CN116124107A - Quartz Gyroscope Circuit - Google Patents

Abstract

The invention provides a quartz gyroscope circuit, which comprises a closed-loop driving circuit; the closed-loop driving circuit comprises a driving interdigital, a driving end circuit and a controller; the driving end circuit is used for converting a driving response charge signal generated by the driving interdigital into a driving response voltage signal and transmitting the driving response voltage signal to the controller; the controller is used for generating an original digital reference signal, adjusting the frequency and the amplitude of the original digital reference signal based on the driving response voltage signal, generating a driving voltage signal and transmitting the driving voltage signal to the driving end circuit; the driving end circuit is used for amplifying the driving voltage signal, and applying the amplified driving voltage signal to the driving interdigital, so that the oscillation frequency of the driving interdigital is in the resonance frequency of the quartz tuning fork, and the oscillation amplitude of the driving interdigital is in the preset amplitude range. The invention is used for solving the defects that the oscillation frequency of the analog quartz gyroscope cannot work at the resonance frequency and the oscillation amplitude is unstable in the prior art.

Description

Quartz gyroscope circuit

Technical Field

The present invention relates to the technical field of gyroscopes, and in particular to a quartz gyroscope circuit.

Background Art

Gyroscope is an important inertial sensitive device, which is a sensor used to measure angular velocity or angular displacement. According to the working principle or structure, gyroscopes can be roughly divided into three categories: mechanical gyroscope, optical gyroscope and micro-electro-mechanical system (MEMS) gyroscope. Compared with other traditional gyroscopes, micro-mechanical gyroscopes have the characteristics of small size, light weight, low power consumption and high reliability, and are widely used in aerospace, automobile, shipbuilding and guidance systems. The quartz gyroscope is a micro-mechanical gyroscope based on the Coriolis force principle, which uses quartz crystal as a sensitive element. Quartz material has a good piezoelectric effect, so the quartz gyroscope does not require a complex structure to realize the control and detection of the gyroscope. In addition, the quartz gyroscope also has the advantages of low cost and high quality factor.

In the prior art, quartz gyroscopes often use full analog circuits to achieve oscillation control and external angular velocity detection. Full analog circuits are implemented using multiple discrete components. The discrete components used in actual engineering applications are all non-ideal components, which will introduce angular velocity zero position errors. There are also differences between the parameters of discrete components, and there are also differences between the parameters of quartz tuning forks. Therefore, the drive circuit cannot guarantee that the quartz tuning fork drive end will work at its resonant frequency point, and the oscillation amplitude varies greatly and is unstable.

Summary of the invention

The invention provides a quartz gyroscope circuit, which is used to solve the defects in the prior art that the oscillation frequency of the analog quartz gyroscope cannot work at the resonance frequency and the oscillation amplitude is unstable.

The present invention provides a quartz gyroscope circuit, comprising a closed-loop driving circuit; the closed-loop driving circuit comprises driving fingers, a driving end circuit and a controller, wherein the driving fingers refer to the driving ends of quartz tuning forks; the driving end circuit is used to convert driving response charge signals generated by the driving fingers into driving response voltage signals, and transmit the driving response voltage signals to the controller; the controller is used to generate an original digital reference signal, adjust the frequency and amplitude of the original digital reference signal based on the driving response voltage signal, generate a driving voltage signal, and transmit the driving voltage signal to the driving end circuit; the driving end circuit is used to amplify the driving voltage signal, and apply the amplified driving voltage signal to the driving fingers, so that the oscillation frequency of the driving fingers is at the resonant frequency of the quartz tuning fork, and the oscillation amplitude of the driving fingers is within a preset amplitude range.

A quartz gyroscope circuit provided according to the present invention also includes a detection circuit; the detection circuit includes detection fork fingers, a detection end circuit and the controller, wherein the detection fork fingers refer to the detection end of the quartz tuning fork; the detection end circuit is used to convert the detection response charge signal generated by the detection fork fingers into a detection response voltage signal, and transmit the detection response voltage signal to the controller; the controller is used to analyze the detection response voltage signal to obtain angular velocity information.

According to a quartz gyroscope circuit provided by the present invention, the controller includes a first analog-to-digital converter and a digital-to-analog converter; the driving end circuit is used to transmit the driving response voltage signal to the first analog-to-digital converter; the first analog-to-digital converter is used to convert the driving response voltage signal into a driving response digital signal; the controller is used to adjust the frequency and amplitude of the original digital reference signal based on the driving response digital signal, generate a digital excitation signal, and transmit the digital excitation signal to the digital-to-analog converter; the digital-to-analog converter is used to convert the digital excitation signal into the driving voltage signal.

According to a quartz gyroscope circuit provided by the present invention, the controller includes a digitally controlled oscillator; the original digital reference signal includes an original sine digital signal and an original cosine digital signal; the digitally controlled oscillator is used to generate the original sine digital signal and the original cosine digital signal; the controller is used to demodulate the drive response digital signal based on the original sine digital signal to generate an original in-phase component, and demodulate the drive response signal based on the original cosine digital signal to generate an original orthogonal component; the controller is used to calculate the response amplitude of the drive response digital signal based on the original in-phase component and the original orthogonal component, and determine the excitation amplitude of the digital excitation signal based on the response amplitude and a preset target amplitude; the controller is used to calculate the response phase of the drive response digital signal based on the original in-phase component and the original orthogonal component, and determine the excitation phase of the digital excitation signal based on the response phase and a preset target phase.

