Electrostatic coupling rejection circuit for quartz tuning fork gyroscope

Abstract

The application provides an electrostatic coupling suppression circuit for a quartz tuning fork gyroscope, comprising a quartz tuning fork sensor, a driving and amplitude control circuit, an inverting circuit, a compensation circuit, an angular velocity detection circuit and a demodulation filter circuit; the quartz tuning fork sensor outputs signals to the driving and amplitude control circuit and the angular velocity detection circuit respectively; the driving and amplitude control circuit generates a driving signal according to the input signal; the driving signal is input to the inverting circuit and the demodulation filter circuit respectively; the inverting circuit generates a driving inverted signal which is the same frequency as the driving signal but in opposite phase; the driving signal and the driving inverted signal pass through the compensation circuit to generate an electrostatic coupling compensation signal, which is input to the angular velocity detection circuit to offset the electrostatic coupling error in the detection circuit; the angular velocity detection circuit generates an angular velocity carrier signal and an angular velocity carrier inverted signal, and outputs an angular velocity signal after passing through the demodulation filter circuit. The application reduces the electrostatic error and improves the performance of the whole gyroscope.

Description

Technical Field

[0001] This invention belongs to the technical field of quartz tuning fork gyroscope measurement and control circuits, and relates to an electrostatic coupling suppression circuit for quartz tuning fork gyroscopes. Background Technology

[0002] Currently, the static errors in the output of quartz tuning fork gyroscopes mainly include two types: in-phase error and quadrature error. These two types of errors are directly related to the static zero-point performance of the quartz tuning fork gyroscope. In-phase error is mainly generated by the electrostatic coupling between the internal drive signal and the detection path of the gyroscope. This error signal has the same frequency and phase as the carrier signal of the angular velocity, hence it is called "in-phase error" or "electrostatic error". Quadrature error is mainly caused by the mechanical coupling between the drive mode and the detection mode due to processing errors and the inherent properties of the material during the manufacturing process of the quartz tuning fork. This error signal has the same frequency as the carrier signal of the angular velocity, but a 90° phase difference, hence it is called "quadrature error" or "mechanical error".

[0003] In practical applications, in-phase errors are typically suppressed by electromagnetic shielding or shortening the coupling path during product manufacturing. Quadrature errors are usually mitigated through mechanical adjustments during production to reduce the impact of normal errors on the output. In commonly used quartz tuning fork gyroscope measurement and control circuits, the presence of coupling capacitors in the sensor and electromagnetic coupling paths in space results in electrostatic coupling errors in the output signal of the detection circuit. These errors, like the drive signal, typically change significantly with external temperature variations. This change leads to redundant errors in the demodulated angular velocity signal, ultimately causing the electrostatic error term in the angular velocity signal to change with temperature. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] To address this, the present invention provides an electrostatic coupling suppression circuit for a quartz tuning fork gyroscope. This circuit can suppress the electrostatic coupling of the drive signal in the drive circuit to the detection circuit (i.e., it can suppress the interference of the electrostatic error signal generated by electrostatic coupling on the angular velocity signal), reduce electrostatic error, and thus improve the overall performance of the gyroscope.

[0006] The technical solution of the present invention is as follows:

[0007] According to one aspect, an electrostatic coupling suppression circuit for a quartz tuning fork gyroscope is provided, the circuit comprising: a quartz tuning fork sensor, a drive and amplitude control circuit, an inverting circuit, a compensation circuit, an angular velocity detection circuit, and a demodulation filter circuit;

[0008] The output signals of the quartz tuning fork sensor refer to the drive and amplitude control circuit and the angular velocity detection circuit, respectively. The drive and amplitude control circuit generates drive signals based on the output signals of the quartz tuning fork sensor.

