A method and system for online automatic calibration of phase of a hemispherical resonator gyroscope

Abstract

This invention discloses an online automatic calibration method and system for the driving phase of a hemispherical resonator gyroscope. After the gyroscope's phase-locked drive stabilizes, a known triangular wave modulation signal of a specific frequency is injected into the phase control word. The response of the orthogonal error suppression signal at the detection end to this modulation is monitored synchronously. Phase error information is extracted through differential processing, and the driving phase is then dynamically adjusted to achieve high-precision, fully automatic online calibration. This invention can compensate for phase deviations caused by temperature, voltage drift, and device aging in real time. Correspondingly, this method can be embedded in an automatic calibration system that can be fully integrated into an FPGA or ASIC, seamlessly interfacing with existing gyroscope measurement and control systems, significantly improving production efficiency and ensuring the gyroscope remains in optimal operating condition for extended periods.

Description

Technical Field

[0001] This invention relates to the field of inertial device calibration technology, and in particular to an online automatic calibration method and system for the driving phase of a hemispherical resonator gyroscope. Background Technology

[0002] In a hemispherical resonant gyroscope operating in force balance mode, the resonator drives the shaft to vibrate at its natural frequency. When the external angular velocity changes, the angular velocity is measured by detecting the output electrical signal of the shaft. The drive shaft relies on a phase-locked loop (PLL) to maintain the resonator's constant amplitude and natural frequency. However, because the phase delay of analog circuits (such as preamplifiers and filters) changes with temperature, voltage, and service life, the PLL, while able to lock the drive frequency, cannot guarantee the absolute phase accuracy of the drive signal. Even small deviations in the drive phase introduce and alter the quadrature error suppression component, becoming a significant source of gyroscope instability due to zero bias.

[0003] Currently, the calibration of the drive phase is performed as a one-time static adjustment at the factory, and the parameters are then fixed. This method leads to the following problems:

[0004] Static calibration cannot handle dynamic deviations: Traditional methods only determine and fix the drive phase parameters by manual adjustment at the factory, while the phase delay of analog circuits will change dynamically with voltage changes and device aging, which will lead to a continuous decrease in gyroscope accuracy;

[0005] Low efficiency and poor consistency in calibration: In batch testing and production, manual calibration of the drive phase is required. Manually adjusting the drive phase of a single-axis gyroscope takes more than 30 minutes, which cannot meet the needs of automated production lines. Summary of the Invention

[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide an online automatic calibration method and system for the driving phase of a hemispherical resonator gyroscope, which can calibrate the driving phase of the hemispherical resonator gyroscope online, automatically and with high precision to ensure its long-term stable and high-performance operation.

[0007] The technical solution of this invention is: an online automatic calibration method for the phase drive of a hemispherical resonator gyroscope, comprising:

[0008] After the driving frequency of the hemispherical resonator gyroscope stabilizes, perform the following steps:

[0009] S1. Inject a triangular wave phase modulation signal with known frequency, amplitude, and center value into the phase control word of the control loop;

[0010] S2. Acquire the quadrature suppression voltage at the detection end of the control loop, and differentiate the quadrature suppression voltage within the modulation period to extract the response rate of the triangular wave phase modulation signal.

[0011] S3. Determine whether the calibration completion conditions are met;

[0012] If the conditions are not met, the triangular wave phase modulation signal is adjusted once, and the adjusted triangular wave phase modulation signal is injected into the phase control word again, returning to S2; wherein, the adjustment strategy for the triangular wave phase modulation signal is: Strategy 1: Determine the phase deviation direction based on the response change rate and adjust the center value of the triangular wave phase modulation signal; Strategy 2: Reduce the modulation amplitude of the triangular wave phase modulation signal; Each adjustment selects one of Strategy 1 and Strategy 2, and Strategy 1 and Strategy 2 are selected alternately;

[0013] If the conditions are met, the automatic calibration is complete.

