Vibration detection device

Abstract

To allow frequency analysis to be performed even when using low-power consumption and low-speed communication standards.SOLUTION: A vibration detection device 10 according to the present disclosure includes a signal processing circuit 100 in which the vibration of a device into which a vibration detection device 10 is installed is input as an input signal and which detects information about the amplitude of the vibration, an AD conversion circuit 101 that converts an output of the signal processing circuit 100 from an analog signal to a digital signal, a wireless communication circuit 16 that wirelessly transmits a signal based on the digital signal, and a control circuit 15 that controls the signal processing circuit 100, the AD conversion circuit 101, and the wireless communication circuit 16.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a vibration detection device.

Background Art

[0002] Generally, a machine including a rotating element such as a motor generates vibrations synchronized with the rotation. When a failure such as a scratch occurs in the motor, vibrations with a frequency different from the normal vibrations synchronized with the rotation may occur.

[0003] Conventionally, a technique for diagnosing an abnormality of a machine by frequency-analyzing a vibration signal of the machine is known (for example, Patent Document 1 and Patent Document 2).

[0004] In the prior art, when frequency-analyzing a vibration signal, the following processing is often performed. (1) Remove high-frequency components of the vibration signal by an anti-aliasing filter. (2) Convert the signal with the high-frequency components removed into a digital signal by an AD converter. (3) Perform an operation such as FFT (Fast Fourier Transform) on the digital signal to perform frequency analysis and separate normal vibration components and abnormal vibration components.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

特許文献2

Summary of the Invention

Problems to be Solved by the Invention

[0006] It should be noted that in the above translation, the Chinese character "四十一" in line 41 should be "

Patent Document 2

[0007] Furthermore, digital calculations such as FFT require a large amount of computation. Therefore, high-speed processors and dedicated computing hardware are necessary to perform digital calculations such as FFT.

[0008] If a vibration detection device includes components such as a high-speed AD converter and a high-speed processor, the circuit size increases, leading to higher costs and power consumption. High power consumption makes it difficult to operate a vibration detection device containing a high-speed AD converter and a high-speed processor for extended periods without battery replacement.

[0009] To reduce the cost and power consumption of vibration detection devices, it is conceivable to have digital calculations such as FFT performed by external equipment. In that case, the vibration detection device would need to transmit a large amount of data to the external equipment. However, if the vibration detection device is a device that transmits data using a low-speed communication standard, transmitting such a large amount of data would take a very long time.

[0010] Thus, when attempting to implement a vibration detection device using low-power and low-speed communication standards, it was difficult to perform frequency analysis using techniques that require a large amount of computation, such as FFT.

[0011] Therefore, the purpose of this disclosure is to provide a vibration detection device that can perform frequency analysis even with low power consumption and low speed communication standards. [Means for solving the problem]

[0012] Some embodiments of the vibration detection device include a signal processing circuit that receives vibrations from a device on which the vibration detection device is installed as an input signal and detects information regarding the amplitude of the vibrations; an AD conversion circuit that converts the output of the signal processing circuit from an analog signal to a digital signal; a wireless communication circuit that wirelessly transmits a signal based on the digital signal; and a control circuit that controls the signal processing circuit, the AD conversion circuit, and the wireless communication circuit. Such a vibration detection device makes it possible to perform frequency analysis even with low power consumption and low-speed communication standards.

[0013] In a vibration detection device according to one embodiment, the signal processing circuit may comprise a plurality of bandpass filters (BPFs) to which the input signal is input, each having different passband frequencies, and the plurality of bandpass filters may comprise a plurality of bandpass filters with different passband frequencies, and a plurality of amplitude detection circuits for detecting information regarding the amplitude of the signal output by each bandpass filter.

[0014] In a vibration detection device according to one embodiment, one of the bandpass filters may be an all-pass filter (APF).

[0015] In a vibration detection device according to one embodiment, the amplitude detection circuit may be a peak hold circuit. This makes it possible to hold the maximum value of the signal output by the bandpass filter.

[0016] In a vibration detection device according to one embodiment, the amplitude detection circuit may be a sample-and-hold circuit. By acquiring multiple data points using a sample-and-hold circuit, averaging processing and the like can be performed.

[0017] In a vibration detection device according to one embodiment, the amplitude detection circuit may be an envelope detection circuit. This allows for the detection of envelope information relating to the amplitude of the signal output by each bandpass filter with a simple configuration.

[0018] In a vibration detection device according to an embodiment, the amplitude detection circuit may be an effective value (RMS) circuit. Thereby, the effective value information of the signal output from each band-pass filter can be detected with a simple configuration.

[0019] In a vibration detection device according to an embodiment, the amplitude detection circuit may be a circuit including a peak hold circuit, a sample hold circuit, an envelope detection circuit, an effective value circuit, or a plurality of functions of any of these circuits.

