Sensing system for gripping control, gripping apparatus, robot apparatus, and method for controlling the same

Abstract

There is provided an apparatus comprising: a hand having a plurality of finger portions, each having a gripping surface capable of gripping a workpiece; a sensor unit, which is provided in at least one of the plurality of finger parts, and which is capable of detecting a pressure distribution on the gripping surface; and a control device configured to detect sliding of the workpiece on the gripping surface based on an output of the sensor unit and generate a control instruction to change a relative position of the hand with respect to the workpiece.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Japanese patent application JP 2022-118100 filed on Jul. 25, 2022, the entire contents of which are hereby incorporated by reference into this application. Technical Field

[0003] The present technology relates to a device equipped with a hand having a sensor system and a control method thereof. Background Art

[0004] In recent years, as the worker population decreases, work automation using robots in various scenarios has been studied. In order to accurately control the behavior of a robot hand, it is necessary to detect the magnitude of a force acting on the surface of the robot hand. For example, the following patent document 1 has disclosed a robot hand equipped with a tactile force sensor that can detect not only a compressive force but also a shear stress or a sliding friction.

[0005] Citation list

[0006] Patent Literature

[0007] PTL1: Japanese Patent Application Publication No. 2019-2905 Summary of the invention

[0008] Technical issues

[0009] For the work of a robot hand, etc., slippage of the workpiece in the hand directly leads to failures such as workpiece drop and position deviation (reduced production). Therefore, control is usually performed to prevent the workpiece in the hand from slipping. For example, in practice, placing the workpiece at the middle point of the fixture, moving the hand away, and re-gripping the workpiece is one method for changing the gripping direction of the workpiece.

[0010] However, this method requires time to place the workpiece at the intermediate point and re-grip the workpiece. This is a big problem in terms of work speed and takes time.

[0011] In view of the above circumstances, an object of the present technology is to provide a robot apparatus capable of changing a gripping direction without re-gripping a workpiece and a control method thereof.

[0012] Solution to the problem

[0013] A device according to an embodiment of the present technology includes a hand, a sensor unit, and a control device.

[0014] The hand includes a plurality of fingers each having a gripping surface capable of gripping a workpiece.

[0015] The sensor unit is provided in at least one of the plurality of finger parts and is capable of detecting pressure distribution on the grip surface.

[0016] The control device is configured to detect sliding of the workpiece on the gripping surface based on an output of the sensor unit, and to generate a control command to change a relative position of the hand with respect to the workpiece.

[0017] In an example embodiment, the robotic device is able to change the grasping direction without re-gripping the workpiece because it detects the sliding of the workpiece on the grasping surface based on the output of the sensor unit capable of detecting the pressure distribution on the grasping surface and changes the relative position of the hand with respect to the workpiece.

[0018] The sensor unit may be composed of an elastically deformable sensor sheet having a plurality of capacitive elements, which detect pressure acting on the gripping surface, and the control device may be configured to detect sliding of the workpiece on the gripping surface based on changes in pressure detected by the plurality of capacitive elements over time.

[0019] The control device may be configured to detect the sliding of the workpiece on the gripping surface when the number of the capacitive elements whose pressure detection values ​​change within a predetermined time becomes a predetermined number or more.

[0020] The control device may be configured to detect the slip of the workpiece on the gripping surface when the pressure center position or the pressure distribution calculated based on the pressure detection values ​​of the plurality of capacitive elements changes within a predetermined time.

[0021] The control device can be configured to generate, as control instructions, a pressure adjustment instruction for adjusting the workpiece from a first gripping force to a second gripping force smaller than the first gripping force from a state in which the workpiece is gripped using the first gripping force, and a movement instruction for changing the relative position of the hand relative to the workpiece.

[0022] The control device may be configured to generate a control instruction to change from a first posture in which the distal end of the hand is oriented downward in the direction of gravity to a second posture as a movement instruction. In the first posture, the distal end of the hand is oriented in a direction orthogonal to the direction of gravity. In the second posture, the distal end of the hand is oriented in a direction orthogonal to the direction of gravity.

[0023] The control device may be configured to generate, as the movement instruction, a control instruction to move the workpiece in the longitudinal direction.

[0024] The sensor unit can be composed of a pressure sensor, a reference electrode layer and a deformation layer, the pressure sensor includes a sensor electrode layer in which multiple capacitive elements are arranged in a matrix form, the reference electrode layer is connected to a reference potential, and the deformation layer is arranged between the sensor electrode layer and the reference electrode layer.

[0025] The sensor sheet may include a pair of pressure sensors, a reference electrode layer and a deformation layer, each of the pressure sensors having a sensor electrode layer in which a plurality of capacitive elements are arranged in a matrix form, the reference electrode layer being connected to a reference potential, the deformation layer being arranged between the sensor electrode layer and the reference electrode layer, and a separation layer composed of a viscoelastic material arranged between the pair of pressure sensors.

[0026] A control method for an apparatus according to an embodiment of the present technology includes: detecting sliding of a workpiece on a gripping surface based on an output of a sensor unit, the sensor unit being capable of detecting pressure distribution on a gripping surface of a hand capable of gripping the workpiece; and generating a control instruction to change a relative position of the hand relative to the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] [ Figure 1 ] Figure 1 : is a perspective view showing main parts of a robot apparatus according to an exemplary embodiment of the present technology.

[0028] [ Figure 2 ] Figure 2 is a schematic side sectional view showing a sectional structure of a sensor sheet as a configuration example of a sensor unit in the robot device.

[0029] [ Figure 3 ] Figure 3 is a schematic plan view showing a sensor electrode layer in a sensor sheet.

[0030] [ Figure 4 ] Figure 4 : is a main-component plan view showing a configuration example of a sensing section in a sensor sheet.

[0031] [ Figure 5 ] Figure 5 is a schematic side sectional view showing another configuration example of the sensor unit.

[0032] [ Figure 6 ] Figure 6 is a block diagram showing the configuration of the control unit 70 .

[0033] [ Figure 7 ] Figure 7 is a block diagram showing the configuration of a control device in the robot device.

[0034] [ Figure 8 ] Figure 8 is a flowchart showing an example of a total slip detection process of a workpiece performed by a control device.

[0035] [ Fig. 9 ] Fig. 9is a block diagram showing an example of a control system of a robot device.

[0036] [ Fig.10 ] Fig.10 is a schematic diagram describing an operation example of the robot apparatus.

[0037] [ Fig.11 ] Fig.11 It shows Fig.10 A flow chart of the operation process of the robotic device is shown in FIG.

[0038] [ Fig.12 ] Fig.12 It shows Fig.10 A flow chart of the operation process of the robotic device is shown in FIG.

[0039] [ Fig.13 ] Fig.13 is a schematic diagram describing another operation example of the robot apparatus.

[0040] [ Fig.14 ] Fig.14 It shows Fig.13 A flow chart of the operation process of the robotic device is shown in FIG.

[0041] [ Fig.15 ] Fig.15 It shows Fig.13 A flow chart of the operation process of the robotic device is shown in FIG. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments according to the present technology will be described with reference to the drawings.

[0043] Figure 1 is a perspective view showing the main components of a robotic device 10 according to an example embodiment of the present technology. In the present embodiment, the robotic device 10 constitutes a robotic hand. Hereinafter, the configuration of the robotic device 10 will be schematically described. It should be understood that the present disclosure may be embodied in the example of a robotic arm shown, or may alternatively be embodied in different implementations or applications of the technology involving any manner of manipulation of a workpiece (e.g., a paintbrush, a screwdriver, a clamp, etc.).

