JP2017198621A - Rotation angle measurement device and capacitance type sensor sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation angle measurement device with which it is possible to measure the rotation angle of a measurement object without using a large-scale facility.SOLUTION: Provided is a rotation angle measurement device used in measuring the rotation angle of a measurement object, comprising: a sensing member 2 extendable in one direction following the rotation of the measurement object and whose electric parameter changes in accordance with a rotation angle; a measurement unit 3 for measuring the electric parameter; and a computation unit 4 for calculating a rotation angle on the basis of the result of measurement by the measurement unit 3. The sensing member 2 includes a detection unit whose electric parameter changes in accordance with the amount of deformation when it is extended or contracted, and a fixing member for attaching the sensing member 2 to the measurement object, the fixing member being provided at two places so as to hold the detection unit therebetween in the extension/contraction direction of the detection unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotation angle measuring device and a capacitive sensor sheet.

In the field of rehabilitation (hereinafter also simply referred to as rehabilitation), measurement of joint angles and movable ranges of patients with motor paralysis such as paralysis and hemiplegia is routinely performed.
As means for measuring joint movement during exercise or rehabilitation, for example, a joint angle, for example, an angle meter and a goniometer are known.
In addition, motion capture is known as a method for measuring body movement including measurement of joint angles and movable ranges (see, for example, Patent Document 1).
Motion capture is a widely used means for motion analysis, and is an effective means for performing body motion analysis.

International Publication No. 2005/096939

However, measurement by motion capture requires large-scale equipment (for example, a dedicated studio), and there are restrictions on the place and space where measurement is possible. In addition, not everyone can easily perform measurement because the equipment is expensive and complicated preparation is required before measurement. In addition, measurement by motion capture cannot measure a portion that is shadowed from the camera.
The present inventors have intensively studied to provide a method capable of easily measuring the rotation angle of a measurement object including a joint angle of a living body, and have completed the present invention based on a new technical idea.

(1) The rotation angle measuring device according to the first aspect of the present invention comprises:
A rotation angle measuring device used for measuring a rotation angle of a measurement object,
A sensing member that can expand and contract in one direction following the rotation of the object to be measured, and whose electrical parameters change according to the rotation angle,
A measurement unit for measuring the electrical parameters;
A calculation unit that calculates the rotation angle based on a measurement result in the measurement unit;
With
The sensing member has a detection unit that changes an electrical parameter according to the amount of deformation during expansion and contraction, and a fixing member that attaches the sensing member to the measurement object.
The fixing member is provided at two locations so as to sandwich the detection unit in the extending and contracting direction of the detection unit.

  According to the rotation angle measuring device, the rotation angle of the measurement object can be measured without using a large facility simply by attaching the sensing member to the measurement object by the fixing member provided on the sensing member. Can do.

(2) In the rotation angle measuring device of (1) above,
The measurement object has two link equivalent parts connected by a connection part, and at least one link equivalent part is configured to be rotatable around the connection part,
The sensing member is attached by the fixing member so as to bridge between the two link equivalent parts,
As the rotation angle of the measurement object, it is preferable to measure the rotation angle of the one link equivalent portion with respect to the other link equivalent portion.
The rotation angle measuring device is suitable for measuring the rotation angle of such a measurement object.

(3) In the rotation angle measuring device of (2) above,
At least one of the fixing members is attached to the sensing member so as to be rotatable with respect to the link equivalent part,
It is preferable that the sensing member attached rotatably is rotatable along the rotation direction of the link equivalent portion.
In this case, the rotation angle of the measurement object can be measured with higher accuracy. The reason for this will be described later.

(4) In the rotation angle measurement device according to any one of (1) to (3), the sensing member includes:
An elastomeric dielectric layer; a first electrode layer formed on an upper surface of the dielectric layer; and a second electrode layer formed on a lower surface of the dielectric layer, the first electrode layer and the second electrode Including a sensor body having a detecting portion as an opposing portion of the layer,
As for the above-mentioned detection part, it is preferred that an electrostatic capacity changes according to expansion and contraction.
In this case, the rotation angle of the measurement target can be easily and accurately measured using the capacitance as the electric parameter.

(5) The capacitance type sensor sheet of the second aspect of the present invention is a capacitance type sensor sheet used as a sensing member of the rotation angle measurement device according to any one of the above (1) to (4),
An elastomeric dielectric layer; a first electrode layer formed on an upper surface of the dielectric layer; and a second electrode layer formed on a lower surface of the dielectric layer, the first electrode layer and the second electrode layer The sensor body in which the opposing part is a detection unit, can be expanded and contracted in one direction, and the capacitance of the detection unit changes according to expansion and contraction,
A fixing member for attaching the capacitance type sensor sheet provided at two locations so as to sandwich the detection unit to the measurement object in the expansion and contraction direction;
With
At least one of the fixing members is configured to rotatably attach the capacitive sensor sheet to the measurement object.
Such a capacitance type sensor sheet is suitable as a sensing member used in the rotation angle measurement device. In the rotation angle measurement device using the capacitance type sensor sheet, the measurement object can be rotated with high accuracy. The angle can be measured.

(6) The rotation angle measuring device of the third aspect of the present invention is:
A measuring object having two link equivalent parts connected by a connecting part, wherein at least one link equivalent part is configured to be rotatable about the connection part as a rotation center; A rotation angle measuring device for measuring a rotation angle with respect to a link equivalent part,
A sensing member that can expand and contract in one direction following the rotation of the object to be measured, and whose electrical parameters change according to the rotation angle,
A first holding link and a second holding link connected by a connecting portion, wherein one holding link is configured to be rotatable with respect to the other holding link about the connecting portion as a rotation center;
A measurement unit for measuring the electrical parameters;
A calculation unit that calculates the rotation angle based on a measurement result in the measurement unit;
With
The sensing member is provided at two locations so as to sandwich the detection unit in the expansion / contraction direction of the detection unit with a detection unit in which an electrical parameter changes according to the amount of deformation during expansion and contraction. A fixing member to be attached, and the fixing member is attached so as to bridge between the first holding link and the second holding link.

According to the rotation angle measuring device, the first holding link and the second holding link are attached along each of the two link-corresponding portions, so that the measurement object can be measured without using a large facility. The rotation angle can be measured.
Moreover, in the said rotation angle measuring device, even if a measurement object changes, it can measure the rotation angle of a measurement object, without performing a calibration.

  ADVANTAGE OF THE INVENTION According to this invention, the rotation angle measuring apparatus which can measure the rotation angle of a measuring object can be provided at low cost, without using a large installation.

It is the schematic which shows the rotation angle measuring device of 1st Embodiment. It is a perspective view which shows the electrostatic capacitance type sensor sheet with which the rotation angle measuring device of 1st Embodiment is provided. (A) is a perspective view which shows the sensor main body which the electrostatic capacitance type sensor sheet shown in FIG. 2 has, (b) is the sectional view on the AA line of (a). (A), (b) is a schematic diagram for demonstrating the method to measure the joint angle of the ankle in 1st Embodiment. (A), (b) is a schematic diagram for demonstrating the measuring method of the rotation angle by the holding | maintenance part with which the rotation angle measuring device in 2nd Embodiment is equipped, and a sensing member. (A), (b) is a schematic diagram for demonstrating another state at the time of the holding | maintenance part which attached the sensor sheet | seat rotated. (A) is a perspective view which shows the sensor main body which concerns on 3rd Embodiment, (b) is the BB sectional drawing of (a). It is a schematic diagram for demonstrating an example of the shaping | molding apparatus used for preparation of a dielectric layer. (A)-(d) is a perspective view for demonstrating the manufacturing process of a sensor main body. It is a schematic diagram for demonstrating the evaluation method of the rotation angle measuring device in Example 1. FIG. 3 is a graph showing measurement results of Example 1. (A) is a figure which shows the state which mounted | wore the subject with the rotation angle measuring device in Example 2, (b) is an actual photograph of the mounting state shown to (a). (A)-(d) is a photograph which shows a subject's ankle movement in Example 2. FIG. It is a graph which shows the measurement result of Example 2.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic view showing a rotation angle measuring device of the present embodiment. FIG. 2 is a perspective view showing a capacitive sensor sheet provided in the rotation angle measurement device of the first embodiment. FIG. 3A is a perspective view showing a sensor main body included in the capacitive sensor sheet shown in FIG. 2, and FIG. 3B is a cross-sectional view taken along line AA in FIG.

