Measurement device

Abstract

To provide a measurement deice capable of grasping both the bending deformation state and elastic deformation state of a measurement target.SOLUTION: A measurement device 20 is provided, comprising: a sensor unit 20A fixed onto a substrate that is deformable in response to deformation of a measurement target object, and provided with multiple sensors 21A, 21B made of conductors having contact resistance that changes in response to deformation of the substrate and arranged to be spaced apart from each other; and a computation unit (arithmetic circuit 20C) configured to compute values indicative of the bending deformation state and the elastic deformation state of the measurement target object from resistance of the conductors while applying a voltage to the sensors 21A, 21B.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a measuring device.

Background Art

[0002] Patent Document 1 below describes a posture measuring device including a strip-shaped elastic thin plate member attached to a human body or a dummy, a plurality of strain detection gauges arranged in the longitudinal direction of the strip-shaped elastic thin plate member, position detection means for detecting at least one position of the strip-shaped elastic thin plate member, and arithmetic means for calculating the posture of the human body or the dummy based on the strain measured by the strain detection gauges and the position information measured by the position detection means.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the posture measuring device disclosed in Patent Document 1 above, a strain gauge is used to measure the strain in the longitudinal direction of the strip-shaped elastic thin plate member, and the shape change of the thin plate member is obtained by calculation based on the measured strain. Specifically, the bending strain distribution detected by the strain gauge is converted into the curvature distribution of the strip-shaped elastic thin plate member, and further, the deformed shape of the strip-shaped elastic thin plate member is obtained from the curvature distribution.

[0005] However, in this posture measuring device, the expansion and contraction of the strip-shaped elastic thin plate member are limited. When the measurement target for measuring the deformed shape not only bends but also expands and contracts, it is difficult to grasp the expansion and contraction deformed state. Further, even if the strain gauge can detect the strain due to the expansion and contraction deformation, it is difficult to separately grasp the bending deformed state and the expansion and contraction deformed state.

[0006] In view of the above facts, an object of the present disclosure is to provide a measuring device capable of grasping the bending deformation state and the stretching and shrinking deformation state of an object to be measured, respectively.

Means for Solving the Problems

[0007] The measuring device according to the first aspect includes a sensor unit in which a plurality of sensors formed using a conductor that is fixed to a deformable base material in synchronization with the deformation of the object to be measured and whose contact resistance changes according to the shape change of the base material are arranged at intervals from each other, and an arithmetic unit that calculates values representing the bending deformation state and the stretching and shrinking deformation state of the object to be measured from the change in the contact resistance of each of the sensors with a voltage applied to the sensor unit.

[0008] In the measuring device according to the first aspect, the contact resistance of the conductor changes according to the shape change of the base material. For example, when the base material expands and contracts, the contact resistance of the conductor changes. Also, even when the base material bends, the contact resistance of the conductor changes.

[0009] Here, in this aspect, a plurality of sensors are arranged at intervals from each other. Thereby, for example, as an example, these sensors can be arranged in a bridge circuit, and values representing the bending deformation state and the stretching and shrinking deformation state of the object to be measured can be calculated respectively.

[0010] As another example, the stretching and shrinking deformation state and the bending deformation state of the object to be measured can be calculated individually from the change in the contact resistance of each of the plurality of sensors.

[0011] That is, by using this measuring device, the stretching and shrinking deformation state and the bending deformation state of the object to be measured can be grasped respectively.

[0012] The measuring device according to the second aspect is the measuring device according to the first aspect, wherein the base material is a fabric, the conductor is a conductive yarn, and the sensor includes a sewn body using the conductive yarn as one of the lower yarn or the upper yarn and a non-conductive yarn as the other of the lower yarn or the upper yarn.

[0013] In the measuring device of the second aspect, each sensor is formed by a sewn body in which a conductive thread is used for one of the lower thread or the upper thread, and a non-conductive thread is used for the other of the lower thread or the upper thread.

[0014] Thereby, the arithmetic unit can calculate a value representing the deformed state of the base material from the contact resistance of either one of the lower thread or the upper thread, that is, either the compressed conductor or the pulled conductor.

[0015] On the other hand, if a sensor is formed with a sewn body using conductive threads for both the lower thread and the upper thread, depending on the bending deformation of the base material, one of the lower thread and the upper thread is compressed and the contact resistance decreases, while the other is pulled and the contact resistance increases.

[0016] For example, if the distances from the neutral axis position of the bending deformation of the base material to the lower thread and the upper thread are equal, and the change rates of the contact resistance according to the density changes accompanying the compression and tension of the lower thread and the upper thread are equal, the contact resistances of the lower thread and the upper thread cancel each other out. When the contact resistances of the lower thread and the upper thread cancel each other out in this way, it is difficult to calculate a value representing the deformed state of the base material.

[0017] The measuring device of the third aspect is the measuring device according to the second aspect, wherein the sensor unit is formed by arranging the fabric in which the sensor in which the upper thread is a conductive thread is sewn and fixed above the measurement object, and arranging the fabric in which the sensor in which the lower thread is a conductive thread is sewn and fixed below the measurement object.

[0018] According to the measuring device of the third aspect, sensors are arranged above and below the measurement object respectively. That is, the sensors are arranged spaced apart with the measurement object in between.

[0019] If the measurement object is bent so as to be convex upward, the base material and the upper thread which is a conductive thread of the sensor arranged above the measurement object are pulled. On the other hand, the base material and the lower thread which is a conductive thread of the sensor arranged below the measurement object are compressed.

[0020] Accordingly, the arithmetic unit can calculate a value representing the deformed state of the measurement object from the change in the contact resistance of the conductor compressed and the conductor stretched in response to the bending deformation of the base material.

[0021] The measuring device according to the fourth aspect is the measuring device according to the second aspect, wherein the sensor unit is formed by alternately arranging on the fabric the sensor in which the lower thread is a conductive thread and the sensor in which the upper thread is a conductive thread.

[0022] According to the measuring device of the fourth aspect, a sensor in which the lower thread is a conductive thread and a sensor in which the upper thread is a conductive thread are alternately arranged on the fabric.

[0023] If the fabric is bent so as to be convex upward as the measurement object deforms, the conductive thread of the lower thread is compressed. On the other hand, the conductive thread of the upper thread is stretched.

[0024] Accordingly, the arithmetic unit can calculate a value representing the deformed state of the base material from the change in the contact resistance of the conductor compressed and the conductor stretched in response to the bending deformation of the base material.

[0025] The measuring device according to the fifth aspect is the measuring device according to the first aspect, wherein the base material is a fabric, the conductor is a conductive thread, the sensor is a sewn body using the conductive thread as a lower thread and an upper thread, and the change rate of the contact resistance according to the deformation of the fabric is different between the lower thread and the upper thread, and the sensor unit includes a parallel arrangement unit in which a plurality of the sensors are arranged in parallel and a series arrangement unit in which a plurality of the sensors are arranged in series.

[0026] According to the measuring device of the fifth aspect, the sensor is formed by using a conductive thread as a lower thread and an upper thread. Further, the sensor unit includes a parallel arrangement unit in which a plurality of sensors are arranged in parallel and a series arrangement unit in which a plurality of sensors are arranged in series.

[0027] If the fabric expands or contracts, the contact resistance of the series arrangement portion changes more significantly than that of the parallel arrangement portion. As a result, the arithmetic unit can calculate a value representing the expansion and contraction state of the base material.

[0028] On the other hand, if the fabric is bent, the contact resistance of the parallel arrangement portion changes. At this time, in response to the bending deformation of the fabric, one of the lower thread and the upper thread is compressed and the contact resistance decreases, while the other is stretched and the contact resistance increases.

[0029] Here, in this aspect, the rate of change of the contact resistance in response to the bending deformation of the fabric is different between the lower thread and the upper thread. That is, the rate of change of the contact resistance of the lower thread and the upper thread in response to the bending deformation of the fabric is different. For this reason, the contact resistances of the lower thread and the upper thread are not canceled out, and in response to the bending deformation of the fabric, the combined contact resistance of the lower thread and the upper thread changes at a predetermined ratio. As a result, the arithmetic unit can calculate a value representing the bending deformation state of the base material from the change in the contact resistance of the conductor in response to the bending deformation of the base material.

