A vibration signal extraction method for piezoelectric self-sensing energy harvesting

Abstract

The present invention discloses a vibration signal extraction method for piezoelectric self-sensing energy capture, which utilizes a single piezoelectric device to capture vibration energy and sense vibration signals. The single piezoelectric device performs vibration energy capture and vibration signal sensing in parallel in a time-space sharing mode. A vibration acceleration calculation model suitable for the time-space sharing mode of piezoelectric self-sensing energy capture is established. When performing vibration signal sensing, the vibration signal is first collected and processed to obtain the angular frequency ω of the vibration acceleration and the voltage value V of the peak voltage divider signal. peak , then the angular frequency ω of the vibration acceleration and the voltage value V of the peak voltage divider signal peak The vibration acceleration amplitude can be calculated by substituting it into the vibration acceleration calculation model; the advantages are high immediacy and efficiency, which can meet the needs of continuous vibration sensing while eliminating the influence of high-order harmonic components in non-sinusoidal piezoelectric voltage signals. It has high vibration acceleration calculation accuracy and can meet the needs of high-precision vibration sensing.

Description

Technical Field

[0001] The present invention relates to a vibration signal extraction method, in particular to a vibration signal extraction method for piezoelectric self-sensing energy capture. Background Art

[0002] Piezoelectric devices exhibit a positive piezoelectric effect and can be used as sensors to sense mechanical vibration signals, such as acceleration, velocity, and displacement. They can also be used as energy harvesters to capture ambient vibration energy, providing sustainable power for low-power microelectronic devices. "Piezoelectric self-sensing energy harvesting" utilizes a single piezoelectric device to achieve both vibration energy capture and vibration signal sensing. Piezoelectric self-sensing energy harvesting has two typical operating modes: time-division multiplexing (TDDM) and time-space sharing (S / P). TDDM involves using a single piezoelectric device for vibration energy capture during a period of time and for vibration signal sensing during another period. While TDDM is technically challenging to implement, it can easily cause the piezoelectric self-sensing energy harvesting system to miss measurements of critical vibration signals. S / PDM uses a single piezoelectric device for both vibration energy capture and vibration signal sensing simultaneously. Compared with the time-division multiplexing mode, the time-space sharing mode is less likely to cause the piezoelectric self-sensing energy harvesting system to miss the measurement of some key vibration signals, but its technical implementation is more difficult. It needs to solve the technical problem of mutual interference caused by the simultaneous performance of two functions on a single piezoelectric device.

[0003] At present, some technical solutions have been proposed to realize the two typical working modes of piezoelectric self-sensing energy capture, but there are still some problems to be solved. For example, the Chinese invention patent application with application number CN202210572620.7 discloses an omnidirectional piezoelectric energy capture and vibration monitoring system, which uses three piezoelectric devices that are perpendicular to each other in space to eliminate the influence of the vibration excitation direction on vibration energy capture and vibration signal sensing; for each of the piezoelectric devices, a time-division multiplexing mode of piezoelectric self-sensing energy capture is implemented, that is, the system cannot simultaneously perform vibration signal sensing while performing vibration energy capture, which may result in the loss of some important vibration signals; therefore, the immediacy and efficiency of the vibration signal sensing of the system are poor, and it cannot be used in occasions where continuous vibration sensing is required. At the same time, the loss of important vibration signals will also affect the overall accuracy of vibration signal sensing, and it cannot be used in occasions where high-precision vibration sensing is required. For example, the Chinese invention patent application with application number CN202110032826.6 discloses a self-powered wireless vibration monitoring node based on a single piezoelectric device. The self-powered wireless vibration monitoring node realizes a spatiotemporal sharing mode of piezoelectric self-sensing energy capture, that is, a single piezoelectric device simultaneously performs vibration energy capture and vibration signal sensing; in order to extract the vibration signal, the self-powered wireless vibration monitoring node directly uses the linear combination of the non-sinusoidal piezoelectric voltage peak and the rectified voltage to calculate the equivalent piezoelectric open-circuit voltage based on an ideal synchronous switching inductor circuit model, and then calculates the vibration acceleration. Although the self-powered wireless vibration monitoring node has high immediacy and efficiency and can be used in situations where continuous vibration sensing is required, since the non-sinusoidal piezoelectric voltage signal contains a large number of high-order harmonic components, and the mechanical vibration signal is usually a low-frequency signal, the self-powered wireless vibration monitoring node does not consider the influence of the above factors when extracting the vibration signal, resulting in a large error in the calculated vibration acceleration, which cannot be used in situations where high-precision vibration sensing is required. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a vibration signal extraction method for piezoelectric self-sensing energy capture that has high immediacy and efficiency, can meet the needs of continuous vibration sensing, can also eliminate the influence of higher harmonic components in non-sinusoidal piezoelectric voltage signals, has high vibration acceleration calculation accuracy, and can meet the needs of high-precision vibration sensing.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a vibration signal extraction method for piezoelectric self-sensing energy capture, which uses a single piezoelectric device to simultaneously capture vibration energy and sense vibration signals. The vibration signal sensing includes first collecting the vibration signal and processing the vibration signal to obtain the angular frequency ω of the vibration acceleration and the voltage value V of the peak voltage divider signal. peakThen the angular frequency ω of the vibration acceleration and the voltage value V of the peak voltage division signal are peak , is substituted into the vibration acceleration calculation model to calculate the vibration acceleration amplitude, wherein the vibration acceleration calculation model is expressed by formula (1):

