WO2023149497A1 - Sensor device and sensor device determination method - Google Patents

Sensor device and sensor device determination method Download PDF

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Publication number
WO2023149497A1
WO2023149497A1 PCT/JP2023/003364 JP2023003364W WO2023149497A1 WO 2023149497 A1 WO2023149497 A1 WO 2023149497A1 JP 2023003364 W JP2023003364 W JP 2023003364W WO 2023149497 A1 WO2023149497 A1 WO 2023149497A1
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signal
monitoring
thermal noise
sensor device
unit
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PCT/JP2023/003364
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French (fr)
Japanese (ja)
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岳志 森
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パナソニックＩｐマネジメント株式会社
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Publication of WO2023149497A1 publication Critical patent/WO2023149497A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
    • G01C19/56—Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
    • G01C19/5776—Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719

Definitions

  • the present disclosure generally relates to sensor devices and methods for determining sensor devices. More particularly, the present disclosure relates to a sensor device that includes a sensing element that detects stress, and a determination method for the sensor device.
  • US 2004/0010001 discloses an acceleration sensor with at least one micromechanical sensor element for detecting acceleration and an electronic evaluation unit with redundant signal paths with an A/D converter each for each sensor element.
  • a sensor is disclosed.
  • the acceleration sensor is provided with monitoring means for monitoring parameters relating to the functionality of the A/D converter of the electronic evaluation unit.
  • the monitoring means comprise an equivalent circuit for the sensor elements integrated in the electronic evaluation unit and redundant further A/D converters.
  • a redundant further A/D converter of the monitoring means responds with the same characteristics as the A/D converter of the electronic evaluation unit with respect to the parameters relating to the functionality of the A/D converter of the electronic evaluation unit.
  • the monitoring means combine the values of the output signals of the redundant further A/D converters of the monitoring means with predetermined fixed limit values in order to determine changes in parameters relating to the functionality of the A/D converters of the electronic evaluation unit. The comparison is used to determine whether the A/D converter of the electronic evaluation unit is faulty.
  • An object of the present disclosure is to provide a sensor device capable of self-diagnosing failures that lead to an increase in thermal noise while suppressing an increase in size, and a determination method for the sensor device.
  • a sensor device includes a detection element, a signal converter, a first filter, and a monitor.
  • the detection element outputs a detection signal according to the stress.
  • the signal conversion section converts the detection signal.
  • the first filter passes a target frequency band, which is a frequency band to be processed in the signal output from the signal conversion unit.
  • the monitoring unit monitors thermal noise contained in a monitoring signal, which is a signal before passing through the first filter.
  • the monitoring unit has a second filter and a determination unit.
  • the second filter extracts a thermal noise signal from the monitor signal by passing a frequency band of the monitor signal excluding the target frequency band.
  • the judging section detects the magnitude of the thermal noise signal, and judges abnormality of at least one of the detecting element and the signal converting section based on the magnitude of the thermal noise signal.
  • a determination method for a sensor device is a determination method for a sensor device that includes a detection element and a signal conversion unit.
  • the detection element outputs a detection signal according to the stress.
  • the signal conversion section converts the detection signal.
  • the method for determining the sensor device includes a first filtering step and a monitoring step.
  • the first filtering step passes a target frequency band, which is a frequency band to be processed, among the signals output from the signal conversion unit.
  • the monitoring step monitors thermal noise contained in a monitoring signal, which is a signal before performing the first filtering step.
  • the monitoring step includes a second filtering step and a determining step.
  • the second filtering step extracts a thermal noise signal from the monitor signal by passing a frequency band of the monitor signal excluding the target frequency band.
  • the determination step detects the magnitude of the thermal noise signal, and determines an abnormality in at least one of the detection element and the signal conversion unit based on the magnitude of the thermal noise signal.
  • FIG. 1 is a block diagram showing a schematic configuration of the sensor device of this embodiment.
  • FIG. 2 is an explanatory diagram for explaining a thermal noise signal of the same sensor device.
  • FIG. 3 is a flow chart showing the operation of the determination method of the same sensor device.
  • FIG. 4 is a block diagram showing a schematic configuration of a sensor device according to a first modified example of the same.
  • the sensor device 1 includes a detection element 2, a signal converter 3, a first filter 61, and a monitor 7, as shown in FIG.
  • the detection element 2 outputs a detection signal S1 according to the stress.
  • the signal converter 3 converts the detection signal S1.
  • the first filter 61 passes a target frequency band, which is a frequency band to be processed in the signal output from the signal conversion unit 3 .
  • the monitoring unit 7 monitors thermal noise contained in the monitoring signal Sa, which is the signal before passing through the first filter 61 .
  • "Thermal noise" as used in this disclosure is frequency-independent noise caused, for example, by random thermal oscillations of free electrons. In this embodiment, thermal noise always occurs over the entire frequency band of the supervisory signal Sa.
  • the monitoring unit 7 has a second filter 8 and a determination unit 9 .
  • the second filter 8 extracts the thermal noise signal S5 from the supervisory signal Sa by passing the frequency band of the supervisory signal Sa excluding the target frequency band.
  • the determination unit 9 detects the magnitude of the thermal noise signal S5 and determines whether at least one of the detection element 2 and the signal conversion unit 3 is abnormal based on the magnitude of the thermal noise signal S5.
  • the sensor device 1 of the present embodiment directly monitors the thermal noise generated in the frequency band excluding the target frequency band in the monitor signal Sa, thereby increasing the thermal noise generated in the target frequency band. It is possible to determine the abnormality of at least one of the detection element 2 and the signal conversion unit 3 leading to . That is, the sensor device 1 of the present embodiment has the effect of eliminating the need to further implement a redundant circuit in order to self-diagnose a failure leading to an increase in thermal noise.
  • the sensor device 1 of the present embodiment has the advantage of being able to self-diagnose failures that lead to an increase in thermal noise while suppressing an increase in size.
  • Self-diagnosis as used in the present disclosure means that the sensor device 1 automatically determines whether or not at least one of the detection element 2 and the signal conversion section 3 is abnormal.
  • the sensor device 1 for example, the external device B1 may be a home appliance, a mobile terminal, a camera, a wearable terminal, a game machine, or various mobile objects such as vehicles (including automobiles and two-wheeled vehicles), drones, aircraft, and ships. equipment.
  • vehicles including automobiles and two-wheeled vehicles
  • drones aircraft, and ships. equipment.
  • the sensor device 1 includes a detection element 2, a signal conversion section 3, a digital processing section 6, and a monitoring section 7, as shown in FIG.
  • the signal converter 3, the digital processor 6, and the monitor 7 are, for example, a single ASIC (Application Specific Integrated Circuit).
  • the signal conversion unit 3, the digital processing unit 6, and the monitoring unit 7 are not limited to a single ASIC, and may be a circuit including one or more ICs, or may be a microcomputer.
  • the detection element 2 outputs a detection signal S1 according to the stress. More specifically, the detection element 2 detects stress and outputs a detection signal S1 corresponding to the magnitude of the stress.
  • the detecting element 2 of this embodiment detects the Coriolis force generated inside the detecting element 2 due to the circular motion of the sensor device 1, and outputs a detection signal S1 according to the Coriolis force.
  • the detection element 2 of this embodiment is a gyro element that converts physical quantities such as rotational angular velocity, rotational angle, and angular acceleration into the detection signal S1, which is a charge signal.
  • the detection element 2 includes a microelectromechanical system.
  • the detection element 2 is a resonator configured by so-called MEMS (Micro Electro Mechanical Systems).
  • the detection element 2 is, for example, a uniaxial gyro element, and detects angular velocity around the detection axis.
  • the detection element 2 has a vibration electrode and a detection electrode.
  • the vibrating electrode vibrates in a first direction orthogonal to the detection axis.
  • the sensing electrode senses movement of the vibrating electrode in a second direction orthogonal to both the sensing axis and the first direction using capacitance.
  • the structure of the detection element 2 is not limited to the structure described above, and may have any structure as long as it can detect the angular velocity around the detection axis.
  • the detection method may be, for example, a piezoelectric method.
  • the signal converter 3 has an analog processor 4 and an AD converter 5, as shown in FIG.
  • the analog processing unit 4 receives the detection signal S1 and outputs the first conversion signal S2. More specifically, the analog processing unit 4 receives the detection signal S1, converts the detection signal S1, which is a charge signal, into a first conversion signal S2, which is an analog voltage signal, and outputs the first conversion signal S2.
  • the AD converter 5 converts the first converted signal S2 into a second converted signal S3, and outputs the second converted signal S3 to the digital processor 6. More specifically, the AD conversion unit 5 converts the analog first conversion signal S2 into a digital second conversion signal S3 and outputs the second conversion signal S3 to the digital processing unit 6 .
  • the digital processing unit 6 is configured to generate an output signal S4 from the second converted signal S3 and output the output signal S4 to the external device B1.
  • the digital processing unit 6 has a first filter 61, as shown in FIG.
  • the first filter 61 passes a target frequency band, which is a frequency band to be processed in the signal output from the signal conversion unit 3 . More specifically, the first filter 61 of this embodiment passes the target frequency band of the second converted signal S3 output from the AD converter 5 .
  • the digital processing section 6 extracts the signal of the target frequency band from the second converted signal S3 through the first filter 61 .
  • the first filter 61 of the present embodiment is a low-pass filter that hardly attenuates frequency components lower than the cutoff frequency and gradually reduces frequency components higher than the cutoff frequency in the second converted signal S3. Specifically, the first filter 61 is a digital low-pass filter because the digital second converted signal S3 passes through the first filter 61 .
  • the digital processing unit 6 performs gain adjustment or offset adjustment on the extracted target frequency band signal, calculates the stress detected by the detection element 2, and outputs information about the calculated stress as an output signal S4.
  • the digital processing unit 6 of the present embodiment calculates the Coriolis force based on the extracted signal of the target frequency band, and outputs information on the calculated Coriolis force as an output signal S4.
  • the digital processing unit 6 of the present embodiment may further calculate physical quantities such as rotational angular velocity, rotational angle and angular acceleration from the calculated Coriolis force and output them as the output signal S4.
  • the external device B1 is a device having a function of receiving the output signal S4 and performing treatment and action using the output signal S4.
  • the monitoring unit 7 monitors thermal noise contained in the monitoring signal Sa. More specifically, the monitoring unit 7 monitors thermal noise occurring in frequency bands other than the target frequency band in the monitoring signal Sa.
  • the monitoring unit 7 of the present embodiment performs intermittent driving for switching between a monitoring state in which thermal noise is monitored and a stop state in which thermal noise monitoring is stopped.
  • the monitoring unit 7 switches from the monitoring state to the stop state when an event (for example, external disturbance such as vibration or impact) occurs. Also, the monitoring unit 7 may switch between the monitoring state and the stop state at regular time intervals.
  • the monitoring unit 7 includes a second filter 8 and a determination unit 9, as shown in FIG.
  • the second filter 8 extracts the thermal noise signal S5 from the monitoring signal Sa by passing the frequency band of the monitoring signal Sa excluding the target frequency band passed by the first filter 61 .
  • the second filter 8 of the present embodiment extracts the thermal noise signal S5 using the second converted signal S3 as the monitoring signal Sa. In other words, the second filter 8 of the present embodiment passes the frequency band of the second converted signal S3 output from the AD converter 5, excluding the target frequency band passed by the first filter 61. 2.
  • a thermal noise signal S5 is extracted from the converted signal S3.
  • the thermal noise signal S5 is a digital signal.
  • the second filter 8 of the present embodiment is a high-pass filter that hardly attenuates the frequency components higher than the cutoff frequency and gradually reduces the frequency components lower than the cutoff frequency in the second converted signal S3.
  • the cut-off frequency of the high-pass filter that is the second filter 8 is equal to or higher than the cut-off frequency of the low-pass filter that is the first filter 61 .
  • the second filter 8 is a digital high-pass filter because the second converted signal S3 in digital form passes through the second filter 8 .
  • the second conversion signal S3 is input to the second filter 8 when the monitoring unit 7 is in the monitoring state, and the second conversion signal S3 is input to the second filter 8 when the monitoring unit 7 is in the stopped state. It is configured so that the conversion signal S3 is not input. That is, the monitoring unit 7 of this embodiment controls whether the monitoring unit 7 is in the monitoring state or in the stopped state depending on whether or not the second conversion signal S3 is input to the second filter 8 .
  • the determination unit 9 detects the magnitude of the thermal noise signal S5, and determines whether at least one of the detection element 2 and the signal conversion unit 3 is abnormal based on the magnitude of the thermal noise signal S5.
  • the magnitude of the thermal noise signal S5 is the energy or amplitude of the thermal noise signal S5.
  • FIG. 2 shows the thermal noise signal S5 with the energy of the thermal noise signal S5 on the vertical axis and the time on the horizontal axis.
  • the determination unit 9 of the present embodiment has a counting unit 91 that counts the number of times the magnitude of the thermal noise signal S5 exceeds the preset range R1.
  • the counting unit 91 counts the number of times the instantaneous value of the magnitude of the thermal noise signal S5 exceeds the predetermined range R1.
  • the count number is the number of times the magnitude of the thermal noise signal S5 exceeds the upper limit value L1 of the predetermined range R1 and the number of times the magnitude of the thermal noise signal S5 falls below the lower limit value L2 of the predetermined range R1.
  • the total value of The predetermined range R1 is set in advance so that the magnitude of the thermal noise signal S5 when both the detection element 2 and the signal converter 3 are normal is included in the predetermined range R1.
  • the counting unit 91 counts the thermal noise signal S5 shown in FIG. 2 as an example.
  • the energy of the thermal noise signal S5 shown in FIG. 2 exceeds the predetermined range R1 three times. More specifically, the energy of the thermal noise signal S5 shown in FIG. 2 is below the lower limit value L2 of the predetermined range R1 at time t1, and exceeds the upper limit value L1 of the predetermined range R1 at times t2 and t3. ing. Therefore, the counting unit 91 counts 3 as the count number.
