A system and method for identifying time-division multiplexing parameters of a hemispherical resonant gyroscope

Abstract

The present invention relates to a time-division multiplexing parameter identification system and method for a hemispherical resonant gyroscope, comprising a signal acquisition and processing unit, a parameter identification unit and a resonant gyroscope loop control unit; the output end of the signal acquisition and processing system is connected to the parameter identification unit, the signal acquisition and processing unit is used to convert the analog signal output by the gyroscope into a digital signal and output it to the parameter identification unit, and at the same time generate a gyroscope control signal to maintain the four-amplitude vibration of the resonant gyroscope; the output end of the parameter identification unit is connected to the resonant gyroscope loop control unit, the parameter identification unit is used to demodulate the two-axis vibration signal detected by the gyroscope head sensor according to the set phase reference, and obtain the vibration state information of the resonator after mathematical operation; the resonant gyroscope loop control unit is used to maintain the four-amplitude state of the gyroscope according to the gyroscope vibration displacement signal provided by the parameter identification unit. The present invention can effectively reduce parameter identification noise.

Description

Technical Field

[0001] The invention belongs to the technical field of inertial instrument control, and relates to a time-division multiplexing parameter identification method for a resonant gyroscope, in particular to a time-division multiplexing parameter identification system and method for a hemispherical resonant gyroscope. Background Art

[0002] As a solid wave gyroscope based on the Coriolis effect, the resonant gyroscope includes quartz hemispherical resonant gyroscope, metal cylindrical resonant gyroscope, nested ring gyroscope and micro hemispherical gyroscope. The quartz hemispherical resonant gyroscope is a Coriolis vibration gyroscope without rotating parts, which has the advantages of high precision, high resolution, high reliability and strong radiation resistance. Therefore, the hemispherical resonant gyroscope has broad application prospects in marine inertial navigation systems, aviation inertial navigation systems, weapon inertial navigation systems and space inertial navigation systems.

[0003] The "time division multiplexing control mode" is a control scheme for a resonant gyroscope. Its characteristic is that the detection electrodes of the resonant gyroscope work in the excitation state or the detection state in turn. That is, the analog-to-digital converter intermittently collects the vibration displacement electrical signals output by the "0" degree electrode and the "45" degree electrode of the resonant gyroscope. Therefore, under the "time division multiplexing control mode", it is difficult to obtain the vibration displacement signal of the vibrating gyroscope in high precision and real time.

[0004] No matter which mode is adopted, the core is to accurately detect and control the standing wave of the resonator to identify the external angular velocity or angle. Due to the limitations of the hemispherical resonator and electrode processing technology and the inconsistency of electronic devices, the hemispherical resonator gyroscope drive channel and the detection channel have inconsistencies in electrode gain and delay. When driving and detecting are carried out at the same time, there is also coupling interference of the drive signal to the detection signal. In order to improve the accuracy of the gyroscope and reduce the inconsistency error, the "time-division multiplexing control mode" control scheme adopts the time-division multiplexing method of exciting the detection electrode to ensure the consistency of the drive detection channel and reduce the gain and delay error of the channel. The key to realizing the "time-division multiplexing control mode" control mode is the identification technology of the gyroscope vibration displacement data, that is, obtaining accurate gyroscope control parameters in discontinuous detection. Therefore, the present invention conducts research on the "time-division multiplexing" scheme parameter rapid identification method.

[0005] After searching, no prior art documents identical or similar to the present invention were found. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a time-division multiplexing parameter identification system and method for a hemispherical resonant gyroscope, which can effectively reduce parameter identification noise.

[0007] The present invention solves the practical problem by adopting the following technical solutions:

[0008] A time-division multiplexing parameter identification system based on a hemispherical resonant gyroscope comprises a signal acquisition and processing unit, a parameter identification unit and a resonant gyroscope loop control unit; the output end of the signal acquisition and processing system is connected to the parameter identification unit, the signal acquisition and processing unit is used to convert the analog signal output by the gyroscope into a digital signal and output it to the parameter identification unit, and at the same time generate a gyroscope control signal to maintain the four-amplitude vibration of the resonant gyroscope; the output end of the parameter identification unit is connected to the resonant gyroscope loop control unit, the parameter identification unit is used to demodulate the two-axis vibration signal detected by the gyroscope head sensor according to a set phase reference, and obtain the vibration state information of the resonator through mathematical operation; the resonant gyroscope loop control unit is used to maintain the four-amplitude working state of the gyroscope according to the gyroscope vibration displacement signal provided by the parameter identification unit.