[0044] Robotic equipment

[0045] like Figure 1 As shown, the robot device 10 includes an arm portion 1 , a wrist portion 2 , and a hand portion 3 .

[0046] The arm 1 includes a plurality of joints 1a. Driving the joints 1a enables the arm 1 to move the hand 3 to any position. The wrist 2 is rotatably connected to the arm 1. The rotation of the wrist 2 can rotate the hand 3.

[0047] The hand 3 has a plurality of fingers. The plurality of fingers can grasp a grasping target object (workpiece). In the present embodiment, the hand 3 has two fingers 3a, 3b facing each other. Driving the two fingers 3a, 3b enables the hand 3 to grasp the workpiece between the two fingers 3a, 3b. It should be noted that the number of fingers can be appropriately changed. For example, three or four or more fingers can be provided.

[0048] The two finger portions 3a, 3b have surfaces facing each other. The surfaces of the two finger portions 3a, 3b include sensor units 20a, 20b, respectively. The sensor units 20a, 20b have pressure detection surfaces. The pressure detection surface is configured to be able to detect a pressure component added in a direction perpendicular to the pressure detection surface and an in-plane distribution of the pressure component. Moreover, the sensor units 20a, 20b may be three-axis sensors that are able to detect a shear force parallel to the pressure detection surface, an in-plane distribution of the shear force, and a pressure distribution. Both of the finger portions 3a, 3b may include the sensor units 20a, 20b. Alternatively, only any one of the finger portions may include a sensor unit. Note that the following will refer to Figure 2 etc. describe the configuration of the sensor units 20a, 20b.

[0049] The controller 11 controls the driving of the robot device 10. For example, the controller 11 includes a control unit and a storage unit. For example, the control unit is a central processing unit (CPU). Based on the program stored in the storage unit, the control unit controls the driving of various parts of the robot device 10. The controller 11 may be a device dedicated to the robot device 10, or may be a general-purpose device. The controller 11 may be a personal computer (PC) connected to the robot device 10 by wire or wirelessly, a server device in a network, etc. The controller 11 may be a part of the robot device 10.

[0050] Sensor unit

[0051] Next, the sensor units 20a, 20b will be described in detail. The sensor units 20a, 20b have the same configuration. The sensor units 20a, 20b are composed of a sensor sheet capable of detecting pressure distribution on a pressure detection surface.

[0052] Configuration Example 1

[0053] Figure 2 0 is a schematic side sectional view showing a cross-sectional structure of a sensor sheet 210 as a configuration example of the sensor units 20a, 20b. Figure 3 2 is a schematic plan view showing the sensor electrode layer 30 of the sensor sheet 210. In one example, the sensor sheet 210 may be located on a gripping device (eg, Figure 1In a sensing system for grasping control in a robotic device or in another alternative embodiment discussed further below.

[0054] exist Figure 2 and Figure 3 In the diagram, the x-axis direction and the y-axis direction are directions parallel to the pressure detection surface S of the sensor sheet 210 (hereinafter, also referred to as in-plane directions). The z-axis direction is a direction perpendicular to the pressure detection surface S (hereinafter, also referred to as a vertical direction). Figure 2 , the upper side corresponds to the front side on which the external force is applied, and the lower side corresponds to the rear side opposite to the front side.

[0055] The sensor sheet 210 has a substantially rectangular flat plate shape in a plan view. Note that the shape of the sensor sheet 210 in a plan view only needs to be appropriately set according to the shape of the portion where the sensor units 20a, 20b are provided, and may be any other shape. For example, the shape of the sensor sheet 210 in a plan view may be a polygon other than a rectangle, a circle, or an ellipse.

[0056] like Figure 2 As shown, the sensor sheet 210 is configured as a laminate including a pressure sensor 21, a surface layer 22, and a support layer 24. The surface layer 22 is provided on the upper surface of the pressure sensor 21. The support layer 24 is provided on the lower surface of the pressure sensor 21.

[0057] The pressure sensor 21 includes a sensor electrode layer 30, a reference electrode layer 25, and a deformation layer 27. The deformation layer 27 is provided between the sensor electrode layer 30 and the reference electrode layer 25.

[0058] The sensor electrode layer 30 includes a flexible printed board or the like. Figure 3 As shown, the sensor electrode layer 30 has a main body portion 36 and a pull-out portion 37. The main body portion 36 has a rectangular shape in a plane. The pull-out portion 37 extends outward from the main body portion 36. Note that the shape of the sensor electrode layer 30 in a plan view is not limited to a rectangular shape and can be appropriately changed.

[0059] The sensor electrode layer 30 includes a substrate 29 and a plurality of sensing portions 28. The substrate 29 is flexible. The plurality of sensing portions 28 are provided on or in the surface of the substrate 29. For example, the substrate 29 is made of a polymer resin such as polyethylene terephthalate, polyimide, polycarbonate, and acrylic resin. The sensing portions 28 are regularly arranged in a matrix form at predetermined vertical and horizontal intervals (vertical: y-axis direction, horizontal: x-axis direction). Figure 3 In the example shown, the number of the sensing portions 28 is 81=9×9 (vertical×horizontal) in total. Note that the number of the sensing portions 28 may be changed appropriately.

[0060] The sensor section 28 includes a plurality of capacitive elements (detection elements) that can detect a change in the distance from the reference electrode layer 25 as a change in capacitance. Figure 4 As shown, the sensing portion 28 has a comb-shaped pulse electrode 281 and a comb-shaped sensing electrode 282. The comb teeth of the comb-shaped pulse electrode 281 and the comb-shaped sensing electrode 282 are arranged facing each other. Each sensing portion 28 includes an area (node ​​area) in which one of the comb teeth is arranged to mesh with other comb teeth. Each pulse electrode 281 is connected to a wiring portion 281a extending in the y-axis direction. Each sensing electrode 281 is connected to a wiring portion 282a extending in the x-axis direction. The wiring portion 281a is arranged along the x-axis direction on the surface of the substrate 29. The wiring portion 282a is arranged along the y-axis direction on the back of the substrate 29. Each sensing electrode 282 is electrically connected to the wiring portion 282a via a through hole 283 formed in the substrate 29. The sensor electrode layer 30 may have a ground line. For example, the ground line is arranged in the peripheral portion of the sensor electrode layer 30 or in a portion where the wiring portions 281a and 282a extend together.

[0061] It should be noted that the sensing portion 28 may have any structure other than the example. For example, the sensor electrode layer 30 may be configured as a laminate of a first electrode sheet and a second electrode sheet. The first electrode sheet has a grid-like first electrode pattern extending in the x-axis direction. The second electrode sheet has a grid-like second electrode pattern extending in the y-axis direction. In this case, the sensing portion 28 is formed at the intersection of the first electrode pattern and the second electrode pattern.

[0062] The reference electrode layer 25 is connected to a reference potential. In the present embodiment, the reference electrode layer 25 is a so-called ground electrode and is connected to a ground potential. The reference electrode layer 25 is flexible. For example, the reference electrode layer 25 has a thickness of about 0.05 μm to 0.5 μm. For example, the reference electrode layer 25 is made of an inorganic conductive material, an organic conductive material, or a conductive material containing an inorganic conductive material and an organic conductive material.

[0063] Examples of inorganic conductive materials include metals such as aluminum, copper, and silver, alloys such as stainless steel, and metal oxides such as zinc oxide and indium oxide. Examples of organic conductive materials include carbon materials such as carbon black and carbon fibers, and conductive polymers such as substituted or unsubstituted polyaniline and polypyrrole. Reference electrode layer 25 may include a metal sheet such as stainless steel and aluminum, conductive fibers, conductive nonwoven fabrics, and the like. For example, reference electrode layer 25 may be formed by methods such as vapor deposition, sputtering, adhesion, and application to a plastic film.