  • the count number counted by the counting unit 91 is reset at regular intervals. In this embodiment, since the monitoring unit 7 performs intermittent driving, the count number counted by the counting unit 91 is reset at the timing when the monitoring unit 7 is stopped.
  • the timing at which the count number of the counting section 91 is reset may be the timing at which the monitoring section 7 is in the stop state for a predetermined number of times.
  • the determination unit 9 determines that at least one of the detection element 2 and the signal conversion unit 3 is abnormal when the count number counted by the counting unit 91 exceeds a predetermined number of times.
  • the predetermined number of times is preferably two or more. That is, it is preferable that the predetermined number of times is set in advance to two or more times.
  • the determination section 9 When determining that at least one of the detection element 2 and the signal conversion section 3 is abnormal, the determination section 9 outputs an error signal S6 that notifies at least one of the detection element 2 and the signal conversion section 3 is abnormal. More specifically, the determining unit 9 determines that at least one of the detecting element 2 and the signal converting unit 3 is abnormal when the number of counts counted by the counting unit 91 exceeds a predetermined number of times, An error signal S6 for notifying of an abnormality in at least one of the detection element 2 and the signal conversion unit 3 is output to the external device B1.
  • the determination method of the sensor device 1 of the present embodiment includes, as shown in FIG. 3, an analog processing step ST1, an AD conversion step ST2, a digital processing step ST3, and a monitoring step ST5.
  • the analog processing section 4 receives the detection signal S1 and outputs the first conversion signal S2. More specifically, in the analog processing step ST1, the analog processing unit 4 receives the detection signal S1, converts the detection signal S1, which is a charge signal, into a first conversion signal S2, which is a voltage signal, and outputs the first conversion signal S2.
  • the AD converter 5 converts the first converted signal S2 into the second converted signal S3. More specifically, in the AD conversion step ST2, the AD conversion unit 5 converts the first converted signal S2 in analog format into a second converted signal S3 in digital format, and transmits the second converted signal S3 to the digital processing unit 6. Output.
  • the digital processing step ST3 includes a first filtering step ST31 and a calculation step ST32.
  • the first filter 61 passes the target frequency band, which is the frequency band to be processed in the second converted signal S3 output from the AD converter 5 in the AD conversion step ST2. That is, in the first filtering step ST31, the digital processing section 6 passes through the first filter 61 and extracts the signal of the target frequency band from the second converted signal S3. Then, in the calculation step ST32, the digital processing unit 6 performs gain adjustment or offset adjustment on the extracted target frequency band signal, calculates the stress detected by the detection element 2, and outputs information on the calculated stress as an output signal. Output as S4.
  • the monitoring unit 7 uses the second converted signal S3 as the monitoring signal Sa to monitor thermal noise contained in the monitoring signal Sa.
  • the monitoring step ST5 includes a second filtering step ST51 and a determination step ST52.
  • the second filter 8 extracts the thermal noise signal S5 from the supervisory signal Sa by passing the frequency band of the supervisory signal Sa excluding the target frequency band passed in the first filtering step ST31. do.
  • the second filter 8 passes the frequency band of the second converted signal S3 output in the AD conversion step ST2, excluding the target frequency band passed by the first filter 61.
  • the thermal noise signal S5 is extracted from the second converted signal S3.
  • the determination section 9 detects the magnitude of the thermal noise signal S5, and determines whether at least one of the detection element 2 and the signal conversion section 3 is abnormal based on the magnitude of the thermal noise signal S5.
  • the determination step ST52 will be described in more detail.
  • the counting section 91 counts the number of times the magnitude of the thermal noise signal S5 exceeds a preset range R1 as a count number. After that, when the number of counts counted by the counting unit 91 exceeds a predetermined number of times, the determining unit 9 determines that at least one of the detecting element 2 and the signal converting unit 3 is abnormal. and output an error signal S6 notifying of an abnormality in at least one of the signal converters 3 to the external device B1.
  • the sensor device 1 does not perform the monitoring step ST5.
  • the flowchart of FIG. 3 is merely an example of the determination method of the sensor device 1 of the present embodiment, and the order of the processing may be changed as appropriate, or any processing may be omitted as appropriate.
  • the monitoring step ST5 is performed after the digital processing step ST3, but the monitoring step ST5 may be performed before the analog processing step ST1. Also, the monitoring step ST5 may be performed at the same timing as the analog processing step ST1, the AD conversion step ST2, and the digital processing step ST3.
  • monitoring step ST5 may be performed at a timing independent of the timing of performing the analog processing step ST1, the AD conversion step ST2, and the digital processing step ST3.
  • the sensor device 1 includes a detection element 2, a signal converter 3, a first filter 61, and a monitor .
  • the detection element 2 outputs a detection signal S1 according to the stress.
  • the signal converter 3 converts the detection signal S1.
  • the first filter 61 passes a target frequency band, which is a frequency band to be processed in the signal output from the signal conversion unit 3 .
  • the monitoring unit 7 monitors thermal noise contained in the monitoring signal Sa, which is the signal before passing through the first filter 61 .
  • the monitoring unit 7 has a second filter 8 and a determination unit 9 .
  • the second filter 8 extracts the thermal noise signal S5 from the supervisory signal Sa by passing the frequency band of the supervisory signal Sa excluding the target frequency band.
  • the determination unit 9 detects the magnitude of the thermal noise signal S5 and determines whether at least one of the detection element 2 and the signal conversion unit 3 is abnormal based on the magnitude of the thermal noise signal S5.
  • the sensor device 1 directly monitors the thermal noise generated in the frequency band excluding the target frequency band in the monitor signal Sa, which leads to an increase in the thermal noise generated in the target frequency band.
  • the abnormality of at least one of the detection element 2 and the signal conversion unit 3 can be determined. More specifically, the sensor device 1 directly monitors the thermal noise generated in the frequency bands other than the target frequency band in the monitor signal Sa, which leads to an increase in the thermal noise generated in the target frequency band.
  • the detection element 2 , the analog processing unit 4 , and the AD conversion unit 5 . That is, the sensor device 1 has the effect of eliminating the need to further implement a redundant circuit in order to self-diagnose a failure leading to an increase in thermal noise. Therefore, the sensor device 1 of the present embodiment has the advantage of being able to self-diagnose failures that lead to an increase in thermal noise while suppressing an increase in size.
  • the determination unit 9 determines that at least one of the detection element 2 and the signal conversion unit 3 is abnormal when the number of counts counted by the counting unit 91 exceeds a predetermined number of times, and The predetermined number of times is set in advance to two or more times.
  • the determination unit 9 when the thermal noise signal S5 suddenly rises, the determination unit 9 does not determine that at least one of the detection element 2 and the signal conversion unit 3 is abnormal. That is, the sensor device 1 of the present embodiment has the advantage of being able to suppress erroneous diagnosis of failures that lead to an increase in thermal noise.
  • the monitoring unit 7 performs intermittent driving to switch between a monitoring state in which thermal noise is monitored and a stop state in which thermal noise monitoring is stopped.
  • the determination unit 9 determines that at least one of the detection element 2 and the signal conversion unit 3 is abnormal due to the influence of the disturbance. Misjudgment can be suppressed. That is, there is an advantage that the influence of disturbance can be suppressed. Moreover, when the monitoring unit 7 switches between the monitoring state and the stop state at regular time intervals, there is an advantage that power consumption can be reduced.
  • the determination section 9 when determining that at least one of the detection element 2 and the signal conversion section 3 is abnormal, the determination section 9 outputs an error signal S6 that notifies of a failure of at least one of the detection element 2 and the signal conversion section 3. Output.
  • the sensing element 2 includes a microelectromechanical system.
  • the sensor device 1 can be miniaturized.
  • FIG. 4 shows the configuration of the sensor device 1a of the first modification.
  • the monitoring unit 7 of the sensor device 1 monitors the thermal noise contained in the second converted signal S3, but the monitoring unit 7a of the sensor device 1a detects the thermal noise contained in the first converted signal S2. may be monitored.
  • the second filter 8 uses the second converted signal S3 as the monitoring signal Sa to extract the thermal noise signal S5. , the thermal noise signal S5 is extracted.
  • the monitoring unit 7a has an AD conversion unit 92 and a second filter 8a, as shown in FIG.
  • the AD conversion section 92 is arranged between the analog processing section 4 and the second filter 8a.
  • the AD conversion section 92 converts the analog first converted signal S2 output from the analog processing section 4 into a digital form, and outputs the converted signal as a third converted signal S21 to the second filter 8a.
  • the second filter 8a passes the frequency band of the third converted signal S21 output from the AD conversion unit 92, excluding the target frequency band passed by the first filter 61, thereby reducing the thermal noise from the third converted signal S21. Extract the signal S5. Since the third conversion signal S21 is obtained by converting the first conversion signal S2 into a digital form, the thermal noise included in the third conversion signal S21 corresponds to the thermal noise included in the first conversion signal S2. Therefore, substantially, the second filter 8a uses the first converted signal S2 as the supervisory signal Sa, and passes the frequency band of the first converted signal S2 excluding the target frequency band passed by the first filter 61. , the thermal noise signal S5 is extracted from the first converted signal S2.
  • the second filter 8a is a digital high-pass filter because the third converted signal S21 in digital form passes through the second filter 8a.
  • the AD conversion section 92 shown in FIG. 4 is arranged between the analog processing section 4 and the second filter 8a, but may be arranged between the second filter 8a and the determination section 9.
  • the second filter 8a uses the first converted signal S2 as the monitor signal Sa, and the first filter
  • the thermal noise signal S5 is extracted from the first converted signal S2 by passing a frequency band excluding the target frequency band passed by 61 .
  • the second filter 8a is an analog high-pass filter because the analog first converted signal S2 passes through the second filter 8a.
  • the AD converter 92 converts the analog thermal noise signal S5 output from the second filter 8a into a digital format and outputs it to the determination unit 9 .
  • the detection element 2 in the above-described embodiment is a gyro sensor, but may be an acceleration sensor.
  • the detection element 2 of the present embodiment is a uniaxial gyro sensor, but may be a biaxial or triaxial gyro sensor. That is, the detection element 2 may be a multi-axis integrated gyro sensor.
  • the first filter 61 in the above embodiment is a low-pass filter, it may be a high-pass filter. If the first filter 61 is a high pass filter, the second filter 8 is a low pass filter. At this time, the cutoff frequency of the low-pass filter that is the second filter 8 is lower than the cutoff frequency of the high-pass filter that is the first filter 61 .
  • the second filter 8 in the above embodiment is a high pass filter.
  • the second filter 8 may be a bandpass filter that passes a specific frequency band out of the frequency bands excluding the target frequency band that the first filter 61 passes.
  • the monitoring unit 7 of the above-described embodiment performs intermittent driving to switch between a monitoring state in which thermal noise is monitored and a stop state in which thermal noise monitoring is stopped.
  • the monitoring unit 7 may be in a constant monitoring state without performing intermittent driving.
  • the second conversion signal S3 is input to the second filter 8 when the monitoring unit 7 is in the monitoring state, and the second filter 8 is input when the monitoring unit 7 is in the stopped state. is configured so that the second conversion signal S3 is not input to the .
  • the monitoring unit 7 inputs the thermal noise signal S5 to the determination unit 9 when the monitoring unit 7 is in the monitoring state, and does not input the thermal noise signal S5 to the determination unit 9 when the monitoring unit 7 is in the stopped state. It may be configured as That is, the monitoring unit 7 of the above-described embodiment controls whether the monitoring unit 7 is in the monitoring state or in the stopped state depending on whether or not the second conversion signal S3 is input to the second filter 8. may be controlled by determining whether or not the thermal noise signal S5 is input to the determination unit 9.
  • the counting unit 91 of the above-described embodiment counts the number of times the instantaneous value of the magnitude of the thermal noise signal S5 exceeds the predetermined range R1 set in advance. Further, the counting unit 91 may count the number of times the average value of the magnitude of the thermal noise signal S5 per unit time exceeds the predetermined range R1. The shorter the unit time, the higher the accuracy with which the determination unit 9 determines whether there is an abnormality. Considering the accuracy with which the determination unit 9 determines whether or not there is an abnormality, it is desirable that the unit time be shorter than the period of the thermal noise.
  • the count number of the counting unit 91 in the above embodiment is reset at the timing when the monitoring unit 7 is stopped.
  • the timing at which the count number of the counting unit 91 is reset does not have to be linked with the timing at which the monitoring unit 7 performs intermittent driving.
  • the sensor device 1 assumes that the detection element 2, the signal conversion section 3, the digital processing section 6, and the monitoring section 7 are integrally packaged.
  • the sensor device 1 at least part of the signal converter 3 , the digital processor 6 , and the monitor 7 may be provided separately from the detection element 2 .
  • the signal conversion unit 3, the digital processing unit 6, and the monitoring unit 7 may be provided separately from the detection element 2, or only the monitoring unit 7 may It may be provided separately from the detection element 2 , the signal conversion section 3 and the digital processing section 6 .
  • a sensor device (1, 1a) of a first aspect includes a detection element (2), a signal converter (3), a first filter (61), a monitor (7, 7a), Prepare.
  • the detection element (2) outputs a detection signal (S1) according to the stress.
  • a signal converter (3) converts the detection signal (S1).
  • a first filter (61) passes a target frequency band, which is a frequency band to be processed in the signal output from the signal converter (3).
  • the monitoring units (7, 7a) monitor thermal noise contained in the monitoring signal (Sa), which is the signal before passing through the first filter (61).
  • the monitoring section (7, 7a) has a second filter (8, 8a) and a determining section (9).
  • the second filter (8, 8a) extracts the thermal noise signal (S5) from the supervisory signal (Sa) by passing the frequency band of the supervisory signal (Sa) excluding the target frequency band.
  • a judging section (9) detects the magnitude of the thermal noise signal (S5) and detects an abnormality in at least one of the detecting element (2) and the signal converting section (3) based on the magnitude of the thermal noise signal (S5). judge.
  • the signal converter (3) has an analog processor (4) and an AD converter (5).
  • the analog processing section (4) receives the detection signal (S1) and outputs a first conversion signal (S2).
  • the AD converter (5) converts the first converted signal (S2) into a second converted signal (S3).