[0009] A method for identifying time-division multiplexing parameters of a hemispherical resonant gyroscope comprises the following steps:

[0010] Step 1: Convert the analog current signals output by the x-axis and y-axis detection electrodes of the resonant gyroscope into analog voltage signals through a charge amplifier;

[0011] Step 2: Convert the analog voltage signal into a digital voltage signal using an analog-to-digital converter;

[0012] Step 3: Transmit the digital voltage signal to the parameter identification unit for parameter identification.

[0013] Moreover, the specific method of step 3 is:

[0014] (1) Constructing the output signal model of the gyroscope detection electrode

[0015] (2) Using the digital voltage signal to construct the observation matrix B, and generating the reference signal to construct the parameter matrix A;

[0016] (3) Continuously and uninterruptedly apply the least squares algorithm to the digital voltage signal and the reference signal to perform multiplication and accumulation operations on the parameter matrix A and the observation matrix B, and complete the multiplication and accumulation operations when a certain number of points are accumulated;

[0017] (4) Obtain the inverse matrix of the parameter matrix A, and apply the inverse matrix of the parameter matrix A and the observation matrix B to obtain the A of the sinusoidal signal. d and The trigonometric function relationship is applied to obtain the gyro vibration displacement data and identify the parameters.

[0018] Advantages and beneficial effects of the present invention:

[0019] The present invention provides a "time-division multiplexing" parameter identification method for a hemispherical resonant gyroscope. By applying the least squares algorithm, the amplitude and phase data of the sinusoidal signal can be estimated within one sinusoidal cycle or shorter. The amplitude and phase can be converted into gyroscope vibration displacement data by converting the calculation formula. The least squares algorithm has high real-time performance, high accuracy and low delay. Compared with the traditional multiplication filter demodulation algorithm, it avoids the introduction of second harmonics and effectively reduces the parameter identification noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the parameter identification principle and loop control block diagram of the present invention;

[0021] Figure 2 It is a block diagram of the digital control system of the hemispherical resonant gyroscope of the present invention;

[0022] Figure 3 is an electrode switching block diagram of the present invention;

[0023] Description of reference numerals:

[0024] 1. Resonator, 2. Multi-way switch, 3. First charge amplifier, 4. Digital-to-analog converter, 5. Gyro control and compensation unit, 6. Parameter conversion unit, 7. Parameter identification unit, 8. Analog-to-digital converter, 9. Second charge amplifier. DETAILED DESCRIPTION

[0025] The following is a further description of the embodiments of the present invention:

[0026] A time-division multiplexing parameter identification system based on a hemispherical resonant gyroscope comprises a signal acquisition and processing unit, a parameter identification unit and a resonant gyroscope loop control unit; the output end of the signal acquisition and processing system is connected to the parameter identification unit, the signal acquisition and processing unit is used to convert the analog signal output by the gyroscope into a digital signal and output it to the parameter identification unit, and at the same time generate a gyroscope control signal to maintain the four-amplitude vibration of the resonant gyroscope; the output end of the parameter identification unit is connected to the resonant gyroscope loop control unit, the parameter identification unit is used to demodulate the two-axis vibration signal detected by the gyroscope head sensor according to a set phase reference, and obtain the vibration state information of the resonator through mathematical operation; the resonant gyroscope loop control unit is used to maintain the four-amplitude working state of the gyroscope according to the gyroscope vibration displacement signal provided by the parameter identification unit.

[0027] A method for identifying time-division multiplexing parameters of a hemispherical resonant gyroscope comprises the following steps:

[0028] Step 1: Convert the analog current signals output by the x-axis and y-axis detection electrodes of the resonant gyroscope into analog voltage signals through a charge amplifier;

[0029] Step 2: Convert the analog voltage signal into a digital voltage signal using an analog-to-digital converter;

[0030] Step 3: Transmit the digital voltage signal to the parameter identification unit for parameter identification.

[0031] Moreover, the specific method of step 3 is:

[0032] (1) Constructing the output signal model of the gyroscope detection electrode

[0033] (2) Using the digital voltage signal to construct the observation matrix B, and generating the reference signal to construct the parameter matrix A;

[0034] (3) Continuously and uninterruptedly apply the least squares algorithm to the digital voltage signal and the reference signal to perform multiplication and accumulation operations on the parameter matrix A and the observation matrix B, and complete the multiplication and accumulation operations when a certain number of points are accumulated;

[0035] (4) Obtain the inverse matrix of the parameter matrix A, and apply the inverse matrix of the parameter matrix A and the observation matrix B to obtain the A of the sinusoidal signal. d and The trigonometric function relationship is applied to obtain the gyro vibration displacement data and identify the parameters.

[0036] The following is a further description of each component in a time-division multiplexing parameter identification system based on a hemispherical resonant gyroscope:

[0037] 1. The signal processing acquisition and processing system converts the analog signal output by the gyroscope into a digital signal for subsequent analysis and processing, and generates a gyroscope control signal to maintain the four-amplitude vibration of the resonant gyroscope.

[0038] 2. The parameter identification unit demodulates the two-axis vibration signals detected by the gyro head sensor according to the set phase reference, and obtains the vibration state information of the resonator through mathematical calculations, which is used for each loop control, parameter identification, and sensitive external angular motion to obtain a response signal. The parameter identification unit comprises a resonator, a multi-way switch, a first charge amplifier, a digital-to-analog converter, a gyro control and compensation unit, a parameter conversion unit, a parameter identification unit, an analog-to-digital converter and a second charge amplifier; the output end of the resonator is connected in sequence through the multi-way switch, the second charge amplifier, the analog-to-digital conversion unit and the parameter identification unit, so as to obtain the vibration information of the resonator, and convert the gyro output analog signal into a digital signal and then separate the gyro vibration displacement data through the parameter identification module; the output end of the parameter identification unit is connected to the parameter conversion unit, so as to convert the gyro vibration displacement data into elliptical orbit parameters, and the output end of the parameter conversion unit is connected to the gyro control and compensation unit, so as to maintain the gyro four-amplitude vibration and compensation according to the given model and its parameters; the output end of the gyro control and compensation unit is connected to the resonator in sequence through the digital-to-analog converter and the multi-way switch, so as to maintain the resonance shedding four-amplitude vibration;

[0039] 3. The resonant gyro loop control unit maintains the gyro's four-amplitude working state according to the gyro vibration displacement signal provided by the parameter identification unit.

[0040] The composition and function of the parameter identification unit are further explained below:

[0041] The resonator 1 is the core sensitive unit of the gyroscope. Depending on the application requirements and the accuracy level, its material can be quartz, silicon-based, metal, etc. The multi-way switch 2 is used to switch the driving and inspection electrodes, including contact and non-contact types, such as piezoelectric ceramics, capacitors, etc. The first charge amplifier 3 converts the x-axis current signal of the resonant gyroscope into an x-axis voltage signal. The second charge amplifier 9 converts the y-axis current signal of the resonant gyroscope into a y-axis voltage signal. The digital-to-analog converter 4 converts the digital quantity into an analog quantity for subsequent gyroscope control. The gyroscope control and compensation unit 5 maintains the four-amplitude vibration and compensation of the gyroscope according to the given model and its parameters. The parameter conversion unit 6 is used to convert the gyroscope vibration displacement data into elliptical orbit parameters, and the parameter identification unit 7 separates the gyroscope vibration displacement data. The analog-to-digital conversion unit 8 converts the gyroscope output analog signal into a digital signal.

[0042] A method for identifying parameters based on "time-division multiplexing" of a hemispherical resonant gyroscope comprises the following steps:

[0043] Step 1: Convert the analog current signals output by the x-axis and y-axis detection electrodes of the resonant gyroscope into analog voltage signals through a charge amplifier;

[0044] Step 2: Convert the analog voltage signal into a digital voltage signal using an analog-to-digital converter;

[0045] Step 3: Transmit the digital voltage signal to the parameter identification unit for parameter identification.

[0046] The specific method of step 3 is:

[0047] First, construct the gyro detection electrode output signal model Secondly, the digital voltage signal is used to construct the observation matrix B, and the reference signal is generated to construct the parameter matrix A. Thirdly, the least squares algorithm is continuously applied to the digital voltage signal and the reference signal to perform multiplication and accumulation operations on the parameter matrix A and the observation matrix B. When a certain number of points are accumulated, the multiplication and accumulation operations are completed. Finally, the inverse matrix of the parameter matrix A is obtained, and the inverse matrix of the parameter A is applied to the observation matrix B to obtain the A of the sinusoidal signal. d and The trigonometric relationship is applied to obtain the gyro vibration displacement data.

[0048] The working process and principle of the present invention are as follows:

[0049] (1) Digital control loop:

[0050] The core control unit of the HRG digital control system uses Xilinx Zynq SoC. Zynq SoC has strong scalability, and its architecture adopts the "FPGA+ARM" structure. It has both the parallel processing of FPGA and the flexibility of ARM. The system will be used to realize the closed-loop control of the hemispherical resonant gyroscope, the online configuration of the gyroscope control parameters and the gyroscope status monitoring. Figure 2 The control block diagram of the hemispherical resonant gyroscope digital system is shown in the figure. The system consists of three parts: digital circuit, analog circuit, and gyroscope head. The key core components of the hardware circuit mainly include high-speed digital-to-analog converter (DAC), high-precision analog-to-digital converter (ADC), control system core Zynq SoC and pre-amplifier.

[0051] The Zynq SoC FPGA part is used for external digital chip driving and control algorithm acceleration. The analog-to-digital converter is used to convert the analog signal output by the gyroscope into a digital signal with a conversion range of -10V to +10V. The digital-to-analog converter is used to generate an excitation signal to control the gyroscope, and its range is -10V to +10V. The asynchronous transceiver interface allows users to input / output functions. The input function is generally used for parameter configuration, such as the modifiable finite impulse response (FIR) filter coefficients and the configurable drive and detection end calibration coefficients, proportional integral (PID) coefficients (Kp, Ki, Kd), etc. The output function is used for internal control parameter data, gyroscope sensitive angular rate or angle output. The closed-loop signal processing flow of the hemispherical resonant gyroscope is as follows Figure 1shown.

[0052] The drive detection time-sharing switching divides a working cycle into 4 parts: X-Sense, Y-Sense, X-Control, and Y-Control. The system works in the 4 parts alternately according to the timing, and stays for a short idle time r during each switching process. The working state is: X-Sense, r, Y-Sense, r, X-Control, r, Y-Control, r, and repeats. The time-sharing multiplexing electrode control timing is as follows Figure 3 As shown. Through state switching, each pair of differential electrodes can work evenly in the driving or detection state on the time axis, effectively suppressing the gain unevenness of the multi-channel control loop and the drift effect of gain change on the working state of the resonator. At a single moment, the resonator only works in the driving or detection state, and an idle beat is placed in the state switching, which effectively suppresses the coupling interference between the driving channel and the detection channel and the instability of the inspection signal during the switching process. And at a single moment, all electrodes in the working mode of the resonator are used for driving or detection state, effectively improving the signal-to-noise ratio and driving efficiency of the inspection signal.

[0053] According to the Lynch equation, in the case of an ideal oscillator, that is, an undamped and axially symmetric oscillator, x 、s x 、c y 、s y Substituting the demodulated variables into equations 1 to 7, we can obtain the following variables.

[0054]

[0055] 2(c x s y -c y s x )=2aq=Q (2)

[0056]

[0057] 2(c x c y +s x s y )=(a 2 -q 2 )sin2θ=S (4)

[0058] 2(c x s x +c y s y )=-(a 2 -q 2 )sin2φ'=L (5)

[0059]

[0060]

[0061] The vibration angle and orbit phase will not change E and Q, so these two variables can be used as amplitude stabilization loop and orthogonal control loop in force feedback mode. S is related to the formation angle, so it can be used in the force feedback loop, and L can be used in the frequency stabilization control loop.

[0062] (2) Signal analysis unit

[0063] Parameter identification principle and loop control block diagram are as follows: Figure 1 As shown in the figure, the control circuit of the hemispherical resonant gyroscope can be divided into "time division multiplexing control mode" and "continuous control mode" according to the time mode of electrode operation. "Time division multiplexing control mode" means that the electrode operates according to time segments, and the electrode switches between the excitation state and the detection state in different time segments, so it is called "time division multiplexing control mode". "Continuous control mode" means that the same electrode only works in the excitation state or the detection state, and the analog-to-digital converter continuously collects the vibration displacement electrical signals output by the "0" degree electrode and the "45" degree electrode of the resonant gyroscope, so it is called "continuous control mode".

[0064] The "continuous control mode" generally adopts the more traditional digital multiplication phase-sensitive parameter identification method, see formula 6 and formula 7. The demodulation result contains a strong double frequency component. and It must then pass through a high-order low-pass filter to filter out the double-frequency components.

[0065]

[0066]

[0067] In the "time division multiplexing control mode", the resonant gyro detection electrodes work in the excitation state or the detection state in turn. That is, the analog-to-digital converter intermittently collects the vibration displacement electrical signals output by the "0" degree electrode and the "45" degree electrode of the resonant gyro. See the electrode control timing for details. Figure 2 , X-Sense, Y-Sense, X-Control, Y-Control four excitation detection cycles, repeated. From the timing diagram, it can be seen that each electrode detection cycle can only obtain data for one vibration cycle, and the two adjacent detections of the same electrode are irrelevant. Therefore, in the "time division multiplexing control mode", it is difficult to obtain the vibration displacement signal of the vibration gyroscope with high precision and in real time.

[0068] Assume that the output model of the “0” electrode is as follows:

[0069]

[0070] Where x is the observed quantity, ω d is the resonant frequency, A d and is an unknown quantity. A is obtained by calculation d and The value of c can also be obtained indirectly x 、s x 、c y 、s y .

[0071] Based on the necessary conditions for the existence of the minimum value, find the residual sum of squares and The minimum value of , after arranging and simplifying, we can get:

[0072]

[0073]

[0074] Substitute the obtained C and D into the formula to find the phase and amplitude.

[0075] The least squares method is used to estimate the parameters of the sinusoidal curve. For the gyro output signal, the amplitude and phase are estimated with a known frequency. The demodulation method based on recursive minimum square error demodulation (LS) can effectively avoid the high-frequency components generated during the demodulation process and avoid the introduction of a low-pass digital filter.

[0076] It should be emphasized that the embodiments of the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation modes. Any other implementation modes derived by those skilled in the art based on the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. An identification method based on a hemispherical resonant gyroscope time-division multiplexing parameter identification system, comprising the following steps: Step 1: Convert the analog current signals output by the x-axis and y-axis detection electrodes of the resonant gyroscope into analog voltage signals through a charge amplifier; Step 2: Convert the analog voltage signal into a digital voltage signal using an analog-to-digital converter; Step 3: transmitting the digital voltage signal to a parameter identification unit for parameter identification; Step 3 is: (1) Constructing the output signal model of the gyroscope detection electrode (2) Using the digital voltage signal to construct the observation matrix B, and generating the reference signal to construct the parameter matrix A; (3) Continuously and uninterruptedly apply the least squares algorithm to the digital voltage signal and the reference signal to perform multiplication and accumulation operations on the parameter matrix A and the observation matrix B, and complete the multiplication and accumulation operations when a certain number of points are accumulated; (4) Obtain the inverse matrix of the parameter matrix A, and apply the inverse matrix of the parameter matrix A and the observation matrix B to obtain the A of the sinusoidal signal. d and Apply trigonometric function relationships to obtain gyro vibration displacement data and identify parameters; The process is as follows: The control circuit of the hemispherical resonant gyroscope is divided into "time division multiplexing control mode" and "continuous control mode" according to the working time of the electrode; "time division multiplexing control mode" means that the electrode works according to the time segment, and the electrode switches between the excitation state and the detection state in different time segments, which is called "time division multiplexing control mode"; "continuous control mode" means that the same electrode only works in the excitation state or the detection state, and the analog-to-digital converter continuously collects the vibration displacement electrical signals output by the "0" degree electrode and the "45" degree electrode of the resonant gyroscope, which is called "continuous control mode"; "Continuous control mode" uses the digital multiplication phase-sensitive parameter identification method, see formula 6 and formula 7; its demodulation result contains a strong double frequency component and It must then pass through a high-order low-pass filter to remove the frequency-doubled components; In the "time division multiplexing control mode", the detection electrodes of the resonant gyroscope work in the excitation state or the detection state in turn; that is, the analog-to-digital converter intermittently collects the vibration displacement electrical signals output by the "0" degree electrode and the "45" degree electrode of the resonant gyroscope; the four excitation and detection cycles of X-Sense, Y-Sense, X-Control, and Y-Control are repeated; It can be concluded from the timing diagram that, for each electrode detection cycle, only data for one vibration cycle can be obtained, and two adjacent detections of the same electrode are unrelated; Assume the output model of the "0" electrode is: Among them, x is the observed quantity, ω d is the resonant frequency, A d and is an unknown quantity; A is obtained by calculation d and The value of c can also be obtained indirectly x 、s x 、c y 、s y ; Based on the necessary conditions for the existence of the minimum value, find the residual sum of squares and The minimum value of , after arranging and simplifying, we can get: Substitute the obtained C and D into the formula to find the phase and amplitude; The least squares method is used to estimate the parameters of the sinusoidal curve. For the gyro output signal, the amplitude and phase are estimated with a known frequency. The demodulation method based on recursive minimum square error demodulation (LS) can avoid the high-frequency components generated during the demodulation process and avoid the introduction of a low-pass digital filter.

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