CN115060988A - High-temperature in-situ piezoelectric performance detection system and method for eliminating influence of pyroelectric effect - Google Patents
High-temperature in-situ piezoelectric performance detection system and method for eliminating influence of pyroelectric effect Download PDFInfo
- Publication number
- CN115060988A CN115060988A CN202210770776.6A CN202210770776A CN115060988A CN 115060988 A CN115060988 A CN 115060988A CN 202210770776 A CN202210770776 A CN 202210770776A CN 115060988 A CN115060988 A CN 115060988A
- Authority
- CN
- China
- Prior art keywords
- signal
- unit
- temperature
- phase
- piezoelectric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 46
- 230000000694 effects Effects 0.000 title claims abstract description 30
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 20
- 238000000034 method Methods 0.000 title abstract description 16
- 238000012545 processing Methods 0.000 claims abstract description 62
- 238000001914 filtration Methods 0.000 claims abstract description 30
- 238000006243 chemical reaction Methods 0.000 claims abstract description 19
- 230000003321 amplification Effects 0.000 claims description 30
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 30
- 238000005259 measurement Methods 0.000 claims description 21
- 238000002156 mixing Methods 0.000 claims description 18
- 230000008859 change Effects 0.000 claims description 14
- 238000012216 screening Methods 0.000 claims description 11
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 6
- 230000010363 phase shift Effects 0.000 claims description 5
- 230000003068 static effect Effects 0.000 description 54
- 239000000463 material Substances 0.000 description 16
- 238000012360 testing method Methods 0.000 description 14
- 238000010586 diagram Methods 0.000 description 10
- 230000010287 polarization Effects 0.000 description 8
- 238000004891 communication Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 238000011056 performance test Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 230000009471 action Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 238000012886 linear function Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000008204 material by function Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/22—Measuring piezoelectric properties
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
Abstract
The invention discloses a high-temperature in-situ piezoelectric performance detection system and method for eliminating the influence of a pyroelectric effect. The detection system comprises a first control circuit and a second control circuit; the first control circuit comprises a first signal processing module and a filtering charge conversion module; the first control circuit strips an original signal containing a temperature signal and a piezoelectric power supply signal, screens out the piezoelectric power supply signal, and converts the piezoelectric power supply signal into a piezoelectric signal for output; the second control circuit comprises a second signal processing module, a low-pass filter and an output unit; the second control circuit strips the original signals containing the temperature signals and the piezoelectric power signals, screens out the temperature signals, performs low-pass filtering on the temperature signals, and then amplifies the temperature signals to form effective pyroelectric signals for output.
Description
Technical Field
The invention relates to the field of performance test of piezoelectric materials, in particular to a high-temperature in-situ piezoelectric performance detection system and method for eliminating the influence of pyroelectric effect.
Background
Piezoelectric materials are a class of important functional materials that can generate a net charge on the surface of a material under the action of an external force. In recent years, piezoelectric materials are widely applied in the fields of aerospace, space technology, medical treatment, weaponry and the like. The use temperature of the piezoelectric material is also developing to a wider temperature range, and especially the performance of the piezoelectric material in a high temperature range becomes important to research. However, most of the current methods for testing the piezoelectric performance of piezoelectric materials are limited to room temperature, and cannot meet the requirements of high-temperature in-situ piezoelectric performance testing. Although a few methods realize high-temperature in-situ piezoelectric performance testing, the accuracy of the testing result still needs to be improved. This is because: piezoelectric materials have, in addition to the piezoelectric effect, a pyroelectric effect, i.e., a net charge is generated on the surface of the material when the temperature changes. When the piezoelectric material is subjected to in-situ high-temperature test, charges generated by the pyroelectric effect and charges generated by the piezoelectric effect are mixed together, so that the test result is seriously interfered. However, if the influence of pyroelectric is not considered, the accuracy of the high-temperature in-situ piezoelectric performance test result is difficult to guarantee. If the pyroelectric signal and the piezoelectric signal can be stripped, the research on the pyroelectric parameters of the piezoelectric material in the high-temperature process is an important parameter for researching the high-temperature effect of the sample.
Disclosure of Invention
Aiming at the problems, the invention provides a high-temperature in-situ piezoelectric performance detection system and method for eliminating the influence of the pyroelectric effect, which can improve the test precision and accuracy of the high-temperature in-situ piezoelectric performance and truly and accurately reflect the piezoelectric performance and pyroelectric parameters of the piezoelectric material under the high-temperature condition.
In a first aspect, the present invention provides a high-temperature in-situ piezoelectric performance detection system for eliminating the influence of pyroelectric effect. The detection system comprises a first control circuit and a second control circuit; the first control circuit comprises a first signal processing module and a filtering charge conversion module; the first signal processing module is provided with a filtering differential amplification unit, a frequency and phase locking and demodulating unit, a phase delay unit and a phase-locked loop unit which form a closed loop; the filtering charge conversion module is provided with a filter and a charge converter; the first control circuit strips an original signal containing a temperature signal and a piezoelectric power supply signal, screens out the piezoelectric power supply signal, and converts the piezoelectric power supply signal into a piezoelectric signal for outputting; the second control circuit comprises a second signal processing module, a low-pass filter and an output unit; the second signal processing module is provided with an input amplifying unit, a band-pass filter, a reference triggering unit, a phase shifting unit and a mixing phase discrimination unit; the second control circuit strips the original signals containing the temperature signals and the piezoelectric power signals, screens out the temperature signals, performs low-pass filtering on the temperature signals, and then amplifies the temperature signals to form effective pyroelectric signals for output.