According to a quartz gyroscope circuit provided by the present invention, the controller also includes an automatic gain control module; the digitally controlled oscillator is used to generate the original sinusoidal digital signal and the original cosine digital signal based on the excitation frequency, wherein the phase of the original sinusoidal digital signal is the target phase; the automatic gain control module is used to generate the digital excitation signal based on the original sinusoidal digital signal and the excitation amplitude, wherein the amplitude of the digital excitation signal is the target amplitude.

According to a quartz gyroscope circuit provided by the present invention, the controller is used to perform phase compensation on the original in-phase component based on the resonant frequency, and to perform phase compensation on the original orthogonal component based on the resonant frequency.

According to a quartz gyroscope circuit provided by the present invention, the controller is used to perform capacitive compensation on the original orthogonal component after phase compensation based on the orthogonal component compensation value, wherein the orthogonal component compensation value is obtained based on the capacitive performance of the quartz tuning fork.

According to a quartz gyroscope circuit provided by the present invention, the controller includes a second analog-to-digital converter; the detection end circuit is used to transmit the detection response voltage signal to the second analog-to-digital converter; the second analog-to-digital converter is used to convert the detection response voltage signal into a detection response digital signal; the controller is used to parse the detection response digital signal to obtain the angular velocity information.

According to a quartz gyroscope circuit provided by the present invention, the controller includes a digitally controlled oscillator; the original digital reference signal includes an original sine digital signal and an original cosine digital signal; the digitally controlled oscillator is used to generate the original sine digital signal and the original cosine digital signal; the controller is used to demodulate the detection response digital signal based on the original sine digital signal to generate a detection in-phase component, and to demodulate the detection response digital signal based on the original cosine digital signal to generate a detection orthogonal component.

According to a quartz gyroscope circuit provided by the present invention, the controller is used to perform phase compensation on the detected in-phase component and the detected orthogonal component; the controller is used to perform temperature compensation on the detected in-phase component based on the real-time ambient temperature.

The quartz gyroscope circuit provided by the present invention comprises a closed-loop driving circuit; the closed-loop driving circuit comprises a driving fork finger, a driving end circuit and a controller, wherein the driving fork finger refers to the driving end of a quartz tuning fork; the driving end circuit is used to convert a driving response charge signal generated by the driving fork finger into a driving response voltage signal, and transmit the driving response voltage signal to the controller; the controller is used to generate an original digital reference signal, adjust the frequency and amplitude of the original digital reference signal based on the driving response voltage signal, generate a driving voltage signal, and transmit the driving voltage signal to the driving end circuit; the driving end circuit is used to amplify the driving voltage signal, and apply the amplified driving voltage signal to the driving fork finger, so that the oscillation frequency of the driving fork finger is at the resonant frequency of the quartz tuning fork, and the oscillation amplitude of the driving fork finger is within a preset amplitude range. In the above process, the frequency and amplitude of the original digital reference signal are adjusted by the driving response voltage signal fed back when the driving fork finger oscillates, so as to generate the driving voltage signal. The amplified driving voltage signal is used to excite the driving fork fingers, so that the oscillation frequency of the driving fork fingers is at the resonant frequency of the quartz tuning fork, and the oscillation amplitude of the driving fork fingers is within the preset amplitude range, thereby ensuring the stability of the oscillation frequency and the oscillation amplitude of the driving fork fingers.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of the structural connection of a quartz gyroscope circuit provided by the present invention;

FIG2 is an equivalent circuit model of a driving interdigital drive provided by the present invention;

FIG3 is a schematic diagram of the closed-loop drive circuit principle provided by the present invention;

FIG4 is a schematic diagram of the principle of the detection circuit provided by the present invention;

5 is a schematic diagram of measured data of original in-phase and original orthogonal components of the driving end of the digital quartz gyroscope provided by the present invention;

6 is a schematic diagram of measured data of the in-direction component and the orthogonal component after compensation of the driving end of the digital quartz gyroscope provided by the present invention;

7 is a schematic diagram of static test data of a digital quartz gyroscope at room temperature provided by the present invention;

FIG8 is a physical example diagram of a digital quartz gyroscope provided by the present invention;

9 is a schematic diagram of zero-position data of a temperature cycle test of a digital quartz gyroscope provided by the present invention;

FIG. 10 is a schematic diagram of the structure of an electronic device provided by the present invention.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments in the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present invention.

The fully analog quartz gyroscope uses discrete components to achieve closed-loop control of the gyroscope and detection of external angular velocity. The quartz gyroscope circuit mainly includes two parts: the drive circuit and the detection circuit. The drive circuit generally uses a self-excited oscillation closed-loop drive scheme to track the quartz resonant frequency, so that the quartz drive end oscillates at the resonant frequency point, ensuring that even if the natural frequency of the quartz drive end drifts, it can still maintain resonance at the new frequency point. In addition, the drive circuit will also add an automatic gain control (AGC) feedback control circuit to the self-excited oscillation circuit to keep the amplitude of the drive signal unchanged or control the change within a certain range, thereby ensuring the stability of the frequency and amplitude of the drive signal.

The detection circuit converts the charge signal of angular velocity into a voltage output signal. Its working process is as follows: when there is an external angular velocity input, the quartz tuning fork generates a charge signal, and the charge/voltage conversion circuit (also known as the Q/V conversion circuit) and the amplifier circuit of the detection circuit convert the charge signal into a voltage signal. The driving signal with the same frequency as the voltage signal is used as the reference signal. After demodulation by a multiplier (generally a switch multiplier) and a low-pass filter circuit, the same-direction component of the detection end is obtained (the same-direction component is used to represent the angular velocity information); the detection circuit finally outputs a DC voltage signal corresponding to the angular velocity.