[0030] The measuring device according to the sixth aspect is the measuring device according to any one of the first to third aspects, and includes a bridge circuit including the two sensors, and a signal switching unit capable of switching the bridge circuit between a two-active-gauge method connection and a two-active-gauge method connection for opposite sides.

[0031] According to the measuring device of the sixth aspect, the signal switching unit switches the sensor unit to a bridge circuit of the two-active-gauge method and the two-active-gauge method for opposite sides. The arithmetic unit can calculate a value representing the bending deformation state of the measurement object when the two-active-gauge method is connected. On the other hand, the arithmetic unit can calculate a value representing the expansion and contraction deformation state of the measurement object when the two-active-gauge method for opposite sides is connected.

[0032] The measuring device according to the seventh aspect is the measuring device according to any one of the first to fourth aspects, wherein the arithmetic unit calculates, from the change in the measurement voltage corresponding to the change in the contact resistance of each of the two sensors, the change in the measurement voltage due to the expansion and contraction deformation of the sensor unit and the change in the voltage due to the bending deformation, and calculates values representing the bending deformation state and the expansion and contraction deformation state of the object to be measured, respectively.

[0033] When the contact resistance of the conductor changes while a voltage is applied to the sensor unit, the voltage acting on each sensor changes. According to the measuring device of the seventh aspect, from the voltage change of each sensor, the arithmetic unit calculates the change in the measurement voltage due to the expansion and contraction deformation of the sensor unit and the change in the voltage due to the bending deformation, respectively. Further, the arithmetic unit calculates values representing the bending deformation state and the expansion and contraction deformation state of the object to be measured from the voltage change amount, respectively.

[0034] As described above, in the measuring device of the seventh aspect, even without using a bridge circuit, it is possible to calculate values representing the bending deformation state and the expansion and contraction deformation state of the object to be measured, respectively.

[0035] The measuring device according to the eighth aspect is the measuring device according to the fifth aspect, wherein the arithmetic unit calculates the change in the voltage due to the bending deformation of the sensor unit from the change in the measurement voltage of the parallel arrangement unit, calculates the change in the voltage due to the expansion and contraction deformation of the sensor unit from the change in the measurement voltage of the series arrangement unit, and calculates values representing the bending deformation state and the expansion and contraction deformation state of the object to be measured, respectively.

[0036] When the contact resistance of the conductor changes while a voltage is applied to the sensor unit, the voltage acting on each of the parallel arrangement unit and the series arrangement unit changes. According to the measuring device of the eighth aspect, the arithmetic unit calculates the change in the voltage due to the bending deformation of the sensor unit from the change in the measurement voltage of the parallel arrangement unit, and calculates the change in the voltage due to the expansion and contraction deformation of the sensor unit from the change in the measurement voltage of the series arrangement unit. Further, the arithmetic unit calculates values representing the bending deformation state and the expansion and contraction deformation state of the object to be measured from the voltage change amount, respectively.

[0037] Thus, in the measuring device of the eighth aspect, even without using a bridge circuit, values representing the bending deformation state and the stretching and contracting deformation state of the object to be measured can be respectively calculated.

Advantages of the Invention

[0038] According to the present disclosure, the bending deformation state and the stretching and contracting deformation state of the object to be measured can be respectively grasped.

Brief Description of the Drawings

[0039]

Figure 1A

Figure 1B

Figure 1C

Figure 1D

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14A

Figure 14B

Figure 14C

Figure 15

Embodiments for Carrying Out the Invention

[0040] Hereinafter, a measuring device according to an embodiment of the present disclosure will be described with reference to the drawings. Components denoted by the same reference numerals in each drawing mean the same components. However, unless otherwise specified in the specification, each component is not limited to one, and a plurality of components may exist.

[0041] Also, descriptions of overlapping configurations and reference numerals in each drawing may be omitted. Note that the present disclosure is not limited to the following embodiments, and appropriate changes can be made and implemented, such as omitting configurations, replacing with different configurations, or combining one embodiment and various modifications within the scope of the object of the present disclosure.

[0042] <Basic Configuration of Measuring Device> (Application Example) FIG. 1A shows an application example of a measuring device 20 according to the first embodiment of the present disclosure. As an example, the measuring device 20 can be used for a seat 12 of a vehicle 10. The seat 12 is an example of an object to be measured for measuring the amount of deformation. The seat 12 deforms according to the presence or absence of an occupant and the posture of the occupant.

[0043] Note that the deformation of the seat 12 is a combination of bending deformation and stretching deformation. Bending deformation is deformation in a direction (out-of-plane direction) intersecting the surface of the seat 12, and stretching deformation is deformation in a direction (in-plane direction) along the surface of the seat 12. The present disclosure separately measures these bending deformation amounts and stretching deformation amounts.

[0044] As will be described later, the measuring device 20 includes a sensor unit 20A. The sensor unit 20A is provided at a position where the amount of deformation is to be measured on the seat 12. FIG. 1A shows an example in which the sensor unit 20A is provided at two locations where the thigh of the occupant contacts, but the sensor unit 20A may be provided at three or more locations or only at one location. Also, the sensor unit 20A may be provided not only on the seat portion of the seat but also on the back.

[0045] (Configuration of Sensor) As will be described in detail later, as shown in FIGS. 1B and 1C, in each sensor unit 20A, a plurality of sensors 21 are arranged at intervals from each other.

[0046] For example, in the example shown in FIG. 1B, the sensors 21 are arranged to face each other at intervals in the thickness direction of the sheet 12. Specifically, as shown in FIG. 1D, an upper surface sensor 21A and a lower surface sensor 21B are fixed to the upper surface and the lower surface of the cushion block 12C, respectively.

[0047] As shown in FIG. 1B, the cushion block 12C is a cushion material fixed to the upper surface of the cushion material 12A that constitutes the sheet 12, which is the object to be measured, and can be deformed in synchronization with the deformation of the cushion material 12A. Therefore, the cushion block 12C is also part of the object to be measured.

[0048] The sensor 21 can be deformed in synchronization with the deformation of the cushion block 12C. The cushion material 12A, the cushion block 12C, and the sensor 21 are covered with the skin material 12B.

[0049] On the other hand, in the example shown in FIG. 1C, the sensors 21 are arranged in the same plane at intervals in the width direction of the sheet 12. Specifically, a plurality of sensors 21 are fixed to the upper surface of the cushion block 12C. The cushion material 12A, the cushion block 12C, and the sensor 21 are covered with the skin material 12B.

[0050] When arranging a plurality of sensors 21 in the same plane, the number of sensors 21 can be provided in any quantity of two or more. Also, when arranging a plurality of sensors 21 in the same plane, the cushion block 12C can be omitted.

[0051] As described above, in the sensor unit 20A, a plurality of sensors 21 are arranged at intervals from each other, facing each other or within the same plane. As will be described later, the first and second embodiments are examples in which two sensors 21 are arranged facing each other. On the other hand, the third and fourth embodiments are examples in which two sensors 21 are arranged within the same plane.

[0052] As shown in FIG. 1D, the sensor 21 includes a base material 30 and a conductor 32. The base material 30 is formed of a stretchable fabric as an example. The conductor 32 is a sewn body zigzag-sewn to the base material 30 using upper yarn 32A and lower yarn 32B.

[0053] At least one of the upper yarn 32A and the lower yarn 32B is formed of a conductive yarn. Thereby, the contact resistance of the conductor 32 changes according to the shape change of the base material 30.

[0054] The configuration of the conductive yarn is not particularly limited. As an example, it is formed by coating fibers such as nylon and cotton with a conductive metal such as silver. Also, as the conductive yarn, a conductive rubber made into a thin wire may be used. Which of the upper yarn 32A and the lower yarn 32B is formed of the conductive yarn will be described later.

[0055] The stretchability of the upper yarn 32A and the lower yarn 32B forming the conductor 32 is lower than the stretchability of the fabric forming the base material 30. However, by being zigzag-sewn to the base material 30, the conductor 32 can stretch following the stretch of the base material 30.

[0056] Specifically, as shown in FIG. 2, the conductor 32 is formed in a zigzag shape by sewing the upper yarn 32A (and the lower yarn 32B not shown) along the substantially Y direction on the base material 30 and repeatedly folding and sewing it to the opposite side of the substantially Y direction.

