CN104296738A - Driving stability lifting method and device for micromechanical gyroscope - Google Patents

Abstract

The invention discloses a method and device for improving driving stability of a micromechanical gyroscope. The steps of the method are as follows: according to the voltage signal output by the micromechanical gyroscope, the natural frequency of the driving mode of the micromechanical gyroscope is the same as that of the driving mode of the micromechanical gyroscope. The AC driving voltage is in phase with the low-frequency signal, and the low-frequency signal is loaded as a DC bias voltage on the parallel capacitor connected in parallel between the driving plates of the micro-mechanical gyroscope, and the high-frequency sinusoidal drive is driven by the DC bias voltage and the AC driving voltage. The carrier wave jointly drives the micro-mechanical gyroscope; the device includes a low-frequency signal acquisition circuit and a parallel capacitor, and the parallel capacitor is connected in parallel between the driving plates of the micro-mechanical gyroscope. The invention can overcome the driving instability caused by the mismatch of the driving capacitance caused by the machining accuracy error of the micro-mechanical gyroscope, and improve the detection accuracy and reliability of the micro-mechanical gyroscope.

Description

Driving stability improvement method and device for micromechanical gyroscope

technical field

The invention relates to the technical field of micromechanical gyroscope drive, in particular to a method and device for improving driving stability of a micromechanical gyroscope.

Background technique

A micromechanical gyroscope is a device used to measure the rotational motion of an object relative to inertial space. The output signal of the micromechanical gyroscope can be used to drive the carrier or platform actuator for stability control and navigation control after weak signal processing. The micro-machined gyroscope is prepared by bulk silicon processing technology, but due to the influence of the machining accuracy, there are more or less differences in the symmetry of the structure of the micro-machined gyroscope, which will make the drive capacitor There is a deviation in the size, so that the driving size of the driving capacitor is different under the same driving voltage, which affects the stable driving of the gyroscope.

Contents of the invention

The technical problem to be solved by the present invention is to provide a driving device for micro-mechanical gyroscopes that can overcome the drive instability caused by the mismatch of drive capacitance caused by the machining accuracy error of micro-mechanical gyroscopes, and improve the detection accuracy and reliability of micro-mechanical gyroscopes. Method and device for improving stability.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A driving stability improvement method for a micromechanical gyroscope, the implementation steps are as follows:

1) Arrange parallel capacitors between the driving plates of the micromechanical gyroscope in advance, so that the capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plates are equal;

2) The voltage signal output by the micro-mechanical gyro is modulated and demodulated, and phase-shifted to generate a low-frequency signal. The driving signal of the micro-mechanical gyro is composed of three parts: DC bias voltage, AC driving voltage and driving high-frequency sinusoidal carrier. The low-frequency signal It is the same as the natural frequency of the driving mode of the micro-mechanical gyroscope, and is in the same phase as the AC driving voltage for driving the micro-mechanical gyroscope;

3) Loading the low-frequency signal to a parallel capacitor arranged in parallel between the driving plates of the micromechanical gyroscope.

Preferably, the step 1) arranging parallel capacitors between the driving plates of the micromechanical gyroscope specifically refers to: arranging parallel capacitors in parallel _with the positive equivalent capacitance C of the driving plate of the micromechanical gyroscope, so that the positive electrode equivalent capacitance C The sum of the capacitance values of _d+ and the parallel capacitor is equal to the capacitance value of the negative equivalent capacitance C _d- of the driving plate, so that the capacitance of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plate The values are equal; or the parallel capacitance is arranged in parallel with the negative equivalent capacitance C _d- of the driving plate, so that the sum of the capacitance values of the negative equivalent capacitance C _d- and the parallel capacitance is equal to the positive equivalent capacitance C _d+ of the driving plate The capacitance value of , so that the capacitance values of the positive electrode equivalent capacitance C _d+ and the negative electrode equivalent capacitance C _d- of the driving plate are equal.

