CN107300433B - A method of static force is measured using piezoelectric force transducer - Google Patents
A method of static force is measured using piezoelectric force transducer Download PDFInfo
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- CN107300433B CN107300433B CN201710465211.6A CN201710465211A CN107300433B CN 107300433 B CN107300433 B CN 107300433B CN 201710465211 A CN201710465211 A CN 201710465211A CN 107300433 B CN107300433 B CN 107300433B
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- 230000005611 electricity Effects 0.000 description 5
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/16—Measuring force or stress, in general using properties of piezoelectric devices
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/0028—Force sensors associated with force applying means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/08—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of piezoelectric devices, i.e. electric circuits therefor
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Abstract
The invention discloses a kind of methods using piezoelectric force transducer measurement static force, it is the following steps are included: 1- establishes the mathematical expression that piezoelectric force transducer measuring system output voltage changes over time；2- determines the timeconstantτ of piezoelectric force transducer measuring system；3- determines time intervalΔtAnd the drop threshold of piezoelectric force transducer measuring system output voltageΔu th ；4- judges it is steady power or change constant force by dynamometry, if in time intervalΔtThe pad value of interior measuring system output voltageΔuNo more than decaying threshold valuesΔ u th , then it is steady power by dynamometry, pressesu 0 Export a steady state value；If pad valueΔuMore than decaying threshold valuesΔu th , then it is to become constant force by dynamometry, according to pad valueΔuTo being exported after the output voltage compensation of measuring system.The solution have the advantages that: in the case where not changing piezoelectric force transducer structure, the compensated influence for overcoming piezoelectric force transducer charge decay obtains stable output voltage, realizes and utilizes measurement of the piezoelectric force transducer to static force.
Description
Technical field
The invention belongs to the measuring techniques of power, and in particular to a kind of measurement that static force is realized using piezoelectric force transducer
Method.
Background technique
Piezoelectric force transducer is a kind of sensor of the carry out power measurement of piezoelectric effect using piezoelectric element.Due to it
Have many advantages, such as that simple structure, small power consumption, dynamic characteristic are good, is widely used in the measurement of dynamic force.But when by dynamometry
When very low for static either frequency, the charge that generates on the piezoelectric element inside piezoelectric force transducer can be when very short
It is interior that very big decaying occurs, therefore industry thinks that this kind of sensor cannot be used directly for the measurement of static force or very low frequencies power.
In order to realize measurement of the piezoelectric force transducer to static force, in recent decades, many researchers are proposed
Various measurement methods.Currently, having piezoelectric resonator frequency measurement with the research method of piezoelectric element measurement static force, capacitor is surveyed
Amount method, die-away time mensuration etc..
Piezoelectric resonator frequency measurement is using piezoelectric element as the resonator of circuit, using effect on the piezoelectric element
The relationship of static force and its equivalent impedance realizes static force measurement by detection admittance or resonance frequency.The reality of capacitance measurement
Matter is to regard piezoelectric element as capacitor, realizes static force measurement by the variation that measurement static force acts on lower capacitor.When decaying
Between mensuration be by measure piezoelectric element output signal die-away time, generally first measurement piezoelectric element static force act on
Then the damping time constant of lower response signal finds survey of the relational implementation between die-away time and static force to static force
Amount.However, since the above-mentioned electric parameter of piezoelectric element can change with measurement environment, by dynamometry size etc., these
Method still cannot achieve static force measurement at present, while these methods require to redesign piezoelectric force transducer.
Summary of the invention
Measurement static force is realized using piezoelectric force transducer the technical problem to be solved by the invention is to provide a kind of
Method, it in the case where not changing piezoelectric force transducer structure, can overcome piezoelectric force transducer static force survey
The adverse effect of charge decay in amount, obtains stable output voltage, accurately measures static force.
