Digital frequency tracking and synchronous sampling control system for resonator gyroscopes

Abstract

The application discloses a kind of digital frequency tracking and synchronous sampling control system for resonant gyro, including self-excitation oscillation and automatic gain control device, preamplifier circuit and digital signal processor, digital signal processor includes first A / D conversion unit, second A / D conversion unit, frequency error detection unit FD, phase error detection unit PD, digital control oscillator NCO, sampling frequency generator and quadrature demodulation unit, the vibration signal of drive channel is handled after device output to first A / D conversion unit, conversion obtains the vibration signal after conversion, FD obtains frequency difference by frequency error detection, PD obtains phase difference by phase error detection, NCO is adjusted the frequency and phase of sampling frequency generator according to frequency difference and phase difference in real time, until the resonant frequency and phase of drive channel are tracked;The vibration signal of detection channel is handled after circuit output to second A / D conversion unit, obtains the vibration signal after conversion, and quadrature demodulation unit carries out quadrature demodulation and obtains speed signal.

Description

Technical Field

[0001] This invention relates to the field of resonant gyroscope control technology, and in particular to a digital frequency tracking and synchronous sampling control system for resonant gyroscopes. Background Technology

[0002] A resonant gyroscope based on the Coriolis coupling principle has two orthogonal resonant modes: a primary vibration mode (driving mode) and a detection vibration mode. Taking a quartz tuning fork resonant gyroscope as an example, the primary vibration mode is first excited by the driving electrode to provide the in-plane linear velocity of the tuning fork teeth in the x-axis direction required to generate Coriolis coupling. The angular velocity input Ω in the z-axis direction causes the vibrational energy of the primary vibration mode to be coupled to the detection vibration mode through the Coriolis coupling principle, causing the detection channel to vibrate out-of-plane in the y-axis direction. The amplitude of this coupled vibration is proportional to the rotational speed. The rotational speed can be obtained by detecting, amplifying, and synchronously detecting the vibration of the detection channel through the detection electrode.

[0003] Depending on the frequency difference between the driving and detection modes, a resonant gyroscope can be selected to operate in either open-loop or closed-loop mode. Due to the simplicity of the measurement and control system, most quartz tuning fork gyroscopes are designed to operate in open-loop mode. Synchronous demodulation is a crucial step in signal processing for resonant gyroscope measurement and control systems. Corresponding to the two types of resonant gyroscopes—frequency difference mode and frequency matching mode—the initial driving signal and vibration response signal are used as reference signals for synchronous demodulation of the Coriolis force response vibration signal of the detection channel. For example, quartz tuning fork gyroscopes generally operate in frequency difference mode, where the driving signal is used as the demodulation reference signal for the detection channel. Signal demodulation can employ analog demodulation circuits based on analog switches and analog multipliers, or it can involve digital demodulation after analog-to-digital conversion of the initial and detected vibration signals. Using a digital demodulation scheme minimizes analog circuitry and reduces zero-point drift and other errors caused by temperature and other environmental changes.

[0004] Existing technology discloses a digital open-loop measurement and control system. Digital synchronous demodulation is more convenient, flexible, and stable than analog circuit demodulation. Although the vibration signal of the drive channel after analog-to-digital conversion can be directly used as the reference signal for digital demodulation, it cannot achieve synchronization between the sampling frequency of the analog-to-digital conversion and the system resonant frequency. Furthermore, this method requires a sampling frequency much higher than the system resonant frequency, resulting in high computational load, long latency, high power consumption, and low signal-to-noise ratio for synchronous demodulation. Summary of the Invention

[0005] This invention provides a digital frequency tracking and synchronous sampling control system for resonant gyroscopes, which can solve the technical problems in the prior art.

[0006] This invention provides a digital frequency tracking and synchronous sampling control system for a resonant gyroscope. The system includes a self-excited oscillation and automatic gain control device for the drive channel, a preamplifier circuit for the detection channel, and a digital signal processor. The digital signal processor includes a first A / D conversion unit, a second A / D conversion unit, a frequency error detection unit (FD), a phase error detection unit (PD), a digitally controlled oscillator (NCO), a sampling frequency generator, and a quadrature demodulation unit.