The fully analog quartz gyroscope uses discrete devices to build the drive circuit and the detection circuit to achieve the measurement of angular velocity, but has the following defects: First, the discrete devices actually used are non-ideal components, so the non-ideal factors of the discrete devices such as the DC bias of the operational amplifier and the injected charge of the switch multiplier will introduce an angular velocity zero position error; Second, the fully analog quartz gyroscope can only demodulate the in-phase component of the detection end, but cannot demodulate the orthogonal component of the detection end, and cannot obtain information such as the drive frequency and AGC, and cannot provide data basis for subsequent gyroscope improvements and quartz watch movement adjustment processes; Third, there are differences between the parameters of independent components, and there are also differences between the parameters of quartz tuning forks, so the drive circuit cannot guarantee that the quartz tuning fork drive end must work at its resonant frequency point, and there will be a certain phase angle deviation; Fourth, the compensability of the fully analog quartz gyroscope is very poor, and batch compensation is difficult.

Based on the above analysis, the present invention provides a quartz gyroscope circuit. The quartz gyroscope circuit of the embodiment of the present invention is described below in conjunction with FIG. 1 to FIG. 9 .

In one embodiment, as shown in FIG1 , the quartz gyroscope circuit includes a closed-loop drive circuit; the closed-loop drive circuit includes drive fingers, a drive end circuit and a controller, wherein the drive fingers refer to the drive end of the quartz tuning fork; the drive end circuit is used to convert the drive response charge signal generated by the drive fingers into a drive response voltage signal, and transmit the drive response voltage signal to the controller; the controller is used to generate an original digital reference signal, adjust the frequency and amplitude of the original digital reference signal based on the drive response voltage signal, generate a drive voltage signal, and transmit the drive voltage signal to the drive end circuit; the drive end circuit is used to amplify the drive voltage signal, and apply the amplified drive voltage signal to the drive fingers, so that the oscillation frequency of the drive fingers is at the resonant frequency of the quartz tuning fork, and the oscillation amplitude of the drive fingers is within a preset amplitude range.

In the present embodiment, the quartz gyroscope includes a quartz tuning fork, which is a sensitive element. The quartz tuning fork includes a driving end and a detection end, the driving end of the quartz tuning fork is called a driving fork finger, and the detection end of the quartz tuning fork is called a detection fork finger. The controller is a component capable of digital information processing, such as a single-chip microcomputer. The driving tuning fork, the driving end circuit and the controller realize closed-loop tracking control of the resonant frequency of the quartz tuning fork, adjust the frequency and amplitude of the original digital reference signal by driving the response digital signal, and finally generate a driving voltage signal, and excite the driving fork finger to oscillate at the resonant frequency point of the quartz tuning fork by the amplified driving voltage signal, so as to ensure that the frequency and amplitude of the driving tuning fork are relatively stable when oscillating. In the present embodiment, the preset amplitude range is an amplitude variation range set according to factors such as the hardware parameters of the gyroscope and the ambient temperature, and the preset amplitude range is a relatively small variation range. When the oscillation amplitude of the driving fork finger changes within the preset amplitude range, it can be determined that the oscillation amplitude of the driving fork finger is relatively stable.

In one embodiment, the quartz gyroscope circuit also includes a detection circuit; the detection circuit includes detection fork fingers, a detection end circuit and a controller, wherein the detection fork fingers refer to the detection end of the quartz tuning fork; the detection end circuit is used to convert the detection response charge signal generated by the detection fork fingers into a detection response voltage signal, and transmit the detection response voltage signal to the controller; the controller is used to analyze the detection response voltage signal to obtain angular velocity information.

In this embodiment, the detection end circuit is used to detect the charge signal generated by the displacement of the detection fork finger, that is, the detection response charge signal, and convert the detection response charge signal into a detection response voltage signal. The controller is responsible for processing the detection response voltage signal into angular velocity information.

In one embodiment, the controller includes a first analog-to-digital converter and a digital-to-analog converter; the driving end circuit is used to transmit the driving response voltage signal to the first analog-to-digital converter; the first analog-to-digital converter is used to convert the driving response voltage signal into a driving response digital signal; the controller is used to adjust the frequency and amplitude of the original digital reference signal based on the driving response digital signal, generate a digital excitation signal, and transmit the digital excitation signal to the digital-to-analog converter; the digital-to-analog converter is used to convert the digital excitation signal into a driving voltage signal.

In this embodiment, the driving response voltage signal of the driving fork finger is sampled by the first analog-to-digital converter (Analog to Digital Converter, ADC) to generate a driving response digital signal, so that the controller can digitally process the driving end response signal (i.e., the digitized driving response digital signal). At the same time, the digital excitation signal generated by the controller is converted into a driving voltage signal by a digital-to-analog converter (Digital to Analog Converter, DAC), and the driving voltage signal is an analog signal, so that the analog driving voltage signal can be applied to the driving fork finger to excite the oscillation of the driving fork finger. The digital processing process is easy to implement and easier to integrate into a smaller chip, thereby reducing the volume of the entire quartz gyroscope. At the same time, the use of analog components is reduced, thereby avoiding the errors caused by analog components and improving the stability of the frequency and amplitude when the quartz tuning fork oscillates.

In this embodiment, the driving end circuit includes a driving preamplifier and a voltage amplification module. The driving preamplifier is used to detect the driving response charge signal generated by the driving fork finger, convert the driving response charge signal into a driving response voltage signal, and transmit the driving response voltage signal to the controller; the controller is used to transmit the driving voltage signal to the voltage amplification module; the voltage amplification module is used to amplify the driving voltage signal and apply the amplified driving voltage signal to the driving fork finger.

