CN104535057A - Silicon micro mechanical vibrating gyroscope and orthoronal error rigidity correction method - Google Patents

Abstract

The invention discloses a silicon micro mechanical vibrating gyroscope and an orthoronal error rigidity correction method. The method comprises the following steps: driving a closed loop to excite a driving mode to enable the driving mode to vibrate on a resonant frequency point thereof at a fixed amplitude; extracting a signal in a detection channel, demodulating a driving displacement signal to obtain an orthoronal signal amplitude, comparing the orthoronal signal amplitude with a reference signal, and sending a comparative result into an orthoronal correction controller; outputting a controller output signal to an orthoronal rigidity correction broach in a gyroscope structure via a voltage regulating module, and generating static negative rigidity to correct coupling rigidity generating an orthoronal error. The controller in the invention can automatically adjust the controlled quantity according to different orthoronal coupling rigidity of the target gyroscope structure to completely eliminate the orthoronal coupling rigidity, so as to greatly reduce the influence of a processing error on the performance of the gyroscope. The method disclosed by the invention has the advantages of small volume, easy implementation, high reliability, good temperature performance, capability of being integrated with the gyroscope structure, etc.

Description

A kind of silicon micro mechanical linearly coupled formula gyro and the bearing calibration of quadrature error rigidity thereof

Technical field

The present invention relates to silicon micromechanical gyroscope field, be specifically related to a kind of silicon micro mechanical linearly coupled formula gyro and the bearing calibration of quadrature error rigidity thereof.

Background technology

Silicon micromechanical gyroscope is one MEMS (Micro-Electro-Mechanical System, MEMS (micro electro mechanical system)) the inertia measurement sensor that processes of technology, it adopts Coriolis effect principle to measure carrier angular rate information, has that volume is little, low in energy consumption, lightweight, cost is low, overload-resistant characteristic strong, is easy to integrated and the advantage such as batch production.Application is had at present, such as: inertial navigation, automotive safety, Industry Control, consumer electronics etc. in a lot of field.It is born at first at the end of the eighties in last century, along with the development of processing technology and observation and control technology, the precision of silicon micromechanical gyroscope also improves gradually, within silicon micromechanical gyroscope degree of precision can reach 1 °/h (bias instaility) in the world at present, can meet the gyrostatic accuracy requirement of Tactics-level.Silicon micro mechanical linearly coupled formula gyro is as the one of silicon micromechanical gyroscope, obtain the high praise of each scientific research institution and company in recent years, compare and the silicon micromechanical gyroscope of other working methods (angular oscillation formula, rotator type etc.), it is simple that linearly coupled formula gyroscope structure has processing structure, and detection signal linearly spends the advantages such as good.At present, the silicon micromechanical gyroscope major part that the precision of international mainstream is higher all have employed linearly coupled structure.

Fig. 1 is typical silicon micromechanical gyroscope composition structural representation, and in desirable gyroscope structure, the kinetic equation that there is gyrosystem is:

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

In formula (A1), x is driven-mode displacement; c _xx, c _yy, k _xx, k _yybe respectively equivalent damping and the equivalent stiffness of driving and sensed-mode; F _dx=F _dsin (ω _dt) driving force suffered by driving axial structure; m _xand m _ybe respectively driving and detection axis to structural equivalents quality; Ω _zfor input angle speed; Y is that detection axis is to displacement structure; m _yfor brother's formula quality; In order to ensure that driven-mode obtains maximum vibration amplitude, there is ω _d=ω _x.And in actual application, due to the error produced in process, cause containing in gyroscope structure coupling stiffness, the undesirable factor such as Coupling Damping, then add undesirable because have in formula (A1):

$\left[\begin{array}{c}{m}_x\stackrel{\·\·}{x}\\ m_y\stackrel{\·\·}{y}\end{array}\right]+\left[\begin{array}{cc}{c}_{\mathrm{xx}}& c_{\mathrm{xy}}\\ c_{\mathrm{yx}}+2m_c{\mathrm{\Ω}}_z& c_{\mathrm{yy}}\end{array}\right]\left[\begin{array}{c}\stackrel{\·}{x}\\ \stackrel{\·}{y}\end{array}\right]+\left[\begin{array}{cc}{k}_{\mathrm{xx}}& k_{\mathrm{xy}}\\ k_{\mathrm{yx}}& k_{\mathrm{yy}}\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]=\left[\begin{array}{c}{F}_{\mathrm{dx}}\\ 0\end{array}\right]---\left(A2\right)$

In formula (A2), c _xy, k _xy, c _yx, k _yxbe respectively Coupling Damping and coupling stiffness that driven-mode is coupled to sensed-mode, sensed-mode is coupled to Coupling Damping and the coupling stiffness of driven-mode.Under normal circumstances, gyroscope structure encapsulation all adopts vacuum form, so Coupling Damping c in formula (A2) _xyand c _yxxiang Jun is very little.And the impact of coupling stiffness is very large by contrast, when inputting without angular speed, the equivalent inpnt angular velocity that coupling stiffness produces is tens of even hundreds of times of brother's formula in-phase signal, and structures most in Practical Project process all exists quadrature error.Producing cause due to orthogonal coupling stiffness is process the elastic axis direction obtained to there is angle β with design major axes orientation _qx, then have:

$\left[\begin{array}{cc}{k}_{\mathrm{xx}}& k_{\mathrm{xy}}\\ k_{\mathrm{yx}}& k_{\mathrm{yy}}\end{array}\right]\left[\begin{array}{cc}{k}_x{\cos }^2{\mathrm{\β}}_Q+k_y{\sin }^2{\mathrm{\β}}_Q& k_x\sin {\mathrm{\β}}_Q\cos {\mathrm{\β}}_Q-k_y\cos {\mathrm{\β}}_Q\sin {\mathrm{\β}}_Q\\ k_x\sin {\mathrm{\β}}_Q\cos {\mathrm{\β}}_Q-k_y\sin {\mathrm{\β}}_Q\cos {\mathrm{\β}}_Q& k_{x}s{\mathrm{in}}^2{\mathrm{\β}}_Q+k_y{\cos }^2{\mathrm{\β}}_Q\end{array}\right]---\left(A3\right)$

In formula (A3), k _xand k _ybe respectively the design rigidity of driven-mode and sensed-mode.Compare above formula further known:

$k_{\mathrm{xy}}=k_{\mathrm{yx}}=\frac{k_x-k_y}{2}\sin 2{\mathrm{\β}}_Q---\left(A4\right)$

Known k from formula (A4) _yxand k _xyequal.

