Rapid closed-loop control method for excitation magnetic field of nuclear magnetic resonance gyroscope

Abstract

The invention discloses a rapid closed-loop control method for an excitation magnetic field of a nuclear magnetic resonance gyroscope, which comprises the following steps of: performing filtering and frequency division on a mixed signal by using a group of cascaded notch filters to obtain a single-phase sinusoidal signal with Larmor precession frequencies of 129Xe and 131Xe as fundamental frequencies, generating an orthogonal signal by using an SOGI second-order generalized integrator, obtaining a phase error by Park conversion, and calculating the excitation magnetic field of the nuclear magnetic resonance gyroscope according to the phase error. And finally, an excitation magnetic field signal is fed back through a loop filter and a voltage controller in the PLL, and closed-loop control is completed. The rapid closed-loop control method for the excitation magnetic field of the nuclear magnetic resonance gyroscope, provided by the invention, has high-precision frequency separation capability and rapid phase tracking capability, and has an effect of improving the stability of the whole system.

Description

Technical Field

[0001] The invention belongs to the technical field of complex system detection and control, and mainly relates to a fast closed-loop control method for a nuclear magnetic resonance gyroscope excitation magnetic field. Background Art

[0002] As a key precision instrument in inertial navigation, gyroscopes are used to measure the angular velocity or angular displacement information of the carrier. Gyroscope technology has a history of more than 160 years. According to the working principle, it can be divided into rotor gyroscopes, optical gyroscopes, vibration gyroscopes and atomic gyroscopes. New atomic gyroscopes include spin-free exchange relaxation gyroscopes (SERFG), atomic interferometer gyroscopes (AIG) and nuclear magnetic resonance gyroscopes (NMRG). These atomic gyroscopes have strong anti-interference capabilities, small size and high precision.

[0003] Among them, the nuclear magnetic resonance gyroscope is a new type of quantum gyroscope with high precision and small size. Its main core component is the atomic gas chamber, which is filled with alkali metal atoms and inert gas atoms. Nuclear magnetic resonance refers to the addition of a static magnetic field and an excitation magnetic field perpendicular to the static magnetic field in the direction of the gas chamber, so that the inert gas atoms produce a three-dimensional macroscopic magnetic moment and produce Larmor precession on the static magnetic field. When the frequency of the excitation magnetic field is consistent with the Larmor precession frequency of the atoms, nuclear magnetic resonance will be formed. When the carrier has a certain rotation speed, the macroscopic magnetic moment precession frequency will be superimposed on the carrier rotation speed. The superimposed rotation speed will be observed by the atomic magnetometer formed by the alkali metal, and the excitation magnetic field frequency needs to be adjusted in real time according to the observation frequency of the macroscopic magnetic moment to form a magnetic field closed loop to achieve the purpose of stabilizing the nuclear magnetic resonance and improving the gyroscope rotation speed measurement range.

[0004] In actual systems, inert gas is generally used. 129 Xe / 131 The Xe nuclear magnetic gyroscope's dual working material gas chamber is used to measure the rotation speed. The reason is that this method can form a differential measurement of the carrier's rotation angular velocity, which can effectively reduce the measurement error caused by static magnetic field interference. Theoretically, this method can ignore the influence of static magnetic field on the rotation speed, so it has more development prospects. At the same time, it also means that the system requires a more complex closed-loop control method for the excitation magnetic field. The main difficulties are:

[0005] (i) It is necessary to separate the observations from the same gas chamber. 129 Xe / 131 Two frequency signals generated by Xe excitation;

[0006] (ii) The excitation closed loop requires a certain degree of adaptive capability to cope with the rapidly changing carrier speed frequency.

