Sensor device and robot device

Abstract

[Problem] To provide a sensor device and a robot device that can detect the distribution of shear forces. [Solution] A sensor device according to a form of the present technology includes a sensor unit, a separation layer, and a first viscoelastic body layer. The sensor unit comprises a first pressure sensor on the front side and a second pressure sensor the rear side that are opposed to each other, and detects, on the basis of pressure detection locations at which pressures are detected respectively by the first and second pressure sensors in an in-plane direction, a force in the in-plane direction. The separation layer is disposed between the first pressure sensor and the second pressure sensor and is formed of a viscoelastic material that is deformed by a load applied to the first pressure sensor. The first viscoelastic body layer is disposed on the front surface of the first pressure sensor and is formed of a viscoelastic material that can be deformed in the in-plane direction with respect to the first pressure sensor.

Description

[Technical field]

[0001] The present technology relates to a sensor device and a robot device that detect shear force. [Background technology]

[0002] In recent years, with the decline in the working population, automation of tasks using robots has been considered in various situations. In order to control the behavior of a robot hand with high precision, it is necessary to detect what forces are acting on the surface of the robot hand. Therefore, a technology is known that uses a sensor installed on the robot hand to detect shear force or slippage on the palm when the robot hand grasps an object.

[0003] For example, Patent Document 1 discloses a sensor device in which a viscoelastic body that deforms due to an external load is sandwiched between two pressure detection units. This sensor device is configured to detect a shear force applied to the viscoelastic body by utilizing the difference between the pressure center position detected by one pressure detection unit and the pressure center position detected by the other pressure detection unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-34742 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, in order to highly control the behavior of a robot hand gripping an object, it is preferable to be able to detect which part and in which direction a multi-axial force acting on the robot hand is acting on the gripping surface of the robot hand. However, if an attempt is made to detect a multi-axial force by combining multiple elements each having a single detection axis, the sensor device will inevitably become larger. In addition, in the sensor device described in Patent Document 1, the viscoelastic body sandwiched between the two pressure detection units is deformed by the effect of the shear force, so that it is not possible to detect the in-plane distribution of the shear force on the gripping surface.

[0006] In view of the above circumstances, an object of the present technology is to provide a sensor device and a robot device capable of detecting shear force distribution. [Means for solving the problem]

[0007] A sensor device according to an embodiment of the present technology includes a sensor unit, a separation layer, and a first viscoelastic layer. The sensor unit includes a first pressure sensor on the front side and a second pressure sensor on the back side which face each other, and detects a force in the in-plane direction based on a pressure detection position in the in-plane direction by the first pressure sensor and the second pressure sensor. The isolation layer is disposed between the first pressure sensor and the second pressure sensor and is made of a viscoelastic material that deforms due to a load applied to the first pressure sensor. The first viscoelastic layer is disposed on a surface of the first pressure sensor and is made of a viscoelastic material that is deformable in the in-plane direction relative to the first pressure sensor.

[0008] The first viscoelastic layer may have a thickness equal to or less than a thickness of the separation layer.

[0009] The hardness of the first viscoelastic layer may be equal to or less than the hardness of the separation layer.

[0010] An area of ​​the first viscoelastic layer relative to the sensor portion may be equal to or smaller than an area of ​​the separation layer relative to the sensor portion.

[0011] The first pressure sensor and the second pressure sensor may each have a sensor electrode layer having a plurality of capacitive elements arranged in the in-plane direction, a reference electrode layer, and a deformation layer arranged between the sensor electrode layer and the reference electrode layer.

[0012] The plurality of capacitive elements in the first pressure sensor may be arranged in a matrix at a first interval within a plane of the sensor electrode layer in the first pressure sensor, in which case the plurality of capacitive elements in the second pressure sensor are arranged in a matrix at a second interval larger than the first interval within a plane of the sensor electrode layer in the second pressure sensor.

[0013] The first viscoelastic layer may be made of a viscoelastic material that is more easily deformed in the in-plane direction than the deformation layer.

[0014] The sensor device may further include a waterproof protective member that covers at least the periphery of the deformation layer. The protective member may be configured to further cover the periphery of the spacing layer and / or the first viscoelastic layer.

[0015] The sensor device may further include a second viscoelastic layer, the second viscoelastic layer being disposed on a rear surface of the second pressure sensor and being made of a viscoelastic material that is deformable in the in-plane direction relative to the second pressure sensor.

[0016] The second viscoelastic layer may have a thickness equal to or less than that of the first viscoelastic layer.

[0017] At least one of the separation layer and the first viscoelastic layer may have a plurality of columns formed by voids and extending in a direction perpendicular to the in-plane direction.

[0018] The void portion may be provided in the form of a groove that does not penetrate the separation layer or the first viscoelastic layer in a direction perpendicular to the in-plane direction.

[0019] The void portion may be provided in the form of a hole penetrating the separation layer or the first viscoelastic layer in a direction perpendicular to the in-plane direction.

[0020] The sensor unit may further include a calculation element that calculates a distribution of shear force in an in-plane direction based on pressure detection positions in the in-plane direction by the first pressure sensor and the second pressure sensor.

[0021] The calculation element may be configured to determine the presence or absence of shear force based on whether or not a deviation amount in the in-plane direction between a first pressure center position detected by the first pressure sensor and a second pressure center position detected by the second pressure sensor reaches a predetermined value or more.

[0022] A robot device according to an embodiment of the present technology includes a sensor device. The sensor device includes a sensor portion, a separation layer, and a viscoelastic layer. The sensor unit includes a first pressure sensor on the front side and a second pressure sensor on the back side which face each other, and detects a force in the in-plane direction based on a pressure detection position in the in-plane direction by the first pressure sensor and the second pressure sensor. The isolation layer is disposed between the first pressure sensor and the second pressure sensor and is made of a viscoelastic material that deforms due to a load applied to the first pressure sensor. The viscoelastic layer is disposed on a surface of the first pressure sensor and is made of a viscoelastic material that is deformable in the in-plane direction relative to the first pressure sensor. [Brief description of the drawings]

[0023] [Figure 1] 1 is a perspective view showing a main part of a robot device including a sensor device according to a first embodiment of the present technology. FIG. [Diagram 2] FIG. 2 is a side cross-sectional view of the sensor device. [Diagram 3] FIG. 2 is a plan view showing an electrode layer in the sensor device. [Figure 4] 3 is a plan view of a main portion showing one configuration example of a sensing unit in the sensor device. FIG. [Diagram 5] 11 is an explanatory diagram showing a state when a load is applied vertically downward to the sensor unit. FIG. [Figure 6] 10 is an explanatory diagram showing a state in which a shear force is applied in an in-plane direction to the sensor unit while a load is applied in a vertical direction. FIG. [Figure 7] 13 is a flowchart illustrating a calculation process of a shear force. [Figure 8] 5 is a schematic side view illustrating an operation of the sensor unit. FIG. [Figure 9] 11A and 11B are schematic side views illustrating the operation of a sensor device not including a first viscoelastic layer. [Figure 10] 4 is a schematic side view illustrating the operation of a sensor device including a first viscoelastic layer. FIG. [Figure 11] 4 is a schematic side view illustrating the operation of a sensor device including a first viscoelastic layer. FIG. [Figure 12] 5 is a flowchart showing an example of a processing procedure executed by a computing element in the sensor device. [Figure 13] FIG. 4 is a graph showing the relationship between the occupation area of ​​a first viscoelastic layer and the minimum load sensitivity. [Figure 14] 4 is a schematic diagram showing an example of the layout of a first viscoelastic layer relative to a separation layer in the sensor device. FIG. [Figure 15] 4 is a schematic diagram showing an example of a relationship between a sensing portion of a first pressure sensor and a sensing portion of a second pressure sensor in the sensor device. FIG. [Figure 16] FIG. 11 is a side cross-sectional view showing a configuration of a sensor device according to a second embodiment of the present technology. [Figure 17] FIG. 4 is a rear view of the separation layer in the sensor device. [Figure 18] 5A to 5C are diagrams illustrating examples of shapes of a separation layer in the sensor device. [Figure 19]10 is a diagram showing the isolating layer in the sensor device as viewed from the back side, illustrating the patterns of the shape of the column portion as viewed in plan; FIG. [Figure 20] FIG. 11 is a side cross-sectional view showing a configuration of a sensor device according to a third embodiment of the present technology. [Figure 21] 1 is a block diagram showing a configuration of a robot device including a sensor device according to a first embodiment. [Figure 22] FIG. 4 is a diagram illustrating a processing procedure executed in a control unit of the robot device. [Figure 23] 11 is a diagram showing the relationship between the pressing force applied to the sensor device and the gripping force of the hand portion. FIG. [Figure 24] 6 is a flowchart showing a processing procedure of an object grasping operation by the robot device. [Diagram 25] 6 is a flowchart showing a processing procedure for an object moving operation performed by the robot device. [Figure 26] 6 is a flowchart showing a processing procedure of an object removal operation performed by the robot device. [Figure 27] 4A to 4C are side views of the main parts showing various configuration examples of the hand unit. [Figure 28] 1A to 1C are diagrams illustrating an example of application of the present technology to a two-fingered parallel plate gripper. [Figure 29] FIG. 13 is a perspective view illustrating a sensor device according to a fifth embodiment of the present technology. [Diagram 30] 4 is a schematic plan view parallel to the XY plane showing an example of division of detection areas of a first pressure sensor and a second pressure sensor in the sensor device. FIG. [Diagram 31] 5A to 5C are schematic diagrams showing pressure distributions in the detection areas of the first pressure sensor. [Diagram 32] 5A to 5C are schematic diagrams showing pressure distributions in the detection areas of the first pressure sensor. [Diagram 33] 4A to 4C are diagrams illustrating the in-plane distribution of shear force in each detection region. [Diagram 34] 13 is a flowchart showing a calculation process of a shear force in each detection area. [Diagram 35]13 is a flowchart showing a calculation process of a shear force in each detection area. [Diagram 36] 1A and 1B are diagrams illustrating a method for measuring the minimum detection sensitivity of a sensor device. [Figure 37] FIG. 4 is a side cross-sectional view showing a modified example of the configuration of the sensor device according to the first embodiment. [Figure 38] 1A and 1B are a schematic cross-sectional side view and a schematic plan view of a sensor device equipped with a protective member. [Figure 39] FIG. 4 is a schematic cross-sectional side view illustrating an operation of the sensor device. [Diagram 40] 11 is a schematic cross-sectional side view showing another configuration example of a sensor device provided with a protective member. FIG. [Diagram 41] 11 is a schematic cross-sectional side view showing another configuration example of a sensor device provided with a protective member. FIG. [Diagram 42] 11 is a schematic cross-sectional side view showing another configuration example of a sensor device provided with a protective member. FIG. [Diagram 43] 11A and 11B are a schematic cross-sectional side view and a schematic plan view showing another configuration example of a sensor device provided with a protective member. [Diagram 44] FIG. 11 is a schematic cross-sectional side view showing another configuration example of the pressure sensor. [Diagram 45] FIG. 2 is a schematic cross-sectional side view showing the pressure sensor provided with a protective member. [Figure 46] 11 is a schematic cross-sectional side view showing another configuration example of a pressure sensor provided with a protective member. FIG. [Figure 47] 11 is a schematic cross-sectional side view showing another configuration example of a pressure sensor provided with a protective member. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0025] <First embodiment> 1 is a perspective view of a main part of a robot device 10 including a sensor device 20 according to a first embodiment of the present technology. As shown in FIG. 1, the robot device 10 has an arm unit 1, a wrist unit 2, and a hand unit 3.

