tactile sensor

Abstract

To provide a tactile sensor capable of measuring the temperature of a contact object at the same time as measuring a dynamic quantity.SOLUTION: A tactile sensor 1 comprises: a housing 2; a contact body 3 which has a translucent elastic member 31 including a convex contact surface 32 protruding forward from one surface 21 of the housing 2, and in which a marker portion 33 is formed on the contact surface 32; and an image sensor 51 that is arranged inside the housing 2 and captures an image of the contact surface 32 through a rear surface of the contact body 3 when an object comes into contact with the contact surface 32. The contact body 3 is configured such that when the contact surface 32 comes into contact with the object, the contact surface 32 exhibits a color corresponding to a temperature of the object.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to tactile sensors, and more particularly to optical contact sensors. [Background technology]

[0002] Patent Document 1 describes a conventional tactile sensor (an optical tactile sensor in Patent Document 1). The optical tactile sensor described in Patent Document 1 includes a tactile unit with a marker unit formed in a convex curved surface, and an imaging means for imaging the rear surface of the tactile unit. The imaging means can convert the behavior of the marker unit into image information (image data) by imaging the rear surface of the tactile unit when an object comes into contact with the tactile unit and the tactile unit is deformed.

[0003] Image information of the marker part is input to the control unit, which performs image processing on the acquired image information to measure the coefficient of friction, normal force, tangential force, and torque acting on the tactile part. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-257343 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the optical tactile sensor described in Patent Document 1 can be installed in a robot hand to perform feedback control based on the measured friction coefficient, normal force, tangential force, and torque, thereby adjusting the gripping force of the robot hand to an appropriate force. This aims to realize a robot hand with tactile functions as close as possible to those of a human.

[0006] However, since humans feel the temperature of an object when grasping it, the amount of information available is insufficient to realize a tactile sensor that is comparable to the human tactile function.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a tactile sensor that can measure the temperature of a contact object at the same time as measuring a mechanical quantity. [Means for solving the problem]

[0008] A tactile sensor according to one aspect of the present invention comprises a housing, a contact body having a translucent elastic material including a convex contact surface protruding forward from one side of the housing, with a marker portion formed on the contact surface, and an imaging element disposed within the housing for capturing an image of the contact surface through the rear surface of the contact body when an object comes into contact with the contact surface, wherein the contact body is configured so that when the contact surface comes into contact with the object, the contact surface exhibits a color corresponding to the temperature of the object. [Effects of the Invention]

[0009] The tactile sensor according to the above aspect of the present invention has an advantage in that it can provide a tactile sensor that can measure the temperature of a contact object at the same time as measuring a mechanical quantity. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating the configuration of a tactile sensor according to one embodiment of the present invention. [Figure 2] Fig. 2(A) is a perspective view of a contact piece of the tactile sensor, Fig. 2(B) is a plan view of the contact piece, and Fig. 2(C) is a cross-sectional view taken along line X1-X1 of Fig. 2(B). [Figure 3] FIG. 3 is a block diagram of the tactile sensor and the control device. [Figure 4] Fig. 4(A) is a diagram showing an image of the contact surface captured by the imaging element, and Fig. 4(B) is a diagram showing the state when a contact object comes into contact with the contact surface. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Embodiment> (1) Overall structure The tactile sensor 1 according to this embodiment is an optical tactile sensor 1. The tactile sensor 1 can convert the mechanical quantity that occurs when it comes into contact with an object (sometimes called a "contact object") and the temperature of the object into electrical signals. Therefore, by using the tactile sensor 1 according to this embodiment, it is possible to simultaneously measure the mechanical quantity that occurs when it comes into contact with an object and the temperature of the object.

[0012] Here, "mechanical quantity" as used herein means at least one of shear force, normal force, tangential force, coefficient of friction, and torque. The tactile sensor 1 according to this embodiment can measure all of the following mechanical quantities: shear force, normal force, tangential force, coefficient of friction, and torque. Furthermore, "normal force" as used herein means a force that acts in a direction perpendicular to the contact surface 32 of an object when the tactile sensor 1 is used to press the object. Furthermore, "tangential force" as used herein means a force that acts parallel to the contact surface 32 of the object when the tactile sensor 1 is used to press the object.