[0007] Although the filter separation excitation magnetic field closed-loop control method based on the traditional integral series filter has a certain effect in dealing with the separation problem of mixed speed signals, it also has some potential defects: 1. Complexity and high cost: Implementing this closed-loop control method requires the design and implementation of complex circuits and algorithms, which will increase the cost and complexity of the system, especially under high precision requirements. 2. High signal processing requirements: This method relies on filtering and separating mixed signals, requiring high requirements for signal processing algorithms and technologies, including filter design and parameter adjustment. 3. Stability and reliability challenges: The stability and reliability of closed-loop control systems are crucial for high-precision instruments such as nuclear magnetic resonance gyroscopes. Since this method involves complex signal processing and control loops, system stability and robustness may face challenges. 4. Sensitive to environmental changes: The performance of the system may be affected by environmental factors, such as temperature changes, electromagnetic interference, etc., which may cause the performance of closed-loop control to degrade or fail.

[0008] Therefore, obtaining the corresponding frequency signal under the operation of a complex duplex dielectric chamber system, quickly responding to and accurately measuring the rapidly changing rotation speed, and performing stable closed-loop feedback on the excitation magnetic field are the key and difficulty of speed measurement and closed-loop control in the nuclear magnetic resonance gyroscope. Summary of the invention

[0009] The present invention aims at the problem that the traditional closed-loop control method of filtering separation excitation magnetic field of integral series filter is highly dependent on high-performance digital signal processing algorithm, which is easily disturbed by the environment, resulting in the feedback excitation magnetic field signal not being able to well sense the atomic gas chamber and being prone to non-resonance. A fast closed-loop control method for the excitation magnetic field of a nuclear magnetic resonance gyroscope is provided, which uses a set of cascaded notch filters to filter and divide the mixed signal to obtain the following 129 Xe and 131 The single-phase sinusoidal signal with the Larmor precession frequency of Xe as the base frequency generates an orthogonal signal through the SOGI second-order generalized integrator, obtains the phase error through Park transformation, and finally feeds back the excitation magnetic field signal through the loop filter and voltage controller in the PLL to complete the closed-loop control. The fast closed-loop control method of the nuclear magnetic resonance gyroscope excitation magnetic field proposed by the present invention has high-precision frequency separation capability and fast phase tracking capability, which has an effect of improving the stability of the overall system.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is: a fast closed-loop control method of the nuclear magnetic resonance gyro excitation magnetic field, using a set of cascaded notch filters to filter and divide the mixed signal to obtain 129 Xe and 131The single-phase sinusoidal signal with the Larmor precession frequency of Xe as the fundamental frequency is used to generate an orthogonal signal through the SOGI second-order generalized integrator, and the phase error is obtained through Park transform. Finally, the excitation magnetic field signal is fed back through the loop filter and voltage controller in the PLL to complete the closed-loop control.

[0011] As an improvement of the present invention, a method for fast closed-loop control of a nuclear magnetic resonance gyro excitation magnetic field comprises the following steps:

[0012] S1: Determine the current gyroscope based on 129 Xe and 131 Xe and two inert isotope gases work in a gas chamber. 87 The Rb magnetometer is sensitive to the macroscopic magnetic moment component to detect the speed signal, where the steady-state magnetic moment detection signal is Ψ dual (t);

[0013] S2: The detection result of step S1 is filtered using a notch filter. 129 Xe and 131 Xe speed signal Ψ dual (t) is subjected to frequency separation, and the following are obtained: 129 Xe and 131 Xe is a single-phase sinusoidal signal of fundamental frequency;

[0014] S3: using a SOGI second-order generalized integrator to generate mutually orthogonal signals from the single-phase sinusoidal signal obtained in step S2;

[0015] S4: Direct phase discrimination is performed based on the orthogonal signal obtained in step S3, and the rotation speed frequency ω is adjusted through a phase-locked loop. r To identify, use the differential method to solve and eliminate the measurement error;

[0016] S5: The rotational speed frequency of step S4 and the Larmor precession frequency of the inert gas are used as the complete closed-loop feedback output of the excitation magnetic field to adjust the motion state of the gyroscope to achieve closed-loop control.