[0064] The deformation layer 27 is provided between the sensor electrode layer 30 and the reference electrode layer 25. For example, the deformation layer 27 has a thickness of about 100 μm to 1000 μm. The deformation layer 27 is configured to be elastically deformable due to an external force. Applying an external force in a direction perpendicular to the sensor sheet 210 elastically deforms the deformation layer 27, while moving the reference electrode layer 25 closer to the sensor electrode layer 30. At this time, the capacitance between the pulse electrode 281 and the sensing electrode 282 changes in the sensing portion 28. Therefore, the sensing portion 28 can detect the capacitance change as a pressure value.

[0065] For example, the thickness of the deformable layer 27 is set to be greater than 100 μm and less than or equal to 1000 μm. For example, the deformable layer 27 has a thickness of 50 mg / cm 2 Or less weight per unit area.

[0066] Setting the thickness and weight per unit area of ​​the deformable layer 27 within such ranges can improve the vertical detection sensitivity of the pressure sensor 21 .

[0067] The lower limit value of the thickness of the deformable layer 27 is not particularly limited as long as it is greater than 100 μm. For example, the lower limit value may be 150 μm or more, 200 μm or more, 250 μm or more, or 300 μm or more. The upper limit value of the thickness of the deformable layer 27 is not particularly limited as long as it is less than or equal to 1000 μm. For example, the upper limit value may be 950 μm or more, 900 μm or less, 850 μm or less, or 800 μm or less.

[0068] In order to more easily achieve deformation in the z-axis direction, the deformable layer 27 may have a pattern structure including, for example, a columnar structure. For example, the pattern structure includes a columnar structure. The pattern structure may include various structures, such as a matrix structure, a stripe structure, a grid structure, a radial structure, a geometric structure, and a spiral structure.

[0069] The surface layer 22 is made of any flexible material selected from plastic film, fabric, non-woven fabric, rubber, leather, etc. The surface layer 22 can be configured as a contact surface that contacts the workpiece when the robot device 10 grasps the workpiece with the finger portions 3a, 3b. In this case, the surface layer 22 serves as a pressure detection surface that receives a load (reaction force of the grasping force) from the workpiece during the grasping operation. Therefore, in order to stably grasp the workpiece, the surface layer 22 advantageously has a surface property that can add a predetermined friction force or greater friction force to the workpiece.

[0070] The support layer 24 supports the pressure sensor 21. For example, the support layer 24 serves as an adhesive layer fixed to the surface of the finger portion 3a, 3b. The support layer 24 includes an adhesive layer such as a double-sided tape.

[0071] The control unit 70 is mounted on the pull-out portion 37 of the sensor electrode layer 30. The control unit 70 calculates the force in the in-plane direction based on the information about the pressure detected by the pressure sensor 21. The control unit 70 is typically a computer including a central processing unit (CPU). The control unit 70 includes an integrated circuit such as an IC chip. The control unit 70 is mounted on the sensor electrode layer 30 (pull-out portion 37) to drive the pressure sensor 21. The control unit 70 is configured to receive a signal output from the pressure sensor 21 as an input. Note that the control unit 70 may be mounted at a location other than the sensor electrode layer 30.

[0072] Configuration Example 2

[0073] Figure 5 2 is a schematic side sectional view showing a cross-sectional structure of a sensor sheet 220 as another configuration example of the sensor units 20a, 20b. Note that parts corresponding to those in configuration example 1 will be denoted by the same reference numerals, and detailed descriptions of these parts will be omitted. In one example, the sensor sheet 210 may be located on a gripping device (such as Figure 1 In a sensing system for grasping control in a robotic device or in another alternative embodiment discussed further below.

[0074] The sensor sheet 220 includes a first pressure sensor 21a, a second pressure sensor 21b, and a separation layer 23. The first pressure sensor 21a is located on the front side (the workpiece side). The second pressure sensor 21b is located on the rear side (the finger portion 3a, 3b side). The separation layer is provided between the first pressure sensor 21a and the second pressure sensor 21b. That is, the sensor sheet 220 has a stacked structure. In the stacked structure, the second pressure sensor 21b, the separation layer 23, and the first pressure sensor 21a are stacked in sequence from the bottom in the vertical direction. The first pressure sensor 21a and the second pressure sensor 21b have the same configuration or substantially the same configuration. Therefore, the description thereof will be omitted.

[0075] The sensor sheet 220 further has a viscoelastic layer 81 provided on the upper side (surface side) of the first pressure sensor 21a. The viscoelastic layer 81 is made of a material that can be deformed by an external force. Examples of deformable materials include silicone gel, urethane gel, synthetic rubber, and foam. Note that the viscoelastic layer 81 can be omitted if necessary.

[0076] The sensor sheet 220 detects a force (shear force Fs) added to the sensor sheet 220 in the in-plane direction based on the pressure center position (pressure detection position) of the first pressure sensor 21a in the in-plane direction and the pressure center position (pressure detection position) of the second pressure sensor 21b in the in-plane direction. The sensor sheet 220 detects a force (load Fz) added from above in a direction perpendicular to the sensor sheet 220 based on the pressure value detected by the first pressure sensor 21a.

[0077] The separation layer 23 is fixed between the first pressure sensor 21a and the second pressure sensor 21b via an adhesive layer (not shown). The separation layer 23 is composed of a viscoelastic material that can be deformed by a load added to the first pressure sensor 21a via the surface layer 22 and the viscoelastic layer 81. Examples of such viscoelastic materials include silicone, polyurethane gel, synthetic rubber, and foam. The separation layer 23 can have any thickness. For example, the separation layer 23 has a thickness greater than or equal to 1000 μm and less than or equal to 5000 μm. For example, the thickness of the separation layer 23 is set according to the thickness of the viscoelastic layer 81. The separation layer 23 can have any planar shape. The separation layer 23 is typically rectangular or circular.

[0078] Control device (sensing system for grip control)

[0079] For example, the control unit 70 includes a control unit and a storage unit to control the gripping device. For example, the control unit is a central processing unit (CPU). The control unit controls the driving of various parts of the hand 3 according to the control instructions from the controller 11 by executing the program stored in the storage unit. Generally, the control unit 70 obtains information related to the force in the three-axis directions detected by the sensor units 20a, 20b, and controls the driving of the hand 3 based on the information related to the force to stably grip the target object with an appropriate gripping force.

[0080] In the present embodiment, the control unit 70 is configured as a control device. The control device detects the sliding of the workpiece on the gripping surface (pressure detection surface S) based on the output of the sensor units 20a, 20b. The control device generates a control instruction to change the relative position of the hand 3 relative to the workpiece. For example, the position of the workpiece is adjusted or changed relative to one or more parts of the hand (such as one or more finger parts 3a, 3b, etc.). Therefore, the position of the workpiece in the hand is changed relative to the position or orientation of at least a part of the hand.

[0081] The storage unit includes a nonvolatile memory for storing various programs and data required for the processing of the control unit and a volatile memory used as a working area of ​​the control unit. Various programs can be read from a portable recording medium such as a semiconductor memory. Alternatively, various programs can be downloaded from a server device in the network.

[0082] Figure 6 is a block diagram showing the configuration of the control unit 70 .