Preferably, the original signal containing the temperature signal and the piezoelectric power signal is divided into one of two paths after passing through a filter of the filtering differential amplification unit and then is sent to the phase delay unit, and the signal with the phase difference eliminated by the phase delay unit is sent to the phase-locked loop unit for natural frequency screening to form a basic measurement signal.
Preferably, the original signal is divided into two paths after passing through a filter of the filtering differential amplification unit, and then the two paths of original signals are sent to the differential amplifier, the frequency-locked phase demodulation unit takes a basic measurement signal provided by the phase-locked loop unit as a reference signal, and takes the phase and frequency of the basic measurement signal as screening conditions, and a voltage power supply signal is stripped from the signals processed by the differential amplification unit.
Preferably, the filter of the filtering charge conversion module is connected to the frequency and phase locking unit of the first signal processing module.
Preferably, the input signal of the second signal processing module has two paths, one of the two paths of input signals is an original signal containing a temperature signal and a voltage power supply signal, and the original signal is amplified by the input amplifying unit and the band-pass filter connected with the input amplifying unit, selectively filtered, and then provided to the frequency mixing phase demodulation unit.
Preferably, the other input signal of the second signal processing module is an input signal provided by the dynamic force reference signal processing module, the input signal provided by the dynamic force reference signal processing module is converted into a standard digital square wave through the reference trigger unit, and then the standard digital square wave is used as a reference signal of the mixing frequency phase demodulation unit for frame voltage removal of the power supply signal after phase compensation is performed by the phase shift unit, so as to extract the temperature signal.
Preferably, the mixing phase detection unit performs frame voltage division on the power supply signal by using a reference signal with a phase opposite to that of the original signal as a recognition condition to obtain the temperature signal.
Preferably, the low-pass filter is connected to the mixing phase detection unit of the second signal processing module.
Preferably, the detection system further comprises a dynamic force reference signal generation module connected with the reference trigger unit, and the dynamic force reference signal generation module is provided with an out-of-phase amplification unit and a zero-crossing point detection unit.
Preferably, the piezoelectric power signal of the original signal is input to the out-of-phase amplifying unit for inverse amplification, and then the signal after inverse amplification is sent to the zero-crossing point detecting unit to be converted into a square wave signal of the zero-crossing point, and input to the reference triggering unit of the second signal processing module.
Preferably, the detection system further comprises a signal processing module for processing the piezoelectric signal and the pyroelectric signal, and the signal processing module is provided with an analog-to-digital conversion unit, a high-speed data processing unit and a micro control unit.
In a second aspect, the present invention provides a detection method using the detection system for detecting high temperature in-situ piezoelectric performance without the influence of pyroelectric effect. The detection method comprises the following steps:
s1, applying a dynamic force F on the surface of a sample to be tested under a temperature-changing condition;
s2, eliminating pyroelectric signals caused by temperature change in the step S1, and measuring the surface charge density Q generated by the direct piezoelectric effect caused by dynamic force;
and S3, calculating the piezoelectric coefficient d of the sample to be measured according to the formula d-Q/F.
Preferably, the piezoelectric signal includes d according to the loading direction of the dynamic force F 33 Signal, d 31 Signal or d 15 A signal.
Drawings
FIG. 1 is a schematic diagram of the structure of a first control circuit and a second control circuit;
FIG. 2 is a schematic diagram of a dynamic force reference signal generation module;
FIG. 3 is a schematic diagram of a signal processing module;
FIG. 4 is a schematic diagram of a measurement condition control module;
FIG. 5 is a schematic circuit diagram of a static force control unit;
FIG. 6 is a schematic diagram of a circuit configuration of a temperature control unit;
FIG. 7 is a schematic circuit diagram of a dynamic force control unit;
FIG. 8 is a Q-F curve with a static clamping force of 0 to 10N;
FIG. 9 is a Q-F curve for a static clamping force of 8N;
FIG. 10 is a Q-F curve for a static clamping force of 6.5N;
FIG. 11 is a Q-F curve for a static clamping force of 4.3N;
FIG. 12 is a Q-F curve for a static clamping force of 1.36N;
FIG. 13 is a Q-F curve for a static clamping force of 0.61N;
FIG. 14 shows the piezoelectric coefficient d of a sample to be measured 33 Trend with increasing static clamping force.
Detailed Description
The present invention is further illustrated by the following examples, which are to be understood as merely illustrative of, and not restrictive on, the present invention.
The high-temperature in-situ piezoelectric performance detection system comprises a first control circuit and a second control circuit. The synchronous measurement of the piezoelectric signal and the pyroelectric signal in the temperature-varying environment is realized by adopting a special circuit design.
The first control circuit comprises a first signal processing module and a filtering charge conversion module. The first control circuit strips an original signal containing a temperature signal and a piezoelectric power supply signal, screens out the piezoelectric power supply signal, and converts the piezoelectric power supply signal into a piezoelectric signal for output.