[0020] In a vibration detection device according to an embodiment, the amplitude detection circuit may have a function of adjusting the output voltage. Thereby, sensitivity adjustment can be realized.

[0021] In a vibration detection device according to an embodiment, the control circuit may perform control to cause the amplitude detection circuit to execute acquisition, holding, and clearing of an amplitude value at an appropriate timing within a measurement cycle.

[0022] In a vibration detection device according to an embodiment, the AD conversion circuit may include a selection circuit that outputs any one of the output signals of the plurality of output signals of the plurality of amplitude detection circuits.

[0023] In a vibration detection device according to an embodiment, the AD conversion circuit may include an individual AD converter that converts an analog signal into a digital signal for each output signal of the amplitude detection circuit.

[0024] In a vibration detection device according to an embodiment, the AD converter may be a multi-bit AD converter. Thereby, high-precision AD conversion becomes possible.

[0025] In a vibration detection device according to an embodiment, the AD converter may be one comparator. Thereby, the data amount of the data transmitted by the communication circuit can be reduced.

[0026] In a vibration detection device according to one embodiment, the AD converter includes a plurality of comparators, and the plurality of comparators may have different reference voltages. This makes it possible to realize a low-resolution flash-type AD converter with a simple configuration.

[0027] In a vibration detection device according to one embodiment, the single comparator or the plurality of comparators may have a function for adjusting their respective reference voltages. This makes it possible to adjust the sensitivity.

[0028] In a vibration detection device according to one embodiment, the AD converter may be a flip-flop or a latch. This allows for circuit simplification.

[0029] In a vibration detection device according to one embodiment, the control circuit may perform multiple measurements, process the values ​​output by the multi-bit AD converter, and perform control to acquire information regarding the amplitude of the signal output by the bandpass filter or the amplitude detection circuit.

[0030] In a vibration detection device according to one embodiment, the control circuit may perform multiple measurements within a measurement cycle and acquire information regarding the amplitude of the signal output by the bandpass filter or the amplitude detection circuit based on the ratio of high signals to low signals output by each of the comparators, flip-flops, or latches.

[0031] In a vibration detection device according to one embodiment, the signal processing circuit may include a bandpass filter with a variable passband frequency to which the input signal is input, and an amplitude detection circuit that detects information regarding the amplitude of the signal output by the bandpass filter with a variable passband frequency.

[0032] In a vibration detection device according to one embodiment, the signal processing circuit may include a variable bandpass filter in which the passband frequency to which the input signal is input is variable.

[0033] In a vibration detection device according to one embodiment, the signal processing circuit may include a plurality of bandpass filters to which the input signal is input.

[0034] In a vibration detection device according to one embodiment, the output voltage of the bandpass filter may be adjustable. [Effects of the Invention]

[0035] According to this disclosure, it is possible to provide a vibration detection device that can perform frequency analysis even with low-power and low-speed communication standards. [Brief explanation of the drawing]

[0036] [Figure 1] This figure shows a schematic configuration of a vibration detection device according to one embodiment. [Figure 2] Figure 1 shows the case where the amplitude detection circuit is a peak hold circuit. [Figure 3] This diagram shows the timing chart of the vibration detection device's operation. [Figure 4] Figure 1 shows the case where the AD converter is a comparator. [Figure 5] Figure 1 shows a case where the AD converter is composed of multiple comparators. [Figure 6] This figure shows the schematic configuration of a vibration detection device according to the first modified example. [Figure 7] This figure shows the schematic configuration of a vibration detection device according to the second modified example. [Figure 8] This is a conceptual diagram showing how the output of a comparator changes in response to amplitude. [Figure 9] This figure shows the schematic configuration of a vibration detection device according to the third modified example. [Modes for carrying out the invention]

[0037] Figure 1 is a diagram showing the schematic configuration of a vibration detection device 10 according to one embodiment. The configuration and function of the vibration detection device 10 according to one embodiment will be described with reference to Figure 1.

[0038] The vibration detection device 10 is installed and used on the device whose vibration is to be detected. The vibration detection device 10 can detect vibrations in the device on which the vibration detection device 10 is installed.

[0039] The vibration detection device 10 includes a signal processing circuit 100 equipped with multiple bandpass filters 11-1 to 11-n and multiple amplitude detection circuits 12-1 to 12-n, an AD conversion circuit 101 equipped with a selection circuit 13 and an AD converter 14, a control circuit 15, a wireless communication circuit 16, and a battery 17. In Figure 1, a bandpass filter is denoted as "BPF".

[0040] The signal processing circuit 100 receives vibrations from the device on which the vibration detection device 10 is installed as an input signal and detects information regarding the amplitude of the vibrations.

[0041] The AD conversion circuit 101 converts the output of the signal processing circuit 100 from an analog signal to a digital signal.

