Control system of Coriolis resonance gyroscope based on frequency mixing excitation signal

Abstract

The invention discloses a control system of a Coriolis resonator gyroscope based on a frequency mixing excitation signal. The control system comprises a frequency mixing excitation driving closed loop and a frequency mixing excitation detection closed loop, the frequency mixing excitation driving closed loop realizes closed-loop driving of the gyroscope and restores a driving modal vibration signal without feed-through interference, and the frequency mixing excitation detection closed loop realizes force balance detection of the gyroscope and restores a detection modal vibration signal without feed-through interference. According to the invention, the square relationship between the excitation voltage and the electrostatic force of the capacitor resonator is utilized, the resonance signal and the feed-through interference signal are separated on the frequency domain by adopting the frequency mixing excitation resonance signal, and the filter technology is combined to obtain the purer gyroscope read-out signal, so that the feed-through interference is inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of Coriolis resonator gyroscopes, and in particular to a control system of a Coriolis resonator gyroscope based on a mixed-frequency excitation signal. Background Art

[0002] The Coriolis resonator gyroscope, a sensor that utilizes the Coriolis effect to sense input angular velocity, is a key application of MEMS technology in inertial navigation. Its advantages include small size, light weight, low cost, mass production, and ease of integration, leading to its widespread use and increasing performance requirements. However, due to non-ideal factors such as processing technology, material properties, and design layout, the Coriolis resonator gyroscope inevitably introduces parasitic capacitance during the electrostatic drive and capacitive detection processes. The parasitic capacitance between the excitation electrode and the readout electrode introduces an interference signal with the same frequency and phase as the excitation signal into the gyroscope output signal, known as feedthrough interference. Feedthrough interference not only reduces the system's signal-to-noise ratio and affects measurement and control accuracy, but can also induce unnecessary high-frequency oscillations, significantly negatively impacting overall performance.

[0003] To address feedthrough interference, methods commonly used include optimizing the gyroscope structure, electromechanical amplitude modulation, parameter excitation, peripheral circuit compensation, and digital algorithm compensation. However, gyroscope structure optimization design is complex, the process is lengthy, and the cost is high. Electromechanical amplitude modulation requires complex modulation and demodulation circuits, which can increase power consumption and high-frequency noise. Parameter excitation has a limited scope of application and limited effectiveness in suppressing feedthrough interference. Feedthrough compensation, on the other hand, lacks universal applicability, resulting in lengthy system debugging cycles. Summary of the Invention

[0004] Purpose of the invention: The present invention provides a control system for a Coriolis resonator gyroscope based on a mixed excitation signal, which realizes the separation of the resonant signal and the feedthrough interference signal in the frequency domain, and combines filtering technology to obtain a purer gyroscope readout signal and suppress feedthrough interference.

[0005] Technical solution: The control system of a Coriolis resonator gyroscope based on a mixed-frequency excitation signal described in the present invention includes: a mixed-frequency excitation drive closed-loop circuit and a mixed-frequency excitation detection closed-loop circuit; the mixed-frequency excitation drive closed-loop circuit implements closed-loop drive of the gyroscope and restores a drive modal vibration signal without feedthrough interference, and the mixed-frequency excitation detection closed-loop circuit implements force balance detection of the gyroscope and restores a detection modal vibration signal without feedthrough interference. The mixed-frequency excitation drive closed-loop circuit ensures that the gyroscope drive frame maintains simple harmonic vibration with constant amplitude and stable frequency in the x-axis direction. Then, according to the Coriolis effect, the gyroscope will vibrate the detection frame under the action of the external input angular velocity Ω, generating a detection modal vibration signal; the mixed-frequency excitation detection closed-loop circuit dynamically constrains the detection frame to a balanced position, improving system stability while obtaining external input angular velocity information.