[0017] As an improvement of the present invention, the steady-state magnetic moment detection signal Ψ in step S1 dual (t) Specifically:

[0018]

[0019] In the formula, Ψ 129 and 131 They are 129 Xe and 131 Xe transverse magnetic moment steady-state detection amplitude, B0 is the Z-axis static magnetic field, γ 129 and γ 131 They are 129 Xe and 131The magnetogyro ratio of Xe, and They are 129 Xe and 131 The phase of the Xe steady-state magnetic moment detection signal, t is the detection time.

[0020] As another improvement of the present invention, in the frequency separation process of step S2, the notch filter is parameter designed, and the equivalent transfer function model of the notch filter is:

[0021]

[0022] Among them, ω th is the notch center frequency selected for the notch filter, ξ1 and ξ2 are the notch coefficients, specifically:

[0023]

[0024] ξ2=Dξ1

[0025]

[0026] Where D is the notch depth at the notch center frequency, B w is the width of the notch at its center frequency.

[0027] As another improvement of the present invention, the notch filter used in step S2 is composed of three notch filters cascaded, the notch center frequency interval is 2π×0.5rad / s, the notch depth is 0.00001 (-100dB), and the notch width is 2π×20rad / s.

[0028] As another improvement of the present invention, the SOGI second-order generalized integrator used in step S3 has a transfer function as follows:

[0029]

[0030] Among them, k sg is the gain coefficient of SOGI, ω n is the natural frequency of SOGI, H α (s) and H β (s) are the transfer function expressions of the second-order band-pass filter and the second-order low-pass filter respectively.

[0031] As another improvement of the present invention, the speed phase detection of the orthogonal signals in step S4 is performed by using the Park transformation method, and the transformation of the two orthogonal signals is as follows:

[0032]

[0033] When the phase-locked loop locks the phase, the difference between the original phase of the signal and the estimated phase is small, which is considered to be 129d is the amplitude estimate of the input signal, Ψ 129q It is proportional to the feedback error of the phase and completes the phase detection process.

[0034] As another improvement of the present invention, the observation frequency of the macroscopic magnetic moment of 129Xe and 131Xe considering the interference of static magnetic field is:

[0035] ω obs129 =γ 129 (B0+δB0)+ω r

[0036] ω obs131 =γ 131 (B0+δB0)+ω r

[0037] By solving the above formula, the obtained speed eliminates the interference of static magnetic field:

[0038]

[0039] As a further improvement of the present invention, the excitation feedback magnetic field obtained in step S5 will be provided to the dual working air chambers as an excitation magnetic field signal, and the frequency of the excitation magnetic field signal will be consistent with the observed rotation speed:

[0040]

[0041] in is the X-axis excitation signal, is the Y-axis excitation magnetic field signal, and Based on 129 Xe and 131 Xe is the excitation magnetic field signal generated by the observed rotation speed, B0 is the static magnetic field on the Z axis, γ 129 and γ 131 They are 129 Xe and 131 The magnetogyro ratio of Xe, and They are 129 Xe and 131 Xe observes the phase of the speed signal, and t is the detection time.

[0042] Compared with the prior art, the present invention has the following beneficial effects: the fast closed-loop control method of the dual-working material nuclear magnetic resonance gyroscope excitation magnetic field proposed in the present invention has a fast and accurate frequency separation effect, and the orthogonal signal generator phase-locked loop can quickly phase-lock the signal after frequency separation, and this closed-loop control method has good real-time performance. Under this closed-loop method, the gyroscope has better dynamic response characteristics and system stability, and can improve the gyroscope's ability to resist common-mode interference. After testing, it has a bandwidth of 7Hz at the resonant frequencies of 85Hz and 25Hz. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of the method of the present invention;

[0044] Figure 2 This is an internal structure diagram of a quadrature signal generator-based phase-locked loop (QSG-PLL) according to Embodiment 2 of the present invention;

