Method for improving stability of virtual precession rotation speed of axisymmetric coriolis vibration gyroscope

Abstract

The application provides a method for improving the stability of a virtual precession speed of a axis-symmetrical Coriolis vibration gyroscope, under the conventional amplitude, quadrature and lock frequency control mode and the virtual precession mode, the gyroscope resonator normally works, the present technology demodulates the angle precession signal output under the conventional full angle and the virtual precession control mode and the amplitude control voltage signal by using a demodulation signal, processes the two amplitude signals after demodulation, obtains the gain to be extracted, compensates the extracted gain to the excitation voltage for controlling the virtual precession in the outside world, compensates the excitation voltage affecting the speed on line, thereby improving the stability of the virtual precession speed. The present application extracts the loop gain in real time without affecting the normal virtual precession of the Coriolis vibration gyroscope, and compensates on line, thereby improving the stability of the Coriolis vibration gyroscope speed under the virtual precession.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gyroscopes, and particularly relates to a method for improving the stability of virtual precession rotation speed of an axisymmetric Coriolis vibration gyroscope. BACKGROUND

[0002] The axisymmetric Coriolis vibration gyroscope is widely used in the military field due to its good environmental adaptability, small size and light weight, and has been verified in actual combat, realizing the application idea of'medium-high precision, low cost, high reliability, large batch and medium-end military' of the axisymmetric gyroscope, and being widely used in military enterprises in many countries such as the United States and Europe. In China, some enterprises have also developed the axisymmetric Coriolis vibration gyroscope, and through various static and dynamic test checks such as principle prototype, initial sample trial production and model application, the axisymmetric Coriolis vibration gyroscope has reached a small batch production level, and is an important direction for future high-end gyroscope development.

[0003] The gyroscope has a threshold effect in the full-angle mode, and cannot sense a small rotation speed. In order to solve this problem, the virtual precession technology is widely used to drive the gyroscope resonator to produce virtual precession by using an external given excitation voltage to overcome the influence of the threshold. Practical research shows that the threshold of the Coriolis vibration gyroscope under virtual precession can be greatly reduced.

[0004] In actual application, it is found that due to the change of loop gain, the rotation speed of the Coriolis vibration gyroscope under virtual precession is unstable in the conventional virtual precession mode, thereby generating a large error. SUMMARY

[0005] To solve the above problems, the application discloses a method for improving the stability of virtual precession rotation speed of an axisymmetric Coriolis vibration gyroscope. Method for improving the stability of the virtual precession speed of an axisymmetric coriolis vibratory gyroscope Figure 1 The resonator works in the conventional full-angle and virtual precession control mode, and outputs an angle value θ and an excitation voltage value V fas to an improved part, wherein the improved part demodulates two signal processing, compares the demodulated amplitude signals, obtains the loop gain 1 / K to be extracted, and multiplies the loop gain 1 / K by an external given excitation voltage V fqs to output to the conventional full-angle and virtual precession control mode, that is, V fqs / K is used to control virtual precession, so as to improve the stability of the rotation speed.

[0006] The specific steps are as follows:

[0007] Step (1): The axisymmetric Coriolis vibration gyroscope resonator works in the conventional full-angle and virtual precession control mode, and outputs an angle signal θ and an excitation voltage signal V fas to an improved part;

[0008] Step (2): in the improvement part, the angle signal θ is input into a differentiator to obtain an angle precession signal V fas After demodulation, a phase error signal is obtained, a controller is used for control, and the controlled voltage is input into a voltage-controlled oscillator II to obtain two demodulation signals sin2α and cos2α, wherein α=θ-θτ;

[0009] Step (3): in the improvement part, after the two demodulation signals are obtained, sin2α is used for demodulation on After multiplication by 2 through a multiplier, an amplitude signal -Δ(1 / τ) is obtained; cos2α is used for demodulation on V fas , an amplitude signal -Δ(1 / τ) / K is obtained;

[0010] Step (4): the two demodulation amplitude signals are divided to obtain a loop gain signal 1 / K to be extracted, which is multiplied by an excitation voltage V fqs given by the outside to control virtual precession, and after multiplication, the output is output to a conventional full angle and virtual precession control mode, so that the online compensation of the gain is realized, and the stability of the gyro resonator speed under the virtual precession is improved.