[0006] Furthermore, the mixing excitation driving closed loop includes a driving mode mixing circuit, a driving mode excitation electrode, a driving mode readout electrode, a driving mode feedthrough capacitor, a driving mode C / V conversion circuit, a driving mode filtering circuit, a phase demodulation module, an amplitude demodulation module, a phase-locked loop, a direct digital frequency synthesizer, an automatic gain controller, a driving mode amplifying circuit, a driving mode A / D conversion circuit and a driving mode D / A conversion circuit; the driving mode mixing circuit mixes the sinusoidal driving signal and modulates its signal frequency band to a high frequency. The generated driving mode mixing excitation signal acts on the driving mode excitation electrode, and the driving mode mixing excitation signal can directly make the driving mode with a frequency of ω x Perform simple harmonic vibration so that the driving mode readout electrode generates a frequency of ω x The sinusoidal vibration current signal of the driving mode readout electrode is processed by the driving mode C / V conversion circuit, the driving mode filter circuit, and the driving mode A / D conversion circuit respectively and then sent to the phase demodulation module and the amplitude demodulation module respectively. The phase demodulation module and the amplitude demodulation module respectively perform demodulation based on the vibration signal after the driving mode is restored to obtain the driving mode vibration phase information and amplitude information respectively. The phase-locked loop tracks the driving mode resonant frequency ω of the gyroscope based on the phase information. x , and ω x The outputs are sent to the direct digital frequency synthesizer and the mixer excitation detection closed loop respectively. The automatic gain controller generates the amplitude V of the driving signal based on the amplitude information. ac , the output frequency of the direct digital frequency synthesizer is ω x The sinusoidal signal sinω x t, the amplitude of the driving signal and the sinusoidal signal sinω x t multiplied by the drive signal V ac sinω xt, realizing closed-loop driving of the gyroscope; the driving signal is sequentially processed by the driving mode D / A conversion circuit, the driving mode amplification circuit, and the driving mode mixing circuit and then sent to the driving mode excitation electrode. The driving mode mixing excitation signal is coupled with the driving mode feedthrough capacitor to generate a driving mode feedthrough interference current signal which is also modulated to a high frequency. After passing through the driving mode C / V conversion circuit and the driving mode filtering circuit, the driving mode feedthrough interference signal is filtered out, and the driving mode vibration signal without feedthrough interference is restored.

[0007] Furthermore, the mixing excitation detection closed loop includes a detection mode mixing circuit, a detection mode excitation electrode, a detection mode readout electrode, a detection mode feedthrough capacitor, a detection mode C / V conversion circuit, a detection mode filter circuit, a Coriolis signal demodulation module, a force balance detection controller, a detection mode amplification circuit, a detection mode A / D conversion circuit and a detection mode D / A conversion circuit; the detection mode mixing circuit mixes the sinusoidal force balance signal and modulates its signal frequency band to a high frequency. The generated mixing excitation signal acts on the detection mode excitation electrode, and the detection mode mixing excitation signal causes the detection mode excitation electrode to generate a frequency of ω x The electrostatic force of the detection mode readout electrode offsets the vibration signal generated by the detection mode readout electrode based on the angular velocity Ω of the gyroscope sensitive axis, so that the detection mode is maintained at a balanced position. The detection mode mixing excitation signal is coupled with the detection mode feedthrough capacitance to generate a detection mode feedthrough interference current signal that is also modulated to a high frequency. The readout signal output by the detection mode readout electrode is sequentially processed by the detection mode C / V conversion circuit, the detection mode filtering circuit, and the detection mode A / D conversion circuit and then sent to the Coriolis signal demodulation module. The Coriolis signal demodulation module demodulates the vibration signal of the detection mode readout electrode to obtain a Coriolis signal. The force balance detection controller generates an angular velocity signal based on the Coriolis signal, and the sinω from the drive closed loop x t is multiplied by the angular velocity signal output by the force balance detection controller to generate a force balance signal, thereby realizing the force balance detection of the gyroscope; the force balance signal is sequentially processed by the detection mode D / A conversion circuit, the detection mode amplification circuit, and the detection mode mixing circuit and then sent to the detection mode excitation electrode. Therefore, after passing through the detection mode C / V conversion circuit and the detection mode filtering circuit, the detection mode feedthrough interference signal is filtered out, and the detection mode vibration signal without feedthrough interference is restored.