[0045] Figure 3 This is a graph showing the test results of the phase-locked loop bandwidth based on the orthogonal signal generator in the test example of the present invention. DETAILED DESCRIPTION

[0046] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0047] Example 1

[0048] A method for fast closed-loop control of a nuclear magnetic resonance gyroscope excitation magnetic field comprises the following steps:

[0049] Step S1: According to the basic composition of the gyro chamber, determine whether the current gyro should be based on 129 Xe and 131 Xe and two inert isotope gases work in a gas chamber. 87 The Rb magnetometer is sensitive to the macroscopic magnetic moment component to detect the speed signal. At this time, the output signal Ψ dual (t) conducting testing;

[0050] The macroscopic magnetic moment component generated in the current dual-working material nuclear magnetic gyroscope is measured in the Y direction, and the measured magnetic moment signal is 129 Xe and 131 The superposition of the two magnetic moment signals of Xe, using Ψ dual (t) is used to realize the closed-loop control of the excitation magnetic field of the two isotopes. At this time, the steady-state magnetic moment detection signal can be written as: Among them Ψ 129 and 131 They are 129 Xe and 131The steady-state detection amplitude of the Xe transverse magnetic moment is a constant; the two dynamic phases are expressed as: as well as The dynamic phase includes the static magnetic field interference δB0 and the carrier rotation angular velocity ω r information.

[0051] Step S2: According to the current detection state of step S1, a notch filter is designed to include 129 Xe and 131 Xe speed signal Ψ dual (t) is subjected to frequency separation, and the following are obtained: 129 Xe and 131 Xe is a single-phase sinusoidal signal of fundamental frequency;

[0052] Consider using a notch filter bank to dual The two signals in (t) are first frequency separated, such as filtering out Component, because the notch filter bank has very little effect on signals far away from the notch frequency, the remaining signal is: In the process of frequency separation, it is necessary to select appropriate parameters to design the notch filter. The equivalent transfer function model of the notch filter is:

[0053]

[0054] where ω th is the notch center frequency selected for the notch filter, ξ1 and ξ2 are the notch coefficients. D is designed as the notch depth at the notch center frequency, B w is the width at the center frequency of the notch, and the formula for calculating the notch coefficient is:

[0055]

[0056] In application, multiple notch filters with similar notch center frequencies are cascaded to form a notch filter group to obtain a wider and deeper stopband. The notch center frequency of the notch filter group changes with the phase-locked loop output. and Real-time adjustment can ensure the reliability of frequency separation, taking into account 129 Xe and 131 The Larmor precession frequency of Xe under a magnetic field strength of 7.143 T is 25 Hz and 85 Hz, so the center frequency of the notch is mainly selected between 25 Hz and 85 Hz.

[0057] The notch filter group used in frequency division is composed of three notch filters cascaded, with a notch center frequency interval of 2π×0.5rad / s, a notch depth of 0.00001 (-100dB), and a notch width of 2π×20rad / s. In this way, the stopband width at -80dB is about 1.5Hz, which means that even without frequency feedback, as long as 129 Xe and 131 The Xe resonance frequency can be effectively separated within ±0.75 Hz.

[0058] Step S3: using a SOGI second-order generalized integrator to generate mutually orthogonal signals from the single-phase sinusoidal signal obtained in step S2;

[0059] An orthogonal signal generator is used to generate two mutually orthogonal signals for a single-phase signal. A SOGI second-order generalized integrator is used, and its transfer function is:

[0060]

[0061] where k sg is the gain coefficient of SOGI, ω n is the natural frequency of SOGI. α (s) and H β (s) is a second-order bandpass filter and a second-order low-pass filter, which can also effectively suppress the high-frequency noise of the signal. The steady-state output signal satisfies orthogonality and has equal amplitude only when the input signal frequency is consistent with the natural frequency of SOGI. At the same time, the input signal frequency is affected by the angular velocity of the carrier and the static magnetic field interference, so it is necessary to adjust the natural frequency of SOGI with the phase-locked loop output, that is, (by 129 Xe shunt for example), thus making SOG I adaptive.

