CN106134453B - A kind of measuring system of quartz resonator impedance operator parameter - Google Patents

Abstract

The present invention relates to a kind of method for fast measuring of quartz resonator impedance operator parameter, the method adopts automated closed-loop to follow the tracks of quartz resonator resonant frequency and the method that accurately frequency sweep combines, and can test fast quartz resonator equivalent impedance property. Utilize DSP technology to carry out signal detection and processing, realize by the CO parameter of compensation quartz resonator the closed loop driving and follow the tracks of to detect its resonant frequency, near resonant frequency, carry out accurate frequency sweep, gated sweep precision is to reach the optimization of precision and speed, thereby obtain the impedance curve of quartz resonator, and calculate its equivalent parameters. The method combines DSP technology and quartz resonator equivalent model, and reasonable design method is feasible, can realize faster the measurement of quartz resonator equivalent impedance property.

Description

A kind of measuring system of quartz resonator impedance operator parameter

Technical field

The present invention relates to a kind of measuring system of quartz resonator impedance operator parameter, this system adopts and automatically closesRing is followed the tracks of quartz resonator resonant frequency and the method that accurately frequency sweep combines, and can test fast quartz humorousDevice equivalent impedance property shakes.

Background technology

Gyro also claims angular rate sensor, and it can coordinate accelerometer composition inertia measurement or guidance system,With other navigation system combination such as GPS, can form navigation and the navigation system of high reliability, be widely used inThe fields such as spacecraft, airborne vehicle, platform stance control, guided missile. Recent years, due to micromechanical gyro toolThere are the advantages such as volume is little, low in energy consumption, cost is low, applicable Mass production and receive much concern, quartz tuning-fork gyroBe one wherein, there is the advantage such as high dynamic response, high sensitivity.

Quartz construction has that processing technology is relatively simple, quality factor q value is higher, properties of product good reliabilityEtc. feature. In actual production, in order to obtain high Q value and good performance, usually close quartzy sensing elementBe enclosed in shell structure, therefore in later stage screening, can judge it by the equivalent parameters of test sensing elementWhether there is short circuit, open circuit, the defect such as gas leakage.

Quartz tuning-fork gyro adopts H type double-ended tuning fork structure more, comprises and drives tuning fork and pick up tuning fork, every endTuning fork is all a quartz resonator. Quartz drives tuning fork and the equivalent model that picks up tuning fork to be a RLCThe circuit model of series circuit and capacitor C 0 parallel connection, as Fig. 2. The natural resonance frequency of tuning fork structure byL1, C1 decision, quality factor q value is determined jointly by R1, L1, C1, when sensing element is in resonance point workWhile work, R1, L1, C1 are equivalent to R1, and because the existence of C0 has produced the phase of arctan (R ω C0)Move, the method about the estimation of C0 and compensation technique with reference to national defence patent 201010048498.0, about numberThe mode that word formula gyro closed loop drives is with reference to the patent US005893054A of Rockwell. At present domestic at stoneThe test aspect of English resonator impedance operator, mainly adopts the electric impedance analyzer of Agilent to test, comparativelyLoaded down with trivial details and efficiency is extremely slow.

Summary of the invention

Technology of the present invention is dealt with problems and is: overcome the deficiencies in the prior art, propose a kind of quartz resonator resistanceThe measuring system of anti-characterisitic parameter, the present invention not only can, for the test of quartz tuning-fork gyro, also can useCan be equivalent to the quartz resonator of a RLC series arm and a C0 branch circuit parallel connection in other electrical model,Measuring accuracy is high.

Technical solution of the present invention is: a kind of measuring system of quartz resonator impedance operator parameter, buildThe equivalent circuit of vertical quartz resonator, comprises C0 measuring and calculating and closed-loop driving circuit and frequency scanning circuit, C0Measuring and calculating and closed-loop driving circuit detect the size of distribution capacity C0 in equivalent circuit and distribution capacity C0 are carried outDigital compensation opens in the time that the driving range value of C0 measuring and calculating and closed-loop driving circuit output is less than driving amplitude thresholdDynamic frequency scanning circuit, frequency scanning circuit carries out frequency sweep to the equivalent circuit of quartz resonator, finally calculatesObtain the equivalent parameters of quartz resonator equivalent circuit;