In this embodiment, the driving preamplifier (referred to as driving preamplifier) is a Q/V conversion circuit designed with a precision operational amplifier as the core device, which converts the detection response charge signal into a driving response voltage signal without distortion, and then converts the driving response voltage signal into a driving response digital signal that can be processed by the controller through the first ADC. After further processing the driving response digital signal, the controller generates a digital excitation signal and transmits it to the DAC. The DAC converts the digital excitation signal into a driving voltage signal. The DAC transmits the driving voltage signal to the voltage amplification module, which amplifies the voltage driving signal to enhance the signal strength, and acts on the driving fork finger after the amplification The voltage driving signal acts on the driving fork finger to excite the driving fork finger oscillation.

In one embodiment, the controller includes a digitally controlled oscillator; and the raw digital reference signal includes a raw sine digital signal and a raw cosine digital signal.

The digital controlled oscillator is used to generate an original sine digital signal and an original cosine digital signal; the controller is used to demodulate the driving response digital signal based on the original sine digital signal to generate an original in-phase component, and to demodulate the driving response signal based on the original cosine digital signal to generate an original orthogonal component; the controller is used to calculate the response amplitude of the driving response digital signal based on the original in-phase component and the original orthogonal component, and determine the excitation amplitude of the digital excitation signal based on the response amplitude and a preset target amplitude; the controller is used to calculate the response phase of the driving response digital signal based on the original in-phase component and the original orthogonal component, and determine the frequency of the digital excitation signal based on the response phase and the preset target phase.

In this embodiment, a digitally controlled oscillator (NCO) outputs a frequency-controllable dual-channel sinusoidal digital drive signal as a reference signal, and the reference signal is demodulated in the same direction to obtain an original sinusoidal digital signal; the reference signal is demodulated in the same direction to obtain an original cosine digital signal. The initial phase of the original sinusoidal digital signal (in the same direction) and the original cosine digital signal (in the same direction) generated by the NCO is 0.

In one embodiment, the controller also includes an automatic gain control module; the digitally controlled oscillator is used to generate an original sinusoidal digital signal and an original cosine digital signal based on an excitation frequency, wherein the phase of the original sinusoidal digital signal is a target phase; the automatic gain control module is used to generate a digital excitation signal based on the original sinusoidal digital signal and an excitation amplitude, wherein the amplitude of the digital excitation signal is a target amplitude.

In this embodiment, a digital phase-locked loop (PLL) is formed based on a closed-loop control circuit and a controller to lock the excitation signal and response signal of the driving fork fingers at a certain phase. The frequency corresponding to the phase is the resonant frequency of the quartz tuning fork, that is, the frequency control of the driving voltage signal is achieved by phase locking.

In one embodiment, the controller is configured to perform phase compensation on the original in-phase component based on the resonant frequency, and to perform phase compensation on the original quadrature component based on the resonant frequency.

In this embodiment, the driving interdigital equivalent circuit model is shown in FIG2 , wherein R1 represents an equivalent resistor, L1 represents an equivalent inductor, C1 represents a series equivalent capacitor, and R1, L1, and C1 form an RLC branch. C0 represents an equivalent parallel static capacitor. _{i s} represents the response of the RLC branch, i _C0 represents the response of the C0 branch, and i represents the total response.

In the full temperature range, since the relative change of the resistor R1 is much greater than the relative change of the capacitor C0, at the resonant frequency point, the phase of the total current flowing through the driving fork fingers is not exactly the same, but has a slight difference, resulting in a large deviation between the frequency of the excitation signal generated by the NCO and the actual resonant frequency of the driving tuning fork.

The processes such as the drive preamplifier frequency response and ADC conversion time in the closed-loop drive circuit will cause a delay in the controller program execution time. Therefore, there will be a phase difference between the drive response digital signal and the original digital reference signal, which will cause the original sine digital signal and the original cosine digital signal to be coupled with each other. Therefore, the original sine digital signal and the original cosine digital signal can be phase compensated. The optimal compensation phase angle of the drive end is calculated. Under the optimal compensation phase angle of the drive end, the RLC series branch at the resonant frequency point is purely resistive, and the in-phase component and the orthogonal component of the drive end are contributed by the equivalent resistance R1 and the static capacitance C0 in the equivalent circuit model respectively.

Furthermore, the phase compensation principle under ideal conditions is as follows:

Under ideal conditions, that is, without considering the delay caused by the program and hardware, the excitation signal F _x (t) generated by the NCO without phase compensation (the excitation signal frequency is not necessarily the resonant frequency) is set to:

_Fx (t)= _Fd *sin(wt) (1);

Among them, _Fd is the amplitude, t is the time, and w is the phase.

Assume that F _sin (t) is the original sine digital signal, F _cos (t) is the original cosine digital signal, and the amplitude F _jt is a constant, as follows:

F _sin (t)=F _jt *sin(wt) (2);

F _cos (t)＝F _jt *cos(wt) (3);

Based on the equivalent circuit model of the driving interdigital finger as shown in FIG2 , according to the frequency response of the RLC series branch, the phase shift corresponding to w in the phase-frequency characteristic is θ _RLC , and when w is equal to the series resonant frequency w _d , θ _RLC is equal to 0°.

Assuming the amplitude of the RLC branch response i _S (t) is F _s , the response i _S (t) of the RLC series branch is:

i _S (t)=F _s *sin (wt+θ _RLC ) (4);

Assuming the amplitude of the _C0 branch response i _C0 (t) is F _c0 , then the static capacitance _C0 branch response i _C0 is:

i _C0 (t)=F _c0 *cos(wt) (5);

Then the total response signal i(t) of the driving interdigit is:

i(t)=i _S (t)+i _C0 (t) (6);

为激励信号与响应信号的相位差，具体为：In the formula,

is the phase difference between the excitation signal and the response signal, specifically:

主要是由石英陀螺仪表芯本身的频率响应导致的。In an ideal situation,

This is mainly caused by the frequency response of the quartz gyro instrument core itself.