[0062] At the same time, it is necessary to consider how to determine the gain coefficient of SOG I. Among them, U and are the amplitude and phase of the input signal, both are constants. When u is input into SOGI as the input signal, k must be satisfied. sg <2, then the output signal can be obtained:

[0063]

[0064] in It's about U, k sg Therefore, the oscillation convergence term should be suppressed in the output signal, and the convergence speed of this term is affected by the coefficient k. sg The influence of k sg =1.414.

[0065] After the single-phase signal passes through SOGI, SOGI can pass the input signal Ψ 129 (t) Generate a pair of orthogonal signals. The amplitude and frequency of the output signal are consistent with the input signal, but the phase is consistent with one and the other lags the original phase by 90° (by 129 Xe split example): and

[0066] Step S4: The speed phase detection of the orthogonal signals is performed by using the Park transformation method. The transformation of the two orthogonal signals is as follows:

[0067]

[0068] When the phase-locked loop locks the phase, the difference between the original phase of the signal and the estimated phase is small. After approximation, it can be considered that Ψ 129d is the amplitude estimate of the input signal, Ψ 129q That is, it is proportional to the phase feedback error, completing the phase detection process.

[0069] The obtained orthogonal signal is used for direct phase discrimination, and the speed frequency ω is controlled by a phase-locked loop. r Identify and solve it using the differential method to eliminate the measurement error caused by static magnetic field fluctuation interference;

[0070] The carrier speed needs to be calculated, and the difference method is used to calculate it to eliminate the measurement error caused by the static magnetic field fluctuation interference. Considering the rotation of the carrier under the static magnetic field:

[0071] ω obs129 =γ 129 (B0+δB0)+ω r

[0072] ω obs131 =γ 131 (B0+δB0)+ω r

[0073] The observed frequency of the macroscopic magnetic moment of 129Xe and 131Xe considering the interference of the static magnetic field. By solving the above equation, the obtained rotation speed excludes the interference of the static magnetic field:

[0074]

[0075] Step S5: Combining the rotational speed frequency of step S4 and the Larmor precession frequency of the inert gas as a complete closed-loop feedback output of the excitation magnetic field, the motion state of the gyroscope is adjusted accordingly.

[0076] At the same time, the rotation speed frequency and the Larmor precession frequency of the inert gas are used as the complete excitation magnetic field closed-loop feedback output, that is, the excitation feedback magnetic field obtained at this time will be provided to the dual working gas chamber as the excitation magnetic field signal, and the frequency of the excitation magnetic field signal will be consistent with the observed rotation speed: in

[0077] Example 2

[0078] A fast closed-loop control method for the excitation magnetic field of a nuclear magnetic resonance gyroscope, such as Figure 1 As shown, a static magnetic field B0 is added to the Z-axis direction of the NMR gyroscope air chamber, and an excitation magnetic field B1cos(ω a t), and add pump light in the Z-axis direction to polarize the alkali metal atoms, so that spin polarization occurs between them and the inert gas atoms, and then add detection aurora in the X-axis direction to be sensitive to the rotating macroscopic magnetic moment, and obtain Ψ with mixed frequency signal dual (t).

[0079] Then, a notch filter bank is used to obtain the baseband signals containing the Larmor frequencies of 129Xe and 131Xe respectively, using the frequencies solved by the two phase-locked loops as the notch center frequencies. For example, Component, because the notch filter bank has very little effect on signals far away from the notch frequency, the remaining signal is: Secondly, the single-phase signal is dephased using QSG-PLL to obtain the carrier speed frequency, which is then fed back to the excitation magnetic field signal generator to complete the magnetic field closed-loop feedback loop. At the same time, the frequencies calculated by the two QSG-PLLs are solved to obtain the actual carrier frequency that is not affected by static magnetic field fluctuations.

