of the suction force determination unit 135. The suction mechanism control unit 137 controls the negative pressure generator 51 to generate a negative pressure in the suction pad 410 of each suction unit 41 such that the suction force of the suction unit 41 becomes the suction force determined in step s5 (in other words, the set value). As a result, each suction unit 41 suctions the object 8 with the suction force determined by the suction force determination unit 135. When the suction units 41 start suctioning the object 8, the control unit 130 outputs suction start information notifying the robot control device 12 that suction has started via the interface 132. A specific example of a method for determining the suction force of the suction mechanism 50 will be described in detail later.

[0083] In step s7, the control unit 120 of the robot control device 12 that has received the suction start information controls the arm 3 to cause the robot 2 to start moving the object 8. The control unit 120 then outputs object movement start information indicating that the movement of the object 8 has started to the hand control device 13 via the interface 123.

[0084] Upon receiving the object movement start information, the hand control device 13 executes step s8. In step s8, the determination unit 138 of the control unit 130 determines the suction state of the object 8 in the suction mechanism 50 based on the detection result of the sensor unit 59. A specific example of step s8 will be described in detail later.

[0085] If the determination unit 138 determines in step s8 that there is no problem with the suction state, step s9 is executed. In step s9, the control unit 130 determines whether or not the movement of the object 8 by the robot 2 has been completed. When the object 8 has been moved to the work target platform, the control unit 120 of the robot control device 12 outputs movement completion information indicating that the movement of the object 8 has been completed to the hand control device 13 via the interface 123. In step s9, if the hand control device 13 has received the movement completion information from the robot control device 12, the control unit 130 determines that the movement of the object 8 by the robot 2 has been completed. On the other hand, if the hand control device 13 has not yet received the movement completion information from the robot control device 12, the control unit 130 determines that the movement of the object 8 by the robot 2 has not been completed.

[0086] If the determination in step s9 is YES, step s10 is executed. In step s10, the control unit 130 controls the negative pressure generator 51 to cause the plurality of suction units 41 to release the suction of the object 8 via the negative pressure generator 51. This places the object 8 on the work target platform. On the other hand, if the determination in step s9 is NO, step s8 is executed again. Thereafter, the hand control unit 13 and the robot control unit 12 operate in the same manner.

[0087] If the determination unit 138 determines in step s8 that there is a problem with the suction state, step s11 is executed. In step s11, the control unit 130 causes the interface 132 to output alert information indicating an alert. As a result, the interface 132, which serves as a notification unit, notifies the outside of the hand control device 13 of the alert. The alert information is input to the robot control device 12. The alert information may include information indicating that there is a problem with the suction state.

[0088] Upon receiving the alert information, the robot control device 12 performs processing in accordance with the alert notification from the hand control device 13. For example, in step s12, the control unit 120 controls the arm 3 to cause the robot 2 to return the object 8 to its original position. That is, the control unit 120 causes the robot 2 to move the object 8 to the work start platform. When the object 8 has moved to the work start platform, the control unit 120 outputs information indicating that the object 8 has returned to its original position to the hand control device 13 via the interface 123. Upon receiving this information, the hand control device 13 executes step s10, and releases the suction structure 40 from suctioning the object 8. As a result, the object 8 is placed on the work start platform.

[0089] The alert information output by the hand control device 13 may be input to the terminal device 14. In this case, the terminal device 14 that receives the alert information may notify the user of the alert. For example, the display unit included in the terminal device 14 may display the alert to the user. Alternatively, the speaker included in the terminal device 14 may output a sound to notify the user of the alert. If the system control device 11 includes a notification unit that notifies the user, such as a display unit, the notification unit of the system control device 11 that receives the alert information may notify the user of the alert. If the hand control device 13 includes a notification unit that notifies the user, the notification unit of the hand control device 13 may notify the user of the alert. If the robot control device 12 includes a notification unit that notifies the user, the notification unit of the robot control device 12 that receives the alert information may notify the user of the alert.

[0090] The control unit 120 may cause the robot 2 to stop moving the object 8 instead of executing step s12. In this case, the control unit 120 may cause the robot 2 to return the object 8 to its original position in response to an instruction from a user. For example, a user who has received an alert from the terminal device 14 issues a reset instruction to the terminal device 14 to instruct it to return the object 8 to its original position. The reset instruction received by the terminal device 14 is input to the robot control device 12. In the robot control device 12 that has received the reset instruction, the control unit 120 controls the arm 3 to cause the robot 2 to return the object 8 to its original position. Thereafter, the hand control device 13 executes step s10.

[0091] As described above, the hand control device 13 determines the suction force with which the suction mechanism 50 suctions the object 8, based on the first object information. This allows the suction force with which the suction mechanism 50 suctions the object 8 to be changed depending on the object 8, making it possible to appropriately suction the object 8. As a result, it is possible to improve the stability of suction of the object 8. Furthermore, by updating the first object information depending on the type of object 8, it is possible to appropriately suction multiple types of objects 8 using the same suction mechanism 50.

[0092] Furthermore, since the drive mechanism 52 can change the position of the suction portion 41, it is possible to change the position of the suction portion 41 depending on the object 8. This improves the stability of suction of the object 8. Furthermore, by changing the position of the suction portion 41 depending on the type of object 8, it is possible to appropriately suction a plurality of types of objects 8 using the same suction mechanism 50.

[0093] Furthermore, when the suction mechanism 50 includes a plurality of suction units 41, the suction mechanism 50 can change the positional relationship between the plurality of suction units 41. This allows the positional relationship between the plurality of suction units 41 to be changed depending on the object 8, thereby improving the stability of suction of the object 8.

[0094] Furthermore, the hand control device 13 determines the position of the suction unit 41 based on the second object information. This allows the position of the suction unit 41 to be changed depending on the object 8, making it possible to appropriately suction the object 8. Furthermore, by updating the second object information depending on the type of object 8, it is possible to use the same suction mechanism 50 to suction multiple types of objects 8.

[0095] Furthermore, the hand control device 13 determines the suction state of the object 8 in the suction mechanism 50 based on the detection result of at least one sensor, and therefore can appropriately determine the suction state.

[0096] Furthermore, the hand control device 13 issues an alert to the outside depending on the result of the suction state determination, so that it is possible to notify the outside that a problem has occurred.

[0097] <Example of Method for Determining the Position of the Suction Portion> The operation of the position determination unit 136 will be described below using an example in which four suction pads 410 are arranged in a square, as in the examples of Figures 5 to 8 described above. Hereinafter, with respect to the suction structure 40, two suction pads 410 arranged diagonally will be referred to as a pad pair. The suction structure 40 includes two pad pairs. However, the arrangement of the multiple suction pads 410 is not limited to this.

[0098] <When Shape Information Is Included in the Second Object Information> First, consider a case where the second object information includes shape information indicating the object shape. In this case, the position determination unit 136 identifies the top surface of the object 8 on the work start table (also referred to as the object top surface) based on, for example, the shape information. The object top surface is a region on the surface of the object 8 on the work start table that can be seen when the object 8 is viewed from above in the direction perpendicular to the placement plane. Next, the position determination unit 136 determines the center of the identified object top surface. Then, the position determination unit 136 determines the positions of the multiple suction units 41 so that, when the multiple suction units 41 adsorb the object 8, each pad pair is positioned symmetrically with respect to the center of the object top surface. Here, "positioning the pad pair symmetrically with respect to a certain position on the surface of the object 8" means that the positions of the two suction pads 410 constituting the pad pair are set symmetrically with respect to the certain position. As a result, in step s3, the positions of the multiple suction units 41 are set so that, when the multiple suction units 41 adsorb the object 8, each pad pair is positioned symmetrically with respect to the center of the object top surface. In other words, the positional relationship of the multiple suction units 41 is set so that when the multiple suction units 41 suction the object 8, each pad pair is disposed at a position symmetrical with respect to the center of the object's upper surface. As a result, when the robot hand 4 descends in the direction perpendicular to the placement plane in step s4, the two diagonally arranged suction pads 410 in each pad pair can suction the object at positions symmetrical with respect to the center on the object's upper surface. The positions on the object's upper surface at which the pad pairs suction may be set as far away from the center of the object's upper surface as possible. In this case, suction of the object 8 by the multiple suction units 41 is more stable.

[0099] Fig. 12 is a schematic diagram showing an example of a state in which the positions of the multiple suction pads 410 are set as described above, and the two suction pads 410 of each pad pair adsorb at positions symmetrical with respect to the center 80a of the top surface 80 of the object 8. Fig. 12 shows an example of a state in which the object 8 and the multiple suction pads 410 are viewed from above the object 8 in the direction perpendicular to the arrangement plane. As in the example of Fig. 12, the four positions on the object top surface 80 to which the four suction pads 410 respectively adsorb may be set equidistant from the center 80a.

[0100] In addition, when the suction structure 40 has one suction portion 41, the position determination unit 136 may determine the position of the suction portion 41 so that the suction portion 41 suctions the center of the top surface of the object.

[0101] <When second object information includes center of gravity position information> As another example, consider a case where the second object information includes center of gravity position information indicating the position of the center of gravity of the object. Here, a planar view in which the object 8 and the plurality of suction pads 410 are viewed from above the object 8 along the direction perpendicular to the arrangement plane is called a specific planar view. It can be said that Fig. 12 shows the object 8 and the suction pads 410 in the specific planar view.

[0102] For example, the position determination unit 136 determines the positions of the multiple suction units 41 so that, when the multiple suction units 41 adsorb the object 8, each pad pair is positioned symmetrically with respect to the center of gravity of the object in a specific planar view. Here, "positioning a pad pair symmetrically with respect to the center of gravity of the object in a specific planar view" means that the positions of the two suction pads 410 constituting the pad pair are set to be symmetrically with respect to the center of gravity of the object in a specific planar view. As a result, in step s3, the positions of the multiple suction units 41 are set to be symmetrically with respect to the center of gravity of the object in a specific planar view when the multiple suction units 41 adsorb the object 8. As a result, when the robot hand 4 descends in the direction perpendicular to the placement plane in step s4, the two diagonally arranged suction pads 410 in each pad pair can adsorb at positions symmetrical with respect to the center of gravity of the object in a specific planar view. This allows the multiple suction units 41 to adsorb the object 8 in a more balanced manner than in the example of FIG. 12 . Therefore, the object 8 is less likely to tilt when the suction mechanism 50 is suctioning the object 8, and the suction mechanism 50 can stably suction the object 8.

[0103] 13 is a schematic diagram showing an example of a state in which the positions of the plurality of suction pads 410 are set as described above, and the two suction pads 410 of each pad pair suction-hold at positions symmetrical with respect to the object's center-of-gravity position 80x in a specific planar view. Fig. 13 shows the object 8 and the suction pads 410 in a specific planar view. As in the example of Fig. 13 , the four positions to which the four suction pads 410 respectively suction-hold may be set equidistant from the object's center-of-gravity position 80x in a specific planar view.

[0104] When the suction structure 40 has only one suction portion 41, the position determination unit 136 may determine the position of the suction portion 41 so that the suction portion 41 overlaps the position of the center of gravity of the object in the specific planar view when the suction portion 41 suctions the object 8. This allows the suction portion 41 to suction a position on the surface of the object 8 that corresponds to the position of the center of gravity of the object in the specific planar view when the robot hand 4 descends in the direction perpendicular to the placement plane in step s4.

[0105] <When the second object information includes at least one of the first range information and the second range information> As another example, consider a case where the second object information includes at least one of the first range information and the second range information. Here, a range on the surface of the object 8 that is represented by at least one of the first range information and the second range information is called a specific range. The specific range is composed of at least one of an adsorption impossible range and an adsorption prohibited range. The specific range can also be said to be a range on the surface of the object 8 that the adsorption mechanism 50 should not attempt to adsorb.

[0106] The position determination unit 136 determines the positions of the multiple suction units 41 so that none of the multiple suction units 41 faces the specific range. As a result, in step s3, the positions of the multiple suction units 41 are set so that none of the multiple suction units 41 faces the specific range. As a result, when a non-suction range is included in the specific range, each suction unit 41 can appropriately suction an area on the surface of the object 8 that is outside the non-suction range. Furthermore, when a non-suction range is included in the specific range, the possibility of the suction mechanism 50 suctioning the non-suction range of the object 8 is reduced.

[0107] 14 is a schematic diagram showing an example of a state in which the positions of the suction units 41 are set at positions such that none of the suction units 41 faces the non-suction range 800. When the suction units 41 set at positions such as those in Fig. 14 move downward in the direction perpendicular to the arrangement plane (the up and down direction in Fig. 1 ) in step s4, the suction pads 410 can suction an area of ​​the surface of the object 8 that is outside the non-suction range 800.

[0108] When the suction structure 40 has one suction portion 41, the position determination unit 136 may determine the position of the suction portion 41 so that the suction portion 41 does not face the specific range.

