CN117782163A - Hemispherical resonator gyro virtual precession calibration method and system based on decay time constant - Google Patents

Abstract

The invention discloses a hemispherical resonator gyro virtual precession calibration method and system based on an attenuation time constant, belongs to the technical field of inertia, and aims to solve the problem that the hemispherical resonator gyro virtual precession speed is difficult to compensate in real time along with the change of environmental temperature. According to the method, the hemispherical harmonic oscillator resonant frequency and the decay time constant at different temperatures are accurately calibrated, and then the calibration data are subjected to function fitting by using a fitting method. Through the process, a correlation model of the resonant frequency of the harmonic oscillator and the decay time constant is obtained. Then, the invention monitors the environment temperature in real time, and adjusts the virtual precession control force in real time by using the decay time constant based on the calibration model, so that the precession speed is stable. The method is applied to the starting and calibrating process of the hemispherical resonator gyroscope.

Description

Hemispheric resonant gyro virtual precession calibration method and system based on decay time constant

Technical field

The invention relates to a virtual precession calibration process of an axisymmetric vibrating gyroscope, and belongs to the technical field of inertia.

Background technique

With the rapid development of navigation technology, the demand for inertial sensors with high accuracy, low power consumption and long life is increasing. Hemispheric resonant gyroscopes have attracted much attention due to their simple structure, high reliability, and long service life. As the core component of the hemispheric resonant gyroscope, the hemispheric resonator's resonant frequency and attenuation time constant will change regularly with changes in temperature. The new generation rate integrating hemispheric resonant gyro uses virtual Coriolis force to control the standing wave to rotate at a constant speed without external rate input, thereby completing the self-calibration of the hemispheric resonant gyro's assembly error, scale factor and gyro bias. , and further reduce the gyro threshold. However, after the hemispheric resonant gyro is powered on, it takes several hours or even more than ten hours to complete the thermal balance of the resonator circumference. Before completing the thermal balance, there is a problem that the virtual precession speed of the hemispheric resonant gyro is difficult to compensate in real time under changes in ambient temperature. , the existing technology can only use virtual precession to achieve the above calibration process after waiting for a long time for thermal equilibrium to be completed.

In summary, from the time the hemispherical resonator gyroscope is powered on to the time the resonator reaches circumferential thermal equilibrium, the virtual precession velocity of the resonator will fluctuate with the ambient temperature, which will limit the performance of the gyroscope and make it impossible to compensate for the virtual precession velocity in real time. Therefore, a new precession calibration method is urgently needed to meet the long-term stability requirements of the gyroscope in a variable temperature environment.

Contents of the invention

Aiming at the problem that the virtual precession speed of a hemispheric resonant gyro is difficult to compensate in real time as the ambient temperature changes, the present invention provides a virtual precession calibration method and system for a hemispheric resonant gyro based on a decay time constant.

Based on one aspect of the present invention, a hemispheric resonant gyro virtual precession calibration method based on attenuation time constant, the method includes the following steps:

Step 1, place the hemispherical resonant gyroscope and its supporting control circuit in a temperature box and power on the gyroscope;

Step 2. Set the temperature of the thermostat to the lowest temperature T ₀ when the gyroscope is actually used, and maintain it at this temperature for at least 4 hours;

Then use the host computer to record the resonant frequency ω ₀ , amplitude control voltage V _a0 and virtual precession control voltage V _w0 of the resonator at this temperature;

Step 3, disconnecting the amplitude control, orthogonal control and virtual precession control of the hemispherical resonant gyroscope to keep the phase-locked loop in working state;

Use the host computer to record the amplitude attenuation at the lowest temperature T ₀ , and then obtain the attenuation time constant τ ₀ of the resonator in the initial temperature control test stage;

Step 4. Increase the set temperature of the thermostat by ΔT to enter the next temperature control test stage, and after maintaining it for at least 4 hours, record the resonant frequency ω _k at this temperature through the host computer;

Step 5. Cut off the amplitude control, orthogonal control and virtual precession control of the hemispheric resonant gyro to keep the phase-locked loop loop in working condition;

