Quartz tuning fork trimming circuit based on orthogonal in-phase demodulation

Abstract

The invention provides a quartz tuning fork trimming circuit based on quadrature in-phase demodulation, which adopts a phase-locked loop driving mode to carry out quartz tuning fork driving phase closed-loop control, so that the phase demodulation precision is greatly improved; meanwhile, orthogonal and in-phase demodulation is carried out on a mixed signal output by a quartz tuning fork detection interdigital based on an orthogonal signal and an in-phase signal controlled by a phase-locked loop, so that the calculation precision of a mechanical coupling error and an electrostatic coupling error is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of quartz tuning fork gyroscope technology, and relates to a quartz tuning fork tuning circuit based on quadrature in-phase demodulation. Background Technology

[0002] Due to the anisotropy of quartz crystals and limitations in processing precision, the driving mode stiffness of the sensitive structure in a quartz tuning fork gyroscope has a component in the detection direction during processing, leading to mechanical coupling errors in the gyroscope's angular velocity output. Since the anisotropy of quartz crystals and processing precision issues are unavoidable, laser trimming is typically used in conjunction with mechanical coupling error detection methods. This involves the precise and quantitative removal of the gold film on the balancing mass block of the sensitive structure to reduce mechanical coupling errors. Currently, mechanical coupling error detection methods generally employ high-speed photography or laser interferometry to detect the displacement of the prongs of the quartz tuning fork in optical methods; and in electrical methods, a quartz tuning fork trimming and detection circuit is designed to detect the electrical signal of the prongs, indirectly reflecting the displacement information. The former provides a more accurate and intuitive reflection of the prong displacement information but is difficult to operate and expensive; the latter is simpler to operate and lower in cost, but only indirectly reflects the prong displacement information. In addition, the mixed electrical signal output from the quartz tuning fork trimming circuit contains not only the aforementioned mechanical coupling errors but also electrostatic coupling errors caused by electrostatic excitation. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] To address this, the present invention provides a quartz tuning fork tuning circuit based on quadrature in-phase demodulation. This scheme is implemented through a digital phase-locked loop driving circuit and a digital demodulation detection circuit, which enables the quartz tuning fork to drive the fork fingers to maintain resonant motion, while simultaneously demodulating the output signal of the detected fork fingers in real time, and finally outputting mechanical coupling error and electrostatic coupling error.

[0005] The technical solution of this invention is as follows: A quartz tuning fork tuning circuit based on quadrature in-phase demodulation is provided. This circuit includes: a first chip unit, a second chip unit, a third chip unit, a fourth chip unit, a quartz tuning fork detection finger, an amplitude detection pickup interface, a quartz tuning fork driving finger, and a driving amplitude pickup interface, wherein:

[0006] The quartz tuning fork drives the finger to output a driving amplitude. The first chip unit controls the second chip unit to acquire the driving amplitude of the quartz tuning fork driven finger through the driving amplitude pickup interface. At the same time, the first chip unit also controls the fourth chip unit to generate a driving signal and input it to the quartz tuning fork driven finger, forming a closed-loop driving circuit. The quartz tuning fork detects the finger to output a detection amplitude. The first chip unit controls the third chip unit in real time to acquire the detection amplitude of the quartz tuning fork detected finger through the detection amplitude pickup interface.

[0007] The first chip unit includes an automatic gain control module (AGC), a phase-locked loop control module (PLL), an electrostatic coupling error demodulation module, and a mechanical coupling error demodulation module. The AGC includes an amplitude calculation module and a controller 1 connected in sequence, and the PLL includes a phase calculation module, a controller 2, and a DDS connected in sequence.

[0008] The output of the second chip unit is an in-phase signal I, which is split into three paths and fed into the Automatic Gain Control (AGC) module, the Phase-Locked Loop (PLL) control module, and the electrostatic coupling error demodulation module, respectively. The in-phase signal I is fed into the amplitude calculation module for amplitude calculation and the phase calculation module for phase calculation. The difference between the calculated amplitude and the control input amplitude Vc is then input to controller 1 to control the signal amplitude. The calculated phase is input to controller 2 to control the signal frequency. Controller 2 outputs a signal to the DDS, and the DDS outputs an in-phase signal. The output signal of controller 1 is modulated onto this signal to obtain the input of the fourth chip unit. The DDS also simultaneously outputs a quadrature signal to the mechanical coupling error demodulation module.