[0007] The vibration signal of the drive channel is processed by the self-excited oscillation and automatic gain control device and then output to the first A / D conversion unit. The first A / D conversion unit performs analog-to-digital conversion on the processed vibration signal to obtain the converted vibration signal. The frequency error detection unit FD is used to detect the frequency error of the converted vibration signal to obtain the frequency difference of the vibration signal. The phase error detection unit PD is used to detect the phase error of the converted vibration signal to obtain the phase difference of the vibration signal. The digitally controlled oscillator NCO is used to adjust the frequency and phase of the sampling frequency generator in real time according to the frequency difference and phase difference until the resonant frequency and phase of the drive channel are tracked.

[0008] The vibration signal from the detection channel is processed by the preamplifier circuit and then output to the second A / D conversion unit. The second A / D conversion unit is used to perform analog-to-digital conversion on the processed vibration signal to obtain the converted vibration signal. The quadrature demodulation unit is used to perform quadrature demodulation on the converted vibration signal to obtain the rotational speed signal.

[0009] Preferably, the frequency error detection unit FD performs frequency error detection on the converted vibration signal to obtain the frequency difference of the vibration signal, including:

[0010] The frequency error detection unit FD performs frequency error detection on the converted vibration signal based on the first quadrature signal and the second quadrature signal output by the digitally controlled oscillator NCO to obtain the frequency difference of the vibration signal.

[0011] Preferably, the phase error detection unit PD performs phase error detection on the converted vibration signal to obtain the phase difference of the vibration signal, including:

[0012] The phase error detection unit PD detects the phase difference of the vibration signal by performing phase error detection on the converted vibration signal based on the first orthogonal signal and the second orthogonal signal output by the digitally controlled oscillator NCO.

[0013] Preferably, the digitally controlled oscillator (NCO) adjusts the frequency and phase of the sampling frequency generator in real time according to the frequency difference and phase difference, including:

[0014] The frequency difference and the phase difference are added together to obtain a first sum value;

[0015] Integrate the first sum to obtain the integral value;

[0016] The phase difference is proportionally adjusted to obtain a proportional adjustment value;

[0017] The integral value and the proportional adjustment value are added together to obtain the second sum value;

[0018] The frequency and phase of the sampling frequency generator are adjusted in real time based on the second sum value.

[0019] Preferably, the frequency error detection unit FD includes a first digital multiplier, a first low-pass filter, a first differentiator, a second digital multiplier, a third digital multiplier, a second low-pass filter, a second differentiator, a fourth digital multiplier, and a first adder. The frequency difference of the vibration signal is obtained by performing frequency error detection on the converted vibration signal based on the first and second quadrature signals output by the digitally controlled oscillator NCO, including:

[0020] The first digital multiplier multiplies the second orthogonal signal and the converted vibration signal to obtain the first multiplication value;

[0021] The first low-pass filter filters the first multiplied value to obtain a first filtered value;

[0022] The first differentiator differentiates the first filtered value to obtain a first differential value;

[0023] The second digital multiplier multiplies the first orthogonal signal and the converted vibration signal to obtain the second multiplied value;

[0024] The second low-pass filter filters the second multiplied value to obtain the second filtered value;

[0025] The second differentiator differentiates the second filtered value to obtain a second differential value;

[0026] The third digital multiplier multiplies the first differential value and the second filtered value to obtain a third multiplied value, which is a positive value.

[0027] The fourth digital multiplier multiplies the second differential value with the first filtered value to obtain a fourth multiplied value, which is negative.

[0028] The first adder adds the third multiplication value and the fourth multiplication value to obtain the frequency difference.

[0029] Preferably, the phase error detection unit PD includes a Hilbert transform unit, a delay unit, a fifth multiplier, a sixth multiplier, and a second adder. The phase error detection unit PD performs phase error detection on the converted vibration signal based on the first quadrature signal and the second quadrature signal output by the digitally controlled oscillator NCO to obtain the phase difference of the vibration signal, including:

[0030] The Hilbert transform unit transforms the converted vibration signal to obtain the transformed signal;

[0031] The delay unit delays the converted vibration signal to obtain a delayed signal;

[0032] The fifth multiplier multiplies the transformed signal and the second orthogonal signal to obtain a fifth multiplication value, which is positive.

[0033] The sixth multiplier multiplies the delayed signal and the first orthogonal signal to obtain the sixth multiplied signal, and the sixth multiplied value is negative.

[0034] The second adder adds the fifth multiplication value to the sixth multiplication value to obtain the phase difference.