Use the host computer to record the amplitude attenuation at this temperature, and then obtain the attenuation time constant τ _k of the resonator in the kth temperature control test stage;

Step 6. Determine whether the set temperature of the thermostat reaches the upper limit T _max of the hemispheric resonant gyro operating temperature. If not, set k=k+1 and jump to step 4. If it reaches it, jump to step 7;

Step 7. According to the resonant frequency and attenuation time constant of the resonator at different temperatures collected by the host computer, use the nonlinear least squares algorithm to fit them using cubic or above polynomials to obtain the resonant frequency-attenuation time constant relationship model;

Step 8: adjusting the virtual precession control voltage according to the resonant frequency-decay time constant relationship model obtained in step 7, thereby maintaining the virtual precession speed stable.

Preferably, ΔT in step 4 is 0.5 to 1 degree, and ΔT is used to divide the temperature control test stage. In the initial temperature control test stage with k=0, the temperature of the thermostat is set to the lowest temperature T ₀ when the gyroscope is actually used. In different temperature control test stages of k=1,2..., the temperature setting of the thermostat increases by ΔT in sequence, and the corresponding temperature of each stage is T _k .

Preferably, the functional relationship between the resonator attenuation time constant and the data sampling time is:

Among them, t _i is the data sampling time, i=0,1,2... is the data sampling sequence number, a _r (i) is the theoretical value of the amplitude at the current time t _i , τ _k ,k=0,1,2 ... is the attenuation time constant of the resonator in the kth temperature control test stage, and a _k is the initial amplitude of the resonator in the kth temperature control test stage.

Preferably, the attenuation time constant τ _k of the resonator in the kth temperature control test stage, k=0,1,2..., and the identification process of the initial amplitude a _k is:

A1. Set the initial values of the identified parameters _ak (i) and τ _k (i) when i = 0: _ak (0) = 0, τ _k (0) = 0;

A2. Calculate the amplitude error r(i) at the current time t _i :

r(i)＝a' _r (i)-a _r (i)

In the formula, a' _r (i) is the actual amplitude at the current time t _i ;

A3. Calculate the Jacobian matrix J _r (i) at the current time t _i :

A4. Calculate the parameter increment at the current time t _i :

In the formula, Δa _k (i) is the amplitude increment of the next moment compared with the current moment, Δτ _k (i) is the attenuation time constant increment of the next moment compared with the current moment;

A5. Update the parameter vector at the next moment:

In the formula, a _k (i+1) and τ _k (i+1) are the amplitude and time attenuation constants at the next time t _i+1 ;

A6. Determine whether there is still amplitude attenuation data input. If there is data input, set i=i+1 and jump to step A2. Otherwise, the fitting is completed to obtain the identification of the parameter vectors a _k and τ _k of the kth temperature control test stage.

Preferably, in step 7, according to the resonant frequency ω _k and the decay time constant τ _k of the resonator at different temperatures collected by the host computer, a cubic or higher polynomial is used to fit them using a nonlinear least squares algorithm, and the resonant frequency and the decay time constant satisfy the functional relationship:

In the formula, τ _r (k) is the theoretical value of the attenuation time constant of the resonator at the current temperature T _k ;

b _j is the j-term coefficient of the function, j=0,1,...,n, n is the fitting order of the function.

Preferably, the resonant frequency ω _k and the decay time constant τ _k of the resonator at different temperatures, k=0, 1, 2, ... are input one by one, and the process of identifying the j-order coefficient b _j of the function is:

B1. Set the initial value of the identified parameter b _j (k) b _j (0) = 0 when k = 0;

B2. Calculate the decay time constant error m(k) at the current temperature T _k :

m(k)＝τ _k -τ _r (k)

B3. Calculate the Jacobian matrix J _m (k) at the current temperature T _k :

B4. Calculate the parameter increment at the current temperature T _k :

[Δb _j (k)]=[J _m (k) ^T J _m (k)] ^-1 J _m (k) ^T m (k)

In the formula: Δb _j (k) is the coefficient increment of the next temperature compared with the current temperature;

B5. Update the parameter vector of the next temperature:

[b _j (k+1)]＝[b _j (k)]+[Δb _j (k)]

b _j (k+1) is the coefficient at the next temperature T _k+1 ;

B6. Determine whether there is still data input. If there is data input, set k=k+1 and jump to step B2. Otherwise, the fitting is completed to obtain the identification of parameter vector b _j .

