JP7334986B2 - Detector and Condition Determining Device - Google Patents

Description

The present invention relates to a detection device, a condition identification device, and a measurement method.

2. Description of the Related Art Conventionally, there is known a technique of detecting displacement of a body surface with a plurality of sensors and detecting states such as respiration and heartbeat of a person. Patent Literature 1 discloses a driver monitoring device capable of monitoring the state of a vehicle driver by applying the technology of electrical impedance tomography (EIT) to seat belts.

JP 2017-136304 A

In the conventional technology, since a plurality of sensors are arranged on the seat belt, the seat belt is provided with wiring for transmitting and receiving signals for each of the plurality of sensors. However, since the seat belt has an elongated shape, if such wiring is arranged while maintaining insulation, the degree of freedom in layout of the plurality of sensors and wiring may be limited.

Therefore, the present invention has been made in view of these points, and provides a detection device, a state identification device, and a measurement method that can improve the degree of freedom in layout of a plurality of sensors and wiring connected to each sensor. With the goal.

A detection device according to a first aspect of the present invention is a detection device for detecting the impedance of each of a plurality of resistors connected in series, wherein each resistor forms a resonance circuit with a different resonance frequency, A predetermined electrical signal between a plurality of capacitive elements and a plurality of inductance elements connected in parallel with each of the plurality of resistors, and one end and the other end of a resistor group including the plurality of resistors an acquisition unit for acquiring output signals output by the plurality of resistors in response to the electrical signals from the one end and the other end; and performing frequency analysis on the output signals, and an analysis unit that calculates the impedance of each of the plurality of resistors.

The plurality of resistors are included in a plurality of regions of a band-shaped resistor formed in a strip shape, and the signal supply unit supplies the electric signal between the one end and the other end of the strip-shaped resistor. and the acquisition unit may acquire the output signal from the one end and the other end of the strip-shaped resistor.

The signal supply unit may output the electrical signals of a plurality of frequencies corresponding to a plurality of frequencies between a predetermined first frequency and a second frequency. The analysis unit measures the signal strength of the output signal when each of the resonance frequencies of a plurality of resonance circuits formed by the plurality of capacitive elements and the plurality of inductance elements matches the frequency of the electrical signal. The impedance may be calculated based on.

The signal supply unit may output a pulse signal having a predetermined pulse width as the electrical signal. The analysis unit may frequency-convert the output signal and calculate the impedance based on signal strengths at resonance frequencies of a plurality of resonance circuits formed by the plurality of capacitive elements and the plurality of inductance elements.

The plurality of resistors are provided on a bendable base, the impedance of which varies according to the curvature of the base, and the base, the plurality of capacitive elements, and the plurality of inductance elements are integrally formed. A belt-like structure may be used. The detection device may further include an attachment section for attaching the belt-like structure to a seat belt provided on the seat. The belt-shaped structure may be included in a seat belt provided on the seat.

A state identifying device according to a second aspect of the present invention comprises: a calculating unit that calculates the curvature of the seat belt based on the change in the impedance calculated by the detecting device; the analyzing unit; and a specifying unit that specifies the state of the user wearing the seat belt.

A measuring method according to a third aspect of the present invention is a measuring method for measuring the impedance of each of a plurality of resistors connected in series in a state in which resonance circuits are connected in parallel to each of the resistors. a step of supplying a predetermined electric signal between one end and the other end of a resistor group including the plurality of resistors; and outputting an output signal output by the plurality of resistors according to the electric signal, A measurement method is provided, comprising the steps of: acquiring from the one end and the other end; and calculating the impedance of each of the plurality of resistors by frequency-analyzing the output signal.

ADVANTAGE OF THE INVENTION According to this invention, it is effective in the degree of freedom of the layout of the wiring connected to several sensors and each sensor being able to be improved.

1 shows a configuration example of a state identification device 10 according to this embodiment. 1 shows a configuration example of a seat belt 100 according to this embodiment. 1 shows a configuration example of a detection device 200 according to this embodiment. An example of the output signal of the resistor group 206 acquired by the acquiring unit 230 according to the present embodiment is shown. An example of the operation flow of the detection device 200 according to the present embodiment is shown. A modification of the operation flow of the detection device 200 according to the present embodiment is shown. 3 shows a modification of the detection circuit 208 according to this embodiment. An example of a capacitive element 212 according to this embodiment is shown. An example of an inductance element 214 according to this embodiment is shown.

<Configuration example of state identification device 10>
FIG. 1 shows a configuration example of a state identification device 10 according to this embodiment. The condition identification device 10 identifies the physical condition of the user sitting on the seat 20 . The state identification device 10 includes a seat belt 100 , a detection device 200 , a calculation section 310 and an identification section 320 .