[0109] <When the Second Object Information Includes Shape Information and Center of Gravity Position Information> As another example, consider a case where the second object information includes shape information and center of gravity position information. In this case, the position determination unit 136 identifies the object top surface 80 based on, for example, the shape information. Then, the position determination unit 136 determines the positions of the multiple suction units 41 so that, when the multiple suction units 41 adsorb the object 8, each pad pair is positioned symmetrically with respect to the center of gravity of the object in a specific planar view. In this case, the position determination unit 136 determines the positions of the multiple suction units 41 so that the multiple suction units 41 adsorb as far outward as possible on the identified object top surface 80. This makes the adsorption of the object 8 by the multiple suction units 41 more stable. For example, the position determination unit 136 may determine the positions of the multiple suction units 41 so that the multiple suction units 41 adsorb near the four corners of the identified object top surface 80.

[0110] As another example, consider a case where the second object information includes shape information and at least one of the first range information and second range information. In this case, the position determination unit 136 identifies the object upper surface 80 based on, for example, the shape information. Next, the position determination unit 136 identifies an area on the object upper surface 80 excluding the specific area as the suction range. Next, the position determination unit 136 determines the center of the suction range. Then, the position determination unit 136 determines the positions of the multiple suction units 41 so that, when the multiple suction units 41 suction the object 8, each pad pair is positioned symmetrically with respect to the center of the suction range. As a result, in step s3, the positions of the multiple suction units 41 are set so that, when the multiple suction units 41 suction the object 8, each pad pair is positioned symmetrically with respect to the center of the suction range. As a result, when the robot hand 4 is lowered in the direction perpendicular to the placement plane in step s4, the two suction pads 410 of each pad pair can suction the object at positions symmetrical with respect to the center of the suction area on the top surface of the object. In the suction area, the positions at which the pad pairs suction the object may be set as far away as possible from the center of the suction area.

[0111] In addition, when the suction structure 40 has one suction portion 41, the position determination unit 136 may determine the position of the suction portion 41 so that the suction portion 41 suctions the center of the suction-capable range.

[0112] <When the Second Object Information Includes Center of Gravity Position Information and At Least One of First Range Information and Second Range Information> As another example, consider a case where the second object information includes center of gravity position information and at least one of first range information and second range information. In this case, the position determination unit 136 determines the positions of the multiple suction units 41 so that none of the multiple suction units 41 faces the specific range. At this time, the position determination unit 136 determines the positions of the multiple suction units 41 so that, when the multiple suction units 41 adsorb the object 8, each pad pair is positioned symmetrically with respect to the center of gravity of the object in a specific planar view. Alternatively, if this is not possible, the position determination unit 136 determines the positions of the multiple suction units 41 so that, when the multiple suction units 41 adsorb the object 8, each pad pair is positioned as close as possible to a position symmetrically with respect to the center of gravity of the object in a specific planar view. This allows the multiple suction units 41 to adsorb the surface of the object 8 in a balanced manner while avoiding the specific range.

[0113] Note that when the suction structure 40 has only one suction portion 41, the position determination unit 136 may determine the position of the suction portion 41 to be a position that does not face the specific range. In this case, the position determination unit 136 determines the position of the suction portion 41 to be a position that overlaps the center of gravity of the object in the specific planar view when the suction portion 41 has adsorbed the object 8. Alternatively, if this is not possible, the position determination unit 136 determines the position of the suction portion 41 to be a position that is as close as possible to the center of gravity of the object in the specific planar view when the suction portion 41 has adsorbed the object 8.

[0114] <A Case Where the Second Object Information Includes Shape Information, Center of Gravity Position Information, and At Least One of First Range Information and Second Range Information> As another example, consider a case where the second object information includes shape information, center of gravity position information, and at least one of first range information and second range information. In this case, the position determination unit 136, for example, identifies the object upper surface 80 based on the shape information. Next, the position determination unit 136 identifies an area on the object upper surface 80 excluding the specific range as the suction range. Then, the position determination unit 136 determines positions of the multiple suction units 41 such that the multiple suction units 41 suction the suction range when the robot hand 4 descends in step s4. At this time, the position determination unit 136, for example, determines positions of the multiple suction units 41 such that, when the multiple suction units 41 suction the object 8, each pad pair is positioned symmetrically with respect to the center of gravity of the object in a specific planar view. Alternatively, if this is not possible, the position determination unit 136 determines the positions of the plurality of suction units 41 so that each pad pair is disposed as close as possible to a position symmetrical with respect to the center of gravity of the object in a specific plan view when the plurality of suction units 41 adsorb the object 8. This allows the plurality of suction units 41 to reliably adsorb the adsorbable area of ​​the object 8 in a balanced manner.

[0115] <Example of Method for Determining Adhesive Force of Adsorption Mechanism> <When Weight Information is Included in First Object Information> First, consider a case where the first object information includes weight information indicating the object weight. In this case, the adhesive force determination unit 135 determines the adhesive force of each adhesive unit 41 to a value corresponding to the object weight indicated by the weight information. In other words, the adhesive force determination unit 135 determines the adhesive force of each adhesive unit 41 to a value that enables the adhesive mechanism 50 to appropriately adsorb the object 8 having the weight indicated by the weight information. As a result, the adhesive force of each adhesive unit 41 increases as the object weight indicated by the weight information increases. Hereinafter, the adhesive force of the adhesive unit 41 determined solely by the object weight, as in this example, will be referred to as weight-based adhesive force.

[0116] <When the First Object Information Includes At Least One of First Range Information and Second Range Information> As another example, consider a case where the first object information includes at least one of the first range information and the second range information. In this case, the suction force determiner 135 increases the set value of the suction force of each suction unit 41, for example, the larger the specific range represented by at least one of the first range information and the second range information included in the first object information. The larger the specific range, the smaller the area of ​​the surface of the object 8 to which the suction mechanism 50 can attach. Therefore, if the specific range is large, the suction force set value of the suction unit 50 may become unstable. As in this example, the larger the specific range, the larger the set value of the suction force of each suction unit 41, thereby improving the stability of suction of the object 8.

[0117] <When Tilt Constraint Information Is Included in First Object Information> As another example, consider a case where tilt constraint information is included in the first object information. In this case, the suction force determiner 135 increases the set value of the suction force of each suction unit 41, for example, as the tilt tolerance range indicated by the tilt constraint information becomes smaller. As a result, the object 8 can be made less likely to tilt when being held and moved by the robot hand 4, as the tilt tolerance range indicated by the tilt constraint information becomes smaller. Therefore, the tilt of the object 8 can satisfy the tilt tolerance range.

[0118] <When the First Object Information Includes Weight Information and At Least One of First Range Information and Second Range Information> As another example, consider a case where the first object information includes weight information and at least one of the first range information and second range information. In this case, the attractive force determination unit 135 determines the weight-based attractive force based on, for example, the weight information. The attractive force determination unit 135 then sets the set value of the attractive force of each attractive unit 41 to be greater than the weight-based attractive force as the specific range becomes larger. For example, the attractive force determination unit 135 sets the set value of the attractive force of each attractive unit 41 to be L times the weight-based attractive force (L is a real number greater than 1). The larger the specific range, the greater the value of L is set. This improves the stability of attraction of the object 8.

[0119] <A Case Where the First Object Information Includes At Least One of First Range Information and Second Range Information, and Inclination Constraint Information> As another example, consider a case where the first object information includes at least one of first range information and second range information, and inclination constraint information. In this case, the adhesive force determination unit 135 determines the adhesive force of each adhesive unit 41 based on, for example, the size of the specific range and the size of the allowable inclination range. For example, the adhesive force determination unit 135 determines the adhesive force of each adhesive unit 41 using an evaluation value of the size of the specific range (also referred to as a first evaluation value) and an evaluation value of the size of the allowable inclination range (also referred to as a second evaluation value). The first evaluation value is, for example, a real number greater than zero, and indicates a larger value as the specific range becomes larger. The second evaluation value is, for example, a real number greater than zero, and indicates a larger value as the allowable inclination range becomes larger. For example, the adhesive force determination unit 135 increases the set value of the adhesive force of each adhesive unit 41 as the division value obtained by dividing the first evaluation value by the second evaluation value becomes larger. As a result, the set value of the suction force of the suction unit 41 is a value that corresponds to both the size of the specific range and the size of the tilt tolerance range. For example, if the specific range is large and the tilt tolerance range is small, the set value of the suction force of the suction unit 41 is large. This makes it possible to improve the stability of suction of the object 8.

[0120] <When the First Object Information Includes Weight Information and Tilt Constraint Information> As another example, consider a case where the first object information includes weight information and tilt constraint information. In this case, the attractive force determination unit 135 calculates the weight-based attractive force based on, for example, the weight information. The attractive force determination unit 135 then sets the attractive force setting value of each attractive unit 41 to be greater than the weight-based attractive force as the tilt tolerance range becomes smaller. For example, the attractive force determination unit 135 sets the attractive force setting value of each attractive unit 41 to be M times the weight-based attractive force (M is a real number greater than 1). The smaller the tilt tolerance range, the greater M is set. This improves the stability of attraction of the object 8.

[0121] <When the First Object Information Includes Weight Information, At Least One of First Range Information and Second Range Information, and Inclination Constraint Information> Consider another example where the first object information includes weight information, at least one of first range information and second range information, and inclination constraint information. In this case, the attractive force determiner 135 calculates the weight-based attractive force based on, for example, the weight information. The attractive force determiner 135 then sets the attractive force setting value of each attractive unit 41 to be greater than the weight-based attractive force, for example, the greater the division value obtained by dividing the first evaluation value by the second evaluation value. For example, the attractive force determiner 135 sets the attractive force setting value of each attractive unit 41 to be N times the weight-based attractive force (N is a real number greater than 1). The greater the division value, the greater N is set. This improves the stability of attraction of the object 8.

[0122] The first object information may include shape information instead of weight information. In this case, the attractive force determination unit 135, for example, identifies the size (e.g., volume) of the object 8 based on the shape information. The larger the object 8, the larger the attractive force setting value of each attractive unit 41. In the above example of the attractive force determination method, the attractive force determination unit 135 may use the attractive force of the attractive unit 41 determined based only on the shape information instead of the weight-based attractive force. Furthermore, the attractive forces of some of the multiple attractive units 41 may be fixed without being controlled. In other words, the attractive forces of some of the multiple attractive units 41 may be fixed without being determined based on the first object information.

[0123] The position of each suction unit 41 may be fixed without being controlled. In other words, steps s2 and s3 may not be performed. In this case, the drive mechanism 52 may not be provided. Also, the grooves 460 may not be provided in the main body portion 46 of the exterior case 45. When the position of each suction unit 41 is not controlled, the positional relationship between the multiple suction units 41 is set in advance according to the shape of the object 8.

[0124] If the positions of the suction units 41 are not controlled, the robot control device 12 may control the arm 3 based on the second object information when positioning the robot hand 4 above the object 8 in step s1. For example, consider a case where the second object information includes shape information. In this case, the control unit 120 of the robot control device 12 determines the center of the object's upper surface based on the shape information, for example. Then, the control unit 120 controls the position and attitude of the arm 3 so that when the robot hand 4 moves downward and the suction units 41 abut against the object 8 in step s4, the robot hand 4 is positioned such that the pad pairs of the suction structure 40 are positioned symmetrically with respect to the center of the object's upper surface.

[0125] As another example, consider a case where the second object information includes center-of-gravity position information. In this case, for example, when the robot hand 4 moves downward in step s4 and each suction unit 41 comes into contact with the object 8, the control unit 120 controls the position and attitude of the arm 3 so that the robot hand 4 is positioned such that each pad pair is positioned symmetrically with respect to the center of gravity of the object in the specific plan view.

[0126] As another example, consider a case where the second object information includes at least one of the first range information and the second range information. In this case, the control unit 120 controls the position and posture of the arm 3 so that the robot hand 4 is positioned so that each of the suction units 41 located above the object 8 does not face the specific range represented by at least one of the first range information and the second range information.

[0127] <Example of Method for Determining Adhesion State> When the suction unit 41 is not properly adsorbing the object 8, the negative pressure in the suction pad 410 of the suction unit 41 may have changed from an appropriate value. Therefore, the determination unit 138 may determine the suction state based on, for example, the detection results of the multiple negative pressure detection sensors 54. In this case, the determination unit 138 identifies the negative pressure in each suction pad 410 based on, for example, the detection results of the multiple negative pressure detection sensors 54. If each of the identified multiple negative pressures is within a predetermined range, the determination unit 138 determines that there is no problem with the suction state. On the other hand, if the identified multiple negative pressures include a negative pressure outside the predetermined range, the determination unit 138 determines that there is a problem with the suction state. Hereinafter, the result of determining the suction state based on the detection results of the multiple negative pressure detection sensors 54 will be referred to as a first determination result.