[0083] The control unit 70 is electrically connected to the sensor units 20a, 20b. The control unit 70 is configured to calculate the pressure acting on each finger portion 3a, 3b and the in-plane distribution of the pressure based on the output of the sensor units 20a, 20b. The control unit 70 is also electrically connected to the controller 11. The control unit 70 outputs a gripping instruction to the drive unit 12a according to the control instruction from the controller 11. The drive unit 12a drives the finger portions 3a, 3b of the hand 3.

[0084] The controller 11 and the control unit 70 are configured as a control device that controls the operation of the hand 3. In the present embodiment, the control unit 70 generates a gripping instruction to the drive unit 12a that drives the finger portions 3a, 3b. Alternatively, the controller 11 that controls the general operation of the robot device 10 may generate a gripping instruction instead.

[0085] In this case, the controller 11 is configured to control the device.

[0086] like Figure 6 As shown, the control unit 70 includes an acquisition unit 71 , an arithmetic unit 72 , a signal generation unit 73 and a storage unit 74 .

[0087] The acquisition unit 71 receives the pressure detection position and pressure value thereof outputted from each sensor unit 20a, 20b and the control command outputted from the controller 11. When the hand 3 (finger portion 3a, 3b) is in the state of grasping the workpiece, the pressure information including the pressure detection position and pressure value thereof outputted from each sensor unit 20a, 20b is information related to the pressure detected when the hand 3 (finger portion 3a, 3b) contacts the workpiece and the pressure acting on the sensor units 20a, 20b. The acquisition unit 71 periodically acquires the pressure information at a predetermined frame rate (sampling rate).

[0088] The arithmetic unit 72 calculates the in-plane distribution of the pressure acting on the pressure detection surface S (i.e., the gripping surface) based on the pressure detection positions of the sensor units 20a, 20b in the in-plane direction and their pressure values. For example, the load perpendicular to the pressure detection surface S is calculated based on the sum of the normal loads obtained in the respective sensing portions 28 of the sensor units 20a, 20b. Note that in the case where the sensor units 20a, 20b are Figure 5 In the case of the configuration of the sensor sheet 220 shown in , the arithmetic unit 72 also calculates the distribution of the shear force in the in-plane direction of the pressure detection surface S.

[0089] The signal generating unit 73 generates a control instruction other than a gripping instruction according to the control instruction from the controller 11 to cause the hand 3 to grip the workpiece. The control instruction includes a movement instruction to change the relative position of the hand 3 relative to the workpiece. The gripping instruction includes information related to the gripping force of the hand 3 relative to the workpiece. The signal generating unit 73 outputs the generated gripping instruction or movement instruction to the driving unit 12a of the hand 3.

[0090] The gripping instruction includes a high gripping instruction (high gripping instruction value) applied when transporting a workpiece, a low gripping instruction (low gripping instruction value) for relatively moving the hand 3 relative to the workpiece while gripping the workpiece, a minimum pressure gripping instruction (minimum gripping force), a gripping cancellation instruction, and the like. The high gripping instruction is a gripping force (first gripping force) sufficient to stably grip the workpiece without causing the workpiece to slip. For example, a low gripping instruction refers to a gripping force (second gripping force) that is less than the high gripping instruction value and allows the workpiece to slide relative to the hand 3 by the workpiece's own weight. The minimum pressure gripping instruction is a minimum pressure value that is less than the low gripping instruction value and is capable of gripping the workpiece to prevent it from falling. The slip of the workpiece includes local slip and general slip. In the following, the general slip of the workpiece relative to the hand 3 is also referred to as "general slip."

[0091] The movement command is a command to change the relative position of the hand 3 with respect to the workpiece in order to change the gripping position and gripping posture of the workpiece (for example, rotation, linear movement).

[0092] The drive unit 12a is an actuator that moves the fingers 3a and 3b between the gripping position and the non-gripping position. For example, in the present embodiment, the drive unit 12a is composed of a pulse motor capable of fine feed control.

[0093] The storage unit 74 is generally composed of a semiconductor memory and stores a program and various parameters for executing a process of calculating the shear force distribution in the in-plane direction from the pressure detection positions in the in-plane direction of the first and second pressure sensors 21a and 21b.

[0094] The control unit 70 detects the sliding of the workpiece on the gripping surface based on the temporal change in the pressure detected by the plurality of sensing portions 28. In the present embodiment, the control unit 70 detects the sliding of the workpiece on the gripping surface when the number of sensing portions 28 whose pressure detection values ​​change within a predetermined time becomes a predetermined number or more, as described later.

[0095] For example, Figure 7 A and B are schematic diagrams of the sensor sheet 210 describing the sliding of the workpiece W on the gripping surface (pressure detection surface S). Figure 7In A and B of FIG. 1 , the node areas as shaded portions show the sensing portion 28 in an open state, and the sensing portion 28 in the open state outputs a pressure detection value equal to or greater than a predetermined threshold value by receiving a reaction to the gripping force on the workpiece W. The other node areas (parts without shades) show the sensing portion 28 in a closed state, and the sensing portion 28 in the closed state outputs a pressure detection value less than the threshold value.

[0096] When the workpiece W grasped with a predetermined grasping force is Figure 7 The state shown in A is Figure 7 When sliding in the gravity direction shown in B (downward in the figure), the output of the sensing portion 28 changes from the open state to the closed state, or from the closed state to the open state in the sliding direction of the workpiece W. The control unit 70 determines whether the number of sensing portions 28 whose open / closed states have changed within a predetermined time has become a predetermined number or more. In the case where the control unit 70 determines that it has become a predetermined number or more, the control unit 70 detects the sliding of the workpiece W on the gripping surface. For example, an exclusive OR (XOR) circuit can determine the change in the open / closed state. The predetermined time can be appropriately set according to the frame rate, and the predetermined time can be, for example, several frames to tens of frames.

[0097] As another method, the arithmetic unit 72 may be configured to detect the sliding of the workpiece W on the gripping surface when the pressure center position or pressure distribution calculated based on the pressure detection values ​​of the plurality of sensing portions 28 changes within a predetermined time. For example, the pressure center position may be calculated by quantitatively detecting the detection values ​​of the respective sensing portions 28 and using an arithmetic operation such as a weighted arithmetic mean. For the pressure distribution, the arithmetic unit 72 may be configured to detect the sliding of the workpiece when the position or shape of the pressure distribution constituted by the sensing portions 28 in the on state changes, for example, by a predetermined amount or more. In this case, image processing techniques and machine learning techniques may be used.

[0098] Figure 8 : is a flowchart showing an example of a gross slip detection process of the workpiece W executed by the control unit 70. Here, the gross slip detection process of the workpiece W in a state where the workpiece W is gripped using a pressure value associated with a low grip instruction will be described.

[0099] First, the control unit 70 determines whether there is a sensing portion 28 (node ​​area) whose on / off state has changed (step 101). This process can be performed using the reference Figure 7 A and B describe the determination method.

[0100] Subsequently, the control unit 70 adds the number of the sensing portions 28 whose on / off states have changed from the previous frame (step 102), and determines whether the number is equal to or greater than a predetermined threshold value (step 103). In the case where the number is less than the threshold value (No in step 103), the control unit 70 increments the total slide detection current frame rate counter set in a memory (such as the storage unit 74), and determines whether the total slide detection current frame rate counter is equal to or greater than the threshold value (steps 104 and 105). In the case where the total slide detection current frame rate counter is less than the threshold value, the control unit 70 repeats the process.

[0101] On the other hand, when the sum of the sensing portions 28 whose open / closed states have changed reaches a predetermined threshold value, the control unit 70 determines that the total sliding of the workpiece W has occurred, and detects the total sliding of the workpiece W (step 106). When the control unit 70 detects the total sliding of the workpiece W, or the total sliding detection current frame rate counter reaches the threshold value, the control unit 70 resets the sum of the sensing portions 28 whose open / closed states have changed and the total sliding detection current frame rate counter to zero (step 107).