[0057] Further, the conductor 32 is arranged such that the longitudinal direction thereof is along the X direction as a whole. The X direction is perpendicular to the Y direction. In the following description, the X direction may be referred to as the "axial direction" of the conductor 32. The length between the folded portions of the conductive yarns forming the conductor 32 is constant. Therefore, the conductor 32 has a constant width in the direction intersecting the axial direction.

[0058] The upper yarn 32A (and the lower yarn 32B not shown) has a gap V1 between the folded and adjacent portions thereof when in a steady state where no external force acts. Further, the upper yarn 32A (and the lower yarn 32B not shown) has a contact portion T1 where the folded and adjacent portions overlap each other.

[0059] Note that the folding angle of the upper yarn 32A (and the lower yarn 32B not shown) is constant. Therefore, in the steady state, the width of the gap V1 and the area of the contact portion T1 are constant over the conductor 32.

[0060] (Change in contact resistance) Here, when the base material 30, which is a fabric, is compressed along the axial direction (X direction) of the zigzag-sewn conductor 32, the base material 30 shrinks in the X direction.

[0061] Therefore, in the upper yarn 32A (and the lower yarn 32B not shown), the gap V1 between the folded and adjacent portions becomes smaller, and the area of the contact portion T1 becomes larger. As a result, when the upper yarn 32A (and the lower yarn 32B not shown) is used as the conductive yarn, the contact resistance of the conductor 32 becomes smaller.

[0062] On the other hand, when the base material 30 is pulled along the axial direction (X direction) of the conductor 32, the base material 30 extends in the X direction.

[0063] Therefore, in the upper yarn 32A (and the lower yarn 32B not shown), the gap V1 between the folded and adjacent portions becomes larger, and the area of the contact portion T1 becomes smaller. As a result, when the upper yarn 32A (and the lower yarn 32B not shown) is used as the conductive yarn, the contact resistance of the conductor 32 becomes larger.

[0064] (Change in Contact Resistance of Conductor due to Deformation of Object to be Measured) When the cushion material 12A shown in Fig. 1B deforms, the cushion block 12C and the base material 30 deform in synchronization with the deformation. Specifically, when the cushion material 12A deforms, the respective base materials 30 disposed on the upper and lower surfaces of the cushion block 12C deform. The base material 30 deforms in at least one of the modes of bending deformation and stretching and contracting deformation according to the deformation mode of the cushion material 12A.

[0065] For example, the base material 30 bends and deforms so as to be convex upward as shown in Fig. 3B from the steady state shown in Fig. 3A. At this time, the portion above the neutral axis in the base material 30 is pulled, and the portion below is compressed.

[0066] When the upper thread 32A is a conductive thread, the contact resistance of the conductor 32 increases. On the other hand, when the lower thread 32B is a conductive thread, the contact resistance of the conductor 32 decreases.

[0067] When both the upper thread 32A and the lower thread 32B are conductive threads, the contact resistance changes according to the total value of the contact resistance changes of the upper thread 32A and the lower thread 32B. However, when the contact resistance change rates due to deformation are equal for the upper thread 32A and the lower thread 32B, the respective contact resistance changes are offset, and the contact resistance of the conductor 32 does not change.

[0068] Also, for example, the base material 30 stretches and contracts as shown in Fig. 3C from the steady state shown in Fig. 3A. When the base material 30 is pulled, the contact resistance of the conductor 32 increases in both the case where the upper thread 32A is a conductive thread and the case where the lower thread 32B is a conductive thread.

[0069] On the other hand, when the base material 30 is compressed, the contact resistance of the conductor 32 decreases in both the case where the upper thread 32A is a conductive thread and the case where the lower thread 32B is a conductive thread.

[0070] <First Embodiment> Based on the above, the measuring device 20 of the first embodiment will be described.

[0071] [Measurement device] As shown in FIG. 4, the measurement device 20 is formed by including a sensor unit 20A, a signal measurement circuit 20B, an arithmetic circuit 20C, and a control device 20D. The arithmetic circuit 20C is an example of the arithmetic unit in the present disclosure.

[0072] The signal measurement circuit 20B is provided for each sensor unit 20A. In FIG. 4, only one sensor unit 20A is illustrated. When a plurality of sensor units 20A are provided, the signal measurement circuits 20B coupled to the respective sensor units 20A are coupled to the arithmetic circuit 20C. The arithmetic circuit 20C may be provided for each of the plurality of sensor units 20A, or may be provided integrally as only one.

[0073] (Sensor unit) In the sensor unit 20A in the present embodiment, as shown in FIG. 1B, the respective sensors 21 are provided to face each other with the cushion block 12C interposed therebetween.

[0074] In the upper surface sensor 21A shown in FIG. 1D, the upper yarn 32A is formed of a conductive yarn, and the lower yarn 32B is formed of a non-conductive yarn. In the lower surface sensor 21B, the upper yarn 32A is formed of a non-conductive yarn, and the lower yarn 32B is formed of a conductive yarn.

[0075] (Signal measurement circuit) The signal measurement circuit 20B includes a signal switching unit 20B1 and a signal control / measurement unit 20B2. A terminal g is provided in the signal measurement circuit 20B, and a voltage E is applied to this terminal g. A bridge circuit including the upper surface sensor 21A and the lower surface sensor 21B is provided in the signal measurement circuit 20B. This bridge circuit is formed as follows.

[0076] First, the end of the upper surface sensor 21A is coupled to the signal switching unit 20B1. One of the coupling parts is coupled to the fixed switching terminals a and f via a fixed resistor Rc. The other of the coupling parts is directly coupled to the fixed switching terminal b.

[0077] On the other hand, the end of the lower sensor 21B is also connected to the signal switching unit 20B1. One of the connection parts is connected to the movable switching terminal c via the fixed resistor Rc. Also, it is connected to the ground G. The other of the connection parts is directly connected to the movable switching terminal d.

[0078] Also, the switching signal terminal h2 of the signal control and measurement unit 20B2 is connected to the switching signal terminal h1 of the signal switching unit 20B1 by a signal line.

[0079] Signal lines connected to the input terminal ADIN of the analog-digital converter in the signal control and measurement unit 20B2 are respectively connected to the terminal I of one connection part and the terminal II of the other connection part in the upper sensor 21A.

[0080] The signal terminal h4 of the arithmetic circuit 20C is connected to the signal terminal h3 in the signal control and measurement unit 20B2 by a signal line.

[0081] The signal measurement circuit 20B executes measurement control processing in response to a start signal output from the control device 20D and input via the arithmetic circuit 20C. In the measurement control processing, first, the movable switching terminals c and d are connected to the fixed switching terminals a and b, respectively.

[0082] This connection corresponds to the bridge circuit M1 in Fig. 5A, and the measurement voltages e1 and e2 are input to the analog-digital converter of the signal control and measurement unit 20B2 via the input terminal ADIN. Also, the measurement voltages e1 and e2 are input to the arithmetic circuit 20C via the signal terminal h4.

[0083] The bridge circuit M1 is a strain gauge bridge of the two-active gauge method that can measure only the amount of bending deformation of the cushion block 12C arranged between the upper sensor 21A and the lower sensor 21B. The change amounts of the measurement voltages e1 and e2 indicate the voltage changes of the respective sensors based on the bending deformation of the cushion block 12C.

[0084] Next, the signal measurement circuit 20B switches the movable switching terminals c and d and connects them to the fixed switching terminals b and f. This connection corresponds to the bridge circuit M2 in Fig. 5B, and the measurement voltages e1 and e2 are input to the analog-digital converter of the signal control and measurement unit 20B2 via the input terminal ADIN. Also, the measurement voltages e1 and e2 are input to the arithmetic circuit 20C via the signal terminal h4.

[0085] The bridge circuit M2 is a strain gauge bridge of the opposite side 2 active gauge method that can measure only the amount of expansion and contraction deformation of the cushion block 12C arranged between the upper surface sensor 21A and the lower surface sensor 21B. The change amounts of the measurement voltages e1 and e2 indicate the voltage changes of each sensor based on the expansion and contraction deformation of the cushion block 12C.

[0086] (Arithmetic circuit) The arithmetic circuit 20C is signal-connected to the signal measurement circuit 20B and the control device 20D. The arithmetic circuit 20C includes a processor (not shown), and the processor executes arithmetic processing in response to a start signal output from the control device 20D.

