MEMS vibratory gyroscope robust control method based on resonance suppression and displacement mirroring

Abstract

The invention discloses an MEMS (Micro Electro Mechanical System) vibrating gyroscope robust control method based on resonance suppression and displacement mirror image, which comprises the following steps of: injecting a high-frequency modulation signal into a common end of a gyroscope, and reading real-time vibration displacement by a reading circuit based on an annular diode; a driving mode closed-loop control circuit is established, and electrostatic tuning and orthogonal pre-correction are completed, so that the driving mode is stable in resonance, the mode frequency difference is constant, and the orthogonal error is approximately corrected to zero; a detection mode closed-loop control circuit is established, a real-time vibration displacement signal is used as the input of a PR controller, and the PR controller maps and controls the output according to the input and applies the output to a sensitive mode driving electrode; the angular rate output is calculated by utilizing a displacement mirror image, and the angular rate is calculated by utilizing a displacement mirror image signal when the control output of the PR controller and the open-loop vibration displacement of the sensitive mode form a displacement mirror image according to the zero-static-error tracking characteristic and the energy conservation law of the PR controller. According to the invention, low-noise and high-bandwidth closed-loop control of the MEMS vibrating gyroscope can be considered.

Description

Technical Field

[0001] The present invention relates to the field of MEMS gyroscope control, and particularly relates to a robust control method for MEMS vibrating gyroscopes based on resonance suppression and displacement mirroring. Background Art

[0002] MEMS vibrating gyroscopes are micromachined inertial sensors that use the Coriolis effect to sense the angular motion of an object. They have the advantages of low cost, small size, low power consumption, and mass production, and are widely used in fields such as aerospace, autonomous driving, military industry, and consumer electronics. For high-precision quality vibrating gyroscopes (with a high Q value in the millions), the sensitive mode force-to-rebalance (FTR) closed-loop working mode has the advantages of high bandwidth, high dynamic range, and high stability compared to the open-loop mode, and is the mainstream working method adopted by MEMS vibrating gyroscopes. At present, MEMS gyroscopes based on FTR have achieved good performance: bias instability (BI) < 0.1° / h, angular rate random walk (ARW) < 0.01° / h. Bias instability is a key indicator restricting the high-precision inertial navigation application of MEMS gyroscopes. The fundamental reason for the zero-offset drift caused by external environmental fluctuations is mainly temperature changes and force field fluctuations. Therefore, scholars at home and abroad have carried out in-depth research and have formed effective temperature compensation methods. However, the structural parameter perturbations of MEMS gyroscopes caused by force field fluctuations have not been effectively solved, such as instantaneous equivalent stiffness perturbations, instantaneous motion state errors, and injected additional energy, which hinder MEMS gyroscopes from entering the inertial level of BI < 0.001° / h.

[0003] In a force field fluctuation environment, the relative energy of the sensitive mode of a high-Q MEMS vibration gyroscope changes greatly. This energy will cause nonlinear perturbations in stiffness (Duffing effect) and even stimulate the intrinsic motion of the sensitive mode, resulting in phase fluctuations or amplitude disturbances, and ultimately causing zero drift in the gyroscope output. The traditional FTR scheme uses the orthogonal and Coriolis components of the sensitive mode to generate a suppression force to achieve vibration energy stability (steady-state energy is 0). In order to filter out demodulation frequency multiplication and high-frequency noise, the response bandwidth of this scheme is usually low (less than 100 Hz, usually a few Hz to more than ten Hz), which makes it difficult to cope with high-frequency energy changes in a force-varying environment. Maintaining the stability of sensitive mode energy in a force field fluctuation environment is a key technology to improve the vibration resistance of the MEMS gyroscope (data stability during and after vibration). In recent years, domestic and foreign scholars have conducted research on the above-mentioned problems. The existing methods can be roughly divided into two categories: structural optimization and control optimization. The former is mainly used to ensure the structural and functional safety of MEMS gyroscopes under strong vibration and impact environments, and has not achieved performance improvement in force-varying environments; the latter starts with control strategies and designs a series of high-dynamic, anti-disturbance control methods, such as sliding film control, adaptive control, and adaptive anti-disturbance control. These methods are subject to factors such as high complexity and low model restoration, and rely on relatively ideal gyroscope structures. Most of them remain at the simulation level, and only a small number of them have been verified in engineering, and the measured performance is far from the traditional FTR solution. Therefore, there is an urgent need for a closed-loop control method for MEMS vibrating gyroscopes that takes into account both low noise and high bandwidth. Summary of the invention

[0004] The present invention aims at a MEMS vibrating gyroscope robust control method based on resonance suppression and displacement mirroring.

