Sinusoidal injection based virtual precession self-calibration method and system for hemispherical resonator gyroscopes

Abstract

This invention relates to a virtual precession self-calibration method and system for hemispherical resonator gyroscopes based on sinusoidal injection, belonging to the field of inertial technology. The invention addresses the problem that existing hemispherical resonator gyroscope calibration relies heavily on extensive prior temperature experiments and model accuracy, failing to meet the demands of large-scale gyroscope production. This invention injects sweep frequency information into the resonant amplitude using a fixed-amplitude sinusoidal injection module to obtain the amplitude-frequency characteristics of the resonator, and then derives the decay time constant based on these characteristics. Subsequently, the characterized decay time constant, resonant amplitude, and amplitude control output are fed back into the virtual precession self-calibration module, ultimately enabling the hemispherical resonator gyroscope to achieve precession velocity self-calibration without prior temperature calibration. This invention can be applied to the calibration process of axisymmetric vibration gyroscopes.

Description

Technical Field

[0001] This invention relates to online self-calibration technology for hemispherical resonant gyroscopes, belonging to the field of inertial technology. Background Technology

[0002] A hemispherical resonator gyroscope is an axisymmetric gyroscope that utilizes the Coriolis effect to sense the angular rate of an external input. It boasts advantages such as simple structure, small size, low power consumption, and long lifespan, thus playing a crucial role in aerospace, missiles, and aircraft. A hemispherical resonator gyroscope primarily consists of a hemispherical resonator and its electrode base. Eight equally spaced flat electrodes are etched on the electrode base, enabling the gyroscope's detection and control. As the hemispherical resonator gyroscope's operating time increases, significant changes occur in the gyroscope's operating environment, the performance of its electronic components, and the electrode gap. Therefore, virtual precession is necessary to achieve online identification of scaling factors, skew angle errors, and gain errors. However, the virtual precession speed is susceptible to environmental interference, thus affecting the identification results and the gyroscope's performance.

[0003] Traditional virtual precession compensation methods fit the relationship between the resonant frequency and the virtual precession velocity, thereby dynamically adjusting the virtual precession control voltage based on the resonant frequency. However, this method relies on extensive prior temperature experiments and the accuracy of the model, which cannot meet the needs of large-scale gyroscope production. Therefore, there is an urgent need for a self-calibration method to ensure the speed and universality of virtual precession calibration. Summary of the Invention

[0004] To address the problem that existing hemispherical resonator gyroscope calibration relies on extensive prior temperature experiments and model accuracy, which cannot meet the needs of large-scale gyroscope production, this invention provides a virtual precession self-calibration method and system for hemispherical resonator gyroscopes based on sinusoidal injection. This method does not rely on a large amount of prior data and can achieve online self-calibration.

[0005] According to one aspect of the present invention, the virtual precession self-calibration method for a hemispherical resonant gyroscope based on sinusoidal injection includes the following steps:

[0006] Step 1: Connect the hemispherical resonant gyroscope to its control circuit and power it on.

[0007] Step 2: The amplitude control loop maintains the resonant amplitude. The stability of the orthogonal control loop will determine the orthogonal amplitude value. With zero suppression, the virtual precession control loop causes the standing wave to precess under the action of the virtual Coriolis force.

[0008] Step 3: Close the amplitude control loop and start the sinusoidal injection module. Apply the open-loop sweep frequency signal to the resonant amplitude and obtain the initial decay time constant τ0 of the gyroscope based on the relationship between the resonant amplitude and the injection frequency during the decay process.

[0009] Step 4: Open the amplitude control loop, simultaneously close the sine injection module, and record the initial amplitude control output under steady-state conditions. and initial virtual precession control voltage ;

[0010] Step 5: Determine whether virtual precession self-calibration is enabled based on the gyroscope's startup time. If enabled, proceed to step 6; otherwise, repeat step 5.

[0011] Step 6: Since the time constant of the hemispherical harmonic oscillator changes slowly with the ambient temperature, after enabling virtual precession self-calibration, the system will perform precession self-calibration at intervals. Inject a sinusoidal signal into the resonant amplitude. The value is taken for several seconds to tens of seconds. If a sine wave signal is injected, proceed to step 7; otherwise, proceed to step 9.

