CN102759365A - Bias stability improving method and device for silicon micromechanical gyroscope - Google Patents

Abstract

The invention discloses a bias stability improving method and device for a silicon micromechanical gyroscope. The method includes the steps as follows: firstly, acquiring the cross coupling error amplitude value of a detection signal of a silicon micromechanical gyroscope in real time; and secondly, setting the cross coupling error amplitude value as a manipulated variable to be input to the static rigidity adjustment voltage of a detection electrode of the silicon micromechanical gyroscope in a closed loop feedback control manner, and revising the variation of coupling rigidity of the silicon micromechanical gyroscope due to environmental factors through the variation of the static rigidity adjustment voltage in case of variation of environmental factors. The device includes a quadrature error amplitude value acquisition unit used for acquiring the cross coupling error amplitude value of the detection signal of the silicon micromechanical gyroscope, and a static rigidity adjustment control unit used for outputting static rigidity adjustment voltage to the silicon micromechanical gyroscope. The method and device, provided by the invention, can remarkably improve the bias stability and detection precision of the silicon micromechanical gyroscope, and have the advantages of excellent real-time adjustment performance, low driving voltage, high efficiency, low cost and power consumption, simplicity and convenience for use, and the like.

Description

The zero stable partially method for improving and the device that are used for silicon micromechanical gyroscope

Technical field

The present invention relates to the silicon micromechanical gyroscope field, be specifically related to a kind of zero stable partially method for improving and device that is used for silicon micromechanical gyroscope.

Background technology

Micromechanical gyro is the device that Measuring Object relative inertness space rotatablely moves; It is the requisite angular velocity sensitive element of inertial guidance system; The output signal of micromechanical gyro is used to drive carrier or platform topworks and stablizes control and Navigation Control after amplification, correction, power amplification.The microstructure of micromechanical gyro adopts body silicon or surface silicon processing technology to be made, and utilizes the coriolis force effect to be coupled to sensitivity through the vibration with drive end and brings in detection angular velocity.

As shown in Figure 1, silicon micromechanical gyroscope generally is made up of brace summer and mass, adopts the form of static driven, capacitance detecting more.Silicon micromechanical gyroscope comprises two operation modes: drive mode and detect mode.Mass is done simple harmonic oscillation in the effect lower edge driving shaft direction (x axle) that drives electrostatic force, is called driving mode; When having angular velocity signal, vibrating in detection direction of principal axis (y axle) generation, be called detection mode by the feasible mass that detects of the coriolis force of coriolis force effect generation along angular velocity input direction (z axle).Detect mode sensitization capacitance variable quantity and be directly proportional, thereby through obtaining the information of input angular velocity after the C-V conversion through this voltage signal of measurement, two mode can adopt the second-order system modeling of quality-spring-damping with input angular velocity.Among Fig. 1, c _sFor detecting damping, the c of mode _dFor driving damping, the k of mode _sFor detecting rigidity, the k of mode _dFor driving the rigidity of mode.

Consider to drive mode and adopt same mass with detection mode, the system dynamics equation of silicon micromechanical gyroscope is:

$m\left[\begin{array}{c}\stackrel{\·\·}{x}\\ \stackrel{\·\·}{y}\end{array}\right]+\begin{array}{}\end{array}\left[\begin{array}{cc}{c}_{\mathrm{xx}}& c_{\mathrm{xy}}\\ c_{\mathrm{yx}}& c_{\mathrm{yy}}\end{array}\right]\left[\begin{array}{c}\stackrel{\·}{x}\\ \stackrel{\·}{y}\end{array}\right]+\left[\begin{array}{cc}{k}_{\mathrm{xx}}& k_{\mathrm{xy}}\\ k_{\mathrm{yx}}& k_{\mathrm{yy}}\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]={2\mathrm{m\Ω}}_z\left[\begin{array}{cc}0& 1\\ -1& 0\end{array}\right]\left[\begin{array}{c}\stackrel{\·}{x}\\ \stackrel{\·}{y}\end{array}\right]+\left[\begin{array}{c}{F}_x\\ F_y\end{array}\right]---\left(A1\right)$

In the formula (A1), m is the quality of mass shown in Fig. 1. $C=\left[\begin{array}{cc}{c}_{\mathrm{Xx}}& c_{\mathrm{Xy}}\\ c_{\mathrm{Yx}}& c_{\mathrm{Yy}}\end{array}\right]$ Be the damping matrix of system, c _XxFor driving damping, the c of mode _YyFor detecting damping, the c of mode _Yx, c _XyRepresent two mode cross-couplings dampings respectively; $K=\left[\begin{array}{cc}{k}_{\mathrm{Xx}}& k_{\mathrm{Xy}}\\ k_{\mathrm{Yx}}& k_{\mathrm{Yy}}\end{array}\right]$ Be the stiffness matrix of system, k _XxFor driving rigidity, the k of mode _YyFor detecting rigidity, the k of mode _Yx, k _XyRepresent two mode cross-couplings rigidity respectively; Ω _zAngular velocity signal for input; $F=\left[\begin{array}{c}{F}_x\\ F_y\end{array}\right]$ Be systemic effect power.