[0128] Furthermore, if the suction unit 41 is not properly adsorbing the object 8, the contact pressure of the suction pad 410 of the suction unit 41 against the object 8 may be different from the appropriate value. Therefore, the determination unit 138 may determine the suction state based on, for example, the detection results of the multiple pressure sensors 55. In this case, the determination unit 138 identifies the contact pressure of the suction pad 410 against the object 8 for each suction pad 410 based on, for example, the detection results of the multiple pressure sensors 55. If each of the identified multiple contact pressures is within a predetermined range, the determination unit 138 determines that there is no problem with the suction state. On the other hand, if the identified multiple contact pressures include a contact pressure outside the predetermined range, the determination unit 138 determines that there is a problem with the suction state. Hereinafter, the result of the determination of the suction state based on the detection results of the multiple pressure sensors 55 will be referred to as a second determination result.

[0129] Furthermore, if the suction unit 41 does not properly suction the object 8, the distance between the suction unit 41 and the object 8 may change from an appropriate value. Therefore, the determination unit 138 may determine the suction state based on, for example, the detection results of the multiple distance sensors 57. In this case, the determination unit 138 specifies the distance between the suction unit 41 and the object 8 for each suction unit 41 based on, for example, the detection results of the multiple distance sensors 57. Then, if each of the specified distances is within a predetermined range, the determination unit 138 determines that there is no problem with the suction state. On the other hand, if the specified distances include a distance outside the predetermined range, the determination unit 138 determines that there is a problem with the suction state. Hereinafter, the result of determining the suction state based on the detection results of the multiple distance sensors 57 will be referred to as a third determination result.

[0130] The determination unit 138 may also determine the suction state based on the detection results of the force sensor 56. Here, it is assumed that when the multiple suction units 41 properly suction the object 8, almost no moment is generated around the x-axis and y-axis set on the robot hand 4. In this case, the determination unit 138 identifies the moment around the x-axis acting on the robot hand 4 and the moment around the y-axis acting on the robot hand 4 based on the detection results of the force sensor 56. The determination unit 138 then determines that there is no problem with the suction state if each of the identified two moments is equal to or less than a threshold value. On the other hand, the determination unit 138 determines that there is a problem with the suction state if the identified two moments include a moment greater than the threshold value. This allows the determination unit 138 to determine that there is a problem with the suction state when the object 8 being suctioned by the robot hand 4 is tilted. Hereinafter, the determination result of the suction state based on the detection results of the force sensor 56 will be referred to as the fourth determination result.

[0131] The determination unit 138 may make a final determination of the adsorption state based on at least two determination results from among the first determination result, the second determination result, the third determination result, and the fourth determination result. Here, the first determination result, the second determination result, the third determination result, and the fourth determination result are referred to as the first provisional determination result, the second provisional determination result, the third provisional determination result, and the fourth provisional determination result, respectively. The determination unit 138 makes a final determination of the adsorption state based on at least two provisional determination results from among the first provisional determination result, the second provisional determination result, the third provisional determination result, and the fourth provisional determination result. For example, if each of the at least two provisional determination results indicates that there is no problem with the adsorption state, the determination unit 138 makes a final determination that there is no problem with the adsorption state and sets this as the determination result of step s8. On the other hand, if at least two provisional determination results include a provisional determination result indicating that there is a problem with the adsorption state, the determination unit 138 makes a final determination that there is a problem with the adsorption state and sets this as the determination result of step s8.

[0132] In this way, the suction state of the object 8 in the suction mechanism 50 is determined based on the detection result of at least one sensor, so that the suction state can be determined appropriately.

[0133] The position determination unit 136 may re-determine the position of the suction unit 41 depending on the result of the suction state determination by the determination unit 138. The suction force determination unit 135 may re-determine the suction force of the suction mechanism 50 depending on the result of the suction state determination by the determination unit 138. Figure 15 is a schematic diagram showing an example of the operation of the hand control device 13 and the robot control device 12 in this case.

[0134] In the example of FIG. 15 , it is determined in step s8 that there is a problem with the suction state, and steps s11 and s12 are executed, followed by step s13. In step s13, similar to step s10, the control unit 130 controls the negative pressure generator 51 to cause the multiple suction units 41 to release suction from the object 8. This causes the object 8 to be placed on the work start platform. Then, step s2 is executed again. In step s2, the position determination unit 136 re-determines the positions of the multiple suction units 41. For example, the position determination unit 136 positions the multiple suction units 41 so that the multiple suction units 41 are positioned more inward as a whole. Alternatively, the position determination unit 136 positions the multiple suction units 41 so that the multiple suction units 41 are positioned more outward as a whole. When step s2 is re-executed, if the multiple suction units 41 are located outside the bottom surface 46a, the position determination unit 136 may position the multiple suction units 41 so that the multiple suction units 41 are positioned more inward as a whole. On the other hand, when step s2 is re-executed, if the multiple suction units 41 are located inside the bottom surface 46a, the position determination unit 136 may position the multiple suction units 41 so that the multiple suction units 41 are positioned more outward as a whole. When the positions of the multiple suction units 41 are re-determined in step s2, step s3 is executed. As a result, the positions of the multiple suction units 41 are changed to the positions re-determined in step s2. Then, step s4 is executed again.

[0135] After step s4, step s5 is executed again to redetermine the suction force of the suction mechanism 50. In step s5, the suction force determination unit 135, for example, increases the set value of the suction force of each suction unit 41. Thereafter, step s6 is executed to set the suction force of each suction unit 41 to the set value redetermined in step s5. This changes the suction force of the suction unit 41 in accordance with the determination result of the suction state by the determination unit 138. Thereafter, the hand control device 13 and the robot control device 12 operate in the same manner.

[0136] In this way, if the position of the suction part 41 is re-determined depending on the result of the suction state judgment by the judgment part 138, the position of the suction part 41 is re-determined when there is a problem with the suction state, and the suction state of the object 8 by the suction mechanism 50 can be improved.

[0137] In addition, if the suction force of the suction mechanism 50 is redetermined depending on the result of the suction state determination by the determination unit 138, the suction force of the suction mechanism 50 is redetermined when there is a problem with the suction state, thereby improving the suction state of the object 8 by the suction mechanism 50.

[0138] In the example of FIG. 15 , both the position of the suction unit 41 and the suction force of the suction mechanism 50 are redetermined in accordance with the determination result of the suction state by the determination unit 138. However, only one of the position of the suction unit 41 and the suction force of the suction mechanism 50 may be redetermined. If only the position of the suction unit 41 is redetermined, step s5 is not executed after step s13, and step s6 is executed. In step s6, the suction force of each suction unit 41 is not changed and the suction mechanism 50 adsorbs the object 8. On the other hand, if only the suction force of the suction mechanism 50 is redetermined, step s2 and s3 are not executed after step s13, and step s4 and subsequent steps are executed. Alternatively, step s12 may be executed without executing step s13, step s2, step s3, and step s4, and subsequent steps are executed. In this case, step s5 and subsequent steps are executed with the suction mechanism 50 adsorbing the object 8. Alternatively, after step s11, step s5 may be executed without executing steps s12, s13, s2, s3, and s4. In this case, after step s11, steps s5 and s6 are executed, and step s8 and subsequent steps are executed without executing step s7.

[0139] Furthermore, in step s5, the attractive force of each suction unit 41 may be set individually. For example, consider a case where the first object information includes shape information indicating the shape of the object 8 having a non-uniform thickness. In this case, in step s5, the attractive force determiner 135 identifies thick portions of the object 8 having a relatively large thickness and thin portions of the object 8 having a relatively small thickness, for example, based on the shape information. Then, for the multiple attractive units 41, the attractive force determiner 135 sets a relatively large set value for the attractive force of the attractive units 41 that attract the thick portions of the object 8 and a relatively small set value for the attractive force of the attractive units 41 that attract the thin portions of the object 8. In this way, the attractive force of each attractive unit 41 is individually set according to the difference in thickness of one object 8.

[0140] As another example, consider a case where the first object information includes center of gravity position information. In this case, the attractive force determination unit 135 determines, for each attractive unit 41, the distance in the specific planar view between the attractive position at which the attractive unit 41 attracts the object 8 and the object center of gravity position indicated by the center of gravity position information. The attractive force determination unit 135 then increases the set value of the attractive force of the attractive unit 41 as the distance determined for the attractive unit 41 decreases. In other words, the attractive force determination unit 135 increases the set value of the attractive force of an attractive unit 41 whose attractive position with respect to the object 8 is closer to the object center of gravity position in the specific planar view. As a result, the attractive force of each attractive unit 41 is individually set according to the distance in the specific planar view between the attractive position and the object center of gravity position of the object 8.

[0141] 15 , in step s5 after it is determined in step s8 that there is a problem with the suction state, the suction force determiner 135 may re-determine the suction force of the suction mechanism 50 based on the center of gravity position information included in the first object information. In this case, for each suction unit 41, for example, the suction force determiner 135 calculates the distance in the specific planar view between the suction position at which the suction unit 41 suctions the object 8 and the object center of gravity position indicated by the center of gravity position information. Then, the suction force determiner 135 increases the setting value of the suction force of the suction unit 41 for which the calculated distance is equal to or less than a threshold value. As a result, the suction force of the suction unit 41 whose suction position is closest to the object center of gravity position in the specific planar view is increased.

[0142] 15 , the suction force determination unit 135 may redetermine the suction force of the suction unit 41 based on information acquired by the sensor unit 59, which information changes depending on the suction state of the object 8 at the suction unit 41. In the example of FIG. 15 , the suction force determination unit 135 may redetermine the suction force of the suction unit 41 corresponding to the negative pressure detection sensor 54, for example, based on the detection result of the negative pressure detection sensor 54 in step s5 after step s13. The detection result of the negative pressure detection sensor 54 is information that changes depending on the suction state of the object 8 at the suction unit 41 corresponding to the negative pressure detection sensor 54. For example, when the negative pressure detected by the negative pressure detection sensor 54 is lower than a predetermined range (in other words, an appropriate range), the suction force determination unit 135 reduces the set value of the suction force of the suction unit 41 corresponding to the negative pressure detection sensor 54. On the other hand, if the negative pressure detected by the negative pressure detection sensor 54 is greater than the predetermined range (in other words, if the negative pressure detected by the negative pressure detection sensor 54 is insufficient), the suction force determination unit 135 increases the set value of the suction force of the suction unit 41 corresponding to the negative pressure detection sensor 54.

[0143] Furthermore, in step s5 after step s13, the suction force determination unit 135 may redetermine the suction force of the suction unit 41 corresponding to the pressure sensor 55 based on the detection result of the pressure sensor 55. The detection result of the pressure sensor 55 is information that changes depending on the suction state of the object 8 at the suction unit 41 corresponding to the pressure sensor 55. For example, when the contact pressure detected by the pressure sensor 55 is greater than a predetermined range, the suction force determination unit 135 decreases the setting value of the suction unit 41 corresponding to the pressure sensor 55. On the other hand, when the contact pressure detected by the pressure sensor 55 is smaller than the predetermined range, the suction force determination unit 135 increases the setting value of the suction unit 41 corresponding to the pressure sensor 55.

[0144] Furthermore, in step s5 after step s13, the adhesive force determination unit 135 may re-determine the adhesive force of the adhesive part 41 corresponding to the distance sensor 57 based on the detection result of the distance sensor 57. The detection result of the distance sensor 57 is information that changes depending on the adhesive state of the object 8 at the adhesive part 41 corresponding to the distance sensor 57. For example, when the distance detected by the distance sensor 57 is greater than a predetermined range, the adhesive force determination unit 135 increases the setting value of the adhesive part 41 corresponding to the distance sensor 57. On the other hand, when the distance detected by the distance sensor 57 is smaller than the predetermined range, the adhesive force determination unit 135 decreases the setting value of the adhesive part 41 corresponding to the distance sensor 57.

[0145] 16 instead of the suction mechanism 50. The suction mechanism 50A includes, for example, the negative pressure generating unit 51 and the drive mechanism 52 described above, an suction structure 40A that suctions the object 8, and a switching mechanism 500.

[0146] FIG. 17 is a schematic diagram showing an example of a robot hand 4 equipped with a suction mechanism 50A, as viewed from the bottom surface 46a. As shown in FIG. 17 , the suction structure 40A is configured by replacing the suction unit 41 in the above-described suction structure 40 with suction units 200. The suction structure 40A includes, for example, four suction units 200. Each suction unit 200 has, for example, a plurality of suction units capable of adsorbing an object 8. Similar to the suction unit 41, each suction unit 200 can move, for example, along a groove 460. The drive mechanism 52 can move each suction unit 200. Note that, similar to the suction unit 41, the position of at least one of the plurality of suction units 200 may be fixed. The number of suction units 200 included in the suction mechanism 50A may be one, two, three, five, or more.