Preferably, in the step 2), the detailed steps of generating the low-frequency signal through modulation and demodulation of the voltage signal output by the micromechanical gyroscope are as follows:

2.1) Capacitance-voltage conversion is performed on the signal signal output by the micromechanical gyroscope;

2.2) Perform high-pass filtering on the voltage signal converted from the capacitor voltage to extract the high-frequency signal;

2.3) performing multiplication and demodulation on the extracted high-frequency signal to obtain a low-frequency signal;

2.4) performing low-pass filtering on the demodulated low-frequency signal to obtain a low-frequency signal identical to the natural frequency of the driving mode;

2.5) The low-frequency signal with the same natural frequency as the drive mode is phase-shifted to obtain a low-frequency signal with the same natural frequency as the drive mode of the micro-mechanical gyroscope and in phase with the AC drive voltage for driving the micro-machined gyroscope.

The present invention also provides a driving stability improvement device for a micromechanical gyroscope, which is characterized in that it includes a low-frequency signal acquisition circuit and a parallel capacitor, and the parallel capacitor is connected in parallel between the driving plates of the micromechanical gyroscope so that the drive plate The capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- are equal, and the low-frequency signal acquisition circuit generates a low-frequency signal through modulation and demodulation and phase shifting according to the voltage signal output by the micromechanical gyro, and the low-frequency signal The low-frequency signal acquisition circuit loads the low-frequency signal to the parallel capacitor, which is the same as the natural frequency of the driving mode of the micro-mechanical gyroscope and in phase with the AC driving voltage for driving the micro-mechanical gyroscope.

Preferably, the parallel connection of the parallel capacitor between the driving plates of the micro-mechanical gyroscope specifically means: the parallel arrangement of the parallel capacitor and the positive equivalent capacitance C _d+ of the drive plate of the micro-mechanical gyroscope, so that the positive equivalent capacitance C The sum of the capacitance values of _d+ and the parallel capacitor is equal to the capacitance value of the negative equivalent capacitance C _d- of the driving plate, so that the capacitance of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plate The values are equal; or the parallel capacitor is arranged in parallel with the negative electrode equivalent capacitance C _d- of the driving plate of the micromechanical gyroscope, so that the sum of the capacitance values of the negative electrode equivalent capacitance C _d- and the parallel capacitor is equal to the driving plate The capacitance value of the positive electrode equivalent capacitance C _d+ of the driving plate makes the capacitance values of the positive electrode equivalent capacitance C _d+ and the negative electrode equivalent capacitance C _d- of the driving plate equal.

Preferably, the low-frequency signal acquisition circuit includes a capacitor-voltage conversion circuit, a high-pass filter circuit, a demodulation circuit, a low-pass filter circuit, and a phase-shifting circuit connected in sequence, and the capacitor-voltage conversion circuit converts the capacitor signal output by the micromechanical gyro is a voltage signal, the high-pass filter circuit performs high-pass filtering on the voltage signal output by the capacitor-to-voltage conversion circuit to extract the high-frequency signal, and the demodulation circuit multiplies and demodulates the high-frequency signal output by the high-pass filter circuit to obtain a low-frequency signal, The driving signal of the micro-mechanical gyro is composed of three parts: DC bias voltage, AC driving voltage and driving high-frequency sinusoidal carrier. The low-frequency signal with the same modal natural frequency, the phase-shifting circuit adjusts the phase-shifting of the low-frequency signal output by the low-pass filter circuit, and obtains the same frequency as the driving modal natural frequency of the micro-mechanical gyroscope, and is the same as the AC drive for driving the micro-mechanical gyroscope. A low-frequency signal with the same voltage phase, the output terminal of the phase shifting circuit is connected to the two poles of the parallel capacitor.