The seat belt 100 is provided on the seat 20 and fixed so as to contact the body of the user sitting on the seat 20 . The seat belt 100 functions to restrain the user in the seat 20 when, for example, the user is suddenly accelerated or decelerated. The seatbelt 100 has a plurality of sensors for detecting the physical condition of the user. Each of the multiple sensors is, for example, a sensor for measuring distortion of an object. In FIG. 1, the sensors are schematically indicated as E1 to E8. Such seat belt 100 will be described later.

The detection device 200 is connected to a plurality of sensors provided on the seat belt 100 and exchanges electric signals with the plurality of sensors. The detection device 200 detects, for example, changes in impedance of the resistors of the plurality of sensors, based on the transmitted and received electrical signals. At least part of the detection device 200 may be provided on the seat 20 and the seat belt 100 . The detection device 200 will be described later.

The calculator 310 calculates the curvature of the seat belt 100 in contact with the user's body based on the impedance change detected by the detector 200 . For example, it is preferable that the calculator 310 can sequentially calculate changes in the seat belt 100 over time.

The specifying unit 320 specifies the state of the user wearing the seatbelt 100 based on the curvature of the seatbelt 100 calculated by the calculating unit 310 . For example, the curvature of at least a portion of the seat belt 100 in contact with the user varies due to the user's breathing, heartbeat, and the like. If the user's respiration and heart rate are normal, the curvature of the seatbelt 100 changes in a substantially constant cycle and within a substantially constant amplitude range.

Therefore, the identification unit 320 analyzes curvatures at a plurality of positions of the seat belt 100 based on a plurality of sensors to identify the breathing and heartbeat states of the user. The identification unit 320 identifies the state of the user by comparing, for example, changes in the curvature of the seat belt 100 acquired in the past. Further, the identifying unit 320 may identify the user's condition by comparing one or more threshold values with the curvature variation of the seat belt 100 .

The condition identifying device 10 described above can identify the physical condition of the user who sits on the seat 20 and wears the seat belt 100 . Thereby, the state identification device 10 can identify the occurrence of abnormalities such as breathing and heartbeat of the user. Such a condition identification device 10 is mounted on a vehicle or the like, for example, and can identify the physical condition of a user sitting on a seat 20 of the vehicle. In this case, the state identification device 10 can be applied to a monitoring device or the like that controls the vehicle based on the identified state. For example, when the state identification device 10 identifies that the user's heartbeat has stopped, the state identification device 10 controls the control device or the like to stop the engine of the vehicle.

As described above, the state identification device 10 can be used for, for example, people riding in vehicles such as cars, trains, and airplanes, people sitting in chairs such as movie theaters, theaters, and playgrounds, people riding in wheelchairs, and people sleeping in beds, beds, and the like. It is possible to identify the physical condition of a person who is wearing a mask and monitor the presence or absence of abnormalities. The seat belt 100 of the state identifying device 10 will be described below.

<Configuration example of seat belt 100>
FIG. 2 shows a configuration example of the seat belt 100 according to this embodiment. FIG. 2 is an example of a plan view of the seat belt 100. FIG. The seat belt 100 has a belt portion 110 , a belt-like structure 120 and a mounting portion 130 .

The belt portion 110 is formed in a belt shape and worn so as to come into contact with the user. One end of the belt portion 110 is, for example, fixed to the seat 20 or the vehicle to which the seat 20 is fixed. In this case, the other end of the belt portion 110 is detachably fitted to a fixture or the like provided on the seat 20 or the vehicle or the like to which the seat 20 is fixed. The belt portion 110 has, for example, a cloth-like material processed with fibers or the like.

The belt-like structure 120 is attached to the belt portion 110 . The band-shaped structure 120 is provided with a plurality of sensors for measuring changes in the curvature of the belt portion 110 according to the user's body movements. Also, the belt-like structure 120 is provided with wiring, electronic parts, and the like for exchanging electrical signals with each of the plurality of sensors. The belt-like structure 120 functions as a sheet-like module in which a plurality of sensors, electronic components, etc. are integrally formed, for example. The strip-shaped structure 120 will be described later.

The mounting portion 130 is a portion for mounting the belt-like structure 120 on the seat belt 100 provided on the seat 20 . That is, the belt-shaped structure 120 is provided so as to be separable from the seat belt 100 . The mounting portion 130 only needs to fix the strip-shaped structure 120 to the belt portion 110 , and is provided on such a strip-shaped structure 120 , for example. Alternatively, the mounting portion 130 may be provided separately from the belt portion 110 and the belt-like structure 120 or may be provided on the belt portion 110 .

The mounting section 130 fixes the strip-shaped structure 120 so that the plurality of sensors provided on the strip-shaped structure 120 can detect changes in the curvature of the belt section 110 according to the movement of the user's body. The mounting part 130 includes members for fixing the belt-like structure 120, such as belts, buttons, and fasteners. Moreover, the mounting portion 130 may have a belt-like shape that covers the circumference of the belt portion 110 in the lateral direction of the belt portion 110 .