Extract brother's formula signal in current sense channel and mostly adopt phase demodulation method, the method can introduce certain demodulation phase angle error due to reasons such as circuit components parameter matching errors in implementation process, to such an extent as to partial orthogonality signal is extracted as brother's formula signal by mistake then affects gyro performance.Therefore, fundamentally eliminating the coupling stiffness producing quadrature error is reduce quadrature error to gyro performance impact, the effective ways improving gyro static properties.

Summary of the invention

Goal of the invention: for solving problems of the prior art, the invention provides the good silicon micro mechanical linearly coupled formula gyro of a kind of static properties and the bearing calibration of quadrature error rigidity thereof, reduce the impact of gyroscope structure by mismachining tolerance, to improve gyro performance, realize automatically to carry out quadrature alignment to different gyro individualities in larger correcting range.

Technical scheme: in order to better realize above-mentioned purpose, the invention provides a kind of silicon micro mechanical linearly coupled formula gyro, comprises the encapsulation of gyroscope structure, gyro telemetry circuit and gyro, particularly:

Described gyroscope structure comprises driving axial structure, detects axial arrangement, coupling stiffness module and quadrature alignment negative stiffness generation structure;

Described driving axial structure comprises and drives incentive structure, drives quality and drive displacement to extract structure, described driving axial structure for ensureing the stable oscillation of brother's formula quality at driving direction, for the generation of Ge Shili provides necessary condition; Wherein, described driving incentive structure is used for external voltage to be converted into electrostatic force, and described driving incentive structure comprises driving fixed fingers and driving activity comb; Described driving quality comprises driver framework and first brother's formula quality; Described driver framework is for connecting driving activity comb, driven-mode brace summer and Ge Shi quality, described driving activity comb dispersion is arranged in electrostatic force conversion efficiency driver framework improving unit area for increasing capacity area, described driven-mode brace summer is for connecting anchor point and driver framework and playing a supportive role, the displacement that driver framework produces is XM, and described brother's formula quality is for generation of Coriolis effect; Described drive displacement extraction structure is used for driver framework displacement XM being converted to driving capacitance signal XV and exports, and described drive displacement extraction structure comprises driving and detects fixed fingers and drive detected activity comb;

Described detection axial arrangement is extracted structure by Detection job and detection displacement and is formed, for extracting the sensed-mode displacement produced by Ge Shili;

Described coupling stiffness module is coupled to by driven-mode the coupling stiffness that the coupling stiffness of sensed-mode and sensed-mode be coupled to driven-mode and forms, and belongs to the non-ideal factor in Gyroscope Design process, is produced by mismachining tolerance;

Described quadrature alignment negative stiffness produces mechanism and comprises four groups of quadrature alignment negative stiffnesses generation comb, and described quadrature alignment negative stiffness produces the central frame both sides crossed-symmetrical arrangement of comb along brother's formula quality, for generation of electrostatic negative stiffness to offset coupling stiffness.

Described gyro telemetry circuit comprises driving closed loop, measure loop and quadrature alignment closed loop; Described driving closed loop is for ensureing that described driving axial structure is along the permanent amplitude vibrations of driving direction and vibration frequency is driven-mode natural resonance frequency; Described measure loop is used for a Detection capacitance variable quantity YV part being adjusted to YSE and exports, and another part is to drive pumping signal XS for benchmark demodulation and to export as gyro after filtering.

Concrete, described measure loop comprises prime and amplifies interface, secondary amplifier, brother's formula detuner and low-pass filter, and wherein, described prime is amplified interface and is used for Detection capacitance variable quantity YV be converted into voltage signal and tentatively amplify; Prime is amplified interface output signal and is amplified further by described secondary amplifier, and outputs signal YSE; Described brother's formula detuner obtains Ge Shi signal and two frequency-doubled signals to drive pumping signal XS for benchmark demodulation YSE; Described low-pass filter comprises the first low-pass filter and the second wave filter, wherein, first wave filter is used for two frequency-doubled signals of filtering detuner output to obtain pure Ge Shi signal amplitude, and the second low-pass filter finally exports as gyroscope for exporting low-pass filtering.

Described coupling stiffness module comprises the coupling stiffness k that driven-mode is coupled to sensed-mode _yxthe coupling stiffness k of driven-mode is coupled to sensed-mode _xy, wherein, described k _yxdriver framework displacement XM can be converted to bonding force FXQ is applied on Detection job; Described k _xydetection block chord position can be moved YM to be converted to bonding force FYQ and to be applied to driving qualitatively.

Described quadrature alignment negative stiffness produces comb and comprises the first fixed fingers, the second fixed fingers, the 3rd fixed fingers, the 4th fixed fingers and Ge Shi quality, wherein, conducting between first fixed fingers and the second fixed fingers, conducting between the 3rd fixed fingers and the 4th fixed fingers; Described quadrature alignment negative stiffness produces comb and adopts unequal-interval design to produce electrostatic negative stiffness; Described quadrature alignment negative stiffness produces sensed-mode is coupled in mechanism coupling stiffness k at correction driven-mode _yxwhile recoverable sensed-mode be coupled to the coupling stiffness k of driven-mode _xy.