Described C0 measuring and calculating and closed-loop driving circuit are by simulated modulation circuit, A/D converter, C0 measuring and calculating and compensationCircuit, tracking filter, phase discriminator, automatic gain controller, phase shifter, reference signal generator,One multiplier, the second multiplier and D/A converter composition, the output of simulated modulation electric circuit inspection equivalent circuitSignal V₁And to output signal V₁After carrying out filtering and amplifying processing, obtain signal V₂, A/D converter is by signal V₂Through being transformed to data signal V₃Export to C0 measuring and calculating and compensating circuit, C0 measuring and calculating and compensating circuit logarithmWord signal V₃After compensating, obtain signal V₄Export tracking filter to, tracking filter is to signal V₄Carry outFiltering obtains signal V₅, phase discriminator is to reference signal Q₂With signal V₅Carry out phase bit comparison, comparative result V6Pass to reference signal generator, reference signal generator according to the value of comparative result V6 adjust output signal I,The frequency of Q, reference signal generator output signal β is used for controlling the centre frequency of tracking filter, referenceSignal generator output signal β 1 is used for controlling the operating frequency of automatic gain controller and phase discriminator, phase shiftDevice becomes reference signal Q after output signal Q is moved to certain phase place₂, the size of travel(l)ing phase equals outputSignal I and signal V₅Phase difference, automatic gain controller is by detection signal V₅Amplitude size adjustDrive the value of range signal aa, after driving range signal aa and output signal I to multiply each other by the first multiplierObtain signal I₁, C0 measuring and calculating and compensating circuit are according to signal I₁Output drive signal V₇, drive range signalAa and output signal Q obtain signal Q after multiplying each other by the second multiplier₁, drive signal V₇Through D/A conversionIt is after-applied to the electrode of quartz resonator that device is transformed to analog signal;

Described frequency scanning circuit by simulated modulation circuit, A/D converter, C0 measuring and calculating and compensating circuit, followTrack wave filter, reference signal generator, D/A converter, multiplier and two frequency multiplication trappers, FREQUENCY CONTROLModule composition, the output signal V of simulated modulation electric circuit inspection equivalent circuit₁And to output signal V₁Carry out filteringAfter processing with amplification, obtain signal V₂, A/D converter is by signal V₂Through being transformed to data signal V₃Export toC0 measuring and calculating and compensating circuit, C0 measuring and calculating and compensating circuit are to data signal V₃After compensating, obtain signal V₄Export tracking filter to, tracking filter is to signal V₄Carry out filtering and obtain signal V₅, frequency control moduleBe used for controlling the output signal frequency of reference signal generator, reference signal generator produces two constant amplitudeSignal I, the Q of quadrature in phase inputs to C0 measuring and calculating and compensation, and C0 measuring and calculating and compensating circuit are defeated according to signal IGo out to drive signal V₇, drive signal V₇Be transformed to analog signal through D/A converter after-applied to quartz resonanceOn the electrode of device, reference signal generator output signal β is used for controlling the centre frequency of tracking filter, ginsengExamine signal generator output signal β 1 and be used for controlling two frequency multiplication trappers, the output signal V of tracking filter₅Multiply each other and obtain signal V at multiplier with signal I₂₆, signal V₂₆Obtain signal V through two frequency multiplication trappers,Obtain eventually the corresponding relation of signal V and frequency control module medium frequency f.

Described C0 measuring and calculating and compensating circuit comprise bandpass filter, assessment signal generator, two frequency multiplication trappers,It is logical that C0 resolves module, the first multiplier, the second multiplier, the 3rd multiplier, I channel compensation parameter, QRoad compensating parameter and first adder, second adder, assessment signal generator produces and departs from quartz resonatorThe assessment signal V of operating frequency₁₀, assessment signal V₁₀With signal I₁After stack, obtain driving signal V₇Be applied toOn the drive circuit of quartz resonator, data signal V₃Output and assessment signal after band-pass filter V₁₀The signal V that frequency is identical₉, multiplier is to signal V₉With assessment signal V₁₀Carry out demodulated output signal signal V₁₁, two frequency multiplication trappers are by the output signal V of multiplier₁₁In two frequency-doubled signals curb and obtain and the electricity that distributesHold the direct current signal V that C0 is directly proportional₁₂, C0 resolves module by signal V₁₂Obtain signal V divided by circuit gain₁₃，Signal V₁₃, I channel compensation parameter and signal I₁After multiplying each other by multiplier, obtain signal V₁₄, signal V₁₃、QChannel compensation parameter and signal Q₁After multiplying each other by multiplier, obtain signal V₁₅, signal V₁₄With signal V₁₅Pass throughAdder obtains signal V after being added₁₆, by signal V₁₆From signal V₃In deduct the signal V after being compensated₄。

Operation principle of the present invention is: the electrical equivalent model of quartz resonator, and by R1, a L1, C1The parallel-connection structure of series circuit and C0. Wherein R1 represents the resistance showing when quartz resonator is operated in resonance pointAnti-characteristic, L1, C1 form the frequency characteristic of quartz resonator, the distribution capacity that C0 is quartz resonator. InstituteTaking its impedance operator parameter as 4, need four Solving Equations to obtain fixed solution. First input one and depart from quartzThe voltage signal of tuning fork resonance frequency is by quartz resonator, and now R1, L1, C1 channel impedance are very large,Can be equivalent to and open circuit, therefore its electrical model can be equivalent to C0.