[0042] Bandpass filters 11-1 to 11-n will be simply referred to as "bandpass filter 11" unless otherwise specified. Similarly, amplitude detection circuits 12-1 to 12-n will be simply referred to as "amplitude detection circuit 12" unless otherwise specified. The same applies to components having multiple identical components.

[0043] In Figure 1, the vibration detection device 10 is shown to have a configuration comprising n bandpass filters 11 and n amplitude detection circuits 12, where n may be any integer greater than or equal to 2.

[0044] The vibrations of the device on which the vibration detection device 10 is installed are input as input signals to the bandpass filters 11-1 to 11-n. The bandpass filters 11-1 to 11-n have different passband frequencies. The input signals input to the bandpass filters 11-1 to 11-n contain frequency components of various amplitudes.

[0045] The bandpass filter 11 is an analog bandpass filter. The bandpass filter 11 may be a bandpass filter with any configuration, for example, a bandpass filter with a configuration that includes resistors, capacitors, operational amplifiers, etc.

[0046] The bandpass filter 11 outputs the signal of the passband frequency component of the input signal to the amplitude detection circuit 12. For example, the bandpass filter 11-1 outputs the signal of the passband frequency component of the bandpass filter 11-1 of the input signal to the amplitude detection circuit 12-1. The bandpass filter 11-2 outputs the signal of the passband frequency component of the bandpass filter 11-2 of the input signal to the amplitude detection circuit 12-2. Similarly, the bandpass filter 11-n outputs the signal of the passband frequency component of the bandpass filter 11-n of the input signal to the amplitude detection circuit 12-n.

[0047] The amplitude detection circuits 12-1 to 12-n each detect information regarding the amplitude of the signals output by the bandpass filters 11-1 to 11-n. Specifically, amplitude detection circuit 12-1 detects information regarding the amplitude of the signal output by bandpass filter 11-1. Amplitude detection circuit 12-2 detects information regarding the amplitude of the signal output by bandpass filter 11-2. Similarly, amplitude detection circuit 12-n detects information regarding the amplitude of the signal output by bandpass filter 11-n. The amplitude detection circuits 12-1 to 12-n output signals to the selection circuit 13.

[0048] For example, if the input signal includes components at the passband frequency of bandpass filter 11-1 but does not include components at the passband frequency of bandpass filter 11-2, the amplitude detection circuit 12-1 will detect a large amplitude, while the amplitude detection circuit 12-2 will detect almost no amplitude.

[0049] The amplitude detection circuit 12 may be any circuit capable of acquiring information regarding the amplitude of the signal output by the bandpass filter 11. The amplitude detection circuit 12 may be, for example, a peak hold circuit, a sample-and-hold circuit, an envelope detection circuit, an RMS circuit, or a circuit that includes multiple functions of these circuits.

[0050] The selection circuit 13 outputs one of the output signals from the amplitude detection circuits 12-1 to 12-n to the AD converter 14. The selection circuit 13 receives a command from the control circuit 15 and selects which of the output signals from the amplitude detection circuits 12-1 to 12-n to output.

[0051] The AD converter 14 converts the signal output by the selection circuit 13 from an analog signal to a digital signal. The AD converter 14 may be an AD converter of any configuration. The AD converter 14 outputs the output signal converted to a digital signal to the control circuit 15.

[0052] Since the AD converter 14 only converts the amplitude information of the signal output by the amplitude detection circuit 12 into a digital signal, it does not need to be a high-speed AD converter and can be a low-speed AD converter.

[0053] The control circuit 15 may include a processor. The processor may be a general-purpose processor or a dedicated processor specialized for a specific process.

[0054] The control circuit 15 processes the digital signal acquired from the AD converter 14 and outputs it to the wireless communication circuit 16.

[0055] The control circuit 15 controls the selection circuit 13 to select which of the output signals from the amplitude detection circuits 12-1 to 12-n will be output.

[0056] The wireless communication circuit 16 transmits the digital signal acquired from the control circuit 15 wirelessly to another device via an antenna. The other device may be, for example, a host computer that collects vibration information from the device on which the vibration detection device 10 is installed. The signal transmitted by the wireless communication circuit 16 is a signal obtained by processing the digital signal output by the AD converter 14 with the control circuit 15. In other words, the signal transmitted by the wireless communication circuit 16 is a signal based on the digital signal output by the AD converter 14.

[0057] Battery 17 is a battery that supplies power to the components of the vibration detection device 10. The vibration detection device 10 can operate using the power supplied by battery 17.

[0058] As described above, the vibration detection device 10 according to one embodiment can perform frequency analysis simply by detecting the amplitude at each passband frequency using analog circuits such as a bandpass filter 11 and an amplitude detection circuit 12, without performing a large amount of digital calculations such as FFT. Therefore, the vibration detection device 10 according to one embodiment can perform frequency analysis with low power consumption. Furthermore, since the vibration detection device 10 according to one embodiment does not require external equipment to perform digital calculations such as FFT, the results of the frequency analysis can be transmitted to external equipment even with low-speed communication standards.