Using the superposition principle, i _S (t) and i _C0 (t) are demodulated respectively. The in-phase component Sin _is and the orthogonal component Cos _is of i _S (t) (after multiplication demodulation and filtering) are as follows:

Sin _is =F _jt *F _s *0.5*cos(θ _RLC ) (9);

Cos _is =F _jt *F _s *0.5*sin(θ _RLC ) (10);

Similarly, the in-phase component Sini _c0 and the orthogonal component Cosi _c0 of i _C0 (t) are shown as follows:

Sin _ic0 = 0 (11);

Cos _ic0 =F _jt *F _c0 *0.5 (12);

The demodulated in-phase component A (the real part of the complex number, that is, the original sine digital signal) and the orthogonal component B (the imaginary part of the complex number, that is, the original cosine digital signal) are respectively:

A＝F _jt *F _s *0.5*cos(θ _RLC ) (13);

B＝F _jt *F _s *0.5*sin(θ _RLC )+F _jt *F _c0 *0.5 (14);

In an ideal state, the static capacitor C1 in the RLC branch only contributes to the orthogonal component. And when the frequency w of the excitation signal is the series resonance frequency, Cos _is equal to 0, then at this time, the original sine digital signal (the real part in the complex number) is only contributed by the equivalent resistor _R1 , and the original cosine digital signal (the imaginary part in the complex number) is only contributed by the static capacitor _C0 .

The amplitude Amp of the demodulated response signal is:

The phase F _θ of the demodulated response signal is:

Therefore, it can be known that the amplitude and initial phase of the response signal can be calculated based on the demodulated in-phase component and quadrature component.

Based on the above, further considering the phase compensation principle under the delayed phase angle is as follows:

Considering the delay phase angle caused by the program and hardware, and assuming that the delay phase angle is Δθ, the excitation signal F _x (t), the original sine digital signal F _sin (t) and the original cosine digital signal F _cos (t) remain unchanged, then i _S (t) is:

i _S (t) = F _s *sin (wt + θ _RLC + Δθ) (19);

i _C0 is:

i _C0 (t)=F _c0 *cos(wt+Δθ) (20);

Under non-ideal conditions, the total response signal i(t) of the driving interdigit is:

i(t)=i _S (t)+i _C0 (t) (21);

The in-phase component Sin _is and the orthogonal component Cos _is of i _S (t) (after multiplication demodulation and filtering) are as follows:

Sin _is =F _jt *F _s *0.5*cos(θ _RLC +Δθ) (23);

Cos _is =F _jt *F _s *0.5*sin(θ _RLC +Δθ) (24);

The in-phase component Sini _c0 and the orthogonal component Cosi _c0 of i _C0 (t) are shown as follows:

Sin _ic0 =-F _jt *F _c0 *0.5*sin(Δθ) (25);

Cos _ic0 =F _jt *F _c0 *0.5*sin(Δθ) (26);

The in-phase component A is and the orthogonal component B is:

A＝F _jt *F _s *0.5*cos(θ _RLC +Δθ)-F _jt *F _c0 *0.5*sin(Δθ) (27);

B＝F _jt *F _s *0.5*sin(θ _RLC +Δθ)+F _jt *F _c0 *0.5*cos(Δθ) (28);

The amplitude Amp of the demodulated response signal is:

When w is the series resonant frequency, θ _RLC = 0°. Because the delay phase angle Δθ exists, the equivalent resistance _R1 and the static capacitance _C0 both contribute the same-direction component and the orthogonal component.

Perform phase angle compensation on the same direction component A:

A _new =A*cos(Δθ)+B*sin(Δθ) (31);

A _new ＝F _jt *F _s *0.5*cos(θ _RLC ) (32);

Perform phase angle compensation on the quadrature component B:

B _mew = B*cos(Δθ)-A*sin(Δθ) (33);

B _mew ＝F _jt *F _s *0.5*sin(θ _RLC )+F _jt *F _c0 *0.5 (34);

A _new and B _new are consistent with the in-phase component A and the orthogonal component B in an ideal situation, thus achieving the purpose of phase compensation.

In this embodiment, during the phase compensation (also called angle compensation) process, compensation can also be performed according to the real-time ambient temperature.

In one embodiment, the controller is configured to perform capacitive compensation on the original orthogonal component after phase compensation based on the orthogonal component compensation value, wherein the orthogonal component compensation value is obtained based on the capacitive performance of the quartz tuning fork.

In this embodiment, an orthogonal component compensation value proportional to C0 can be obtained based on the original orthogonal component after phase compensation. The orthogonal component compensation value is subtracted from the original orthogonal component after phase compensation. If the target phase is 0, the orthogonal component of the driving end after phase angle compensation and C0 coefficient compensation is 0.

By performing phase compensation and capacitive compensation on the original in-phase component and the original orthogonal component, it can be ensured that the phase difference between the excitation signal and the response signal driving the fork finger is always 0° within the full temperature range, ensuring that the frequency of the analog drive signal generated by the NCO is stable at the resonant frequency of the quartz tuning fork.

