Vibration signal acquisition equipment

Abstract

The utility model provides a vibration signal acquisition device comprising a signal preprocessing module and a signal conversion module, the signal preprocessing module is electrically connected with an acquisition sensor, the signal conversion module comprises a precision full-wave rectification circuit and a voltage comparator, the signal preprocessing module is electrically connected with the precision full-wave rectification circuit, and the voltage comparator is electrically connected with the precision full-wave rectification circuit. The precise full-wave rectification circuit is electrically connected with the voltage comparator, the voltage comparator is electrically connected with the U3 digital frequency synthesizer, the U3 digital frequency synthesizer is electrically connected with the microcontroller through the analog-to-digital converter, and the microcontroller is electrically connected with the U3 digital frequency synthesizer. Through the signal conversion module and the U3 digital frequency synthesizer, conversion from a non-stationary dynamic signal to a variance stationary signal is realized, the FFT processing characteristic is adapted, the monitoring error probability is reduced, and the monitoring accuracy is improved.

Description

Technical Field

[0001] This utility model relates to the field of engineering measurement technology, and in particular to a vibration signal acquisition device. Background Technology

[0002] Vibration signal acquisition and analysis of structures is an important means of monitoring the structural safety of structures. Examples include natural frequency analysis of bridges, cable force analysis of bridges, and fundamental frequency analysis of string sensors. By performing spectrum analysis on the acquired vibration signals, the natural frequency, interference frequency, and amplitude of characteristic frequencies of the structure can be obtained.

[0003] However, the vibration signal of a structure is generally a non-stationary dynamic signal, that is, the mean, variance, and covariance of the signal do not change with time.

[0004] Currently, frequency domain analysis of dynamic signals often uses FFT to transform time-domain samples into the frequency domain. However, FFT is only suitable for processing stationary signals. For non-stationary dynamic signals, FFT processing can lead to significant errors in the monitoring results. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a vibration signal acquisition device, which aims to solve the technical problem that the use of FFT to process non-stationary dynamic signals in the existing technology will lead to large errors in the monitoring results.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0007] A vibration signal acquisition device includes a signal preprocessing module and a signal conversion module electrically connected to the signal preprocessing module. The signal preprocessing module is electrically connected to a sensor. The signal preprocessing module amplifies and filters the non-stationary dynamic signal acquired by the sensor to form a non-stationary processed signal. The signal conversion module includes a precision full-wave rectifier circuit and a voltage comparator. The precision full-wave rectifier circuit includes operational amplifiers U1A and U1B, resistors R1 and R5. The voltage comparator includes comparator U12. The signal preprocessing module is electrically connected to the inverting input of operational amplifier U1A through resistor R3. The output of operational amplifier U1A is electrically connected to the inverting input of operational amplifier U1B. A diode D2 and a resistor R4 are connected in series between the output of operational amplifier U1A and the inverting input of operational amplifier U1B. One end of resistor R1 is connected to the sensor. Resistor R3 is connected to the inverting input terminal of operational amplifier U1A. The other end of resistor R1 is connected between diode D2 and resistor R4. One end of resistor R5 is connected between the signal preprocessing module and resistor R3. The other end of resistor R5 is connected between resistor R4 and the inverting input terminal of operational amplifier U1B. Diode D1 is placed between the output terminal of operational amplifier U1A and the inverting input terminal of operational amplifier U1A. Resistor R2 is placed between the output terminal of operational amplifier U1B and the inverting input terminal of operational amplifier U1B. The output terminal of operational amplifier U1B is electrically connected to the non-inverting input terminal of comparator U12. The output terminal of comparator U12 is electrically connected to digital frequency synthesizer U3. Digital frequency synthesizer U3 is electrically connected to microcontroller via analog-to-digital converter. Microcontroller is electrically connected to digital frequency synthesizer U3 to configure fixed counting step parameters for digital frequency synthesizer U3.