[0087] In the arithmetic processing, values representing the bending deformation state and the expansion and contraction deformation state of the cushion block 12C are calculated from the measurement voltages e1 and e2 input from the signal measurement circuit 20B with a voltage E applied to the terminal g.

[0088] Specifically, when the cushion block 12C deforms, the contact resistances of the upper surface sensor 21A and the lower surface sensor 21B change, and the measurement voltages e1 and e2 also change. The arithmetic circuit 20C calculates values representing the bending deformation state and the expansion and contraction deformation state of the cushion block 12C from the measurement voltages e1 and e2 input from the signal measurement circuit 20B.

[0089] That is, the arithmetic circuit 20C calculates values representing the bending deformation state and the expansion and contraction deformation state of the portion of the cushion material 12A where the cushion block 12C is provided.

[0090] When calculating values representing the bending deformation state and the stretching and shrinking deformation state of the cushion block 12C from the measured voltages e1 and e2, first measure the shape of the cushion block 12C according to the contact resistance in advance, obtain a conversion coefficient that relates the two, and perform conversion processing based on the conversion coefficient.

[0091] Note that "calculating values representing the bending deformation state and the stretching and shrinking deformation state of the measurement object from the change in the contact resistance of each sensor" in the present disclosure means calculating values representing the bending deformation state and the stretching and shrinking deformation state of the measurement object from the measured voltages of each sensor whose contact resistance has changed in this way.

[0092] (Control device) The control device 20D is signal-connected to a measurement object control device or the like (not shown) that is a control object. The measurement object control device controls, for example, an electric motor that moves the seat 12. A start signal is input to the control device 20D from the measurement object control device.

[0093] The control device 20D inputs a control signal to the measurement object control device based on the bending deformation state and the stretching and shrinking deformation state of the seat 12 calculated by the arithmetic circuit 20C. Thereby, the control object is controlled. For example, the inclination angle of the backrest portion of the seat 12 can be controlled by an electric motor.

[0094] [Operation and effect] In the measuring device 20 according to the present embodiment, the contact resistance of the conductor 32 changes according to the shape change of the base material 30. For example, when the base material 30 expands and contracts, the contact resistance of the conductor 32 changes. Also, even when the base material 30 bends, the contact resistance of the conductor 32 changes.

[0095] Here, in the present embodiment, the upper surface sensor 21A and the lower surface sensor 21B are arranged at intervals from each other. Further, the signal measurement circuit 20B is provided with a bridge circuit including the upper surface sensor 21A and the lower surface sensor 21B.

[0096] Then, the signal switching unit 20B1 switches the sensor unit 20A to the bridge circuits of the two-active gauge method and the opposite-side two-active gauge method.

[0097] The arithmetic circuit 20C can calculate a value representing the bending deformation state of the object to be measured when the two-active gauge method is connected. On the other hand, the arithmetic circuit 20C can calculate a value representing the expansion and contraction deformation state of the object to be measured when the opposite-side two-active gauge method is connected.

[0098] That is, by using this measuring device, the expansion and contraction deformation state and the bending deformation state of the object to be measured can be grasped respectively.

[0099] In addition, in the measuring device 20 according to the present embodiment, as shown in FIG. 1D, the sensor 21 is formed by a sewn body in which a conductive yarn is used for one of the lower yarn 32B or the upper yarn 32A, and a non-conductive yarn is used for the other of the lower yarn 32B or the upper yarn 32A.

[0100] Thereby, in response to the bending deformation of the base material 30, the arithmetic circuit 20C shown in FIG. 4 can calculate a value representing the deformation state of the base material 30 based on the change in the contact resistance of either the lower yarn 32B or the upper yarn 32A, that is, either the compressed conductor 32 or the pulled conductor 32.

[0101] For example, when the cushion block 12C shown in FIG. 1D is deformed so as to be convex upward, the base material 30 constituting the upper surface sensor 21A also bends, but the lower surface of the base material 30 shrinks relatively with respect to the upper surface. Here, by using only the upper yarn 32A provided on the upper surface of the base material 30 as a conductor, a value representing the deformation state of the base material 30 can be calculated without being affected by the change in the contact resistance of the lower yarn 32B.

[0102] Similarly, the base material 30 constituting the lower surface sensor 21B also bends, but the upper surface of the base material 30 extends relatively downward. Here, by using only the lower yarn 32B provided on the lower surface of the base material 30 as a conductor, a value representing the deformation state of the base material 30 can be calculated without being affected by the change in the contact resistance of the upper yarn 32A.

[0103] On the other hand, if the sensor 21 is formed on a sewn body using conductive yarns for both the lower yarn 32B and the upper yarn 32A, in response to the bending deformation of the base material 30, one of the lower yarn 32B and the upper yarn 32A is compressed and the contact resistance decreases, while the other is stretched and the contact resistance increases.

[0104] For example, if the distances of the lower yarn 32B and the upper yarn 32A from the neutral axis position of the bending deformation of the base material 30 are equal and the change rates of the contact resistance according to the density changes accompanying the compression and stretching of the lower yarn 32B and the upper yarn 32A are equal, the contact resistances of the lower yarn 32B and the upper yarn 32A cancel each other out. When the contact resistances of the lower yarn 32B and the upper yarn 32A cancel each other out in this way, it is difficult to calculate a value representing the deformed state of the base material 30.

[0105] Also, according to the measuring device 20 according to the present embodiment, as shown in FIG. 1D, sensors 21 are respectively arranged above and below the cushion block 12C as the object to be measured. That is, the sensors 21 are arranged spaced apart with the cushion block 12C interposed therebetween.

[0106] If the cushion block 12C is bent so as to be convex upward, the base material 30 and the upper yarn 32A which is the conductive yarn of the upper surface sensor 21A arranged above the cushion block 12C are stretched. On the other hand, the base material 30 and the lower yarn 32B which is the conductive yarn of the lower surface sensor 21B arranged below the cushion block 12C are compressed.

[0107] Thereby, the arithmetic circuit 20C shown in FIG. 4 can calculate a value representing the deformed state of the cushion block 12C from the changes in the contact resistances of the conductor compressed (the lower yarn 32B of the lower surface sensor 21B) and the conductor stretched (the upper yarn 32A of the upper surface sensor 21A) in response to the bending deformation of the base material 30.

[0108] <Second Embodiment> FIG. 6 shows a measuring device 40 according to the second embodiment. In each of the embodiments described below, the description of the configuration similar to that of the measuring device 20 of the first embodiment is omitted. The measuring device 20 of the first embodiment includes a signal switching unit 20B1 in a signal measurement circuit 20B. On the other hand, the measuring device 40 of the second embodiment does not include the signal switching unit 20B1.

[0109] (Signal measurement circuit) The signal measurement circuit 20B in the measuring device 40 includes a signal control and measurement unit 20B2.

[0110] A voltage E is applied to one end of the upper surface sensor 21A and the lower surface sensor 21B. The other ends of the upper surface sensor 21A and the lower surface sensor 21B are connected to the input terminal ADIN of an analog-digital converter in the signal control and measurement unit 20B2.

[0111] In addition, terminals a and b are provided on the other end side of the upper surface sensor 21A and the lower surface sensor 21B, respectively, and signal lines connected to the terminals a and b are connected to the ground G via a fixed resistor Rc.

[0112] (Arithmetic circuit) Since the measuring device 40 of the second embodiment does not include the signal switching unit 20B1, the coupling form of the signal measurement circuit 20B does not switch between the bridge circuit M1 in FIG. 5A and the bridge circuit M2 in FIG. 5B.

[0113] Therefore, the arithmetic circuit 20C cannot separately measure the voltage change based on the bending deformation of the cushion block 12C and the voltage change based on the expansion and contraction deformation from the measured voltages e1 and e2.

[0114] However, in the present embodiment, the arithmetic circuit 20C can calculate the voltage change based on the bending deformation of the cushion block 12C and the voltage change based on the expansion and contraction deformation from the measured voltages e1 and e2.

[0115] (Relationship between deformation amount and change amount of contact resistance) Prior to explaining the direction of calculating the voltage change based on the bending deformation and the expansion / contraction deformation of the cushion block 12C from the measured voltages e1 and e2, the relationship between the amount of deformation of the cushion block 12C and the change amount of the contact resistance of the sensor unit 20A will be explained.

