End effector, end effector control device, and gripper control method

Abstract

The present invention provides an end effector and the like capable of eliminating a robot jamming problem that an action part collides with a carrying surface of an object and cannot be controlled. According to one embodiment of the present invention, an end effector is provided. This end effector is provided with an action part, a support body, and a detection surface. The acting portion is configured to be in contact with an object by protruding toward one end side. The support body is configured so as to flexibly support the acting part such that at least one of the position and posture of the acting part is displaced when receiving a force generated by contact between the acting part and the object. The detection surface is configured so as not to be in contact with the object on the other end side of the operating part relative to the one end side, and so that at least one of the position and orientation thereof is displaced together with the operating part. The robot arm is disposed so as to face a sensor capable of measuring at least one of a position and a posture in a state in which the end effector is attached to the robot arm.

Description

Technical Field

[0001] The present invention relates to an end effector, a control device for the end effector, and a control method for a robotic gripper. Background Art

[0002] In Patent Document 1, there is disclosed a robotic gripper (robotic hand) as an example of an end effector. The robotic hand includes a hand base portion, at least one finger, a wrist connection frame coupled to the front end portion of a robotic arm, and a force sensor that detects the feed force or torque of at least one axis. The hand base portion is formed by combining a palm-side frame located on the palm side of the robotic hand and a back-side frame located on the back side of the robotic hand. The force sensor is configured to be enclosed within the hand base portion. One mounting surface of the force sensor is coupled to the wrist connection frame, and the other mounting surface of the force sensor is coupled to the hand base portion. The force sensor detects the force acting on the hand base portion and the force acting on the finger. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015-47680 Summary of the Invention Problems to be Solved by the Invention

[0004] On the other hand, in the prior art disclosed in Patent Document 1, when the placement surface of the object on which the object to be grasped is placed is arbitrary, the placement surface collides with the grasping portion of the robotic gripper, and the problem of the robotic gripper getting stuck and unable to be controlled easily becomes an issue. Not limited to the robotic gripper, the same issue exists in the end effector.

[0005] In the present invention, in view of the above situation, there is provided an end effector or the like that can eliminate the problem of the robotic gripper getting stuck and unable to be controlled due to the collision between the acting portion and the placement surface of the object. Means for Solving the Problems

[0006] According to one aspect of the present invention, there is provided an end effector. The end effector includes an acting portion, a support body, and a detection surface. The acting portion is configured to contact an object by protruding toward one end side. The support body is configured to flexibly support the acting portion so that at least one of the position and posture of the acting portion is displaced when a force generated by the contact between the acting portion and the object is received. The detection surface is configured to be non-contact with the object on the other end side of the acting portion relative to the one end side, and at least one of its position and posture is displaced together with the acting portion. It is configured to face a sensor that can measure at least one of the position and posture in a state where the end effector is mounted on a robotic arm.

[0007] According to the present invention, it is possible to eliminate the problem of the robotic gripper getting stuck and unable to be controlled due to the collision between the acting portion and the placement surface of the object. Brief Description of the Drawings

[0008] Figure 1 FIG. is a perspective view showing the structure of the end effector 2 of the present embodiment. Figure 2 FIG. is a perspective view showing the state before the end effector 2 shown in Figure 1 is installed in the robot system 1 of the present embodiment. Figure 3 FIG. is a perspective view showing the state after the end effector 2 shown in Figure 1 is installed in the robot system 1 of the present embodiment. Figure 4 FIG. is a block diagram showing the control device 4 electrically connected to the sensor 3 and the robot arm 5. Figure 5 FIG. is a schematic diagram showing the input parameters used for the control of the gripper composed of a pair of end effectors 2. Figure 6 FIG. is a schematic diagram showing the input parameters used for the control of the gripper composed of three end effectors 2. FIG. 7 (including Figure 7A , Figure 7B , Figure 7C , and Figure 7D ) is a schematic diagram showing the end effector 2 having various functional parts. Figure 8 FIG. is a top view showing the structure outline of the sensor S1, mainly the detection part S2. Detailed Description of the Invention

[0009] [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Various characteristic matters shown in the following embodiments can be combined with each other.

[0010] However, the program for implementing the software that appears in the present embodiment can be provided as a non-transitory computer-readable medium (Non-Transitory Computer-Readable Medium), can also be provided by being downloaded from an external server, or can be provided in such a way that the program is started on an external computer and its functions are implemented on a client terminal (so-called cloud computing).

[0011] In addition, in the present embodiment, the "section" may also include, for example, a structure formed by combining hardware resources implemented by a generalized circuit and information processing of software that can be specifically realized by these hardware resources. In addition, in the present embodiment, various information is processed, and this information is represented, for example, by a physical value indicating a signal value of voltage / current, a high or low of a signal value that is a binary bit aggregate composed of 0 or 1, or quantum superposition (so-called qubit), and communication / operation can be performed on a generalized circuit.

[0012] In addition, the generalized circuit refers to a circuit implemented by appropriately combining at least a circuit, circuitry, a processor, and a memory, etc. That is, it includes an application specific integrated circuit (ASIC), programmable logic devices (such as a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)), etc.

[0013] 1. Hardware Structure In this section, the hardware structure of the robot system 1 of the present embodiment will be described. Figure 1 It is a perspective view showing the structure of the end effector 2 of the present embodiment. Figure 2 It is shown installed in the robot system 1 of the present embodiment Figure 1 A perspective view of the state before the end effector 2 shown is installed. Figure 3 It is shown installed in the robot system 1 of the present embodiment Figure 1 A perspective view of the state after the end effector 2 shown is installed. Figure 4 It is a block diagram showing the control device 4 electrically connected to the sensor 3 and the robot arm 5.

[0014] As Figure 3 and Figure 4 shown, the robot system 1 includes an end effector 2, a sensor 3, a control device 4, and a robot arm 5.

[0015] (End Effector 2) The end effector 2 is configured to be installed on the robot arm 5, and its position and posture are controlled by the robot arm 5, so that a desired task can be executed. Preferably, as Figures 1 to 3As shown, the end effector 2 is configured to be detachable from the sensor 3 located at the front end of the robot arm 5. The method of attachment and detachment is not particularly limited, and for example, screw fixation is sufficient. As desired tasks, for example, various objects Ob (refer to FIG. 7, FIG. 7 includes Figure 7A , Figure 7B , Figure 7C , and Figure 7D ) picking, stirring, etc. That is, the end effector 2 can also function as a mechanical claw configured to be able to hold the object Ob.