Preferably, the virtual precession control voltage in step 8 is adjusted as follows:

In the formula, V _w0 is the virtual precession control voltage recorded in the initial temperature control test stage, V _a0 is the amplitude control voltage recorded in the initial temperature control test stage, τ ₀ is the attenuation obtained by fitting in the initial temperature control test stage time constant,

τ is the current attenuation time constant, and is obtained by inputting the resonant frequency ω measured by the current system into the fitted resonant frequency-attenuation time constant relationship model to obtain the corresponding attenuation time constant;

V _a is the current amplitude control output voltage, which is obtained by the following formula:

In the formula, K is the control gain, a is the amplitude measured by the current system.

Preferably, the virtual precession control loop adopts open-loop control, and the virtual precession speed Ω _w is expressed as:

The virtual precession speed Ω _w follows the virtual precession output voltage V _w and rotates stably.

According to another aspect of the present invention, a hemispherical resonant gyroscope virtual precession calibration system based on decay time constant is provided, and the system is used to implement the hemispherical resonant gyroscope virtual precession calibration method based on decay time constant. The calibration system includes a temperature box, a hemispherical resonant gyroscope, a gyroscope supporting circuit board and a host computer; the hemispherical resonant gyroscope and the gyroscope supporting circuit board are placed in the temperature box;

The thermostat is used to adjust the operating temperature of the hemispherical resonant gyroscope;

The hemispherical resonant gyro supporting circuit board is used to realize the amplitude control, orthogonal control and virtual precession control of the gyro, and transmits the resonant frequency, amplitude attenuation and virtual precession speed information to the host computer through the serial port;

The host computer is used to receive the resonant frequency, amplitude attenuation and virtual precession speed information sent by the supporting circuit board of the hemispheric resonant gyro. The collected resonant frequency and amplitude attenuation information are fitted to obtain the relationship between resonant frequency and attenuation time constant at different temperatures, and the fitting results are programmed into the hemispherical resonant gyro supporting circuit board.

Beneficial effects of the present invention: The present invention calibrates the vibration frequency and attenuation time constant of the hemispheric resonator at different temperatures, uses a fitting method to perform function fitting on the calibrated vibration frequency and attenuation time constant, and uses the attenuation time constant to calculate the virtual The precession control force is adjusted in real time, so that the virtual precession speed of the gyro is not affected by the ambient temperature, allowing the gyro to start quickly under changing temperature conditions.

The invention solves the problem that the virtual precession speed of a gyroscope is difficult to calibrate in real time as the ambient temperature changes, and improves the stability of the precession speed in long-term operation in a variable temperature environment.

Description of drawings

Figure 1 is a flow chart of the virtual precession calibration method of hemispheric resonant gyro based on attenuation time constant according to the present invention;

Figure 2 is a block diagram of the virtual precession calibration system of the hemispherical resonant gyroscope based on the attenuation time constant of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without any creative work fall within the scope of protection of the present invention.

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but shall not be used as a limitation of the present invention.

Specific Embodiment 1: This embodiment will be described below with reference to Figure 1. This embodiment describes a hemispheric resonant gyro virtual precession calibration method based on attenuation time constant. The method includes the following steps:

Step 1, place the hemispherical resonant gyroscope and its supporting control circuit in a temperature box and power on the gyroscope;

Step 2. Set the temperature of the thermostat to the lowest temperature T ₀ when the gyroscope is actually used, and maintain it at this temperature for at least 4 hours;

Then use the host computer to record the resonant frequency ω ₀ , amplitude control voltage V _a0 and virtual precession control voltage V _w0 of the resonator at this temperature;

Step 3. Cut off the amplitude control, orthogonal control and virtual precession control of the hemispheric resonant gyro to keep the phase-locked loop loop in working condition;