[0147] Fig. 18 is a schematic diagram showing an example of the configuration of the suction unit 200. As shown in Figs. 17 and 18 , the suction unit 200 includes, for example, a first suction unit 210 capable of suctioning the object 8 and a second suction unit 220 capable of suctioning the object 8. The suction mechanism 50A can switch, for each suction unit 200, between a first state in which the first suction unit 210 suctions the object 8 and a second state in which the second suction unit 220 suctions the object 8. The upper side of Fig. 18 shows an example of the suction unit 200 in the first state, and the lower side of Fig. 18 shows an example of the suction unit 200 in the second state.

[0148] The first suction portion 210 has a first suction pad 211 at its tip. The first suction pad 211 is hollow and has a first suction opening 212. The second suction portion 220 has a second suction pad 221 at its tip. The second suction pad 221 is hollow and has a second suction opening 222. The first suction opening 212 is larger than the second suction opening 222. In other words, the opening area of ​​the first suction opening 212 is larger than the opening area of ​​the second suction opening 222. The first suction opening 212 and the second suction opening 222 are each shaped, for example, circular. The diameter of the first suction opening 212 is larger than the diameter of the second suction opening 222. The first suction pad 211 and the second suction pad 221 are made of an elastic material such as synthetic rubber. The first suction pad 211 and the second suction pad 221 may be flat or bellows-shaped. One of the first suction pad 211 and the second suction pad 221 may be flat, and the other of the first suction pad 211 and the second suction pad 221 may be bellows-shaped.

[0149] The multiple suction portions included in the suction unit 200 form a multi-stage nested structure. Specifically, the first suction portion 210 and the second suction portion 220 form a multi-stage nested structure in which the second suction portion 220 can pop out from the inside of the first suction portion 210 to the outside. The second suction portion 220 can move relative to the first suction portion 210 within the first suction portion 210 so that the second suction opening 222 moves in and out of the first suction portion 210 relatively. The second suction portion 220 can be in a retracted state in which the entire second suction portion 220 is located within the first suction portion 210, and a protruding state in which the second suction opening 222 of the second suction pad 221 is located outside the first suction opening 212 of the first suction pad 211. The upper side of FIG. 18 shows the second suction portion 220 in the retracted state, and the lower side of FIG. 18 shows the second suction portion 220 in the protruding state. In the second suction portion 220 in the protruding state, for example, the second suction pad 221 is partially located outside the first suction portion 210. Hereinafter, the suction portion 200 in which a plurality of suction portions form a multi-stage nested structure may be referred to as a multi-stage suction portion 200.

[0150] 18 , when the first suction unit 210 suctions the object 8, that is, when the multistage suction unit 200 is in the first state, the opening edge of the first suction opening 212 in the first suction pad 211 abuts against the object 8, and the first suction opening 212 is blocked by the object 8. Then, the negative pressure generator 51 reduces the pressure inside the first suction pad 211, causing the opening edge of the first suction pad 211 to tightly contact the object 8. This causes the object 8 to be suctioned to the first suction pad 211. The same applies when the second suction unit 220 suctions the object 8. If the negative pressure inside the first suction pad 211 and the negative pressure inside the second suction pad 221 are the same, the suction force of the first suction pad 211 with the larger first suction opening 212 will be greater than the suction force of the second suction pad 221 with the smaller second suction opening 222.

[0151] Hereinafter, the first suction pad 211 may be referred to as the large pad 211, and the second suction pad 221 may be referred to as the small pad 221. The first suction portion 210 may be referred to as the large pad suction portion 210, and the second suction portion 220 may be referred to as the small pad suction portion 220. The first state may be referred to as the large pad use state, and the second state may be referred to as the small pad use state. The suction portion of the large pad suction portion 210 or the small pad suction portion 220 that suctions the object 8 may be referred to as the used suction portion. The suction pad of the used suction portion may be referred to as the used pad. For example, when the multi-stage suction portion 200 is in the large pad use state, the used suction portion is the large pad suction portion 210, and the used pad is the large pad 211.

[0152] When each multistage suction unit 200 is in the large pad use state, the multiple large pads 211 are located on the same plane, as are the multiple suction pads 410. Similarly, when each multistage suction unit 200 is in the small pad use state, the multiple small pads 221 are located on the same plane. The used pads of the multiple multistage suction units 200 are located on the same plane.

[0153] Hereinafter, in the description of the suction mechanism 50A, the term "pad arrangement plane" refers to a virtual arrangement plane on which multiple used pads are arranged. The pad arrangement plane for the suction mechanism 50A is, for example, parallel to the bottom surface 46a. Furthermore, in the description of the suction mechanism 50A, the term "arrangement plane perpendicular direction" refers to a direction perpendicular to the virtual arrangement plane on which multiple used pads are arranged. Furthermore, in the description of the suction mechanism 50A, the term "specific planar view" refers to a planar view in which the object 8 and multiple used pads are viewed from above the object 8 along the arrangement plane perpendicular direction.

[0154] The switching mechanism 500 can switch the state of each multistage suction unit 200 between a large pad use state and a small pad use state. That is, the switching mechanism 500 can set the state of each multistage suction unit 200 to either a large pad use state or a small pad use state. The switching mechanism 500 can set the state of each second suction unit 220 to either a retracted state or a protruding state. The switching mechanism 500 may be able to individually set the state of each multistage suction unit 200. In this case, when the state of one multistage suction unit 200 is set to the large pad use state, the switching mechanism 500 can set the state of another multistage suction unit 200 to the small pad use state.

[0155] The switching mechanism 500 includes a plurality of switching units 501 corresponding to the plurality of multistage suction units 200, respectively. Each switching unit 501 can switch the state of the corresponding multistage suction unit 200 between a large pad use state and a small pad use state.

[0156] 19 and 20 are schematic diagrams showing an example of the configuration of the switching unit 501 and the corresponding multistage suction unit 200. Fig. 19 shows the multistage suction unit 200 in a state where a large pad is used, and Fig. 20 shows the multistage suction unit 200 in a state where a small pad is used.

[0157] 19 and 20 , the large pad suction portion 210 has a hollow first cylinder 215. The large pad 211 is provided at the tip of the first cylinder 215. A hollow portion 216 inside the first cylinder 215 forms a first duct 216 through which air flows. The first duct 216 is connected to the hollow portion inside the large pad 211.

[0158] The small pad suction portion 220 has a second cylinder 225 having a second duct 226 through which air flows. The small pad 221 is provided at the tip of the second cylinder 225. The second duct 226 communicates with the hollow portion inside the small pad 221. The second cylinder 225 is located within the first duct 216 of the first cylinder 215.

[0159] A plurality of pipes 550 through which air flows extend from the negative pressure generating unit 51 to the first cylinders 215 of the plurality of multistage adsorption units 200. A through-hole 217 is provided in the peripheral wall of the first cylinder 215. The through-hole 217 communicates with the inner conduit of the pipes 550 extending from the negative pressure generating unit 51 to the first cylinder 215.

[0160] When the conduit of the piping 550 extending from the negative pressure generating unit 51 is connected to the first conduit 216 of the first cylinder 215 of the large pad suction unit 210, the negative pressure generating unit 51 can reduce the pressure inside the large pad 211 to generate negative pressure inside the large pad 211. On the other hand, when the conduit of the piping 550 is connected to the second conduit 226 of the second cylinder 225 of the small pad suction unit 220, the negative pressure generating unit 51 can reduce the pressure inside the small pad 221 to generate negative pressure inside the small pad 221.

[0161] The switching unit 501 includes, for example, a conduit switching cylinder 502 and a drive mechanism 505 capable of moving the conduit switching cylinder 502. The conduit switching cylinder 502 is located within the first conduit 216 of the first cylinder 215. The conduit switching cylinder 502 is driven by the drive mechanism 505 to move within the first conduit 216 along the length of the first conduit 216 (the up-and-down direction in FIGS. 19 and 20 ). The conduit switching cylinder 502 is capable of moving in a direction perpendicular to the arrangement plane. A small pad suction portion 220 is fixed to the conduit switching cylinder 502. Specifically, a second cylinder 225 of the small pad suction portion 220 is fixed to the conduit switching cylinder 502. The drive mechanism 505 is capable of moving the small pad suction portion 220 in the direction perpendicular to the arrangement plane via the conduit switching cylinder 502. The drive mechanism 505 can set the state of the second suction portion 220 to a retracted state (see FIG. 19 ) or a protruding state (see FIG. 20 ) by moving the small pad suction portion 220. The drive mechanism 505 can move the small pad suction portion 220 relative to the large pad suction portion 210 within the large pad suction portion 210 so that the second suction opening 222 of the small pad suction portion 220 moves in and out of the large pad suction portion 210 relatively. The drive mechanism 505 may be formed, for example, by a solenoid. Alternatively, the drive mechanism 505 may be formed by an electric actuator including a motor.

[0162] In addition, the drive mechanism 505 connected to the large pad suction portion 210 may drive the large pad suction portion 210, thereby moving the small pad suction portion 220 relative to the large pad suction portion 210 within the large pad suction portion 210 so that the second suction opening 222 of the small pad suction portion 220 moves in and out of the large pad suction portion 210 relatively.

[0163] The conduit switching cylinder 502 is a member for switching whether the conduit of the piping 550 is connected to the first conduit 216 of the large pad suction portion 210 or the second conduit 226 of the small pad suction portion 220. The conduit switching cylinder 502 has a first connecting conduit 503 for connecting the first conduit 216 to the conduit of the piping 550. One end of the first connecting conduit 503 is connected to the first conduit 216. The other end of the first connecting conduit 503 is exposed from the outer surface of the conduit switching cylinder 502 and is connected to a gap between the conduit switching cylinder 502 and the peripheral wall of the first cylinder 215. The conduit switching cylinder 502 also has a second connecting conduit 504 for connecting the second conduit 226 to the conduit of the piping 550. One end of the second connecting conduit 504 is connected to the second conduit 226. The other end of the second connecting pipe 504 is exposed from the outer surface of the pipe switching cylinder 502 and is connected to the gap between the pipe switching cylinder 502 and the peripheral wall of the first cylinder 215. The other end of the second connecting pipe 504 is not connected to the other end of the first connecting pipe 503 by a member that partitions the gap between the pipe switching cylinder 502 and the peripheral wall of the first cylinder 215.

[0164] As shown in Figure 19, when the small pad suction portion 220 is in the retracted state, the first connecting pipe 503 is connected to the through-hole 217 of the first cylinder 215 through the gap between the pipe switching cylinder 502 and the peripheral wall of the first cylinder 215. As a result, the pipe 550 is connected to the first pipe 216 of the large pad suction portion 210, and the multi-stage suction portion 200 is in the large pad use state. In Figure 19, the route through which air flows when the multi-stage suction portion 200 is in the large pad use state is shown by a dashed dotted line. When the small pad suction portion 220 is in the retracted state, the second connecting pipe 504 is not connected to the through-hole 217 of the first cylinder 215 and is not connected to the pipe 550.

[0165] 20 , when the small pad suction portion 220 is in the protruding state, the second connection pipe 504 is connected to the through-hole 217 of the first cylinder 215 through the gap between the pipe switching cylinder 502 and the peripheral wall of the first cylinder 215. As a result, the pipe of the piping 550 is connected to the second pipe 226 of the small pad suction portion 220, and the multistage suction portion 200 is in the small pad use state. In FIG. 20 , the route through which air flows when the multistage suction portion 200 is in the small pad use state is shown by a dashed dotted line. When the small pad suction portion 220 is in the protruding state, the first connection pipe 503 is not connected to the through-hole 217 and is not connected to the pipe of the piping 550.

[0166] As described above, the suction mechanism 50A can switch the state of each multistage suction unit 200 between the large pad use state and the small pad use state. The suction mechanism control unit 137 can switch the state of each multistage suction unit 200 between the large pad use state and the small pad use state by controlling each drive mechanism 505 of the switching mechanism 500.

[0167] When the suction mechanism 50 shown in Figures 4 to 8 is used, the negative pressure generated in each suction pad of the suction structure 40 is adjustable. However, when the suction mechanism 50A is used, the negative pressure generated in each suction pad of the suction structure 40A is fixed and does not need to be adjusted. When the suction mechanism 50A is used, the suction force of the multistage suction unit 200 may be changed in two stages by switching the state of the multistage suction unit 200 between a large pad use state and a small pad use state, that is, by switching the pads used by the multistage suction unit 200 between the large pad 211 and the small pad 221. An example of the operation of the hand control device 13 and the robot control device 12 in this case will be described below with reference to Figure 21.

[0168] 21 is a schematic diagram showing an example of the operation of the hand control device 13 and the robot control device 12. When a work start instruction is input, the robot control device 12 executes step s1 described above and positions the robot hand 4 above the object 8. When the robot hand 4 moves to above the object 8, positioning completion information is input to the hand control device 13.