Based on the above embodiment, the response phase of the driving finger driving response digital signal can be calculated according to the compensated original in-phase component and the original orthogonal component, and the difference with the target phase is calculated. The preset frequency control algorithm determines the frequency of the NCO output digital excitation signal by the phase difference. This working process is a phase loop. The amplitude of the driving response digital signal can be obtained by taking the modulus of the compensated original in-phase component and the original orthogonal component, and the amplitude difference can be obtained by comparing with the set target amplitude. Then, the AGC control factor is calculated by the preset amplitude control algorithm to ensure the stability of the NCO driving signal amplitude. This loop is an amplitude loop. The quartz gyroscope controls the NCO to generate a digital excitation signal with controllable frequency and stable amplitude by the amplitude loop and then the DAC outputs the corresponding driving voltage signal.

In one embodiment, the controller includes a second analog-to-digital converter; the detection end circuit is used to transmit the detection response voltage signal to the second analog-to-digital converter; the second analog-to-digital converter is used to convert the detection response voltage signal into a detection response digital signal; the controller is used to analyze the detection response digital signal to obtain angular velocity information.

In this embodiment, the detection end circuit includes a detection preamplifier and an AC amplification module. The detection preamplifier is used to detect the detection response charge signal generated when the detection interdigital oscillation occurs, convert the detection response charge signal into a detection response voltage signal, and transmit the detection response voltage signal to the AC amplification module; the AC amplification module is used to amplify the detection response voltage signal and transmit the detection response voltage signal to the second ADC.

In this embodiment, a detection preamplifier (referred to as detection preamplifier) is constructed with a low-noise precision operational amplifier. The detection preamplifier converts the detection response charge signal into a detection response voltage signal, and the AC amplification module enhances the signal strength of the detection response voltage signal, so that the controller can better analyze the amplified detection response voltage signal. Furthermore, when the sampling accuracy of the detection end is required to be high, the second ADC uses an 18-bit ADC chip, and the second ADC converts the detection response voltage signal into a corresponding detection response digital signal.

In one embodiment, the controller includes a digitally controlled oscillator; the original digital reference signal includes an original sine digital signal and an original cosine digital signal; the digitally controlled oscillator is used to generate an original sine digital signal and an original cosine digital signal; the controller is used to demodulate the detection response digital signal based on the original sine digital signal to generate a detection in-phase component, and to demodulate the detection response digital signal based on the original cosine digital signal to generate a detection orthogonal component.

In this embodiment, the dual-path sinusoidal discrete digital driving signal output by the NCO is used as a reference signal, and the detection response digital signal is demodulated to obtain a detection in-phase component and a detection orthogonal component.

In one embodiment, the controller is used to perform phase compensation on the detected in-phase component and to perform phase compensation on the detected quadrature component; the controller is used to perform temperature compensation on the detected in-phase component based on the real-time ambient temperature.

In this embodiment, there is also a phase difference between the original digital reference signal and the detection response digital signal (i.e., the detection of the same direction component and the detection of the orthogonal component), so the detection response digital signal can be phase compensated to achieve a complete separation of the detection of the orthogonal component and the angular velocity (detection of the same direction component), thereby suppressing the influence of the orthogonal coupling on the angular velocity measurement accuracy of the gyroscope. In addition, the angular velocity output of the digital quartz gyroscope can be compensated according to the real-time temperature measured by the temperature sensor to optimize the full-temperature performance of the digital quartz gyroscope.

In this embodiment, the controller can demodulate the detection of the same direction component and the detection of the orthogonal component, and can also obtain information such as the driving frequency and AGC. The controller can also send information such as the angular velocity and AGC to the host computer through wireless or wired communication. For example, the controller includes a universal synchronous/asynchronous serial receiver/transmitter (USART) communication interface to provide data basis for subsequent digital gyroscope optimization, movement adjustment and other processing processes.

In a specific embodiment, based on the implementation methods provided by the above-mentioned embodiments, a schematic diagram of the closed-loop driving circuit principle as shown in FIG3 is established, wherein the target phase is set to 0, and a voltage amplifier module can be connected in series after the DAC to increase the oscillation amplitude and improve the sensitivity of the quartz gyroscope. As shown in FIG3, the charge output signal of the driving fork finger is converted into a corresponding digital quantity signal by the driving preamplifier and the first analog-to-digital converter, and then the driving end displacement signal (i.e., the driving response digital signal) is demodulated and filtered in the controller, and then the driving voltage signal is generated by the digital-to-analog converter. The driving closed-loop circuit uses a driving closed-loop solution of a digital phase-locked loop and a digital automatic gain control to ensure that the driving fork finger always oscillates at its resonant frequency, and the oscillation amplitude of the driving fork finger is within a preset amplitude range, that is, the oscillation amplitude of the driving fork finger remains unchanged or has only a small change.

In this embodiment, based on the implementation methods provided by the above-mentioned embodiments, a detection circuit principle schematic diagram as shown in FIG4 is established, wherein an AC amplifier module can be added before and after the detection to facilitate subsequent signal processing. When temperature compensation is performed on the detection of the same-direction component, a temperature sensor can be used to collect the real-time ambient temperature, and the set third ADC converts the temperature analog signal into a temperature digital signal and transmits it to the controller for processing. The detection circuit collects the detection response digital signal of the detection fork finger, and the controller performs digital signal processing such as filtering and demodulation on it, and finally the external angular velocity can be accurately measured.

In one embodiment, based on the implementation method provided in any of the above embodiments, a digital quartz gyroscope is constructed and tested, and the results are as follows:

The frequency sweep test is carried out at the resonance frequency of the driving tuning fork ±25Hz. According to the normal temperature frequency sweep data of the digital quartz gyroscope, the optimal compensation phase angle and C0 compensation coefficient of the driving end can be calculated, and the optimal compensation phase angle and C0 compensation coefficient of the driving end can be burned into the controller through the host computer. After the compensation of the driving end of the digital quartz gyroscope, the normal temperature static test is carried out for 600S. The original digital reference signal in the form of digital discrete is used to demodulate the driving response digital signal after ADC conversion in the same direction and in the same direction. Figure 5 shows the digital quantity data of the original in-direction component and the original orthogonal component of the driving end of the digital quartz gyroscope measured for 600S. As shown in Figure 5, the original in-direction component and the original orthogonal component of the driving end are consistent in magnitude, both of which are 10^6.