[0009] The detection interdigital output signal JC from the third chip enters the electrostatic coupling error demodulation module and the mechanical coupling error demodulation module, respectively. Based on the electrostatic coupling error demodulation module and the mechanical coupling error demodulation module, JC is demodulated by the quadrature signal output from DDS and the in-phase signal I output from the second chip unit, respectively. After demodulation, the mechanical coupling error and electrostatic coupling error of the tuning fork are obtained.

[0010] Furthermore, the quartz tuning fork circuit also includes a fifth chip unit, wherein the first chip unit sends the calculation results to the fifth chip unit via USART, and blindly sends data out in real time.

[0011] Furthermore, the first chip unit, the second chip unit, the third chip unit, the fourth chip unit, and the fifth chip unit are respectively configured as an ARM chip, an ADC chip, an ADC chip, a DAC chip, and an RS422 chip.

[0012] Furthermore, when the quartz tuning fork circuit is operating:

[0013] When the center frequency of the phase-locked loop (PLL) is set to the set frequency, the PLL operates. The quartz tuning fork is equivalent to a quartz crystal. When the quartz tuning fork drives the interdigitated finger to resonate, it is equivalent to a resistor. Therefore, when the PLL locks the resonant frequency of the driving interdigitated finger, the phase difference between the driving interdigitated finger detection signal output through the driving interdigitated finger vibration pickup interface and its driving signal is 0°, and the quartz tuning fork drives the interdigitated finger to maintain the resonant state. At the same time, the AGC controls the detection signal to work at a stable amplitude by adjusting the amplitude of the driving signal.

[0014] Furthermore, the set frequency is a frequency near the resonant frequency of the interdigital fingers driven by the quartz tuning fork.

[0015] Furthermore, controller 1 is a PID controller; the expression of controller 2 is designed as follows:

[0016]

[0017] Where ω is the angular frequency of the detection signal; k ω Frequency gain; ω is the phase gain; ω0 is the center frequency; it is set to a frequency near the interdigital resonant frequency.

[0018] Furthermore, the amplitude calculation method is shown in the following formula:

[0019]

[0020] In the formula: t is time; Asinω1t is the expression for the detection signal; ω1 is the frequency of the detection signal; A is the amplitude of the detection signal.

[0021] Furthermore, the phase calculation method is shown in the following equation:

[0022]

[0023] In the formula: t is time; Here is the expression for the detection signal; ω1 is the frequency of the detection signal; A represents the phase of the detection signal; A represents the amplitude of the detection signal. Here is the expression for the driving signal; ω2 is the frequency of the driving signal. For the phase of the driving signal; For phase gain; It is the phase difference; when it is zero, This indicates that phase-locked loop (PLL) was successful. The input and output signals of the PLL are 90° out of phase. The software controls the DDS to generate a drive signal with a 90° phase difference from the PLL output signal, which serves as the drive input signal for the interdigitator.

[0024] Furthermore, the electrostatic coupling error is obtained in the following manner:

[0025] The in-phase demodulation model is obtained as shown in the following equation:

[0026]

[0027] Where: t—time; ω—drive signal frequency; Acos(ωt)—in-phase demodulation reference signal expression; A—in-phase demodulation reference signal amplitude, consistent with drive signal amplitude; KΩcosωt—vibration signal expression caused by Coriolis force, i.e., vibration signal caused by angular velocity; K—gyroscope theoretical scaling factor; Ω—gyroscope angular velocity; Bcosωt—electrostatic coupling signal expression; B—electrostatic coupling signal amplitude; Ccosωt—orthogonal coupling signal expression; C—orthogonal coupling signal amplitude;

[0028] The right side of the equation for this in-phase demodulation model is the in-phase demodulation result, which includes the amplitude information of the electrostatic coupling signal, i.e., the electrostatic coupling error.

