CN102759365B - 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

For bias instaility method for improving and the device of silicon micromechanical gyroscope

Technical field

The present invention relates to silicon micromechanical gyroscope field, be specifically related to a kind of bias instaility method for improving for silicon micromechanical gyroscope and device.

Background technology

Micromechanical gyro is the device measuring the motion of object relative inertness Space Rotating, it is the requisite angular velocity sensitive element of inertial guidance system, the output signal of micromechanical gyro, after amplification, correction, power amplification, carries out stability contorting and Navigation Control for driving carrier or platform topworks.The microstructure of micromechanical gyro adopts body silicon or surface silicon processing technology to be made, and is coupled to responsive end carrys out detection angle speed by the vibration of drive end being utilized coriolis force effect.

As shown in Figure 1, silicon micromechanical gyroscope is generally made up of brace summer and mass, the form adopting electrostatic driving, capacitance detecting more.Silicon micromechanical gyroscope comprises two operation modes: driven-mode and sensed-mode.Mass does simple harmonic oscillation along driving shaft direction (x-axis) under the effect driving electrostatic force, is called driven-mode; When there is angular velocity signal along turning rate input direction (z-axis), the coriolis force produced by coriolis force effect makes Detection job block produce vibration in detection axis direction (y-axis), is called sensed-mode.Sensed-mode sensitization capacitance variable quantity is directly proportional to input angular velocity, and namely by measuring this voltage signal thus the information of acquisition input angular velocity after being transformed by C-V, two mode can adopt the second-order system modeling of mass-spring-damper.In Fig. 1, c _sfor damping, the c of sensed-mode _dfor damping, the k of driven-mode _sfor rigidity, the k of sensed-mode _dfor the rigidity of driven-mode.

Consider that driven-mode and sensed-mode adopt same mass, 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 formula (A1), m is the quality of mass shown in Fig. 1. $C=\left[\begin{array}{cc}{c}_{\mathrm{xx}}& c_{\mathrm{xy}}\\ c_{\mathrm{yx}}& c_{\mathrm{yy}}\end{array}\right]$ For the damping matrix of system, c _xxfor damping, the c of driven-mode _yyfor damping, the c of sensed-mode _yx, c _xyrepresent two mode cross-couplings dampings respectively; $K=\left[\begin{array}{cc}{k}_{\mathrm{xx}}& k_{\mathrm{xy}}\\ k_{\mathrm{yx}}& k_{\mathrm{yy}}\end{array}\right]$ For the stiffness matrix of system, k _xxfor rigidity, the k of driven-mode _yyfor rigidity, the k of sensed-mode _yx, k _xyrepresent two mode cross-couplings rigidity respectively; Ω _zfor the angular velocity signal of input; $F=\left[\begin{array}{c}{F}_x\\ F_y\end{array}\right]$ For system action force.

When the Z axis of silicon micromechanical gyroscope has turning rate input, sensed-mode is subject to a dynamic mechanically coupling, and driven-mode is used as simple harmonic oscillation by driving force, and the resonance frequency of simple harmonic oscillation is ω _x, then driven-mode displacement x (t) is:

x(t)＝X ₀cos(ω _xt) (A2)

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

Formula (A2) is substituted into formula (A1), definition F _y=0, then sensed-mode kinetics equation is

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

In formula (A3), right-hand member Section 1 (2mX ₀ω _xΩ _zsin (ω _xt)) coriolis force signal is represented; Right-hand member Section 2 (-X ₀ω _xc _yxsin (ω _xt)) offset error signal with coriolis force homophase is represented; Right-hand member Section 3 (-k _yxx ₀cos (ω _xt)) error signal with coriolis force signal in orthogonal is represented, i.e. orthogonal coupling error.The implication of the letter parameter related in formula (A3) is identical with formula (A1).Ignore the impact of offset error signal, only consider the impact of orthogonal coupling error.Then formula (A3) can 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 the principal element producing orthogonal coupling error, and in the middle of actual processing, foozle is mainly manifested in silicon micromechanical gyroscope brace summer non complete symmetry, thus make elastic axis and the desirable principal axis of inertia inconsistent.As shown in Figure 2.Silicon micromechanical gyroscope drives and detects elastic axis stiffness coefficient and is respectively k _xxand k _yy(generalized case k _xx> k _yy).Suppose that the error angle of actual elastic main shaft and the desirable principal axis of inertia is α, then the stiffness matrix K of system becomes K':