Use the host computer to record the amplitude attenuation at the lowest temperature T ₀ , and then obtain the attenuation time constant τ ₀ of the resonator in the initial temperature control test stage;

Step 4. Increase the set temperature of the thermostat by ΔT to enter the next temperature control test stage, and after maintaining it for at least 4 hours, record the resonant frequency ω _k at this temperature through the host computer;

ΔT=0.5~1 degree, use ΔT to divide the temperature control test stage. In the initial temperature control test stage when k=0, the temperature of the thermostat is set to the lowest temperature T ₀ when the gyroscope is actually used. When k=1,2... In different temperature control test stages, the temperature setting of the thermostat increases by ΔT in sequence, and the corresponding temperature in each stage is T _k .

Step 5. Cut off the amplitude control, orthogonal control and virtual precession control of the hemispheric resonant gyro to keep the phase-locked loop loop in working condition;

Use the host computer to record the amplitude attenuation at this temperature, and then obtain the attenuation time constant τ _k of the resonator in the kth temperature control test stage;

The method of obtaining the attenuation time constant and initial amplitude of the resonator in the initial temperature control test stage and the temperature control test stage such as k=1,2...are the same, and are combined into a _k , τ _k , k=0,1,2. ..

The functional relationship between the resonator decay time constant and the data sampling time is:

Among them, t _i is the data sampling time, i=0,1,2... is the data sampling sequence number, a _r (i) is the theoretical value of the amplitude at the current time t _i , τ _k ,k=0,1,2 ... is the attenuation time constant of the resonator in the kth temperature control test stage, and a _k is the initial amplitude of the resonator in the kth temperature control test stage.

4. The virtual precession calibration method of hemispheric resonant gyro based on attenuation time constant according to claim 3, characterized in that the attenuation time constant τ _k of the resonator in the kth temperature control test stage,k=0,1,2 ..., the identification process of the initial amplitude a _k is:

A1. Set the initial values of the identified parameters a _k (i) and τ _k (i) when i = 0: a _k (0) = 0, τ _k (0) = 0;

A2. Calculate the amplitude error r(i) at the current time t _i :

r(i)＝a' _r (i)-a _r (i)

In the formula, a' _r (i) is the actual amplitude at the current time t _i ;

A3. Calculate the Jacobian matrix J _r (i) at the current time t _i :

A4. Calculate the parameter increment at the current time t _i :

Wherein, _Δak (i) is the amplitude increment of the next moment compared with the current moment, and _Δτk (i) is the decay time constant increment of the next moment compared with the current moment;

A5. Update the parameter vector at the next moment:

In the formula, a _k (i+1) and τ _k (i+1) are the amplitude and time attenuation constants at the next time t _i+1 ;

A6. Determine whether there is still amplitude attenuation data input. If there is data input, set i=i+1 and jump to step A2. Otherwise, the fitting is completed to obtain the identification of the parameter vectors a _k and τ _k of the kth temperature control test stage.

When k=0, a ₀ and τ ₀ are obtained by fitting. Similarly, when k=1, a ₁ and τ ₁ are obtained by fitting. When k=2, a ₂ and τ ₂ are obtained by fitting. At the same time, each temperature control test is recorded. The resonant frequency ω _k of the stage; prepare for subsequent model construction.

Step 6. Determine whether the set temperature of the thermostat reaches the upper limit T _max of the hemispheric resonant gyroscope's operating temperature. If not, set k=k+1 and jump to step 4. If it reaches it, jump to step 7;

Step 7. According to the resonant frequency and attenuation time constant of the resonator at different temperatures collected by the host computer, use the nonlinear least squares algorithm to fit them using cubic or above polynomials to obtain the resonant frequency-attenuation time constant relationship model;

The resonant frequency and decay time constant satisfy the functional relationship:

Wherein, τ _r (k) is the theoretical value of the oscillator decay time constant at the current temperature T _k ;

b _j is the coefficient of the j-order term of the function, j = 0, 1,…, n, and n is the fitting order of the function.

