JP2020201124A - Tactile sensor and tactile sensing method - Google Patents

Abstract

To provide a tactile sensor for detecting physical changes such as temperature and pressure.SOLUTION: A tactile sensor 70 includes a tactile sensor terminal 10 having a thermistor 101, a housing section 102 of an elastic body for housing the thermistor 101, and a fluid 103 arranged around the thermistor 101 in the housing section 102. The tactile sensor 70 can have a measurement section 30 for measuring an electric resistance Rx of the thermistor 101 and a capacitance Cx by wiring connected to the thermistor 101, and a detection section 40 for obtaining temperature of an analyte 20 coming into contact with the housing section 102 and displacement of thickness of the housing section 102 from the electric resistance Rx and the capacitance Cx measured by the measurement section 30.SELECTED DRAWING: Figure 1

Description

The present invention relates to a tactile sensor and a tactile sensing method.

Humanoid robots that reproduce human movements are being actively developed, and those that perform movements similar to humans have also appeared and are attracting attention. Such humanoid robots are required to be closer to human movements. For this purpose, not only mechanical reproduction but also advanced reproduction of the sensory system, nervous system, and thinking system is required. Research for such advanced reproduction is also being actively conducted.

Tactile sensors, which are responsible for the sensory system, also occupy an important position in the advanced reproduction of this humanoid robot. This tactile sensor is a part that must handle and process a plurality of physical information such as pressure and temperature at the same time. However, with regard to the tactile mechanism in the human body, there are still many parts that have not been scientifically elucidated, and sensors capable of handling multiple pieces of information at the same time have not been sufficiently developed. Further, by providing a sensor capable of acquiring various physical information, it can be expected to be applied not only to humanoid robots but also to versatile devices.

Regarding the tactile sensor, Patent Document 1 discloses a tactile sensor capable of feeling pressure and temperature, particularly a tactile sensor using a Hall element.

Patent Document 2 includes an elastic body, a sensor portion supported in the elastic body, and a protective film covering the sensor portion, and the protective film forms an internal space around the sensor portion. The characteristic tactile sensor is disclosed.

Patent Document 3 is a method of measuring surface properties such as hardness and sliminess of a target using a fluid, which comprises a contact step of pressing a flexible balloon filled with the fluid against the target and a fluid of the balloon. A fluid control step of controlling and inflating the balloon, a measurement step of measuring a change in the shape of the fluid or the balloon in the expansion of the balloon, and a signal processing of information obtained from the measurement step to obtain hardness and slime. A tactile sensing method using a fluid is disclosed, which comprises an evaluation process for calculating an evaluation value of surface properties such as, etc., and a tactile sensing method using a fluid.

Non-Patent Document 1 discloses a biomimetic tactile sensor that measures force, vibration, and temperature information by using an electrode, a pressure sensor, and a thermistor incorporated inside an artificial finger.

Japanese Patent No. 5999591 Japanese Unexamined Patent Publication No. 2010-1659597 JP-A-2009-198302

T. Yamamoto, N.M. Wettels, J.W. A. Fisher, C.I. H. Lin, G.M. E. Loeb, "BioTac-Biomimetic Tactile Sensor", Journal of the Robotics Society of Japan, Vol. 30 No. 5 PP. 496-498 (2012)

As for the tactile sensor, various tactile sensors have been studied as in Patent Documents 1 to 3. The environment and conditions in which the tactile sensor can be used change depending on the configuration, and the control for detecting the sensor changes. For example, depending on the structure of the sensor, if the magnet in the sensor is affected by the magnetic field and the contact target is metal or the like, detection may not be possible. Therefore, various tactile sensors capable of detecting physical displacement due to temperature, pressure, etc. are required so that the options that can be used in various environments increase.
Under such circumstances, an object of the present invention is to provide a tactile sensor and a tactile sensing method capable of detecting a physical change such as a change in temperature or shape.

As a result of diligent research to solve the above problems, the present inventor has found that the following invention meets the above object, and has reached the present invention. That is, the present invention relates to the following invention.