$K^{\′}=\left[\begin{array}{cc}\cos \mathrm{\α}& -\sin \\ \sin \mathrm{\α}& \cos \mathrm{\α}\end{array}\right]\left[\begin{array}{cc}{k}_{\mathrm{xx}}& \\ & k_{\mathrm{yy}}\end{array}\right]\left[\begin{array}{cc}\cos \mathrm{\α}& \sin \mathrm{\α}\\ -\sin \mathrm{\α}& \cos \mathrm{\α}\end{array}\right]=\left[\begin{array}{cc}{k}_{\mathrm{xx}}{\cos }^2\mathrm{\α}+k_{\mathrm{yy}}{\sin }^2\mathrm{\α}& \sin \mathrm{\α}\cos \mathrm{\α}(k_{\mathrm{xx}}-k_{\mathrm{yy}})\\ \sin \mathrm{\α}\cos \mathrm{\α}(k_{\mathrm{xx}}-k_{\mathrm{yy}})& k_{\mathrm{yy}}{\cos }^2\mathrm{\α}+k_{\mathrm{xx}}{\sin }^2\mathrm{\α}\end{array}\right]---\left(A5\right)$

Because α is very little, approximate 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:

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

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

k _xy＝k _yx＝(k _xx-k _yy)α (A7)

From formula (A4), the output of sensed-mode is made up of two parts: the orthogonal coupling error signal that the angular velocity sensitive signal that Coriolis effect causes and mechanical couplings effect cause.Both are directly proportional with displacement signal x (t) to rate signal x ' (t) of driven-mode respectively, and therefore both phase differential are 90 °, and both are separated by available orthogonal phase sensitive demodulation method.

The responsive demodulation method principle of quadrature phase as shown in Figure 3, cos (ω _cart) be the carrier signal of sensed-mode, y _it () is angular velocity signal, y _qt () is mechanical coupling error amplitude, K ₁and K ₂the gain of angular velocity signal and mechanical coupling error signal respectively.Hi-pass filter F ₀the cutoff frequency ω of (s) _h< ω _car, low-pass filter F ₁the cutoff frequency ω of (s) _x< ω _l< 2 ω _x, the cutoff frequency ω of low-pass filter F (s) _l< ω _x; The transport function of driven-mode is k _x=1/X ₀for driving the enlargement factor of loop; V _d(t)=K _x* X ₀cos (ω _xt)=cos (ω _xt); with for V _dt two-way orthogonal signal that () exports after phase shifter, for the responsive demodulation of quadrature phase.

The transfer function H (s) of sensed-mode is:

$H\left(s\right)=\frac{1}{s^2+\frac{{\mathrm{\&omega;}}_y}{Q_y}s+{\mathrm{\&omega;}}_y^2}---\left(A8\right)$

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

Suppose that the angular velocity signal inputted is Ω _z(t)=Ω cos (ω _Ωt), then the angular velocity sensitive signal y that in output displacement y (t) of sensed-mode, Coriolis effect causes _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 in displacement y (t) of sensed-mode, mechanical couplings effect causes 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 letter parameter related in formula (A9), (A10) is identical with formula (A1) ~ (A9).

The angular velocity signal y exported after the responsive demodulation of quadrature phase _i(t) be:

In formula (A11), for the phase shifter phase shift of the responsive demodulation of quadrature phase.Other parameters are identical with formula (A1) ~ (A10).The quadrature error amplitude y exported _q(t) be:

Because the driven-mode resonance frequency of silicon micromechanical gyroscope is much larger than the bandwidth of silicon micromechanical gyroscope system, i.e. ω _Ω<< ω _x, so can ω be supposed _Ω± ω _x≈ ω _x.Now 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 _zt ()=0, zero of silicon micromechanical gyroscope exports y partially _zb(t) be:

Now the amplitude of quadrature error exports and is:

The implication of the letter parameter related in formula (A15), (A16) is identical with formula (A1) ~ (A14).From formula (A15), silicon micromechanical gyroscope zero partially mainly by coupling stiffness coefficient k _yxand the difference of system phase shift and phase shifter phase shift determine.From formula, (the A15), when the difference of system phase shift and phase shifter phase shift when determining, can from coupling stiffness coefficient k _yxstart with, maintain it and remain unchanged, thus promote silicon micromechanical gyroscope system zero bias stability.From formula (A16), the same and coupling stiffness coefficient k of the amplitude of quadrature error _yxand the difference of system phase shift and phase shifter phase shift relevant, when consistent, i.e. difference determine, the amplitude of quadrature error is by coupling stiffness coefficient k _yxdetermine.So according to the quadrature error amplitude inputted as the electrostatic stiffness adjustment voltage of close-loop feedback signal control inputs to silicon micromechanical gyroscope detecting electrode, by close loop negative feedback signal closed-loop control coupling stiffness k _yxvariable quantity, can reach the object promoting silicon micromechanical gyroscope system zero bias stability.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of bias instaility and the accuracy of detection that significantly can promote silicon micromechanical gyroscope, the bias instaility method for improving for silicon micromechanical gyroscope that adjustment real-time is good, driving voltage is little, efficiency is high, cost is low, power consumption is little, easy to use and device.

In order to solve the problems of the technologies described above, the technical solution used in the present invention is:

For a bias instaility method for improving for silicon micromechanical gyroscope, implementation step is as follows:

1) the orthogonal coupling error magnitude that causes because of coupling stiffness of Real-time Obtaining silicon micromechanical gyroscope;

2) using described orthogonal coupling error magnitude as controlled quentity controlled variable, close-loop feedback control inputs is to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode, when environmental factor changes by the knots modification of the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of described electrostatic stiffness adjustment voltage, the bias instaility of silicon micromechanical gyroscope thus maintenance silicon micromechanical gyroscope coupling stiffness remains unchanged, promotes.

The further improvement of the bias instaility method for improving of silicon micromechanical gyroscope is used for as the present invention:

The detailed step of described step 1) comprises:

1.1) Real-time Obtaining silicon micromechanical gyroscope export detection signal and drive singal;

1.2) described detection signal amplified and carry out demodulation according to described drive singal;

1.3) demodulation result low-pass filtering demodulation obtained, rejects high-frequency signal and obtains orthogonal coupling error;

1.4) described orthogonal coupling error is controlled to obtain orthogonal coupling error magnitude through PID.

Described step 2) detailed step comprise:

2.1) the orthogonal coupling error magnitude described step 1) obtained carries out anti-phase;

2.2) using anti-phase orthogonal coupling error magnitude as controlled quentity controlled variable, close-loop feedback control inputs adjusts voltage to the electrostatic stiffness of silicon micromechanical gyroscope detecting electrode, the knots modification occurred because of environmental factor by the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of described electrostatic stiffness adjustment voltage.

Described step 2.2) in control inputs specifically refer to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode: the electrostatic stiffness of through type (A17) control inputs silicon micromechanical gyroscope detecting electrode adjusts voltage;

VDC＝24.98-1.249*Vde5 （A17）

In formula (A17), VDC is the final electrostatic stiffness adjustment voltage exported, and Vde5 is orthogonal coupling error magnitude.

The present invention also provides a kind of bias instaility lifting gear for silicon micromechanical gyroscope, comprise the quadrature error amplitude acquiring unit of the orthogonal coupling error magnitude for obtaining silicon micromechanical gyroscope and the electrostatic stiffness adjustment control module for exporting electrostatic stiffness adjustment voltage to silicon micromechanical gyroscope detecting electrode according to orthogonal coupling error magnitude, the orthogonal coupling error magnitude that quadrature error amplitude acquiring unit exports by described electrostatic stiffness adjustment control module is as controlled quentity controlled variable close-loop feedback control inputs to the electrostatic stiffness of silicon micromechanical gyroscope detecting electrode adjustment voltage, when environmental factor changes, described electrostatic stiffness adjustment control module is by the knots modification of the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of described electrostatic stiffness adjustment voltage, thus keep silicon micromechanical gyroscope coupling stiffness to remain unchanged, promote the bias instaility of silicon micromechanical gyroscope.