[0016] As Figure 1 shown, the end effector 2 includes a gripping claw 21 as an example of an acting part, a detected body 22 including at least a detection surface 222, a support body 23, and an elastic member 24. The gripping claw 21 as an example of an acting part is configured to contact the object Ob by protruding toward one end side. Here, one end side refers to Figure 1 the side located in the -z direction in the coordinate system shown. In contrast, the side located in the +z direction is sometimes referred to as the other end side. Regarding the illustrated coordinate system, it will be described in further detail later.

[0017] In Figure 1 , one gripping claw 21 in one end effector 2 is illustrated, but as Figure 3 shown, a plurality of end effectors 2 are mounted on the robot arm 5, and thus the object Ob is held by the plurality of gripping claws 21. In other words, the acting part is the gripping claw 21, and it is configured to hold the object Ob between the gripping claws 21 of the respective end effectors 2 in a state where the plurality of end effectors 2 are mounted on the robot arm 5. Hereinafter, a mechanical claw capable of holding the object Ob by the two gripping claws 21 based on the two end effectors 2 will be described. Specifically, the gripping claw 21 is integrally formed in a thin flat plate shape and has a substantially N shape. The gripping claw 21 is preferably made of metal, has rigidity, and its shape itself does not deform. The front end portion 211 of the gripping claw 21 is the portion that directly contacts the object Ob and extends along the z-axis. The central portion 212 connected to the front end portion 211 is bent with respect to the front end portion 211 and extends with at least a component in the y-axis direction. Moreover, the rear end portion 213 connected to the central portion 212 is bent with respect to the central portion 212 and extends along the z-axis in the same manner as the front end portion 211.

[0018] The detected body 22 is a component including at least the detection surface 222. Here, as the detected body 22, a claw fixing portion 221 and a detection surface 222 are illustrated. The above-mentioned gripping claw 21 is fixed to the claw fixing portion 221. The claw fixing portion 221 is inserted through a hole (not shown) in a flat plate 231 in a support body 23 described later and extends toward the other end side. The detection surface 222, which is the object to be detected by a sensor 3 described later, is the surface on the other end side of the detected body 22. In other words, asFigure 3 As shown, the detection surface 222 is configured to face a sensor 3 capable of measuring at least one of position and posture when the end effector 2 is mounted on the robot arm 5.

[0019] The object to be detected 22 is supported by a support 23 via an elastic member 24. The elastic member 24 may be, for example, a plurality of springs. The support 23 has a flat plate 231, a support column 232, and a flat plate 233. The flat plate 233 is fixedly mounted on the sensor 3 located at the front end of the robot arm 5. The flat plate 231 and the flat plate 233 are arranged in the z-axis direction and are substantially parallel to each other. The flat plate 231 and the flat plate 233 are connected to each other by a plurality of support columns 232. In addition, the flat plate 233 is provided with a hole 233a so that the sensor 3 described later can detect the detection surface 222.

[0020] Here, the support 23 is fixedly arranged on the robot arm 5. In contrast, the object to be detected 22 supported by the support 23 via the elastic member 24 is configured such that at least one of its position and posture is displaced when a force is applied. In addition, the object to be detected 22 is configured to be connected to the gripping claw 21 as an acting portion. Therefore, due to the force generated when the gripping claw 21 contacts the object Ob, at least one of the position and posture of the gripping claw 21 and the object to be detected 22 can be changed. In other words, the support 23 is configured to flexibly support the gripping claw 21 so that at least one of the position and posture of the gripping claw 21 is displaced when a force generated by the contact between the gripping claw 21 (an example of the acting portion) and the object Ob is received. Moreover, the detection surface 222 is configured to be non-contact with the object Ob on the other end side of the gripping claw 21 relative to one end side, and at least one of its position and posture is displaced together with the gripping claw 21.

[0021] Preferably, the detection surface 222 is configured such that its position can be displaced by 0.01 mm or more. Specifically, the displacement amount is, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10 mm, and may also be within the range between any two of the values exemplified herein. Through the support via the elastic member 24, such a displacement amount can be achieved. Instead of a general force sensor, a sensor 3 capable of measuring such a displacement amount can be used to control the end effector 2 in a desired manner, and the problem of the manipulator getting stuck can be eliminated. This will be further described in detail later.

[0022] In addition, in Figure 3In the figure, the end effector 2 on the left side is illustrated as the end effector 2l, and the end effector 2 on the right side is illustrated as the end effector 2r. Similarly, each component related to the left end effector 2l is labeled with l at the end of the symbol, and each component related to the right end effector 2r is labeled with r at the end of the symbol. Additionally, in Figures 1 to 3 an xyz coordinate system is shown, and the direction in which the end effectors 2l and 2r are arranged is defined as the y-axis direction. The direction in which the detection surface 222 faces the sensor 3 described later is defined as the z-axis direction. The direction perpendicular to the plane defined by the y-axis and the z-axis is defined as the x-axis direction. This definition remains the same even when the posture of the end effector 2 changes due to rotational movement.

[0023] (Sensor 3) The sensor 3 is configured to include a housing 31 and a detection unit 32, and is capable of measuring the distance and posture (the formed angle) of the detection surface 222 relative to the detection unit 32. For a sensor 3 with such properties, its details are not particularly limited. The housing 31 has a substantially flat plate shape, and preferably has the same or a similar shape as the flat plate 233 in the end effector 2. When the end effector 2 is mounted on the robot arm 5, the flat plate 233 in the end effector 2 having the same or a similar shape as the housing 31 of the sensor 3 is mounted on the housing 31 of the sensor 3. The sensor 3 detects the detection surface 222 located inside the support 23 through the hole 233a provided in the flat plate 233. In this way, the end effector 2 functions as an attachment relative to the sensor 3, and the positional relationship between the detection surface 222 described later and the sensor 3 is fixed, and the accuracy can be further improved. Additionally, the sensor 3 is connected to Figure 4 the communication unit 41 of the control device 4 shown. That is, electrophysical quantities such as current, charge amount, and voltage output from the sensor 3 can be input into the control device 4 through the wiring 33 and the communication unit 41.

[0024] In addition, in Figure 3 the sensor 3 on the left side is illustrated as the sensor 3l, and the sensor 3 on the right side is illustrated as the sensor 3r.

