A method for testing and compensating for the asymmetry error of a fiber-optic gyroscope scale factor

Abstract

The present application belongs to the technical field of fiber-optic gyroscope testing, and particularly relates to a method for testing and compensating for the asymmetric error of the scale factor of a fiber-optic gyroscope. The method comprises the following steps: (1) rapid alignment of an inertial navigation device; (2) testing of the static zero bias of a to-be-tested azimuth gyroscope; (3) calculation of the equivalent zero bias error corresponding to the asymmetric error of the scale factor of the gyroscope; (4) calculation of a compensation model according to the swing spectrum and the equivalent zero bias error; and (5) a compensation model for the asymmetric error of the scale factor of the gyroscope. The present application adopts a turntable to simulate live swing, and calculates and parameter-fits the accumulation of the dynamic error excited by the asymmetric error of the scale factor of the gyroscope in the reciprocating motion of the gyroscope, so as to realize compensation for the asymmetric error of the scale factor of the fiber-optic gyroscope. The present application has strong universality and can be easily and conveniently tested.

Description

Technical Field

[0001] This invention belongs to the field of inertial device testing technology, and in particular, it is a method for testing and compensating for the asymmetric error of the scaling factor of a fiber optic gyroscope. Background Technology

[0002] With the development of navigation technology, fiber optic gyroscope inertial navigation systems are being used more and more widely in the field of inertial navigation. During dynamic testing of the carrier, especially in application scenarios such as lakes and seas, the carrier with the inertial navigation equipment is constantly in a swaying state due to the influence of waves. The asymmetric error of the scaling factor, under the excitation of both positive and negative angular velocities, will produce significant equivalent gyroscope drift.

[0003] The calibration process for scaling parameters in inertial navigation systems typically does not consider the compensation for asymmetric errors in the gyroscope scaling factor under dynamic testing conditions. This leads to instability in the system's accuracy during dynamic testing due to the excitation of the dynamic environment.

[0004] Existing calibration methods only test the scaling factor asymmetry at specific rates, which is not suitable for practical applications. Therefore, designing a gyroscope scaling factor testing method that is accurate, simple, convenient, and applicable to real-world scenarios is of great significance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for testing and compensating for the asymmetric error of the scaling factor of a fiber optic gyroscope.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A method for testing and compensating for the asymmetric error of the scaling factor of a fiber optic gyroscope, comprising the following steps:

[0008] (1) Rapid alignment of inertial navigation equipment;

[0009] The inertial navigation device was installed on a three-axis turntable. After installation, the turntable was powered on, each axis was returned to zero and kept stationary. After the temperature of the gyroscope and accelerometer stabilized, the test was started.

[0010] The orientation cosine matrix of the inertial navigation device is determined using a solidified coordinate system alignment method. Using the inertial coordinate system as a reference, two inertial coordinate systems are initially fixed: the initial navigation system n0 and the carrier system b0. Then, the quaternion of the angular motion of the carrier relative to the inertial coordinate system is updated. The transformation matrix of the two fixed inertial coordinate systems is obtained using the transformation relationship between gravity and the carrier's linear motion. From this, the transformation is deduced... ;

[0011] (2) Testing the static zero bias of the azimuth gyroscope under test;

[0012] Based on the alignment result of step (1), adjust the inner frame and middle frame of the three-axis turntable to -R and -P angles respectively, so that the horizontal attitude angle of the system is zero, and record the heading angle as H at this time. 0；

[0013] Navigation updates are performed using the common attitude, velocity, and position update algorithms for inertial navigation systems at a frequency of 200Hz. After each 5ms inertial navigation update calculation, the inertial navigation update velocity is set to zero, and the position is set to the local position. After 1 hour of inertial navigation algorithm updates, the current heading angle is recorded as H. 1；

[0014] (3) Calculation of the equivalent zero bias error corresponding to the asymmetric error of the gyroscope scaling factor;

[0015] Static constant error under static bench conditions of the computing system Based on this, the additional error caused by different swing spectra is calculated and tested;

[0016] (4) Calculate the compensation model based on the swing spectrum and the equivalent zero bias error;

[0017] In step (3), the compensation model parameters corresponding to different swing spectra are calculated;

[0018] (5) Asymmetric error compensation model for gyroscope scaling factor;

[0019] Based on the calculation results of step (4), the asymmetry error of the scaling factor of the gyroscope is compensated.

