WO2022255412A1

WO2022255412A1 - Steering, biometric information detection device, and control system

Info

Publication number: WO2022255412A1
Application number: PCT/JP2022/022354
Authority: WO
Inventors: 展弘丸子; 哲史大塚; 光伸吉田; 勝敏尾崎
Original assignee: 三井化学株式会社
Priority date: 2021-06-03
Filing date: 2022-06-01
Publication date: 2022-12-08
Also published as: JPWO2022255412A1; TW202302030A

Abstract

This steering comprises a grip body to be gripped by a user and a piezoelectric substrate that detects pressure received by the grip body, the piezoelectric substrate including an axial inner conductor and an elongated piezoelectric body provided coaxially in the periphery of the inner conductor and containing an optically active polypeptide.

Description

Steering, biological information detector, and control system

The technology of the present disclosure relates to steering, biological information detection devices, and control systems.

In recent years, in order to detect the condition of the driver who drives the vehicle, a device has been disclosed in which a sensor is installed on the steering wheel of the vehicle and the biological information of the driver is detected from the steering wheel.

For example, in International Publication No. WO 2007/066513, in a steering handle in which a contact layer made of an epoxy resin containing a dielectric filler is formed on a base material containing a polyurethane resin, biometric information is transmitted from the contact layer. Techniques characterized by detecting have been proposed.

Further, for example, Japanese Patent Application Laid-Open No. 2016-146953 discloses a technology characterized by acquiring biometric information using a pressure-sensitive sensor to which film-like polyvinylidene fluoride (hereinafter referred to as "PVDF") is applied. is proposed.

According to International Publication No. 2007/066513, biometric information may not be detected depending on the way of gripping. In addition, if a piezoelectric body containing PVDF described in Japanese Patent Application Laid-Open No. 2016-146953 is used, biometric information can be detected regardless of how it is gripped. There is
For example, the interior of the vehicle and the steering wheel portion of the vehicle are exposed to direct sunlight under the scorching sun, and the interior of the vehicle and the steering wheel portion may become hot. Therefore, the sensitivity of the sensor may fluctuate in an environment that can reach high temperatures, and it is not always possible to acquire biological information with high accuracy.

The technology of the present disclosure has been made in view of the above facts, and provides a steering wheel, a biological information detection device, and a control system that can acquire biological information regardless of how they are gripped even in an environment that can reach high temperatures. intended to

The specific means for achieving the above tasks are as follows.

<1> A grasping body to be grasped by a user;
a piezoelectric substrate that detects the pressure received by the gripping body,
The piezoelectric substrate is
an axial inner conductor;
an elongated piezoelectric body provided coaxially around the inner conductor and containing an optically active polypeptide;
steering wheel.

<2> In the piezoelectric substrate, the length direction of the elongated piezoelectric body is substantially parallel to the main orientation direction of the optically active polypeptide.
The steering according to <1>.

<3> The degree of orientation F of the optically active polypeptide determined by the following formula (a) from X-ray diffraction measurement is 0.50 or more and less than 1.00.
The steering according to <1> or <2>.
Orientation F = (180°-α)/180°... Formula (a)
[In the formula (a), α represents the half width (°) of the orientation-derived peak. ]

<4> The long piezoelectric body is spirally wound in one direction,
The steering according to any one of <1> to <3>.
<5> The elongated piezoelectric body includes the piezoelectric base material wound in the clockwise direction, and the piezoelectric base material wound in the counterclockwise direction. ,
The steering according to <1>.

<6> The piezoelectric base material further comprises an outer conductor on the outer circumference,
The steering according to any one of <1> to <5>.

<7> The piezoelectric base material further comprises an insulator on the outer circumference of the outer conductor,
The steering according to <6>.

<8> the optically active polypeptide comprises at least one of silk and spider silk,
The steering according to any one of <1> to <7>.

<9> The steering according to any one of <1> to <8>;
a detection unit that detects a signal corresponding to the pressure of the piezoelectric substrate;
a detection unit that detects biological information in the human body based on the signal detected by the detection unit;
A biological information detection device comprising:

<10> The holding body includes a plurality of piezoelectric substrates,
The detection unit independently detects a signal from each piezoelectric base material,
The detection unit detects position information indicating a position where the human body is in contact from the signals detected from each piezoelectric base material.
The biological information detection device according to <9>.

<11> The biological information detection device according to <9> or <10>;
a control device that controls equipment provided on the moving body operated by the steering, based on the information detected by the biological information detection device;
A control system with

<12> The control device controls the device according to information related to the heartbeat of the human body obtained from the biological information.
The control system according to <11>.

According to the technology of the present disclosure, biometric information can be obtained with high accuracy even in an environment that can reach high temperatures.

It is a block diagram showing an example of a control system concerning each embodiment. FIG. 2 is a front view showing an example of a steering wheel for explaining the arrangement of piezoelectric substrates according to the first embodiment; FIG. 3 is a cross-sectional view of the steering wheel according to the first embodiment taken along the line X-X' of FIG. 2; It is a block diagram showing an example of hardware constitutions of a living body information detecting device concerning each embodiment. It is a block diagram which shows an example of the hardware constitutions of the control apparatus which concerns on each embodiment. It is a block diagram showing an example of functional composition of a control system concerning a 1st embodiment. FIG. 2 is a schematic side view schematically showing a piezoelectric base material according to each embodiment; 8 is a cross-sectional view taken along the line X-X' of FIG. 7 in the piezoelectric base material according to each embodiment. FIG. FIG. 5 is a schematic side view schematically showing a piezoelectric base material according to a modified example of each embodiment; FIG. 10 is a front view showing an example of a steering for explaining the arrangement of piezoelectric substrates according to the second embodiment; FIG. 11 is a front view showing an example of a steering for explaining the arrangement of piezoelectric substrates according to the third embodiment; FIG. 11 is a block diagram showing an example of a functional configuration of a control system according to a third embodiment; FIG. FIG. 11 is a front view showing an example of a steering for explaining the arrangement of piezoelectric substrates according to a modification of the third embodiment; FIG. 4 is a diagram showing an example of a piezoelectric base material installed in the steering wheel according to Example 1; 3 is a block diagram showing an example of a detection circuit that detects biological information from the piezoelectric base material according to Example 1. FIG. 5 is a graph showing an example of biological tremor detected from the piezoelectric base material according to Example 1. FIG. 7 is a graph showing an example of voltage signals detected from a PVDF and a piezoelectric base material according to a comparative example; FIG. 10 is a schematic diagram showing an example of the configuration of a piezoelectric substrate and an instrumentation amplifier according to Example 2; 9 is a graph showing an example of measurement results of FFT analysis when the steering wheel according to Example 2 is gripped. 9 is a graph showing an example of measurement results of FFT analysis when the steering wheel is not held according to Example 2. FIG. FIG. 11 is a schematic diagram showing an example of the configuration of a piezoelectric substrate and an instrumentation amplifier according to Example 3; 10 is a graph showing an example of FFT analysis measurement results when the steering wheel according to Example 3 is gripped.

Embodiments of the technology of the present disclosure will be described below. The present disclosure is not limited to the following embodiments.
In this specification, a numerical range represented by "to" means a range including the numerical values before and after "to" as lower and upper limits.
In this specification, the "surface" of a member means the "principal surface" of the member unless otherwise specified.
As used herein, thickness, width, and length satisfy the relationship thickness<width<length, as is commonly defined.
In this specification, the angle formed by two line segments is expressed in the range of 0° or more and 90° or less.
In this specification, "film" is a concept that includes not only what is generally called "film" but also what is generally called "sheet".
When embodiments are described herein with reference to the drawings, the configurations of the embodiments are not limited to the configurations shown in the drawings. In addition, the sizes of the members in each drawing are conceptual, and the relative relationship between the sizes of the members is not limited to this.
In this specification, a "vehicle" will be described as an example of a mobile object. However, it is not limited to this. The mobile body may be an aircraft, a ship, or any vehicle as long as it is movable.
Also, in this specification, steering refers to a "steering wheel" in a vehicle. However, it is not limited to this. It may be a "control pole" in an aircraft, a "rudder" in a ship, or any grip that a user grips in order to steer a moving object.

[First embodiment]
The control system will be described with reference to FIGS. 1 to 9. FIG.

<Configuration of control system>
As an example, as shown in FIG. 1, a control system 1 according to this embodiment is mounted on a vehicle 2 and includes a biological information detection device 10, a control device 100, and a device 200. As shown in FIG. The biological information detection device 10 includes a steering wheel 20 and detects biological information of a driver holding the steering wheel 20 from a sensor installed on the steering wheel 20 . The control device 100 controls the device 200 mounted on the vehicle 2 using the information detected by the biological information detection device 10 . Here, the device 200 includes devices such as air conditioners, seat heaters, lighting, drowsiness prevention devices, diffusers, and audio devices in the vehicle, and actuators for operating steering, throttle, brakes, and the like. For example, the control device 100 performs control such as activation of air conditioning, generation of an odor to prevent drowsiness, notification to the driver, and stopping of the vehicle, according to the detected biological information.