[0035] The above technical solution can quickly lock the vibration signal of the drive channel, thereby providing a clock signal for electromechanical synchronous sampling, realizing analog-to-digital conversion, real-time control and resonant frequency synchronization, reducing the amount of calculation and time delay in the signal processing process, reducing power consumption, improving the signal-to-noise ratio, and helping to improve the zero-bias stability of the gyroscope. Attached Figure Description

[0036] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the embodiments of the invention and illustrate the principles of the invention together with the textual description. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0037] Figure 1 A schematic diagram of a digital frequency tracking and synchronous sampling control system for a resonant gyroscope according to an embodiment of the present invention is shown;

[0038] Figure 2 A schematic diagram of a digital signal processor according to an embodiment of the present invention is shown;

[0039] Figure 3 A schematic diagram of a frequency error detection unit FD according to an embodiment of the present invention is shown;

[0040] Figure 4A schematic diagram of a phase error detection unit (PD) according to an embodiment of the present invention is shown. Detailed Implementation

[0041] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. 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 a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0042] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0043] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0044] Figure 1 A schematic diagram of a digital frequency tracking and synchronous sampling control system for a resonant gyroscope according to an embodiment of the present invention is shown.

[0045] in, Figure 1 Taking the open-loop operation mode of a quartz tuning fork gyroscope as an example. Alternatively, the system described in this invention is also applicable to the closed-loop operation mode.

[0046] like Figure 1As shown, this embodiment of the invention provides a digital frequency tracking and synchronous sampling control system for a resonant gyroscope. The system includes a self-excited oscillation and automatic gain control device 1 for the drive channel, a preamplifier circuit 2 for the detection channel, and a digital signal processor (DSP) 3. The DSP 3 includes a first A / D conversion unit 31, a second A / D conversion unit 32, a frequency error detection unit FD, a phase error detection unit PD, a digitally controlled oscillator NCO, a sampling frequency generator 33, and a quadrature demodulation unit 34.

[0047] The vibration signal of the drive channel is processed by the self-excited oscillation and automatic gain control device 1 and output to the first A / D conversion unit 31. The first A / D conversion unit 31 performs analog-to-digital conversion on the processed vibration signal to obtain the converted vibration signal r(t). The frequency error detection unit FD is used to detect the frequency error of the converted vibration signal r(t) to obtain the frequency difference of the vibration signal. The phase error detection unit PD is used to detect the phase error of the converted vibration signal to obtain the phase difference of the vibration signal. The digitally controlled oscillator NCO is used to adjust the frequency and phase of the sampling frequency generator 33 in real time according to the frequency difference and phase difference until the resonant frequency and phase of the drive channel are tracked.

[0048] The vibration signal from the detection channel is processed by the preamplifier circuit 2 and then output to the second A / D conversion unit 32. The second A / D conversion unit 32 is used to perform analog-to-digital conversion on the processed vibration signal to obtain the converted vibration signal. The quadrature demodulation unit 33 is used to perform quadrature demodulation on the converted vibration signal to obtain the rotational speed signal.

[0049] The quadrature demodulation unit 33 performs quadrature demodulation based on the digital reference frequency signal generated by the digitally controlled oscillator (NCO).

[0050] The above technical solution can quickly lock the vibration signal of the drive channel, thereby providing a clock signal for electromechanical synchronous sampling, realizing analog-to-digital conversion, real-time control and resonant frequency synchronization, reducing the amount of calculation and time delay in the signal processing process, reducing power consumption, improving the signal-to-noise ratio, and helping to improve the zero-bias stability of the gyroscope.

[0051] In other words, the system described in this invention can provide a sinusoidal reference frequency signal synchronized with the resonant frequency of the resonant gyroscope drive channel and various clock trigger signals. The sinusoidal reference frequency signal is used for synchronous demodulation, and the synchronous clock is used to control analog-to-digital conversion, data transmission, and feedback control. Based on typical digital phase-locked loop control, this invention integrates phase detection and auxiliary frequency difference detection to ensure fast and reliable tracking of the resonant frequency by the digital reference frequency.