[0012] Step 7: Close the amplitude control loop and simultaneously start the sinusoidal injection module. Apply the open-loop sweep frequency signal to the resonant amplitude, and obtain the gyroscope's decay time constant based on the relationship between the resonant amplitude and the injection frequency during the decay process. ;

[0013] Step 8: Open the amplitude control loop and simultaneously close the sine injection module;

[0014] Step 9: Based on the resonance amplitude Amplitude control output and decay time constant This is used to self-calibrate the virtual precession control voltage, keeping its precession speed stable.

[0015] Preferably, step 2, gyroscope control, involves the vibration signal output by the charge amplifier and two reference signals output by the phase-locked loop;

[0016] The gyroscope outputs electrical signals through the base electrode plates, which are detected by a charge amplifier and output as two channels of vibration signals:

[0017]

[0018] in and These are the vibration signals detected by the X channel and the Y channel, respectively. and These represent the resonance amplitude and the quadrature wave amplitude, respectively. It is the resonant frequency of the harmonic oscillator. For time, The azimuth angle of the standing wave;

[0019] The two reference signals output by the phase-locked loop are:

[0020] ,

[0021] in Represents the initial phase of the reference signal; For cosine reference signals of the same frequency and phase, It is a sinusoidal reference signal with the same frequency and phase;

[0022] The specific process of the spinning top is as follows:

[0023] Step A1: Multiply the two-channel detection signals with the reference signal, and then pass the result through a low-pass filter to obtain the four slow-variable signals of the gyroscope. , , , :

[0024]

[0025] In the formula, Represented as the cosine component of the X channel. Represents the cosine component of the Y channel. Represents the sinusoidal component of the X channel. Represents the sinusoidal component of the X channel;

[0026] Step A2: Perform a secondary combination of the four slow variable signals to obtain the gyroscope's control parameters E, Q, and L:

[0027]

[0028]

[0029]

[0030] Where E is the total energy of the gyroscope, Q is the orthogonality of the gyroscope, and L is the phase-locked loop (PLL) input for phase-locked error.

[0031] Step A3: Calculate and combine the total energy and orthogonal quantities to obtain the resonance amplitude and orthogonal wave amplitude:

[0032]

[0033] Step A4: Set the resonant amplitude Orthogonal amplitude The input is a PI control module, which includes a quadrature control loop, an amplitude control loop, and a virtual precession loop. The quadrature control loop outputs a quadrature control output voltage. Amplitude control circuit outputs amplitude control output voltage The virtual precession loop outputs the virtual precession output voltage. ;

[0034] Then, the amplitude control force is obtained by following the formula. Orthogonal control force With virtual precession control force :

[0035]

[0036] Step A5: Project the control force from step A4 onto the X / Y mode and apply it to the gyroscope's plate electrodes:

[0037]

[0038] in For x-mode control force, For y-mode control force.

[0039] Preferably, the initial decay time constant of the gyroscope in step 3 is... The identification process is as follows:

[0040] Step B1: Set the sweep frequency range of the sine injection module according to the initial resonant frequency and quality factor of the resonator. :

[0041]

[0042] in The initial resonant frequency, This is the initial quality factor;

[0043] Simultaneously, the resonant frequency of the phase-locked loop output is used as the center frequency of the sweep frequency;

[0044] Step B2: Fix the amplitude of the sweep signal and gradually increase its frequency from the center frequency to the upper frequency limit, then record the center frequency. Resonance amplitude at If the resonant amplitude attenuation reaches 0.707 during the frequency sweep process... Then record the frequency of the sweep signal at this time. , as the upsweep frequency threshold;

[0045] Step B3: Fix the amplitude of the frequency sweep signal and gradually increase its frequency from the lower limit to the center frequency. During the frequency sweep process, if the resonant amplitude attenuates to 0.707... Then record the frequency of the sweep signal at this time. , as the downsweep frequency threshold;

[0046] Step B4: Based on the downsweep frequency threshold and the upper sweep frequency threshold The initial decay time constant of the harmonic oscillator is further obtained:

[0047] .

[0048] Preferably, the decay time constant of the gyroscope in step 7 The method of obtaining it is the same as in step 4.

[0049] Preferably, the self-calibration control in step 9 to keep the precession velocity stable includes two phases: steady state and during sinusoidal injection.