[0008] Compared with the prior art, the beneficial effects of this utility model are as follows: When acquiring and processing the non-stationary dynamic signal to obtain the non-stationary processed signal, the non-stationary processed signal is precisely rectified by the precision full-wave rectifier circuit, that is, the absolute value operation is performed on the non-stationary signal. The signal after absolute value operation contains the second harmonic component and DC component of the non-stationary processed signal. At the same time, the bipolar signal is conditioned into a unipolar signal and input to the comparator U12. The comparator U12 shapes the unipolar signal into a standard square wave signal and replaces the clock signal input to the U3 digital frequency synthesizer. Utilizing the characteristic that the U3 digital frequency synthesizer can generate periodic wavelengths, after the microcontroller configures a fixed counting step size parameter to it, a variance-stationary signal is generated. That is, the conversion of the non-stationary dynamic signal into a variance-stationary signal is realized through the signal conversion module and the U3 digital frequency synthesizer, which is adapted to the processing characteristics of FFT, reduces the probability of monitoring errors, and improves the accuracy of monitoring.

[0009] Furthermore, the resistance values ​​of resistor R2 and resistor R5 are the same, the resistance ratio of resistor R2 to resistor R1 is 1:2, the resistance ratio of resistor R2 to resistor R3 is 1:2, and the resistance ratio of resistor R2 to resistor R4 is 1:2.

[0010] Furthermore, a resistor R26 is provided between the output terminal of the operational amplifier U1B and the non-inverting input terminal of the comparator U12, a resistor R24 ​​is provided between the output terminal of the comparator U12 and the non-inverting input terminal of the comparator U12, and the output terminal of the comparator U12 is electrically connected to a resistor R25.

[0011] Furthermore, the signal preprocessing module includes a signal amplification circuit electrically connected to the acquisition sensor, and the signal amplification circuit is electrically connected to the inverting input terminal of the operational amplifier U1A through a filter circuit.

[0012] Furthermore, a low-pass filter is provided between the U3 digital frequency synthesizer and the analog-to-digital converter. The low-pass filter includes an amplifier U4. The microcontroller is electrically connected to the DAT pin, CLK pin, and SYNC pin of the U3 digital frequency synthesizer. The output of the comparator U12 is electrically connected to the Fin pin of the U3 digital frequency synthesizer. The U3 digital frequency synthesizer is electrically connected to the non-inverting input of the amplifier U4 via the VOUT pin. The output of the amplifier U4 is electrically connected to the analog-to-digital converter. Resistors R40 and R50 are sequentially provided between the VOUT pin of the U3 digital frequency synthesizer and the non-inverting input of the amplifier U4. A capacitor C10 is provided between resistor R50 and the non-inverting input of the amplifier U4. The output of the amplifier U4 is connected to one end of capacitor C4, and the other end of capacitor C4 is connected between resistor R40 and resistor R50.

[0013] Furthermore, a signal gate is provided between the voltage comparator and the U3 digital frequency synthesizer, and a judgment circuit is provided between the filter circuit and the signal gate. The judgment circuit is used to compare the envelope signal of the non-stationary processed signal with the reference voltage value to control the opening and closing of the signal gate.

[0014] Furthermore, the judgment circuit includes operational amplifier U5A, operational amplifier U5B, and comparator U6. The filter circuit is electrically connected to the non-inverting input terminal of operational amplifier U5A. A diode D3 is disposed between the output terminal and the inverting input terminal of operational amplifier U5A. The output terminal of operational amplifier U5A is electrically connected to the non-inverting input terminal of operational amplifier U5B. The output terminal of operational amplifier U5B is electrically connected to the non-inverting input terminal of comparator U6. The output terminal of comparator U6 is electrically connected to the signal gate.

[0015] Furthermore, a diode D4 is provided between the output terminal of the operational amplifier U5A and the non-inverting input terminal of the operational amplifier U5B, and a resistor R7 and a capacitor C11 are connected in parallel between the diode D4 and the non-inverting input terminal of the operational amplifier U5B.

[0016] Furthermore, a resistor R6 is provided between the diode D3 and the inverting input terminal of the operational amplifier U5B.