[0005] The technical solution to realize the present invention is: a MEMS vibrating gyroscope robust control method based on resonance suppression and displacement mirroring, comprising the following steps:

[0006] Step 1, establish a real-time detection circuit for vibration displacement of a MEMS gyroscope, inject a high-frequency modulation signal into the common end of the gyroscope, adopt a readout circuit based on a ring diode, and obtain the real-time vibration displacement of the driving mode and the sensitive mode by measuring the relative change of the paired comb capacitance;

[0007] Step 2, establishing a MEMS vibrating gyro driving mode closed-loop control circuit, based on PLL and PI controllers, respectively realizing driving mode resonant frequency tracking and amplitude automatic control;

[0008] Step 3, electrostatic tuning and orthogonal pre-correction of the MEMS vibrating gyroscope are performed, and DC voltages are applied to the tuning electrode and the orthogonal correction electrode respectively, so that the driving mode and the sensitive mode operate at the desired frequency difference, and the orthogonal error is approximately corrected to zero;

[0009] Step 4: Establish a closed-loop control circuit for detecting and driving the modal of the MEMS vibration gyroscope. Based on the output voltage signal representing the vibration displacement from the readout circuit using a ring diode, it is used as the input of the PR controller. The PR controller controls the output according to the input mapping and applies it to the drive electrodes of the sensitive mode.

[0010] Step 5: Use displacement mirroring to calculate and output the angular rate. According to the zero-static-error tracking characteristic of the PR controller and the law of conservation of energy, when the control output of the PR controller forms a displacement mirror with the open-loop vibration displacement of the sensitive mode, use the displacement mirror signal to calculate the angular rate.

[0011] Further, in Step 1: Establish a real-time detection circuit for the vibration displacement of the MEMS gyroscope. Inject a high-frequency modulation signal into the common terminal of the gyroscope. Use a readout circuit based on a ring diode to obtain the real-time vibration displacements of the drive mode and the sensitive mode by measuring the relative changes in the paired comb capacitors, where:

[0012] The readout circuit based on a ring diode includes a ring diode formed by connecting the positive and negative electrodes of diodes D1 to D4 in sequence, a parallel circuit of capacitor C L1 and resistor R1, a parallel circuit of capacitor C L2 and resistor R2, and a divider. The positive electrode of diode D1 is connected to the detection comb capacitor C comb1 , the positive electrode of diode D3 is connected to the detection comb capacitor C comb2 , the negative electrodes of diode D1 and diode D3 are connected to the divider. One end of the parallel circuit of capacitor C L1 and resistor R1 is grounded, and the other end is connected to the negative electrode of diode D1. One end of the parallel circuit of capacitor C L2 and resistor R2 is grounded, and the other end is connected to the negative electrode of diode D3;

[0013] During the positive half-cycle of the high-frequency modulation signal V c , diodes D2 and D4 are conducting, diodes D1 and D3 are non-conducting, and the charge of capacitor C L1 flows through diode D2 to capacitor C comb2 , and the charge of capacitor C L2 flows through diode D4 to capacitor C comb1 ; during the negative half-cycle of the high-frequency modulation signal V c , diodes D1 and D3 are conducting, diodes D2 and D4 are non-conducting, and the charge of capacitor C comb2 flows through diode D3 to capacitor C L2 , and the charge of capacitor C comb1 flows through diode D1 to C L1 ; that is, capacitor C L1 is charged by capacitor C comb1 and discharged by capacitor C comb2 , while capacitor CL2 Charged by capacitor C comb2 Charged and discharged by capacitor C comb1 The charging and discharging speed is proportional to capacitor C comb1 And capacitor C comb2 The capacitance value of capacitor C is proportional, so the voltage difference between the two ends of capacitor C L1 And capacitor C L2 Is proportional to ΔC; Capacitor C comb1 And capacitor C comb2 Is symmetric about the gyro vibration mass. When the vibration displacement changes, the capacitance value of capacitor C comb1 And capacitor C comb2 Will change with the displacement. The output voltage V O (t) represents the real-time vibration displacement x(t).

