JPH06273396A - Tactile sensor - Google Patents

Abstract

PURPOSE:To make it possible to acquire tactile information of an object by detecting physical characteristics representative of the hardness or softness of the object, i.e., elastic characteristics, time response and nonlinear elastic characteristics. CONSTITUTION:A detecting section 33 comprises a horizontally polarized piezoelectric 23 and a vertically polarized piezoelectric 18 fixed integrally to the same plane of a substrate 32. Since at least two piezoelectrics 23 are employed, directions of polarization do not match each other and, therefore, they are disposed perpendicularly to each other. Detection circuits 39, 41 detect elastic characteristics in the longitudinal and lateral directions from the potential differences between the electrodes 37, 38 and 35, 36 of the piezoelectrics 18, 23 and further detect transmitting/receiving waves, caused by the longitudinal and lateral oscillations generated from drive circuits 40, 42, by the piezoelectric effects of the piezoelectrics 18, 23. An arithmetic processing circuit 60 calculates the central frequency and the maximum amplitude of the voltage waveform, and the position of nonlinear elastic part caused by an echo signal in ultrasonic probing and outputs an elastic characteristic output 8, a time response output 55 and a nonlinear elastic characteristic output 59.

Description

Detailed Description of the Invention

[0001]

The present invention aims to obtain tactile information in minimally invasive surgery such as closed surgery in the medical field and cell manipulation in the bio field.
The present invention relates to a tactile sensor arranged in a portion that comes into contact with an object such as a manipulator.

[0002]

2. Description of the Related Art Recently, endoscopes, microscopes and the like have come to place more importance on the function of manipulating an observation object while observing, rather than the function of an instrument for observing.

As a manifestation of this, a rigid endoscope has recently been used for cholecystectomy, and a sample has been manipulated by micromanipulation under a microscope.

However, in such a situation where the field of view is limited, tactile information is more important than visual information in order to appropriately perform more complicated and finer operations. Of this tactile information, the most important information is the hardness and softness of the object.

[0005] For example, it is impossible or impossible at all to perform palpation of cancer metastasis or the like, which was previously possible with open surgery during surgery, as a closed surgery. I am falling.

[0006] Further, in the operation of cells under a microscope, the softness of the cells is not transmitted to the operator, which is a very difficult task such as destroying or dropping the cells.

Thus, the transmission of tactile information has become an important issue.

However, what is the sense of touch is not currently defined, but in the present invention, various factors that are considered to constitute the sense of touch are listed, and the sense of touch is extracted by extracting those factors from the object. I thought it would be possible to sense

The hardness and softness of the object were considered to be composed of the following three factors.

The first is an elastic characteristic (here, it means a contact stress characteristic), the second is a time response, and the third is a non-linear elastic characteristic.

The elastic characteristics are elastic characteristics in the direction perpendicular to the surface of the object (longitudinal direction) (contact stress characteristics) and elastic characteristics in the direction along the surface of the object (lateral direction) (contact stress characteristics). The characteristic is that the parts having different mechanical impedances other than the contact part in the depth direction of the object affect the mechanical impedance of the contact part.

The nonlinear elastic property is, for example, the hardness on the surface in the case where the contact part is connected to a hard tissue such as bone in the living body and the condition where the contact object is not in contact with other objects such as dangling. It is empirical to know that the senses of are different.

However, the conventional tactile sensor is represented by a tactile sensor using conductive rubbers 101 and 102 as shown in FIG. 36, and when this tactile sensor applies a voltage to both ends of the conductive rubbers 101 and 102 and an external force is applied thereto. The conductive rubber in that portion is deformed, and the resistance value of the rubber changes.

By detecting the change in the resistance value as the change in the voltage, the elasticity of the tactile sense in the vertical direction is detected.

Further, as a method and an apparatus for measuring the hardness characteristic of a substance, a method for obtaining the hardness and softness of the object by obtaining the natural frequency of the object (for example, JP-A-3-816).
41).

In this method, as shown in FIG. 37, the piezoelectric vibrator 103 is incorporated into a self-exciting circuit P composed of an amplifying circuit section 104 and a measuring section 105 composed of a frequency measuring instrument 106 or a voltage measuring instrument 107, and the The natural frequency when not in contact and the natural frequency when in contact with the target object are obtained from the frequency detected by the vibration detecting element 108 attached to the piezoelectric vibrator 103, and the difference between the two determines the target object. An apparatus and method for detecting hardness and softness.

[0017]

However, as shown in FIG.
The tactile sensor is a pressure sensor, that is, it can detect only elastic characteristics in a direction (vertical direction) perpendicular to the surface of an object that is a part of the elements forming the sense of touch.

The method for determining the hardness and softness by detecting the natural frequency of the tactile sensor of FIG. 37 is to measure the hardness by detecting only the imaginary part of the mechanical impedance composed of the real number part and the imaginary number part. However, other factors such as non-linear elastic properties are not detected, which is insufficient to measure the hardness and softness of the object.

Further, in this method, since a sensor for a vibration pickup is attached to a contact portion with an object,
Miniaturization becomes very difficult, and the resonance frequency of the sensor itself is low, so it is easily affected by vibration due to disturbance, and a large resonance sharpness (Q) is required to detect the deviation of the resonance frequency. It is necessary to have it, but it is difficult due to its structure.

Further, even if a relatively large resonance sharpness is obtained, the resonance frequency becomes sensitive to the ambient temperature change and the temperature drift becomes large.

Therefore, the sensitivity is lower than that in the method of obtaining the vibration amplitude.

Further, regarding the elastic characteristic, only one of the horizontal direction and the vertical direction can be detected.

Next, an ultrasonic probe used in an ultrasonic diagnostic apparatus which is considered to be relatively close to the concept of the present invention will be described.

FIG. 1 is a sectional view of a general ultrasonic probe.

The ultrasonic diagnostic apparatus is generally known as a device for detecting a non-linear elastic characteristic, and the ultrasonic diagnostic apparatus uses ultrasonic waves so that the internal state of an object that cannot be seen directly by the human eye. It is a device that can visualize the object without destroying the object.

FIG. 2 shows the basic structure of the ultrasonic probe.

The probe has a structure in which electrodes 8 and 9 are provided on the left and right of the piezoelectric body 7, and by applying an electric signal 10 (for example, continuous wave or pulse wave) to the electrodes, the amplitude of the signal is changed. The structure is such that ultrasonic waves of the appropriate intensity are generated.

Using this ultrasonic wave, the structure in the depth direction is sensed. The basic measurement principle is as shown in FIG. 3, and the ultrasonic wave 11 transmitted from the probe 6 hits the object,
The reflected waves 13 and 14 are repeated by repeating reflection 13 and transmission 12.
The principle is to receive by the sensor.