[0026] The arm unit 1 has multiple joints 1a, and the hand unit 3 can be moved to any position by driving the joints 1a. The wrist unit 2 is rotatably connected to the arm unit 1, and the hand unit 3 can be rotated by the rotation of the wrist unit 2.

[0027] The hand unit 3 has two fingers 3a facing each other, and can grasp an object between the two fingers 3a by driving the two fingers 3a. Note that, although the hand unit 3 has two fingers in the example shown in Fig. 1, the number of fingers 3a can be changed appropriately to three, four or more.

[0028] A sensor device 20 is provided on each of the opposing surfaces of the two finger portions 3a. The sensor device 20 has a pressure detection surface and is capable of detecting a force applied in a direction perpendicular to the pressure detection surface (Z-axis direction) and is also capable of detecting a force applied in the in-plane directions of the pressure detection surface (X-axis direction and Y-axis direction). In other words, the sensor device 20 is a three-axis sensor capable of detecting forces corresponding to three axial directions. The configuration of the sensor device 20 will be described later with reference to FIG. 2 etc.

[0029] The robot device 10 is driven under the control of a control device (not shown). The control device may be a dedicated device for the robot device 10, or may be a general-purpose device. When the control device is a general-purpose device, the control device may be, for example, a PC (Personal Computer), a mobile phone (including a smartphone), a server device on a network, or the like.

[0030] The control device includes a control unit, a storage unit, etc. The control unit is, for example, a CPU (Central Processing Unit), and controls the driving of each unit in the robot device 10 based on a program stored in the storage unit. Typically, the control unit acquires force information in three axial directions detected by the sensor device 20, and controls the driving of the hand unit 3 based on this force information so as to stably grip an object with an appropriate gripping force.

[0031] The storage unit includes a non-volatile memory for storing various programs and data required for processing by the control unit, and a volatile memory used as a working area for the control unit. The various programs may be read from a portable recording medium such as a semiconductor memory, or may be downloaded from a server device on a network.

[0032] [Sensor device] Fig. 2 is a cross-sectional side view of the sensor device 20. Fig. 3 is a plan view showing the electrode layer 30 in the sensor device 20.

[0033] In each figure of the sensor device 20, the X-axis direction and the Y-axis direction are parallel to the sensing surface, which is the pressure detection surface of the sensor device 20 (hereinafter also referred to as the in-plane direction), and the Z-axis direction is perpendicular to the sensing surface (hereinafter also referred to as the vertical direction). Note that in Fig. 2, the upper side corresponds to the front side to which an external force is applied, and the lower side corresponds to the opposite back side.

[0034] 2 and 3, the sensor device 20 has a rectangular, flat plate shape as a whole in a plan view. Typically, the shape of the sensor device 20 in a plan view may be appropriately set according to the shape of the location where the sensor device 20 is disposed, and the shape of the sensor device 20 in a plan view is not particularly limited. For example, the shape of the sensor device 20 in a plan view may be a polygon other than a rectangle, a circle, an ellipse, or the like.

[0035] The sensor device 20 includes a sensor section 21 including a first pressure sensor 22a on the front side and a second pressure sensor 22b on the back side, and a separation layer 23 disposed between the first pressure sensor 22a and the second pressure sensor 22b. In other words, the sensor device 20 has a structure in which the second pressure sensor 22b, the separation layer 23, and the first pressure sensor 22a are stacked in this order from the bottom in the vertical direction. In the following description, the two pressure sensors 22a and 22b will be simply referred to as pressure sensors 22 unless they are to be particularly distinguished from one another.

[0036] The sensor device 20 further includes a viscoelastic layer 81 (first viscoelastic layer) disposed on the upper side (surface side) of the first pressure sensor 22a. The viscoelastic layer 81 transmits the external force to the sensor unit 21 while deforming in response to the external force, as described below.

[0037] The viscoelastic layer 81 is covered with a surface layer 24. The surface layer 24 is made of any material, such as a flexible plastic film, a woven fabric, a nonwoven fabric, rubber, or leather. The surface layer 24 constitutes a contact surface that comes into contact with an object when the robot device 10 grasps the object with the fingers 3a, and also functions as a pressure detection surface that receives a load (a reaction force to the grasping force) from the object during the grasping operation. Therefore, the surface layer 24 preferably has a surface property that can obtain a predetermined or higher friction force between the surface layer 24 and the object in order to stably grasp the object.

[0038] (Sensor section) Next, the sensor unit 21 will be described in detail. The sensor unit 21 detects a force (shear force Fs) applied to the sensor device 20 in an in-plane direction based on the pressure center position (pressure detection position) in the in-plane direction by the first pressure sensor 22a and the pressure center position (pressure detection position) in the in-plane direction by the second pressure sensor 22b. The sensor unit 21 also detects a force (load Fz) applied to the sensor device 20 from above in a vertical direction based on the pressure value detected by the first pressure sensor 22a.

[0039] The sensor unit 21 may detect a force applied from above in the vertical direction to the sensor device 20 based on two values, that is, the pressure value detected by the first pressure sensor 22a and the pressure value detected by the second pressure sensor 22b. That is, typically, the sensor unit 21 may be configured to detect a force applied from above in the vertical direction based on the pressure value detected by at least the first pressure sensor 22a of the first pressure sensor 22a and the second pressure sensor 22b.

[0040] The first pressure sensor 22a and the second pressure sensor 22b are arranged to face each other in the vertical direction. The first pressure sensor 22a has a structure in which a sensor electrode layer 30a, a deformation layer 27a, and a reference electrode layer 25a are laminated in this order from the bottom in the vertical direction via adhesive layers (not shown). The second pressure sensor 22b has a structure in which a reference electrode layer 25b, a deformation layer 27b, and a sensor electrode layer 30b are laminated in this order from the bottom in the vertical direction, with adhesive layers (not shown) interposed between them.

[0041] As will be understood from the description herein, the first pressure sensor 22a and the second pressure sensor 22b are arranged so that the layer arrangement is upside down. Therefore, the first pressure sensor 22a and the second pressure sensor 22b are both configured so that the sensor electrode layer 30 is arranged on the separation layer 23 side. The first pressure sensor 22a and the second pressure sensor 22b are basically configured in the same way except that they are upside down. The first pressure sensor 22a and the second pressure sensor 22b may be arranged so that the layer arrangement is the same upside down.

[0042] In the following description, when there is no particular distinction between the two sensor electrode layers 30a, 30b, they are simply referred to as sensor electrode layer 30, and when there is no particular distinction between the two deformation layers 27a, 27b, they are simply referred to as deformation layer 27. When there is no particular distinction between the two reference electrode layers 25a, 25b, they are simply referred to as reference electrode layer 25.

[0043] The sensor electrode layer 30 is composed of a flexible printed circuit board or the like. As shown in Fig. 3, the sensor electrode layer 30 has a main body 36 that is rectangular in plan view, and an extraction portion 37 that extends outward from the main body 36. Note that the shape of the sensor electrode layer 30 in plan view is not limited to a rectangular shape and can be changed as appropriate.

[0044] The drawer section 37 is equipped with a calculation element 70 that calculates a force in an in-plane direction based on information on the pressure detected by the pressure sensor 22. The calculation element 70 is typically a computer including a CPU (Central Processing Unit) and is configured with an integrated circuit such as an IC chip. The calculation element 70 is electrically connected to the first pressure sensor 22a and the second pressure sensor 22b, and includes a memory that stores a program and various parameters for executing a processing procedure (described later) that calculates the distribution of shear force in the in-plane direction based on the pressure detection positions in the in-plane direction by the first pressure sensor 22a and the second pressure sensor 22b. The calculation element 70, together with the pressure sensor 22, constitutes a part of the sensor section 21.

[0045] The sensor electrode layer 30 has a flexible substrate 29 and a plurality of sensing sections 28 provided on the surface of the substrate 29 or inside the substrate 29 . The material of the base material 29 is, for example, a polymer resin such as polyethylene terephthalate, polyimide, polycarbonate, or acrylic resin. The sensing units 28 are regularly arranged in a matrix at predetermined intervals in both the vertical and horizontal directions (vertical: Y-axis direction, horizontal: X-axis direction). In the example shown in Fig. 3, the number of sensing units 28 is 5 x 5 (vertical x horizontal), making a total of 25. The number of sensing units 28 can be changed as appropriate. The number of sensing units 28 may be the same or different in the sensor electrode layers 30a, 30b.

[0046] The sensing unit 28 is composed of a capacitive element capable of detecting a change in distance from the reference electrode layer 25 as a change in capacitance. The sensing unit 28 includes a comb-shaped pulse electrode 281 and a comb-shaped sense electrode 282, as shown in FIG. 4, for example. The comb-shaped pulse electrode 281 and the comb-shaped sense electrode 282 are arranged so that their comb teeth face each other, and each sensing unit 28 is composed of an area (node ​​area) in which one comb tooth is inserted between the other comb tooth. Each pulse electrode 281 is connected to a wiring portion 281a extending in the Y-axis direction, and each sense electrode 281 is connected to a wiring portion 282a extending in the X-axis direction. The wiring portions 281a are arranged in the X-axis direction on the front surface of the base material 29, and the wiring portions 282a are arranged in the Y-axis direction on the back surface of the base material 29. Each sense electrode 282 is electrically connected to the wiring portion 282a via a through hole 283 provided in the base material 29. The sensor electrode layer 30 may have a ground line. The ground line is provided, for example, on the outer periphery of the sensor electrode layer 30 or in a portion where the wiring portions 281a and 282a run in parallel.

[0047] The method of the sensing unit 28 is not limited to the above example, and any method may be used. For example, the sensor electrode layer 30 may be formed of a laminate of a first electrode sheet having a lattice-shaped first electrode pattern extending in the X-axis direction and a second electrode sheet having a lattice-shaped second electrode pattern extending in the Y-axis direction. In this case, the sensing unit 28 is formed at the intersection of the first electrode pattern and the second electrode pattern.

[0048] 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 and has a thickness of, for example, about 0.05 μm to 0.5 μm. Examples of the material for the reference electrode layer 25 include inorganic conductive materials, organic conductive materials, and conductive materials containing both inorganic and organic conductive materials.

[0049] 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. The reference electrode layer 25 may be made of a thin metal plate such as stainless steel or aluminum, conductive fibers, or conductive nonwoven fabric. The reference electrode layer 25 may be formed on a plastic film by a method such as deposition, sputtering, adhesion, or coating.

[0050] The reference electrode layer 25 constituting the second pressure sensor 22b is attached to the surface of the finger portion 3a of the robot device 10 via a support 40. The support 40 is typically an adhesive layer such as a double-sided tape.

[0051] The deformation layer 27 is disposed between the sensor electrode layer 30 and the reference electrode layer 25. The deformation layer 27 has a thickness of, for example, about 100 μm to 1000 μm.

[0052] The deformation layer 27 is configured to be elastically deformable in response to an external force. When an external force is applied to the sensor device 20 in a vertical direction, the deformation layer 27 elastically deforms in response to the external force, and the reference electrode layer 25 approaches the sensor electrode layer 30. At this time, the capacitance between the pulse electrode 281 and the sense electrode 282 in the sensing unit 28 changes, so that the sensing unit 28 can detect this change in capacitance as a pressure value.

[0053] The thickness of the deformation layer 27 is, for example, greater than 100 μm and less than or equal to 1000 μm, and the weight per unit area of ​​the deformation layer 27 is, for example, 50 mg / cm 2 By setting the thickness and basis weight of the deformation layer 27 within this range, the detection sensitivity of the pressure sensor 22 in the vertical direction can be improved.

