Sensor device, robot device, and electronic device

Abstract

A sensor device according to an embodiment of the present technology includes a sensor portion and a surface layer. The sensor portion is configured to be capable of detecting a pressure distribution. The surface layer is disposed on the sensor portion and includes an inner layer portion and an outer layer portion. And the inner layer part is arranged on the pressure detection surface and is made of a flexible material. The outer layer portion covers the inner layer portion and is made of a deformable material having a higher elastic modulus than the material of the inner layer portion.

Description

TECHNICAL FIELD

[0001] The present technology relates to a sensor device capable of detecting a stress distribution, and a robot device and an electronic device each including the sensor device. BACKGROUND

[0002] In recent years, with a decrease in the labor population, automation of work using robots has been discussed in various scenes. In order to highly accurately control the behavior of a robot hand, it is necessary to detect a distribution of stress acting on a gripping surface of the robot hand without damaging a gripped object.

[0003] For example, Patent Literature 1 discloses a gripping shell of a robot including a tactile sensor, an inner skin covering the tactile sensor, and an outer skin tightly contacting an outer side of the inner skin, the outer skin being softer than the inner skin and having a high coefficient of friction.

[0004] LIST OF CITATIONS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 4-57695 SUMMARY

[0007] TECHNICAL PROBLEM

[0008] However, because the outer skin is softer than the inner skin and is formed using a material having a high coefficient of friction, the technology disclosed in Patent Literature 1 is likely to cause permanent deformation. This results in low durability of repeated use and also causes the sensor characteristics to be affected.

[0009] In view of the above, an object of the present technology is to provide a sensor device, a robot hand, and an electronic device that make it possible to improve durability while ensuring accuracy of detecting a stress distribution.

[0010] SOLUTION TO PROBLEM

[0011] A sensor device according to an embodiment of the present technology includes a sensor portion and a surface layer.

[0012] The sensor portion is configured to be capable of detecting a stress distribution.

[0013] The surface layer is arranged to the sensor portion and includes an inner layer portion and an outer layer portion. The inner layer portion is arranged to a stress detection surface and is made of a flexible material. The outer layer portion covers the inner layer portion and is made of a deformable material having a higher modulus of elasticity than a material of the inner layer portion.

[0014] Since the outer layer portion is made of a material having a higher elastic modulus than the material of the inner layer portion, the sensor device makes it possible to improve durability while ensuring accuracy of detection of a stress distribution.

[0015] The sensor portion can include a sensor electrode layer including a plurality of capacitive elements arranged in a matrix, and a deformation layer deformable to support the sensor electrode layer, the deformation layer being made of a material having a lower elastic modulus than the material of the inner layer portion.

[0016] The surface layer can further include an intermediate layer portion arranged between the inner layer portion and the outer layer portion, the intermediate layer portion being made of a material having a higher elastic modulus than the material of the outer layer portion.

[0017] The surface layer can have a stacked structure in which the inner layer portion and the outer layer portion are alternately stacked.

[0018] The inner layer portion can have a trapezoidal cross section parallel to a thickness direction of the inner layer portion.

[0019] The inner layer portion can be made of a flowable material or a rubber material.

[0020] The outer layer portion can be made of a rubber material or an elastomer material.

[0021] The sensor portion can further include a reference electrode layer connected to a reference potential, and the deformation layer can be arranged between the sensor electrode layer and the reference electrode layer.

[0022] The sensor portion can include a pair of pressure sensors each including the sensor electrode layer, the deformation layer, and the reference electrode layer, and an isolation layer made of a viscoelastic material arranged between the pressure sensors of the pair of pressure sensors.

[0023] A robot device according to an embodiment of the present technology includes a hand including a plurality of finger portions each including a gripping surface that can grip a workpiece, and a sensor device provided to the gripping surface, respectively.

[0024] The sensor device includes a sensor portion configured to be able to detect a distribution of a pressure acting on the gripping surface, and a surface layer including an inner layer portion arranged to a pressure detection surface, the inner layer portion being made of a flexible material, and an outer layer portion covering the inner layer portion, the outer layer portion being made of a material having a higher elastic modulus than a material of the inner layer portion.

[0025] An electronic device according to an embodiment of the present technology includes an input operation surface, and a sensor device provided to the input operation surface.

[0026] The sensor device includes a sensor portion and a surface layer. The sensor portion is configured to be able to detect a distribution of pressure acting on the input operation surface. The surface layer includes an inner layer portion disposed on a pressure detection surface, the inner layer portion being made of a flexible material; and an outer layer portion covering the inner layer portion, the outer layer portion being made of a material having a higher elastic modulus than that of the material of the inner layer portion. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a perspective view of a main portion of a robot device including a sensor device according to an embodiment of the present technology.

[0028] Figure 2 is a schematic cross-sectional side view illustrating a cross-sectional structure of a sensor sheet as a configuration example of a sensor device.

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

[0030] Figure 4 is a plan view of a main portion of a sensing portion of a sensor device as a configuration example.

[0031] Figure 5 is a schematic cross-sectional side view illustrating a cross-sectional structure of a sensor sheet as another configuration example of a sensor device.

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

[0033] Figure 7 is a schematic cross-sectional side view of a sensor device according to a second embodiment of the present technology.

[0034] Figure 8 is a schematic cross-sectional side view of a sensor device according to a third embodiment of the present technology.