This ultrasonic reflection signal is the acoustic impedance of the propagation media A, B and C shown in FIG. 3 (defined by the product of the speed of sound and the density of the substance and equivalent to the resistance of the electric circuit).
Is reflected by each interface and contains information in each medium.

For example, when ultrasonic waves are transmitted from the probe 6 to the sponge object 15 as shown in FIG. 4A, the ultrasonic waves are respectively generated at points A, B, C and D of the sponge 15. Is reflected.

What receives this reflected wave becomes the RF output signal of FIG. 4 (b), which is point A, point B, point C, and D, respectively.
The signal waveform corresponding to the point is output.

When the signals of points A, B, C, and D of this RF signal are detected as shown in FIG. 4C and the brightness is modulated as shown in FIG. 4D, the front surface of the probe 6 is detected. Information of the ultrasonic radiation direction, that is, point A with different acoustic impedance,
The positions of points B, C, and D can be displayed as one scanning line.

The information displayed when the probe 6 is scanned laterally becomes a signal having a different brightness due to the difference in the acoustic impedance inside the target, and the information between the water 16, the sponge 15 having a different acoustic impedance, and the surrounding water. A tomographic image is displayed as a grayscale image on.

As described above, this is for capturing the ultrasonic echo signal and not for detecting the mechanical impedance of the target object. Hardness and softness cannot be detected.

Further, at the time of measurement, the probe 6 is passed through the water 16
Since the vibration is transmitted between the object 15 and the object 15, only the vibration of the longitudinal wave propagates due to the characteristics of water, and the measurement is performed using only the longitudinal ultrasonic wave, so that the hardness in the lateral direction cannot be detected.

In the structure shown in FIG. 4A, tissues having different elastic characteristics exist in the traveling direction of the ultrasonic beam, and such a structure is nonlinear in the present invention. It is defined as an elastic body.

Therefore, what can be measured by the ultrasonic diagnostic apparatus is that the existence of the non-linear elastic body is known, and the hardness and softness of the object cannot be measured.

It is an object of the present invention to provide a tactile sensor which detects the above-mentioned problems and detects an elastic characteristic, a time response and a non-linear elastic characteristic which are physical characteristics indicating hardness and softness of an object.

[0039]

First, the basic principle of the present invention will be described.

The hardness and softness of the object are considered to be composed of the following three elements, the first being the elastic characteristic,
The third is the time response and the third is the nonlinear elastic property.

The elastic characteristic is detected by measuring contact stress in a direction perpendicular to the surface of the object (longitudinal direction) and contact stress along the surface of the object (lateral direction), that is, a sliding force, and time response. Is detected by measuring the vibration response to the vibration and calculating the mechanical impedance of the object.The detection of the non-linear elastic characteristics is performed using ultrasonic waves, and the mechanical impedance of the parts with different mechanical impedance other than the contact part is detected. And that position is performed.

Therefore, the sensor for detecting these characteristics is made of a material capable of transmitting and receiving ultrasonic waves and capable of detecting force, and it is considered that the piezoelectric body is suitable as the material. To be For example, piezoelectric ceramics, polymer piezoelectric materials, and composite piezoelectric materials can be considered as piezoelectric materials.

The piezoelectric material is shown in FIGS. 5 (a), 5 (b) and 6
5A, 5B, 7A, and 7B, the piezoelectric effect of generating charges by applying stress or strain to the crystal, and conversely to FIGS. 5C and 5D, FIG. 6 (c),
As shown in (d), FIG. 7 (c), and (d), it has an inverse piezoelectric effect in which force and strain are generated when an electric field is applied.

The piezoelectric effect is the stress T applied to the crystal, the electric field E,
This is an effect that the four factors of strain S and electric displacement D occurring in the crystal are mutually related. When T and E are selected as independent variables, the relational expression is as follows.

[0045]

[Equation 1] The formula (1) is called a piezoelectric basic formula (d form), and the electric field E and the electric displacement D can be expressed by vector quantities, and the stress T and the strain S can be expressed by symmetric tensor quantities.

The subscript of the voltage output constant g _ij indicates the direction vector i of the electric displacement with respect to the stress applying direction (second-order tensor) j, and the subscript of d _ij indicates the electric field strength with respect to the straining direction i. , The subscript of ε _ij indicates the direction j of electric field strength with respect to the direction i of electrical displacement, and the subscript of s _ij indicates the direction j of strain with respect to the direction i of stress. There is.

S ^E is the elastic compliance when the electric field is constant, and ε ^T is the dielectric constant when the stress is constant.

The total number of coefficients contained in this is 9 × 9 = 8
Although it is one, the symmetry of both the matrices s ^E and ε ^T is taken into consideration, and the symmetry of the crystal becomes high, and the direction of the polarization axis of the piezoelectric body is taken as the x-axis, and in the plane perpendicular to this. The two axes orthogonal to each other are defined as y-axis and z-axis.

The x, y, and z axes may be referred to as 1-axis, 2-axis, and 3-axis.

Then, the coefficient matrix of the basic piezoelectric equation becomes very simple.

That is, there are only 10 non-zero independent coefficients of s ₁₁ ^E , s ₁₂ ^E , s ₁₃ ^E , s ₃₃ ^E , s ₄₄ ^E d ₁₅ , d ₃₁ , d ₃₃ ε ₁₁ ^T and ε ₃₃ ^T. .

Therefore, by using these ten coefficients, the piezoelectric effect and the inverse piezoelectric effect can be expressed by mathematical expressions.

The piezoelectric effect is as shown in FIG.
Is an effect of generating an electric charge by applying a force to the force.

[0054]

[Equation 2] Here, V is the generated voltage, F is the applied force, and L is the piezoelectric body 18.
, S is the cross-sectional area of the piezoelectric body 18, and g _ij is the voltage output constant. The voltage output constant g _ij refers to the strength of the electric field generated when a unit stress is applied in the state of zero electric displacement, and is generally called the g constant. The g constant is obtained from the following equation.

[0055]

[Equation 3] The g ₃₃ constant is a proportional constant of a voltage generated in proportion to a strain amount Δx when a force is applied from the polarization direction and the strain is distorted in the polarization direction as shown in FIGS. 5A and 5B.

The generated voltage is detected by the electrodes 19 and 20 mounted on the surface perpendicular to the polarization direction.

The g ₁₅ constant has a sliding stress applied in a direction along the polarization direction as shown in FIGS.
It is a proportional constant of the voltage generated in proportion to the slip strain amount Δy when strained in that direction.

The generated voltage is detected by the electrodes 19 and 20 attached to the surface to which force is applied.

As shown in FIGS. 7A and 7B, the g ₃₁ constant is proportional to the strain amount Δy when a force is applied in a direction perpendicular to the polarization direction and the strain is distorted in the direction perpendicular to the polarization direction. Is a proportional constant of the generated voltage.

