CN103115618A - Isolation test method for orthoronal errors and parasitic coriolis force based on vibrating type micromechanical gyroscope - Google Patents

Abstract

The invention discloses an isolation test method for orthoronal errors and parasitic coriolis force vibrating type micromechanical gyroscope-based. The method comprises the following steps of: inputting a large angular velocity signal rotating around a sensitive shaft into a vibrating type micromechanical gyroscope, and measuring the amplitude of an alternating current signal of an output end of a detection direction processing circuit and the phase difference between the alternating current single and a drive signal of the vibrating type micromechanical gyroscope; resetting the input angular velocity signal to be zero, and measuring the amplitude of the alternating current signal of the output end of the detection direction processing circuit and the phase difference between the alternating current single and the drive signal; and successfully isolating the orthoronal errors from the parasitic coriolis force according to a measurement result; adjusting the phase of a single of an output end of a feedback direction processing circuit by a phase shifter in the feedback direction processing circuit, so that the phase of the signal of the output end of the feedback direction processing circuit is accordant with the phase of a signal, caused by a coriolis acceleration signal, of the output end of the detection direction processing circuit; and therefore, the maximum sensitivity of a gyroscope system can be realized through the coherent demodulation and the lowpass filtering of a rear-stage circuit.

Description

A kind of based on the quadrature error of vibrating micromechanical gyro and the discrete testing method of parasitic coriolis force

Technical field

The present invention relates to the micromechanical gyro sensor field, relate in particular to the discrete testing to vibrating micromechanical gyro inside quadrature error and these two kinds of coupled signals of parasitic coriolis force.

Background technology

The principle of work of vibrating micromechanical gyro all is based on Coriolis (Coriolis) effect, and its kinetic model as shown in Figure 1.When movable mass is done simple harmonic oscillation along directions X, if this moment, rich Z axis had an angular velocity of rotation input, movable mass will be subject in Y-direction the effect of Coriolis acceleration so.Wherein, the size of Coriolis acceleration is directly proportional to the movement velocity v of input angular velocity Ω and mass, and the direction of its direction and angular velocity and movement velocity is perpendicular, shown in (1).Therefore can obtain the size of input angular velocity by the movement velocity that detects Coriolis acceleration and mass.

${\stackrel{\→}{a}}_C=2\stackrel{\→}{\mathrm{\Ω}}\×\stackrel{\→}{v}---\left(1\right)$

Vibrating micromechanical gyro sensor driving direction and detection side to the equation of motion can represent respectively as shown in (2) and (3).

$M_x\stackrel{\·\·}{x\left(t\right)}+c_x\stackrel{\·}{x\left(t\right)}+k_{x}x\left(t\right)=F_{\mathrm{drive}}---\left(2\right)$

$M_y\stackrel{\·\·}{y\left(t\right)}+c_y\stackrel{\·}{y\left(t\right)}+k_{y}y\left(t\right)=2M_y\mathrm{\Ω}\stackrel{\·}{x\left(t\right)}---\left(3\right)$

In formula (2) and formula (3), M _xAnd M _yRespectively expression drive and the detection side to the mass quality; c _xAnd c _yRespectively expression drive and the detection side to ratio of damping; k _xAnd k _yRespectively expression drive and the detection side to elasticity coefficient; X (t),

Represent respectively driving direction displacement, speed, acceleration; Y (t),

Represent that respectively the detection side is to displacement, speed, acceleration; Ω represents input angular velocity;

Expression Coriolis power; F _DriveExpression makes gyro at the driving force that adds of driving direction resonance, F _Drive=F ₀Sin (ω _dT), F ₀Be the amplitude of driving force, ω _dAngular frequency for driving force.

The vibrating micromechanical gyro detection side to the displacement expression formula suc as formula shown in (4).

y(t)＝B _ysin(ω _dt-φ _y) (4)

In formula (4), B _yBe the amplitude of detection side to vibration displacement, φ _yBe the phase place of detection side to vibration displacement.

In vibrating micromechanical gyro manufacturing of the fiber grating sensors process, the driving force direction that adds that causes due to fabrication error is not to overlap fully with driving shaft, but departs from certain angle θ ₁, as shown in Figure 2.Angle θ ₁Existence make driving force upwards have certain component the detection side.This moment the detection side to kinetics equation suc as formula shown in (5).Here it is so-called parasitic coriolis force.Because the phase place of parasitic coriolis force is consistent with the phase place of Coriolis power, therefore can't it be eliminated the method by phase demodulation on circuit, thereby introduce direct current biasing at the output terminal of gyrosystem.