Signal through quartz resonator amplifies and filtering through simulated modulation circuit, when equivalent model tableWhile being shown C0, the gain of simulated modulation circuit is:

$H_1\left(s\right)=\frac{{\mathrm{sR}}_2{C}_0}{1+{\mathrm{sR}}_2{C}_2}\·\frac{R_4}{R_3}\frac{1}{1+{\mathrm{sR}}_4{C}_3}---\left(1\right)$

Transfer function H₁(s) amplitude and phase place are as follows:

${\mathrm{\φ}}_1\left(\mathrm{\ω}\right)=atan\left(\frac{1}{{\mathrm{\ωR}}_2{C}_2}\right)-a\tan \left({\mathrm{\ωR}}_4{C}_3\right)---\left(2\right)$

$\left|H_1\left(\mathrm{\ω}\right)\right|=\frac{{\mathrm{\ωR}}_2{C}_0}{\sqrt{{\mathrm{\ω}}^2{R_2}^2{C_2}^2+1}}\·\frac{R_4}{R_3\·\sqrt{{\mathrm{\ω}}^2{R_4}^2{C_3}^2+1}}=A_1\left(\mathrm{\ω}\right)C_0---\left(3\right)$

Whereinω is the angular frequency of input signal.

Can be found out by formula (2), (3), now the phase place of simulated modulation circuit transfer function and C0 are irrelevant,Amplitude is directly proportional to C0, can be calculated by the output signal of quartz resonator being carried out to demodulation filtering etc.The value of C0. According to the value of C0, signal is compensated, can make whole loop be easy to be operated in resonance shapeState, obtains the resonant frequency of quartz resonator.

Then, near resonant frequency, input that an amplitude is fixed, the voltage signal of frequency gradual change is humorous to quartzThe device that shakes carries out frequency scanning, can obtain the amplitude of quartz resonator output waveform. Quartz resonator is similar toA narrow-band pass filter, at resonant frequency point, it is output as maximum V_max, now corresponding frequency is f_Resonance, at V_max'sLocating corresponding frequency isCan obtain the quality factor q of quartz resonator:

WhereinFor curve of output is at V_max'sFrequency poor at place.

At f_ResonancePoint, quartz resonator is in work resonant condition, and after compensation C0, its electrical model canBe equivalent to R1. The voltage signal of resonance work is applied on quartz resonator, carries out through simulated modulation circuitAmplify and filtering, now the transfer function of simulated modulation circuit is:

$H_2\left(s\right)=\frac{R_2}{R_1}\frac{1}{1+{\mathrm{sR}}_2{C}_2}\·\frac{R_4}{R_3}\frac{1}{1+{\mathrm{sR}}_4{C}_3}---\left(5\right)$

Transfer function H₂(s) phase place and amplitude are as follows:

φ₂(ω)＝-atan(ωR₂C₂)-atan(ωR₄C₃) (6)

$\left|H_2\left(\mathrm{\ω}\right)\right|=\frac{R_2}{R_1}\frac{1}{\sqrt{{\mathrm{\ω}}^2{R_2}^2{C_2}^2+1}}\·\frac{R_4}{R_3}\frac{1}{\sqrt{{\mathrm{\ω}}^2{R_4}^2{C_3}^2+1}}=A_2\left(\mathrm{\ω}\right)\frac{1}{R_1}---\left(7\right)$

Wherein,ω₀For the resonance angular frequency of quartz resonatorRate.

Can be found out by formula (6), (7), now the phase place of simulated modulation circuit transfer function and R1 are irrelevant,Amplitude and R1 are inversely proportional to, and the output that detects the respective signal of quartz resonator can calculate the value of R1.

The relation of quality factor q and R1, C1, ω is as follows:

Q＝1/(R1×C1×ω) (8)

Can obtain the value of C1 by formula (8).

Have again the relation of input signal angular frequency and L1, C1 as follows:

$\mathrm{\ω}=1/\sqrt{L1\×C1}---\left(9\right)$

Can obtain from formula (9) value of L1.

The present invention's beneficial effect is compared with prior art: test at present quartz resonator impedance operator parameterMostly adopt electric impedance analyzer, electric impedance analyzer heaviness and program are loaded down with trivial details, the present invention be easy at DSP orFpga chips etc. are for realizing in basic digital circuit, and circuit volume is little, lightweight, easily carry testProcess is simple, and measuring accuracy is high.

Brief description of the drawings

Fig. 1 is " H " type quartz tuning-fork structural representation;

Fig. 2 is the electrical equivalent circuit figure of quartz resonator;

Fig. 3 is the test flow chart of quartz resonator impedance operator parameter;

Fig. 4 is the composition schematic diagram of C0 measuring and calculating of the present invention and closed-loop driving circuit;

Fig. 5 is the composition structure chart of simulated modulation circuit;

Fig. 6 is the composition structure chart of C0 measuring and calculating and compensating circuit;

Fig. 7 is the composition structure chart of assessment signal generator;

Fig. 8 is the composition structure chart of bandpass filter;

Fig. 9 is the composition structure chart of two frequency multiplication trappers;

Figure 10 is the composition structure chart of tracking filter;

Figure 11 is the composition structure chart of phase discriminator;

Figure 12 is the composition structure chart that two frequencys multiplication are followed the tracks of trapper;

Figure 13 is the composition structure chart of phase corrector;

Figure 14 is the composition structure chart of reference signal generator;

Figure 15 is the composition structure chart of phase shifter;

Figure 16 is the composition structure chart of automatic gain controller;

Figure 17 is the composition structure chart of frequency scanning circuit;

Figure 18 is resonator output amplitude and scan frequency graph of a relation.