[0029] Furthermore, the mechanical coupling error is obtained in the following manner:

[0030] The orthogonal demodulation model is obtained as shown in the following equation:

[0031]

[0032] Where: t—time; ω—drive signal frequency; Asin(ωt)—orthogonal demodulation reference signal expression; A—orthogonal demodulation reference signal amplitude, consistent with drive signal amplitude; KΩcosωt—vibration signal expression caused by Coriolis force; K—gyroscope theoretical scaling factor; Ω—gyroscope angular velocity; Bcosωt—electrostatic coupling signal expression; B—electrostatic coupling signal amplitude; Ccosωt—orthogonal coupling signal expression; C—orthogonal coupling signal amplitude;

[0033] The right side of the equation for this quadrature demodulation model is the quadrature demodulation result, which includes the amplitude information of the mechanically coupled signal, i.e., the mechanical coupling error.

[0034] By applying the above technical solution, a phase-locked loop (PLL) drive method is used for closed-loop phase control of the quartz tuning fork drive, which greatly improves the accuracy of phase demodulation. Based on the quadrature and in-phase signals controlled by the PLL, the mixed signal output by the quartz tuning fork detection finger is demodulated in both quadrature and in-phase directions, significantly improving the accuracy of mechanical coupling error and electrostatic coupling error calculation. Furthermore, in the quartz tuning fork tuning circuit based on quadrature and in-phase demodulation of this invention, except for the quartz tuning fork sensing structure and its interface circuit, which are analog devices, all other circuits are implemented using digital circuits, effectively avoiding the impact of analog device parameter drift on measurement accuracy. Attached Figure Description

[0035] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. 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.

[0036] Figure 1 This is a schematic diagram of a quartz tuning fork tuning circuit based on quadrature in-phase demodulation;

[0037] in:

[0038] PLL is the phase-locked loop control module; AGC is the automatic gain control module; Controller 1 is the amplitude controller; Controller 2 is the phase controller; I is the in-phase signal; Q is the quadrature signal; A is the amplitude of the detected signal; is the phase error; JC is the detected interdigitated output signal. Detailed Implementation

[0039] 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.

[0040] 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.

[0041] 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.

[0042] Based on the deficiencies in the existing technology mentioned in the background section, it is necessary to design a quartz tuning fork tuning circuit based on quadrature in-phase demodulation. This circuit demodulates the mixed signal to obtain accurate mechanical coupling error information, which is then used to evaluate the tuning effect of the quartz tuning fork. Through precise tuning, the mechanical coupling error of the sensitive structure of the quartz tuning fork gyroscope is further reduced, thereby improving the accuracy of the quartz tuning fork gyroscope. That is, the embodiments of this invention design such a quartz tuning fork tuning circuit based on quadrature in-phase demodulation.

[0043] like Figure 1 As shown, in one embodiment of the present invention, the technical solution of the present invention is as follows: a quartz tuning fork tuning circuit based on quadrature in-phase demodulation is provided. The circuit includes: a first chip unit, a second chip unit, a third chip unit, a fourth chip unit, a quartz tuning fork detection finger, a detection amplitude pickup interface, a quartz tuning fork driving finger, and a driving amplitude pickup interface, wherein: the quartz tuning fork driving finger outputs a driving amplitude, the first chip unit controls the second chip unit to acquire the driving amplitude of the quartz tuning fork driving finger output through the driving amplitude pickup interface, and the first chip unit also controls the fourth chip unit to generate a driving signal input to the quartz tuning fork driving finger, forming a closed-loop driving circuit; the quartz tuning fork detection finger outputs a detection amplitude, and the first chip unit controls the third chip unit in real time to acquire the detection amplitude of the quartz tuning fork detection finger output through the detection amplitude pickup interface;