The method for improving the driving stability of the micromechanical gyroscope of the present invention has the following advantages: the present invention pre-arranges parallel capacitors between the driving plates of the micromechanical gyroscope, so that the positive equivalent capacitance C _d+ of the driving plate and the negative equivalent capacitance C _{d -} The capacitance values of the two are relatively equal. According to the voltage signal output by the micro-mechanical gyroscope, a low-frequency signal that is the same as the natural frequency of the driving mode of the micro-mechanical gyroscope and in phase with the AC driving voltage that drives the micro-mechanical gyroscope is generated. The low-frequency signal with the same natural frequency of the driving mode of the mechanical gyroscope and the same phase as the AC driving voltage driving the micro-mechanical gyroscope is loaded on the parallel capacitor connected in parallel between the driving plates of the micro-mechanical gyroscope. The driving signal of the micromachined gyroscope consists of three parts: DC bias voltage, AC driving voltage and driving high-frequency sinusoidal carrier. The low-frequency signal that is the same as the natural frequency of the driving mode of the micro-mechanical gyro and in phase with the AC driving voltage driving the micro-mechanical gyroscope is fed back to the parallel capacitor to offset the mismatch of the driving capacitance caused by the machining accuracy to achieve stable control. The AC driving voltage The frequency is the same as the natural frequency of the driving mode, so as to realize the vibration in the resonance state, and drive the high-frequency sinusoidal carrier for signal modulation. Loading a low-frequency signal that is the same as the natural frequency of the driving mode of the micro-machined gyroscope and in phase with the AC drive voltage that drives the micro-machined gyroscope to the parallel capacitor connected in parallel between the driving plates of the micro-machined gyroscope can overcome the machining accuracy of the micro-machined gyroscope. The driving instability caused by the mismatch of the driving capacitance caused by the error improves the detection accuracy and reliability of the micro-mechanical gyroscope.

The driving stability improving device for micromechanical gyroscopes of the present invention is a device corresponding to the method of the driving stability improving device for micromechanical gyroscopes of the present invention, and includes a circuit corresponding to the method for improving driving stability for micromechanical gyroscopes of the present invention The components and their connections also have the same technical effect as the method for improving the driving stability of the micromechanical gyroscope of the present invention, so details are not repeated here.

Description of drawings

Fig. 1 is a schematic diagram of the principle of the method of the embodiment of the present invention.

Fig. 2 is a schematic diagram of the frame structure of the device of the embodiment of the present invention.

Legend: 1. Low-frequency signal acquisition circuit; 11. Capacitor voltage conversion circuit; 12. High-pass filter circuit; 13. Demodulation circuit; 14. Low-pass filter circuit; 15. Phase-shifting circuit; 2. Parallel capacitor.

Detailed ways

As shown in Figure 1, the implementation steps of the method for improving the driving stability of the micromechanical gyroscope in this embodiment are as follows:

1) Arrange parallel capacitors between the driving plates of the micromechanical gyroscope in advance, so that the capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plates are relatively equal;

2) The voltage signal output by the micro-mechanical gyroscope is modulated and demodulated, and phase-shifted to generate a low-frequency signal. The driving signal of the micro-mechanical gyroscope is composed of three parts: DC bias voltage, AC drive voltage and driving high-frequency sinusoidal carrier. The low-frequency signal and micro-mechanical gyroscope The driving modal natural frequency of the mechanical gyroscope is the same and in phase with the AC driving voltage driving the micromechanical gyroscope;

3) Loading the low-frequency signal to the parallel capacitance arranged between the driving plates of the micromachined gyroscope to offset the mismatch of the driving capacitance caused by the processing error and realize the stable control.

In this embodiment, a parallel capacitor is connected in parallel with the position equivalent to the driving capacitor of the micromechanical gyroscope on the circuit. After the output voltage is modulated and demodulated, an output signal with the same natural frequency as the driving mode can be obtained, and this signal is fed back to the parallel capacitor. , so that the driving voltage input from one end of the parallel capacitor can be adjusted, and the micro-mechanical gyroscope is jointly driven by the DC bias voltage and the AC driving voltage to drive the high-frequency sinusoidal carrier, thereby realizing the stable control of the driving circuit. The mismatch of the driving capacitance caused by the machining accuracy can be offset by connecting the capacitor in parallel to improve the driving stability.

In this embodiment, step 1) arranging a parallel capacitor between the driving plates of the micromechanical gyroscope specifically refers to arranging a parallel capacitor in parallel _with the positive equivalent capacitance C of the driving plate of the micromechanical gyroscope, so that the positive electrode equivalent capacitance C The sum of the capacitance values of _d+ and the parallel capacitor is equal to the capacitance value of the negative equivalent capacitance C _d- of the driving plate, so that the capacitance of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plate The values are relatively equal; or the parallel capacitance is arranged in parallel with the negative equivalent capacitance C _d- of the driving plate, so that the sum of the capacitance values of the negative equivalent capacitance C _d- and the parallel capacitance is equal to the positive equivalent capacitance C of the driving plate The capacitance value of _d+ makes the capacitance values of the positive electrode equivalent capacitance C _d+ and the negative electrode equivalent capacitance C _d− of the driving plate relatively equal.