  • a second filter (8) extracts a thermal noise signal (S5) using the second converted signal (S3) as a supervisory signal (Sa).
  • the signal converter (3) has an analog processor (4) and an AD converter (5).
  • the analog processing section (4) receives the detection signal (S1) and outputs a first conversion signal (S2).
  • the AD converter (5) converts the first converted signal (S2) into a second converted signal (S3).
  • a second filter (8a) extracts a thermal noise signal (S5) using the first converted signal (S2) as a supervisory signal (Sa).
  • the determination section (9) is configured such that the magnitude of the thermal noise signal (S5) is preset. It has a counting section (91) that counts the number of times that the predetermined range (R1) is exceeded as the number of counts.
  • the determination unit (9) detects the detection element (2 ) and signal converter (3) is determined to be abnormal.
  • the predetermined number of times is 2 or more.
  • the detection element (2) includes a microelectromechanical system.
  • the sensor device (1) can be made more compact.
  • the monitoring unit (7) monitors a thermal noise monitoring state and a thermal noise monitoring state. Intermittent drive is performed to switch between a stop state in which monitoring is stopped and a state in which monitoring is stopped.
  • the determination unit (9) comprises the detection element (2) and the signal conversion unit (3). If it is determined that at least one of them is abnormal, it outputs an error signal (S6) that reports that at least one of the detection element (2) and the signal converter (3) is abnormal.
  • the user and administrator of the sensor device (1, 1a) can know the abnormality of at least one of the detection element (2) and the signal conversion section (3).
  • a determination method for a sensor device (1, 1a) is a determination method for a sensor device (1, 1a) including a detection element (2) and a signal conversion section (3).
  • the detection element (2) outputs a detection signal (S1) according to the stress.
  • a signal converter (3) converts the detection signal.
  • the determination method of the sensor device (1, 1a) includes a first filtering step (ST31) and a monitoring step (ST5).
  • the first filtering step (ST31) passes the target frequency band, which is the frequency band to be processed, among the signals output from the signal converter (3).
  • the monitoring step (ST5) monitors thermal noise contained in the monitoring signal (Sa), which is the signal before performing the first filtering step (ST31).
  • the monitoring step (ST5) includes a second filtering step (ST51) and a determining step (ST52).
  • the second filtering step (ST51) extracts the thermal noise signal (S5) from the supervisory signal (Sa) by passing the frequency band of the supervisory signal (Sa) excluding the target frequency band.
  • a determination step (ST52) detects the magnitude of the thermal noise signal (S5), and detects an abnormality in at least one of the detection element (2) and the signal converter (3) based on the magnitude of the thermal noise signal (S5). judge.
  • Reference Signs List 1 1a sensor device 2 detection element 3 signal conversion unit 4 analog processing unit 5 AD conversion unit 61 first filter 7, 7a monitoring unit 8, 8a second filter 9 determination unit 91 counting unit R1 predetermined range S1 detection signal S2 first Conversion signal S3 Second conversion signal S5 Thermal noise signal S6 Error signal Sa Monitoring signal ST31 First filtering step ST5 Monitoring step ST51 Second filtering step ST52 Judgment step

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Abstract

The purpose of the present disclosure is to provide: a sensor device which makes it possible to self-diagnose a failure linked to an increase in thermal noise while suppressing an increase in device size; and a sensor device determination method. This sensor device (1) is equipped with a detection element (2), a signal conversion unit (3), a first filter (61) and a monitoring unit (7). The first filter (61) allows passage therethrough of a target frequency band, which is a frequency band to be targeted for processing, of a signal outputted from the signal conversion unit (3). The monitoring unit (7) monitors the thermal noise included in a monitoring signal (Sa), which is the signal before passage through the first filter (61). The monitoring unit (7) has a second filter (8) and a determination unit (9). The second filter (8) extracts a thermal noise signal (S5) from the monitoring signal (Sa) by causing passage therethrough of a frequency band of the monitoring signal (Sa) which excludes the target frequency band. The determination unit (9) detects the size of the thermal noise signal (S5), and determines whether there is an abnormality in the detection element (2) and/or the signal conversion unit (3) on the basis of the size of the thermal noise signal (S5).

Description

センサ装置、及びセンサ装置の判定方法SENSOR DEVICE AND METHOD OF DETERMINING SENSOR DEVICE
　本開示は、一般に、センサ装置、及びセンサ装置の判定方法に関する。より詳細には、本開示は、応力を検出する検出素子を備えるセンサ装置、及びセンサ装置の判定方法に関する。 The present disclosure generally relates to sensor devices and methods for determining sensor devices. More particularly, the present disclosure relates to a sensor device that includes a sensing element that detects stress, and a determination method for the sensor device.
　特許文献１には、加速度を検出するための少なくとも１つのマイクロメカニカルセンサ素子と、センサ素子毎にそれぞれ１つのＡ／Ｄ変換器を伴う冗長的な信号パスを有する電子評価ユニットと、を備える加速度センサが開示されている。加速度センサは、電子評価ユニットのＡ／Ｄ変換器の機能性に関するパラメータを監視する監視手段が設けられている。 US 2004/0010001 discloses an acceleration sensor with at least one micromechanical sensor element for detecting acceleration and an electronic evaluation unit with redundant signal paths with an A/D converter each for each sensor element. A sensor is disclosed. The acceleration sensor is provided with monitoring means for monitoring parameters relating to the functionality of the A/D converter of the electronic evaluation unit.
　監視手段は、電子評価ユニット内に集積されたセンサ素子に対する等価回路と、冗長なさらなるＡ／Ｄ変換器と、を含む。監視手段の冗長なさらなるＡ／Ｄ変換器は、電子評価ユニットのＡ／Ｄ変換器の機能性に関するパラメータに関して、電子評価ユニットのＡ／Ｄ変換器と同じ特性で反応する。監視手段は、電子評価ユニットのＡ／Ｄ変換器の機能性に関するパラメータの変化を決定するために、監視手段の冗長なさらなるＡ／Ｄ変換器の出力信号の値を、所定の固定限界値と比較することで、電子評価ユニットのＡ／Ｄ変換器の故障判定を行う。 The monitoring means comprise an equivalent circuit for the sensor elements integrated in the electronic evaluation unit and redundant further A/D converters. A redundant further A/D converter of the monitoring means responds with the same characteristics as the A/D converter of the electronic evaluation unit with respect to the parameters relating to the functionality of the A/D converter of the electronic evaluation unit. The monitoring means combine the values of the output signals of the redundant further A/D converters of the monitoring means with predetermined fixed limit values in order to determine changes in parameters relating to the functionality of the A/D converters of the electronic evaluation unit. The comparison is used to determine whether the A/D converter of the electronic evaluation unit is faulty.
　ところで、センサ装置において、ノイズの増大につながる故障を自己診断するために、特許文献１に開示されるように冗長な回路を更に実装すると、センサ装置の回路規模が増大し、センサ装置のサイズが大きくなってしまうという問題があった。 By the way, in the sensor device, if a redundant circuit is further implemented as disclosed in Patent Document 1 in order to self-diagnose failures that lead to an increase in noise, the circuit scale of the sensor device increases, and the size of the sensor device increases. I had a problem with it getting bigger.
特許第５８３７２５５号公報Japanese Patent No. 5837255
　本開示の目的とするところは、サーマルノイズの増大につながる故障を自己診断しつつ、大型化の抑制を図ることができるセンサ装置、及びセンサ装置の判定方法を提供することにある。 An object of the present disclosure is to provide a sensor device capable of self-diagnosing failures that lead to an increase in thermal noise while suppressing an increase in size, and a determination method for the sensor device.
　本開示の一態様に係るセンサ装置は、検出素子と、信号変換部と、第１フィルタと、監視部と、を備える。前記検出素子は、応力に応じて検出信号を出力する。前記信号変換部は、前記検出信号の信号変換を行う。前記第１フィルタは、前記信号変換部から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる。前記監視部は、前記第１フィルタを通過する前の信号である監視信号に含まれるサーマルノイズを監視する。前記監視部は、第２フィルタと、判定部と、を有する。前記第２フィルタは、前記監視信号のうち前記対象周波数帯域を除く周波数帯域を通過させることで、前記監視信号からサーマルノイズ信号を抽出する。前記判定部は、前記サーマルノイズ信号の大きさを検出し、前記サーマルノイズ信号の前記大きさに基づいて前記検出素子及び前記信号変換部の少なくとも一方の異常を判定する。 A sensor device according to an aspect of the present disclosure includes a detection element, a signal converter, a first filter, and a monitor. The detection element outputs a detection signal according to the stress. The signal conversion section converts the detection signal. The first filter passes a target frequency band, which is a frequency band to be processed in the signal output from the signal conversion unit. The monitoring unit monitors thermal noise contained in a monitoring signal, which is a signal before passing through the first filter. The monitoring unit has a second filter and a determination unit. The second filter extracts a thermal noise signal from the monitor signal by passing a frequency band of the monitor signal excluding the target frequency band. The judging section detects the magnitude of the thermal noise signal, and judges abnormality of at least one of the detecting element and the signal converting section based on the magnitude of the thermal noise signal.
　本開示の一態様に係るセンサ装置の判定方法は、検出素子と、信号変換部と、を備えるセンサ装置の判定方法である。前記検出素子は、応力に応じて検出信号を出力する。前記信号変換部は、前記検出信号の信号変換を行う。前記センサ装置の判定方法は、第１フィルタリングステップと、監視ステップと、を含む。前記第１フィルタリングステップは、前記信号変換部から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる。前記監視ステップは、前記第１フィルタリングステップを行う前の信号である監視信号に含まれるサーマルノイズを監視する。前記監視ステップは、第２フィルタリングステップと、判定ステップと、を含む。前記第２フィルタリングステップは、前記監視信号のうち前記対象周波数帯域を除く周波数帯域を通過させることで、前記監視信号からサーマルノイズ信号を抽出する。前記判定ステップは、前記サーマルノイズ信号の大きさを検出し、前記サーマルノイズ信号の前記大きさに基づいて前記検出素子及び前記信号変換部の少なくとも一方の異常を判定する。 A determination method for a sensor device according to one aspect of the present disclosure is a determination method for a sensor device that includes a detection element and a signal conversion unit. The detection element outputs a detection signal according to the stress. The signal conversion section converts the detection signal. The method for determining the sensor device includes a first filtering step and a monitoring step. The first filtering step passes a target frequency band, which is a frequency band to be processed, among the signals output from the signal conversion unit. The monitoring step monitors thermal noise contained in a monitoring signal, which is a signal before performing the first filtering step. The monitoring step includes a second filtering step and a determining step. The second filtering step extracts a thermal noise signal from the monitor signal by passing a frequency band of the monitor signal excluding the target frequency band. The determination step detects the magnitude of the thermal noise signal, and determines an abnormality in at least one of the detection element and the signal conversion unit based on the magnitude of the thermal noise signal.
図１は、本実施形態のセンサ装置の概略構成を示すブロック図である。FIG. 1 is a block diagram showing a schematic configuration of the sensor device of this embodiment. 図２は、同上のセンサ装置のサーマルノイズ信号を説明する説明図である。FIG. 2 is an explanatory diagram for explaining a thermal noise signal of the same sensor device. 図３は、同上のセンサ装置の判定方法の動作を示すフローチャートである。FIG. 3 is a flow chart showing the operation of the determination method of the same sensor device. 図４は、同上の第１変形例に係るセンサ装置の概略構成を示すブロック図である。FIG. 4 is a block diagram showing a schematic configuration of a sensor device according to a first modified example of the same.
　（実施形態）
　（１）概要
　以下、実施形態に係るセンサ装置１の概要について、図１を参照して説明する。 (embodiment)
(1) Overview An overview of the sensor device 1 according to the embodiment will be described below with reference to FIG.
　実施形態に係るセンサ装置１は、図１に示すように、検出素子２と、信号変換部３と、第１フィルタ６１と、監視部７と、を備える。 The sensor device 1 according to the embodiment includes a detection element 2, a signal converter 3, a first filter 61, and a monitor 7, as shown in FIG.
　検出素子２は、応力に応じて検出信号Ｓ１を出力する。信号変換部３は、検出信号Ｓ１の信号変換を行う。第１フィルタ６１は、信号変換部３から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる。監視部７は、第１フィルタ６１を通過する前の信号である監視信号Ｓａに含まれるサーマルノイズを監視する。本開示でいう「サーマルノイズ」は、周波数に依存しないノイズであり、例えば、自由電子の不規則な熱振動によって生じる。本実施形態では、サーマルノイズは、監視信号Ｓａの周波数帯域の全体にわたって常時発生する。 The detection element 2 outputs a detection signal S1 according to the stress. The signal converter 3 converts the detection signal S1. The first filter 61 passes a target frequency band, which is a frequency band to be processed in the signal output from the signal conversion unit 3 . The monitoring unit 7 monitors thermal noise contained in the monitoring signal Sa, which is the signal before passing through the first filter 61 . "Thermal noise" as used in this disclosure is frequency-independent noise caused, for example, by random thermal oscillations of free electrons. In this embodiment, thermal noise always occurs over the entire frequency band of the supervisory signal Sa.
　監視部７は、第２フィルタ８と、判定部９と、を有する。第２フィルタ８は、監視信号Ｓａのうち対象周波数帯域を除く周波数帯域を通過させることで、監視信号Ｓａからサーマルノイズ信号Ｓ５を抽出する。判定部９は、サーマルノイズ信号Ｓ５の大きさを検出し、サーマルノイズ信号Ｓ５の大きさに基づいて検出素子２及び信号変換部３の少なくとも一方の異常を判定する。 The monitoring unit 7 has a second filter 8 and a determination unit 9 . The second filter 8 extracts the thermal noise signal S5 from the supervisory signal Sa by passing the frequency band of the supervisory signal Sa excluding the target frequency band. The determination unit 9 detects the magnitude of the thermal noise signal S5 and determines whether at least one of the detection element 2 and the signal conversion unit 3 is abnormal based on the magnitude of the thermal noise signal S5.