[0044] The first chip unit includes an Automatic Gain Control (AGC) module, a Phase-Locked Loop (PLL) control module, an electrostatic coupling error demodulation module, and a mechanical coupling error demodulation module. The AGC includes an amplitude calculation module and controller 1 connected in sequence, and the PLL includes a phase calculation module, controller 2, and a DDS connected in sequence. The output of the second chip unit is an in-phase signal I, which is split into three paths and fed into the AGC, PLL, and electrostatic coupling error demodulation modules respectively. The in-phase signal I is fed into the amplitude calculation module for amplitude calculation and into the phase calculation module for phase calculation. The difference between the calculated amplitude and the control input amplitude Vc is then input to controller 1. The amplitude of the tuning fork is calculated; the calculated phase is input to controller 2 to control the signal frequency. Controller 2 outputs a signal to DDS, and DDS outputs an in-phase signal. The output signal of controller 1 is modulated onto this signal to obtain the input of the fourth chip unit. DDS also outputs a quadrature signal to the mechanical coupling error calculation module. The detection interdigital output signal JC of the third chip enters the electrostatic coupling error demodulation module and the mechanical coupling error demodulation module, respectively. Based on the electrostatic coupling error demodulation module and the mechanical coupling error demodulation module, JC is demodulated by the quadrature signal output by DDS and the in-phase signal I output by the second chip unit, respectively. After demodulation, the mechanical coupling error and electrostatic coupling error of the tuning fork are obtained. In the embodiments of the present invention, as shown... Figure 1 As shown, V is obtained by multiplying the I signal by the I signal and then low-pass filtering, which is called the amplitude calculation process. The calculated amplitude is then subtracted from Vc and passed to controller 1 to control the signal amplitude. The phase is obtained by multiplying the I signal by the Q signal and then low-pass filtering, which is called the phase calculation process. The calculated phase is input to controller 2 to control the frequency and phase of the DDS output signal. JC is demodulated by Q and I respectively, and the mechanical coupling error and electrostatic coupling error of the tuning fork are obtained after demodulation.

[0045] In this embodiment of the invention, the quartz tuning fork circuit further includes a fifth chip unit, wherein the first chip unit sends the calculation results to the fifth chip unit via USART and blindly sends data out in real time.

[0046] Preferably, the first chip unit, the second chip unit, the third chip unit, the fourth chip unit, and the fifth chip unit are respectively configured as an ARM chip, an ADC chip, an ADC chip, a DAC chip, and an RS422 chip.

[0047] In other words, this invention employs an ARM chip, ADC chip, DAC chip, and 422 chip in its hardware to design a quartz tuning fork tuning circuit based on quadrature in-phase demodulation. In its software, it designs an AGC control algorithm and a PLL algorithm based on the characteristics of the quartz tuning fork. During the tuning process, the output signal of the quartz tuning fork's sensitive structure is an analog signal. The ARM chip controls the ADC chip to acquire the analog signal and convert it into a digital signal. In addition, the ARM chip's computing unit runs embedded control software to implement frequency sweep control and AGC phase-locked loop drive control of the core, obtaining the control signal through digital calculations. Subsequently, the ARM chip controls the DAC chip to generate an analog signal, which serves as the input to the quartz tuning fork's sensitive structure. Simultaneously, the ARM chip's computing unit demodulates the acquired quartz tuning fork detection finger output signal to obtain the mechanical coupling error and electrostatic coupling error of the quartz tuning fork. The 422 chip blindly transmits the calculation results at a certain frequency and frame format.

[0048] Preferably, in the adjustment process of the embodiment of the present invention, the center frequency of the phase-locked loop is set to a frequency near the resonant frequency of the quartz tuning fork driving interdigit, and the phase-locked loop works; the quartz tuning fork is equivalent to a quartz crystal, and when the interdigit is driven to resonate, it is equivalent to a resistor. Therefore, when the PLL locks the resonant frequency of the driving interdigit, the phase difference between the driving interdigit detection signal output through the driving interdigit pickup interface and its driving signal is 0°, and the driving interdigit maintains the resonant state; at the same time, the AGC controls the detection signal to work at a stable amplitude by adjusting the amplitude of the driving signal.