The above-described seat belt 100 makes it possible to directly or indirectly contact the belt-shaped structure 120 with the user to detect the physical state of the user. The band-shaped structure 120 contacts the user's chest, for example. It is desirable that such a band-like structure 120 allows the sensors to contact a plurality of different parts of the user's body. In this case, in each sensor, the wiring for receiving the power supply and the wiring for outputting the detection result to the outside are connected while maintaining insulation from other wirings.

However, since the belt-like structure 120 has a long structure with a width approximately equal to the width of the belt portion 110, it may be difficult to lay out the plurality of sensors and the wiring connected to each of the plurality of sensors. Therefore, the detection device 200 according to the present embodiment uses a plurality of sensors connected in series, and electrically connects to sensors at both ends of the connection among the plurality of sensors to exchange signals, thereby reducing complexity. The detection result of each of the plurality of sensors is calculated while omitting the electrical wiring. Such a detection device 200 will be described below.

<Configuration Example of Detection Device 200 Using Individual Resistor 202>
FIG. 3 shows a configuration example of a detection device 200 according to this embodiment. The detection device 200 detects the impedance of each of the plurality of resistors 202 provided on the strip-shaped structure 120 . FIG. 3 shows an example in which a plurality of resistors 202 are used as the plurality of sensors of the strip-shaped structure 120 . The strip-shaped structure 120 has, for example, a base 204 and a plurality of resistors 202 are formed on the base 204 . The plurality of resistors 202 may be provided on one side of the base 204 or alternatively on both sides of the base 204 . Here, the number of resistors 202 is n, and the impedance of each resistor is _Rn .

The base 204 is made of a bendable material. The substrate 204 is desirably made of an insulating material. Substrate 204 is, for example, a flexible substrate. Such a base 204 is bent with a curvature corresponding to the shape of the user's body when the belt-shaped structure 120 contacts the user. Further, when the surface of the user's body fluctuates due to breathing or the like of the user, the base 204 is bent so as to have a curvature corresponding to the fluctuation. For example, the user's breathing and heartbeat displace the user's chest, and the substrate 204 is bent to a curvature corresponding to the displacement. The plurality of resistors 202 provided on the substrate 204 are formed so that their resistance values change according to the curvature of the substrate 204 when a DC signal is applied. Moreover, the resistor 202 is formed so that the impedance changes when an AC signal is applied. The resistor 202 is, for example, an element mainly having a resistance component.

The plurality of resistors 202 are, for example, thin films or the like provided on the base 204, and the impedance changes according to the bending of the base 204 and the generation of strain. The multiple resistors 202 include metal, semiconductor, or the like. It should be noted that the plurality of resistors 202 are desirably strain gauges capable of detecting the strain of the substrate 204 . Each of the multiple resistors 202 is connected in series. The detection device 200 detects the impedance of each of the plurality of resistors 202 connected in series. The detection device 200 includes a plurality of capacitive elements 212 , a plurality of inductance elements 214 , a signal supply section 220 , an acquisition section 230 , a storage section 240 , an analysis section 250 and a control section 260 .

A plurality of capacitive elements 212 and a plurality of inductance elements 214 are connected in parallel with each of the plurality of resistors 202 . For example, one capacitive element 212 and one inductive element 214 are connected in parallel with one resistor 202 to form one resonant circuit. In this case, the multiple capacitive elements 212 are connected in series. Similarly, multiple inductance elements 214 are also connected in series. Here, the number of the plurality of capacitive elements 212 is n, and the capacitance value of each is _Cn . Let n be the number of the plurality of inductance elements 214, and _Ln be the inductance value of each.

FIG. 3 shows an example in which a set of one capacitive element 212 and one inductive element 214 is provided for each resistor 202 to form n resonant circuits, the same number as n resistors 202 . In this case, like the n resistors 202, the n capacitive elements 212 are connected in series, and the n inductive elements 214 are also connected in series. In this case, n resonant circuits each formed of the n-th resistor 202, capacitive element 212 and inductive element 214 are connected in series. A detector circuit 208 is made up of n resonant circuits connected in series. Note that the detection circuit 208 may be covered with a protective film such as resin.

Here, the element constants and the like of the plurality of capacitive elements 212 and the plurality of inductance elements 214 are predetermined so that each resistor 202 forms a resonance circuit with a different resonance frequency. For example, the plurality of capacitive elements 212 and the plurality of inductive elements 214 form n resonant circuits to have n resonant frequencies. Here, let n resonance frequencies be f _RESn . Such a plurality of capacitive elements 212 and a plurality of inductive elements 214 are preferably formed in the strip-like structure 120 . In this case, the belt-shaped structure 120 functions as a module in which the substrate 204, the plurality of capacitive elements 212, and the plurality of inductive elements 214 are integrally formed, for example.