As shown in FIG. 1, the rotation angle measuring device 1 of the present embodiment includes a capacitive sensor sheet (hereinafter also simply referred to as a sensor sheet) 2 having a detection unit in which electrode layers are arranged to face each other via a dielectric layer. A measuring unit 3 that measures the capacitance electrically connected to the sensor sheet 2 via an external wiring, and a calculation unit 4 that calculates the rotation angle of the measurement object based on the measurement result of the measuring unit 3 And.
The measuring unit 3 includes a Schmitt trigger oscillation circuit 3a for converting the capacitance C into a frequency signal F, an F / V conversion circuit 3b for converting the frequency signal F into a voltage signal V, and a power supply circuit (not shown). Then, after the capacitance C detected by the detection unit of the sensor sheet 2 is converted into a frequency signal F, it is further converted into a voltage signal V and transmitted to the calculation unit 4. In addition, the structure of the measurement part 3 is not necessarily limited to such a structure.
The calculation unit 4 includes a monitor 4b and a storage unit 4c in addition to the calculation circuit 4a, and calculates the rotation angle of the measurement object based on the measured value of the capacitance C measured by the measurement unit 3. In addition, the measured value of the capacitance C and the calculated rotation angle are displayed on the monitor 4b or stored as recording data in the storage unit. As the calculation unit 4, a computer including a storage unit such as a CPU, RAM, ROM, and HDD, a monitor, various input / output interfaces, and the like can be used.

  As shown in FIG. 2, the sensor sheet 2 includes a sensor body 10, a covering member 21 provided around the sensor body 10, and a connection member 22 for electrically connecting the sensor body 10 and the measurement unit 3. And a fixing member 23 for mounting the sensor sheet 2 on the measurement object.

  As shown in FIG. 3, the sensor body 10 includes a sheet-like dielectric layer 11 made of an elastomer composition, a front-side electrode layer 12 </ b> A formed on the surface (front surface) of the dielectric layer 11, and a dielectric layer 11. The back side electrode layer 12B formed on the back surface, the front side wiring 13A connected to the front side electrode layer 12A, the back side wiring 13B connected to the back side electrode layer 12B, and the end of the front side wiring 13A opposite to the front side electrode layer 12A The front side connection part 14A attached to the back side, the back side connection part 14B attached to the end of the back side wiring 13B opposite to the back side electrode layer 12B, and the front side protection laminated on the front side and the back side of the dielectric layer 11, respectively. A layer 15A and a back side protective layer 15B.

Here, the front-side electrode layer 12A and the back-side electrode layer 12B have the same plan view shape, and the front-side electrode layer 12A and the back-side electrode layer 12B face each other across the dielectric layer 11.
In the sensor sheet 2 (sensor main body 10), a portion where the front electrode layer 12A and the back electrode layer 12B face each other serves as a detection unit.
In the sensor body 10, the front electrode layer 12A corresponds to the first electrode layer, and the back electrode layer 12B corresponds to the second electrode layer.
Note that the front-side electrode layer and the back-side electrode layer provided in the sensor main body do not necessarily have to face each other across the dielectric layer, and at least part of them may face each other.

The sensor body 10 can be deformed (stretched) in the plane direction because the dielectric layer 11 is made of an elastomer composition. In the sensor body 10, when the dielectric layer 11 is deformed in the surface direction, the front electrode layer 12 </ b> A and the back electrode layer 12 </ b> B, and the front protective layer 15 </ b> A and the back protective layer 15 </ b> B (hereinafter, both are combined) Simply referred to as a protective layer).
Therefore, in the sensor sheet 2, the capacitance of the detection unit changes in correlation with the deformation amount of the dielectric layer 11 as the sensor body 10 is deformed. Therefore, the deformation amount of the sensor body 10 can be detected by detecting the change in capacitance.

  Returning to FIG. 2, covering members 21 made of a stretchable cloth are provided on both surfaces of the sensor body 10. The covering member 21 is made of two stretchable cloth fabrics whose length in the longitudinal direction is longer than the length in the longitudinal direction of the sensor body 10. The sensor body 10 is sandwiched between the two cloth cloths. By providing the covering member 21, the sensor body 10 can be protected.

At both ends of the sensor sheet 2 (covering member 21), one of the convex side and the concave side of the snap button is attached as a fixing member 23. Here, the fixing member 23 is attached at two locations so as to sandwich the detection portion of the sensor main body 10 in the extending and contracting direction of the sensor main body 10.
The fixing member 23 is a member for mounting the sensor sheet 2 to the measurement object, and the sensor sheet 2 is measured by attaching the other of the convex side and the concave side of the snap button to the measurement object side. Can be attached to an object.

The rotation angle measuring device 1 is used for measuring the rotation angle of a measurement object.
The rotation angle measuring device 1 can track the rotation operation (bending operation) of the measurement object by continuously or intermittently measuring the rotation angle of the measurement object.

Hereinafter, a method for measuring the rotation angle in the present embodiment will be described.
In this embodiment, for example, an object to be measured has two link equivalent parts connected by a connection part, and at least one link equivalent part is configured to be rotatable around the connection part as a rotation center. be able to. As the rotation angle of such an object to be measured, the rotation angle of the one link equivalent portion with respect to the other link equivalent portion can be measured.

  Specific examples of the rotation angle of the measurement object include a joint angle of a living body (human or animal) or a robot, a rotation angle of a hinge (hinge), a bending condition of cables or a flexible plate, and the like. Among these, the joint angle of the living body is preferable. This is because the sensor sheet 2 is less likely to inhibit the bending motion of the measurement object, and in this respect, is compatible with the measurement of the joint angle of the living body.

When the measurement target of the rotation angle measuring device 1 is a joint angle of a living body, the target joint is not particularly limited as long as it is a joint that can be bent and stretched. Examples of such a joint include a finger, a wrist, an elbow, a shoulder, a neck, a waist, a knee, and an ankle.
Here, when the target joint is a wrist, the hand and the forearm correspond to the link equivalent part, and the wrist joint corresponds to the connection part. When the target joint is an elbow, the forearm and the upper arm correspond to the link equivalent part, and the elbow joint corresponds to the connection part. When the target joint is an ankle, the foot and the lower leg correspond to the link equivalent part, and the ankle joint corresponds to the connection part.

4A and 4B are schematic diagrams for explaining a method of measuring an ankle joint angle in the present embodiment.
When measuring the joint angle of the ankle using the rotation angle measuring device 1, for example, the sensor sheet 2 is attached to the supporter 100 as shown in FIGS.
At this time, the sensor sheet 2 is attached to the supporter 100 by the fixing member 23. In addition to the supporter 100, the sensor sheet 2 may be attached to clothes, a bandage, or the like.
The supporter 100 to which the sensor sheet 2 is attached is attached to the ankle.
In the ankle movement, the joint portion (ankle) P of the ankle is the center of rotation, and the lower leg 101 and the foot 102 rotate about the joint portion P, respectively. Therefore, for example, the rotation angle of the lower leg 101 relative to the foot 102 when the lower leg 101 is moved can be measured.

  With the supporter 100 attached with the sensor sheet 2 attached, when the ankle exercise is performed such that the lower leg 101 is moved from the dorsiflexion state (see FIG. 4A) to the plantar flexion state (see FIG. 4B). The sensor body 10 of the sensor sheet 2 extends in accordance with this movement. When the sensor body 10 expands, the capacitance in the detection unit of the sensor body 10 changes according to the extension amount. Therefore, the rotation angle of the lower leg 101 relative to the foot 102 can be measured according to the amount of change in capacitance of the detection unit.