Detailed description of the invention

Describe the specific embodiment of the present invention in detail below in conjunction with accompanying drawing.

Fig. 1 is " H " type double-ended tuning fork structure that quartz tuning-fork gyro adopts, and comprises and drives tuning fork 1 and pick up2 two parts of tuning fork, add by cut a series of techniques such as plated film on quartz wafer, photoetching, corrosion at ZWork obtains its structure and surface electrode 3,4. Although drive and to pick up electrode and the structure of tuning fork different,They all belong to the one of quartz resonator, and just the direction of vibration is different. The voltage signal of alternation loadsTo drive electrode, under inverse piezoelectric effect effect in XY plane double vibrations, in like manner, the voltage of alternationSignal loading to pickoff electrode, under inverse piezoelectric effect effect in YZ plane double vibrations.

Fig. 2 is the electrical equivalent model of quartz tuning-fork, and R1, L1, C1, C0 have reflected quartz tuning-fork jointlyState, object of the present invention is exactly to adopt the method for Digital Signal Processing, measure fast R1, L1, C1,The parameter of C0.

As shown in Figure 3, the present invention includes C0 measuring and calculating and drive closed loop circuit 7 and frequency scanning circuit 9. C0Measuring and calculating and closed-loop driving circuit 7 detect the size of distribution capacity C0 in equivalent circuit and distribution capacity C0 are enteredRow digital compensation, when the driving range value that C0 calculates and closed-loop driving circuit 7 is exported is less than driving amplitude thresholdShi Qidong frequency scanning circuit 9, frequency scanning circuit 9 carries out frequency sweep to the equivalent circuit of quartz resonator,Rationally control frequency sweep precision and speed, obtain corresponding curve of output, finally calculate equivalent circuit etc.Effect parameter Q, R1, L1, C1; This threshold value determines by hardware circuit, and different hardware circuits may be different.

Fig. 4 is the schematic diagram that C0 measuring and calculating resonator of the present invention drives closed loop circuit, and it mainly comprises simulationModulate circuit 10, C0 measuring and calculating and compensation 12, tracking filter 13, phase discriminator 14, automatic gain controller15, the module such as phase shifter 16, reference signal generator 17. Simulated modulation circuit 10 detects quartz resonator5 output signal V₁, and carry out filtering and amplify and process, be transformed to data signal through A/D converter 11 V₃After offer C0 measuring and calculating and compensation 12, the signal V after compensation₄Input tracking filter 13. Tracking filterThe resonant frequency that the centre frequency of device 13 in steady operation situation is quartz resonator, it is to quartz resonatorThe signal of operating frequency carries out filtering and obtains signal V₅. The effect of C0 measuring and calculating and compensation 12 calculates C0Size also compensates service frequency signal, eliminates the impact of C0 on service frequency signal. Phase discriminator 14Be used for the output signal V of comparison reference signal and tracking filter 13₅Between phase place whether meet driving ringRoad oscillation phase relation, by phase information V₆Pass to reference signal generator 17, reference signal generator17 according to V₆Value adjust the frequency of output signal I, Q, to make the standard signal I of its generation, the frequency of QRate can make to meet oscillation phase relation after whole driving loop stability.

The output signal β of reference signal generator 17 is used for controlling the centre frequency of tracking filter 14, protectsThe centre frequency of card tracking filter 14 can adapt to the change of frequency of standard signal I. Reference signal generator17 output signal β 1 is used for controlling the operating frequency of automatic gain controller 15 and phase discriminator 14, ensuresThe operating frequency of automatic gain controller 15 and phase discriminator 14 can adapt to the change of frequency of standard signal I.Phase shifter 16 becomes signal Q after signal Q is moved to certain phase place₂, the size of travel(l)ing phase equals to drive electricityThe phase difference of pressing signal I and signal V5, this phase difference can calculate by theory. Automatic gain controller15 effect is by detection signal V₅Amplitude size adjust the value of output signal aa, signal aa and letterNumber I, Q multiply each other respectively and obtain signal I₁、Q₁, the function that multiplies each other is realized by multiplier 18,19. Drive signal V₇Comprise the service frequency signal I of quartz resonator₁With the operating frequency that departs from of inputting in order to calculate C0Signal, V₇Through D/A converter 20 be transformed to the after-applied electrode 3 to quartz resonator of analog signal orOn electrode 4. Signal V₆Determine the frequency f of working signal in circuit, signal V₆With the relation of frequency f asFormula (10).