The original in-phase component of the driving end is phase compensated, and the original orthogonal component of the driving end is phase compensated and the C0 coefficient is compensated, and the compensated in-phase component and orthogonal component data can be obtained, as shown in Figure 6. As shown in Figure 6, the magnitude of the compensated in-phase component is 10^7, which is slightly larger than the original in-phase component of the original driving end. The orthogonal component of the driving end after compensation fluctuates around 0, which is much smaller than the original orthogonal component of the driving end, which shows that the compensation method of the driving end is effective.

After the digital gyroscope is subjected to the drive end compensation, detection end phase compensation and zero position calibration compensation tests, the compensation parameters are burned into the controller and the static repeatability test at room temperature is carried out: the temperature of the incubator is set to 25°C, and after the temperature of the incubator is stable, the digital quartz gyroscope is powered and 1800S of static data are collected, and then the power is turned off and the test is repeated 5 times. Figure 7 shows the measured zero position data of the digital quartz gyroscope static test at room temperature. It can be seen that the zero position of the compensated digital quartz gyroscope can reach the order of 10^-3 (°/S), and the zero position stability is calculated to be 1.26°/h, the zero position repeatability is 1.76°/h, and the angle random walk is 2.35°/h/sqrt (Hz). It can be seen that the angular velocity output white noise of the digital quartz gyroscope is low, and the zero position has good stability and repeatability.

In a specific embodiment, a quartz tuning fork and a quartz gyroscope circuit are integrated into a digital quartz gyroscope. The actual picture of the digital quartz gyroscope is shown in FIG8 . The overall structure is relatively small, and it is powered by 5V±0.2V. It uses a swing-wire output to realize the functions of sending data and powering the external device. Different wire colors represent different signal definitions.

A temperature cycle test is performed on the compensated digital quartz gyroscope to verify the full-temperature performance of the digital quartz gyroscope.

The test conditions are as follows:

Power supply: +5VDC;

Temperature cycle times: 2 times;

Working temperature: -45℃ to 80℃;

Data collection section: data of the heating section from low temperature to high temperature.

Since the digital quartz gyroscope uses the data of the heating stage for calibration compensation, only the data of the heating stage is analyzed in the temperature cycle test. Figure 9 is a graph of the zero position data of the digital quartz gyroscope in two heating stages. It can be seen that the digital quartz gyroscope has good zero position repeatability and good stability in the full temperature range, which can be maintained at the order of 10^-3 (°/S). The temperature cycle test proves that the digital quartz gyroscope has excellent full temperature performance.

The quartz gyroscope circuit provided by the present invention comprises a closed-loop driving circuit; the closed-loop driving circuit comprises a driving fork finger, a driving end circuit and a controller, wherein the driving fork finger refers to the driving end of a quartz tuning fork; the driving end circuit is used to convert a driving response charge signal generated by the driving fork finger into a driving response voltage signal, and transmit the driving response voltage signal to the controller; the controller is used to generate an original digital reference signal, adjust the frequency and amplitude of the original digital reference signal based on the driving response voltage signal, generate a driving voltage signal, and transmit the driving voltage signal to the driving end circuit; the driving end circuit is used to amplify the driving voltage signal, and apply the amplified driving voltage signal to the driving fork finger, so that the oscillation frequency of the driving fork finger is at the resonant frequency of the quartz tuning fork, and the oscillation amplitude of the driving fork finger is within a preset amplitude range. In the above process, the frequency and amplitude of the original digital reference signal are adjusted by the driving response voltage signal fed back when the driving fork finger oscillates, so as to generate the driving voltage signal. The amplified driving voltage signal is used to excite the driving fork fingers, so that the oscillation frequency of the driving fork fingers is at the resonant frequency of the quartz tuning fork, and the oscillation amplitude of the driving fork fingers is within the preset amplitude range, thereby ensuring the stability of the oscillation frequency and the oscillation amplitude of the driving fork fingers.

Furthermore, the quartz gyroscope circuit also includes a detection circuit, which includes detection fork fingers, a detection end circuit and a controller, wherein the detection fork fingers refer to the detection end of the quartz tuning fork; the detection end circuit is used to convert the detection response charge signal generated by the detection fork fingers into a detection response voltage signal, and transmit the detection response voltage signal to the controller; the controller is used to analyze the detection response voltage signal to obtain angular velocity information.

Furthermore, the controller realizes digital demodulation and filtering of the driving displacement signal (i.e., the driving response digital signal) and the detection displacement signal (i.e., the detection response digital signal), and realizes closed-loop control of the driving fork finger drive by using a digital phase-locked loop and a digital automatic gain control method, which saves a large number of devices, makes the circuit design simpler, reduces the overall size of the gyroscope, and realizes the high precision and small size of the quartz gyroscope. The digital quartz gyroscope increases the compensability of the gyroscope sensor, and the driving fork finger can be compensated inside the gyroscope to ensure that the driving tuning fork oscillates at its resonant frequency point within the full temperature range, and the detection end can also be phase compensated and zero-bias compensated. The driving, demodulation and filtering processing are realized in a digital manner, which is convenient to control, simple to compensate the gyroscope, and has good stability and linearity. The controller can perform co-directional demodulation and orthogonal demodulation, and can output data such as the driving frequency, AGC, phase and orthogonal components to obtain information about the quartz tuning fork itself, providing a basis for subsequent optimization and improvement of the digital quartz gyroscope.