<1> A tactile sensor having a thermistor, an accommodating portion of an elastic body accommodating the thermistor, and a tactile sensor terminal having a fluid arranged around the thermistor inside the accommodating portion.
<2> From a measuring unit connected to the thermistor and measuring the electric resistance Rx and the capacitance Cx of the thermistor, and the electric resistance Rx and the capacitance Cx measured by the measuring unit, the accommodating unit The tactile sensor according to <1>, which has a detection unit for obtaining the temperature of the subject in contact with the subject and the displacement of the thickness of the housing portion.
<3> The tactile sensor according to <1> or <2>, wherein the thermistor is an NTC type thermistor.
<4> The tactile sensor according to any one of <1> to <3>, wherein the relative permittivity of the fluid is 10 or more.
<5> Contact of the thermistor, the accommodating portion of the elastic body accommodating the thermistor, and the accommodating portion of the tactile sensor terminal having a fluid arranged around the thermistor inside the accommodating portion in contact with the subject. Process and
A measurement step of measuring the electrical resistance Rx and the capacitance Cx of the thermistor when the housing portion is brought into contact with the subject.
A tactile sensing method comprising a detection step of obtaining the temperature of a subject in contact with the accommodating portion and the displacement of the thickness of the accommodating portion from the electric resistance Rx and the capacitance Cx measured in the measuring step.

According to the tactile sensor and the tactile sensing method of the present invention, it is possible to measure the temperature of the subject to which the tactile sensor terminal contacts and the change in the shape of the tactile sensor terminal when the tactile sensor terminal comes into contact with the subject.

It is a schematic diagram of the 1st Embodiment which concerns on the tactile sensor of this invention. It is a schematic diagram for demonstrating the state when the tactile sensor of 1st Embodiment comes into contact with a subject. It is a figure for demonstrating the flow of tactile sensing of a subject using the tactile sensor of this invention. It is an image which imaged the tactile sensor terminal which concerns on Example. It is a figure which shows the result of having evaluated the relationship between the change of the shape of the accommodating part and the ambient temperature, and the change of the electric resistance and the capacitance of the thermistor by the tactile sensor which concerns on this invention. It is a figure which mapped the detection space used by the tactile sensor of this invention for detecting the temperature of the subject which a tactile sensor terminal comes in contact with from the measurement result of the electric resistance and the capacitance. The figure which maps the detection space used by the tactile sensor of this invention for detecting the displacement of the thickness of the accommodating part when the tactile sensor terminal comes into contact with a subject from the measurement result of electric resistance and capacitance. is there.

Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of the embodiments of the present invention, and the present invention is described below unless the gist thereof is changed. It is not limited to the contents of. In addition, when the expression "~" is used in this specification, it is used as an expression including numerical values before and after it.

[Tactile sensor of the present invention]
The tactile sensor of the present invention has a tactile sensor terminal having a thermistor, an accommodating portion of an elastic body accommodating the thermistor, and a fluid arranged around the thermistor inside the accommodating portion. By using such a tactile sensor, the temperature of the subject in contact with the tactile sensor terminal and the change in the shape of the tactile sensor terminal when in contact with the subject are measured from the resistance and capacitance detected by the thermistor. be able to.

[Tactile Sensing Method of the Present Invention]
The tactile sensing method of the present invention covers the accommodating portion of a tactile sensor terminal having a thermistor, an accommodating portion of an elastic body accommodating the thermistor, and a fluid arranged around the thermistor inside the accommodating portion. The contact process of contacting the sample and
A measurement step of measuring the electrical resistance Rx and the capacitance Cx of the thermistor when the housing portion is brought into contact with the subject.
It has a detection step of obtaining the temperature of a subject in contact with the accommodating portion and the displacement of the thickness of the accommodating portion from the electric resistance Rx and the capacitance Cx measured in the measuring step.
According to the tactile sensing method of the present invention, it is possible to measure the temperature of the subject in contact with the tactile sensor terminal and the change in the shape of the tactile sensor terminal when it comes into contact with the subject.
In the present application, the tactile sensing method of the present invention can be performed using the tactile sensor of the present invention, and the configurations corresponding to the respective can be mutually used in the present application.