The technical problem to be solved by the present invention is in this way technical solution realize, it the following steps are included:
Step 1 establishes the mathematical expression that piezoelectric force transducer measuring system output voltage u (t) is changed over time
In formula, u0The output voltage of piezoelectric force transducer measuring system when for t=0；T is discharge time；R is piezoelectric type
The equivalent insulation leakagel volume leakage resistance of force sensor measuring system；C is the equivalent capacity of piezoelectric force transducer measuring system；Take piezoelectric forces
Timeconstantτ=RC of sensor measuring system, then have:
Step 2, the timeconstantτ for determining piezoelectric force transducer measuring system
In the use environment of piezoelectric force transducer measuring system, to the output electricity of piezoelectric force transducer measuring system
The test curve of pressure is fitted, and obtains timeconstantτ；
Step 3, determine time interval Δ t and piezoelectric force transducer measuring system output voltage drop threshold Δ uth
Time interval Δ t=t1-t0< τ, and Δ t ∈ [Δ tmin,Δtmax], t0It is initial time, t1When being the end of Δ t
It carves, Δ tminIt is determined by the sample frequency of piezoelectric force transducer measuring system, Δ tmaxBy being determined by the frequency of dynamometry；
The drop threshold Δ u of the output voltage of piezoelectric force transducer measuring systemth=Δ umax:
ΔumaxBe when applying full scale static force, in the time interval since initial time, piezoelectric force transducer
The pad value of measuring system output voltage；
Step 4 judges that static force is steady power or becomes constant force, and to the output of piezoelectric force transducer measuring system electricity
Pressure compensates
If pad value Δ u is less than drop threshold Δ u in determining time interval Δ tth, then judge static force for steady
Power then exports a steady state value at this time；
If the pad value Δ u is more than this drop threshold Δ u in determining time interval Δ tth, then determine that static force is sent out
Changing, referred to as change constant force, at this time mend the output voltage of piezoelectric force transducer measuring system using the pad value Δ u
It repays.
The solution have the advantages that:
The present invention does not change existing piezoelectric force transducer structure, overcomes piezoelectric force transducer electricity by software compensation
Lotus decaying influence, realize the measurement using piezoelectric force transducer measuring system to static force, and not by measurement environment and
By the influence of dynamometry size.
Detailed description of the invention
Detailed description of the invention of the invention is as follows:
Fig. 1 (A) is the schematic diagram of existing piezoelectric force transducer static state force measuring system
It (B) is the schematic diagram of piezoelectric force transducer static state force measuring system of the present invention；
Fig. 2 is piezoelectric force transducer and the two-part equivalent circuit diagram of charge amplifier；
Fig. 3 is Voltage Compensation Control Method flow chart of the invention；
Fig. 4 is that the present invention uses response signal comparison diagram of the Commercial piezoelectric formula force snesor under 21N static pressure；
Fig. 5 is that the present invention uses response signal comparison diagram of the Commercial piezoelectric formula force snesor under static force step-loaded.
Specific embodiment
Present invention will be further explained below with reference to the attached drawings and examples:
Shown in existing piezoelectric force transducer measuring system schematic diagram such as Fig. 1 (A), including piezoelectric force transducer, charge
Amplifier and signal display unit.Shown in piezoelectric force transducer measuring system such as Fig. 1 (B) of the present invention, including piezoelectricity
Formula force snesor, charge amplifier, Signal Pretreatment unit and signal display unit are measured compared to existing piezoelectric force transducer
System increases Signal Pretreatment unit；The force signal of input is converted into charge signal output, charge by piezoelectric force transducer
Signal is converted into voltage signal through charge amplifier, and voltage signal, which enters after pretreatment unit, handles realization static force through overcompensation
Measurement, finally enter signal display unit and show.Piezoelectric force transducer and charge amplifier two parts can be equivalent to
Circuit shown in Fig. 2.
The present invention the following steps are included:
Step 1 establishes the mathematical expression that piezoelectric force transducer measuring system output voltage u (t) is changed over time
Since there are equivalent capacity C and equivalent insulation leakagel volume leakage to hinder R for piezoelectric force transducer measuring system, since R cannot reach
To infinity, so the output voltage u (t) of piezoelectric force transducer measuring system cannot keep constant value, any time output
Voltage u (t) is
In formula (1), u0The output voltage of piezoelectric force transducer measuring system when for t=0；T is discharge time, pressure electricity
Formula force sensor measuring system time constant τ=RC, then can have
By (2) formula it is found that since the output voltage of piezoelectric force transducer measuring system is decayed according to exponential form,
It must determine the timeconstantτ of piezoelectric force transducer measuring system.