[0014] Furthermore, a 2MHz sinusoidal modulation signal with an amplitude of 10V is injected into the gyro common terminal. The working mode frequency is about 4.5kHz. Capacitor C L1 And capacitor C L2 A 10pf capacitor is selected. It is 1.5 - 2 times that of capacitor C comb1 And capacitor C comb2 R L1 And R L2 A 20K resistor is selected.

[0015] Furthermore, in step 2, establish a closed-loop control circuit for the drive mode of the MEMS vibration gyro. Based on the PLL and PI controllers, achieve drive mode resonance frequency tracking and amplitude automatic control respectively. The specific method is as follows:

[0016] The voltage signal representing the real-time vibration displacement output by the readout circuit based on the ring diode enters the high-speed ADC through the analog front end. The converted discrete digital signal is downsampled and low-pass filtered to obtain a vibration displacement signal with high SNR. On the one hand, this signal passes through the phase discriminator, low-pass filter and PI controller to achieve drive mode resonance frequency tracking. After phase control and waveform generation, the drive reference sine wave is obtained; on the other hand, it passes through amplitude detection, low-pass filter and PI controller to achieve automatic gain control. The drive reference sine wave is amplitude modulated by the gain to obtain the drive signal of the drive mode. Finally, it reaches the gyro internal actuator through the DAC and the analog back end.

[0017] Furthermore, in step 4, establish a closed-loop control circuit for detecting the drive mode of the MEMS vibration gyro. The voltage signal representing the vibration displacement output by the readout circuit based on the ring diode is used as the input of the PR controller. The PR controller controls the output according to the input mapping and applies it to the sensitive mode drive electrode. The specific method is as follows:

[0018] The resonant frequency ω of the PR controller rSet to drive the modal resonance frequency ω x , the cut-off frequency ω c is set to be greater than 10 times the PLL error, the control target is set to 0, and the proportional gain k p and the resonance gain k r are adjusted until zero-static-error tracking is achieved. At this time, the vibration energy of the sensitive mode will be controlled to 0. The transfer function of the PR controller is as follows:

[0019]

[0020] Furthermore, in step 5, the angular rate output is calculated using the displacement mirror. According to the zero-static-error tracking characteristic of the PR controller and the law of conservation of energy, when the control output of the PR controller forms a displacement mirror with the open-loop vibration displacement of the sensitive mode, the angular rate is calculated using this displacement mirror signal. The specific method is as follows:

[0021] The frequency information of the PLL undergoes phase control to generate a demodulation waveform. The phase-sensitive demodulation of the mirror displacement signal filters out the residual quadrature error to obtain the angular rate signal, which is then low-pass filtered to serve as the angular rate output of the MEMS gyroscope.

[0022] Furthermore, the working principle is as follows:

[0023] A high-frequency modulation signal V c is applied to the common terminal of the gyro. The symmetric detection comb capacitors C comb1 and C comb2 of the gyro sensitive mode are obtained using a readout circuit based on a ring diode. The difference ΔC between the capacitors is converted into a voltage V O (t) that characterizes the vibration displacement of the gyro mass. This voltage value is converted into the input u of the PR controller to obtain the control output y, which is then converted into the drive voltages of the symmetric drive comb capacitors C comb3 and C comb4 of the sensitive mode, thereby suppressing the vibration energy of the sensitive mode. When the control is stable, the vibration energy of the sensitive mode is approximately 0, and the control output y of the PR controller is the real-time vibration displacement mirror of the sensitive mode. The angular rate output of the MEMS gyro is calculated using y.