The present inventors have obtained the following findings in examining a tactile sensor that detects temperature and pressure. The thermistor is a sensor member generally used for measuring temperature. When a liquid is placed around the thermistor's electrodes in a container that houses the thermistor's electrodes, the thermistor's electricity depends on the temperature change of the placed liquid and how the liquid is placed around the thermistor. We have found that the resistance and the capacitance around it are affected. The changes in electrical resistance and capacitance that are affected by this temperature change and the change in the arrangement of liquids behave differently. Therefore, the temperature of the subject is measured by measuring the electrical resistance and capacitance of the thermistor when the tactile sensor terminal comes into contact with the subject by using a tactile sensor terminal having a configuration in which a liquid is arranged around the thermistor. Alternatively, the deformation of the tactile sensor terminal due to the contact between the subject and the tactile sensor terminal, that is, the pressure due to the contact can be measured. The present invention is based on such findings.

[First Embodiment]
FIG. 1 is a schematic diagram for explaining a first embodiment of the tactile sensor of the present invention. The tactile sensor 70 has a tactile sensor terminal 10. The tactile sensor terminal 10 has a thermistor 101, an accommodating portion 102, and a fluid 103. Further, the tactile sensor 70 has a measuring unit 30, a detecting unit 40, a storage unit 50, and a display unit 60 connected to the wiring of the thermistor 101 of the tactile sensor terminal 10. The tactile sensor 70 is used to detect the temperature of the subject 20 and the like.

[Thermistor 101]
The tactile sensor terminal 10 has a thermistor 101. The thermistor 101 is a sensor member that measures the temperature by measuring the current and the voltage with the measuring unit 30 because the electric resistance, the capacitance, and the like change with the change of the temperature. Further, as described in the above-mentioned findings, the thermistor 101 has a change in electric resistance, capacitance, and the like under the influence of the surrounding fluid 103. In the present invention, by measuring the electric resistance and the capacitance of the thermistor 101, such a change in the arrangement of the fluid 103 around the thermistor 101 is also detected.

As the thermistor 101, one whose electric resistance and capacitance change in the temperature range in which the tactile sensor terminal 10 is used can be appropriately used. As the thermistor 101, it is preferable to use an NTC type thermistor (Negative Temperature Coefficient Thermistor). The NTC type thermistor is a thermistor whose resistance gradually decreases with respect to an increase in temperature, and since the tactile sensor 70 can use an object or the like in contact with a person as a subject or the like, it is in a temperature range assuming its usage state. , Easy to measure electrical resistance and capacitance. Most of the commercially available thermistors have electrodes coated with a resin film or the like, but in the thermistor 101 of the tactile sensor terminal 10, the electrodes come into direct contact with the fluid 103 in a state where the electrodes are exposed. When the electrode comes into direct contact with the fluid 103, the change in capacitance corresponding to the state in which the fluid 103 is arranged around the fluid 103 becomes large, and it becomes easy to detect the displacement of the temperature and the thickness of the accommodating portion. It is also possible to detect the pressure from the displacement of the thickness of the accommodating portion by converting the elasticity of the accommodating portion into consideration.

[Accommodation unit 102]
The accommodating portion 102 is an elastic body that accommodates the thermistor 101. The accommodating portion 102 also accommodates the fluid 103, and the fluid 103 is arranged around the thermistor 101 in the accommodating portion 102. As the accommodating portion 102, one having a high sealing property can be used so that the accommodating fluid 103 does not leak. Further, a fluid that is not easily eroded even if it comes into contact with a fluid can be used. Further, the accommodating portion 102 can use a flexible member that deforms when it comes into contact with the subject 20. Further, the accommodating portion 102 may be an insulating member so as not to affect the fluid 103 and the thermistor 101 inside the subject 20 such as magnetic properties and conductivity. Examples of the member suitable for such a housing portion 102 include a rubber member, a plastic member, and a silicone rubber member.

The accommodating portion 102 has a container shape in which one end of a columnar member having a hollow portion such as a cylinder is closed, an electrode portion of the thermistor 101 is arranged inside, the fluid 103 is filled, and the remaining opening portion is sealed. can do. At this time, the wiring connected to the electrode of the thermistor 101 is assumed to protrude from the wall of the accommodating portion 102. Further, the portion where the wiring of the thermistor 101 and the accommodating portion 102 are in contact with each other inside the accommodating portion 102 is sealed.

The shape of the accommodating portion 102 and the thickness of the wall can be arbitrary depending on the use of the tactile sensor 70. The accommodating portion 102 has a main structure of the outer shape of the tactile sensor terminal 10. Therefore, the shape of the accommodating portion 102 is designed according to the shape of the tactile sensor terminal 10 adjusted according to the application of the tactile sensor 70.