[0052] Continue to refer to Figure 1The self-excited oscillation and automatic gain control device 1 includes an automatic gain control circuit (AGC), a comparator 10, and a first current-to-voltage converter 11. The self-excited oscillation and automatic gain control device 1 can generate a stable resonance and obtain a digitized vibration signal through analog-to-digital conversion. Then, the digitized vibration signal is compared with a digitally controlled oscillator (NCO) (containing a digital reference signal) to obtain the frequency difference and phase difference. The frequency control increment of the NCO is adjusted accordingly until the frequency difference and phase difference are completely eliminated. The digitally controlled oscillator (NCO) generates a synchronization reference signal and also triggers the analog-to-digital conversion (i.e., the sampling frequency of the analog-to-digital conversion is controlled by the NCO and always maintains an integer multiple of the frequency, such as 4xf, 8xf, and 16xf, etc.; 4xf is used as an example in this invention), thereby achieving electromechanical synchronous sampling of the vibration signal. The preamplifier circuit 2 includes a second current-to-voltage converter 20.

[0053] The drive channel employs a self-excited circuit based on positive feedback of vibration velocity to lock the vibration at the natural frequency of the drive mode. The vibration amplitude is stabilized at a constant value by an automatic gain control (AGC) circuit to eliminate the influence of slow changes in the resonator's quality factor. The vibration signals from both the drive and detection channels are converted into digital signals by an analog-to-digital converter (ADC), with their sampling frequency synchronized with the resonator's vibration frequency. This electromechanically synchronized sampling method, along with subsequent signal processing, simplifies calculations, reduces time delays caused by demodulation, and improves the signal-to-noise ratio. The Coriolis force vibration response signal from the detection channel can be decoded using a synchronous demodulation method to calculate the low-frequency rotation signal modulated on the high-frequency vibration signal.

[0054] According to one embodiment of the present invention, the frequency error detection unit FD performs frequency error detection on the converted vibration signal to obtain the frequency difference of the vibration signal, including:

[0055] The frequency error detection unit FD performs frequency error detection on the converted vibration signal based on the first orthogonal signal sin(ω0t) and the second orthogonal signal cos(ω0t) output by the digitally controlled oscillator NCO to obtain the frequency difference of the vibration signal.

[0056] Where ω0 is the initial frequency of the digitally controlled oscillator NCO.

[0057] According to one embodiment of the present invention, the phase error detection unit PD performs phase error detection on the converted vibration signal to obtain the phase difference of the vibration signal, including:

[0058] The phase error detection unit PD performs phase error detection on the converted vibration signal based on the first orthogonal signal sin(ω0t) and the second orthogonal signal cos(ω0t) output by the digitally controlled oscillator NCO to obtain the phase difference of the vibration signal.

[0059] Figure 2 A schematic diagram of a digital signal processor according to an embodiment of the present invention is shown.

[0060] According to one embodiment of the present invention, such as Figure 2 As shown, the digitally controlled oscillator (NCO) adjusts the frequency and phase of the sampling frequency generator 33 in real time according to the frequency difference and phase difference, including:

[0061] The frequency difference Δω and the phase difference are added together to obtain the first sum value;

[0062] Integrating the first sum (corresponding to) Figure 2 k in FD The integral value is obtained by s / S;

[0063] The phase difference is proportionally adjusted (corresponding to) Figure 2 k in PD The proportional adjustment value is obtained;

[0064] The integral value and the proportional adjustment value are added together to obtain the second sum value;

[0065] The frequency and phase of the sampling frequency generator 33 are adjusted in real time according to the second sum value.

[0066] Therefore, this invention employs an auxiliary frequency difference detection stage to indicate the direction in which the NCO output frequency should change. Combined with phase error detection, it can track and lock the vibration frequency over a wide range (i.e., increase the frequency locking range), ensuring the gyroscope's startup and stable operation under any temperature conditions and initial frequency error.

[0067] Figure 3 A schematic diagram of a frequency error detection unit FD according to an embodiment of the present invention is shown.