Input the resonant frequency ω _k and the decay time constant τ _k of the resonator at different temperatures, k=0,1,2... one by one, and the process of identifying the coefficient b _j of the j-th order term of the function is:

B1. When k=0, the initial value of the identified parameter b _j (k) is set to b _j (0)=0;

B2. Calculate the decay time constant error m(k) at the current temperature T _k :

m(k)＝τ _k -τ _r (k)

B3. Calculate the Jacobian matrix J _m (k) at the current temperature T _k :

B4. Calculate the parameter increment at the current temperature T _k :

[Δb _j (k)]=[J _m (k) ^T J _m (k)] ^-1 J _m (k) ^T m (k)

In the formula: Δb _j (k) is the coefficient increment of the next temperature compared with the current temperature;

B5. Update the parameter vector of the next temperature:

[b _j (k+1)]=[b _j (k)]+[Δb _j (k)]

b _j (k+1) is the coefficient at the next temperature T _k+1 ;

B6. Determine whether there is still data input. If there is data input, set k=k+1 and jump to step B2. Otherwise, the fitting is completed to obtain the identification of parameter vector b _j .

Step 8: Adjust the virtual precession control voltage according to the resonant frequency-decay time constant relationship model obtained in step 7, thereby maintaining the stability of the virtual precession speed.

Obtaining the resonant frequency-attenuation time constant relationship model can realize the calibration work of the hemispheric resonant gyroscope in a variable temperature environment. When the temperature changes, the resonant frequency and attenuation time constant will change. The present invention uses the method of building a model to reflect this change. In this way, the stable rotation of the virtual precession speed can be achieved by adjusting the virtual precession control voltage, and then the self-calibration of the assembly error, scale factor and gyro bias of the hemispheric resonant gyro can be completed.

The virtual precession control voltage is adjusted as follows:

Where _Vw0 is the virtual precession control voltage recorded in the initial temperature control test phase, _Va0 is the amplitude control voltage recorded in the initial temperature control test phase, _τ0 is the decay time constant obtained by fitting in the initial temperature control test phase,

τ is the current attenuation time constant, and is obtained by inputting the resonant frequency ω measured by the current system into the fitted resonant frequency-attenuation time constant relationship model to obtain the corresponding attenuation time constant;

V _a is the current amplitude control output voltage, which is obtained by the following formula:

In the formula, K is the control gain, a is the amplitude measured by the current system.

The virtual precession control loop adopts open-loop control, and the virtual precession speed Ω _w is expressed as:

The virtual precession speed Ω _w follows the virtual precession output voltage V _w and rotates stably.

Specific Embodiment 2: This embodiment will be described below with reference to Figure 2. In this embodiment, the hemispheric resonant gyro virtual precession calibration system based on the attenuation time constant of the present invention is implemented using the method described in Embodiment 1. The calibration system includes a thermostat. , hemispheric resonant gyro, gyro supporting circuit board and host computer; hemispheric resonant gyro and gyro supporting circuit board are placed in the thermostat;

The temperature box is used to adjust the working temperature of the hemispherical resonant gyroscope;

The hemispherical resonant gyro supporting circuit board is used to realize the amplitude control, orthogonal control and virtual precession control of the gyro, and transmits the resonant frequency, amplitude attenuation and virtual precession speed information to the host computer through the serial port;

The host computer is used to receive the resonant frequency, amplitude attenuation and virtual precession speed information sent by the supporting circuit board of the hemispheric resonant gyro. The collected resonant frequency and amplitude attenuation information are fitted to obtain the relationship between resonant frequency and attenuation time constant at different temperatures, and the fitting results are programmed into the hemispherical resonant gyro supporting circuit board.

Although the present invention is described herein with reference to specific embodiments, it is to be understood that these embodiments are merely exemplary of the principles and applications of the invention. It is therefore to be understood that many modifications may be made to the exemplary embodiments and other arrangements may be devised without departing from the spirit and scope of the invention as defined by the appended claims. It is to be understood that the features described in the different dependent claims may be combined in a different manner than that described in the original claims. It will also be understood that features described in connection with individual embodiments can be used in other described embodiments.