[0116] If the cushion block 12C shown in FIG. 1D is deformed (a combined deformation of expansion / contraction deformation and bending deformation), the upper thread 32A which is the conductor of the upper surface sensor 21A, and the lower thread 32B which is the conductor of the lower surface sensor 21B are each subjected to expansion / contraction deformation and bending deformation.

[0117] FIG. 7 shows the relationship between the amount of bending deformation and the change amount of the contact resistance in a state where the contact resistances of the upper thread 32A of the upper surface sensor 21A and the lower thread 32B of the lower surface sensor 21B are changed by the expansion / contraction deformation.

[0118] The amounts of expansion / contraction deformation of the upper thread 32A of the upper surface sensor 21A and the lower thread 32B of the lower surface sensor 21B are equal. For this reason, the change amounts of the contact resistances in the state where the amount of bending deformation is "0" are equal (change amount RS) between the upper surface sensor 21A and the lower surface sensor 21B.

[0119] Then, as the amount of bending deformation increases, the contact resistances of the upper surface sensor 21A and the lower surface sensor 21B change respectively, but for these sensors, one is compressed and the other is pulled.

[0120] For example, when the upper surface sensor 21A is pulled, the contact resistance increases, and the change amount of the contact resistance due to the bending deformation becomes the change amount RA. On the other hand, the lower surface sensor 21B is compressed and the contact resistance decreases, and the change amount of the contact resistance due to the bending deformation becomes the change amount RB.

[0121] The sum of the change amount of the contact resistance due to the expansion / contraction deformation and the change amount of the contact resistance due to the bending deformation of the upper surface sensor 21A is the change amount ΔR1 = (RS + RA). This change amount ΔR1 can be calculated from the measured voltage e1.

[0122] On the other hand, the sum of the change amount of the contact resistance due to the expansion and contraction deformation and the change amount of the contact resistance due to the bending deformation of the lower surface sensor 21B is the change amount ΔR2 = (RS + RB). This change amount ΔR2 can be calculated from the measurement voltage e2.

[0123] In the measuring device 40, the change amounts of the contact resistances due to bending of the upper surface sensor 21A and the lower surface sensor 21B are adjusted to be equal. That is, the absolute values of the change amount RA and the change amount RB are equal.

[0124] As a result, the change amount RA of the contact resistance due to "bending" of the sensor unit 20A including the upper surface sensor 21A and the lower surface sensor 21B is calculated as [(ΔR1 - ΔR2) / 2]. When RA is a positive number, the cushion block 12C is bent and deformed so as to be convex upward.

[0125] On the other hand, the change amount RS of the contact resistance due to "expansion and contraction" of the sensor unit 20A including the upper surface sensor 21A and the lower surface sensor 21B is calculated as [(ΔR1 + ΔR2) / 2]. Alternatively, RS may be calculated by subtracting the calculated RS from ΔR1 calculated from the measurement voltage e1. When RS is a positive number, the cushion block 12C is elastically deformed in the extending direction.

[0126] (Relationship between measurement voltage and deformation state of sensor) FIG. 8 shows an outline of the change modes of the measurement voltage e1 of the upper surface sensor 21A and the measurement voltage e2 of the lower surface sensor 21B according to the deformation state of the cushion block 12C.

[0127] ·Mode 1 Let the measurement voltages e1 and e2 in the "steady" state (the state where the cushion block 12C is not deformed) be the voltage e0.

[0128] ·Mode 2 When the cushion block 12C is "extended" and deformed, the contact resistances of the upper surface sensor 21A and the lower surface sensor 21B increase, and the measurement voltages e1 and e2 of the upper surface sensor 21A and the lower surface sensor 21B decrease (change amount -es).

[0129] ·Aspect 3 When the cushion block 12C is "contracted" and deformed, the contact resistances of the upper surface sensor 21A and the lower surface sensor 21B become smaller, and the measured voltages e1 and e2 of the upper surface sensor 21A and the lower surface sensor 21B become larger (change amount +es).

[0130] ·Aspect 4 When the cushion block 12C is "bent" and deformed (concave on the upper side), the contact resistance of the upper surface sensor 21A becomes smaller, and the measured voltage e1 of the upper surface sensor 21A becomes larger (change amount +e1B). On the other hand, the contact resistance of the lower surface sensor 21B becomes larger, and the measured voltage e2 of the lower surface sensor 21B becomes smaller (change amount -e2B).

[0131] ·Aspect 5 When the cushion block 12C is "bent" and deformed (convex on the upper side), the contact resistance of the upper surface sensor 21A becomes larger, and the measured voltage e1 of the upper surface sensor 21A becomes smaller (change amount -e1B). On the other hand, the contact resistance of the lower surface sensor 21B becomes smaller, and the measured voltage e2 of the lower surface sensor 21B becomes larger (change amount +e2B).

[0132] Fig. 9 also shows an overview of the change patterns of the measured voltage e1 of the upper surface sensor 21A and the measured voltage e2 of the lower surface sensor 21B according to the deformation state of the cushion block 12C.

[0133] ·Aspect 6 When the cushion block 12C is "extended" and "bent" and deformed (concave on the upper side), due to the "extension" deformation, the contact resistances of the upper surface sensor 21A and the lower surface sensor 21B become larger, and the measured voltages e1 and e2 of the upper surface sensor 21A and the lower surface sensor 21B become smaller (change amount -es).

[0134] On the other hand, due to the "bending" deformation (concave on the upper side), the contact resistance of the upper surface sensor 21A becomes smaller, and the measured voltage e1 becomes larger (change amount +e1B). The contact resistance of the lower surface sensor 21B becomes larger, and the measured voltage e2 of the lower surface sensor 21B becomes smaller (change amount -e2B).

[0135] The measured voltages e1 and e2 are the total values of the changes due to these "elongation" deformations and "bending" deformations (concave on the upper side).

[0136] ·Aspect 7 When the cushion block 12C undergoes "elongation" deformation and "bending" deformation (convex on the upper side), the contact resistances of the upper surface sensor 21A and the lower surface sensor 21B increase due to the "elongation" deformation, and the measured voltages e1 and e2 of the upper surface sensor 21A and the lower surface sensor 21B decrease (change amount -es).

[0137] On the other hand, due to the "bending" deformation (convex on the upper side), the contact resistance of the upper surface sensor 21A increases, and the measured voltage e1 of the upper surface sensor 21A decreases (change amount -e1B). On the other hand, the contact resistance of the lower surface sensor 21B decreases, and the measured voltage e2 of the lower surface sensor 21B increases (change amount +e2B).

[0138] The measured voltages e1 and e2 are the total values of the changes due to these "elongation" deformations and "bending" deformations (concave on the upper side).

[0139] ·Aspect 8 When the cushion block 12C undergoes "contraction" deformation and "bending" deformation (concave on the upper side), the contact resistances of the upper surface sensor 21A and the lower surface sensor 21B decrease due to the "contraction" deformation, and the measured voltages e1 and e2 of the upper surface sensor 21A and the lower surface sensor 21B increase (change amount +es).

[0140] On the other hand, due to the "bending" deformation (concave on the upper side), the contact resistance of the upper surface sensor 21A decreases, and the measured voltage e1 increases (change amount +e1B). On the other hand, the contact resistance of the lower surface sensor 21B increases, and the measured voltage e2 of the lower surface sensor 21B decreases (change amount -e2B).

[0141] The measured voltages e1 and e2 are the total values of the changes due to these "elongation" deformations and "bending" deformations (concave on the upper side).

[0142] ·Aspect 9 When the cushion block 12C undergoes "shrinkage" deformation and "bending" deformation (convex on the upper side), the contact resistance between the upper surface sensor 21A and the lower surface sensor 21B decreases due to the "shrinkage" deformation, and the measured voltages e1 and e2 of the upper surface sensor 21A and the lower surface sensor 21B increase (change amount +es).

[0143] On the other hand, due to the "bending" deformation (convex on the upper side), the contact resistance of the upper surface sensor 21A increases, and the measured voltage e1 of the upper surface sensor 21A decreases (change amount -e1B). On the other hand, the contact resistance of the lower surface sensor 21B decreases, and the measured voltage e2 of the lower surface sensor 21B increases (change amount +e2B).