[0013] The tactile sensor 1 of this embodiment can measure the temperature of an object at the same time as the mechanical quantities that occur when the object is touched. Therefore, by installing the tactile sensor 1 on the fingers of a robot hand, it can be used appropriately for the following purposes, for example:

[0014] For example, it can be used in a robot hand that handles frozen foods. By using the electrical signal from the tactile sensor 1 to perform feedback control, the robot hand is controlled so that it can grip the frozen food with an appropriate force. At this time, the temperature of the frozen food can be measured while it is being handled. This makes it possible to manage the temperature at a specific time (location) on the production line, and as a result, there is no need to set up a process for measuring the temperature of the frozen food on the production line, thereby shortening the takt time.

[0015] The object to be grasped (contact object) by the robot hand is not limited to frozen food, but may be any object that needs to be grasped with an appropriate force and whose temperature needs to be measured. In addition to food, examples of objects to be grasped include industrial products, tableware, textiles, cloth products, and paper products. Furthermore, the tactile sensor 1 is not limited to robot hands, and may be used in, for example, manufacturing equipment, automobiles, aircraft, and conveyors.

[0016] As shown in FIG. 1, the tactile sensor 1 includes a housing 2, a contact body 3, a half mirror 6, a camera 5 with an image sensor 51, and a light emitter 4. The tactile sensor 1 outputs an electrical signal generated by contact with a contact object to a control device 7. The tactile sensor 1 and the control device 7 constitute a sensing system. As described above, the sensing system can be used to control, for example, a robot hand.

[0017] (2) Housing The housing 2 is a hollow body that houses a part of the contact body 3, the half mirror 6, the light emitter 4, and the camera 5. In this embodiment, the housing 2 is a rectangular parallelepiped box, but the shape is not particularly limited in the present invention. The housing 2 may be, for example, cylindrical, rectangular tubular, spherical, or the like. When the tactile sensor 1 is installed on a robot hand, the housing 2 may be formed in the shape of a finger.

[0018] A contact body 3 is provided on one surface 21 of the housing 2. Here, the direction of the housing 2 that is perpendicular to the surface 21 on which the contact body 3 is provided is defined as the "front-rear direction," and the direction from the surface opposite the surface 21 toward the surface 21 in the front-rear direction is defined as the "front direction," and the opposite direction is defined as the "rear direction." Additionally, the direction that is perpendicular to the front-rear direction and runs along the longitudinal direction of the housing 2 is defined as the "left-right direction." However, these definitions of directions are provided merely for the convenience of explanation and are not intended to specify the intended use of the tactile sensor 1.

[0019] The housing 2 has a light-blocking property and blocks light traveling from the outside of the housing 2 to the inside of the housing 2. There are no particular limitations on the material of the housing 2, and examples include synthetic resin, metal, wood, paper, carbon, and cloth. The housing 2 according to this embodiment is made of black ABS (Acrylonitrile Butadiene Styrene) resin.

[0020] The housing 2 according to this embodiment houses the contact body 3, the half mirror 6, the light emitter 4, and the camera 5, but does not house the control device 7. However, the control device 7 may be disposed inside the housing 2.

[0021] (3) Contact body The contact piece 3 is a member of the tactile sensor 1 that has a portion that comes into contact with the contact object. When the contact piece 3 comes into contact with the contact object, the portion that comes into contact with the contact object deforms and takes on a color that corresponds to the temperature of the contact object. As shown in FIG. 2(A), the contact piece 3 includes a translucent elastic material 31 that has a contact surface 32, and a presser plate 37 that forms the rear surface of the contact piece 3.

[0022] The light-transmitting elastic material 31 is an elastic material that transmits at least a certain amount of light, and has a convex contact surface 32 that protrudes forward from one surface 21 of the housing 2. As shown in FIG. 2(A), the light-transmitting elastic material 31 is formed in a hemispherical shape, and therefore the contact surface 32 is configured as a convex curved surface. When an object comes into contact with the contact surface 32, the contact surface 32 elastically deforms and assumes a color that corresponds to the temperature of the object.