[Fluid 103]
The fluid 103 is arranged around the thermistor 101 in the accommodating portion 102. When the accommodating portion 102 comes into contact with the subject 20, the shape of the accommodating portion 102 changes according to the hardness and elasticity of the subject 20, the force with which the tactile sensor terminal 10 comes into contact with the subject, and the like. In order to facilitate the change in the shape of the accommodating portion 102, the accommodating portion 102 has a hollow portion inside, and the hollow portion is filled with the fluid 103. Further, the electric resistance and the capacitance detected by the thermistor 101 also change depending on the state in which the fluid 103 is arranged around the thermistor 101. The electrical resistance and capacitance are also affected by the physical properties of the fluid 103.

Here, the fluid 103 used in the present application refers to a fluid having a fluidity that allows the shape to change in conjunction with the accommodating portion 102 when stress is applied to the accommodating portion 102. The fluid 103 preferably has a density of 0.5 or more, more preferably 0.7 or more. If the density is too low, changes in electrical resistance and capacitance are unlikely to occur, and measurement and detection may be difficult. The upper limit of the density is not particularly set, but an upper limit such as 20 or less, 15 or less, 10 or less, or 5 or less may be set. The fluid 103 has an appropriate density, relative permittivity, etc., and becomes a liquid, gel, or sol in an environment in which the tactile sensor terminal 10 is used so that it can be easily maintained in a sealed state in the accommodating portion 102. Is preferable.

The fluid 103 preferably has a relative permittivity of 10 or more. The relative permittivity is, for example, about 80 for water, 24 for ethanol, 33 for methanol, 32 for propylene glycol, 39 for ethylene glycol, and 47 for glycerin. The higher the relative permittivity, the easier it is to measure the electrical resistance and capacitance of the thermistor 101 of the tactile sensor terminal 10, and it is possible to suppress the influence of noise and detect even slight temperature changes. It also improves accuracy and accuracy. The higher the relative permittivity, the easier it is to measure the electrical resistance and capacitance. Therefore, 20 or more is more preferable, and 30 or more or 40 or more may be the lower limit. The upper limit of the relative permittivity may not be particularly set, but an upper limit such as 1000 or less, 500 or less, or 200 or less may be set.

As the fluid 103, for example, water (tap water or the like), a polar solvent such as alcohol, or a mixed composition thereof can be used. Further, as a thickening liquid, a sol, or a gel obtained by adding a thickener or the like for improving the viscosity to these liquids, a conductive member for suppressing leakage from the accommodating portion 102 or improving the relative permittivity was mixed. It may be a composition.

[Tactile sensor terminal 10]
The tactile sensor terminal 10 has a thermistor 101, an accommodating portion 102, and a fluid 103. The shape of the tactile sensor terminal 10 can be, for example, a finger imitation. Further, regardless of the shape of the finger, any shape may be used to detect the temperature of the subject in contact. For example, the outer shape may be a cylinder, a prism of a polygonal prism, or a planar shape. The diameter of the cylinder can be 0.3 mm or more. One side of the surface can be 0.3 mm or more. The diameter and the size of the sides may be 0.5 mm or more, 1 mm or more, and 2 mm or more.

Further, the number of thermistors 101 arranged inside the accommodating portion of the tactile sensor terminal 10 may be one, but a plurality of thermistors 101 may be provided, such as two or more or three or more. Alternatively, the tactile sensor terminals 10 may be arranged in an array. By using a tactile sensor having a plurality of thermistors and a plurality of tactile sensor terminals, it is possible to map and detect the state such as the temperature of the subject at the position corresponding to each thermistor or the tactile sensor terminal in more detail.

The subject 20 can be any one used by contacting the tactile sensor. For example, metal members, resin members, wood, industrial products, foods, household products, etc., and the members and uses thereof can be arbitrary.

The tactile sensor 70 of the first embodiment has a tactile sensor terminal 10, further includes a measuring unit 30, a detecting unit 40, a storage unit 50, and a display unit 60. With these configurations, the temperature of the subject 20 to which the tactile sensor terminal 10 comes into contact can be measured, and the measurement result can be appropriately displayed on the display unit 60.