[0006]

[0007] In formula (1), A is the amplitude of vibration acceleration; M is the equivalent mass of the piezoelectric device, D is the equivalent damping of the piezoelectric device, K is the equivalent stiffness of the piezoelectric device, C is P is the clamping capacitance of the piezoelectric device, α is the force-pressure conversion coefficient of the piezoelectric device, M, D, K, C P and α are determined in advance by performing mechanical and electrical tests on the piezoelectric device; k is a voltage division coefficient, the value of which is determined by a specific circuit structure for obtaining a peak voltage division signal; and π is pi.

[0008] The specific process of using a single piezoelectric device to simultaneously capture vibration energy and sense vibration signals is as follows:

[0009] S1. A piezoelectric device senses vibrations in an external environment, and the positive and negative output terminals of the piezoelectric device each generate an AC voltage signal output. The AC voltage signal output from the positive output terminal of the piezoelectric device is referred to as a positive-end AC voltage signal, and the AC voltage signal output from the negative output terminal is referred to as a negative-end AC voltage signal. The positive-end AC voltage signal and the negative-end AC voltage signal constitute a differential AC voltage signal.

[0010] S2. Converting the differential AC voltage signal into a DC voltage signal to charge the rechargeable battery and store electrical energy; at the same time, on the one hand, tracking the peak value of the positive AC voltage signal and outputting a peak voltage division signal proportional to the peak voltage of the positive AC voltage signal; on the other hand, shaping and triggering the positive AC voltage signal to generate a square wave voltage signal having the same frequency as the vibration signal in the external environment;

[0011] S3. Periodically collect the peak voltage division signal and the square wave voltage signal, and process the peak voltage division signal and the square wave voltage signal collected in each period to obtain the angular frequency of the vibration acceleration in each period and the voltage value of the peak voltage division signal, and substitute them into the vibration acceleration calculation model to calculate the vibration acceleration amplitude, thereby realizing the extraction of the vibration signal.

[0012] The differential AC voltage signal is converted into a DC voltage signal through a synchronous charge extraction circuit; the peak value of the positive-end AC voltage signal is tracked through a peak detection circuit, and a peak voltage division signal proportional to the peak voltage of the positive-end AC voltage signal is output. The voltage division coefficient k in the vibration acceleration calculation model is determined by the peak detection circuit; the positive-end AC voltage signal is shaped and triggered by a same-frequency square wave generation circuit to generate a square wave voltage signal with the same frequency as the vibration signal in the external environment; the vibration acceleration calculation model is pre-stored in a single-chip microcomputer, and the single-chip microcomputer periodically collects the peak voltage division signal and the square wave voltage signal, and processes the peak voltage division signal and square wave voltage signal collected in each period in turn to obtain the angular frequency of the vibration acceleration in each period and the value of the peak voltage division signal, which are substituted into the vibration acceleration calculation model to calculate the vibration acceleration amplitude.

[0013] The specific process of step S3 is as follows:

[0014] A1. Setting a timing period in the single chip microcomputer, wherein the timing period is 20ms to 100ms;

[0015] A2. Within a timing cycle, on the one hand, the single-chip microcomputer counts the number of rising edges of the square wave voltage signal of the timing cycle through its internal counter, and calculates the angular frequency ω of the vibration acceleration of the timing cycle based on the number of rising edges of the square wave voltage signal collected during the timing cycle. On the other hand, the single-chip microcomputer samples the peak voltage divided signal of the timing cycle through its internal analog-to-digital converter, and calculates the voltage value V of the peak voltage divided signal of the timing cycle. peak ;

[0016] A3. Combine ω and V peak Substitute the vibration acceleration calculation model to calculate the amplitude A of the vibration acceleration of the timing period.