As shown in FIG. 4A, in the ankle to which the sensor sheet 2 is attached, the distance between the two fixing members 23A and 23B is a ₁ , from the ankle joint portion P to the fixing member 23A attached to the lower leg 101 side. and the distance b, and the distance from the ankle joint portion P to the fixing member 23B which is attached to the foot 102 side c, the angle and theta ₁ with respect to the foot 102 of the lower leg 101, each parameter is represented by the following formula by the cosine theorem ( Satisfy 1).
a ₁ ² = b ² + c ² -2bccos θ ₁ (1)
When the ankle moves and the lower leg 101 rotates from the state of FIG. 4A to the state of FIG. 4B with the joint portion P of the ankle as the rotation center, the distance between the two fixing members 23A and 23B becomes a. ₂ and the angle of the lower leg 101 with respect to the foot 102 is θ ₂ . At this time, each parameter now satisfies the following formula (2).
a ₂ ² = b ² + c ² -2bccosθ ₂ (2)
Here, b and c are constant values that can be measured in advance. Therefore, by calculating the amount of change Δa in the distance between the fixing members 23A and 23B due to the rotation of the lower leg 101 based on the amount of change in the capacitance of the sensor sheet 2 (sensor body 10), The rotation angle Δθ can be calculated.
As described above, in the rotation angle measurement device 1 according to the present embodiment, the rotation angle of the lower leg 101 with respect to the foot 102 due to the movement of the ankle can be detected based on the change amount of the capacitance in the detection unit of the sensor body 10. .

Further, in the rotation angle measuring device 1 of the present embodiment, snap buttons are used as the fixing members 23A and 23B. Therefore, the sensor sheet 2 is rotatably attached to the measurement object. At this time, the sensor sheet 2 is preferably attached so as to be rotatable in a direction along the rotation direction of the measurement object.
In this case, the rotation angle can be measured more accurately. The reason for this is that, as will be described in detail later, distorted deformation of the sensor sheet 2 can be avoided.

When measuring the rotation angle of the measurement object by such a method, calibration may be performed in advance.
In addition, when the distance b and the distance c are known, the relationship between the rotation angle θ and the change amount ΔC of the capacitance can be obtained as described above without performing the calibration.
In the rotation angle measuring device, the rotation angle of the measurement object can be calculated by performing the calculation as described above by the calculation unit 4.

In the rotation angle measurement device of the present embodiment, when the sensor sheet 2 is attached to the supporter 100, the distance b and the distance c can be set to arbitrary values.
At this time, the distance b and the distance c are not particularly limited. For example, if one distance (for example, the distance b) is sufficiently smaller than the other distance (for example, the distance c), the rotation angle of the measurement object is measured. Even if becomes large, the elongation rate of the sensor sheet 2 is difficult to increase, which is suitable for measuring a large rotation angle.

(Second Embodiment)
The rotation angle measurement device according to the present embodiment includes a sensor sheet (sensing member), a holding unit, a measurement unit, and a calculation unit. Here, the configurations of the sensor sheet, the measurement unit, and the calculation unit are the same as those in the first embodiment.
In the present embodiment, the sensor sheet is attached to the holding portion in a predetermined manner.
FIGS. 5A and 5B are schematic diagrams for explaining a method of measuring a rotation angle using a holding unit and a sensing member included in the rotation angle measurement device according to the second embodiment.

In the present embodiment, as shown in FIGS. 5A and 5B, the sensor sheet 2 is attached to a holding unit 50 in which a first holding link 52 and a second holding link 53 are connected by a connecting unit 51. Here, the sensor sheet 2 is fixed so as to be bridged between the first and second holding links 52 and 53 by fixing members 23A and 23B provided on both ends of the sensor main body 10.
In the holding part 50, one or both of the first holding link 52 and the second holding link 53 are configured to be rotatable about the connecting part 51 as a rotation center.

  With the sensor sheet 2 attached in this manner, the first holding link 52 of the holding unit 50 is rotated with respect to the second holding link 53 around the connecting portion 51 as a rotation center (from the state of FIG. 5A). 5 (b)), the sensor sheet 2 (sensor body 10) expands in accordance with the rotation of the first holding link 52, and the detection portion of the sensor body 10 is detected according to the extension amount of the sensor body 10. The capacitance changes. Therefore, the rotation angle of the first holding link 52 relative to the second holding link 53 can be measured based on the amount of change in capacitance of the detection unit.

As shown in FIG. 5A, in the holding part 50 to which the sensor sheet 2 is attached, the distance between the two fixing members 23A and 23B is d ₁ , and the fixing member attached to the connecting part 51 and the first holding link 52. the distance between 23A e, the connecting portion 51 the distance between the fixing member 23B which is attached to the second holding link 53 f, the first holding link 52 the angle of the second holding link 53 and theta _3, Each parameter satisfies the following expression (3) by the cosine theorem, as in the first embodiment.
d ₁ ² = e ² + f ² -2ef cos θ ₃ (3)
Then, the first holding link 52 of the holding unit 50 rotates from the state of FIG. 5A to the state of FIG. 5B, and the distance between the two fixing members 23A and 23B becomes d ₂ , and the first holding link. 52 and the angle between the second holding link 53 is theta _4, now the parameters are to satisfy the following equation (4).
d ₂ ² = e ² + f ² -2ef cos θ ₄ (4)
Also in this case, since e and f are constant values, the change amount Δd of the distance between the fixing members 23A and 23B due to the rotation of the first holding link 52 is used as the change amount of the capacitance of the sensor sheet 2 (sensor body 10). The rotation angle Δθ of the first holding link 52 with respect to the second holding link 53 can be calculated by calculating based on the above.

And in the rotation angle measuring device of this embodiment provided with the holding | maintenance part 50 to which the sensor sheet | seat 2 was attached, each of the 1st holding link 52 and the 2nd holding link 53 is two measurement objects (not shown). The rotation angle of the link equivalent part in the measurement object can be measured by attaching it along each of the link equivalent parts.
Moreover, in the said rotation angle measuring device of this embodiment, even if a measurement object changes, it can measure the rotation angle of a measurement object, without performing calibration.

Further, in the rotation angle measuring device 1 of the present embodiment, snap buttons are used as the fixing members 23A and 23B. Therefore, the sensor sheet 2 can be rotatably attached to the holding unit.
In this case, the rotation angle can be measured more accurately. The reason for this will be described with reference to the drawings.

FIGS. 6A and 6B are schematic views for explaining another state when the holding unit to which the sensor sheet is attached rotates.
As shown in FIG. 6A, when the sensor sheet 2 ′ is attached to the holding portion 50, the sensor sheet 2 ′ is attached to the links 52 and 53 via a non-rotatable fixing member 23 ′ such as a hook-and-loop fastener. . In this case, when the first holding link 52 rotates with respect to the second holding link 53 and the angle between the first holding link 52 and the second holding link 53 changes as shown in FIG. Since the sensor sheet 2 'cannot rotate with respect to the first holding link 52 and the second holding link 53, the sensor sheet 2' cannot maintain a linear shape between the two fixing members 23 '. It becomes a distorted shape bent in the vicinity of the fixing member 23 '.
Thus, if the sensor sheet becomes distorted when the holding part (holding link) rotates, there is a correlation between the amount of change in capacitance in the detection part of the sensor sheet 2 and the amount of expansion / contraction in the sensor sheet 2. May fall. As a result, the measurement accuracy of the rotation angle of the measurement object may be lowered.
Therefore, in this embodiment, it is preferable that the sensor sheet 2 is configured to be rotatably attached to the first and second holding links 52 and 53 by the fixing members 23A and 23B. At this time, it is preferable that the fixing member 23A, 23B is attached to the sensor sheet 2 so that the sensor sheet 2 attached to be rotatable can be rotated along the rotation direction of the holding link.
In addition, in 1st Embodiment, the reason why it is preferable that fixing member 23A, 23B is comprised so that sensor sheet 2 can be rotatably fixed to the supporter 100 is also the same.