[0025] (Control device 4) Next, the control device 4 will be described. The control device 4 is a device or circuit configured to control the operation of the sensor 3 and the robot arm 5 described later, and is, for example, a computer or a microcomputer. The control device 4 has a communication unit 41, a storage unit 42, and a processor 43, and these components are electrically connected inside the control device 4 via a communication bus 40. Each component will be further described.

[0026] The communication unit 41 is configured to be able to send various electrical signals from the control device 4 to external components. In addition, the communication unit 41 is configured to be able to receive various electrical signals from external components to the control device 4. Specifically, the communication unit 41 receives, via the wiring 33, an electro-physical quantity corresponding to the spatial physical quantity (input parameter of the detection surface 222) detected by the detection unit 32. In addition, the communication unit 41 controls mechanical parameters such as the position and posture of the robot arm 5, for example, based on the input parameter measured by the sensor 3. More preferably, the communication unit 41 has a network communication function, whereby various information can also be communicated between the control device 4 and external devices via a network such as the Internet.

[0027] The storage unit 42 stores various information defined by the above description. This information is implemented, for example, as a storage device such as a solid state drive (SSD) that stores various programs related to the control device 4 executed by the processor 43, or as a memory such as a random access memory (RAM) that stores information (parameters, arrangements, etc.) temporarily required for the operation of the program. The storage unit 42 stores various programs or variables related to the control device 4 executed by the processor 43.

[0028] The processor 43 is, for example, a central processing unit (CPU) not shown in the figure. The processor 43 realizes various functions related to the control device 4 by reading a prescribed program stored in the storage unit 42. That is, the information processing executed by the software stored in the storage unit 42 is specifically realized by the processor 43 as an example of hardware, and thus can be executed as each functional unit included in the processor 43. In addition, the processor 43 is not limited to one, and may be implemented in such a manner that there are multiple processors 43 for each function. Alternatively, it may be a combination thereof.

[0029] (Robot arm 5) The robotic arm 5 is configured to have multiple degrees of freedom and can control its mechanical parameters. Preferably, the robotic arm 5 has 3 translational degrees of freedom and 3 rotational degrees of freedom. That is, the robotic arm 5 is configured to be able to control the mechanical parameters of the end effector 2 mounted at its front end. The mechanical parameters of the robotic arm 5 are controlled by the processor 43 of the control device 4. The end effector 2 is mounted on the robotic arm 5. That is to say, in other words, the control device 4 is a device that controls the end effector 2 and includes a processor 43 (an example of a control unit). The processor 43 controls the mechanical parameters of the gripping claw 21 in the end effector 2 based on the results measured by the sensor 3. Preferably, the mechanical parameters include at least one of position and posture. In this way, feedback control of the position or posture of the end effector 2 can be performed. Additionally, preferably, the mechanical parameters include at least one of speed and acceleration. In this way, feedback control of the speed or acceleration of the end effector 2 can be performed. The control method of the robotic arm 5 will be described in detail later.

[0030] 2. Control Method In this section, the control method of the robotic arm 5 equipped with the end effector 2 in this embodiment will be described. In this example, the control method is for the end effector 2 (mechanical claw) having multiple gripping claws 21. This control method includes the following steps. First, in the acquisition step, input parameters of the detection surface 222 corresponding to each gripping claw 21 are respectively acquired for each gripping claw 21. Additionally, as described above, the input parameters are at least one of the position and posture of the detection surface 222. Then, in the control step, the mechanical parameters of the gripping claw 21 are controlled based on the sum or difference of the respective input parameters.

[0031] 2.1 Mechanical Claw Composed of a Pair of End Effectors 2 Figure 5 is a schematic diagram showing the input parameters used for the control of the mechanical claw composed of a pair of end effectors 2. As Figure 5 shown, the sensor 3l detects the mechanical parameters of the detection surface 222l in the end effector 2l. Preferably, the mechanical parameters here include the distance d_l between the sensor 3l and the detection surface 222l, the tilt angle α_l of the detection surface 222l around the x-axis, and the tilt angle β_l of the detection surface 222l around the y-axis. Similarly, the sensor 3r detects the mechanical parameters of the detection surface 222r in the end effector 2r. Preferably, the mechanical parameters here include the distance d_r between the sensor 3r and the detection surface 222r, the tilt angle α_r of the detection surface 222r around the x-axis, and the tilt angle β_r of the detection surface 222r around the y-axis.

[0032] Table 1 is a table showing the control methods in the respective axial directions related to the advancing or rotation of the gripper constituted by a pair of end effectors 2. Preferably, the controls in the respective axial directions related to the advancing or rotation shown in Table 1 are sequentially and simultaneously executed. Hereinafter, each item will be described in detail. [Table 1] Types of movement Control operation Linear movement in the x-axis direction <![CDATA[Δx = G x (β l + β r )]]> Linear movement in the y-axis direction <![CDATA[Δ y = G y (α l + α r )]]> Linear movement in the z-axis direction <![CDATA[Δz = G z (d l + d r - 2 dref )]]> Rotational movement about the x-axis <![CDATA[ΔR x = GR x (d l - d r )]]> Rotational movement about the z-axis <![CDATA[ΔR z = GR z (β l - β r )]]>

[0033] (Advancing movement in the x-axis direction) Assume that, when a force in the x-axis direction is applied to the holding claws 21l in the end effector 2l and the holding claws 21r in the end effector 2r, the front end of the robot arm 5 is advanced in the x-axis direction to relieve the force. When such a force in the x-axis direction is applied, the holding claws 21l, 21r rotate around the y-axis and lift up. Therefore, the processor 43 can use the sum of the tilt angle β_l and the tilt angle β_r as an input parameter and output a control value obtained by multiplying it by the gain G_x. By sequentially performing such control at a prescribed control rate, even without using a force sensor, the positions of the end effectors 2l, 2r can be advanced in the x-axis direction.

[0034] (Advancing movement in the y-axis direction) Assume that, when a force in the y-axis direction is applied to the holding claws 21l in the end effector 2l and the holding claws 21r in the end effector 2r, the front end of the robot arm 5 is advanced in the y-axis direction to relieve the force. When such a force in the y-axis direction is applied, the holding claws 21l, 21r rotate around the x-axis and lift up. Therefore, the processor 43 can use the sum of the tilt angle α_l and the tilt angle α_r as an input parameter and output a control value obtained by multiplying it by the gain G_y. By sequentially performing such control at a prescribed control rate, even without using a force sensor, the positions of the end effectors 2l, 2r can be advanced in the y-axis direction.