[0102] Device Control

[0103] Fig. 9 An example of device control is provided. Fig. 9 1 is a block diagram showing an example of a control system of the robot device 10. The robot device 10 includes a controller 11 and a drive section 12. The drive section 12 drives the arm section 1, the hand section 3, etc. The drive section 12 includes a drive unit 12a that drives the finger sections 3a, 3b. The controller 11 is configured to be able to execute a control program for operating the robot device 10 based on input signals from various sensors.

[0104] The sensor units 20a, 20b constitute one of various sensors and are attached to the workpiece gripping surface of the hand 3. Based on the control instruction from the controller 11, the sensor units 20a, 20b output the gripping instruction for gripping the workpiece to the drive unit 12a that drives the finger portions 3a, 3b of the hand 3. The sensor units 20a, 20b detect the compressive force (pressure distribution, gripping force (normal load) or shear force) acting on the pressure detection surface S. The sensor units 20a, 20b calculate the value of the compressive force in the control unit 70 and input the value to the controller 11. The controller 11 generates a drive signal for controlling the position and posture of the arm 1 and the hand 3 (finger portions 3a, 3b). The controller 11 outputs the drive signal to the drive unit 12. The drive unit 12 is generally an actuator such as an electric motor and a hydraulic cylinder. The drive unit 12 drives the arm 1, the hand 3, etc. based on the drive signal from the controller 11.

[0105] As described above, in the present embodiment, the control unit 70 is configured to control the gripping of the hand 3. The present technology is not limited thereto, and the controller 11 may directly output the gripping instruction to the drive unit 12a and control the gripping of the hand 3. In this case, the control unit 70 is only used to calculate the pressure acting on the sensor units 20a, 20b and output the pressure to the controller 11.

[0106] Next, the operation of the robot device 10 according to the present embodiment will be described in association with the details of the controller 11 and the control unit 70 .

[0107] Operation Example 1

[0108] Fig.10 A to C are schematic diagrams describing an operation example of placing bottles B as workpieces on a rack R one by one. Fig.11 and 12 : is a flowchart showing the operation procedure of the robot device 10 at this time.

[0109] For example, in a task of picking up beverage bottles in a box and displaying them on a shelf in a factory or store, people automatically reposition the bottles held vertically downward to horizontal positions, avoiding contact with the upper and lower plates of the shelf, and place the bottles properly. However, this method takes time to arrange and re-grip the workpiece at the intermediate point. This is a big problem in terms of work speed and cycle time.

[0110] In view of this, according to the present embodiment, by being able to re-place the bottle B in the hand 3 by manual manipulation and accordingly transporting the bottle B directly to a predetermined position on the rack R, the working speed and tact time can be improved. Hereinafter, this will be described in detail.

[0111] like Fig.10 As shown in A of FIG. 1 , the robot device 10 moves the arm portion 1 to a predetermined position (hereinafter, a workpiece rotation position (also referred to as a position where the hand is rotated relative to the workpiece) on the rack R while grasping the cap portion Bc of the bottle B using a high grasping force instruction value by the hand portion 3 (step 201). At this time, the hand portion 3 grasps the cap portion Bc in a posture (first posture) in which its distal end is oriented downward in the gravity direction (lower side in the figure). This posture of the hand 3 corresponds to the posture when picking up one of the bottles B.

[0112] Subsequently, the robot device 10 stops the arm 1 at the workpiece rotation position and sets the gripping force of the hand 3 to a low gripping instruction value (step 202). Fig.10As shown in FIG. 2B , the robot device 10 rotates the hand 3, thereby changing the hand 3 to a posture (second posture) in which the distal end is oriented in a horizontal direction (rightward in the figure) in a direction orthogonal to the direction of gravity, and causes the workpiece (bottle B) to rotate within the hand 3 due to its own weight (step 203 ).

[0113] At this time, the control unit 70 performs a reference Figure 8 The total sliding detection of the workpiece described above (step 204). For example, in the case where the control unit 70 detects the total sliding (yes in step 204), the control unit 70 resets the stable frame rate counter in the memory of the storage unit 74 (step 205). The stable frame rate counter is referenced to determine whether the posture is stable after the total sliding of the workpiece ends.

[0114] After resetting the stable frame rate counter, the control unit 70 detects the total slide of the workpiece again (step 206). In the case where the control unit 70 detects the total slide of the workpiece (yes in step 206), the control unit 70 resets the stable frame rate counter and performs the total slide detection of the workpiece again (steps 207 and 206). In the case where the total slide of the workpiece is not detected (no in step 206), the control unit 70 increments the stable frame rate counter and determines whether the stable frame rate counter is equal to or greater than a predetermined threshold (steps 208 and 209). When the stable frame rate counter is less than the threshold (no in step 209), the control unit 70 repeats the processing of steps 206 to 208.

[0115] A series of processes (steps 204 to 209) are usually performed immediately after the workpiece rotation begins. During the rotation of the hand 3, the workpiece (bottle B) should also be kept upright, such as Fig.10 Thus, this series of processing can monitor whether the workpiece immediately starts to rotate in the hand 3 as expected after the hand 3 rotates (total slip).

[0116] On the other hand, in the case where the stable frame rate counter is equal to or greater than the threshold value (Yes in step 209), the control unit 70 resets the stable frame rate counter and performs the workpiece total slide detection again (steps 210 and 211). In the case where the workpiece total slide is detected (Yes in step 211), the control unit 70 resets the stable frame rate counter and performs the workpiece total slide detection again (steps 212 and 211). In the case where the workpiece total slide is not detected (No in step 211), the control unit 70 increments the stable frame rate counter and determines whether the stable frame rate counter is equal to or greater than a predetermined threshold value (steps 213 and 214).

[0117] This series of processing (steps 210 to 214) is usually performed immediately before the workpiece is rotated. Fig.10When the workpiece (bottle B) is in the horizontal position shown in B, it should be kept upright, as shown in Fig.10 However, in some cases, the hand 3 slightly rotates the workpiece during the rotation of the hand 3. In those cases, the workpiece is not kept upright. Therefore, there is a possibility that the workpiece cannot be stably placed on the rack R. In order to avoid this, a process of further reducing the gripping force of the hand 3 to prevent the workpiece from falling and promoting the workpiece to return to an upright posture is performed as described below.

[0118] In the case where the stable frame rate counter is less than the predetermined threshold value (No in step 214), the control unit 70 determines whether the current gripping force of the hand 3 is greater than the minimum gripping force (step 215). In the case where the current gripping force of the hand 3 is greater than the minimum gripping force (Yes in step 215), the control unit 70 reduces the gripping force by a certain constant value and performs the workpiece total slide detection again (steps 216 and 211). On the other hand, in the case where the current gripping force is the minimum gripping force (No in step 215), the control unit 70 performs the workpiece total slide detection again without reducing the gripping force (step 211). By repeating this process until the stable frame rate counter is equal to or greater than the threshold value (Yes in step 214), the workpiece (bottle B) can be reliably kept upright after the rotation operation of the hand 3 ends. It is to be noted that in the case where the workpiece can be stably kept upright, this series of processes (steps 210 to 216) can be omitted.

[0119] When the stable frame rate counter is equal to or greater than the predetermined threshold value (Yes in step 214), the control unit 70 sets the gripping force of the hand 3 to a high gripping instruction value and moves the arm 1 to place the workpiece (bottle B) at the next working position ( Fig.10 In the example of C, it is the height of the upper surface of the rack R) (steps 217 and 218). Then, the control unit 70 cancels the gripping force of the hand 3 to complete the task of placing the bottle B on the rack R.