[0068] According to one embodiment of the present invention, such as Figure 3 As shown, the frequency error detection unit FD includes a first digital multiplier 40, a first low-pass filter (LPF) 41, a first differentiator (d / dt) 42, a second digital multiplier 43, a third digital multiplier 44, a second low-pass filter (LPF) 45, a second differentiator (d / dt) 46, a fourth digital multiplier 47, and a first adder 48. The frequency difference of the vibration signal is obtained by detecting the frequency error of the converted vibration signal based on the first and second quadrature signals output by the digitally controlled oscillator NCO, including:

[0069] The first digital multiplier 40 multiplies the second orthogonal signal cos(ω0t) and the converted vibration signal r(t) to obtain the first multiplication value;

[0070] The first low-pass filter filters the first multiplication value 41 to obtain the first filtered value;

[0071] The first differentiator 42 differentiates the first filtered value to obtain a first differential value;

[0072] The second digital multiplier 43 multiplies the first orthogonal signal sin(ω0t) and the converted vibration signal r(t) to obtain the second multiplied value;

[0073] The second low-pass filter 45 filters the second multiplied value to obtain the second filtered value;

[0074] The second differentiator 46 differentiates the second filtered value to obtain a second differential value;

[0075] The third digital multiplier 44 multiplies the first differential value and the second filtered value to obtain a third multiplied value, which is a positive value.

[0076] The fourth digital multiplier 47 multiplies the second differential value with the first filtered value to obtain a fourth multiplied value, which is negative.

[0077] The first adder 48 adds the third multiplication value and the fourth multiplication value to obtain the frequency difference Δω.

[0078] Therefore, the frequency difference of the vibration signal can be obtained.

[0079] Figure 4 A schematic diagram of a phase error detection unit (PD) according to an embodiment of the present invention is shown.

[0080] According to one embodiment of the present invention, such as Figure 4 As shown, the phase error detection unit PD includes a Hilbert transform unit (HT) 50, a delay unit (Delay) 51, a fifth multiplier 52, a sixth multiplier 53, and a second adder 54. The phase error detection unit PD performs phase error detection on the transformed vibration signal based on the first quadrature signal and the second quadrature signal output by the digitally controlled oscillator (NCO) to obtain the phase difference of the vibration signal, including:

[0081] The Hilbert transform unit 50 transforms the converted vibration signal r(t) to obtain the transformed signal Q. S ;

[0082] The delay unit 51 delays the converted vibration signal r(t) to obtain the delayed signal I. S ;

[0083] The fifth multiplier 52 multiplies the transformed signal and the second orthogonal signal cos(ω0t) to obtain a fifth multiplication value, which is positive.

[0084] The sixth multiplier 53 multiplies the delayed signal and the first orthogonal signal sin(ω0t) to obtain the sixth multiplied signal, and the sixth multiplied value is negative.

[0085] The second adder 54 adds the fifth multiplication value and the sixth multiplication value to obtain the phase difference.

[0086] In other words, the phase error detection stage obtains the analytic signal corresponding to the input signal (converted vibration signal) r(t) through Hilbert transform and delay unit, and further calculates the phase error between the NCO output signal and the tracked signal (converted vibration signal) r(t) through multiplier.

[0087] The system described in this invention can generate the digital reference frequency signal required for digital demodulation. This digital reference frequency signal is not only used for digital demodulation of the vibration signal in the detection channel, but also for generating various clocks for the system, enabling synchronous control of analog-to-digital conversion, data transmission, and feedback control. This invention is applicable to open-loop or closed-loop measurement and control systems, as well as various resonant gyroscopes employing different driving and detection methods, such as quartz tuning fork gyroscopes using the piezoelectric effect and capacitive silicon-based microelectromechanical resonant gyroscopes.

[0088] As can be seen from the above embodiments, the digital frequency tracking and synchronous sampling control system for resonant gyroscopes described in this invention has at least the following advantages: 1) It provides a demodulation reference frequency signal for the digital resonant gyroscope measurement and control system using minimal hardware circuitry; 2) It provides a clock signal for electromechanical synchronous sampling, enabling analog-to-digital conversion, real-time control, and resonant frequency synchronization, reducing computational load and time delay in signal processing, lowering power consumption, improving signal-to-noise ratio, and improving the zero-bias stability of the gyroscope; 3) Ordinary phase-locked loop control suffers from slow or inability to lock the frequency when there is an initial frequency error. This invention achieves wide-range and rapid synchronization of the digital frequency reference signal with the vibration signal of the drive channel.