[0035] (Advancing movement in the z-axis direction) Assume that when a force in the z-axis direction is applied to the holding claws 21l in the end effector 2l and the holding claws 21r in the end effector 2r, the front end of the robot arm 5 is moved forward in the z-axis direction to relieve the force. When such a force in the z-axis direction is applied, the holding claws 21l and 21r are lifted or stretched, whereby the distance d_l between the detection surface 222l and the detection unit 32l and the distance d_r between the detection surface 222r and the detection unit 32r change. Therefore, the processor 43 can use the value obtained by appropriately adding an offset to the sum of the distance d_l and the distance d_r as an input parameter and output a control value obtained by multiplying it by the gain G_z. In addition, by adding an offset, it is possible to perform control in such a way as to intentionally apply a force to the placement surface. In addition, d_ref is a preset offset having a distance dimension in each end effector 2. Since there are end effectors 2l and 2r, twice the value of d_ref is subtracted from the sum of the distance d_l and the distance d_r. By performing such control successively at a prescribed control rate, it is possible to move the positions of the end effectors 2l and 2r forward in the z-axis direction even without using a force sensor.

[0036] In other words, in the control step of the control method, based on the sum of the respective input parameters, the mechanical parameters related to the forward movement of the holding claw 21 are controlled. According to this method, having a forward movement degree of freedom, it is possible to control the end effector 2 (mechanical claw).

[0037] (Rotation movement about the x-axis) Assume that when a force in the z-axis direction is applied to either the holding claws 21l in the end effector 2l or the holding claws 21r in the end effector 2r, the front end of the robot arm 5 is rotated about the x-axis to relieve the force. When such a force in the z-axis direction is applied, one of the holding claws 21l and 21r is lifted or stretched, whereby a difference is generated between the distance d_l between the detection surface 222l and the detection unit 32l and the distance d_r between the detection surface 222r and the detection unit 32r. Therefore, the processor 43 can use the difference between the distance d_l and the distance d_r as an input parameter and output a control value obtained by multiplying it by the gain G_Rx. By performing such control successively at a prescribed control rate, it is possible to rotate the positions of the end effectors 2l and 2r about the x-axis even without using a force sensor. In addition, the same applies even when forces in the z-axis direction are applied to the holding claws 21l in the end effector 2l and the holding claws 21r in the end effector 2r in opposite directions.

[0038] (Rotation movement about the z-axis) Assume that when a force in the x-axis direction is applied to either the holding claw 21l in the end effector 2l or the holding claw 21r in the end effector 2r, the front end of the robot arm 5 is rotated and moved about the z-axis to relieve the force. When such a force in the x-axis direction is applied, one of the holding claws 21l and 21r rotates about the y-axis and lifts up, whereby a difference is generated between the tilt angle β_l and the tilt angle β_r. Therefore, the processor 43 can use the difference between the tilt angle β_l and the tilt angle β_r as an input parameter and output a control value obtained by multiplying it by the gain G_Rz. By successively performing such control at a prescribed control rate, even without using a force sensor, it is possible to rotate and move the positions of the end effectors 2l and 2r about the z-axis. In addition, the same applies to the case where forces in opposite directions in the x-axis direction are applied to the holding claw 21l in the end effector 2l and the holding claw 21r in the end effector 2r.

[0039] In other words, in the control step of the control method, based on the difference between the respective input parameters, the mechanical parameters related to the rotational motion of the holding claw 21 are controlled. According to this manner, having a rotational degree of freedom, it is possible to control the end effector 2 (mechanical claw).

[0040] 2.2 Mechanical claw composed of three end effectors 2 It can also be implemented by a mechanical claw composed of three or more end effectors 2. Figure 6 It is a schematic diagram showing the input parameters used for the control of the mechanical claw composed of three end effectors 2. In addition to the above-described end effectors 2l and 2r, this mechanical claw further includes an end effector 2c. Hereinafter, the components included in the end effector 2c are denoted by adding c at the end of the symbol. In addition, the sensor 3c is configured to detect the detection surface 222c of the end effector 2c. The end effectors 2l and 2r are arranged side by side in the y-axis direction. In addition, the end effector 2c is arranged together with the end effectors 2l and 2r at the positions of the vertices forming an equilateral triangle. Table 2 is a table showing the control methods in the respective axial directions related to the translation or rotation of the mechanical claw composed of three end effectors 2. Preferably, the control in the respective axial directions related to the translation or rotation shown in Table 2 is successively and simultaneously performed. Hereinafter, each item will be described in detail. [Table 2]

[0041] (Translation movement in the x-axis direction) Assume that when a force in the x-axis direction is applied to the holding claws 21l in the end effector 2l, the holding claws 21r in the end effector 2r, and the holding claws 21c in the end effector 2c, the front end of the robot arm 5 is moved forward in the x-axis direction to relieve the force. When such a force in the x-axis direction is applied, the holding claws 21l, 21r, and 21c rotate around the y-axis and lift up. Therefore, the processor 43 can use the sum of the tilt angles β_l, β_r, and β_c as an input parameter and output a control value obtained by multiplying it by the gain G_x. By successively performing such control at a prescribed control rate, even without using a force sensor, it is possible to move the positions of the end effectors 2l, 2r, and 2c forward in the x-axis direction.

[0042] (Translation in the y-axis direction) Assume that when a force in the y-axis direction is applied to the holding claws 21l in the end effector 2l, the holding claws 21r in the end effector 2r, and the holding claws 21c in the end effector 2c, the front end of the robot arm 5 is moved forward in the y-axis direction to relieve the force. When such a force in the y-axis direction is applied, the holding claws 21l, 21r, and 21c rotate around the x-axis and lift up. Therefore, the processor 43 can use the sum of the tilt angles α_l, α_r, and α_c as an input parameter and output a control value obtained by multiplying it by the gain G_y. By successively performing such control at a prescribed control rate, even without using a force sensor, it is possible to move the positions of the end effectors 2l, 2r, and 2c forward in the y-axis direction.