　以上から、本実施形態のセンサ装置１は、監視信号Ｓａのうち対象周波数帯域を除く周波数帯域に発生しているサーマルノイズを直接監視することで、対象周波数帯域で発生しているサーマルノイズの増大につながる、検出素子２及び信号変換部３の少なくとも一方の異常を判定することができる。すなわち、本実施形態のセンサ装置１は、サーマルノイズの増大につながる故障を自己診断するために、冗長な回路を更に実装する必要がなくなるという効果を奏する。 As described above, the sensor device 1 of the present embodiment directly monitors the thermal noise generated in the frequency band excluding the target frequency band in the monitor signal Sa, thereby increasing the thermal noise generated in the target frequency band. It is possible to determine the abnormality of at least one of the detection element 2 and the signal conversion unit 3 leading to . That is, the sensor device 1 of the present embodiment has the effect of eliminating the need to further implement a redundant circuit in order to self-diagnose a failure leading to an increase in thermal noise.
　そのため、本実施形態のセンサ装置１は、サーマルノイズの増大につながる故障を自己診断しつつ、大型化の抑制を図ることができるという利点がある。本開示でいう「自己診断」は、センサ装置１が検出素子２及び信号変換部３の少なくとも一方の異常の有無を自動的に判定することである。 Therefore, the sensor device 1 of the present embodiment has the advantage of being able to self-diagnose failures that lead to an increase in thermal noise while suppressing an increase in size. “Self-diagnosis” as used in the present disclosure means that the sensor device 1 automatically determines whether or not at least one of the detection element 2 and the signal conversion section 3 is abnormal.
　（２）詳細な構成
　（２－１）センサ装置
　以下に、本実施形態のセンサ装置１の詳細な構成について、図１及び図２を参照して説明する。センサ装置１は、例えば、外部装置Ｂ１は、家電製品、携帯端末、カメラ、ウェアラブル端末、ゲーム機、又は車両（自動車及び二輪自動車等を含む）、ドローン、航空機若しくは船舶等の移動体等の様々な装置に用いられる。 (2) Detailed Configuration (2-1) Sensor Device A detailed configuration of the sensor device 1 of the present embodiment will be described below with reference to FIGS. 1 and 2. FIG. The sensor device 1, for example, the external device B1 may be a home appliance, a mobile terminal, a camera, a wearable terminal, a game machine, or various mobile objects such as vehicles (including automobiles and two-wheeled vehicles), drones, aircraft, and ships. equipment.
　センサ装置１は、図１に示すように、検出素子２と、信号変換部３と、デジタル処理部６と、監視部７と、を備える。信号変換部３、デジタル処理部６、及び監視部７は、例えば、単一のＡＳＩＣ（Application Specific Integrated Circuit）である。なお、信号変換部３、デジタル処理部６、及び監視部７は単一のＡＳＩＣに限られず、１以上のＩＣを含む回路であってもよく、又は、マイクロコンピュータであってもよい。 The sensor device 1 includes a detection element 2, a signal conversion section 3, a digital processing section 6, and a monitoring section 7, as shown in FIG. The signal converter 3, the digital processor 6, and the monitor 7 are, for example, a single ASIC (Application Specific Integrated Circuit). The signal conversion unit 3, the digital processing unit 6, and the monitoring unit 7 are not limited to a single ASIC, and may be a circuit including one or more ICs, or may be a microcomputer.
　（検出素子）
　検出素子２は、応力に応じて検出信号Ｓ１を出力する。より詳細には、検出素子２は、応力を検出し、応力の大きさに対応した検出信号Ｓ１を出力する。本実施形態の検出素子２は、センサ装置１の円運動によって検出素子２の内部に生じたコリオリ力を検出し、コリオリ力に応じて検出信号Ｓ１を出力する。言い換えれば、本実施形態の検出素子２は、回転角速度、回転角及び角加速度等の物理量を、電荷信号である検出信号Ｓ１に変換するジャイロ素子である。 (detection element)
The detection element 2 outputs a detection signal S1 according to the stress. More specifically, the detection element 2 detects stress and outputs a detection signal S1 corresponding to the magnitude of the stress. The detecting element 2 of this embodiment detects the Coriolis force generated inside the detecting element 2 due to the circular motion of the sensor device 1, and outputs a detection signal S1 according to the Coriolis force. In other words, the detection element 2 of this embodiment is a gyro element that converts physical quantities such as rotational angular velocity, rotational angle, and angular acceleration into the detection signal S1, which is a charge signal.
　検出素子２は、微小電気機械システムを含む。例えば、検出素子２は、いわゆる、ＭＥＭＳ（Micro Electro Mechanical Systems）により構成された共振子である。 The detection element 2 includes a microelectromechanical system. For example, the detection element 2 is a resonator configured by so-called MEMS (Micro Electro Mechanical Systems).
　検出素子２は、例えば、１軸のジャイロ素子であり、検出軸周りの角速度を検出する。検出素子２は、振動電極と、検出電極とを有する。振動電極は、検出軸に直交する第１方向に振動する。検出電極は、検出軸と第１方向との両方に直交する第２方向における振動電極の移動を、静電容量を用いて検出する。なお、検出素子２の構造は上述の構造に限られず、検出軸周りの角速度を検出可能なものであれば、任意の構造であってよい。検出方式は、例えば、圧電方式でもよい。 The detection element 2 is, for example, a uniaxial gyro element, and detects angular velocity around the detection axis. The detection element 2 has a vibration electrode and a detection electrode. The vibrating electrode vibrates in a first direction orthogonal to the detection axis. The sensing electrode senses movement of the vibrating electrode in a second direction orthogonal to both the sensing axis and the first direction using capacitance. Note that the structure of the detection element 2 is not limited to the structure described above, and may have any structure as long as it can detect the angular velocity around the detection axis. The detection method may be, for example, a piezoelectric method.
　（信号変換部）
　信号変換部３は、図１に示すように、アナログ処理部４と、ＡＤ変換部５と、有する。 (Signal converter)
The signal converter 3 has an analog processor 4 and an AD converter 5, as shown in FIG.
　アナログ処理部４は、検出信号Ｓ１が入力され、第１変換信号Ｓ２を出力する。より詳細には、アナログ処理部４は、検出信号Ｓ１が入力され、電荷信号である検出信号Ｓ１をアナログ形式の電圧信号である第１変換信号Ｓ２に変換し、出力する。 The analog processing unit 4 receives the detection signal S1 and outputs the first conversion signal S2. More specifically, the analog processing unit 4 receives the detection signal S1, converts the detection signal S1, which is a charge signal, into a first conversion signal S2, which is an analog voltage signal, and outputs the first conversion signal S2.
　ＡＤ変換部５は、第１変換信号Ｓ２を第２変換信号Ｓ３に変換し、デジタル処理部６に第２変換信号Ｓ３を出力する。より詳細には、ＡＤ変換部５は、アナログ形式の第１変換信号Ｓ２をデジタル形式の第２変換信号Ｓ３に変換して、デジタル処理部６に第２変換信号Ｓ３を出力する。 The AD converter 5 converts the first converted signal S2 into a second converted signal S3, and outputs the second converted signal S3 to the digital processor 6. More specifically, the AD conversion unit 5 converts the analog first conversion signal S2 into a digital second conversion signal S3 and outputs the second conversion signal S3 to the digital processing unit 6 .
　（デジタル処理部）
　デジタル処理部６は、第２変換信号Ｓ３から出力信号Ｓ４を生成し、外部装置Ｂ１に出力信号Ｓ４を出力するように構成される。 (Digital processing part)
The digital processing unit 6 is configured to generate an output signal S4 from the second converted signal S3 and output the output signal S4 to the external device B1.
　デジタル処理部６は、図１に示すように、第１フィルタ６１を有する。第１フィルタ６１は、信号変換部３から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる。より詳細には、本実施形態の第１フィルタ６１は、ＡＤ変換部５から出力される第２変換信号Ｓ３のうち対象周波数帯域を通過させる。デジタル処理部６は、第１フィルタ６１を通して、第２変換信号Ｓ３から対象周波数帯域の信号を抽出する。本実施形態の第１フィルタ６１は、第２変換信号Ｓ３のうち、遮断周波数より低い周波数の成分はほとんど減衰させず、遮断周波数より高い周波数の成分を逓減させるローパスフィルタである。具体的には、第１フィルタ６１にはデジタル形式の第２変換信号Ｓ３が通過するため、第１フィルタ６１はデジタルローパスフィルタである。 The digital processing unit 6 has a first filter 61, as shown in FIG. The first filter 61 passes a target frequency band, which is a frequency band to be processed in the signal output from the signal conversion unit 3 . More specifically, the first filter 61 of this embodiment passes the target frequency band of the second converted signal S3 output from the AD converter 5 . The digital processing section 6 extracts the signal of the target frequency band from the second converted signal S3 through the first filter 61 . The first filter 61 of the present embodiment is a low-pass filter that hardly attenuates frequency components lower than the cutoff frequency and gradually reduces frequency components higher than the cutoff frequency in the second converted signal S3. Specifically, the first filter 61 is a digital low-pass filter because the digital second converted signal S3 passes through the first filter 61 .
　デジタル処理部６は、抽出した対象周波数帯域の信号について、ゲイン調整又はオフセット調整を行い、検出素子２が検出した応力を算出し、算出された応力に関する情報を出力信号Ｓ４として出力する。本実施形態のデジタル処理部６は、抽出した対象周波数帯域の信号に基づいてコリオリ力を算出し、算出されたコリオリ力に関する情報を出力信号Ｓ４として出力する。なお、本実施形態のデジタル処理部６は、算出されたコリオリ力から回転角速度、回転角及び角加速度等の物理量を更に算出し、出力信号Ｓ４として出力してもよい。外部装置Ｂ１は、出力信号Ｓ４を受け取って、出力信号Ｓ４を用いた処置及び動作を行う機能を有する装置である。 The digital processing unit 6 performs gain adjustment or offset adjustment on the extracted target frequency band signal, calculates the stress detected by the detection element 2, and outputs information about the calculated stress as an output signal S4. The digital processing unit 6 of the present embodiment calculates the Coriolis force based on the extracted signal of the target frequency band, and outputs information on the calculated Coriolis force as an output signal S4. The digital processing unit 6 of the present embodiment may further calculate physical quantities such as rotational angular velocity, rotational angle and angular acceleration from the calculated Coriolis force and output them as the output signal S4. The external device B1 is a device having a function of receiving the output signal S4 and performing treatment and action using the output signal S4.
　（監視部）
　監視部７は、監視信号Ｓａに含まれるサーマルノイズを監視する。より詳細には、監視部７は、監視信号Ｓａのうち対象周波数帯域を除く周波数帯域に発生しているサーマルノイズを監視する。本実施形態の監視部７は、サーマルノイズの監視を行う監視状態と、サーマルノイズの監視を停止する停止状態と、を切り替える間欠駆動を行う。監視部７は、イベント（例えば、外部から加えられる振動又は衝撃等の外乱）が発生したときに、監視状態から停止状態に切り替える。また、監視部７は、一定の時間間隔で、監視状態と停止状態とを切り替えてもよい。 (monitoring department)
The monitoring unit 7 monitors thermal noise contained in the monitoring signal Sa. More specifically, the monitoring unit 7 monitors thermal noise occurring in frequency bands other than the target frequency band in the monitoring signal Sa. The monitoring unit 7 of the present embodiment performs intermittent driving for switching between a monitoring state in which thermal noise is monitored and a stop state in which thermal noise monitoring is stopped. The monitoring unit 7 switches from the monitoring state to the stop state when an event (for example, external disturbance such as vibration or impact) occurs. Also, the monitoring unit 7 may switch between the monitoring state and the stop state at regular time intervals.
　監視部７は、図１に示すように、第２フィルタ８と、判定部９と、を具備する。 The monitoring unit 7 includes a second filter 8 and a determination unit 9, as shown in FIG.
　第２フィルタ８は、監視信号Ｓａのうち、第１フィルタ６１が通過させる対象周波数帯域を除く周波数帯域を通過させることで、監視信号Ｓａからサーマルノイズ信号Ｓ５を抽出する。本実施形態の第２フィルタ８は、第２変換信号Ｓ３を監視信号Ｓａとして、サーマルノイズ信号Ｓ５を抽出する。言い換えれば、本実施形態の第２フィルタ８は、ＡＤ変換部５から出力される第２変換信号Ｓ３のうち、第１フィルタ６１が通過させる対象周波数帯域を除く周波数帯域を通過させることで、第２変換信号Ｓ３からサーマルノイズ信号Ｓ５を抽出する。本実施形態では、サーマルノイズ信号Ｓ５はデジタル形式の信号である。 The second filter 8 extracts the thermal noise signal S5 from the monitoring signal Sa by passing the frequency band of the monitoring signal Sa excluding the target frequency band passed by the first filter 61 . The second filter 8 of the present embodiment extracts the thermal noise signal S5 using the second converted signal S3 as the monitoring signal Sa. In other words, the second filter 8 of the present embodiment passes the frequency band of the second converted signal S3 output from the AD converter 5, excluding the target frequency band passed by the first filter 61. 2. A thermal noise signal S5 is extracted from the converted signal S3. In this embodiment, the thermal noise signal S5 is a digital signal.
　本実施形態の第２フィルタ８は、第２変換信号Ｓ３のうち、遮断周波数より高い周波数の成分はほとんど減衰させず、遮断周波数より低い周波数の成分を逓減させるハイパスフィルタである。第２フィルタ８であるハイパスフィルタの遮断周波数は、第１フィルタ６１であるローパスフィルタの遮断周波数以上である。具体的には、第２フィルタ８にはデジタル形式の第２変換信号Ｓ３が通過するため、第２フィルタ８は、デジタルハイパスフィルタである。 The second filter 8 of the present embodiment is a high-pass filter that hardly attenuates the frequency components higher than the cutoff frequency and gradually reduces the frequency components lower than the cutoff frequency in the second converted signal S3. The cut-off frequency of the high-pass filter that is the second filter 8 is equal to or higher than the cut-off frequency of the low-pass filter that is the first filter 61 . Specifically, the second filter 8 is a digital high-pass filter because the second converted signal S3 in digital form passes through the second filter 8 .