The first signal processing module is provided with a filtering differential amplification unit, a frequency and phase locking unit, a phase delay unit and a phase-locked loop unit (PLL unit) which form a closed loop. The first signal processing module strips and extracts a piezoelectric power supply signal from an input original signal.
As can be seen from fig. 1, the filtering differential amplifying unit has a filter and a differential amplifier. The filter of the filtering differential amplification unit receives an input original signal and denoises the input original signal, so that noise generated by a power supply and other circuits is removed. The denoised original signal is amplified by a low-noise operational amplifier connected with a filter, so that the interference of high-frequency radiation interference signals and 50HZ common frequency is avoided. The other end of the filter is connected with the phase delay unit. The phase delay unit eliminates phase difference caused by mechanical reaction, and can also eliminate phase deviation caused by time difference caused by transmission of a piezoelectric power supply signal generated by a sample to be detected in a dynamic force environment. The signals processed by the phase delay unit are transmitted to the PLL unit, and the PLL unit carries out natural frequency screening on the signals containing the clutter and then completes basic signal screening. Basic measurement signals screened by the PPL unit are sent to the frequency and phase locking unit, the frequency and phase locking unit takes the basic measurement signals provided by the PLL unit as reference signals, the phase and frequency of the basic measurement signals as references, to-be-detected sample signals containing clutter signals are identified and tracked in the signals processed and completed by the differential amplification unit, and piezoelectric power supply signals are stripped. Thus forming a closed loop.
The filtering charge conversion module has a filter and a charge converter. The other end of the frequency and phase locking unit is connected with the filtering charge converter. The filter filters the stripped piezoelectric power supply signal to eliminate burrs and further optimize the signal purity, and the processed piezoelectric power supply signal is subjected to collection and integration by the charge converter to convert the piezoelectric power supply signal into a piezoelectric signal for output. The piezoelectric signal is a related signal representing a piezoelectric coefficient. The piezoelectric signal comprises d according to the loading direction of the dynamic force 33 Signal, d 31 Signal or d 15 Signals, etc.
The piezoelectric power supply signal is essentially an electric signal formed by releasing electric charges generated after the sample to be tested is subjected to an external acting force. The sample to be tested is subjected to an external dynamic force to generate electron release, and a weak piezoelectric power supply signal is formed. The piezoelectric power signal is therefore at the same frequency as the vibration source. The piezoelectric power supply signal is also mixed with part of interference signals and circuit radiation signals. The temperature signal is a direct current signal generated by the electronic shift of the sample to be measured due to the temperature difference in the variable temperature environment (either a temperature-rising environment or a temperature-lowering environment). That is, the positive phase or negative phase of the temperature signal increases depending on the temperature difference between the sample to be measured and the environment. The pyroelectric effect of the temperature of the measured sample is increased to the negative phase when the temperature of the measured sample is higher than the ambient temperature, and conversely, the pyroelectric effect is increased to the positive phase. The invention designs a special frequency-locking phase-detecting technology aiming at weak voltage power signals. The piezoelectric power supply signal can be stripped in a targeted manner by the frequency and phase locking technology, other invalid signals are filtered, and the measurement precision and accuracy of the piezoelectric coefficient are improved. The inherent frequency screening condition of the PLL unit and the piezoelectric signal (dynamic force signal) are in the same frequency and phase as screening conditions, and the original signal is screened to obtain a basic measurement signal. In addition, the frequency-locking phase demodulation unit eliminates pyroelectric signals caused by temperature change by taking the frequency and the phase of basic measurement signals provided by the reference PLL unit as screening conditions and strips the voltage power supply signals of original signals so as to achieve the purpose of frequency-locking phase demodulation.
As can be seen from the above, the original signal is first filtered by the filter of the filtering differential amplification unit, so as to remove the power supply and the interference noise of the original signal. The removed signal is divided into two paths, one path is sent to the phase delay unit, and the other path is sent to the differential amplifier. The differential amplifier amplifies the original signal by low-noise operational amplification, thereby avoiding the interference of high-frequency radiation interference signals and 50HZ common frequency. The phase delay unit eliminates the phase difference caused by mechanical reaction, and the signal for eliminating the phase difference is sent to the PLL unit to carry out natural frequency screening and follow to complete basic signal screening. The screened basic signals are sent to a frequency-locked phase demodulation unit as reference signals, the phase and frequency of the basic signals are used as reference in the signals processed by the differential amplification unit, and the signals of the sample to be detected containing clutter signals are identified and tracked and piezoelectric power signals are stripped. The piezoelectric power supply signal is sent to the filtering charge conversion unit, the filter further improves the purity of the piezoelectric power supply signal, then the piezoelectric power supply signal is sent to the charge converter for piezoelectric power supply signal collection and integration, and finally the piezoelectric signal is obtained.
As can also be seen from fig. 1, the second control circuit comprises a second signal processing module, a low pass filter and an output unit. The second signal processing module is provided with an input amplifying unit, a band-pass filter, a reference triggering unit, a phase shifting unit and a mixing phase demodulation unit. The second signal processing module does not form a closed loop.