[0054] The lower limit of the thickness of deformation layer 27 is not particularly limited as long as it is greater than 100 μm, but this lower limit may be, for example, 150 μm or more, 200 μm or more, 250 μm or more, 300 μm or more, etc. Furthermore, the upper limit of the thickness of deformation layer 27 is not particularly limited as long as it is 1000 μm or less, but this upper limit may be, for example, 950 μm or more, 900 μm or less, 850 μm or less, 800 μm or less, etc.

[0055] The deformation layer 27 may be formed of a patterned structure including, for example, a columnar structure, and may have a variety of patterns, such as a matrix, stripe, mesh, radial, geometric, or spiral pattern.

[0056] (separation layer) The separation layer 23 is fixed between the first pressure sensor 22a and the second pressure sensor 22b via an adhesive layer (not shown). The separation layer 23 is made of a viscoelastic material that deforms due to a load applied to the first pressure sensor 22a via the surface layer 24 and the viscoelastic layer 81. Examples of this type of viscoelastic material include silicone gel, urethane gel, synthetic rubber, and foam. The thickness of the separation layer 23 is not particularly limited and is, for example, 1000 μm or more and 5000 μm or less, and is set according to the thickness of the viscoelastic layer 81, etc. The planar shape of the separation layer 23 is not particularly limited and is typically rectangular or circular.

[0057] (Viscoelastic layer) The viscoelastic layer 81 is disposed between the surface layer 24 and the first pressure sensor 22a (on the surface of the first pressure sensor 22a) via an adhesive layer (not shown). The viscoelastic layer 81 is made of a viscoelastic material that is deformable in an in-plane direction relative to the first pressure sensor 22a. Examples of this type of viscoelastic material include silicone gel, urethane gel, synthetic rubber, and foam. The thickness of the viscoelastic layer 81 is not particularly limited and is set, for example, to 1000 μm or more and 5000 μm or less depending on the thickness of the isolation layer 23, etc.

[0058] As described below, the viscoelastic layer 81 is provided to separate the multi-axial forces acting on the surface layer 24 in the in-plane direction and detect the shear force distribution (also called shear distribution or multi-point shear) in the plane of the surface layer 24. Therefore, the viscoelastic layer 81 is preferably made of a viscoelastic material that is more easily deformed in the in-plane direction than the deformation layer 27a constituting the first pressure sensor 22a. The detection principle of the shear force Fs in the sensor unit 21 will be described below.

[0059] [Detection principle of shear force Fs in the sensor] Fig. 5 is a diagram showing a model of a state when a load Fz is applied vertically downward to the sensor unit 21. Fig. 6 is a diagram showing a model of a state when a shear force Fs is applied in an in-plane direction to the sensor unit 21 in a state where a load Fz in the vertical direction is applied to the sensor unit 21. In Figs. 5 and 6, the contour lines of the detected pressure are shown by dashed circles.

[0060] 5, when a load Fz is applied vertically downward to the sensor unit 21, the pressure center position P in the in-plane direction detected by the first pressure sensor 22a coincides with the pressure center position Q in the in-plane direction detected by the second pressure sensor 22b. Note that the pressure center position means the position in the in-plane direction corresponding to the highest pressure in the detected pressure distribution.

[0061] On the other hand, as shown in Figure 6, when a load Fz is applied to the sensor part 21 in the vertical downward direction while a shear force Fs is applied in the in-plane direction, the pressure center position P in the in-plane direction detected by the first pressure sensor 22a does not coincide with the pressure center position Q in the in-plane direction detected by the second pressure sensor 22b.

[0062] The separation layer 23 is distorted according to the shear force Fs applied in the in-plane direction, and at this time, the separation layer 23 generates a shear stress σ corresponding to the shear force Fs. Here, the rigidity modulus of the separation layer 23 is G, and the thickness of the separation layer 23 is t. In addition, the difference between the pressure center position P of the first pressure sensor 22a and the pressure center position Q of the second pressure sensor 22b (hereinafter also referred to as the coordinate movement amount) is d (= t × tan θ). In this case, the shear stress σ (shear force Fs) is expressed by the following formula (1). σ = Fs = G × d (1)

[0063] Here, the modulus of rigidity G of the separation layer 23 is known on the right side of the equation. Therefore, by determining the coordinate shift amount d, which is the difference between the pressure center position P in the in-plane direction of the first pressure sensor 22a and the pressure center position Q in the in-plane direction of the second pressure sensor 22b, the shear stress Fs, i.e., the force in the in-plane direction, can be detected.

[0064] 7 is a flowchart illustrating the shear force calculation process (F10). This process can be executed by the processor 70, for example. When a load is applied to the sensor unit 21, it is determined whether or not there is any sensing unit 28 (node) of the second pressure sensor 22b whose capacitance change amount is equal to or greater than the threshold. If there is at least one sensing unit 28 whose capacitance change amount is equal to or greater than the threshold (Yes in step 101), the upper limit (e.g., position P) and lower limit (e.g., position Q) of the pressure center position are calculated based on the outputs of the first pressure sensor 22a and the second pressure sensor 22b (step 102). Then, based on the coordinate movement amount obtained from these pressure center positions, the shear force is calculated by the above formula (1) (step 103).

[0065] [Function of the sensor device] Incidentally, the force acting on the sensing surface of the sensor device 20 is not limited to a single load Fz or shear force Fs, and these may act simultaneously. However, if an attempt is made to detect the load Fz and the shear force Fs using only the sensor unit 21, it is difficult to detect the shear force distribution in the in-plane direction because the load Fz and the shear force cannot be separated.

[0066] As an example, consider the case where two taps Wa, Wb act simultaneously on the sensor device 20, as shown in Fig. 8. A load Fz is applied to each tap Wa in a direction perpendicular to the sensor unit 21, and a shear force Fs is applied to only one tap Wa in an arbitrary direction (in the illustrated example, the direction toward the tap Wb). The isolating layer 23 is deformed in an in-plane direction by the shear force Fs applied to the tap Wa.

[0067] Here, when the tapping elements Wa, Wb act directly on the sensor section 21 without the viscoelastic layer 81, as shown in Fig. 9, the tapping element Wa receives a shear force Fs acting thereon, and the first pressure sensor 22a on the front side is likely to move integrally with the separating layer 23. In other words, the first pressure sensor 22a moves a predetermined amount (X1 in the illustrated example) in the in-plane direction relative to the second pressure sensor 22b, following the deformation of the separating layer 23.

[0068] As a result, the coordinate movement amount X2a (corresponding to d above) in the shear area (directly below the tap Wa) and the coordinate movement amount X2b (corresponding to d above) in the non-shear area (directly below the tap Wb) become equal in magnitude. In other words, even though only the vertical load Fs acts on the tap Wb, it is erroneously detected as if the shear force Fs is acting (see step 103 in FIG. 7). In this way, since the sensor unit 21 alone cannot separate the pressing forces of the taps Wa and Wb, it is very difficult to detect the shear force distribution in the in-plane direction.

[0069] In contrast, the sensor device 20 of this embodiment has a viscoelastic layer 81 on the first pressure sensor 22a, so that the movement of the first pressure sensor 22a caused by the shear force Fs acting on the tap Wa can be suppressed. Figures 10 and 11 are schematic diagrams showing the relationship between the sensor device 20 and the taps Wa, Wb, where Figure 10 shows the state before the shear force Fs is applied to the tap Wa, and Figure 11 shows the state after the shear force Fs is applied to the tap Wa.

[0070] As shown in Fig. 10, the tapping elements Wa and Wb face the first pressure sensor 22a via the viscoelastic layer 81. In this state, when a shear force Fs is applied to the tapping element Wa as shown in Fig. 11, the viscoelastic layer 81 and the separation layer 23 are deformed in the in-plane direction. At this time, the first pressure sensor 22a is deformed by an amount corresponding to the deformation amount of the viscoelastic layer 81, but the deformation is localized, and the deformation of the viscoelastic body 81 in the area directly below the tapping element Wb is suppressed. In addition, since the first pressure sensor 22a is deformed in accordance with the deformation of the viscoelastic layer 81, the amount of movement X1 in the in-plane direction is smaller than when there is no viscoelastic layer 81 (Fig. 8).

[0071] As a result, the deformation in the in-plane direction in the separation layer 23 is large in the detection area of ​​the tap Wa and small in the detection area of ​​the tap Wb, so the coordinate movement amount X2b in the non-shear area is kept small compared to the coordinate movement amount X2a in the shear area. This makes it possible to separate the pressing forces of the taps Wa and Wb from each other, and therefore makes it possible to detect the in-plane distribution of the shear force acting on the sensor unit 21.

[0072] FIG. 12 is a flowchart showing an example of a processing procedure (F20) executed by the arithmetic element 70 in the sensor device 20 of this embodiment.

[0073] When a load is applied to the sensor device 20, the calculation element 70 judges whether or not there is any sensing unit 28 whose capacitance change amount is equal to or greater than the threshold among the multiple sensing units 28 (nodes) of the second pressure sensor 22b on the lower layer side. If there is at least one sensing unit 28 whose capacitance change amount is equal to or greater than the threshold (Yes in step 201), the calculation element 70 calculates the upper limit (e.g., position P) and lower limit (e.g., position Q) of the pressure center position based on the outputs of the first pressure sensor 22a and the second pressure sensor 22b (step 202). The processing up to this point is the same as the processing procedure described with reference to FIG. 7.

[0074] Next, the calculation element 70 judges whether the coordinate shift amount of the pressing force is equal to or greater than a predetermined value (step 203). The coordinate shift amount corresponds to the difference d between the pressure center position P of the first pressure sensor 22a and the pressure center position Q of the second pressure sensor 22b, as described above. When the coordinate shift amount is equal to or greater than the predetermined value (Yes in step 203), the calculation element 70 judges that a significant shear force (or slippage) is occurring on the sensing surface, and calculates the shear force by the above formula (1) (step 204).

[0075] On the other hand, when the coordinate movement amount is less than the predetermined value (No in step 203), the calculation element 70 determines that no significant shear force is occurring on the sensing surface (step 205). In this case, the calculation element 70 stores the initial value of the pressure center position P of the first pressure sensor 22a on the upper layer side (step 206). The above procedure is repeatedly executed at a predetermined cycle, whereby the change over time in the pressing force applied to the sensor device 2 is detected.

[0076] The predetermined value in step 203 can be set arbitrarily depending on the physical properties such as the thickness, area or viscoelasticity of the separation layer 23 and the viscoelastic layer 81, the ease of deformation of the first pressure sensor 22a, the arrangement pitch of the sensing portions 28 in each of the pressure sensors 22a, 22b, etc. The predetermined value is preferably set to a value at which it can be determined that substantially no shear force is generated at the detection point of the tap Wb due to the shear force applied by the tap Wa.

[0077] The computing element 70 outputs the calculated value of the shear force calculated in step 204 or the initial value of the pressure center position P stored in step 206 to the control unit of the robot device 10. The computing element 70 controls the driving of the arm unit 1, the wrist unit 2, and the hand unit 3 of the robot device 10.

[0078] According to this embodiment, the presence or absence of shear is detected based on the deformation amount of the separation layer 23, and the shear sensitivity of each pressed portion is detected based on the deformation amount of the viscoelastic body 81, thereby making it possible to detect the shear force distribution on the sensing surface. In this way, by adding the step of determining the presence or absence of shear (step 203), it is possible to individually determine whether a significant shear force is acting at each pressed point, and therefore it is possible to appropriately determine whether the force acting at the pressed point is a shear force or a normal load, thereby enabling the detection of the shear force distribution to be performed with high accuracy.