[Measuring unit 30]
The measuring unit 30 is a part that measures the electric resistance Rx and the capacitance Cx. The measuring unit 30 is used in a state of being connected to the wiring of the thermistor 101 of the tactile sensor terminal 10.

The electric resistance Rx changes according to the type of thermistor, the size of the tactile sensor terminal 10, the temperature of the subject, the amount of change in shape such as the displacement of the thickness of the accommodating portion 102, and the like. Use a device that can measure according to this changing range. For example, the range of electrical resistance can be assumed to be displacement in the range of about 1Ω to 1MΩ, and when it is assumed to be used at a temperature of about 0 ° C to 50 ° C, the range of about 1kΩ to 100kΩ is measured. Can be. The electric resistance Rx includes the case where a value measured by another physical quantity that correlates with the electric resistance Rx is used. For example, the case where a voltage or the like is measured and the value is used as corresponding to the electric resistance Rx is also included.

The capacitance Cx changes according to the type of thermistor, the size of the tactile sensor terminal 10, the temperature of the subject, the amount of change in shape such as the displacement of the thickness of the accommodating portion 102, and the like. Use a device that can measure according to this changing range. For example, the capacitance range can be assumed to be a displacement in the range of 1 picofarad (pF) to 1 millifarad (mF), and it is assumed to be used at a temperature of about 0 ° C to 50 ° C. In this case, it is possible to measure a range of about 100 pF to 10 μF.

[Detection unit 40]
The detection unit 40 is a portion that obtains the temperature of the subject 20 in contact with the storage unit 102 and the displacement of the thickness due to the deformation of the storage unit 20 from the electric resistance Rx and the capacitance Cx measured by the measurement unit 30.
In the thermistor 101, the electric resistance Rx and the capacitance Cx change under the influence of the temperature Tx in the place where the thermistor 101 is arranged. Further, when the fluid 103 is arranged around the thermistor 101, the electric resistance Rx and the capacitance Cx change depending on the fluid 103 around the fluid 103. When the tactile sensor terminal 10 does not come into contact with the subject, the thickness of the accommodating portion 102 in the same direction as the direction (D1) of connecting the centers of the pair of electrodes of the thermistor 101 is L0 (FIG. 1). When the end portion of the thickness L0 is brought into contact with the subject 20 with a constant force, since the accommodating portion 102 is an elastic body, it becomes flat due to the hardness and elasticity of the subject 20, the stress applied to the tactile sensor terminal 10, and the like. Deform. FIG. 2A shows a state in which the tactile sensor terminal 10 is brought into contact with the subject 20 with a relatively weak force, the amount of deformation is small, and the thickness is L1. Further, FIG. 2B is a diagram showing an outline of the tactile sensor terminal 10 when the subject 20 is brought into contact with the subject 20 with a stronger force than that of FIG. 2A. At this time, the accommodating portion 102 is deformed in a more flat shape, and the thickness is L2. When this thickness is deformed from L0 to L1 or L2, the arrangement of the liquid around the electrodes changes, the electric charge moving around the electrodes changes, and the electric resistance Rx and the capacitance Cx change. The thickness Lx under a predetermined condition varies depending on the pressure of pressing the tactile sensor terminal 10 against the subject, the elastic modulus of the accommodating portion 102, the hardness of the subject 20, and the like. Therefore, the hardness of the subject 20 is obtained by keeping the pressure applied to the tactile sensor terminal 10 constant, and the stress is obtained from the thickness Lx by grasping information such as the hardness of the subject 20 in advance. It may be a thing.

Generalizing the relationship between the electrical resistance Rx, the capacitance Cx, the temperature Tx of the subject 20 when the tactile sensor terminal 10 comes into contact with the subject 20, and the thickness Lx of the accommodating portion 102 around the thermistor 101. , The equations (A1) and (A2) are established, respectively. gx is a coefficient for obtaining Rx, and gc is a coefficient for obtaining Cx. Here, the electric resistance Rx is more susceptible to changes in the temperature Tx. On the other hand, the capacitance Cx is easily affected by the amount of liquid between the electrodes of the thermistor 101 and is easily affected by the thickness Lx because the capacitance of the fluid 103 around it is also apparently easily measured.
Rx = gx (Tx, Lx) equation (A1)
Cx = gc (Tx, Lx) equation (A2)