In the present embodiment, the detailed steps of step 2) are as follows:

2.1) Perform capacitive-voltage conversion (C/V conversion) on the voltage signal output by the micromechanical gyroscope;

2.2) Perform high-pass filtering on the voltage signal converted from the capacitor voltage to extract the high-frequency signal;

2.3) performing multiplication and demodulation on the extracted high-frequency signal to obtain a low-frequency signal;

2.4) performing low-pass filtering on the demodulated low-frequency signal to obtain a low-frequency signal identical to the natural frequency of the driving mode;

2.5) The low-frequency signal with the same natural frequency as the drive mode is phase-shifted to obtain a low-frequency signal with the same natural frequency as the drive mode of the micro-mechanical gyroscope and in phase with the AC drive voltage for driving the micro-machined gyroscope.

Step 3) of this embodiment loads the low-frequency signal to the parallel capacitor arranged in parallel between the driving plates of the micromechanical gyroscope. The driving signal of the micromechanical gyroscope is composed of three parts: DC bias voltage, _AC driving voltage and driving high- _frequency sinusoidal carrier. Show.

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}\mathrm{<span\; class="notranslate">\; t</span>}\\ {\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}\mathrm{<span\; class="notranslate">\; t</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In formula (1), V _d represents the DC bias voltage, V _a sinω _x t represents the AC drive voltage, and E _fd sinω _fd t represents the driving high-frequency sinusoidal carrier.

As shown in Figure 2, the driving stability improvement device for the micromechanical gyroscope in this embodiment includes a low-frequency signal acquisition circuit 1 and a parallel capacitor 2, and the parallel capacitor 2 is connected in parallel between the driving plates of the micromechanical gyroscope to make the positive electrode of the driving plate The capacitance values of the equivalent capacitance C _d+ and the negative electrode equivalent capacitance C _d- are relatively equal. The low-frequency signal acquisition circuit 1 generates a low-frequency signal through modulation and demodulation and phase shifting according to the voltage signal output by the micromechanical gyroscope. The low-frequency signal and the micromechanical The natural frequency of the driving mode of the gyroscope is the same as that of the AC driving voltage for driving the micromechanical gyroscope. The low-frequency signal acquisition circuit 1 loads the low-frequency signal to the parallel capacitor 2 to offset the mismatch of the driving capacitance caused by the processing error and realize stable control.

In this embodiment, the parallel connection of the parallel capacitor 2 between the driving plates of the micromechanical gyroscope specifically refers to the parallel arrangement of the parallel capacitor 2 and the positive capacitance C _d+ of the driving plate of the micromechanical gyroscope, so that the positive capacitance C _d+ and the parallel capacitance 2 The sum of the capacitance values of the two is equal to the capacitance value of the negative capacitance C _d- of the driving plate, so that the capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plate are relatively equal; or The parallel capacitor 2 is arranged in parallel with the negative capacitance C _d- of the driving plate of the micromechanical gyroscope, so that the sum of the capacitance values of the negative capacitance C _d- and the parallel capacitor 2 is equal to the capacitance value of the positive capacitance C _d+ of the driving plate , so that the capacitance values of the positive electrode equivalent capacitance C _d+ and the negative electrode equivalent capacitance C _d− of the driving plate are relatively equal.