The second signal processing module of the second control circuit has two input signals. One path of input signal is an original signal. The original signal is amplified and selectively filtered after passing through an input amplifying unit and a band-pass filter connected with the input amplifying unit. In the process, the original signal of the sample to be measured is amplified, and then the signals of ineffective high frequency and ineffective low frequency are removed. The other end of the band-pass filter is connected with the frequency mixing phase discrimination unit. The other path of input signal is the input signal provided by the dynamic force reference signal processing module. An input signal provided by the dynamic force reference signal processing module is converted into a standard digital square wave through the reference trigger unit, and then the standard digital square wave is used as a final reference signal for frame voltage removal of a power supply signal after phase compensation is carried out by the phase shift unit, so that a temperature signal is extracted. Namely, the mixing phase detection unit takes the digital square wave processed by the phase shift unit as a reference. Specifically, the mixing phase discrimination unit refers to a reference (square wave) signal with a phase opposite to that of the original signal as a recognition condition, so that the reference signal is just in a negative half shaft when the original signal is in a positive half shaft, and the purpose of dividing the voltage of the power supply signal by a frame is achieved, and the signal finally output by the mixing phase discrimination unit is a temperature signal of a non-voltage power supply signal.
The mixing phase discrimination unit is connected with the low-pass filter. The low-pass filter is used for retaining low-frequency temperature signals and filtering out interference signals with higher frequencies. The other end of the low-pass filter is connected with the output unit. The output unit amplifies the temperature signal after the dynamic force signal is peeled off, and outputs the temperature signal as a pyroelectric signal. And (4) low-pass filtering the stripped temperature signal, eliminating high-frequency clutter and interference signals, amplifying the processed temperature signal, and finally outputting a pyroelectric signal.
The signal path of the second signal processing module inputs an original signal into the amplifying unit for amplification, and then the processed original signal is sent to the mixing phase discrimination unit through selective filtering of the band-pass filter. The reference signal provided by the dynamic force reference signal processing module is converted into a standard digital square wave through the reference trigger unit, and then the standard digital square wave is used as a final reference signal of the mixing frequency phase discrimination unit after phase compensation and is used for frame voltage division of a power supply signal to extract a temperature signal. The temperature signal is subjected to low-pass filtering to eliminate high-frequency interference signals and then is sent to an amplification output unit to be amplified and output a pyroelectric signal.
As can be seen from fig. 2, the dynamic force reference signal generation module has an out-of-phase amplification unit and a zero-crossing detection unit. The dynamic force signal is provided by a dynamic force control unit of the measurement condition control module. The dynamic force original signal is input to the out-phase amplifying unit, the out-phase amplifying unit performs out-phase amplification on the dynamic force original signal, and then the out-phase amplified signal is sent to the zero crossing point detecting unit to change the out-phase signal into a square wave signal of the zero crossing point. The square wave signal, i.e., the dynamic force reference signal processing module, provides an input signal to the reference trigger unit of the second signal processing module. As mentioned above, the reference trigger unit of the second control circuit converts the square wave signal at the zero crossing point into a standard digital square wave signal, so that the digital circuit can generate trigger conveniently, and the processed square wave signal is sent to the phase shift unit to compensate the phase difference caused by the hardware batch.
As can be seen from fig. 3, the detection system may further comprise a signal processing module. The signal processing module is provided with an analog-to-digital conversion unit (ADC), a high-speed data processing unit (FPGA) and a Micro Control Unit (MCU). The analog-to-digital conversion unit is used for converting the processed piezoelectric signal and the pyroelectric signal into a digital signal. The analog-to-digital conversion unit and the high-speed data processing unit are connected through a 16-bit parallel transmission port. The high-speed data processing unit is used for processing signal calculation after measurement is completed and controlling measurement. The high-speed data processing unit and the micro control unit are connected through a 16-bit parallel transmission port. The micro control unit is used for displaying communication, man-machine interaction and external communication control and providing an external communication port. The external communication ports include, but are not limited to, USB communication ports, communication serial ports, and communication network ports.
The measurement condition control module provides a test environment for the sample to be tested. The measurement condition control module is not the innovative point of the present invention. As can be seen from fig. 4, the measurement condition control module mainly includes a temperature control module, a dynamic force control module, and a static force control module. The static force control module comprises a static force clamping motor, a static force sensor and a static force control unit. The static force clamping motor may be in rotational motion and/or linear motion. When the static force clamping motor moves up and down linearly in the vertical direction, the static force sensor detects the clamping pressure and feeds the clamping pressure back to the static force control unit so as to adjust the rotating direction and speed of the motor. The temperature control module comprises a heating hearth, a temperature control unit and a hearth temperature sensor. The hearth temperature sensor senses the hearth environment temperature and feeds the hearth environment temperature back to the temperature control unit, so that the hearth environment temperature is adjusted through the temperature control unit to change the heated environment of the sample to be detected. The dynamic force control module includes an oscillator, a dynamic force sensor, and a dynamic force control unit. The dynamic force sensor is connected to the oscillator. The oscillator is capable of providing dynamic forces of varying magnitudes. The dynamic force sensor detects the magnitude of the dynamic force and feeds the magnitude back to the dynamic force control unit, so that the magnification (reduction) times of the dynamic force are regulated and controlled.