[0014] Furthermore, the signal form of the triangular wave phase modulation signal is as follows:

[0015]

[0016] In the formula, The signal is a triangular wave phase modulated signal, where A0 is the initial modulation amplitude, T is the modulation period, and t is the time.

[0017] Furthermore, the calibration completion condition is that the mean of the response change rate approaches zero and the modulation amplitude drops to a preset threshold.

[0018] Furthermore, the modulation amplitude of the triangular wave phase modulation signal is reduced, specifically by reducing the modulation amplitude to half of the current modulation amplitude.

[0019] Furthermore, the frequency of the triangular wave phase modulation signal is less than the driving frequency of the resonator of the hemispherical resonator gyroscope.

[0020] Furthermore, the frequency range of the triangular wave phase modulation signal is 10Hz to 100Hz.

[0021] This invention also relates to an online automatic phase calibration system for a hemispherical resonator gyroscope, comprising:

[0022] The phase modulation module is used to generate a triangular wave phase modulation signal with known frequency, amplitude, and center value, and inject it into the phase control word of the control loop; it is also used to receive adjustments to the triangular wave phase modulation signal from the control and logic module, and inject the adjusted triangular wave phase modulation signal into the phase control word of the control loop.

[0023] The response extraction and processing module is used to acquire the quadrature suppression voltage at the detection end of the control loop, and to perform differential processing on the quadrature suppression voltage within the modulation period to extract the response change rate to the triangular wave phase modulation signal.

[0024] The control and logic module is used to determine whether the calibration completion conditions are met. If not, the current triangular wave phase modulation signal is adjusted once, the phase modulation module is called, the adjusted triangular wave phase modulation signal is injected into the phase control word, and the response extraction and processing module is entered. If the calibration completion conditions are not met, the above adjustment process is repeated until they are met. The adjustment strategy for the triangular wave phase modulation signal is as follows: Strategy 1: Determine the phase deviation direction based on the response change rate and adjust the center value of the triangular wave phase modulation signal; Strategy 2: Reduce the modulation amplitude of the triangular wave phase modulation signal; Each adjustment selects one of Strategy 1 and Strategy 2, and Strategy 1 and Strategy 2 are selected alternately.

[0025] Furthermore, the differentiation process is implemented using a digital differentiator.

[0026] Furthermore, the system is integrated into the measurement and control FPGA or ASIC of the hemispherical resonator gyroscope.

[0027] The advantages of this invention compared to the prior art are:

[0028] This invention innovatively proposes an online automatic calibration method for the drive phase based on orthogonal error feedback. After the gyroscope's phase-locked drive stabilizes, a known triangular wave modulation signal of a specific frequency is injected into the phase control word. The response of the orthogonal error suppression signal at the detection end to this modulation is monitored synchronously. Phase error information is extracted through differential processing, and the drive phase is then dynamically adjusted to achieve high-precision, fully automatic online calibration. This invention can compensate for phase deviations caused by temperature, voltage drift, and device aging in real time. Correspondingly, this method can be embedded in an automatic calibration system that can be fully integrated into an FPGA or ASIC, seamlessly interfacing with existing gyroscope measurement and control systems, significantly improving production efficiency and ensuring the gyroscope remains in optimal operating condition for extended periods. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0030] Figure 2 This is a schematic diagram of the system workflow of the present invention. Detailed Implementation

[0031] To better understand the technical solution of the present invention, the specific embodiments of the present invention are described below.

[0032] like Figure 1 As shown, the online automatic calibration method for the driving phase of a hemispherical resonator gyroscope proposed in this invention performs the following steps after the phase-locked drive of the hemispherical resonator gyroscope has stabilized:

[0033] Step 1: Inject a low-frequency, small-amplitude triangular wave phase modulation signal into the phase control word of the control loop.

[0034]

[0035] Where A0 is the initial modulation amplitude, which can be set to 45°, and T is the modulation period.