[0024] Compared with the prior art, the present invention has the following remarkable advantages: 1) The PR controller is adopted for closed-loop control of the sensitive mode, achieving high-gain control at the resonant frequency of the drive mode and avoiding the signal demodulation and filtering processes of traditional closed-loop schemes. It has a higher control bandwidth and control accuracy, enhances the seismic resistance of the MEMS gyroscope, and improves the zero-output stability under force-varying environments; 2) By separating the closed-loop control process of the sensitive mode from the angular rate calculation process, the filtering link in the angular rate calculation process does not affect the performance of the sensitive mode closed-loop control, improving the flexibility of the bandwidth setting of the MEMS gyroscope; 3) The displacement mirror is adopted as the signal input for the angular rate calculation process. By adjusting the gain of the PR controller, the signal-to-noise ratio of the displacement mirror signal can be amplified without loss within a certain range, having the potential to match the dynamic range of the backend angular rate calculation process in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. is a schematic diagram of the principle of a robust control method for a MEMS vibrating gyroscope based on resonance suppression and displacement mirror according to the present invention.

[0026] Figure 2 FIG. is a block diagram of the system application implementation of a robust control method for a MEMS vibrating gyroscope based on resonance suppression and displacement mirror according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] A block diagram of the system application implementation of a robust control method for a MEMS vibrating gyroscope based on resonance suppression and displacement mirror according to the present invention, as shown in Figure 2 FIG., includes three parts: a MEMS vibrating gyroscope, a drive-mode closed loop, and a sensitive-mode closed loop. Among them, taking the high-Q value Z-axis gyroscope of the MEMS vibrating gyroscope as an example, the electrode interfaces include: a drive-mode detection (DM) interface, a drive-mode drive (DD) interface, a sensitive-mode detection (SM) interface, a sensitive-mode drive (SD) interface, a common terminal (COM), a tuning (T) interface, and a quadrature suppression (QC) interface. Taking the analog-digital hybrid control system as an example, the specific steps for implementing the present invention are as follows:

[0029] Step 1, establish a real-time detection circuit for the vibration displacement of the MEMS gyroscope. Inject a high-frequency modulation signal into the common terminal (substrate) of the gyroscope, and adopt a readout circuit based on a ring diode (abbreviation: ring tube circuit). By measuring the relative changes of the paired comb capacitors, obtain the real-time vibration displacements of the drive mode and the sensitive mode;

[0030] Build a real-time detection circuit for the vibration displacement of the MEMS gyroscope. Inject a 2MHz sinusoidal modulation signal with an amplitude of 10V into the common terminal (substrate) of the gyroscope (the working mode frequency is about 4.5kHz), and build a loop circuit to obtain the real-time vibration displacements of the driving mode and the sensitive mode. Among them, C L1 and C L2 Select 10pf capacitors (1.5 to 2 times that of C comb1 and C comb2 ), and select 20K resistors for R L1 and R L2 .

[0031] The specific principle of vibration displacement detection in the loop circuit is as follows: In the positive half-cycle of the high-frequency modulation signal V c , D2 and D4 are turned on, D1 and D3 are turned off, and the charge of capacitor C L1 flows through D2 to C comb2 , and the charge of capacitor C L2 flows through D4 to C comb1 ; in the negative half-cycle of the high-frequency modulation signal V c , D1 and D3 are turned on, D2 and D4 are turned off, and the charge of capacitor C comb2 flows through D3 to C L2 , and the charge of capacitor C comb1 flows through D1 to C L1 . In short, C L1 is charged by C comb1 and discharged by C comb2 , while C L2 is charged by C comb2 and discharged by C comb1 . The charging and discharging speed is proportional to the capacitance values of C comb1 and C comb2 . Therefore, the difference between the voltages V1 and V2 across C L1 and C L2 is proportional to ΔC. C comb1 and C comb2 are symmetric about the vibration mass of the gyroscope. When the vibration displacement changes, the capacitance values of C comb1 and C comb2 will change with the displacement (one positive and one negative in correlation). Therefore, the output voltage V O (t) of the loop circuit can represent the real-time vibration displacement x(t).

[0032] Step 2: Establish a closed-loop control for the driving mode of the MEMS vibration gyroscope. Since the resonant controller is not applicable to the control of the resonant state system, the traditional method should be used to achieve the closed-loop control of the driving mode. For example, based on the phase-locked loop (PLL) and the proportional-integral (PI) controller, the resonant frequency tracking and amplitude automatic control of the driving mode are respectively achieved;

[0033] Establish the closed-loop control of the driving mode of the MEMS vibratory gyroscope. Based on the PLL and PI controllers, the closed-loop control of the driving mode is realized. The voltage signal representing the real-time vibration displacement output by the loop pipe circuit enters the high-speed ADC through the analog front end. The converted discrete digital signal is downsampled and low-pass filtered to obtain a vibration displacement signal with high SNR. On the one hand, this signal passes through a phase detector, low-pass filter, and PI controller to achieve the tracking of the resonant frequency of the driving mode. After phase control and waveform generation, the driving reference sine wave is obtained. On the other hand, through amplitude detection, low-pass filter, and PI controller, automatic gain control is realized. The driving reference sine wave is amplitude-modulated using the gain to obtain the driving signal of the driving mode. Finally, it reaches the gyroscope internal actuator through the DAC and analog back end.