When the Z of silicon micromechanical gyroscope axle has the angular velocity input, detect mode and receive a dynamic mechanically coupling, drive mode and receive driving force to be used as simple harmonic oscillation, the resonance frequency of simple harmonic oscillation is ω _x, then drive modal displacement x (t) and be:

x(t)＝X ₀cos(ω _xt) (A2)

In the formula (A2), X ₀Drive the amplitude of mode for silicon micromechanical gyroscope; T is a time parameter.

With formula (A2) substitution formula (A1), definition F _y=0, then detect the mode kinetics equation and do

$m\stackrel{\·\·}{y}+c_{\mathrm{yy}}\stackrel{\·}{y}+k_{\mathrm{yy}}y=2m{X}_0{\mathrm{\ω}}_x{\mathrm{\Ω}}_Z\sin \left({\mathrm{\ω}}_{x}t\right)-X_0{\mathrm{\ω}}_x{c}_{\mathrm{yx}}\sin \left({\mathrm{\ω}}_{x}t\right)-k_{\mathrm{yx}}{X}_0\cos \left({\mathrm{\ω}}_{x}t\right)---\left(A3\right)$

In the formula (A3), first (2mX of right-hand member ₀ω _xΩ _ZSin (ω _xT)) expression coriolis force signal; Second (X of right-hand member ₀ω _xc _YxSin (ω _xT)) the offset error signal of expression and coriolis force homophase; The 3rd (k of right-hand member _YxX ₀Cos (ω _xT)) error signal of expression and coriolis force signal in orthogonal, i.e. quadrature coupling error.Identical in the implication of the alphabetical parameter that relates in the formula (A3) and the formula (A1).Ignore the influence of offset error signal, only consider the influence of quadrature coupling error.Then can formula (A3) be simplified and be expressed as:

$m\stackrel{\·\·}{y}+c_{\mathrm{yy}}\stackrel{\·}{y}+k_{\mathrm{yy}}y=2m{X}_0{\mathrm{\ω}}_x{\mathrm{\Ω}}_Z\sin \left({\mathrm{\ω}}_{x}t\right)-k_{\mathrm{yx}}{X}_0\cos \left({\mathrm{\ω}}_{x}t\right)---\left(A4\right)$

Silicon micromechanical gyroscope processing and manufacturing error is to produce quadrature coupling main error, and in the middle of the actual processing, foozle mainly shows not exclusively symmetry of silicon micromechanical gyroscope brace summer, thereby makes elastic axis and the desirable principal axis of inertia inconsistent.As shown in Figure 2.Silicon micromechanical gyroscope drives and detects the elastic axis stiffness coefficient and is respectively k _XxAnd k _Yy(generalized case k _Xx＞k _Yy).The error angle of supposing the actual elastic main shaft and the desirable principal axis of inertia is α, and then the stiffness matrix K of system becomes K':

$K^{\&prime;}=\left[\begin{array}{cc}\cos \mathrm{\&alpha;}& -\sin \\ \sin \mathrm{\&alpha;}& \cos \mathrm{\&alpha;}\end{array}\right]\left[\begin{array}{cc}{k}_{\mathrm{xx}}& \\ & k_{\mathrm{yy}}\end{array}\right]\left[\begin{array}{cc}\cos \mathrm{\&alpha;}& \sin \mathrm{\&alpha;}\\ -\sin \mathrm{\&alpha;}& \cos \mathrm{\&alpha;}\end{array}\right]=\left[\begin{array}{cc}{k}_{\mathrm{xx}}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA00001879577300031.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&alpha;}+k_{\mathrm{yy}}{\sin }^2\mathrm{\&alpha;}& \sin \mathrm{\&alpha;}\cos \mathrm{\&alpha;}(k_{\mathrm{xx}}-k_{\mathrm{yy}})\\ \sin \mathrm{\&alpha;}\cos \mathrm{\&alpha;}(k_{\mathrm{xx}}-k_{\mathrm{yy}})& k_{\mathrm{yy}}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA00001879577300031.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&alpha;}+k_{\mathrm{xx}}{\sin }^2\mathrm{\&alpha;}\end{array}\right]---\left(A5\right)$

Because α is very little, approximately think cos α ≈ 1, sin α ≈ α, and ignore the higher order term in (A5), sin ²α ≈ 0, then the further abbreviation of formula (A5) is:

$K^{\&prime;}=\left[\begin{array}{cc}{k}_{\mathrm{xx}}& (k_{\mathrm{xx}}-k_{\mathrm{yy}})\mathrm{\&alpha;}\\ (k_{\mathrm{xx}}-k_{\mathrm{yy}})\mathrm{\&alpha;}& k_{\mathrm{yy}}\end{array}\right]---\left(A6\right)$

Formula (A6) shows, after the coordinate axis of elastic system deflects, has produced direct coupling between driving shaft x and the detection axle y, and the coupling stiffness coefficient is:

k _xy＝k _yx＝(k _xx-k _yy)α (A7)

(A4) can know by formula, detects the output of mode and is made up of two parts: the quadrature coupling error signal that angular velocity sensitive signal that Coriolis effect causes and mechanical couplings effect cause.Both (t) are directly proportional with displacement signal x (t) with the rate signal x ' that drives mode respectively, so both phase differential are 90 °, and available orthogonal phase sensitive demodulation method separates both.