The further improvement of the bias instaility lifting gear of silicon micromechanical gyroscope is used for as the present invention:

Described quadrature error amplitude acquiring unit comprises amplifier, multiplier, wave filter and PID controller, the input end of described amplifier is connected with the detection signal output terminal of silicon micromechanical gyroscope, an input end of described multiplier is connected with amplifier, another input end of described multiplier is connected with the drive singal output terminal of silicon micromechanical gyroscope, the output terminal of described multiplier is connected with PID controller by wave filter, and output terminal and the electrostatic stiffness of described PID controller adjust control module and be connected; The detection signal that described amplifier Real-time Obtaining silicon micromechanical gyroscope exports also exports to multiplier after amplifying, the drive singal that described multiplier exports according to silicon micromechanical gyroscope in real time carries out demodulation to the detection signal after described amplifier amplification, described demodulation result is obtained orthogonal coupling error magnitude by wave filter, PID controller by described multiplier successively, and orthogonal coupling error magnitude is exported to electrostatic stiffness adjustment control module by described PID controller.

Described electrostatic stiffness adjustment control module comprises the phase inverter and DC-DC module that are connected successively, described quadrature error amplitude acquiring unit is connected with the input end of DC-DC module by phase inverter, and the voltage output end of described DC-DC module is connected with the detecting electrode of silicon micromechanical gyroscope; Described phase inverter is by anti-phase orthogonal coupling error magnitude input DC-DC module, described DC-DC module according to the electrostatic stiffness adjustment voltage of the controlled quentity controlled variable close-loop feedback control inputs of input to silicon micromechanical gyroscope detecting electrode, described DC-DC module by the coupling stiffness that controls electrostatic stiffness and adjust the variable quantity correction silicon micromechanical gyroscope of voltage because knots modification that environmental factor occurs promotes the bias instaility of silicon micromechanical gyroscope.

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

VDC＝24.98-1.249*Vde5 （A17）

In formula (A17), VDC is the final electrostatic stiffness adjustment voltage exported, and Vde5 is orthogonal coupling error magnitude.

The bias instaility method for improving that the present invention is used for silicon micromechanical gyroscope has following advantage: the present invention utilizes drive singal and the feature of the orthogonal coupling error signal in detection signal with frequency homophase, extract quadrature error amplitude analog amount close-loop feedback and control electrostatic stiffness adjustment voltage, by the variable quantity of the variable quantity closed-loop control coupling stiffness of electrostatic stiffness adjustment voltage, the knots modification that the coupling stiffness can revising silicon micromechanical gyroscope occurs because of environmental factor, maintain system, coupled rigidity constant, thus keep zero inclined output constant, promote the bias instaility of silicon micromechanical gyroscope.The existence of the coupling stiffness that the present invention allows mismachining tolerance to cause, variable quantity only for coupling stiffness controls, by measuring the change of the orthogonal coupling error magnitude changing the silicon micromechanical gyroscope caused because of coupling stiffness, controlled the variable quantity of coupling stiffness by orthogonal coupling error magnitude close loop negative feedback, effectively can promote the bias instaility of silicon micromechanical gyroscope.The present invention is as a kind of silicon micromechanical gyroscope bias instaility method for improving of brand-new angle, by the electrostatic stiffness adjustment voltage of closed-loop control input silicon micromechanical gyroscope, significantly can promote bias instaility and the accuracy of detection of silicon micromechanical gyroscope, improve accuracy and the real-time of the measurement of silicon micromechanical gyroscope coupling stiffness, there is the advantage that adjustment real-time is good, driving voltage is little, efficiency is high, cost is low, power consumption is little, easy to use.

The bias instaility lifting gear that the present invention is used for silicon micromechanical gyroscope has and the above-mentioned technique effect corresponding for the bias instaility method for improving of silicon micromechanical gyroscope, does not repeat them here.