(Third embodiment)
The sensor body used in the embodiment of the present invention is not limited to the sensor body 10 of the first and second embodiments.
In addition to the first dielectric layer made of elastomer, the first electrode layer formed on the upper surface of the dielectric layer, and the second electrode layer formed on the lower surface of the dielectric layer, the sensor body according to the present embodiment is provided. And a second dielectric layer made of elastomer laminated on the first electrode layer, and a third electrode layer laminated on the upper surface of the second dielectric layer, wherein the first electrode layer and the second electrode layer The opposing part of the electrode layer is the first detection part, the opposing part of the first electrode layer and the third electrode layer is the second detection part, and the first detection part and the second detection part are statically moved according to expansion and contraction. The capacitance changes.

Fig.7 (a) is a perspective view which shows the sensor main body which concerns on this embodiment, (b) is the BB sectional drawing of (a).
The sensor body 40 is made of an elastomer sheet-like back side dielectric layer (first dielectric layer) 41B, and a central electrode layer (first side) formed on the surface (front surface: upper side in FIG. 7) of the back side dielectric layer 41B. One electrode layer) 42A, a back side electrode layer (second electrode layer) 42C formed on the back side (lower side in FIG. 7) of the back side dielectric layer 41B, and a front side (upper side in FIG. 7) of the central electrode layer 42A A front-side dielectric layer (second dielectric layer) 41A and a front-side electrode layer (third electrode layer) 42B formed on the surface of the front-side dielectric layer 41A.
Further, the sensor main body 40 includes a central wiring 43A connected to the central electrode layer 42A, a front wiring 43B connected to the front electrode layer 42B, a back wiring 43C connected to the back electrode layer 42C, and a central wiring 43A. A central connection portion 44A attached to an end opposite to the central electrode layer 42A, a front side connection portion 44B attached to an end opposite to the front side electrode layer 42B of the front side wiring 43B, and a back side electrode of the back side wiring 43C A back side connection portion 44C attached to the end opposite to the layer 42C.
In the sensor body 40, a front side protective layer (first protective layer) 45A and a back side protective layer (second protective layer) 45B are provided on the front side of the front side dielectric layer 41A and the back side of the back side dielectric layer 41B.

Here, the central electrode layer 42A, the front electrode layer 42B, and the back electrode layer 42C have the same planar view shape. Further, the central electrode layer 42A and the front electrode layer 42B are opposed to each other across the front dielectric layer 41A, and the central electrode layer 42A and the back electrode layer 42C are opposed to each other across the back dielectric layer 41B. Yes. In the sensor main body 40, a portion where the central electrode layer 42A and the front side electrode layer 42B face each other serves as a front side detection unit (second detection unit), and a portion where the central electrode layer 42A and the back side electrode layer 42C face each other is a back side detection unit ( A first detection unit).
In the sensor body 40, the center electrode layer and the front electrode layer, and the center electrode layer and the back electrode layer do not necessarily have to face each other across the dielectric layer, and at least a part of them is not required. It only needs to be opposite.

In the sensor body 40, the total capacitance obtained by adding the capacitance of the front side detection unit (second detection unit) and the capacitance of the back side detection unit (first detection unit) is used as the capacitance of the detection unit. To do.
Therefore, in the sensor main body 40, measurement is performed via a lead wire or the like in a state where the front side electrode layer 42B (front side connection part 44B) and the back side electrode layer 42C (back side connection part 44C) are electrically connected (short-circuited state). The central electrode layer 42A (central connection portion 44A) is connected to another terminal of the measurement unit 3 via a lead wire or the like.

  In the sensor main body 40, as in the sensor main body 10, as the sensor main body 40 is deformed, the capacitance of each detection unit changes in correlation with the deformation amount of the dielectric layers (the front-side dielectric layer 41A and the back-side dielectric layer 41B). Therefore, when the sensor main body 40 is used, the rotation angle of the measurement object can be measured as in the case where the sensor main body 10 is used.

Moreover, the sensor sheet provided with the sensor body 40 is suitable for suppressing fluctuations in the measured capacitance value due to noise. Therefore, high correlation can be maintained between the deformation amount (expansion / contraction amount) of the sensor sheet and the capacitance of the detection unit even in a situation where noise exists or in a situation where noise varies during measurement.
When using a sensor sheet, if the sensor sheet is used in a place where electromagnetic noise or power supply noise is likely to enter, or in an environment where the electrode layer of the sensor body is in contact with or close to the conductor, the measured value of the capacitance of the detector will depend on the usage situation. May vary regardless of the deformation of the sensor body. For example, when the sensor main body 10 is used, noise enters from the upper surface side of the sensor main body 10 (whether the upper surface side is close to the noise source), or noise enters from the lower surface side (the lower surface side is close to the noise source). The measured value of capacitance may vary depending on whether or not.

On the other hand, when the sensor body 40 is used, the total capacitance obtained by adding the capacitance of the first detection unit and the capacitance of the second detection unit is measured. That is, in the sensor body, the capacitance is measured by regarding the structure of the detection unit (the structure of the first detection unit and the second detection unit) as a structure in which two capacitors are arranged in parallel. Therefore, in the sensor sheet provided with the sensor main body 40, the measurement unit is in a state where the front electrode layer (third electrode layer) and the back electrode layer (second electrode layer) are electrically connected (short-circuited). Connect to. Thereby, even when noise enters from the upper surface side of the sensor body 40 (upper surface side is close to the noise source) and when noise enters from the lower surface side (lower surface side is close to the noise source), the measured capacitance value is It becomes substantially the same value, and the influence of noise can be reduced.
In the embodiment of the present invention, the conductor is close to the electrode layer, not only when a conductive member such as a metal member is close, but also when the surface of the living body is close, water, sweat, body fluid, etc. This is a concept including a case where a liquid having conductivity adheres to the electrode layer.

(Other embodiments)
In the rotation angle measuring devices of the first and second embodiments, the sensor sheet is attached so as to be rotatable with respect to the link equivalent portion, and at this time, the two fixing members included in the sensor sheet can be rotated together. Is attached.
On the other hand, in the rotation angle measuring device according to the embodiment of the present invention, only one of the two fixing members may be rotatably attached to the link equivalent portion. In this case, the measurement accuracy can be improved.

In the rotation angle measurement device of the embodiment of the present invention, when one fixing member is rotatably attached and the other fixing member is non-rotatably attached, the rotation angle measurement device is configured as follows. It is preferable.
For example, when the measurement object has two link equivalent parts connected by a connection part, and at least one link equivalent part is configured to be rotatable around the connection part, the connection part ( The distance between the rotation center) and the rotatable fixing member (hereinafter referred to as distance g) is sufficiently smaller than the distance between the connecting portion and the non-rotatable fixing member (hereinafter referred to as distance h). preferable.
The reason for this is as follows.

For example, the distance g and the distance h are set to be the same, and the angle of the link equivalent portion where the fixing member is rotatably attached to the link equivalent portion where the fixing member is non-rotatably changed is 0 to 180 degrees. In this case, the angle formed between the longitudinal direction of the sensor body and the link-corresponding portion on the side on which the fixing member is non-rotatably changed (hereinafter referred to as angle I) varies from 0 to 45 degrees.
On the other hand, if the distance g is sufficiently shorter than the distance h, the maximum value of the angle I can be sufficiently reduced (for example, about 5 to 10 degrees). And if the maximum value of the said angle I becomes small, when the link equivalent part to which the fixing member was rotatably attached was rotated, the extended sensor sheet hardly distorts. Therefore, even if one of the two fixing members cannot rotate, the rotation angle of the measurement object can be measured sufficiently.
In this case, if the connecting member is attached to the non-rotatable fixing member, the external force applied between the sensor main body and the connecting member due to the rotation of the link equivalent portion can be suppressed.