[0050] In steady state, the virtual precession control voltage is dynamically adjusted based on the amplitude control output voltage and the resonator decay time constant, thereby achieving self-calibration of the precession speed.

[0051]

[0052] in This is the current amplitude control output voltage. It is the current decay time constant;

[0053] The virtual precession control loop uses open-loop control, and the virtual precession speed in steady state is... for:

[0054]

[0055] Virtual precession velocity in steady state The system remains stable under the adjustment of the virtual precession control voltage in steady state; K is the gain coefficient determined by the gyroscope structure.

[0056] During sinusoidal injection, the stability of the virtual precession of the calibration process is maintained based on the resonance amplitude:

[0057]

[0058] in, This refers to the virtual precession control voltage during the sinusoidal injection period. For the target resonance amplitude, This represents the actual resonance amplitude during the decay process. The virtual precession control voltage before the steady state of sinusoidal injection;

[0059] The virtual precession control loop adopts open-loop control, and the virtual precession speed during sinusoidal injection... for:

[0060]

[0061] Virtual precession velocity during sinusoidal injection It remains stable under the adjustment of the virtual precession control voltage during sinusoidal injection.

[0062] According to another aspect of the present invention, a virtual precession self-calibration system for a hemispherical resonator gyroscope based on sinusoidal injection is provided. This system is used to implement the aforementioned virtual precession self-calibration method for a hemispherical resonator gyroscope based on sinusoidal injection. The system includes a charge amplifier, an analog-to-digital converter, a signal demodulation module, a gyroscope control module, a sinusoidal injection module, a virtual precession calibration module, and a digital-to-analog converter; wherein:

[0063] The charge amplifier is connected to the eight plate electrodes of the hemispherical resonant gyroscope and is used to convert the capacitance change caused by the vibration of the resonator into a voltage signal.

[0064] The analog-to-digital converter is used to convert the analog voltage signal output by the charge amplifier into a digital signal;

[0065] The signal demodulation module includes a multiplication demodulation module, a low-pass filter, and a control parameter calculation module. The multiplication demodulation module is used to multiply the X / Y channel detection signal with the phase-locked loop reference signal. The low-pass filter is used to remove the second harmonic information in the product signal and output four slow variable signals. The control parameter calculation module is used to perform a secondary combination of the four slow variable signals to obtain the gyroscope resonance amplitude, the quadrature wave amplitude, and the phase-locked error.

[0066] The gyroscope control module includes a phase-locked loop (PLL), a PI control module, a switch selection module, a control signal modulation module, and a vector synthesis module. The PLL tracks the resonator's vibration frequency and generates a reference signal with the same frequency and phase for signal demodulation and drive modulation. The PI control module controls the resonant amplitude and quadrature wave amplitude to target values. The switch selection module switches the control voltage applied to the resonant amplitude; if sinusoidal injection is performed, a fixed-amplitude sweep signal is applied to the resonant amplitude; otherwise, normal amplitude control is performed. The control signal modulation module multiplies the amplitude control, quadrature control, and virtual precession control signals with the corresponding reference signals. The vector synthesis module projects the output of the control signal modulation module onto the two vibration modes.

[0067] The sinusoidal injection module is used to inject a fixed-amplitude sweep frequency signal into the direction of the resonant amplitude, and then obtain the decay time constant of the harmonic oscillator based on its amplitude-frequency characteristics.

[0068] The virtual precession calibration module uses the resonance amplitude, amplitude control output, and decay time constant to dynamically adjust the virtual precession control voltage, thereby realizing the virtual precession self-calibration of the gyroscope in the working state.

[0069] The digital-to-analog converter is used to convert the digital quantity output by the gyroscope control module into an analog voltage signal and apply the control voltage to the plate electrode.

[0070] The beneficial effects of this invention are as follows: This invention obtains the decay time constant of the resonator by injecting sweep frequency information into the resonant amplitude through a constant amplitude sinusoidal injection module. By feeding back the obtained decay time constant, resonant amplitude, and amplitude control output to the virtual precession calibration module, efficient and accurate calibration of the virtual precession velocity of the hemispherical resonant gyroscope can be achieved without prior temperature calibration.