[0049] In this embodiment of the invention, the amplitude calculation method is as follows:

[0050]

[0051] In the formula:

[0052] t — time;

[0053] Asinωt — Expression for the detection signal;

[0054] ω1 — Frequency of the detected signal;

[0055] A—Amplitude of the detected signal;

[0056] After passing the term on the right side of the above equation through a low-pass filter, multiplying it by 2 and taking the square root, the amplitude A of the detected signal can be calculated.

[0057] In this embodiment of the invention, the phase calculation method is as follows:

[0058]

[0059] The right side of the above equation is filtered out by a low-pass filter to remove high-frequency components. Considering that when in phase-locked state, ω1=ω2, and They are very close to being almost equal, which can be simplified to:

[0060]

[0061] In the formula:

[0062] t — time;

[0063] — Expression of the detection signal;

[0064] ω1 — Frequency of the detected signal;

[0065] —Detect signal phase;

[0066] A—Amplitude of the detected signal;

[0067] —Drive signal expression;

[0068] ω2 — driving signal frequency;

[0069] —Drive signal phase;

[0070] —Phase gain;

[0071] —Phase difference;

[0072] When it is zero This indicates successful phase-locked loop (PLL) operation, with the input and output signals of the PLL out of phase by 90°. The software-controlled DDS generates a drive signal with a 90° phase difference from the PLL output signal, which serves as the drive input signal for the interdigitator.

[0073] In this embodiment of the invention, controller 1 is a PID controller, and the expression of controller 2 is as follows:

[0074]

[0075] ω — Angular frequency of the detected signal;

[0076] k ω —Frequency gain;

[0077] ω0 — Center frequency, set to a frequency near the interdigital resonant frequency.

[0078] In this embodiment of the invention, electrostatic coupling error and mechanical coupling error are obtained in the following manner:

[0079] The in-phase demodulation model is as follows:

[0080]

[0081] The right side of the above equation is filtered out by a low-pass filter to remove high-frequency components. Since the tuning fork's sensitive axis points east-west and is insensitive to the Earth's rotation speed, we can obtain the following equation:

[0082]

[0083] In the formula:

[0084] t — time;

[0085] ω — driving signal frequency;

[0086] Acos(ωt) — Expression for the in-phase demodulation reference signal;

[0087] A – Amplitude of the in-phase demodulation reference signal, which is consistent with the amplitude of the drive signal;

[0088] KΩcosωt——The expression for the vibration signal caused by the Coriolis force, i.e., the vibration signal caused by the angular velocity;

[0089] K – The theoretical scaling factor for gyroscopes;

[0090] Ω—Gyroscope angular velocity;

[0091] Bcosωt — Expression for electrostatic coupling signal;

[0092] B—Amplitude of the electrostatic coupling signal;

[0093] Ccosωt — Expression for orthogonal coupled signal;

[0094] C—Amplitude of the orthogonal coupling signal;

[0095] The right side of the above equation is the in-phase demodulation result, which includes the amplitude information of the electrostatic coupling signal, i.e., the electrostatic coupling error.

[0096] The orthogonal demodulation model is as follows:

[0097]

[0098] After passing a low-pass filter to remove high-frequency components from the right side of the above equation, we obtain the following equation:

[0099]

[0100] In the formula:

[0101] t — time;

[0102] ω — driving signal frequency;

[0103] Asin(ωt) — Expression for the quadrature demodulation reference signal;

[0104] A—Amplitude of the quadrature demodulation reference signal, which is consistent with the amplitude of the drive signal;

[0105] KΩcosωt——Expression of vibration signal caused by Coriolis force;

[0106] K – The theoretical scaling factor for gyroscopes;

[0107] Ω—Gyroscope angular velocity;

[0108] Bcosωt — Expression for electrostatic coupling signal;

[0109] B—Amplitude of the electrostatic coupling signal;

[0110] Ccosωt — Expression for orthogonal coupled signal;

[0111] C—Amplitude of the orthogonal coupling signal;

[0112] The right side of the above equation is the result of quadrature demodulation, which includes the amplitude information of the mechanical coupling signal, i.e., the mechanical coupling error.