FIG10 illustrates a schematic diagram of the physical structure of an electronic device. As shown in FIG10 , the electronic device may include: a processor 1001, a communications interface 1002, a memory 1003, and a communication bus 1004, wherein the processor 1001, the communications interface 1002, and the memory 1003 communicate with each other via the communication bus 1004. The processor 1001 may call the logic instructions in the memory 1003 to execute the processing process implemented by the controller in any of the above embodiments.

In addition, the logic instructions in the above-mentioned memory 1003 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the embodiment of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the processing process implemented by the controller in any one of the above-mentioned embodiments.

On the other hand, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to perform the processing process implemented by the controller in any one of the above embodiments.

The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative work.

Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM/RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A quartz gyroscope circuit, characterized in that it comprises a closed-loop drive circuit; the closed-loop drive circuit comprises a drive fork finger, a drive end circuit and a controller, wherein the drive fork finger refers to the drive end of a quartz tuning fork; The driving end circuit is used to convert the driving response charge signal generated by the driving fingers into a driving response voltage signal, and transmit the driving response voltage signal to the controller; The controller is used to generate an original digital reference signal, adjust the frequency and amplitude of the original digital reference signal based on the drive response voltage signal, generate a drive voltage signal, and transmit the drive voltage signal to the drive end circuit; The driving end circuit is used to amplify the driving voltage signal and apply the amplified driving voltage signal to the driving fork finger so that the oscillation frequency of the driving fork finger is at the resonant frequency of the quartz tuning fork and the oscillation amplitude of the driving fork finger is within a preset amplitude range. 2. The quartz gyroscope circuit according to claim 1, characterized in that it also includes a detection circuit; the detection circuit includes a detection fork finger, a detection end circuit and the controller, wherein the detection fork finger refers to the detection end of the quartz tuning fork; The detection end circuit is used to convert the detection response charge signal generated by the detection fork finger into a detection response voltage signal, and transmit the detection response voltage signal to the controller; The controller is used to analyze the detection response voltage signal to obtain angular velocity information. 3. The quartz gyroscope circuit according to claim 1, characterized in that the controller comprises a first analog-to-digital converter and a digital-to-analog converter; The driving end circuit is used to transmit the driving response voltage signal to the first analog-to-digital converter; The first analog-to-digital converter is used to convert the driving response voltage signal into a driving response digital signal; The controller is used to adjust the frequency and amplitude of the original digital reference signal based on the drive response digital signal, generate a digital excitation signal, and transmit the digital excitation signal to the digital-to-analog converter; The digital-to-analog converter is used to convert the digital excitation signal into the driving voltage signal. 4. The quartz gyroscope circuit according to claim 3, characterized in that the controller comprises a digitally controlled oscillator; the original digital reference signal comprises an original sine digital signal and an original cosine digital signal; The digital controlled oscillator is used to generate the original sine digital signal and the original cosine digital signal; The controller is used to demodulate the drive response digital signal based on the original sine digital signal to generate an original in-phase component, and demodulate the drive response signal based on the original cosine digital signal to generate an original orthogonal component; The controller is used to calculate the response amplitude of the drive response digital signal based on the original in-phase component and the original orthogonal component, and determine the excitation amplitude of the digital excitation signal based on the response amplitude and a preset target amplitude; The controller is used to calculate the response phase of the drive response digital signal based on the original in-phase component and the original quadrature component, and determine the excitation phase of the digital excitation signal based on the response phase and a preset target phase. 5. The adaptive gyroscope circuit according to claim 4, characterized in that the controller further comprises an automatic gain control module; The digitally controlled oscillator is used to generate the original sinusoidal digital signal and the original cosine digital signal based on the excitation frequency, wherein the phase of the original sinusoidal digital signal is the target phase; The automatic gain control module is used to generate the digital excitation signal based on the original sinusoidal digital signal and the excitation amplitude, wherein the amplitude of the digital excitation signal is the target amplitude. 6 . The quartz gyroscope circuit according to claim 4 , wherein the controller is used to perform phase compensation on the original in-phase component based on the resonant frequency, and to perform phase compensation on the original quadrature component based on the resonant frequency. 7. The quartz gyroscope circuit according to claim 6 is characterized in that the controller is used to perform capacitive compensation on the original orthogonal component after phase compensation based on the orthogonal component compensation value, wherein the orthogonal component compensation value is obtained based on the capacitive performance of the quartz tuning fork. 8. The quartz gyroscope circuit according to claim 2, characterized in that the controller comprises a second analog-to-digital converter; The detection end circuit is used for transmitting the detection response voltage signal to the second analog-to-digital converter; The second analog-to-digital converter is used to convert the detection response voltage signal into a detection response digital signal; The controller is used to analyze the detection response digital signal to obtain the angular velocity information. 9. The quartz gyroscope circuit according to claim 8, characterized in that the controller comprises a digitally controlled oscillator; the original digital reference signal comprises an original sine digital signal and an original cosine digital signal; The digitally controlled oscillator is used to generate the original sine digital signal and the original cosine digital signal; The controller is used to demodulate the detection response digital signal based on the original sine digital signal to generate a detection in-phase component, and to demodulate the detection response digital signal based on the original cosine digital signal to generate a detection quadrature component. 10. The quartz gyroscope circuit according to claim 9, characterized in that the controller is used to perform phase compensation on the detected in-phase component and to perform phase compensation on the detected orthogonal component; The controller is used to perform temperature compensation on the detected isotropic component based on the real-time ambient temperature.

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