The rotation angle measuring device according to the embodiment of the present invention may include a plurality of sensing members.
Thereby, for example, when measuring the ankle joint angle (see, for example, FIG. 4), the ankle joint angle can be measured by attaching sensing members (sensor sheets) to both the outside and inside of the ankle. . When sensor sheets are attached to both sides of the ankle and the joint angle of the ankle is measured, it is possible to correct the effects of ankle adduction and abduction, etc. .

In the rotation angle measurement devices according to the first to third embodiments, the capacitive sensor sheet is employed as the sensing member. However, in the rotation angle measurement device according to the embodiment of the present invention, as the sensing member, For example, a resistance type sensor member or the like may be employed.
The resistance type sensor member includes, for example, a detection unit made of an elastic member that can expand and contract in at least one direction, and expands and contracts in the one direction, so that the resistance value of the detection unit changes according to the expansion and contraction amount. A sensor member etc. are mentioned.

Hereafter, the structural member of the said rotation angle measuring device is demonstrated. Here, a case where the sensing member is a capacitive sensor sheet will be described as an example.
In the following description, the first dielectric layer and the second dielectric layer may be simply referred to as “dielectric layer” when it is not necessary to distinguish between them. In addition, in the description of the front side electrode layer, the back side electrode layer, and the center electrode layer, when it is not necessary to distinguish each electrode layer, it may be simply expressed as “electrode layer”.

<Sensor sheet>
<< Dielectric layer >>
The sensor body constituting the sensor sheet includes a dielectric layer made of elastomer. These dielectric layers can be formed using an elastomer composition.
Further, when the sensor body includes the first dielectric layer and the second dielectric layer, they may be formed using the same elastomer composition, or may be formed using different elastomer compositions. Also good. Both are preferably formed using the same elastomer composition. This is because the same behavior is exhibited during deformation.

  The dielectric layer is a sheet-like material formed using an elastomer composition, and can be reversibly deformed so that the areas of the front and back surfaces thereof are changed. In the present invention, the front and back surfaces of the dielectric layer mean the front and back surfaces of the dielectric layer.

As said elastomer composition, what contains an elastomer and another arbitrary component as needed is mentioned, for example.
Examples of the elastomer include natural rubber, isoprene rubber, nitrile rubber (NBR), ethylene propylene rubber (EPDM), styrene / butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR), silicone rubber, and fluorine. Examples thereof include rubber, acrylic rubber, hydrogenated nitrile rubber, and urethane rubber. These may be used alone or in combination of two or more.
Among these, urethane rubber and silicone rubber are preferable in that permanent set (or permanent elongation) is small. In addition, urethane rubber is preferable in terms of excellent adhesion to the carbon nanotube.

  In addition to the elastomer, the elastomer composition may contain additives such as a plasticizer, an antioxidant, an antioxidant, a colorant, a dielectric filler, and the like.

The average thickness of the dielectric layer is preferably 10 to 1000 μm from the viewpoint of increasing the capacitance C and improving the detection sensitivity. More preferably, it is 30-200 micrometers.
The dielectric layer is preferably deformable so that the area (the surface area and the back surface area) of the dielectric layer is increased by 30% or more from the unstretched state when deformed. In this case, it is suitable for measuring a large rotational motion (for example, a rotational motion in which the angle formed by the link equivalent portions greatly changes).
The fact that the area can be deformed so as to increase by 30% or more means that it does not break even when the load is increased and the area is increased by 30%, and it is restored to its original state when the load is released (ie, elastic It is within the deformation range.
The deformable range of the area of the dielectric layer is more preferably deformable to increase by 50% or more, more preferably deformable to increase by 100% or more, and increased by 200% or more. It is particularly preferable that it can be deformed.
The range in which the dielectric layer can be deformed in the plane direction can be controlled by the design (material, shape, etc.) of the dielectric layer.

<< Electrode layer >>
The sensor body includes the electrode layer made of a conductive composition containing a conductive material.
Here, each of the electrode layers may be composed of conductive compositions having the same composition, or may be composed of conductive compositions having different compositions.

Examples of the conductive material include carbon nanotubes, graphene, carbon nanohorns, carbon fibers, conductive carbon black, graphite, metal nanowires, metal nanoparticles, and conductive polymers. These may be used alone or in combination of two or more.
As the conductive material, carbon nanotubes are preferable. This is because it is suitable for forming an electrode layer that deforms following the deformation of the dielectric layer.

A known carbon nanotube can be used as the carbon nanotube. The carbon nanotube may be a single-walled carbon nanotube (SWNT), a double-walled carbon nanotube (DWNT), or a multi-walled carbon nanotube having three or more layers (MWNT) (in this specification, Both are simply referred to as multi-walled carbon nanotubes). Furthermore, two or more types of carbon nanotubes having different numbers of layers may be used in combination.
In addition, the shape (average length, fiber diameter, aspect ratio) of each carbon nanotube is not particularly limited, and the conductivity and durability required for the sensor sheet, as well as the processing and cost for forming the electrode layer are comprehensive. Judgment can be made as appropriate.

In addition to the conductive material, the conductive composition may contain, for example, a binder component and various additives that function as a connecting material for the conductive material.
Examples of the additive include a dispersant for a conductive material, a crosslinking agent for a binder component, a vulcanization accelerator, a vulcanization aid, an anti-aging agent, a plasticizer, a softener, and a colorant. Can be mentioned.

<< Protective layer >>
As for the said sensor main body, it is preferable that the protective layer (a front side protective layer and a back side protective layer) is laminated | stacked like the example shown in FIG. By providing the protective layer, the electrode layer and the like can be electrically insulated from the outside. Further, by providing the protective layer, the strength and durability of the sensor body can be increased.
Examples of the material for the protective layer include the same elastomer composition as the material for the dielectric layer.

<< Coating member >>
The sensor sheet is preferably provided with a covering member around the sensor body as in the example shown in FIG.
As said coating | coated member, the cloth fabric which has a stretching property is mentioned, for example.
The cloth fabric is not particularly limited as long as it has stretchability, and may be a woven fabric, a knitted fabric, or a non-woven fabric.
<< Fixing member >>

The sensor sheet is attached to a supporter, a holding link or the like by a fixing member.
As the fixing member, for example, a snap button, a magnet, a caulking, a bear link, a combination of an eyelet and a shaft member or the like is adopted as a fixing member for rotatably mounting the sensor sheet to a supporter, a holding link, or the like. .
Moreover, as a fixing member (fixing method) for attaching the sensor sheet so as not to rotate, for example, a hook-and-loop fastener, an adhesive, sewing, or the like may be employed.

<< Other >>
As in the example shown in FIGS. 3 and 7, the sensor body is usually provided with wirings connected to the electrode layers.
Each wiring may be any wire as long as it does not hinder the deformation of the dielectric layer and can maintain conductivity even when the dielectric layer is deformed. For example, each wiring is made of the same conductive composition as the electrode layer. Can be mentioned.

  Further, as shown in the examples shown in FIGS. 3 and 7, the connection portion (central connection portion, front side connection portion) for connecting to the external wiring is usually provided at the end opposite to the electrode layer of each wiring described above. And a back side connecting portion). As each of these connection parts, what was formed using copper foil etc. is mentioned, for example.

Next, a method for manufacturing the sensor body will be described. Here, a method for manufacturing the sensor main body will be described using the sensor main body 10 shown in FIG. 3 as an example.
The sensor body can be produced, for example, through the following steps (1) to (3).

(1) First, one sheet-like dielectric layer made of an elastomer composition and two sheet-like protective layers made of an elastomer composition are prepared. The dielectric layer and the protective layer can be manufactured by the same method.
In the production of the dielectric layer, first, an elastomer (or a raw material thereof), if necessary, a chain extender, a crosslinking agent, a vulcanization accelerator, a catalyst, a dielectric filler, a plasticizer, an antioxidant, an anti-aging agent, A raw material composition containing additives such as a colorant is prepared.
Next, a dielectric layer is produced by molding this raw material composition. Here, as a forming method, a conventionally known method can be employed.