Described quadrature alignment closed loop comprises drive displacement amplifier, quadrature demodulator, orthogonal low-pass filter, comparer, quadrature alignment benchmark, quadrature alignment controller and chromacoder, wherein, XV amplifies, to meet the amplitude demand of demodulation reference signal by described drive displacement amplifier under the prerequisite not changing drive displacement XV; Orthogonal signal in the output signal of amplifier secondary in sense channel are extracted by described quadrature demodulator, produce two frequency-doubled signals and quadrature error amplitude signal; Two frequency-doubled signals filter by described orthogonal low-pass filter, only retain quadrature amplitude signal; Quadrature amplitude signal and described quadrature alignment benchmark compare by described comparer, produce comparative result; Described quadrature alignment controller produces control signal according to described comparative result; Described chromacoder comprises flow directing device, phase inverter, the first impact damper and the second impact damper, delivers to quadrature alignment negative stiffness generation mechanism for generation QS signal after control signal conversion being delivered to quadrature alignment negative stiffness generation mechanism by producing QS signal after control signal conversion.

Present invention further proposes the bearing calibration of a kind of silicon micro mechanical linearly coupled formula gyroscope quadrature error rigidity, comprise the steps:

(1) orthogonal signal amplitude in Real-time Obtaining sense channel;

(2) using described for step (1) orthogonal signal amplitude as controlled quentity controlled variable, obtain corresponding quadrature alignment control signal by comparing itself and reference signal relation;

(3) described for step (2) quadrature alignment control signal changed, send into gyroscope structure, and quadrature alignment negative stiffness wherein produces mechanism and coordinates and produce electrostatic negative stiffness, described electrostatic negative stiffness can balanced quadrature coupling stiffness; Thus, described quadrature alignment negative stiffness produces mechanism and can eliminate the coupling stiffness k that driven-mode is coupled to sensed-mode simultaneously _yxthe coupling stiffness k of driven-mode is coupled to sensed-mode _xy.

Ultimate principle is by driving closed loop excitation driven-mode, making driven-mode vibrate on its resonant frequency point with fixed amplitude; Orthogonal signal amplitude is obtained through drive displacement signal (orthogonal with Ge Shi signal phase) demodulation extract signal in sense channel after; Comparative result is sent into quadrature alignment controller with reference signal by orthogonal signal amplitude more afterwards; The orthogonal rigidity that controller output signal exports in gyroscope structure through voltage regulator module corrects comb, and produces electrostatic negative stiffness to correct the coupling stiffness producing quadrature error.

Particularly, the concrete steps of step (1) are:

Real-time Obtaining drive displacement is extracted the output signal XV of structure and is detected the output signal YV that structure is extracted in displacement, and described drive displacement signal should in the same homophase frequently of driver framework displacement;

Output signal XV amplitude drive displacement being extracted structure carries out adjustment makes its amplitude be suitable as demodulation benchmark, obtains XSE, its frequency and phase invariant in described processing procedure;

Extract the output signal YV amplitude of structure and carry out adjustment by detecting displacement that its amplitude is applicable to is demodulated, obtain YSE, its frequency and phase invariant in described processing procedure;

Using XSE as benchmark demodulation YSE;

By the high-frequency signal of above-mentioned demodulation result after low-pass filter filtering demodulation, then obtain orthogonal signal amplitude.

The concrete steps of step (2) are:

The orthogonal signal amplitude described step (1) obtained compares with quadrature alignment benchmark and judges;

Above-mentioned judged result is sent into quadrature alignment controller, obtains Quadrature control signals further;

Described Quadrature control signals is inputed to chromacoder, with obtain quadrature alignment negative stiffness produce mechanism have quadrature alignment control signal.

The concrete steps of step (3) are:

Obtain new coupling stiffness after the electrostatic negative stiffness produced superposes with the original orthogonal coupling stiffness of structure, then produce new quadrature error signal;

According to the result of described step (1) and step (2), readjust quadrature alignment control signal, finally make quadrature signal amplitude equal with quadrature alignment benchmark;

Above-mentioned middle quadrature alignment benchmark is set to 0, then after system stability, quadrature alignment negative stiffness can eliminate orthogonal coupling stiffness completely.

Beneficial effect: the present invention is used for silicon micro mechanical linearly coupled formula gyroscope quadrature error rigidity and corrects, and can effectively reduce the quadrature error caused due to mismachining tolerance in gyroscope structure, compared with prior art, it has following advantage:

(1) the present invention utilizes the feature that drive displacement signal is identical with orthogonal signal frequency equal phase, quadrature signal amplitude is extracted based on phase demodulation method, adopt quadrature alignment closed loop control method, offset structure Coupling rigidity with electrostatic negative stiffness, significantly can reduce driven-mode simultaneously and be coupled to the coupling stiffness that the coupling stiffness of sensed-mode and sensed-mode are coupled to driven-mode;

(2), after adopting method of the present invention, silicon micromechanical gyroscope performance can significantly improve;

(3) the present invention has the advantages such as real-time is good, efficiency is high, cost is low, volume is little, power consumption is little, easy to use, automatically can carry out quadrature alignment to different gyro individualities simultaneously in larger correcting range, be applicable to very much the through engineering approaches batch production of gyro;

(4) the present invention is directed to the actual conditions that the individual orthogonal coupling stiffness of different gyro is different, propose quadrature alignment automatic control system, this system can carry out automatic calibration according to different orthogonal coupling stiffness in correcting range, is of very high actual application value in gyro through engineering approaches is produced.

Accompanying drawing explanation

Fig. 1 is gyroscope structure overall schematic of the present invention;

Fig. 2 is gyroscope structure and telemetry circuit connection diagram;

Fig. 3 is structure Coupling stiffness schematic diagram;

Fig. 4 is that quadrature alignment negative stiffness produces structural scheme of mechanism;

Fig. 5 is for detecting open loop framed structure schematic diagram;

Fig. 6 is quadrature alignment closed loop framed structure schematic diagram;

Fig. 7 is chromacoder structural representation.

Embodiment

Below in conjunction with the drawings and specific embodiments, illustrate the method for the invention further, these embodiments should be understood only be not used in for illustration of the present invention and limit the scope of the invention, after reading the present invention, the amendment of those skilled in the art to the various equivalent form of value of the present invention all falls within the application's claims limited range.