[0017] Furthermore, the filtering circuit is a fourth-order active low-pass filter. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of the vibration signal acquisition device in an embodiment of this utility model;

[0019] Figure 2 This is a circuit diagram showing the connection between the precision full-wave rectifier circuit and the voltage comparator in the vibration signal acquisition device of this utility model embodiment;

[0020] Figure 3 This is a circuit diagram showing the connection between the U3 digital frequency synthesizer and the low-pass filter in the vibration signal acquisition device of this utility model embodiment;

[0021] Figure 4 This is a circuit diagram of the judgment circuit in the vibration signal acquisition device in this embodiment of the utility model;

[0022] Explanation of key component symbols:

[0023] 1. Signal amplification circuit; 2. Filtering circuit; 3. Precision full-wave rectifier circuit; 4. Voltage comparator; 5. Signal gate; 6. U3 digital frequency synthesizer; 7. Low-pass filter; 8. Judgment circuit; 9. Analog-to-digital converter; 10. Microcontroller.

[0024] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0025] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0026] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Please see Figures 1 to 4 The vibration signal acquisition device in this embodiment includes a signal preprocessing module and a signal conversion module electrically connected to the signal preprocessing module. The signal preprocessing module is electrically connected to an acquisition sensor, which is used to acquire vibration signals generated by a structure after excitation. These vibration signals are non-stationary dynamic signals. The signal preprocessing module is used to amplify and filter noise in the non-stationary dynamic signals acquired by the acquisition sensor to form a non-stationary processed signal. Specifically, the signal preprocessing module includes a signal amplification circuit 1 electrically connected to the acquisition sensor. The signal amplification circuit 1 is electrically connected to the signal conversion module through a filter circuit 2. The signal amplification circuit 1 is used to amplify the non-stationary dynamic signals to improve the signal-to-noise ratio. The filter circuit 2 is used to suppress aliasing signals to meet sampling requirements and filter out interference and noise outside the signal bandwidth. In this embodiment, the filter circuit 22 is a fourth-order active low-pass filter.

[0029] The signal conversion module includes a precision full-wave rectifier circuit 3 and a voltage comparator 4. The precision full-wave rectifier circuit 3 includes operational amplifiers U1A and U1B, resistors R1 and R5. The voltage comparator 4 includes a comparator U12. The signal preprocessing module is electrically connected to the inverting input terminal of operational amplifier U1A through resistor R3. The output terminal of operational amplifier U1A is electrically connected to the inverting input terminal of operational amplifier U1B. A diode D2 and a resistor R4 are connected in series between the output terminal of operational amplifier U1A and the inverting input terminal of operational amplifier U1B. One end of resistor R1 is connected between resistor R3 and the inverting input terminal of operational amplifier U1A, and the other end of resistor R1... A diode D2 is connected between the diode D2 and the resistor R4. One end of the resistor R5 is connected between the signal preprocessing module and the resistor R3. The other end of the resistor R5 is connected between the resistor R4 and the inverting input terminal of the operational amplifier U1B. A diode D1 is placed between the output terminal of the operational amplifier U1A and the inverting input terminal of the operational amplifier U1A. A resistor R2 is placed between the output terminal of the operational amplifier U1B and the inverting input terminal of the operational amplifier U1B. The output terminal of the operational amplifier U1B is electrically connected to the non-inverting input terminal of the comparator U12. The output terminal of the comparator U12 is electrically connected to the digital frequency synthesizer U3 6. The inverting input terminal of the comparator U12 is connected to the threshold voltage.

[0030] The resistors R2 and R5 have the same resistance value. The ratio of the resistance values ​​of R2 to R1 is 1:2. The ratio of the resistance values ​​of R2 to R3 is 1:2. The ratio of the resistance values ​​of R2 to R4 is 1:2. When a non-stationary signal enters the operational amplifier U1A, the input voltage of the precision full-wave rectifier circuit 3 is obtained. When the input voltage is greater than 0V, diode D1 is cut off and diode D2 is turned on, and the output voltage of the precision full-wave rectifier circuit 3 is equal to the input voltage. When the input voltage is less than 0V, diode D1 is turned on and diode D2 is cut off, and the output voltage of the precision full-wave rectifier circuit 3 is equal to the negative input voltage. Then, by comparing the output voltage of the precision full-wave rectifier circuit 3 with the threshold voltage value, which is 50mV to 100mV, a standard square wave signal is output to the digital frequency synthesizer U3 via the comparator U12.