Claims (9)

1. A virtual precession calibration method for a hemispherical resonant gyroscope based on a decay time constant, characterized in that the method comprises the following steps: Step 1. Place the hemispherical resonant gyro and its supporting control circuit in the temperature box and power on the gyro; Step 2. Set the temperature of the thermostat to the lowest temperature T ₀ when the gyroscope is actually used, and maintain it at this temperature for at least 4 hours; Then use the host computer to record the resonant frequency ω ₀ , amplitude control voltage V _a0 and virtual precession control voltage V _w0 of the resonator at this temperature; Step 3. Cut off the amplitude control, orthogonal control and virtual precession control of the hemispheric resonant gyro to keep the phase-locked loop loop in working condition; Use the host computer to record the amplitude attenuation at the lowest temperature T ₀ , and then obtain the attenuation time constant τ ₀ of the resonator in the initial temperature control test stage; Step 4. Increase the set temperature of the thermostat by ΔT to enter the next temperature control test stage, and after maintaining it for at least 4 hours, record the resonant frequency ω _k at this temperature through the host computer; Step 5. Cut off the amplitude control, orthogonal control and virtual precession control of the hemispheric resonant gyro to keep the phase-locked loop loop in working condition; Use the host computer to record the amplitude decay at this temperature, and then obtain the decay time constant τ _k of the resonator in the kth temperature control test stage; Step 6, judging whether the set temperature of the temperature box reaches the upper limit T _max of the operating temperature of the hemispherical resonant gyroscope, if not, set k=k+1 and jump to step 4, if reached, jump to step 7; Step 7. According to the resonant frequency and attenuation time constant of the resonator at different temperatures collected by the host computer, use the nonlinear least squares algorithm to fit them using cubic or above polynomials to obtain the resonant frequency-attenuation time constant relationship model; Step 8: adjusting the virtual precession control voltage according to the resonant frequency-decay time constant relationship model obtained in step 7, thereby maintaining the virtual precession speed stable. 2. The virtual precession calibration method of a hemispherical resonant gyroscope based on a decay time constant according to claim 1, characterized in that, in step 4, ΔT=0.5-1 degree, the temperature control test stage is divided by ΔT, in the initial temperature control test stage k=0, the temperature of the temperature box is set to the lowest temperature T ₀ when the gyroscope is actually used, in different temperature control test stages k=1, 2..., the temperature setting of the temperature box is increased by ΔT in sequence, and the corresponding temperature of each stage is T _k . 3. The virtual precession calibration method of the hemispherical resonant gyroscope based on the decay time constant according to claim 2 is characterized in that the functional relationship between the decay time constant of the resonator and the data sampling time is: Among them, t _i is the data sampling time, i=0,1,2... is the data sampling sequence number, a _r (i) is the theoretical value of the amplitude at the current time t _i , τ _k ,k=0,1,2 ... is the attenuation time constant of the resonator in the kth temperature control test stage, and a _k is the initial amplitude of the resonator in the kth temperature control test stage. 4. The hemispheric resonant gyro virtual precession calibration method based on attenuation time constant according to claim 3, characterized in that the attenuation time constant τ _k of the resonator in the kth temperature control test stage,k=0,1,2 ..., the identification process of the initial amplitude a _k is: A1. Set the initial values of the identified parameters a _k (i) and τ _k (i) when i = 0: a _k (0) = 0, τ _k (0) = 0; A2. Calculate the amplitude error r(i) at the current time t _i : r(i)＝a' _r (i)-a _r (i) Where _a'r (i) is the actual amplitude at the current time _ti ; A3. Calculate the Jacobian matrix J _r (i) at the current time t _i : A4. Calculate the parameter increment at the current time t _i : In the formula, Δa _k (i) is the amplitude increment of the next moment compared with the current moment, Δτ _k (i) is the attenuation time constant increment of the next moment compared with the current moment; A5. Update the parameter vector at the next moment: Where a _k (i+1) and τ _k (i+1) are the amplitude and time decay constant at the next moment ti ₊₁ ; A6. Determine whether there is still amplitude attenuation data input. If there is data input, set i=i+1 and jump to step A2. Otherwise, the fitting is completed to obtain the identification of the parameter vectors a _k and τ _k of the kth temperature control test stage. 