Analog signal amplitude modulation circuit, quartz tuning fork gyroscope circuit and quartz tuning fork gyroscope

Abstract

The invention provides an analog signal amplitude modulation circuit, a quartz tuning fork gyroscope circuit and a quartz tuning fork gyroscope, the amplitude modulation circuit comprises an operational amplifier U1, resistors R1, R2, R3 and R4 and a JFET, the JFET is represented by Q1, the number of the resistors R1 is two, an input signal of the amplitude modulation circuit is a high-frequency input signal ui, and an output signal of the amplitude modulation circuit is a high-frequency output signal uo; current generated by a high-frequency input signal ui enters the two branches at the same time, for the first branch, the high-frequency input signal ui flows to the ground after passing through one resistor R1 and parallel connection of R3 and Q1, and input voltage of the in-phase end of the operational amplifier is partial voltage of parallel connection of R3 and Q1; for the second branch, the current generated by the high-frequency input signal ui flows to the ground after passing through another resistor R1 and another resistor R2, and the current generated by the high-frequency input signal ui also flows into the inverting input end of the operational amplifier; in addition, the current generated when the high-frequency output signal uo passes through the R4 flows out of the inverting input end of the operational amplifier to form a negative feedback circuit. According to the invention, the higher harmonic interference of the gyro signal is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of quartz tuning fork gyroscopes, and relates to an analog signal amplitude modulation circuit, a quartz tuning fork gyroscope circuit and a quartz tuning fork gyroscope, which are applicable to the implementation of analog signal amplitude modulation in automatic gain control technology. Background Art

[0002] The quartz tuning fork gyroscope circuit is divided into a drive circuit and a detection circuit, and the drive circuit therein realizes the stable amplitude resonance movement of the drive mode. A typical quartz tuning fork drive circuit is realized by an automatic gain control circuit and a self-excited oscillation circuit. The amplitude generated by the automatic gain control circuit is usually modulated to the drive signal through a comparator and fed back to the drive electrode to achieve positive feedback. The drive signal generated in this way is a square wave, which will bring high-order harmonics to the entire circuit and affect the performance of the gyroscope. Summary of the Invention

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

[0004] To this end, the present invention provides an analog signal amplitude modulation circuit, a quartz tuning fork gyroscope circuit and a quartz tuning fork gyroscope. The amplitude modulation circuit can replace the amplitude modulation link in the drive loop of the quartz tuning fork gyroscope, change the square wave drive to a sine wave drive, and avoid harmonic interference.

[0005] The technical solution of the present invention is as follows:

[0006] According to one aspect, an analog signal amplitude modulation circuit is provided. The amplitude modulation circuit includes an operational amplifier U1, resistors R1, R2, R3 and R4, and a JFET, which is represented by Q1. There are two R1 resistors. The input signal of the amplitude modulation circuit is a high-frequency input signal u i , and the output signal is a high-frequency output signal u o ; wherein:

[0007] The current generated by the high-frequency input signal u i enters two branches simultaneously. For the first branch, the high-frequency input signal u i flows to the ground after passing through one of the R1 resistors and the parallel connection of R3 and Q1. The input voltage of the non-inverting terminal of the operational amplifier is the voltage division of the parallel connection of R3 and Q1. For the second branch, the current generated by the high-frequency input signal u i flows to the ground after passing through the other R1 resistor and the R2 resistor, and the current generated by the high-frequency input signal u i also flows into the inverting input terminal of the operational amplifier;

[0008] The current generated by the high-frequency output signal u o flows out of the inverting input terminal of the operational amplifier through R4, forming a negative feedback circuit;

[0009] Provide a low-frequency DC input signal u gs to the JFET. By changing u gs , change the voltage u ds between the drain and source of the JFET, thereby changing the voltage at the non-inverting input terminal and achieving amplitude modulation of the high-frequency input signal u i to generate a high-frequency output signal u o .

[0010] Furthermore, the output signal of the operational amplifier is u o , satisfying the following formula:

[0011]

[0012] In the formula, |u o | is a physical quantity representing the amplitude of the high-frequency output signal u o , |u i | is a physical quantity representing the amplitude of the high-frequency input signal u i ; is the equivalent parallel resistance of R ds , R 1 , R 3 ; is the equivalent parallel resistance of R 1 , R 2 , R 4 .

[0013] Furthermore, based on formula (1), by configuring the resistors, the following can be achieved:

[0014]

[0015] Among them, formulas (2) and (3) show two control effects. (2) is the control effect where |u o | is positively correlated with R ds , that is, |u o | increases as R ds increases; (3) is the control effect where |u o | is negatively correlated with R ds , that is, |u o | decreases as R ds increases. When Q1 is an N-JFET, R ds decreases as u gs increases; when Q1 is a P-JFET, R ds increases as u gs increases. Selecting JFETs with different channels has different control effects and can be arbitrarily combined.