[0079] As an evaluation index for the shear force distribution, the ratio of the deformation amounts (mutual interference) at each pressing point of the separating layer 23 and the viscoelastic layer 81 may be referred to. For example, in Fig. 11, under the conditions that the diameter of the contact surface of the tapping elements Wa, Wb is 6 mm, the center-to-center distance between the tapping elements Wa, Wb is 12 mm, the magnitude of the vertical load Fz is 5 N, and the movement amount of the tapping element Wa is 3 mm, the coordinate movement amount X1 of the first pressure sensor 22a in the upper layer and the difference X2 in the pressure center position between the first and second pressure sensors 22a, 22b are measured for each pressing point. The results are shown in Table 1.

[0080] Here, an example is shown in which the magnitudes of X1 and X2 are calculated using the processing procedure F20 shown in Fig. 12. Note that the results shown in Table 1 are merely examples, and vary depending on the thickness and physical properties of the isolation layer 23 and the viscoelastic layer 81, the node pitch of the pressure sensor 22 (the arrangement pitch of the sensing portions 28), etc.

[0081] [Table 1]

[0082] The coordinate shift amount X1 corresponds to the in-plane deformation amount of the viscoelastic layer 81, and the difference X2 corresponds to the in-plane deformation amount of the isolation layer 23. The ratio Wb / Wa was calculated as the mutual interference for each of X1 and X2, and the ratio was approximately 5% for X1 and approximately 62% for X2. This indicates that the presence of the viscoelastic layer 81 reduces the mutual interference of the pressing forces between the pressing points (Wa, Wb), and this reduction effect also reduces the mutual interference of the pressing forces between the pressing points in the isolation layer 23.

[0083] The smaller the mutual interference value at X2, the higher the detection resolution for the shear force distribution can be obtained. The mutual interference at X2 is, for example, preferably 65% ​​or less, more preferably 50% or less, and most preferably 10% or less. Therefore, by using the mutual interference as an evaluation index to select the thickness, area, and physical properties of the separation layer 23 and the viscoelastic layer 81, the resolution of the shear force distribution can be set to a desired value. In addition, the mutual interference can be used as a control index to set a predetermined value in step 203 of process procedure F20 (FIG. 12).

[0084] [Relationship between the isolation layer and the viscoelastic layer, etc.] The thickness of the viscoelastic layer 81 is not particularly limited, but is preferably equal to or less than the thickness of the separation layer 23, and more preferably less than the thickness of the separation layer 23. If the thickness of the viscoelastic layer 81 is greater than the thickness of the separation layer 23, the mutual interference between the pressing points in the separation layer 23 tends to be further alleviated, but it becomes difficult to ensure the desired minimum load sensitivity of the sensor device 20. For example, when the thickness of the separation layer 23 is 4 mm, the thickness of the viscoelastic layer 81 is 4 mm or less, more preferably 2 mm or less.

[0085] The hardness of the viscoelastic layer 81 is not particularly limited, but is preferably equal to or less than the hardness of the separation layer 23, and more preferably less than the hardness of the separation layer 23. If the hardness of the viscoelastic layer 81 is too high, the sensitivity to the vertical load increases, but the mutual interference at each pressing point also tends to increase. The hardness is, for example, 60° or more in hardness using the penetration as an index (JIS K2207) and 10° or less in Shore A hardness.

[0086] The occupation area of ​​the viscoelastic layer 81 (the area relative to the sensor section 21 as viewed from a direction perpendicular to the sensing surface; the same applies below) is not particularly limited, but is preferably equal to or smaller than the occupation area of ​​the separation layer 23, and more preferably smaller than the occupation area of ​​the separation layer 23. The smaller the occupation area of ​​the viscoelastic layer 81 is compared to the occupation area of ​​the separation layer 23, the smaller the minimum load sensitivity of the sensor device 20 can be.

[0087] 13 is a schematic diagram showing the relationship between the occupation area of ​​the viscoelastic layer 81 and the minimum load sensitivity. There is a nearly linear relationship between the occupation area of ​​the viscoelastic layer 81 and the minimum load sensitivity. Therefore, when the object to be grasped is relatively light, it is preferable that the occupation area of ​​the viscoelastic layer 81 is small.

[0088] The planar shape of the viscoelastic layer 81 is not limited to a rectangle, and may be any shape such as a circle, a trapezoid, a triangle, a parallelogram, etc. The viscoelastic layer 81 may be formed by dividing it into a plurality of regions. Fig. 14 shows a schematic diagram of a layout example of the viscoelastic layer 81 relative to the separation layer 23.

[0089] Furthermore, the arrangement intervals of the sensing parts 28 (28a, 28b) of the first pressure sensor 22a and the second pressure sensor 22b may be different from each other. In general, the smaller the arrangement interval of the sensing parts 28, the higher the detection resolution of the pressure distribution. Also, as shown in FIG. 15, the arrangement interval (first interval) of the sensing parts 28a of the first pressure sensor 22a is made smaller than the arrangement interval (second interval) of the sensing parts 28b of the second pressure sensor 22b, thereby improving the detection sensitivity of the shear force. Also, the initial capacitance (capacitance before load detection) of the sensing parts 28 may be different between the first pressure sensor 22a and the second pressure sensor 22b.

[0090] 15, the number of sensing units 28a arranged on one side is 9 vertically×9 horizontally, and the number of sensing units 28b arranged on the other side is 6 vertically×6 horizontally, but this is not limited thereto, and for example, one sensing unit 28a may be 12 vertically×12 horizontally, and the other sensing unit 28b may be 8 vertically×8 horizontally. The arrangement interval (number) of sensing units 28a, 28b can be set arbitrarily according to the sensor size, the desired nose size, etc.

[0091] <Second embodiment> 16 is a side cross-sectional view showing a configuration of a sensor device 50 according to a second embodiment of the present technology. Hereinafter, configurations different from the first embodiment will be mainly described, and configurations similar to those in the first embodiment will be denoted by the same reference numerals and descriptions thereof will be omitted or simplified.

[0092] In the sensor device 50 of this embodiment, the configuration of the separation layer 230 is different from that of the first embodiment. Fig. 17 is a rear view of the separation layer 230 in the sensor device 50. Details of the separation layer 230 will be mainly described below.

[0093] The isolation layer 230 has a void portion 33 and a plurality of pillar portions 34 extending in the vertical direction formed by the void portion 33. The void portion 33 is provided on the back surface side (second pressure sensor 22b side) of the isolation layer 230 in the form of a groove that does not penetrate the isolation layer 230 in the vertical direction.

[0094] The isolation layer 230 has a filling layer 31 (first layer) on the front side (first pressure sensor 22a side) with a filling structure that does not have a void portion 33. The isolation layer 23 has a column layer 32 (second layer) on the back side (second pressure sensor 22b side) that has a void portion 33 and a plurality of column portions 34 formed by the void portion 33.

[0095] Each of the multiple pillars 34 has a shape in which the thickness is not constant in the vertical direction, but varies. In the example shown in Fig. 16 and Fig. 17, the multiple pillars 34 are formed so that the thickness gradually decreases from the front side (the first pressure sensor 22a side) to the back side (the second pressure sensor 22b side) in the vertical direction. Specifically, each of the multiple pillars 34 has an inverted quadrangular pyramid shape. Note that the pillars 34 may be formed in an inverted circular truncated cone shape, an inverted triangular truncated pyramid shape, an inverted pentagonal truncated pyramid shape, an inverted hexagonal truncated pyramid shape, or the like.

[0096] The pillars 34 are regularly arranged vertically and horizontally. The pillars 34 are provided at positions corresponding to the sensing portions 28 in the vertical direction, and therefore the voids 33 for forming the pillars 34 are provided at positions not corresponding to the sensing portions 28 in the vertical direction. The number of pillars 34 is the same as the number of sensing portions 28b in the second pressure sensor 22b, and is 5×5 (vertical×horizontal) for a total of 25. The number of pillars 34 can be changed as appropriate.

[0097] The isolation layer 230 has a thickness of, for example, about 1000 μm to 5000 μm. The vertical height of the column portion 34 (i.e., the depth of the groove-like void portion 33) is 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, etc., of the thickness of the isolation layer 23. Note that although there is no problem if the height of the column portion 34 is high (for example, 100% of the thickness of the isolation layer 230), if the height is too low (for example, less than 20% of the thickness of the isolation layer 230), the column portion 34 may not function effectively.

[0098] The area (in-plane direction) of the underside of the column portion 34 (the portion that contacts the second pressure sensor 22b) is set according to the area of ​​the sensing portion 28b of the second pressure sensor 22b, and is, for example, approximately the same as the area of ​​the sensing portion 28b.

[0099] The separation layer 230 is typically made of a viscoelastic material having viscoelastic properties, such as silicone gel, urethane gel, synthetic rubber, and foam.

[0100] Next, examples of the shape of the isolation layer 230 will be described. Fig. 18 is a diagram showing examples of the shape of the isolation layer 230. Fig. 18 shows five patterns of the shape of the isolation layer 230, shape A to shape E. Note that Fig. 18 shows the first pressure sensor 22a and the second pressure sensor 22b in a simplified manner.

[0101] (Shape A) Shape A is the shape already described with reference to FIGS.

[0102] (Shape B) In shape B, similar to shape A, the void portion 33 is provided in the shape of a groove that does not vertically penetrate the isolation layer 230 on the back surface side (the second pressure sensor 22b side) of the isolation layer 230. Also, in shape B, similar to shape A, a two-layer structure of a filling layer 31 and a columnar layer 32 is formed.

[0103] In shape A, the thickness of the column portion 34 varies in the vertical direction, but in shape B, the thickness of the column portion 34 is the same in the vertical direction. Specifically, in shape B, the column portion 34 has a quadrangular prism shape. Note that the column portion 34 may be formed in a cylindrical shape, a triangular prism shape, a pentagonal prism shape, a hexagonal prism shape, a circle shape, or the like.

[0104] Note that the column portion 34 in Shape B is typically provided at a position corresponding to the sensing portion 28b of the second pressure sensor 22b in the vertical direction, similar to the column portion 34 in Shape A. Note that this also applies to Shapes C to E.

[0105] (Shape C) In shapes A and B, the voids 33 are groove-shaped and do not vertically penetrate the isolation layer 23, but in shape C, the voids 33 are hole-shaped and vertically penetrate the isolation layer 23. In this relationship, in shape C, the height of the column portions 34 is higher than in shapes A and B, and the height of the column portions 34 matches the thickness of the isolation layer 23. In other words, the height of the column portions 34 is 100% of the thickness of the isolation layer 230.

[0106] In addition, in shapes A and B, the isolation layer 230 has a two-layer structure of the filling layer 31 and the column layer 32, but in shape C, the filling layer 31 does not exist, and the isolation layer 230 has a single-layer structure of the column layer 32. In shape C, the shape of the column portion 34 is an inverted truncated square pyramid, but the shape of the column portion 34 may be an inverted truncated circular cone shape, an inverted truncated triangular pyramid shape, an inverted truncated pentagonal pyramid shape, an inverted truncated hexagonal pyramid shape, or the like.

[0107] (Shape D) In shape D, similar to shape C, the voids 33 are hole-shaped and penetrate the isolation layer 23 in the vertical direction. Also, in shape D, similar to shape C, the height of the column portions 34 matches the thickness of the isolation layer 23, and the height of the column portions 34 is 100% of the thickness of the isolation layer 23.

[0108] In shape C, the thickness of the column portion 34 varies in the vertical direction, but in shape D, the thickness of the column portion 34 is the same in the vertical direction. Specifically, in shape D, the column portion 34 has a quadrangular prism shape. Note that the column portion 34 may be formed in a cylindrical shape, a triangular prism shape, a pentagonal prism shape, a hexagonal prism shape, or the like.