　本実施形態の監視部７は、監視部７が監視状態である場合に第２フィルタ８に第２変換信号Ｓ３が入力され、監視部７が停止状態である場合に第２フィルタ８に第２変換信号Ｓ３が入力されないように構成されている。すなわち、本実施形態の監視部７は、監視部７が監視状態であるか停止状態であるかを、第２フィルタ８に第２変換信号Ｓ３が入力されるか否かによって制御している。 In the monitoring unit 7 of this embodiment, the second conversion signal S3 is input to the second filter 8 when the monitoring unit 7 is in the monitoring state, and the second conversion signal S3 is input to the second filter 8 when the monitoring unit 7 is in the stopped state. It is configured so that the conversion signal S3 is not input. That is, the monitoring unit 7 of this embodiment controls whether the monitoring unit 7 is in the monitoring state or in the stopped state depending on whether or not the second conversion signal S3 is input to the second filter 8 .
　判定部９は、サーマルノイズ信号Ｓ５の大きさを検出し、サーマルノイズ信号Ｓ５の大きさに基づいて検出素子２及び信号変換部３の少なくとも一方の異常を判定する。例えば、サーマルノイズ信号Ｓ５の大きさは、サーマルノイズ信号Ｓ５のエネルギー又は振幅である。一例として、縦軸をサーマルノイズ信号Ｓ５のエネルギーとし、横軸を時間とした場合のサーマルノイズ信号Ｓ５を図２に示す。 The determination unit 9 detects the magnitude of the thermal noise signal S5, and determines whether at least one of the detection element 2 and the signal conversion unit 3 is abnormal based on the magnitude of the thermal noise signal S5. For example, the magnitude of the thermal noise signal S5 is the energy or amplitude of the thermal noise signal S5. As an example, FIG. 2 shows the thermal noise signal S5 with the energy of the thermal noise signal S5 on the vertical axis and the time on the horizontal axis.
　本実施形態の判定部９は、サーマルノイズ信号Ｓ５の大きさが予め設定された所定範囲Ｒ１を超えた回数をカウント数としてカウントするカウント部９１を有する。カウント部９１は、サーマルノイズ信号Ｓ５の大きさの瞬時値が所定範囲Ｒ１を超えた回数をカウント数としてカウントする。 The determination unit 9 of the present embodiment has a counting unit 91 that counts the number of times the magnitude of the thermal noise signal S5 exceeds the preset range R1. The counting unit 91 counts the number of times the instantaneous value of the magnitude of the thermal noise signal S5 exceeds the predetermined range R1.
　より詳細には、カウント数は、サーマルノイズ信号Ｓ５の大きさが所定範囲Ｒ１の上限値Ｌ１を上回った回数と、サーマルノイズ信号Ｓ５の大きさが所定範囲Ｒ１の下限値Ｌ２を下回った回数と、の合計値である。所定範囲Ｒ１は、検出素子２及び信号変換部３の両方に異常がない場合のサーマルノイズ信号Ｓ５の大きさが所定範囲Ｒ１に含まれるように予め設定される。 More specifically, the count number is the number of times the magnitude of the thermal noise signal S5 exceeds the upper limit value L1 of the predetermined range R1 and the number of times the magnitude of the thermal noise signal S5 falls below the lower limit value L2 of the predetermined range R1. , is the total value of The predetermined range R1 is set in advance so that the magnitude of the thermal noise signal S5 when both the detection element 2 and the signal converter 3 are normal is included in the predetermined range R1.
　具体的に、カウント部９１が図２に示すサーマルノイズ信号Ｓ５をカウントする場合を例に挙げて説明する。図２に示すサーマルノイズ信号Ｓ５のエネルギーは、所定範囲Ｒ１を３回超えている。より詳細には、図２に示すサーマルノイズ信号Ｓ５のエネルギーは、時間ｔ１において所定範囲Ｒ１の下限値Ｌ２を下回っており、時間ｔ２及び時間ｔ３のそれぞれにおいて、所定範囲Ｒ１の上限値Ｌ１を上回っている。そのため、カウント部９１は、３をカウント数としてカウントする。 Specifically, a case where the counting unit 91 counts the thermal noise signal S5 shown in FIG. 2 will be described as an example. The energy of the thermal noise signal S5 shown in FIG. 2 exceeds the predetermined range R1 three times. More specifically, the energy of the thermal noise signal S5 shown in FIG. 2 is below the lower limit value L2 of the predetermined range R1 at time t1, and exceeds the upper limit value L1 of the predetermined range R1 at times t2 and t3. ing. Therefore, the counting unit 91 counts 3 as the count number.
　カウント部９１がカウントするカウント数は、一定周期毎にリセットされる。本実施形態では、監視部７が間欠駆動を行うため、カウント部９１がカウントするカウント数は、監視部７が停止状態になったタイミングでリセットされる。なお、カウント部９１のカウント数がリセットされるタイミングは、監視部７が所定の回数停止状態になったタイミングでリセットされていてもよい。 The count number counted by the counting unit 91 is reset at regular intervals. In this embodiment, since the monitoring unit 7 performs intermittent driving, the count number counted by the counting unit 91 is reset at the timing when the monitoring unit 7 is stopped. The timing at which the count number of the counting section 91 is reset may be the timing at which the monitoring section 7 is in the stop state for a predetermined number of times.
　判定部９は、カウント部９１がカウントするカウント数が予め設定された所定回数を超えた場合に、検出素子２及び信号変換部３の少なくとも一方の異常があると判定する。所定回数は、２以上であることが好ましい。すなわち、所定回数は、２以上の回数に予め設定されることが好ましい。 The determination unit 9 determines that at least one of the detection element 2 and the signal conversion unit 3 is abnormal when the count number counted by the counting unit 91 exceeds a predetermined number of times. The predetermined number of times is preferably two or more. That is, it is preferable that the predetermined number of times is set in advance to two or more times.
　判定部９は、検出素子２及び信号変換部３の少なくとも一方の異常があると判定する場合、検出素子２及び信号変換部３の少なくとも一方の異常を報知するエラー信号Ｓ６を出力する。より詳細には、判定部９は、カウント部９１がカウントするカウント数が予め設定された所定回数を超えた場合に、検出素子２及び信号変換部３の少なくとも一方の異常があると判定し、検出素子２及び信号変換部３の少なくとも一方の異常を報知するエラー信号Ｓ６を外部装置Ｂ１に出力する。 When determining that at least one of the detection element 2 and the signal conversion section 3 is abnormal, the determination section 9 outputs an error signal S6 that notifies at least one of the detection element 2 and the signal conversion section 3 is abnormal. More specifically, the determining unit 9 determines that at least one of the detecting element 2 and the signal converting unit 3 is abnormal when the number of counts counted by the counting unit 91 exceeds a predetermined number of times, An error signal S6 for notifying of an abnormality in at least one of the detection element 2 and the signal conversion unit 3 is output to the external device B1.
　（２－２）センサ装置の判定方法
　本実施形態のセンサ装置１の判定方法の動作について図３のフローチャートを用いて説明する。本実施形態のセンサ装置１の判定方法は、図３に示すように、アナログ処理ステップＳＴ１と、ＡＤ変換ステップＳＴ２と、デジタル処理ステップＳＴ３と、監視ステップＳＴ５と、を含む。 (2-2) Determination Method of Sensor Device The operation of the determination method of the sensor device 1 of the present embodiment will be described with reference to the flowchart of FIG. The determination method of the sensor device 1 of this embodiment includes, as shown in FIG. 3, an analog processing step ST1, an AD conversion step ST2, a digital processing step ST3, and a monitoring step ST5.
　まず、アナログ処理ステップＳＴ１では、アナログ処理部４は、検出信号Ｓ１が入力され、第１変換信号Ｓ２を出力する。より詳細には、アナログ処理ステップＳＴ１では、アナログ処理部４は、検出信号Ｓ１が入力され、電荷信号である検出信号Ｓ１を電圧信号である第１変換信号Ｓ２に変換し、出力する。 First, in the analog processing step ST1, the analog processing section 4 receives the detection signal S1 and outputs the first conversion signal S2. More specifically, in the analog processing step ST1, the analog processing unit 4 receives the detection signal S1, converts the detection signal S1, which is a charge signal, into a first conversion signal S2, which is a voltage signal, and outputs the first conversion signal S2.
　そして、ＡＤ変換ステップＳＴ２では、ＡＤ変換部５は、第１変換信号Ｓ２を第２変換信号Ｓ３に変換する。より詳細には、ＡＤ変換ステップＳＴ２では、ＡＤ変換部５は、アナログ形式の第１変換信号Ｓ２をデジタル形式の第２変換信号Ｓ３に変換して、デジタル処理部６に第２変換信号Ｓ３を出力する。 Then, in the AD conversion step ST2, the AD converter 5 converts the first converted signal S2 into the second converted signal S3. More specifically, in the AD conversion step ST2, the AD conversion unit 5 converts the first converted signal S2 in analog format into a second converted signal S3 in digital format, and transmits the second converted signal S3 to the digital processing unit 6. Output.
　デジタル処理ステップＳＴ３は、第１フィルタリングステップＳＴ３１と、算出ステップＳＴ３２と、を含む。第１フィルタリングステップＳＴ３１では、第１フィルタ６１は、ＡＤ変換ステップＳＴ２においてＡＤ変換部５から出力される第２変換信号Ｓ３のうち処理対象となる周波数帯域である対象周波数帯域を通過させる。すなわち、第１フィルタリングステップＳＴ３１では、デジタル処理部６は、第１フィルタ６１を通して、第２変換信号Ｓ３から対象周波数帯域の信号を抽出する。そして、算出ステップＳＴ３２では、デジタル処理部６は、抽出した対象周波数帯域の信号について、ゲイン調整又はオフセット調整を行い、検出素子２が検出した応力を算出し、算出された応力に関する情報を出力信号Ｓ４として出力する。 The digital processing step ST3 includes a first filtering step ST31 and a calculation step ST32. In the first filtering step ST31, the first filter 61 passes the target frequency band, which is the frequency band to be processed in the second converted signal S3 output from the AD converter 5 in the AD conversion step ST2. That is, in the first filtering step ST31, the digital processing section 6 passes through the first filter 61 and extracts the signal of the target frequency band from the second converted signal S3. Then, in the calculation step ST32, the digital processing unit 6 performs gain adjustment or offset adjustment on the extracted target frequency band signal, calculates the stress detected by the detection element 2, and outputs information on the calculated stress as an output signal. Output as S4.
　その後、監視部７が監視状態であるとき（ＳＴ４：Ｙｅｓ）、監視ステップＳＴ５では、監視部７が、第２変換信号Ｓ３を監視信号Ｓａとして、監視信号Ｓａに含まれるサーマルノイズを監視する。 After that, when the monitoring unit 7 is in the monitoring state (ST4: Yes), in the monitoring step ST5, the monitoring unit 7 uses the second converted signal S3 as the monitoring signal Sa to monitor thermal noise contained in the monitoring signal Sa.
　より詳細には、監視ステップＳＴ５は、第２フィルタリングステップＳＴ５１と、判定ステップＳＴ５２と、を含む。第２フィルタリングステップＳＴ５１では、第２フィルタ８は、監視信号Ｓａのうち、第１フィルタリングステップＳＴ３１において通過させる対象周波数帯域を除く周波数帯域を通過させることで、監視信号Ｓａからサーマルノイズ信号Ｓ５を抽出する。本実施形態の第２フィルタリングステップＳＴ５１では、第２フィルタ８は、ＡＤ変換ステップＳＴ２において出力される第２変換信号Ｓ３のうち、第１フィルタ６１が通過させる対象周波数帯域を除く周波数帯域を通過させることで、第２変換信号Ｓ３からサーマルノイズ信号Ｓ５を抽出する。 More specifically, the monitoring step ST5 includes a second filtering step ST51 and a determination step ST52. In the second filtering step ST51, the second filter 8 extracts the thermal noise signal S5 from the supervisory signal Sa by passing the frequency band of the supervisory signal Sa excluding the target frequency band passed in the first filtering step ST31. do. In the second filtering step ST51 of the present embodiment, the second filter 8 passes the frequency band of the second converted signal S3 output in the AD conversion step ST2, excluding the target frequency band passed by the first filter 61. Thus, the thermal noise signal S5 is extracted from the second converted signal S3.
　その後、判定ステップＳＴ５２では、判定部９は、サーマルノイズ信号Ｓ５の大きさを検出し、サーマルノイズ信号Ｓ５の大きさに基づいて検出素子２及び信号変換部３の少なくとも一方の異常を判定する。より詳細に、判定ステップＳＴ５２について説明する。まず、判定ステップＳＴ５２では、カウント部９１は、サーマルノイズ信号Ｓ５の大きさが予め設定された所定範囲Ｒ１を超えた回数をカウント数としてカウントする。その後、判定部９は、カウント部９１がカウントするカウント数が予め設定された所定回数を超えた場合に、検出素子２及び信号変換部３の少なくとも一方の異常があると判定し、検出素子２及び信号変換部３の少なくとも一方の異常を報知するエラー信号Ｓ６を外部装置Ｂ１に出力する。 After that, in determination step ST52, the determination section 9 detects the magnitude of the thermal noise signal S5, and determines whether at least one of the detection element 2 and the signal conversion section 3 is abnormal based on the magnitude of the thermal noise signal S5. The determination step ST52 will be described in more detail. First, in determination step ST52, the counting section 91 counts the number of times the magnitude of the thermal noise signal S5 exceeds a preset range R1 as a count number. After that, when the number of counts counted by the counting unit 91 exceeds a predetermined number of times, the determining unit 9 determines that at least one of the detecting element 2 and the signal converting unit 3 is abnormal. and output an error signal S6 notifying of an abnormality in at least one of the signal converters 3 to the external device B1.