[0035] Figure 9 schematically illustrates a configuration of a sensor device according to a fourth embodiment of the present technology.

[0036] Figure 10 is a set of schematic plan views illustrating examples of a shape of an upper surface of an inner layer portion.

[0037] Figure 11 is a schematic cross-sectional side view of a modification example of a configuration of a surface layer included in the above-described sensor device.

[0038] Figure 12 is a schematic cross-sectional side view of a modification example of a configuration of a surface layer included in the above-described sensor device.

[0039] Figure 13 are a set of cross-sectional views of the structure of the surface layer used in experimental examples of the present technology.

[0040] Figure 14 is a graph for describing a measurement of the rigidity of the surface layer in the thickness direction in experimental examples.

[0041] Figure 15 is a graph for describing a measurement of the rigidity of the surface layer in the shear direction in experimental examples.

[0042] Figure 16 is a perspective view of an electronic device for describing another embodiment of the present technology.

[0043] Figure 17 is a cross-sectional side view of a modification of the configuration of the sensor device.

[0044] Figure 18 is a graph for describing the effects of another modification of the configuration of the sensor device. DETAILED DESCRIPTION

[0045] Embodiments according to the present technology will be described below with reference to the drawings.

[0046] <First Embodiment>

[0047] [Robot Device]

[0048] Figure 1 is a perspective view of the main part of a robot device 10 including a sensor device 20 according to an embodiment of the present technology. As Figure 1 illustrated in the graph in FIG. 1, the robot device 10 includes an arm portion 1, a wrist portion 2, and a hand portion 3.

[0049] The arm portion 1 includes a joint portion la, and by driving the joint portion la, the hand portion 3 can be moved to an arbitrary position. The wrist portion 2 is rotatably connected to the arm portion 1, and by rotation of the wrist portion 2, the hand portion 3 can be rotated.

[0050] The hand portion 3 includes 2 finger portions 3a and 3b opposite each other, and by driving the 2 finger portions 3a and 3b, it is possible to grip a target object between the 2 finger portions 3a and 3b. Note that in the example illustrated in Figure 1 , the hand portion 3 includes 2 fingers. However, the number of finger portions can be changed as appropriate, such as 3, 4, or more.

[0051] The sensor devices 20a and 20b (hereinafter also collectively referred to as sensor devices 20) are respectively provided on the opposite surfaces (gripping surfaces) of the two finger portions 3a and 3b. The sensor devices 20 include a pressure detection surface, and are capable of detecting a force applied to the pressure detection surface in the vertical direction (Z-axis direction). Furthermore, the sensor devices 20 are capable of detecting a force applied in the in-plane direction (X-axis direction and Y-axis direction) of the pressure detection surface. In other words, the sensor devices 20 are three-axis sensors capable of detecting forces corresponding to the directions of the three axes. Note that the configuration of the sensor devices 20 will be described later with reference to, for example, FIGS. 6A and 6B. Figure 2

[0052] The robot device 10 is driven by control by the controller 11. The controller 11 includes, for example, a control section and a storage device. The control section is, for example, a central processing unit (CPU), and controls the driving of each structural element of the robot device 10 based on a program stored in the storage device. The controller 11 can be a dedicated device for the robot device 10, or can be a general-purpose device. The controller 11 can be, for example, a personal computer (PC) connected to the robot device 10 by wire or wirelessly, or can be a server device in a network. The controller 11 can be a part of the robot device 10.

[0053] [Sensor Device]

[0054] Subsequently, the sensor devices 20 (20a, 20b) will be described in detail. The sensor devices 20 have the same configuration. As described above, the sensor devices 20 are sensor sheets capable of detecting the distribution of pressure acting on the pressure detection surface.

[0055] (First Configuration Example)

[0056] Figure 2 is a schematic cross-sectional side view illustrating the cross-sectional structure of a sensor sheet 210 as a configuration example of the sensor devices 20. Figure 3 is a schematic plan view of a sensor electrode layer 30 of the sensor sheet 210.

[0057] In Figure 2 and Figure 3 , the X-axis direction and the Y-axis direction are directions parallel to the pressure detection surface S of the sensor sheet 210 (hereinafter also referred to as in-plane directions), and the Z-axis direction is a direction perpendicular to the pressure detection surface S (hereinafter also referred to as a vertical direction). Furthermore, Figure 2 the upper portion in corresponds to the front side to which an external force is applied, and Figure 2 the lower portion in corresponds to the back side opposite to the front side.

[0058] ​The sensor sheet 210 as a whole has the shape of a rectangular flat plate in a plan view. Note that the shape of the sensor sheet 210 in a plan view is not particularly limited as long as it is appropriately set in accordance with the shape of the portion in which the sensor device 20 is arranged. For example, the shape of the sensor sheet 210 in a plan view can be a polygon other than a rectangle, a circle, or an ellipse.

[0059] As Figure 2 As

[0060] The pressure sensor 21 includes a sensor electrode layer 30, a pair of reference electrode layers 25 that face each other in the Z-axis direction with the sensor electrode layer 20 positioned therebetween, and a deformation layer 27 that is arranged between the sensor electrode layer 30 and a corresponding one of the reference electrode layers 25.