[0169] In the hand control device 13 to which the placement completion information has been input, step s25 is executed. In step s25, the suction force determination unit 135 determines the suction force of the suction mechanism 50A. The suction force determination unit 135 determines the suction force of each multi-stage suction unit 200 based on the first object information in the memory unit 131.

[0170] For example, if the object weight indicated by the weight information included in the first object information is less than a threshold value, the adsorptive force determination unit 135 sets the setting value of the adsorptive force of each multi-stage adsorptive unit 200 to a relatively small first setting value. On the other hand, if the object weight is equal to or greater than the threshold value, the adsorptive force determination unit 135 sets the setting value of the adsorptive force of each multi-stage adsorptive unit 200 to a relatively large second setting value.

[0171] Furthermore, when the size (e.g., area) of the specific range represented by at least one of the first range information and the second range information included in the first object information is less than a threshold value, the attractive force determination unit 135 sets the setting value of the attractive force of each multi-stage attractive unit 200 to a relatively small first setting value. On the other hand, when the size of the specific range is equal to or greater than the threshold value, the attractive force determination unit 135 sets the setting value of the attractive force of each multi-stage attractive unit 200 to a relatively large second setting value.

[0172] Furthermore, when the tilt tolerance indicated by the tilt constraint information included in the first object information is equal to or greater than the threshold value, the attractive force determination unit 135 sets the setting value of the attractive force of each multi-stage attractive unit 200 to a relatively small first setting value. On the other hand, when the tilt tolerance is less than the threshold value, the attractive force determination unit 135 sets the setting value of the attractive force of each multi-stage attractive unit 200 to a relatively large second setting value.

[0173] Furthermore, if the first object information includes shape information, the attractive force determination unit 135 determines the size (e.g., volume) of the object 8 based on the shape information. If the determined size is less than a threshold, the attractive force determination unit 135 sets the setting value of the attractive force of each multi-stage attractive unit 200 to a relatively small first setting value. On the other hand, if the determined size is equal to or greater than the threshold, the attractive force determination unit 135 sets the setting value of the attractive force of each multi-stage attractive unit 200 to a relatively large second setting value.

[0174] Once the suction force of each multistage suction unit 200 is determined in step s25, step s26 is executed. In step s26, the suction mechanism control unit 137 controls the suction mechanism 50A based on the determination result of the suction force determination unit 135. Specifically, the suction mechanism control unit 137 controls each switching unit 501 of the switching mechanism 500 of the suction mechanism 50A based on the determination result of the suction force determination unit 135. When the setting value of a multistage suction unit 200 is a relatively small first setting value, the suction mechanism control unit 137 controls the drive mechanism 505 of the switching unit 501 corresponding to that multistage suction unit 200 to set the state of that multistage suction unit 200 to the small pad use state. This sets the use suction unit to the small pad suction unit 220. On the other hand, when the setting value of the multistage suction unit 200 is the relatively large second setting value, the suction mechanism control unit 137 causes the drive mechanism 505 of the switching unit 501 corresponding to the multistage suction unit 200 to set the state of the multistage suction unit 200 to the large pad use state. As a result, the use suction unit is set to the large pad suction unit 210.

[0175] After step s26, in step s22, the position determination unit 136 determines the position of each multistage suction unit 200 based on the second object information in the storage unit 121. The method for determining the position of each multistage suction unit 200 based on the second object information is similar to the method for determining the position of each suction unit 41 based on the second object information described above. In the above description of the method for determining the position of each suction unit 41, if the suction unit 41 and the suction pad 410 are replaced with the suction unit and pad to be used in the multistage suction unit 200, respectively, the method for determining the position of each multistage suction unit 200 based on the second object information is described.

[0176] Next, in step s23, the suction mechanism control unit 137 controls the drive mechanism 52 so that the position of each multistage suction unit 200 becomes the position determined in step s22. Once the position of each multistage suction unit 200 has been set, the suction mechanism control unit 137 outputs setting completion information, which indicates that setting of the position of each multistage suction unit 200 has been completed, to the robot control device 12 via the interface 132.

[0177] In the robot control device 12 to which the setting completion information has been input, step s24 is executed. In step s24, the control unit 120 of the robot control device 12 controls the attitude of the arm 3 to move the robot hand 4 downward until the multiple used pads abut against the object 8. At this time, the control unit 120 controls the attitude of the arm 3 so that the opening edges of the multiple used pads appropriately abut against the object 8. The attitude control of the arm 3 in step s24 is the same as the attitude control of the arm 3 in step s4 described above. In the above description of the attitude control of the arm 3 in step s4, if the suction unit 41 and the suction pad 410 are replaced with the used suction unit and used pad, respectively, the description of the attitude control of the arm 3 in step s24 is the same.

[0178] When the suction mechanism 50A is used, the multiple pressure sensors 55 correspond to the multiple multistage suction units 200, respectively. Each pressure sensor 55 detects the contact pressure of the used pad of the corresponding multistage suction unit 200 against the object 8. Similarly, the multiple distance sensors 57 correspond to the multiple multistage suction units 200, respectively. Each distance sensor 57 detects the distance between the used suction unit of the corresponding multistage suction unit 200 and the object 8. Similarly, the multiple negative pressure detection sensors 54 correspond to the multiple multistage suction units 200, respectively. Each negative pressure detection sensor 54 detects the negative pressure in the used pad of the corresponding multistage suction unit 200.

[0179] When the multiple active suction units 200 have completed contacting the object 8, the control unit 120 outputs preparation completion information indicating that preparation for starting suction has been completed to the hand control unit 13 via the interface 123. Upon receiving the preparation completion information, the hand control unit 13 executes step s29. In step s29, the suction mechanism control unit 137 controls the negative pressure generating unit 51 to generate a predetermined negative pressure in the active pad of each multi-stage suction unit 200. This causes the active pads of the multiple multi-stage suction units 200 to suction the object 8. At this time, if the active pad is the large pad 211, the suction force of the active suction unit is set to a relatively large second set value. On the other hand, if the active pad is the small pad 221, the suction force of the active suction unit is set to a relatively small first set value. When the multiple multi-stage suction units 200 start suctioning the object 8, the control unit 130 outputs suction start information notifying the robot control unit 12 of the start of suction via the interface 132.

[0180] Thereafter, the above-described step s7 is executed. Then, step s28 is executed. In step s28, the determination unit 138 determines the suction state of the object 8 in the suction mechanism 50A based on the detection result of the sensor unit 59. The method for determining the suction state of the object 8 in the suction mechanism 50A in step s28 is the same as the method for determining the suction state of the object 8 in the suction mechanism 50 in step s8 described above. In the above description of the method for determining the suction state of the object 8 in the suction mechanism 50, if the suction unit 41 and the suction pad 410 are replaced with the used suction unit and the used pad, respectively, the description becomes a method for determining the suction state of the object 8 in the suction mechanism 50A.

[0181] If it is determined in step s28 that there is a problem with the suction state, then step s11 described above is executed. After step s11, steps s12 and s10 described above are executed. On the other hand, if it is determined in step s28 that there is no problem with the suction state, then step s9 described above is executed, and thereafter, the hand control device 13 and the robot control device 12 operate in the same manner as in FIG. 11.

[0182] When the suction mechanism 50A is used, the position determination unit 136 may redetermine the position of the multistage suction mechanism 200 in accordance with the result of the suction state determination by the determination unit 138, similar to the example of Fig. 15 described above. Furthermore, the suction force determination unit 135 may redetermine the suction force of the suction mechanism 50A in accordance with the result of the suction state determination by the determination unit 138. Fig. 22 is a schematic diagram showing an example of the operation of the hand control device 13 and the robot control device 12 in this case.

[0183] In the example of FIG. 22 , if it is determined in step s28 that there is a problem with the suction state, the above-described steps s11, s12, and s13 are sequentially executed. As a result, the object 8 is placed on the work start table. Then, step s25 is executed, and the suction force of the suction mechanism 50A is redetermined. In step s25, the suction force determination unit 135, for example, increases the set value of the suction force of each multi-stage suction unit 200. After step s25, step s26 is executed. If each active suction unit is a small pad suction unit 220, in step s26, each active suction unit is changed to a large pad suction unit 210. Then, step s22 is executed. On the other hand, if each active suction unit is a large pad suction unit 210, step s26 is not executed, and step s22 is executed. In step s22, the positions of the multiple multi-stage suction units 200 are redetermined. In the above description of the re-determination of the positions of the plurality of suction units 41, if the suction unit 41 is replaced with the multistage suction unit 200, the description becomes one of the re-determination of the positions of the plurality of multistage suction units 200.

[0184] When the positions of the multiple multistage suction units 200 are redetermined in step s22, step s23 is executed. As a result, the positions of the multiple multistage suction units 200 are changed to the positions redetermined in step s22. Thereafter, steps s24 and s29 are executed sequentially. In step s29, similar to step s29 in FIG. 21 , when the active suction units are changed to the large pad suction units 210 in step s26, the suction mechanism control unit 137 controls the negative pressure generating unit 51 to generate a predetermined negative pressure in the active pad (i.e., the large pad 211) of each multistage suction unit 200. In step s26, changing the active suction units from the small pad suction units 220 to the large pad suction units 210 increases the suction force of each multistage suction unit 200 even if the negative pressure in the active pad remains the same, and the suction force of each multistage suction unit 200 is set to the set value redetermined in step s25. On the other hand, if step s26 is not executed, in step s29, the negative pressure generating unit 51 increases the negative pressure in each used adsorption unit under the control of the adsorption mechanism control unit 137, and sets the adsorption force of each used adsorption unit to the set value re-determined in step s25.

[0185] In this way, in the example of Figure 22, the suction force of the multi-stage suction unit 200 is re-determined depending on the suction state judgment result by the judgment unit 138, so that the suction state of the object 8 by the multi-stage suction unit 200 can be improved.

[0186] In the example of Figure 22, both the position of the multi-stage suction unit 200 and the suction force of the suction mechanism 50A are redetermined in accordance with the result of the suction state determination by the determination unit 138, but just one of the position of the multi-stage suction unit 200 and the suction force of the suction mechanism 50A may be redetermined, as in the case where the suction mechanism 50 is used.

[0187] Furthermore, similar to step s5, in step s25, the suction force of each multi-stage suction unit 200 may be individually set. For example, consider a case where the first object information includes shape information indicating the shape of the object 8 having a non-uniform thickness. In this case, steps s25 and s26 are executed, for example, between steps s23 and s24. That is, the suction force of each multi-stage suction unit 200 is set after the position of the multi-stage suction unit 200 is set. In step s25, the suction force determination unit 135 identifies thick portions with a relatively large thickness and thin portions with a relatively small thickness on the object 8, for example, based on the shape information. Then, the suction force determination unit 135 determines, among the multiple multi-stage suction units 200, the suction force setting values ​​of the multi-stage suction units 200 that suction the thick portions of the object 8 to be a relatively large second setting value, and the suction force setting values ​​of the multi-stage suction units 200 that suction the thin portions of the object 8 to be a relatively small first setting value. After step s25, in step s26, the state of the multi-stage suction unit 200 whose suction force setting value has been determined to be the first setting value is set to a small pad usage state, and the state of the multi-stage suction unit 200 whose suction force setting value has been determined to be the second setting value is set to a large pad usage state.

[0188] As another example, consider a case where the first object information includes center-of-gravity position information. In this case, steps s25 and s26 are executed, for example, between steps s23 and s24. In step s25, the attractive force determination unit 135 calculates, for each multi-stage attraction unit 200, the distance in the specific planar view between the attraction position at which the multi-stage attraction unit 200 attracts the object 8 and the object center-of-gravity position indicated by the center-of-gravity position information. If the calculated distance for the multi-stage attraction unit 200 is less than a threshold value, the attractive force determination unit 135 determines the set value of the attractive force of the multi-stage attraction unit 200 to be the second set value. On the other hand, if the calculated distance for the multi-stage attraction unit 200 is equal to or greater than the threshold value, the attractive force determination unit 135 determines the set value of the attractive force of the multi-stage attraction unit 200 to be the first set value. After step s25, in step s26, the state of the multi-stage suction unit 200 whose suction force setting value has been determined to be the first setting value is set to a small pad usage state, and the state of the multi-stage suction unit 200 whose suction force setting value has been determined to be the second setting value is set to a large pad usage state.