　一方、監視部７が監視状態でないとき（ＳＴ４：Ｎｏ）、すなわち、監視部７が停止状態であるとき、センサ装置１は監視ステップＳＴ５を実施しない。 On the other hand, when the monitoring unit 7 is not in the monitoring state (ST4: No), that is, when the monitoring unit 7 is in the stopped state, the sensor device 1 does not perform the monitoring step ST5.
　図３のフローチャートは、本実施形態のセンサ装置１の判定方法の一例に過ぎず、その処理の順序が適宜入れ替わっていてもよいし、いずれかの処理について適宜省略されてもよい。 The flowchart of FIG. 3 is merely an example of the determination method of the sensor device 1 of the present embodiment, and the order of the processing may be changed as appropriate, or any processing may be omitted as appropriate.
　例えば、本実施形態では、デジタル処理ステップＳＴ３の後に監視ステップＳＴ５を実施しているが、アナログ処理ステップＳＴ１の前に監視ステップＳＴ５を実施してもよい。また、監視ステップＳＴ５は、アナログ処理ステップＳＴ１、ＡＤ変換ステップＳＴ２、及びデジタル処理ステップＳＴ３を実施するタイミングと同じタイミングで実施してもよい。 For example, in this embodiment, the monitoring step ST5 is performed after the digital processing step ST3, but the monitoring step ST5 may be performed before the analog processing step ST1. Also, the monitoring step ST5 may be performed at the same timing as the analog processing step ST1, the AD conversion step ST2, and the digital processing step ST3.
　なお、監視ステップＳＴ５は、アナログ処理ステップＳＴ１、ＡＤ変換ステップＳＴ２、及びデジタル処理ステップＳＴ３を実施するタイミングと独立したタイミングで実施してもよい。 Note that the monitoring step ST5 may be performed at a timing independent of the timing of performing the analog processing step ST1, the AD conversion step ST2, and the digital processing step ST3.
　（３）利点
　センサ装置１は、図１に示すように、検出素子２と、信号変換部３と、第１フィルタ６１と、監視部７と、を備える。検出素子２は、応力に応じて検出信号Ｓ１を出力する。信号変換部３は、検出信号Ｓ１の信号変換を行う。第１フィルタ６１は、信号変換部３から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる。監視部７は、第１フィルタ６１を通過する前の信号である監視信号Ｓａに含まれるサーマルノイズを監視する。監視部７は、第２フィルタ８と、判定部９と、を具備する。第２フィルタ８は、監視信号Ｓａのうち対象周波数帯域を除く周波数帯域を通過させることで、監視信号Ｓａからサーマルノイズ信号Ｓ５を抽出する。判定部９は、サーマルノイズ信号Ｓ５の大きさを検出し、サーマルノイズ信号Ｓ５の大きさに基づいて検出素子２及び信号変換部３の少なくとも一方の異常を判定する。 (3) Advantages As shown in FIG. 1, the sensor device 1 includes a detection element 2, a signal converter 3, a first filter 61, and a monitor . The detection element 2 outputs a detection signal S1 according to the stress. The signal converter 3 converts the detection signal S1. The first filter 61 passes a target frequency band, which is a frequency band to be processed in the signal output from the signal conversion unit 3 . The monitoring unit 7 monitors thermal noise contained in the monitoring signal Sa, which is the signal before passing through the first filter 61 . The monitoring unit 7 has a second filter 8 and a determination unit 9 . The second filter 8 extracts the thermal noise signal S5 from the supervisory signal Sa by passing the frequency band of the supervisory signal Sa excluding the target frequency band. The determination unit 9 detects the magnitude of the thermal noise signal S5 and determines whether at least one of the detection element 2 and the signal conversion unit 3 is abnormal based on the magnitude of the thermal noise signal S5.
　この構成によると、センサ装置１は、監視信号Ｓａのうち対象周波数帯域を除く周波数帯域に発生しているサーマルノイズを直接監視することで、対象周波数帯域で発生しているサーマルノイズの増大につながる、検出素子２及び信号変換部３の少なくとも一方の異常を判定することができる。より詳細には、センサ装置１は、監視信号Ｓａのうち対象周波数帯域を除く周波数帯域に発生しているサーマルノイズを直接監視することで、対象周波数帯域で発生しているサーマルノイズの増大につながる、検出素子２、アナログ処理部４、及びＡＤ変換部５の少なくともいずれか１つの異常を判定することができる。すなわち、センサ装置１は、サーマルノイズの増大につながる故障を自己診断するために、冗長な回路を更に実装する必要がなくなるという効果を奏する。そのため、本実施形態のセンサ装置１は、サーマルノイズの増大につながる故障を自己診断しつつ、大型化の抑制を図ることができるという利点がある。 According to this configuration, the sensor device 1 directly monitors the thermal noise generated in the frequency band excluding the target frequency band in the monitor signal Sa, which leads to an increase in the thermal noise generated in the target frequency band. , the abnormality of at least one of the detection element 2 and the signal conversion unit 3 can be determined. More specifically, the sensor device 1 directly monitors the thermal noise generated in the frequency bands other than the target frequency band in the monitor signal Sa, which leads to an increase in the thermal noise generated in the target frequency band. , the detection element 2 , the analog processing unit 4 , and the AD conversion unit 5 . That is, the sensor device 1 has the effect of eliminating the need to further implement a redundant circuit in order to self-diagnose a failure leading to an increase in thermal noise. Therefore, the sensor device 1 of the present embodiment has the advantage of being able to self-diagnose failures that lead to an increase in thermal noise while suppressing an increase in size.
　センサ装置１では、判定部９は、カウント部９１がカウントするカウント数が予め設定された所定回数を超えた場合に、検出素子２及び信号変換部３の少なくとも一方の異常があると判定し、所定回数は２以上の回数に予め設定される。 In the sensor device 1, the determination unit 9 determines that at least one of the detection element 2 and the signal conversion unit 3 is abnormal when the number of counts counted by the counting unit 91 exceeds a predetermined number of times, and The predetermined number of times is set in advance to two or more times.
　この構成によると、サーマルノイズ信号Ｓ５が突発的に上昇した場合において、判定部９は、検出素子２及び信号変換部３の少なくとも一方の異常があるとは判定しない。すなわち、本実施形態のセンサ装置１は、サーマルノイズの増大につながる故障を誤診断することを抑制することができるという利点がある。 According to this configuration, when the thermal noise signal S5 suddenly rises, the determination unit 9 does not determine that at least one of the detection element 2 and the signal conversion unit 3 is abnormal. That is, the sensor device 1 of the present embodiment has the advantage of being able to suppress erroneous diagnosis of failures that lead to an increase in thermal noise.
　センサ装置１では、監視部７は、サーマルノイズの監視を行う監視状態と、サーマルノイズの監視を停止する停止状態と、を切り替える間欠駆動を行う。 In the sensor device 1, the monitoring unit 7 performs intermittent driving to switch between a monitoring state in which thermal noise is monitored and a stop state in which thermal noise monitoring is stopped.
　この構成によると、外乱が発生したときに監視部７が監視状態から停止状態に切り替える場合、判定部９が、外乱の影響によって、検出素子２及び信号変換部３の少なくとも一方の異常があると誤判定することを抑制できる。すなわち、外乱の影響を抑制することができるという利点がある。また、一定の時間間隔で監視部７が監視状態と停止状態とを切り替える場合、消費電力を削減することができるという利点がある。 According to this configuration, when the monitoring unit 7 switches from the monitoring state to the stop state when a disturbance occurs, the determination unit 9 determines that at least one of the detection element 2 and the signal conversion unit 3 is abnormal due to the influence of the disturbance. Misjudgment can be suppressed. That is, there is an advantage that the influence of disturbance can be suppressed. Moreover, when the monitoring unit 7 switches between the monitoring state and the stop state at regular time intervals, there is an advantage that power consumption can be reduced.
　センサ装置１では、判定部９は、検出素子２及び信号変換部３の少なくとも一方の異常があると判定する場合、検出素子２及び信号変換部３の少なくとも一方の故障を報知するエラー信号Ｓ６を出力する。 In the sensor device 1, when determining that at least one of the detection element 2 and the signal conversion section 3 is abnormal, the determination section 9 outputs an error signal S6 that notifies of a failure of at least one of the detection element 2 and the signal conversion section 3. Output.
　この構成によれば、センサ装置１の使用者及び管理者が、検出素子２及び信号変換部３の少なくとも一方の異常を知ることができるという利点がある。 According to this configuration, there is an advantage that the user and administrator of the sensor device 1 can know the abnormality of at least one of the detection element 2 and the signal conversion section 3.
　センサ装置１では、検出素子２は、微小電気機械システムを含む。 In the sensor device 1, the sensing element 2 includes a microelectromechanical system.
　この構成によると、センサ装置１を小型化することができるという利点がある。 According to this configuration, there is an advantage that the sensor device 1 can be miniaturized.
　（４）変形例
　上述の実施形態は、本開示の様々な実施形態の一つに過ぎない。上述の実施形態は、本開示の目的を達成できれば、設計等に応じて種々の変更が可能である。 (4) Modifications The above-described embodiment is just one of various embodiments of the present disclosure. The above-described embodiments can be modified in various ways according to design and the like as long as the object of the present disclosure can be achieved.
　（４－１）第１変形例
　第１変形例のセンサ装置１ａの構成を図４に示す。 (4-1) First Modification FIG. 4 shows the configuration of the sensor device 1a of the first modification.
　上述の実施形態では、センサ装置１の監視部７は第２変換信号Ｓ３に含まれるサーマルノイズを監視していたが、センサ装置１ａの監視部７ａは第１変換信号Ｓ２に含まれるサーマルノイズを監視してもよい。言い換えれば、上述の実施形態では、第２フィルタ８は、第２変換信号Ｓ３を監視信号Ｓａとして、サーマルノイズ信号Ｓ５を抽出するが、第１変形例では、第１変換信号Ｓ２を監視信号Ｓａとして、サーマルノイズ信号Ｓ５を抽出する。 In the above embodiment, the monitoring unit 7 of the sensor device 1 monitors the thermal noise contained in the second converted signal S3, but the monitoring unit 7a of the sensor device 1a detects the thermal noise contained in the first converted signal S2. may be monitored. In other words, in the above-described embodiment, the second filter 8 uses the second converted signal S3 as the monitoring signal Sa to extract the thermal noise signal S5. , the thermal noise signal S5 is extracted.
　より詳細には、監視部７ａは、図４に示すように、ＡＤ変換部９２と、第２フィルタ８ａを有する。ＡＤ変換部９２は、アナログ処理部４と第２フィルタ８ａとの間に配置される。ＡＤ変換部９２は、アナログ処理部４から出力されるアナログ形式の第１変換信号Ｓ２をデジタル形式に変換し、第３変換信号Ｓ２１として第２フィルタ８ａに出力する。 More specifically, the monitoring unit 7a has an AD conversion unit 92 and a second filter 8a, as shown in FIG. The AD conversion section 92 is arranged between the analog processing section 4 and the second filter 8a. The AD conversion section 92 converts the analog first converted signal S2 output from the analog processing section 4 into a digital form, and outputs the converted signal as a third converted signal S21 to the second filter 8a.
　第２フィルタ８ａは、ＡＤ変換部９２から出力された第３変換信号Ｓ２１のうち、第１フィルタ６１が通過させる対象周波数帯域を除く周波数帯域を通過させることで、第３変換信号Ｓ２１からサーマルノイズ信号Ｓ５を抽出する。第３変換信号Ｓ２１は第１変換信号Ｓ２をデジタル形式に変換したものであるため、第３変換信号Ｓ２１に含まれるサーマルノイズは、第１変換信号Ｓ２に含まれるサーマルノイズに相当する。そのため、実質的には、第２フィルタ８ａは、第１変換信号Ｓ２を監視信号Ｓａとして、第１変換信号Ｓ２のうち、第１フィルタ６１が通過させる対象周波数帯域を除く周波数帯域を通過させることで、第１変換信号Ｓ２からサーマルノイズ信号Ｓ５を抽出する。なお、第２フィルタ８ａにはデジタル形式の第３変換信号Ｓ２１が通過するため、第２フィルタ８ａは、デジタルハイパスフィルタである。 The second filter 8a passes the frequency band of the third converted signal S21 output from the AD conversion unit 92, excluding the target frequency band passed by the first filter 61, thereby reducing the thermal noise from the third converted signal S21. Extract the signal S5. Since the third conversion signal S21 is obtained by converting the first conversion signal S2 into a digital form, the thermal noise included in the third conversion signal S21 corresponds to the thermal noise included in the first conversion signal S2. Therefore, substantially, the second filter 8a uses the first converted signal S2 as the supervisory signal Sa, and passes the frequency band of the first converted signal S2 excluding the target frequency band passed by the first filter 61. , the thermal noise signal S5 is extracted from the first converted signal S2. The second filter 8a is a digital high-pass filter because the third converted signal S21 in digital form passes through the second filter 8a.
　なお、図４に示すＡＤ変換部９２は、アナログ処理部４と第２フィルタ８ａとの間に配置されているが、第２フィルタ８ａと判定部９の間に配置されていてもよい。ＡＤ変換部９２が第２フィルタ８ａと判定部９の間に配置されている場合、第２フィルタ８ａは、第１変換信号Ｓ２を監視信号Ｓａとして、第１変換信号Ｓ２のうち、第１フィルタ６１が通過させる対象周波数帯域を除く周波数帯域を通過させることで、第１変換信号Ｓ２からサーマルノイズ信号Ｓ５を抽出する。この場合、第２フィルタ８ａにはアナログ形式の第１変換信号Ｓ２が通過するため、第２フィルタ８ａはアナログハイパスフィルタである。ＡＤ変換部９２は、第２フィルタ８ａから出力されるアナログ形式のサーマルノイズ信号Ｓ５をデジタル形式に変換し、判定部９に出力する。 Note that the AD conversion section 92 shown in FIG. 4 is arranged between the analog processing section 4 and the second filter 8a, but may be arranged between the second filter 8a and the determination section 9. When the AD converter 92 is arranged between the second filter 8a and the determination unit 9, the second filter 8a uses the first converted signal S2 as the monitor signal Sa, and the first filter The thermal noise signal S5 is extracted from the first converted signal S2 by passing a frequency band excluding the target frequency band passed by 61 . In this case, the second filter 8a is an analog high-pass filter because the analog first converted signal S2 passes through the second filter 8a. The AD converter 92 converts the analog thermal noise signal S5 output from the second filter 8a into a digital format and outputs it to the determination unit 9 .