The temperature control module, the dynamic force control module and the static force control module respectively provide a test temperature environment, a dynamic force and a static clamping force for the sample to be tested, so that the sample to be tested is in a charge release condition for subsequent measurement. The sample to be measured needs a certain static clamping force to be pre-tightened in the measuring process, and then the piezoelectric performance is measured. The sample to be tested is clamped between the upper electrode of the static force clamping motor and the lower electrode of the dynamic force control unit. After the static clamping is stable, the dynamic force control unit generates dynamic force, the upper surface and the lower surface of the sample to be tested quickly generate surface charge density Q, and when the upper electrode and the lower electrode of the clamped sample are conducted through the conducting wire, the original signal of the sample to be tested is output. The signal is provided to a control circuit of the detection system for piezoelectric performance detection. Different deformations of the sample to be measured can be caused by different static force magnitudes. The deformation may cause the charge amount generated by the sample to be tested under the driving of the dynamic force to change, thereby affecting the piezoelectric performance testing accuracy of the sample. Therefore, the static clamping force is changed through the static force control unit, the variation trend of the piezoelectric performance of the sample to be tested along with the variation of the static clamping force is counted, and an effective way is provided for simulating the performance test of the piezoelectric material under the real working condition.
FIG. 5 is a schematic circuit diagram of a static force control unit. The effect is to provide the (pressing down) static clamping force required by the sample to be tested. The control signal is sent by a high-speed data processing unit (FPGA) to a stepping motor control signal conversion circuit unit to convert the digital control signal into a pulse signal which can be identified by the stepping motor, then the motor of the executing motor unit is pressed down or lifted up to control the action of pressing down the static force after receiving the pulse signal, the state of the motor after being executed can be reflected to the static force sensing circuit unit, the static force sensing circuit can detect the pressing down static force of the motor at all times, and the detected pressing static force is fed back to the force sensor acquisition circuit unit, the force sensor acquisition circuit unit firstly amplifies the analog signal given by the static force sensing circuit unit, and then the analog signal is converted into a digital signal through the ADC acquisition part and is given to the high-speed data processing unit for pressing static force control adjustment, so that a closed loop is formed to achieve the purpose of accurately controlling the pressing static clamping force.
Fig. 6 is a schematic circuit diagram of the temperature control unit. A temperature rise control signal (such as temperature rise of 60 ℃) is fed into a high-speed data processing unit (FPGA), a PID control unit controls a high-power control unit to start after receiving the control signal, the high-power control unit sends current to a heating wire unit according to an instruction of the PID control unit, the heating wire is heated discontinuously according to the control instruction to generate an action that the temperature reaches a control temperature, a temperature sensor unit feeds back a real-time temperature state to an amplification acquisition unit, the amplification acquisition unit amplifies a temperature signal of the temperature sensor unit firstly and then converts the temperature signal into a digital signal through an ADC acquisition part to be sent to the PID control unit to form a closed loop circuit to realize accurate temperature control.
Fig. 7 is a schematic circuit diagram of a dynamic force control unit. Firstly, a control signal (such as 60Hz and 0.7V amplitude alternating current waveform required to be generated) is fed by a high-speed data processing unit (FPGA), a DDS unit of a programmed dynamic force generation circuit unit generates a corresponding signal according to a control instruction, then the generated signal is amplified and respectively sent to a dynamic force power amplification unit and a dynamic force reference signal processing module, the dynamic force power amplification unit further amplifies an original dynamic force signal to achieve power capable of driving a dynamic force excitation unit, and the dynamic force excitation unit generates upward vibration dynamic force according to the signal. The dynamic force can be constantly reflected to the dynamic force sensor, the dynamic force sensor feeds sensed upward vibration force back to the filtering and amplifying unit in the form of analog electric signals, the filtering and amplifying unit filters received signals to remove interference signals and clutter signals, then the signals are amplified and sent to the AD acquisition unit, the AD acquisition unit performs analog-to-digital conversion on the processed analog signals, the analog signals are converted into digital signals which can be identified by the FPGA to achieve a control detection loop, and the FPGA adjusts output signals with the fed back dynamic force signals to further achieve the purpose of accurate control.
It should be noted that the high-speed data processing units in fig. 5 to 7 are the same unit, and the high-speed data processing unit of the signal processing module and the high-speed data processing unit of the measurement condition control module are independent of each other.
In summary, the detection system of the invention introduces a frequency-locking phase-demodulation unit in the first control circuit, identifies the original signal, tracks and amplifies the effective signal, and removes the ineffective interference signal and the temperature electric signal, thereby extracting the dynamic force signal; a mixing phase discrimination unit is introduced into the second control circuit to process the original signal, strip the dynamic force signal and amplify the temperature signal.
The detection method using the high-temperature in-situ piezoelectric performance detection system of the invention is described next.