[0189] 22 , in step s25 after it is determined in step s28 that there is a problem with the suction state, the suction force determiner 135 may re-determine the suction force of the suction mechanism 50A based on the center-of-gravity position information included in the first object information. In this case, steps s25 and s26 may be executed, for example, between steps s23 and s24. In step s25 after step s23, the suction force determiner 135 calculates, for each multi-stage suction unit 200, the distance in the specific planar view between the suction position at which the multi-stage suction unit 200 suctions the object 8 and the object's center-of-gravity position indicated by the center-of-gravity position information. Then, the suction force determiner 135 increases the suction force setting value of the multi-stage suction unit 200 for which the calculated distance is equal to or less than a threshold value. In step s26 after step s25, if the state of the multi-stage suction unit 200 whose setting value has been increased is the small-pad use state, the state of the multi-stage suction unit 200 is changed to the large-pad use state. On the other hand, if the state of the multi-stage suction unit 200 with the increased setting value is a large pad usage state, step s26 is not executed, and in step s29, the negative pressure in the usage pad of the usage suction unit of the multi-stage suction unit 200 is reduced.

[0190] 22 , the suction force determination unit 135 may redetermine the suction force of the multi-stage suction unit 200 based on information obtained by the sensor unit 59 that changes depending on the suction state of the object 8 at the multi-stage suction unit 200. In step s25 after step s13, the suction force determination unit 135 may redetermine the suction force of the multi-stage suction unit 200 corresponding to the negative pressure detection sensor 54 based on, for example, the detection result of the negative pressure detection sensor 54. For example, when the negative pressure detected by the negative pressure detection sensor 54 is lower than a predetermined range (in other words, an appropriate range), the suction force determination unit 135 reduces the set value of the suction force of the multi-stage suction unit 200 corresponding to the negative pressure detection sensor 54. On the other hand, when the negative pressure detected by the negative pressure detection sensor 54 is higher than the predetermined range, the suction force determination unit 135 increases the set value of the suction force of the multi-stage suction unit 200 corresponding to the negative pressure detection sensor 54. If the set value of the suction force of the multistage suction unit 200 whose active suction unit is the large pad suction unit 210 is reduced in step s25, the active suction unit of the multistage suction unit 200 is changed to the small pad suction unit 220 in step s26. On the other hand, if the set value of the suction force of the multistage suction unit 200 whose active suction unit is the small pad suction unit 220 is reduced in step s25, step s26 is not executed, and the negative pressure in the active pad of the active suction unit of the multistage suction unit 200 is increased in step s29. Also, if the set value of the suction force of the multistage suction unit 200 whose active suction unit is the small pad suction unit 220 is increased in step s25, the active suction unit of the multistage suction unit 200 is changed to the large pad suction unit 210 in step s26. On the other hand, if the set value of the suction force of the multi-stage suction unit 200 whose used suction unit is the large pad suction unit 210 is increased in step s25, step s26 is not executed, and in step s29, the negative pressure in the used pad of the used suction unit of the multi-stage suction unit 200 is reduced.

[0191] In step s25 after step s13, the suction force determination unit 135 may redetermine the suction force of the multistage suction unit 200 corresponding to the pressure sensor 55 based on the detection result of the pressure sensor 55. For example, when the contact pressure detected by the pressure sensor 55 is greater than a predetermined range, the suction force determination unit 135 reduces the setting value of the multistage suction unit 200 corresponding to the pressure sensor 55. On the other hand, when the contact pressure detected by the pressure sensor 55 is less than the predetermined range, the suction force determination unit 135 increases the setting value of the multistage suction unit 200 corresponding to the pressure sensor 55. The processing after step s25 is similar to the case where the suction force of the multistage suction unit 200 corresponding to the negative pressure detection sensor 54 is redetermined based on the detection result of the negative pressure detection sensor 54.

[0192] In step s25 after step s13, the suction force determination unit 135 may redetermine the suction force of the multi-stage suction unit 200 corresponding to the distance sensor 57 based on the detection result of the distance sensor 57. For example, if the distance detected by the distance sensor 57 is greater than a predetermined range, the suction force determination unit 135 increases the setting value of the multi-stage suction unit 200 corresponding to the distance sensor 57. On the other hand, if the distance detected by the distance sensor 57 is smaller than the predetermined range, the suction force determination unit 135 increases the setting value of the multi-stage suction unit 200 corresponding to the distance sensor 57. The processing after step s25 is similar to the case where the suction force of the multi-stage suction unit 200 corresponding to the negative pressure detection sensor 54 is redetermined based on the detection result of the negative pressure detection sensor 54.

[0193] In the example described above, the suction unit 200 includes the first suction unit 210 and the second suction unit 220 having a multi-stage nested structure, but may include the first suction unit 210 and the second suction unit 220 arranged adjacent to each other, as shown in Fig. 23. In each suction unit 200, the first suction pad 211 and the second suction pad 221 are arranged on the same plane. In the example of Fig. 23, the suction mechanism 50A may be configured so that the positions of the first suction unit 210 and the second suction unit 220 constituting one suction unit 200 can be changed individually.

[0194] In the example of FIG. 23 , in addition to the first and second states, the suction unit 200 may also have a third state (also referred to as a both-pads-in-use state) in which both the large pad suction unit 210 and the small pad suction unit 220 suction the object 8. In the both-pads-in-use state, negative pressure is generated in both the large pad 211 and the small pad 221, and the large pad 211 and the small pad 221 simultaneously suction the object 8. The suction mechanism 50A can switch the state of the suction unit 200 among the large pad-in-use state, the small pad-in-use state, and the both-pads-in-use state under control of the suction mechanism control unit 137. For example, when the same negative pressure is generated in the large pad 211 and the small pad 221, the suction force of the suction unit 200 in the both-pads-in-use state is greater than the suction force of the suction unit 200 in the large pad-in-use state, and the suction force of the suction unit 200 in the large pad-in-use state is greater than the suction force of the suction unit 200 in the small pad-in-use state.

[0195] The hand control device 13 can set the suction force of the suction unit 200 to at least three levels by switching the state of the suction unit 200 between a large pad use state, a small pad use state, and a both-pad use state. For example, consider a case where the same negative pressure is generated in the large pad 211 and the small pad 221 regardless of the state of the suction unit 200. If the object weight indicated by the weight information included in the first object information is less than a first threshold, the suction force determination unit 135 determines the set value of the suction force of each suction unit 200 to be a first set value in step s25. If the object weight is equal to or greater than the first threshold and less than a second threshold (where the second threshold is greater than the first threshold), the suction force determination unit 135 determines the set value of the suction force of each suction unit 200 to be a second set value. If the object weight is equal to or greater than the second threshold, the suction force determination unit 135 determines the set value of the suction force of each suction unit 200 to be a third set value, which is greater than the first and second set values. In step s26, if the setting value of the suction force of the suction unit 200 is the first setting value, the suction mechanism control unit 137 sets the state of the suction unit 200 to a small pad usage state. As a result, the suction force of the suction unit 200 is set to the small first setting value. On the other hand, if the setting value of the suction force of the suction unit 200 is the second setting value, the suction mechanism control unit 137 sets the state of the suction unit 200 to a large pad usage state. As a result, the suction force of the suction unit 200 is set to the medium second setting value. On the other hand, if the setting value of the suction force of the suction unit 200 is the third setting value, the suction mechanism control unit 137 sets the state of the suction unit 200 to a both pad usage state. As a result, the suction force of the suction unit 200 is set to the large third setting value.

[0196] 22 , when the state of the suction unit 200 is the large pad use state, if the suction force of the suction unit 200 is increased by redetermining the suction force of the suction unit 200, the state of the suction unit 200 may be changed to the both pad use state. Furthermore, when the state of the suction unit 200 is the both pad use state, if the suction force of the suction unit 200 is increased, at least one of the negative pressures in the large pad 211 and the small pad 221 may be decreased. Furthermore, when the state of the suction unit 200 is the both pad use state, if the suction force of the suction unit 200 is decreased by redetermining the suction force of the suction unit 200, the state of the suction unit 200 may be changed to the large pad use state or the small pad use state.

[0197] The suction unit 200 may include three or more suction units with suction openings of different sizes. In this case, the three or more suction units with suction openings of different sizes may form a multi-stage nested structure in the suction unit 200. Alternatively, the three or more suction units with suction openings of different sizes may be arranged in a plane in the suction unit 200. For example, consider a case where the suction unit 200 includes a large-opening suction unit with a large suction opening, a medium-opening suction unit with a medium suction opening, and a small-opening suction unit with a small suction opening. In this case, an object 8 with a weight equal to or greater than a second threshold may be attracted by the large-opening suction unit, an object 8 with a weight equal to or greater than a first threshold but less than a second threshold may be attracted by the medium-opening suction unit, and an object 8 with a weight less than the first threshold may be attracted by the small-opening suction unit. Furthermore, the suction unit 200 may include a multi-stage nested structure of the large-opening suction unit, the medium-opening suction unit, and the small-opening suction unit. That is, the suction unit 200 may be configured such that the medium-opening suction unit protrudes from the large-opening suction unit, and the small-opening suction unit protrudes from the medium-opening suction unit. Also, when the suction unit 200 has three or more suction units with suction openings of different sizes, at least two of the three or more suction units may simultaneously suction the object 8.

[0198] The first object information used in determining the suction force of the suction unit may include strength information indicating the strength of the object 8. The strength information may, for example, indicate a portion of the object 8 with weak strength (also referred to as a weak strength portion). In this case, the set value of the suction force of the suction unit 41 that suctions the weak strength portion indicated by the strength information may be smaller than the set value of the suction force of the suction unit 41 that suctions the portion other than the weak strength portion. Furthermore, the set value of the suction force of the suction unit 200 that suctions the weak strength portion may be smaller than the set value of the suction force of the suction unit 200 that suctions the portion other than the weak strength portion. In this case, for example, the suction unit 200 that suctions the weak strength portion may suction the object 8 with the small pad suction unit 220 having a small suction force, and the suction unit 200 that suctions the portion other than the weak strength portion may suction the object 8 with the large pad suction unit 210 having a large suction force.

[0199] Furthermore, the suction force of the small pad suction portion 220 that suctions the weak strength portion may be set to be the same as the suction force of the large pad suction portion 210 that suctions the portion other than the weak strength portion. In this case, the force per unit area (also called suction pressure) applied to the weak strength portion suctioned by the small pad suction portion 220 is smaller than the force per unit area applied to the portion other than the weak strength portion suctioned by the large pad suction portion 210, making the weak strength portion less likely to be damaged.

[0200] In this way, when the multiple suction units 200 provided in the suction mechanism 50A include a suction unit 200 that suctions the object 8 with a large pad suction unit 210 (also referred to as a large pad-using suction unit 200) and a suction unit 200 that suctions the object 8 with a small pad suction unit 220 (also referred to as a small pad-using suction unit 200), the suction force of the small pad suction unit 220 of the small pad-using suction unit 200 does not necessarily have to be smaller than the suction force of the large pad suction unit 210 of the large pad-using suction unit 200. The suction force of the small pad suction unit 220 of the small pad-using suction unit 200 may be the same as, greater than, or smaller than the suction force of the large pad suction unit 210 of the large pad-using suction unit 200.

[0201] When the suction mechanism 50 is used, the drive mechanism 52 may be configured to be able to change the position of at least one of the plurality of suction pads 410 in a direction away from or toward the bottom surface 46a of the main body portion 46 of the exterior case 45 under the control of the suction mechanism control unit 137. In this case, for example, the drive mechanism 52 may change the position of the suction pad 410 in a direction away from or toward the bottom surface 46a by extending or contracting the suction unit 41. The position of at least one of the plurality of suction pads 410 may change, for example, along a direction perpendicular to the bottom surface 46a.

[0202] In this way, by changing the position of the suction pad 410 in a direction away from the bottom surface 46a or in a direction towards the bottom surface 46a, even if there is an area 800 on the top surface of the object 8 that is lower than the surrounding area, as in the example of Figure 10 above, the position of the suction pad 410 above the area 800 changes in a direction away from the bottom surface 46a, making it possible for the suction pad 410 to adsorb the area 800.

[0203] Furthermore, when the suction mechanism 50A is used, at least one of the plurality of suction portions 200 may be entirely extendable and contractable in a direction perpendicular to the bottom surface 46a. Even in this case, for example, as in the example of Fig. 10, even if there is an area 800 on the top surface of the object 8 that is lower than the surrounding area, the suction portion 200 above the area 800 can extend entirely, thereby enabling the large pad suction portion 210 or the small pad suction portion 220 of the suction portion 200 to suction the area 800.

[0204] In the above example, the switching mechanism 500 does not change the position of the small pad 221 when the suction unit 200 is in the small pad use state. However, the switching mechanism 500 may be capable of changing the position of the small pad 221 of at least one of the multiple suction units 200 in the small pad use state, moving it away from the bottom surface 46a of the main body 46 or moving it closer to the bottom surface 46a. In this case, for example, when the region 800 shown in FIG. 10 is narrow, the position of the small pad 221 of the small pad use suction unit 200 located above the region 800 changes away from the bottom surface 46a, allowing the small pad 221 to suction the narrow region 800. In this case, the region other than the region 800 may be suctioned by, for example, the large pad 211. The suction force of the small pad suction unit 220 that suctions the region 800 may be the same as, smaller than, or greater than the suction force of the large pad suction unit 210 that suctions the region other than the region 800.