[0023] In this embodiment, the translucent elastic material 31 is formed in a hemispherical shape, but in the present invention, the shape is not limited to a hemispherical shape and the material may be formed in, for example, a cylindrical shape, a prismatic shape, a sheet shape, or the like, as long as it protrudes from one surface 21 of the housing 2. In addition, the contact surface 32 is not limited to a spherical surface and may be a gently curved surface or a flat surface.

[0024] Marker portions 33 are formed on the contact surface 32. The marker portions 33 are marks formed on the contact surface 32. When a contact object comes into contact with the contact surface 32, the marker portions 33 deform in accordance with the deformation of the contact surface 32. Examples of the marker portions 33 include a grid pattern, a dot pattern, and a stripe pattern. In this embodiment, a grid pattern as shown in FIG. 2(B) is adopted as the marker portions 33.

[0025] The marker portion 33 is formed on the contact surface 32 by, for example, forming a groove, a protrusion, a projection, a depression, a cut, printing, painting, or pasting colored paper. The marker portion 33 may be formed on the contact surface 32 or buried just below the contact surface 32. Therefore, in this specification, "the marker portion 33 is formed on the contact surface 32" means that the marker portion 33 is present on the contact surface 32 in such a manner that the marker portion 33 deforms in accordance with the deformation of the contact surface 32.

[0026] The light-transmitting elastic material 31 is made of an elastomer (sometimes called a "thermochromic elastomer") containing a matrix material, a light-shielding pigment, and a thermochromic pigment, and exhibits a color according to the temperature of the object it comes into contact with. The light-transmitting elastic material 31 may be made of a single layer structure containing a light-shielding pigment and a thermochromic pigment in a matrix material, but in this embodiment, it is made of a multilayer structure including a light-shielding layer 34 and a thermochromic layer 35, as shown in Figure 2(C).

[0027] Here, if the concentration of the light-shielding pigment in the light-transmitting elastic material 31 is too high, it becomes difficult to see the color change in response to the temperature of the object in contact with it, while if the concentration of the light-shielding pigment is too low, it tends to be more susceptible to the color of the object in contact with it. If the light-transmitting elastic material 31 has a single-layer structure containing the light-shielding pigment and the thermochromic pigment, localized unevenness in concentration is likely to occur, but a two-layer structure has the advantage of being able to suppress localized unevenness in the concentration of the light-shielding pigment.

[0028] The light-shielding layer 34 is a layer that has a certain degree of light-shielding properties, and suppresses external light from passing through the light-transmitting elastic material 31 when the color of the thermosensitive layer 35 and the marker portion 33 are imaged by the camera 5. This makes it possible to improve the accuracy of image recognition when image processing is performed on the image captured by the camera 5.

[0029] The light-blocking layer 34 is formed by mixing a light-blocking pigment into a matrix material. The matrix material is formed of one or more materials selected from silicone rubber, polyurethane resin, and thermoplastic elastomer. Examples of thermoplastic elastomers include styrene-based, polyamide-based, polyester-based, and halogen-based elastomers. Inorganic pigments can be used as the light-blocking pigment. Depending on the color tone, organic pigments may also be mixed. Examples of inorganic pigments include one or more pigments selected from calcium carbonate, zinc oxide, and titanium oxide. Examples of organic pigments include one or more pigments selected from azo-based and phthalocyanine-based pigments.

[0030] The color of the light-shielding layer 34 is the base color of the light-transmitting elastic material 31. The color of the light-shielding layer 34 is preferably set to a color that can be distinguished from the color of the temperature-indicating layer 35. Furthermore, the light-shielding layer 34 according to this embodiment is formed with the marker portion 33, and since the light-transmitting elastic material 31 is imaged from the rear, the light-shielding layer 34 needs to have a color that allows the deformation of the marker portion 33 to be distinguished.

[0031] The temperature-indicating layer 35 is a layer that exhibits a color corresponding to the temperature of a contact object when the contact object comes into contact with the contact surface 32. The temperature-indicating layer 35 is laminated on the inner side in the thickness direction (the rear side in the front-to-rear direction) of the light-shielding layer 34. The temperature-indicating layer 35 and the light-shielding layer 34 may be formed as separate sheets and then overlapped with each other, or one of the temperature-indicating layer 35 and the light-shielding layer 34 may be formed and then the other formed so as to overlap it, or one may be formed and then the other may be coated or painted. Alternatively, the temperature-indicating layer 35 may be coated on one side of a transparent substrate and the light-shielding layer 34 may be coated on the other side and then laminated.