[0071] This invention solves the problem that the virtual precession velocity of a hemispherical resonant gyroscope varies with ambient temperature and that the compensation method relies on a large amount of experimental data. It improves the performance of the gyroscope under variable temperature conditions and can meet the needs of large-scale gyroscope production. Attached Figure Description

[0072] Figure 1 This is a flowchart of the virtual precession self-calibration method for hemispherical resonant gyroscopes based on sinusoidal injection described in this invention;

[0073] Figure 2 This is a block diagram of the virtual precession self-calibration system for a hemispherical resonant gyroscope based on sinusoidal injection, as described in this invention. Detailed Implementation

[0074] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0075] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0076] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0077] Specific Implementation Method 1: The following is combined with... Figure 1 This embodiment describes a virtual precession self-calibration method for a hemispherical resonant gyroscope based on sinusoidal injection. The method includes the following steps:

[0078] Step 1: Connect the hemispherical resonant gyroscope to its control circuit and power it on.

[0079] Step 2: The amplitude control loop maintains the resonant amplitude. The stability of the orthogonal control loop will determine the orthogonal amplitude value. With zero suppression, the virtual precession control loop causes the standing wave to precess under the action of the virtual Coriolis force.

[0080] Gyroscope control involves the vibration signal output from the charge amplifier and two reference signals output from the phase-locked loop;

[0081] The gyroscope outputs electrical signals through the base electrode plates, which are detected by a charge amplifier and output as two channels of vibration signals:

[0082]

[0083] in and These are the vibration signals detected by the X channel and the Y channel, respectively. and These represent the resonance amplitude and the quadrature wave amplitude, respectively. It is the resonant frequency of the harmonic oscillator. For time, The azimuth angle of the standing wave;

[0084] The two reference signals output by the phase-locked loop are:

[0085] ,

[0086] in Represents the initial phase of the reference signal; For cosine reference signals of the same frequency and phase, It is a sinusoidal reference signal with the same frequency and phase;

[0087] The specific process of the spinning top is as follows:

[0088] Step A1: Multiply the vibration signal output from the charge amplifier and the two reference signals output from the phase-locked loop, and then pass the result through a low-pass filter to obtain the four slow variable signals of the gyroscope. , , , :

[0089]

[0090] In the formula, Represented as the cosine component of the X channel. Represents the cosine component of the Y channel. Represents the sinusoidal component of the X channel. Represents the sinusoidal component of the X channel;

[0091] Step A2: Perform a secondary combination of the four slow variable signals to obtain the gyroscope's control parameters E, Q, and L:

[0092]

[0093]

[0094]

[0095] Where E is the total energy of the gyroscope, Q is the orthogonality of the gyroscope, and L is the phase-locked loop (PLL) input for phase-locked error.

[0096] Step A3: Calculate and combine the total energy and orthogonal quantities to obtain the resonance amplitude and orthogonal wave amplitude:

[0097]

[0098] Step A4: Set the resonant amplitude Orthogonal amplitude The input is a PI control module, which includes a quadrature control loop, an amplitude control loop, and a virtual precession loop. The quadrature control loop outputs a quadrature control output voltage. Amplitude control circuit outputs amplitude control output voltage The virtual precession loop outputs the virtual precession output voltage. ;

[0099] Then, the amplitude control force is obtained by following the formula. Orthogonal control force With virtual precession control force :

[0100]

[0101] Step A5: Project the control force from step A4 onto the X / Y mode and apply it to the gyroscope's plate electrodes:

[0102]

[0103] in For x-mode control force, For y-mode control force.

[0104] Step 3: Close the amplitude control loop and start the sinusoidal injection module. Apply the open-loop sweep frequency signal to the resonant amplitude and obtain the initial decay time constant τ0 of the gyroscope based on the relationship between the resonant amplitude and the injection frequency during the decay process.

[0105] Initial decay time constant of the gyroscope The identification process is as follows:

[0106] Step B1: Set the sweep frequency range of the sine injection module according to the initial resonant frequency and quality factor of the resonator. :

[0107]

[0108] in The initial resonant frequency, This is the initial quality factor;

[0109] Simultaneously, the resonant frequency of the phase-locked loop output is used as the center frequency of the sweep frequency;

[0110] Step B2: Fix the amplitude of the sweep signal and gradually increase its frequency from the center frequency to the upper frequency limit, then record the center frequency. Resonance amplitude at If the resonant amplitude attenuation reaches 0.707 during the frequency sweep process... Then record the frequency of the sweep signal at this time. , as the upsweep frequency threshold;

[0111] Step B3: Fix the amplitude of the frequency sweep signal and gradually increase its frequency from the lower limit to the center frequency. During the frequency sweep process, if the resonant amplitude attenuates to 0.707... Then record the frequency of the sweep signal at this time. , as the downsweep frequency threshold;

[0112] Step B4: Based on the downsweep frequency threshold and the upper sweep frequency threshold The initial decay time constant of the harmonic oscillator is further obtained:

[0113] .