[0011] The application is further improved in that:

[0012] The conventional full angle and virtual precession control mode in the step (1) comprises C / V conversion, a demodulation module I, a calculation module I, a calculation module II, a voltage-controlled oscillator I, a first PID controller, a second PID controller, a third PID controller, a voltage conversion module and a modulation module; after a detection signal output by a detection electrode of an axisymmetric Coriolis vibration gyroscope is converted by C / V, corresponding voltage signals V x , V y are obtained; after the voltage signals are demodulated, calculation amounts C x , C y , S x , S y are obtained; after calculation through the calculation module I, control amounts E, Q, L, R and S are obtained; R and S are used for calculating an angle output value, and calculation is carried out through the calculation module II:

[0013] θ=1 / 2arctan(R / S)

[0014] The angle output θ;L is obtained as a phase judging quantity, the frequency of the reference signal is adjusted by a first PID controller to make L=0, at this time the frequency of the reference signal is the same as the actual resonance frequency of the resonator, the frequency tracking is realized, and two demodulation signals sin(ωt) and cos(ωt) are obtained after a voltage-controlled oscillator I; E is the total energy of the current resonator, compared with a set energy value, the error signal obtained is controlled by a second PID controller to control the driving voltage; Q is the quadrature error, the quadrature error is pressed to zero by a third PID controller; E and Q are outputted as excitation voltages V fas and V fqc to a voltage conversion module, and the following operations are carried out:

[0015]

[0016] Wherein, V fac is set to 0, and the voltage values of the x direction and the y direction on the sin and cos components are obtained after the above operations, and are V fxc , V fyc , V fxs , V fys , and the two modulation signals sin(ωt) and cos(ωt) obtained by the voltage-controlled oscillator I are modulated as follows:

[0017] V fx = V fxc cos(ωt) + V fxs sin(ωt),

[0018] V fy = V fyc cos(ωt) + V fys sin(ωt),

[0019] and V fx and V fy are applied to the excitation electrodes X and Y of the resonator of the gyro, so that the conventional full angle and virtual precession control of the Coriolis vibration gyro resonator are realized.

[0020] The further improvement of the application lies in that:

[0021] The improved part in the step (2) comprises a differentiator, a demodulation module II-1, a demodulation module II-2, a divider, a demodulation module II-3, a controller, a voltage-controlled oscillator II and a multiplier; the angle θ is inputted into the differentiator to obtain the angle precession value V fas is obtained after demodulation, the voltage after control is inputted into the voltage-controlled oscillator II to obtain the demodulation signals sin2α and cos2α, wherein α=θ-θτ.

[0022] A further improvement of the present invention is that: in step (3), sin2α is used to... Demodulation is performed, and the signal is multiplied by 2 by a multiplier to obtain the amplitude signal -Δ(1 / τ); V is then modulated using cos2α. fas Demodulation is performed to obtain the amplitude signal -Δ(1 / τ) / K; the two demodulated amplitude signals are input to a divider; the two input signals of the divider are A and B, and the output signal is A / B. The output of the divider is the desired loop gain 1 / K; the gain is compensated to V. fqs The output is sent to the conventional full-angle and virtual precession control modes, using V. fqs / K controls virtual precession, which can be offset. The gain K in the expression improves the stability of the gyroscope speed under virtual precession.

[0023] A further improvement of the present invention is that the amplitude control voltage V in step (4) is... fas and angular precession value The expressions are as follows:

[0024] V fas = -Δ(1 / τ)cos2(θ-θτ) / K

[0025]

[0026] Where Δ(1 / τ) represents the degree of damping mismatch, θ is the mode shape angle of the harmonic oscillator, θτ is the angle of the damping axis, η is the angular precession factor, Ω is the external angular velocity input, and V fqs The excitation voltage for controlling the virtual precession is set externally; in the improved part, a multiplier is used to combine the extracted loop gain 1 / K with V. fqs Multiply and replace the original V fqs That is, using V fqs / K controls virtual precession, counteracting K's influence. To mitigate the impact of [the virus], online gain compensation is achieved.

[0027] The beneficial effects of this invention are:

[0028] (1) When the axisymmetric Coriolis gyroscope is in virtual precession, the speed error is large under the given virtual precession excitation voltage. This invention extracts the loop gain and compensates it to the excitation voltage, which not only does not affect the normal operation of the Coriolis gyroscope, but also reduces the influence of loop gain change on the speed.

[0029] (2) Compared with ordinary gain adjustment, the present invention achieves real-time gain compensation by extracting loop gain online. Attached Figure Description

[0030] Figure 2 This is a block diagram illustrating the system implementation of the present invention.

[0031] Figure 3 The block diagram of the demodulation module I is implemented for the application.

[0032] Figure 4 The block diagram of the demodulation module I is implemented for the application.

[0033] Figure 1 The block diagram of the demodulation module II-1 and II-2 is implemented for the application. DETAILED DESCRIPTION

[0034] The application will be further clarified by the following examples and drawings, which should not be taken as limiting the scope of the application. It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" as used in the following description refer to directions in the drawings and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of the device under discussion.