[0009] The driving signal is also input to the inverting circuit and the demodulation filter circuit respectively. The inverting circuit generates a driving inverted signal with the same frequency and opposite phase according to the driving signal. The driving signal and the driving inverted signal are processed by the compensation circuit to generate an electrostatic coupling compensation signal, which is input to the angular velocity detection circuit to cancel the electrostatic coupling error in the detection circuit. The angular velocity detection circuit generates an angular velocity carrier signal and an angular velocity carrier inverted signal, which are then processed by the demodulation filter circuit to output the angular velocity signal.

[0010] Furthermore, the driving and amplitude control circuit includes a driving detection circuit, a driving signal circuit, and an amplitude control circuit. The driving detection circuit converts the charge signal representing the displacement of the driving fork finger generated by the piezoelectric effect of the quartz tuning fork sensor into a voltage signal, and outputs the driving detection signal to the amplitude control circuit and the driving signal circuit respectively. The driving signal circuit generates a driving signal with the same frequency as the driving detection signal. The amplitude control circuit generates an amplitude control signal for controlling the amplitude of the driving signal by comparing the amplitude of the driving detection signal with a reference value.

[0011] Furthermore, the drive detection circuit is implemented using a charge amplifier.

[0012] Furthermore, the driving signal circuit is implemented using a comparator.

[0013] Furthermore, the demodulation and filtering circuit includes a demodulator and a filtering circuit. The driving signal is input to the demodulator, and the angular velocity detection circuit generates an angular velocity carrier signal and an inverted angular velocity carrier signal, both of which are input to the demodulator. The demodulator is used to generate an angular velocity demodulated signal, and the angular velocity demodulated signal is filtered by the filtering circuit to output an angular velocity signal.

[0014] According to another aspect, a quartz tuning fork gyroscope is provided, which includes the electrostatic coupling suppression circuit described above.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] In the quartz tuning fork gyroscope measurement and control circuit of this invention, to suppress the additional error generated in the angular velocity signal by the drive signal through electrostatic coupling, an anti-phase coupling method is used to suppress the electrostatic error signal in the output signal of the detection path. Specifically, this invention obtains an anti-phase drive signal by inverting the drive signal. Based on the polarity of the electrostatic coupling signal in the angular velocity signal, either the drive signal or the anti-phase drive signal is selected and, after passing through a compensation circuit, generates an electrostatic coupling compensation signal. This signal is then input to the detection circuit, where it cancels out the electrostatic coupling signal in the detection circuit, thereby eliminating the interference of the electrostatic coupling signal on the angular velocity measurement signal. In other words, this invention, through improved circuit design and the use of anti-phase coupling to suppress the electrostatic coupling signal, significantly reduces the interference of the electrostatic error signal on the angular velocity measurement signal, thus improving the overall performance of the instrument. Attached Figure Description

[0017] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0018] Figure 1 This is a schematic diagram of the electrostatic coupling suppression circuit of the quartz tuning fork gyroscope after the improvement of the present invention. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0022] like Figure 1 As shown, in one embodiment of the present invention, an electrostatic coupling suppression circuit for a quartz tuning fork gyroscope is provided. The circuit includes: a quartz tuning fork sensor 1, a drive and amplitude control circuit 4, an inverting circuit 8, a compensation circuit 9, an angular velocity detection circuit 5, and a demodulation and filtering circuit 7. The output signals of the quartz tuning fork sensor 1 refer to the drive and amplitude control circuit 4 and the angular velocity detection circuit 5, respectively. The drive and amplitude control circuit 4 generates a drive signal 12 based on the output signal of the quartz tuning fork sensor 1. The drive signal 12 is also input to the inverting circuit 8 and the demodulation and filtering circuit 7, respectively. The inverting circuit 8 generates a drive inverting signal 18 with the same frequency and inverse phase as the drive signal 12. The drive signal 12 and the drive inverting signal 18 are processed by the compensation circuit 9 to generate an electrostatic coupling compensation signal 19, which is input to the angular velocity detection circuit 5 to cancel the electrostatic coupling error in the detection circuit. The angular velocity detection circuit 5 generates an angular velocity carrier signal 14 and an angular velocity carrier inverting signal 15, which are then processed by the demodulation and filtering circuit 7 to output an angular velocity signal 17.