[0114] Step 4: Open the amplitude control loop, simultaneously close the sine injection module, and record the initial amplitude control output under steady-state conditions. and initial virtual precession control voltage ;

[0115] Step 5: Determine whether virtual precession self-calibration is enabled based on the gyroscope's startup time. If enabled, proceed to step 6; otherwise, repeat step 5.

[0116] Virtual precession self-calibration typically starts 5 to 10 minutes after startup.

[0117] Step 6: Since the time constant of the hemispherical harmonic oscillator changes slowly with the ambient temperature, after enabling virtual precession self-calibration, the system will perform precession self-calibration at intervals. Inject a sinusoidal signal into the resonant amplitude. The value is taken for several seconds to tens of seconds. If a sine wave signal is injected, proceed to step 7; otherwise, proceed to step 9.

[0118] To achieve online calibration, the system performs calibration at intervals. A sinusoidal signal is injected into the resonant amplitude, and a new decay time constant is calculated to ensure stable precession velocity.

[0119] Step 7: Close the amplitude control loop and start the sinusoidal injection module. Apply the open-loop sweep frequency signal to the resonant amplitude and obtain the gyroscope's decay time constant τ based on the relationship between the resonant amplitude and the injection frequency during the decay process.

[0120] The method for obtaining the gyroscope's decay time constant τ in step 7 is the same as in step 4. The only difference is the time period in which it occurs.

[0121] Step 8: Open the amplitude control loop and simultaneously close the sine injection module;

[0122] Step 9: Based on the resonance amplitude Amplitude control output voltage and decay time constant This is used to self-calibrate the virtual precession control voltage, keeping its precession speed stable.

[0123] Self-calibration control maintains a stable precession velocity in two phases: steady state and during sinusoidal injection.

[0124] In steady state, the virtual precession control voltage is dynamically adjusted based on the amplitude control output voltage and the resonator decay time constant, thereby achieving self-calibration of the precession speed.

[0125]

[0126] in This is the current amplitude control output voltage. It is the current decay time constant;

[0127] The virtual precession control loop uses open-loop control, and the virtual precession speed in steady state is... for:

[0128]

[0129] Virtual precession velocity in steady state The system remains stable under the adjustment of the virtual precession control voltage in steady state; K is the gain coefficient determined by the gyroscope structure.

[0130] During sinusoidal injection, the stability of the virtual precession of the calibration process is maintained based on the resonance amplitude:

[0131]

[0132] in, This refers to the virtual precession control voltage during the sinusoidal injection period. For the target resonance amplitude, This represents the actual resonance amplitude during the decay process. The virtual precession control voltage before the steady state of sinusoidal injection;

[0133] The virtual precession control loop adopts open-loop control, and the virtual precession speed during sinusoidal injection... for:

[0134]

[0135] Virtual precession velocity during sinusoidal injection It remains stable under the adjustment of the virtual precession control voltage during sinusoidal injection.

[0136] Specific Implementation Method Two: The following is combined with... Figure 2 This embodiment describes a sinusoidal injection-based virtual precession self-calibration system for hemispherical resonator gyroscopes, used to implement the sinusoidal injection-based virtual precession self-calibration method for hemispherical resonator gyroscopes described in Embodiment 1. The system includes a charge amplifier, an analog-to-digital converter, a signal demodulation module, a gyroscope control module, a sinusoidal injection module, a virtual precession calibration module, and a digital-to-analog converter; wherein:

[0137] The charge amplifier is connected to the eight plate electrodes of the hemispherical resonant gyroscope and is used to convert the capacitance change caused by the vibration of the resonator into a voltage signal.