[0032] The temperature indicating layer 35 is composed of a matrix material containing a thermochromic pigment component that changes color when heated. The matrix material is composed of one or more materials selected from silicone rubber, polyurethane resin, and thermoplastic elastomer. The matrix material of the temperature indicating layer 35 may be the same as the matrix material of the light-shielding layer 34, or may be composed of a different material.

[0033] The thermochromic dye component may be one or more components selected from a microencapsulated pigment containing a leuco dye, vanadium oxide, and bismuth oxide. Among these, a microencapsulated pigment containing a leuco dye is preferred. Examples of leuco dyes include a combination of a lactone ring compound, a color developer, and a desensitizer that melts at a thermosensitive temperature. When the temperature of the thermochromic layer 35 is below a predetermined temperature, the color developer acts as an acid in the microcapsules, opening the lactone ring compound and converting it to a carboxylic acid, thereby developing a color. On the other hand, when the temperature of the thermochromic layer 35 increases, the desensitizer melts, and the base component contained in the desensitizer combines with the color developer, closing the ring and returning to a lactone ring, causing the color of the thermochromic layer 35 to fade (increasing transparency).

[0034] Examples of lactone ring compounds include one or more pigments selected from crystal violet lactone, spirolactones, and the like. Among these, crystal violet lactone is preferred. Examples of color developers include compounds having a phenolic hydroxyl group, such as benzotriazole, monophenols, diphenols, and triphenols. Examples of phlegmizers include higher hydrocarbons, aliphatic higher alcohols, aliphatic higher fatty acids, and aliphatic higher fatty acid esters. Examples of base components contained in phlegmizers include higher fatty acids and quaternary ammonium salts.

[0035] As shown in FIG. 2(C), the light-transmitting elastic material 31 has a central layer 36 inside a hemisphere formed by the light-shielding layer 34 and the temperature-indicating layer 35. Examples of the central layer 36 include an elastic body such as silicone rubber, a gel with a certain viscosity, and an air layer. The central layer 36 needs to be light-transmitting in order to capture an image of the color of the temperature-indicating layer 35 and the marker portion 33. Here, it is preferable that the central layer 36 be transparent.

[0036] The light-transmitting elastic material 31 is deformed when it comes into contact with an object, and elastically returns to its original shape when the object is released. For this reason, it is preferable that the light-transmitting elastic material 31 has the following physical properties.

[0037] The elongation at break in accordance with JIS K 6251 is preferably 200% or more, and more preferably 300% or more. If the elongation at break is less than 200%, the tactile sensor 1 may not have the durability against fatigue required.

[0038] The tensile strength is preferably 6.0 MPa or more, and more preferably 8.0 MPa or more, in accordance with JIS K 6251. If the tensile strength is less than 6.0 MPa, the strength required for the tactile sensor 1 may not be obtained.

[0039] The durometer hardness (Type A) according to JIS K 6253-2 is preferably A20 or more and A60 or less, and more preferably A30 or more and A50 or less. If the durometer hardness is less than A20 or more than A60, the flexibility required for the tactile sensor 1 may not be obtained.

[0040] The pressure plate 37 is attached to the rear surface of the translucent elastic material 31 and constitutes the rear surface of the contact body 3. The pressure plate 37 is harder than the translucent elastic material 31. The translucent elastic material 31 is attached to the pressure plate 37 by, for example, adhesive bonding, pressure bonding, welding, etc. The pressure plate 37 is made of a transparent plate. Examples of the pressure plate 37 include an acrylic plate, a glass plate, and a polycarbonate plate. By fixing the pressure plate 37 to the housing 2, the contact body 3 is attached to the housing 2 so that the contact surface 32 protrudes from one surface 21 of the housing 2.

[0041] (4) Light-emitting body The light-emitting body 4 is disposed inside the housing 2 and emits light to illuminate the inside of the housing 2. When light is emitted from the light-emitting body 4, the camera 5 can capture images of the color of the thermosensitive layer 35 of the contact body 3 and the manner in which the marker portion 33 changes.