[0205] In the above example, the suction force determination unit 135 determines the suction force of the suction unit (the suction unit 41 or the suction unit 200) based on the first object information in step s5 or step s25. However, the suction force of the suction unit may be determined based on the first object information and other information. For example, the viscoelastic properties of a suction pad made of an elastic material may change depending on the environment surrounding the suction pad. Therefore, the suction force determination unit 135 may determine the suction force of the suction unit based on the first object information and environmental changes in the viscoelastic properties of the suction pad of the suction unit. For example, the suction force determination unit 135 may determine the suction force of the suction unit based on the first object information and temperature changes in the viscoelastic properties of the suction pad of the suction unit. In this case, the sensor unit 59 includes, for example, a temperature sensor 58 that detects the temperature around the suction pad of the suction unit, as shown in FIG. 24 . The temperature sensor 58 may be, for example, a semiconductor temperature sensor such as a thermistor, or may be composed of other components. The temperature sensor 58 may be provided, for example, in the main body 46 of the exterior case 45 of the robot hand 4. The temperature sensor 58 , for example, repeatedly detects the temperature around the suction pad and outputs the detection result to the hand control device 13 .

[0206] When the suction mechanism 50 is used, the sensor unit 59 may be provided with multiple temperature sensors 58 that detect the ambient temperatures of the multiple suction pads 410, respectively. Alternatively, the sensor unit 59 may be provided with a single temperature sensor 58 that is common to the multiple suction pads 410. In this case, the temperature detected by the single temperature sensor 58 is used as the ambient temperature of each suction pad. Furthermore, when the suction mechanism 50A is used, multiple temperature sensors 58 may be provided that correspond to the multiple suction units 200, respectively. In this case, the temperatures detected by the temperature sensors 58 are used as the ambient temperatures of the large pads 211 and the small pads 221 of the corresponding suction units 200. Alternatively, a single temperature sensor 58 may be provided that is common to the multiple suction units 200. In this case, the temperatures detected by the single temperature sensor 58 are used as the ambient temperatures of the large pads 211 and the small pads 221 of the corresponding suction units 200. Note that the temperature of the suction pad itself may be used as the ambient temperature of the suction pad.

[0207] When determining the adhesive force of the adhesive part based on the first object information and the temperature change in the viscoelastic properties of the adhesive pad of the adhesive part, the adhesive force determination unit 135, for example, first provisionally determines the adhesive force based on the first object information as described above. Then, the adhesive force determination unit 135 changes the provisionally determined adhesive force (also referred to as provisional adhesive force) in accordance with the temperature detected by the temperature sensor 58. The adhesive force determination unit 135 sets the changed provisional adhesive force as the final adhesive force.

[0208] The suction pad tends to become harder as the ambient temperature decreases due to changes in its viscoelastic properties. Therefore, the suction force determination unit 135 increases the temporary suction force as the ambient temperature of the suction pad of the suction unit decreases. This improves the stability of the suction of the object 8 at the suction unit, regardless of changes in the viscoelastic properties of the suction pad of the suction unit due to temperature.

[0209] The suction force determination unit 135 may determine the suction force of the suction unit based on the first object information and the change over time in the viscoelastic properties of the suction pad of the suction unit. In this case, for example, as shown in Fig. 25 , the non-volatile memory included in the storage unit 131 may store first index information 131b that serves as an index of the change over time in the viscoelastic properties of the suction pad.

[0210] The first index information 131b may be, for example, the time elapsed since a reference timing (also simply referred to as elapsed time). The reference timing may be, for example, the timing when the robot hand 4 equipped with the suction pad is shipped, the timing when the robot hand 4 is first introduced into a work environment, or the timing when the robot hand 4 is first put into operation. Since the longer the elapsed time, the more rapidly the viscoelastic properties of the suction pad change over time, the elapsed time can be considered information that serves as an index of the change in the viscoelastic properties over time. The control unit 130 updates the first index information 131b in the memory unit 131 based on, for example, an output signal from a timer provided in the hand control device 13.

[0211] When determining the suction force of the suction part based on the first object information and the secular change in the viscoelasticity characteristics of the suction pad of the suction part, the suction force determination unit 135 changes the temporary suction force, for example, in accordance with the elapsed time indicated by the first index information 131b in the storage unit 131. The suction force determination unit 135 sets the changed temporary suction force as the final suction force.

[0212] The suction pad tends to become harder as its viscoelasticity changes over time. Therefore, the suction force determination unit 135 increases the temporary suction force as the elapsed time indicated by the first index information 131b increases. This improves the stability of the suction portion's ability to suction the object 8, regardless of changes over time in the viscoelasticity of the suction pad.

[0213] The suction force determination unit 135 may determine the suction force of the suction unit based on the first object information and a change in the viscoelasticity due to use of the suction pad of the suction unit. In this case, for example, as shown in Fig. 26 , the non-volatile memory included in the storage unit 131 may store second index information 131c that serves as an index of a change in the viscoelasticity due to use of the suction pad.

[0214] The second index information 131c may be, for example, the total operating time of the robot hand 4. The longer the total operating time, the greater the change in viscoelastic properties due to the use of each suction pad. Therefore, the total operating time can be considered information that serves as an index of the change in viscoelastic properties due to the use of the suction pads. The control unit 130 updates the second index information 131c in the memory unit 131 based on the output signal of a timer included in the hand control device 13, etc.

[0215] When determining the suction force of the suction unit based on the first object information and the change in the viscoelasticity characteristics due to use of the suction pad of the suction unit, the suction force determination unit 135 changes the temporary suction force, for example, in accordance with the total operating time indicated by the second index information 131c in the storage unit 131. The suction force determination unit 135 sets the changed temporary suction force as the final suction force.

[0216] Here, the suction pad tends to become harder as the viscoelastic properties change due to use. Therefore, the suction force determination unit 135 increases the temporary suction force as the total operating time indicated by the second index information 131c increases. This improves the stability of the suction unit's ability to suction the object 8, regardless of changes in the viscoelastic properties due to use of the suction pad. Note that the second index information 131c is not limited to the total operating time of the robot hand 4. For example, the second index information 131c may be the total number of suction attempts by the suction unit or the total suction time (also referred to as total usage time) of the suction unit.

[0217] The suction force determination unit 135 may determine the suction force of the suction unit based on at least two of the following: environmental changes in the viscoelastic properties of the suction pad, changes in the viscoelastic properties of the suction pad over time, and changes in the viscoelastic properties of the suction pad due to use. For example, the suction force determination unit 135 may determine the suction force of the suction unit based on at least two of the detection result of the ambient temperature of the suction pad, the first index information 131b, and the second index information 131c.

[0218] For example, consider a case in which the suction force determination unit 135 determines the suction force of the suction unit based on the temperature detection result around the suction pad and the first index information 131b. In this case, the suction force determination unit 135 changes the temporary suction force using, for example, an evaluation value (also referred to as a third evaluation value) of the temperature detected by the temperature sensor 58 and an evaluation value (also referred to as a fourth evaluation value) of the elapsed time indicated by the first index information 131b. The third evaluation value is, for example, a real number greater than zero, and indicates a larger value as the temperature detected by the temperature sensor 58 increases. The fourth evaluation value is, for example, a real number greater than zero, and indicates a larger value as the elapsed time indicated by the first index information 131b increases. For example, the suction force determination unit 135 increases the temporary suction force as the division value obtained by dividing the fourth evaluation value by the third evaluation value increases. This improves the stability of suction of the object 8, regardless of changes in the viscoelastic properties of the suction pad due to temperature or changes over time in the viscoelastic properties of the suction pad.

[0219] As another example, consider a case where the suction force determination unit 135 determines the suction force of the suction unit based on the detection result of the ambient temperature of the suction pad and the second index information 131c. In this case, the suction force determination unit 135 changes the temporary suction force using, for example, the third evaluation value and an evaluation value (also referred to as a fifth evaluation value) of the total operating time indicated by the second index information 131c. The fifth evaluation value is, for example, a real number greater than zero, and indicates a larger value as the total operating time indicated by the second index information 131c increases. For example, the suction force determination unit 135 increases the temporary suction force as the division value obtained by dividing the fifth evaluation value by the third evaluation value increases. This improves the stability of suction of the object 8, regardless of changes in the viscoelastic properties of the suction pad due to temperature changes and changes in the viscoelastic properties caused by use of the suction pad.

[0220] As another example, consider a case where the suction force determination unit 135 determines the suction force of the suction unit based on the first index information 131b and the second index information 131c. In this case, the suction force determination unit 135 changes the temporary suction force using, for example, the fourth evaluation value and the fifth evaluation value. For example, the suction force determination unit 135 increases the temporary suction force as the multiplication value obtained by multiplying the fourth evaluation value by the fifth evaluation value increases. This improves the stability of suction of the object 8, regardless of changes in the viscoelastic properties of the suction pad over time or changes in the viscoelastic properties due to use of the suction pad.

[0221] As another example, consider a case where the suction force determination unit 135 determines the suction force of the suction unit based on the detection result of the ambient temperature of the suction pad, the first index information 131b, and the second index information 131c. In this case, the suction force determination unit 135 changes the temporary suction force using, for example, the third evaluation value, the fourth evaluation value, and the fifth evaluation value. For example, the suction force determination unit 135 increases the temporary suction force as the calculated value obtained by multiplying the fourth evaluation value by the fifth evaluation value and dividing the result by the third evaluation value increases. This improves the stability of suction of the object 8, regardless of changes in the viscoelastic properties of the suction pad due to temperature, changes in the viscoelastic properties of the suction pad over time, or changes in the viscoelastic properties due to use of the suction pad.

[0222] The suction pads in the suction unit may be replaceable. In this case, the control unit 130 of the hand control device 13 may determine when to replace the suction pads. Furthermore, the control unit 130 may cause the interface 132 to output replacement notification information notifying the user when it is time to replace the suction pads. The control unit 130 may determine when to replace the suction pads, for example, based on the first index information 131b in the storage unit 131. In this case, the control unit 130 may determine that it is time to replace the suction pads when the elapsed time indicated by the first index information 131b reaches a predetermined time. Alternatively, the control unit 130 may determine when to replace the suction pads based on the second index information 131c in the storage unit 131, for example. In this case, the control unit 130 may determine that it is time to replace the suction pads when the total operating time indicated by the second index information 131c reaches a predetermined time.

[0223] The replacement notification information output by the hand control device 13 may be input to, for example, the terminal device 14. In this case, the terminal device 14 that has received the replacement notification information may notify the user that it is time to replace the suction pad. For example, the display unit included in the terminal device 14 may display a message to notify the user that it is time to replace the suction pad. Alternatively, the speaker included in the terminal device 14 may output a sound to notify the user that it is time to replace the suction pad. If the system control device 11 has a notification unit that notifies the user, such as a display unit, the notification unit of the system control device 11 that has received the replacement notification information may notify the user that it is time to replace the suction pad. If the hand control device 13 has a notification unit that notifies the user, the notification unit of the hand control device 13 may notify the user that it is time to replace the suction pad. If the robot control device 12 has a notification unit that notifies the user, the notification unit of the robot control device 12 that has received the replacement time information may notify the user that it is time to replace the suction pad.

[0224] Furthermore, the memory unit 131 of the hand control device 13 may store replacement implementation information indicating when (e.g., date and time) the suction pads were replaced. The control unit 130 may then determine the next time to replace the suction pads based on the replacement implementation information in the memory unit 131. For example, the control unit 130 may determine that the next time to replace the suction pads has arrived when a predetermined time has elapsed since the time indicated by the replacement implementation information. When the next time to replace the suction pads has arrived, the control unit 130 may cause the interface 132 to output replacement notification information notifying the user of this fact.

[0225] The suction structure 40A may include at least one suction portion 41 instead of some of the plurality of suction portions 200. In other words, the suction structure 40A may include at least one suction portion 200 and at least one suction portion 41.

[0226] The control unit 130 of the hand control device 13 may estimate the weight of the object 8 while the object 8 is moving, for example, based on the detection result of the force sensor 56. In this case, the control unit 130 may determine the suction state in step s8 or step s28 and compare the estimated weight (also referred to as the "estimated weight") with the set weight of the object 8 stored in the memory unit 131. Here, the "set weight" of the object 8 refers to the weight of the object 8 set by the user. The user inputs the set weight, for example, into the terminal device 14. The set weight input into the terminal device 14 is input to the hand control device 13 and stored in the memory unit 131. In step s8 or step s28, the control unit 130 determines, for example, whether the absolute value of the difference between the estimated weight and the set weight is within a predetermined range. If the absolute value of the difference between the estimated weight and the set weight is within the predetermined range and there is no problem with the suction state, the control unit 130 executes step s9. On the other hand, not only when there is a problem with the suction state, but also when the absolute value of the difference between the estimated weight and the set weight is outside a predetermined range, the control unit 130 executes step s11 to output alert information to the interface 132. This alert information may include information indicating that the estimated weight is different from the set weight.