The composition and structure of the sample to be tested are not limited. Preferably, the sample to be measured has stronger piezoelectric performance. The sample to be detected comprises but is not limited to a piezoelectric ceramic piece, a ceramic column, a PVDF piezoelectric film, soft ceramic, a hard ceramic material, a single crystal material and the like. The shape of the sample to be detected can be a circular sheet, a thin film, a square column, a cylinder and the like. Particular embodiments employ a sample of the wafer to be tested. The size of the sample to be detected can also be adaptively changed according to actual needs. In order to reduce the nonlinear piezoelectric effect caused by the static clamping force, the thickness of the sample to be measured of the wafer is preferably not less than 1 mm. As an example, the size of the sample to be measured is 20mm diameter × 1mm thickness. The sample to be tested is a polarized piezoelectric sample. The poling process is a conventional operation in the art and will not be described herein.
And applying a dynamic force F on the surface to be measured under the condition of variable temperature. The temperature can be changed continuously, namely, the temperature is increased from the room temperature to a certain temperature above 100 ℃ or is reduced from the certain temperature above 100 ℃ to the room temperature at a certain speed. The temperature rising rate or the temperature lowering rate can be 1-2 ℃/min. Preferably, the temperature increase rate or decrease rate is 2 ℃/min. A step-wise heating mode may also be employed. The heating rate can be 3-8 ℃/min. After the target temperature is reached, the temperature is preferably kept constant for 10 min. The maximum temperature may be less than 800 ℃.
In some embodiments, the frequency of the dynamic force is lower than the resonant frequency of the sample to be measured. Preferably, the frequency of the dynamic force is much lower than the resonance frequency of the sample to be measured. The resonant frequency of the piezoelectric sample is derived from an auto-balanced bridge test. The resonant frequency of the sample to be measured is generally high. When the frequency of the dynamic force is high, the operation performance of the vibration table fails to reach its resonance frequency and is out of effect. In some embodiments, the dynamic force is applied at a frequency of 20 to 300 Hz.
The direction of the dynamic force can be changed adaptively according to the requirement. For example, the direction of the dynamic force is perpendicular or parallel to the polarization direction of the sample to be tested. Alternatively, the direction of the dynamic force is in a tangential included angle relationship with the polarization direction.
The surface charge density Q resulting from the positive piezoelectric effect was measured. Specifically, a pyroelectric signal generated due to temperature change is removed, and then the remaining surface charge density Q generated by the positive piezoelectric effect is measured. The principle of rejecting the pyroelectric signal is as described above, the piezoelectric power supply signal is an alternating current signal in phase with the dynamic force signal, the pyroelectric signal is a signal which monotonically increases or monotonically decreases, and the piezoelectric power supply signal and the pyroelectric signal are discriminated by circuit design and phase locking technology, so that the pyroelectric signal is rejected.
And calculating the piezoelectric coefficient of the sample to be measured according to the formula d-Q/F. d is the piezoelectric coefficient, Q is the surface charge density, and F is the dynamic force. As an example, d 33 : aiming at a sample to be tested of a wafer, electrodes are coated on two end faces of the sample to be tested, polarization is carried out along the thickness direction, and dynamic force is appliedThe application direction is parallel to the polarization direction, and a dynamic force F is applied 3 And testing the amount of charge Q at both ends of the electrode face 3 。d 31 : for a rectangular sheet sample, electrodes are coated on two larger end faces of the sample, the sample is polarized along the thickness direction, the dynamic force application direction is vertical to the polarization direction, and the dynamic force F is applied in the direction 1 Collected charge test Q on the coated electrode side 3 。d 15 : for a rectangular sheet sample, polarizing along the length direction of the sample to be tested, coating electrodes on a section parallel to the polarization direction and having a large cross section, and applying a tangential force F on a surface narrower in the length direction 1 And collecting the charge Q at the coated electrode surface 5 。
The method comprehensively considers the piezoelectric effect and the pyroelectric effect in the high-temperature in-situ piezoelectric performance test process, and retains the charge generated by the pure piezoelectric effect by eliminating the pyroelectric effect, so that the precision and the accuracy of the high-temperature in-situ piezoelectric performance test are improved.
Example 1
Specifically, the method for measuring the high-temperature in-situ piezoelectric performance for eliminating the influence of the pyroelectric effect comprises the following steps:
s1, applying dynamic force F on a sample to be tested under the condition of continuous temperature change. The sample to be tested is a thin wafer. The upper surface and the lower surface of the sample to be detected are coated with electrode materials, and the polarization direction of the sample to be detected is vertical to the upper surface and the lower surface. The continuous temperature changing condition is that the temperature is increased from room temperature to 400 ℃ at the speed of 2 ℃/min. The magnitude of the dynamic force is 0.25N, the frequency is 110Hz, and the action direction of the dynamic force is parallel to the polarization direction.
And S2, eliminating the pyroelectric signals generated due to the temperature change in the step S1, and then measuring the remaining charge density Q generated on the surface of the electrode of the sample to be detected by the positive piezoelectric effect.
S3, calculating the piezoelectric coefficient d of the sample to be tested according to the formula d-Q/F 33 。
The sample to be measured needs a certain static clamping force to be pre-tightened in the measuring process, and then the piezoelectric performance is measured. Different static force magnitudes cause different deformations of the sample to be measured. TheThe magnitude of the deformation may cause the Q value of the sample to be detected, which is driven by the dynamic force F, to change, thereby affecting the piezoelectric coefficient d of the sample 33 The value is obtained. Therefore, the static clamping force and the sample d to be measured are obtained by changing the magnitude of the static clamping force for many times and recording the Q-F curve under the condition of the static clamping force 33 A trend of the value change.