[0023] As can be seen, to suppress the additional error generated in the angular velocity signal by the drive signal through electrostatic coupling, an anti-phase coupling method is used to suppress the electrostatic error signal in the output signal of the detection path. Specifically, in this embodiment of the invention, the drive signal is inverted to obtain an anti-phase drive signal. Based on the polarity of the electrostatic coupling signal in the angular velocity signal, either the drive signal or the anti-phase drive signal is selected and, after passing through a compensation circuit, generates an electrostatic coupling compensation signal. This signal is then input to the detection circuit, where it cancels out the electrostatic coupling signal in the detection circuit, thereby eliminating the interference of the electrostatic coupling signal on the angular velocity measurement signal. In other words, this embodiment of the invention, through improved circuit design and the use of anti-phase coupling to suppress the electrostatic coupling signal, significantly reduces the interference of the electrostatic error signal on the angular velocity measurement signal, thus improving the overall performance of the instrument.

[0024] According to one embodiment of the present invention, the driving and amplitude control circuit 4 includes a driving detection circuit 2, a driving signal 12 circuit 3, and an amplitude control circuit 4. The driving detection circuit 2 is used to convert the charge signal representing the displacement of the driving fork finger generated by the piezoelectric effect of the quartz tuning fork sensor 1 into a voltage signal, and outputs a driving detection signal 11 to the amplitude control circuit 4 and the driving signal 12 circuit 3 respectively. The driving signal 12 circuit 3 generates a driving signal 12 with the same frequency as the driving detection signal 11. The amplitude control circuit 4 generates an amplitude control signal 13 for controlling the amplitude of the driving signal 12 by comparing the amplitude of the driving detection signal 11 with a reference value.

[0025] According to one embodiment of the present invention, the drive detection circuit 2 is implemented using a charge amplifier.

[0026] According to one embodiment of the present invention, the driving signal 12 circuit 3 is implemented using a comparator.

[0027] According to one embodiment of the present invention, the demodulation and filtering circuit 7 includes a demodulator 6 and a filtering circuit 7, wherein a driving signal 12 is input to the demodulator 6, and an angular velocity carrier signal 14 and an angular velocity carrier inversion signal 15 generated by the angular velocity detection circuit 5 are both input to the demodulator 6. The demodulator 6 is used to generate an angular velocity demodulated signal 16, and the angular velocity demodulated signal 16 is filtered by the filtering circuit 7 to output an angular velocity signal 17.

[0028] According to another embodiment, a quartz tuning fork gyroscope is provided, the gyroscope including the electrostatic coupling suppression circuit described above.

[0029] This invention provides an electrostatic coupling suppression circuit for a quartz tuning fork gyroscope. This circuit can suppress the interference of electrostatic error signals generated by electrostatic coupling on the angular velocity signal, thereby improving the overall performance of the gyroscope. A specific embodiment is described in detail below:

[0030] like Figure 1 As shown, an improved quadrature error measurement circuit for a quartz tuning fork gyroscope consists of a controlled object quartz tuning fork sensor 1, a drive detection circuit 2, a drive signal circuit 3, an amplitude control circuit 4, an angular velocity detection circuit 5, a demodulator 6, a filter circuit 7, an inverting circuit 8, and a compensation circuit 9.