The generated voltage is detected by the electrodes 19 and 20 mounted on the surface perpendicular to the polarization direction.

Since the tactile sensor of the present invention detects elastic properties in the vertical and horizontal directions, g ₃₃ and g _{15 of the} three g constants are used.
Is used as a sensor.

Then, g ₃₃ is used for detecting the elastic characteristic in the vertical direction, and g ₁₅ is used for detecting the elastic characteristic in the horizontal direction.

The respective output voltages V ₃ and V ₁ are given by the equation (4).

[0064]

[Equation 4] Becomes

The voltage generated by this piezoelectric effect is detected by using a circuit as shown in FIG.

This circuit is a circuit that simply uses an operational amplifier with a high input impedance to amplify the voltage generated by the piezoelectric effect.

Using the above effects, the force applied to the piezoelectric body can be converted into a voltage, and the elastic characteristic of the object can be obtained from this voltage signal.

On the other hand, the inverse piezoelectric effect is used for measuring the time response and the non-linear elastic characteristic as shown in FIGS. 5 (c), (d) to 7 (c), (d). Is the effect that force or strain is generated when an electric field is applied.

[Equation 5] Where s is the compliance (elastic constant)
And S and L are the same as those used in the equation (4). The amount of displacement L that occurs is expressed by equation (6)

[Equation 6] Is.

Since both the time response and the measurement of the non-linear elastic characteristic vibrate the object, an AC voltage 22 is applied to the piezoelectric body 18 and the surface of the piezoelectric body is vibrated according to the frequency of the AC voltage.

Although ultrasonic waves can be generated from the piezoelectric body 18 by this phenomenon, since the resonance frequency differs depending on the vibration mode determined by the shape and size of the vibrator, it is advantageous in terms of circuit configuration to use the impedance response. .

FIGS. 10A and 10B show the impulse response when the piezoelectric body 18 has no load.

When a pulse signal as shown in FIG. 10A is applied to the piezoelectric body 18, the piezoelectric body vibrates as shown in FIG. 10B, and the resonance frequency f _noload at this time _{depends on} the shape and size of the piezoelectric body. It is a determined resonance frequency, and vibrates with an amplitude V _noload depending on the resonance sharpness Q.

However, in FIG. 10B, for the sake of explanation, the applied pulse voltage waveform component is removed from the output signal from the piezoelectric body.

The constant related to the resonance frequency is the frequency constant N.

The sound velocity of the vibration wave propagating through the piezoelectric body has a constant value for each vibration mode, and the piezoelectric body having a constant shape has a vibration wavelength λ and a length 1 in the propagation direction at resonance. There is a relationship of expression (7) between them, and expressions (8) and (9) are established from the relationship between the sound velocity v, the frequency f and the wavelength.

[0076]

[Equation 7]

[Equation 8]

[Equation 9] Therefore, the frequency of the ultrasonic wave is the formula (10)

[Equation 10] Given in.

Since the mechanical quality factor Q _m (resonance sharpness) is involved in the amplitude at resonance, the amplitude L at resonance is given by the equation (11).

[0078]

[Equation 11] Since it is necessary for tactile sensing to detect not only longitudinal changes but also lateral changes in both time responsiveness and non-linear elastic characteristics, it is necessary to use the vertical direction as the polarization direction of the piezoelectric body used for measuring elastic characteristics. Uses polarization and horizontal polarization.

Although ultrasonic waves are transmitted as described above, reception is performed as follows.

Since the piezoelectric body has a piezoelectric effect and an inverse piezoelectric effect, ultrasonic waves can be transmitted and received by one element.

The piezoelectric body vibrates due to the reflected ultrasonic waves or the vibration of the object, and a voltage is generated by the piezoelectric effect.
It becomes possible to detect vibration as an electric signal.

Therefore, it is possible to detect the amplitude and frequency of the vibration by attaching a circuit capable of reading the time change, and it is possible to detect the time responsiveness and the non-linear elasticity characteristic by using the transmission and reception of ultrasonic waves. Become.

The detection of the non-linear elasticity characteristic is performed by a deep echo using an ultrasonic transducer which is generally used.

An ultrasonic probe 6 as shown in FIG. 1 is composed of a piezoelectric vibrator 1, a damping layer 2, a matching layer 3, a housing 4 and a lead wire 5. The piezoelectric vibrator 6 of this ultrasonic probe 6 has a structure as shown in FIG. The electroacoustic connection including the damping layer 2, the matching layer 3 and the matching layer 3 can be expressed as shown in FIG. 11 by a subordinate connection of a four-terminal circuit and a two-terminal connection at the terminal.

The damping layer 2 and the matching layer 3 here play the following roles.

When ultrasonic waves are transmitted to the object with the structure as shown in FIG. 2, the ultrasonic waves are directly transmitted from the substance having high impedance such as the piezoelectric body to the object having low impedance, and the matching between them is measured. The matching layer 3 is an element that needs to be matched.

Impedance matching is measured by this layer.

Further, a structure for suppressing the vibration of the piezoelectric body on the surface which does not need to be transmitted is required.

Therefore, the dampening layer 2 is provided in order to absorb the ultrasonic waves emitted to the surface that does not come into contact with the object.

There is an optimum degree of matching and damping.

When ultrasonic waves are used to measure the non-linear elastic characteristics and the time response, theoretical support for the ultrasonic wave transmission / reception characteristics of the ultrasonic transducer 1, that is, the ultrasonic transducer, can be obtained by the handling described below.

That is, the 3-port theory of the transducer and Mason's equivalent circuit are used.

According to this equivalent circuit, the piezoelectric vibrator 1 is shown in FIG.
2, the matching layer 3 can be represented as shown in FIG. 13, the damping layer 2 as shown in FIG. 14 (a), and the target object 27 as shown in FIG. 14 (b).

Therefore, the load medium 27 and the electrical matching circuit 2
When the entire system including 8 is shown, it becomes a subordinate connection of a 4-terminal circuit and a connection with a 2-terminal circuit at the terminal end as shown in FIG.

When this FIG. 15 is displayed in a matrix form, it becomes FIGS. 16 (a) and 16 (b).

Here, A _P , B _P , C _P and D _{P in FIG.}
The F parameter of the 4-terminal circuit is expressed by equation (12),

[Equation 12] Further, the entire matrix elements A, B, C and D including the matching circuits of FIGS. 16 (a) and 16 (b) are expressed by the equation (13).

[0097]

[Equation 13] Using these matrix elements A, B, C and D, FIG.
The response voltage E ₁ when the voltage E _s is applied to the systems of (a) and (b) can be expressed as in equation (14).