Step 2, the timeconstantτ for determining piezoelectric force transducer measuring system
Due to measuring the influence of environment and measuring condition, the timeconstantτ of piezoelectric force transducer measuring system is not one
A steady state value, at this moment, can in the actual measurement environment of piezoelectric force transducer measuring system measuring system export decaying
Curve fits timeconstantτ.
Step 3, the drop threshold Δ u for determining time interval Δ t and piezoelectric force transducer measuring system output voltageth
Key parameter of the invention is time interval Δ t and drop threshold Δ uth, the minimum value of time interval Δ t is by piezoelectricity
The sample frequency fs decision of formula force sensor measuring system, Δ tmin=1/fs；The maximum value of time interval Δ t is by by dynamometry
Working frequency fwIt determines, Δ tmax=1/ (2fw), it is desirable that: fs> 2fw。
Set initial time t0With last moment t1, time interval Δ t=t1-t0, Δ t is a sufficiently small number, meets Δ
t∈[Δtmin,Δtmax], the pad value Δ u of piezoelectric force transducer measuring system output voltage is obtained according to formula (2):
Obviously, the decaying that piezoelectric force transducer measuring system output voltage is carved at the beginning is most fast, and static force is bigger,
u0It is bigger, in the time interval Δ t since initial time, the pad value of piezoelectric force transducer measuring system output voltage
Δ u is bigger, thus when applying full scale static force, in the time interval Δ t since initial time, piezoelectric forces sensing
The pad value Δ u of device measuring system output voltage is maximum
The value can be used as the drop threshold Δ u of piezoelectric force transducer measuring system output voltageth；When static force is steady
Constant force, then in determining time interval Δ t, the pad value Δ u of the output voltage of piezoelectric force transducer measuring system is not
It can be more than Δ uth, therefore can be by Δ uthJudge whether static force is steady power as a drop threshold.
Step 4 judges that static force is steady power or becomes constant force, and compensates to piezoelectric force transducer output voltage
If pad value Δ u is less than drop threshold Δ u in determining time interval Δ tth, then judge static force for steady
Power then exports a steady state value at this time.
If the pad value Δ u is more than this drop threshold Δ u in determining time interval Δ tth, then determine that static force is sent out
Changing, referred to as change constant force, at this time compensate the output voltage of measuring system using the pad value Δ u.
In above-mentioned steps 4, the flow chart of voltage compensation is as shown in Figure 3:
In step 01, assignment t=0, u (t)=u (0) and compensated output voltage u (t)offset=u (0)；
When load is by dynamometry, the voltage measured is not have enough time also decaying, so piezoelectric force transducer when starting is enabled to survey
Output voltage u (t) after the compensation of amount systemoffsetIt is equal to initially export u (0) with actually measured voltage u (t).
In step 02, compare | and u (t+ Δ t)-u (t) | > Δ uth, after Δ t, the output u (t+ of sampled charge amplifier
Δ t), by previous sampled value u (t) and the current sample values u (absolute value of the difference of t+ Δ t), with drop threshold Δ uthCompared
Compared with.
If inequality is set up, 03 is thened follow the steps；Otherwise step 04 is executed；
In step 03, u (t+ Δ t)offset=u (t)offset(t+ Δ t)-u (t) then executes step 05 to+u；
In this step, static force is changed, and output voltage needs compensate, i.e., the output voltage after original compensation
u(t)offsetOn the basis of plus output voltage changing value in Δ t time interval, if u (t+ Δ t)-u (t) > 0, u (t+
Δt)offseIncrease；If u (t+ Δ t)-u (t) < 0, u (t+ Δ t)offseReduce.