[0035] As shown in Figure 2 , the method for improving the virtual precession rotation speed stability of the axisymmetric Coriolis vibration gyroscope in the embodiment comprises the following steps of online extraction compensation of the gain of the loop under the virtual precession of the gyroscope resonator:

[0036] (1) When the gyroscope is normally working, the output signal of the detection electrode is converted by C / V, and then output control quantities E, Q, L, R and S are output after the demodulation module I (as shown in Figure 3 ) and the demodulation module I (as shown in Figure 1 ), wherein E represents the total energy of the loop, Q is the quadrature error, L is the phase judgment quantity, and R and S are used for angle calculation output;

[0037] (2) Under the conventional full angle and virtual precession control mode, R and S are processed to obtain θ output to the improved part, and L is processed by the first PID controller and the voltage controlled oscillator I to obtain two demodulation signals sin(ωt) and cos(ωt), and E and Q are processed by the second PID controller and the third PID controller to output voltages V fas and V fqc , and V fxc , V fyc , V fxs and V fys are obtained through the voltage conversion module, and the converted voltage values are modulated and then applied to the excitation electrode to realize the conventional full angle and virtual precession control;

[0038] (3) In the improved part, θ output under the conventional full angle and virtual precession control mode is differentiated to obtain V fasAfter demodulation module II-3, the phase error signal is obtained. Based on the magnitude of the phase error signal, the controller is used for adjustment until the sinusoidal signal output by voltage-controlled oscillator II is consistent with V. fas After demodulation, the output is 0. At this point, the output of voltage-controlled oscillator II consists of two demodulated signals, sin2α and cos2α, which are respectively related to V. fas and demodulation;

[0039] (4) After processing the two amplitude signals after demodulation, divide them to obtain the required loop gain 1 / K. Then, compensate the extracted gain into the conventional full-angle and virtual precession control modes to achieve online gain compensation.

[0040] Step 1:

[0041] like Figure 2 The diagram shown is a system block diagram of the present invention. The detection electrodes X and Y output capacitance detection signals, which are then converted to voltage signals V by a C / V converter. fx and V fy To demodulation module I, such as Figure 3 Demodulate as shown; convert the demodulated signal C x C y S x S y Input to solver module I, such as Figure 4 As shown, E, Q, L, S, and R are obtained after the solution.

[0042] Step 2:

[0043] R and S enter the solution module II and perform the following calculations:

[0044] θ = 1 / 2 arctan(R / S)

[0045] Angle output θ is obtained; L serves as the phase judgment quantity. The frequency of the reference signal is adjusted by the first PID controller to make L = 0. At this point, the frequency of the reference signal is the same as the actual resonant frequency of the resonator, achieving frequency tracking. After passing through voltage-controlled oscillator I, two demodulated signals sin(ωt) and cos(ωt) are obtained. In this invention, voltage-controlled oscillator I and voltage-controlled oscillator II are implemented in the same way, referring to an oscillation circuit where the output frequency corresponds to the input control voltage. The frequency is a function of the input signal voltage. The input signal F is the reference phase error signal, and the output is two sine and cosine signals corresponding to the frequency. E is the total energy of the current resonant gyroscope, compared with the set energy value. The resulting error signal is used by the second PID controller to control the magnitude of the drive voltage. Q is the quadrature error, which is reduced to zero by the third PID controller. E and Q, after passing through the PID controller, respectively output the excitation voltage V. fas and V fqcThe voltage conversion module is used to perform the following operation:

[0046]

[0047] wherein V fac is set to 0, and after the above operation, the voltage values of the x-axis and the y-axis on the sin and cos components are obtained as V fxc , V fyc , V fxs , and V fys The two modulated signals obtained by the voltage-controlled oscillator I are modulated as follows:

[0048] V fx = V fxc cos(ωt) + V fxs sin(ωt),

[0049] V fy = V fyc cos(ωt) + V fys sin(ωt),

[0050] Step 3:

[0051] In the improvement part, V fas is demodulated to obtain a phase error signal, and the controller is used for control. The voltage after control is input into the voltage-controlled oscillator II to obtain two demodulated signals sin2α and cos2α, wherein α = θ - θτ. The output θ under the conventional virtual precession mode is differentiated by the differentiator to obtain V fas and The expressions are as follows:

[0052] V fas = -Δ(1 / τ)cos2(θ - θτ) / K

[0053]

[0054] wherein Δ(1 / τ) represents the degree of damping mismatch, θ is the mode angle of the harmonic oscillator, θτ is the angle of the damping axis, η is the angle precession factor, Ω is the external angular velocity input, V fqs is the excitation voltage set by the external control virtual precession. In the demodulation module II-1, sin2α is used to demodulate , and after being multiplied by 2 by the multiplier, the amplitude signal -Δ(1 / τ) is obtained. In the demodulation module II-2, cos2α is used to demodulate V fas to obtain the amplitude signal -Δ(1 / τ) / K. The demodulation module II-1, the demodulation module II-2, and the demodulation module II-3 have the same implementation manner, as shown in Figure 1As shown, it includes a multiplier and a low-pass filter. M is the demodulated signal and N is the demodulated signal. After multiplying the two signals and passing them through a low-pass filter, the amplitude signal to be extracted from M can be obtained.