As shown in Figure 1, a kind of silicon micro mechanical linearly coupled formula gyro, comprises gyroscope structure 1, gyro telemetry circuit 2 and gyro encapsulation 3, for correcting the quadrature error of silicon micro mechanical linearly coupled formula gyro.Gyroscope structure 1 by driving axial structure 11, detect axial arrangement 12, coupling stiffness module 13 and quadrature alignment negative stiffness and produce mechanism 14 and form, as shown in Figure 2.

Driving axial structure 11 comprises driving incentive structure 111, drives quality 112 and drive displacement to extract structure 113, and driving axial structure 11 is for ensureing the stable oscillation of brother's formula quality at driving direction.Wherein, drive incentive structure 111 for external voltage is converted into electrostatic force, it comprises driving fixed fingers and driving activity comb; Quality 112 is driven to comprise driver framework and Ge Shi quality; Described driver framework is for connecting driving activity comb, driven-mode brace summer and Ge Shi quality, the dispersion of driving activity comb is arranged in electrostatic force conversion efficiency driver framework improving unit area for increasing capacity area, driven-mode brace summer is for connecting anchor point and driver framework and playing a supportive role, the displacement that driver framework produces is XM, and described brother's formula quality is for generation of Coriolis effect; Drive displacement is extracted structure 113 and is driven capacitance signal XV to export for being converted to by driver framework displacement XM, and drive displacement extraction structure 113 comprises driving and detects fixed fingers and drive detected activity comb.

Detect axial arrangement 12 to be made up of, for extracting the sensed-mode displacement produced by Ge Shili Detection job 121 and detection displacement extraction structure 122.

Coupling stiffness module 13 is coupled to by driven-mode the coupling stiffness 132 that the coupling stiffness 131 of sensed-mode and sensed-mode be coupled to driven-mode and forms, as shown in Figure 3.Wherein, described k _yxdriver framework displacement XM can be converted to bonding force FXQ by 131 to be applied on Detection job 121; Described k _xydetection block chord position can be moved YM by 132 to be converted to bonding force FYQ and to be applied to and to drive in quality 121.

Quadrature alignment negative stiffness produces mechanism 14 and comprises four groups of quadrature alignment negative stiffnesses generation comb, and quadrature alignment negative stiffness produces the central frame both sides crossed-symmetrical arrangement of comb along brother's formula quality, for generation of electrostatic negative stiffness to offset coupling stiffness.

Gyro telemetry circuit 2 comprises driving closed loop 21, measure loop 22 and quadrature alignment closed loop 23; Drive closed loop 21 for ensureing that described driving axial structure 11 is along the permanent amplitude vibrations of driving direction and vibration frequency is driven-mode natural resonance frequency; Measure loop 22 exports for a Detection capacitance variable quantity YV part being adjusted to YSE, and another part is to drive pumping signal XS for benchmark demodulation and to export as gyro after filtering.

Wherein, measure loop 22 comprises prime and amplifies interface 221, secondary amplifier 222, brother's formula detuner 223 and low-pass filter, and wherein, prime amplifies interface 221 for Detection capacitance variable quantity YV is converted into voltage signal and tentatively amplifies; Prime is amplified interface 221 and is outputed signal further amplification by secondary amplifier 222, and outputs signal YSE; Described brother's formula detuner 223 obtains Ge Shi signal and two frequency-doubled signals to drive pumping signal XS for benchmark demodulation YSE; Low-pass filter comprises the first low-pass filter 224 and the second wave filter 225, wherein, two frequency-doubled signals that first wave filter 224 exports for filtering detuner are to obtain pure Ge Shi signal amplitude, second low-pass filter 225 finally exports as gyroscope for exporting low-pass filtering, as shown in Figure 5.

As shown in Figure 4, quadrature alignment negative stiffness produces comb and comprises the first fixed fingers 141, second fixed fingers 142, the 3rd fixed fingers 143, the 4th fixed fingers 144 and Ge Shi quality, wherein, conducting between first fixed fingers (141) and the second fixed fingers (142), conducting between the 3rd fixed fingers (143) and the 4th fixed fingers (144); Described quadrature alignment negative stiffness produces comb and adopts unequal-interval design to produce electrostatic negative stiffness; Described quadrature alignment negative stiffness produces sensed-mode is coupled in mechanism 14 coupling stiffness k at correction driven-mode _yxwhile 131, recoverable sensed-mode is coupled to the coupling stiffness k of driven-mode _xy132.

As shown in Figure 6, quadrature alignment closed loop 23 comprises drive displacement amplifier 231, quadrature demodulator 232, orthogonal low-pass filter 233, comparer 234, quadrature alignment benchmark 235, quadrature alignment controller 236 and chromacoder 237, wherein, XV amplifies, to meet the amplitude demand of demodulation reference signal by drive displacement amplifier 231 under the prerequisite not changing drive displacement XV; Orthogonal signal in the output signal of amplifier 222 secondary in sense channel are extracted by quadrature demodulator 232, produce two frequency-doubled signals and quadrature error amplitude signal; Two frequency-doubled signals filter by orthogonal low-pass filter 233, only retain quadrature amplitude signal; Quadrature amplitude signal and quadrature alignment benchmark 235 compare by comparer 234, produce comparative result; Quadrature alignment controller 236 produces control signal according to described comparative result; Chromacoder 237 comprises flow directing device 2371, phase inverter 2372, first impact damper 2373 and the second impact damper 2374, and for delivering to quadrature alignment negative stiffness generation mechanism 14 by producing QS signal after control signal conversion, it outputs signal as QS contains V _qkl1and V _qkl2.