[0109] (Shape E) Shape E shows an example of a combination of shapes A to D. That is, shapes A to D can be combined as appropriate. In shape E, the leftmost pillar portion 34 corresponds to the pillar portion 34 in shape C. The other four pillar portions 34 correspond to the pillar portions 34 in shape D, but each has a different thickness. The second pillar portion 34 from the right has a circular gap 33 (gap portion 33 that is not in contact with either the first pressure sensor 22a or the second pressure sensor 22b) in the vertical center.

[0110] FIG. 19 is a diagram showing the isolating layer 230 as viewed from the back surface side, illustrating the patterns of the shape of the column portion 34 as viewed in plan.

[0111] The top diagram in Fig. 19 shows the column portion 34 in a square prism shape. The second diagram from the top in Fig. 19 shows the column portion 34 in a hexagonal prism shape (honeycomb structure). The bottom diagram in Fig. 19 shows the column portion 34 in a combination of different shapes (cylinder, square prism, triangular prism, etc.).

[0112] In the sensor device 50 of this embodiment configured as above, since the separating layer 230 has the above-mentioned configuration, it is possible to improve the detection sensitivity to shear force. That is, in this embodiment, since the separation layer 230 has the voids 33, when the shear force Fs is applied, the separation layer 230 is locally distorted in the in-plane direction where the shear force Fs occurs, and the distortion is not transmitted much to the other parts. The local distortion (shear stress σ) is uniform regardless of the point in the in-plane direction. Therefore, in this embodiment, the detection sensitivity of the shear force Fs is uniform in the in-plane direction.

[0113] In addition, in this embodiment, since a void portion 33 is provided in the isolation layer 230, the isolation layer 230 is more easily distorted by the shear force Fs at each point in the in-plane direction (the shear stress σ is smaller), thereby improving the detection sensitivity of the shear force Fs.

[0114] In addition, in this embodiment, the pillar portion 34 formed by the gap portion 33 is provided at a position corresponding to the sensing portion 28 of the second pressure sensor 22b. Therefore, when a vertical load Fz is applied to the sensor device 20, the pillar portion 34 locally presses a portion of the second pressure sensor 22b corresponding to the sensing portion 28, so that the force can be efficiently transmitted to the second pressure sensor 22b. Therefore, even if the vertical load Fz is small, the pressure center position Q can be accurately detected in the second pressure sensor 22b, and the shear force Fs can be accurately measured.

[0115] In addition, when the shape of the isolation layer 230 is a two-layer structure of the filling layer 31 and the columnar layer 32, such as shape A or shape B, the columnar layer 32 may be made of a material that is relatively harder than the filling layer 31. In this case, when a vertical load Fz is applied to the sensor device 20, the columnar portion 34 of the relatively hard columnar layer 32 locally presses a portion of the second pressure sensor 22b corresponding to the sensing portion 28, so that the force can be transmitted more efficiently in the second pressure sensor 22b.

[0116] The above-described configuration of the separation layer 230 may also be applied to the viscoelastic layer 81, as described below. In this case, the viscoelastic layer 81 becomes more susceptible to distortion by the shear force Fs at each point in the in-plane direction of the viscoelastic layer 81, so that the detection sensitivity of the shear force Fs can be improved. The above-described configuration of the separation layer 230 can be applied to at least one of the separation layer 23 and the viscoelastic layer 81 in FIG. 2.

[0117] <Third embodiment> 20 is a side cross-sectional view showing a configuration of a sensor device 60 according to a third embodiment of the present technology. Hereinafter, configurations different from the first embodiment will be mainly described, and configurations similar to those in the first embodiment will be denoted by the same reference numerals and descriptions thereof will be omitted or simplified.

[0118] In the sensor device 60 of this embodiment, the configuration of the viscoelastic layer 810 is different from that of the first embodiment. The viscoelastic layer 810 is configured similarly to the separation layer 230 described in the second embodiment, and the back surface of the viscoelastic layer 810 is formed in an uneven shape as shown in FIG.

[0119] That is, the viscoelastic layer 810 has a void portion 33 and a plurality of pillar portions 34 extending in the vertical direction formed by the void portion 33. The void portion 33 is provided on the back side (second pressure sensor 22b side) of the viscoelastic layer 810 in the shape of a groove that does not penetrate the viscoelastic layer 810 in the vertical direction. The plurality of pillar portions 34 each have a shape with a different thickness, rather than a constant thickness in the vertical direction. In the example shown in FIG. 20, the plurality of pillar portions 34 are formed so that their thickness gradually decreases from the front side (surface layer 24 side) to the back side (first pressure sensor 22a side) in the vertical direction. Specifically, the plurality of pillar portions 34 each have an inverted quadrangular pyramid shape. The pillar portions 34 may be formed in a shape such as an inverted circular truncated cone shape, an inverted triangular truncated pyramid shape, an inverted pentagonal truncated pyramid shape, or an inverted hexagonal truncated pyramid shape.

[0120] The pillars 34 are regularly arranged vertically and horizontally. The pillars 34 are provided at positions corresponding to the sensing portions 28 in the vertical direction, and therefore the voids 33 for forming the pillars 34 are provided at positions not corresponding to the sensing portions 28 in the vertical direction. The number of pillars 34 is the same as the number of sensing portions 28b in the second pressure sensor 22b, and is 5×5 (vertical×horizontal) for a total of 25. The number of pillars 34 can be changed as appropriate.

[0121] The thickness of the viscoelastic layer 810 is, for example, about 1000 μm to 5000 μm. The vertical height of the column portion 34 (i.e., the depth of the groove-like void portion 33) is 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, etc., of the thickness of the viscoelastic layer 810. Note that although there is no problem if the height of the column portion 34 is high (for example, 100% of the thickness of the viscoelastic layer 810), if the height is too low (for example, less than 20% of the thickness of the viscoelastic layer 810), the column portion 34 may not function effectively.

[0122] The area (in-plane direction) of the underside of the column portion 34 (the portion that contacts the first pressure sensor 22a) is set according to the area of ​​the sensing portion 28a of the first pressure sensor 22a, and is, for example, approximately the same as the area of ​​the sensing portion 28a.

[0123] The viscoelastic layer 810 is typically made of a viscoelastic material having viscoelastic properties. Examples of materials used for the separation layer 810 include silicone gel, urethane gel, synthetic rubber, and foam. The shape of the viscoelastic layer 810 can be any of the various shapes shown in Figs. 18 and 19, similar to the separation layer 230 in the second embodiment described above.

[0124] In the sensor device 60 of this embodiment configured as described above, the detection sensitivity to shear force can be improved, as in the second embodiment described above. That is, in this embodiment, since the viscoelastic layer 810 has the voids 33, when a shear force Fs is applied, the viscoelastic layer 810 is locally distorted in the in-plane direction where the shear force Fs occurs, and the distortion is not transmitted much to parts other than the local area. The local distortion tendency (shear stress σ) is uniform regardless of the point in the in-plane direction. Therefore, in this embodiment, the detection sensitivity of the shear force Fs is uniform in the in-plane direction.

[0125] <Fourth embodiment> Next, a fourth embodiment of the present technology will be described. Fig. 21 is a block diagram showing a configuration of a robot device 10 (see Fig. 1) including a sensor device 20 according to the first embodiment.

[0126] The robot device 10 has a control unit 11 and a drive unit 12 that drives the arm unit 1, the hand unit 3, etc. The control unit 11 is typically configured as a computer including a CPU and a memory, and is configured to be capable of executing a control program for operating the robot device 10 based on input signals from various sensors.

[0127] The sensor device 20 constitutes one of the above-mentioned various sensors, and is attached to the gripping surface of the hand unit 3 for gripping an object. The sensor device 20 detects the pressing force (pressure distribution, gripping force (vertical load) or shear force) acting on the sensing surface with the sensor unit 21, calculates the value of the pressing force with the calculation element 70, and inputs it to the control unit 11. Based on the input signal from the calculation element 70, the control unit 11 generates a drive signal for controlling the positions of the arm unit 1 and the hand unit 3 (fingers 3a), and outputs it to the drive unit 12. The drive unit 12 is typically an actuator such as an electric motor or a fluid pressure cylinder, and drives the arm unit 1, hand unit 3, etc. based on the drive signal from the control unit 11.

[0128] As an example, as shown in FIG. 22, an operation example in which a target object T placed on a placement surface S is transported to another location and a processing procedure executed by the control unit 11 will be described.

[0129] [Grabbing of an object] The control unit 11 sets an initial position, which is a gripping position of the object T, and then narrows the hand position (the facing distance between the fingers 3a) (steps 301 and 302). When the finger portion 3a comes into contact with the object T and the target value for gripping force detection (typically the pressing force acting upon contact with the object) is reached, the control unit 11 executes control to grip the object T with the hand portion 3 (steps 303, 304). At this time, the control unit 11 adjusts the position of the hand unit 3 (the posture of the hand unit 3 and the opposing distance between the fingers 3a) to control the gripping force on the object T or the shear force acting on the sensor device 20 (step 305). Then, the control unit 11 lifts the object T and controls the gripping force of the hand unit 3 so as to stably grip the object T (steps 306 and 307).

[0130] [Object movement] Next, the control unit 11 executes control to grip the hand unit 3, further adjust the gripping force as necessary, and then move the arm unit 1 to the destination (steps 308, 309). At this time, shear force acting on the hand unit 3 may change due to the influence of inertia and the like accompanying the movement of the arm unit 1. The control unit 11 executes control to maintain stable grip of the target object T by adjusting the posture or gripping force of the hand unit 3 (step 310).

[0131] [Object leaving action] When the object T reaches the target position, the control unit 11 executes control to stop the movement of the arm unit 1. In this case as well, if the shear force acting on the hand unit 3 changes due to the influence of inertia or the like, the control unit 11 executes control to control the hand unit 3 to maintain stable gripping of the object T, and then executes a lowering operation of the arm (steps 311, 312). When the object T is placed on the placement surface S, the control unit 11 executes control to stop the lowering operation of the arm unit 1, release the gripping operation by the hand unit 3, and release the object T (step 313).

[0132] There is a linear correlation between the pressing force applied to the sensor device 20 and the gripping force of the hand unit 3 as shown in Fig. 23, and the pressing force increases in proportion to the gripping force. The adjustment range of the gripping force for the object T differs between the gripping operation, the moving operation, and the removing operation of the object T. Typically, the gripping force is adjusted within the range of arrow C1 during the gripping operation, within the range of arrow C2 during the moving operation, and within the range of arrow C3 during the removing operation.

[0133] FIG. 24 is a flowchart showing details of a processing procedure for the gripping operation of the target object T. Step 305 includes step 305a of controlling the hand position and step 305b of detecting the gripping force. For example, the gripping force is determined based on the in-plane distribution of the vertical load Fz and the shear force Fs output from the sensor device 20, and the hand unit 3 is controlled so that the gripping force becomes a target value. Step 306 also includes step 306a of detecting the shear force Fs, and steps 306b and 306c of resetting the position and orientation of the hand unit or the target value of the gripping force based on the shear force Fs so that the gripping operation is stabilized.

[0134] FIG. 25 is a flowchart showing details of the processing procedure for the movement operation of the target object T. Step 307a includes a step of checking whether or not the object T is stably gripped. Step 308 includes a step 308a of controlling the hand position and a step 308b of detecting the gripping force. Step 309 also includes step 309a of detecting the shear force Fs, and steps 309b and 309c of resetting the position and posture of the hand unit or the target value of the gripping force based on the shear force Fs so that the gripping operation is stabilized.