[0043] (Translation in the z-axis direction) Assume that, when a force in the z-axis direction is applied to the holding claws 21l in the end effector 2l, the holding claws 21r in the end effector 2r, and the holding claws 21c in the end effector 2c, the front end of the robot arm 5 is moved in parallel in the z-axis direction to relieve the force. When such a force in the z-axis direction is applied, the holding claws 21l, 21r, and 21c are lifted or stretched, whereby the distances d_l between the detection surface 222l and the detection unit 32l, d_r between the detection surface 222r and the detection unit 32r, and d_c between the detection surface 222c and the detection unit 32c change. Therefore, the processor 43 can use, as an input parameter, a value obtained by appropriately adding an offset to the sum of the distances d_l, d_r, and d_c, and output a control value obtained by multiplying it by the gain G_z. Further, d_ref is a preset offset having a distance dimension in each end effector 2, and since there are end effectors 2l, 2r, and 2c, a value three times d_ref is subtracted from the sum of the distances d_l and d_r. By successively performing such control at a prescribed control rate, the positions of the end effectors 2l, 2r, and 2c can be moved in parallel in the z-axis direction even without using a force sensor.

[0044] (Rotation movement about the x-axis) Since it is the same as the case in the previous section, the description is omitted.

[0045] (Rotation movement about the y-axis) Assume that, when a force in the z-axis direction is applied to any one of the holding claws 21l in the end effector 2l, the holding claws 21r in the end effector 2r, and the holding claws 21c in the end effector 2c, the front end of the robot arm 5 is rotated about the y-axis to relieve the force. When such a force in the z-axis direction is applied, one of the holding claws 21l, 21r, and 21c is lifted or stretched, whereby a difference is generated between the sum of the distances d_l between the detection surface 222l and the detection unit 32l and d_r between the detection surface 222r and the detection unit 32r, and the distance d_c between the detection surface 222c and the detection unit 32c. Therefore, the processor 43 can use, as an input parameter, the difference between the sum of the distances d_l and d_r and the distance d_c, and output a control value obtained by multiplying it by the gain G_Ry. By successively performing such control at a prescribed control rate, the positions of the end effectors 2l, 2r, and 2c can be rotated about the x-axis even without using a force sensor.

[0046] (Rotation movement about the z-axis) Assume that when a force in the x-axis direction is applied to either the holding claw 21l in the end effector 2l or the holding claw 21r in the end effector 2r, or a force in the y-axis direction is applied to the holding claw 21c in the end effector 2c, the front end of the robot arm 5 rotates and moves around the z-axis to relieve the force. When a force in the x-axis direction is applied to the holding claws 21l and 21r, one of the holding claws 21l and 21r rotates around the y-axis and lifts up, whereby a difference is generated between the tilt angle β_l and the tilt angle β_r. Alternatively, when a force in the y-axis direction is applied to the holding claw 21c, the holding claw 21c rotates around the x-axis and lifts up, whereby a difference is generated between the tilt angle α_l or the tilt angle α_r and the tilt angle α_c. Therefore, the processor 43 can set the sum of the above conceivable differences as an input parameter and output a control value obtained by multiplying it by the gain G_Rz. By performing such control successively at a prescribed control rate, even without using a force sensor, the positions of the end effectors 2l, 2r, and 2c can be rotated and moved around the z-axis.

[0047] Summarizing the above, the end effector of the present embodiment includes a holding claw 21 (an example of an acting portion), a support body 23, and a detection surface 222. The holding claw 21 is configured to contact the object Ob by protruding toward one end side. The support body 23 is configured to flexibly support the holding claw 21 so that at least one of the position and posture of the holding claw 21 is displaced when a force generated due to the contact between the holding claw 21 and the object Ob is received. The detection surface 222 is configured to be non-contact with the object Ob on the other end side of the holding claw 21 relative to the one end side, and at least one of its position and posture is displaced together with the holding claw 21. The detection surface 222 is arranged to face a sensor capable of measuring at least one of the position and posture in a state where the end effector 2 is mounted on the robot arm 5. In the conventional method using a force sensor, a problem of the robot hand getting stuck occurs because a force exceeding the numerical range that the force sensor can measure is generated. However, according to such a method, at least one of the position and posture of the holding claw 21 (acting portion) flexibly changes, and it is measured by the sensor 3 with a sufficiently large measurement range. Thus, the problem of the robot hand getting stuck where the holding claw 21 (acting portion) collides with the mounting surface of the object and cannot be controlled can be eliminated.

[0048] In addition, according to another aspect, the processor 43 respectively obtains input parameters of the detection surface 222 corresponding to each holding claw 21 for each holding claw 21. The input parameters are at least one of the position and posture of the detection surface 222. The input parameters are configured to control the mechanical parameters of the holding claw 21 based on the sum or difference of the respective input parameters. Preferably, the processor 43 controls the mechanical parameters related to the advancing movement of the holding claw 21 based on the sum of the respective input parameters. Preferably, the processor 43 controls the mechanical parameters related to the rotational movement of the holding claw 21 based on the difference of the respective input parameters. According to this method, by using feedback control of simple calculated values, the end effector 2 (robotic gripper) can perform a stable picking task without causing the problem of the robotic arm getting stuck. That is, for example, it is also possible to perform difficult tasks such as picking up multiple bulk objects Ob one by one.

[0049] [Other] Creative research can also be further carried out on the robot system 1 of this embodiment.

[0050] In the above embodiment, the robotic gripper composed of multiple end effectors 2 has been described, but the end effector 2 that can be implemented in various ways also includes the robotic gripper. FIG. 7 (including Figure 7A , Figure 7B , Figure 7C , and Figure 7D ) is a schematic diagram showing the end effector 2 having various acting parts. As Figure 7A shown, the method is a robotic gripper with a tapered front end like tweezers, suitable for the task of picking up multiple bulk objects Ob one by one. Figure 7B shown, the method is a robotic gripper expanded in a V shape, and a bottom surface holding part 214 is provided further in front of the front end part 211. Such a method is suitable for the task of grasping and holding the object Ob placed on the placement surface. Figure 7C shown, the method is a robotic gripper composed of a pair of end effectors 2 formed in a straight line, suitable for tasks such as picking up an object Ob such as food with chopsticks. Figure 7D shown, the method is a stirring rod composed of an end effector 2 formed in a straight line, suitable for the task of properly stirring an object Ob such as food.