[0008] Furthermore, in the driving mode mixing circuit, exciting the gyroscope driving mode simple harmonic vibration requires applying mixing excitation signals to the positive and negative excitation electrodes respectively, and the mixing excitation signal corresponding to each electrode needs to be modulated by the switching circuit.

[0009] Furthermore, the generation process of the mixed frequency excitation signal corresponding to the positive electrode of the excitation electrode is as follows: the sinusoidal signal output by the D / A conversion circuit passes through the RC high-pass filter composed of the isolation capacitor and the pull-up resistor and is superimposed with the positive DC voltage V dc , get the AC / DC coupling signal V ac sinω x t+V dc The other side of the sinusoidal signal output by the D / A converter circuit passes through the inverting circuit and then passes through the RC high-pass filter composed of the isolation capacitor and the pull-down resistor, and then a negative DC voltage -V is superimposed. dc Get AC / DC coupled signal -V ac sinω x tV dc The two AC / DC coupled signals are mixed and modulated by a single-pole double-throw switch circuit to obtain a mixed excitation signal V R .

[0010] Furthermore, the generation process of the mixed frequency excitation signal corresponding to the negative electrode of the excitation electrode is as follows: the sinusoidal signal output by the D / A conversion circuit passes through the RC high-pass filter composed of the isolation capacitor and the pull-down resistor, and is superimposed with the negative DC voltage -V dc , get the AC / DC coupling signal V ac sinω x tV dc The other side of the sinusoidal signal output by the D / A converter circuit passes through the inverting circuit and then passes through the RC high-pass filter composed of the isolation capacitor and the pull-up resistor, and then the positive DC voltage V is superimposed. dc , get the AC / DC coupling signal -V ac sinω x t+V dc The two AC / DC coupled signals are mixed and modulated through a single-pole double-throw switch circuit to obtain a mixed excitation signal V L The switching period of the switch is T s , the duty cycle is 50%.

[0011] Furthermore, the expression of the mixing excitation signal is:

[0012]

[0013] According to the electrostatic driving principle, the electrostatic driving force generated by the mixing excitation signal is:

[0014]

[0015] Where V R 、V L Respectively represent the excitation signals applied to the positive and negative electrodes of the excitation electrodes, K oIt represents the voltage-electrostatic force conversion gain, that is, the mixing excitation signal can excite the gyroscope driving mode simple harmonic vibration, and the corresponding feedthrough interference signal is modulated to ω d ±(2n+1)ω s and nω s In the frequency band, n=1,2,3,…,∞, the angular frequency of the square wave ω s =2π / T s , set the cutoff frequency of the driving modal filter circuit to ω x and ω s The feedthrough interference signal can be accurately filtered out and the ideal gyroscope readout signal can be restored.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) A mixing excitation signal is used to separate the gyroscope vibration signal and the feedthrough interference signal in the frequency domain, and an excellent feedthrough interference suppression effect can be achieved after the feedthrough interference signal is filtered out by a filter circuit; (2) The mixing modulation circuit can be realized only by a switching circuit, and the generated mixing excitation signal can directly excite the gyroscope to perform simple harmonic vibration, without the need for a complex demodulation circuit, and is simple to implement and has low circuit power consumption; (3) The scheme has strong universality and is applicable to all resonant gyroscopes of different structures that adopt an electrostatic excitation scheme. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the system structure of the present invention.

[0018] Figure 2 This is a connection diagram of the driving mode mixing circuit of the present invention.