The temperature Tx and the thickness Lx can be detected by using the formulas (A1) and (A2). ft is a coefficient for obtaining Tx, and fl is a coefficient for obtaining Lx. By obtaining in advance the coefficients of the equations (B1) and (B2) corresponding to the electrical resistance Rx corresponding to the conditions of the tactile sensor terminal 10 and the measurement result of the capacitance Cx, the temperature of the subject 20 and the temperature of the subject 20 can be determined. It is possible to obtain the change in the thickness of the tactile sensor terminal 10 when it comes into contact with the subject 20.
Tx = ft (Rx, Cx) equation (B1)
Lx = fl (Rx, Cx) equation (B2)

In addition, in order to make it easy to measure the temperature Tx and the thickness Lx based on the equations (B1) and (B2), the thickness L0 is such that the thickness around the thermistor changes sufficiently to increase the electric resistance Rx and the static value. It is preferable that the size is such that the displacement of the capacitance Cx can be easily detected. From such a viewpoint, the lower limit of the thickness L0 is preferably 0.8 mm or more, and more preferably 1.0 mm or more. Further, it may be 1.5 mm or more, 2.0 mm or more, or 2.5 mm or more. It is not necessary to set an upper limit for the thickness L0, but if it becomes too thick, the ratio of the amount of change such as the relative capacitance to the amount of change such as the displacement of the thickness becomes small, or the sensor becomes large. Therefore, since it may be difficult to handle, an upper limit such as 50 mm or less, 30 mm or less, 20 mm or less, and 15 mm or less may be set.

The electrical resistance Rx and capacitance Cx measured by the measuring unit 30, the equations (B1) and (B2) for the detecting unit 40 to obtain the temperature Tx and the thickness Lx, and the detected temperature Tx and thickness. Information such as Lx can be appropriately stored in the storage unit 50, and the stored information can be read as needed to use the tactile sensor 70.
In addition, predetermined information such as the detected temperature Tx and the thickness Lx can be displayed on the display unit 60 as necessary. The electric resistance Rx, the capacitance Cx, or the voltage to be measured as corresponding to these can be measured by the measuring unit 30. The measuring unit 30 may have a microcomputer or the like provided with an electronic circuit for measuring them. Further, the detection unit 40 or the like that processes the data measured by the measurement unit 30 shall show these functions by using a personal computer having a program or the like having these functions, a notebook PC, a tablet terminal, or the like. can do.

FIG. 3 is a flowchart of the tactile sensing method S1 according to the present invention. As the tactile sensor terminal for performing this tactile sensing method, for example, the tactile sensor terminal 10 as described in the first embodiment can be used.
The tactile sensing method S1 first performs a contact step S11 in which the accommodating portion of the tactile sensor terminal is brought into contact with the subject. Next, the measurement step S21 for measuring the electrical resistance Rx of the thermistor and the capacitance Cx when the accommodating portion of the tactile sensor terminal is brought into contact with the subject is performed by the measuring unit connected to the wiring of the thermistor. Then, there is a detection step S31 for obtaining the temperature of the subject in contact with the accommodating portion and the displacement of the thickness of the accommodating portion from the electric resistance Rx and the capacitance Cx measured in the measuring step S21. The temperature of the subject detected in the detection step S31 and the displacement of the thickness of the accommodating portion are displayed by the display step S41 displayed on the display unit.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is changed.

[Tactile sensor terminal (1)]
-Thermistor (1): An ultra-thin thermistor (thickness 500 μm, "103JT-050" manufactured by SEMITEC) was used in a state where the electrode was exposed by removing the coating on the tip portion.
-Accommodation part (1): A silicone tube having a diameter of 3.8 mm was used.
-Fluid (1): Tap water was used.
One end of the opening of the cylinder of the accommodating portion (1) was sealed, the thermistor (1) was placed in the hollow portion of the accommodating portion (1), and the fluid (1) was added. Then, in a state where the wiring of the thermistor (1) was led out to the outside, the opening of the accommodating portion (1) was sealed. As a result, a tactile sensor terminal (1) filled with a fluid (1) around the electrode portion of the thermistor (1) was obtained in the accommodating portion (1).
FIG. 4 is an image of the tactile sensor terminal (1).