The signal supply unit 220 supplies a predetermined electrical signal between one end and the other end of a resistor group 206 including a plurality of resistors 202 . Here, a plurality of resistors 202 connected in series are used as a resistor group 206 . The signal supply unit 220 is connected to, for example, a resonance circuit at one end and a resonance circuit at the other end of a plurality of resonance circuits connected in series, and supplies electric signals to all the resonance circuits. FIG. 3 shows an example in which the signal supply unit 220 is connected to the first resonant circuit and the n-th resonant circuit among n resonant circuits connected in series. As such, the signal provider 220 provides an electrical signal to the detection circuit 208 .

The signal supply unit 220 sequentially outputs a plurality of electric signals having a plurality of frequencies between a predetermined first frequency and a second frequency, for example. The first frequency and the second frequency are predetermined such that the resonance frequency of each of the plurality of resonance circuits is included between the first frequency and the second frequency. Therefore, the first frequency is a frequency lower than the lowest frequency of the plurality of resonance frequencies, and the second frequency is a frequency higher than the highest frequency of the plurality of resonance frequencies. The signal supply unit 220 outputs an electrical signal having predetermined maximum and minimum amplitude strength values.

Here, the amplitude intensity is a voltage value or a current value. For example, if the frequency of the electrical signal output by the signal supply unit 220 is f _IN , the electrical signal is I _IN ·cos(2π·f _IN ·t+θ ₀ )+C ₀ or V _IN ·cos(2π·f _IN ·t+θ ₀ )+C ₀ . Here, I _IN is the amplitude intensity of a predetermined current value, V _IN is the amplitude intensity of a predetermined voltage value, θ ₀ , θ ₁ , C ₀ , and C ₁ are initial constants, and t is time. .

The acquisition unit 230 acquires output signals output by the plurality of resistors 202 according to electrical signals from one end and the other end of the resistor group 206 . The obtaining unit 230 obtains, for example, output signals of a plurality of frequencies between a first frequency and a second frequency output by the plurality of resistors 202 . The acquiring unit 230 has an AD converter, for example, and acquires information on the amplitude value of the output signal.

Storage unit 240 stores the signal acquired by acquisition unit 230 . The storage unit 240 may also store information such as setting values of the detection device 200 . In addition, the storage unit 240 may store intermediate data generated (or used) in the process of operation of the detection device 200, calculation results, thresholds, parameters, and the like. Further, the storage unit 240 may supply the stored data to the request source in response to a request from each unit in the detection device 200 .

The analysis unit 250 calculates the impedance of each of the resistors 202 by frequency-analyzing the output signal. For example, when each of the resonance frequencies of a plurality of resonance circuits formed by a plurality of capacitive elements 212 and a plurality of inductance elements 214 matches the frequency of the output signal acquired by the acquisition section 230, the analysis section 250 The impedance is calculated based on the signal strength of the output signal at .

For example, let the impedance of the first resistor 202 be R ₁ , and let the resonance frequency of the first resonance circuit including the first resistor 202 be f _RES1 . In this case, in a state in which the signal supply unit 220 supplies an electrical signal substantially matching the resonance frequency f _RES1 to the resistor group 206, based on the output signal of the frequency f _RES1 output by the resistor group 206, the analysis unit 250 , the impedance _R1 of the resistor 202 is calculated. Since the signal supply unit 220 sweeps the frequency f _IN of the electrical signal, the analysis unit 250 generates the output signal of the resistor group 206 each time the frequency f _IN of the output signal matches one of the plurality of resonance frequencies f _RESn . may sequentially calculate the impedance based on the intensity of

Control unit 260 controls operations of signal supply unit 220 , acquisition unit 230 , storage unit 240 , and analysis unit 250 . The control unit 260 controls, for example, the timing at which the signal supply unit 220 supplies an electrical signal to the resistor group 206, the timing at which the acquisition unit 230 acquires an output signal from the resistor group 206, and the timing at which the analysis unit 250 analyzes the output signal. to control. The control unit 260 is, for example, a CPU (Central Processing Unit).

<Example of Output Signal of Resistor Group 206>
FIG. 4 shows an example of the output signal of the resistor group 206 acquired by the acquisition unit 230 according to this embodiment. In FIG. 4, the horizontal axis indicates frequency, and the vertical axis indicates impedance. For example, when the signal supply unit 220 outputs an electrical signal I _IN ·cos(2π·f _IN ·t+θ ₀ )+C ₀ having predetermined maximum and minimum current values, the acquisition unit 230 outputs impedance to obtain the amplitude value of the voltage of the output signal according to Further, when the signal supply unit 220 outputs the electrical signal V _IN ·cos(2π·f _IN ·t+θ ₁ )+C ₁ having predetermined maximum and minimum voltage values, the acquisition unit 230 outputs the impedance to obtain the amplitude value of the current of the output signal according to FIG. 4 shows an example in which the acquisition unit 230 acquires the amplitude value of the voltage of the output signal.