[0019] Figure 3 This is a schematic diagram of key signal outputs in the feedthrough suppression process of the present invention. DETAILED DESCRIPTION

[0020] like Figure 1 As shown, a control system of a Coriolis resonator gyroscope based on a mixed-frequency excitation signal includes: a mixed-frequency excitation drive closed-loop circuit and a mixed-frequency excitation detection closed-loop circuit; the mixed-frequency excitation drive closed-loop circuit realizes the closed-loop drive of the gyroscope, and the mixed-frequency excitation detection closed-loop circuit realizes the force balance detection of the gyroscope.

[0021] The mixing excitation driving closed loop includes a driving mode mixing circuit, a driving mode excitation electrode, a driving mode readout electrode, a driving mode feedthrough capacitor, a driving mode C / V conversion circuit, a driving mode filter circuit, a phase demodulation module, an amplitude demodulation module, a phase-locked loop, a direct digital frequency synthesizer, an automatic gain controller, a driving mode amplifying circuit, a driving mode A / D conversion circuit and a driving mode D / A conversion circuit; the driving mode mixing circuit mixes the sinusoidal driving signal and modulates its signal frequency band to a high frequency. The generated driving mode mixing excitation signal acts on the driving mode excitation electrode. The driving mode mixing excitation signal can directly make the driving mode have a frequency of ω x Perform simple harmonic vibration so that the driving mode readout electrode generates a frequency of ω x The sinusoidal vibration current signal of the driving mode readout electrode is processed by the driving mode C / V conversion circuit, the driving mode filter circuit, and the driving mode A / D conversion circuit respectively and then sent to the phase demodulation module and the amplitude demodulation module respectively. The phase demodulation module and the amplitude demodulation module respectively perform demodulation based on the vibration signal after the driving mode is restored to obtain the driving mode vibration phase information and amplitude information respectively. The phase-locked loop tracks the driving mode resonant frequency ω of the gyroscope based on the phase information. x , and ω x The outputs are sent to the direct digital frequency synthesizer and the mixer excitation detection closed loop respectively. The automatic gain controller generates the amplitude V of the driving signal based on the amplitude information. ac , the output frequency of the direct digital frequency synthesizer is ω x The sinusoidal signal sinω x t, the amplitude of the driving signal and the sinusoidal signal sinω x t multiplied by the drive signal V ac sinω x t, realize the closed-loop drive of gyroscope;

[0022] The driving signal is processed in sequence by the driving mode D / A conversion circuit, the driving mode amplification circuit, and the driving mode mixing circuit and then sent to the driving mode excitation electrode. The driving mode feedthrough interference current signal generated by the driving mode mixing excitation signal through the driving mode feedthrough capacitor coupling is also modulated to a high frequency. After passing through the driving mode C / V conversion circuit and the driving mode filtering circuit, the driving mode feedthrough interference signal is filtered out, and the driving mode vibration signal without feedthrough interference is restored.

[0023] The mixing excitation detection closed loop includes a detection mode mixing circuit, a detection mode excitation electrode, a detection mode readout electrode, a detection mode feedthrough capacitor, a detection mode C / V conversion circuit, a detection mode filter circuit, a Coriolis signal demodulation module, a force balance detection controller, a detection mode amplification circuit, a detection mode A / D conversion circuit, and a detection mode D / A conversion circuit; the detection mode mixing circuit mixes the sinusoidal force balance signal and modulates its signal frequency band to a high frequency. The generated mixing excitation signal acts on the detection mode excitation electrode, and the detection mode mixing excitation signal causes the detection mode excitation electrode to generate a frequency of ω x The electrostatic force of the detection mode readout electrode offsets the vibration signal generated by the detection mode readout electrode based on the angular velocity Ω of the gyroscope sensitive axis, so that the detection mode is maintained at a balanced position. The detection mode mixing excitation signal is coupled with the detection mode feedthrough capacitance to generate a detection mode feedthrough interference current signal that is also modulated to a high frequency. The readout signal output by the detection mode readout electrode is sequentially processed by the detection mode C / V conversion circuit, the detection mode filtering circuit, and the detection mode A / D conversion circuit and then sent to the Coriolis signal demodulation module. The Coriolis signal demodulation module demodulates the vibration signal of the detection mode readout electrode to obtain a Coriolis signal. The force balance detection controller generates an angular velocity signal based on the Coriolis signal, and the sinω from the drive closed loop x t is multiplied by the angular velocity signal output by the force balance detection controller to generate a force balance signal, thereby realizing the force balance detection of the gyroscope;