[0098]

[Equation 14] From the equation (14), the input voltage E _s , the power source resistance R _s , the acoustic impedance Z _{0t of the} medium, the load resistance R _l , and each matrix element are known, and from the equation (14), the mechanical impedance Z _{0t of the} object is Desired.

That is, the frequency characteristic which is the absolute value can be known.

The frequency characteristic of the real part and the imaginary part of the mechanical impedance can be obtained from the frequency characteristic of the absolute value and the phase of the mechanical impedance of this complex display.

Since the frequency characteristic represented by the equation (14) and the time response have a Fourier transform relationship, that is, a one-to-one correspondence relationship, the physical meanings are equivalent characteristics.

Therefore, the mechanical impedance of the object can be known from the time response.

Further, the nonlinear elasticity characteristic can be detected from the time until the reflected wave of the transmitted ultrasonic wave is received and the frequency time characteristic at that time.

The operation method based on the above theory will be described below.

FIG. 17 is an explanatory diagram showing the operating method.

FIG. 18 is a schematic diagram of ultrasonic wave propagation in a living body. 17 (a), (b), (c), and (d) are diagrams of the frequency characteristics of the input signal, the output signal, the transmission signal waveform 29, and the reception signal waveform 30, respectively.

However, in FIG. 17B, for the sake of explanation, the pulse component is removed from the output signal of the piezoelectric body.

The voltage applied to the piezoelectric vibrator is shown in FIG.
As shown in, the voltage waveform is close to the delta function.

By applying this delta function-like voltage, the piezoelectric body is vibrated and excited at its resonance frequency, and this vibration vibrates as a single vibration system with the object 27 as shown in FIG. 18 to obtain a transmission signal waveform 29 ( (Impulse response as shown in FIG. 17B), propagated in the object 27 as the ultrasonic wave 11,
When reaching the nonlinear elastic tissue portion 31, the vibration is reflected there, and returns to the piezoelectric body 7 as an echo signal 13 to vibrate the piezoelectric body 7 to obtain a reception signal waveform 30 as shown in FIG. 17B. To be

It is _assumed that the amplitude of the transmission signal waveform 29 is V _1max and the center frequency is f _10, and the amplitude of the reception signal waveform 30 is V _2max and the center frequency is f ₂₀ .

Amplitude V when there is no load in FIG.
_noload , center frequency f _noload , amplitudes V _1max and V _{2max of} transmission signal waveform 29 and reception signal waveform 30, and center frequency f ₁₀ ,
When f ₂₀ is compared, there is a relationship between the amplitude attenuation of V _noload > V _1max > V _2max and the shift of the frequency of f _noload > f ₁₀ > f ₂₀ to the low frequency side.

Thus, the attenuation of the amplitude of the transmission signal waveform 29 (V _noload > V _1max ) and the frequency shift (f _noload >).
f ₁₀ ) is related to the time characteristic of the object, that is, the mechanical impedance.

Therefore, the time response can be detected by using the transmission signal waveform 29.

Further, the echo is observed as in the received signal waveform 30, the amplitude is attenuated (V _1max > V _2max or V _noload > V _2max ), and the center frequency is shifted (f ₁₀ > f).
₂₀ or f _noload > f ₂₀ ) is related to the nonlinear elastic properties of the object.

In particular, the echo corresponds to the discontinuity in the acoustic impedance.

Therefore, the nonlinear elasticity characteristic can be detected by using the received signal waveform 30.

Further, the mechanical impedance of the object is detected from the received voltage waveform, but since it contains not only the information of the object but also the characteristics peculiar to the transducer, it is necessary to separate it.

For the separation, the amplitude V _noload and the center frequency f _noload in FIG. 10 are actually measured, and the separation is performed using these.

In FIG. 11, the load impedance is the ratio of F2 'and U2' at the output port of the acoustic matching layer that contacts the object.

Therefore, the difference between the impedance seen from the port when there is no load and the impedance seen from the port when there is a load can be said to be the impedance information of the object.

That is, since this is reflected in the deviation of the center frequency and the amplitude change, the signals are individually sampled,
The FFT and the peak detector are separately applied to each other, and the maximum value and the frequency showing the maximum value are obtained from the waveforms, so that the separation can be performed, and the time response characteristic and the nonlinear elastic characteristic can be obtained.

Here, if the physical quantities to be detected are arranged again, the following Table 1 is obtained.

[0123]

[Table 1]

[Equation 15]

[Equation 16] Here, f is frequency, V is amplitude, t ₁ is transmission signal waveform 2
The vibration time width of 9 is T, and T is the time until the reception signal waveform 30 is received.

The subscript 1 in Table 1 means the vertical direction and s means the horizontal direction. The numbers 1 and 2 correspond to the transmission signal waveform 29 and the reception signal waveform 30, respectively.

From the transmission signal waveform 29, the frequency shift in the vertical and horizontal directions and the change in the maximum amplitude are detected, and the time response is detected from this. Also, in the vertical direction from the received signal waveform 30,
The non-linear elastic characteristic is detected from the frequency shift in the lateral direction, the change in the maximum amplitude, and the time until the echo signal is received.

The above is the means and actions for solving the problems of the present invention.

[0127]

FIG. 19 shows a first embodiment of the present invention based on the above basic principle.

FIG. 19 is a basic configuration diagram of the tactile sensor device 83. The substrate 32, a detection unit 33 provided on the substrate for detecting a tactile sensation with an object, and a process connected to the detection unit 33. And a circuit 34.

In the tactile sensor device 83, the detecting portion 33 is provided on the substrate 32, and the piezoelectric body 23 horizontally polarized with respect to the substrate 32 and the piezoelectric body 2 horizontally polarized.
3, the electrodes 35 and 36 attached so as to sandwich the electrode 3, the piezoelectric body 18 vertically polarized with respect to the substrate 32, and the electrode 3 attached so as to sandwich the piezoelectric body 18 vertically polarized.
It is composed of 7, 38.

Further, the processing circuit 34 includes a detection circuit 39 for detecting elastic characteristics in the vertical direction, time response, and nonlinear elastic characteristics, a drive circuit 40 for driving the piezoelectric body 18, and elastic characteristics in the horizontal direction, time response. , A detection circuit 41 for detecting the non-linear elasticity characteristic, and a drive circuit 42 for driving the piezoelectric body 23.

In the detection unit 33, the horizontally polarized piezoelectric body 23 and the vertically polarized piezoelectric body 18 are integrated on the same plane, and at least two horizontally polarized piezoelectric bodies 23 are used. The electrodes 3 are arranged so that the polarization directions do not coincide with each other and are perpendicular to each other.
Reference numerals 5 and 37 are connected to the ground 84, respectively.