The responsive demodulation method principle of quadrature phase is as shown in Figure 3, cos (ω _CarT) for detecting the carrier signal of mode, y _I(t) be angular velocity signal, y _Q(t) be mechanical couplings error amplitude, K ₁And K ₂It is respectively the gain of angular velocity signal and mechanical couplings error signal.Hi-pass filter F ₀(s) cutoff frequency ω _H＜ω _Car, low-pass filter F ₁(s) cutoff frequency ω _x＜ω _L＜2 ω _x, the cutoff frequency ω of low-pass filter F (s) _L＜ω _xThe transport function that drives mode does K _x=1/X ₀For driving the enlargement factor of loop; V _d(t)=K _x* X ₀Cos (ω _xT)=cos (ω _xT);

With

Be V _d(t) the two-way orthogonal signal of behind phase shifter, exporting are used for the responsive demodulation of quadrature phase.

The transfer function H (s) that detects mode is:

$H\left(s\right)=\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00001879577300031.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+\frac{{\mathrm{\&omega;}}_y}{Q_y}s+{\mathrm{\&omega;}}_y^2}---\left(A8\right)$

In the formula (A8), S is the expression parameter in S territory.ω _yFor detecting resonance frequency, the Q of mode _yFor detecting the quality factor of mode.

The angular velocity signal of supposing input is Ω _z(t)=Ω cos (ω _ΩT), then detect the angular velocity sensitive signal y that Coriolis effect causes among the output displacement y (t) of mode _Ω(t) be:

y _Ω(t)＝ω _xX ₀ΩH _Ω+sin((ω _x+ω _Ω)t+φ _Ω+)+ω _xX ₀ΩH _Ω-sin((ω _x-ω _Ω)t+φ _Ω-) (A9)

Wherein $H_{\mathrm{\&Omega;}\&PlusMinus;}={\left|H\left(s\right)\right|}_{s=j({\mathrm{\&omega;}}_x\&PlusMinus;{\mathrm{\&omega;}}_{\mathrm{\&Omega;}})},$ ${\mathrm{\&phi;}}_{\mathrm{\&Omega;}\&PlusMinus;}={\&angle;\left|H\left(s\right)\right|}_{s=j({\mathrm{\&omega;}}_x\&PlusMinus;{\mathrm{\&omega;}}_{\mathrm{\&Omega;}})}.$

The quadrature error signal that the mechanical couplings effect causes among the displacement y (t) of detection mode is:

$y_q\left(t\right)=\sqrt{k_{\mathrm{yx}}/m}{X}_{0}H\cos ({\mathrm{\&omega;}}_{x}t+\mathrm{\&phi;})---\left(A10\right)$

Wherein $H={\left|H\left(s\right)\right|}_{s={\mathrm{J\&omega;}}_x},$ $\mathrm{\&phi;}=\&angle;{\left|H\left(s\right)\right|}_{x=j{\mathrm{\&omega;}}_x}$

The implication of the alphabetical parameter that relates among formula (A9), (A10) is identical with formula (A1)～(A9).

Through the angular velocity signal y that exports after the responsive demodulation of quadrature phase _I(t) be:

In the formula (A11),

is the phase shifter phase shift of the responsive demodulation of quadrature phase.Identical in other parameters and the formula (A1)～(A10).The quadrature error amplitude y of output _Q(t) be:

Because the driving mode resonance frequency of silicon micromechanical gyroscope is much larger than the bandwidth of silicon micromechanical gyroscope system, i.e. ω _Ω<<ω _xSo, can suppose ω _Ω± ω _x≈ ω _xThis moment is then by H _Ω+≈ H _Ω-≈ H, φ _Ω+≈ φ _Ω-≈ φ.

Therefore formula (A11) and formula (A12) abbreviation are described as:

When input angular velocity is zero, i.e. Ω _z(t)=0, zero of silicon micromechanical gyroscope export y partially _Zb(t) be:

This moment, the amplitude of quadrature error was output as:

The implication of the alphabetical parameter that relates among formula (A15), (A16) is identical with formula (A1)～(A14).(A15) can know by formula, and zero of silicon micromechanical gyroscope partially mainly is by the coupling stiffness coefficient k _YxAnd the difference of system's phase shift and phase shifter phase shift Decision.(the A15) is when the difference of system's phase shift and phase shifter phase shift from formula When confirming, can be from the coupling stiffness coefficient k _YxStart with, keep it and remain unchanged, thereby promote silicon micromechanical gyroscope system zero stability partially.(A16) can know from formula, the same and coupling stiffness coefficient k of the amplitude of quadrature error _YxAnd the difference of system's phase shift and phase shifter phase shift

Relevant, when term harmonization, i.e. difference

Confirm that the amplitude of quadrature error is by the coupling stiffness coefficient k _YxDecision.So the quadrature error amplitude according to input is adjusted voltage as the electrostatic stiffness that the close-loop feedback signal controlling is input to the silicon micromechanical gyroscope detecting electrode, through close loop negative feedback signal closed-loop control coupling stiffness k _YxVariable quantity can reach the lifting silicon micromechanical gyroscope system zero purpose of stability partially.