<Structure of Steering Wheel>
The steering wheel 20 will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a front view showing an example of the steering wheel 20 for explaining the arrangement of the piezoelectric base material according to this embodiment, and FIG. 3 is a cross-sectional view taken along line XX' of FIG.
In the following description, the radially outer side of the cross section of the rim 21 is simply referred to as the "radial outer side", and the radially inner side of the rim 21 is simply referred to as the "radial inner side".

As shown in FIG. 2 as an example, the steering wheel 20 according to this embodiment includes a rim 21 gripped by the driver and a hub 22 of the steering wheel 20 connected to the steering shaft. The rim 21 includes a sensor unit 23. The sensor unit 23 includes a piezoelectric substrate 50 that generates a voltage when pressure is input, and wiring 29, which will be described later, connected to the line-shaped piezoelectric substrate 50. , is equipped with Here, the rim 21 is an example of a "gripping body".

As shown in FIG. 3 as an example, the rim 21 includes a core material (not shown) such as an aluminum alloy, and a surface material 24 such as urethane-based resin or polypropylene that covers the core material (not shown). The piezoelectric base material 50 is installed on the surface material 24 that constitutes the rim 21 and is provided inside the notch 25 on the outer diameter side of the core material (not shown) of the rim 21 . Specifically, the notch 25 is provided over the entire circumference of the outer diameter side of the rim 21 , and one piezoelectric substrate 50 is placed on the rim 21 on the sponge rubber 26 provided at the bottom of the notch 25 . are placed all around the circumference of the The cut 25 is provided on the outer diameter side of the core material (not shown) of the rim 21 . Alternatively, the piezoelectric substrate 50 may be placed directly on the surface material 24 covering the core material of the rim 21 without cutting the core material. As a result, the piezoelectric substrate 50 can detect pressure fluctuations with which the driver grips the rim 21 and weak vibrations related to biological vibrations.

<Configuration of biological information detection device>
Next, the hardware configuration of the biological information detection device 10 will be described with reference to FIG. 4 . The biological information detection device 10 detects an output signal from the piezoelectric substrate 50 . As shown in FIG. 4, the biological information detection device 10 includes an AD converter 28 that converts the voltage output, which is an analog signal output from the piezoelectric substrate 50, into a digital signal, and a digital signal of each piezoelectric substrate 50 that has been converted. and a vehicle-mounted device 30 that detects a signal. The AD converter 28 is provided with a plurality of input terminals for inputting analog signals, and the piezoelectric substrate 50 is electrically connected to each input terminal via the wiring 29 .
The vehicle-mounted device 30 includes a CPU (Central Processing Unit) 31, a ROM (Read Only Memory) 32, a RAM (Random Access Memory) 33, a storage 34, a communication I/F (Inter Face) 35, and an input/output I/F 36. consists of The CPU 31 , ROM 32 , RAM 33 , storage 34 , communication I/F 35 , and input/output I/F 36 are connected via a bus 37 so as to be able to communicate with each other.

The CPU 31 is a central processing unit that executes various programs and controls each section. That is, the CPU 31 reads a program from the ROM 32 or the storage 34 and executes the program using the RAM 33 as a work area. In this embodiment, execution programs for executing various processes are stored in the storage 34 . The CPU 31 functions as the detection unit 41 and the detection unit 42A shown in FIG. 6 by executing the execution program.
The ROM 32 stores various programs and various data. The RAM 33 temporarily stores programs or data as a work area. The storage 34 as a storage unit is configured by a HDD (Hard Disk Drive) or SSD (Solid State Drive), and stores various programs including an operating system and various data.

The communication I/F 35 is an interface for communicating with the control device 100, and communication is performed according to the CAN (Controller Area Network) protocol. Note that the communication I/F 35 may apply a communication standard based on Ethernet (registered trademark). Communication I/F 35 is connected to an external bus (not shown). In other words, data transmitted/received between the biological information detection device 10 and the control device 100 is transmitted/received as a communication frame based on the CAN protocol on an external bus (not shown). Here, the communication I/F 35 may be directly connected to the device 200 without going through the control device 100 to transmit and receive data between the biological information detection device 10 and the device 200 .

<Configuration of control device>
As shown in FIG. 5, the control device 100 includes a CPU 101, a ROM 102, a RAM 103, a storage 104, an input/output unit 105, a display unit 106, and a communication I/F 107. In the control device 100, a CPU 101, a ROM 102, a RAM 103, a storage 104, an input/output unit 105, a display unit 106, and a communication I/F 107 are connected via a bus 108 so as to be able to communicate with each other.

The CPU 101 is a central processing unit that executes various programs and controls each part. That is, the CPU 101 reads a program from the ROM 102 and executes the program using the RAM 103 as a work area.

The ROM 102 stores various programs and various data. A control program for controlling the control device 100 is stored in the ROM 102 of the present embodiment.
The RAM 103 temporarily stores programs or data as a work area.

The storage 104 is, for example, an HDD, SSD, flash memory, or the like. Note that the storage 104 may store control programs and the like. The input/output unit 105 is, for example, a mouse, keyboard, touch panel, speaker, and the like. The display unit 106 displays a notification to the driver according to the detected biological information.

The communication I/F 107 is an interface for connecting the biological information detection device 10, the control device 100, and the device 200. The interface performs communication according to the CAN protocol. In addition, in the communication I/F 107, a communication standard by Ethernet (registered trademark) may be applied. Communication I/F 107 is connected to an external bus (not shown). That is, data transmitted/received between the biological information detection device 10, the control device 100, and the device 200 is transmitted/received as a communication frame based on the CAN protocol on an external bus (not shown).

<Functional configuration of biological information detection device and control device>
FIG. 6 is a block diagram showing an example of functional configurations of the biological information detection device 10 and the control device 100. As shown in FIG. As shown in FIG. 6, the biological information detection device 10 has a detection section 41 and a detection section 42A. Each functional configuration is realized by the CPU 31 reading an execution program stored in the storage 34 and executing it.

The detection unit 41 has a function of detecting a digital signal related to each piezoelectric substrate 50 output from the AD converter 28 via the input/output I/F 36 .

The detection unit 42A obtains biological information such as respiration and pulse from the magnitude and period of the digital signal detected by the detection unit 41, and vibration due to mechanical micromotion of muscles (so-called biological tremor) as a physiological phenomenon of the living body. and has a function to detect

Also, as shown in FIG. 6, the control device 100 has an acquisition unit 111A and a control unit 112A. Each functional configuration is realized by the CPU 101 reading an execution program stored in the storage 104 and executing it.

The acquisition unit 111A has a function of acquiring biometric information from the biometric information detection device 10.

The control unit 112A has a function of controlling the device 200 using the acquired biological information. For example, the control unit 112A transmits an instruction to execute processing to each device 200 according to the biometric information. Specifically, the control unit 112A detects fluctuations in the interval between heartbeats from the biological information, and when the fluctuations in the heartbeats become smaller (the intervals between heartbeats are stable), the driver is sleepy. , and transmits an instruction to brake the actuator as the device 200 . The heartbeat fluctuation may be obtained by directly measuring the heartbeat interval, or by converting the heartbeat interval into a frequency. In addition, the control unit 112A detects the magnitude and number of heartbeats from the biological information, the magnitude of the heartbeat is greater than the average value for the driver, and the number of heartbeats in a predetermined period is greater than the average value for the driver. In this case, it is determined that the driver is in a tense state, and an instruction to apply the brake to the actuator as the device 200 is transmitted.

<Piezoelectric substrate>
The piezoelectric substrate of this embodiment includes an axial inner conductor and an elongated piezoelectric body coaxially provided around the inner conductor and containing an optically active polypeptide.

In the piezoelectric base material of the present embodiment, the elongated piezoelectric body is provided coaxially around the inner conductor, and the elongated piezoelectric body contains the optically active polypeptide. (piezoelectric sensitivity) is expressed.
In the piezoelectric substrate of this embodiment, a piezoelectric body is spirally wound in one direction around an inner conductor.

Furthermore, since the piezoelectric substrate of the present embodiment contains an optically active polypeptide that is excellent in hydrolysis resistance in a high-temperature, high-humidity environment, compared with a piezoelectric substrate using polylactic acid, for example, Excellent durability in wet environments).
In this specification, "excellent in durability" means that a decrease in piezoelectric sensitivity is suppressed (especially in a high-temperature and high-humidity environment).

<Piezoelectric material>
The piezoelectric substrate of this embodiment includes an elongated piezoelectric body.
The orientation degree F of the elongated piezoelectric body is in the range of 0.50 or more and less than 1.00.
The degree of orientation F of the piezoelectric material is a value obtained by the following formula (a) from X-ray diffraction measurement, and means the degree of c-axis orientation.