[0031] In this embodiment, the drive detection circuit 2 converts the charge signal representing the displacement of the driven fork finger generated by the piezoelectric effect of the quartz tuning fork sensor 1 into a voltage signal, which is implemented using a charge amplifier. It outputs a drive detection signal 11. The amplitude control circuit 4 generates an amplitude control signal 13 to control the amplitude of the drive signal 12 by comparing the amplitude of the drive detection signal 11 with a reference value. The drive signal circuit 3 generates a drive signal 12 with the same frequency as the drive detection signal 11, implemented using a comparator. The amplitude of the comparator output is controlled by the amplitude control signal 13. The inverting circuit 8 generates a drive inverting signal 18 with the same frequency and inverse phase as the drive signal 12. The drive signal 12 and the drive inverting signal 18 are processed by a compensation circuit to generate an electrostatic coupling compensation signal 19. The electrostatic coupling compensation signal is input to the angular velocity detection circuit 5 to cancel the electrostatic coupling error in the detection circuit. The angular velocity detection circuit 5 generates an angular velocity carrier signal 14 and an angular velocity carrier inverting signal 15. These are then processed by a demodulator 6 to generate an angular velocity demodulated signal 16. The angular velocity demodulated signal 16 is filtered by a filter circuit 7 and output as an angular velocity signal 17.

[0032] The features described and / or illustrated above with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, and / or in combination with or in lieu of features in other embodiments.

[0033] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, components, or combinations thereof.

[0034] The methods described above in this invention can be implemented in hardware or in combination with software. This invention relates to computer-readable programs that, when executed by a logic component, enable the logic component to implement the aforementioned apparatus or constituent parts, or to implement the various methods or steps described above. This invention also relates to storage media for storing the above programs, such as hard disks, magnetic disks, optical disks, DVDs, flash memory, etc.

[0035] Many features and advantages of these embodiments are apparent from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since many modifications and alterations will readily occur to those skilled in the art, the embodiments of the invention are not intended to be limited to the precise structures and operations illustrated and described, but rather to encompass all suitable modifications and equivalents falling within their scope.

[0036] The parts of this invention not described in detail are techniques known to those skilled in the art.

Claims

1. An electrostatic coupling suppression circuit for a quartz tuning fork gyroscope, characterized in that, The circuit includes: a quartz tuning fork sensor, a driving and amplitude control circuit, an inverting circuit, a compensation circuit, an angular velocity detection circuit, and a demodulation and filtering circuit; The output signals of the quartz tuning fork sensor refer to the drive and amplitude control circuit and the angular velocity detection circuit, respectively. The drive and amplitude control circuit generates drive signals based on the output signals of the quartz tuning fork sensor. The driving signal is also input to the inverting circuit and the demodulation filter circuit respectively. The inverting circuit generates a driving inverting signal with the same frequency but opposite phase according to the driving signal. The driving signal and the driving inverting signal are processed by the compensation circuit to generate an electrostatic coupling compensation signal, which is input to the angular velocity detection circuit to cancel the electrostatic coupling error in the detection circuit. The angular velocity detection circuit generates an angular velocity carrier signal and an angular velocity carrier inverting signal, which are then processed by the demodulation filter circuit to output the angular velocity signal. The driving and amplitude control circuit includes a driving detection circuit, a driving signal circuit, and an amplitude control circuit. The driving detection circuit converts the charge signal representing the displacement of the driving fork finger generated by the piezoelectric effect of the quartz tuning fork sensor into a voltage signal, and outputs the driving detection signal to the amplitude control circuit and the driving signal circuit respectively. The driving signal circuit generates a driving signal with the same frequency as the driving detection signal. The amplitude control circuit generates an amplitude control signal for controlling the amplitude of the driving signal by comparing the amplitude of the driving detection signal with a reference value. The drive detection circuit is implemented using a charge amplifier; the drive signal circuit is implemented using a comparator. The demodulation and filtering circuit includes a demodulator and a filtering circuit. A driving signal is input to the demodulator. An angular velocity carrier signal and an inverted angular velocity carrier signal generated by the angular velocity detection circuit are both input to the demodulator. The demodulator is used to generate an angular velocity demodulated signal. The angular velocity demodulated signal is filtered by the filtering circuit and then output as an angular velocity signal.

2. A quartz tuning fork gyroscope, characterized in that, The gyroscope includes the electrostatic coupling suppression circuit as described in claim 1.

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