$M_y\stackrel{\·\·}{y\left(t\right)}+c_y\stackrel{\·}{y\left(t\right)}+k_{y}y\left(t\right)=2M_y\mathrm{\Ω}\stackrel{\·}{\stackrel{\·}{x\left(t\right)}+F_{\mathrm{drive}}\sin {\mathrm{\θ}}_1}---\left(5\right)$

In vibrating micromechanical gyro manufacturing of the fiber grating sensors process, be not complete quadrature because the reasons such as craft precision and material stress have caused driving shaft and detected axle, must angle θ but depart from ₂, as shown in Figure 3.Angle θ ₂Existence make mass the detection side, one oscillating component be arranged upwards in the vibration of driving direction, the detection side to the displacement expression formula as shown in (6).The vibration phase that causes due to this oscillating component and Coriolis power differs 90 degree, so this coupling effect is called as quadrature error.Can adopt the method for phase demodulation to eliminate this error to the impact of sensor output signal in late-class circuit.

y(t)＝B _ysin(ω _dt-φ _y)+x(t)sinθ ₂ (6)

The block diagram of existing vibrating micromechanical gyro system as shown in Figure 4.Gyrosystem is comprised of vibrating micromechanical gyro sensor and peripheral processes circuit two parts.Treatment circuit comprises that drive signal generation circuit, feedback direction treatment circuit, detection side are to treatment circuit, coherent demodulator and low-pass filter.the output terminal of drive signal generation circuit is connected with the drive end of vibrating micromechanical gyro sensor, the detection signal output terminal of vibrating micromechanical gyro sensor is connected to the input end for the treatment of circuit with the detection side, the feedback signal output terminal of vibrating micromechanical gyro sensor is connected with the input end of feedback direction treatment circuit, the detection side is connected with two signal input parts of coherent demodulator respectively to the output terminal for the treatment of circuit and the output terminal of feedback direction treatment circuit, the output terminal of coherent demodulator is connected with the input end of low-pass filter, low-pass filter output dc voltage signal, this signal is directly proportional to the input angular velocity signal.Described detection side to treatment circuit with the vibrating micromechanical gyro detection side to displacement signal be converted to voltage signal, described feedback direction treatment circuit is converted to voltage signal with the displacement signal that vibrating micromechanical gyro feeds back direction.The expression formula of the output signal of feedback direction treatment circuit is suc as formula shown in (7).

V _feedback＝V _fsin(ω _dt-φ _x+φ _f) (7)

${\mathrm{\φ}}_x={\mathrm{tg}}^{-1}\frac{2{\mathrm{\ζ}}_x{\mathrm{\ω}}_x{\mathrm{\ω}}_d}{{{\mathrm{\ω}}_x}^2-{\mathrm{\ω}}_d^2}---\left(8\right)$

In formula (7) and (8), ω _xBe the natural angular frequency of driven-mode, ζ _x=c _x/ 2M _xω _xBe the damping ratio of driven-mode, φ _fBe the phase shift of feedback direction treatment circuit to feedback signal.

The detection side to the expression formula of the output signal for the treatment of circuit suc as formula shown in (9).

V _sense＝V _Coriolis sin(ω _dt-φ _y+φ _s)+Asin(ω _dt+φ _s)+Bsin(ω _dt-φ _x+φ _s) (9)

${\mathrm{\&phi;}}_y={\mathrm{tg}}^{-1}\frac{2{\mathrm{\&zeta;}}_y{\mathrm{\&omega;}}_y{\mathrm{\&omega;}}_d}{{{\mathrm{\&omega;}}_y}^2-{\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HSA00000615228700013.png,HSA00000615228700022.png"\; state="\{\{state\}\}">d</figure-callout>}}^2}+{\mathrm{\&phi;}}_x---\left(10\right)$

In formula (9) and (10), ω _yBe the natural angular frequency of sensed-mode, ζ _y=c _y/ 2M _yω _yBe the damping ratio of sensed-mode, φ _sFor the detection side to the phase shift for the treatment of circuit to detection signal, V _CoriolisBe the caused voltage signal of Coriolis acceleration, A is the amplitude of the caused coupled voltages signal of parasitic coriolis force, and B is the amplitude of the caused coupled voltages signal of quadrature error.