Summary of the invention

The technical matters that the present invention will solve provides a kind of zero inclined to one side stability and accuracy of detection that can significantly promote silicon micromechanical gyroscope, adjustment real-time is good, driving voltage is little, efficient is high, cost is low, power consumption is little, the easy to use zero stable partially method for improving and the device that are used for silicon micromechanical gyroscope.

In order to solve the problems of the technologies described above, the technical scheme that the present invention adopts is:

A kind of zero stable partially method for improving that is used for silicon micromechanical gyroscope, implementation step is following:

1) obtains the quadrature coupling error amplitude that silicon micromechanical gyroscope causes because of coupling stiffness in real time;

2) with said quadrature coupling error amplitude as controlled quentity controlled variable; Close-loop feedback control is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode; The change amount of the coupling stiffness of variable quantity correction silicon micromechanical gyroscope through said electrostatic stiffness adjustment voltage when environmental factor changes, thus keep the silicon micromechanical gyroscope coupling stiffness to remain unchanged, promote the zero stable partially of silicon micromechanical gyroscope.

Be used for the further improvement of the zero stable partially method for improving of silicon micromechanical gyroscope as the present invention:

The detailed step of said step 1) comprises:

1.1) obtain the detection signal and the drive signal of silicon micromechanical gyroscope output in real time;

1.2) carry out demodulation with said detection signal amplification and according to said drive signal;

1.3) with the demodulation result LPF that demodulation obtains, reject high-frequency signal and obtain the quadrature coupling error;

1.4) said quadrature coupling error is obtained quadrature coupling error amplitude through PID control.

Said step 2) detailed step comprises:

2.1) quadrature coupling error amplitude that said step 1) is obtained carries out anti-phase;

2.2) with the quadrature coupling error amplitude of anti-phase as controlled quentity controlled variable; Close-loop feedback control is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode, the change amount that the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope through said electrostatic stiffness adjustment voltage takes place because of environmental factor.

Said step 2.2) controlling the electrostatic stiffness adjustment voltage that is input to the silicon micromechanical gyroscope detecting electrode in specifically is meant: the electrostatic stiffness adjustment voltage of through type (A17) control input silicon micromechanical gyroscope detecting electrode;

VDC＝24.98-1.249*Vde5 （A17）

In the formula (A17), VDC is the electrostatic stiffness adjustment voltage of final output, and Vde5 is a quadrature coupling error amplitude.

The present invention also provides a kind of zero stable partially lifting gear that is used for silicon micromechanical gyroscope; The quadrature error amplitude acquiring unit that comprises the quadrature coupling error amplitude that is used to obtain silicon micromechanical gyroscope be used for according to the electrostatic stiffness adjustment control module of quadrature coupling error amplitude to silicon micromechanical gyroscope detecting electrode output electrostatic stiffness adjustment voltage; Said electrostatic stiffness adjustment control module is input to the quadrature coupling error amplitude of quadrature error amplitude acquiring unit output the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode as the controlled quentity controlled variable close-loop feedback control; Said electrostatic stiffness is adjusted the change amount of control module through the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of said electrostatic stiffness adjustment voltage when environmental factor changes, thereby keeps the silicon micromechanical gyroscope coupling stiffness to remain unchanged, promote the zero stability partially of silicon micromechanical gyroscope.

Be used for the further improvement of the zero stable partially lifting gear of silicon micromechanical gyroscope as the present invention:

Said quadrature error amplitude acquiring unit comprises amplifier, multiplier, wave filter and PID controller; Said amplifier input terminal links to each other with the detection signal output terminal of silicon micromechanical gyroscope; An input end of said multiplier links to each other with amplifier; Another input end of said multiplier links to each other with the drive signal output terminal of silicon micromechanical gyroscope; The output terminal of said multiplier links to each other with the PID controller through wave filter, and the output terminal of said PID controller links to each other with electrostatic stiffness adjustment control module; Said amplifier obtain the detection signal of silicon micromechanical gyroscope output in real time and amplify after export to multiplier; Detection signal after said multiplier amplifies said amplifier according to the drive signal of silicon micromechanical gyroscope output in real time carries out demodulation; Said multiplier obtains quadrature coupling error amplitude through wave filter, PID controller successively with said demodulation result, and said PID controller exports quadrature coupling error amplitude to electrostatic stiffness adjustment control module.

Said electrostatic stiffness adjustment control module comprises phase inverter and the DC-DC module that links to each other successively; Said quadrature error amplitude acquiring unit links to each other with the input end of DC-DC module through phase inverter, and the voltage output end of said DC-DC module links to each other with the detecting electrode of silicon micromechanical gyroscope; Said phase inverter is with the quadrature coupling error amplitude input DC-DC module of anti-phase; Said DC-DC module is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode according to the controlled quentity controlled variable close-loop feedback control of input, and the change amount that the coupling stiffness of said DC-DC module through the variable quantity correction silicon micromechanical gyroscope of control electrostatic stiffness adjustment voltage takes place because of environmental factor promotes the zero stable partially of silicon micromechanical gyroscope.

The electrostatic stiffness adjustment voltage of said DC-DC module through type (A17) control input silicon micromechanical gyroscope detecting electrode;

VDC＝24.98-1.249*Vde5 （A17）

In the formula (A17), VDC is the electrostatic stiffness adjustment voltage of final output, and Vde5 is a quadrature coupling error amplitude.