　（４－２）第２変形例
　以下、上述の実施形態の変形例を列挙する。以下の変形例は、適宜組み合わせて実現されてもよい。 (4-2) Second Modification Modifications of the above embodiment will be listed below. The following modified examples may be implemented in combination as appropriate.
　上述の実施形態の検出素子２は、ジャイロセンサであるが、加速度センサであってもよい。 The detection element 2 in the above-described embodiment is a gyro sensor, but may be an acceleration sensor.
　また、本実施形態の検出素子２は、１軸のジャイロセンサであるが、２軸又は３軸のジャイロセンサであってもよい。すなわち、検出素子２は、多軸一体型のジャイロセンサであってもよい。 Also, the detection element 2 of the present embodiment is a uniaxial gyro sensor, but may be a biaxial or triaxial gyro sensor. That is, the detection element 2 may be a multi-axis integrated gyro sensor.
　上述の実施形態の第１フィルタ６１は、ローパスフィルタであるが、ハイパスフィルタであってもよい。第１フィルタ６１がハイパスフィルタである場合、第２フィルタ８はローパスフィルタである。このとき、第２フィルタ８であるローパスフィルタの遮断周波数は、第１フィルタ６１であるハイパスフィルタの遮断周波数よりも低い。 Although the first filter 61 in the above embodiment is a low-pass filter, it may be a high-pass filter. If the first filter 61 is a high pass filter, the second filter 8 is a low pass filter. At this time, the cutoff frequency of the low-pass filter that is the second filter 8 is lower than the cutoff frequency of the high-pass filter that is the first filter 61 .
　上述の実施形態の第２フィルタ８は、ハイパスフィルタである。しかし、第２フィルタ８は、第１フィルタ６１が通過させる対象周波数帯域を除く周波数帯域のうち特定の周波数帯域を通過させるバンドパスフィルタであってもよい。 The second filter 8 in the above embodiment is a high pass filter. However, the second filter 8 may be a bandpass filter that passes a specific frequency band out of the frequency bands excluding the target frequency band that the first filter 61 passes.
　上述の実施形態の監視部７は、サーマルノイズの監視を行う監視状態と、サーマルノイズの監視を停止する停止状態と、を切り替える間欠駆動を行う。しかし、監視部７は、間欠駆動を行わず、常時監視状態であってもよい。 The monitoring unit 7 of the above-described embodiment performs intermittent driving to switch between a monitoring state in which thermal noise is monitored and a stop state in which thermal noise monitoring is stopped. However, the monitoring unit 7 may be in a constant monitoring state without performing intermittent driving.
　また、上述の実施形態の監視部７は、監視部７が監視状態である場合に第２フィルタ８に第２変換信号Ｓ３が入力され、監視部７が停止状態である場合に第２フィルタ８に第２変換信号Ｓ３が入力されないように構成されている。しかし、監視部７は、監視部７が監視状態である場合に判定部９にサーマルノイズ信号Ｓ５に入力され、監視部７が停止状態である場合に判定部９にサーマルノイズ信号Ｓ５に入力されないように構成されていてもよい。すなわち、上述の実施形態の監視部７は、監視部７が監視状態であるか停止状態であるかを、第２フィルタ８に第２変換信号Ｓ３が入力されるか否かによって制御しているが、判定部９にサーマルノイズ信号Ｓ５に入力されるか否かによって制御してもよい。 Further, in the monitoring unit 7 of the above-described embodiment, the second conversion signal S3 is input to the second filter 8 when the monitoring unit 7 is in the monitoring state, and the second filter 8 is input when the monitoring unit 7 is in the stopped state. is configured so that the second conversion signal S3 is not input to the . However, the monitoring unit 7 inputs the thermal noise signal S5 to the determination unit 9 when the monitoring unit 7 is in the monitoring state, and does not input the thermal noise signal S5 to the determination unit 9 when the monitoring unit 7 is in the stopped state. It may be configured as That is, the monitoring unit 7 of the above-described embodiment controls whether the monitoring unit 7 is in the monitoring state or in the stopped state depending on whether or not the second conversion signal S3 is input to the second filter 8. may be controlled by determining whether or not the thermal noise signal S5 is input to the determination unit 9. FIG.
　上述の実施形態のカウント部９１は、サーマルノイズ信号Ｓ５の大きさの瞬時値が予め設定された所定範囲Ｒ１を超えた回数をカウント数としてカウントする。また、カウント部９１は、サーマルノイズ信号Ｓ５の大きさの単位時間における平均値が、所定範囲Ｒ１を超えた回数をカウント数としてカウントしてもよい。単位時間が短いほど、判定部９が異常の有無を判定する精度は高くなる。なお、判定部９が異常の有無を判定する精度を考慮すると、単位時間は、サーマルノイズの周期よりも短いことが望ましい。 The counting unit 91 of the above-described embodiment counts the number of times the instantaneous value of the magnitude of the thermal noise signal S5 exceeds the predetermined range R1 set in advance. Further, the counting unit 91 may count the number of times the average value of the magnitude of the thermal noise signal S5 per unit time exceeds the predetermined range R1. The shorter the unit time, the higher the accuracy with which the determination unit 9 determines whether there is an abnormality. Considering the accuracy with which the determination unit 9 determines whether or not there is an abnormality, it is desirable that the unit time be shorter than the period of the thermal noise.
　上述の実施形態のカウント部９１のカウント数は、監視部７が停止状態になったタイミングでリセットされる。しかし、カウント部９１のカウント数がリセットされるタイミングは、監視部７が間欠駆動を行うタイミングと連動していなくてもよい。 The count number of the counting unit 91 in the above embodiment is reset at the timing when the monitoring unit 7 is stopped. However, the timing at which the count number of the counting unit 91 is reset does not have to be linked with the timing at which the monitoring unit 7 performs intermittent driving.
　上記の実施形態では、センサ装置１は、検出素子２、信号変換部３、デジタル処理部６、及び監視部７が一体的にパッケージ化されていることを想定する。しかし、センサ装置１では、信号変換部３、デジタル処理部６、及び監視部７の少なくとも一部が検出素子２と別体となって提供されてもよい。具体的には、例えば、センサ装置１は、信号変換部３、デジタル処理部６、及び監視部７が検出素子２と別体となって提供されてもよいし、或いは監視部７だけが、検出素子２、信号変換部３、及びデジタル処理部６と別体となって提供されてもよい。 In the above embodiment, the sensor device 1 assumes that the detection element 2, the signal conversion section 3, the digital processing section 6, and the monitoring section 7 are integrally packaged. However, in the sensor device 1 , at least part of the signal converter 3 , the digital processor 6 , and the monitor 7 may be provided separately from the detection element 2 . Specifically, for example, in the sensor device 1, the signal conversion unit 3, the digital processing unit 6, and the monitoring unit 7 may be provided separately from the detection element 2, or only the monitoring unit 7 may It may be provided separately from the detection element 2 , the signal conversion section 3 and the digital processing section 6 .
　（まとめ）
　実施形態に係る第１の態様のセンサ装置（１、１ａ）は、検出素子（２）と、信号変換部（３）と、第１フィルタ（６１）と、監視部（７、７ａ）と、を備える。検出素子（２）は、応力に応じて検出信号（Ｓ１）を出力する。信号変換部（３）は、検出信号（Ｓ１）の信号変換を行う。第１フィルタ（６１）は、信号変換部（３）から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる。監視部（７、７ａ）は、第１フィルタ（６１）を通過する前の信号である監視信号（Ｓａ）に含まれるサーマルノイズを監視する。監視部（７、７ａ）は、第２フィルタ（８、８ａ）と、判定部（９）と、を有する。第２フィルタ（８、８ａ）は、監視信号（Ｓａ）のうち対象周波数帯域を除く周波数帯域を通過させることで、監視信号（Ｓａ）からサーマルノイズ信号（Ｓ５）を抽出する。判定部（９）は、サーマルノイズ信号（Ｓ５）の大きさを検出し、サーマルノイズ信号（Ｓ５）の大きさに基づいて検出素子（２）及び信号変換部（３）の少なくとも一方の異常を判定する。 (summary)
A sensor device (1, 1a) of a first aspect according to an embodiment includes a detection element (2), a signal converter (3), a first filter (61), a monitor (7, 7a), Prepare. The detection element (2) outputs a detection signal (S1) according to the stress. A signal converter (3) converts the detection signal (S1). A first filter (61) passes a target frequency band, which is a frequency band to be processed in the signal output from the signal converter (3). The monitoring units (7, 7a) monitor thermal noise contained in the monitoring signal (Sa), which is the signal before passing through the first filter (61). The monitoring section (7, 7a) has a second filter (8, 8a) and a determining section (9). The second filter (8, 8a) extracts the thermal noise signal (S5) from the supervisory signal (Sa) by passing the frequency band of the supervisory signal (Sa) excluding the target frequency band. A judging section (9) detects the magnitude of the thermal noise signal (S5) and detects an abnormality in at least one of the detecting element (2) and the signal converting section (3) based on the magnitude of the thermal noise signal (S5). judge.
　この態様によれば、サーマルノイズの増大につながる故障を自己診断しつつ、大型化の抑制を図ることができる、という利点がある。 According to this aspect, there is an advantage that it is possible to self-diagnose failures that lead to an increase in thermal noise, and to suppress an increase in size.
　実施形態に係る第２の態様のセンサ装置（１）では、第１の態様において、信号変換部（３）は、アナログ処理部（４）と、ＡＤ変換部（５）と、を有する。アナログ処理部（４）は、検出信号（Ｓ１）が入力され、第１変換信号（Ｓ２）を出力する。ＡＤ変換部（５）は、第１変換信号（Ｓ２）を第２変換信号（Ｓ３）に変換する。第２フィルタ（８）は、第２変換信号（Ｓ３）を監視信号（Ｓａ）として、サーマルノイズ信号（Ｓ５）を抽出する。 In the sensor device (1) of the second aspect according to the embodiment, in the first aspect, the signal converter (3) has an analog processor (4) and an AD converter (5). The analog processing section (4) receives the detection signal (S1) and outputs a first conversion signal (S2). The AD converter (5) converts the first converted signal (S2) into a second converted signal (S3). A second filter (8) extracts a thermal noise signal (S5) using the second converted signal (S3) as a supervisory signal (Sa).
　この態様によれば、検出素子（２）及び信号変換部（３）におけるサーマルノイズの増大につながる故障を自己診断しつつ、大型化の抑制を図ることができる、という利点がある。 According to this aspect, there is an advantage that it is possible to self-diagnose failures that lead to an increase in thermal noise in the detection element (2) and the signal conversion section (3), while suppressing an increase in size.
　実施形態に係る第３の態様のセンサ装置（１ａ）では、第１の態様において、信号変換部（３）は、アナログ処理部（４）と、ＡＤ変換部（５）と、を有する。アナログ処理部（４）は、検出信号（Ｓ１）が入力され、第１変換信号（Ｓ２）を出力する。ＡＤ変換部（５）は、第１変換信号（Ｓ２）を第２変換信号（Ｓ３）に変換する。第２フィルタ（８ａ）は、第１変換信号（Ｓ２）を監視信号（Ｓａ）として、サーマルノイズ信号（Ｓ５）を抽出する。 In the sensor device (1a) of the third aspect according to the embodiment, in the first aspect, the signal converter (3) has an analog processor (4) and an AD converter (5). The analog processing section (4) receives the detection signal (S1) and outputs a first conversion signal (S2). The AD converter (5) converts the first converted signal (S2) into a second converted signal (S3). A second filter (8a) extracts a thermal noise signal (S5) using the first converted signal (S2) as a supervisory signal (Sa).
　この態様によれば、検出素子（２）及びアナログ処理部（４）におけるサーマルノイズの増大につながる故障を自己診断しつつ、大型化の抑制を図ることができる、という利点がある。 According to this aspect, there is an advantage that it is possible to self-diagnose failures that lead to an increase in thermal noise in the detection element (2) and the analog processing section (4), while suppressing an increase in size.
　実施形態に係る第４の態様のセンサ装置（１、１ａ）では、第１～第３のいずれかの態様において、判定部（９）は、サーマルノイズ信号（Ｓ５）の大きさが予め設定された所定範囲（Ｒ１）を超えた回数をカウント数としてカウントするカウント部（９１）を有する。 In the sensor device (1, 1a) of the fourth aspect according to the embodiment, in any one of the first to third aspects, the determination section (9) is configured such that the magnitude of the thermal noise signal (S5) is preset. It has a counting section (91) that counts the number of times that the predetermined range (R1) is exceeded as the number of counts.
　この態様によれば、サーマルノイズ信号（Ｓ５）の大きさを定量的に評価することができる、という利点がある。 According to this aspect, there is an advantage that the magnitude of the thermal noise signal (S5) can be quantitatively evaluated.
　実施形態に係る第５の態様のセンサ装置（１、１ａ）では、第４の態様において、判定部（９）は、カウント数が予め設定された所定回数を超えた場合に、検出素子（２）及び信号変換部（３）の少なくとも一方の異常があると判定する。 In the sensor device (1, 1a) of the fifth aspect according to the embodiment, in the fourth aspect, the determination unit (9) detects the detection element (2 ) and signal converter (3) is determined to be abnormal.
　この態様によれば、サーマルノイズの増大につながる故障をより精度高く自己診断することができる、という利点がある。 According to this aspect, there is an advantage that it is possible to more accurately self-diagnose failures that lead to an increase in thermal noise.
　実施形態に係る第６の態様のセンサ装置（１、１ａ）では、第５の態様において、所定回数は、２以上である。 In the sensor device (1, 1a) of the sixth aspect according to the embodiment, in the fifth aspect, the predetermined number of times is 2 or more.