In this embodiment, the low-frequency signal acquisition circuit 1 includes a capacitor-voltage conversion circuit 11, a high-pass filter circuit 12, a demodulation circuit 13, a low-pass filter circuit 14, and a phase-shifting circuit 15 connected in sequence. The capacitor-voltage conversion circuit 11 converts the micromechanical gyro The output signal is converted into a voltage signal, the high-pass filter circuit 12 performs high-pass filtering on the voltage signal output by the capacitor-voltage conversion circuit 11 to extract the high-frequency signal, and the demodulation circuit 13 multiplies and demodulates the high-frequency signal output by the high-pass filter circuit 12 to obtain Low-frequency signal, the driving signal of the micromechanical gyro is composed of three parts: DC bias voltage, AC driving voltage and driving high-frequency sinusoidal carrier. The low-pass filter circuit 14 performs low-pass filtering on the low-frequency signal output by the demodulation circuit 13 to obtain For the low-frequency signal with the same natural frequency of the driving mode of the gyroscope, the phase-shifting circuit 15 performs phase-shift adjustment on the low-frequency signal output by the low-pass filter circuit 14 to obtain the same frequency as the natural frequency of the driving mode of the micro-mechanical gyroscope, and to drive the micro-mechanical gyroscope. The AC driving voltage is in phase with the low-frequency signal, and the output terminal of the phase shifting circuit 15 is connected to the two poles of the parallel capacitor 2 .

In this embodiment, the output voltage of the capacitance-to-voltage conversion circuit 11 is shown in formula (2).

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; +</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; +</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; -</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

In formula (2), _Vc represents the output voltage signal of the capacitor-to-voltage conversion circuit 11, V _d+ and V _d- represent the loading voltage of the two poles of the driving plate of the micro-mechanical gyroscope, and C _d+ represents the positive pole of the driving plate of the micro-mechanical gyroscope, etc. Effective capacitance, C _d- represents the negative electrode equivalent capacitance of the micromechanical gyroscope drive plate, C _f represents the capacitance value of the capacitor C _f in the capacitance-to-voltage conversion circuit 11 shown in Figure 2, V _d represents the DC bias voltage, V _a sinω _x t represents the AC driving voltage, and E _fd sinω _fd t represents driving the high-frequency sinusoidal carrier.

In this embodiment, the high-pass filter circuit 12 is used to high-pass filter the output voltage signal _Vc of the capacitor-voltage conversion circuit 11 to remove the DC voltage signal and the low-frequency signal with frequency _ωx , and the output voltage signal is as shown in formula (3). Show.

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In formula (3), V _ch represents the output voltage signal of the high-pass filter circuit 12, K _h represents the voltage amplification factor of the high-pass filter circuit 12, E _fd sinω _fd t represents driving a high-frequency sinusoidal carrier, and ΔC _d represents the micromechanical gyro drive The difference between the positive electrode equivalent capacitance and the negative electrode equivalent capacitance of the plate, C _f represents the capacitance value of the capacitor C _f in the capacitance-to-voltage conversion circuit 11 shown in FIG. 2 .

In this embodiment, the demodulation circuit 13 is used to multiply and demodulate the output voltage signal of the high-pass filter circuit 12 to obtain a low-frequency signal. Because the difference ΔC _d between the positive equivalent capacitance and the negative equivalent capacitance of the driving plate of the micromechanical gyro is related to the displacement of the driving axis, when the operating frequency of the gyro system is the natural frequency of the driving mode, its changing frequency is The resonant frequency of the driving mode is ω _x , and the amplitude of ΔC _d is constant. Therefore, formula (4) can be assumed.

$\frac{{\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

In formula (4), ΔC _d represents the difference between the positive equivalent capacitance and the negative equivalent capacitance of the plate driven by the micromechanical gyroscope, and C _f represents the capacitance value of the capacitor C _f in the capacitance-to-voltage conversion circuit 11 shown in FIG. 2 , K _d represents the proportional coefficient between the relative capacitance change of the driving axis and the displacement amplitude of the driving axis, and ω _x represents the resonant frequency of the driving mode. According to formula (4), formula (5) can be obtained. Therefore, the demodulation circuit 13 multiplies and demodulates V _ch to obtain an output voltage signal V _de as shown in formula (6).

V _ch ＝K _d ·K _h ·E _fd ·sinω _fd t·cosω _x t (5)

In formula (5), V _ch represents the output voltage signal of the high-pass filter circuit 12, K _d represents the proportional coefficient of the relative capacitance change of the driving axis and the displacement amplitude of the driving axis, and K _h represents the voltage amplification factor of the high-pass filter circuit 12 , E _fd represents the amplitude of the driving high-frequency sinusoidal carrier, sinω _fd t represents the phase of the driving high-frequency sinusoidal carrier, and ω _x represents the resonance frequency of the driving mode.