The zero stable partially method for improving that the present invention is used for silicon micromechanical gyroscope has following advantage: the present invention utilizes the characteristic of the quadrature coupling error signal of drive signal and detection signal with the frequency homophase; Extract quadrature error amplitude analog quantity close-loop feedback control electrostatic stiffness adjustment voltage; Adjust the variable quantity of the variable quantity closed-loop control coupling stiffness of voltage through electrostatic stiffness; The change amount that the coupling stiffness that can revise silicon micromechanical gyroscope takes place because of environmental factor, to keep system, coupled rigidity constant, thus keep zero partially output constant, promote the zero stable partially of silicon micromechanical gyroscope.The present invention allows the existence of the coupling stiffness that mismachining tolerance causes; Only control to the variable quantity of coupling stiffness; Through measuring the variation that changes the quadrature coupling error amplitude of the silicon micromechanical gyroscope that causes because of coupling stiffness; Through the variable quantity of quadrature coupling error amplitude close loop negative feedback control coupling stiffness, can effectively promote the zero stability partially of silicon micromechanical gyroscope.The present invention is as a kind of silicon micromechanical gyroscope zero stable partially method for improving of brand-new angle; Electrostatic stiffness adjustment voltage through closed-loop control input silicon micromechanical gyroscope; Can significantly promote zero inclined to one side stability and accuracy of detection of silicon micromechanical gyroscope; Improve accuracy and real-time that the silicon micromechanical gyroscope coupling stiffness is measured, have the adjustment advantage that real-time is good, driving voltage is little, efficient is high, cost is low, power consumption is little, easy to use.

The zero stable partially lifting gear that the present invention is used for silicon micromechanical gyroscope has and the above-mentioned zero stable partially method for improving corresponding techniques effect that is used for silicon micromechanical gyroscope, repeats no more at this.

Description of drawings

Fig. 1 is the structural representation of prior art silicon micromechanical gyroscope.

Fig. 2 is the principle schematic of prior art silicon micromechanical gyroscope elastic axis rotation ɑ angle.

Fig. 3 is the principle schematic of the responsive demodulation method of prior art quadrature phase.

Fig. 4 is the framed structure synoptic diagram of the embodiment of the invention.

Fig. 5 is the circuit theory synoptic diagram of amplifier in the embodiment of the invention.

Fig. 6 is the circuit theory synoptic diagram of multiplier in the embodiment of the invention.

Fig. 7 is the circuit theory synoptic diagram of embodiment of the invention median filter.

Fig. 8 is the circuit theory synoptic diagram of quadrature error amplitude acquiring unit in the embodiment of the invention.

Fig. 9 is the framed structure synoptic diagram of static adjustment rigidity control module in the embodiment of the invention.

Figure 10 is the circuit theory synoptic diagram of static adjustment rigidity control module in the embodiment of the invention.

Marginal data: 1, quadrature error amplitude acquiring unit; 11, amplifier; 12, multiplier; 13, wave filter; 14, PID controller; 2, electrostatic stiffness adjustment control module; 21, phase inverter; 22, DC-DC module; 3, demodulating unit; 4, silicon micromechanical gyroscope; 5, secondary demodulation unit.

Embodiment

As shown in Figure 4, the implementation step of zero stable partially method for improving that present embodiment is used for silicon micromechanical gyroscope is following:

1) obtains the quadrature coupling error amplitude that silicon micromechanical gyroscope causes because of coupling stiffness in real time;

2) with quadrature coupling error amplitude as controlled quentity controlled variable; Close-loop feedback control is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode; When environmental factor changes, pass through electrostatic stiffness and adjust the change amount that the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of voltage takes place because of environmental factor, thereby keep the silicon micromechanical gyroscope coupling stiffness to remain unchanged, promote the zero stable partially of silicon micromechanical gyroscope.

The existence of the coupling stiffness that present embodiment permission mismachining tolerance causes; Only control to the variable quantity of coupling stiffness; Through measuring the variation that changes the quadrature coupling error amplitude of the silicon micromechanical gyroscope that causes because of coupling stiffness; Through the variable quantity of quadrature coupling error amplitude close loop negative feedback control coupling stiffness, can effectively promote the zero stability partially of silicon micromechanical gyroscope.

In the present embodiment, the detailed step of step 1) comprises:

1.1) obtain the detection signal and the drive signal of silicon micromechanical gyroscope output in real time;

1.2) carry out demodulation with the detection signal amplification and according to drive signal;

1.3) with the demodulation result LPF that demodulation obtains, reject high-frequency signal and obtain the quadrature coupling error;

1.4) the quadrature coupling error is obtained quadrature coupling error amplitude through PID control.

In the present embodiment, step 2) detailed step comprises:

2.1) quadrature coupling error amplitude that step 1) is obtained carries out anti-phase;

2.2) with the quadrature coupling error amplitude of anti-phase as controlled quentity controlled variable; Close-loop feedback control is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode, the change amount that the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope through electrostatic stiffness adjustment voltage takes place because of environmental factor.