[0061] The sensor electrode layer 30 includes, for example, a flexible printed circuit. As Figure 3 As

[0062] The sensor electrode layer 30 includes a flexible base material 29 and a plurality of sensing portions 28 provided on a surface of the base material 29 or inside the base material 29. As a material of the base material 29, for example, a polymer resin such as polyethylene terephthalate, polyimide, polycarbonate, or acrylic resin is used. The sensing portions 28 are regularly arranged in a matrix at a prescribed interval in the length direction and the width direction (length: Y-axis direction, width: X-axis direction). In the example illustrated in Figure 3 In the example illustrated in

[0063] The sensing portion 28 includes a plurality of capacitive elements (detection elements) that can detect a change in distance to the reference electrode layer 25 as a change in capacitance. For example, as Figure 4As shown in the cross-sectional view, the sensing portion 28 includes a pulse electrode 281 in the form of a comb tooth and a sensing electrode 282 in the form of a comb tooth. The pulse electrode 281 in the form of a comb tooth and the sensing electrode 282 in the form of a comb tooth are arranged such that the comb teeth of the pulse electrode 281 and the comb teeth of the sensing electrode 282 face each other, and each sensing portion 28 includes a region (a node region) in which the comb teeth of one of the pulse electrode 281 and the sensing electrode 282 are placed in the corresponding space formed between the comb teeth of the other of the pulse electrode 281 and the sensing electrode 282, respectively. Each pulse electrode 281 is connected to a wiring 281a extending in the Y-axis direction, and each sensing electrode 281 is connected to a wiring 282a extending in the X-axis direction. The wirings 281a are arranged in the front surface of the substrate 29 in the X-axis direction, and the wirings 282a are arranged in the rear surface of the substrate 29 in the Y-axis direction. Each sensing electrode 282 is electrically connected to the wiring 282a through a through-hole 283 provided in the substrate 29. The sensor electrode layer 30 can include a ground line. The ground line is provided, for example, at the outer peripheral portion of the sensor electrode layer 30, or at the portion in which the wirings 281a and the wirings 282a are placed side by side.

[0064] Note that the structure of the sensing portion 28 is not particularly limited to the above-described example, and any structure can be employed. For example, the sensor electrode layer 30 can be a laminate including a first electrode sheet having a first electrode pattern in the form of a lattice and a second electrode sheet having a second electrode pattern in the form of a lattice, the first electrode pattern extending in the X-axis direction and the second electrode pattern extending in the Y-axis direction. In this case, the sensing portion 28 is formed at the intersection of the first electrode pattern and the second electrode pattern.

[0065] The reference electrode layer 25 is connected to a reference potential. In the present embodiment, the reference electrode layer 25 is a so-called ground electrode, and is connected to a ground potential. The reference electrode layer 25 is flexible, and has a thickness of, for example, about 0.05 mm to about 0.5 mm. As the material of the reference electrode layer 25, for example, an inorganic conductive material, an organic conductive material, or a conductive material containing both an inorganic conductive material and an organic conductive material is used.

[0066] Examples of the inorganic conductive material include metals such as aluminum, copper, and silver; alloys such as stainless steel; and metal oxides such as zinc oxide and indium oxide. Further, examples of the organic conductive material include carbon materials such as carbon black and carbon fiber, and conductive polymers such as substituted or unsubstituted polyaniline and polypyrrole. The reference electrode layer 25 can be constituted of, for example, a thin plate made of a metal such as stainless steel or aluminum; a conductive fiber; or a conductive nonwoven fabric. The reference electrode layer 25 can be formed by, for example, vapor deposition, sputtering, adhesion, or coating on a plastic film.

[0067] 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 about 1000 μm. The deformation layer 27 is elastically deformable in response to an external force. When an external force is applied vertically to the sensor sheet 210, the deformation layer 27 is elastically deformed in response to the external force, and the reference electrode layer 25 becomes closer to the sensor electrode layer 30. At this time, in the sensing portion 28, there is a change in the capacitance between the pulse electrode 281 and the sensing electrode 282. This enables the sensing portion 28 to detect this change in the capacitance as a pressure value.

[0068] For example, the thickness of the deformation layer 27 is greater than 100 μm and equal to or less than 1000 μm. The basis weight of the deformation layer 27 is, for example, equal to or less than 50 mg / cm 2 When the thickness and the basis weight of the deformation layer 27 are set in these ranges, respectively, this makes it possible to improve the detection sensitivity of the pressure sensor 22 in the vertical direction.

[0069] The lower limit value of the thickness of the deformation layer 27 is not particularly limited as long as it is greater than 100 μm, and may, for example, be 150 μm or greater, 200 μm or greater, 250 μm or greater, or 300 μm or greater. Further, the upper limit value of the thickness of the deformation layer 27 is not particularly limited as long as it is equal to or less than 1000 μm, and may, for example, be 950 μm or less, 900 μm or less, 850 μm or less, or 800 μm or less.

[0070] In order to be easily deformable in the Z-axis direction, the deformation layer 27 can include, for example, a patterned structure including a columnar structure. As the patterned structure, various structures such as a matrix structure, a stripe structure, a grid structure, a radial structure, a geometric structure, and a spiral structure can be employed.

[0071] The surface layer 22 is formed as a contact surface that comes into contact with a workpiece when the robot device 10 grips the workpiece with the fingers 3a and 3b. The surface layer 22 includes an inner layer portion 221 and an outer layer portion 222.