Further, in the processing circuit 34, the driving circuits 40 and 42 apply a pulsed voltage to the electrodes 36 and 38 of the piezoelectric bodies 18 and 23 to vibrate the piezoelectric bodies 18 and 23 so that they are integrated with the object. Vibrate.

The detection circuit 39 is a vertically polarized piezoelectric body 28.
The elastic characteristic in the vertical direction is detected from the potential difference between the electrodes 37 and 38, and the transmitted / received wave due to the vertical vibration generated by the drive circuit 40 is detected by the piezoelectric effect of the piezoelectric body 18.

Then, the calculation processing circuit 60 executes the calculation processing of the center frequency and maximum amplitude of the voltage waveform and the calculation of the position of the non-linear elastic portion by the echo signal of the ultrasonic probe.

The detection circuit 41 is a horizontally polarized piezoelectric body 23.
The elastic characteristic in the lateral direction is detected from the potential difference between the electrodes 35 and 36, and the transmitted / received wave due to the lateral vibration generated by the drive circuit 42 is detected by the piezoelectric effect of the piezoelectric body 23.

The calculation processing circuit 60 executes the calculation processing of the center frequency and maximum amplitude of this voltage waveform and the calculation of the position of the non-linear elastic portion by the echo signal of the ultrasonic probe.
An elastic characteristic output 48, a time response output 55, and a non-linear elastic characteristic 59 are output.

Next, the structure of the tactile sensor 45 based on the above basic principle will be described below with reference to FIG.

FIG. 20 is a layered exploded perspective view of the tactile sensor 45.

The tactile sensor 45 basically generates strains for detecting elastic characteristics, vibrations for detecting time responsiveness and non-linear elastic characteristics, and independently of each other the piezoelectric bodies 18 for receiving the vibrations. , 23a to 23d, the matching layers 3a to 3e divided for each piezoelectric body, and the electrodes 35 which are electrically independent and are opposed to each other across the piezoelectric body.
a to 35d, 36a to 36d, 37, 38, and acoustically independent damping layers 2a to 2 for absorbing vibrations
e, the corrosion-resistant films 43a to 43e for preventing corrosion by the object, and the substrate 32 on which they are arranged.

The piezoelectric body is composed of two types of piezoelectric bodies 23a to 23d which are horizontally polarized and a piezoelectric body 18 which is vertically polarized.

The vertically polarized piezoelectric body 18 is arranged at the center of the detecting portion, and the horizontally polarized piezoelectric bodies 23a to 23d.
Is arranged around the vertically polarized piezoelectric body 18 in such a manner that the vertically polarized piezoelectric body 18 is point-symmetrical and the polarization axes of the adjacent horizontally polarized piezoelectric bodies are orthogonal to each other.

Since the piezoelectric bodies 18, 23a to 23d vibrate, a gap 44 having a width larger than the amplitude of each piezoelectric body is provided in order to eliminate the influence of crosstalk between the piezoelectric bodies.

Since the matching layers 3a to 3e match the impedance of the piezoelectric body with the impedance of the object, the materials of the vertically polarized piezoelectric body 18 and the horizontally polarized piezoelectric bodies 23a to 23d are slightly different. ing.

Further, the matching layers 3a to 3d of the horizontally polarized piezoelectric bodies 23a to 23d for removing the influence of the crosstalk between the piezoelectric bodies due to the vibration due to the pressure are also independent.

The thickness and materials of the matching layers 3a to 3e are selected by, for example, performing Mason's equivalent circuit calculation, calculating a suitable impedance, and selecting a material close to the value to determine the materials of the matching layers 3a to 3e. It

Electrodes 35a to 35d, 36a to 36e, which are opposed to each other with the piezoelectric bodies 18, 23a to 23d interposed therebetween,
37 and 38 apply a pulse voltage for vibrating the piezoelectric bodies 18, 23a to 23d by an inverse piezoelectric effect,
It is used to convert vibration into a voltage signal by the piezoelectric effect and output the voltage, and Ag or the like is used as the material.

Electrodes 3 of the piezoelectric bodies 18, 23a to 23d
5a to 35d, 36a to 36d, 37, and 38 are also independent in order to eliminate the influence of crosstalk due to vibration.

The damping layers 2a to 2e are the piezoelectric bodies 1 respectively.
8,23a to 23d are provided for the purpose of suppressing the vibration of a portion that does not come into contact with an object and suppressing the influence on other portions. Generally used damping materials include resin such as epoxy or silicon, and tungsten. A powder obtained by dispersing the powder is used.

The damping layers 2a to 2e are also divided for each piezoelectric body and are independent of each other. However, when the thickness of the layer is a certain value or more, it is not necessary to divide the damping layers 2a to 2e, and the integrated layers are formed. The damping layer 2 may be used.

The anticorrosion films 43a to 43e are provided to prevent corrosion by an object, and since they are coated by spraying or coating, the surface of the anticorrosion film becomes flat or grooves are left due to the viscosity of the material of the anticorrosion film.

The board 32 is provided by stacking the above-mentioned components and also serves as an attachment member for providing the tactile sensor on a finger pad of a robot or the like.

As shown in FIG. 19, the tactile sensor 4
In addition to the structure of FIG. 5, there is a drive circuit 42 for transmitting ultrasonic waves from the piezoelectric bodies 18, 23a to 23d and a processing circuit 60 for processing the output converted by the piezoelectric effect.

FIG. 21 shows a flowchart of an example of the processing.

First, it is necessary to measure (blank measurement) the impulse response of a single piezoelectric body as shown in FIG. 10 when there is no load (step 47).

The blank value obtained here is stored as an initial memory.

Then, the sensor is brought into contact with the object (step 49), and a load is applied to the sensor.

First, contact stress measurement of elastic characteristics is performed (step 46), and the output thereof is used as a signal for perceptual data conversion (step 55) as a signal of elastic characteristics.

When the contact stress measurement (step 46) is completed, impulse response characteristic measurement (step 48) is performed as shown in FIG. 17 to measure the response signal to the vibration of the piezoelectric body.

At the same time, different analysis is performed depending on the time of the response signal. Here, the transmission signal waveform 2 of FIG. 17B is used.
9 is analyzed (step 50) and the received signal waveform 30 is analyzed (step 51).

First, in step 50, the transmission signal waveform is analyzed, and then in step 51, the reception signal waveform is analyzed. The analysis value thus obtained is compared with the blank value in step 53.

In addition, analysis of the received signal waveform (step 5
When 1) is completed, the echo time from the transmission of the transmission signal waveform 29 to the reception of the reception signal 30 is then analyzed in step 5
Do 2.

Based on the comparison signal with the blank value and the echo signal analysis result, the time response characteristic value and the non-linear elasticity characteristic value are divided (step 54).

Then, using this time response characteristic value, non-linear elastic characteristic value and elastic characteristic value, perceptual data is created (step 55).