As shown in FIG. 4, the output signal acquired by acquisition section 230 has a plurality of extreme values. A plurality of extrema occur at frequencies that substantially coincide with each of the resonant frequencies f _RESn of the plurality of resonant circuits. For example, if the frequency _fIN of the electrical signal output by the signal supply unit 220 does not match any of the multiple resonance frequencies _fRESn , most of the electrical signal passes through the multiple capacitive elements 212 connected in series. do. That is, the impedance of the entire resonator circuits arranged in series is reduced, almost no current flows through the resistor group 206, and the acquisition unit 230 acquires an output signal with a reduced amplitude value.

On the other hand, consider a case where the frequency f _IN of the electrical signal output by the signal supply unit 220 substantially matches the k-th resonance frequency f _RESk . Here, since each resonant circuit constitutes an RCL parallel resonant circuit having one resistor, one capacitor, and one inductance, the resonant frequency f _RESk of the k-th resonant circuit is 1/{2π·(L _k ·C _k ) ^1/2 }. If the frequency f _IN approximately coincides with such a resonant frequency f _RESk , most of the electrical signal will pass through the resistor 202 in the kth resonant circuit.

In the n−1 resonant circuits other than the k-th resonant circuit, since the resonant frequency does not match the frequency f _IN of the electrical signal, almost no current flows through the resistor 202 included in each resonator. passes through the capacitive element 212 . Therefore, the impedance of the entire resonator circuits arranged in series is substantially equal to the impedance RES _k of the k-th resistor 202 included in the k-th resonance circuit. That is, the acquisition unit 230 acquires an output signal whose amplitude value corresponds to the impedance RES _k . The obtaining unit 230 obtains, for example, an extreme value whose amplitude value corresponds to I _IN ·RES _k . Therefore, the analysis unit 250 can calculate the impedance RES _k of the k-th resistor 202 based on the amplitude value.

For example, when the resonance frequencies f _RESn of the n resonance circuits are all different frequencies, the signal supply unit 220 sweeps the frequencies from the first frequency to the second frequency to generate an electric signal, so that the acquisition unit 230 n extreme values are observed in the obtained output signal. Therefore, the analysis unit 250 can calculate the impedances R _n of the n resistors 202 based on the amplitude values of the n extrema.

As described above, in the detection device 200 according to the present embodiment, the capacitive element 212 and the inductance element 214 are arranged in parallel for each resistor 202 so that each of the n resistors 202 forms a part of the resonant circuit. do. As a result, the detection device 200 according to the present embodiment can detect the impedance _Rn of the n resistors 202 without providing wiring for detecting impedance in each of the n resistors 202. can be done. Therefore, according to such a detection device 200, the degree of freedom of layout in the substrate 204 on which the plurality of resistors 202 functioning as sensors are mounted is improved, and the belt-shaped structure 120 that can be attached to the seat belt 100 can be easily manufactured. realizable. The operation of such detection device 200 will be described below.

<First Example of Operation Flow of Detecting Device 200>
FIG. 5 shows an example of the operation flow of the detection device 200 according to this embodiment. The detection device 200 detects the impedance of each of the plurality of resistors 202 provided on the strip-shaped structure 120 by executing the operations from S410 to S450 in FIG. Before the detection operation of the detection device 200, the user sitting on the seat 20 fastens the seat belt 100 so that at least a part of the belt-like structure 120 attached to the seat belt 100 contacts the user. and

First, in S<b>410 , the control unit 260 causes the signal supply unit 220 to supply an electrical signal to the detection circuit 208 . Note that the frequency of the electrical signal at the time when the detection device 200 starts detection is the first frequency.

Next, in S<b>420 , the control unit 260 causes the acquisition unit 230 to acquire the output signal from the detection circuit 208 . Acquisition section 230 stores the acquired output signal in storage section 240 . It is desirable that the acquisition unit 230 stores the output signal in association with information on the frequency of the output signal.

Next, in S430, the control unit 260 confirms whether or not the frequency of the electrical signal output by the signal supply unit 220 is the second frequency. If the frequency is not the second frequency (S430: No), the control unit 260 proceeds to S440 and causes the signal supply unit 220 to continue the frequency sweep.

That is, in S440, the control section 260 sweeps the frequency of the electrical signal output from the signal supply section 220 from the first frequency toward the second frequency. Here, the amount of change in frequency is, for example, a predetermined amount of change. The predetermined amount of change may be a constant value, or alternatively, it may be determined such that the amount of change decreases when approaching one of the resonant frequencies f _RESn of the resonant circuit. Then, the control unit 260 returns to S410 and repeats the supply of the electric signal to the detection circuit 208 and the acquisition of the output signal from the resistor group 206 .