Mechanism 14 is produced for quadrature alignment negative stiffness, as shown in Figure 4, its fixed fingers plate 141,8 parallel plate capacitors formed between 142,143,144 and brother's formula quality, when mass has displacement x and y to driving shaft and detection axis direction, then above-mentioned electric capacity can be expressed with matrix form:

$\left[\begin{array}{cccc}{C}_{\mathrm{ql}1s}& C_{\mathrm{ql}2s}& C_{\mathrm{ql}3s}& C_{\mathrm{ql}4s}\\ C_{\mathrm{ql}1x}& C_{\mathrm{ql}2x}& C_{\mathrm{ql}3x}& C_{\mathrm{ql}4x}\end{array}\right]=\left[\begin{array}{cc}\frac{1}{\mathrm{\λ}{y}_{q0}-y}& \frac{1}{y_{q0}-y}\\ \frac{1}{y_{q0}+y}& \frac{1}{\mathrm{\λ}{y}_{q0}+y}\end{array}\right]\left[\begin{array}{cccc}{x}_{q0}-x& 0& 0& x_{q0}+x\\ 0& x_{q0}+x& x_{q0}-x& 0\end{array}\right]---\left(A5\right)$

In formula (A5), C _ql1s, C _ql2s, C _ql3s, C _ql4sbe respectively the upper plate electric capacity that the first fixed fingers 141, second fixed fingers 142, the 3rd fixed fingers 143 and the 4th fixed fingers 144 produce with brother's formula quality; C _ql1x, C _ql2x, C _ql3x, C _ql4xbe respectively the lower plate electric capacity that the first fixed fingers 141, second fixed fingers 142, the 3rd fixed fingers 143, the 4th fixed fingers 144 and brother's formula quality produce; Comb lap length is in the x-direction x _q0; Comb long spacing is λ y _q0; Short spacing is y _q0; H is comb thickness; ε ₀for permittivity of vacuum.By carrying out the analysis of parallel plate capacitor electrostatic force to above-mentioned electric capacity, equation below can be obtained:

$\begin{array}{c}\left[\begin{array}{cccc}{F}_{x{C}_{\mathrm{ql}1s}}& F_{x{C}_{\mathrm{ql}2s}}& F_{x{C}_{\mathrm{ql}3s}}& F_{x{C}_{\mathrm{ql}4s}}\\ F_{x{C}_{\mathrm{ql}1x}}& F_{x{C}_{\mathrm{ql}2x}}& F_{x{C}_{\mathrm{ql}3x}}& F_{x{C}_{\mathrm{ql}4x}}\end{array}\right]=\frac{1}{2}\left[\begin{array}{cccc}\frac{\∂C_{\mathrm{ql}1s}}{\∂x}& \frac{\∂C_{\mathrm{ql}2s}}{\∂x}& \frac{\∂C_{\mathrm{ql}3s}}{\∂x}& \frac{\∂C_{\mathrm{ql}4s}}{\∂x}\\ \frac{\∂C_{\mathrm{ql}1x}}{\∂x}& \frac{\∂C_{\mathrm{ql}2x}}{\∂x}& \frac{\∂C_{\mathrm{ql}3x}}{\∂x}& \frac{\∂C_{\mathrm{ql}4x}}{\∂x}\end{array}\right]V_{\mathrm{qkl}}^2\\ =\frac{{\mathrm{\ϵ}}_{0}h}{2}\left[\begin{array}{cc}\frac{1}{\mathrm{\λ}{y}_{q0}-y}& \frac{1}{y_{q0}-y}\\ \frac{1}{y_{q0}+y}& \frac{1}{\mathrm{\λ}{y}_{q0}+y}\end{array}\right]\left[\begin{array}{cccc}-V_{\mathrm{qkl}1}^2& 0& 0& V_{\mathrm{qkl}2}^2\\ 0& V_{\mathrm{qkl}1}^2& -V_{\mathrm{qkl}2}^2& 0\end{array}\right]\end{array}---\left(A6\right)$

$\begin{array}{c}\left[\begin{array}{cccc}{F}_{x{C}_{\mathrm{ql}1s}}& F_{x{C}_{\mathrm{ql}2s}}& F_{x{C}_{\mathrm{ql}3s}}& F_{x{C}_{\mathrm{ql}4s}}\\ F_{x{C}_{\mathrm{ql}1x}}& F_{x{C}_{\mathrm{ql}2x}}& F_{x{C}_{\mathrm{ql}3x}}& F_{x{C}_{\mathrm{ql}4x}}\end{array}\right]=\frac{1}{2}\left[\begin{array}{cccc}\frac{\∂C_{\mathrm{ql}1s}}{\∂x}& \frac{\∂C_{\mathrm{ql}2s}}{\∂x}& \frac{\∂C_{\mathrm{ql}3s}}{\∂x}& \frac{\∂C_{\mathrm{ql}4s}}{\∂x}\\ \frac{\∂C_{\mathrm{ql}1x}}{\∂x}& \frac{\∂C_{\mathrm{ql}2x}}{\∂x}& \frac{\∂C_{\mathrm{ql}3x}}{\∂x}& \frac{\∂C_{\mathrm{ql}4x}}{\∂x}\end{array}\right]\\ =\frac{{\mathrm{\ϵ}}_{0}h}{2}\left[\begin{array}{cc}\frac{1}{\mathrm{\λ}{y}_{q0}-y}& \frac{1}{y_{q0}-y}\\ \frac{1}{y_{q0}+y}& \frac{1}{\mathrm{\λ}{y}_{q0}+y}\end{array}\right]\left[\begin{array}{cccc}-V_{\mathrm{qkl}1}^2& 0& 0& V_{\mathrm{qkl}2}^2\\ 0& V_{\mathrm{qkl}1}^2& -V_{\mathrm{qkl}2}^2& 0\end{array}\right]\end{array}---\left(A6\right)$

V in formula (A6) _qkl1and V _qkl2be respectively the voltage that fixed fingers 141,142 and 143,144 applies.What formula (A6) described is each electric capacity in the direction of the x axis stressed, what formula (A7) described is each electric capacity in the y-axis direction stressed.Get respectively above-mentioned two matrix all elements and, then this value is making a concerted effort on a direction, considers and corrects comb number n _q, then on x and y-axis direction, stressed sum has:

$\begin{array}{c}{F}_{x{C}_{\mathrm{ql}}}=n_q\underset{i=1}{\overset{4}{\mathrm{\Σ}}}(F_{x{C}_{\mathrm{qlis}}}+F_{x{C}_{\mathrm{qlix}}})=\\ \frac{{\mathrm{\ϵ}}_{0}h{n}_q(V_{\mathrm{qkl}2}^2-2V)}{2}(\frac{1}{\mathrm{\λ}{y}_{q0}-y}-\frac{1}{y_{q0}-y}+\frac{1}{y_{q0}+y}-\frac{1}{\mathrm{\λ}{y}_{q0}+y})\end{array}---\left(A8\right)$

$\begin{array}{c}{F}_{y{C}_{\mathrm{ql}}}=n_q\underset{i=1}{\overset{4}{\mathrm{\Σ}}}(F_{y{C}_{\mathrm{qlis}}}+F_{y{C}_{\mathrm{qlix}}})\\ =\frac{{\mathrm{\ϵ}}_{0}h{n}_q}{2}(\frac{(x_{q0}+x)V_{\mathrm{qkl}2}^2+(x_{q0}-x)V_{\mathrm{qkl}1}^2}{{(\mathrm{\λ}{y}_{q0}-y)}^2}+\frac{(x_{q0}-x)V_{\mathrm{qkl}2}^2+(x_{q0}+x)V_{\mathrm{qkl}1}^2}{{(y_{q0}-y)}^2}\\ -\frac{(x_{q0}+x)V_{\mathrm{qkl}2}^2+(x_{q0}-x)V_{\mathrm{qkl}1}^2}{{(y_{q0}+y)}^2}-\frac{(x_{q0}-x)V_{\mathrm{qkl}2}^2+(x_{q0}+x)V_{\mathrm{qkl}1}^2}{{({\mathrm{\λy}}_{q0}+y)}^2})\end{array}---\left(A9\right)$

Negate after the right and left of above-mentioned two formulas asks local derviation to x and y respectively, then can obtain this two power

Driving and the stiffness matrix of detection axis:

$k_q=\left[\begin{array}{cc}{k}_{\mathrm{qxx}}& k_{\mathrm{qxy}}\\ k_{\mathrm{qyx}}& k_{\mathrm{qyy}}\end{array}\right]=-\frac{n_q{\mathrm{\ϵ}}_{0}h}{{y_{q0}}^2}\left[\begin{array}{cc}0& (1-\frac{1}{{\mathrm{\λ}}^2})({V_{\mathrm{qkl}1}}^2-{V_{\mathrm{qkl}2}}^2)\\ (1-\frac{1}{{\mathrm{\λ}}^2})({V_{\mathrm{qkl}1}}^2-{V_{\mathrm{qkl}2}}^2)& \frac{2x_{q0}}{y_{q0}}(1+\frac{1}{{\mathrm{\λ}}^3})({V_{\mathrm{qkl}1}}^2+{V_{\mathrm{qkl}2}}^2)\end{array}\right]---\left(A10\right)$

In above formula, counter-diagonal element is coupling correction rigidity, and two coupling stiffness are equal, convolution (A4), work as k _qxy+ k _xywhen=0, there is k _qyx+ k _yx=0, then the coupling stiffness of detection and driven-mode can be corrected simultaneously, has after substituting into relevant equations:

$\frac{k_x-k_y}{2}\sin 2{\mathrm{\β}}_{\mathrm{Qx}}=\frac{n_q{\mathrm{\ϵ}}_{0}h}{{y_{q0}}^2}(1-\frac{1}{{\mathrm{\λ}}^2})({V_{\mathrm{qkl}1}}^2-{V_{\mathrm{qkl}2}}^2)---\left(A11\right)$

The present embodiment is further simplified control system, order:

V _qkl1＝V _qD+V _qc(A12)

V _qkl2＝v _qD-V _qc(A13)

In formula, V _qDfor fixed voltage; V _qcfor control voltage.Then according to formula (A11), have:

$k_{\mathrm{qxy}}=k_{\mathrm{qyx}}=-\frac{4n_q{\mathrm{\ϵ}}_{0}h}{{y_{q0}}^2}(1-\frac{1}{{\mathrm{\λ}}^2})V_{\mathrm{qD}}{V}_{\mathrm{qc}}---\left(A14\right)$

In formula (A14), only has V _qcfor variable, by controlling this variable to reach the object controlled orthogonal coupling stiffness.

Produce at described quadrature alignment negative stiffness on the basis of mechanism, the step of the present embodiment is as follows:

1) orthogonal signal amplitude in Real-time Obtaining sense channel: described orthogonal signal are included in the output signal YV detecting displacement extraction structure 122, itself and driver framework displacement XM are with frequency homophase.With drive displacement signal for benchmark obtains orthogonal signal amplitude by phase demodulation mode;

2) quadrature alignment signal controls: obtaining step 1) after described orthogonal signal amplitude, itself and quadrature alignment benchmark 235 are compared in comparer 234, comparative result to be sent in the quadrature alignment controller 236 be made up of PI control circuit and is produced control signal V _qc, then signal QS is obtained after chromacoder 237 processes, and export quadrature alignment negative stiffness generation mechanism 14 to;

3) generation of negative stiffness and the elimination of coupling stiffness: step 2) described QS signal comprises V _qkl1and V _qkl2, through the process of quadrature alignment closed-loop system, in very short time, coupling stiffness can be offset with electrostatic negative stiffness, and make system reach steady state (SS);

4) quadrature error eliminates the acquisition of rear gyro brother formula signal: on the basis of above-mentioned three steps, the orthogonal signal in sense channel are almost suppressed, obtain brother's formula signal by phase demodulation mode.