[0113] In summary, the embodiments of this invention employ a phase-locked loop (PLL) drive method for closed-loop phase control of the quartz tuning fork, significantly improving the accuracy of phase demodulation. Based on the quadrature and in-phase signals controlled by the PLL, the mixed signal output from the quartz tuning fork's fork finger is demodulated in both quadrature and in-phase directions, greatly enhancing the accuracy of mechanical and electrostatic coupling error calculations. Furthermore, in the quartz tuning fork tuning circuit based on quadrature and in-phase demodulation in these embodiments, except for the quartz tuning fork sensing structure and its interface circuit, which are analog devices, all other circuits are implemented using digital circuits. This effectively avoids the impact of analog device parameter drift on measurement accuracy.

[0114] The features described and / or illustrated above with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, and / or in combination with or in lieu of features in other embodiments.

[0115] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, components, or combinations thereof.

[0116] The methods described above in this invention can be implemented in hardware or in combination with software. This invention relates to computer-readable programs that, when executed by a logic component, enable the logic component to implement the aforementioned apparatus or constituent parts, or to implement the various methods or steps described above. This invention also relates to storage media for storing the above programs, such as hard disks, magnetic disks, optical disks, DVDs, flash memory, etc.

[0117] Many features and advantages of these embodiments are apparent from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since many modifications and alterations will readily occur to those skilled in the art, the embodiments of the invention are not intended to be limited to the precise structures and operations illustrated and described, but rather to encompass all suitable modifications and equivalents falling within their scope.

[0118] The parts of this invention not described in detail are techniques known to those skilled in the art.

Claims

1. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation, characterized in that, The circuit includes: a first chip unit, a second chip unit, a third chip unit, a fourth chip unit, a quartz tuning fork detection finger, a detection amplitude pickup interface, a quartz tuning fork driving finger, and a driving amplitude pickup interface, wherein: The quartz tuning fork drives the finger to output a driving amplitude. The first chip unit controls the second chip unit to acquire the driving amplitude of the quartz tuning fork driven finger through the driving amplitude pickup interface. At the same time, the first chip unit also controls the fourth chip unit to generate a driving signal and input it to the quartz tuning fork driven finger, forming a closed-loop driving circuit. The quartz tuning fork detects the finger to output a detection amplitude. The first chip unit controls the third chip unit in real time to acquire the detection amplitude of the quartz tuning fork detected finger through the detection amplitude pickup interface. The first chip unit includes an automatic gain control module (AGC), a phase-locked loop control module (PLL), an electrostatic coupling error demodulation module, and a mechanical coupling error demodulation module. The AGC includes an amplitude calculation module and a controller 1 connected in sequence, and the PLL includes a phase calculation module, a controller 2, and a DDS connected in sequence. The output of the second chip unit is an in-phase signal I, which is split into three paths and fed into the Automatic Gain Control (AGC) module, the Phase-Locked Loop (PLL) control module, and the electrostatic coupling error demodulation module, respectively. The in-phase signal I is fed into the amplitude calculation module for amplitude calculation and the phase calculation module for phase calculation. The difference between the calculated amplitude and the control input amplitude Vc is then input to controller 1 to control the signal amplitude. The calculated phase is input to controller 2 to control the signal frequency. Controller 2 outputs a signal to the DDS, and the DDS outputs an in-phase signal. The output signal of controller 1 is modulated onto this signal to obtain the input of the fourth chip unit. The DDS also simultaneously outputs a quadrature signal to the mechanical coupling error demodulation module. The detection interdigital output signal JC from the third chip enters the electrostatic coupling error demodulation module and the mechanical coupling error demodulation module, respectively. Based on the electrostatic coupling error demodulation module and the mechanical coupling error demodulation module, JC is demodulated by the quadrature signal output from DDS and the in-phase signal I output from the second chip unit, respectively. After demodulation, the mechanical coupling error and electrostatic coupling error of the tuning fork are obtained.

2. The quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to claim 1, characterized in that, The quartz tuning fork circuit also includes a fifth chip unit, wherein the first chip unit sends the calculation results to the fifth chip unit via USART and blindly sends data out in real time.

3. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to claim 2, characterized in that, The first chip unit, the second chip unit, the third chip unit, the fourth chip unit, and the fifth chip unit are respectively configured as an ARM chip, an ADC chip, an ADC chip, a DAC chip, and an RS422 chip.

4. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to any one of claims 1-3, characterized in that, When the quartz tuning fork circuit is working: When the center frequency of the phase-locked loop (PLL) is set to the set frequency, the PLL operates. The quartz tuning fork is equivalent to a quartz crystal. When the quartz tuning fork drives the interdigitated finger to resonate, it is equivalent to a resistor. Therefore, when the PLL locks the resonant frequency of the driving interdigitated finger, the phase difference between the driving interdigitated finger detection signal output through the driving interdigitated finger vibration pickup interface and its driving signal is 0°, and the quartz tuning fork drives the interdigitated finger to maintain the resonant state. At the same time, the AGC controls the detection signal to work at a stable amplitude by adjusting the amplitude of the driving signal.

5. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to claim 4, characterized in that, The set frequency is a frequency near the resonant frequency of the interdigital fingers driven by the quartz tuning fork.

6. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to any one of claims 1-5, characterized in that, The controller 1 is a PID controller; the expression of the controller 2 is designed as follows: Where ω is the angular frequency of the detection signal; k ω Frequency gain; ω is the phase gain; ω0 is the center frequency; it is set to a frequency near the interdigital resonant frequency.

7. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to any one of claims 1-6, characterized in that, The amplitude calculation method is shown in the following formula: In the formula: t is time; Asinω1t is the expression for the detection signal; ω1 is the frequency of the detection signal; A is the amplitude of the detection signal.

8. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to claim 7, characterized in that, The phase calculation method is shown in the following formula: In the formula: t is time; Here is the expression for the detection signal; ω1 is the frequency of the detection signal; A represents the phase of the detection signal; A represents the amplitude of the detection signal. Here is the expression for the driving signal; ω2 is the frequency of the driving signal. For the phase of the driving signal; For phase gain; It is the phase difference; when it is zero, This indicates that phase-locked loop (PLL) was successful. The input and output signals of the PLL are 90° out of phase. The software controls the DDS to generate a drive signal with a 90° phase difference from the PLL output signal, which serves as the drive input signal for the interdigitator.

9. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to claim 8, characterized in that, Electrostatic coupling error is obtained in the following manner: The in-phase demodulation model is obtained as shown in the following equation: Where: t—time; ω—drive signal frequency; Acos(ωt)—in-phase demodulation reference signal expression; A—in-phase demodulation reference signal amplitude, consistent with drive signal amplitude; KΩcosωt—vibration signal expression caused by Coriolis force, i.e., vibration signal caused by angular velocity; K—gyroscope theoretical scaling factor; Ω—gyroscope angular velocity; Bcosωt—electrostatic coupling signal expression; B—electrostatic coupling signal amplitude; Ccosωt—orthogonal coupling signal expression; C—orthogonal coupling signal amplitude; The right side of the equation for this in-phase demodulation model is the in-phase demodulation result, which includes the amplitude information of the electrostatic coupling signal, i.e., the electrostatic coupling error.

10. A quartz tuning fork tuning circuit based on quadrature in-phase demodulation according to claim 9, characterized in that, The mechanical coupling error is obtained in the following way: The orthogonal demodulation model is obtained as shown in the following equation: Where: t—time; ω—drive signal frequency; Asin(ωt)—orthogonal demodulation reference signal expression; A—orthogonal demodulation reference signal amplitude, consistent with drive signal amplitude; KΩcosωt—vibration signal expression caused by Coriolis force; K—gyroscope theoretical scaling factor; Ω—gyroscope angular velocity; Bcosωt—electrostatic coupling signal expression; B—electrostatic coupling signal amplitude; Ccosωt—orthogonal coupling signal expression; C—orthogonal coupling signal amplitude; The right side of the equation for this quadrature demodulation model is the quadrature demodulation result, which includes the amplitude information of the mechanically coupled signal, i.e., the mechanical coupling error.

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