Accompanying drawing explanation

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

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

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

Fig. 4 is the framed structure schematic diagram of the embodiment of the present invention.

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

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

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

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

Fig. 9 is the framed structure schematic diagram of electrostatic adjustment stiffness reliability unit in the embodiment of the present invention.

Figure 10 is the circuit theory schematic diagram of electrostatic adjustment stiffness reliability unit in the embodiment of the present 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, a demodulating unit; 4, silicon micromechanical gyroscope; 5, secondary demodulation unit.

Embodiment

As shown in Figure 4, the present embodiment is as follows for the implementation step of the bias instaility method for improving of silicon micromechanical gyroscope:

1) the orthogonal coupling error magnitude that causes because of coupling stiffness of Real-time Obtaining silicon micromechanical gyroscope;

2) using orthogonal coupling error magnitude as controlled quentity controlled variable, close-loop feedback control inputs is to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode, when environmental factor changes by the knots modification that the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of electrostatic stiffness adjustment voltage occurs because of environmental factor, the bias instaility of silicon micromechanical gyroscope thus maintenance silicon micromechanical gyroscope coupling stiffness remains unchanged, promotes.

The existence of the coupling stiffness that the present embodiment allows mismachining tolerance to cause, variable quantity only for coupling stiffness controls, by measuring the change of the orthogonal coupling error magnitude changing the silicon micromechanical gyroscope caused because of coupling stiffness, controlled the variable quantity of coupling stiffness by orthogonal coupling error magnitude close loop negative feedback, effectively can promote the bias instaility of silicon micromechanical gyroscope.

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

1.1) Real-time Obtaining silicon micromechanical gyroscope export detection signal and drive singal;

1.2) detection signal amplified and carry out demodulation according to drive singal;

1.3) demodulation result low-pass filtering demodulation obtained, rejects high-frequency signal and obtains orthogonal coupling error;

1.4) orthogonal coupling error is controlled to obtain orthogonal coupling error magnitude through PID.

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

2.1) orthogonal coupling error magnitude step 1) obtained carries out anti-phase;

2.2) using anti-phase orthogonal coupling error magnitude as controlled quentity controlled variable, close-loop feedback control inputs adjusts voltage to the electrostatic stiffness of silicon micromechanical gyroscope detecting electrode, the knots modification occurred because of environmental factor by the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of electrostatic stiffness adjustment voltage.

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

VDC＝24.98-1.249*Vde5 （A17）

In formula (A17), VDC is the final electrostatic stiffness adjustment voltage exported, and Vde5 is orthogonal coupling error magnitude.

As shown in Figure 4, the bias instaility lifting gear that the present embodiment is used for silicon micromechanical gyroscope comprises the quadrature error amplitude acquiring unit 1 of the orthogonal coupling error magnitude for obtaining silicon micromechanical gyroscope and the electrostatic stiffness adjustment control module 2 for exporting electrostatic stiffness adjustment voltage to silicon micromechanical gyroscope detecting electrode according to orthogonal coupling error magnitude, the orthogonal coupling error magnitude that quadrature error amplitude acquiring unit 1 exports by electrostatic stiffness adjustment control module 2 is as controlled quentity controlled variable close-loop feedback control inputs to the electrostatic stiffness of silicon micromechanical gyroscope detecting electrode adjustment voltage, when environmental factor changes, electrostatic stiffness adjustment control module 2 is by the knots modification of the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of electrostatic stiffness adjustment voltage, thus keep silicon micromechanical gyroscope coupling stiffness to remain unchanged, promote the bias instaility of silicon micromechanical gyroscope.Label 4 in Fig. 4 is the silicon micromechanical gyroscope of application the present embodiment, demodulating unit 3 output detections signal and drive singal respectively of silicon micromechanical gyroscope, the detection signal that demodulating unit 3 exports carries out the sensitive angular signal as final output after secondary demodulation by secondary demodulation unit 5.The present embodiment is on the basis of existing observation and control technology, by being connected successively by the detecting electrode of the detection signal output terminal of silicon micromechanical gyroscope with drive singal output terminal, quadrature error amplitude acquiring unit 1, electrostatic stiffness adjustment control module 2, silicon micromechanical gyroscope, form the close loop negative feedback loop of the knots modification occurred because of environmental factor by the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of electrostatic stiffness adjustment voltage.Close loop negative feedback loop is by the variable quantity of closed-loop control electrostatic stiffness adjustment Voltage Cortrol coupling stiffness, the knots modification that the coupling stiffness can revising silicon micromechanical gyroscope occurs because of environmental factor, maintenance system, coupled rigidity are constant, thus keep zero partially to export constant, that promote silicon micromechanical gyroscope bias instaility and accuracy of detection.