[0072] The inner layer portion 221 is disposed at the sensor portion, and is made of a flexible material. Examples of the flexible material include a flowable material such as a gel, and a relatively less hard rubber material such as silicone rubber. In particular, in the present embodiment, the inner layer portion 221 is made of a material having a higher elastic modulus (Young's modulus) (for example, 100 kPa or less) than that of the deformation layer 27. In the present embodiment, the elastic modulus of the inner layer portion 221 is about 30 kPa, while the elastic modulus of the deformation layer 27 is about 5 kPa.

[0073] The outer layer portion 222 covers the inner layer portion 221 and is made of a deformable material having a higher modulus of elasticity than the material of the inner layer portion 221. The outer layer portion 222 includes a function of transmitting a pressure acting on the pressure detection surface S to the inner layer portion 221 by stretching mainly in the in-plane direction. Generally, the outer layer portion 222 is formed as a sheet or a film having a smaller thickness than the inner layer portion 221. The modulus of elasticity of the outer layer portion 222 is, for example, 1 MPa or more, and specifically, the outer layer portion 222 is made of any material such as a relatively hard rubber material including acrylic rubber, a synthetic resin material including elastomer, a fabric, a non-woven fabric, or leather. The surface of the outer layer portion 222 serves as the pressure detection surface S that receives a load (reaction force of the gripping force) applied by the workpiece during the gripping operation. Note that the outer layer portion 222 desirably has a surface texture that makes it possible to obtain a specified frictional force or more with the workpiece so as to stably grip the workpiece.

[0074] The inner layer portion 221 and the outer layer portion 222 are closely adhered at their interface by using, for example, an adhesive. Thus, when the stress on the surface layer 22 is released, the deformation in the inner layer portion 221 is also simultaneously eliminated with the elastic recovery of the outer layer portion 222. This results in enhanced adaptability to the temporal change in the stress distribution acting on the surface layer 22. Furthermore, the outer layer portion 222 serves as a protective layer for the inner layer portion 221, which makes it possible to improve the durability of the inner layer portion 221.

[0075] The thickness of the outer layer portion 222 is not particularly limited, and generally, the outer layer portion 222 is formed to have a smaller thickness than the inner layer portion 221. For example, the thickness of the outer layer portion 222 can be less than or equal to half the thickness of the inner layer portion 221. In the present embodiment, the inner layer portion 221 has a thickness of 1 mm, and the outer layer portion 222 has a thickness of 0.5 mm.

[0076] The support layer 24 supports the pressure sensor 21 and, for example, serves as an adhesive layer for fixing the pressure sensor 21 to the surface (gripping surface) of the finger portion 3a, 3b. The support layer 24 includes, for example, an adhesive layer such as a double-sided tape.

[0077] A control unit 70 is mounted on the extended portion 37 of the sensor electrode layer 30, and the control unit 70 calculates the force in the in-plane direction based on information about the pressure detected by the pressure sensor 21. The control unit 70 is generally a computer including a central processing unit (CPU), and includes an integrated circuit such as an IC chip. The control unit 70 is mounted to the sensor electrode layer 30 (the extended portion 37), and is configured so that the control unit 70 drives the pressure sensor 21, and so that the output signal from the pressure sensor 21 is input to the control unit 70. Note that the control unit 70 is not limited to the example in which the control unit 70 is mounted to the sensor electrode layer 30.

[0078] (Second Configuration Example)

[0079] Figure 5 is a schematic cross-sectional side view that illustrates the cross-sectional structure of a sensor sheet 220 that is another configuration example of the sensor device 20. Note that portions corresponding to those in the first configuration example are denoted by the same reference numerals as in the first configuration example, and detailed description thereof is omitted.

[0080] The sensor sheet 220 includes a first pressure sensor 21a on the front side (workpiece side), a second pressure sensor 21b on the rear side (finger portions 3a, 3b side), and a separation layer 23 disposed between the first pressure sensor 21a and the second pressure sensor 21b, where both the first pressure sensor 21a and the second pressure sensor 21b function as sensor portions. In other words, the sensor sheet 220 has a structure in which the second pressure sensor 21b, the separation layer 23, and the first pressure sensor 21a are vertically stacked in that order from the lower layer of the sensor sheet 220. Both the first pressure sensor 21a and the second pressure sensor 21b have a configuration similar or substantially similar to that of the pressure sensor 21 described above. Therefore, description thereof is omitted.

[0081] The sensor sheet 220 detects the force (shear force Fs) applied to the sensor sheet 220 in the in-plane direction based on the in-plane direction pressure center position of the pressure center (pressure detection position in the in-plane direction of the pressure) detected by the first pressure sensor 21a, and based on the in-plane direction pressure center position of the pressure center (pressure detection position in the in-plane direction of the pressure) detected by the second pressure sensor 21b. Furthermore, the sensor sheet 220 detects the force (load Fz) applied vertically from the upper side to the sensor sheet 220 based on the pressure value detected by the first pressure sensor 21a.