[0138] The analog-to-digital converter is used to convert the analog voltage signal output by the charge amplifier into a digital signal;

[0139] The signal demodulation module includes a multiplication demodulation module, a low-pass filter, and a control parameter calculation module. The multiplication demodulation module is used to multiply the X / Y channel detection signal with the phase-locked loop reference signal. The low-pass filter is used to remove the second harmonic information in the product signal and output four slow variable signals. The control parameter calculation module is used to perform a secondary combination of the four slow variable signals to obtain the gyroscope resonance amplitude, the quadrature wave amplitude, and the phase-locked error.

[0140] The gyroscope control module includes a phase-locked loop (PLL), a PI control module, a switch selection module, a control signal modulation module, and a vector synthesis module. The PLL tracks the resonator's vibration frequency and generates a reference signal with the same frequency and phase for signal demodulation and drive modulation. The PI control module controls the resonant amplitude and quadrature wave amplitude to target values. The switch selection module switches the control voltage applied to the resonant amplitude; if sinusoidal injection is performed, a fixed-amplitude sweep signal is applied to the resonant amplitude; otherwise, normal amplitude control is performed. The control signal modulation module multiplies the amplitude control, quadrature control, and virtual precession control signals with the corresponding reference signals. The vector synthesis module projects the output of the control signal modulation module onto the two vibration modes.

[0141] The sinusoidal injection module is used to inject a fixed-amplitude sweep frequency signal into the direction of the resonant amplitude, and then obtain the decay time constant of the harmonic oscillator based on its amplitude-frequency characteristics.

[0142] The virtual precession calibration module uses the resonance amplitude, amplitude control output, and decay time constant to dynamically adjust the virtual precession control voltage, thereby realizing the virtual precession self-calibration of the gyroscope in the working state.

[0143] The digital-to-analog converter is used to convert the digital quantity output by the gyroscope control module into an analog voltage signal and apply the control voltage to the plate electrode.

[0144] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A virtual precession self-calibration method for a hemispherical resonant gyroscope based on sinusoidal injection, characterized in that, The method includes the following steps: Step 1: Connect the hemispherical resonant gyroscope to its control circuit and power it on. Step 2: The amplitude control loop maintains the resonant amplitude. The stability of the orthogonal control loop will determine the orthogonal amplitude value. With zero suppression, the virtual precession control loop causes the standing wave to precess under the action of the virtual Coriolis force. Step 3: Close the amplitude control loop and simultaneously start the sinusoidal injection module. Apply the open-loop sweep frequency signal to the resonant amplitude, and obtain the initial decay time constant of the gyroscope based on the relationship between the resonant amplitude and the injection frequency during the decay process. ; The initial decay time constant of the gyroscope in step 3 The identification process is as follows: Step B1: Set the sweep frequency range of the sine injection module according to the initial resonant frequency and quality factor of the resonator. : in The initial resonant frequency, This is the initial quality factor; Simultaneously, the resonant frequency of the phase-locked loop output is used as the center frequency of the sweep frequency; Step B2: Fix the amplitude of the sweep signal and gradually increase its frequency from the center frequency to the upper frequency limit, then record the center frequency. Resonance amplitude at If the resonant amplitude attenuation reaches 0.707 during the frequency sweep process... Then record the frequency of the sweep signal at this time. , as the upsweep frequency threshold; Step B3: Fix the amplitude of the frequency sweep signal and gradually increase its frequency from the lower limit to the center frequency. During the frequency sweep process, if the resonant amplitude attenuates to 0.707... Then record the frequency of the sweep signal at this time. , as the downsweep frequency threshold; Step B4: Based on the downsweep frequency threshold and the upper sweep frequency threshold The initial decay time constant of the harmonic oscillator is further obtained: Step 4: Open the amplitude control loop, simultaneously close the sine injection module, and record the initial amplitude control output voltage under steady-state conditions. and initial virtual precession control voltage ; Step 5: Determine whether virtual precession self-calibration is enabled based on the gyroscope's startup time. If enabled, proceed to step 6; otherwise, repeat step 5. Step 6: Since the time constant of the hemispherical harmonic oscillator changes slowly with the ambient temperature, after enabling virtual precession self-calibration, the system will perform precession self-calibration at intervals. Inject a sinusoidal signal into the resonant amplitude. The value is taken for several seconds to tens of seconds. If a sine wave signal is injected, proceed to step 7; otherwise, proceed to step 9. Step 7: Close the amplitude control loop and simultaneously start the sinusoidal injection module. Apply the open-loop sweep frequency signal to the resonant amplitude, and obtain the gyroscope's decay time constant based on the relationship between the resonant amplitude and the injection frequency during the decay process. ; Step 8: Open the amplitude control loop and simultaneously close the sine injection module; Step 9: Control the output voltage based on the resonant amplitude 'a'. and decay time constant This is used to self-calibrate the virtual precession control voltage, ensuring that its precession speed remains stable. Step 9's self-calibration control stabilizes the precession velocity, encompassing two phases: steady-state and during sinusoidal injection. In steady state, the virtual precession control voltage is dynamically adjusted based on the amplitude control output voltage and the resonator decay time constant, thereby achieving self-calibration of the precession speed. in This is the current amplitude control output voltage. It is the current decay time constant; The virtual precession control loop uses open-loop control, and the virtual precession speed in steady state is... for: Virtual precession velocity in steady state The system remains stable under the adjustment of the virtual precession control voltage in steady state; K is the gain coefficient determined by the gyroscope structure. During sinusoidal injection, the stability of the virtual precession of the calibration process is maintained based on the resonance amplitude: in, This refers to the virtual precession control voltage during the sinusoidal injection period. For the target resonance amplitude, This represents the actual resonance amplitude during the decay process. The virtual precession control voltage before the steady state of sinusoidal injection; The virtual precession control loop adopts open-loop control, and the virtual precession speed during sinusoidal injection is... for: Virtual precession velocity during sinusoidal injection It remains stable under the adjustment of the virtual precession control voltage during sinusoidal injection.