[0080] like Figure 2 As shown in the figure, the orthogonal signal generator combines with Park change to form a phase detector, the loop filter is still composed of PI links, and the integral link corresponds to the voltage-controlled oscillator. Ideally, the orthogonal signal generator can be based on the input signal Ψ 129 (t) immediately generate a pair of orthogonal signals, and then 129α and 129β Perform Park transformation to obtain the dq axis signal Ψ 129d and 129q , when the phase-locked loop is in the quasi-locked state, and The difference is small, and after approximation, it can be seen that Ψ 129d is the amplitude estimate of the input signal, Ψ 129q It is proportional to the phase feedback error, thus completing the phase detection.

[0081] Test Case

[0082] Select three notch filters to form a notch filter group, the notch frequency interval is 2×π×0.5rad / s, the notch depth is 0.00001, and the notch width is 2×π×20rad / s. Adjust the phase-locked loop PI parameters so that 129 The closed-loop bandwidth of the Xe excitation magnetic field is about 10Hz. 131 The Xe closed-loop bandwidth is about 4 Hz. In the traditional frequency-based phase-locked loop closed-loop solution, the excitation magnetic field closed-loop bandwidth is determined by the LPF cutoff frequency, which is set at 3.5 Hz.

[0083] During the simulation, wait for the system to enter a steady state, then add a 5° / s step angular velocity signal after 150s. The output is used to measure the performance of the gyroscope under the two schemes. The bandwidth of the traditional scheme is about 3.5Hz; the bandwidth of the scheme in this paper is about 7Hz, which is between the set 10Hz and 4Hz. The bandwidth of the two schemes is in line with expectations. Figure 3 As shown in the figure, the resonance peak of the traditional solution at 2.5Hz is 10.8dB, while the resonance peak of the solution in this paper is only 1.6dB at 2Hz. The gyro system composed of the traditional solution has poor stability, and the step response of the system will have a larger overshoot.

[0084] In summary, the present invention discloses a fast closed-loop control method for the excitation magnetic field of a nuclear magnetic resonance gyroscope, which separates the mixed signal containing 129 Xe and 131 Xe is a single-phase sinusoidal signal with base frequency. The orthogonal signal is generated by SOGI second-order generalized integrator, and the phase error is obtained by Park transform. Finally, the excitation magnetic field signal is fed back through the loop filter and voltage controller in PLL to complete the complete closed-loop control. It has fast and accurate frequency separation effect and good real-time performance.

[0085] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A fast closed-loop control method for a nuclear magnetic resonance gyro excitation magnetic field, characterized in that: A set of cascaded notch filters are used to filter and divide the mixed signal to obtain 129 Xe and 131 The single-phase sinusoidal signal with the Larmor precession frequency of Xe as the fundamental frequency is used to generate an orthogonal signal through the SOGI second-order generalized integrator, and the phase error is obtained through Park transform. Finally, the excitation magnetic field signal is fed back through the loop filter and voltage controller in the PLL to complete the closed-loop control.

2. The method for rapid closed-loop control of the NMR gyro excitation magnetic field as claimed in claim 1, characterized in that: The steps include: S1: Determine the current gyroscope based on 129 Xe and 131 Xe and two inert isotope gases work in a gas chamber. 87 The Rb magnetometer is sensitive to the macroscopic magnetic moment component to detect the speed signal, where the steady-state magnetic moment detection signal is Ψ dual (t); S2: The detection result of step S1 is filtered using a notch filter. 129 Xe and 131 Xe speed signal Ψ dual (t) is subjected to frequency separation, and the following are obtained: 129 Xe and 131 Xe is a single-phase sinusoidal signal of fundamental frequency; S3: using a SOGI second-order generalized integrator to generate mutually orthogonal signals from the single-phase sinusoidal signal obtained in step S2; S4: Direct phase discrimination is performed based on the orthogonal signal obtained in step S3, and the rotation speed frequency ω is adjusted through a phase-locked loop. r To identify, use the differential method to solve and eliminate the measurement error; S5: The rotational speed frequency of step S4 and the Larmor precession frequency of the inert gas are used as the complete closed-loop feedback output of the excitation magnetic field to adjust the motion state of the gyroscope to achieve closed-loop control.