[0059] Figure 2 shows an example where the amplitude detection circuit 12 is a peak hold circuit. In Figure 2, the fact that the amplitude detection circuit 12 is a peak hold circuit is indicated by the notation "P / H". Also, the amplitude detection circuits 12-1 to 12-n are denoted as P / H1 to P / Hn, respectively.

[0060] Referring to Figure 2, the operation of the vibration detection device 10 in detecting vibrations of the device on which the vibration detection device 10 is installed will be explained, using the case where the amplitude detection circuit 12 is a peak hold circuit as an example.

[0061] The vibration detection device 10 detects vibrations in the device on which it is installed at predetermined measurement cycles. The predetermined cycle can be any length of time, but for example, it may be about 10 minutes. In this way, by detecting vibrations only about once every 10 minutes, for example, the vibration detection device 10 can reduce power consumption and operate for a longer period of time compared to when vibrations are detected at shorter cycles.

[0062] The operation of the vibration detection device 10 will be explained with reference to the timing chart shown in Figure 3.

[0063] The control circuit 15 clears the values ​​held by the peak hold circuits P / H1 to P / Hn at the beginning of the measurement cycle. After clearing, P / H1 to P / Hn compare the input value with the held value during the amplitude value acquisition period, and if the input value is larger, they update the held value with the input value. Also, during the amplitude value holding period, P / H1 to P / Hn do not update the held value even if a value larger than the held value is input.

[0064] During the amplitude value holding period, the control circuit 15 causes the selection circuit 13 to sequentially output the output signals of the peak hold circuit, P / H1 to P / Hn. The AD converter 14 sequentially converts the output signals of P / H1 to P / Hn, which are output sequentially by the selection circuit 13, into digital signals and outputs them to the control circuit 15.

[0065] This allows the control circuit 15 to acquire the amplitude of the passband frequency components of each of the bandpass filters 11-1 to 11-n included in the input signal. The control circuit 15 processes the amplitude of each passband frequency component acquired as a digital signal into an appropriate format and transmits it wirelessly via the wireless communication circuit 16.

[0066] The vibration detection device 10 repeats the operation of detecting vibrations, with this measurement cycle being considered as one cycle.

[0067] In this way, the vibration detection device 10 can detect the maximum amplitude of various frequency components included in the input signal.

[0068] Referring to Figure 2, the case where the amplitude detection circuit 12 is a peak hold circuit has been explained, but the amplitude detection circuit 12 may also be a sample-and-hold circuit.

[0069] If the amplitude detection circuit 12 is a sample-and-hold circuit, the sample-and-hold circuit may acquire multiple signals output by the bandpass filter 11 to obtain information regarding the amplitude of the signals output by the bandpass filter 11.

[0070] If the amplitude detection circuit 12 is a sample-and-hold circuit, the control circuit 15 may obtain information about the amplitude by processing multiple signals acquired by the sample-and-hold circuit.

[0071] The control circuit 15 may, for example, average the multiple signals acquired by the sample-and-hold circuit. Alternatively, the control circuit 15 may, for example, remove the largest signal from the multiple signals acquired by the sample-and-hold circuit and average the remaining multiple signals. By removing the largest signal in this way, the influence of large signals caused by noise or other factors can be eliminated.

[0072] Furthermore, although the case where the amplitude detection circuit 12 is a peak hold circuit was explained with reference to Figure 2, the amplitude detection circuit 12 may also be an envelope detection circuit.

[0073] Even when the amplitude detection circuit 12 is an envelope detection circuit, the control circuit 15 may obtain information about the amplitude by processing multiple signals acquired by the envelope detection circuit, similar to the case when the amplitude detection circuit 12 is a sample-and-hold circuit.

[0074] Furthermore, although the case where the amplitude detection circuit 12 is a peak hold circuit was explained with reference to Figure 2, the amplitude detection circuit 12 may also be an RMS circuit.

[0075] Even when the amplitude detection circuit 12 is an RMS circuit, the control circuit 15 may obtain information about the amplitude by processing multiple signals acquired by the RMS circuit, similar to the case when the amplitude detection circuit 12 is a sample-and-hold circuit.

[0076] The vibration detection device 10a shown in Figure 4 is a diagram showing the case where the AD converter 14 is replaced with a comparator 18 in the vibration detection device 10 shown in Figure 1. In Figure 4, the comparator is denoted as "CMP".

[0077] Since the comparator 18 is a 1-bit AD converter, the vibration detection device 10a shown in Figure 4 is an example of the vibration detection device 10 shown in Figure 1.

[0078] The comparator 18 compares the signal output by the selection circuit 13 with a reference voltage. If the signal output by the selection circuit 13 is greater than or equal to the reference voltage, it outputs a high signal. If the signal output by the selection circuit 13 is less than the reference voltage, it outputs a low signal.