FIG. 22 shows an example of a block diagram of a circuit for performing such a series of flow processing.

FIG. 22A is a schematic block diagram, and FIG. 22B is a detailed diagram of the impulse response waveform analysis circuit.

Since the tactile sensor performs transmission and reception with one piezoelectric body 7 and the signal processing method changes depending on the driving time, a control circuit 61 for controlling these is required.

First, the blank measurement of FIG. 21 (step 4
In order to perform 7), the sensor mounting portion 58 is brought into a state where it is not in contact with the object by the drive circuit 57 controlled by the control circuit 61.

Then, the control circuit 61 sends a signal to the pulse oscillation circuit 88 to apply a pulse to the piezoelectric body 7.

As a result, the piezoelectric body 7 vibrates, and the vibrating state is received by the pulse receiving circuit 62 as a signal as shown in FIG. 10 (b).

The impulse response signal waveform of the pulse receiving circuit 62 is input to the impulse response waveform analysis circuit 59, and the applied voltage from the pulse oscillation circuit 88 is also input to the impulse response waveform analysis circuit 59, and the signal from the control circuit 61 is input. To analyze impulse response waveform (step 48)
I do.

This analysis value is input to the analysis value storage circuit 63. Next, the control circuit 61 controls the drive circuit 57 to bring the sensor mounting portion 58 into contact with the object.

Then, the voltage generated from the piezoelectric body 7 is detected by the voltage detection circuit 56 and input to the analysis value storage circuit 63 as an elastic characteristic value.

Next, in order to detect the impulse response, the control circuit 61 sends a signal to the pulse oscillation circuit 88 to vibrate the piezoelectric body 7.

This vibration state is shown in the pulse receiving circuit 62 in FIG.
7 (b), the impulse response signal waveform of the pulse reception circuit 62 is input to the impulse response waveform analysis circuit 59, and the pulse oscillation circuit 88 is also provided.
The pulse applied voltage is also from the impulse response waveform analysis circuit 59.
17 and a signal from the control circuit 61 is input to FIG.
The transmission signal waveform 29 and the reception signal waveform 30 as shown in (b) are analyzed.

This analysis value is input to the analysis value storage circuit 63.

Therefore, the analysis value storage circuit 63 stores the elasticity characteristic value, the time response characteristic value and the non-linear elasticity characteristic value. By inputting these values to the analysis value calculating circuit 85, the values relating to the tactile sense are calculated. To do.

Then, the calculation result is once output to the output circuit 86 such as a CRT, and the value is output to the perceptual data processing circuit 8.
In step 7, it is set as tactile data.

Further, the impulse response waveform analysis circuit 59
22B has a configuration as shown in FIG. 22B. The output from the signal waveform pulse oscillation circuit 88 obtained from the pulse receiving circuit 62 and the difference signal circuit 89 take a difference signal to receive the pulse voltage component. Remove from transmitted signal waveform.

After that, the gate circuit 90 causes the circuit shown in FIG.
The transmission signal waveform 29 and the reception signal waveform 30 shown in (a) are separated.

With respect to the signal waveform passing through the gate circuit 90, the maximum amplitude and center frequency of the signal waveform are detected by the digital FFT 91, and these values are input to the arithmetic circuit 92 to obtain the maximum amplitude and center frequency of the longitudinal and transverse waves.

These are input to the analysis value storage circuit 63.

The above is the contents of the impulse response waveform analysis circuit 59.

The signal processing is performed by the processing circuit as described above.

For example, as shown in FIG. 23, when the object 27 is in contact with the detection unit 33 at a certain pressure, the strain due to the pressure applied to the tactile sensor causes the strain in the same direction as the pressure direction as shown in FIG. It can be decomposed into (vertical strain) and strain in the direction perpendicular to the direction of pressure (lateral strain).

The vertical strain is detected by the piezoelectric effect of the vertically polarized piezoelectric body 18 arranged at the center of the detecting portion 33, and the signal thereof is input to the circuit as shown in FIG.

The lateral strain is detected by the piezoelectric effect of the horizontally polarized piezoelectric bodies 23a to 23d arranged around the detecting portion 33.

Assuming that the deformation of the object is isotropic in the lateral direction, the amounts of strain in the symmetrical directions about the contact point are equal, so the voltage values output from the piezoelectric bodies 23a and 23c are equal, This output is added by the addition operational amplifier 64, and this output is taken as the X-axis distortion amount of the lateral distortion.

The voltage values output from the piezoelectric bodies 23b and 23d are also equal, and this output is also added by the addition operational amplifier 64,
This output is the amount of distortion on the Y axis.

With such a structure, the output signal becomes high output.

The signal thus obtained is output as an elastic characteristic.

Then, the elasticity characteristic detection signal serves as a trigger, and the pulse voltage is applied from the pulse oscillation circuit 88 to the vibrator by the control circuit 61, and the time response and the nonlinear elasticity are applied by the piezoelectric body driving and processing circuit as described above. The characteristics are output.

FIG. 25 shows a second embodiment of the tactile sensor.

This tactile sensor basically generates strains for detecting elastic characteristics, vibrations for detecting time responsiveness and non-linear elastic characteristics, and each independent piezoelectric body that receives the vibrations. 18, 23a to 23d, and an electrode 35 at a position facing each other with an electrically independent piezoelectric body interposed therebetween.
a to 35d, 36a to 36d, 37, 38, and films 65a to 65e for preventing corrosion by an object and matching acoustic impedance, and the piezoelectric body 18,
It is composed of a substrate 66 for damping the vibrations of 23a to 23d.

Piezoelectric bodies 18, 23a to 23d and piezoelectric body 1
8, 23a to 23d of electrodes 35a to 35d, 36a
The structure of to 36d, 37 and 38 is the same as that of the first embodiment. The corrosion resistant films 65a to 65e of this embodiment are shown in FIG.
20 and the functions of the matching layers 3a to 3e in FIG.
It is made of a material having the functions of the corrosion-resistant films 43a to 43e in (a).

The substrate 66 is the substrate 32 shown in FIG.
20 (f) and the functions of the damping layers 2a to 2e shown in FIG. 20 (f). As described above, the structure is very simple as compared with the first embodiment, so that it is suitable for downsizing and the like.

FIG. 26 is a perspective view showing the third embodiment.

FIG. 27 is a sectional view taken along the line AA 'in FIG.

Since the resonance frequency of the piezoelectric body changes depending on the material, the vibration direction and the shape of the piezoelectric body, an assembly of the piezoelectric bodies 18, 23a to 23d as shown in FIG. 20 is formed, and the dimensional ratio is as shown in FIG. When the same material is used, horizontally polarized piezoelectric bodies 23a to 23d and vertically polarized piezoelectric body 18
And have different resonance frequencies of vibration.