[0082] The isolation layer 23 is fixed between the first pressure sensor 21a and the second pressure sensor 21b by an adhesive layer (not shown). The isolation layer 23 is made of a viscoelastic material that deforms due to a load applied to the first pressure sensor 21a through the surface layer 22 and the viscoelastic body layer 81. Examples of such a viscoelastic material include silicone gel, polyurethane gel, synthetic rubber, and foam. The isolation layer 23 has a higher elastic modulus than the deformation layer 27, for example, the isolation layer 23 has an elastic modulus (100 kPa or less) equivalent to that of the inner layer portion 221 included in the surface layer 22. The thickness of the isolation layer 23 is not particularly limited, for example, between 1000 μm (inclusive) and 5000 μm (inclusive). The thickness of the isolation layer 23 is set, for example, in accordance with the thickness of the viscoelastic body layer 81. The planar shape of the isolation layer 23 is not particularly limited, and is typically rectangular or circular.

[0083] The sensor sheet 220 further includes a surface layer 22 arranged at the pressure sensor 21. The surface layer 22 has a similar configuration to that of the surface layer 22 in the first configuration example. Therefore, the description thereof is omitted.

[0084] [Control device]

[0085] The control unit 70 includes, for example, a control section and a storage device. The control section is, for example, a central processing unit (CPU), and controls the drive of each structural element of the hand 3 by executing a program stored in the storage device based on a control instruction given by the controller 11. Generally, the control unit 70 acquires information about the force in the three-axis direction detected by the sensor device 20, and controls the drive of the hand 3 based on the information about the force, so that the hand 3 stably grips a target object with an appropriate gripping force.

[0086] In the present embodiment, the control unit 70 is a control device that detects the distribution of the pressure acting on the gripping surface (pressure detection surface S) based on the output of the sensor device 20, and issues a control instruction for changing the relative position of the hand 3 with respect to the workpiece.

[0087] The storage device includes a nonvolatile memory in which various programs and data required for the processing performed by the control section are stored, and a volatile memory that serves as a work area of the control section. The various programs can be read from a portable recording medium such as a semiconductor memory, or can be downloaded from a server device in a network.

[0088] Figure 6 is a block diagram of the configuration of the control unit 70.

[0089] The control unit 70 is electrically connected to the sensor apparatus 20 and is configured to calculate the pressure acting on each of the finger portions 3a and 3b and the in-plane distribution of the pressure based on the output from the sensor apparatus 20. Further, based on the time variation of the above-mentioned pressure and the in-plane distribution of the pressure, the control unit 70 is able to detect the shear force acting on the pressure detection surface S. Further, the control unit 70 is electrically connected to the controller 11, and based on the control instruction given by the controller 11, the control unit 70 outputs a gripping instruction to the drive units 12a that drive the finger portions 3a and 3b of the hand 3.

[0090] [Effects]

[0091] Since the surface layer 22 includes the inner layer portion 221 made of a flexible material, the sensor apparatus 20 of the present embodiment having the above-mentioned configuration makes it possible to highly accurately detect the distribution of the stress acting on the pressure detection surface S. Further, the surface layer 22 includes the outer layer portion 222 that covers the inner layer portion 221, and the outer layer portion 222 is made of a stretchable material having a higher elastic modulus than the material of the inner layer portion. This makes it possible to simultaneously eliminate the deformation in the inner layer portion 221 along with the elastic recovery of the outer layer portion 222 while reducing the fluidity of the inner layer portion 221 made of a flexible material. This makes it possible to enhance the adaptability to the time variation of the stress distribution acting on the surface layer 22.

[0092] Further, the outer layer portion 222 functions as a protective layer for the inner layer portion 221. For example, compared to when there is no outer layer portion 222, it is possible to greatly reduce the deformation in the inner layer portion 221 that can be caused at the boundary between the contact region and the non-contact region of the gripped object on the surface of the surface layer 22. This makes it possible to improve the durability of the inner layer portion 221, and also enables to improve the durability of the sensor electrode layer 30 by reducing the stress applied to the sensor electrode layer 30 located just below the boundary.

[0093] [Second Embodiment]

[0094] Figure 7 is a schematic cross-sectional side view of a sensor apparatus according to a second embodiment of the present technology. The sensor apparatus 230 of the present embodiment differs from the sensor apparatus of the above-mentioned first embodiment in that the surface layer 22A includes an inner layer portion 221, an outer layer portion 222, and an intermediate layer portion 223.

[0095] The intermediate layer portion 223 is arranged between the inner layer portion 221 and the outer layer portion 222 and is made of a material such as a plastic film or an elastomer sheet that has a higher elastic modulus (i.e., is less stretchable) than the material of the outer layer portion 222. Since the intermediate layer portion 223 is provided between the inner layer portion 221 and the outer layer portion 222, the present embodiment makes it possible to improve the recovery performance of the inner layer portion 221, thereby improving the durability to repeated loads.

[0096] <Third Embodiment>

[0097] Figure 8 is a schematic cross-sectional side view of a sensor device according to a third embodiment of the present technology. The sensor device 240 of the present embodiment differs from the sensor device of the above-described first embodiment in that the surface layer 22B has a structure in which the inner layer portion 221 and the outer layer portion 222 are alternately stacked multiple times. In the present embodiment, two laminates J each including a pair of the inner layer portion 221 and the outer layer portion 222 are stacked. The inner layer portions 221 included in the laminates J, respectively, are made of the same material and have the same thickness, and the outer layer portions 222 included in the laminates J, respectively, are made of the same material and have the same thickness.