[0227] If a current sensor that detects the current flowing through the motor that drives the joints of the arm 3 is provided within the arm 3, the control unit 130 may estimate the weight of the object 8 based on the detection result of the current sensor. The current sensor may be, for example, a magnetic type, or may be a type that uses a shunt resistor and an amplifier. The hand control device 13 may receive the detection result of the current sensor within the arm 3 directly from the current sensor, or may receive it via the robot control device 12 that controls the arm 3.

[0228] In the above example, the adsorption state is determined regardless of the contents of the first object information and the second object information. However, the adsorption state may be determined depending on the contents of the first object information and the second object information. For example, the adsorption state determination in step S8 or S28 may be performed when the second object information includes at least one of center of gravity position information, first range information, and second range information, but may not be performed when the second object information includes only shape information. Furthermore, the adsorption state determination may be performed when the first object information includes at least one of first range information, second range information, and tilt constraint information, but may not be performed when the first object information includes only weight information. If the adsorption state determination in step S8 or S28 is not performed, step S9 is repeatedly performed until the movement of object 8 to the work target platform is completed. Furthermore, the adsorption state determination may not be performed when the second object information includes only center of gravity position information.

[0229] The robot control device 12 and the hand control device 13 may be configured as a single control device. Furthermore, at least some of the functions of the control unit 130 of the hand control device 13 (for example, at least one of the suction force determination unit 135, the position determination unit 136, and the judgment unit 138) may be implemented by the control unit 120 of the robot control device 12. Furthermore, at least one of the robot control device 12 and the hand control device 13 may control the robot 2 via a network including the Internet. In this case, at least one of the robot control device 12 and the hand control device 13 may be configured as, for example, a cloud server. The cloud server may be implemented by multiple computer devices. Furthermore, the robot control system 10 does not need to include at least one of the system control device 11 and the terminal device 14.

[0230] As described above, the suction mechanism and the system including the same have been described in detail, but the above description is merely an example in all respects and does not limit the scope of this disclosure. Furthermore, the various examples described above can be combined and applied as long as they are not mutually contradictory. It is understood that countless examples not illustrated can be envisioned without departing from the scope of this disclosure.

[0231] This disclosure includes the following:

[0232] In one embodiment, (1) the processing device includes an attraction force determination unit that determines an attraction force when the attraction mechanism attracts an object based on first object information about the object.

[0233] (2) In the processing device of (1) above, the first object information includes at least one of weight information indicating the weight of the object, first range information indicating the range on the surface of the object that the suction mechanism cannot suction, second range information indicating the range on the surface of the object that the suction mechanism is prohibited from suctioning, and tilt constraint information indicating a constraint on the tilt of the object.

[0234] (3) In the processing device of (1) or (2) above, the suction mechanism has a plurality of suction parts, and the suction force determination unit individually determines, for each of the plurality of suction parts, the suction force when the suction part suctions the object based on the first object information.

[0235] (4) The processing apparatus according to any one of (1) to (3) above includes a suction mechanism control unit that controls the suction mechanism based on the suction force determination result of the suction force determination unit.

[0236] (5) In the processing device of (4) above, the suction mechanism has at least one suction unit and a negative pressure generating unit that generates negative pressure in the at least one suction unit, the suction force determining unit determines the suction force when the at least one suction unit suctions the object based on the first object information, and the suction mechanism control unit controls the negative pressure generating unit based on the suction force determination result.

[0237] (6) In the processing device of (4) above, the suction mechanism has an suction unit, the suction force determination unit determines the suction force when the suction unit suctions the object based on the first object information, the suction unit has a first suction unit having a first suction opening and a second suction unit having a second suction opening smaller than the first suction opening, the suction mechanism is capable of switching between a first state in which the first suction unit suctions the object and a second state in which the second suction unit suctions the object, and the suction mechanism control unit causes the suction mechanism to switch between the first state and the second state based on the suction force determination result.

[0238] (7) In the processing device of (6) above, the suction mechanism is capable of switching between the first state, the second state, and a third state in which the first suction portion and the second suction portion suction the object, and the suction mechanism control unit causes the suction mechanism to switch between the first state, the second state, and the third state based on the suction force determination result.

[0239] (8) In the processing device of (6) above, the second suction portion is capable of moving relative to the first suction portion within the first suction portion so that the second suction opening moves in and out of the first suction portion relatively.

[0240] (9) In any one of the processing devices (1) to (8) above, the suction mechanism includes an suction unit having an suction pad, and the suction force determination unit determines the suction force when the suction unit suctions the object based on the first object information and environmental changes in the viscoelastic properties of the suction pad.

[0241] (10) In any one of the processing devices (1) to (9) above, the suction mechanism includes an suction unit having an suction pad, and the suction force determination unit determines the suction force when the suction unit suctions the object based on the first object information and changes over time in the viscoelastic properties of the suction pad.

[0242] (11) In any one of the processing devices (1) to (10) above, the suction mechanism includes an suction unit having an suction pad, and the suction force determination unit determines the suction force when the suction unit suctions the object based on the first object information and a change in the viscoelastic properties due to use of the suction pad.

[0243] (12) The processing device according to any one of (1) to (11) above includes a determination unit that determines the suction state of the object in the suction mechanism based on the detection result of at least one sensor.

[0244] (13) In the processing device of (12) above, the suction force determination unit redetermines the suction force when the suction mechanism suctions the object, depending on the determination result of the determination unit.

[0245] (14) The processing device of (12) or (13) above includes a notification unit that notifies an alert to an outside of the control device in accordance with the determination result of the determination unit.

[0246] (15) In any one of the processing devices (1) to (14) above, the suction mechanism has at least one suction unit, and the processing device is equipped with a position determination unit that determines the position of the at least one suction unit based on second object information regarding the object.

[0247] (16) In the processing device of (15) above, the second object information includes at least one of shape information indicating the shape of the object, center of gravity position information indicating the center of gravity position of the object, first range information indicating the range on the surface of the object that cannot be adsorbed by the adsorption mechanism, and second range information indicating the range on the surface of the object where adsorption by the adsorption mechanism is prohibited.

[0248] (17) The processing device of (15) or (16) above includes a suction mechanism control unit that controls the suction mechanism based on the position determination result of the position determination unit.

[0249] (18) The adsorption mechanism control unit is an adsorption mechanism control unit provided in the processing device of (4) or (17) above.

[0250] (19) The program is a program for causing a computer device to function as any one of the processing devices (1) to (17) above.

[0251] (20) The program is a program for causing a computer device to function as the suction mechanism control unit described above in (18).

[0252] (21) A processing system includes an adsorption mechanism for adsorbing an object, and a processing device according to any one of (1) to (17) above for determining an adsorption force when the adsorption mechanism adsorbs the object.

[0253] (22) The suction mechanism is an suction mechanism for suctioning an object, and includes a first suction portion having a first suction opening, a second suction portion having a second suction opening smaller than the first suction opening and movable relative to the first suction portion within the first suction portion, and a drive mechanism that moves the second suction portion relative to the first suction portion within the first suction portion so that the second suction opening moves in and out of the first suction portion relatively, and the drive mechanism is capable of switching between a first state in which the first suction portion suctions the object and a second state in which the second suction portion suctions the object.

[0254] 8 Object 10 Robot control system (processing system) 13 Hand control device (processing device) 131a Program 41, 200 Suction unit 50, 50A Drive mechanism 51 Negative pressure generating unit 54 Negative pressure detection sensor 55 Pressure sensor 56 Force sensor 57 Distance sensor 132 Interface 135 Suction force determining unit 136 Position determining unit 137 Suction mechanism control unit 138 Determination unit 210 First suction unit 220 Second suction unit 211 First suction pad 212 First suction opening 221 Second suction pad 222 Second suction opening 410 Suction pad

Claims

1. A processing device comprising: an attraction force determination unit that determines an attraction force when an attraction mechanism attracts an object based on first object information regarding the object.

2. 2. The processing device according to claim 1, The first object information includes at least one of weight information indicating a weight of the object, first range information indicating a range on the surface of the object in which the suction mechanism cannot be adsorbed, second range information indicating a range on the surface of the object in which adsorption by the suction mechanism is prohibited, and tilt constraint information indicating a constraint on the tilt of the object.

3. 2. The processing device according to claim 1, The suction mechanism has a plurality of suction portions, The suction force determination unit determines, for each of the plurality of suction units, an suction force when the suction unit adsorbs the object, based on the first object information.

4. 2. The processing device according to claim 1, a suction mechanism control unit that controls the suction mechanism based on a suction force determination result of the suction force determination unit.

5. 5. The processing device according to claim 4, the suction mechanism includes at least one suction unit and a negative pressure generating unit that generates a negative pressure in the at least one suction unit, the adsorptive force determination unit determines an adsorptive force when the at least one adsorptive unit adsorps the object, based on the first object information; The suction mechanism control unit controls the negative pressure generating unit based on the suction force determination result.

6. 5. The processing device according to claim 4, The suction mechanism has a suction portion, the adsorptive force determination unit determines an adsorptive force when the adsorptive unit adsorps the object, based on the first object information; The adsorption portion is a first suction portion having a first suction opening; a second suction portion having a second suction opening smaller than the first suction opening; having the suction mechanism is capable of switching between a first state in which the first suction portion suctions the object and a second state in which the second suction portion suctions the object, The suction mechanism control unit switches the suction mechanism between the first state and the second state based on the suction force determination result.

7. 7. The processing device according to claim 6, the suction mechanism is capable of switching between the first state, the second state, and a third state in which the first suction portion and the second suction portion suction the object, The suction mechanism control unit switches the suction mechanism between the first state, the second state, and the third state based on the suction force determination result.

8. 7. The processing device according to claim 6, A processing device, wherein the second suction portion is capable of moving within the first suction portion relative to the first suction portion such that the second suction opening moves relatively in and out of the first suction portion.

9. 9. The processing apparatus according to claim 1, The suction mechanism includes a suction portion having a suction pad, The suction force determination unit determines an suction force when the suction unit suctions the object based on the first object information and an environmental change in viscoelastic properties of the suction pad.

10. 9. The processing apparatus according to claim 1, The suction mechanism includes a suction portion having a suction pad, The suction force determination unit determines an suction force when the suction unit suctions the object based on the first object information and a change over time in viscoelastic properties of the suction pad.

11. 9. The processing apparatus according to claim 1, The suction mechanism includes a suction portion having a suction pad, The suction force determination unit determines an adhesive force when the suction unit adsorbs the object based on the first object information and a change in viscoelastic properties due to use of the suction pad.

12. 9. The processing apparatus according to claim 1, A processing device comprising a determination unit that determines an adsorption state of the object by the adsorption mechanism based on a detection result of at least one sensor.

13. 13. The processing device of claim 12, The suction force determination unit re-determines an suction force when the suction mechanism suctions the object, depending on a determination result of the determination unit.

14. 13. The processing device of claim 12, a notification unit that notifies an outside of the processing device of an alert in response to a determination result of the determination unit.

15. 2. The processing device according to claim 1, The suction mechanism has at least one suction portion, A processing device comprising a position determination unit that determines a position of the at least one suction portion based on second object information regarding the object.

16. 16. The processing device of claim 15, The second object information includes at least one of shape information indicating a shape of the object, center of gravity position information indicating a center of gravity position of the object, first range information indicating a range on the surface of the object in which the suction mechanism cannot be adsorbed, and second range information indicating a range on the surface of the object in which adsorption by the suction mechanism is prohibited.

17. 16. The processing device of claim 15, A processing device comprising a suction mechanism control unit that controls the suction mechanism based on a position determination result of the position determination unit.

18. The processing apparatus according to claim 4 or 17, further comprising a suction mechanism control unit.

19. A program for causing a computer device to function as the processing device according to any one of claims 1 to 8 and claims 15 to 17.

20. A program for causing a computer device to function as the suction mechanism control unit according to claim 18.

21. An adsorption mechanism for adsorbing an object; The processing apparatus according to any one of claims 1 to 8 and claims 15 to 17, which determines an attraction force when the attraction mechanism attracts the object. A processing system comprising:

22. An adsorption mechanism for adsorbing an object, comprising: a first suction portion having a first suction opening; a second suction portion having a second suction opening smaller than the first suction opening and movable relative to the first suction portion within the first suction portion; a drive mechanism that moves the second suction portion relative to the first suction portion within the first suction portion so that the second suction opening moves in and out of the first suction portion relatively; Equipped with The drive mechanism is capable of switching between a first state in which the first suction portion suctions the object and a second state in which the second suction portion suctions the object.