V₆＝-cos(ωT) (10)

In formula, ω is angular frequency, ω=2 π f, the sampling time that T is A/D converter. When circuit working is stablizedAfter, signal aa is less than setting threshold big or small stable, and signal V₆Size is also stable, now signal V₆Corresponding frequency f is resonant frequency f_Resonance。

Fig. 5 is the schematic diagram of simulated modulation circuit 10, and it is by two operational amplifiers 21,22 and capacitance-resistanceDevice R 2, R3, R4, C2, C3 composition. In the time that quartz resonator is in duty, it exports V₁ForCurrent signal, therefore amplifier 21, R2, C2 form current amplifier to V₁Detect and amplify, and transportingPut 22, R3, R4, C4 form frequency overlapped-resistable filter.

Fig. 6 is C0 measuring and calculating and the schematic diagram that compensates 12 modules, and it comprises bandpass filter 32, assessment signalGenerator 23, two frequency multiplication trappers 26, C0 resolve 27, multiplier 25,30,31, I channel compensation ginsengSeveral 28, Q channel compensation parameter 29 and two adders 33,34. Assessment signal generator 23 produces and departs fromThe standard signal V of quartz resonator operating frequency (Δ f > 1kHz)₁₀, then folded by adder 24Be added in signal I₁In obtain signal V₇, by V₇Be applied on the drive electrode of quartz resonator. Signal V₁₀WithIn time, offers multiplier 25 and carries out demodulation. The centre frequency of bandpass filter 32 is assessment signal V₁₀Frequency,Bandwidth is 5Hz, its output signal V₉Frequency and assessment signal V₁₀Identical. The work of two frequency multiplication trappers 26With being that two frequency-doubled signals by the output signal of demodulator 25 curb, obtain the direct current being directly proportional to C0Signal. In C0 resolves 27 by signal V₁₂Obtain signal V divided by circuit gain₁₃, i.e. the size of C0, electricityRoad gain mainly comprises two parts: the one, and the gain size producing when assessment signal V10 process hardware circuit,Can calculate by theory, computational methods are shown in formula (3); Two is gains of two frequency multiplication trappers 26. WithReason, according to formula (1), (2), (3) can be by I channel compensation parameter 28 and Q channel compensation parameter 29Calculate. I channel compensation parameter is A₁(ω)cos(φ₁(ω)), the compensating parameter of Q passage is A₁(ω)sin(φ₁(ω)), now ω is signal I₁Angular frequency, its value with signal V₆Pass be arccos(-V₆)f_s, wherein f_sFor the sample frequency of digital circuit. Signal V₁₃, I channel compensation parameter and signal I₁After multiplying each other by multiplier 30, obtain signal V₁₄, signal V₁₃, Q channel compensation parameter and signal Q₁Pass throughAfter multiplying each other, multiplier 31 obtains signal V₁₅, signal V₁₄With signal V₁₅After being added by adder 33, obtain letterNumber V₁₆, by signal V₁₆From signal V₃In deduct and complete C0 compensation process, the signal after compensation is V₄.

Fig. 7 is the schematic diagram of assessment signal generator 23, and it comprises 35,37, one of two delay cellsAdder 36 and a multiplier (-icator) 38. The output of delay cell 37 is also the output of generator simultaneously, itJust the value of establishing is sin (ω_eT)，ω_eFor the angular frequency of assessment signal, the sampling period that T is digital circuit. ProlongFirst value of establishing of unit 35 is 0 late, and it is by a sampling period of the output delay of signal generator. Multiplier (-icator) 38Multiplication factor be 2cos (ω_eT), it amplifies the output of signal generator. The output letter of adder 36Number for the output signal of multiplier (-icator) 38 deducts the output signal of delay cell 35, it is exported as delay cell37 input, assessment signal generator 23 is output as:

V₁₀＝cos(ω_et) (11)

Fig. 8 is the schematic diagram of bandpass filter 32, it comprise six summation nodes 39,41,42,44,46,48, three multiplier (-icator)s 40,43,49 and 45 and 47, two delay cells 45 of two delay cell,Input signal is separately postponed a sampling period by 47. The multiplication factor A of the multiplier (-icator) 40 of bandpass filterDetermine the bandwidth of wave filter, the multiplication factor B of multiplier (-icator) 43 determines the centre frequency of wave filter, multiplier (-icator)Output signal amplitude is reduced by 1 times by 49, is 1 thereby make the gain multiple of whole wave filter. Wherein

$A=\frac{1-\tan \left(0.5f_{h}T\right)}{1+\tan \left(0.5f_{h}T\right)}---\left(12\right)$

B＝cos(ω_eT) (13)

Wherein f_hFor bandwidth, T is the sampling period, ω_eCentered by angular frequency. The transfer function of bandpass filterFor:

$H\left(Z\right)=\frac{A-1}{2}\·\frac{z^{-2}-1}{{\mathrm{Az}}^{-2}+B(1+A)z^{-1}+1}---\left(14\right)$