[0031] A resistor R26 is provided between the output terminal of the operational amplifier U1B and the non-inverting input terminal of the comparator U12. A resistor R24 ​​is provided between the output terminal of the comparator U12 and the non-inverting input terminal of the comparator U12. The output terminal of the comparator U12 is electrically connected to a resistor R25. The comparator U12, the resistor R24, the resistor R25, and the resistor R26 constitute a voltage comparator 4 with hysteresis function. Considering that spectrum analysis is only concerned with the periodicity of the signal, the voltage comparator 4 with hysteresis function can not only filter out the small interference near the threshold, but also does not affect the accuracy of frequency monitoring.

[0032] The U3 digital frequency synthesizer 6 is electrically connected to the microcontroller 10 via the analog-to-digital converter 9. The microcontroller 10 is electrically connected to the U3 digital frequency synthesizer 6 to configure a fixed counting step size parameter for the U3 digital frequency synthesizer 6. When acquiring and processing the non-stationary dynamic signal to obtain the non-stationary processed signal, the non-stationary processed signal is precisely rectified by the precision full-wave rectifier circuit 3, that is, the absolute value operation is performed on the non-stationary signal. The signal after absolute value operation contains the second harmonic component and DC component of the non-stationary processed signal. At the same time, the bipolar signal is conditioned into a unipolar signal and input to the comparator U12. The comparator U12 shapes the unipolar signal into a standard square wave signal and replaces the clock signal input to the U3 digital frequency synthesizer 6. Utilizing the characteristic that the U3 digital frequency synthesizer 6 can generate periodic wavelengths, after the microcontroller 10 configures a fixed counting step size parameter to it, a variance-stationary signal is generated. That is, the conversion of the non-stationary dynamic signal into a variance-stationary signal is realized through the signal conversion module and the U3 digital frequency synthesizer 6, which adapts to the processing characteristics of FFT, reduces the probability of monitoring errors, and improves the accuracy of monitoring.

[0033] The U3 digital frequency synthesizer 6 consists of a phase accumulator, a phase amplitude table, and a digital-to-analog converter. As a commonly used frequency synthesis method, it generates periodic waveforms, producing sine waves, triangle waves, and square waves ranging from low frequencies to hundreds of MHz. The data output from the phase accumulator is used as the phase sampling address of the waveform memory. This allows the waveform sample value (binary code) stored in the waveform memory (sine wave) to be retrieved via a lookup table, completing the phase-to-amplitude conversion.

[0034] In this embodiment, the microcontroller 10 writes a fixed counting step parameter to the U3 digital frequency synthesizer 6 to generate a sine wave signal. Its transfer function is fo = (M*fi) / 2^n, where fi represents the frequency of the input signal, fo represents the frequency of the output signal, M represents the fixed counting step parameter, and n represents the number of bits for phase accumulation. Since the output of the U3 digital frequency synthesizer 6 is a signal sampled according to the Nyquist sampling principle, the output signal frequency is equivalent to the signal to be sampled, while the input signal frequency is equivalent to the sampling frequency. Therefore, M = 2^(n-1). It can count from 0 to 2^n; therefore, the output frequency fo = fi / 2, that is, the output frequency is half of the input frequency. Because the signal undergoes frequency multiplication in the precision full-wave rectifier circuit 3, the signal frequency is restored to its original frequency after passing through the U3 digital frequency synthesizer 6.

[0035] A low-pass filter 7 is provided between the U3 digital frequency synthesizer 6 and the analog-to-digital converter 9. The low-pass filter 7 includes an amplifier U4. The microcontroller 10 is electrically connected to the DAT pin, CLK pin, and SYNC pin of the U3 digital frequency synthesizer 6. The output of the comparator U12 is electrically connected to the Fin pin of the U3 digital frequency synthesizer 6. The U3 digital frequency synthesizer 6 is electrically connected to the non-inverting input of the amplifier U4 through the VOUT pin. The output of the amplifier U4 is electrically connected to the analog-to-digital converter 9. Resistors R40 and R50 are sequentially provided between the VOUT pin of the U3 digital frequency synthesizer 6 and the non-inverting input of the amplifier U4. A capacitor C10 is provided between the resistor R50 and the non-inverting input of the amplifier U4. The output of the amplifier U4 is connected to one end of the capacitor C4, and the other end of the capacitor C4 is connected between the resistor R40 and the resistor R50.