[0144] The measured voltages e1 and e2 are the total values of the change amounts due to these "stretching" deformation and "bending" deformation (concave on the upper side).

[0145] In each aspect shown in FIGS. 8 and 9, (1 / 2) of the difference between the measured voltages e1 and e2, that is, [(e1 - e2) / 2], indicates the voltage changes (e1B, e2B) of the sensor unit 20A due to the bending deformation of the cushion block 12C.

[0146] On the other hand, the difference between (1 / 2) of the sum of the measured voltages e1 and e2 and the voltage e0 in the steady state, that is, [{(e1 + e2) / 2} - e0], indicates the voltage change (es) of the sensor unit 20A due to the expansion and contraction deformation of the cushion block 12C.

[0147] The arithmetic circuit 20C calculates the voltage changes (e1B, e2B) of the sensor unit 20A due to the bending deformation of the cushion block 12C and the voltage change (es) of the sensor unit 20A due to the expansion and contraction deformation from the measured voltages e1 and e2 of the sensor unit 20A.

[0148] Furthermore, the arithmetic circuit 20C calculates a value representing the bending deformation state and the expansion and contraction deformation state of the cushion block 12C from these values (e1B, e2B, and es). The "value representing the bending deformation" is, for example, the curvature. The "value representing the expansion and contraction deformation state" is, for example, the amount of expansion (amount of shrinkage) from the steady state.

[0149] When calculating the values representing the bending deformation state and the stretching and shrinking deformation state of the cushion block 12C, first measure the shape of the cushion block 12C according to the voltage change in advance, obtain the conversion coefficient relating the two, and perform the conversion process based on the conversion coefficient.

[0150] [Calculation process] Next, with reference to FIG. 10, the calculation process by the calculation circuit 20C will be described. When a start signal is input from a measurement object control device (not shown) to the control device 20D (see FIG. 6), the control device 20D outputs the start signal to the calculation circuit 20C. Further, the calculation circuit 20C controls the signal measurement circuit 20B to apply a voltage to the upper surface sensor 21A and the lower surface sensor 21B.

[0151] When the calculation process is started, in step S102, the calculation circuit 20C acquires the measured voltages e0 of the upper surface sensor 21A and the lower surface sensor 21B in the steady state. The next step after step S102 is to shift to step S104.

[0152] In step S104, after acquiring the measured voltage e0, the calculation circuit 20C determines whether or not a predetermined time has elapsed. If the determination in step S104 is affirmative, the process shifts to step S106. On the other hand, if the determination in step S104 is negative, step S104 is repeatedly executed to wait for the elapse of the predetermined time.

[0153] In step S106, the calculation circuit 20C acquires the measured voltage e1 of the upper surface sensor 21A and the measured voltage e2 of the lower surface sensor 21B. The next step after step S106 is to shift to step S108.

[0154] In step S108, the calculation circuit 20C determines whether or not the measured voltage e1 and the measured voltage e2 have changed with respect to the measured voltage e0. If the determination in step S108 is affirmative, the process shifts to step S110. On the other hand, if the determination in step S108 is negative, the process returns to step S104.

[0155] In step S110, the arithmetic circuit 20C calculates the voltage changes (e1B, e2B, and es shown in FIGS. 8 and 9) of the sensor unit 20A from the measured voltages e0, e1, and e2. The next step after step S110 is to proceed to step S112.

[0156] In step S112, the arithmetic circuit 20C calculates the deformation state of the cushion block 12C, which is the object to be measured, from the voltage changes (e1B, e2B, and es shown in FIGS. 8 and 9) of the sensor unit 20A. The next step after step S112 is to proceed to step S114.

[0157] In step S114, the arithmetic circuit 20C transmits the deformation state of the cushion block 12C, which is the object to be measured, to the control device 20D. The next step after step S114 is to proceed to step S116. Note that the control device 20D controls the object-to-be-measured control device according to the acquired deformation state of the cushion block 12C.

[0158] In step S116, the arithmetic circuit 20C determines whether the end timing of the arithmetic processing has arrived. For example, when a stop signal is input from an object-to-be-measured control device (not shown) to the control device 20D, the control device 20D outputs an arithmetic stop signal to the arithmetic circuit 20C. With the acquisition of this arithmetic stop signal, the end timing of the arithmetic processing arrives. If an affirmative determination is made in step S116, the arithmetic processing ends. On the other hand, if a negative determination is made in step S116, the process returns to step S116.

[0159] (Adjustment of Contact Resistance) As described above, in the measuring device 40, the measuring device 40 is adjusted so that the amounts of change in the contact resistance of the upper surface sensor 21A and the lower surface sensor 21B due to "bending" are equal. Such adjustment of the contact resistance can be adjusted by the diameters of the upper thread 32A and the lower thread 32B and sewing parameters such as the feed amount and pitch, which are the sewing conditions of the zigzag stitch.

[0160] Also, the contact resistance can be adjusted by other parameters. For example, the contact resistance can be adjusted by setting the tension balance between the upper thread 32A and the lower thread 32B during sewing.

[0161] Specifically, even if the feeding amount and pitch of the zigzag stitch are the same, the lengths of the upper thread 32A and the lower thread 32B can be changed by adjusting the tension balance. For example, when the tension of the lower thread 32B is large, the upper thread 32A wraps around to the lower thread 32B side and the thread length becomes longer (see Fig. 14C).

[0162] Except for the fourth embodiment described later, it is desirable that the tensions of the upper thread 32A and the lower thread 32B be formed equally (see Fig. 14B). Thereby, it is easy to make the change amounts of the contact resistance associated with "bending" of each of the upper surface sensor 21A and the lower surface sensor 21B equal.

[0163] Also, for example, the contact resistance can be adjusted by changing sewing parameters such as the thicknesses of the upper thread 32A and the lower thread 32B and various conductive characteristics.

[0164] Note that desired characteristics can be obtained by adjusting various sewing parameters so that the characteristics of the upper surface sensor and the lower surface sensor are the same also with respect to the change amount of the contact resistance associated with "stretching and contracting".

[0165] If the tensions of the upper thread 32A and the lower thread 32B are different or due to differences in sewing parameters, when the changes in the contact resistance associated with the bending and stretching of each of the upper surface sensor 21A and the lower surface sensor 21B are different, it is preferable to appropriately correct the calculation results.

[0166] [Function and Effect] When the contact resistances of the upper thread 32A of the upper surface sensor 21A and the lower thread 32B of the lower surface sensor 21B change while a voltage is applied to the sensor unit 20A, the voltages acting on the upper thread 32A of the upper surface sensor 21A and the lower thread 32B of the lower surface sensor 21B change.

[0167] According to the measuring device 40 of the present embodiment, from the voltage changes (e1, e2) of the upper thread 32A of the upper surface sensor 21A and the lower thread 32B of the lower surface sensor 21B, the arithmetic circuit 20C calculates the measurement voltage change amount (es) due to the expansion and contraction deformation of the sensor unit and the voltage change amount (e1B, e2B) due to the bending deformation, respectively. Further, the arithmetic circuit 20C calculates values representing the bending deformation state and the expansion and contraction deformation state of the cushion block 12C from the voltage change amounts, respectively.

[0168] In this way, in the measuring device 40, even without using a bridge circuit, values representing the bending deformation state and the expansion and contraction deformation state of the object to be measured can be calculated respectively.

[0169] Also, in the measuring device 40, since the conductor is formed of a conductive thread, the gauge factor can be increased compared to a strain gauge using a metal wire or the like. As a result, as shown in FIG. 6, the signal switching unit 20B1 can be omitted, and voltage changes due to bending or expansion and contraction can be obtained by a simple voltage dividing circuit in which the upper surface sensor 21A and the lower surface sensor 21B are serially coupled with the fixed resistor RC. That is, the configuration of the signal measurement circuit 20B can be simplified.

[0170] <Third Embodiment> FIG. 11 shows a measuring device 50 of the third embodiment. In the measuring device 20 of the first embodiment and the measuring device 20 of the second embodiment, as outlined in FIG. 1B, two sensors 21 are arranged opposite to each other with the cushion block 12C interposed therebetween.