In the present embodiment, step 2.2) the electrostatic stiffness adjustment voltage that control is input to the silicon micromechanical gyroscope detecting electrode in specifically is meant: the electrostatic stiffness adjustment voltage of through type (A17) control input silicon micromechanical gyroscope detecting electrode;

VDC＝24.98-1.249*Vde5 （A17）

In the formula (A17), VDC is the electrostatic stiffness adjustment voltage of final output, and Vde5 is a quadrature coupling error amplitude.

As shown in Figure 4; The quadrature error amplitude acquiring unit 1 that the zero stable partially lifting gear that present embodiment is used for silicon micromechanical gyroscope comprises the quadrature coupling error amplitude that is used to obtain silicon micromechanical gyroscope be used for according to the electrostatic stiffness adjustment control module 2 of quadrature coupling error amplitude to silicon micromechanical gyroscope detecting electrode output electrostatic stiffness adjustment voltage; Electrostatic stiffness adjustment control module 2 is input to the quadrature coupling error amplitude of quadrature error amplitude acquiring unit 1 output the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode as the controlled quentity controlled variable close-loop feedback control; Electrostatic stiffness is adjusted the change amount of control module 2 through the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of electrostatic stiffness adjustment voltage when environmental factor changes, thereby keeps the silicon micromechanical gyroscope coupling stiffness to remain unchanged, promote the zero stable partially of silicon micromechanical gyroscope.Label 4 among Fig. 4 is for using the silicon micromechanical gyroscope of present embodiment; The demodulating unit 3 of silicon micromechanical gyroscope is output detection signal and drive signals respectively, and the detection signal of demodulating unit 3 outputs carries out behind the secondary demodulation sensitive angular signal as final output through secondary demodulation unit 5.Present embodiment is on the basis of existing observation and control technology; Detecting electrode through detection signal output terminal and drive signal output terminal, quadrature error amplitude acquiring unit 1, the electrostatic stiffness of silicon micromechanical gyroscope are adjusted control module 2, silicon micromechanical gyroscope links to each other successively, constitutes the close loop negative feedback loop of the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope that passes through electrostatic stiffness adjustment voltage because of the change amount of environmental factor generation.The close loop negative feedback loop is through the variable quantity of closed-loop control electrostatic stiffness adjustment voltage adjustment coupling stiffness; The change amount that the coupling stiffness that can revise silicon micromechanical gyroscope takes place because of environmental factor, to keep system, coupled rigidity constant, thereby keep zero constant, zero stability and the accuracy of detection partially that promotes silicon micromechanical gyroscope of output partially.

In the present embodiment; Quadrature error amplitude acquiring unit 1 comprises amplifier 11, multiplier 12, wave filter 13 and PID controller 14; The input end of amplifier 11 links to each other with the detection signal output terminal of silicon micromechanical gyroscope; An input end of multiplier 12 links to each other with amplifier 11; Another input end of multiplier 12 links to each other with the drive signal output terminal of silicon micromechanical gyroscope, and the output terminal of multiplier 12 links to each other with PID controller 14 through wave filter 13, and the output terminal of PID controller 14 links to each other with electrostatic stiffness adjustment control module 2; Amplifier 11 obtain the detection signal of silicon micromechanical gyroscope output in real time and amplify after export to multiplier 12; Multiplier 12 carries out demodulation according to the detection signal after drive signal pair amplifier 11 amplifications of silicon micromechanical gyroscope output in real time; Multiplier 12 obtains quadrature coupling error amplitude through wave filter 13, PID controller 14 successively with demodulation result, and PID controller 14 exports quadrature coupling error amplitude to electrostatic stiffness adjustment control module 2.

Like Fig. 5, Fig. 6, Fig. 7 and shown in Figure 8; Amplifier 11 adopts operational amplifier OP4177 to realize; No. 2 pins of OP4177 link to each other with the detection signal output terminal of isolation capacitance with a demodulating unit 3 of silicon micromechanical gyroscope through 33K resistance, and No. 1 pin links to each other with the input end of multiplier 12 as the output pin of amplifier 11.Multiplier 12 adopts AD633 to realize; No. 1 pin of AD633 links to each other with the drive signal output terminal of a demodulating unit 3 of silicon micromechanical gyroscope through 0.1uF isolation capacitance CT14; No. 7 pin links to each other as the output pin of another input pin with amplifier 11, and No. 5 pins link to each other with the input end of wave filter 13 as the output pin of multiplier 12.Wave filter 13 adopts two-stage calculation amplifier OP4177 to realize; No. 3 pins of first order OP4177 link to each other with the output terminal of multiplier 12 through 2.2K resistance, and No. 14 pins of second level OP4177 link to each other with the input end of PID controller 14 as the output pin of wave filter 13.PID controller 14 adopts operational amplifier OP4177 to realize; No. 13 pins of operational amplifier OP4177 link to each other with No. 14 pins of output terminal of wave filter 13 as input pin; No. 12 pin connects ground, and No. 14 pin links to each other as the input end of output pin with electrostatic stiffness adjustment control module 2.