[0036] A signal gate 5 is provided between the voltage comparator 4 and the digital frequency synthesizer 6 (U3). A judgment circuit 8 is provided between the filter circuit 2 and the signal gate 5. The judgment circuit 8 is used to compare the envelope signal of the non-stationary processed signal with a reference voltage value to control the opening and closing of the signal gate 5. The judgment circuit 8 includes operational amplifiers U5A and U5B and a comparator U6. The filter circuit 2 is electrically connected to the non-inverting input terminal of operational amplifier U5A. A dual-channel comparator is provided between the output terminal and the inverting input terminal of operational amplifier U5A. A diode D3 is connected to the output terminal of operational amplifier U5A, which is electrically connected to the non-inverting input terminal of operational amplifier U5B. The output terminal of operational amplifier U5B is electrically connected to the non-inverting input terminal of comparator U6. The output terminal of comparator U6 is electrically connected to signal gate 5. A diode D4 is placed between the output terminal of operational amplifier U5A and the non-inverting input terminal of operational amplifier U5B. A resistor R7 and a capacitor C11 are connected in parallel between diode D4 and the non-inverting input terminal of operational amplifier U5B. A resistor R6 is placed between diode D3 and the inverting input terminal of operational amplifier U5B.

[0037] The diode D3 and the operational amplifier U5A form an ideal diode circuit to eliminate errors caused by diode charging voltage drop. Diode D4 acts as a clamping mechanism when re-establishing the peak value of the input signal, preventing slow circuit response during negative saturation. The voltage across capacitor C11 tracks the voltage (envelope) of the input signal; capacitor C11 is an NPO capacitor. Resistor R6 is a current-limiting resistor, designed to suppress the sinking current of operational amplifier U5A, providing protection. Resistor R7 is a bleeder resistor. Operational amplifier U5B is configured as a voltage follower for impedance matching. In this embodiment, comparator U6 is also configured as a voltage comparator with hysteresis.

[0038] When the envelope signal is higher than the reference voltage value, a high level is output to drive the signal gate 5 to open; when the envelope signal is lower than the reference voltage value, a low level is output to drive the signal gate 5 to close. At the same time, the judgment circuit 8 is electrically connected to the microcontroller 10 so that when the signal judgment circuit 8 outputs a high level to drive the signal gate 5 to open, a signal is synchronously sent to the microcontroller 10. The microcontroller 10 controls the analog-to-digital converter 9 to sample the signal.

[0039] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A vibration signal acquisition device, characterized by, The signal pre-processing module is electrically connected with a signal conversion module, the signal pre-processing module is electrically connected with a collection sensor, the signal pre-processing module is used for signal amplification and noise filtering on the non-stationary dynamic signal collected by the collection sensor to form a non-stationary processing signal, the signal conversion module comprises a precision full-wave rectifier circuit and a voltage comparator, the precision full-wave rectifier circuit comprises an operational amplifier U1A, an operational amplifier U1B, a resistor R1 and a resistor R5, the voltage comparator comprises a comparator U12, the signal pre-processing module is electrically connected with the inverting input end of the operational amplifier U1A through a resistor R3, the output end of the operational amplifier U1A is electrically connected with the inverting input end of the operational amplifier U1B, a diode D2 and a resistor R4 are arranged in series between the output end of the operational amplifier U1A and the inverting input end of the operational amplifier U1B, one end of the resistor R1 is connected between the resistor R3 and the inverting input end of the operational amplifier U1A, the other end of the resistor R1 is connected between the diode D2 and the resistor R4, one end of the resistor R5 is connected between the signal pre-processing module and the resistor R3, the other end of the resistor R5 is connected between the resistor R4 and the inverting input end of the operational amplifier U1B, a diode D1 is arranged between the output end of the operational amplifier U1A and the inverting input end of the operational amplifier U1A, a resistor R2 is arranged between the output end of the operational amplifier U1B and the inverting input end of the operational amplifier U1B, the output end of the operational amplifier U1B is electrically connected with the non-inverting input end of the comparator U12, the output end of the comparator U12 is electrically connected with a U3 digital frequency synthesizer, the U3 digital frequency synthesizer is electrically connected with a microcontroller through an analog-to-digital converter, and the microcontroller is electrically connected with the U3 digital frequency synthesizer to configure a fixed counting step parameter for the U3 digital frequency synthesizer.