Orientation F=(180°-α)/180°... Formula (a)
[In the formula (a), α represents the half width (°) of the orientation-derived peak. ]

The degree of orientation F is an index indicating the degree of orientation of the optically active polypeptide contained in the piezoelectric material.
In this embodiment, the fact that the orientation degree F of the elongated piezoelectric body is 0.50 or more contributes to the development of piezoelectricity.
The fact that the orientation degree F of the elongated piezoelectric body is less than 1.00 contributes to the productivity of the piezoelectric body.
The orientation degree F of the elongated piezoelectric body is preferably 0.50 or more and 0.99 or less, more preferably 0.70 or more and 0.98 or less, and 0.80 or more and 0.97 or less. It is particularly preferred to have

In the present embodiment, the fact that the length direction of the piezoelectric body and the main orientation direction of the optically active polypeptide contained in the piezoelectric body are substantially parallel also contributes to the development of piezoelectricity.
The fact that the length direction of the piezoelectric body and the main orientation direction of the optically active polypeptide contained in the piezoelectric body are substantially parallel also has the advantage that the piezoelectric body has excellent tensile strength in the length direction. . Therefore, when the piezoelectric body is spirally wound, the piezoelectric body is less likely to break.
In this specification, the term “substantially parallel” means that the angle formed by the two line segments is 0° or more and less than 30° when the angle formed by the two line segments is expressed in the range of 0° or more and 90° or less. (Preferably 0° or more and 22.5° or less, more preferably 0° or more and 10° or less, still more preferably 0° or more and 5° or less, particularly preferably 0° or more and 3° or less).
For example, when the piezoelectric body is silk or spider silk, in the process of producing silk or spider silk, the length direction of the piezoelectric body (silk or spider silk) and the optically active polypeptide (for example, fibroin) contained in the piezoelectric body or spider silk protein) are substantially parallel to each other.

The fact that the length direction of the piezoelectric body and the main orientation direction of the optically active polypeptide contained in the piezoelectric body are substantially parallel means that in X-ray diffraction measurement, the installation direction of the sample and the azimuth angle of the crystal peak can be verified by comparing .

In this embodiment, the inclusion of an optically active polypeptide in the piezoelectric also contributes to the development of piezoelectricity.
In addition, as described above, optically active polypeptides are excellent in hydrolysis resistance. Excellent material durability.
In addition, as described above, since the optically active polypeptide does not have pyroelectricity, the inclusion of the optically active polypeptide in the piezoelectric material is advantageous in that the piezoelectric material and the piezoelectric base material are more advantageous than the piezoelectric material containing PVDF as a main component. Excellent durability.

In addition, since the piezoelectric body including PVDF has high pyroelectricity, the change in output of the amount of charge due to temperature change is large. On the other hand, the piezoelectric body containing the optically active polypeptide of the present embodiment has a smaller change in the output of the charge amount due to temperature changes, and the output of the charge amount is more stable than the piezoelectric body containing PVDF. Excellent in points.
On the other hand, a piezoelectric body containing polylactic acid tends to lower its sensor sensitivity when the temperature rises above a predetermined temperature. In contrast, the piezoelectric body containing the optically active polypeptide of the present embodiment has more stable sensor sensitivity than the piezoelectric body containing polylactic acid even when the temperature is higher than a predetermined temperature. Excellent in points.
Therefore, the piezoelectric body of the present embodiment has excellent sensitivity and is suitable for use in detecting biological information from the human body when placed in an environment that changes to a high temperature.

As used herein, an optically active polypeptide means a polypeptide having optical activity (that is, a polypeptide having an asymmetric carbon atom and having a biased abundance of optical isomers).
The optically active polypeptide preferably has a β-sheet structure from the viewpoint of piezoelectricity and strength.
Optically active polypeptides include animal proteins having optical activity (eg, fibroin, sericin, collagen, keratin, elastin, spider silk protein, etc.).
The optically active polypeptide preferably contains at least one of fibroin and spider silk protein, and particularly preferably consists of at least one of fibroin and spider silk protein.

The spider silk protein is not particularly limited as long as it is a natural spider silk protein or derived from or similar to a natural spider silk protein (hereinafter collectively referred to as "origin").
Here, "derived from natural spider silk protein" means having an amino acid sequence that is the same as or similar to the repeating sequence of amino acids that natural spider silk protein has.
"Those derived from natural spider silk proteins" include, for example, recombinant spider silk proteins, mutants of natural spider silk proteins, analogues of natural spider silk proteins, derivatives of natural spider silk proteins, and the like.

From the viewpoint of excellent toughness, the spider silk protein is preferably a major duct dragline protein produced in the greater vasculature gland of spiders or a spider silk protein derived from the major duct dragline protein.
Major duct dragline proteins include MaSp1 or MaSp2, which are major pituitary gland spidroins derived from Nephila clavipes, ADF3 or ADF4 derived from Araneus diadematus, and the like.

The spider silk protein may be a spider silk protein produced in the arachnoid glands of spiders or a spider silk protein derived from the silker silk protein.
Small duct dragline proteins include MiSp1 and MiSp2, which are small humeral gland spidroins derived from Nephila clavipes.

Alternatively, the spider silk protein may be a weft protein produced in the flagelliform gland of spiders or a spider silk protein derived from this weft protein.
Examples of the weft protein include flagelliform silk protein derived from Nephila clavipes.

Examples of the spider silk protein derived from the above-described large discharge tube dragline silk protein include recombinant spider silk proteins containing units of the amino acid sequence represented by the following formula (1).
The recombinant spider silk protein may contain 2 or more (preferably 4 or more, more preferably 6 or more) units of the amino acid sequence represented by the following formula (1).
When the recombinant spider silk protein contains two or more amino acid sequence units represented by the following formula (1), the two or more amino acid sequence units may be the same or different.

REP1-REP2 ... Formula (1)
[In the formula (1), REP1 is a polyalanine region composed mainly of alanine and represented by (X1)p, and REP2 is an amino acid sequence consisting of 10 to 200 amino acids. ]

In formula (1), REP1 is a polyalanine region composed mainly of alanine and represented by (X1)p. REP1 is preferably polyalanine.
In (X1) p, p is not particularly limited, but preferably an integer of 2-20, more preferably an integer of 4-12.
In (X1) p, X1 represents alanine (Ala), serine (Ser), or glycine (Gly).
(X1) In the polyalanine region represented by p, the total number of alanine residues is preferably 80% or more (more preferably 85% or more) of the total number of amino acid residues in the polyalanine region.
In REP1 in formula (1), the consecutively arranged alanine residues are preferably 2 or more residues, more preferably 3 residues or more, still more preferably 4 residues or more, and particularly preferably is 5 or more residues.
Further, in REP1 in formula (1), the consecutively arranged alanines are preferably 20 residues or less, more preferably 16 residues or less, still more preferably 12 residues or less, Particularly preferably, it is 10 residues or less.

In formula (1), REP2 is an amino acid sequence consisting of 10 to 200 amino acids. The total number of glycine, serine, glutamine, proline and alanine residues contained in this amino acid sequence is preferably 40% or more, more preferably 50% or more, and 60% or more of the total number of amino acid residues. Especially preferred.

Examples of spider silk proteins derived from the above-mentioned small discharge tube dragline silk proteins include recombinant spider silk proteins containing the amino acid sequence represented by the following formula (2).

REP3-REP4-REP5... Formula (2)
[In formula (2), REP3 is an amino acid sequence represented by (Gly-Gly-Z)m, REP4 is an amino acid sequence represented by (Gly-Ala)l, and REP5 is (Ala) It is the amino acid sequence represented by r.
In REP3, Z means any one amino acid.
In REP3, m is 1-4, in REP4, l is 0-4, and in REP5, r is 1-6. ]

In REP3, Z means any one amino acid, preferably one amino acid selected from the group consisting of Ala, Tyr and Gln.

The above-described recombinant spider silk protein (for example, a recombinant spider silk protein containing a unit of the amino acid sequence represented by formula (1), a recombinant spider silk protein containing an amino acid sequence represented by formula (2), etc.) is It can be produced using a host transformed with an expression vector containing a gene encoding a natural spider silk protein to be recombined.

From the viewpoint of piezoelectricity, the elongated piezoelectric body preferably contains fibers made of an optically active polypeptide.
Fibers composed of optically active polypeptides include fibers composed of optically active animal proteins (eg, silk, wool, mohair, cashmere, camel, llama, alpaca, vicuna, angora, spider silk, etc.).
From the viewpoint of piezoelectricity, the optically active polypeptide fiber preferably contains at least one of silk and spider silk, more preferably at least one of silk and spider silk.

Silk includes raw silk, refined silk, regenerated silk, and the like.
As silk, raw silk or refined silk is preferable, and refined silk is particularly preferable.
Here, refined silk means silk obtained by removing sericin from raw silk having a double structure of sericin and fibroin, and refinement means an operation to remove sericin from raw silk. The color of raw silk is dull white, but by removing sericin from raw silk (that is, refining), it changes from dull white to shiny silvery white. Refining also increases the softness of the texture.

From the viewpoint of piezoelectricity, the elongated piezoelectric body preferably contains long fibers made of an optically active polypeptide. The reason for this is thought to be that the stress applied to the piezoelectric base material is more easily transmitted to the piezoelectric body in long fibers than in short fibers.
Here, "long fiber" means a fiber having a length that can be continuously wound from one end to the other end in the longitudinal direction of the piezoelectric substrate.
Silk, wool, mohair, cashmere, camel, llama, alpaca, vicuna, angora, and spider silk described above all correspond to long fibers.
Among long fibers, silk and spider silk are preferable from the viewpoint of piezoelectricity.

When the elongated piezoelectric body contains the fiber, it is preferable that the elongated piezoelectric body includes at least one thread made of at least one fiber.
When the long piezoelectric body includes the thread, the long piezoelectric body is made of one thread, and the long piezoelectric body is an aggregate of a plurality of the threads. , etc.
The yarn may be a twisted yarn or a non-twisted yarn, but from the viewpoint of piezoelectricity, a yarn with a twist number of 500 T/m or less It is preferably several 0 T/m)).
Non-twisted yarns include a single raw yarn, an aggregate of multiple raw yarns, and the like.