[0034] Step 3: Conduct electrostatic tuning and orthogonal pre-correction of the MEMS vibratory gyroscope. Apply DC voltages to the tuning electrodes and orthogonal correction electrodes respectively, so that the driving mode and the sensitive mode work at the desired frequency difference (for high-Q gyroscopes, usually a frequency difference of 0.1 - 1 Hz is reserved to avoid mode matching), and the orthogonal error is approximately corrected to zero.

[0035] Step 4: Establish the closed-loop control of the detection driving mode of the MEMS vibratory gyroscope. The voltage signal representing the vibration displacement output by the loop pipe circuit, after necessary front-end preprocessing (such as basic signal processing processes like digital-to-analog conversion, up / down sampling, noise shaping, etc.), is used as the input of the proportional-resonant (PR) controller. The PR controller maps the control output according to the input. After necessary back-end preprocessing (such as basic signal processing processes like digital-to-analog conversion, up / down sampling, noise shaping, etc.), it is applied to the driving electrode of the sensitive mode. Among them, the resonant frequency of the PR controller is set to the locking frequency of the driving mode phase-locked loop, and the control target is set to 0. Since the PR controller can achieve zero-static-error tracking for a specific frequency, when the loop control is stable, the vibration energy of the sensitive mode will be controlled to 0.

[0036] Establish the closed-loop control of the detection driving mode of the MEMS vibratory gyroscope, obtain a vibration displacement signal with high SNR (the same as in Step 2), as the input of the proportional-resonant (PR) controller. The PR controller maps the control output according to the input. After passing through the DAC and analog back end, it reaches the gyroscope internal actuator to form a PR control closed-loop of the sensitive mode. Among them, the resonant frequency ω r of the PR controller is set to the resonant frequency ω x of the driving mode, and the cut-off frequency ω c is set to 2 Hz (>10 times the PLL error), the control target is set to 0, and the appropriate proportional gain k p and resonant gain k r are adjusted until a stable control state with negligible tracking static error and acceptable overshoot is achieved.

[0037] Furthermore, the transfer function of the proportional-resonant controller (PR) adopted in the present invention is as shown in Equation 1.

[0038]

[0039] Step 5: Use the displacement mirror to calculate the angular rate output. According to the zero-static-error tracking characteristic of the PR controller and the law of conservation of energy, when the loop control is stable, the control output of the PR controller is in a fixed proportion (negative proportional coefficient) to the open-loop vibration displacement of the sensitive mode, that is, the displacement mirror. Use this displacement mirror signal to calculate the angular rate. For example, use phase-sensitive demodulation to filter the residual quadrature error from the displacement mirror to obtain the angular rate signal, and then after necessary signal processing, it is used as the angular rate output of the MEMS gyroscope.

[0040] Use the displacement mirror to calculate the angular rate output. The frequency information of the PLL passes through phase control to generate the demodulation waveform, perform phase-sensitive demodulation on the mirror displacement signal, filter out the residual quadrature error to obtain the angular rate signal, and then after low-pass filtering (frequency doubling filtering, bandwidth control), it is used as the angular rate output of the MEMS gyroscope.

[0041] In the method proposed by the present invention, using the loop pipe circuit to obtain the vibration displacement is a key step. The feedback control process from displacement to force has higher control margin and control accuracy.

[0042] Apply a high-frequency modulation signal V to the common terminal of the gyro. c , and use the loop pipe circuit to obtain the differential capacitance ΔC between the symmetric detection comb capacitors C comb1 and C comb2 of the gyro sensitive mode, convert the capacitance difference into a voltage V O (t) representing the vibration displacement of the gyro mass. This voltage value is converted into the input u of the PR controller to obtain the control output y, and then converted into the drive voltages of the symmetric drive comb capacitors C comb3 and C comb4 of the sensitive mode, thereby suppressing the vibration energy of the sensitive mode. When the control is stable, the vibration energy of the sensitive mode is approximately 0, and the control output y of the PR controller is the real-time vibration displacement mirror of the sensitive mode (with a fixed proportional scaling). Use y to calculate the angular rate output of the MEMS gyro.