[0079] As shown in Figure 4, when the AD converter 14 is a comparator 18, the amount of data transmitted by the wireless communication circuit 16 can be reduced compared to when the AD converter 14 is a multi-bit AD converter.

[0080] Figure 5 shows a vibration detection device 10b in which the AD converter 14 is configured to include multiple comparators 18-1 to 18-3, as in the vibration detection device 10 shown in Figure 1. Note that in Figure 5, the vibration detection device 10b is shown to have three comparators 18, but this is just one example; the vibration detection device 10b may also have two comparators 18, or four or more comparators 18.

[0081] Note that the configuration with multiple comparators 18-1 to 18-3 is a low-resolution flash AD converter, so the vibration detection device 10b shown in Figure 5 is an example of the vibration detection device 10 shown in Figure 1.

[0082] Comparator 18-1 compares the signal output by selection circuit 13 with reference voltage 1. If the signal output by selection circuit 13 is greater than or equal to reference voltage 1, it outputs a high signal. If the signal output by selection circuit 13 is less than reference voltage 1, it outputs a low signal. Comparator 18-2 compares the signal output by selection circuit 13 with reference voltage 2. If the signal output by selection circuit 13 is greater than or equal to reference voltage 2, it outputs a high signal. If the signal output by selection circuit 13 is less than reference voltage 2, it outputs a low signal. Comparator 18-3 compares the signal output by selection circuit 13 with reference voltage 3. If the signal output by selection circuit 13 is greater than or equal to reference voltage 3, it outputs a high signal. If the signal output by selection circuit 13 is less than reference voltage 3, it outputs a low signal.

[0083] Reference voltage 1, reference voltage 2, and reference voltage 3 are all different voltages.

[0084] According to the vibration detection device 10 of the above embodiment, frequency analysis can be performed even with low power consumption and low-speed communication standards. More specifically, the vibration detection device 10 of the above embodiment includes a plurality of bandpass filters 11 with different passband frequencies, a plurality of amplitude detection circuits 12 that detect information regarding the amplitude of the signals output by each bandpass filter 11, a selection circuit 13 that outputs one of the output signals from the plurality of amplitude detection circuits 12, an AD converter 14 that converts the signal output by the selection circuit 13 from an analog signal to a digital signal, and a wireless communication circuit 16 that wirelessly transmits a signal based on the digital signal output by the AD converter 14. In this way, by detecting the amplitude of the signals output by a plurality of bandpass filters 11 with different passband frequencies, the vibration detection device 10 can perform frequency analysis without performing a large amount of digital calculations such as FFT, thus enabling low power consumption for frequency analysis. Furthermore, since the vibration detection device 10 does not require external equipment to perform digital calculations such as FFT, it does not need to transmit a large amount of data, and the results of the frequency analysis can be transmitted to external equipment even with low-speed communication standards.

[0085] (First variation) Figure 6 shows a schematic configuration of the vibration detection device 10c according to the first modified example. The vibration detection device 10c according to the first modified example comprises a plurality of bandpass filters 11-1 to 11-n, a plurality of amplitude detection circuits 12-1 to 12-n, a plurality of comparators 18-1 to 18-n, a control circuit 15, a wireless communication circuit 16, and a battery 17.

[0086] The vibration detection device 10c according to the first modification differs from the vibration detection device 10 shown in Figure 1 in that it does not have a selection circuit 13 and has n comparators 18. The differences between the vibration detection device 10c according to the first modification and the vibration detection device 10 shown in Figure 1 will be mainly explained, and explanations of things that are common to the vibration detection device 10 shown in Figure 1 will be omitted as appropriate.

[0087] The amplitude detection circuit 12 outputs a value related to the amplitude of the signal output by the bandpass filter 11.

[0088] The amplitude detection circuit 12 may be configured to output the same voltage as the reference voltage of the comparator 18 when the signal output by the bandpass filter 11 has a predetermined amplitude. By adjusting the magnitude of the output of the amplitude detection circuit 12 in this way, the amplitude detection circuit 12 can directly output a signal to the comparator 18.

[0089] The amplitude detection circuits 12-1 to 12-n each output signals to comparators 18-1 to 18-n.

[0090] The comparator 18 compares the signal output by the amplitude detection circuit 12 with a reference voltage. If the signal output by the amplitude detection circuit 12 is greater than or equal to the reference voltage, it outputs a high signal. If the signal output by the amplitude detection circuit 12 is less than the reference voltage, it outputs a low signal. Note that in Figure 6, the reference voltage input to the comparator 18 is omitted.

[0091] The comparator 18 may be, for example, a flip-flop or a latch. By using a flip-flop or a latch for the comparator 18, the circuit can be simplified.