[0024] The force balance signal is processed in sequence by the detection mode D / A conversion circuit, the detection mode amplification circuit, and the detection mode mixing circuit and then sent to the detection mode excitation electrode. Therefore, after passing through the detection mode C / V conversion circuit and the detection mode filtering circuit, the detection mode feedthrough interference signal is filtered out, and the detection mode vibration signal without feedthrough interference is restored.

[0025] like Figure 2 As shown, the driving mode mixing circuit includes: an inverting circuit, an isolation capacitor, a pull-up resistor, a pull-down resistor, and a switching circuit. To stimulate the simple harmonic vibration of the gyroscope driving mode, it is necessary to apply mixing excitation signals to the positive and negative excitation electrodes respectively. The mixing excitation signal corresponding to each electrode needs to be modulated by the switching circuit.

[0026] The generation process of the mixed frequency excitation signal corresponding to the positive electrode of the excitation electrode is as follows: the sinusoidal signal output by the D / A conversion circuit passes through the RC high-pass filter composed of the isolation capacitor and the pull-up resistor, and then the positive DC voltage V is superimposed. dc , get the AC / DC coupling signal V ac sinω x t+V dcThe other side of the sinusoidal signal output by the D / A converter circuit passes through the inverting circuit and then passes through the RC high-pass filter composed of the isolation capacitor and the pull-down resistor, and then a negative DC voltage -V is superimposed. dc Get AC / DC coupled signal -V ac sinω x tV dc The two AC / DC coupled signals are mixed and modulated by a single-pole double-throw switch circuit to obtain a mixed excitation signal V R .

[0027] The generation process of the mixed frequency excitation signal corresponding to the negative electrode of the excitation electrode is as follows: the sinusoidal signal output by the D / A conversion circuit passes through the RC high-pass filter composed of the isolation capacitor and the pull-down resistor, and then superimposed with the negative DC voltage -V dc , get the AC / DC coupling signal V ac sinω x tV dc The other side of the sinusoidal signal output by the D / A converter circuit passes through the inverting circuit and then passes through the RC high-pass filter composed of the isolation capacitor and the pull-up resistor, and then the positive DC voltage V is superimposed. dc , get the AC / DC coupling signal -V ac sinω x t+V dc The two AC / DC coupled signals are mixed and modulated through a single-pole double-throw switch circuit to obtain a mixed excitation signal V L The switching period of the switch is T s , the duty cycle is 50%.

[0028] The expression of the mixing excitation signal is:

[0029]

[0030] According to the electrostatic driving principle, the electrostatic driving force generated by the mixing excitation signal is:

[0031]

[0032] Where V R 、V L Respectively represent the excitation signals applied to the positive and negative electrodes of the excitation electrodes, K o It represents the voltage-electrostatic force conversion gain, that is, the mixing excitation signal can excite the gyroscope driving mode simple harmonic vibration, and the corresponding feedthrough interference signal is modulated to ω d ±(2n+1)ω s and nω s In the frequency band, n=1,2,3,…,∞, the angular frequency of the square wave ω s =2π / T s , set the cutoff frequency of the driving modal filter circuit to ω x and ωs The feedthrough interference signal can be accurately filtered out and the ideal gyroscope readout signal can be restored. Figure 3 shown.