Work as ω _d=ω _x=ω _yThe time, φ _x=90 °, φ _v=180 °.Therefore formula (7) and formula (9) can be reduced to:

V _feedback＝V _fcos(ω _dt+φ _f) (11)

V _sense＝-V _Coriolis sin(ω _dt+φ _s)+Asin(ω _dt+φ _s)+Bcos(ω _dt+φ _s) (12)

When the input angular velocity signal is zero, V _Coriolis=0, so the detection side only comprises parasitic coriolis force and the caused coupled signal of quadrature error in the signal for the treatment of circuit output terminal, its expression formula is:

V _sense＝Asin(ω _dt+φ _s)+Bcos(ω _dt+φ _s) (13)

The phase shifter of utilization feedback direction treatment circuit inside is regulated feedback direction treatment circuit output end signal V _FeedbackPhase place, make it consistent with the phase place of the caused voltage signal of Coriolis acceleration, namely the phase place with the caused coupled signal of parasitic coriolis force is consistent.At this moment, the sensitivity of gyrosystem is maximum.But due to V _SenseIn comprise parasitic coriolis force and the caused two kinds of coupled signals of quadrature error, and have the phase differential of 90 degree, so V between the two _SensePhase place namely the phase place with the caused coupled signal of parasitic coriolis force is not consistent, also the phase place with the caused coupled signal of quadrature error is not consistent, signal schematic representation as shown in Figure 5.So just can't determine to feed back the phase shift size of the phase shifter of direction treatment circuit inside.If can not the accurate adjustment phase place, just can not obtain the sensitivity of maximum gyrosystem.

Therefore, need to take someway with V _SenseThe caused two kinds of coupled signals of the middle parasitic coriolis force that comprises and quadrature error are separated, thus can accurate adjustment the phase place of feedback direction treatment circuit output signal, realize the maximization of gyrosystem sensitivity.

Summary of the invention

The purpose of this invention is to provide a kind of can be with quadrature error and the caused two kinds of methods that coupled signal is separated of parasitic coriolis force of vibrating micromechanical gyro sensor internal.

The technical solution used in the present invention is: in the vibrating micromechanical gyro system, to large angular velocity signal that rotates around Z axis of system's input.Measure the detection side to the amplitude for the treatment of circuit output terminal AC signal.Measure the detection side to the phase differential between the driving signal for the treatment of circuit output terminal AC signal and vibrating micromechanical gyro sensor.The input angular velocity that makes the vibrating micromechanical gyro system is zero, measures the detection side to the amplitude for the treatment of circuit output terminal AC signal.Measure the detection side to the phase differential between the driving signal for the treatment of circuit output terminal AC signal and vibrating micromechanical gyro sensor.Utilize the resulting result of above-mentioned measurement can calculate parasitic coriolis force and quadrature error respectively in the detection side of the vibrating micromechanical gyro system size to the caused coupled voltages signal for the treatment of circuit output terminal, successfully realized two coupled signals are separated.The phase shifter of utilization feedback direction treatment circuit inside is regulated the phase place of feedback direction treatment circuit output end signal, makes it consistent to the phase place of the signal for the treatment of circuit output terminal with the caused detection side of Coriolis acceleration signal.After the signal that feeds back direction treatment circuit output terminal this moment and detection side carried out coherent demodulation and low-pass filtering to the signal for the treatment of circuit output terminal, the sensitivity of gyrosystem was maximum.

The beneficial effect that the present invention has is:

1) the invention provides a kind of can be with quadrature error and the caused two kinds of methods that coupled signal is separated of parasitic coriolis force of vibrating micromechanical gyro sensor internal.The implementing of the method helps analyze the size of the parasitic coriolis force of vibrating micromechanical gyro sensor internal and quadrature error, for the technological process of optimizing sensor processing provides guidance.

2) the present invention can accurately separate quadrature error and the caused two kinds of coupled signals of parasitic coriolis force, therefore can the accurate adjustment vibrating micromechanical gyro phase place of feedback direction treatment circuit output signal in system, make the sensitivity of gyrosystem reach maximum.

Description of drawings

Fig. 1 is the kinetic model of vibrating micromechanical gyro.

Fig. 2 is the schematic diagram of vibrating micromechanical gyro endophyte coriolis force.

Fig. 3 is the schematic diagram of the inner quadrature error of vibrating micromechanical gyro.

Fig. 4 is the schematic diagram of vibrating micromechanical gyro system architecture diagram.

Fig. 5 is the caused coupled signal of parasitic coriolis force in the vibrating micromechanical gyro system, the caused coupled signal of quadrature error and waveform schematic diagram two coupled signals and signal.

Embodiment

According to formula (12) as seen, the phase place of the caused Coriolis signal of input angular velocity is identical with the phase place of the caused coupled signal of parasitic coriolis force, and both sums can be expressed as:

-V _Coriolis sin(ω _dt+φ _s)+Asin(ω _dt+φ _s)＝Csin(ω _dt+φ _s) (14)

At this moment, the detection side to the expression formula of the output signal for the treatment of circuit suc as formula shown in (15).