The thickness of the long piezoelectric body (the thickness of the entire assembly when the long piezoelectric body is an assembly of a plurality of threads) is not particularly limited, but is preferably 0.0001 to 2 mm. , 0.001 to 1 mm, and particularly preferably 0.005 to 0.8 mm.

When the long piezoelectric body is one raw yarn or an aggregate of a plurality of raw yarns, the fineness of one raw yarn is preferably 0.01 to 10000 denier, more preferably 0.1 to 1000 denier. It is preferred, and 1 to 100 denier is particularly preferred.

In this embodiment, the elongated piezoelectric body is spirally wound.
In this embodiment, an electric charge is generated by applying a shear stress to the spirally wound long piezoelectric body. Thereby, piezoelectricity is exhibited.
Shear stress applied to the piezoelectric body can be generated, for example, by pulling the entire helically wound long piezoelectric body in the direction of the helical axis, or by pulling part of the helically wound long piezoelectric body. It can be applied by twisting (that is, twisting a part of the piezoelectric body around the helical axis), bending a part or the whole of the helically wound long piezoelectric body, or the like. .

The elongated piezoelectric body is preferably wound at a spiral angle of 20° to 70°.
Here, the helical angle means the angle between the helical axis direction (the length direction of the core material when the core material is provided) and the length direction of the wound piezoelectric body (FIG. 7). See spiral angle β1 in the middle).
The helix angle is more preferably 25° to 65°, still more preferably 30° to 60°, and particularly preferably 35° to 55°.

The elongated piezoelectric body is preferably spirally wound in one direction.
Here, "helically wound in one direction" means that when viewed from one end of the piezoelectric substrate, it is left-handed (that is, counterclockwise) from the front side to the back side. , the piezoelectric body is spirally wound in a left-handed direction; It means that the piezoelectric body is spirally wound in the right-handed direction.
When the long piezoelectric body is spirally wound in one direction, the phenomenon in which the polarities of the generated charges cancel each other out (that is, the phenomenon in which the piezoelectricity decreases) is suppressed. Therefore, the piezoelectricity of the piezoelectric substrate is further improved.

The embodiment in which a piezoelectric base material is spirally wound in one direction to include a long piezoelectric body includes not only a mode in which only one layer of the piezoelectric body is provided, but also a mode in which multiple layers of the piezoelectric bodies are stacked. be done.
As a mode in which a plurality of layers of the piezoelectric bodies are stacked, for example, the piezoelectric bodies are stacked on the first piezoelectric body spirally wound in one direction, and the second piezoelectric body is spirally wound in the same direction as the one direction. An embodiment in which the wire is wound in a shape is mentioned.

As an aspect of the piezoelectric base material of this embodiment, as an elongated piezoelectric body, a first piezoelectric body spirally wound in one direction and a spirally wound in a direction different from the one direction and a second piezoelectric body, wherein the chirality of the optically active polypeptide contained in the first piezoelectric body and the chirality of the optically active polypeptide contained in the second piezoelectric body are different from each other.

The piezoelectric substance may contain components other than the optically active polypeptide, if necessary.
For example, when the piezoelectric body is an assembly of a plurality of raw yarns, the piezoelectric body may contain an adhesive for fixing the assembly of the plurality of raw yarns. A preferred embodiment of the adhesive will be described later.

<Core material, outer conductor>
The piezoelectric base material of this embodiment includes an elongated core material.
In the piezoelectric base material of the present embodiment, a long piezoelectric body is helically wound around the long core material.

The core material may be a conductor.
The aspect in which the piezoelectric base material includes a core material that is a conductor has the advantage that an electrical signal (voltage signal or charge signal) can be easily extracted from the piezoelectric body through the core material that is a conductor.
In addition, since this aspect has the same structure as the internal structure (inner conductor and dielectric) provided in the coaxial cable, for example, when the piezoelectric base material of this aspect is applied to the coaxial cable, the electromagnetic shielding property is high, The structure can be resistant to noise.
The conductor is preferably a good electrical conductor, such as copper wire, aluminum wire, SUS wire, metal wire coated with an insulating film, carbon fiber, resin fiber integrated with carbon fiber, tinsel wire, organic conductive wire. materials and the like.
Tinsel wire means a fiber in which copper foil is spirally wound.
Among the conductors, tinsel wire and carbon fiber are preferable from the viewpoint of improving piezoelectric sensitivity and imparting high flexibility.

In particular, it is preferable to use a tinsel wire for applications that require low electrical resistance, bendability, and flexibility.
The form of the tinsel wire has a structure in which a copper foil is spirally wound around a fiber, and the use of copper, which has high electrical conductivity, makes it possible to reduce the output impedance. Therefore, by using the tinsel wire as the core material, the piezoelectricity of the piezoelectric substrate is further improved.

In addition, in processing applications for woven fabrics and knitted fabrics (for example, piezoelectric fabrics, piezoelectric knitted fabrics, piezoelectric sensors (woven piezoelectric sensors, knitted piezoelectric sensors)) that require extremely high flexibility and flexibility, carbon fiber is preferably used.
Moreover, when the piezoelectric base material of the present embodiment is used as a fiber to produce a piezoelectric woven fabric or piezoelectric knitted fabric, suppleness and high flexibility are required. In such applications, filamentous or fibrous signal line conductors are preferred. A piezoelectric base material having filamentous or fibrous signal line conductors has high flexibility, and therefore is suitable for processing with a loom or a knitting machine.

In the case where the piezoelectric substrate includes a conductor core material, the piezoelectric substrate includes an outer conductor on the outer peripheral side of the elongated piezoelectric body spirally wound around the core material, and is a conductor. It is preferable that the core material and the outer conductor are electrically insulated.
In this aspect, the outer conductor can electrostatically shield the inside of the piezoelectric substrate (piezoelectric body and conductive core material). voltage change or charge change is suppressed.
Therefore, more stable piezoelectricity can be obtained in the piezoelectric substrate.
The outer conductor is preferably connected to ground potential.

Although there is no particular limitation on the material of the outer conductor, there are mainly the following materials depending on the cross-sectional shape.
For example, as the material of the outer conductor having a rectangular cross section, a copper foil ribbon obtained by rolling a copper wire having a circular cross section into a flat plate, an Al foil ribbon, or the like can be used.
For example, as the material of the outer conductor having a circular cross section, copper wire, aluminum wire, SUS wire, metal wire coated with an insulating film, carbon fiber, resin fiber integrated with carbon fiber, and tinsel wire can be used.
Also, as the material of the outer conductor, an organic conductive material coated with an insulating material may be used.

It is preferable that the outer conductor is arranged so as to wrap the conductor core material and the piezoelectric body so as not to cause a short circuit with the conductor core material.
As a method of wrapping the core material and the piezoelectric body, which are conductors, select a method of spirally winding a copper foil or the like, or a method of wrapping a copper wire or the like into a cylindrical braid and wrapping it in the braid. can be done.
In addition, the said wrapping method is not limited to these methods.
By wrapping the conductive core material and the piezoelectric body, the electrostatic shielding effect can be further enhanced.
In addition, it is also one of the preferred forms that the external conductor is arranged so as to enclose the minimum basic structural unit (that is, the conductor and the piezoelectric body) of the piezoelectric base material in a cylindrical shape.
Further, for example, when a piezoelectric knitted fabric or a piezoelectric woven fabric, which will be described later, is processed into a sheet by using a piezoelectric base material having the above minimum basic structural unit, a planar or sheet-shaped It is also one of the preferred forms to arrange the conductors in close proximity to each other.

Various cross-sectional shapes such as circular, elliptical, rectangular, and irregular shapes can be applied to the cross-sectional shape of the outer conductor. In particular, since the rectangular cross section can be in flat contact with conductors, piezoelectric bodies, and the like, charges generated by the piezoelectric effect can be efficiently detected as voltage signals.

<Insulator>
(Insulator of first aspect)
The piezoelectric substrate of this embodiment may further comprise the insulator of the first aspect.
The insulator of the first aspect is preferably spirally wound along the outer peripheral surface of the internal conductor.
In this case, the insulator of the first mode may be arranged on the side opposite to the internal conductor when viewed from the piezoelectric body, or may be arranged between the internal conductor and the piezoelectric body.
Moreover, the winding direction of the insulator of the first mode may be the same as or different from the winding direction of the piezoelectric body.
In particular, when the piezoelectric base material includes an outer conductor, the piezoelectric base material further includes the insulator of the first aspect, so that an electrical short circuit occurs between the inner conductor and the outer conductor when the piezoelectric base material bends and deforms. has the advantage of being easier to suppress

The insulator of the first mode is not particularly limited, but for example, vinyl chloride resin, polyethylene resin, polypropylene resin, ethylene/tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene/hexafluoropropylene copolymer Polymer (FEP), tetrafluoroethylene resin (PTFE), tetrafluoroethylene/perfluoropropyl vinyl ether copolymer (PFA), fluororubber, polyester resin, polyimide resin, polyamide resin, polyethylene terephthalate resin (PET), rubber (including elastomer) and the like.
The shape of the insulator of the first mode is preferably an elongated shape from the viewpoint of winding around the conductor.
(Insulator of Second Aspect)
In the piezoelectric base material of the present disclosure, when the outer conductor is provided on the outer circumference, the insulator of the second mode may be provided on the outer circumference of the first outer conductor.
This enables electrostatic shielding and suppresses voltage changes in the conductor (preferably the internal conductor) due to the influence of external static electricity.