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 is connected with the detection signal output terminal of silicon micromechanical gyroscope, an input end of multiplier 12 is connected with amplifier 11, another input end of multiplier 12 is connected with the drive singal output terminal of silicon micromechanical gyroscope, the output terminal of multiplier 12 is connected with PID controller 14 by wave filter 13, and output terminal and the electrostatic stiffness of PID controller 14 adjust control module 2 and be connected; The detection signal that amplifier 11 Real-time Obtaining silicon micromechanical gyroscope exports also exports to multiplier 12 after amplifying, the drive singal that multiplier 12 exports according to silicon micromechanical gyroscope in real time carries out demodulation to the detection signal after amplifier 11 amplification, demodulation result is obtained orthogonal coupling error magnitude by wave filter 13, PID controller 14 by multiplier 12 successively, and orthogonal coupling error magnitude is exported to electrostatic stiffness adjustment control module 2 by PID controller 14.

As shown in Fig. 5, Fig. 6, Fig. 7 and Fig. 8, amplifier 11 adopts operational amplifier OP4177 to realize, No. 2 pins of OP4177 are connected with the detection signal output terminal of isolation capacitance with a demodulating unit 3 of silicon micromechanical gyroscope by 33K resistance, and No. 1 pin is connected 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 is connected with the drive singal output terminal of a demodulating unit 3 of silicon micromechanical gyroscope by 0.1uF isolation capacitance CT14, No. 7 pins are connected as the output pin of another input pin with amplifier 11, and No. 5 pins are connected 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 are connected by the output terminal of 2.2K resistance with multiplier 12, and No. 14 pins of second level OP4177 are connected 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 are connected with output terminal No. 14 pins of wave filter 13 as input pin, No. 12 pins connect ground, and the input end that No. 14 pins adjust control module 2 as output pin and electrostatic stiffness is connected.

As shown in figures 4 and 9, electrostatic stiffness adjustment control module 2 comprises the phase inverter 21 and DC-DC module 22 that are connected successively, quadrature error amplitude acquiring unit 1 is connected by the input end of phase inverter 21 with DC-DC module 22, and the voltage output end of DC-DC module 22 is connected with the detecting electrode of silicon micromechanical gyroscope; Phase inverter 21 is by anti-phase orthogonal coupling error magnitude input DC-DC module 22, DC-DC module 22 according to the electrostatic stiffness adjustment voltage of the controlled quentity controlled variable close-loop feedback control inputs of input to silicon micromechanical gyroscope detecting electrode, DC-DC module 22 by the coupling stiffness that controls electrostatic stiffness and adjust the variable quantity correction silicon micromechanical gyroscope of voltage because knots modification that environmental factor occurs promotes the bias instaility of silicon micromechanical gyroscope.

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

VDC＝24.98-1.249*Vde5 （A17）

In formula (A17), VDC is the final electrostatic stiffness adjustment voltage exported, and Vde5 is the orthogonal coupling error magnitude obtained.