In step 04, u (t+ Δ t)offset=u (t)offset, then execute step 05；
In this step, there is no variation, output voltages should also keep stable for static force, current compensated output electricity
Press u (t+ Δ t)offsetEqual to output voltage u (t) after original compensationoffset。
In step 05, time of measuring t=t+ Δ t is calculated, by u (t+ Δ t)offsetIt is assigned to u (t+ Δ t)；And export u (t+
Δt)outWith time t；
In step 06, judge whether to terminate measurement, if so, thening follow the steps 07；Otherwise, step 02 is executed；
In step 07, terminate program.
Embodiment
CL-YD-305A type piezoelectric force transducer, the pressure limit of receiving reach as high as 10KN, and precision can achieve
0.03%, sensitivity is about 4PC/N, and nonlinearity erron can control within 1%, this experiment is using CL-YD-305A model
Piezoelectric force transducer.Apply maximum, force first, attenuation data is measured, using least square method matched curve, thus when obtaining
Between constant, τ, therefore R, C do not need directly to measure.Sample rate herein is set as f=10kHz, still, in existing experiment item
Under part, when being timed operation in an operating system, the smallest interval of the operation of experiment is 2ms, it is therefore desirable to set Δ t to
A value not less than 2ms.According to Experimental Hardware condition, the ripple interference in experiment, selected threshold Δ in experiment are considered further that
uth=0.02V.
Then applying steady power F on a sensor is 21N, obtains the output voltage of measuring system as shown in figure 4, dotted line is
The characteristic curve that piezoelectric force transducer measuring system output voltage after processed by the invention changes over time, solid line are existing
The characteristic curve that the output voltage of piezoelectric force transducer measuring system itself changes over time, the two compare, and the present invention is 2
1V is stabilized the output voltage in time second, existing piezoelectric force transducer measuring system output voltage gradually decreases increase with time,
When after 2 seconds, output voltage drops to 0.5V.As it can be seen that the present invention can be accurately to piezoelectric force transducer measuring system
Attenuation implement compensation, obtain stable output voltage, realize static force measurement.
Under the conditions of change constant force F acts on piezoelectric force transducer, increase the power of 10N every time, obtains piezoelectric forces sensing
The output voltage of device measuring system as shown in figure 5, dotted line be it is processed by the invention after the characteristic that changes over time of output voltage
Curve, solid line are the characteristic curve that the output voltage of existing piezoelectric force transducer measuring system itself changes over time, the two
Compare, it is processed by the invention after output voltage can really reflect active force Spline smoothing.So energy effective compensation of the present invention
Output voltage gradually decreases increase with time, is stablized, true output voltage.
In figures 4 and 5, there is an impact signal in the initial stage of reinforcing, which is to reinforce
When inevitably there is impact signal to apply on a sensor, but will soon disappear, therefore output voltage has one
Impact signal.
Claims (1)
1. a kind of method using piezoelectric force transducer measurement static force, characterized in that the following steps are included:
The mathematical expression that step 1, the output voltage u (t) for establishing piezoelectric force transducer measuring system are changed over time；
In formula, u0The output voltage of piezoelectric force transducer measuring system when for t=0；T is discharge time；R is piezoelectric forces biography
The equivalent insulation leakagel volume leakage of sensor measuring system hinders；C is the equivalent capacity of piezoelectric force transducer measuring system；Piezoelectric forces are taken to pass
Timeconstantτ=RC of sensor measuring system, then have:
Step 2, the timeconstantτ for determining piezoelectric force transducer measuring system；
Survey in piezoelectric force transducer measuring system use environment, to the output voltage of piezoelectric force transducer measuring system