[0017] The piezoelectric device is a cantilever beam piezoelectric device.

[0018] Compared with the prior art, the advantage of the present invention is that a single piezoelectric device is used to simultaneously capture vibration energy and sense vibration signals. The single piezoelectric device performs vibration energy capture and vibration signal sensing in parallel in a time-space sharing manner, thereby avoiding the loss of important vibration signals and improving the immediacy and efficiency of vibration signal sensing. The captured vibration energy can be stored in a rechargeable battery to provide additional power for other low-power devices, thereby extending the battery life of the devices. At the same time, a vibration acceleration calculation model suitable for the piezoelectric self-sensing energy capture time-space sharing mode is established. When performing vibration signal sensing, the vibration signal is first collected and processed to obtain the angular frequency ω of the vibration acceleration and the voltage value V of the peak voltage divider signal.peak , then the angular frequency ω of the vibration acceleration and the voltage value V of the peak voltage divider signal peak The vibration acceleration amplitude can be calculated by substituting it into the vibration acceleration calculation model. High-precision vibration acceleration can be obtained through only some simple signal measurement and processing steps. Therefore, the present invention has high immediacy and efficiency, can meet the needs of continuous vibration sensing, and can also eliminate the influence of high-order harmonic components in non-sinusoidal piezoelectric voltage signals. It has high vibration acceleration calculation accuracy and can meet the needs of high-precision vibration sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A system block diagram for signal acquisition in the vibration signal extraction method for piezoelectric self-sensing energy harvesting of the present invention;

[0020] Figure 2 This is a waveform diagram of the piezoelectric voltage during the data processing process in the vibration signal extraction method for piezoelectric self-sensing energy capture of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0022] Example 1: A vibration signal extraction method for piezoelectric self-sensing energy capture, using a single piezoelectric device 1 to simultaneously capture vibration energy and sense vibration signals. Vibration signal sensing includes first collecting and processing the vibration signal to obtain the angular frequency ω of the vibration acceleration and the voltage value V of the peak voltage divider signal. peak , then the angular frequency ω of the vibration acceleration and the voltage value V of the peak voltage divider signal peak Substitute into the vibration acceleration calculation model to calculate the vibration acceleration amplitude, where the vibration acceleration calculation model is expressed by formula (1):

[0023]

[0024] In formula (1), A is the amplitude of vibration acceleration; M is the equivalent mass of piezoelectric device 1, D is the equivalent damping of piezoelectric device 1, K is the equivalent stiffness of piezoelectric device 1, C is P is the clamping capacitance of the piezoelectric device 1, α is the force-pressure conversion coefficient of the piezoelectric device 1, M, D, K, C P and α are determined in advance by performing mechanical and electrical tests on the piezoelectric device 1; k is a voltage division coefficient, and its value is determined by a specific circuit structure for obtaining a peak voltage division signal; and π is pi.

[0025] Example 2: This example is basically the same as Example 1, except that:

[0026] In this embodiment, the specific process of simultaneously performing vibration energy capture and vibration signal sensing using a single piezoelectric device 1 is as follows:

[0027] S1. A piezoelectric device 1 senses vibrations in the external environment. The positive and negative output terminals of the piezoelectric device 1 each generate an AC voltage signal output. The AC voltage signal output from the positive output terminal of the piezoelectric device 1 is referred to as a positive AC voltage signal Vp, and the AC voltage signal output from the negative output terminal is referred to as a negative AC voltage signal Vn. The positive AC voltage signal Vp and the negative AC voltage signal Vn constitute a differential AC voltage signal Vp-Vn.

[0028] S2. Convert the differential AC voltage signal Vp-Vn into a DC voltage signal to charge the rechargeable battery and store electrical energy. At the same time, on the one hand, track the peak value of the positive AC voltage signal Vp and output a peak voltage division signal proportional to the peak voltage of the positive AC voltage signal Vp. On the other hand, shape and trigger the positive AC voltage signal Vp to generate a square wave voltage signal with the same frequency as the vibration signal in the external environment.

[0029] S3. Periodically collect the peak voltage division signal and the square wave voltage signal, and process the peak voltage division signal and the square wave voltage signal collected in each period to obtain the angular frequency of the vibration acceleration in each period and the voltage value of the peak voltage division signal. Substitute them into the vibration acceleration calculation model to calculate the vibration acceleration amplitude and realize the extraction of the vibration signal.

[0030] like Figure 1 As shown, in this embodiment, the differential AC voltage signal Vp-Vn is converted into a DC voltage signal by the synchronous charge extraction circuit 2 to charge the rechargeable battery BAT; the peak value of the positive AC voltage signal Vp is tracked by the peak detection circuit 3, and a peak voltage division signal proportional to the peak voltage of the positive AC voltage signal Vp is output. The voltage division coefficient k in the vibration acceleration calculation model is determined by the peak detection circuit 3; the positive AC voltage signal Vp is shaped and triggered by the same frequency square wave generation circuit 4 to generate a square wave voltage signal V with the same frequency as the vibration signal in the external environment. freq ; The vibration acceleration calculation model is pre-stored in the single-chip microcomputer 5. The single-chip microcomputer 5 periodically collects the peak voltage division signal and the square wave voltage signal, and processes the peak voltage division signal and the square wave voltage signal collected in each period in turn to obtain the angular frequency of the vibration acceleration in each period and the value of the peak voltage division signal, which are substituted into the vibration acceleration calculation model to calculate the vibration acceleration amplitude; wherein, the rechargeable battery BAT can provide the operating voltage VCC for the single-chip microcomputer 5.

[0031] In this embodiment, the synchronous charge extraction circuit 2, the peak detection circuit 3, the same-frequency square wave generation circuit 4 and the single-chip microcomputer 5 are all mature products in their respective technical fields.

[0032] In this embodiment, the specific process of step S3 is:

[0033] A1. Set a timing period in the single chip microcomputer 5, the timing period being 20ms to 100ms;

[0034] A2. Within a timing cycle, on the one hand, the single-chip microcomputer 5 counts the number of rising edges of the square wave voltage signal of the timing cycle through its internal counter, and calculates the angular frequency ω of the vibration acceleration of the timing cycle based on the number of rising edges of the square wave voltage signal collected during the timing cycle. On the other hand, the single-chip microcomputer 5 samples the peak voltage divided signal of the timing cycle through its internal analog-to-digital converter, and calculates the voltage value V of the peak voltage divided signal of the timing cycle. peak ;

[0035] A3. Combine ω and V peak Substitute it into the vibration acceleration calculation model to calculate the amplitude A of the vibration acceleration of this timing period.

[0036] In this embodiment, the piezoelectric device 1 is a cantilever beam piezoelectric device 1 .

[0037] In this embodiment, the specific working process of the single chip microcomputer 5 is as follows:

[0038] Step 1: When the microcontroller 5 is powered on, its internal timer is started and the square wave voltage signal V is inputted into it. freq Perform rising edge trigger counting; synchronously start the peak voltage divider signal V peak Conduct continuous sampling;

[0039] Step 2: When the timing reaches a timing cycle T, turn off the internal timer and stop timing;

[0040] Step 3: Convert the current statistical square wave voltage signal V freq The number of rising edges is recorded as N, and the angular frequency of vibration acceleration is recorded as ω, then the angular frequency of vibration acceleration is calculated as ω=2*π*N / T;

[0041] Step 4: The sampling frequency of the analog voltage continuously sampled by the microcontroller 5 through its internal analog-to-digital converter is f S , the number of samples of the peak voltage divided signal collected in the current timing period T is S, then S=f S *T; calculate the sample average of the S peak voltage divider signals, recorded as V peak , V peak That is the voltage value of the peak voltage division signal of the current timing cycle;

[0042] Step 5: Substitute the angular frequency ω and V of the vibration acceleration peakSubstitute the vibration acceleration calculation model to calculate the amplitude A of the vibration acceleration in the current timing period T.

[0043] At this point, the extraction of the vibration acceleration signal of one timing cycle T is completed, and then the next timing cycle is entered, and the process repeats itself over and over again.