The wiring of the tactile sensor terminal (1) was connected to an impedance meter (Hioki Electric "impedance analyzer IM3570") so that the electrical resistance and capacitance of the tactile sensor terminal (1) could be measured.
The tactile sensor terminal (1) was gripped by a miniature device having a predetermined temperature, and the influence of the temperature change and the change in diameter (deformation amount) gripped by the miniature device was evaluated. The tactile sensor terminal (1) was deformed so as to be crushed from the direction perpendicular to the electrode surface of the thermistor (1).
FIG. 5 shows the results of evaluating the relationship between the electric resistance and the amount of deformation, the electric resistance and the temperature, the capacitance and the amount of deformation, and the capacitance and the temperature. Further, in the measurement, the measurement was performed when the measurement frequency was 1 kHz and when the measurement frequency was 10 kHz. The measurement results are summarized in FIG.

As is clear from FIG. 5, the electric resistance and the capacitance show different behaviors in the amount of deformation and the temperature. From this, it is possible to measure the temperature of the subject in contact with the tactile sensor (1) and the amount of deformation of the tactile sensor (1) by measuring the electric resistance and the capacitance.

FIG. 6 shows a spatial distribution for measuring the temperature from the measurement results of the electrical resistance and the capacitance based on the measurement results of the tactile sensor terminal (1). Further, FIG. 7 shows a spatial distribution for measuring the displacement (change in shape) of the thickness of the accommodating portion from the measurement results of the electric resistance and the capacitance.

Using the spatial distributions of FIGS. 6 and 7, the temperature and thickness displacements when the tactile sensor terminal (1) was pressed by a miniature device prepared separately from the test for FIG. 5 were detected. The values detected from the measurement results of the electric resistance and the capacitance by pressing with this miniature device were a temperature of 25.5 ° C. and a thickness of 1.4 mm (displacement 2.4 mm). The set values of the miniature device in this test state were a temperature of 25.7 ° C. and a thickness of 1.3 mm (displacement 2.5 mm). From this result, it was confirmed that the displacement of temperature and thickness can be measured with excellent accuracy by the tactile sensor using the tactile sensor terminal (1).

The tactile sensor terminal (2) was manufactured using ethanol instead of water as the fluid (1). Further, the tactile sensor terminal (3) was manufactured by using silicone oil instead of water as the fluid (1).
As for the configuration of the tactile sensor terminal (2) and the tactile sensor terminal (3), the displacement of temperature and thickness can be measured by obtaining the electric resistance and capacitance corresponding to the displacement of temperature and thickness. It was. On the other hand, ethanol and silicone oil have a lower relative permittivity than water, have less change in electrical resistance and capacitance, and have slightly lower measurement accuracy. In particular, silicone oil has a low absolute value of capacitance, which makes it difficult to measure.

The present invention applies to a tactile sensor that measures temperature and pressure, can be used as a tactile mechanism of a robot, and is industrially useful.

10 Tactile sensor terminal 101 Thermistor 102 Accommodating unit 103 Fluid 20 Subject 30 Measuring unit 40 Detection unit 50 Storage unit 60 Display unit 70 Tactile sensor

Claims (5)

A tactile sensor having a thermistor, an accommodating portion of an elastic body accommodating the thermistor, and a tactile sensor terminal having a fluid arranged around the thermistor inside the accommodating portion. A measuring unit connected to the thermistor and measuring the electric resistance Rx and the capacitance Cx of the thermistor,
The first aspect of claim 1, further comprising a detecting unit for obtaining the temperature of a subject in contact with the accommodating portion and the displacement of the thickness of the accommodating portion from the electric resistance Rx and the capacitance Cx measured by the measuring unit. Tactile sensor. The tactile sensor according to claim 1 or 2, wherein the thermistor is an NTC type thermistor. The tactile sensor according to any one of claims 1 to 3, wherein the relative permittivity of the fluid is 10 or more. A contact step of bringing the thermistor, an accommodating portion of an elastic body accommodating the thermistor, and the accommodating portion of a tactile sensor terminal having a fluid arranged around the thermistor inside the accommodating portion into contact with a subject.
A measurement step of measuring the electrical resistance Rx and the capacitance Cx of the thermistor when the housing portion is brought into contact with the subject.
A tactile sensing method comprising a detection step of obtaining the temperature of a subject in contact with the accommodating portion and the displacement of the thickness of the accommodating portion from the electric resistance Rx and the capacitance Cx measured in the measuring step.