Like Fig. 4 and shown in Figure 9; Electrostatic stiffness adjustment control module 2 comprises the phase inverter 21 and DC-DC module 22 that links to each other successively; Quadrature error amplitude acquiring unit 1 links to each other with the input end of DC-DC module 22 through phase inverter 21, and the voltage output end of DC-DC module 22 links to each other with the detecting electrode of silicon micromechanical gyroscope; Phase inverter 21 is with the quadrature coupling error amplitude input DC-DC module 22 of anti-phase; DC-DC module 22 is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode according to the controlled quentity controlled variable close-loop feedback control of input, and the change amount that the coupling stiffness of DC-DC module 22 through the variable quantity correction silicon micromechanical gyroscope of control electrostatic stiffness adjustment voltage takes place because of environmental factor promotes the zero stable partially of silicon micromechanical gyroscope.

In the present embodiment, the electrostatic stiffness adjustment voltage of DC-DC module 22 through types (A17) control input silicon micromechanical gyroscope detecting electrode;

VDC＝24.98-1.249*Vde5 （A17）

In the formula (A17), VDC is the electrostatic stiffness adjustment voltage of final output, and Vde5 is the quadrature coupling error amplitude of obtaining.

Shown in figure 10; Phase inverter 21 adopts operational amplifier OP4177 to realize; No. 9 pins of operational amplifier OP4177 link to each other with No. 14 output pins of output terminal of PID controller 14 as the resistance of input pin through a 36K; No. 10 pin connects with reference to 5V voltage source (Vref+5), and No. 8 pin links to each other as the input end of output pin with DC-DC module 22.DC-DC module 22 adopts super low-power consumption DC voltage conversion chip LT8410 as master chip.LT8410 is according to (A17) output VDC (being electrostatic stiffness control voltage).(A17) can know by formula; The electrostatic stiffness control voltage of DC-DC module 22 outputs and the close loop negative feedback signal of input are inversely proportional to; Total system is a feedback loop, thereby can effectively control the variable quantity of silicon micromechanical gyroscope microstructure coupling stiffness, promotes the zero stability partially of little gyro.(A15) can know by formula, and zero of silicon micromechanical gyroscope mainly receives the influence of system, coupled rigidity partially, and the stability of system, coupled rigidity has determined that zero is stable partially.(A16) can know by formula; The system, coupled rigidity quadrature coupling error amplitude with system again is relevant; Therefore present embodiment adopts the close loop negative feedback control method; Control electrostatic stiffness adjustment control module 2 outputs to the size of the electrostatic stiffness control voltage of silicon micromechanical gyroscope detecting electrode, the stability of quadrature coupling error that can self-adaption regulation system, improves the stability of system, coupled rigidity, thereby promotes the zero stable partially of silicon micromechanical gyroscope.

The job step of zero stable partially lifting gear that present embodiment is used for silicon micromechanical gyroscope is following:

B1) quadrature error amplitude acquiring unit 1 obtains the detection signal and the drive signal of a demodulating unit 3 outputs of silicon micromechanical gyroscope in real time.

B2) amplifier 11 amplifies detection signal, and the detection signal after multiplier 12 will amplify carries out demodulation according to drive signal.

B3) wave filter 13 obtains quadrature coupling error signal with the restituted signal LPF rejecting high-frequency signal that demodulation obtains.

B4) PID controller 14 obtains stable quadrature coupling error amplitude according to quadrature coupling error signal.

B5) phase inverter 21 carries out anti-phase with quadrature coupling error amplitude.

B6) phase inverter 21 is imported DC-DC module 22 with the quadrature coupling error amplitude of anti-phase as the controlled quentity controlled variable close loop negative feedback; DC-DC module 22 is according to the electrostatic stiffness adjustment voltage of close loop negative feedback and aforesaid formula (A17) control silicon micromechanical gyroscope detecting electrode, the change amount that the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope through electrostatic stiffness adjustment voltage takes place because of environmental factor.When environmental impact factor changes; The coupling stiffness of silicon micromechanical gyroscope system and quadrature error amplitude all change; DC-DC module 22 produces electrostatic stiffness adjustment voltage according to the quadrature error amplitude voltage, and electrostatic stiffness is adjusted the detecting electrode that voltage is loaded on silicon micromechanical gyroscope, thereby realizes close loop negative feedback; Revise coupling stiffness because of the variable quantity of environmental impact generation, the stability of maintenance coupling stiffness, thereby can effectively promote the zero stability partially of silicon micromechanical gyroscope.

The above only is a preferred implementation of the present invention, and protection scope of the present invention also not only is confined to the foregoing description, and all technical schemes that belongs under the thinking of the present invention all belong to protection scope of the present invention.Should be pointed out that for those skilled in the art in the some improvement and the retouching that do not break away under the principle of the invention prerequisite, these improvement and retouching also should be regarded as protection scope of the present invention.

Claims (8)

1. zero stable partially method for improving that is used for silicon micromechanical gyroscope is characterized in that implementation step is following:

1) obtains the quadrature coupling error amplitude that silicon micromechanical gyroscope causes because of coupling stiffness in real time;

2) with said quadrature coupling error amplitude as controlled quentity controlled variable; Close-loop feedback control is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode; The change amount of the coupling stiffness of variable quantity correction silicon micromechanical gyroscope through said electrostatic stiffness adjustment voltage when environmental factor changes, thus keep the silicon micromechanical gyroscope coupling stiffness to remain unchanged, promote the zero stable partially of silicon micromechanical gyroscope.