Also, in S430, if the frequency is the second frequency (S430: Yes), the control unit 260 terminates the frequency sweep and the acquisition of the output signal, and proceeds to S450. In this case, information of an output signal having a plurality of extreme values as shown in FIG. 4 is stored in the storage unit 240 .

Next, in S450, the control unit 260 causes the analysis unit 250 to frequency-analyze the output signal. The analysis unit 250 calculates the impedance of the corresponding resistor 202 for each extreme value of the output signal. Note that the frequency analysis by the analysis unit 250 has been described with reference to FIG. 4 and the like, so description thereof will be omitted here.

As described above, the detection device 200 according to the present embodiment performs frequency analysis by supplying an electric signal to the detection circuit 208 having a plurality of resistors 202 connected in series, thereby enabling simple wiring connection. The impedance of each resistor 202 can be detected. In FIG. 5, an example in which the control unit 260 causes the signal supply unit 220 to output an electrical signal while sweeping the frequency and causes the acquisition unit 230 to acquire the output signal has been described, but the present invention is not limited to this. . Alternatively, the control unit 260 causes the signal supply unit 220 to output an electric signal while sweeping the frequency, and confirms that the output signal based on the electric signal substantially coincides with one resonance frequency or that the output signal has a peak. The analysis unit 250 may be caused to analyze the output signal in response to the detection of .

<Example where the electric signal is a pulse signal>
Moreover, although the detection device 200 according to the present embodiment has been described as an example in which the signal supply unit 220 outputs a plurality of electrical signals having different frequencies, the detection device 200 is not limited to this. The signal supply section 220 may output a pulse signal having a predetermined pulse width as an electrical signal. Here, when the pulse signal is transformed on the frequency axis by Fourier transform or the like, the pulse width and peak value are such that the frequency band between the first frequency and the second frequency has a signal component equal to or greater than a threshold value. is preferably predetermined.

Since such a pulse signal substantially includes a plurality of frequency components, for example, one pulse signal is supplied to the detection circuit 208, and the output signal from the detection circuit 208 corresponding to the pulse signal is output as a frequency component. By transforming, an output signal having multiple extrema as shown in FIG. 4 can be obtained. Therefore, the analysis unit 250 frequency-converts the output signal, and then calculates the impedances of the plurality of resistors 202 based on the signal intensities at the resonance frequencies of the plurality of resonance circuits. The operation of such detection device 200 will be described below.

<Second Example of Operation Flow of Detecting Device 200>
FIG. 6 shows a modification of the operation flow of the detection device 200 according to this embodiment. The detection device 200 detects the impedance of each of the plurality of resistors 202 provided on the strip-shaped structure 120 by executing the operations from S510 to S540 in FIG. Also in the operation flow of the modified example, it is assumed that the user sitting on the seat 20 fastens the seat belt 100 before the detection operation of the detection device 200 .

First, in S510, the control unit 260 causes the signal supply unit 220 to supply the pulse signal to the detection circuit 208 as an electric signal. Next, in S<b>520 , the control section 260 causes the acquisition section 230 to acquire the output signal from the detection circuit 208 . Next, in S530, the control unit 260 causes the analysis unit 250 to frequency-convert the output signal. For example, the analysis unit 250 may frequency-convert the output signal from the detection circuit 208 acquired by the acquisition unit 230 by FFT. Next, in S540, the control unit 260 causes the analysis unit 250 to frequency-analyze the output signal. The analysis unit 250 calculates the impedance of the corresponding resistor 202 for each extreme value of the output signal. The detection device 200 can acquire the output signal from the detection circuit 208 in a shorter time by such an impulse response using a finite pulse width.

An example in which the belt-like structure 120 is attached to the seat belt 100 in the detection device 200 according to the present embodiment has been described above. Accordingly, by attaching the belt-shaped structure 120 to the seat belt 100 of the conventional seat 20 that does not function as the detection device 200, the state of the user sitting on the seat 20 can be detected. In addition, as long as the band-shaped structure 120 can detect the movement of the user's body, the configuration is not limited to this. The belt-shaped structure 120 may be included in the seat belt 100 provided on the seat 20 .

The belt-shaped structure 120 may be formed as part of the belt portion 110, for example. In this case, the strip-shaped structure 120 may be fixed to the belt portion 110 . Instead of this, the members forming the belt-shaped structure 120 may be fixed to the belt portion 110 . Also, a plurality of resistors 202 , a plurality of capacitive elements 212 , a plurality of inductance elements 214 , and wiring connecting them may be provided on the belt portion 110 . By fixing the plurality of resistors 202 functioning as sensors to the belt portion 110 in this manner, the plurality of resistors 202 can be easily positioned at positions where variations in the user's body can be detected.

Also, in the detection device 200 according to the present embodiment described above, an example in which each of the plurality of resistors 202 is an independent member has been described, but the present invention is not limited to this. Each resistor 202 may be part of one or more group resistors. For example, the plurality of resistors 202 may be included in a plurality of regions of a band-shaped resistor.