[0098] According to the present embodiment, the surface layer 22C has a stacked structure including stacked laminates J. Therefore, compared with a structure including a single laminate J, the rigidity of the surface layer 22C in the in-plane direction of the surface layer 22C is smaller than the rigidity in the thickness direction of the surface layer 22C. This makes it possible to improve the durability against stress applied in the thickness direction of the surface layer 22C while ensuring the accuracy of the in-plane distribution of the pressure on the surface layer 22C and the shear force acting on the surface layer 22C. This effect and advantage can be more easily obtained as the number of stacked laminates J increases.

[0099] <Fourth Embodiment>

[0100] Figure 9 is schematically illustrated. The sensor device 250 of the present embodiment differs from the sensor device of the above-described first embodiment in that the inner layer portion 221a forming the surface layer 22C has a trapezoidal cross section in the thickness direction of the inner layer portion 221a.

[0101] The upper surface of the inner layer portion 221a is formed to have a smaller area than the lower surface of the inner layer portion 221a. In the present embodiment, the area of the inner layer portion 221a is set to be smaller than the detection region of the sensor electrode layer 30. The shape of the upper surface of the inner layer portion 221a is not particularly limited, and the upper surface of the inner layer portion 221a can be rectangular as illustrated on the left side of Figure 10 , or can be circular as illustrated on the right side of Figure 10 . The outer layer portion 222 is stacked on the upper surface of the inner layer portion 221a. The present embodiment makes it possible to detect the shear force acting on the pressure detection surface S even if the contact area with the gripped object is relatively large by forming the inner layer portion 221a in the above-described shape.

[0102] Figure 11and Figure 12 is a schematic cross-sectional side view of a modification of the configuration of the surface layer 22C included in the sensor device. Figure 10 The surface layer 22C1 illustrated in (B) is obtained by stacking another laminate J on the surface layer 22C illustrated in (A). Figure 9 The surface layer 22C1 illustrated in (B) is obtained by stacking another laminate J on the surface layer 22C illustrated in (A).

[0103] On the other hand, Figure 12 The surface layer 22C2 illustrated in (C) differs from the surface layer included in the sensor device illustrated in (A) in that the outer layer portion 222a covers not only the upper surface of the inner layer portion 221a but also the entire surface of the inner layer portion 221a including the upper surface. This makes it possible to obtain similar effects and advantages to those described above, and further improve the durability of the inner layer portion 222a. Further, the entire surface of the inner layer portion 221a is covered by the outer layer portion 222a. This makes it possible to improve the shape recovery performance of the inner layer portion 221a at the time of stress elimination, and thus improve the durability against repeated loading. Figure 9

[0104] <Experimental Example>

[0105] As Figure 13 illustrated in (B), a laminate J1 (corresponding to the surface layer 22A illustrated in (A)) in which an inner layer portion 221 having a thickness of 1 mm, an intermediate layer portion 223 having a thickness of 0.1 mm, and an outer layer portion 222 having a thickness of 0.5 mm are sequentially stacked is used as a unit of layers, and a 1-layer laminate J1, a 2-layer laminate J2, a 3-layer laminate J3, and a 4-layer laminate J4 are formed. Each of the laminates J1 to J4 has a planar shape of a square with a side length of 24 mm. For example, the inner layer portion 221 included in each of the laminates J1 to J4 is made of the same material and has the same thickness, the intermediate layer portion 223 included in each of the laminates J1 to J4 is made of the same material and has the same thickness, and the outer layer portion 222 included in each of the laminates J1 to J4 is made of the same material and has the same thickness. Figure 7 Under the respective conditions shown below, the rigidity in the thickness direction (Z direction) of each of the laminates J1 to J4 formed, and the shear rigidity in the in-plane direction (XY direction) of each of the laminates J1 to J4 were measured.

[0106]

[0107] (Measurement of rigidity in thickness direction)

[0108] As Figure 14 ​​As shown in the middle diagram, the center portion of the laminate J1 was pressed using a pusher 70 having a diameter of 20 mm, and the displacement Za of the laminate J1 when the reaction force was 10 N was measured. The stiffness in the Z direction (Young's modulus) was calculated based on the measured displacement Za (reaction force / Za). For the laminates J2 to J4, the stiffness in the Z direction (Young's modulus) of each of the laminates J2 to J4 was calculated by a method similar to the above-described method.

[0109] (Shear Stiffness)

[0110] As shown in the middle diagram, the center portion of the laminate J1 was pressed using a pusher 70 having a diameter of 20 mm, and the displacement Za of the laminate J1 when the reaction force was 10 N was measured. The stiffness in the Z direction (Young's modulus) was calculated based on the measured displacement Za (reaction force / Za). For the laminates J2 to J4, the stiffness in the Z direction (Young's modulus) of each of the laminates J2 to J4 was calculated by a method similar to the above-described method. Figure 15

[0111] In addition, the laminates J1 and J2 each including an inner layer portion 221 having a thickness of 2 mm were formed, and the stiffness in the Z direction of each of the laminates J1 and J2, and the stiffness in the XY direction of each of the laminates J1 and J2 were calculated by a method similar to the above-described method.

[0112] The calculation results are collectively given in Table 1.

[0113] [Table 1]

[0114]

[0115] As can be seen from Table 1, both the stiffness value in the thickness direction (Item C) and the stiffness value in the shear direction (Item F) tend to become smaller as the number of stacked laminates J1 increases. In addition, if the number of stacked laminates J1 is the same, both the stiffness value in the thickness direction (Item C) and the stiffness value in the shear direction (Item F) tend to become smaller as the thickness of the inner layer portion 221 increases.