[0120] As described above, according to the present embodiment, the gripping direction can be changed without re-gripping the workpiece, thereby improving the working speed and tact time.

[0121] Operation Example 2

[0122] Fig.13 A and B are schematic diagrams describing an operation example of moving the hand 3 grasping the cable C to the distal end Ca of the cable C. Fig.14 and Fig.15 : is a flowchart showing the operation procedure of the robot device 10 at this time.

[0123] The task of picking up a connector attached to one end of a cable in a factory or the like has a problem in that the position of the connector varies depending on how the cable is bent or bundled, so it is difficult to determine the gripping position using a camera. In this case, a wide-angle camera that can recognize the position of all connectors can be used, but such cameras are expensive and increase costs. This is also a problem because camera-based image recognition usually takes time and increases the work cycle time, which also increases the system computing cost.

[0124] In view of this, according to the present embodiment, while the hand 3 grasps the cable C, moving the distal end Ca of the cable C close to the hand 3 improves the tact time and system calculation cost without requiring a wide-angle camera and high-precision image processing, regardless of the form of the cable C. Hereinafter, this will be described in detail.

[0125] like Fig.13 As shown in FIG. 1A , the robot device 10 moves the arm 1 to an arbitrary portion (such as a root position) of the cable C, sets the gripping force of the hand 3 to a low gripping instruction value, and then grips a portion of the cable C (steps 301 and 302). For gripping the cable C, for example, an arbitrary portion of the cable C set in an arbitrary form at a preset gripping position can be gripped by executing a constant gripping sequence. Alternatively, an arbitrary portion of the cable C can be gripped using a camera mounted on an arbitrary portion such as an arm.

[0126] Subsequently, the control unit 70 determines whether a predetermined pressure distribution curve exists based on the outputs of the sensor units 20a, 20b of the hand 3 grasping the cable C (step 303). For example, the predetermined pressure distribution curve is a pressure distribution extending across the grasping surface of the sensing portion 28 in one axial direction whose pressure detection value is equal to or greater than a predetermined threshold. In the case where the pressure of such a pressure distribution curve is detected (yes in step 303), the control unit 70 moves the arm portion 1 in the longitudinal direction of the cable C toward the distal end of the cable C (step 304). On the other hand, in the case where the pressure distribution curve is not detected, the control unit 70 determines that the desired grasping state is not obtained, releases the grasping force of the hand 3, and performs the grasping operation again (step 305).

[0127] When the arm 1 is moved toward the distal end of the cable C, the control unit 70 determines whether the pressure distribution curve detected by the sensor units 20a, 20b of the hand 3 is moved to the right by a constant distance or longer relative to the traveling direction (step 306). In the case where the control unit 70 determines that the pressure distribution curve is moved to the right (yes in step 306), the control unit 70 modifies the movement direction of the arm 1 to the right by a constant angle relative to the traveling direction (step 307).

[0128] On the other hand, in the case where the control unit 70 determines that the pressure distribution curve has not moved to the right (No in step 306), the control unit 70 determines whether the pressure distribution curve has moved to the left by a constant distance or more relative to the traveling direction (step 308). In the case where the control unit 70 determines that the pressure distribution curve has moved to the left (Yes in step 308), the control unit 70 modifies the moving direction of the arm part 1 to the left by a constant angle relative to the traveling direction (step 309).

[0129] This series of processes (steps 306 to 309 ) can maintain the gripping position of the cable C in the middle area of ​​the gripping surface while the arm 1 is moved.

[0130] Subsequently, the control unit 70 determines again whether a predetermined pressure distribution curve exists based on the outputs of the sensor units 20a, 20b (step 310). This process is for checking whether the cable C falls off from the hand 3 or deviates greatly from the gripping position during the operation of moving the cable C closer. If the cable C falls off from the hand 3 (yes in step 310), the control unit 70 releases the gripping force and repeats the gripping operation process (steps 312 and 301 to 305).

[0131] When the control unit 70 confirms that the predetermined pressure distribution curve exists, the control unit 70 determines whether the pressure distribution curve at the distal end of the cable C is detected (step 311). The pressure distribution curve at the distal end of the cable is a pressure distribution curve corresponding to the shape near the distal end Ca of the cable C and pre-stored in the storage unit 74. The control unit 70 repeats the processing of steps 306 to 310 until the pressure distribution curve at the distal end of the cable C is detected (No in step 311).

[0132] On the other hand, when the control unit 70 detects the pressure distribution curve at the distal end of the cable C (Yes in step 311), the control unit 70 sets the gripping force of the hand 3 to a high gripping instruction value and grips the distal end Ca of the cable C (step 313). Thus, the operation of moving the cable C closer by the hand 3 ends. Then, the arm 1 is moved to the next working position to transport the cable C to the working position (step 314).

[0133] As described above, according to the present embodiment, the hand 3 can move a flexible linear member such as a cable C from any position to a desired position. Therefore, the cable C can be transported to the next step in a desired posture. As the cable C, in addition to wires with connection plugs such as connectors and harnesses, various linear members such as electric wires and hoses can be applied.

[0134] Modify the example

[0135] As described above, various modifications of the disclosed device can be implemented according to the present disclosure, for example, the wearable device is a gripping device having a sensing system for gripping control as described above. For example, the wearable device can be a glove having a hand portion and finger portions with gripping surfaces, which can detect pressure distribution on each gripping surface. In some examples, the gripping device can be implemented in a virtual reality application or an augmented reality application.

[0136] In one example embodiment, the total sliding of the workpiece W relative to the hand 3 is detected based on whether the number of the sensing portions 28 whose open / closed states have changed reaches a predetermined threshold, but is not limited thereto. Figure 5 The sensor unit of the sensor structure shown in can detect the total sliding of the workpiece while taking into account the magnitude and direction of the shear force and the pressure detection value. This can detect the sliding direction of the workpiece. Therefore, it can be determined whether the sliding direction of the workpiece is appropriate.

[0137] In addition, in the embodiment, the change of the capacitance detection element is used to detect the pressure distribution, but it is not limited thereto. For example, a variable resistance detection element having a variable resistance value can be used according to the magnitude of the pressure.

[0138] In the example of a gripping device as a wearable device, there may be a variety of different applications. For example, a glove device can impart the skills of a skilled craftsman to a less experienced glove user. In an example, a glove having a pressure sensor (such as a sensor sheet) placed on the finger portion of the glove can sense the work data of a skilled craftsman, which is recorded and analyzed, so that feedback can be provided to the less experienced glove user to correct the grip of the workpiece (such as a paint brush). Therefore, the training of the craftsman's skills or traditional skills can be achieved using a glove device. For example, glove device training can include training to improve sports skills using equipment such as bats, rackets, and golf clubs. In other examples, glove device training can include training to improve skills such as painting and calligraphy using brushes and pens. In other examples, glove device training can include training to improve the skills of playing musical instruments such as piano and guitar.

[0139] In another example of a gripping device as a wearable device, a glove device can assist the user's work, such as routine or single tasks (such as screw tightening) or work that requires fine details, where the glove can ensure sufficient grip control while detecting manpower and compensating for differences (such as insufficient strength) to relatively easily manipulate screwdrivers, etc. Therefore, glove devices can be used to achieve training or assistance for simple tasks or advanced work assistance. For example, glove device training or assistance can include making food, such as Japanese dim sum or dumplings, fried rice, or turning pots. In other examples, glove device training or assistance can include correct cap tightening work at a chemical plant, electronic equipment production work, such as soldering irons, connector insertion, etc. In other examples, glove device training or assistance can be used for medical practice tasks, such as surgery on patients, disease diagnosis (such as lymphadenopathy), or physical therapy. In other examples, glove device training or assistance can be used for sheet metal processing accuracy assessment of aircraft and automobiles, such as contact assessment of parts.