[0092] The amplitude detection circuit 12 may be configured to output the same voltage as the high / low discrimination threshold of the flip-flop or latch (often 50% of the power supply voltage in the case of a CMOS circuit) when the signal output by the bandpass filter 11 has a predetermined amplitude. By adjusting the magnitude of the output of the amplitude detection circuit 12 in this way, the amplitude detection circuit 12 can directly output the signal to the flip-flop or latch.

[0093] Alternatively, the comparator 18 may be omitted, and the output of the amplitude detection circuit 12 may be directly input to the I / O port of the control circuit 15. This further simplifies the circuit.

[0094] The amplitude detection circuit 12 may be configured to output the same voltage as the high / low discrimination threshold of the I / O port (often 50% of the power supply voltage in the case of a CMOS circuit) when the signal output by the bandpass filter 11 has a predetermined amplitude. By adjusting the magnitude of the output of the amplitude detection circuit 12 in this way, the amplitude detection circuit 12 can directly output a signal to the I / O port.

[0095] (Second variation) Figure 7 shows a schematic configuration of the vibration detection device 10d according to the second modified example. The vibration detection device 10d according to the second modified example comprises a plurality of bandpass filters 11-1 to 11-n, a plurality of comparators 18-1 to 18-n, a control circuit 15, a wireless communication circuit 16, and a battery 17.

[0096] The vibration detection device 10d according to the second modification differs from the vibration detection device 10c according to the first modification shown in Figure 6 in that it does not have amplitude detection circuits 12-1 to 12-n. The differences between the vibration detection device 10d according to the second modification and the vibration detection device 10c according to the first modification shown in Figure 6 will be mainly explained, and explanations of content common to the vibration detection device 10c according to the first modification will be omitted as appropriate.

[0097] The bandpass filters 11-1 to 11-n each output signals to comparators 18-1 to 18-n.

[0098] The comparator 18 compares the signal output by the bandpass filter 11 with a reference voltage. If the signal output by the bandpass filter 11 is greater than or equal to the reference voltage, it outputs a high signal. If the signal output by the bandpass filter 11 is less than the reference voltage, it outputs a low signal. Note that in Figure 7, the reference voltage input to the comparator 18 is omitted.

[0099] In the vibration detection device 10d according to the second modified example, the signal output by the bandpass filter 11 is directly input to the comparator 18. Therefore, the comparator 18 receives a sequentially changing signal. Figure 8 shows a conceptual diagram of the case where the control circuit 15 samples the output of the comparator 18 according to the amplitude multiple times at regular intervals.

[0100] In Figure 8, the left side shows the situation when a signal with a large amplitude is input to the comparator 18. The right side shows the situation when a signal with a small amplitude is input to the comparator 18.

[0101] When a large amplitude signal is input to the comparator 18, and the output of the comparator 18 is sampled multiple times at regular intervals, the high signal (H) is sampled more often than the low signal (L), as shown on the left side of Figure 8. In the example shown in Figure 8, the ratio of sampled high signals to low signals is 6:2.

[0102] When a small amplitude signal is input to the comparator 18, and the output of the comparator 18 is sampled multiple times at regular intervals, the low signal is sampled more often than the high signal, as shown on the right side of Figure 8. In the example shown in Figure 8, the ratio of sampled high signals to low signals is 2:6.

[0103] The vibration detection device 10d according to the second modification can simplify the circuit compared to the vibration detection device 10c according to the first modification by omitting the amplitude detection circuit 12.

[0104] (Third variation) Figure 9 shows a schematic configuration of the vibration detection device 10e according to the third modified example. The vibration detection device 10e according to the third modified example comprises a variable bandpass filter 20, an amplitude detection circuit 12, an AD converter 14, a control circuit 15, a wireless communication circuit 16, and a battery 17.

[0105] The vibration detection device 10e according to the third modification differs from the vibration detection device 10 shown in Figure 1 in that it has a variable bandpass filter 20 instead of multiple bandpass filters 11-1 to 11-n, and does not have a selection circuit 13. The differences between the vibration detection device 10e according to the third modification and the vibration detection device 10 shown in Figure 1 will be mainly explained, and explanations of things that are common to the vibration detection device 10 shown in Figure 1 will be omitted as appropriate.

[0106] The variable bandpass filter 20 is a bandpass filter whose passband frequency can be arbitrarily set and changed. The variable bandpass filter 20 can also sweep the passband frequency in response to a command from the control circuit 15.

[0107] The control circuit 15 changes the passband frequency of the variable bandpass filter 20 at a predetermined period.

[0108] The amplitude detection circuit 12 detects information regarding the amplitude of the signal output by the variable bandpass filter 20 at the changed passband frequency when the passband frequency of the variable bandpass filter 20 changes.

[0109] In this way, the vibration detection device 10e according to the third modified example can operate like a simple spectrum analyzer.