Fig. 9 is the schematic diagram of two frequency multiplication line traps 26, and it comprises 52, one multiplier (-icator)s of a summation node53 and 50,51, two delay cells of two delay cell output signal is separately postponed to a sampling period.Multiplier (-icator) is that the output of delay cell 50 is amplified to 2cos (2 ω_eT) doubly. Summation node is by signal V₁₁With prolongThe output signal that then signal plus of slow unit 51 deducts multiplier (-icator) obtains signal V₁₂, signal V₁₂With C0Size be directly proportional. The gain of two octave filters is 2-2cos (2 ω as we know from the figure_eT)。

Figure 10 is the schematic diagram of tracking filter 13, its place different with Fig. 8 bandpass filter be byMultiplier (-icator) 40,43 changes multiplier 55 and 59 into, multiplies each other respectively with signal alpha and β, and its following function isRealize by signal beta, signal beta has determined the centre frequency of tracking filter.

$\mathrm{\α}=\frac{1-\tan \left(0.5f_{h}T\right)}{1+\tan \left(0.5f_{h}T\right)}---\left(15\right)$

$H\left(z\right)=\frac{0.5(1-\mathrm{\α})(1-z^{-2})}{1+\mathrm{\β}(1+\mathrm{\α})z^{-1}+{\mathrm{\αz}}^{-2}}---\left(16\right)$

In the time of the output signal aa=1.75 of automatic gain controller in Fig. 4, f_h=20Hz, in the time of aa < 1.75, f_h＝5Hz。

Figure 11 is the schematic diagram of phase discriminator 14, by signal V₅With signal Q₂Multiply each other and obtain signal V₁₇, signal V₁₇Obtain signal V through two frequency multiplication trappers 67₁₈，V₁₈Obtain V through phase corrector 68₁₉，V₁₉LetterNumber amplify C doubly, the value of C is generally in 0.002 left and right. Signal after amplification obtains signal V through integrator₆。Integrator is made up of adder 71, limiter 72 and register 73, and the effect of limiter is by signal V₆Be limited between-0.707～0.707.

Figure 12 is the schematic diagram that two frequencys multiplication are followed the tracks of trapper, compares different places by multiplier (-icator) 53 with Fig. 9Made multiplier 77 into, its trap centre frequency is determined by signal beta 1, realizes following function.

Figure 13 is phase corrector, and major function is two frequencys multiplication to be followed the tracks of to trapper output signal V18 hinderBuddhist nun's damping, prevents sign mutation. Phase corrector is by 79,80,84,85,87, two of five adders78,83 and 3 multiplier (-icator)s 82,81,86 of register, wherein

D＝exp(-Lω_hT) (17)

$E=\frac{1}{2L}---\left(18\right)$

F＝2L (19)

L is resistance coefficient, ω_hFor the corner frequency of damper, its value is believed by input in system debug processNumber concrete condition determine.

Figure 14 is the concrete schematic diagram of reference signal generator 17, it comprise 5 multiplication units 89,96,98,97,100, two compensators of 91,94,95, two delay cells of 99,101, three adder units102,103. Signal V₆Self multiply each other and obtain signal V₂₀，V₂₀Input to arithmetic element 92, arithmetic element 92Transmission characteristic beSignal V₂₀Obtain signal beta 1, β 1 through multiplier (-icator) 90 and adder 91Determine the centre frequency of two frequencys multiplication tracking trappers; Signal V₆Obtain signal beta, β through multiplier (-icator) 88Determine the centre frequency of tracking filter. The output of reference signal generator comprises signal I, Q, β, β 1,Signal I, Q are that amplitude is 1 sine wave, 90 ° of phase phasic differences, and its frequency is by signal V₆Value determine.There is following relational expression in whole reference signal generator

β＝-V₆＝cos(ωT) (20)

$\mathrm{\&beta;}1=4V_6^2-2=4{\cos }^2\left(\mathrm{\&omega;}T\right)-2=2\cos \left(2\mathrm{\&omega;}T\right)---\left(21\right)$

Delayer 97,100 obtains V by a sampling period of input delay separately respectively₂₁、V₂₂, at the beginning of itInitial value is respectively 1,0, and the transmission characteristic of compensator 102,103 is as follows:

signal(i)＝1，V₂₁＞0 (22)

signal(i)＝-1，V₂₁＜0 (23)

signal(i)＝0，V₂₁＝0 (24)

signal(q)＝1，V₂₂＞0 (25)

signal(q)＝-1，V₂₂＜0 (26)

signal(q)＝0，V₂₂＝0 (27)

$I=signal\left(i\right)\&times;(1+b_1{V}_{21}^2+b_2{V}_{21}^4),V_{21}<0.1---\left(28\right)$

I＝V₂₁，V₂₁＜0.1 (29)

$Q=signal\left(q\right)\&times;(1+b_1{V}_{22}^2+b_2{V}_{22}^4),V_{21}<0.1---\left(30\right)$

Q＝V₂₂，V₂₂＜0.1 (31)

Wherein b₁＝-0.5，b₂＝-0.1259。

Figure 15 is the schematic diagram of phase shifter 16, it comprise 105,108,2 registers 104 of 2 adders,109 and multiplier 107 and constant G, its effect is signal Q to be moved to the phase place that size is θ obtainSignal Q₂, the size of phase theta determines by constant G, G and θ meet following relation.