[0051] In the case where the stirring rod or the like is implemented as an end effector 2, the mechanical parameters of the acting portion can also be controlled based on at least one of the position and posture of a detection surface 222 in the end effector 2. In this case, it is possible to perform control of three translational degrees of freedom, or control of one translational degree of freedom and two rotational degrees of freedom. Table 3 is a table showing a method for controlling three translational degrees of freedom of an end effector 2. In addition, Table 4 is a table showing a method for controlling one translational degree of freedom and two rotational degrees of freedom of an end effector 2. Preferably, the control in each axial direction shown in Table 3 or Table 4 is sequentially and simultaneously executed. In the control, the distance d between the sensor 3 and the detection surface 222, the inclination angle α of the detection surface 222 around the x-axis, and the inclination angle β of the detection surface 222 around the y-axis can be used as input parameters. G_x, G_y, G_z, G_Rx, and G_Ry are gains in each control, and d_ref is a preset offset having a distance dimension. [Table 3] Types of movement Control operation Linear movement in the x-axis direction <![CDATA[Δx = G x β]]> Linear movement in the y-axis direction <![CDATA[Δy = G y α]]> Linear movement in the z-axis direction <![CDATA[Δz = G z (d - d ref )]]> [Table 4] Types of movement Control operation Rotational movement about the x-axis <![CDATA[ΔR x = G Rx α]]> Rotational movement about the y-axis <![CDATA[ΔR y = G Rx β]]> Linear movement in the z-axis direction <![CDATA[Δz = G z (d - d ref )]]>

[0052] By sequentially performing the control shown in the items of the above tables at a specified control rate, even without using a force sensor, it is possible to make the end effector 2 perform translational movement or rotational movement.

[0053] In the above-described embodiment, the end effector 2 can be detachably attached to the sensor 3 mounted at the front end of the robot arm 5, but it can also be a mode in which the end effector 2 further includes the sensor 3. According to such a mode, the structure is such that the sensor 3 is included in the end effector 2, the positional relationship between the detection surface 222 and the sensor 3 is fixed, and the accuracy can be further improved.

[0054] The sensor 3 of this embodiment is not particularly limited. For example, the sensor S1 described in detail below can also be used. The sensor S1 is a sensor for measuring an object. The object is, for example, the detection surface 222 described above. More specifically, the sensor S1 is configured to be able to measure the spatial physical quantities related to the reference plane and the object in the sensor S1. The spatial physical quantities here can at least include the distance d between the reference plane and the object and the angles α, β of the object with respect to the reference plane (parameters representing the three-dimensional posture). Particularly preferably, the distance d is the closest distance. For example, the distance d is 50 mm or less. Specifically, for example, it is 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 mm, and it can also be within the range between any two of the values exemplified here. According to this method, the distance d and the angles α, β with respect to the object can be measured and applied to various occasions such as object picking and inspection. In addition, according to this method, the object located at a very close distance can be accurately grasped.

[0055] Figure 8 It is a top view showing the structural outline of the sensor S1 according to this embodiment, mainly the detection unit S2. As Figure 8 shown, the sensor S1 mainly includes a detection unit S2. The detection unit S2 includes a base material S21 and a light-emitting and receiving block S3 provided on the base material S21. Each structural element will be further described below.

[0056] The base material S21 constitutes the housing of the sensor S1. In this embodiment, the base material S21 has, for example, a substantially circular shape and is configured as a flat plate, but this is only an example and is not limited thereto. Preferably, the base material S21 is formed of a material that is black, matte, and has a low reflectivity. In addition, the base material S21 is provided with the light-emitting and receiving block S3 on it.

[0057] As Figure 8 shown, a plurality of light-emitting and receiving blocks S3 are provided on the base material S21. In each light-emitting and receiving block S3, a light-emitting element S31 and a light-receiving element S32 are arranged. Here, one light-emitting element S31 and one light-receiving element S32 are arranged in one light-emitting and receiving block S3. In other words, the light-receiving element S32 and the corresponding light-emitting element S31 are adjacent to each other to form the light-emitting and receiving block S3. A plurality of light-emitting and receiving blocks S3 are provided on the base material S21.

[0058] Here, the number of the light-emitting elements S31 is preferably 2 to 30, more preferably 2 to 10, and most preferably the number of the light-emitting elements S31 is 2 to 4. Specifically, for example, the number of the light-emitting elements S31 is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and it can also be within the range between any two of the values illustrated herein.

[0059] In addition, the number of the light-receiving blocks S3 can be two or more, preferably three or more. In the present embodiment, four light-receiving blocks S3a, S3b, S3c, and S3d are provided. As Figure 8 shown, it is further preferred that each of the light-receiving blocks S3 is arranged on the base material S21 in a ring shape and at equal intervals. In other words, the light-receiving blocks S3 are symmetrically arranged on the base material S21. Specifically, a light-emitting element S31a and a light-receiving element S32a are arranged in the light-receiving block S3a, a light-emitting element S31b and a light-receiving element S32b are arranged in the light-receiving block S3b, a light-emitting element S31c and a light-receiving element S32c are arranged in the light-receiving block S3c, and a light-emitting element S31d and a light-receiving element S32d are arranged in the light-receiving block S3d. According to this form, symmetry is generated for each of the photocurrents (an example of electrophysical quantities) based on the plurality of light-receiving elements S32, and the accuracy of the sensor S1 can be further improved. In other words, the number of the light-receiving elements S32 is the same as that of the light-emitting elements S31, and they correspond to each of the light-emitting elements S31 one by one. According to this form, photocurrents based on the plurality of light-receiving elements S32 are obtained, and thus the accuracy of the sensor S1 can be further improved.

[0060] As Figure 8 shown, the light-emitting elements S31 are respectively arranged at different positions on the base material S21. The light-emitting element S31 only needs to be an element that irradiates diffused light. For example, it is a light-emitting diode (LED), and preferably an infrared LED that emits infrared rays invisible to humans and harmless to the human body. Of course, it is not limited thereto, and the light-emitting element S31 can be a red LED, a green LED, or a blue LED. By connecting the positive electrode side of a power supply (not shown) to the anode side of the light-emitting element S31 that is such a light-emitting diode, current flows, and diffused light of a specific frequency is irradiated onto the object.