5. The virtual precession calibration method of the hemispherical resonant gyroscope based on the decay time constant according to claim 1 is characterized in that, in step 7, according to the resonant frequency ω _k and the decay time constant τ _k of the resonator at different temperatures collected by the host computer, a cubic or higher polynomial is used to fit it using a nonlinear least squares algorithm, and the resonant frequency and the decay time constant satisfy the functional relationship: In the formula, τ _r (k) is the theoretical value of the attenuation time constant of the resonator at the current temperature T _k ; b _j is the coefficient of the j-order term of the function, j = 0, 1,…, n, and n is the fitting order of the function. 6. The hemispheric resonant gyro virtual precession calibration method based on the attenuation time constant according to claim 5, characterized in that the resonant frequency ω _k of the resonator at different temperatures and the attenuation time constant τ _k ,k=0,1, 2...Input one by one, and the process of identifying the j-th order coefficient b _j of the function is: B1. Set the initial value of the identified parameter b _j (k) b _j (0) = 0 when k = 0; B2. Calculate the decay time constant error m(k) at the current temperature T _k : m(k)＝τ _k -τ _r (k) B3. Calculate the Jacobian matrix J _m (k) at the current temperature T _k : B4. Calculate the parameter increment at the current temperature _Tk : [Δb _j (k)]=[J _m (k) ^T J _m (k)] ^-1 J _m (k) ^T m (k) In the formula: Δb _j (k) is the coefficient increment of the next temperature compared with the current temperature; B5. Update the parameter vector of the next temperature: [b _j (k+1)]=[b _j (k)]+[Δb _j (k)] b _j (k+1) is the coefficient at the next temperature T _k+1 ; B6. Determine whether there is still data input. If there is data input, set k=k+1 and jump to step B2. Otherwise, the fitting is completed to obtain the identification of parameter vector b _j . 7. The hemispheric resonant gyro virtual precession calibration method based on attenuation time constant according to claim 5, characterized in that the virtual precession control voltage in step 8 is adjusted according to the following formula: In the formula, V _w0 is the virtual precession control voltage recorded in the initial temperature control test stage, V _a0 is the amplitude control voltage recorded in the initial temperature control test stage, τ ₀ is the attenuation obtained by fitting in the initial temperature control test stage time constant, τ is the current attenuation time constant, and is obtained by inputting the resonant frequency ω measured by the current system into the fitted resonant frequency-attenuation time constant relationship model to obtain the corresponding attenuation time constant; _Va is the current amplitude control output voltage, which can be obtained as follows: In the formula, K is the control gain, a is the amplitude measured by the current system. 8. The hemispheric resonant gyro virtual precession calibration method based on attenuation time constant according to claim 7, characterized in that the virtual precession control loop adopts open-loop control, and the virtual precession speed Ω _w is expressed as: The virtual precession speed Ω _w follows the virtual precession output voltage V _w and rotates stably. 9. A hemispheric resonant gyro virtual precession calibration system based on attenuation time constant, which is used to implement the attenuation time constant-based hemispheric resonant gyro virtual precession calibration method according to any one of claims 1 to 8, characterized in that, The calibration system includes a thermostat, a hemispheric resonant gyro, a gyro supporting circuit board and a host computer; the hemispheric resonant gyro and the gyro supporting circuit board are placed in the thermostat; The thermostat is used to adjust the operating temperature of the hemispherical resonant gyroscope; The hemispherical resonant gyro supporting circuit board is used to realize the amplitude control, orthogonal control and virtual precession control of the gyro, and transmits the resonant frequency, amplitude attenuation and virtual precession speed information to the host computer through the serial port; The host computer is used to receive the resonant frequency, amplitude attenuation and virtual precession speed information sent by the supporting circuit board of the hemispheric resonant gyro. The collected resonant frequency and amplitude attenuation information are fitted to obtain the relationship between resonant frequency and attenuation time constant at different temperatures, and the fitting results are programmed into the hemispherical resonant gyro supporting circuit board.