Specifically, for example, when a dielectric layer containing urethane rubber is produced, the following method can be employed.
First, a raw material composition in which raw material components such as a polyol component, an isocyanate component, and a catalyst are mixed is prepared. Thereafter, the obtained raw material composition is poured into a molding apparatus 30 shown in FIG. 8 and crosslinked and cured to obtain a sheet. Furthermore, a dielectric layer can be produced by post-crosslinking if necessary and then cutting.

FIG. 8 is a schematic diagram for explaining an example of a molding apparatus used for producing a dielectric layer. In the molding apparatus 30 shown in FIG. 8, the raw material composition 33 is poured into the gap between the protective films 31 made of polyethylene terephthalate (PET) that is continuously fed from a pair of rolls 32, 32 that are spaced apart from each other. While proceeding with a curing reaction (crosslinking reaction) with the raw material composition 33 held in the gap, it was introduced into the heating device 34 and thermally cured with the raw material composition 33 held between the pair of protective films 31, A sheet 35 to be a dielectric layer is formed.
The dielectric layer may be prepared using a general-purpose film forming apparatus or film forming method such as various coating apparatuses, bar coats, doctor blades, etc. after preparing the raw material composition.

(2) Next, separately from the step (1), a coating solution for forming an electrode layer is prepared.
Here, first, a conductive material such as carbon nanotube is added to the dispersion medium. At this time, you may further add other components and dispersing agents mentioned above, such as a binder component (or the raw material of a binder component), as needed.
Next, a coating liquid for forming an electrode layer is prepared by dispersing (or dissolving) each component including a conductive material in a dispersion medium using a wet disperser.
Here, for example, the dispersion may be performed using an existing disperser such as an ultrasonic disperser, a jet mill, or a bead mill.
Examples of the dispersion medium include toluene, methyl isobutyl ketone (MIBK), alcohols, water, and the like. These dispersion media may be used independently and may be used together 2 or more types.

(3) Next, an electrode layer and the like are formed at appropriate times while superposing the dielectric layer and the protective layer, thereby producing a sensor body. FIGS. 9A to 9D are perspective views for explaining a manufacturing process of the sensor body 10.

(A) First, the coating liquid prepared in the step (2) is spray-coated on a predetermined position on one side (front surface) of one protective layer (back side protective layer 15B) prepared in the step (1). Etc. and dried (see FIG. 9A). Thereby, the back side electrode layer 12B and the back side wiring 13B are formed on the back side protective layer 15B.
As a coating method of the coating solution, for example, a screen printing method, an ink jet printing method, or the like may be employed in addition to spray coating.
Moreover, when apply | coating the said coating liquid, you may apply | coat the said coating liquid, masking the position which does not form an electrode layer.

(B) Next, the dielectric layer 11 produced in the step (1) is laminated on the back side protective layer 15B so as to cover the entire back side electrode layer 12B and a part of the back side wiring 13B. Thereafter, the front electrode layer 12A and the front wiring 13A are formed at predetermined positions on the upper surface of the dielectric layer 11 by using the same method as in the above (a) (see FIG. 9B).

(C) Next, another protective layer (front protective layer 15A) produced in the step (1) is laminated so as to cover the entire front electrode layer 12A and a part of the front wiring 13A.
Thereafter, a copper foil is attached to each end of the front side wiring 13A and the back side wiring 13B to form a front side connection part 14A and a back side connection part 14B (see FIG. 9C).
Through such steps, the sensor body 10 as shown in FIG. 3 can be manufactured.

(D) Furthermore, in the sensor main body 10 used in the embodiment of the present invention, a reinforcing film 17 such as a PET film is pasted on the back side protective layer 15B of the front side connecting portion 14A and the back side connecting portion 14B via an adhesive tape 16. Also good. Thereby, each connection part can be reinforced (refer FIG.9 (d)).
Further, as shown in FIG. 9D, in the sensor main body 10, lead wires 19 serving as external wiring are fixed to the front side connection portion 14A and the back side connection portion 14B with solder.

  When the sensor body 40 having two dielectric layers and three electrode layers as shown in FIG. 7 is produced, another dielectric layer is produced in advance, and the process (b) described above is performed. After performing the above, before forming the front protective layer, by repeating the step (b) again, the second dielectric layer is laminated and the electrode layer and the wiring are formed on the upper surface of the second dielectric layer. After that, the above-described steps (c) and (d) may be performed.

  Here, the method of stacking predetermined members (dielectric layer, electrode layer, and protective layer) in order from the back side protective layer side has been described, but the method of manufacturing the sensor body is not necessarily limited to such a method. For example, after preparing a dielectric layer in which an electrode layer is formed first, a protective layer may be bonded to both surfaces thereof.

<Measurement unit>
The measurement unit is electrically connected to the sensor body, and has a function of measuring the capacitance C of the detection unit that changes according to deformation of the dielectric layer. As a method for measuring the capacitance C, a conventionally known method can be used, and the measurement unit includes a capacitance measurement circuit, an arithmetic circuit, an amplifier circuit, a power supply circuit, and the like necessary for the measurement. . As a method of measuring the capacitance C, for example, a method of measuring with a measuring instrument such as an LCR meter, a method of measuring with a CV conversion circuit using an automatic balanced bridge circuit, or a CV conversion using an inverting amplifier circuit A measurement method using a circuit, a measurement method using a CV conversion circuit using a half-wave voltage doubler rectifier circuit, a measurement method using a CF oscillation circuit using a Schmitt trigger oscillation circuit, a Schmitt trigger oscillation circuit and F Examples include a method of measuring with a measuring instrument such as a voltage measuring instrument or a frequency counter after the capacitance is converted into voltage or frequency by a / V conversion circuit or the like.

<Calculation unit>
The rotation angle measurement device includes a calculation unit that calculates the rotation angle of the measurement object based on the capacitance of the detection unit of the sensor body. A specific method for calculating the rotation angle is as described above.
The arithmetic unit includes an arithmetic circuit, an amplifier circuit, a power supply circuit, a storage unit such as a RAM, a ROM, and an HDD, a monitor, and the like.
As said calculating part, terminal devices, such as a personal computer, a smart phone, a tablet, can be utilized, for example.
Further, in the rotation angle measuring device 1 shown in FIG. 1, the measurement unit 3 and the calculation unit 4 are connected by wire, but may be connected wirelessly.

As described above, the rotation angle measuring device of the present invention can measure the rotation angle at the bent portion of various measurement objects that can be bent and deformed, including the joint angle of a living body.
Therefore, it can be used in various fields such as the medical field, the care / rehabilitation field, the health management field, the apparel field, the robot field, the amusement field, the measurement field, the device control field, the sports field, and the interface communication field.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

Example 1
<Production of sensor body>
Here, a sensor body having the same configuration as that of the sensor body 10 shown in FIG. 3 was produced.
(1) Preparation of dielectric layer For 100 parts by mass of polyol (Pandex GCB-41, manufactured by DIC), 40 parts by weight of plasticizer (dioctyl sulfonate) and isocyanate (Pandex GCA-11, manufactured by DIC) 17 .62 parts by weight were added and stirred and mixed with an agitator for 90 seconds to prepare a raw material composition for a dielectric layer. Next, the raw material composition is poured into the molding apparatus 30 shown in FIG. 8 and conveyed in a sandwich form with the protective film 31, and is crosslinked and cured under the conditions of a furnace temperature of 70 ° C. and a furnace time of 30 minutes for protection. A roll-wound sheet with a predetermined thickness with a film was obtained. Then, after cross-linking in a furnace adjusted to 70 ° C. for 12 hours, a sheet made of a polyether urethane elastomer was produced. The obtained urethane sheet was cut into a size of 14 mm × 80 mm × thickness 100 μm, and one corner was cut off at a size of 7 mm × 20 mm × thickness 100 μm to produce a dielectric layer.