The second insulator is not particularly limited, but examples thereof include the materials exemplified as the insulator of the first aspect.
Moreover, the shape of the insulator in the second aspect is not particularly limited as long as it can cover at least a part of the outer conductor.

As a method of providing an insulator on the outermost periphery of the piezoelectric base material of this embodiment, a method of winding a long insulator around the piezoelectric base material before the insulator is provided; a method of winding a cylindrical insulator; A method in which a piezoelectric base material before an insulator is provided is placed in the inner space of (e.g., a heat-shrinkable tube), and then the cylindrical insulator is shrunk and adhered by heat; covered with an insulating molten resin and cooled A method of solidifying; a method of coating and solidifying an insulating resin coating liquid; and the like.

<Adhesive>
The piezoelectric substrate of this embodiment may contain an adhesive.
In a mode in which the piezoelectric substrate contains an adhesive, at least the spirally wound piezoelectric body can be mechanically integrated.
In addition, when the piezoelectric substrate includes a member other than the piezoelectric body such as a core material (core material, external conductor, etc.), the piezoelectric body and the member other than the piezoelectric body can be integrated with an adhesive. .
By mechanically integrating the piezoelectric body (or the piezoelectric body and a member other than the piezoelectric body), when a force is applied to the piezoelectric base material, the force tends to act on the piezoelectric body in the piezoelectric base material. . Therefore, piezoelectricity is further improved.

Adhesive materials include epoxy adhesives, urethane adhesives, vinyl acetate resin emulsion adhesives, (EVA) emulsion adhesives, acrylic resin emulsion adhesives, and styrene-butadiene rubber latex adhesives. Adhesives, silicone resin adhesives, α-olefin (isobutene-maleic anhydride resin) adhesives, vinyl chloride resin solvent adhesives, rubber adhesives, elastic adhesives, chloroprene rubber solvent adhesives, Nitrile rubber-based solvent-based adhesives, cyanoacrylate-based adhesives, and the like are included.

<Other elements>
The piezoelectric base material of this embodiment may include elements other than the elements described above.
Other elements include, for example, fibers other than long piezoelectric bodies.
In the piezoelectric substrate of the present embodiment, fibers other than the long piezoelectric body may be wound together with the long piezoelectric body.
Also, a known extraction electrode can be joined to the piezoelectric base material of the present embodiment. Examples of extraction electrodes include electrode parts such as connectors, crimp terminals, and the like. The electrode component can be joined to the piezoelectric base material by brazing such as soldering, a conductive adhesive, or the like.

Specific examples of the piezoelectric substrate of this embodiment will be described below with reference to the drawings, but the piezoelectric substrate of this embodiment is not limited to the following specific examples.
It should be noted that substantially the same elements are denoted by the same reference numerals throughout the drawings, and redundant description may be omitted. Further, in specific examples of the piezoelectric substrate of the present embodiment, a piezoelectric substrate 50A, a piezoelectric substrate 50B, and a piezoelectric substrate 50C, which will be described later, are examples of the piezoelectric substrate 50 described above.

<Specific example A>
FIG. 7 is a schematic side view schematically showing a piezoelectric substrate according to Specific Example A of the present embodiment, and FIG. 8 is a cross-sectional view taken along line XX' of FIG.
Specific example A is a specific example of a piezoelectric base material (piezoelectric base material having a core material) of the first embodiment that does not include an external conductor.

As shown in FIG. 7, a piezoelectric base material 50A, which is a specific example A, includes an elongated core member 52 that is a conductor, and an elongated piezoelectric body 54A. The piezoelectric body 54A is spirally wound in one direction along the outer peripheral surface of the core material 52 at a spiral angle β1 from one end to the other end without a gap.
Here, the helix angle β1 is an angle formed by the direction of the helix axis G1 (the axial direction of the core material 52 in this example) and the length direction of the piezoelectric body 54A in a side view.
In this piezoelectric base material 50A, the piezoelectric body 54A is wound counterclockwise around the core material 52. As shown in FIG. Specifically, when the piezoelectric base material 50A is viewed from one end side of the core material 52 in the axial direction (the right end side in FIG. 8), the piezoelectric body 54A is left-handed from the front side of the core material 52 toward the back side. is wound with
Also, in FIG. 8, the main orientation direction of the optically active polypeptide contained in the piezoelectric body 54A is indicated by a double arrow E1. That is, the main orientation direction of the optically active polypeptide and the length direction of the piezoelectric body 54A are substantially parallel.
In the piezoelectric base material 50A, each member (the core material 52 and the piezoelectric body 54A) is integrated (fixed) by impregnating an adhesive (not shown) between the members.

The effects of the piezoelectric substrate 50A will be described below.
For example, when tension is applied in the longitudinal direction of the piezoelectric substrate 50A, shear stress is applied to the optically active polypeptide contained in the piezoelectric body 54A, and the optically active polypeptide is polarized. The polarization of this optically active polypeptide is considered to occur with the phase aligned in the radial direction of the piezoelectric substrate 50A, as indicated by the arrows in FIG. Thereby, the piezoelectricity of the piezoelectric substrate 50A is exhibited.
Furthermore, since the piezoelectric base material 50A includes the core material 52 that is a conductor, an electrical signal (voltage signal or charge signal) generated in the piezoelectric body 54A can be more easily extracted via the core material 52.

<Specific example B>
FIG. 9 is a schematic side view schematically showing a piezoelectric base material according to Specific Example B of the present embodiment.
Specific example B is a specific example of the piezoelectric base material (piezoelectric base material having a core material) of the first embodiment that includes an external conductor.

As shown in FIG. 9, the piezoelectric base material 50B of the specific example B has an outer conductor 56 on the outer peripheral side of the piezoelectric body 54A in contrast to the piezoelectric base material 50A of the above-described specific example A, and the core material 52 and the outer conductor 56 are electrically insulated. Other configurations are the same as those of the piezoelectric base material 50A of the specific example A described above.
Preferred aspects of the outer conductor 56 are as described above. The outer conductor 56 is formed, for example, by spirally winding a copper foil ribbon around the piezoelectric body 54A spirally wound around the core 52 .
In the piezoelectric substrate 50B, each member (the core member 52, the piezoelectric body 54A, and the outer conductor 56) is impregnated with an adhesive (not shown) to be integrated (fixed).
As shown in FIG. 9, in the piezoelectric base material 50B, when viewed from the side, the ends of the wound body of the piezoelectric body 54A (that is, the spirally wound piezoelectric body 54A) and the ends of the external conductor 56 are separated from each other. Out of position. Thereby, the core material 52 and the outer conductor 56 are reliably insulated. However, the positions of these end portions do not necessarily have to be shifted, and as long as the core material and the outer conductor, which are conductors, are electrically insulated, the positions of these end portions overlap when viewed from the side. There may be.

The piezoelectric base material 50B also has the same effects as the piezoelectric base material 50A.
Furthermore, since the piezoelectric base material 50B includes the outer conductor 56, the inside of the piezoelectric base material 50B (the piezoelectric body 54A and the core material 52, which is a conductor) can be electrostatically shielded by the outer conductor 56. Therefore, it is possible to suppress the voltage change of the core material 52 due to the influence of static electricity outside the piezoelectric base material 50B, and as a result, more stable piezoelectricity can be obtained.

Note that the outer conductor 56 may be omitted from the piezoelectric substrate 50B.
Needless to say, even when the outer conductor 56 is omitted, the effect of the core material 52, which is a conductor, is exhibited.
In addition, even if the outer conductor 56 is omitted, the structure is the same as the inner structure (inner conductor and dielectric) provided in the coaxial cable. It can be a structure that is strong against

<Summary of the first embodiment>
The steering wheel 20 of this embodiment includes a rim 21 (a grip) that is gripped by the driver, and a piezoelectric substrate 50 that is provided on the rim 21 and detects the pressure that the rim 21 receives from the driver. The steering wheel 20 has a piezoelectric substrate 50 coaxially provided around an axial inner conductor (core material 52) and an elongated piezoelectric body containing an optically active polypeptide. 54A.

The piezoelectric base material 50 can output an electrical signal corresponding to the shear stress in a direction different from the direction in which the pressure is applied by spirally winding the piezoelectric body 54A around the internal conductor (core material 52). be. Therefore, the line-shaped piezoelectric base material 50 installed on the steering wheel 20 outputs an electric signal when tension is generated in the axial direction due to pressure on the steering wheel 20 .
In addition, the piezoelectric body 54A containing an optically active polypeptide that constitutes the piezoelectric substrate 50 can be arranged in a line rather than in a sheet. Compared to piezoelectric bodies, they are superior in that there are fewer restrictions on where they can be placed.