That is, the five piezoelectric bodies 18, 23a to 23
When d is regarded as one vibrator, there are exactly two resonance frequencies (the resonance frequency of the vertically polarized piezoelectric body 18 and the resonance frequencies of the vertically polarized piezoelectric bodies 23a to 23d).

Dividing such an output signal into information concerning the sensor and information concerning the object causes the sensor itself to have two resonances, which complicates the signal processing circuit.

Therefore, it is desirable that the resonance frequencies be unity.

Therefore, the thickness of the vertically polarized piezoelectric body 18 is changed so that the resonant frequencies of the vertically polarized piezoelectric body 18 and the horizontally polarized piezoelectric bodies 23a to 23d match.

However, since it is not preferable to provide a gap on the contact surface with the object 27, the contact surface is flattened by changing a part of the thickness of the substrate 67 (67a).

Further, as the vibrating body, the electrodes 35a to 35 are used.
Since d, 36a to 36d, 37, and 38 are also included, it goes without saying that the resonance frequency can be changed by changing the thickness of the electrode.

FIG. 28 is a diagram showing a fourth embodiment of the tactile sensor, in which a vertically polarized disk-shaped piezoelectric body 68 is arranged at the center of the detecting portion, and horizontally polarized flat plate-shaped piezoelectric bodies 69a to 6a.
9d is arranged around it so that the polarization axes are orthogonal to each other.

By doing so, the piezoelectric body 6 horizontally polarized with respect to the center of gravity of the piezoelectric body 68 vertically polarized.
9a to 69d can be arranged symmetrically, and follow the deformation of the object well.

FIG. 29 is a view showing a fifth embodiment of the tactile sensor, in which the vertically polarized piezoelectric body 18 and the horizontally polarized piezoelectric bodies 23a and 23b are arranged as shown in the drawing, and the horizontally polarized piezoelectric bodies 23a and 23b are arranged. Are arranged so that their polarization axes are orthogonal to each other.

The tactile sensor of the fifth embodiment is smaller in number than the horizontally polarized piezoelectric body of the tactile sensor shown in the first embodiment, but the longitudinal elastic characteristic, time response and non-linear elastic characteristic are the same. Needless to say, it can be detected in the same manner as in the first embodiment, but lateral elastic characteristics, time response, and non-linear elastic characteristics can also be detected although the output is small. Further, since the structure is simple, manufacturing and assembling can be facilitated by reducing the number of wires.

FIG. 30 is a diagram showing a sixth embodiment of the tactile sensor, in which a vertically polarized disk-shaped piezoelectric body 68 is arranged at the center of the detecting portion and horizontally polarized flat plate-shaped piezoelectric bodies 69a to 69a.
9c is arranged around it so that the polarization axes have a positional relationship of 120 ° with each other.

With such a structure, the horizontally polarized piezoelectric bodies 69a to 69c are symmetrical with respect to the vertically polarized piezoelectric body 68, and the structure is more than that of the tactile sensor shown in the fourth embodiment. Since it is simple, the sensor can be easily manufactured and assembled.

FIG. 31 is a diagram showing a seventh embodiment, in which a vertically polarized disk-shaped piezoelectric body 68 is arranged at the center of a detection portion, and horizontally polarized flat plate-shaped piezoelectric bodies 69a to 69f are arranged around the polarization axis. Are arranged so as to have a positional relationship of 60 ° with each other.

As described above, by providing a plurality of horizontal detecting portions, it becomes possible to detect the horizontal anisotropy of the symmetrical object with a certain degree of sensitivity.

FIG. 32 is a view showing an eighth embodiment, in which a vertically polarized disk-shaped piezoelectric body 68 is arranged at the center of the detecting portion,
Horizontally polarized flat plate-shaped piezoelectric elements 69a to 69c are arranged around the piezoelectric elements 69a to 69c so that their polarization axes are in a positional relationship of 60 ° with each other and the three piezoelectric elements 69a to 69c form a triangle. With this structure, the same effect as the effect shown in the sixth embodiment can be obtained.

The relationship between the vertically polarized piezoelectric body 18 and the horizontally polarized piezoelectric body 23 in FIG. 20 is not limited to this, and the structure in which the vertically polarized piezoelectric body 18 and the horizontally polarized piezoelectric body 23 are arranged is not limited to this. If so, any form will do.

Also, the number of horizontally polarized piezoelectric bodies 23 is four.
The number is not limited to one, and may be any number as long as it is possible to detect lateral elastic characteristics, time response, and nonlinear elastic characteristics, or two or more.

FIG. 33 shows the ninth embodiment.

FIG. 33 shows the electrodes 35a to 35d and 36a to 36 of the tactile sensor shown in the first and second embodiments.
The gap 44 between d, 37 and 38 was filled with the flexible resin 73 to form an integral electrode.

With such a structure, the piezoelectric bodies 18, 2
A pulse is applied synchronously to 3a to 23d,
When 23a to 23d are collectively vibrated, a transmission signal waveform 70 as shown in FIG. 34 is obtained, which contains frequency components of vertical vibration and horizontal vibration. The received signal waveform due to this vibration has vertical vibration and horizontal vibration. Depending on the difference in the speed of vibration in the object, it can be obtained by dividing it into longitudinal vibration 71 and lateral vibration 72 as shown in FIG.

Therefore, it becomes possible to mechanically divide the echo signal by the longitudinal vibration and the lateral vibration, and the processing circuit can be simplified.

At the same time, since the electrodes are integrated, the wiring and the like are simplified, and the manufacturing and assembling are easy.

FIG. 35 shows a tactile sensor attached to a manipulator or the like.

As described above, by providing the sensor on the part of the operator's finger pad, the condition becomes very close to the tactile sense received by the operator's finger. For example, in the master slave manipulator, this tactile sense is transmitted to the operator. This makes it possible to obtain a feeling as if the operator is actually touching the target object without directly touching the target object.

[0223]

As described above, the tactile sensor of the present invention constitutes the hardness and softness of the object in contact with the detecting portion,
Since it is possible to detect elastic properties, time response, and non-linear elastic properties, such tactile sensors should be placed in the part of the mechanism such as a manipulator that acts on behalf of the operator's hand in contact with the operation target. As a result, it becomes possible to obtain tactile information of the object, and by transmitting this information to the operator, operability is significantly improved.

Therefore, obtaining tactile information by using such a tactile sensor is important in fields requiring tactile information in the operation such as cholecystectomy using a rigid endoscope and cell operation using a micromanipulator. Not only will the operability be improved, but it will also be possible to contribute to significant progress in the field.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an ultrasonic probe.

FIG. 2 is a diagram showing a basic structure of an ultrasonic probe.

FIG. 3 is a diagram showing a measurement principle using an ultrasonic probe.