V _de =K _d K _h E _fd ² sin ² ω _fd t cosω _x t (6)

In formula (6), V _de represents the output voltage signal of the demodulation circuit 13, K _d represents the proportional coefficient of the relative capacitance variation of the driving axis and the displacement amplitude of the driving axis, and K _h represents the voltage amplification factor of the high-pass filter circuit 12 , E _fd represents the amplitude of the driving high-frequency sinusoidal carrier, sinω _fd t represents the phase of the driving high-frequency sinusoidal carrier, and ω _x represents the resonance frequency of the driving mode.

In this embodiment, the low-pass filter circuit 14 is used to low-pass filter the demodulated low-frequency signal to obtain a low-frequency signal V _deo having the same natural frequency as the driving mode. The filtered output voltage signal V _deo is shown in formula (7).

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; deo</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; the\; se</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; fd</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

In formula (7), K _d represents the proportional coefficient of the relative capacitance change of the driving axis and the displacement amplitude of the driving axis, K _h represents the voltage amplification factor of the high-pass filter circuit 12, K _se is the amplification factor of the low-pass filter, E _fd represents the amplitude of the driving high-frequency sinusoidal carrier, and ω _x represents the resonant frequency of the driving mode. The low-frequency signal obtained by the low-pass filter circuit 14 is the same as the natural frequency of the driving mode, but there is a deviation in the phase, so it is necessary to further perform phase-shift processing through the phase-shift circuit 15, and the output voltage signal V _deo of the low-pass filter circuit 14 The stable control of the drive can be achieved by feeding back to the parallel capacitor at the input end after phase shifting. The phase-shifting circuit 15 performs phase-shifting adjustment on the low-frequency signal V _deo output by the low-pass filter which is the same as the natural frequency of the driving mode, and obtains a low-frequency signal in phase with the AC driving voltage for driving the micromechanical gyroscope, and uses the low-frequency signal as a DC bias voltage Loaded into the parallel capacitor, the DC bias voltage and the AC drive voltage are used to drive the high-frequency sinusoidal carrier to jointly drive the micro-mechanical gyroscope.

The above descriptions are only preferred implementations of the present invention, and the scope of protection of the present invention is not limited to the above-mentioned implementations. All technical solutions belonging to the principle of the present invention belong to the scope of protection of the present invention. For those skilled in the art, some improvements and modifications made without departing from the principles of the present invention should also be regarded as the protection scope of the present invention.

Claims (6)