[0036] The frequency of the triangular wave phase modulation signal is much lower than the driving frequency of the resonator, preferably between 10Hz and 100Hz.

[0037] Step 2: Acquire the quadrature suppression voltage at the detection end of the control loop, and differentiate it within the modulation period to extract the response rate of the triangular wave phase modulation signal;

[0038]

[0039] Where Δt is the calculation period of the digital circuit within the modulation period, and f qc(i,j) f is the quadrature suppression voltage at point j within the i-th cycle. qc(i,j+1) Let be the quadrature suppression voltage at point j+1 within the i-th cycle, and k(i,j) represent the rate of change of the response at point j within the i-th cycle.

[0040] via k i,j The minimum point can determine the optimal point of the driving phase.

[0041] Step 3: Determine if the calibration completion conditions are met:

[0042] If the conditions are not met, the triangular wave phase modulation signal is adjusted once, and the adjusted triangular wave phase modulation signal is injected into the phase control word. The process returns to step 2, and the response rate of change is recalculated to successively approximate the optimal driving phase. If the conditions are met, the automatic calibration is complete.

[0043] Specifically, the adjustment strategy for the triangular wave phase modulation signal is as follows:

[0044] Strategy 1: Determine the phase deviation direction based on the response change rate and adjust the center value of the triangular wave phase modulation signal; Strategy 2: Reduce the modulation amplitude of the triangular wave phase modulation signal; Each adjustment selects either Strategy 1 or Strategy 2, and the two are alternately selected; that is, if the center value is adjusted this time, return to step 2 to calculate the new response change rate, and then re-enter step 3 for judgment. If further adjustment is needed, then adjust the modulation amplitude; and so on.

[0045] The first cycle uses the default triangular wave center value C0 and amplitude A0. After calculation, the response rate of the quadrature suppression voltage is obtained.

[0046] Following the above method, in the second cycle, the center value of the triangular wave is set to a new center value C1 and the previous amplitude A0, thus obtaining the response rate of the new quadrature suppression voltage.

[0047] In the third cycle, the center value C1 of the second cycle is used, and a reduced amplitude A0 / 2 is used to obtain the new response rate of the quadrature suppression voltage;

[0048] The adjustment method for the second and third cycles is repeated gradually until the mean of the rate of change of the quadrature suppression voltage approaches zero and the modulation amplitude drops to the preset threshold.

[0049] Through a closed-loop feedback mechanism, the phase control word is continuously corrected according to the above steps to achieve online automatic calibration of the drive phase. After calibration, the gyroscope enters steady-state operation and can periodically trigger the calibration process to cope with environmental changes.

[0050] like Figure 2 As shown, the present invention also provides an online automatic calibration system for the phase drive of a hemispherical resonator gyroscope, used to implement the aforementioned method, comprising:

[0051] Phase modulation module: Implemented by a DDS IP core or digital waveform generator, this module allows configuration of the frequency, amplitude, and center value of the triangular wave. It generates and injects a low-frequency, small-amplitude triangular wave phase modulation signal.

[0052]

[0053] Response Extraction and Processing Module: Includes digital processing circuitry and a digital differentiator, used to acquire the quadrature suppression voltage at the detection end in real time, and to differentiate it within the modulation period to extract the response rate of change k. i,j

[0054]

[0055] Control and Logic Module: Alternately adjusts the center value and modulation amplitude of the triangular wave phase modulation signal to gradually approach the optimal driving phase. The calibration is considered complete when the mean of the rate of change of the quadrature suppression voltage approaches zero and the modulation amplitude drops to a preset threshold.

[0056] It is understood that this invention has been described through embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific circumstances without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this invention.