[0110] Furthermore, the vibration detection device 10e, according to the third modification, can detect the amplitude at each passband frequency with higher resolution than the vibration detection device 10 shown in Figure 1, by changing the passband frequency of the variable bandpass filter 20 in fine steps.

[0111] It will be apparent to those skilled in the art that this disclosure can be implemented in other predetermined forms besides the embodiments described above without deviating from its spirit or essential features. Therefore, the prior description is illustrative and not limiting. The scope of the disclosure is defined not by the prior description but by the added claims. Any modifications within their equivalent scope are incorporated therein.

[0112] For example, the arrangement and number of each component described above are not limited to those shown in the above description and drawings. The arrangement and number of each component may be configured arbitrarily, as long as it can achieve its function.

[0113] For example, although the control circuit 15 shown in Figure 1 was described as performing both the control of the selection circuit 13 and the processing of the digital signal acquired from the AD converter 14, the control circuit 15 may only perform the processing of the digital signal acquired from the AD converter 14, and the control of the selection circuit 13 may be performed by another control circuit. [Explanation of symbols]

[0114] 10, 10a, 10b, 10c, 10d, 10e Vibration detection device 11 Bandpass filter 12 Amplitude detection circuit 13 Selection Circuit 14 AD converters 15 Control circuits 16 Wireless communication circuit 17 Batteries 18 Comparator 20 Variable bandpass filter 100 Signal Processing Circuits 101 AD Conversion Circuit

Claims

1. A vibration detection device, A signal processing circuit receives the vibration of the device on which the vibration detection device is installed as an input signal and detects information regarding the amplitude of the vibration, The signal processing circuit's output is converted from an analog signal to a digital signal by an AD conversion circuit, A wireless communication circuit that wirelessly transmits a signal based on the aforementioned digital signal, A control circuit that controls the signal processing circuit, the AD conversion circuit, and the wireless communication circuit, Equipped with, The aforementioned signal processing circuit is Multiple bandpass filters with different passband frequencies to which the aforementioned input signal is input, Multiple amplitude detection circuits that detect multiple amplitude-related information for multiple signals output by the multiple bandpass filters, Equipped with, The vibration detection device comprises an AD conversion circuit which includes individual AD converters that convert each output signal of the amplitude detection circuit from an analog signal to a digital signal.

2. In the vibration detection device according to claim 1, A vibration detection device in which one of the aforementioned multiple bandpass filters is a full-band pass filter.

3. In the vibration detection device according to claim 1 or 2, The amplitude detection circuit is a peak hold circuit, in this vibration detection device.

4. In the vibration detection device according to claim 1 or 2, The amplitude detection circuit is a sample-and-hold circuit, which is a vibration detection device.

5. In the vibration detection device according to claim 1 or 2, The amplitude detection circuit is an envelope detection circuit, and the vibration detection device is a vibration detection device.

6. In the vibration detection device according to claim 1 or 2, The amplitude detection circuit is an RMS value circuit, which is a vibration detection device.

7. In the vibration detection device according to claim 1 or 2, A vibration detection device in which the amplitude detection circuit is a circuit that includes the functions of a peak hold circuit, a sample hold circuit, an envelope detection circuit, an RMS circuit, or a combination of these circuits.

8. In the vibration detection device according to claim 1, The amplitude detection circuit is a vibration detection device having an output voltage adjustment function.

9. In the vibration detection device according to claim 1, The control circuit controls the amplitude detection circuit to acquire, hold, and clear the amplitude value at appropriate timings within the measurement cycle, thereby providing a vibration detection device.

10. In the vibration detection device according to claim 1, The vibration detection device comprises an AD conversion circuit, a selection circuit that outputs one of the output signals from the plurality of amplitude detection circuits.

11. In the vibration detection device according to claim 1, The aforementioned AD converter is a multi-bit AD converter, and the vibration detection device is also an AD converter.

12. In the vibration detection device according to claim 1, The aforementioned AD converter is a vibration detection device, which is a single comparator.

13. In the vibration detection device according to claim 1, The AD converter is a vibration detection device comprising a plurality of comparators, each of which has a different reference voltage.

14. In the vibration detection device according to claim 12 or 13, A vibration detection device in which the one or more comparators each have a function to adjust their respective reference voltages.

15. In the vibration detection device according to claim 11, The control circuit performs multiple measurements, processes the values ​​output by the multi-bit AD converter, and obtains information regarding the amplitude of the signal output by the amplitude detection circuit.

16. A vibration detection device, A signal processing circuit receives the vibration of the device on which the vibration detection device is installed as an input signal and detects information regarding the amplitude of the vibration, The signal processing circuit's output is converted from an analog signal to a digital signal by an AD conversion circuit, A wireless communication circuit that wirelessly transmits a signal based on the aforementioned digital signal, A control circuit that controls the signal processing circuit, the AD conversion circuit, and the wireless communication circuit, Equipped with, The signal processing circuit includes a variable bandpass filter in which the passband frequency to which the input signal is input is variable. The aforementioned variable bandpass filter is a vibration detection device in which the output voltage can be adjusted.