2. The virtual precession self-calibration method for a hemispherical resonant gyroscope based on sinusoidal injection according to claim 1, characterized in that, Step 2, gyroscope control, involves the vibration signal output from the charge amplifier and two reference signals output from the phase-locked loop; The gyroscope outputs electrical signals through the base electrode plates, which are detected by a charge amplifier and output as two channels of vibration signals: in and These are the vibration signals detected by the X channel and the Y channel, respectively. and These represent the resonance amplitude and the quadrature wave amplitude, respectively. It is the resonant frequency of the harmonic oscillator. For time, The azimuth angle of the standing wave; The two reference signals output by the phase-locked loop are: ， in Represents the initial phase of the reference signal; For cosine reference signals of the same frequency and phase, It is a sinusoidal reference signal with the same frequency and phase; The specific process of the spinning top is as follows: Step A1: Multiply the vibration signal output from the charge amplifier and the two reference signals output from the phase-locked loop, and then pass the result through a low-pass filter to obtain the four slow variable signals of the gyroscope. , , , : In the formula, Represented as the cosine component of the X channel. Represents the cosine component of the Y channel. Represents the sinusoidal component of the X channel. Represents the sinusoidal component of the X channel; Step A2: Perform a secondary combination of the four slow variable signals to obtain the gyroscope's control parameters E, Q, and L: Where E is the total energy of the gyroscope, Q is the orthogonality of the gyroscope, and L is the phase-locked loop (PLL) input for phase-locked error. Step A3: Calculate and combine the total energy and orthogonal quantities to obtain the resonance amplitude and orthogonal wave amplitude: Step A4: Set the resonance amplitude Orthogonal amplitude The input is a PI control module, which includes a quadrature control loop, an amplitude control loop, and a virtual precession loop. The quadrature control loop outputs a quadrature control output voltage. Amplitude control circuit outputs amplitude control output voltage The virtual precession loop outputs the virtual precession output voltage. ; Then, the amplitude control force is obtained by following the formula. Orthogonal control force With virtual precession control force : Step A5: Project the control force from step A4 onto the X / Y mode and apply it to the gyroscope's plate electrodes: in For x-mode control force, For y-mode control force.

3. The virtual precession self-calibration method for a hemispherical resonant gyroscope based on sinusoidal injection according to claim 1, characterized in that, The decay time constant of the gyroscope in step 7 The method of obtaining it is the same as in step 3.