[0171] On the other hand, in the measuring device 50 of the third embodiment, as outlined in FIG. 1C, a plurality of sensors 21 are arranged on the upper surface of the cushion block 12C (in the same plane). In FIG. 1C, an example in which two sensors 21 are arranged side by side for each sensor unit 20A is shown, but as shown in FIG. 11, three or more sensors 21 may be arranged side by side. Further, the measuring device 50 can also be used by omitting the cushion block 12C.

[0172] In the sensor unit 20A of the measuring device 50, a sensor 21C with the lower thread 32B being a conductive thread and a sensor 21D with the upper thread 32A being a conductive thread are alternately sewn to the base material 30 with a space therebetween. In this way, the base material 30 can also be shared among a plurality of sensors 21.

[0173] Signal lines N1, N2,... are connected to the sensors 21C and 21D. Each of the signal lines N1, N2,... is connected to the signal terminals of the selection circuit 20B3 in the signal measurement circuit 20B.

[0174] By using the selection circuit 20B3, it is possible to select whether to connect a voltage source to the signal lines N1, N2,... to apply a voltage E, connect to the ground G via a fixed resistor Rc, or leave it electrically unconnected.

[0175] For example, a voltage source is connected to the signal line N1 to apply a voltage E, and the signal line N2 is connected to the input terminal ADIN of the analog-digital converter in the fixed resistor Rc and the signal control and measurement unit 20B2. At this time, the signal lines N3, N4,... other than the selected signal lines N1 and N2 are in an electrically unconnected state.

[0176] According to such an aspect, by switching the signal lines connected to the voltage source and the fixed resistor Rc, the measured voltages e1 and e2 of the sensors 21C and 21D can be individually input to the arithmetic circuit 20C.

[0177] Note that the method of respectively calculating the measured voltage change amount (es) due to the stretching and shrinking deformation of the sensor unit and the voltage change amounts (e1B, e2B) due to the bending deformation from the measured voltages e1 and e2 is the same as that in the second embodiment, and the description thereof is omitted.

[0178] [Operation and Effect] According to the measuring device 50 of the third embodiment, a sensor 21C with the lower thread 32B being a conductive thread and a sensor with the upper thread 32A being a conductive thread are alternately sewn to the base material 30.

[0179] If the base material 30 is bent and deformed so as to be convex upward, the conductive yarn of the lower yarn 32B in the sensor 21C is compressed. On the other hand, the conductive yarn of the upper yarn 32A in the sensor 21D adjacent to the sensor 21C is stretched.

[0180] Thereby, the arithmetic circuit 20C can calculate a value representing the bent deformation state of the base material 30 from the changes in the contact resistance of the lower yarn 32B compressed and the upper yarn 32A stretched in response to the bending deformation of the base material 30.

[0181] Here, let the section where the sensor 21C is arranged be section L1, and the section where the sensor 21D adjacent to the sensor 21C is arranged be section L2.

[0182] When the length of the section L1 and the section L2 is small with respect to the amount of bending (curvature) and the amount of expansion and contraction when the cushion block 12C is deformed, the amount of bending of the section L2 and the section L2 can be regarded as being substantially equal. On the other hand, the amount of expansion and contraction of the section L2 and the section L2 can also be regarded as being equal.

[0183] In such a case, the voltage changes e1B and e2B of the sensors 21C and 21D due to the bending deformation have equal absolute values and different signs. On the other hand, the voltage changes es of the sensors 21C and 21D due to the expansion and contraction deformation are equal to each other.

[0184] Therefore, by measuring the voltage changes in the section L1 and the section L2, it is possible to calculate a value representing the bent deformation state and the expansion and contraction deformation state of the cushion block 12C, similar to the measuring device 40 of the second embodiment.

[0185] Further, according to the measuring device 50 of such an aspect, since a plurality of sensors 21C and 21D can be formed by sewing them on a cloth which is the same base material 30, the sensor unit 20A can be disposed on clothing or the like. Thereby, it is possible to grasp the bent deformation state and the expansion and contraction deformation state of a human body or the like as a measurement object.

[0186] <Fourth Embodiment> FIG. 12 shows a measuring device 60 according to the fourth embodiment. In the measuring device 60, as outlined in FIG. 1C, a plurality of sensors 21 are arranged on the upper surface of the cushion block 12C.

[0187] In FIG. 1C, an example is shown in which two sensors 21 are arranged in parallel for each sensor unit 20A. However, in the present embodiment, as shown in FIG. 12, three or more sensors 21 are arranged. Further, the measuring device 60 can be used by omitting the cushion block 12C.

[0188] Specifically, the sensors 21E and 21F used in the measuring device 60 are sewing bodies using conductors for both the lower thread 32B and the upper thread 32A. Three sensors 21E are arranged in parallel at intervals, and these sensors 21E constitute a parallel arrangement portion F1. The sensors 21E are separated from each other.

[0189] On the other hand, five sensors 21F are arranged in series at intervals, and these sensors 21E constitute a series arrangement portion F2. In the present disclosure, when the sensors are arranged "at intervals", it means that the voltages applied to the respective sensors can be measured individually, and the conductors of adjacent sensors may be connected.

[0190] The number of sensors 21E arranged in parallel and the number of sensors 21F arranged in series can be appropriately changed respectively.

[0191] In the measuring device 60, this parallel arrangement portion F1 and series arrangement portion F2 are arranged alternately, and signal lines N1, N2,... are connected between the parallel arrangement portion F1 and the series arrangement portion F2.

[0192] (Elongation measurement unit) The deformed state due to the expansion and contraction of the object to be measured is calculated from the change in the contact resistance of the series arrangement portion F2 shown in FIG. 12.

[0193] A case where the object to be measured expands and contracts, and the contact resistance values of sensors 21E and 21F change will be described. Assume that the contact resistance values of sensors 21E and 21F are equal, the amount of expansion and contraction is equal, and the change in contact resistance due to expansion and contraction is also equal.

[0194] Let the contact resistance value of each of sensors 21E and 21F before the expansion and contraction of the object to be measured be R, and the contact resistance value of each of sensors 21E and 21F after the expansion and contraction be XR.

[0195] In this case, the contact resistance value of the parallel arrangement part F1 before expansion and contraction is (R / 3). On the other hand, the contact resistance value of the series arrangement part F2 is 5R. Also, the contact resistance value of the parallel arrangement part F1 after expansion and contraction is (XR / 3). On the other hand, the contact resistance value of the series arrangement part F2 is 5XR.

[0196] The ratio of the contact resistance value (XR / 3) of the parallel arrangement part F1 to the contact resistance value 5XR of the series arrangement part F2 after expansion and contraction is (1 / 15) = approximately 6.7%. That is, the change in contact resistance due to expansion and contraction deformation of the parallel arrangement part F1 is small, while the change in contact resistance due to expansion and contraction deformation of the series arrangement part F2 is large.

[0197] In this way, the change in contact resistance due to expansion and contraction deformation of the parallel arrangement part F1 is relatively small. For example, as shown in FIG. 13A, the change rate of contact resistance with respect to the elongation rate is small. On the other hand, the series arrangement part F2 has a relatively high sensitivity for grasping the expansion and contraction deformation state of the object to be measured. Therefore, the deformation state due to the expansion and contraction of the object to be measured can be calculated from the change in the contact resistance of the series arrangement part F2.

[0198] (Bending measurement part, tension of the sewn body) The deformation state due to the bending of the object to be measured can be calculated from the change in the contact resistance of the parallel arrangement part F1 shown in FIG. 12, which is based on the following principle.

[0199] In sensors 21E and 21F, the tensions of the lower thread 32B and the upper thread 32A forming the sewn body are different.

[0200] For example, in the example shown in FIG. 14A, the tension of the upper thread 32A is greater than the tension of the lower thread 32B. As a result, the lower thread 32B with a smaller tension is drawn toward the upper thread 32A with a larger tension, and the contact relationship between adjacent conductive threads is relatively dense for the lower thread 32B and sparse for the upper thread 32A.

[0201] Also, for example, in the example shown in FIG. 14B, the tension of the upper thread 32A and the tension of the lower thread 32B are in balance, and no density difference occurs between the upper thread 32A and the lower thread 32B.

[0202] Also, for example, in the example shown in FIG. 14C, the tension of the upper thread 32A is smaller than the tension of the lower thread 32B. As a result, the upper thread 32A with a smaller tension is drawn toward the lower thread 32B with a larger tension, and the contact relationship between adjacent conductive threads is relatively dense for the upper thread 32A and sparse for the lower thread 32B.