FIG. 4 is a diagram showing the principle of an ultrasonic diagnostic apparatus.

FIG. 5 is a diagram showing a basic function of a piezoelectric body in a thickness direction.

FIG. 6 is a view showing a basic function of a piezoelectric body in a length direction.

FIG. 7 is a diagram showing a basic function of a piezoelectric body in a sliding direction.

FIG. 8 is a diagram showing a piezoelectric effect.

FIG. 9 is a diagram showing a generated voltage detection circuit.

FIG. 10 is a diagram showing an impulse response of a piezoelectric body.

FIG. 11 is a diagram showing an electroacoustic connection of ultrasonic probes.

FIG. 12 is a diagram showing an equivalent circuit of a piezoelectric body.

FIG. 13 is a diagram showing an equivalent circuit of a matching layer.

FIG. 14 is a diagram showing an equivalent circuit of a damping layer and an equivalent circuit of an object.

FIG. 15 is a diagram showing an equivalent circuit of the entire system.

FIG. 16 is a diagram showing an equivalent circuit of the entire system.

FIG. 17 is a diagram showing input / output signals of time response and nonlinear elasticity.

FIG. 18 is a diagram schematically showing the propagation of ultrasonic waves in a living body.

FIG. 19 is a diagram showing a basic configuration of a tactile sensor.

FIG. 20 is a layered exploded perspective view of the tactile sensor of the first embodiment.

FIG. 21 is a diagram showing a processing flow.

FIG. 22 is a block diagram of a processing circuit.

FIG. 23 is a diagram showing a state where the sensor and the object are in contact with each other.

FIG. 24 is a diagram showing an example of elastic characteristic detection.

FIG. 25 is a layered exploded perspective view showing the tactile sensor of the second embodiment.

FIG. 26 is a perspective view showing a tactile sensor of the third embodiment.

FIG. 27 is a sectional view of the tactile sensor of the third embodiment.

FIG. 28 is a perspective view showing a tactile sensor of the fourth embodiment.

FIG. 29 is a top view showing the tactile sensor of the fifth embodiment.

FIG. 30 is a top view showing the tactile sensor of the sixth embodiment.

FIG. 31 is a top view showing the tactile sensor of the seventh embodiment.

FIG. 32 is a top view showing the tactile sensor of the eighth embodiment.

FIG. 33 is a sectional view showing a tactile sensor of the ninth embodiment.

FIG. 34 is a diagram showing a received / transmitted signal waveform according to a ninth embodiment.

FIG. 35 is a view showing an example of attaching a tactile sensor.

FIG. 36 is a diagram showing a tactile sensor using conductive rubber.

FIG. 37 is a diagram showing a tactile sensor by measuring resonance frequency.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric body of ultrasonic probe, 2 ... Damping layer of ultrasonic probe, 3 ... Matching layer of ultrasonic probe, 4 ... Housing of ultrasonic probe, 5 ... Ultrasonic probe Lead wire, 6 ... Ultrasonic probe, 7 ... Piezoelectric body, 8, 9 ... Electrode, 10 ... AC power supply, 11 ... Radiant wave, 12 ... Transmitted wave, 13, 14 ... Reflected wave, 15 ... Sponge, 16 ... Water, 17 ... Water tank, 18 ... Vertically polarized piezoelectric body, 19, 20 ... Electrode, 21 ... Voltmeter, 22 ... Signal generator, 23 ... Horizontally polarized piezoelectric body, 24 ... Detection part, 25 ... Treatment Circuit, 26 ... Operation amplifier, 27 ... Object, 28 ... Matching circuit, 29 ... Transmitting signal waveform, 30 ... Received signal waveform, 31 ... Non-linear elastic tissue part, 32 ... Substrate, 33 ... Detecting part, 34 ... Signal processing part, 35, 36, 37, 38 ... Electrodes, 39 ... Vertical direction detection circuit, 40 ... Direction drive circuit, 41 ... Lateral direction detection circuit, 42 ... Lateral direction drive circuit, 43 ... Corrosion resistant film, 44 ... Gap, 45 ... Tactile sensor, 46 ... Contact stress measurement, 47 ... Blank measurement, 48 ... Impulse response characteristic measurement, 49 ... Object contact, 50 ... Transmission signal waveform analysis step, 51 ... Reception signal waveform analysis step, 52 ... Echo time analysis step, 53 ... Comparison of reception / transmission signal waveform analysis value and blank value, 54 ... Time response characteristic value And 55. Perceptual data conversion step, 56 ... Voltage detection circuit, 57 ... Drive circuit, 59 ... Impulse response waveform analysis circuit, 60 ... Calculation processing, 61 ... Control circuit, 62 ... Pulse receiving circuit , 63 ... Analytical value storage circuit, 64 ... Addition operational amplifier, 65 ... Corrosion resistant matching layer, 66 ... Group having damping function , 67 ... Convex substrate, 67a ... Substrate convex portion, 68 ... Disc-shaped piezoelectric body, 69 ... Plate-shaped piezoelectric body, 70 ... Transmission signal waveform of ninth embodiment, 71 ... Longitudinal vibration reception signal waveform of ninth embodiment , 72 ... Lateral vibration reception signal waveform of the ninth embodiment, 73 ... Flexible resin, 74, 75, 76, 77 ... Circuit constant of four-terminal circuit network of piezoelectric body, 78, 79, 80 ... Four-terminal circuit of matching layer Circuit constant of the net, 81 ... Circuit constant of the two-terminal circuit network of the damping layer, 82 ... Circuit constant of the two-terminal circuit network of the object, 83 ... Tactile sensor device, 84 ... Ground, 85 ... Analysis value calculation circuit, 86 ... Calculation result output circuit, 87 ... Perceptual data conversion processing circuit, 88 ... Pulse oscillation circuit, 89 ... Difference signal circuit, 90 ... Gate circuit, 91 ... FFT (digital), 92 ... Calculation circuit, 101, 102 ... Conductive rubber, 103 ... Piezoelectric Doko, 104 ... amplifier circuit section, 105 ... measurement unit, 106 ... frequency meter, 107 ... voltage meter, 108 ... vibration detecting element, P ... self-excited circuit.

Claims (3)

[Claims] 1. A tactile sensor comprising a unit for detecting a mechanical impedance of an object and a unit for detecting a non-linear elastic characteristic of the object integrally. 2. A means for detecting an elastic characteristic in a direction perpendicular to a surface of an object and a means for detecting an elastic characteristic in a direction along the surface of the object are integrally provided. Tactile sensor that does. 3. A detection direction when detecting a mechanical impedance of an object and a detection direction when detecting a nonlinear elastic characteristic of the object are a direction perpendicular to the surface of the object and a surface of the object. A tactile sensor having means for integrally detecting both directions along the direction.