1. A driving stability promotion method for a micromechanical gyroscope, characterized in that the implementation steps are as follows: 1) Arrange parallel capacitors between the driving plates of the micromechanical gyroscope in advance, so that the capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plates are equal; 2) The voltage signal output by the micro-mechanical gyro is modulated and demodulated, and phase-shifted to generate a low-frequency signal. The driving signal of the micro-mechanical gyro is composed of three parts: DC bias voltage, AC driving voltage and driving high-frequency sinusoidal carrier. The low-frequency signal It is the same as the natural frequency of the driving mode of the micro-mechanical gyroscope, and is in the same phase as the AC driving voltage for driving the micro-mechanical gyroscope; 3) Loading the low-frequency signal to a parallel capacitor arranged in parallel between the driving plates of the micromechanical gyroscope. 2. The method for improving driving stability of a micromachined gyroscope according to claim 1, wherein said step 1) arranging parallel capacitors between the driving plates of the micromachined gyroscope specifically refers to: in the micromachined gyroscope The positive equivalent capacitance C _d+ of the driving plate is arranged in parallel in parallel, so that the sum of the capacitance values of the positive equivalent capacitance C _d+ and the parallel capacitance is equal to the capacitance value of the negative equivalent capacitance C _d- of the driving plate, so that The capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plate are equal; or the parallel capacitors are arranged in parallel with the negative equivalent capacitance C _d- of the driving plate, so that the negative equivalent capacitance C _{d -} The sum of the capacitance values of the parallel capacitors is equal to the capacitance value of the positive equivalent capacitance C _d+ of the driving plate, so that the capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plate equal. 3. The driving stability improvement method for micro-mechanical gyroscope according to claim 1 or 2, characterized in that, in the step 2), the details of generating the low-frequency signal through modulation and demodulation of the voltage signal output by the micro-mechanical gyroscope Proceed as follows: 2.1) The signal output by the micromechanical gyroscope is converted into a capacitor voltage; 2.2) Perform high-pass filtering on the voltage signal converted from the capacitor voltage to extract the high-frequency signal; 2.3) performing multiplication and demodulation on the extracted high-frequency signal to obtain a low-frequency signal; 2.4) performing low-pass filtering on the demodulated low-frequency signal to obtain a low-frequency signal identical to the natural frequency of the driving mode; 2.5) The low-frequency signal with the same natural frequency as the drive mode is phase-shifted to obtain a low-frequency signal with the same natural frequency as the drive mode of the micro-mechanical gyroscope and in phase with the AC drive voltage for driving the micro-machined gyroscope. 4. A driving stability improving device for a micromechanical gyroscope, characterized in that: it comprises a low-frequency signal acquisition circuit (1) and a parallel capacitor (2), and the parallel capacitor (2) is connected in parallel to the driving pole of the micromechanical gyroscope. Between the plates, the capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plate are equal, and the low-frequency signal acquisition circuit (1) is modulated and demodulated according to the voltage signal output by the micromechanical gyroscope, Phase-shifting generates a low-frequency signal, the low-frequency signal is the same as the natural frequency of the driving mode of the micro-mechanical gyroscope, and has the same phase as the AC driving voltage for driving the micro-mechanical gyroscope, and the low-frequency signal is loaded on the parallel capacitor (2). 5. The driving stability improving device for micro-mechanical gyroscope according to claim 4, characterized in that, said parallel capacitor (2) is connected in parallel between the drive plates of micro-mechanical gyroscope and specifically refers to: said parallel capacitor (2) Arranged in parallel with the positive equivalent capacitance C _d+ of the driving plate of the micromechanical gyroscope, so that the sum of the capacitance values of the positive equivalent capacitance C _d+ and the parallel capacitance (2) is equal to the negative equivalent of the driving plate The capacitance value of the capacitor C _d- , so that the capacitance values of the positive equivalent capacitance C _d+ and the negative equivalent capacitance C _d- of the driving plate are equal; or the parallel capacitor (2) and the driving pole of the micromechanical gyroscope The negative electrode equivalent capacitance C _d- of the plate is arranged in parallel, so that the sum of the capacitance values of the negative electrode equivalent capacitance C _d- and the parallel capacitance (2) is equal to the capacitance value of the positive electrode equivalent capacitance C _d+ of the driving plate, so that the driving The capacitance values of the positive electrode equivalent capacitance C _d+ and the negative electrode equivalent capacitance C _d− of the plate are equal. 6. according to claim 4 or 5 described drive stability promotion devices for micromachined gyroscopes, it is characterized in that, described low-frequency signal acquisition circuit (1) comprises the capacitance-voltage conversion circuit (11) that is connected successively, high-pass filter Circuit (12), demodulation circuit (13), low-pass filter circuit (14), phase-shifting circuit (15), described capacitance-voltage conversion circuit (11) converts the capacitance signal output by the micromechanical gyroscope into a voltage signal, so The high-pass filter circuit (12) performs high-pass filtering to extract the high-frequency signal from the voltage signal output by the capacitor-to-voltage conversion circuit (11), and the demodulation circuit (13) performs high-frequency signal output from the high-pass filter circuit (12). The low-frequency signal is obtained by multiplication and demodulation, and the driving signal of the micromechanical gyroscope is composed of three parts: DC bias voltage, AC driving voltage and driving high-frequency sinusoidal carrier, and the low-pass filter circuit (14) outputs the The low-frequency signal is subjected to low-pass filtering to obtain a low-frequency signal identical to the natural frequency of the driving mode of the micromechanical gyroscope, and the phase-shifting circuit (15) performs phase-shifting adjustment on the low-frequency signal output by the low-pass filtering circuit (14) to obtain the same low-frequency signal as the micromechanical gyroscope. The drive mode natural frequency of the mechanical gyroscope is the same and the low-frequency signal is in phase with the AC drive voltage for driving the micromechanical gyroscope. The output terminal of the phase shifting circuit (15) is connected to the two poles of the parallel capacitor (2).