2. The vibration signal acquisition device of claim 1, wherein, The resistor R2 and the resistor R5 have the same resistance value, the ratio of the resistance value of the resistor R2 to the resistance value of the resistor R1 is 1:2, the ratio of the resistance value of the resistor R2 to the resistance value of the resistor R3 is 1:2, and the ratio of the resistance value of the resistor R2 to the resistance value of the resistor R4 is 1:

2.

3. The vibration signal acquisition device of claim 1, wherein, A resistor R26 is arranged between the output end of the operational amplifier U1B and the non-inverting input end of the comparator U12, a resistor R24 is arranged between the output end of the comparator U12 and the non-inverting input end of the comparator U12, and the output end of the comparator U12 is electrically connected with a resistor R25.

4. The vibration signal acquisition device of claim 1, wherein, The signal pre-processing module comprises a signal amplification circuit electrically connected with the collection sensor, and the signal amplification circuit is electrically connected with the inverting input end of the operational amplifier U1A through a filter circuit.

5. The vibration signal acquisition device of claim 1, wherein, The low pass filter is arranged between the U3 digital frequency synthesizer and the analog-digital converter, the microcontroller is electrically connected with the DAT pin, the CLK pin and the SYNC pin of the U3 digital frequency synthesizer, the output terminal of the comparator U12 is electrically connected with the Fin pin of the U3 digital frequency synthesizer, the U3 digital frequency synthesizer is electrically connected with the non-inverting input terminal of the amplifier U4 through the VOUT pin, the output terminal of the amplifier U4 is electrically connected with the analog-digital converter, the resistor R40 and the resistor R50 are arranged between the VOUT pin of the U3 digital frequency synthesizer and the non-inverting input terminal of the amplifier U4 in sequence, the capacitor C10 is arranged between the resistor R50 and the non-inverting input terminal of the amplifier U4, one end of the capacitor C4 is connected with the output terminal of the amplifier U4, and the other end of the capacitor C4 is connected between the resistor R40 and the resistor R50.

6. The vibration signal acquisition device of claim 4, wherein, The signal gate is arranged between the voltage comparator and the U3 digital frequency synthesizer, the judgment circuit is arranged between the filter circuit and the signal gate, and the judgment circuit is used for comparing the envelope signal of the non-stationary processing signal with the reference voltage value to control the opening and closing of the signal gate.

7. The vibrational signal acquisition device of claim 6, wherein, The judgment circuit comprises the operational amplifier U5A, the operational amplifier U5B and the comparator U6, the filter circuit is electrically connected with the non-inverting input terminal of the operational amplifier U5A, the diode D3 is arranged between the output terminal of the operational amplifier U5A and the inverting input terminal of the operational amplifier U5A, the output terminal of the operational amplifier U5A is electrically connected with the non-inverting input terminal of the operational amplifier U5B, the output terminal of the operational amplifier U5B is electrically connected with the non-inverting input terminal of the comparator U6, and the output terminal of the comparator U6 is electrically connected with the signal gate.

8. The vibrational signal acquisition device of claim 7, wherein, The diode D4 is arranged between the output terminal of the operational amplifier U5A and the non-inverting input terminal of the operational amplifier U5B, and the resistor R7 and the capacitor C11 are arranged in parallel between the diode D4 and the non-inverting input terminal of the operational amplifier U5B.

9. The vibration signal acquisition device of claim 7, wherein, The resistor R6 is arranged between the diode D3 and the inverting input terminal of the operational amplifier U5B.

10. The vibration signal acquisition device of claim 4, wherein, The filter circuit is a four-order active low pass filter.

Images