For example, a certain constant static clamping force is maintained, the amount of charge under different dynamic forces is obtained by changing the magnitude of the dynamic force, and d is calculated 33 The value is obtained. The invention applies a series of dynamic forces on a sample to be measured to obtain a series of corresponding electric charge quantities Q, and the slope of a linear function is taken as d of the sample 33 And the value is compared with the ratio of the charge quantity to the dynamic force of the single sample to be tested, and the test result has higher precision. Verification shows that the piezoelectric coefficient d of the sample to be tested 33 Q/F can be expressed by the slope of a linear function and has high accuracy.
FIG. 8 is a Q-F curve for a static clamping force of 10N. FIG. 9 is a Q-F curve for a static clamping force of 8N. FIG. 10 is a Q-F curve for a static clamping force of 6.5N. FIG. 11 is a Q-F curve for a static clamping force of 4.3N. FIG. 12 is a Q-F curve for a static clamping force of 1.36N. FIG. 13 is a Q-F curve for a static clamping force of 0.61N. It can be seen that the piezoelectric coefficient d of the sample to be measured is within a certain range under the static clamping force 33 The value will change with the change of the static clamping force.
FIG. 14 shows the piezoelectric coefficient d of a sample to be measured 33 Trend with increasing static clamping force. For some piezoceramic materials, the actual piezoelectric d of the sample is different when the static clamping force is different 33 Coefficient values are different, and when the static holding force exceeds a certain value, d of the sample 33 Basically, the change does not occur any more, and an effective way is provided for the performance test of the simulation material under the real working condition.
While embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments and applications described above, which are intended to be illustrative, instructive, and not limiting. Those skilled in the art, having the benefit of this disclosure, may effect numerous modifications thereto without departing from the scope of the invention as defined by the appended claims.
Claims (13)
1. The high-temperature in-situ piezoelectric performance detection system is characterized by comprising a first control circuit and a second control circuit; the first control circuit comprises a first signal processing module and a filtering charge conversion module; the first signal processing module is provided with a filtering differential amplification unit, a frequency and phase locking and demodulating unit, a phase delay unit and a phase-locked loop unit which form a closed loop; the filtering charge conversion module is provided with a filter and a charge converter; the first control circuit strips an original signal containing a temperature signal and a piezoelectric power supply signal, screens out the piezoelectric power supply signal, and converts the piezoelectric power supply signal into a piezoelectric signal for output; the second control circuit comprises a second signal processing module, a low-pass filter and an output unit; the second signal processing module is provided with an input amplifying unit, a band-pass filter, a reference triggering unit, a phase shifting unit and a mixing phase discrimination unit; the second control circuit strips the original signals containing the temperature signals and the piezoelectric power signals, screens out the temperature signals, performs low-pass filtering on the temperature signals, and then amplifies the temperature signals to form effective pyroelectric signals for output.
2. The detecting system of claim 1, wherein the original signal containing the temperature signal and the voltage power signal is divided into one of two paths after passing through a filter of the filtering differential amplifying unit and then is sent to the phase delay unit, and the signal with the phase difference removed by the phase delay unit is sent to the phase-locked loop unit for natural frequency screening to form a basic measuring signal.
3. The detection system according to claim 1 or 2, wherein the original signal is divided into two paths after passing through a filter of the filtering differential amplification unit, and then is provided to the differential amplifier, and the frequency-locked phase detection unit takes the basic measurement signal provided by the phase-locked loop unit as a reference signal and the phase and frequency of the basic measurement signal as screening conditions, and strips out the voltage power supply signal from the signal processed by the differential amplification unit.
4. The detection system according to any one of claims 1 to 3, wherein the filter of the filtering charge conversion module is connected with the frequency and phase locking unit of the first signal processing module.
5. The detection system according to any one of claims 1 to 4, wherein the input signal of the second signal processing module has two paths, one path of the input signal is an original signal containing a temperature signal and a voltage power signal, and the original signal is amplified and selectively filtered by an input amplification unit and a band-pass filter connected to the input amplification unit and then provided to the mixing phase detection unit.
6. The detection system according to any one of claims 1 to 5, wherein another input signal of the second signal processing module is an input signal provided by a dynamic force reference signal processing module, the input signal provided by the dynamic force reference signal processing module is converted into a standard digital square wave by a reference trigger unit, and then the standard digital square wave is used as a reference signal of a mixing frequency phase discrimination unit for frame voltage division power supply signal after phase compensation is performed by a phase shift unit, so as to extract a temperature signal.
7. The detection system of claim 6, wherein the mixed frequency phase detection unit performs frame division on the power signal to obtain the temperature signal under the condition that a reference signal with a phase opposite to that of the original signal is used as a recognition condition.
8. The detection system according to any one of claims 1 to 7, wherein the low pass filter is connected to the mixing phase detection unit of the second signal processing module.
9. The detection system according to any one of claims 1 to 8, further comprising a dynamic force reference signal generation module connected to the reference triggering unit, the dynamic force reference signal generation module having an out-of-phase amplification unit and a zero-crossing detection unit.