[0044] The process of establishing the vibration acceleration calculation model of the vibration signal extraction method for piezoelectric self-sensing energy capture of the present invention is as follows:

[0045] Step 1: Establish the electromechanical coupling dynamic equation of the piezoelectric device 1:

[0046]

[0047] In formula (1), t represents time; λ(t) is the vibration acceleration input to the piezoelectric device 1, V P (t) is the periodic non-sinusoidal voltage signal output by the piezoelectric device 1, u(t) is the vibration displacement of the piezoelectric device 1, and are the first-order derivative and second-order derivative of the vibration displacement u(t), respectively; M is the equivalent mass of the piezoelectric device 1, D is the equivalent damping of the piezoelectric device 1, K is the equivalent stiffness of the piezoelectric device 1, C P is the clamping capacitance of the piezoelectric device 1, α is the force-pressure conversion coefficient of the piezoelectric device 1;

[0048] Step 2: The vibration displacement u(t) of the piezoelectric device 1 can be expressed as:

[0049] u(t)=-u m cosωt (2)

[0050] In formula (2), u m is the amplitude of the vibration displacement u(t) of the piezoelectric device 1; ω is the vibration angular frequency; cos is the cosine function;

[0051] Step 3: After the piezoelectric device 1 is connected to the synchronous charge extraction circuit 2, the piezoelectric device 1 outputs a periodic non-sinusoidal voltage signal V P Peak value V (t) M It can be expressed as:

[0052]

[0053] Step 4: Piezoelectric device 1 outputs a periodic non-sinusoidal voltage signal V P The waveform of (t) is as follows Figure 2 As shown in (a), the voltage waveform can be expressed as:

[0054]

[0055] Step 5: Output the periodic non-sinusoidal voltage signal V of the piezoelectric device 1 P (t) is expanded into a Fourier series, and its expansion can be expressed as:

[0056]

[0057] In formula (5), a0 is the DC component, a n is the coefficient of the cosine term in the nth harmonic component, b n is the coefficient of the sine term in the nth harmonic component; cos is the cosine function, sin is the sine function; ∑ is the accumulation symbol; when n is 27, we can get the following: Figure 2 (b) The voltage waveform shown;

[0058] Step 6: Since the piezoelectric device 1 works under low-frequency vibration excitation, its mechanical structure itself has the function of filtering out high-frequency vibration, so the periodic non-sinusoidal voltage signal V is ignored. P (t) The higher harmonic components in the Fourier series expansion and only retain its fundamental component, which is Figure 2 (c) shows the voltage waveform; since the fundamental component contains most of the vibration energy, the periodic non-sinusoidal voltage signal V P (t) can be approximately replaced by its fundamental component, and its approximate expression is:

[0059]

[0060] Step 7: For the periodic non-sinusoidal voltage signal V obtained in step 6 P Perform Laplace transform on the fundamental component expression of (t) to obtain the corresponding frequency domain expression:

[0061]

[0062] In formula (7), j is an imaginary unit, and its value is equal to V P (jω) is the periodic non-sinusoidal voltage signal V output by the piezoelectric device 1 P (t), U(jω) is the frequency expression corresponding to the vibration displacement u(t) of the piezoelectric device 1;

[0063] Step 8: Take the modulus of both sides of formula (7) obtained in step 7 and combine it with formula (3) obtained in step 3 to obtain the periodic non-sinusoidal voltage signal V P The fundamental component amplitude of (t) and the periodic non-sinusoidal voltage signal V P Peak value V (t) M The relationship between them is:

[0064]

[0065] In formula (8), V PM is the periodic non-sinusoidal voltage signal V output by the piezoelectric device 1 P (t) is the amplitude of the fundamental component.

[0066] Step 9: Perform Laplace transform on formula (1) obtained in step 1 and combine it with formula (7) obtained in step 7 to obtain:

[0067]

[0068] In formula (9), Λ(jω) is the frequency expression corresponding to the vibration acceleration λ(t) input to the piezoelectric device 1.

[0069] Step 10: Modulo both sides of formula (9) obtained in step 9 and combine it with formula (8) obtained in step 8 to obtain:

[0070]

[0071] In formula (10), A is the amplitude of the vibration acceleration λ(t) input to the piezoelectric device 1.