Further, when the elongation (%) at break and the relative dielectric constant of the produced dielectric layer were measured, the elongation at break (%) was 505% and the relative dielectric constant was 5.8.
Here, the elongation at break was measured according to JIS K 6251. The dielectric constant is measured by measuring the capacitance at a measurement frequency of 1 kHz using an LCR high tester (manufactured by Hioki Electric Co., Ltd., 3522-50) after sandwiching a dielectric layer between 20 mmΦ electrodes, and then measuring the electrode area and the thickness of the measurement sample. From the above, the relative dielectric constant was calculated.

(2) Preparation of electrode layer material 30 mg of highly oriented carbon nanotubes manufactured by Taiyo Nippon Sanso Co., Ltd. was added to 30 g of methyl isobutyl ketone (MIBK), and wet using a jet mill (Nanojet PAL JN10-SP003, manufactured by Joko). Dispersion treatment was performed and diluted 10 times to obtain a carbon nanotube dispersion having a concentration of 0.01% by weight.

(3) Production of Protective Layer Using the same method as the production of (1) dielectric layer described above, a back side protective layer made of polyether urethane elastomer, 14 mm × 80 mm × 50 μm thick, and 14 mm × 60 mm × thickness A front protective layer having a thickness of 50 μm was produced.

(4) Production of sensor body A sensor body was produced according to the procedure shown in FIG.
First, a mask (not shown) in which an opening having a predetermined shape was formed on a PET film subjected to a release treatment was attached to one surface (front surface) of the back side protective layer 15B produced in the step (3). .
The mask is provided with openings corresponding to the back side electrode layer and the back side wiring. The size of the opening is 10 mm wide × 50 mm long corresponding to the back side electrode layer, and the part corresponding to the back side wiring. It is 5 mm wide x 20 mm long.

  Next, 7.2 g of the carbon nanotube dispersion prepared in the above step (2) was applied from a distance of 10 cm using an air brush. Then, it was made to dry at 100 degreeC for 10 minute (s), and the back side electrode layer 12B and back side wiring 13B were formed. Thereafter, the mask was peeled off (see FIG. 9A).

Next, the dielectric layer 11 produced in the step (1) was laminated on the back side protective layer 15B so as to cover the entire back side electrode layer 12B and a part of the back side wiring 13B.
Further, a front electrode layer 12A and a front wiring 13A were formed on the dielectric layer 11 on the front side (see FIG. 9B). The front side electrode layer 12A and the front side wiring 13A were formed using the same method as the formation of the back side electrode layer 12B and the back side wiring 13B.

Next, the front side produced in the above step (3) so that the front side of the dielectric layer 11 on which the front side electrode layer 12A and the front side wiring 13A are formed covers the entire front side electrode layer 12A and a part of the front side wiring 13A. The protective layer 15A was laminated by lamination.
Furthermore, copper foil was attached to each end part of the front side wiring 13A and the back side wiring 13B, and it was set as the front side connection part 14A and the back side connection part 14B (refer FIG.9 (c)). Thereafter, lead wires 19 serving as external wirings were fixed to the front side connection portion 14A and the back side connection portion 14B with solder.

  Next, an acrylic adhesive tape (manufactured by 3M, Y-4905 (thickness 0.5 mm)) is applied to the PET film 17 having a thickness of 100 μm on the portion located on the back side protective layer 15B of the front side connection portion 14A and the back side connection portion 14B. ) 16 is pasted and reinforced (see FIG. 9D), and the sensor body 10 is completed.

<Preparation of sensing member and holding part>
First, a sensor sheet 62 having substantially the same configuration as that of the sensor sheet 2 shown in FIG. 2 was produced by the following method.
First, a stretchable polyester cloth (KKF5550, Uni Fiber Co., Ltd.) was cut into 95 mm × 20 mm. Next, two elastic polyester cloths were bonded together using an elastic adhesive so as to sandwich the sensor body 10 between the elastic polyester cloths, and the covering member 21 was formed.
Next, a woven fabric (Munsell patchwork) using a double-sided tape (double-sided tape for super-strong cloth, manufactured by Kawaguchi Co., Ltd.) at both ends in the longitudinal direction of the covering member 21 so as not to overlap with the detection part in the thickness direction. Cross, obtained from Yuzawaya Trading Co., Ltd.). The convex side of the snap button (Kiyohara Co., Ltd., spring hook 10mm SUN18-12) was attached to this woven fabric. The distance between snap buttons (center distance) was 72 mm.
At this time, the snap button 23A on the side to be attached to the first holding link 52 described later was rotatably attached by caulking and fixing in a hole provided in the woven fabric. On the other hand, the snap button 23B on the side to be attached to the second holding link 53, which will be described later, is caulked and fixed in the hole provided in the woven fabric, and then another woven fabric is attached to the back side of the snap button with double-sided tape. The button was mounted non-rotatably.
Finally, a connection terminal was attached to the end of the lead wire opposite to the sensor body 10 to form the connection member 22, thereby completing the sensor sheet 62.

Separately from the sensor sheet 62, the holding unit 50 shown in FIG.
The first holding link 52 and the second holding link 53 were produced by cutting an ABS resin plate having a thickness of 1 mm into 20 mm × 120 mm. Next, a hole of about 3 mm was formed at a central position of 10 mm from the end of each holding link, and fixed with caulking to form a connecting portion 51.

Next, a hole of about 5 mm was made at a central position of 20 mm from the rotation center of the first holding link 52 (connecting portion 51), and a snap button (concave side) was attached. Here, the caulking pressure is adjusted so that the snap button can rotate with respect to the first holding link 52.
Further, a hole of about 5 mm was made at a central position of 90 mm from the rotation center (connecting portion 51) of the second holding link 53, and the snap button (concave side) was fixed. Here, the caulking pressure is adjusted so that the snap button does not rotate with respect to the second holding link 53.
Thereby, the holding part 50 was completed.

FIG. 10 is a schematic diagram for explaining an evaluation method of the rotation angle measuring device in the present embodiment.
As shown in FIG. 10, the sensor sheet 62 was attached to the holding unit 50, and the connection member 22 of the sensor sheet 62 was connected to the LCR HiTester 3522-50 (manufactured by Hioki Electric Co., Ltd.) 3.
Further, the second holding link 53 was aligned with the 0 degree position of the protractor 5 and fixed with double-sided tape.

In this state, as shown in FIGS. 10 (a) to 10 (c), the angle θ of the first holding link 52 with respect to the second holding link 53 changes so as to change from 45 degrees to 180 degrees. While rotating the holding link 52, the capacitance of the detection part of the sensor sheet 62 was measured. Here, the capacitance of θ = 45 degrees and the capacitance at intervals of 10 degrees at θ = 50 to 180 degrees were measured.
Thereafter, the distance between the snap buttons 23A and 23B was calculated based on the measured capacitance, and θ was calculated based on the above-described equation (3) based on the cosine theorem.

The angle θ between the first holding link 52 and the second holding link 53 calculated from the capacitance measurement result in the sensor sheet 62, and the first holding link 52 and the second holding link 53 measured by the protractor 5. The relationship with the angle was plotted on a graph as shown in FIG.
As a result, as shown in FIG. 11, the angle θ calculated from the capacitance measurement result has a high correlation with the angle actually measured by the protractor, and the sensor sheet 62 is attached to the holding unit 50. Thus, it has become clear that the rotation angle of the first holding link 52 with respect to the second holding link 53 can be accurately measured.

(Example 2)
<Production of sensor body>
A sensor main body was produced in the same manner as in Example 1.