[0042] The light emitter 4 is configured by, for example, a white LED lamp, but is not particularly limited to an LED lamp. In this embodiment, the light emitter 4 is arranged along the rear surface of the housing 2, but the arrangement position can be changed appropriately depending on the brightness of the area where light is required.

[0043] The light emitter 4 according to this embodiment is formed in a flat plate shape, but may also be, for example, rod-shaped or ring-shaped.

[0044] (5) Camera The camera 5 has an imaging element 51. The imaging element 51 images the contact surface 32 through the rear surface of the contact body 3. By imaging the contact surface 32 when an object comes into contact with the contact surface 32, the color of the translucent elastic material 31 and the state of the marker portion 33 can be imaged and converted into an electrical signal. Examples of the imaging element 51 include a CMOS (Complementary Metal Oxide Semiconductor) and a CCD (Charge Coupled Device).

[0045] The camera 5 is disposed inside the housing 2. The camera 5 is disposed on the rear side of the contact surface 32 on the contact body 3. The camera 5 captures an image of the behavior (displacement, distortion) of the marker portion 33 when a contact object comes into contact with the contact body 3, so the focus of the camera 5 is on the marker portion 33.

[0046] 1, the camera 5 captures an image of the contact surface 32 via the half mirror 6. The camera 5 is disposed so that an optical axis L1 between the camera 5 and the half mirror 6 and an optical axis L2 between the half mirror 6 and the contact body 3 are perpendicular to each other. However, in the present invention, the camera 5 may also be disposed behind the contact body 3 so that the optical axis is linear.

[0047] (6) Control device The control device 7 has a control unit that receives an electrical signal from the imaging element 51 and controls an object to be controlled, such as a robot hand. As shown in Fig. 3, the control device 7 includes a CPU 71, a ROM 72, a RAM 73, and an input / output port 74. The ROM 72, the RAM 73, and the input / output port 74 are connected to the CPU 71.

[0048] The CPU 71 executes various processes for controlling the entire sensing system and outputs the processing results as control signals. The ROM 72 stores a control program for controlling the sensing system. The RAM 73 temporarily stores various information necessary for the operation of the sensing system. The input / output port 74 is connected to the camera 5 and the light emitter 4.

[0049] An electrical signal generated by capturing an image of the behavior of the marker unit 33 and the color of the contact surface 32 by the imaging element 51 is input to the CPU 71 via the input / output port 74. This electrical signal includes image data. The CPU 71 outputs an electrical signal for turning on the light emitter 4 to the light emitter 4 via the input / output port 74.

[0050] Image data captured at regular time intervals (for example, every 33 ms) is input to the CPU 71. When image data about the marker portion 33 of the contact body 3 before deformation is input to the CPU 71, the CPU 71 performs image processing and recognizes the pattern of the marker portion 33 as a reference. Here, as shown in FIG. 4(A), the CPU 71 recognizes the marker portion 33 as a lattice pattern.

[0051] The image data acquired at regular intervals is stored for a certain period in a storage area of the RAM 73, and is sequentially deleted starting with the oldest one. There are no particular limitations on the software that executes the image processing, and for example, HALCON (manufactured by MVTec) is used.

[0052] When a contact object comes into contact with the contact surface 32 of the contact body 3 and the contact surface 32 is deformed, image data after the deformation is input to the CPU 71. The CPU 71 determines the contact area T1 from the input image data after the deformation, and determines the sticking area T11 and the slipping area T12 within the contact area T1 (see FIG. 4(B)).

[0053] The "contact area T1" here refers to the area of the contact surface 32 that is in contact with the contact object. In an image (FIG. 4(B)) captured by the image sensor 51 of the state in which the contact object is in contact with the contact surface 32, the marker section 33 is recognized as a grid pattern, and the area in contact with the contact object appears to have a different brightness than the non-contact area (specifically, the contact area is brighter than the non-contact area). Therefore, the CPU 71 can extract the contact area T1 from the marker section 33 in the image data. Moreover, in the tactile sensor 1 according to this embodiment, the light-emitting body 4 emits white light, so the difference in brightness between the contact area T1 and the non-contact area T1 is clearly visible. This allows the CPU 71 to more accurately determine the contact area T1. In particular, in this embodiment, the contact object 3 exhibits a color that corresponds to the temperature of the contact object, so the temperature of the area in contact with the contact object changes. This improves the accuracy of extracting the contact area T1.