$G=\frac{\sin \left(\frac{\mathrm{\&theta;}-\mathrm{\&omega;}T}{2}\right)}{\sin \left(\frac{\mathrm{\&theta;}+\mathrm{\&omega;}T}{2}\right)}---\left(32\right)$

Figure 16 is the schematic diagram of automatic gain controller 15, and it comprises multiplier 110, by 111,118 groupsThe comparator becoming, two frequencys multiplication are followed the tracks of trapper 112, and phase corrector 113, by 119,114 width that formValue adjuster 1 and by 115,116,, 117 integrators that form. Constant 118 is 0.5*A², A is electricityV when road is designed₅Setting amplitude, constant 119 is in 0.003 left and right. The final output of automatic gain controllerSignal is aa. The structure chart that two frequencys multiplication are followed the tracks of trappers 112 and phase corrector 113 is as Figure 12,13Show, just input and output signal difference.

Figure 17 is the schematic diagram of frequency scanning circuit 9, and it comprises that tracking filter 13, reference signal occurDevice 17, multiplier 120, two frequency multiplication trappers 121, C0 measuring and calculating and compensation 12 and hardware circuit part.The value of module 122 is used for controlling the frequency of reference signal generator 17 output signal I, Q, sweeps in order to realizeFrequently function, only need be by f value in module 122 by changing the time and step-length. Module 122Middle f value will be at f_ResonanceWithin the scope of ± Δ f, change from small to large, the value of Δ f determines by the characteristic of quartz resonator,Ensure that the minimum amplitude of signal V in frequency sweep process is than maximum amplitude < 0.707, the accuracy selection of step-length byMeasuring accuracy decision, required precision is higher, and change step is less. Reference signal generator 17 produces two widthOrthogonal signal I, the Q of value constant phase directly inputs to C0 measuring and calculating and calculates with compensation at letter with compensation 12, C0On number I, add output signal V after assessment signal₇，V₇Process D/A converter 20 is applied to quartz resonatorOn electrode. The output signal V of quartz resonator₁Form through simulated modulation circuit 10 and A/D converter 11Signal V₄, signal V₄Output signal V after tracking filter 13 filtering₅, the center of tracking filter frequentlyRate is controlled by the output signal β of reference signal generator 17, ensures the frequency one of its centre frequency and signal ICause. The output signal V of tracking filter 13₅After multiplying each other by multiplier 120 with signal I, obtain signal V₂₆，Signal V₂₆Obtain signal V through two frequency multiplication trappers, tracer signal V is corresponding with module 122 medium frequency f'sRelation.

Figure 18 is frequency f and amplitude V graph of a relation. Pass through f_ResonanceCorresponding amplitude V_maxAnd formula (5)～(7)Can calculate R1 value, pass throughCorresponding frequency f₁And f₂, and formula (4) can calculate stoneThe quality factor q of English resonator, can calculate the value of L1, C1 by formula (8) and (9).

Claims (2)

1. a measuring system for quartz resonator impedance operator parameter, sets up the equivalent circuit of quartz resonator,It is characterized in that: measuring system comprises CO measuring and calculating and closed-loop driving circuit (7) and frequency scanning circuit (9),CO measuring and calculating and closed-loop driving circuit (7) detect the big or small of distribution capacity CO in equivalent circuit and to distribution capacityCO carries out digital compensation, when the driving range value of CO measuring and calculating and closed-loop driving circuit (7) output is less than drivingWhen amplitude threshold, start frequency scanning circuit (9), the equivalent electric of frequency scanning circuit (9) to quartz resonatorFrequency sweep is carried out on road, finally calculates the equivalent parameters of quartz resonator equivalent circuit;