[0072] Step 11: According to the working principle of the peak detection circuit 3, the peak voltage signal V collected by the microcontroller 5 peak Equal to the peak value V of the periodic non-sinusoidal voltage signal output by the piezoelectric device 1 M k times of , and substituting this relationship into the formula (10) obtained in step 10, we can obtain the vibration acceleration calculation model applicable to the spatiotemporal sharing mode of piezoelectric self-sensing energy harvesting:

[0073]

Claims

1. A vibration signal extraction method for piezoelectric self-sensing energy capture, which uses a single piezoelectric device to simultaneously capture vibration energy and sense vibration signals, characterized in that The vibration signal sensing includes first collecting the vibration signal and processing the vibration signal to obtain the angular frequency of the vibration acceleration. ω and the voltage value of the peak voltage divided signal V peak , then the angular frequency of the vibration acceleration ω and the voltage value of the peak voltage divided signal V peak Substitute into the vibration acceleration calculation model to calculate the vibration acceleration amplitude, wherein the vibration acceleration calculation model is expressed by formula (1): (1) In formula (1), A is the amplitude of vibration acceleration; M is the equivalent mass of the piezoelectric device, D is the equivalent damping of the piezoelectric device, K is the equivalent stiffness of the piezoelectric device, C P is the clamping capacitance of the piezoelectric device, α is the force-pressure conversion coefficient of the piezoelectric device, M 、 D 、 K 、 C P and α This is determined in advance by performing mechanical and electrical tests on the piezoelectric device; k is the voltage division coefficient, whose value is determined by the specific circuit structure for obtaining the peak voltage division signal; π is the circumference of a circle; The specific process of using a single piezoelectric device to simultaneously capture vibration energy and sense vibration signals is as follows: S1. A piezoelectric device senses vibrations in an external environment, and the positive and negative output terminals of the piezoelectric device each generate an AC voltage signal output. The AC voltage signal output from the positive output terminal of the piezoelectric device is referred to as a positive-end AC voltage signal, and the AC voltage signal output from the negative output terminal is referred to as a negative-end AC voltage signal. The positive-end AC voltage signal and the negative-end AC voltage signal constitute a differential AC voltage signal. S2. Converting the differential AC voltage signal into a DC voltage signal to charge the rechargeable battery and store electrical energy; at the same time, on the one hand, tracking the peak value of the positive AC voltage signal and outputting a peak voltage division signal proportional to the peak voltage of the positive AC voltage signal; on the other hand, shaping and triggering the positive AC voltage signal to generate a square wave voltage signal having the same frequency as the vibration signal in the external environment; S3. Periodically collect the peak voltage division signal and the square wave voltage signal, and process the peak voltage division signal and the square wave voltage signal collected in each period to obtain the angular frequency of the vibration acceleration in each period and the voltage value of the peak voltage division signal, and substitute them into the vibration acceleration calculation model to calculate the vibration acceleration amplitude, thereby realizing the extraction of the vibration signal.

2. A vibration signal extraction method for piezoelectric self-sensing energy harvesting according to claim 1, characterized in that The differential AC voltage signal is converted into a DC voltage signal through a synchronous charge extraction circuit; the peak value of the positive AC voltage signal is tracked by a peak detection circuit, and a peak voltage division signal proportional to the peak voltage of the positive AC voltage signal is output. The voltage division coefficient in the vibration acceleration calculation model is k Determined by the peak detection circuit; the positive-end AC voltage signal is shaped and triggered by the same-frequency square wave generation circuit to generate a square wave voltage signal with the same frequency as the vibration signal in the external environment; the vibration acceleration calculation model is pre-stored in the single-chip microcomputer, and the peak voltage division signal and the square wave voltage signal are periodically collected by the single-chip microcomputer, and the peak voltage division signal and the square wave voltage signal collected in each period are processed in turn to obtain the angular frequency of the vibration acceleration of each period and the value of the peak voltage division signal, which are substituted into the vibration acceleration calculation model to calculate the vibration acceleration amplitude.

3. A vibration signal extraction method for piezoelectric self-sensing energy harvesting according to claim 2, characterized in that The specific process of step S3 is as follows: A1. Set a timing period in the microcontroller, the timing period being 20ms to 100ms; A2. Within a timing cycle, on the one hand, the single-chip microcomputer counts the number of rising edges of the square wave voltage signal of the timing cycle through its internal counter, and calculates the angular frequency of the vibration acceleration of the timing cycle based on the number of rising edges of the square wave voltage signal collected during the timing cycle. ω On the other hand, the single chip microcomputer samples the peak voltage divided signal of the timing cycle through its internal analog-to-digital converter and calculates the voltage value of the peak voltage divided signal of the timing cycle. V peak ; A3. ω and V peak Substitute the vibration acceleration calculation model to calculate the amplitude A of the vibration acceleration of the timing period.

4. The vibration signal extraction method for piezoelectric self-sensing energy harvesting according to claim 1 is characterized in that The piezoelectric device is a cantilever beam piezoelectric device.

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