[0043] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered to be within the scope described in this specification.

[0044] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A robust control method for MEMS vibrating gyroscopes based on resonance suppression and displacement mirroring, characterized in that It includes the following steps: Step 1: Establish a real-time detection circuit for the vibration displacement of the MEMS gyroscope. Inject a high-frequency modulation signal into the common terminal of the gyroscope. Adopt a readout circuit based on a ring diode. By measuring the relative changes in the paired comb capacitors, obtain the real-time vibration displacements of the drive mode and the sensitive mode; Step 2: Establish a closed-loop control circuit for the drive mode of the MEMS vibrating gyroscope. Based on the PLL and PI controllers, respectively achieve the resonance frequency tracking of the drive mode and the automatic amplitude control; Step 3: Conduct electrostatic tuning and orthogonal pre-correction for the MEMS vibrating gyroscope. Apply DC voltages to the tuning electrodes and the orthogonal correction electrodes respectively, so that the drive mode and the sensitive mode operate at the desired frequency difference, and the orthogonal error is approximately corrected to zero; Step 4: Establish a closed-loop control circuit for detecting the drive mode of the MEMS vibrating gyroscope. The voltage signal representing the vibration displacement output by the readout circuit based on the ring diode is used as the input of the PR controller. The PR controller controls the output according to the input mapping and applies it to the drive electrode of the sensitive mode; Step 5: Use the displacement mirror to calculate the angular rate output. According to the zero-static-error tracking characteristic of the PR controller and the law of conservation of energy, when the control output of the PR controller forms a displacement mirror with the open-loop vibration displacement of the sensitive mode, use the displacement mirror signal to calculate the angular rate.

2. The robust control method of the MEMS vibration gyroscope based on resonance suppression and displacement mirroring according to claim 1, wherein Step 1: Establish a real-time detection circuit for the vibration displacement of the MEMS gyroscope. Inject a high-frequency modulation signal into the common terminal of the gyroscope. Adopt a readout circuit based on a ring diode. By measuring the relative changes in the paired comb capacitors, obtain the real-time vibration displacements of the drive mode and the sensitive mode, where: The ring-diode-based readout circuit includes a ring diode formed by sequentially connecting the positive and negative electrodes of diodes D1 to D4, and a capacitor C L1 in parallel with a resistor R1, and a capacitor C L2 in parallel with a resistor R2, and a divider. The positive electrode of diode D1 is connected to a detection comb capacitor C comb1 , and the positive electrode of diode D3 is connected to a detection comb capacitor C comb2 . The negative electrodes of diodes D1 and D3 are connected to the divider. One end of the parallel circuit of capacitor C L1 and resistor R1 is grounded, and the other end is connected to the negative electrode of diode D1. One end of the parallel circuit of capacitor C L2 and resistor R2 is grounded, and the other end is connected to the negative electrode of diode D3; During the positive half - cycle of the high - frequency modulation signal V c , diodes D2 and D4 conduct, diodes D1 and D3 are cut off, and the charge of capacitor C L1 flows through diode D2 to capacitor C comb2 , and the charge of capacitor C L2 flows through diode D4 to capacitor C comb1 ; during the negative half - cycle of the high - frequency modulation signal V c , diodes D1 and D3 conduct, diodes D2 and D4 are cut off, and the charge of capacitor C comb2 flows through diode D3 to capacitor C L2 , and the charge of capacitor C comb1 flows through diode D1 to C L1 ; that is, capacitor C L1 is charged by capacitor C comb1 and discharged by capacitor C comb2 , while capacitor C L2 is charged by capacitor C comb2 and discharged by capacitor C comb1 . The charging and discharging speed is proportional to the capacitance values of capacitor C comb1 and capacitor C comb2 . Therefore, the difference between the voltages V1 and V2 across capacitor C L1 and capacitor C L2 is proportional to ΔC; capacitor C comb1 and capacitor C comb2 are symmetric about the gyro vibration mass. When the vibration displacement changes, the capacitance values of capacitor C comb1 and capacitor C comb2 will change with the displacement. The output voltage V O (t) of the divider represents the real - time vibration displacement x(t).