[0061] As Figure 8As shown, the light-receiving element S32 is disposed on the substrate S21. The light-receiving element S32 is an element that detects the received light, and on this occasion, generates a photocurrent as an example of an electro-physical quantity. In other words, the light-receiving element S32 is configured to be able to output a photocurrent according to the illuminance of the received light. Preferably, the characteristics of the illuminance of the light and the photocurrent are linear. As the main light-receiving element S32, for example, there can be mentioned: a phototube, a photomultiplier tube, a phototransistor utilizing the internal photo-electric effect of a semiconductor, a photodiode, an avalanche photodiode, a photoconductive cell, and an image sensor, etc. Preferably, the light-receiving element S32 is a photodiode having a wide directivity, or a phototransistor combining the photodiode and an amplifier.

[0062] Here, the light-receiving element S32 receives, as the main light, the reflected light that is emitted from the light-emitting element S31 belonging to the same light-emitting and receiving block 3 and reflected from the object. In addition, the light-receiving element S32 receives, as the crosstalk light, the reflected light that is emitted from the light-emitting element S31 belonging to the adjacent light-emitting and receiving block S3 and reflected from the object. For example, the light-receiving element S32a receives, as the main light, the reflected light caused by the light-emitting element S31a, and the reflected lights caused by the light-emitting elements S31b and S31d as the crosstalk light, respectively. In other words, the light-receiving element S32 is configured to receive one of the reflected lights caused by each light-emitting element S31 as the main light, and to receive, distinguishable from the main light, the reflected light other than the main light as the crosstalk light, and generate a photocurrent (an example of an electro-physical quantity) corresponding to the reflected light. The reflected light here is the light that is emitted from each of the light-emitting elements S31 and reflected from the object respectively. Thus, based on the respective photocurrents respectively based on the distinguishable main light and crosstalk light, the spatial physical quantity related to the reference plane and the object on the sensor S1 is measured.

[0063] Specifically, the value of the photocurrent or the calculated value based on the photocurrent is input as an input parameter into the learned model stored in the storage unit 42 of the above control device 4. That is, the AI input unit 22 can be a wire from each light-receiving element 32 in the detection unit 2 to the information processing unit 4. According to such a scheme, the spatial physical quantity of the object can be measured by the sensor S1 alone without using another computer or the like.

[0064] Moreover, it can also be provided in each of the following-described manners.

[0065] (1) An end effector, comprising an acting portion, a support body, and a detection surface. The acting portion is configured to protrude toward one end side to contact an object. The support body is configured to flexibly support the acting portion so that at least one of the position and posture of the acting portion is displaced when a force generated by the contact between the acting portion and the object is received. The detection surface is configured to be non-contact with the object on the other end side of the acting portion relative to the one end side, and at least one of its position and posture is displaced together with the acting portion, and is arranged to face a sensor capable of measuring at least one of the position and posture in a state where the end effector is mounted on a robotic arm.

[0066] According to this way, it is possible to eliminate the problem of robotic arm jamming where the acting portion collides with the placement surface of the object and cannot be controlled.

[0067] (2) The end effector according to (1) above, wherein the end effector is configured to be detachable from the sensor located at the front end of the robotic arm.

[0068] According to this way, the end effector functions as an accessory for the sensor, the positional relationship between the detection surface and the sensor is fixed, and the accuracy can be further improved.

[0069] (3) The end effector according to (1) above, wherein the end effector further comprises the sensor.

[0070] According to this way, it becomes a structure in which the sensor is included in the end effector, the positional relationship between the detection surface and the sensor is fixed, and the accuracy can be further improved.

[0071] (4) The end effector according to any one of (1) to (3) above, wherein the detection surface is configured such that its position can be displaced by 0.01 mm or more.

[0072] According to this way, it is possible to control the end effector using a sensor capable of measuring such a displacement instead of using a force sensor, and eliminate the problem of robotic arm jamming.

[0073] (5) The end effector according to any one of (1) to (4) above, wherein the acting portion is a gripping claw, and is configured to grip the object with the gripping claws of each end effector in a state where a plurality of the end effectors are mounted on the robotic arm.

[0074] According to this way, it is possible to provide a mechanical claw that can stably perform a picking task on an object placed on a placement surface without causing a problem of robotic arm jamming.

[0075] (6) A control device for an end effector, comprising a control unit, wherein the end effector is the end effector according to any one of the above (1) to (5), and the control unit controls the mechanical parameters of the acting unit based on the measurement results obtained by the sensor.

[0076] In this way, it is possible to control the end effector without causing the problem of the manipulator getting stuck.

[0077] (7) The control device according to the above (6), wherein the end effector is configured as follows: the acting unit is a gripping claw, and in a state where a plurality of the end effectors are mounted on the robot arm, the gripping claws of the respective end effectors grip the object with each other, and the control unit is configured as follows: input parameters of a detection surface corresponding to each gripping claw are respectively obtained for each gripping claw, where the input parameter is at least one of the position and posture of the detection surface, and based on the sum or difference of the respective input parameters, the mechanical parameters of the gripping claw are controlled.

[0078] In this way, by using feedback control of simple calculated values, it is possible to make the mechanical claw perform a stable picking task without causing the problem of the manipulator getting stuck.

[0079] (8) The control device according to the above (7), wherein the control unit controls the mechanical parameters related to the concurrent movement of the gripping claw based on the sum of the respective input parameters.

[0080] In this way, having a concurrent degree of freedom, it is possible to control the mechanical claw.

[0081] (9) The control device according to the above (7) or (8), wherein the control unit controls the mechanical parameters related to the rotational movement of the gripping claw based on the difference of the respective input parameters.

[0082] In this way, having a rotational degree of freedom, it is possible to control the mechanical claw.

[0083] (10) The control device according to any one of the above (6) to (9), wherein the mechanical parameters include at least one of position and posture.

[0084] In this way, it is possible to perform feedback control on the position or posture of the mechanical claw.

[0085] (11) The control device according to any one of the above (6) to (10), wherein the mechanical parameters include at least one of speed and acceleration.

[0086] In this way, it is possible to perform feedback control on the speed or acceleration of the mechanical claw.

[0087] (12) A control method, which is a control method for a robotic gripper having multiple gripping claws. Among them, the following steps are included: In the acquisition step, input parameters of the detection surface corresponding to each of the gripping claws are respectively acquired for each of the gripping claws. Here, the input parameter is at least one of the position and posture of the detection surface. In the control step, based on the sum or difference of the respective input parameters, the mechanical parameters of the gripping claws are controlled.