[0055] Step 4:

[0056] The two amplitude signals -Δ(1 / τ) and -Δ(1 / τ) / K obtained in step 3 are input into the divider, where the divider is as follows: ​ As shown, the input signals are A and B, and the output signal is A / B. The divider outputs the desired loop gain 1 / K, which is then used to compensate for the gain in V. fqs The output is sent to the voltage conversion module in the conventional full-angle and virtual precession control modes, using V fqs / K controls virtual precession, which can be canceled out. In the expression V fqs The effect of the gain K, and the expression for the rotational speed of the Coriolis gyroscope output under virtual precession after compensation, are as follows:

[0057]

[0058] It can be seen that the output speed is independent of the loop gain, which reduces the impact of loop gain changes on the speed of the axisymmetric gyroscope under virtual precession and improves the stability of the speed under virtual precession.

[0059] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims

1. A method for improving the stability of virtual precession speed of an axisymmetric Coriolis gyroscope, characterized in that, Includes the following steps: Step (1): The axisymmetric Coriolis gyroscope resonator operates under conventional full-angle and virtual precession control modes. The mode angle θ of the resonator and the excitation voltage signal V fas To the improved section; Step (2): In the improved section, the mode angle θ of the resonator is input into the differentiator to obtain the angular precession signal. V fas After demodulation, a phase error signal is obtained. The controller is used to control the voltage, and the controlled voltage is input to the voltage-controlled oscillator II to obtain two demodulated signals sin2α and cos2α, where α=θ-θτ; Step (3): In the improved section, after obtaining the two demodulated signals, sin2α is used to... Demodulation is performed, and after multiplication by 2 by a multiplier, the damped mismatch signal -Δ(1 / τ) is obtained; V is then modulated using cos2α. fas Demodulation yields the amplitude signal -Δ(1 / τ) / K; Step (4): Divide the two demodulated amplitude signals to obtain the loop gain signal 1 / K to be extracted, and then divide it by the externally given excitation voltage V for virtual precession control. fqs The multiplication is performed, and the output is then fed into the conventional full-angle and virtual precession control modes to achieve online gain compensation and improve the stability of the gyro resonator speed under virtual precession.

2. The method for improving the stability of the virtual precession speed of an axisymmetric Coriolis gyroscope according to claim 1, characterized in that, The improved part in step (2) includes a differentiator, demodulation module II-1, demodulation module II-2, divider, demodulation module II-3, controller, voltage-controlled oscillator II, and multiplier; Inputting angle θ into the differentiator yields the angular precession value. V fas After demodulation, the phase error signal is obtained. The controller is used to control the voltage, and the controlled voltage is input to the voltage-controlled oscillator II to obtain the demodulated signals sin2α and cos2α, where α=θ-θτ.

3. The method for improving the stability of the virtual precession speed of an axisymmetric Coriolis gyroscope according to claim 1, characterized in that, In step (3), sin2α is used to... Demodulation is performed, and after multiplication by 2 by a multiplier, the damped mismatch signal -Δ(1 / τ) is obtained; V is then modulated using cos2α. fas Demodulate the signal to obtain the amplitude signal -Δ(1 / τ) / K; input the two demodulated amplitude signals into a divider; the two input signals of the divider are A and B, and the output signal is A / B. The output of the divider is the desired loop gain 1 / K.

4. The method for improving the stability of the virtual precession speed of an axisymmetric Coriolis gyroscope according to claim 1, characterized in that, In step (4), the amplitude control voltage V fas and angular precession value The expressions are as follows: V fas =-Δ(1 / τ)cos2(θ-θτ) / K Where Δ(1 / τ) represents the degree of damping mismatch, θ is the mode shape angle of the harmonic oscillator, θτ is the angle of the damping axis, η is the angular precession factor, Ω is the external angular velocity input, and V fqs The excitation voltage for controlling the virtual precession is set externally; in the improved part, a multiplier is used to combine the extracted loop gain 1 / K with V. fqs Multiply and replace the original V fqs That is, using V fqs / K controls virtual precession, counteracting K's influence. To mitigate the impact of [the virus], online gain compensation is achieved.

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