3. The robust control method for MEMS vibrating gyroscope based on resonance suppression and displacement mirror according to claim 2, wherein A sinusoidal modulation signal with an amplitude of 10V and a frequency of 2MHz is injected into the common terminal of the gyro. The working mode frequency is about 4.5kHz, and capacitors C L1 and capacitor C L2 Select 10pf capacitors, which are 1.5 to 2 times that of capacitor C comb1 and capacitor C comb2 For R L1 and R L2 Select 20K resistors.

4. The robust control method for MEMS vibrating gyroscope based on resonance suppression and displacement mirroring according to claim 1, characterized in that Step 2: Establish a closed-loop control circuit for the drive mode of the MEMS vibrating gyroscope. Based on the PLL and PI controllers, respectively achieve the resonance frequency tracking of the drive mode and the automatic amplitude control. The specific method is: The voltage signal representing the real-time vibration displacement output by the readout circuit based on the ring diode enters the high-speed ADC through the analog front end. The converted discrete digital signal is downsampled and low-pass filtered to obtain a vibration displacement signal with high SNR. On the one hand, this signal passes through a phase detector, a low-pass filter and a PI controller to achieve the resonance frequency tracking of the drive mode. After phase control and waveform generation, a drive reference sine wave is obtained; On the other hand, it passes through amplitude detection, low-pass filtering and a PI controller to achieve automatic gain control. Use the gain to amplitude-modulate the drive reference sine wave to obtain the drive signal of the drive mode. Finally, it reaches the internal actuator of the gyroscope through the DAC and the analog back end.

5. The robust control method for MEMS vibrating gyro based on resonance suppression and displacement mirror according to claim 1, characterized in that, Step 4: Establish a closed-loop control circuit for detecting the drive mode of the MEMS vibrating gyroscope. The voltage signal representing the vibration displacement output by the readout circuit based on the ring diode is used as the input of the PR controller. The PR controller controls the output according to the input mapping and applies it to the drive electrode of the sensitive mode. The specific method is: The resonant frequency ω of the PR controller r is set to the resonant frequency ω of the driving mode x , and the cut-off frequency ω c is set to be greater than 10 times the PLL error, the control target is set to 0, and the proportional gain k p and the resonant gain k r are adjusted until zero-static-error tracking is achieved. At this time, the vibration energy of the sensitive mode will be controlled to 0. The transfer function of the PR controller is as follows:

6. The robust control method of the MEMS vibration gyroscope based on resonance suppression and displacement mirroring according to claim 1, characterized in that, Step 5: Use the displacement mirror to calculate the angular rate output. According to the zero-static-error tracking characteristic of the PR controller and the law of conservation of energy, when the control output of the PR controller forms a displacement mirror with the open-loop vibration displacement of the sensitive mode, use this displacement mirror signal to calculate the angular rate. The specific method is: The frequency information of the PLL undergoes phase control to generate a demodulation waveform. Phase-sensitive demodulation is performed on the mirror displacement signal to filter out the residual quadrature error, obtaining the angular rate signal, which is then low-pass filtered and used as the angular rate output of the MEMS gyroscope.

7. The robust control method for MEMS vibration gyroscope based on resonance suppression and displacement mirroring according to claim 1, wherein The working principle is as follows: Apply a high-frequency modulation signal V to the common terminal of the gyroscope c , and use a readout circuit based on a ring diode to obtain the differential capacitance ΔC of the symmetric detection comb capacitors C comb1 and C comb2 . Convert the capacitance difference into a voltage V O (t) that characterizes the vibration displacement of the gyroscope mass. Convert this voltage value into the input u of a PR controller to obtain a control output y, and then convert it into the drive voltages of the symmetric drive comb capacitors C comb3 and C comb4 to suppress the vibration energy of the sensitive mode. When the control is stable, the vibration energy of the sensitive mode is approximately 0, and the control output y of the PR controller is the real-time vibration displacement mirror image of the sensitive mode. Use y to calculate the angular rate output of the MEMS gyroscope

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