In addition, the piezoelectric body containing PVDF has a large change in output of the amount of electric charge due to temperature change. On the other hand, the piezoelectric base material 50 of the present embodiment has a smaller change in the output of the charge amount due to temperature changes, and the output of the charge amount is stable, as compared with the steering wheel including the piezoelectric body containing PVDF. excellent in terms of
On the other hand, a piezoelectric body containing polylactic acid tends to lower its sensor sensitivity when the temperature rises above a predetermined temperature. In contrast, the piezoelectric substrate 50 of the present embodiment has stable sensor sensitivity even when the temperature exceeds a predetermined temperature, compared to a steering wheel including a piezoelectric body containing polylactic acid. excellent in terms of

Therefore, the piezoelectric substrate 50 of the present embodiment has excellent sensitivity and is suitable for use in detecting biological information from the human body by placing it on the steering wheel 20 of a vehicle in an environment that changes to high temperatures. is.

In addition, when the method of providing electrodes and detecting the biological information from the potential difference between the electrodes caused by the human body in contact with the electrodes is applied to the steering wheel, it is necessary to hold the electrodes on the steering wheel with both hands. There are constraints to detect In addition, static electricity is generated in the electrodes of the steering wheel, which may result in erroneous detection of biometric information.
On the other hand, since the steering wheel 20 of the present embodiment is provided with the piezoelectric base material 50 over the entire circumference of the rim 21, it is possible to detect the pressure of gripping the rim 21 and biometric information regardless of whether one hand or both hands. is. Moreover, even if static electricity is generated, the piezoelectric substrate 50 is arranged inside the rim 21 and is not affected by static electricity, so erroneous detection of biometric information can be prevented.

Further, when applying a method of detecting biological information by irradiating a hand of a user holding a steering wheel and detecting reflected light reflected from the hand of the user to the steering wheel, in order to operate the vehicle, The user's hand may move out of the illuminated area. Therefore, the biometric information may not be detected with high accuracy, and the detection sensitivity of the biometric information may be lowered.
On the other hand, in the steering wheel 20 of the present embodiment, since the piezoelectric base material 50 is provided over the entire circumference of the rim 21, biological information can be detected while the rim 21 is held. Therefore, even if the user moves his/her hand to operate the vehicle, the detection sensitivity of biometric information does not decrease.

In addition, when two films are superimposed with a predetermined gap therebetween, the top film is flexed when touched, and the flexure brings the top film into contact with the bottom film. There is a resistive pressure-sensitive pressure sensor that detects contact with a film by detecting energization from the contact point. When the resistive pressure sensor is applied to the steering wheel, in order to detect the position of the contact point, it is necessary to constantly supply a voltage to the sensor and measure the resistance by measuring the flowing current, so power is not supplied. I need to continue.
On the other hand, the steering wheel 20 of the present embodiment detects an electrical signal generated by pressure input to the piezoelectric base material 50, and biometric information can be detected, so power supply is not required.

Therefore, the steering wheel 20 of the present embodiment has excellent sensitivity and can suppress power consumption, so it is suitable for use in detecting biological information from the human body.

[Second embodiment]
Next, a steering wheel 20 according to a second embodiment will be described with reference to FIG. FIG. 10 is a front view showing an example of the steering wheel 20 for explaining the arrangement of the piezoelectric base material according to this embodiment. The present embodiment differs from the first embodiment only in the arrangement of the piezoelectric substrate 50, but the other aspects are the same. In the following description, the same reference numerals are given to the same configurations as in the first embodiment, and overlapping descriptions are omitted.

As shown in FIG. 10 as an example, the piezoelectric substrate 50 is arranged inside the rim 21 so as to be wound around the rim 21 . In this case, the incisions 25 are likewise wound around the surface 24 of the rim 21 .

According to the second embodiment, in addition to the effects of the first embodiment, the following effects are obtained. That is, in the present embodiment, one piezoelectric base material 50 is arranged so as to be wound around the rim 21 inside the rim 21, so that the rim 21 can be biometric information is detected from a wide range on the surface of the

[Third embodiment]
Next, a steering wheel 20 according to a third embodiment will be described with reference to FIG. FIG. 11 is a front view showing an example of the steering wheel 20 for explaining the arrangement of the piezoelectric base material according to this embodiment. It should be noted that this embodiment differs from the second embodiment only in the arrangement of the piezoelectric substrate 50 and the functional configuration, but the other aspects are the same. In the following description, the same reference numerals are given to the same configurations as in the second embodiment, and overlapping descriptions are omitted.

As an example, as shown in FIG. 11, in the steering wheel 20, a plurality of independent piezoelectric substrates 50 are arranged inside the rim 21 gripped by the user. Specifically, six piezoelectric substrates 50 are installed at regular intervals along the shape of the rim 21 .

Next, with reference to FIG. 12, functional configurations of the biological information detection device 10 and the control device 100 when a plurality of sensor units 23 are arranged independently of each other will be described. As shown in FIG. 12, the biological information detection device 10 has a detection section 41 and a detection section 42B. Each functional configuration is realized by the CPU 31 reading an execution program stored in the storage 34 and executing it. 12 that are the same as the functions of the biological information detecting device 10 and the control device 100 shown in FIG. 6 are denoted by the same reference numerals as in FIG. 6, and description thereof will be omitted.

The detection unit 42B shown in FIG. 12 has a function of detecting biological information such as respiration and pulse from the magnitude and cycle of the digital signal detected by the detection unit 41. The detection unit 42B also has a function of detecting position information indicating the position where the driver grips the rim 21 by comparing the output signals of the adjacent piezoelectric substrates 50 .

Also, as shown in FIG. 12, the control device 100 has an acquisition unit 111B and a control unit 112B. Each functional configuration is realized by the CPU 101 reading an execution program stored in the storage 104 and executing it.

The acquisition unit 111B has a function of acquiring biometric information and position information from the biometric information detection device 10.

The control unit 112B has a function of controlling the device 200 using the acquired biological information and position information. For example, the control unit 112B transmits an instruction to execute processing to each device 200 according to the biometric information. Specifically, the control unit 112B detects fluctuations in the interval between heartbeats from the biological information, and when the fluctuations in the heartbeats become smaller (the intervals between heartbeats are stable), the driver is sleepy. , and transmits an instruction to brake the actuator as the device 200 . In addition, the control unit 112B detects the magnitude and number of heartbeats from the biological information, the magnitude of the heartbeat is greater than the average value for the driver, and the number of heartbeats in a predetermined period is greater than the average value for the driver. In this case, it is determined that the driver is in a tense state, and an instruction to apply the brake to the actuator as the device 200 is transmitted. In addition, the control unit 112B uses the position information to determine the state in which the driver is gripping the rim 21, and outputs voice information regarding the state in which the driver is gripping the rim 21 and the state in which the rim 21 is not being gripped. An instruction to output may be transmitted to the input/output unit 105 such as a speaker, or an instruction to output the character information may be transmitted to the display unit 106 such as a monitor.

By arranging a plurality of piezoelectric substrates 50 that are independent of each other, the pressure detected by each piezoelectric substrate 50 is compared and the biological information of the driver and positional information (when the driver is gripping the rim 21) are obtained. positional information) is detected, and the device 200 is controlled using the biological information and the positional information.

[Modified example of the third embodiment]
In the third embodiment, the form in which the plurality of piezoelectric substrates 50 are arranged along the shape of the rim 21 has been described. However, it is not limited to this. As an example, as shown in FIG. 13 , a plurality of piezoelectric substrates 50 may be arranged so as to be wound around the rim 21 . Specifically, eight piezoelectric substrates 50 are arranged at equal intervals so as to be wound around the rim 21 .

A plurality of mutually independent piezoelectric substrates 50 are arranged so as to be wound around the rim 21, so that biological information and positional information of the driver (when the driver grips the rim 21) is collected from a wide range on the surface of the rim 21. location information) is detected.

Here, when a plurality of mutually independent piezoelectric substrates 50 are provided on the rim 21, only the piezoelectric substrates 50 in which the piezoelectric members 54A are wound in the clockwise direction may be arranged on the rim 21, or the piezoelectric members 54A may be arranged on the rim 21. Alternatively, only the piezoelectric substrate 50 wound counterclockwise may be arranged on the rim 21 . In addition, both the piezoelectric base material 50 with the piezoelectric body 54A wound in the right-handed direction and the piezoelectric base material 50 with the piezoelectric body 54A wound in the left-handed direction are arranged on the rim 21, for example, alternately. good too. Two piezoelectric substrates 50 wound in the right-handed direction and two piezoelectric substrates wound in the left-handed direction are arranged side by side, and the respective detection signals are differentially amplified to output the vital signal. It is possible to double and cancel the common mode noise superimposed on the signal line. This makes it possible to improve the SN ratio of the vital signal.

In the above embodiment, the piezoelectric substrate 50 is installed on the rim 21 (holding body) held by the driver. However, it is not limited to this. For example, piezoelectric substrate 50 may be mounted on hub 22 . By installing the piezoelectric substrate 50 on the hub 22, it becomes possible to detect that the driver is gripping the hub 22, and the rim 21 can be adjusted to the driver's driving posture, especially when the rim 21 is not gripped. It is possible to make a notification to grasp.
Also, the piezoelectric substrate 50 may be arranged on a steering switch (not shown). For example, the piezoelectric substrate 50 is placed under a button installed on the steering wheel 20, and the piezoelectric substrate 50 detects the pressure when the button is pressed, thereby detecting that the button has been pressed. It is possible to

The technology of the present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to the following examples as long as it does not exceed the gist of the present disclosure.