[0016] According to another aspect, a quartz tuning fork gyro circuit is provided. The tuning fork gyro circuit includes a driving circuit and a detecting circuit. In the driving circuit, the above-mentioned analog signal amplitude modulation circuit is used to replace the amplitude modulation link in the driving loop, and the square wave driving is changed to sine wave driving.

[0017] According to still another aspect, a quartz tuning fork gyro is provided, which includes the above-mentioned quartz tuning fork gyro circuit.

[0018] The above technical solution provides a simple analog signal amplitude modulation circuit, which is implemented by using an operational amplifier, resistors and a JFET. The input end of the operational amplifier is a high-frequency signal, and the input end of the JFET is a low-frequency DC signal. By changing the magnitude of the low-frequency DC signal, the magnitude of the signal at the output end of the operational amplifier is changed, so as to achieve the amplitude modulation effect on the high-frequency signal. This circuit is applied to the quartz tuning fork gyro driving automatic gain control circuit, replacing the traditional square wave amplitude modulation with sine wave amplitude modulation, and optimizing the square wave driving to sine wave driving, reducing the high-order harmonic interference of the gyro signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings included are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification, for illustrating the embodiments of the present invention, and are used to explain the principles of the present invention together with the text description. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 is a schematic diagram of an analog signal amplitude modulation circuit according to an embodiment of the present invention;

[0021] Figure 1 In the figure: U1 is an operational amplifier; R1, R2, R3, R4 are resistors; u i high-frequency input signal; u o high-frequency output signal; Q1 is a JFET; d is the drain of the JFET; s is the source of the JFET; g is the gate of the JFET; u ds drain-source voltage of the JFET; u gs low-frequency DC input signal. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way restricts the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0025] As Figure 1 shown, in an embodiment of the present invention, an analog signal amplitude modulation circuit is provided. The amplitude modulation circuit includes an operational amplifier U1, resistors R1, R2, R3, and R4, and a JFET, which is represented by Q1. There are two resistors R1. The input signal of the amplitude modulation circuit is a high-frequency input signal u i , and the output signal is a high-frequency output signal u o ; where: the current generated by the high-frequency input signal u i enters two branches simultaneously. For the first branch, the high-frequency input signal u iAfter passing through one of the R1 resistors and the parallel combination of R3 and Q1, it flows to the ground. The input voltage at the non-inverting terminal of the operational amplifier is the divided voltage of the parallel combination of R3 and Q1. For the second branch, the current generated by the high-frequency input signal u i flows to the ground after passing through the other R1 resistor and the R2 resistor, and the current generated by the high-frequency input signal u i also flows into the inverting input terminal of the operational amplifier. In addition, the current generated by the high-frequency output signal u o flows out of the inverting input terminal of the operational amplifier through R4, forming a negative feedback circuit. Among them, a low-frequency DC input signal u gs is provided to the JFET. By changing u gs , the voltage u ds between the drain and source of the JFET is changed, thereby changing the voltage at the non-inverting input terminal and realizing amplitude modulation of the high-frequency input signal u i to generate a high-frequency output signal u o .

[0026] In the embodiment of the present invention, since u ds is very small, the JFET operates in the variable resistance region. The effect of u gs is that a change in u gs will cause a change in the drain-source resistance R gs . Then the output signal of the operational amplifier, that is, u o satisfies the following formula:

[0027] The output signal of the operational amplifier satisfies the following formula:

[0028]

[0029] In the formula, |u o | is a physical quantity representing the amplitude of the high-frequency output signal u o , and |u i | is a physical quantity representing the amplitude of the high-frequency input signal u i is the equivalent parallel resistance of R ds , R 1 , R 3 , is the equivalent parallel resistance of R 1 , R 2 , R 4 .

[0030] Furthermore, based on formula (1), by configuring the resistors, it is achieved that:

[0031]

[0032] Among them, formulas (2) and (3) show two control effects. (2) is |u o | and R dsA control effect with a positive correlation, i.e., |u o | increases as R ds increases; (3) is a control effect with a negative correlation between |u o | and R ds , i.e., |u o | decreases as R ds increases. When Q1 is an N-JFET, R ds decreases as u gs increases; when Q1 is a P-JFET, R ds increases as u gs increases. Selecting JFETs with different channels has different control effects and can be arbitrarily combined.

[0033] It can be seen that the embodiment of the present invention provides a simple analog signal amplitude modulation circuit, which is implemented by an operational amplifier, a resistor and a JFET. The input end of the operational amplifier is a high-frequency signal, and the input end of the JFET is a low-frequency DC signal. By changing the magnitude of the low-frequency DC signal, the magnitude of the signal at the output end of the operational amplifier is changed, realizing the amplitude modulation of the high-frequency signal. This circuit is applied to the quartz tuning fork gyro drive automatic gain control circuit, replacing the traditional square wave amplitude modulation with sine wave amplitude modulation and optimizing the square wave drive to sine wave drive, reducing the high-order harmonic interference of the gyro signal.