2. the zero stable partially method for improving that is used for silicon micromechanical gyroscope according to claim 1 is characterized in that the detailed step of said step 1) comprises:

1.1) obtain the detection signal and the drive signal of silicon micromechanical gyroscope output in real time;

1.2) carry out demodulation with said detection signal amplification and according to said drive signal;

1.3) with the demodulation result LPF that demodulation obtains, reject high-frequency signal and obtain the quadrature coupling error;

1.4) said quadrature coupling error is obtained quadrature coupling error amplitude through PID control.

3. the zero stable partially method for improving that is used for silicon micromechanical gyroscope according to claim 1 and 2 is characterized in that said step 2) detailed step comprise:

2.1) quadrature coupling error amplitude that said step 1) is obtained carries out anti-phase;

2.2) with the quadrature coupling error amplitude of anti-phase as controlled quentity controlled variable; Close-loop feedback control is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode, the change amount that the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope through said electrostatic stiffness adjustment voltage takes place because of environmental factor.

4. based on the described zero stable partially method for improving that is used for silicon micromechanical gyroscope of claim 3; It is characterized in that said step 2.2) in the control electrostatic stiffness adjustment voltage that is input to the silicon micromechanical gyroscope detecting electrode specifically be meant: the electrostatic stiffness adjustment voltage of through type (A17) control input silicon micromechanical gyroscope detecting electrode;

VDC＝24.98-1.249*Vde5 （A17）

In the formula (A17), VDC is the electrostatic stiffness adjustment voltage of final output, and Vde5 is a quadrature coupling error amplitude.

5. zero stable partially lifting gear that is used for silicon micromechanical gyroscope; It is characterized in that: comprise the quadrature error amplitude acquiring unit (1) of the quadrature coupling error amplitude that is used to obtain silicon micromechanical gyroscope and be used for according to the electrostatic stiffness adjustment control module (2) of quadrature coupling error amplitude to silicon micromechanical gyroscope detecting electrode output electrostatic stiffness adjustment voltage; Said electrostatic stiffness adjustment control module (2) is input to the quadrature coupling error amplitude of quadrature error amplitude acquiring unit (1) output the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode as the controlled quentity controlled variable close-loop feedback control; Said electrostatic stiffness adjustment control module (2) is through the change amount of the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of said electrostatic stiffness adjustment voltage when environmental factor changes, thereby keeps the coupling stiffness of silicon micromechanical gyroscope constant, promote the zero stable partially of silicon micromechanical gyroscope.

6. the zero stable partially lifting gear that is used for silicon micromechanical gyroscope according to claim 5; It is characterized in that: said quadrature error amplitude acquiring unit (1) comprises amplifier (11), multiplier (12), wave filter (13) and PID controller (14); The input end of said amplifier (11) links to each other with the detection signal output terminal of silicon micromechanical gyroscope; An input end of said multiplier (12) links to each other with amplifier (11); Another input end of said multiplier (12) links to each other with the drive signal output terminal of silicon micromechanical gyroscope; The output terminal of said multiplier (12) links to each other with PID controller (14) through wave filter (13), and the output terminal of said PID controller (14) links to each other with electrostatic stiffness adjustment control module (2); Said amplifier (11) obtain the detection signal of silicon micromechanical gyroscope output in real time and amplify after export to multiplier (12); Detection signal after said multiplier (12) amplifies said amplifier (11) according to the drive signal of silicon micromechanical gyroscope output in real time carries out demodulation; Said multiplier (12) obtains quadrature coupling error amplitude through wave filter (13), PID controller (14) successively with said demodulation result, and said PID controller (14) exports quadrature coupling error amplitude to electrostatic stiffness adjustment control module (2).

7. according to claim 5 or the 6 described zero stable partially lifting gears that are used for silicon micromechanical gyroscope; It is characterized in that: said electrostatic stiffness adjustment control module (2) comprises phase inverter (21) and the DC-DC module (22) that links to each other successively; Said quadrature error amplitude acquiring unit (1) links to each other with the input end of DC-DC module (22) through phase inverter (21), and the voltage output end of said DC-DC module (22) links to each other with the detecting electrode of silicon micromechanical gyroscope (4); Said phase inverter (21) is with the quadrature coupling error amplitude input DC-DC module (22) of anti-phase; Said DC-DC module (22) is input to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode according to the controlled quentity controlled variable close-loop feedback control of input, and the change amount that the coupling stiffness of said DC-DC module (22) through the variable quantity correction silicon micromechanical gyroscope of control electrostatic stiffness adjustment voltage takes place because of environmental factor promotes the zero stable partially of silicon micromechanical gyroscope.

8. the zero stable partially lifting gear that is used for silicon micromechanical gyroscope according to claim 7 is characterized in that, the electrostatic stiffness adjustment voltage of said DC-DC module (22) through type (A17) control input silicon micromechanical gyroscope detecting electrode;

VDC＝24.98-1.249*Vde5 （A17）

In the formula (A17), VDC is the electrostatic stiffness adjustment voltage of final output, and Vde5 is a quadrature coupling error amplitude.

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