<Detection Circuit 208 Using Band-shaped Resistor 210>
FIG. 7 shows a modification of the detection circuit 208 according to this embodiment. In the detection circuit 208 of the modified example shown in FIG. 7, the same reference numerals are given to the parts that are substantially the same as the operation of the detection circuit 208 shown in FIG. 3, and the description thereof is omitted. A modified detection circuit 208 has a resistor strip 210 that includes a plurality of resistors 202 .

In the strip-shaped resistor 210 , for example, electric wirings are connected to positions dividing the respective resistors 202 in the longitudinal direction of the strip-shaped resistor 210 . A plurality of capacitive elements 212 and a plurality of inductive elements 214 are connected to the electric wiring so as to correspond to each other. Thereby, a circuit equivalent to the detection circuit 208 shown in FIG. 3 can be constructed. In this case, the signal supply section 220 supplies an electrical signal between one end and the other end of the strip resistor 210, and the acquisition section 230 acquires an output signal from one end and the other end of the strip resistor 210. FIG.

Thereby, the analysis unit 250 can calculate the impedance for each region obtained by dividing the band-shaped resistor 210 into a plurality of regions. That is, the plurality of resistors 202 can be formed as, for example, one band-shaped resistor 210 instead of corresponding independent elements, so that the detection circuit 208 can be configured more simply.

Moreover, since the detection circuit 208 according to the present embodiment described with reference to FIGS. 3 and 7 does not require a power supply circuit, the degree of freedom in designing the detection device 200 can be improved. For example, by forming the strip-shaped structure 120 as an independent module and connecting the strip-shaped structure 120 with the signal supply unit 220 and the acquisition unit 230 by wire, the strip-shaped structure 120 does not include a power supply circuit. It can be a simple module.

Alternatively, for example, the strip-shaped structure 120 may be formed as an independent module, and the strip-shaped structure 120 may be wirelessly connected to the signal supply section 220 and the acquisition section 230 . In this case, the strip-shaped structure 120 may further include a circuit for transmitting and receiving an electric signal to be supplied to the detection circuit 208 and an output signal from the detection circuit 208, and the detection circuit 208 may be of a simple configuration. .

In this way, when the belt-shaped structure 120 is formed as an independent module, the signal supply unit 220, the acquisition unit 230, the storage unit 240, the analysis unit 250, the control unit 260, etc. are provided at positions different from the seat belt 100. can be At least part of the detection device 200 is desirably housed integrally, for example, in the lower part of the seat 20 or the like. Further, when configuring the state identification device 10 described in FIG. It may be integrally formed with at least a portion of 320 .

<Example of band-shaped resistor 210 made of fiber>
When the belt-shaped structure 120 is formed of fibers such as cloth, or included in the fibers of the seat belt 100, a plurality of resistors 202, a plurality of capacitive elements 212, a plurality of inductance elements 214, and at least a portion of the wiring connecting them may contain fibers. For example, the resistor 202 may be formed by attaching, adsorbing, bonding, or printing a resistive material to a fabric; alternatively, the resistor 202 may be formed by attaching, adsorbing, bonding, or printing a resistive material. The fibers may be woven into the fibers of the belt-shaped structure 120 .

In addition, for example, the capacitive element 212 is formed by weaving capacitive fibers in which a conductive material is attached, adsorbed, bonded, or printed at a plurality of locations into cloth. An example of such a capacitive element 212 is shown in FIG. Capacitive element 212 includes non-conductive fibers 332 and conductive material 334 . Non-conductive fibers 332 are, for example, polymers or the like. Alternatively, the non-conductive fibers 332 may be elastic, such as rubber. Also, the conductive material 334 is a conductive film or the like. Alternatively, the conductive material 334 may be formed by applying conductive ink or the like containing a conductive material. Also, the capacitive element 212 may be formed by combining one or more non-conductive fibers 332 and one or more conductive fibers.

In addition, for example, the inductance element 214 is formed by weaving a conductive fiber wound around an insulating material into a cloth. Conductive fibers can be, for example, fibers formed by attaching, adsorbing, bonding, or printing conductive material to one or more locations. An example of such an inductance element 214 is shown in FIG. Inductance element 214 includes non-conductive fibers 336 and conductive fibers 338 . Non-conductive fibers 336 are elastic such as polymers or rubbers. The conductive fibers 338 are fibers to which a conductive material is attached and which have conductivity. The constant of the inductance element 214 can be determined according to the number of turns, diameter, length, etc. of the conductive fiber 338 .