[0135] FIG. 26 is a flowchart showing details of the processing procedure for the removal operation of the target T. Step 310a includes a step of checking whether or not the object T is stably gripped. Step 311 includes a step 311a of controlling the hand position and a step 311b of detecting the gripping force. Step 312 also includes step 312a of detecting the shear force Fs, and steps 312b and 312c of resetting the position and posture of the hand unit or the target value of the gripping force based on the shear force Fs so that the gripping operation is stabilized.

[0136] 27 is a side view of the main part showing various configuration examples of the hand unit 3. In the drawing, the hatched area indicates the sensor device 20.

[0137] The upper left of Figure 27 shows a two-fingered parallel plate gripper, with a sensor device 20 located on the inner surface of each finger 3a. The upper right of Fig. 27 shows a similar two-fingered parallel plate gripper, but differs in that the tip 3a1 of each finger 3a has a curved shape. The sensor device 20 arranged on the inner surface of each finger 3a is arranged to cover the tip 3a1 of the finger 3a, so that it can detect not only the gripping force but also the contact force with the tip 3a1.

[0138] The center left of FIG. 27 shows an example of a two-fingered parallel plate gripper, but with a sensor device 20 disposed only on one of the fingers 3a. The center right of FIG. 27 shows a three-fingered gripper, with a sensor device 20 disposed on the inner surface of each finger 3a. The lower left of Fig. 27 shows an example of a two-fingered gripper in which a fingertip portion 3b is connected to the tip of each finger portion 3a via a rotating portion P. In this case, the sensor device 20 is disposed on the inner surface of each finger portion 3a and each fingertip portion 3b. The lower right of FIG. 27 shows an example of a two-fingered rotating gripper that is rotatable at a rotating part P, in which a sensor device 20 is disposed on the inner surface of each finger part 3a.

[0139] FIG. 28 shows an example of the in-plane distribution of the shear force Fs detected by the sensor device 20 arranged on the inner surface of each finger portion 3a of a two-fingered parallel plate gripper. Here, the sensor device arranged on the finger portion 3a on one side (e.g., the left side) is sensor device 20L, and the sensor device arranged on the finger portion 3a on the other side (e.g., the right side) is sensor device 20R. When slippage occurs such that the object gripped between the fingers 3a rotates around an axis parallel to the gripping direction, each of the sensor devices 20L and 20R detects the in-plane distribution of the shear force Fs as shown in the figure. In this case, the in-plane distribution of the shear force Fs is detected symmetrically by each of the sensor devices 20L and 20R. Therefore, it is possible to detect the in-plane distribution of the shear force Fs acting on the finger portion 3a with high accuracy.

[0140] <Fifth embodiment> 29 is a perspective view that illustrates a sensor device 90 according to a fifth embodiment of the present technology. As in the first embodiment, the sensor device 90 of this embodiment includes a first pressure sensor 220a on the upper layer side, which is the sensing surface side, a second pressure sensor 220b on the lower layer side, and a separation layer 23 disposed between the first pressure sensor 220a and the second pressure sensor 220b. Note that the viscoelastic layer 81 disposed on the upper layer side of the first pressure sensor 220a is omitted in the illustration.

[0141] Here, four tapping elements W1 to W4 are shown to be simultaneously subjected to a vertical load Fz in the Z-axis direction and a shear force Fs in the X-axis direction on the sensor device 90. Four points P1 to P4 on the first pressure sensor 220a and four points Q1 to Q4 on the second pressure sensor 220b indicate the detection center positions (pressure center positions) of the pressures by the tapping elements W1 to W4, respectively.

[0142] This embodiment differs from the first embodiment described above in that each of the first pressure sensor 220a and the second pressure sensor 220b is divided into a plurality of detection regions. Fig. 30 is a schematic plan view parallel to the XY plane showing an example of division of the detection regions of the first pressure sensor 220a and the second pressure sensor 220b.

[0143] 30, the first pressure sensor 220a is divided into four detection areas A1 to A4, and the second pressure sensor 220b is similarly divided into four detection areas B1 to B4. The detection area B1 of the second pressure sensor 220b detects the vertical load Fz and shear force Fs caused by the tapping element W1 acting on the detection area A1 of the first pressure sensor 220a. Similarly, the detection areas B2 to B4 of the second pressure sensor 220b detect the vertical load Fz and shear force Fs caused by the tapping element W2 to W4 acting on the detection areas A2 to A4 of the first pressure sensor 220a, respectively.

[0144] By dividing the first pressure sensor 220a and the second pressure sensor 220b into a plurality of detection areas A1 to A4 and B1 to B4, respectively, the load and shear force acting on each detection area can be accurately detected without each detection area being affected by the other detection areas.

[0145] For example, Fig. 31 shows a schematic diagram of pressure distribution of tapping elements W1 to W4 in each of detection areas A1 to A4 of the first pressure sensor 220a. On the right side of the figure, multiple square areas in each of detection areas A1 to A4 correspond to sensing units 28 (see Fig. 3), which are nodes, and their pressure detection values ​​are shown by shading (the darker the shading, the higher the pressure detection value, and the lighter the shading, the lower the pressure detection value).

[0146] In this state, when each of the tapping elements W1 to W4 is rotated around the same rotation axis while being pressed by hand as shown by the arrow C in the left side of Fig. 32, the pressure distribution in each of the detection areas A1 to A4 changes, for example, as shown in the right side of Fig. 32. That is, in this case, the high pressure area in each of the detection areas A1 to A4 expands, and the pressure center position of each of the detection areas A1 to A4 moves along the movement direction of each of the tapping elements W1 to W4. Fig. 33 also shows the in-plane distribution of the shear force in the four detection areas (areas 1 to 4) determined by taking into consideration the time change in the pressure center position in the detection areas B1 to B4 of the second pressure sensor 220b.

[0147] In this embodiment, the detection areas A1 to A4 of the first pressure sensor 220a are set so that a part of each area overlaps a part of the other areas. When the detection surface of the first pressure sensor 220a is divided into four equal parts, 2 vertically and 2 horizontally, for example, as shown by hatching in the left of Fig. 30, the detection area A1 is set so that a part of it overlaps a part of the other detection areas A2 and A3 adjacent in the vertical and horizontal directions. This increases the number of sensors (the number of sensing units 28) in each detection area, and therefore, for example, the loss of pressure detection data in the periphery of the detection area is suppressed, and the detection accuracy of the pressure center positions P1 to P4 can be improved. However, the present invention is not limited to this, and the detection regions A1 to A4 may be divided without overlapping with each other, similar to the divided regions B1 to B4 of the second pressure sensor 220b.

[0148] The detection regions A1 to A4 and B1 to B4 of the first pressure sensor 220a and the second pressure sensor 220b are each divided into four regions, but are not limited to this and may be divided into two, three, five or more regions.

[0149] The number of divisions and size (width) of each of the detection regions A1-A4 and B1-B4 may be set in advance, or may be set variably according to the number and positions of the loads acting on the first pressure sensor 220a. In this case, the setting of the detection regions can be optimized when the load acting on the sensor device 90 changes from moment to moment, making it possible to detect the pressure or shear force distribution with high accuracy.

[0150] In addition, in each of the sensing units 28 constituting the first pressure sensor 220a and the second pressure sensor 220b, the change in capacitance with respect to the pressing force may not necessarily be linear. For this reason, a correction algorithm may be adopted that linearly approximates the change in capacitance with respect to the pressing force of each of the sensing units 28.

[0151] 34 and 35 are flowcharts showing the procedure of the calculation process of the shear forces in the detection regions A1 to A4 and B1 to B4 of the calculation element 70 (see FIG. 3). A processing procedure F10a shown in FIG. 34 is similar to the processing procedure F10 shown in FIG. 7, and a processing procedure F20a shown in FIG. 35 is similar to the processing procedure F20 shown in FIG. In either case, when the capacitance change amount of any sensing unit 28 (node) of the second pressure sensor 220b is equal to or greater than the threshold (Yes in steps 101 and 201), the first pressure sensor 220a and the second pressure sensor 220b are divided into a plurality of detection areas A1-A4 and B1-B4 (steps 102a and 202a). Then, the pressure center positions P1-P4 and Q1-Q4 are calculated for each divided detection area to calculate the shear force Fs acting on each detection area (steps 102b, 202b, 103 and 204).

[0152] The sensor device 90 of this embodiment is applicable not only to the sensor device described in the first embodiment, but also to the sensor devices in the second to fourth embodiments. EXAMPLES

[0153] In the sensor device 20 shown in Fig. 2, a number of sensor device samples were produced in which the separation layer 23 and the viscoelastic layer 81 were made different in thickness, size, hardness, etc., and the mutual interference between pressing points in the separation layer 23 and the minimum load sensitivity were evaluated by the method shown in Fig. 11. In the following examples, each layer of the sensor device 20 was made of the same material. In the following description, the thickness, length, and width refer to the dimensions along the Z-axis, X-axis, and Y-axis directions in Fig. 2, respectively, and hardness refers to the penetration degree (degrees).

[0154] Example 1 A sensor device 20 was fabricated having a viscoelastic layer 81 having a thickness of 4.0 mm, a length of 29 mm, a width of 29 mm, and a hardness of 60 degrees, and a separation layer 23 having a thickness of 4.0 mm, a length of 29 mm, a width of 29 mm, and a hardness of 100 degrees, and the mutual interference between pressure points in the separation layer 23 and the minimum detection sensitivity were measured. The external dimensions of the sensor unit 21 were 29 mm in height and 29 mm in width, the number of sensing units 28 (nodes) of the first pressure sensor 22a (height x width) was 12 x 12 (2 mm square), and the number of sensing units 28 (nodes) of the second pressure sensor 22b (height x width) was 8 x 8 (3 mm square).

[0155] As in the example of Fig. 11, the conditions for measuring the mutual interference were set as follows: diameter of the contact surface of the tapping elements Wa, Wb was 6 mm, center distance between the tapping elements Wa, Wb was 12 mm, magnitude of the vertical load Fz was 5 N, movement of the tapping element Wa was 3 mm, and the ratio of deformation in the Z-axis direction at each pressing point of the isolation layer 23 (deformation at Wb / deformation at Wa) was set as the mutual interference (%). In addition, to calculate the mutual interference, both measurements using the process procedure F10 shown in Fig. 7 and the process procedure F20 shown in Fig. 12 were performed.

[0156] As a measurement condition for the minimum detection sensitivity, as shown in Fig. 36, a tapping element W having an area larger than the sensing surface of the sensor device 20 was placed on the sensing surface of the sensor device 20, and a vertical load F was applied to the tapping element W toward the sensor unit 20. The minimum vertical load F (N) at which the sensor device 20 detects a significant pressing force was determined as the minimum detection sensitivity.

[0157] The measurement results are shown in Table 2. As a result of the measurements, the mutual interference due to the processing procedure F20 was 20%, the mutual interference due to the processing procedure F10 was 60%, and the minimum detection sensitivity was 2.5N.

[0158] Example 2 The mutual interference between the pressing points in the separation layer 23 of the sensor device 20 and the minimum detection sensitivity were measured under the same conditions as in Example 1, except that the thickness of the viscoelastic layer 81 was set to 1.0 mm. As a result of the measurement, as shown in Table 2, the mutual interference due to the process F20 was 10%, the mutual interference due to the process F10 was 60%, and the minimum detection sensitivity was 1.6N.