Comprise multiple circuit form in the present embodiment, everyly meet above-mentioned steps, and the device that can realize (comprising mimic channel, digital circuit etc.) is in circuit all within the present embodiment scope.In the present embodiment,

Step 1) detailed step comprise:

1.1) acquisition of quadrature demodulation reference signal: driver framework displacement signal XM extracts after structure structure 113 through drive displacement and obtains XV signal, and this process does not change frequency and phase information, so XV and orthogonal signal are still with frequency homophase.XV obtains XSE signal (this process does not change signal frequency and phase place equally) after drive displacement amplifier 231 amplifies further, and this signal is connected to quadrature demodulator 232 demodulation reference edge, for the demodulation benchmark of orthogonal signal;

1.2) amplitude of orthogonal signal obtains: YV signal obtains YSE after the prime of measure loop amplifies the amplification of interface 221 and secondary amplifier 222, and described signal contains orthogonal signal amplitude information, is connected to the input end of quadrature demodulator 232.Obtain containing driving frequency two frequency-doubled signal and orthogonal signal amplitude after quadrature demodulator 232 processes, then filter two frequency-doubled signals through the process of orthogonal low-pass filter 233 both must orthogonal signal amplitude;

1.3) the drive displacement amplifier 231 described in adopts the amplifier of high phase accuracy, low noise;

1.4) quadrature demodulator 232 described in adopts switch demodulation principle;

1.5) the orthogonal low-pass filter 233 described in adopts second-order low-pass filter.

Described step 2) detailed step comprise:

2.1) the comparing of orthogonal signal amplitude and benchmark: set quadrature alignment benchmark 235 for " 0 ", by described step 1) the orthogonal signal amplitude that obtains and quadrature alignment benchmark 235 compare, when the former be greater than the latter's comparer 234 export on the occasion of, otherwise output amplitude;

2.2) generation of quadrature alignment control signal: quadrature alignment controller 236 mainly adopts PI control form and based on integration, when comparer 234 exports on the occasion of Time Controller 236 for negative saturated, otherwise is just saturated.The sensitivity of choose reasonable PI Parameter adjustable joint controller, make it suitable solution demand, its control signal is V _qc;

2.3) acquisition of QS signal: in order to meet the control signal form that formula (A12) and formula (A13) describe, add phase inverter 2372 for obtaining-V in chromacoder 237 _qc, then superpose with DC voltage generator 2371 and obtain V _qD+ V _qcand V _qD-V _qc.To the interference of circuit, the first impact damper 2373 and the second impact damper 2374 is added in order to reduce signal in structure;

2.4) by regulating the direct current signal V in flow directing device 2371 _qDthe V of certain variation range can be made _qcthe scope of Signal Regulation quadrature alignment rigidity is larger.

Described step 3) detailed step comprise:

3.1) generation of electrostatic negative stiffness: according to formula (A14), different control signal V _qccorresponding electrostatic negative stiffness can be produced;

3.2) electrostatic negative stiffness is to the compensation of coupling stiffness: in original state, and coupling stiffness is not also corrected and is in maximum rating, and the orthogonal signal amplitude in loop is maximum, and control signal is in saturated (supposing to be in just saturated).Then negative stiffness k _qyxmaximum, work as k _qyx+ k _yxbe in overcorrect state during < 0, then orthogonal signal phase place is reverse, then controller output signal is reversed to negative saturated, then k _qyxreduce, only have and work as k _qyx=k _yxtime system be in stable, controller output valve can reflect the size of coupling stiffness.

Comprehensive above-described embodiment, the present invention, for the purpose of correction of orthogonal coupling stiffness, produces mechanism and reaches with simple, the quadrature alignment of quadrature alignment controller cooperation reliably negative stiffness the object eliminating orthogonal rigidity.System can according to the different coupling stiffness coefficient auto-adjustment control amounts of gyroscope structure, the scale factory non-linearity of silicon micromechanical gyroscope greatly can be improved on existing process technology basis, improve bias drift, reduce constant error, producing the through engineering approaches of silicon micromechanical gyroscope has great practical significance.

Claims (9)

1. a silicon micro mechanical linearly coupled formula gyro, comprises gyroscope structure (1), gyro telemetry circuit (2) and gyro encapsulation (3), it is characterized in that,

Described gyroscope structure (1) comprises driving axial structure (11), detects axial arrangement (12), coupling stiffness module (13) and quadrature alignment negative stiffness generation structure (14);

Described driving axial structure (11) comprises driving incentive structure (111), drives quality (112) and drive displacement to extract structure (113), and described driving axial structure (11) is for ensureing the stable oscillation of brother's formula quality at driving direction; Wherein, described driving incentive structure (111) is for being converted into electrostatic force by external voltage, and described driving incentive structure (111) comprises driving fixed fingers and driving activity comb; Described driving quality (112) comprises driver framework and Ge Shi quality; Described driver framework is for connecting driving activity comb, driven-mode brace summer and Ge Shi quality, described driving activity comb dispersion is arranged in electrostatic force conversion efficiency driver framework improving unit area for increasing capacity area, described driven-mode brace summer is for connecting anchor point and driver framework and playing a supportive role, the displacement that driver framework produces is XM, and described brother's formula quality is for generation of Coriolis effect; Described drive displacement is extracted structure (113) and is driven capacitance signal XV to export for being converted to by driver framework displacement XM, and described drive displacement extraction structure (113) comprises driving and detects fixed fingers and drive detected activity comb;

Described detection axial arrangement (12) is extracted structure (122) by Detection job (121) and detection displacement and is formed, for extracting the sensed-mode displacement produced by Ge Shili;

Described coupling stiffness module (13) is coupled to by driven-mode the coupling stiffness (132) that the coupling stiffness (131) of sensed-mode and sensed-mode be coupled to driven-mode and forms;

Described quadrature alignment negative stiffness produces mechanism (14) and comprises four groups of quadrature alignment negative stiffnesses generation comb, described quadrature alignment negative stiffness produces the central frame both sides crossed-symmetrical arrangement of comb along brother's formula quality, for generation of electrostatic negative stiffness to offset coupling stiffness;

Described gyro telemetry circuit (2) comprises driving closed loop (21), measure loop (22) and quadrature alignment closed loop (23); Described driving closed loop (21) is for ensureing that described driving axial structure (11) is along the permanent amplitude vibrations of driving direction and vibration frequency is driven-mode natural resonance frequency; Described measure loop (22) exports for a Detection capacitance variable quantity YV part being adjusted to YSE, and another part is to drive pumping signal XS for benchmark demodulation and to export as gyro after filtering.