Described CO measuring and calculating and closed-loop driving circuit (7) by simulated modulation circuit (10), A/D converter (11),CO measuring and calculating and compensating circuit (12), tracking filter (13), phase discriminator (14), automatic gain controller(15), phase shifter (16), reference signal generator (17), the first multiplier (18), the second multiplier(19) and D/A converter (20) composition, simulated modulation circuit (10) detects the defeated of equivalent circuit (5)Go out signal V₁And to output signal V₁After carrying out filtering and amplifying processing, obtain signal V₂, A/D converter (11)By signal V₂Be transformed to data signal V₃Export to CO measuring and calculating and compensating circuit (12), CO measuring and calculating and compensation electricityRoad (12) is to data signal V₃After compensating, obtain signal V₄Export tracking filter (13) to, follow the tracks ofWave filter (13) is to signal V₄Carry out filtering and obtain signal V₅, phase discriminator (14) is to reference signal Q₂And letterNumber V₅Carry out phase bit comparison, comparative result V6 passes to reference signal generator (17), and reference signal occursDevice (17) is adjusted the frequency of output signal I, Q, reference signal generator (17) according to the value of comparative result V6Output signal β is used for controlling the centre frequency of tracking filter (13), and reference signal generator (17) is defeatedGo out the operating frequency that signal beta 1 is used for controlling automatic gain controller (15) and phase discriminator (14), phase shiftDevice (16) becomes reference signal Q after output signal Q is moved to certain phase place₂, the size of travel(l)ing phase etc.In output signal I and signal V₅Phase difference, automatic gain controller (15) is by detection signal V₅WidthValue size is adjusted the value that drives range signal aa, drives range signal aa and output signal I by firstAfter multiplying each other, multiplier (18) obtains signal I₁, CO measuring and calculating and compensating circuit (12) are according to signal I₁Output is drivenMoving signal V₇, after driving range signal aa and output signal Q multiply each other by the second multiplier (19), obtain letterNumber Q₁, drive signal V₇Be transformed to analog signal through D/A converter (20) after-applied to quartz resonatorElectrode on;

Described frequency scanning circuit (9) is by simulated modulation circuit (10), A/D converter (11), CO measuring and calculatingAnd compensating circuit (12), tracking filter (13), reference signal generator (17), D/A converter (20),Multiplier (120) and two frequency multiplication trappers (121), frequency control module (122) composition, simulated modulationCircuit (10) detects the output signal V of equivalent circuit (5)₁And to output signal V₁Carry out filtering and amplificationAfter processing, obtain signal V₂, A/D converter (11) is by signal V₂Be transformed to data signal V₃Export to COMeasuring and calculating and compensating circuit (12), CO measuring and calculating and compensating circuit (12) are to data signal V₃After compensatingTo signal V₄Export tracking filter (13) to, tracking filter (13) is to signal V₄Carrying out filtering obtainsSignal V₅, frequency control module (122) is used for controlling the output signal frequency of reference signal generator (17),Signal I, Q that reference signal generator (17) produces two constant amplitude quadrature in phases input to CO measuring and calculatingAnd compensating circuit (12), CO measuring and calculating and compensating circuit (12) are according to signal I output drive signal V₇, driveMoving signal V₇Be transformed to analog signal through D/A converter (20) after-applied to the electrode of quartz resonator,Reference signal generator (17) output signal β is used for controlling the centre frequency of tracking filter (13), ginsengExamine signal generator (17) output signal β 1 and be used for controlling two frequency multiplication trappers (121), tracking filter(13) output signal V₅Multiply each other and obtain signal V at multiplier (120) with signal I₂₆, signal V₂₆ProcessTwo frequency multiplication trappers (121) obtain signal V, finally obtain in signal V and frequency control module (122)The corresponding relation of frequency f.

2. the measuring system of a kind of quartz resonator impedance operator parameter according to claim 1, its spyLevy and be: the CO measuring and calculating in described CO measuring and calculating and closed-loop driving circuit (7) and frequency scanning circuit (9)And compensating circuit (12) comprises bandpass filter (32), assessment signal generator (23), two frequency multiplication trapsDevice (26), CO resolve module (27), the first multiplier (25), the second multiplier (30), the 3rd multiplicationDevice (31), I channel compensation parameter (28), Q channel compensation parameter (29) and first adder (33),Second adder (34), assessment signal generator (23) produces the assessment that departs from quartz resonator operating frequencySignal V₁₀, assessment signal V₁₀With signal I₁After stack, obtain driving signal V₇Be applied to driving of quartz resonatorOn moving circuit, data signal V₃Output and assessment signal V after bandpass filter (32) filtering₁₀Frequency phaseSame signal V₉, the first multiplier (25) is to signal V₉With assessment signal V₁₀Carry out demodulated output signal V₁₁，Two frequency multiplication trappers (26) are by the output signal V of the first multiplier (25)₁₁In two frequency-doubled signals curbObtain the direct current signal V being directly proportional to distribution capacity CO₁₂, CO resolves module (27) by signal V₁₂Divided by electricityRoad gain obtains signal V₁₃, signal V₁₃, I channel compensation parameter (28) and signal I₁By the second multiplier(30) obtain signal V after multiplying each other₁₄, signal V₁₃, Q channel compensation parameter (29) and signal Q₁By the 3rdAfter multiplying each other, multiplier (31) obtains signal V₁₅, signal V₁₄With signal V₁₅By first adder (33) phaseAfter adding, obtain signal V₁₆, by signal V₁₆From signal V₃In deduct the signal V after being compensated₄, wherein circuitThe gain producing while gaining by assessment signal V10 process hardware circuit and the gain of two frequency multiplication trappers (26)Composition.