[0159] Example 3 The mutual interference between the pressing points in the separation layer 23 of the sensor device 20 and the minimum detection sensitivity were measured under the same conditions as in Example 1, except that the thickness of the viscoelastic layer 81 was 1.0 mm and the hardness was 100 degrees. As a result of the measurement, as shown in Table 2, the mutual interference due to the process F20 was 5%, the mutual interference due to the process F10 was 60%, and the minimum detection sensitivity was 1.4N.

[0160] Example 4 The mutual interference between pressure points on the separation layer 23 of the sensor device 20 and the minimum detection sensitivity were measured under the same conditions as in Example 1, except that the thickness of the viscoelastic layer 81 was 1.0 mm, the length and width were each 24 mm, and the hardness was 120 degrees. As a result of the measurements, as shown in Table 2, the mutual interference due to the process F20 was 2%, the mutual interference due to the process F10 was 60%, and the minimum detection sensitivity was 1.0N.

[0161] Example 5 The mutual interference between pressure points on the separation layer 23 of the sensor device 20 and the minimum detection sensitivity were measured under the same conditions as in Example 1, except that the thickness of the viscoelastic layer 81 was 1.0 mm, the length and width were each 20 mm, and the hardness was 120 degrees. As a result of the measurement, as shown in Table 2, the mutual interference due to the process F20 was 2%, the mutual interference due to the process F10 was 60%, and the minimum detection sensitivity was 0.7N.

[0162] Example 6 The mutual interference between pressure points and the minimum detection sensitivity in the separation layer 23 of the sensor device 20 were measured under the same conditions as in Example 1, except that the thickness of the viscoelastic layer 81 was 1.0 mm, the length and width were each 20 mm, and the hardness was 120 degrees, and the hardness of the separation layer 230 was 120 degrees. As a result of the measurement, as shown in Table 2, the mutual interference due to the process F20 was 2%, the mutual interference due to the process F10 was 55%, and the minimum detection sensitivity was 0.7N.

[0163] Example 7 The mutual interference between pressure points and the minimum detection sensitivity in the separation layer 23 of the sensor device 20 were measured under the same conditions as in Example 1, except that the thickness of the viscoelastic layer 81 was 2.0 mm, the length and width were each 20 mm, and the hardness was 120 degrees, and the hardness of the separation layer 230 was 120 degrees. As a result of the measurements, as shown in Table 2, the mutual interference due to the process F20 was 1%, the mutual interference due to the process F10 was 50%, and the minimum detection sensitivity was 1.0N.

[0164] Example 8 A sensor device 60 was produced that had a viscoelastic layer 810 shown in Fig. 20 instead of the viscoelastic layer 81. The viscoelastic layer 810 according to this example had a thickness of 1.0 mm, a length of 24 mm, a width of 24 mm, and a hardness of 120 degrees, and the separation layer 23 had a thickness of 4.0 mm, a length of 29 mm, a width of 29 mm, and a hardness of 100 degrees. The viscoelastic layer 810 had a plurality of inverted truncated square pyramid-shaped pillars 34 (see Fig. 17) arranged in 12 columns and 12 rows, and the length and width of each pillar 34 at its tip was 3.0 mm.

[0165] In the sensor device 60 having the above configuration, the mutual interference between the pressing points in the separation layer 23 and the minimum detection sensitivity were measured under the same conditions as in Example 1. As a result of the measurement, as shown in Table 2, the mutual interference by process procedure F20 was 1%, the mutual interference by process procedure F10 was 60%, and the minimum detection sensitivity was 0.7 N.

[0166] Comparative Example 1 Except for omitting the viscoelastic layer 81, the mutual interference between the pressed points and the minimum detection sensitivity in the release layer 23 of the sensor device were measured under the same conditions as in the example. As a result of the measurement, it was impossible to calculate the mutual interference caused by the process F20, as shown in Table 2. In addition, the mutual interference caused by the process F10 was 90%, and the minimum detection sensitivity was 1.4N.

[0167] [Table 2]

[0168] As shown in Table 2, in Examples 1 to 8 including the viscoelastic layer 81 (viscoelastic layer 810 in Example 8), the mutual interference due to the process procedure F10 can be suppressed to a small level in comparison with the comparative example not including the viscoelastic layer 81. This confirms that Examples 1 to 8 can improve the detection sensitivity of the pressure distribution compared to the comparative example.

[0169] Furthermore, in Examples 1 to 8, it was confirmed that process procedure F20 can reduce mutual interference between pressure points more effectively than process procedure F10, and therefore, by using process procedure F20, the shear force distribution acting on the sensor device can be detected with high accuracy.

[0170] In particular, focusing on Examples 1 and 2 to 8, by making the viscoelastic layer 81 (810) thinner than the separation layer 23, the detection sensitivity of the shear force distribution and the minimum detection sensitivity of the normal load by process procedure F20 can be improved.

[0171] Furthermore, focusing on Examples 2 and 3 to 8, by making the viscoelastic layer 81 (810) softer than the separating layer 23 (by increasing the penetration), the detection sensitivity of the shear force distribution by process procedure F20 and the minimum detection sensitivity of the normal load can be improved.

[0172] Furthermore, focusing on Examples 3 and 4 to 8, by making the size of the viscoelastic layer 81 (810) (the area it occupies relative to the sensor portion 21) smaller than the size of the isolation layer 23 (the area it occupies relative to the sensor portion 21), the detection sensitivity of the shear force distribution by processing procedure F20 and the minimum detection sensitivity of the normal load can be improved.

[0173] Furthermore, focusing on Examples 4 and 8, by forming the contact surface of the viscoelastic layer 810 with the sensor section 21 as an uneven surface, it is possible to improve the detection sensitivity of the shear force distribution and the minimum detection sensitivity of the normal load by processing procedure F20 compared to when the contact surface is formed as a flat surface.

[0174] <Other embodiments> [Second viscoelastic layer] In each of the above embodiments, an example in which the viscoelastic layers 81, 810 (first viscoelastic layer) are disposed between the surface layer 24 and the sensor section 21 has been described, but the present invention is not limited to this. For example, as shown in Fig. 37, a second viscoelastic layer 82 made of a similar material to the first viscoelastic layer 81 may be disposed between the sensor section 21 and the support 40.

[0175] The second viscoelastic layer 82 is disposed on the rear surface of the second pressure sensor 22b of the sensor unit 21, and is made of a viscoelastic material that is deformable in the in-plane direction relative to the second pressure sensor 22b. This relaxes the restraint state between the sensor unit 21 and the support 40, making it easier for the separation layer 23 to follow the multiaxial stress acting on the first viscoelastic layer 81. As a result, it is possible to further improve the detection accuracy of the shear force distribution. In this case, in order to maintain the detection sensitivity of the vertical load, it is preferable that the thickness of the second viscoelastic layer 82 is equal to or less than the thickness of the first viscoelastic layer 81, and it is more preferable that the thickness of the second viscoelastic layer 82 is smaller than that of the first viscoelastic layer 81.

[0176] [Protective material] The sensor device according to the present technology may have any waterproof function depending on the usage environment, the type of the object to be detected, etc. For example, Fig. 38 is a schematic side cross-sectional view and a schematic plan view of a sensor device 101 having a waterproof protective member 91. Below, configurations different from the first embodiment will be mainly described, and configurations similar to those in the first embodiment will be denoted by the same reference numerals and descriptions thereof will be omitted or simplified.

[0177] (Configuration example 1) 38 includes a protective member 91 that covers the surface layer 24, the viscoelastic layer 81, the first pressure sensor 22a, the separation layer 23, the second pressure sensor 22b, and the support 40. The protective member 91 may be a film packaging material, or may be a coating of a paste material. The protective member 91 is not particularly limited as long as it is made of a material that has elasticity and waterproofness capable of responding to an external force, and examples of the protective member 91 include silicone rubber, urethane rubber, acrylic rubber, silicon gel, urethane gel, synthetic rubber, foam, silicone grease, PTFE (polytetrafluoroethylene) grease, adhesive, and pressure sensitive adhesive (the same applies to protective members 92 to 95 described below).

[0178] Since the sensor device 101 includes the protective member 301, when the viscoelastic layer 81, the deformation layer 27 (27a, 27b) of the pressure sensor 22 (22a, 22b), the separation layer 23, etc. are made of a material with relatively high hygroscopicity, the sensor device 101 can be protected from moisture in the outside air and moisture contained on the surface or inside of the detection target. Furthermore, since the protective member 301 is made of an elastic material capable of responding to an external force, the protective member 91 can easily deform in response to an external force (normal load, shear force) acting on the surface layer 24, and the deterioration of the detection accuracy of the shear force in the pressure sensor 22 can be suppressed, for example, as shown in Fig. 39.

[0179] (Configuration example 2) 40 includes a protective member 92 that covers the first pressure sensor 22a, the separating layer 23, the second pressure sensor 22b, and the support 40. The sensor device 102 differs from configuration example 1 in that the surface layer 24 and the viscoelastic layer 81 are disposed on the upper surface of the protective member 92. The sensor device 102 can be used, for example, when the surface layer 24 and the viscoelastic layer 81 are made of a waterproof material. Furthermore, with this configuration, the surface layer 24 and the viscoelastic layer 81 can be easily replaced.

[0180] (Configuration example 3) 41 includes a protective member 93 that covers the first pressure sensor 22a, the separation layer 23, the second pressure sensor 22b, and the support 40. The sensor device 103 differs from configuration example 2 in that the protective member 93 covers the periphery (four side surfaces) of the separation layer 23, the second pressure sensor 22b, and the support 40. As in configuration example 2, the sensor device 103 can be used in the case where the surface layer 24 and the viscoelastic layer 81 are made of a waterproof material, for example.

[0181] (Configuration Example 4) The sensor device 104 shown in Fig. 42 includes a protective member 94 that covers the pressure sensor 22 (22a, 22b). The sensor device 104 differs from configuration example 3 in that the protective member 94 covers the periphery (four sides) of the pressure sensor 22. This example can be used, for example, when the surface layer 24, the viscoelastic layer 81, and the separation layer 23 are made of a waterproof material. In addition, when the deformation layer 27 (27a, 27b) constituting the pressure sensor 22 (22a, 22b) is made of, for example, a foam or a columnar structure, the protective member 94 may be configured to cover at least the periphery of the deformation layer 27.

[0182] (Configuration Example 5) Other configuration examples in which only the deformation layer 27 is covered with a protective member are not limited to the above example. For example, as in a sensor device 105 shown in Fig. 43, the periphery of the deformation layer 27 may be covered with a protective member 95 formed in a frame shape. The protective member 95 is disposed between the reference electrode layer 25 (25a, 25b) and the sensor electrode layer 30 (30a, 30b), and the deformation layer 27 is disposed inside the protective member 27. By forming the protective member 95 in a frame shape that houses the deformation layer 27 in this way, it is possible to reduce the dead zone (area ratio where sensitivity can be detected) compared to, for example, configuration example 1.

[0183] [Pressure sensor] The pressure sensor 22 may have a five-layer structure in which a deformation layer 27 and a reference electrode layer 25 are laminated on the front and back of the sensor electrode layer 30. For example, FIG. 44 shows a pressure sensor 221 having a five-layer structure. The pressure sensor 221 includes a sensor electrode layer 30 having a plurality of capacitance elements arranged in the in-plane direction, a first reference electrode layer 251, a first deformation layer 271 arranged between the front surface of the sensor electrode layer 30 and the first reference electrode layer 35, a second reference electrode layer 252, and a second deformation layer 272 arranged between the back surface of the sensor electrode layer 30 and the second reference electrode layer 252. The reference electrode layer 252 is also arranged on the back surface side of the sensor electrode layer 30 via the deformation layer 272, so that the capacitance change of the sensor electrode layer 30 during pressure detection is increased, and the detection sensitivity of the pressure sensor 22 can be further improved.