[0203] When the sensor 21 formed using the lower thread and the upper thread with different tensions is placed in contact with the measurement object, the change rate of the contact resistance of the sensor 21 is different depending on which side of the base material 30 is placed in contact with the measurement object. That is, when the thread interval is dense, the sensitivity to the deformation of the measurement object is higher than when it is sparse. FIG. 15 shows an example of the relationship between the change rate of the contact resistance with respect to deformation.

[0204] The curve K1 shows the change rate of the contact resistance of the sensor 21 when the measurement object is bent so that the sensor 21 side is convex. In this example, as the bending diameter of the measurement object decreases (that is, as the bending amount increases), the change rate of the contact resistance increases. That is, the contact resistance increases. In such a case, the influence of the change rate of the thread resistance on the pulled side is greater than the influence of the change rate of the thread resistance on the compressed side, so the resistance increases.

[0205] On the other hand, the curve K2 indicates the change rate of the contact resistance of the sensor 21 when it is bent so that the side of the sensor 21 is concave. In this example, as the bending diameter of the object to be measured decreases (that is, as the amount of bending increases), the change rate of the contact resistance decreases. That is, the contact resistance decreases. In such a case, since the influence of the change rate of the yarn resistance on the compressed side is greater than the influence of the change rate of the yarn resistance on the pulled side, the resistance decreases.

[0206] In the present embodiment, the tensions of the lower thread 32B and the upper thread 32A forming the sewn body are different in this way, and by using the sensor 21E in which both are conductors, the contact resistance changes with bending. Thereby, the deformed state due to the bending of the object to be measured can be calculated from the change in the contact resistance of the parallel arrangement portion F1 shown in FIG. 12.

[0207] [Operation and Effect] According to the measuring device 60 of the fourth embodiment, the sensor 21 is formed by using conductive yarns for the lower thread 32B and the upper thread 32A. The sensor unit 20A includes a parallel arrangement portion F1 in which a plurality of sensors 21E are arranged in parallel and a series arrangement portion F2 in which a plurality of sensors 21F are arranged in series.

[0208] If the fabric expands and contracts, the contact resistance of the series arrangement portion changes more greatly than the contact resistance of the parallel arrangement portion. Thereby, the calculation unit can calculate a value representing the expansion and contraction deformation state of the base material.

[0209] On the other hand, if the fabric is bent and deformed, the contact resistance of the parallel arrangement portion changes. At this time, in response to the bending deformation of the fabric, one of the lower thread and the upper thread is compressed and the contact resistance decreases, and the other is pulled and the contact resistance increases.

[0210] Here, in this aspect, the rate of change of the contact resistance according to the bending deformation of the fabric is different between the lower yarn and the upper yarn. That is, the rate of change of the contact resistance of the lower yarn and the upper yarn according to the bending deformation of the fabric is different. Therefore, the contact resistances of the lower yarn and the upper yarn are not canceled out, and according to the bending deformation of the fabric, the combined contact resistance of the lower yarn and the upper yarn changes at a predetermined ratio. Thereby, the calculation unit can calculate a value representing the bending deformation state of the base material from the change in the contact resistance of the conductor according to the bending deformation of the base material.

[0211] <Other Embodiments> In each of the above embodiments, for example, as shown in FIG. 2, the length between the folded-back portions of the conductive yarns forming the conductor 32 is constant. Therefore, the conductor 32 has a constant width in the direction (Y direction) intersecting the axial direction (X direction). However, the embodiments of the present disclosure are not limited to this, and the length between the folded-back portions of the conductive yarns forming the conductor 32 may be increased partially.

[0212] Also, in each of the above embodiments, the folding angle of the conductive yarns forming the conductor 32 is constant. However, the embodiments of the present disclosure are not limited to this, and the folding angle of the conductive yarns may be changed partially. That is, the width of the gap V1 and the area of the contact portion T1 shown in FIG. 3 may be changed partially.

[0213] By adjusting the length between the folded-back portions of the conductive yarns and the folding angle in this way, the influence caused by the sewing state and the non-uniform conductivity of the conductive yarns can be reduced.

[0214] Also, conductive yarns may be added partially to the conductor 32 in which the length between the folded-back portions of the conductive yarns and the folding angle are formed to be constant. By adding conductive yarns in contact with the conductor, the conductivity can be increased and the electrical resistance can be decreased.

[0215] Alternatively, conductive yarns may be thinned out partially from the conductor 32. When thinning out, the conductive yarns adjacent to the thinned-out section are connected to each other. By thinning out the conductive yarns, the conductivity can be lowered and the electrical resistance can be increased.

[0216] Further, in the above embodiment, the conductor 32 is formed of a conductive thread zigzag-sewn to the base material 30, but the embodiment of the present disclosure is not limited to this. For example, the conductor may be formed of a conductive rubber or film. Thus, as long as the electrical resistance changes according to the expansion / contraction and the density change due to the action of an external force, the configuration of the conductor is not particularly limited. Thus, the present disclosure can be implemented in various modes.

Explanation of Signs

[0217] 12A Cushion material (object to be measured) 12C Cushion block (object to be measured) 20 Measuring device 20A Sensor unit 20C Arithmetic circuit (arithmetic unit) 21 Sensor 21A Upper surface sensor (sensor) 21B Lower surface sensor (sensor) 21C Sensor 21D Sensor 21E Sensor 21F Sensor 30 Base material (fabric) 32 Conductor 32A Upper thread 32B Lower thread 40 Measuring device 50 Measuring device 60 Measuring device F1 Parallel arrangement part F2 Serial arrangement part

Claims

1. A plurality of sensors formed using a conductor that is fixed to a deformable base material in synchronization with the deformation of the object to be measured and whose contact resistance changes according to the shape change of the base material are arranged at intervals from each other in a sensor unit, an arithmetic unit that calculates values representing the bending deformation state and the stretching and contracting deformation state of the object to be measured from the change in the contact resistance of each of the sensors with a voltage applied to the sensor unit, A measuring device comprising.

2. The base material is a fabric, The conductor is a conductive thread, The sensor includes a sewn body using the conductive thread for one of the lower thread or the upper thread and a non-conductive thread for the other of the lower thread or the upper thread, The measuring device according to claim 1.

3. The sensor unit is The fabric on which the sensor with the upper thread being a conductive thread is sewn and fixed is arranged above the object to be measured, The fabric on which the sensor with the lower thread being a conductive thread is sewn and fixed is arranged below the object to be measured, The measuring device according to claim 2.

4. The sensor unit is The measuring device according to claim 2, formed by alternately arranging the sensor with the lower thread being a conductive thread and the sensor with the upper thread being a conductive thread on the fabric.

5. The base material is a fabric, The conductor is a conductive thread, The sensor is a sewn body using the conductive thread for both the lower thread and the upper thread, and the rate of change of the contact resistance according to the deformation of the fabric is different between the lower thread and the upper thread, The sensor unit is A parallel arrangement part in which a plurality of the sensors are arranged in parallel, A series arrangement part in which a plurality of the sensors are arranged in series, The measuring device according to claim 1.

6. A bridge circuit including two of the sensors, A signal switching unit capable of switching the bridge circuit between a two-active-gauge method connection and a two-active-gauge method connection for opposite sides, The measuring device according to any one of claims 1 to 3.

7. The arithmetic unit is From the change in the measurement voltage according to the change in the contact resistance of each of the two sensors, calculate the amount of change in the measurement voltage due to the stretching and contracting deformation of the sensor unit and the amount of change in the voltage due to the bending deformation respectively, From the amount of change in the voltage, calculate values representing the bending deformation state and the stretching and contracting deformation state of the object to be measured respectively, The measuring device according to any one of claims 1 to 4.

8. The arithmetic unit is From the change in the measurement voltage of the parallel arrangement part, calculate the amount of change in the voltage due to the bending deformation of the sensor unit, From the change in the measured voltage of the series arrangement unit, calculate the amount of voltage change due to the expansion and contraction deformation of the sensor unit. From the amount of voltage change, calculate values representing the bending deformation state and the expansion and contraction deformation state of the object to be measured, respectively. The measuring device according to claim 5.

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