[0089] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0090] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0091] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A digital frequency tracking and synchronous sampling control system for a resonant gyroscope, characterized in that, The system includes a self-excited oscillation and automatic gain control device for the drive channel, a preamplifier circuit for the detection channel, and a digital signal processor. The digital signal processor includes a first A / D conversion unit, a second A / D conversion unit, a frequency error detection unit (FD), a phase error detection unit (PD), a digitally controlled oscillator (NCO), a sampling frequency generator, and a quadrature demodulation unit. The vibration signal of the drive channel is processed by the self-excited oscillation and automatic gain control device and then output to the first A / D conversion unit. The first A / D conversion unit performs analog-to-digital conversion on the processed vibration signal to obtain the converted vibration signal. The frequency error detection unit FD is used to detect the frequency error of the converted vibration signal to obtain the frequency difference of the vibration signal. The phase error detection unit PD is used to detect the phase error of the converted vibration signal to obtain the phase difference of the vibration signal. The digitally controlled oscillator NCO is used to adjust the frequency and phase of the sampling frequency generator in real time according to the frequency difference and phase difference until the resonant frequency and phase of the drive channel are tracked. The vibration signal from the detection channel is processed by the preamplifier circuit and then output to the second A / D conversion unit. The second A / D conversion unit is used to perform analog-to-digital conversion on the processed vibration signal to obtain the converted vibration signal. The quadrature demodulation unit is used to perform quadrature demodulation on the converted vibration signal to obtain the rotational speed signal. The frequency error detection unit FD includes a first digital multiplier, a first low-pass filter, a first differentiator, a second digital multiplier, a third digital multiplier, a second low-pass filter, a second differentiator, a fourth digital multiplier, and a first adder. It performs frequency error detection on the converted vibration signal based on the first and second orthogonal signals output by the digitally controlled oscillator NCO to obtain the frequency difference of the vibration signal, including: The first digital multiplier multiplies the second orthogonal signal and the converted vibration signal to obtain the first multiplication value; The first low-pass filter filters the first multiplied value to obtain a first filtered value; The first differentiator differentiates the first filtered value to obtain a first differential value; The second digital multiplier multiplies the first orthogonal signal and the converted vibration signal to obtain the second multiplied value; The second low-pass filter filters the second multiplied value to obtain the second filtered value; The second differentiator differentiates the second filtered value to obtain a second differential value; The third digital multiplier multiplies the first differential value and the second filtered value to obtain a third multiplied value, which is a positive value. The fourth digital multiplier multiplies the second differential value with the first filtered value to obtain a fourth multiplied value, which is negative. The first adder adds the third multiplication value and the fourth multiplication value to obtain the frequency difference; The phase error detection unit PD includes a Hilbert transform unit, a delay unit, a fifth multiplier, a sixth multiplier, and a second adder. The phase error detection unit PD performs phase error detection on the converted vibration signal based on the first and second quadrature signals output by the digitally controlled oscillator (NCO) to obtain the phase difference of the vibration signal, including: The Hilbert transform unit transforms the converted vibration signal to obtain the transformed signal; The delay unit delays the converted vibration signal to obtain a delayed signal; The fifth multiplier multiplies the transformed signal and the second orthogonal signal to obtain a fifth multiplication value, which is positive. The sixth multiplier multiplies the delayed signal and the first orthogonal signal to obtain a sixth multiplication value, which is negative. The second adder adds the fifth multiplication value to the sixth multiplication value to obtain the phase difference.

2. The system according to claim 1, characterized in that, The frequency error detection unit FD performs frequency error detection on the converted vibration signal to obtain the frequency difference of the vibration signal, including: The frequency error detection unit FD performs frequency error detection on the converted vibration signal based on the first quadrature signal and the second quadrature signal output by the digitally controlled oscillator NCO to obtain the frequency difference of the vibration signal.

3. The system according to claim 2, characterized in that, The phase error detection unit PD performs phase error detection on the converted vibration signal to obtain the phase difference of the vibration signal, including: The phase error detection unit PD detects the phase difference of the vibration signal by performing phase error detection on the converted vibration signal based on the first orthogonal signal and the second orthogonal signal output by the digitally controlled oscillator NCO.

4. The system according to claim 3, characterized in that, The digitally controlled oscillator (NCO) adjusts the frequency and phase of the sampling frequency generator in real time according to the frequency difference and phase difference, including: The frequency difference and the phase difference are added together to obtain a first sum value; Integrate the first sum to obtain the integral value; The phase difference is proportionally adjusted to obtain a proportional adjustment value; The integral value and the proportional adjustment value are added together to obtain the second sum value; The frequency and phase of the sampling frequency generator are adjusted in real time based on the second sum value.

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