Claims

1. A control system for a Coriolis resonator gyroscope based on a mixed frequency excitation signal, characterized in that: include: Mixing excitation drive closed loop and mixing excitation detection closed loop; The mixed frequency excitation drive closed loop realizes the closed loop drive of the gyroscope and restores the drive modal vibration signal without feedthrough interference. The mixed frequency excitation detection closed loop realizes the force balance detection of the gyroscope and restores the detection modal vibration signal without feedthrough interference.

2. The control system of the Coriolis resonator gyroscope based on the mixed frequency excitation signal according to claim 1, characterized in that: The mixing excitation driving closed loop includes a driving mode mixing circuit, a driving mode excitation electrode, a driving mode readout electrode, a driving mode feedthrough capacitor, a driving mode C / V conversion circuit, a driving mode filter circuit, a phase demodulation module, an amplitude demodulation module, a phase-locked loop, a direct digital frequency synthesizer, an automatic gain controller, a driving mode amplifying circuit, a driving mode A / D conversion circuit and a driving mode D / A conversion circuit; the driving mode mixing circuit mixes the sinusoidal driving signal and modulates its signal frequency band to a high frequency. The generated driving mode mixing excitation signal acts on the driving mode excitation electrode. The driving mode mixing excitation signal can directly make the driving mode have a frequency of ω x Perform simple harmonic vibration so that the driving mode readout electrode generates a frequency of ω x The sinusoidal vibration current signal of the driving mode readout electrode is processed by the driving mode C / V conversion circuit, the driving mode filter circuit, and the driving mode A / D conversion circuit respectively and then sent to the phase demodulation module and the amplitude demodulation module respectively. The phase demodulation module and the amplitude demodulation module respectively perform demodulation based on the vibration signal after the driving mode is restored to obtain the driving mode vibration phase information and amplitude information respectively. The phase-locked loop tracks the driving mode resonant frequency ω of the gyroscope based on the phase information. x , and ω x The outputs are sent to the direct digital frequency synthesizer and the mixer excitation detection closed loop respectively. The automatic gain controller generates the amplitude V of the driving signal based on the amplitude information. ac , the output frequency of the direct digital frequency synthesizer is ω x The sinusoidal signal sinω x t, the amplitude of the driving signal and the sinusoidal signal sinω x t multiplied by the drive signal V ac sinω x t, realize the closed-loop drive of gyroscope; The driving signal is processed in sequence by the driving mode D / A conversion circuit, the driving mode amplification circuit, and the driving mode mixing circuit and then sent to the driving mode excitation electrode. The driving mode feedthrough interference current signal generated by the driving mode mixing excitation signal through the driving mode feedthrough capacitor coupling is also modulated to a high frequency. After passing through the driving mode C / V conversion circuit and the driving mode filtering circuit, the driving mode feedthrough interference signal is filtered out, and the driving mode vibration signal without feedthrough interference is restored.

3. The control system of the Coriolis resonator gyroscope based on the mixed frequency excitation signal according to claim 1, characterized in that: The mixing excitation detection closed loop includes a detection mode mixing circuit, a detection mode excitation electrode, a detection mode readout electrode, a detection mode feedthrough capacitor, a detection mode C / V conversion circuit, a detection mode filter circuit, a Coriolis signal demodulation module, a force balance detection controller, a detection mode amplification circuit, a detection mode A / D conversion circuit, and a detection mode D / A conversion circuit; the detection mode mixing circuit mixes the sinusoidal force balance signal and modulates its signal frequency band to a high frequency. The generated mixing excitation signal acts on the detection mode excitation electrode, and the detection mode mixing excitation signal causes the detection mode excitation electrode to generate a frequency of ω x The electrostatic force of the detection mode readout electrode offsets the vibration signal generated by the detection mode readout electrode based on the angular velocity Ω of the gyroscope sensitive axis, so that the detection mode is maintained at a balanced position. The detection mode mixing excitation signal is coupled with the detection mode feedthrough capacitance to generate a detection mode feedthrough interference current signal that is also modulated to a high frequency. The readout signal output by the detection mode readout electrode is sequentially processed by the detection mode C / V conversion circuit, the detection mode filtering circuit, and the detection mode A / D conversion circuit and then sent to the Coriolis signal demodulation module. The Coriolis signal demodulation module demodulates the vibration signal of the detection mode readout electrode to obtain a Coriolis signal. The force balance detection controller generates an angular velocity signal based on the Coriolis signal, and the sinω from the drive closed loop x t is multiplied by the angular velocity signal output by the force balance detection controller to generate a force balance signal, thereby realizing the force balance detection of the gyroscope; The force balance signal is processed in sequence by the detection mode D / A conversion circuit, the detection mode amplification circuit, and the detection mode mixing circuit and then sent to the detection mode excitation electrode. Therefore, after passing through the detection mode C / V conversion circuit and the detection mode filtering circuit, the detection mode feedthrough interference signal is filtered out, and the detection mode vibration signal without feedthrough interference is restored.