[0088] According to this way, through the feedback control using simple calculated values, the robotic gripper can perform a stable picking task without causing the problem of the manipulator getting stuck.

[0089] (13) According to the control method described in the above (12), wherein, in the control step, based on the sum of the respective input parameters, the mechanical parameters of the gripping claws related to the in - line movement are controlled.

[0090] According to this way, it has an in - line degree of freedom and can control the robotic gripper.

[0091] (14) According to the control method described in the above (12) or (13), wherein, in the control step, based on the difference of the respective input parameters, the mechanical parameters of the gripping claws related to the rotational movement are controlled.

[0092] According to this way, it has a rotational degree of freedom and can control the robotic gripper.

[0093] (15) According to the control method described in any one of the above (12) to (14), wherein the mechanical parameters include at least one of position and posture.

[0094] According to this way, the position or posture of the robotic gripper can be feedback - controlled.

[0095] (16) According to the control method described in any one of the above (12) to (15), wherein the mechanical parameters include at least one of speed and acceleration.

[0096] According to this way, the speed or acceleration of the robotic gripper can be feedback - controlled. Of course, it is not limited to this.

[0097] Finally, although various embodiments of the present invention have been described, these are presented as examples and are not intended to limit the scope of the invention. This new embodiment can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. This embodiment and its variations are included in the scope and gist of the invention and are included in the scope of the invention described in the claims and its equivalents. Explanation of reference numerals

[0098] 1: Robot system 2: End effector 2c: End effector 2l: End effector 2r: End effector 21: Gripping claw 21c: Gripping claw 21l: Gripping claw 21r: Gripping claw 211: Front end part 212: Central part 213: Rear end part 214: Bottom surface holding part 22: Object to be detected 221: Claw fixing part 222: Detection surface 222c: Detection surface 222l: Detection surface 222r: Detection surface 23: Support body 231: Flat plate 232: Support pillar 233: Flat plate 233a: Hole 24: Elastic member 3: Sensor 3c: Sensor 3l: Sensor 3r: Sensor 31: Housing 32: Detection part 32c: Detection part 32l: Detection part 32r: Detection part 33: Wiring 4: Control device 40: Communication bus 41: Communication part 42: Storage part 43: Processor 5: Robot arm G_Rx: Gain G_Ry: Gain G_Rz: Gain G_x: Gain G_y: Gain G_z: Gain Ob: Object S1: Sensor S2: Detection part S21: Substrate S3: Light-receiving and emitting block S31: Light-emitting element S31a: Light-emitting element S31b: Light-emitting element S31c: Light-emitting element S31d: Light-emitting element S32: Light-receiving element S32a: Light-receiving element S32b: Light-receiving element S32c: Light-receiving element S32d: Light-receiving element S3a: Light-receiving and emitting block S3b: Light-receiving and emitting block S3c: Light-receiving and emitting block S3d: Light-receiving and emitting block d: Distance d_c: Distance d_l: Distance d_r: Distance α_c: Tilt angle α_l: Tilt angle α_r: Tilt angle β_c: Tilt angle β_l: Tilt angle β_r: Tilt angle

Claims

1. An end effector, wherein, it includes an acting part, a support body, and a detection surface, the acting part is configured to protrude toward one end side and contact an object, the support body is configured to flexibly support the acting part so that at least one of the position and posture of the acting part is displaced when a force generated due to the contact between the acting part and the object is received, the detection surface is configured to be non-contact with the object on the other end side of the acting part relative to the one end side, and at least one of its position and posture is displaced together with the acting part, and is arranged to face a sensor capable of measuring at least one of the position and posture in a state where the end effector is mounted on a robot arm.

2. The end effector according to claim 1, wherein, the end effector is configured to be detachable from the sensor located at the front end of the robot arm.

3. The end effector according to claim 1, wherein, the end effector further includes the sensor.

4. The end effector according to any one of claims 1 to 3, wherein, the detection surface is configured such that its position can be displaced by 0.01 mm or more.

5. The end effector according to any one of claims 1 to 4, wherein, the acting part is a gripping claw, and is configured to grip the object with the gripping claws of the respective end effectors in a state where a plurality of the end effectors are mounted on the robot arm.

6. A control device for an end effector, wherein, it includes a control unit, the end effector is the end effector according to any one of claims 1 to 5, and the control unit controls the mechanical parameters of the acting part based on the result measured by the sensor.

7. The control device according to claim 6, wherein, the end effector is configured as follows: the acting part is a gripping claw, in a state where a plurality of the end effectors are mounted on the robot arm, the object is gripped with the gripping claws of the respective end effectors, the control unit is configured as follows: input parameters of the detection surface corresponding to each gripping claw are respectively obtained for each gripping claw, where the input parameters are at least one of the position and posture of the detection surface, and the mechanical parameters of the gripping claw are controlled based on the sum or difference of the respective input parameters.

8. The control device according to claim 7, wherein, the control unit controls the mechanical parameters related to the in-phase movement of the gripping claw based on the sum of the respective input parameters.

9. The control device according to claim 7 or 8, wherein, the control unit controls the mechanical parameters related to the rotational movement of the gripping claw based on the difference of the respective input parameters.

10. The control device according to any one of claims 6 to 9, wherein, the mechanical parameters include at least one of position and posture.

11. The control device according to any one of claims 6 to 10, wherein, the mechanical parameters include at least one of speed and acceleration.

12. A control method, which is a control method for a robotic gripper having a plurality of gripping claws, wherein, it includes the following steps: In the acquisition step, input parameters of a detection surface corresponding to each of the holding claws are acquired respectively, where the input parameter is at least one of the position and the posture of the detection surface. In the control step, the mechanical parameters of the holding claws are controlled based on the sum or difference of the respective input parameters.

13. The control method according to claim 12, wherein, in the control step, the mechanical parameters related to the concurrent movement of the holding claws are controlled based on the sum of the respective input parameters.

14. The control method according to claim 12 or 13, wherein, in the control step, the mechanical parameters related to the rotational movement of the holding claws are controlled based on the difference of the respective input parameters.

15. The control method according to any one of claims 12 to 14, wherein, the mechanical parameters include at least one of the position and the posture.

16. The control method according to any one of claims 12 to 15, wherein, the mechanical parameters include at least one of the speed and the acceleration.

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