3. The method for rapid closed-loop control of the NMR gyro excitation magnetic field as claimed in claim 2, characterized in that: The steady-state magnetic moment detection signal Ψ in step S1 dual (t) Specifically: In the formula, Ψ 129 and 131 They are 129 Xe and 131 Xe transverse magnetic moment steady-state detection amplitude, B0 is the Z-axis static magnetic field, γ 129 and γ 131 They are 129 Xe and 131 The magnetogyro ratio of Xe, and They are 129 Xe and 131 The phase of the Xe steady-state magnetic moment detection signal, t is the detection time.

4. The method for rapid closed-loop control of the NMR gyro excitation magnetic field as claimed in claim 2, characterized in that: In the frequency separation process of step S2, the parameters of the notch filter are designed, and the equivalent transfer function model of the notch filter is: Among them, ω th is the notch center frequency selected for the notch filter, ξ1 and ξ2 are the notch coefficients, specifically: ξ2=Dξ1 Where D is the notch depth at the notch center frequency, B w is the width of the notch at its center frequency.

5. The method for rapid closed-loop control of the NMR gyro excitation magnetic field as claimed in claim 4, characterized in that: The notch filter used in step S2 is formed by cascading three notch filters, the notch center frequency interval is 2π×0.5rad / s, the notch depth is 0.00001 (-100dB), and the notch width is 2π×20rad / s.

6. The method for rapid closed-loop control of the excitation magnetic field of a nuclear magnetic resonance gyro according to claim 3 or 5, characterized in that: The SOGI second-order generalized integrator used in step S3 has a transfer function as follows: Among them, k sg is the gain coefficient of SOGI, ω n is the natural frequency of SOGI, H α (s) and H β (s) are the transfer function expressions of the second-order band-pass filter and the second-order low-pass filter respectively.

7. The method for rapid closed-loop control of the NMR gyro excitation magnetic field as claimed in claim 6, characterized in that: In step S4, the speed phase detection of the orthogonal signals is performed using the Park transformation method, and the transformation of the two orthogonal signals is as follows: When the phase-locked loop locks the phase, the difference between the original phase of the signal and the estimated phase is small, which is considered to be 129d is the amplitude estimate of the input signal, Ψ 129q It is proportional to the feedback error of the phase and completes the phase detection process.

8. The method for rapid closed-loop control of the NMR gyro excitation magnetic field as claimed in claim 7, characterized in that: In step S4, the observation frequency of the macroscopic magnetic moment of 129Xe and 131Xe is considered with the interference of static magnetic field. oh obs129 =c 129 (B0+δB0)+ω r oh obs131 =c 131 (B0+δB0)+ω r By solving the above formula, the obtained speed eliminates the interference of static magnetic field:

9. The method for rapid closed-loop control of the excitation magnetic field of a nuclear magnetic resonance gyro as claimed in claim 8, characterized in that: The excitation feedback magnetic field obtained in step S5 will be provided to the dual working air chambers as an excitation magnetic field signal, and the frequency of the excitation magnetic field signal will be consistent with the observed rotation speed: in is the X-axis excitation signal, is the Y-axis excitation magnetic field signal, and Based on 129 Xe and 131 Xe is the excitation magnetic field signal generated by the observed rotation speed, B0 is the static magnetic field on the Z axis, γ 129 and γ 131 They are 129 Xe and 131 The magnetogyro ratio of Xe, and They are 129 Xe and 131 Xe observes the phase of the speed signal, and t is the detection time.

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