4. A virtual precession self-calibration system for a hemispherical resonator gyroscope based on sinusoidal injection, the system being used to implement the virtual precession self-calibration method for a hemispherical resonator gyroscope based on sinusoidal injection as described in claim 2, characterized in that... The system includes a charge amplifier, an analog-to-digital converter, a signal demodulation module, a gyroscope control module, a sine wave injection module, a virtual precession calibration module, and a digital-to-analog converter; among which: The charge amplifier is connected to the eight plate electrodes of the hemispherical resonant gyroscope and is used to convert the capacitance change caused by the vibration of the resonator into a voltage signal. The analog-to-digital converter is used to convert the analog voltage signal output by the charge amplifier into a digital signal; The signal demodulation module includes a multiplication demodulation module, a low-pass filter, and a control parameter calculation module; the multiplication demodulation module is used to compare the X-channel detection signal with the in-phase cosine reference signal output by the phase-locked loop. and in-phase sinusoidal reference signal Multiply the two reference signals, and multiply the Y-channel detection signal with the same frequency and phase cosine reference signal output by the phase-locked loop. and in-phase sinusoidal reference signal The two reference signals are multiplied to obtain four product signals; the low-pass filter is used to remove the second harmonic information in the product signals and output four slow variable signals; the control parameter calculation module is used to perform a secondary combination of the four slow variable signals to obtain the total energy E, orthogonality Q and phase-locked error L of the gyroscope, and then calculate the gyroscope resonance amplitude and orthogonal wave amplitude based on the total energy E and orthogonality Q. The gyroscope control module includes a phase-locked loop (PLL), a PI control module, a switch selection module, a control signal modulation module, and a vector synthesis module. The PLL tracks the resonator's oscillation frequency and generates a reference signal of the same frequency and phase for signal demodulation and drive modulation. The PI control module controls the resonant amplitude and quadrature wave amplitude to target values. The switch selection module switches the control voltage applied to the resonant amplitude; if sinusoidal injection is performed, a fixed amplitude sweep signal is applied to the resonant amplitude; otherwise, normal amplitude control is performed. The control signal modulation module modulates the amplitude control output voltage with the sinusoidal reference signal of the same frequency and phase. Multiplication, quadrature control output voltage and in-phase cosine reference signal Multiplication and virtual precession control output voltage and in-phase sinusoidal reference signal Multiplication generates the corresponding amplitude control force. Orthogonal control force and virtual precession control force The vector synthesis module is used to convert the amplitude control force Orthogonal control force and virtual precession control force Projecting this force onto the X and Y vibration modes yields the control force of the X mode. and y-mode control force ; The sinusoidal injection module is used to inject a fixed amplitude sweep signal into the direction of the resonant amplitude, and then obtain the initial decay time constant of the gyroscope based on the decay relationship of the resonant amplitude with the injection frequency during the sweep process. Initial decay time constant of the gyroscope The identification process is as follows: Step B1: Set the sweep frequency range of the sine injection module according to the initial resonant frequency and quality factor of the resonator. : in The initial resonant frequency, This is the initial quality factor; Simultaneously, the resonant frequency of the phase-locked loop output is used as the center frequency of the sweep frequency; Step B2: Fix the amplitude of the sweep signal and gradually increase its frequency from the center frequency to the upper frequency limit, then record the center frequency. Resonance amplitude at If the resonant amplitude attenuation reaches 0.707 during the frequency sweep process... Then record the frequency of the sweep signal at this time. , as the upsweep frequency threshold; Step B3: Fix the amplitude of the frequency sweep signal and gradually increase its frequency from the lower limit to the center frequency. During the frequency sweep process, if the resonant amplitude attenuates to 0.707... Then record the frequency of the sweep signal at this time. , as the downsweep frequency threshold; Step B4: Based on the downsweep frequency threshold and the upper sweep frequency threshold The initial decay time constant of the harmonic oscillator is further obtained: ； The virtual precession calibration module is used to dynamically adjust the virtual precession control voltage in two phases: during steady state and during sinusoidal injection. In steady state, the output voltage Va and the current decay time constant are controlled according to the current amplitude. Initial amplitude control output Initial decay time constant and initial virtual precession control voltage ,according to Calculate and adjust the steady-state virtual precession control voltage. ; During sinusoidal injection, the virtual precession control voltage at the steady state before sinusoidal injection is used. Target resonance amplitude and the actual resonance amplitude during the decay process ,according to Calculate and adjust the virtual precession control voltage during sinusoidal injection. ; This enables virtual precession self-calibration of the gyroscope during operation; The digital-to-analog converter is used to convert the digital quantity output by the gyroscope control module into an analog voltage signal and apply the control voltage to the plate electrode.

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