4. The control system of the Coriolis resonator gyroscope based on the mixed frequency excitation signal according to claim 2, characterized in that: In the driving mode mixing circuit, exciting the gyroscope driving mode simple harmonic vibration requires applying mixing excitation signals to the positive and negative excitation electrodes respectively. The mixing excitation signal corresponding to each electrode needs to be modulated by the switching circuit.

5. The control system of the Coriolis resonator gyroscope based on the mixed frequency excitation signal according to claim 4, characterized in that: The generation process of the mixed frequency excitation signal corresponding to the positive electrode of the excitation electrode is as follows: the sinusoidal signal output by the D / A conversion circuit passes through the RC high-pass filter composed of the isolation capacitor and the pull-up resistor, and then the positive DC voltage V is superimposed. dc , get the AC / DC coupling signal V ac sinω x t+V dc The other side of the sinusoidal signal output by the D / A converter circuit passes through the inverting circuit and then passes through the RC high-pass filter composed of the isolation capacitor and the pull-down resistor, and then a negative DC voltage -V is superimposed. dc Get AC / DC coupled signal -V ac sinω x tV dc The two AC / DC coupled signals are mixed and modulated by a single-pole double-throw switch circuit to obtain a mixed excitation signal V R .

6. The control system of the Coriolis resonator gyroscope based on the mixed frequency excitation signal according to claim 4, characterized in that: The generation process of the mixed frequency excitation signal corresponding to the negative electrode of the excitation electrode is as follows: the sinusoidal signal output by the D / A conversion circuit passes through the RC high-pass filter composed of the isolation capacitor and the pull-down resistor, and then superimposed with the negative DC voltage -V dc , get the AC / DC coupling signal V ac sinω x tV dc The other side of the sinusoidal signal output by the D / A converter circuit passes through the inverting circuit and then passes through the RC high-pass filter composed of the isolation capacitor and the pull-up resistor, and then the positive DC voltage V is superimposed. dc , get the AC / DC coupling signal -V ac sinω x t+V dc The two AC / DC coupled signals are mixed and modulated through a single-pole double-throw switch circuit to obtain a mixed excitation signal V L , the switching period of the switch is T s , the duty cycle is 50%.

7. The control system of the Coriolis resonator gyroscope based on the mixed frequency excitation signal according to claim 4, characterized in that: The expression of the mixing excitation signal is: According to the electrostatic driving principle, the electrostatic driving force generated by the mixing excitation signal is: Where V R 、V L Respectively represent the excitation signals applied to the positive and negative electrodes of the excitation electrodes, K o It represents the voltage-electrostatic force conversion gain, that is, the mixing excitation signal can excite the gyroscope driving mode simple harmonic vibration, and the corresponding feedthrough interference signal is modulated to ω d ±(2n+1)ω s and nω s In the frequency band, n=1,2,3,…,∞, the angular frequency of the square wave ω s =2π / T s , set the cutoff frequency of the driving modal filter circuit to ω x and ω s The feedthrough interference signal can be accurately filtered out and the ideal gyroscope readout signal can be restored.

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