2. silicon micro mechanical linearly coupled formula gyro according to claim 1, it is characterized in that, described measure loop (22) comprises prime and amplifies interface (221), secondary amplifier (222), brother's formula detuner (223) and low-pass filter, wherein, described prime amplifies interface (221) for Detection capacitance variable quantity YV is converted into voltage signal and tentatively amplifies; Prime is amplified interface (221) output signal and is amplified further by described secondary amplifier (222), and outputs signal YSE; Described brother's formula detuner (223) obtains Ge Shi signal and two frequency-doubled signals to drive pumping signal XS for benchmark demodulation YSE; Described low-pass filter comprises the first low-pass filter (224) and the second wave filter (225), wherein, two frequency-doubled signals that first wave filter (224) exports for filtering detuner are to obtain pure Ge Shi signal amplitude, and the second low-pass filter (225) finally exports as gyroscope for exporting low-pass filtering.

3. silicon micro mechanical linearly coupled formula gyro according to claim 1, is characterized in that, described coupling stiffness module (13) comprises the coupling stiffness k that driven-mode is coupled to sensed-mode _yx(131) and sensed-mode be coupled to the coupling stiffness k of driven-mode _xy(132), wherein, described k _yx(131) driver framework displacement XM can be converted to bonding force FXQ is applied on Detection job (121); Described k _xy(132) detection block chord position can be moved YM to be converted to bonding force FYQ and to be applied to and to drive on quality (121).

4. silicon micro mechanical linearly coupled formula gyro according to claim 1, it is characterized in that, described quadrature alignment negative stiffness produces comb and comprises the first fixed fingers (141), the second fixed fingers (142), the 3rd fixed fingers (143), the 4th fixed fingers (144) and brother's formula quality, wherein, conducting between first fixed fingers (141) and the second fixed fingers (142), conducting between the 3rd fixed fingers (143) and the 4th fixed fingers (144); Described quadrature alignment negative stiffness produces comb and adopts unequal-interval design to produce electrostatic negative stiffness; Described quadrature alignment negative stiffness produces sensed-mode is coupled in mechanism (14) coupling stiffness k at correction driven-mode _yx(131) while, recoverable sensed-mode is coupled to the coupling stiffness k of driven-mode _xy(132).

5. silicon micro mechanical linearly coupled formula gyro according to claim 1, it is characterized in that, described quadrature alignment closed loop (23) comprises drive displacement amplifier (231), quadrature demodulator (232), orthogonal low-pass filter (233), comparer (234), quadrature alignment benchmark (235), quadrature alignment controller (236) and chromacoder (237), wherein, XV amplifies, to meet the amplitude demand of demodulation reference signal by described drive displacement amplifier (231) under the prerequisite not changing drive displacement XV; Orthogonal signal in the output signal of amplifier (222) secondary in sense channel are extracted by described quadrature demodulator (232), produce two frequency-doubled signals and quadrature error amplitude signal; Two frequency-doubled signals filter by described orthogonal low-pass filter (233), only retain quadrature amplitude signal; Quadrature amplitude signal and described quadrature alignment benchmark (235) compare by described comparer (234), produce comparative result; Described quadrature alignment controller (236) produces control signal according to described comparative result; Described chromacoder (237) comprises flow directing device (2371), phase inverter (2372), the first impact damper (2373) and the second impact damper (2374), for delivering to quadrature alignment negative stiffness generation mechanism (14) by producing QS signal after control signal conversion.

6. the bearing calibration of silicon micro mechanical linearly coupled formula gyroscope quadrature error rigidity, is characterized in that, comprise the steps:

(1) orthogonal signal amplitude in Real-time Obtaining sense channel;

(2) using described for step (1) orthogonal signal amplitude as controlled quentity controlled variable, obtain corresponding quadrature alignment control signal by comparing itself and reference signal relation;

(3) described for step (2) quadrature alignment control signal changed, send into gyroscope structure, and quadrature alignment negative stiffness wherein produces mechanism's cooperation generation electrostatic negative stiffness, described electrostatic negative stiffness can balanced quadrature coupling stiffness.

7. method according to claim 6, is characterized in that, the concrete steps of step (1) are:

Real-time Obtaining drive displacement is extracted the output signal XV of structure and is detected the output signal YV that structure is extracted in displacement, and described drive displacement signal should in the same homophase frequently of driver framework displacement;

Output signal XV amplitude drive displacement being extracted structure carries out adjustment makes its amplitude be suitable as demodulation benchmark, obtains XSE, its frequency and phase invariant in described processing procedure;

Extract the output signal YV amplitude of structure and carry out adjustment by detecting displacement that its amplitude is applicable to is demodulated, obtain YSE, its frequency and phase invariant in described processing procedure;

Using XSE as benchmark demodulation YSE;

By the high-frequency signal of above-mentioned demodulation result after low-pass filter filtering demodulation, then obtain orthogonal signal amplitude.

8. method according to claim 6, is characterized in that, the concrete steps of step (2) are:

The orthogonal signal amplitude described step (1) obtained compares with quadrature alignment benchmark and judges;

Above-mentioned judged result is sent into quadrature alignment controller, obtains Quadrature control signals further;

Described Quadrature control signals is inputed to chromacoder, with obtain quadrature alignment negative stiffness produce mechanism have quadrature alignment control signal.

9. method according to claim 6, is characterized in that, the concrete steps of step (3) are:

Obtain new coupling stiffness after the electrostatic negative stiffness produced superposes with the original orthogonal coupling stiffness of structure, then produce new quadrature error signal;

According to the result of described step (1) and step (2), readjust quadrature alignment control signal, finally make quadrature signal amplitude equal with quadrature alignment benchmark;

Above-mentioned middle quadrature alignment benchmark is set to 0, then after system stability, quadrature alignment negative stiffness can eliminate orthogonal coupling stiffness completely.