10. The detection system according to claim 9, wherein the piezoelectric power signal of the original signal is input to the out-of-phase amplification unit for inverse amplification, and then the signal after inverse amplification is sent to the zero-crossing point detection unit to be converted into a square wave signal of the zero-crossing point, and input to the reference triggering unit of the second signal processing module.
11. The detection system according to any one of claims 1 to 10, further comprising a signal processing module for processing the piezoelectric signal and the pyroelectric signal, the signal processing module having an analog-to-digital conversion unit, a high-speed data processing unit and a micro control unit.
12. The detection method of the high-temperature in-situ piezoelectric performance detection system for eliminating the influence of the pyroelectric effect, which is characterized by comprising the following steps of:
step S1, applying a dynamic force F on the surface of the sample to be tested under the condition of variable temperature;
step S2, eliminating the pyroelectric signal caused by the temperature change in the step S1, and measuring the surface charge density Q generated by the direct piezoelectric effect caused by the dynamic force;
and step S3, calculating the piezoelectric coefficient d of the sample to be measured according to the formula d = Q/F.
13. The detection method using the high-temperature in-situ piezoelectric performance detection system capable of eliminating the influence of the pyroelectric effect as claimed in claim 12, wherein the piezoelectric signal comprises d according to the loading direction of the dynamic force F 33 Signal, d 31 Signal or d 15 A signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210770776.6A CN115060988A (en) | 2022-06-30 | 2022-06-30 | High-temperature in-situ piezoelectric performance detection system and method for eliminating influence of pyroelectric effect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210770776.6A CN115060988A (en) | 2022-06-30 | 2022-06-30 | High-temperature in-situ piezoelectric performance detection system and method for eliminating influence of pyroelectric effect |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115060988A true CN115060988A (en) | 2022-09-16 |
Family
ID=83203917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210770776.6A Pending CN115060988A (en) | 2022-06-30 | 2022-06-30 | High-temperature in-situ piezoelectric performance detection system and method for eliminating influence of pyroelectric effect |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115060988A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117782379A (en) * | 2024-02-27 | 2024-03-29 | 太原理工大学 | Piezoelectric/pyroelectric dual-function flexible high-temperature-resistant sensor |
-
2022
- 2022-06-30 CN CN202210770776.6A patent/CN115060988A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117782379A (en) * | 2024-02-27 | 2024-03-29 | 太原理工大学 | Piezoelectric/pyroelectric dual-function flexible high-temperature-resistant sensor |
| CN117782379B (en) * | 2024-02-27 | 2024-05-14 | 太原理工大学 | Piezoelectric/pyroelectric dual-function flexible high-temperature-resistant sensor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Gawad et al. | Impedance spectroscopy using maximum length sequences: Application to single cell analysis | |
| CN115060988A (en) | High-temperature in-situ piezoelectric performance detection system and method for eliminating influence of pyroelectric effect | |
| Dong et al. | An improved phase-locked loop method for automatic resonance frequency tracing based on static capacitance broadband compensation for a high-power ultrasonic transducer | |
| CN105137125A (en) | Double-frequency multichannel synchronization detection method for electric domain imaging | |
| US11121662B2 (en) | Closed loop resonance tracking using phase matching | |
| CN112083042A (en) | Method and device for testing high-power characteristics of piezoelectric ceramics | |
| CN106768756A (en) | A kind of shake table ultralow frequency sine sweep signal amplitude recognition methods and system | |
| CN109365250A (en) | A kind of high-frequency transducer's frequency locking implementation method | |
| CN106932093B (en) | Auto frequency locking photoelectricity active balance system | |
| CN1866747B (en) | Digital phase-locked closed-loop of resistance vibration pickup type silicon micromechanical resonant sensor | |
| CN110673063A (en) | Method for modulating and detecting magnetic field based on nonlinear magnetoelectric effect | |
| CN110243400A (en) | Tactile and slip sensor based on Active spurring signal acquisition resonance signal | |
| EP3964878B1 (en) | Method and circuit for obtaining capacitive feedback signal of capacitive feedback-type micro torsion mirror | |
| Yin et al. | A photoacoustic spectrum detection system based on chaos detection of weak signal | |
| CN102136830A (en) | Frequency-raising drive control method for micromechanical resonant device | |
| Li et al. | A circuit design in piezoelectric vibration measurement system | |
| CN114235229A (en) | Ultra-precision cutting quasi-static force detection system based on piezoelectric ceramic sensor | |
| CN109059744A (en) | Micro-displacement signal detection system and measurement method based on ADA2200 | |
| Chen et al. | A multi-parameter driving and measurement circuit of ultrasonic motor | |
| CN114564985B (en) | Improved least square-based resonant sensor resonant frequency rapid identification method | |
| Wenbin et al. | Analysis and Design of Piezoelectric Sensor Conditioning Circuit | |
| CN112798991B (en) | High-speed processing device for induction signals of fluxgate magnetometer | |
| SU1651186A1 (en) | Capacitive sensor parameter transducer | |
| Wu et al. | Design and implementation of a versatile and variable-frequency piezoelectric coefficient measurement system | |
| CN116203137A (en) | Compensation device and method for improving generation precision of ultrasonic guided wave signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |