Digital control system of resonant gyroscope based on electromechanical synchronous sampling

Abstract

The application discloses a resonant gyroscope digital control system based on electromechanical synchronous sampling, which comprises a first preamplifier, a second preamplifier, a first A / D conversion unit, a second A / D conversion unit, a control unit, a D / A conversion unit and a low-pass filter. The control unit comprises a first demodulation unit, a second demodulation unit, a phase-locked loop and an automatic gain control unit and an NCO. The first preamplifier processes the vibration signal of a driving channel resonator, and the processed signal is converted into a digital signal by the first A / D conversion unit. The first demodulation unit demodulates the digital signal to obtain the phase and amplitude of the vibration signal. The phase-locked loop and the automatic gain control unit adjust the frequency increment of the NCO according to the phase and amplitude. The D / A conversion unit converts the driving signal into an analog signal. The low-pass filter filters the analog signal and outputs the filtered signal to the driving channel resonator. The second preamplifier processes the vibration signal of a detection channel resonator. The second A / D conversion unit converts the processed signal into a digital signal. The second demodulation unit demodulates the digital signal to obtain a rotation speed signal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resonant gyroscopes, and in particular to a resonant gyroscope digital control system based on electromechanical synchronous sampling. BACKGROUND

[0002] The resonant gyroscope measurement and control system based on the Coriolis force coupling principle generally includes three control loops: a phase-locked loop for automatically tracking the resonant frequency of the resonator in the drive loop, an automatic gain control loop for stabilizing the amplitude of the drive loop, and a synchronous demodulation detection loop for detecting the coupled vibration. If the gyroscope works in a closed loop mode, the measurement and control system also includes a closed-loop force feedback control link for suppressing coupled vibration. The above three control loops can be implemented using analog circuits, which has the disadvantage that each analog circuit link is susceptible to environmental temperature changes, affecting the zero bias stability of the gyroscope. In addition, the analog circuit implementation method also has the disadvantages of inconvenient debugging, inflexible system, and being not conducive to implementing complex control and compensation algorithms. SUMMARY

[0003] The present application provides a resonant gyroscope digital control system based on electromechanical synchronous sampling, which can solve the technical problems in the prior art.

[0004] The present application provides a resonant gyroscope digital control system based on electromechanical synchronous sampling, wherein the system includes a first preamplifier, a second preamplifier, a first A / D conversion unit, a second A / D conversion unit, a control unit, a D / A conversion unit and a low-pass filter, the control unit includes a first demodulation unit, a second demodulation unit, a phase-locked loop and an automatic gain control unit, and a digital control oscillator, wherein

[0005] The first preamplifier is connected to the drive channel resonator of the resonant gyroscope, and is used for preamplification processing of the vibration signal output by the drive channel resonator to obtain a processed signal. The first A / D conversion unit is used for converting the processed signal into a digital signal. The first demodulation unit is used for demodulating the digital signal to obtain the phase and amplitude of the vibration signal. The phase-locked loop and the automatic gain control unit adjust the frequency increment of the digital control oscillator according to the phase and amplitude, so that the frequency of the drive signal output by the digital control oscillator tracks the resonant frequency of the drive channel resonator. The D / A conversion unit is used for converting the drive signal into an analog signal. The low-pass filter is used for filtering the analog signal and outputting the filtered drive signal to the drive channel resonator to form a closed-loop control.

[0006] The second preamplifier is connected with a detection channel resonator of the resonant gyroscope, and is configured to preamplify a vibration signal output by the detection channel resonator to obtain a processed signal.

[0007] Preferably, the first demodulation unit demodulates the digital signal to obtain a phase and an amplitude of the vibration signal, and the method comprises:

[0008] The first demodulation unit demodulates the digital signal to obtain a phase and an amplitude of the vibration signal according to the first and second quadrature digital frequency signals output by the digital control oscillator.

[0009] Preferably, the second demodulation unit demodulates the digital signal to obtain the rotation speed signal, and the method comprises:

[0010] The second demodulation unit demodulates the digital signal to obtain the rotation speed signal according to the first and second quadrature digital frequency signals output by the digital control oscillator.

[0011] Preferably, the control unit is a field programmable logic gate array (FPGA).

[0012] Preferably, the preamplification of the vibration signal output by the drive channel resonator comprises current-voltage conversion processing and amplification processing of the vibration signal output by the drive channel resonator.

[0013] Preferably, the preamplification of the vibration signal output by the detection channel resonator comprises current-voltage conversion processing and amplification processing of the vibration signal output by the detection channel resonator.

[0014] Preferably, the digital control oscillator comprises an accumulation register configured to control sampling triggering of the first and second A / D conversion units.

[0015] By the above technical solution, the analog-digital conversion / detection of the vibration signal, the generation of the drive / force feedback signal, and the real-time control between the frequency tracking phase-locked loop and the vibration amplitude automatic gain adjustment can be synchronized based on the resonator frequency. Thus, the vibration signal can be coherently demodulated under the condition of significantly reduced sampling frequency, the time delay of signal processing is reduced, the detection bandwidth is increased, and high-precision digital control is facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. It is readily understood that the drawings are merely illustrative of some embodiments of the application and therefore are not to be construed as limiting the scope of the application as described herein.

[0017] Figure 1 Fig. 1 shows a schematic diagram of a resonator gyroscope digital control system based on electromechanical synchronous sampling according to an embodiment of the application;

[0018] Figure 2 Fig. 2 shows a schematic diagram of a digital control oscillator (NCO) and synchronous sampling control bits according to an embodiment of the application. DETAILED DESCRIPTION

[0019] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The description of the at least one example embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0021] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples are not intended to limit the scope of the application unless specifically stated otherwise. It is to be understood that the drawings are not necessarily to scale as the dimensions of the parts shown are for the purpose of illustration and description only and not to limit the scope of the application. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered within the scope of the disclosure where appropriate. In all examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not as a limitation. Thus, other examples of exemplary embodiments can have different values. It should be noted that like reference numerals and letters refer to like items in the several views of the drawings, and thus, once an item is defined in one view, it need not be discussed further in subsequent views.

[0022] Figure 1 A schematic diagram of a resonator gyroscope digitization control system based on electromechanical synchronous sampling according to an embodiment of the present application is shown.

[0023] As Figure 1 shown, an embodiment of the present application provides a resonator gyroscope digitization control system based on electromechanical synchronous sampling, wherein the system comprises a first preamplifier 1, a second preamplifier 2, a first A / D conversion unit 3, a second A / D conversion unit 4, a control unit 5, a D / A conversion unit 6, and a low-pass filter (LPF) 7, the control unit 5 comprises a first demodulation unit (DEMO) 50, a second demodulation unit (DEMO) 51, a phase-locked loop (PLL) and automatic gain control unit (AGC) 52, and a digital control oscillator (NCO) 53, wherein,

[0024] The first preamplifier 1 is connected with a drive channel resonator 8 of the resonator gyroscope, for preamplification processing of the vibration signal output by the drive channel resonator 8, to obtain a processed signal, the first A / D conversion unit 3 is used to convert the processed signal into a digital signal, the first demodulation unit 50 is used to demodulate the digital signal to obtain the phase and amplitude A of the vibration signal, the phase-locked loop and automatic gain control unit 52 adjusts the frequency increment of the digital control oscillator 53 according to the phase and amplitude, so that the frequency of the drive signal output by the digital control oscillator 53 tracks the resonant frequency of the drive channel resonator, the D / A conversion unit 6 is used to convert the drive signal into an analog signal, and the low-pass filter 7 is used to filter the analog signal and output a filtered drive signal Fd to the drive channel resonator 8, forming a closed-loop control.

[0025] That is, for the resonators of the drive channel and the detection channel of the resonator gyroscope, a preamplifier is respectively arranged for preamplification processing.​

[0026] The second preamplifier 2 is connected with the detection channel resonator 9 of the resonant gyro, and is used for preamplifying the vibration signal output by the detection channel resonator 9 to obtain a processed signal; the second A / D conversion unit 4 is used for converting the processed signal into a digital signal; and the second demodulation unit 51 is used for demodulating the digital signal to obtain a rotation speed signal Ω.

[0027] Wherein, when the system reaches a steady state, the vibration signal can be uniformly sampled N times in each cycle.

[0028] Through the above technical solution, the analog-digital conversion / detection (phase and amplitude detection) of the vibration signal, the generation of the drive / force feedback signal, and the real-time control among the frequency tracking phase-locked loop and the vibration amplitude automatic gain adjustment can be synchronized based on the resonator frequency. Thus, the vibration signal can be coherently demodulated under the condition of greatly reducing the sampling frequency, the time delay of signal processing is reduced, the detection bandwidth is increased, and high-precision digital control is facilitated.

[0029] According to an embodiment of the present application, the first demodulation unit 50 demodulates the digital signal to obtain the phase and the amplitude A of the vibration signal, and comprises:

[0030] The first demodulation unit 50 demodulates the digital signal to obtain the phase and the amplitude A of the vibration signal according to the first quadrature digital frequency signal sin(ωt) and the second quadrature digital frequency signal cos(ωt) output by the digital control oscillator 53.

[0031] That is, the two-way quadrature digital frequency signals sin(ωt) and cos(ωt) output by the digital control oscillator NCO are used as reference signals to perform synchronous demodulation to obtain the phase and the amplitude of the vibration signal.

[0032] According to an embodiment of the present application, the second demodulation unit 51 demodulates the digital signal to obtain the rotation speed signal Ω, and comprises:

[0033] The second demodulation unit demodulates the digital signal to obtain the rotation speed signal Ω according to the first quadrature digital frequency signal sin(ωt) and the second quadrature digital frequency signal cos(ωt) output by the digital control oscillator.

[0034] That is, the two-way quadrature digital frequency signals sin(ωt) and cos(ωt) output by the digital control oscillator NCO are used as reference signals to demodulate the digital signal to obtain the rotation speed signal.

[0035] According to an embodiment of the present application, the control unit 5 is a field programmable gate array (FPGA).

[0036] FPGA can use higher refresh frequency than similar DSP-based system, so the frequency resolution is higher, and the synchronization trigger is more accurate.

[0037] According to an embodiment of the present application, the pre-amplification processing of the vibration signal output by the drive channel resonator 8 includes current-voltage conversion (C / V conversion) and amplification processing.

[0038] That is, the vibration signal output by the drive channel resonator is subjected to current-voltage conversion, and the converted vibration signal is amplified, so that the amplified vibration signal is subjected to analog-digital conversion to obtain a digital vibration signal.

[0039] According to an embodiment of the present application, the pre-amplification processing of the vibration signal output by the detection channel resonator 9 includes current-voltage conversion (C / V conversion) and amplification processing.

[0040] That is, the vibration signal output by the detection channel resonator is subjected to current-voltage conversion, and the converted vibration signal is amplified, so that the amplified vibration signal is subjected to analog-digital conversion to obtain a digital vibration signal.

[0041] Figure 2 A schematic diagram of a numerically controlled oscillator (NCO) and a synchronization sampling control bit according to an embodiment of the present application is shown.

[0042] According to an embodiment of the present application, as shown in Figure 2 The NCO 53 includes an accumulation register for controlling the sampling trigger of the first A / D conversion unit and the second A / D conversion unit.

[0043] With reference to Figure 2 , the high bit states B31, B30, B29 of the accumulation register of the NCO control the sampling trigger of the A / D, so that the synchronization of the A / D sampling frequency and the resonant frequency is realized. The length of the accumulation register, the frequency increment, and the refresh frequency of the NCO can determine the frequency range and the resolution of the NCO. Further, the accumulation register outputs the lookup address of a sine table, and the sine waveform data is converted into an analog signal by a digital-to-analog converter (DAC), and is output as a drive signal of the resonator through a low-pass filter, to form a closed-loop control.

[0044] From the above embodiments, the above-mentioned resonator gyroscope digital control system based on electromechanical synchronous sampling has at least the following advantages: 1) through synchronous sampling, the vibration signal can be quickly and synchronously demodulated, and the influence of the time delay caused by synchronous demodulation on detection and control can be reduced; 2) the sampling frequency requirement of the measurement and control system to the ADC can be reduced, and the cost and power consumption can be saved; 3) the requirement for the operation speed of the digital processing chip is reduced, and the power consumption is reduced.

[0045] In general, the resonator gyroscope digital control system based on electromechanical synchronous sampling solves the contradiction between the high performance requirement of the gyroscope sensor and the limited A / D conversion rate, the processor speed and the low power consumption requirement, and realizes the performance requirements of low noise, high precision and high bandwidth of the sensor.

[0046] In the description of the present application, it should be understood that the orientation words such as "front, rear, upper, lower, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and in the absence of contrary statements, these orientation words do not indicate and imply that the indicated device or element must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0047] For the convenience of description, spatial relative terms such as "on", "above", "upper surface", "upper" and the like can be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "on" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0048] In addition, it should be noted that the use of the words "first", "second" and the like to define parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0049] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A resonator gyroscope digitization control system based on electromechanical synchronous sampling, characterized by, The system comprises a first preamplifier, a second preamplifier, a first A / D conversion unit, a second A / D conversion unit, a control unit, a D / A conversion unit and a low-pass filter, the control unit comprises a first demodulation unit, a second demodulation unit, a phase-locked loop and an automatic gain control unit and a digital control oscillator, wherein, The first preamplifier is connected with a drive channel resonator of the resonator gyroscope, and is used for preamplifying a vibration signal output by the drive channel resonator to obtain a processed signal; the first A / D conversion unit is used for converting the processed signal into a digital signal; the first demodulation unit is used for demodulating the digital signal to obtain a phase and an amplitude of the vibration signal; the phase-locked loop and the automatic gain control unit adjust a frequency increment of the digital control oscillator according to the phase and the amplitude, so that a frequency of a drive signal output by the digital control oscillator tracks a resonant frequency of the drive channel resonator; the D / A conversion unit is used for converting the drive signal into an analog signal; and the low-pass filter is used for filtering the analog signal and outputting a filtered drive signal to the drive channel resonator, so as to form a closed-loop control. The second preamplifier is connected with a detection channel resonator of the resonator gyroscope, and is used for preamplifying a vibration signal output by the detection channel resonator to obtain a processed signal; the second A / D conversion unit is used for converting the processed signal into a digital signal; and the second demodulation unit is used for demodulating the digital signal to obtain a rotation speed signal. The first demodulation unit demodulates the digital signal to obtain the phase and the amplitude of the vibration signal, and comprises: The first demodulation unit demodulates the digital signal to obtain the phase and the amplitude of the vibration signal according to a first quadrature digital frequency signal and a second quadrature digital frequency signal output by the digital control oscillator. The second demodulation unit demodulates the digital signal to obtain the rotation speed signal, and comprises: The second demodulation unit demodulates the digital signal to obtain the rotation speed signal according to the first quadrature digital frequency signal and the second quadrature digital frequency signal output by the digital control oscillator.

2. The system of claim 1, wherein, The control unit is a field programmable gate array (FPGA).

3. The system of claim 2, wherein, The preamplifying the vibration signal output by the drive channel resonator comprises current-voltage conversion processing and amplification processing on the vibration signal output by the drive channel resonator.

4. The system of claim 2, wherein, The preamplifying the vibration signal output by the detection channel resonator comprises current-voltage conversion processing and amplification processing on the vibration signal output by the detection channel resonator.

5. The system of any one of claims 1-4, wherein, The digital control oscillator comprises an accumulation register, which is used for controlling sampling triggering of the first A / D conversion unit and the second A / D conversion unit.

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