As shown in Figure 10, phase inverter 21 adopts operational amplifier OP4177 to realize, No. 9 pins of operational amplifier OP4177 are connected with output terminal No. 14 output pins of PID controller 14 by the resistance of a 36K as input pin, No. 10 pins connect with reference to 5V voltage source (Vref+5), and No. 8 pins are connected 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 exports VDC(and electrostatic stiffness control voltage according to (A17)).From formula (A17), the close loop negative feedback signal of the electrostatic stiffness control voltage that DC-DC module 22 exports and input is inversely proportional to, whole system is feedback loop, thus effectively can control the variable quantity of silicon micromechanical gyroscope microstructure coupling stiffness, promotes the bias instaility of microthrust test.From formula (A15), zero of silicon micromechanical gyroscope is partially mainly subject to the impact of system, coupled rigidity, and the stability of system, coupled rigidity determines bias instaility.From formula (A16), system, coupled rigidity is relevant to the orthogonal coupling error magnitude of system again, therefore the present embodiment adopts close loop negative feedback control method, control the size that electrostatic stiffness adjustment control module 2 outputs to the electrostatic stiffness control voltage of silicon micromechanical gyroscope detecting electrode, can self-adaption regulation system orthogonal coupling error stability, improve the stability of system, coupled rigidity, thus promote the bias instaility of silicon micromechanical gyroscope.

The job step that the present embodiment is used for the bias instaility lifting gear of silicon micromechanical gyroscope is as follows:

B1) detection signal that exports of demodulating unit 3 of quadrature error amplitude acquiring unit 1 Real-time Obtaining silicon micromechanical gyroscope and drive singal.

B2) detection signal amplifies by amplifier 11, and the detection signal after amplification is carried out demodulation according to drive singal by multiplier 12.

B3) the restituted signal low-pass filtering that demodulation obtains by wave filter 13 is rejected high-frequency signal and is obtained orthogonal coupling error signal.

B4) PID controller 14 obtains stable orthogonal coupling error magnitude according to orthogonal coupling error signal.

B5) orthogonal coupling error magnitude carries out anti-phase by phase inverter 21.

B6) anti-phase orthogonal coupling error magnitude is inputted DC-DC module 22 as controlled quentity controlled variable close loop negative feedback by phase inverter 21, DC-DC module 22 controls the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode according to close loop negative feedback and aforesaid formula (A17), the knots modification occurred because of environmental factor by the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of electrostatic stiffness adjustment voltage.When environmental impact factor changes, coupling stiffness and the quadrature error amplitude of silicon micromechanical gyroscope system all change, DC-DC module 22 produces electrostatic stiffness adjustment voltage according to quadrature error amplitude voltage, and electrostatic stiffness is adjusted the detecting electrode of voltage-drop loading to silicon micromechanical gyroscope, thus realize close loop negative feedback, revise the variable quantity that coupling stiffness produces because of environmental impact, the stability keeping coupling stiffness, thus effectively can promote the bias instaility of silicon micromechanical gyroscope.

The above is only the preferred embodiment of the present invention, protection scope of the present invention be not only confined to above-described embodiment, and all technical schemes belonged under thinking of the present invention all belong to protection scope of the present invention.It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principles of the present invention, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (4)

1., for a bias instaility method for improving for silicon micromechanical gyroscope, it is characterized in that implementation step is as follows:

1) the orthogonal coupling error magnitude that causes because of coupling stiffness of Real-time Obtaining silicon micromechanical gyroscope;

2) using described orthogonal coupling error magnitude as controlled quentity controlled variable, close-loop feedback control inputs is to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode, when environmental factor changes by the knots modification of the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of described electrostatic stiffness adjustment voltage, the bias instaility of silicon micromechanical gyroscope thus maintenance silicon micromechanical gyroscope coupling stiffness remains unchanged, promotes;

Described step 1) detailed step comprise:

1.1) Real-time Obtaining silicon micromechanical gyroscope export detection signal and drive singal;

1.2) described detection signal amplified and carry out demodulation according to described drive singal;

1.3) demodulation result low-pass filtering demodulation obtained, rejects high-frequency signal and obtains orthogonal coupling error;

1.4) described orthogonal coupling error is controlled to obtain orthogonal coupling error magnitude through PID;

Described step 2) detailed step comprise:

2.1) by described step 1) the orthogonal coupling error magnitude that obtains carries out anti-phase;

2.2) using anti-phase orthogonal coupling error magnitude as controlled quentity controlled variable, close-loop feedback control inputs adjusts voltage to the electrostatic stiffness of silicon micromechanical gyroscope detecting electrode, the knots modification occurred because of environmental factor by the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of described electrostatic stiffness adjustment voltage.