Examination curve is fitted, and obtains timeconstantτ；
Step 3, the drop threshold Δ u for determining time interval Δ t and piezoelectric force transducer measuring system output voltageth；
Time interval Δ t=t1-t0< τ, and Δ t ∈ [Δ tmin,Δtmax], t0It is initial time, t1It is the last moment of Δ t, Δ
tminIt is determined by the sample frequency of piezoelectric force transducer measuring system, Δ tmaxBy being determined by the frequency of dynamometry；
The drop threshold Δ u of piezoelectric force transducer measuring system output voltageth=Δ umax:
ΔumaxIt is piezoelectric force transducer in the time interval Δ t when applying full scale static force, since initial time
The pad value of measuring system output voltage；
Step 4, judge static force be steady power or become constant force, and to the output voltage of piezoelectric force transducer measuring system into
Row compensation；
If pad value Δ u is less than this drop threshold Δ u in determining time interval Δ tth, then judge static force for steady
Power then exports a steady state value at this time；
If the pad value Δ u is more than this drop threshold Δ u in determining time interval Δ tth, then determine that static force becomes
Change, referred to as change constant force, the output voltage of the measuring system of piezoelectric force transducer is mended using the pad value Δ u at this time
It repays；
The specific steps of voltage compensation are carried out to static force are as follows:
Step 01, assignment t=0, u (t)=u (0) and compensated output voltage u (t)offset=u (0)；
Step 02, compare | and u (t+ Δ t)-u (t) | > Δ uth, if inequality is set up, then follow the steps 03；Otherwise step is executed
Rapid 04；
Step 03, u (t+ Δ t)offset=u (t)offset(t+ Δ t)-u (t) then executes step 05 to+u；
Step 04, u (t+ Δ t)offset=u (t)offset, then execute step 05；
Step 05, time of measuring t=t+ Δ t is calculated, by u (t+ Δ t)offsetIt is assigned to u (t+ Δ t)；And export u (t+ Δ t)outWith time t；
Step 06, judge whether to terminate measurement, if so, thening follow the steps 07；Otherwise, step 02 is executed；
Step 07, terminate program.
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Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108458817A (en) * | 2018-05-04 | 2018-08-28 | 上海路虹电子科技有限公司 | A kind of novel pressure electric-type pressure sensor |
| CN108775978B (en) * | 2018-05-21 | 2021-06-04 | 长江大学 | PZT-based static prestress monitoring device and method |
| CN110868193B (en) * | 2019-11-13 | 2022-06-10 | 宁波大学 | Self-sensing method for output displacement and output force of piezoelectric actuator |
| CN112284435B (en) * | 2020-09-23 | 2022-09-23 | 北京致感致联科技有限公司 | Piezoelectric substrate device, self-calibration method and system thereof, and monitoring system |
| WO2023108663A1 (en) * | 2021-12-18 | 2023-06-22 | 浙江大学 | Ultra-precision cutting quasi-static force measurement system based on piezoelectric ceramic sensor |
| CN114235229B (en) * | 2021-12-18 | 2022-11-08 | 浙江大学 | Ultra-precise cutting quasi-static force detection method based on piezoelectric ceramic sensor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2800250Y (en) * | 2003-11-17 | 2006-07-26 | 重庆大学 | Piezoelectric three-dimensional force transducer |
| CN203191135U (en) * | 2013-04-10 | 2013-09-11 | 济南大学 | Spoke-type parallel piezoelectric six-dimensional force sensor |
| CN103630273A (en) * | 2012-09-12 | 2014-03-12 | 贝辛电子科技（上海）有限公司 | Device for measuring quasi-static force via piezoelectric sensing element |
| CN204330900U (en) * | 2014-12-29 | 2015-05-13 | 中国计量科学研究院 | Based on the piezoelectric strain constant measurement mechanism that dynamic force is directly measured |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2800250Y (en) * | 2003-11-17 | 2006-07-26 | 重庆大学 | Piezoelectric three-dimensional force transducer |
| CN103630273A (en) * | 2012-09-12 | 2014-03-12 | 贝辛电子科技（上海）有限公司 | Device for measuring quasi-static force via piezoelectric sensing element |
| CN203191135U (en) * | 2013-04-10 | 2013-09-11 | 济南大学 | Spoke-type parallel piezoelectric six-dimensional force sensor |
| CN204330900U (en) * | 2014-12-29 | 2015-05-13 | 中国计量科学研究院 | Based on the piezoelectric strain constant measurement mechanism that dynamic force is directly measured |
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