[0057] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for online automatic calibration of the driving phase of a hemispherical resonator gyroscope, characterized in that, include: After the driving frequency of the hemispherical resonator gyroscope stabilizes, perform the following steps: S1. Inject a triangular wave phase modulation signal with known frequency, amplitude, and center value into the phase control word of the control loop; S2. Acquire the quadrature suppression voltage at the detection end of the control loop, and differentiate the quadrature suppression voltage within the modulation period to extract the response rate of the triangular wave phase modulation signal. S3. Determine whether the calibration completion conditions are met; If the conditions are not met, the triangular wave phase modulation signal is adjusted once, and the adjusted triangular wave phase modulation signal is injected into the phase control word again, returning to S2; wherein, the adjustment strategy for the triangular wave phase modulation signal is: Strategy 1: Determine the phase deviation direction based on the response change rate and adjust the center value of the triangular wave phase modulation signal; Strategy 2: Reduce the modulation amplitude of the triangular wave phase modulation signal; Each adjustment selects one of Strategy 1 and Strategy 2, and Strategy 1 and Strategy 2 are selected alternately; If the conditions are met, the automatic calibration is complete.

2. The method for online automatic calibration of the phase drive of a hemispherical resonator gyroscope according to claim 1, characterized in that: The signal form of the triangular wave phase modulation signal is: In the formula, The signal is a triangular wave phase modulated signal, where A0 is the initial modulation amplitude, T is the modulation period, and t is the time.

3. The method for online automatic calibration of the phase drive of a hemispherical resonator gyroscope according to claim 1, characterized in that: The calibration completion condition is that the mean of the response change rate approaches zero and the modulation amplitude drops to a preset threshold.

4. The method for online automatic calibration of the phase drive of a hemispherical resonator gyroscope according to claim 1, characterized in that: To reduce the modulation amplitude of the triangular wave phase modulation signal, the specific method is to reduce the modulation amplitude to half of the current modulation amplitude.

5. The method for online automatic calibration of the phase drive of a hemispherical resonator gyroscope according to claim 1, characterized in that: The frequency of the triangular wave phase modulation signal is less than the driving frequency of the resonator of the hemispherical resonator gyroscope.

6. The method for online automatic calibration of the phase of a hemispherical resonator gyroscope according to claim 5, characterized in that: The frequency range of the triangular wave phase modulation signal is 10Hz to 100Hz.

7. A hemispherical resonator gyroscope driving phase online automatic calibration system, characterized in that, include: The phase modulation module is used to generate a triangular wave phase modulation signal with known frequency, amplitude, and center value, and inject it into the phase control word of the control loop; It is also used to receive adjustments to the triangular wave phase modulation signal from the control and logic module, and to inject the adjusted triangular wave phase modulation signal into the phase control word of the control loop; The response extraction and processing module is used to acquire the quadrature suppression voltage at the detection end of the control loop, and to perform differential processing on the quadrature suppression voltage within the modulation period to extract the response change rate to the triangular wave phase modulation signal. The control and logic module is used to determine whether the calibration completion conditions are met. If not, the current triangular wave phase modulation signal is adjusted once, the phase modulation module is called, the adjusted triangular wave phase modulation signal is injected into the phase control word, and the response extraction and processing module is entered. If the calibration completion conditions are not met, the above adjustment process is repeated until they are met. The adjustment strategy for the triangular wave phase modulation signal is as follows: Strategy 1: Determine the phase deviation direction based on the response change rate and adjust the center value of the triangular wave phase modulation signal; Strategy 2: Reduce the modulation amplitude of the triangular wave phase modulation signal; Each adjustment selects one of Strategy 1 and Strategy 2, and Strategy 1 and Strategy 2 are selected alternately.

8. The online automatic phase calibration system for a hemispherical resonator gyroscope according to claim 7, characterized in that: The differentiation process is implemented using a digital differentiator.

9. The online automatic phase calibration system for a hemispherical resonator gyroscope according to claim 7, characterized in that: The system is integrated into the measurement and control FPGA or ASIC of the hemispherical resonator gyroscope.

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