2. the bias instaility method for improving for silicon micromechanical gyroscope according to claim 1, it is characterized in that, described step 2.2) in control inputs specifically refer to the electrostatic stiffness adjustment voltage of silicon micromechanical gyroscope detecting electrode: the electrostatic stiffness of through type (A17) control inputs silicon micromechanical gyroscope detecting electrode adjusts voltage;

VDC＝24.98-1.249*Vde5 (A17)

In formula (A17), VDC is the final electrostatic stiffness adjustment voltage exported, and Vde5 is orthogonal coupling error magnitude.

3. the bias instaility lifting gear for silicon micromechanical gyroscope, it is characterized in that: comprise the quadrature error amplitude acquiring unit (1) of the orthogonal coupling error magnitude for obtaining silicon micromechanical gyroscope and electrostatic stiffness adjustment control module (2) for exporting electrostatic stiffness adjustment voltage to silicon micromechanical gyroscope detecting electrode according to orthogonal coupling error magnitude, the orthogonal coupling error magnitude that quadrature error amplitude acquiring unit (1) exports by described electrostatic stiffness adjustment control module (2) is as controlled quentity controlled variable close-loop feedback control inputs to the electrostatic stiffness of silicon micromechanical gyroscope detecting electrode adjustment voltage, when environmental factor changes, described electrostatic stiffness adjustment control module (2) is by the knots modification of the coupling stiffness of the variable quantity correction silicon micromechanical gyroscope of described electrostatic stiffness adjustment voltage, thus keep the coupling stiffness of silicon micromechanical gyroscope constant, promote the bias instaility of silicon micromechanical gyroscope,

Described quadrature error amplitude acquiring unit (1) comprises amplifier (11), multiplier (12), wave filter (13) and PID controller (14), the input end of described amplifier (11) is connected with the detection signal output terminal of silicon micromechanical gyroscope, an input end of described multiplier (12) is connected with amplifier (11), another input end of described multiplier (12) is connected with the drive singal output terminal of silicon micromechanical gyroscope, the output terminal of described multiplier (12) is connected with PID controller (14) by wave filter (13), output terminal and the electrostatic stiffness of described PID controller (14) adjust control module (2) and are connected, the detection signal that described amplifier (11) Real-time Obtaining silicon micromechanical gyroscope exports also exports to multiplier (12) after amplifying, the drive singal that described multiplier (12) exports according to silicon micromechanical gyroscope in real time carries out demodulation to the detection signal after described amplifier (11) amplification, described demodulation result is passed through wave filter (13) by described multiplier (12) successively, PID controller (14) obtains orthogonal coupling error magnitude, orthogonal coupling error magnitude is exported to electrostatic stiffness adjustment control module (2) by described PID controller (14),

Described electrostatic stiffness adjustment control module (2) comprises the phase inverter (21) and DC-DC module (22) that are connected successively, described quadrature error amplitude acquiring unit (1) is connected by the input end of phase inverter (21) with DC-DC module (22), and the voltage output end of described DC-DC module (22) is connected with the detecting electrode of silicon micromechanical gyroscope (4); Described phase inverter (21) is by anti-phase orthogonal coupling error magnitude input DC-DC module (22), described DC-DC module (22) according to the electrostatic stiffness adjustment voltage of the controlled quentity controlled variable close-loop feedback control inputs of input to silicon micromechanical gyroscope detecting electrode, described DC-DC module (22) by the coupling stiffness that controls electrostatic stiffness and adjust the variable quantity correction silicon micromechanical gyroscope of voltage because knots modification that environmental factor occurs promotes the bias instaility of silicon micromechanical gyroscope.

4. the bias instaility lifting gear for silicon micromechanical gyroscope according to claim 3, it is characterized in that, the electrostatic stiffness adjustment voltage of described DC-DC module (22) through type (A17) control inputs silicon micromechanical gyroscope detecting electrode;

VDC＝24.98-1.249*Vde5 (A17)

In formula (A17), VDC is the final electrostatic stiffness adjustment voltage exported, and Vde5 is orthogonal coupling error magnitude.