[Example 1]
<Preparation of Optically Active Polypeptide Fiber>
Raw silk was prepared as an optically active polypeptide fiber. Raw silk is a long fiber composed of optically active polypeptides. Raw silk is 21 denier. The thickness of raw silk is 0.06mm-0.04mm.
(Measurement of Orientation Degree F of Optically Active Polypeptide Fiber)
Using a wide-angle X-ray diffractometer ("RINT2550" manufactured by Rigaku Co., Ltd., accessory: rotating sample stage, X-ray source: CuKα, output: 40 kV 370 mA, detector: scintillation counter), raw silk (optically active polypeptide fiber) was fixed to a holder, and the azimuth angle distribution intensity of the crystal face peak [2θ=20°] was measured.
In the obtained azimuth angle distribution curve (X-ray interferogram), the degree of orientation F (degree of c-axis orientation) of raw silk (optically active polypeptide fiber) is calculated from the half width (α) of the peak according to the following formula (a) was calculated.
The orientation degree F of the optically active polypeptide fiber is 0.91.
Orientation (F) = (180°-α)/180° (a)
(α is the half width of the peak derived from the orientation)

<Production of piezoelectric yarn>
A scouring silk was produced by scouring a six-twisted yarn (twisting number: 150 T/m) as a piezoelectric yarn from raw silk by a known method. The orientation degree F of the twisted yarn of this refined silk is 0.86.
Since the orientation degree F of the optically active polypeptide fiber is 0.86 and the six-piece twisted yarn (piezoelectric yarn) was produced using the scouring silk, the length direction of the piezoelectric yarn and the scouring silk ( It can be evaluated that the main orientation direction of the optically active polypeptide contained in the optically active polypeptide fiber) is substantially parallel.

<Production of Piezoelectric Substrate>
As an internal conductor, a tinsel wire "U24-01-00" (wire diameter 0.26 mm, length 200 mm) manufactured by Meisei Sangyo Co., Ltd. was prepared.
The piezoelectric thread was wound counterclockwise on the outer peripheral surface of the internal conductor so as to have a spiral angle of about 45° with as few gaps as possible. As a result, a layer (hereinafter referred to as a "piezoelectric yarn layer") was formed on the outer peripheral surface of the internal conductor, and a piezoelectric substrate precursor was obtained. The piezoelectric thread layer covered the entire outer peripheral surface of the internal conductor. That is, the outer peripheral surface of the inner conductor was not exposed.
"Left-handed" means that the piezoelectric thread is wound counterclockwise from the front side to the back side of the inner conductor (tinshi wire) when viewed from one end in the axial direction of the inner conductor. "Helix angle" refers to the angle formed by the longitudinal direction of the piezoelectric yarn with respect to the axial direction of the inner conductor.
Next, Aron Alpha 902H3 (a cyanoacrylate-based adhesive) manufactured by Toagosei Co., Ltd. was dripped as an adhesive and impregnated to mechanically integrate the raw silk.
Next, a copper foil ribbon slit to a width of 0.3 mm was prepared as an outer conductor. This copper foil ribbon was wound around the core material and tightly wound around the mechanically integrated raw silk so that the raw silk was hardly exposed. Here, the winding direction of the copper foil ribbon was right-handed. Also, the copper foil ribbon was wound so as not to come into contact with the two crimp terminals.
Next, as an insulating coating, a PTFE film having a thickness of 0.15 mm was wound counterclockwise to cover the whole so that the external copper foil was not exposed.
As described above, a piezoelectric substrate was obtained.

<Piezoelectric substrate placed directly under the skin>
The end of the piezoelectric substrate is connected to the coaxial line, the inner conductor and the outer conductor are arranged so as not to be in electrical contact, the connection portion is covered with a copper foil so as to wrap it from the outside, and the copper foil and the outer conductor are soldered. were electrically connected, and the whole was fixed with Kapton tape. A length of piezoelectric substrate was placed so as to wrap around the rim of the steering wheel. Specifically, as shown in FIG. 14, the genuine leather part of a steering wheel with genuine leather used in a passenger car is once peeled off, and a piezoelectric base material is placed on the urethane resin cushion material under the genuine leather. I installed this and put the genuine leather part back on.

<Detection of Piezoelectric Sensitivity of Piezoelectric Substrate>
Signals from the piezoelectric substrate were detected by the following method.
A coaxial line connected to the end of the piezoelectric substrate was connected to a detection circuit. Here, the wiring on the outer conductor side was connected to the ground side of the detection circuit. As the detection circuit, an amplifier circuit as shown in FIG. 15 was used, and the variable resistance was adjusted to set the amplification factor to 100 times. The output voltage (OutPut) of this circuit is connected to NI's USB-6002, converted to a digital signal, input to a personal computer via a USB connection, passed through a high-pass filter using the control software LabView on the personal computer, and moving average After processing, the voltage signal was measured. Here, a 3rd order Butterworth filter with a cutoff frequency of 1 Hz was used as the high-pass filter, and the moving average process was performed 50 times.
Using this system, grip detection was performed by the following method.
In the steering wheel shown in FIG. 14, in order to detect gripping, a portion A of the steering wheel where the piezoelectric base material was installed was gripped and then released (the range of the double arrow A in FIG. 16 is time during which the steering part A is gripped). On the other hand, gripping the portion B of the steering wheel where the piezoelectric base material is not installed (the range of the double arrow B in FIG. 16 is the time when the steering portion B is gripped in FIG. 14), and the detected voltage confirmed the difference.
As a result, as shown in FIG. 16, a low voltage was detected before the steering wheel was gripped, but a large voltage was detected when the steering wheel portion A was gripped, indicating the gripped state. Furthermore, during the gripping period, vibration due to mechanical micro-vibration of muscles (so-called biological tremor) is detected as a physiological phenomenon of the living body. A biological tremor is considered to be a constant frequency vibration detected within a predetermined frequency band (for example, a band of about 5 Hz to 20 Hz) and a voltage level rising at a constant value.
Also, when the gripping hand was released, the pressure fluctuation was detected, a large voltage was once detected, and then the voltage dropped to the base level.

Also, when gripping the part B (diagonal position) of the steering wheel where the piezoelectric base material is not installed, the gripped pressure fluctuation was detected in the same way, and the voltage level increased, but immediately decreased. In addition, biotremor vibrations were detected while gripping the steering wheel at region B. However, since the gripped position was far from the position where the piezoelectric base material was installed, the signal level showed a low value. Furthermore, when the hand holding the steering wheel portion B was released, the voltage due to the pressure fluctuation was detected and then dropped to the base level.

As described above, it is possible to detect whether or not the steering wheel is being gripped by voltage rise and fluctuation due to biological tremor. In addition, the position where the steering wheel is gripped can be detected from the magnitude of the output of the piezoelectric substrate.
By appropriately increasing the number of divisions in the steering wheel and arranging the piezoelectric base material, the detection sensitivity can be adjusted, and the gripped position information can be detected more accurately from the magnitude of the vibration output due to the biological tremor.

[Comparative example]
Next, as a comparative example of Example 1, a PVDF piezoelectric sensor was arranged on a steering wheel in parallel with the piezoelectric substrate. A polarized PVDF sheet (PVDF-P0045) manufactured by Waki Laboratory Co., Ltd. is cut to a length of 200 mm and a width of 15 mm. It was soldered and connected to the coaxial line in the same way as the piezoelectric substrate.

<Piezoelectric substrate placed directly under the skin>
The piezoelectric base material of Example 1 and the PVDF piezoelectric sensor are arranged side by side on the urethane resin cushion material under the genuine leather of the steering wheel in the same manner as in Example 1, and the whole is wrapped with Kapton tape. After fixing, the genuine leather portion was reattached and returned in the same manner as in Example 1.

<Detection of Piezoelectric Sensitivity of Piezoelectric Substrate>
A piezoelectric base material and a PVDF piezoelectric sensor are used in a detection circuit as shown in FIG. The voltage signal was input to a personal computer via a USB connection, and the voltage signal was measured using control software LabView on the personal computer without setting a filter. The output of the PVDF piezoelectric sensor was connected to the detection circuit, and the amplification of the detection circuit was set so that the voltage level was the same as in Example 1 when the object was held.
After that, the steering wheel is grasped and released several times, and then a signal indicating that the steering wheel is grasped (for example, the range of 0 to 10 seconds in FIG. 17) is detected, and the two sensors detect the same voltage. I confirmed that I did. After that, a 54 W krypton bulb was placed at a distance of about 15 cm above the sensor to heat the steering wheel. After about 12 seconds from the start of heating, it was confirmed that the surface temperature of the steering wheel had risen to about 45 degrees. confirmed. FIG. 17 shows the result of detecting the voltage signal indicating gripping over time when the steering wheel is heated. Here, in FIG. 17, the voltage detected by the piezoelectric substrate is indicated by a solid line, and the voltage detected by the PVDF piezoelectric sensor is indicated by a dotted line.