17. In the vibration detection device according to claim 16, The signal processing circuit further includes an amplitude detection circuit that detects amplitude-related information for the signal output by the variable bandpass filter. The amplitude detection circuit is a peak hold circuit, in this vibration detection device.

18. In the vibration detection device according to claim 16, The signal processing circuit further includes an amplitude detection circuit that detects amplitude-related information for the signal output by the variable bandpass filter. The amplitude detection circuit is a sample-and-hold circuit, which is a vibration detection device.

19. In the vibration detection device according to claim 16, The signal processing circuit further includes an amplitude detection circuit that detects amplitude-related information for the signal output by the variable bandpass filter. The amplitude detection circuit is an envelope detection circuit, and the vibration detection device is a vibration detection device.

20. In the vibration detection device according to claim 16, The signal processing circuit further includes an amplitude detection circuit that detects amplitude-related information for the signal output by the variable bandpass filter. The amplitude detection circuit is an RMS value circuit, which is a vibration detection device.

21. In the vibration detection device according to claim 16, The signal processing circuit further includes an amplitude detection circuit that detects amplitude-related information for the signal output by the variable bandpass filter. A vibration detection device in which the amplitude detection circuit is a circuit that includes the functions of a peak hold circuit, a sample hold circuit, an envelope detection circuit, an RMS circuit, or a combination of these circuits.

22. In the vibration detection device according to claim 16, The signal processing circuit further includes an amplitude detection circuit that detects amplitude-related information for the signal output by the variable bandpass filter. The amplitude detection circuit is a vibration detection device having an output voltage adjustment function.

23. In the vibration detection device according to claim 16, The signal processing circuit further includes an amplitude detection circuit that detects amplitude-related information for the signal output by the variable bandpass filter. The control circuit controls the amplitude detection circuit to acquire, hold, and clear the amplitude value at appropriate timings within the measurement cycle, thereby providing a vibration detection device.

24. In the vibration detection device according to claim 16, The aforementioned AD conversion circuit includes an AD converter, The aforementioned AD converter is a multi-bit AD converter, and the vibration detection device is also an AD converter.

25. In the vibration detection device according to claim 16, The aforementioned AD conversion circuit includes an AD converter, The aforementioned AD converter is a vibration detection device, which is a single comparator.

26. In the vibration detection device according to claim 16, The aforementioned AD conversion circuit includes an AD converter, The AD converter is a vibration detection device comprising a plurality of comparators, each of which has a different reference voltage.

27. In the vibration detection device according to claim 25, The aforementioned comparator is a vibration detection device having a function for adjusting the reference voltage.

28. In the vibration detection device according to claim 26, The aforementioned plurality of comparators are vibration detection devices, each having a function to adjust its own reference voltage.

29. In the vibration detection device according to claim 24, The signal processing circuit further includes an amplitude detection circuit that detects amplitude-related information for the signal output by the variable bandpass filter. The control circuit performs multiple measurements, processes the values ​​output by the multi-bit AD converter, and obtains information regarding the amplitude of the signal output by the amplitude detection circuit.

30. A vibration detection device, A signal processing circuit receives the vibration of the device on which the vibration detection device is installed as an input signal and detects information regarding the amplitude of the vibration, The signal processing circuit's output is converted from an analog signal to a digital signal by an AD conversion circuit, A wireless communication circuit that wirelessly transmits a signal based on the aforementioned digital signal, A control circuit that controls the signal processing circuit, the AD conversion circuit, and the wireless communication circuit, Equipped with, The signal processing circuit includes a plurality of bandpass filters to which the input signal is input, The aforementioned bandpass filter is a vibration detection device in which the output voltage is adjustable.

31. In the vibration detection device according to claim 30, The aforementioned AD conversion circuit includes an AD converter, The aforementioned AD converter is a multi-bit AD converter, and the vibration detection device is also an AD converter.

32. In the vibration detection device according to claim 30, The aforementioned AD conversion circuit includes an AD converter, The aforementioned AD converter is a vibration detection device, which is a single comparator.

33. In the vibration detection device according to claim 30, The aforementioned AD conversion circuit includes an AD converter, The AD converter is a vibration detection device comprising a plurality of comparators, each of which has a different reference voltage.

34. In the vibration detection device according to claim 32 or 33, A vibration detection device in which the one or more comparators each have a function to adjust their respective reference voltages.

35. In the vibration detection device according to claim 31, The control circuit performs multiple measurements, processes the values ​​output by the multi-bit AD converter, and obtains information regarding the amplitude of the signal output by the bandpass filter, thereby providing a vibration detection device.

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