　この態様によれば、サーマルノイズの増大につながる故障を誤診断することを抑制することができる、という利点がある。 According to this aspect, there is an advantage that it is possible to suppress erroneous diagnosis of failures that lead to an increase in thermal noise.
　実施形態に係る第７の態様のセンサ装置（１、１ａ）では、第１～第６のいずれかの態様において、検出素子（２）は、微小電気機械システムを含む。 In the sensor device (1, 1a) of the seventh aspect according to the embodiment, in any one of the first to sixth aspects, the detection element (2) includes a microelectromechanical system.
　この態様によれば、センサ装置（１）をより小型化することができる、という利点がある。 According to this aspect, there is an advantage that the sensor device (1) can be made more compact.
　実施形態に係る第８の態様のセンサ装置（１、１ａ）では、第１～第７のいずれかの態様において、監視部（７）は、サーマルノイズの監視を行う監視状態と、サーマルノイズの監視を停止する停止状態と、を切り替える間欠駆動を行う。 In the sensor device (1, 1a) of the eighth mode according to the embodiment, in any one of the first to seventh modes, the monitoring unit (7) monitors a thermal noise monitoring state and a thermal noise monitoring state. Intermittent drive is performed to switch between a stop state in which monitoring is stopped and a state in which monitoring is stopped.
　この態様によれば、外乱の影響を抑制することができる、という利点がある。 According to this aspect, there is an advantage that the influence of disturbance can be suppressed.
　実施形態に係る第９の態様のセンサ装置（１、１ａ）では、第１～第８のいずれかの態様において、判定部（９）は、検出素子（２）及び信号変換部（３）の少なくとも一方の異常があると判定する場合、検出素子（２）及び信号変換部（３）の少なくとも一方の異常を報知するエラー信号（Ｓ６）を出力する。 In the sensor device (1, 1a) of the ninth aspect according to the embodiment, in any one of the first to eighth aspects, the determination unit (9) comprises the detection element (2) and the signal conversion unit (3). If it is determined that at least one of them is abnormal, it outputs an error signal (S6) that reports that at least one of the detection element (2) and the signal converter (3) is abnormal.
　この態様によれば、センサ装置（１、１ａ）の使用者及び管理者が、検出素子（２）及び信号変換部（３）の少なくとも一方の異常を知ることができる、という利点がある。 According to this aspect, there is an advantage that the user and administrator of the sensor device (1, 1a) can know the abnormality of at least one of the detection element (2) and the signal conversion section (3).
　実施形態に係る第１０の態様のセンサ装置（１、１ａ）の判定方法は、検出素子（２）と、信号変換部（３）と、を備えるセンサ装置（１、１ａ）の判定方法である。検出素子（２）は、応力に応じて検出信号（Ｓ１）を出力する。信号変換部（３）は、検出信号の信号変換を行う。センサ装置（１、１ａ）の判定方法は、第１フィルタリングステップ（ＳＴ３１）と、監視ステップ（ＳＴ５）と、を含む。第１フィルタリングステップ（ＳＴ３１）は、信号変換部（３）から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる。監視ステップ（ＳＴ５）は、第１フィルタリングステップ（ＳＴ３１）を行う前の信号である監視信号（Ｓａ）に含まれるサーマルノイズを監視する。監視ステップ（ＳＴ５）は、第２フィルタリングステップ（ＳＴ５１）と、判定ステップ（ＳＴ５２）と、を含む。第２フィルタリングステップ（ＳＴ５１）は、監視信号（Ｓａ）のうち対象周波数帯域を除く周波数帯域を通過させることで、監視信号（Ｓａ）からサーマルノイズ信号（Ｓ５）を抽出する。判定ステップ（ＳＴ５２）は、サーマルノイズ信号（Ｓ５）の大きさを検出し、サーマルノイズ信号（Ｓ５）の大きさに基づいて検出素子（２）及び信号変換部（３）の少なくとも一方の異常を判定する。 A determination method for a sensor device (1, 1a) according to a tenth aspect of the embodiment is a determination method for a sensor device (1, 1a) including a detection element (2) and a signal conversion section (3). . The detection element (2) outputs a detection signal (S1) according to the stress. A signal converter (3) converts the detection signal. The determination method of the sensor device (1, 1a) includes a first filtering step (ST31) and a monitoring step (ST5). The first filtering step (ST31) passes the target frequency band, which is the frequency band to be processed, among the signals output from the signal converter (3). The monitoring step (ST5) monitors thermal noise contained in the monitoring signal (Sa), which is the signal before performing the first filtering step (ST31). The monitoring step (ST5) includes a second filtering step (ST51) and a determining step (ST52). The second filtering step (ST51) extracts the thermal noise signal (S5) from the supervisory signal (Sa) by passing the frequency band of the supervisory signal (Sa) excluding the target frequency band. A determination step (ST52) detects the magnitude of the thermal noise signal (S5), and detects an abnormality in at least one of the detection element (2) and the signal converter (3) based on the magnitude of the thermal noise signal (S5). judge.
　この態様によれば、専用のセンサ装置（１、１ａ）を用いなくとも、サーマルノイズの増大につながる故障を自己診断しつつ、大型化の抑制を図ることができる、という利点がある。 According to this aspect, there is an advantage that it is possible to self-diagnose failures that lead to an increase in thermal noise and to suppress an increase in size without using a dedicated sensor device (1, 1a).
　なお、上述の実施の形態は本発明の一例である。このため、本発明は、上述の実施形態に限定されることはなく、この実施の形態以外であっても、本発明に係る技術的思想を逸脱しない範囲であれば、設計等に応じて種々の変更が可能であることは勿論である。 It should be noted that the above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiments, and various other embodiments may be used depending on the design etc. as long as they do not deviate from the technical idea of the present invention. is of course possible to change.
　１、１ａ　センサ装置
　２　検出素子
　３　信号変換部
　４　アナログ処理部
　５　ＡＤ変換部
　６１　第１フィルタ
　７、７ａ　監視部
　８、８ａ　第２フィルタ
　９　判定部
　９１　カウント部
　Ｒ１　所定範囲
　Ｓ１　検出信号
　Ｓ２　第１変換信号
　Ｓ３　第２変換信号
　Ｓ５　サーマルノイズ信号
　Ｓ６　エラー信号
　Ｓａ　監視信号
　ＳＴ３１　第１フィルタリングステップ
　ＳＴ５　監視ステップ
　ＳＴ５１　第２フィルタリングステップ
　ＳＴ５２　判定ステップ Reference Signs List 1, 1a sensor device 2 detection element 3 signal conversion unit 4 analog processing unit 5 AD conversion unit 61 first filter 7, 7a monitoring unit 8, 8a second filter 9 determination unit 91 counting unit R1 predetermined range S1 detection signal S2 first Conversion signal S3 Second conversion signal S5 Thermal noise signal S6 Error signal Sa Monitoring signal ST31 First filtering step ST5 Monitoring step ST51 Second filtering step ST52 Judgment step

Claims (10)

  1. 　応力に応じて検出信号を出力する検出素子と、
    　前記検出信号の信号変換を行う信号変換部と、
    　前記信号変換部から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる第１フィルタと、
    　前記第１フィルタを通過する前の信号である監視信号に含まれるサーマルノイズを監視する監視部と、を備え、
    　前記監視部は、
    　　前記監視信号のうち前記対象周波数帯域を除く周波数帯域を通過させることで、前記監視信号からサーマルノイズ信号を抽出する第２フィルタと、
    　　前記サーマルノイズ信号の大きさを検出し、前記サーマルノイズ信号の前記大きさに基づいて前記検出素子及び前記信号変換部の少なくとも一方の異常を判定する判定部と、を有する、
    　センサ装置。     a detection element that outputs a detection signal according to the stress;
    a signal conversion unit that converts the detection signal;
    a first filter that passes a target frequency band, which is a frequency band to be processed among the signals output from the signal conversion unit;
    a monitoring unit that monitors thermal noise included in a monitoring signal that is a signal before passing through the first filter,
    The monitoring unit
    a second filter that extracts a thermal noise signal from the monitoring signal by passing a frequency band of the monitoring signal excluding the target frequency band;
    a determination unit that detects the magnitude of the thermal noise signal and determines an abnormality in at least one of the detection element and the signal conversion unit based on the magnitude of the thermal noise signal;
    sensor device.
  2. 　前記信号変換部は、
    　　前記検出信号が入力され、第１変換信号を出力するアナログ処理部と、
    　　前記第１変換信号を第２変換信号に変換するＡＤ変換部と、を有し、
    　前記第２フィルタは、前記第２変換信号を前記監視信号として、前記サーマルノイズ信号を抽出する、
    　請求項１に記載のセンサ装置。     The signal conversion unit is
    an analog processing unit that receives the detection signal and outputs a first conversion signal;
    an AD converter that converts the first converted signal into a second converted signal,
    The second filter extracts the thermal noise signal using the second converted signal as the monitor signal.
    A sensor device according to claim 1 .
  3. 　前記信号変換部は、
    　　前記検出信号が入力され、第１変換信号を出力するアナログ処理部と、
    　　前記第１変換信号を第２変換信号に変換するＡＤ変換部と、を有し、
    　前記第２フィルタは、前記第１変換信号を前記監視信号として、前記サーマルノイズ信号を抽出する、
    　請求項１に記載のセンサ装置。     The signal conversion unit is
    an analog processing unit that receives the detection signal and outputs a first conversion signal;
    an AD converter that converts the first converted signal into a second converted signal,
    The second filter extracts the thermal noise signal using the first converted signal as the monitor signal.
    A sensor device according to claim 1 .
  4. 　前記判定部は、前記サーマルノイズ信号の前記大きさが予め設定された所定範囲を超えた回数をカウント数としてカウントするカウント部を有する、
    　請求項１～３のいずれか１項に記載のセンサ装置。     The determination unit has a count unit that counts the number of times the magnitude of the thermal noise signal exceeds a predetermined range set in advance as a count number.
    The sensor device according to any one of claims 1-3.
  5. 　前記判定部は、前記カウント数が予め設定された所定回数を超えた場合に、前記検出素子及び前記信号変換部の少なくとも一方の前記異常があると判定する、
    　請求項４に記載のセンサ装置。     The determination unit determines that at least one of the detection element and the signal conversion unit is abnormal when the count exceeds a predetermined number of times.
    5. The sensor device according to claim 4.
  6. 　前記所定回数は、２以上である、
    　請求項５に記載のセンサ装置。     The predetermined number of times is 2 or more,
    The sensor device according to claim 5.
  7. 　前記検出素子は、微小電気機械システムを含む、
    　請求項１～６のいずれか１項に記載のセンサ装置。     the sensing element comprises a micro-electromechanical system;
    The sensor device according to any one of claims 1-6.
  8. 　前記監視部は、前記サーマルノイズの監視を行う監視状態と、前記サーマルノイズの前記監視を停止する停止状態と、を切り替える間欠駆動を行う、
    　請求項１～７のいずれか１項に記載のセンサ装置。     The monitoring unit performs intermittent driving to switch between a monitoring state in which the thermal noise is monitored and a stop state in which the monitoring of the thermal noise is stopped.
    The sensor device according to any one of claims 1-7.
  9. 　前記判定部は、前記検出素子及び前記信号変換部の少なくとも一方の前記異常があると判定する場合、前記検出素子及び前記信号変換部の少なくとも一方の異常を報知するエラー信号を出力する、
    　請求項１～８のいずれか１項に記載のセンサ装置。     When determining that there is an abnormality in at least one of the detection element and the signal conversion unit, the determination unit outputs an error signal that notifies of an abnormality in at least one of the detection element and the signal conversion unit.
    The sensor device according to any one of claims 1-8.
  10. 　応力に応じて検出信号を出力する検出素子と、
    　前記検出信号の信号変換を行う信号変換部と、を備えるセンサ装置の判定方法であって、
    　前記信号変換部から出力された信号のうち処理対象となる周波数帯域である対象周波数帯域を通過させる第１フィルタリングステップと、
    　前記第１フィルタリングステップを行う前の信号である監視信号に含まれるサーマルノイズを監視する監視ステップと、を含み、
    　前記監視ステップは、
    　　前記監視信号のうち前記対象周波数帯域を除く周波数帯域を通過させることで、前記監視信号からサーマルノイズ信号を抽出する第２フィルタリングステップと、
    　　前記サーマルノイズ信号の大きさを検出し、前記サーマルノイズ信号の前記大きさに基づいて前記検出素子及び前記信号変換部の少なくとも一方の異常を判定する判定ステップと、を含む、
    　センサ装置の判定方法。     a detection element that outputs a detection signal according to the stress;
    A determination method for a sensor device comprising a signal conversion unit that converts the detection signal,
    a first filtering step of passing a target frequency band, which is a frequency band to be processed, among the signals output from the signal conversion unit;
    a monitoring step of monitoring thermal noise included in a monitoring signal that is a signal before performing the first filtering step;
    The monitoring step includes:
    a second filtering step of extracting a thermal noise signal from the monitoring signal by passing a frequency band of the monitoring signal excluding the target frequency band;
    a determination step of detecting the magnitude of the thermal noise signal and determining an abnormality in at least one of the detection element and the signal conversion unit based on the magnitude of the thermal noise signal;
    A judgment method of a sensor device.
PCT/JP2023/003364 2022-02-07 2023-02-02 Sensor device and sensor device determination method WO2023149497A1 (en)

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JP2003291842A (en) * 2002-03-29 2003-10-15 Toyoda Mach Works Ltd Motor-driven power steering device
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JP2017156088A (en) * 2016-02-29 2017-09-07 日立オートモティブシステムズ株式会社 Inertial force detection device
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003291842A (en) * 2002-03-29 2003-10-15 Toyoda Mach Works Ltd Motor-driven power steering device
JP2015515616A (en) * 2012-03-20 2015-05-28 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ Acceleration sensor with at least one micromechanical sensor element for an occupant protection system in a vehicle
JP2014185936A (en) * 2013-03-22 2014-10-02 Seiko Epson Corp Detector, sensor, electronic apparatus and moving body
JP2017156088A (en) * 2016-02-29 2017-09-07 日立オートモティブシステムズ株式会社 Inertial force detection device
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