<Production of sensing member>
A sensor sheet 72 having substantially the same configuration as that of the sensor sheet 2 shown in FIG. 2 was produced by the following method.
An elastic polyester cloth (KKF5550, Uni Fiber Co., Ltd.) was cut into 95 mm × 20 mm. Next, two elastic polyester cloths were bonded together using an elastic adhesive so as to sandwich the sensor body 10 between the elastic polyester cloths, and the covering member 21 was formed.
Next, a woven fabric (Munsell patchwork) using a double-sided tape (double-sided tape for super-strong cloth, manufactured by Kawaguchi Co., Ltd.) at both ends in the longitudinal direction of the covering member 21 so as not to overlap with the detection part in the thickness direction. A cross) was pasted.
Then, a product (Fashup, manufactured by Morito Co., Ltd.) in which a snap button is previously attached to a polyester cloth is cut into a size of about 20 mm × 20 mm around the snap button, and the convex side is double-sided tape (super It was pasted using a double-sided tape for strong cloth). At this time, the polyester cloth to which the snap button was attached was attached so that the distance between the snap buttons 23A and 23B was 88 mm.
Finally, a connection terminal was attached to the end of the lead wire opposite to the sensor body 10 to form a connection member, and the sensor sheet 72 was completed.

<Attaching the sensing member to the supporter>
A sensor sheet 72 was attached to an ankle supporter (ZAMST FA-1 (M size) 200 manufactured by Nippon Sigma Co., Ltd.) 200 as shown in FIG. Here, the sensor sheet 72 is attached so that the position corresponding to the ankle when the supporter 200 is mounted becomes the center of rotation, and the supporter 200 is preliminarily fitted with a polyester having a concave snap button attached thereto. The cloth was sewn and fixed.

Next, the supporter 200 to which the sensor sheet 72 was attached was attached to the subject's ankle, and the ankle was bent and stretched in that state, and the sensor sheet 72 was evaluated.
FIG. 12A is a diagram illustrating a state in which the rotation angle measurement device (supporter) is mounted on the subject in Example 2, and FIG. 12B is an actual photograph of the mounting state illustrated in FIG. is there. 13A to 13D are photographs showing the movement of the ankle of the subject in Example 2. FIG. FIG. 14 is a graph showing the measurement results of Example 2.

In this evaluation, as shown in FIGS. 12A and 12B, the supporter 200 was attached to the ankle of the subject. Further, the position P1 of the ankle, the position P2 of the knee side surface on the virtual line L1 extending from the P1 along the lower leg, and the position P3 of the side surface of the toe of the little finger on the virtual line L2 extending from the P1 toward the toes. Each was equipped with a marker for image capture.
In the supporter 200, the snap button 23A of the sensor sheet 72 is located on the virtual line L1, and the snap button 23B is located on the virtual line L2. Here, the distance from the position P1 to the snap button 23A is 38 mm, and the distance from the position P1 to the snap button 23B is 90 mm.

In this state, as shown in FIGS. 13A to 13D, the ankle was exercised from the dorsiflexion state to the toe standing state, and the capacitance at the detection portion of the sensor sheet 72 at that time was measured. The capacitance was measured with an LCR meter (LCR high tester 3522-50, not shown) connected via the connection member 22. Thereafter, based on the measured capacitance, the extension amount of the detection unit 10 (the distance between the snap buttons 23A and 23B) was calculated. Further, the joint angle of the ankle (angle formed between the lower leg and the foot) was calculated based on the extension amount of the detection unit 10.
Simultaneously with the measurement of the capacitance, an ankle motion is photographed with a video camera, and the ankle joint angle (angle formed between the lower leg and the foot) is determined with reference to the markers attached to the positions P1 to P3. Calculated.

The relationship between the joint angle calculated from the measurement result of the electrostatic capacitance in the sensor sheet 72 and the joint angle calculated from the video image was plotted on a graph as shown in FIG.
As a result, as shown in FIG. 14, the joint angle calculated from the capacitance measurement result correlates with the joint angle calculated from the video image, and the sensor sheet 72 is attached to the supporter 200. Thus, it became clear that the joint angle of the ankle can be measured.

DESCRIPTION OF SYMBOLS 1 Rotation angle measuring device 2, 62, 72 Sensor sheet 3 Measurement part 4 Calculation part 10, 40 Sensor main body 11 Dielectric layer 12A Front side electrode layer 12B Back side electrode layer 13A Front side wiring 13B Back side wiring 14A Front side connection part 14B Back side connection part 15A Front side Protective layer 15B Back side protective layer 21 Coating member 22 Connection member 23 Fixing member 41A Front side dielectric layer (second dielectric layer)
41B Back side dielectric layer (first dielectric layer)
42A Central electrode layer (first electrode layer)
42B Front side electrode layer (third electrode layer)
42C Back side electrode layer (second electrode layer)
43A Central wiring 43B Front side wiring 43C Back side wiring 44A Central connection part 44B Front side connection part 44C Back side connection part 45A Front side protective layer (first protective layer)
45B Back side protective layer (second protective layer)
50 holding part 51 connecting part 52 first holding link 53 second holding link 100, 200 supporter

Claims (6)

A rotation angle measuring device used for measuring a rotation angle of a measurement object,
A sensing member that can expand and contract in one direction following the rotation of the object to be measured, and whose electric parameter changes according to the rotation angle;
A measurement unit for measuring the electrical parameter;
A calculation unit that calculates the rotation angle based on a measurement result in the measurement unit;
With
The sensing member has a detection unit in which an electrical parameter changes according to the amount of deformation during expansion and contraction, and a fixing member that attaches the sensing member to the measurement object.
The rotation angle measuring device according to claim 1, wherein the fixing member is provided at two locations so as to sandwich the detection unit in an extension / contraction direction of the detection unit. The measurement object has two link equivalent parts connected by a connection part, and at least one link equivalent part is configured to be rotatable around the connection part,
The sensing member is attached by the fixing member so as to bridge between the two link equivalent parts,
The rotation angle measuring device according to claim 1, wherein a rotation angle of the one link equivalent portion with respect to the other link equivalent portion is measured as the rotation angle of the measurement object. At least one of the fixing members is attached to the sensing member so as to be rotatable with respect to the link equivalent part,
The rotation angle measuring device according to claim 2, wherein the sensing member rotatably attached is rotatable along a rotation direction of the link equivalent portion. The sensing member is
A dielectric layer made of elastomer; a first electrode layer formed on an upper surface of the dielectric layer; and a second electrode layer formed on a lower surface of the dielectric layer, wherein the first electrode layer and the second electrode Including a sensor body having a detecting portion as an opposing portion of the layer,
The rotation angle measuring device according to claim 1, wherein the detection unit has a capacitance that changes according to expansion and contraction. A capacitance type sensor sheet used as a sensing member of the rotation angle measurement device according to claim 1,
An elastomeric dielectric layer; a first electrode layer formed on an upper surface of the dielectric layer; and a second electrode layer formed on a lower surface of the dielectric layer, the first electrode layer and the second electrode layer And a sensor body that can be expanded and contracted in one direction and the capacitance of the detection unit changes according to expansion and contraction.
A fixing member for attaching the capacitance type sensor sheet provided at two locations so as to sandwich the detection unit in the stretching direction;
With
At least one of the fixing members is configured to rotatably attach the capacitive sensor sheet to the object to be measured. A measuring object having two link-corresponding parts connected by a connecting part, wherein at least one link-corresponding part is configured to be rotatable about the connecting part as a rotation center; A rotation angle measuring device for measuring a rotation angle with respect to a link equivalent part,
A sensing member that can expand and contract in one direction following the rotation of the object to be measured, and whose electric parameter changes according to the rotation angle;
A first holding link and a second holding link connected by a connecting portion, wherein one holding link is configured to be rotatable with respect to the other holding link about the connecting portion as a rotation center;
A measurement unit for measuring the electrical parameter;
A calculation unit that calculates the rotation angle based on a measurement result in the measurement unit;
With
The sensing member is provided at two locations so as to sandwich the detection unit in the expansion / contraction direction of the detection unit with a detection unit whose electrical parameter changes according to the amount of deformation during expansion / contraction, and the sensing member is attached to the holding unit A rotation angle measuring device, comprising: a fixing member to be attached, wherein the fixing member is attached so as to bridge between the first holding link and the second holding link.