[0184] The second deformation layer 272 may be formed of a material having a higher elastic modulus than the first deformation layer 271. In other words, the second deformation layer 272 may be formed as a gap layer that forms a certain gap between the sensor electrode layer 30 and the second reference electrode layer 252. The above configuration can be applied not only to the first pressure sensor 22a on the front side, but also to the second pressure sensor 22b on the back side in the same manner.

[0185] Fig. 45 is a cross-sectional view of a main part showing an application example of protective member 91 according to the above-mentioned Configuration Example 1 to pressure sensor 221. Similarly, Fig. 46 is a cross-sectional view of a main part showing an application example of protective member 92 according to the above-mentioned Configuration Example 2 to pressure sensor 221, and Fig. 47 is a cross-sectional view of a main part showing an application example of protective member 95 according to the above-mentioned Configuration Example 5 to pressure sensor 221. In this way, by providing a protective member that covers at least the periphery of deformation layer 27, it is possible to increase the waterproofness of pressure sensor 221 and improve its durability.

[0186] <Modification> In the above description, the robot device 10 has been taken as an example of a device in which the sensor device 20 is mounted. However, the device in which the sensor device 20 is mounted is not limited to a robot device, and may be an electronic device such as a mobile phone (including a smartphone) or a PC. Typically, the present technology is applicable to any device in which the sensor device 20 is mounted.

[0187] The present technology can also have the following configurations. (1) A sensor unit including a first pressure sensor on a front side and a second pressure sensor on a back side facing each other, and detecting a force in an in-plane direction based on a pressure detection position in the in-plane direction by the first pressure sensor and the second pressure sensor; a separation layer disposed between the first pressure sensor and the second pressure sensor and made of a viscoelastic material that deforms due to a load applied to the first pressure sensor; a first viscoelastic layer disposed on a surface of the first pressure sensor and made of a viscoelastic material capable of deforming in the in-plane direction relative to the first pressure sensor; A sensor device comprising: (2) The sensor device according to (1), The thickness of the first viscoelastic layer is equal to or less than the thickness of the separation layer. Sensor device. (3) The sensor device according to (1) or (2), The hardness of the first viscoelastic layer is equal to or less than the hardness of the separation layer. Sensor device. (4) The sensor device according to any one of (1) to (3), The area of ​​the first viscoelastic layer relative to the sensor unit is equal to or smaller than the area of ​​the separation layer relative to the sensor unit. Sensor device. (5) The sensor device according to any one of (1) to (4), The first pressure sensor and the second pressure sensor are a sensor electrode layer having a plurality of capacitance elements arranged in the in-plane direction; A reference electrode layer; a deformation layer disposed between the sensor electrode layer and the reference electrode layer. Sensor device. (6) The sensor device according to (5), the plurality of capacitive elements in the first pressure sensor are arranged in a matrix at a first interval within a surface of the sensor electrode layer in the first pressure sensor; The plurality of capacitive elements in the second pressure sensor are arranged in a matrix at second intervals larger than the first intervals in a plane of the sensor electrode layer in the second pressure sensor. Sensor device. (7) The sensor device according to (5) or (6), The first viscoelastic layer is made of a viscoelastic material that is more easily deformed in the in-plane direction than the deformation layer. Sensor device. (8) The sensor device according to any one of (5) to (7), The device further includes a waterproof protective member that covers at least the periphery of the deformation layer. Sensor device. (9) The sensor device according to (8), The protective member further covers the periphery of the separation layer. Sensor device. (10) The sensor device according to (8) or (9), The protective member further covers the first viscoelastic layer. Sensor device. (11) The sensor device according to any one of (1) to (10), The pressure sensor further includes a second viscoelastic layer that is arranged on a rear surface of the second pressure sensor and is made of a viscoelastic material that is deformable in the in-plane direction relative to the second pressure sensor. Sensor device. (12) The sensor device according to (11), The thickness of the second viscoelastic layer is equal to or less than the thickness of the first viscoelastic layer. Sensor device. (13) The sensor device according to any one of (1) to (12), At least one of the separation layer and the first viscoelastic layer has a plurality of columns formed by voids and extending in a direction perpendicular to the in-plane direction. Sensor device. (14) The sensor device according to (13), The void portion is provided in the shape of a groove that does not penetrate the separation layer or the first viscoelastic layer in a direction perpendicular to the in-plane direction. Sensor device. (15) The sensor device according to (13) or (14), The void portion is provided in the form of a hole penetrating the separation layer or the first viscoelastic layer in a direction perpendicular to the in-plane direction. Sensor device. (16) The sensor device according to any one of (1) to (15), The sensor unit further includes a calculation element that calculates a distribution of shear force in an in-plane direction based on pressure detection positions in the in-plane direction by the first pressure sensor and the second pressure sensor. Sensor device. (17) The sensor device according to (16), The computing element determines the presence or absence of a shear force based on whether or not a deviation amount in the in-plane direction between a first pressure center position detected by the first pressure sensor and a second pressure center position detected by the second pressure sensor reaches a predetermined value or more. Sensor device. (18) The sensor device according to any one of (1) to (17), The first pressure sensor and the second pressure sensor are each divided into a plurality of detection regions. Sensor device. (19) The sensor device according to (18), The plurality of detection regions have regions that partially overlap with adjacent detection regions. Sensor device. (20) A sensor unit including a first pressure sensor on a front side and a second pressure sensor on a back side facing each other, the sensor unit detecting a force in an in-plane direction based on a pressure detection position in the in-plane direction by the first pressure sensor and the second pressure sensor; a separation layer disposed between the first pressure sensor and the second pressure sensor and made of a viscoelastic material that deforms due to a load applied to the first pressure sensor; a viscoelastic layer disposed on a surface of the first pressure sensor and made of a viscoelastic material capable of deforming in the in-plane direction relative to the first pressure sensor; A sensor device having Equipped with a robotic device. (21) A sensor electrode layer having a plurality of capacitance elements arranged in an in-plane direction; A first reference electrode layer; a first deformation layer disposed between a surface of the sensor electrode layer and the first reference electrode layer; a second reference electrode layer; a second deformation layer disposed between the back surface of the sensor electrode layer and the second reference electrode layer; a waterproof protective member that covers at least the periphery of the first and second deformation layers; A pressure sensor comprising: [Explanation of symbols]

[0188] 10. Robot device 20,50,60,70,101,102,103,104,105...Sensor device 21…Sensor section 22,221...Pressure sensor 23,230…Separation layer 24…Surface layer 25…Reference electrode device 27…Deformation layer 28…Sensing section 30...Sensor electrode layer 33...Void part 34...Column part 70...Calculation element 81, 810... Viscoelastic layer (first viscoelastic layer) 82...Second viscoelastic layer 91, 92, 93, 94, 95...Protective materials

Claims

1. a sensor unit including a first pressure sensor on a front side and a second pressure sensor on a back side facing each other, the sensor unit detecting a force in an in-plane direction based on a pressure detection position in the in-plane direction by the first pressure sensor and the second pressure sensor; a separation layer disposed between the first pressure sensor and the second pressure sensor and made of a viscoelastic material that deforms due to a load applied to the first pressure sensor; a first viscoelastic layer disposed on a surface of the first pressure sensor and made of a viscoelastic material capable of deforming in the in-plane direction relative to the first pressure sensor; Equipped with the sensor unit further includes a calculation element that calculates a distribution of shear force in an in-plane direction based on a plurality of pressure detection positions in the in-plane direction by the first pressure sensor and the second pressure sensor, The computing element determines the presence or absence of a shear force based on whether or not a deviation amount in the in-plane direction between a first pressure center position detected by the first pressure sensor and a second pressure center position detected by the second pressure sensor has reached a predetermined value or more for each of the plurality of pressure detection positions. Sensor device.

2. The sensor device according to claim 1 , The thickness of the first viscoelastic layer is equal to or less than the thickness of the separation layer. Sensor device.

3. The sensor device according to claim 1 , The hardness of the first viscoelastic layer is equal to or less than the hardness of the separation layer. Sensor device.

4. The sensor device according to claim 1 , The area of ​​the first viscoelastic layer relative to the sensor portion is equal to or smaller than the area of ​​the separation layer relative to the sensor portion. Sensor device.

5. The sensor device according to claim 1 , The first pressure sensor and the second pressure sensor are a sensor electrode layer having a plurality of capacitance elements arranged in the in-plane direction; A reference electrode layer; a deformation layer disposed between the sensor electrode layer and the reference electrode layer. Sensor device.

6. The sensor device according to claim 5, the plurality of capacitance elements in the first pressure sensor are arranged in a matrix at a first interval within a surface of the sensor electrode layer in the first pressure sensor; The plurality of capacitive elements in the second pressure sensor are arranged in a matrix at second intervals larger than the first intervals in a plane of the sensor electrode layer in the second pressure sensor. Sensor device.

7. The sensor device according to claim 5, The first viscoelastic layer is made of a viscoelastic material that is more easily deformed in the in-plane direction than the deformation layer. Sensor device.

8. The sensor device according to claim 5, The device further includes a waterproof protective member that covers at least the periphery of the deformation layer. Sensor device.

9. The sensor device according to claim 8, The protective member further covers the periphery of the separation layer. Sensor device.

10. The sensor device according to claim 8, The protective member further covers the first viscoelastic layer. Sensor device.

11. The sensor device according to claim 1 , The pressure sensor further includes a second viscoelastic layer that is arranged on a rear surface of the second pressure sensor and is made of a viscoelastic material that is deformable in the in-plane direction relative to the second pressure sensor. Sensor device.

12. The sensor device according to claim 11, The thickness of the second viscoelastic layer is equal to or less than the thickness of the first viscoelastic layer. Sensor device.

13. The sensor device according to claim 1 , At least one of the separation layer and the first viscoelastic layer has a plurality of column portions formed by voids and extending in a direction perpendicular to the in-plane direction. Sensor device.

14. The sensor device according to claim 13, The void portion is provided in the shape of a groove that does not penetrate the separation layer or the first viscoelastic layer in a direction perpendicular to the in-plane direction. Sensor device.

15. The sensor device according to claim 13, The void portion is provided in the form of a hole penetrating the separation layer or the first viscoelastic layer in a direction perpendicular to the in-plane direction. Sensor device.

16. The sensor device according to claim 1 , the first pressure sensor and the second pressure sensor are divided into a plurality of detection areas; The computing element detects a load and a shear force acting on each of the plurality of detection areas. Sensor device.

17. a sensor unit including a first pressure sensor on a front side and a second pressure sensor on a back side facing each other, the sensor unit detecting a force in an in-plane direction based on a pressure detection position in the in-plane direction by the first pressure sensor and the second pressure sensor; a separation layer disposed between the first pressure sensor and the second pressure sensor and made of a viscoelastic material that deforms due to a load applied to the first pressure sensor; a first viscoelastic layer disposed on a surface of the first pressure sensor and made of a viscoelastic material capable of deforming in the in-plane direction relative to the first pressure sensor; A sensor device having Preparation, the sensor unit further includes a calculation element that calculates a distribution of shear force in an in-plane direction based on a plurality of pressure detection positions in the in-plane direction by the first pressure sensor and the second pressure sensor, The computing element determines the presence or absence of a shear force based on whether or not a deviation amount in the in-plane direction between a first pressure center position detected by the first pressure sensor and a second pressure center position detected by the second pressure sensor has reached a predetermined value or more for each of the plurality of pressure detection positions. Robot device.

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