[0054] The "sticky region T11" refers to a region in the image data where the marker part 33 does not move when a contact object is in contact with the contact surface 32. The "slippery region T12" refers to a region where the marker part 33 can move when a contact object is in contact with the contact surface 32.

[0055] After determining the contact area T1, the sticking area T11, and the slipping area T12, the CPU 71 can calculate the shear force, the normal force, the tangential force, the friction coefficient, and the torque. A specific method for calculating these mechanical quantities can be achieved using known techniques (for example, as described in Japanese Patent Application Laid-Open No. 2005-257343), and therefore a description thereof will be omitted here.

[0056] The CPU 71 can calculate the temperature of the contact object from the color of the contact surface 32 in the image data. The CPU 71 extracts RGB values from the color of the contact surface 32. The RGB values and the temperature of the contact object are stored in association with each other in the ROM 72. The CPU 71 can read the temperature of the contact object from the ROM 72 by referring to the RGB values.

[0057] The control device 7 calculates the shear force, normal force, tangential force, friction coefficient, torque, and temperature of the contact object, and based on this, can output a control signal for controlling an actuator (e.g., a robot hand) not shown.

[0058] <Modification> The above embodiment is merely one of various embodiments of the present invention. The embodiment can be modified in various ways depending on the design, etc., as long as the object of the present invention can be achieved. Modifications of the embodiment are listed below. The modifications described below can be applied in appropriate combinations.

[0059] In the tactile sensor 1 according to the above embodiment, the rear surface of the contact body 3 is configured by the pressing plate 37, but in the present invention, the pressing plate 37 may be omitted.

[0060] In the contact sensor according to the above embodiment, the contact surface 32 is configured as a convex curved surface, but at least shear force can be measured even if the contact surface 32 is flat. Therefore, the contact sensor according to the present invention only needs to be able to measure at least one of shear force, normal force, tangential force, friction coefficient, and torque as a mechanical quantity.

[0061] Although the contact sensor according to the above embodiment has the half mirror 6, the present invention does not necessarily require the half mirror 6. The half mirror 6 may also be a mirror.

[0062] In the contact sensor according to the above embodiment, the surface 21 of the housing 2 from which the contact surface 32 of the contact body 3 protrudes is flat, but the surface 21 may be a curved surface or may not be flat.

[0063] The contact body 3 in the above embodiment has a thermochromic layer 35 and a light-shielding layer 34 laminated thereon, but in the present invention, a single matrix material may contain a thermochromic pigment and a light-shielding pigment.

[0064] <Summary> As described above, the tactile sensor 1 according to the first aspect includes a housing 2, a contactor 3 having a light-transmitting elastic material 31 including a convex contact surface 32 that protrudes forward from one surface 21 of the housing 2, with a marker portion 33 formed on the contact surface 32, and an imaging element 51 that is disposed within the housing 2 and captures an image of the contact surface 32 through the rear surface of the contactor 3 when an object comes into contact with the contact surface 32. The contactor 3 is configured so that when the contact surface 32 comes into contact with an object, the contact surface 32 exhibits a color that corresponds to the temperature of the object.

[0065] According to this embodiment, it is possible to provide a tactile sensor 1 that can simultaneously measure the mechanical quantity that occurs when touching an object and the temperature of the object.

[0066] In the tactile sensor 1 according to the second embodiment, the contact surface 32 in the first embodiment is a convex curved surface that protrudes forward.

[0067] According to this aspect, it is possible to provide a sensor that can measure the shear force, normal force, tangential force, friction coefficient, and torque that occur when coming into contact with an object, as well as the temperature of the object.

[0068] In the tactile sensor 1 according to the third aspect, in the first or second aspect, the light-transmitting elastic material 31 has a light-shielding layer 34 containing a light-shielding pigment in a matrix material, and a thermochromic layer 35 laminated on the light-shielding layer 34 and containing a thermochromic pigment in a matrix material.

[0069] This embodiment can prevent localized variations in the concentration of the light-blocking pigment, making it easier to recognize the color change of the light-transmitting elastic material 31 when it comes into contact with an object through image processing, thereby improving the accuracy of the object temperature measured by the tactile sensor 1.