When the turning rate input signal is very large, namely C＞＞B, therefore

Namely

Being the detection side to the signal for the treatment of circuit output terminal is:

$V_{\mathrm{sense}}=C\sin ({\mathrm{\&omega;}}_{d}t+{\mathrm{\&phi;}}_s)+B\cos ({\mathrm{\&omega;}}_{d}t+{\mathrm{\&phi;}}_s)=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HSA00000615228700013.png,HSA00000615228700022.png"\; state="\{\{state\}\}">C</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HSA00000615228700013.png,HSA00000615228700022.png"\; state="\{\{state\}\}">B</figure-callout>}}^2}\sin ({\mathrm{\&omega;}}_{d}t+{\mathrm{\&phi;}}_s)---\left(17\right)$

By the phase differential between the driving signal of determining this signal and vibrating micromechanical gyro sensor, can obtain the detection side is ω to treatment circuit to frequency _dThe phase shift φ of signal _s

When the input angular velocity signal is zero, V _Coriolis=0, so the detection side only comprises parasitic coriolis force and the caused coupled signal of quadrature error in the signal for the treatment of circuit output terminal, its expression formula is:

Therefore, can obtain to the amplitude for the treatment of circuit output end signal by the measurement detection side

Big or small V _x, can obtain to the phase differential between the driving signal for the treatment of circuit output end signal and vibrating micromechanical gyro sensor by measuring the detection side

Size, the phase shift φ that has recorded before utilizing _s, can obtain

Size.Obtain the following system of equations relevant with A and B.

Solving equations (20) can obtain the size of A and B, thereby with V _SenseThe middle caused coupled signal of parasitic coriolis force that comprises and the caused coupled signal of quadrature error are separated.

Implementation step is as follows:

1) in the vibrating micromechanical gyro system, to angular velocity signal that rotates around Z axis of system's input,

Size can be 300 degree/second.

2) measure the detection side to the amplitude for the treatment of circuit output terminal AC signal, can obtain

Size.

3) measure the detection side to the phase differential between the driving signal for the treatment of circuit output terminal AC signal and vibrating micromechanical gyro sensor, can obtain φ _sSize.

4) making the input angular velocity of vibrating micromechanical gyro system is zero, measures the detection side to the amplitude for the treatment of circuit output terminal AC signal, can obtain

Big or small V _x

5) measure the detection side to the phase differential between the driving signal for the treatment of circuit output terminal AC signal and vibrating micromechanical gyro sensor, can obtain

Size.

6) utilize

And φ _sSize can obtain Size.

7) utilize V _xWith

Size, can calculate the value of A and B.Therefore parasitic coriolis force and quadrature error respectively in the detection side of the vibrating micromechanical gyro system size to the caused coupled voltages signal for the treatment of circuit output terminal, have successfully realized two coupled signals are separated as can be known.

8) according to φ _sSize, utilize the phase shifter of feedback direction treatment circuit inside to regulate feedback direction treatment circuit output end signal V _FeedbackPhase place, make it consistent to the phase place of the signal for the treatment of circuit output terminal with the caused detection side of Coriolis acceleration signal, i.e. φ _f=90 °+φ _sAfter the signal that feeds back direction treatment circuit output terminal this moment and detection side carried out coherent demodulation and low-pass filtering to the signal for the treatment of circuit output terminal, the sensitivity of gyrosystem was maximum.

Claims (2)

1. one kind based on the quadrature error of vibrating micromechanical gyro and the discrete testing method of parasitic coriolis force, it is characterized in that: to large angular velocity signal that rotates around sensitive axes of vibrating micromechanical gyro input, measure the detection side to the amplitude for the treatment of circuit output terminal AC signal and detection side to the phase differential between the driving signal for the treatment of circuit output terminal AC signal and vibrating micromechanical gyro sensor, the input angular velocity that makes again vibrating micromechanical gyro is zero, measure the detection side to the amplitude for the treatment of circuit output terminal AC signal and measure the detection side to the phase differential between the driving signal for the treatment of circuit output terminal AC signal and vibrating micromechanical gyro sensor, utilize above-mentioned measurement result to obtain quadrature error and parasitic coriolis force respectively in the size of detection side to the caused coupled voltages signal for the treatment of circuit output terminal, success realizes two coupled signals are separated.

2. maximized method that realizes gyrosystem sensitivity, it is characterized in that: according to the result of the discrete testing of quadrature error and parasitic coriolis force, the phase shifter of utilization feedback direction treatment circuit inside is regulated the phase place of feedback direction treatment circuit output end signal, make it consistent to the phase place of the signal for the treatment of circuit output terminal with the caused detection side of Coriolis acceleration signal, can realize the maximization of the sensitivity of gyrosystem.

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