As shown in FIG. 17, the piezoelectric base material stably detects a voltage signal indicating that the steering has been gripped when the steering is repeatedly gripped and released for a period of 10 seconds from the start of heating. did. Also, when 15 seconds or more have passed since the start of heating of the piezoelectric substrate (the temperature of the steering wheel reached 45 degrees or more), when the steering wheel was gripped and released repeatedly, A voltage signal was detected stably (range 15 to 25 seconds in FIG. 17).
On the other hand, the PVDF piezoelectric sensor stably detected a voltage signal during a period of 10 seconds after the start of heating, when the operation of gripping and releasing the steering was repeated. However, when 15 seconds have passed since the start of heating (the temperature of the steering wheel reached 45 degrees or higher), the PVDF piezoelectric sensor repeatedly gripped and released the steering wheel, and the voltage changed. The range increased significantly, and when 20 seconds or more had passed since the start of heating, the range was over, and the voltage signal indicating the gripping could not be detected.

As described above, even when the temperature of the steering wheel rises, the piezoelectric base material according to this embodiment can stably detect a voltage signal indicating that the steering wheel is gripped.

[Example 2]
A piezoelectric substrate was produced in the same manner as in Example 1, except that two piezoelectric substrates were prepared in which the piezoelectric yarn and the rolled copper foil ribbon were wound in different directions. In Example 2, an example of detecting biological tremors using two piezoelectric substrates with different winding directions of a piezoelectric yarn and a rolled copper foil ribbon will be described.

<Production of Piezoelectric Substrate>
The piezoelectric substrate according to this example includes a first piezoelectric substrate composed of a left-handed piezoelectric yarn and a right-handed rolled copper foil ribbon similar to those in Example 1, and the winding direction of the first piezoelectric substrate is Differently, a second piezoelectric substrate composed of a right-handed piezoelectric yarn and a left-handed rolled copper foil ribbon was prepared.

Each piezoelectric base material is arranged so that the inner conductor and the outer conductor are not electrically connected, the end is connected to the coaxial line, the connection part is covered with copper foil so as to wrap it from the outside, and the copper foil and the outer conductor are Electrical connection was made by soldering, and the whole was fixed with Kapton tape.

<Piezoelectric substrate placed directly under the skin>
The respective piezoelectric substrates were arranged in parallel on a urethane resin cushion material so as to be wound around the rim of the steering wheel. The leather part was reattached in the same way. Here, as an example, as shown in FIG. 18, the inner conductor 50D1 of the first piezoelectric base material 50D is connected to the first lead wire 29A1 on the central axis side of the coaxial line in the wiring 29A, and the outer conductor of the first piezoelectric base material 50D is connected. 50D2 was connected to a second conductor 29A2 outside the coaxial line in wiring 29A. Similarly, the inner conductor 50E1 of the second piezoelectric base material 50E is connected to the first conductor 29B1 of the coaxial line of the wiring 29B, and the outer conductor 50E2 of the second piezoelectric base material 50E is connected to the coaxial line of the wiring 29B. was connected to the second conductor 29B2 on the outside of the .

<Detection of Piezoelectric Sensitivity of Piezoelectric Substrate>
Next, each of the first piezoelectric substrate 50D and the second piezoelectric substrate 50E was electrically connected to an instrumentation amplifier housed in a metal housing (GND). A first conductor 29A1 of the wiring 29A was connected to the first differential input terminal V _IN ⁻ of the instrumentation amplifier. The second conductor 29B1 of the wiring 29B was connected to the second differential input terminal V _IN ⁺ of the instrumentation amplifier. The reference terminal V _ref of the instrumentation amplifier, the second conductor 29A2 of the wiring 29A, and the second conductor 29B2 of the wiring 29B were connected to a metal housing (GND) housing the instrumentation amplifier 30 .

After the arrangement is completed, the part of the steering wheel in which the piezoelectric substrate is embedded is kept lightly gripped with one hand, and signals obtained from each of the first piezoelectric substrate 50D and the second piezoelectric substrate 50E are sent to the instrumentation amplifier. The output of the instrumentation amplifier was measured using the "USB-6001" manufactured by National Instruments, the data was imported into a personal computer, the voltage signal was analyzed by FFT (Fast Fourier Transform), and the frequency characteristics were evaluated. .

The FFT analysis was performed using the spectrum measurement configuration Express VI of LabView under the conditions of amplitude measurement, Hanning window, number of samples: 32768, and rate of 1 kHz. FIG. 19 shows the measurement results of the FFT analysis in Example 2. FIG.
For comparison, FIG. 20 shows the results of FFT analysis of signals detected in the same arrangement as in Example 2, but in a state where the steering wheel is not gripped and left stationary.

Comparing FIG. 19 and FIG. 20, the signal indicating that the steering wheel is gripped is significantly detected by using two piezoelectric substrates with different winding directions of the piezoelectric yarn and the rolled copper foil ribbon. .

[Example 3]
Signal detection was performed in the same manner as in Example 2, except that the internal conductor 50E1 of the second piezoelectric substrate 50E was not electrically connected to the second differential input terminal V _IN ⁺ of the instrumentation amplifier 30. . Specifically, as shown in FIG. 21 as an example, the internal conductor 50D1 of the first piezoelectric substrate 50D is electrically connected to the first differential input terminal V _IN ⁻ of the instrumentation amplifier 30, and the second input terminal of the instrumentation amplifier 30 is electrically connected. A metal housing (GND) housing the instrumentation amplifier 30 was connected to the differential input terminal V _IN ⁺ . In addition, the reference terminal V _ref of the instrumentation amplifier, the second conductor 29A2 of the wiring 29A, and the second conductor 29B2 of the wiring 29B were connected to the metal housing (GND) housing the instrumentation amplifier 30 . That is, in Example 3, only the first piezoelectric substrate 50D was used to detect a signal indicating that it was gripped, and FFT analysis was performed.
FIG. 22 shows the measurement results of FFT analysis in Example 3 in the same manner as in Example 2. In FIG.

Comparing FIGS. 20 and 22, a signal indicating gripping is detected even when only the first piezoelectric substrate 50D is used. On the other hand, when comparing FIGS. 19 and 22, when only the first piezoelectric substrate 50D is used, the piezoelectric yarn and the rolled copper foil ribbon are wound in different directions in two piezoelectric substrates. also reduces the voltage of the signal. In other words, when two piezoelectric substrates with different winding directions are used, the signal indicating that the steering wheel is gripped is more prominently detected than when one piezoelectric substrate is used.

In addition, regarding one embodiment of the technology disclosed above, the following additional remarks are disclosed.

(Appendix 1)
The piezoelectric substrate further comprises an insulator spirally wound along the outer peripheral surface of the internal conductor,
the insulator is disposed between the inner conductor and the piezoelectric body;
The steering according to <6>.

The disclosure of Japanese Patent Application No. 2021-093908 filed on June 3, 2021 is incorporated herein by reference in its entirety. All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.

1 Control system 10 Biological information detection device 20 Steering wheel 21 Rim (gripping body)
41

detection parts

42A,

42B detection parts

50, 50A, 50B, 50C piezoelectric substrate 52 core material (inner conductor)
54A Piezoelectric body 56 External conductor 100 Control device

Claims

a grasping body to be grasped by a user;
a piezoelectric substrate that detects the pressure received by the gripping body,
The piezoelectric substrate is
an axial inner conductor;
an elongated piezoelectric body provided coaxially around the inner conductor and containing an optically active polypeptide;
steering wheel.
In the piezoelectric substrate, the length direction of the elongated piezoelectric body and the main orientation direction of the optically active polypeptide are substantially parallel.
A steering according to claim 1.
The orientation degree F of the optically active polypeptide determined by the following formula (a) from X-ray diffraction measurement is 0.50 or more and less than 1.00.
The steering according to claim 1 or 2.
Orientation F = (180°-α)/180°... Formula (a)
[In the formula (a), α represents the half width (°) of the orientation-derived peak. ]
The elongated piezoelectric body is spirally wound in one direction,
The steering according to any one of claims 1 to 3.
the piezoelectric substrate in which the elongated piezoelectric body is wound in a right-handed direction;
and the piezoelectric substrate on which the elongated piezoelectric body is wound in a counterclockwise direction.
A steering according to claim 4.
The piezoelectric substrate further comprises an outer conductor on its perimeter,
A steering according to any one of claims 1 to 5.
The steering according to claim 6, wherein the piezoelectric base material further comprises an insulator around the outer conductor.
wherein the optically active polypeptide comprises at least one of silk and spider silk;
A steering according to any one of claims 1 to 7.
A steering according to any one of claims 1 to 8;
a detection unit that detects a signal corresponding to the pressure of the piezoelectric substrate;
a detection unit that detects biological information in the human body based on the signal detected by the detection unit;
A biological information detection device comprising:
The gripping body comprises a plurality of piezoelectric substrates,
The detection unit independently detects a signal from each piezoelectric base material,
The detection unit detects position information indicating a position where the human body is in contact from the signals detected from each piezoelectric base material.
The biological information detecting device according to claim 9.
A biological information detection device according to claim 9 or claim 10,
a control device that controls equipment provided on the moving body operated by the steering, based on the information detected by the biological information detection device;
A control system with
The control device controls the device according to information related to the heartbeat of the human body obtained from the biological information.
12. The control system of claim 11.