[0070] In a tactile sensor 1 according to a fourth aspect, the light-blocking pigment is an inorganic pigment or a mixture of an inorganic pigment and an organic pigment. The inorganic pigment is one or more pigments selected from calcium carbonate, zinc oxide, and titanium oxide, and the organic pigment is one or more pigments selected from azo pigments and phthalocyanine pigments.

[0071] According to this embodiment, the tactile sensor 1 can be configured to output a signal that allows the color of the thermosensitive layer 35 to be appropriately recognized through image processing.

[0072] In the tactile sensor 1 according to the fifth aspect, in the third or fourth aspect, the thermochromic pigment is one or more pigments selected from a pigment microencapsulated with a leuco dye, vanadium oxide, and bismuth oxide.

[0073] According to this embodiment, the thermosensitive layer 35 can change color appropriately depending on the temperature of the object, and therefore, the tactile sensor 1 can be made to output a signal that allows the color of the thermosensitive layer 35 to be appropriately recognized through image processing.

[0074] In the tactile sensor 1 according to a sixth aspect, in any one of the third to fifth aspects, the matrix material is one or more materials selected from silicone rubber, polyurethane resin, and thermoplastic elastomer.

[0075] According to this embodiment, the contact body 3 can be configured to be capable of appropriate elastic deformation when measuring a mechanical quantity.

[0076] In the tactile sensor 1 according to the seventh aspect, in any one of the first to sixth aspects, the elongation at break of the light-transmitting elastic material 31 is 200% or more.

[0077] According to this embodiment, it is possible to provide a tactile sensor 1 having a contact body 3 that exhibits a color corresponding to the temperature of an object when it comes into contact with the object, while being able to withstand deformation.

[0078] In the tactile sensor 1 according to the eighth aspect, in any one of the first to seventh aspects, the tensile strength of the light-transmitting elastic material 31 is 6.0 MPa or more.

[0079] According to this embodiment, it is possible to provide a tactile sensor 1 having a contact body 3 that can withstand deformation while exhibiting a color that corresponds to the temperature of an object.

[0080] In the tactile sensor 1 according to the ninth aspect, in any one of the first to eighth aspects, the durometer hardness of the light-transmitting elastic material 31 is not less than A20 and not more than A60.

[0081] According to this embodiment, it is possible to provide a tactile sensor 1 having a contact body 3 that can withstand deformation while exhibiting a color that corresponds to the temperature of an object. [Explanation of symbols]

[0082] 1. Tactile sensor 2. Case 21 one side 3 contact body 31 Translucent elastic material 32 Contact surface 33 Marker section 34 Light blocking layer 35 Temperature layer 51 Image sensor

Claims

1. The housing and a contact body having a light-transmitting elastic material including a convex contact surface protruding forward from one surface of the housing, the contact body having a marker portion formed on the contact surface; an imaging element disposed within the housing, which captures an image of the contact surface through a rear surface of the contact body when an object comes into contact with the contact surface; Equipped with the contact body is configured so that when the contact surface comes into contact with the object, the contact surface exhibits a color corresponding to a temperature of the object; The translucent elastic material is a light-shielding layer containing a light-shielding pigment in a matrix material; a thermochromic layer laminated on the light-shielding layer and containing a thermochromic pigment in a matrix material; having Tactile sensor.

2. The contact surface is a convex curved surface that protrudes forward. The tactile sensor according to claim 1 .

3. the thermochromic pigment is one or more pigments selected from the group consisting of a microencapsulated pigment containing a leuco dye, vanadium oxide, and bismuth oxide; The tactile sensor according to claim 1 .

4. the matrix material is one or more materials selected from silicone rubber, polyurethane resin, and thermoplastic elastomer; The tactile sensor according to claim 1 or 3.

5. The translucent elastic material has an elongation at break of 200% or more. The tactile sensor according to any one of claims 1 to 4.

6. The tensile strength of the translucent elastic material is 6.0 MPa or more. The tactile sensor according to any one of claims 1 to 5.

7. The durometer hardness of the translucent elastic material is A20 or more and A60 or less. The tactile sensor according to any one of claims 1 to 6.

Images