[0116] In addition, in Table 1, the stiffness anisotropy parameter 1 (Item H) is the ratio of the stiffness in the thickness direction (Item C) to the stiffness in the shear direction (Item F), and the stiffness anisotropy parameter 2 (Item I) is the ratio of the stiffness in the thickness direction per mm thickness (Item D) to the stiffness in the shear direction per mm width (Item G). This means that if these parameters have a larger value, the stiffness is larger in the thickness direction than in the planar direction. Note that for each of Item D and Item G, conversion was made to obtain the stiffness per mm so as to equally evaluate all axes.​

[0117] The above optimization of the number of stacked laminates J1 and the elastic modulus of the inner layer portion 221 makes it possible to design a surface layer that is sufficiently soft in the shear direction and sufficiently hard in the Z direction.

[0118] [Other Embodiments]

[0119] In each of the above embodiments, an example in which the sensor device 20 according to the present technology is applied as a pressure distribution sensor provided to the hand 3 of the robot device 10 is described. The sensor device according to the present technology is not limited to this, and can also be applied to an input operation surface included in a user interface (UI) of an electronic device. For example, as illustrated in Figure 16 the present technology can also be applied to a tablet-type portable information terminal 100, such as a smartphone or a tablet personal computer (PC), that functions as an electronic device. In the portable information terminal 100, an input operation surface 103 is provided around a main body 102 including a display portion 101. The arrangement of the sensor device 120 in the input operation surface 103 makes it possible to electrostatically detect a touch operation or a movement operation with a user's finger F.

[0120] In this case, the surface layer of the sensor device 120 is not limited to being formed to have a flat surface, and the surface layer can have a non-flat surface, for example, as illustrated in Figure 17 . Figure 17 An example in which protrusions Sa each having a partial spherical shape (spherical segment shape) are formed in the surface of the surface layer 22 is illustrated. Of course, the shape of the protrusions Sa is not limited to this, and the cross section of the protrusions Sa can have an arbitrary shape, such as a rectangular shape or a triangular shape. This surface shape of the surface layer 22 can also be applied to each of the above embodiments.

[0121] In addition to the above example, examples of the input operation surface of an electronic device include an operation button and an operation lever included in a controller for a game machine, and various operation portions of an image capturing device, such as a digital camera.

[0122] Furthermore, the sensitivity of the pressure distribution sensor detection varies depending on which of the gripped object and the surface layer 22 is harder. For example, as illustrated in Figure 18When the grasped object is harder than the outer layer portion 222 (the surface layer 22), the grasped object is not easily deformed, and the surface layer 22 is easily deformed, as illustrated in (1). Therefore, as illustrated in (1), the pressure distribution area is small, and the maximum value of the sensitivity is large. In contrast, when the grasped object is softer than the surface layer 22, the grasped object is easily deformed, and the surface layer 22 is not easily deformed, as illustrated in (2) or (3). Therefore, as illustrated in (2) or (3), the pressure distribution area is large, and the maximum value of the sensitivity is small. (2) illustrates a case in which the grasped object is harder than the inner layer portion 221, and (3) illustrates a case in which the grasped object is softer than the inner layer portion 222. As described above, when detection is performed by obtaining the relationship (slope) between the sum of the sensitivities of all the nodes and the maximum sensitivity of all the nodes, this makes it possible to detect whether the grasped object is harder or softer than the surface layer 22, or whether the grasped object is harder or softer than the inner layer portion 221. When this relationship is obtained by calculation or machine learning, this makes it possible to grasp the grasped object with an appropriate grasping force even when the grasped object is unknown.

[0123] <Modification example>

[0124] For example, in the above-described embodiment, a capacitance change type detection element is used to detect the pressure distribution. This is not limiting, and, for example, a resistance change type detection element in which a resistance value changes in accordance with the magnitude of the pressure can be used.

[0125] Note that the present technology can also adopt the following configuration.

[0126] (1) A sensor device including:

[0127] a sensor portion capable of detecting a pressure distribution; and

[0128] a surface layer including

[0129] an inner layer portion disposed in the sensor portion, the inner layer portion being made of a flexible material, and

[0130] an outer layer portion covering the inner layer portion, the outer layer portion being made of a deformable material having a higher elastic modulus than the material of the inner layer portion.

[0131] (2) The sensor device according to (1), in which

[0132] the sensor portion includes

[0133] a sensor electrode layer including a plurality of capacitance elements arranged in a matrix, and

[0134] a deformation layer deformable to support the sensor electrode layer, the deformation layer being made of a material having a lower elastic modulus than the material of the inner layer portion.

[0135] (3) The sensor device according to (2), wherein

[0136] The surface layer further includes an intermediate layer portion arranged between the inner layer portion and the outer layer portion, the intermediate layer portion being made of a material having a higher elastic modulus than a material of the outer layer portion.

[0137] (4) The sensor device according to (2) or (3), wherein

[0138] The surface layer has a stacked structure in which the inner layer portion and the outer layer portion are alternately stacked.

[0139] (5) The sensor device according to any one of (2) to (4), wherein

[0140] The inner layer portion has a trapezoidal cross section parallel to a thickness direction of the inner layer portion.