[0034] According to another embodiment, a quartz tuning fork gyro circuit is provided. The quartz tuning fork gyro circuit includes a drive circuit and a detection circuit. In the drive circuit, the above analog signal amplitude modulation circuit is used to replace the amplitude modulation link in the drive loop, changing the square wave drive to a sine wave drive.

[0035] In this embodiment, the remaining structures of the drive circuit in the quartz tuning fork gyro circuit are well-known techniques in the art and will not be described in detail here.

[0036] It can be seen that applying the above embodiment circuit to the quartz tuning fork gyro drive automatic gain control circuit, replacing the traditional square wave amplitude modulation with sine wave amplitude modulation and optimizing the square wave drive to sine wave drive, reducing the high-order harmonic interference of the gyro signal.

[0037] According to still another embodiment, a quartz tuning fork gyro is provided, which includes the above quartz tuning fork gyro circuit.

[0038] In summary, the present invention provides a simple analog signal amplitude modulation circuit, which is implemented by analog devices such as an operational amplifier, a resistor and a JFET, plays a role in amplitude modulation in the automatic gain control circuit, and realizes sine wave drive.

[0039] Features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or replace features in other embodiments.

[0040] It should be emphasized that the term "comprising / including" as used herein refers to the presence of features, wholes, steps or components, but does not exclude the presence or addition of one or more other features, wholes, steps, components or combinations thereof.

[0041] The above method of the present invention can be implemented by hardware or by a combination of hardware and software. The present invention relates to such a computer-readable program that, when executed by a logic component, can enable the logic component to implement the device or component described above, or enable the logic component to implement the various methods or steps described above. The present invention also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, etc.

[0042] Many features and advantages of these embodiments are apparent from this detailed description, so the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. In addition, since many modifications and changes are readily envisioned by those skilled in the art, the embodiments of the present invention are not to be limited to the exact structures and operations illustrated and described, but may cover all suitable modifications and equivalents that fall within their scope.

[0043] The parts not described in detail in the present invention are well-known techniques to those skilled in the art.

Claims

1. An analog signal amplitude modulation circuit, characterized in that: The amplitude modulation circuit includes an operational amplifier U1, resistors R1, R2, R3 and R4, and a JFET, where the JFET is represented by Q1. There are two resistors R1. The input signal of the amplitude modulation circuit is a high-frequency input signal u i , the output signal is a high frequency output signal u o ;in: High frequency input signal u i The generated current enters two branches at the same time. For the first branch, the high-frequency input signal u i After passing through one of the R1 resistors and the parallel connection of R3 and Q1, it flows to the ground. The op amp non-inverting input voltage is the voltage divided by the parallel connection of R3 and Q1. For the second branch, the high-frequency input signal u i The generated current flows to the ground after passing through another resistor R1 and R2. In addition, the high-frequency input signal u i The generated current will also flow into the inverting input terminal of the op amp; the high-frequency output signal u o The current generated by R4 will flow out of the op amp’s inverting input terminal, forming a negative feedback circuit; Provide low frequency DC input signal u gs to JFET, by changing u gs , changing the voltage u between the drain and source of the JFET ds , thereby changing the voltage at the in-phase input terminal to achieve high-frequency input signal u i Amplitude modulation produces a high-frequency output signal u o .

2. The analog signal amplitude modulation circuit according to claim 1, characterized in that: The output signal of the op amp satisfies the following formula: In the formula, |u o | is the representation of u o The physical quantity of the high-frequency output signal amplitude, |u i | is the representation of u i The physical quantity of the high-frequency input signal amplitude For R ds , R1, R3 equivalent parallel resistance, is the equivalent parallel resistance of R1, R2, and R4.

3. An analog signal amplitude modulation circuit according to claim 2, characterized in that: Based on formula (1), by configuring the resistor, we can achieve: Among them, formulas (2) and (3) show two control effects, (2) is |u o |With R ds The control effect is positively correlated, that is, |u o |With R ds increases and increases; (3) is |u o |With R ds The control effect is negatively correlated, that is, |u o |With R ds increases and decreases. When Q1 is N-JFET, R ds Follow u gs When Q1 is a P-JFET, R ds Follow u gs Choosing JFETs with different channels has different control effects and can be matched arbitrarily.

4. A quartz tuning fork gyroscope circuit, the quartz tuning fork gyroscope circuit comprising a driving circuit and a detection circuit, characterized in that: In the driving circuit, the analog signal amplitude modulation circuit described in claims 1-3 is used to replace the amplitude modulation link in the driving circuit to convert the square wave drive into a sine wave drive.

5. A quartz tuning fork gyroscope, characterized in that: The invention comprises the quartz tuning fork gyroscope circuit as claimed in claim 4.

Images