[0140] In another example of a gripping device as a wearable device, a glove device can provide a user with remote control of a workpiece, such as executing remote instructions of a gripping device (such as a robotic arm), such as for remotely manipulating a clamp or other tool. Therefore, the use of remote tools can be achieved using a glove device. For example, a glove device is used for training or cleaning work using a remote robot, such as picking up garbage, cleaning bathrooms and toilets, etc. In other examples, a glove device is used to train or work in extreme areas using a remote robot, such as disaster response or rescue, ruins excavation, nuclear material processing, or space development. In other examples, a glove device is used for training or equipment maintenance services using a remote robot, or for equipment instructions. In other examples, a glove device is used for training or shopping using a remote robot, which allows consumers to remotely touch and grip the product to confirm the appropriate size or weight characteristics. In other examples, a glove device can be used for a virtual handshake activity with an idol or celebrity using a remote robot. There are many other examples of wearable devices. In one example, a glove can have a hand, which includes a complete glove with a finger portion having all fingers and a thumb. In another example, the glove can be a partial glove with some parts omitted, such as omitting one or more finger portions, or there is no palm portion between the finger portions. The wearable device may include a wearable wrist portion, or may be wearable in other ways. Such devices may include finger portions having pressure sensors for detecting slippage of the workpiece, for repositioning the hand relative to the position of the workpiece, etc.

[0141] In one example of the present disclosure, multiple or all fingers are repositioned on the workpiece. In another example, only one finger is repositioned to avoid slipping while maintaining at least two contact points on the workpiece in addition to the repositioned finger.

[0142] It should be understood that in embodiments of the glove apparatus, in some cases, the hand may not contact the workpiece, and only the fingers may contact the workpiece. Furthermore, the user's fingers or hand may or may not directly contact the workpiece, wherein, for example, the glove may apply pressure to the workpiece from the user's fingers. In addition, the glove itself may not be able to grasp the workpiece on its own, and the workpiece can only be grasped by the hand of the user wearing the glove through the glove.

[0143] As used herein, the term "workpiece" should be understood as any suitable item that is manipulated by a user for various possible purposes, such as a tool, a pen, a workpiece, a product, etc. Therefore, the workpiece is not limited to any specific example set forth herein.

[0144] It should be noted that the present technology can also adopt the following configurations.

[0145] (1) A robotic device comprising:

[0146] A hand having a plurality of fingers, each of the plurality of fingers having a gripping surface capable of gripping a workpiece;

[0147] a sensor unit provided in at least one of the plurality of finger parts and capable of detecting a pressure distribution on a grip surface; and

[0148] A control device is configured to detect sliding of the workpiece on the gripping surface based on the output of the sensor unit and generate a control command to change a relative position of the hand with respect to the workpiece.

[0149] (2) A robotic device according to (1), wherein

[0150] The sensor unit is composed of an elastically deformable sensor sheet having a plurality of capacitive elements which detect the pressure acting on the gripping surface, and

[0151] The control device detects sliding of the workpiece on the gripping surface based on changes over time in pressure detected by the plurality of capacitive elements.

[0152] (3) The robotic device according to (2), wherein

[0153] When the number of the capacitance elements whose pressure detection values ​​change within a predetermined time becomes a predetermined number or more, the control device detects the sliding of the workpiece on the gripping surface.

[0154] (4) The robotic device according to (2), wherein

[0155] When the pressure center position or the pressure distribution calculated based on the pressure detection values ​​of the plurality of capacitive elements changes within a predetermined time, the control device detects the sliding of the workpiece on the gripping surface.

[0156] (5) The robot device according to (1) to (4), wherein

[0157] The control device generates, as control instructions, a pressure adjustment instruction for adjusting the workpiece from a first gripping force to a second gripping force smaller than the first gripping force and a movement instruction for changing a relative position of the hand with respect to the workpiece.

[0158] (6) The robotic device according to (5), wherein

[0159] The control device generates a control instruction to change from a first posture in which the distal end of the hand is oriented downward in the gravity direction to a second posture in which the distal end of the hand is oriented in a direction orthogonal to the gravity direction as a movement instruction.

[0160] (7) A robotic device according to (5) or (6), wherein

[0161] The control device generates a control command for moving the workpiece in the longitudinal direction as a movement command.

[0162] (8) The robotic device according to (2), wherein

[0163] The sensor sheet is composed of a pressure sensor, a reference electrode layer and a deformation layer. The pressure sensor includes a sensor electrode layer in which multiple capacitive elements are arranged in a matrix form. The reference electrode layer is connected to a reference potential, and the deformation layer is arranged between the sensor electrode layer and the reference electrode layer.

[0164] (9) The robotic device according to (2), wherein

[0165] The sensor sheet includes

[0166] a pair of pressure sensors, a reference electrode layer and a deformation layer, the pressure sensors each having a plurality of capacitive elements arranged in a matrix form in the sensor electrode layer, the reference electrode layer being connected to a reference potential, the deformation layer being disposed between the sensor electrode layer and the reference electrode layer, and

[0167] A separation layer is formed of a viscoelastic material disposed between a pair of pressure sensors.

[0168] (10) A method for controlling a robot device, comprising:

[0169] detecting sliding of the workpiece on the gripping surface based on an output of a sensor unit capable of detecting a pressure distribution on the gripping surface of a hand capable of gripping the workpiece; and

[0170] Generate control commands to change the relative position of the hand with respect to the workpiece.

[0171] (11) An apparatus comprising:

[0172] A hand having a plurality of fingers, each of the plurality of fingers having a gripping surface capable of gripping a workpiece;

[0173] a sensor unit provided in at least one of the plurality of finger parts and capable of detecting a pressure distribution on a grip surface; and

[0174] A control device is configured to detect sliding of the workpiece on the gripping surface based on the output of the sensor unit and change a relative position of the hand with respect to the workpiece.

[0175] (12) The device according to (11), wherein

[0176] The sensor unit includes an elastically deformable sensor sheet having a plurality of capacitive elements that detect pressure applied to a gripping surface, and

[0177] The control device detects sliding of the workpiece on the gripping surface based on the pressure change detected by the plurality of capacitive elements.

[0178] (13) The apparatus according to (11) or (12), wherein

[0179] The control device detects sliding of the workpiece on the gripping surface in response to the number of capacitive elements whose pressure detection values ​​change within a predetermined time satisfying a predetermined threshold.

[0180] (14) The apparatus according to (11) or (12), wherein

[0181] The control device detects the sliding of the workpiece on the gripping surface in response to a change in the pressure center position or the pressure distribution calculated based on the pressure detection values ​​of the plurality of capacitive elements within a predetermined time.

[0182] (15) The apparatus according to (11) to (14), wherein

[0183] The control device causes a movement to adjust the pressure of the workpiece from the first gripping force to a second gripping force smaller than the first gripping force and to change the relative position of the hand with respect to the workpiece from a state where the workpiece is gripped using the first gripping force.

[0184] (16) The apparatus according to (11) to (15), wherein

[0185] The control device causes a change from a first posture in which the distal end of the hand is oriented downward in the direction of gravity to a second posture in which the distal end of the hand is oriented in a direction orthogonal to the direction of gravity.