Also, for example, the wiring is a conductive fiber. Conductive fibers are fibers to which a conductive material is attached and which have electrical conductivity. As described above, the plurality of resistors 202, the plurality of capacitive elements 212, the plurality of inductance elements 214, and at least part of the wiring connecting them can be formed using fibers. Therefore, since these elements can be woven into the strip-shaped structure 120, the strip-shaped structure 120 can be configured easily. In this case, the substrate 204 may be omitted. Also, at least part of the strip-shaped structure 120 may be formed by printing a conductive material and a non-conductive material.

At least part of the state identifying device 10 according to the present embodiment described above is, for example, a computer or the like. The computer functions as at least part of the acquisition unit 230, the analysis unit 250, the control unit 260, the calculation unit 310, and the identification unit 320 according to the present embodiment, for example, by executing a program or the like.

The computer includes a processor such as a CPU, and functions as at least part of the acquisition unit 230, the analysis unit 250, the control unit 260, the calculation unit 310, and the identification unit 320 by executing the programs stored in the storage unit 240. do. The computer may further include a GPU (Graphics Processing Unit) or the like.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist thereof. be. For example, specific embodiments of device distribution/integration are not limited to the above-described embodiments. can be done. In addition, new embodiments resulting from arbitrary combinations of multiple embodiments are also included in the embodiments of the present invention. The effect of the new embodiment caused by the combination has the effect of the original embodiment.

For example, in the above description, the belt-shaped structure 120 is provided on the seat belt 100 to identify the user's body condition, but the configuration and application of the belt-shaped structure 120 are not limited to this. The present invention can be applied to any form of belt-like structure 120 that can be worn on the human body. The present invention can also be applied to a measuring apparatus that measures the impedance of devices connected in series with a simple configuration.

10 State identification device 20 Seat 100 Seat belt 110 Belt portion 120 Strip structure 130 Mounting portion 200 Detection device 202 Resistor 204 Base 206 Resistor group 208 Detection circuit 210 Strip resistor 212 Capacitance element 214 Inductance element 220 Signal supply unit 230 Acquisition Unit 240 Storage unit 250 Analysis unit 260 Control unit 310 Calculation unit 320 Identification unit 332 Non-conductive fiber 334 Conductive material 336 Non-conductive fiber 338 Conductive fiber

Claims (8)

A detection device for detecting the impedance of each of a plurality of resistors connected in series,
a band-shaped resistor formed in an integral band shape so as to have the plurality of resistors in the longitudinal direction;
The plurality of resistors are connected to an electric wiring connected to a position that divides the band-shaped resistor into the plurality of resistors in the longitudinal direction so that each resistor forms a resonance circuit having a different resonance frequency. a plurality of capacitive elements and a plurality of inductive elements connected in parallel with each of the bodies;
a signal supply unit that supplies a predetermined electrical signal between one end and the other end of the band-shaped resistor including the plurality of resistors;
an acquisition unit configured to acquire, from the one end and the other end, an output signal output by the strip-shaped resistor in response to the electrical signal;
an analysis unit that calculates the impedance of each of the plurality of resistors by frequency-analyzing the output signal,
The plurality of resistors included in the strip-shaped resistor are provided on a bendable base, and have impedances that change according to the curvature of the base,
the base, the plurality of capacitive elements, and the plurality of inductance elements are band-shaped structures integrally formed,
The strip-shaped structure further comprises an attachment portion for attaching the strip-shaped structure to a seat belt provided on the seat, and is separable from the seat belt.
detection device. 2. The detection device according to claim 1 , wherein said signal supply unit outputs said electrical signals of a plurality of frequencies corresponding to a plurality of frequencies between a predetermined first frequency and a second frequency. The analysis unit measures the signal strength of the output signal when each of the resonance frequencies of a plurality of resonance circuits formed by the plurality of capacitive elements and the plurality of inductance elements matches the frequency of the electrical signal. 3. The detection device according to claim 2 , wherein said impedance is calculated based on . 2. The detection device according to claim 1 , wherein said signal supply unit outputs a pulse signal having a predetermined pulse width as said electrical signal. The analysis unit frequency-converts the output signal, and calculates the impedance based on the signal intensity at the resonance frequency of a plurality of resonance circuits formed by the plurality of capacitive elements and the plurality of inductance elements. 5. The detection device according to 4 . The belt-like structure is a cloth made of fibers,
The plurality of resistors, the plurality of capacitive elements, the plurality of inductance elements, and the connection wiring are formed of fibers that can be woven into the strip-shaped structure,
6. A detection device according to any one of claims 1-5 . The plurality of capacitive elements have a non-conductive fiber and a conductive material provided on the non-conductive fiber,
The conductive material is provided on the non-conductive fibers so as to form two opposing electrodes by stretching in the stretching direction of the non-conductive fibers.
7. A detection device according to claim 6. a detection device according to any one of claims 1 to 7;
a calculation unit that calculates the curvature of the seat belt based on the change in the impedance calculated by the analysis unit;
and a state identification device that identifies a state of a user wearing the seat belt based on the curvature of the seat belt.

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