[0141] (6) The sensor device according to any one of (2) to (5), wherein

[0142] The inner layer portion is made of a flowable material or a rubber material.

[0143] (7) The sensor device according to any one of (2) to (6), wherein

[0144] The outer layer portion is made of a rubber material or an elastomer material.

[0145] (8) The sensor device according to any one of (2) to (7), wherein

[0146] The sensor portion further includes a reference electrode layer connected to a reference potential, and

[0147] The deformation layer is arranged between the sensor electrode layer and the reference electrode layer.

[0148] (9) The sensor device according to any one of (2) to (7), wherein

[0149] The sensor portion includes

[0150] a pair of pressure sensors each including the sensor electrode layer, the deformation layer, and the reference electrode layer, and

[0151] a separation layer arranged between the pressure sensors of the pair of pressure sensors, the separation layer being made of a viscoelastic material.

[0152] (10) A robot device, comprising:

[0153] a hand including a plurality of finger portions each including a gripping surface capable of gripping a workpiece, and

[0154] sensor devices respectively provided to the gripping surfaces,

[0155] the sensor devices include

[0156] a sensor portion capable of detecting a distribution of pressure acting on the gripping surfaces, and

[0157] a surface layer including

[0158] an inner layer portion arranged to the sensor portion, the inner layer portion being made of a flexible material, and

[0159] an outer layer portion covering the inner layer portion, the outer layer portion being made of a material having a higher elastic modulus than that of the material of the inner layer portion.

[0160] (11) An electronic device comprising:

[0161] an input operation surface; and

[0162] sensor devices provided to the input operation surface,

[0163] the sensor devices include

[0164] a sensor portion capable of detecting a distribution of pressure acting on the input operation surface, and

[0165] a surface layer including

[0166] an inner layer portion arranged to the sensor portion, the inner layer portion being made of a flexible material, and

[0167] an outer layer portion covering the inner layer portion, the outer layer portion being made of a material having a higher elastic modulus than that of the material of the inner layer portion.

[0168] LIST OF REFERENCE NUMERALS

[0169] 10 robot device

[0170] 20, 20A, 20B sensor device

[0171] 21, 21a, 21b pressure sensor

[0172] 22, 22A, 22B, 22C1, 22C2 surface layer

[0173] 23 spacer layer

[0174] 25 reference electrode layer

[0175] 27 deformation layer

[0176] 30 sensor electrode layer

[0177] 70 control unit

[0178] 210 sensor sheet

[0179] 221 inner layer portion

[0180] 222 outer layer portion

[0181] 223 intermediate layer portion

Claims

1. A sensor device, comprising: The sensor unit is capable of detecting pressure distribution; and Surface layer, the surface layer comprising An inner layer portion disposed on the sensor portion, the inner layer portion being made of a flexible material, and An outer layer covering the inner layer, the outer layer being made of a deformable material with a higher elastic modulus than the material of the inner layer.

2. The sensor device according to claim 1, wherein, The sensor unit includes A sensor electrode layer, the sensor electrode layer comprising a plurality of capacitive elements arranged in a matrix, and A deformable layer for supporting the sensor electrode layer, the deformable layer being made of a material with a lower elastic modulus than the material of the inner layer portion.

3. The sensor device according to claim 2, wherein The surface layer also includes an intermediate layer portion disposed between the inner layer portion and the outer layer portion, the intermediate layer portion being made of a material having a higher elastic modulus than the material of the outer layer portion.

4. The sensor device according to claim 2, wherein The surface layer has a stacking structure in which the inner layer portion and the outer layer portion are alternately stacked.

5. The sensor device according to claim 2, wherein The inner layer portion has a trapezoidal cross-section parallel to the thickness direction of the inner layer portion.

6. The sensor device according to claim 2, wherein The inner layer is made of a flowable material or a rubber material.

7. The sensor device according to claim 2, wherein The outer layer is made of rubber or elastomer material.

8. The sensor device according to claim 2, wherein The sensor unit also includes a reference electrode layer connected to a reference potential, and The deformable layer is disposed between the sensor electrode layer and the reference electrode layer.

9. The sensor device according to claim 2, wherein The sensor unit includes A pair of pressure sensors, each pressure sensor including the sensor electrode layer, the deformable layer, and the reference electrode layer, and An isolation layer, made of a viscoelastic material, is disposed between the pressure sensors of the pair of pressure sensors.

10. A robotic device, comprising: The hand includes multiple fingers, each of which includes a gripping surface capable of grasping a workpiece; and Sensor devices respectively disposed on the gripping surface, The sensor device includes The sensor unit is capable of detecting the distribution of pressure acting on the gripping surface, and Surface layer, the surface layer comprising An inner layer portion disposed on the sensor portion, the inner layer portion being made of a flexible material, and An outer layer covering the inner layer, the outer layer being made of a material with a higher elastic modulus than the material of the inner layer.

11. An electronic device, comprising: Input operation surface; and Sensor devices disposed on the input operation surface, The sensor device includes The sensor unit is capable of detecting the distribution of pressure acting on the input operating surface, and Surface layer, the surface layer comprising An inner layer portion disposed on the sensor portion, the inner layer portion being made of a flexible material, and An outer layer covering the inner layer, the outer layer being made of a material with a higher elastic modulus than the material of the inner layer.

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