[0186] (17) The apparatus according to (11) to (16), wherein

[0187] The control device causes the workpiece to move in the longitudinal direction.

[0188] (18) The apparatus according to (12) to (17), wherein

[0189] The sensor unit includes a pressure sensor, a reference electrode layer and a deformation layer. The pressure sensor includes a sensor electrode layer in which a plurality of capacitive elements are arranged in a matrix form. The deformation layer is disposed between the sensor electrode layer and the reference electrode layer.

[0190] (19) The apparatus according to (12) to (17), wherein

[0191] The sensor sheet includes

[0192] a pair of pressure sensors, a reference electrode layer and a deformation layer, the pressure sensors each having a sensor electrode layer in which a plurality of capacitive elements are arranged in a matrix form, the deformation layer being disposed between the sensor electrode layer and the reference electrode layer, and

[0193] A separation layer includes a viscoelastic material disposed between a pair of pressure sensors.

[0194] (20) The apparatus according to (11) to (19), wherein

[0195] The device is a robotic arm with a hand at one end of the arm.

[0196] (21) A method for controlling a hand of a device, comprising:

[0197] detecting sliding of the workpiece on the gripping surface based on an output of a sensor unit capable of detecting a pressure distribution on the gripping surface of at least one finger portion of a hand capable of gripping the workpiece; and

[0198] Change the relative position of the hand with respect to the workpiece.

[0199] (22) The control method according to (21), further comprising incrementing a total slide detection frame rate counter.

[0200] (23) The control method according to (22), further comprising determining whether a total slide detection frame rate counter satisfies a threshold value.

[0201] (24) The control method according to (23), further comprising:

[0202] In response to determining that the total slide detection frame rate counter satisfies the threshold, the total slide detection frame rate counter is reset to zero.

[0203] (25) The control method according to (21) to (24), further comprising setting the gripping force for the first object to a first value.

[0204] (26) The control method according to (21) to (25), further comprising determining whether a predetermined pressure distribution curve exists.

[0205] (27) The control method according to (26), further comprising: in response to the presence of a predetermined pressure distribution curve, setting the gripping force to a second value, the second value being greater than the first value.

[0206] (28) The control method according to (26), further comprising: releasing the gripping force in response to the absence of the predetermined pressure distribution curve.

[0207] (29) The control method according to (28), further comprising: retrying to grasp the first object by setting the grasping force to the first value.

[0208] (30) A robotic device comprising:

[0209] A hand having a plurality of fingers, each of the plurality of fingers having a gripping surface capable of gripping a workpiece;

[0210] a sensor unit provided in at least one of the plurality of finger parts and capable of detecting a pressure distribution on a grip surface; and

[0211] A control device is configured to detect sliding of the workpiece on the gripping surface based on the output of the sensor unit and change a relative position of the hand with respect to the workpiece.

[0212] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations are possible depending on design requirements and other factors insofar as they fall within the scope of the appended claims or the equivalents thereof.

[0213] Reference numerals list

[0214] 3a, 3b Finger

[0215] 10 Robotic equipment

[0216] 11 Controller

[0217] 12. Drive unit

[0218] 12a Driver

[0219] 20a, 20b Sensor unit

[0220] 21 Sensor unit

[0221] 23 Separation layer

[0222] 25 Reference electrode layer

[0223] 27 Deformation Layer

[0224] 28 Sensor

[0225] 30 Sensor electrode layer

[0226] 70 Control unit

[0227] 210, 220 sensor sheet

[0228] W, C workpiece

Claims

1. A device comprising: A hand, the hand having a plurality of fingers, each of the plurality of fingers having a gripping surface capable of gripping a workpiece; a sensor unit provided in at least one of the plurality of finger portions and capable of detecting a pressure distribution on the grip surface; as well as A control device is configured to detect sliding of the workpiece on the gripping surface based on an output of the sensor unit and change a relative position of the hand with respect to the workpiece.

2. The device according to claim 1, wherein The sensor unit includes an elastically deformable sensor sheet having a plurality of capacitive elements that detect pressure applied to the gripping surface, and The control device detects sliding of the workpiece on the gripping surface based on changes in pressure detected by the plurality of capacitive elements.

3. The device according to claim 2, wherein The control device detects sliding of the workpiece on the gripping surface in response to the number of capacitive elements whose pressure detection values ​​change within a predetermined time satisfying a predetermined threshold.

4. The device according to claim 2, wherein The control device detects sliding of the workpiece on the gripping surface in response to a change in a pressure center position or a pressure distribution calculated based on the pressure detection values ​​of the plurality of capacitive elements within a predetermined time.

5. The device according to claim 1, wherein The control device causes a movement of adjusting the pressure of the workpiece from a first gripping force to a second gripping force smaller than the first gripping force and changing the relative position of the hand with respect to the workpiece from a state where the workpiece is gripped using the first gripping force.

6. The device according to claim 5, wherein The control device causes a change from a first posture in which the distal end of the hand is oriented downward in the direction of gravity to a second posture in which the distal end of the hand is oriented in a direction orthogonal to the direction of gravity.

7. The device according to claim 5, wherein The control device causes the workpiece to move in a longitudinal direction.

8. The device according to claim 2, wherein The sensor unit includes a pressure sensor, a reference electrode layer and a deformation layer. The pressure sensor includes a sensor electrode layer, the plurality of capacitive elements are arranged in a matrix form in the sensor electrode layer, and the deformation layer is disposed between the sensor electrode layer and the reference electrode layer.

9. The device according to claim 2, wherein The sensor sheet includes a pair of pressure sensors, a reference electrode layer and a deformation layer, the pressure sensors each having a sensor electrode layer, the plurality of capacitive elements being arranged in a matrix in the sensor electrode layer, the deformation layer being disposed between the sensor electrode layer and the reference electrode layer, and A separation layer includes a viscoelastic material disposed between the pair of pressure sensors.

10. The device according to claim 1, wherein The device is a robotic arm having the hand at one end of an arm.

11. A method for controlling a hand of a device, comprising: detecting sliding of the workpiece on the gripping surface based on an output of a sensor unit capable of detecting a pressure distribution on the gripping surface of at least one finger of a hand capable of gripping the workpiece; as well as The relative position of the hand with respect to the workpiece is changed. 12 . The control method according to claim 11 , further comprising incrementing a total slide detection frame rate counter. 13 . The control method according to claim 12 , further comprising determining whether the total slide detection frame rate counter satisfies a threshold.

14. The control method according to claim 13, further comprising: In response to determining that the total slide detection frame rate counter satisfies the threshold, the total slide detection frame rate counter is reset to zero. 15 . The control method according to claim 11 , further comprising setting the gripping force to a first value for the first object. 16 . The control method of claim 15 , further comprising determining whether a predetermined pressure distribution curve exists.

17. The control method according to claim 16, further comprising: In response to the presence of the predetermined pressure profile, the gripping force is set to a second value, the second value being greater than the first value.

18. The control method according to claim 16, further comprising: In response to the absence of the predetermined pressure profile, the gripping force is released.

19. The control method according to claim 18, further comprising: Reattempting to grasp the first object is performed by setting the grasping force to the first value.

20. A robotic device comprising: A hand having a plurality of fingers, each of the plurality of fingers having a gripping surface capable of gripping a workpiece; a sensor unit provided in at least one of the plurality of finger portions and capable of detecting a pressure distribution on the grip surface; as well as A control device is configured to detect sliding of the workpiece on the gripping surface based on an output of the sensor unit and change a relative position of the hand with respect to the workpiece.

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