[0020] Furthermore, the specific steps of step (1) are as follows:

[0021] (1.1) Installation of inertial navigation equipment

[0022] The inertial navigation device was mounted on a three-axis turntable. The X, Y, and Z axes of the device corresponded to the middle frame, inner frame, and outer frame of the turntable, respectively. The Z-axis gyroscope was the fiber optic gyroscope to be tested. After the device was installed, the turntable was powered on, and each axis was returned to zero and kept stationary. After the device was powered on, the temperature of the gyroscope and accelerometer was allowed to stabilize (temperature change less than 1°C in 1 hour) before the test was started.

[0023] (1.2) Alignment method for rapid alignment

[0024] First, decompose the azimuth cosine matrix into:

[0025] ;

[0026] in, This represents the direction cosine matrix from the carrier coordinate system to the Earth's geographic coordinate system. The direction cosine matrix represents the distance from the geographic coordinate system at the moment of freezing to the geographic coordinate system at the current moment. This represents the direction cosine matrix from the carrier coordinate system at the time of solidification to the geographic coordinate system at the time of solidification. The transformation matrix represents the transformation from the carrier coordinate system at the current moment to the carrier coordinate system at the solidification moment;

[0027] It can be broken down into:

[0028] ;

[0029] in This is the direction cosine matrix from the geocentric coordinate system to the geographic coordinate system. Let be the direction cosine matrix from the geocentric coordinate system at the time of solidification to the geocentric coordinate system at the current time. The direction cosine matrix is ​​the distance from the geographic coordinate system at the time of freezing to the geocentric coordinate system at the time of freezing.

[0030] The cosine matrix in each direction is expanded as follows:

[0031] ;

[0032] ;

[0033] ;

[0034] in, and To align the initial longitude and latitude; and For alignment The longitude and latitude of the moment, where t is the alignment time;

[0035] The calculation method uses attitude quaternions to update and obtain the differential equation:

[0036] ;

[0037] in, To and The corresponding quaternion representation, Let k-1 be the quaternion representation of the carrier's attitude. The quaternion representation of the carrier attitude change from time k-1 to the current time;

[0038] The corresponding equivalent rotation vector matrix is ;

[0039] ;

[0040] in The increment of angular displacement is obtained by direct measurement of the gyroscope.

[0041] According to the rules of vector coordinate system transformation, establish and... The relevant transformation equation is:

[0042] ;

[0043] The matrix in the formula expands to:

[0044] ;

[0045] ;

[0046] in, The acceleration measured by the accelerometer The gravitational acceleration is in the local geographic coordinate system.

[0047] The above equation can be derived by reverse deduction. The calculation formula is as follows:

[0048] ;

[0049] Finally according to The direction cosine matrix of the current carrier attitude can then be calculated;

[0050] Depend on The matrix elements are used to extract the attitude angle in real time, as shown in the following formula:

[0051] ;

[0052] ;

[0053] ;

[0054] Where P is the pitch angle, R is the roll angle, and H is the heading angle.

[0055] Furthermore, the specific steps of step (2) are as follows:

[0056] A solution cycle is defined as The time interval is ;

[0057] Record The carrier posture of time is Corresponding The quaternion at time is The quaternion attitude update formula is:

[0058] ;

[0059] in, and These represent the rotation angles of the navigation coordinate system and the vehicle coordinate system relative to inertial space, respectively. The corresponding equivalent rotation vectors need to be calculated separately. This represents a recording point at a specific moment. This indicates the previous record point at a given moment;

[0060] for The update requires the use of Integrate to obtain the equivalent rotation vector. ;

[0061] ;

[0062] The matrix in the formula expands to:

[0063] ;

[0064] and The corresponding equivalent rotation vector is The calculation method is as follows:

[0065] ;

[0066] Since the speed and position are set to zero speed and local position, their update process can be ignored;

[0067] Based on the navigation calculation with an update frequency of 1 hour, the static zero position of the gyroscope under test can be obtained as follows:

[0068] ;

[0069] In the formula: This is a static constant error. To quickly align and level the heading angle on the turntable, The heading angle of the vehicle after 1 hour of navigation.

[0070] Furthermore, the specific steps of step (3) are as follows:

[0071] Repeat steps (1) and (2), changing the static holding for 1 hour after alignment and leveling in step 2 to keeping the inner frame of the middle frame locked, and operate according to the parameters of different dynamic test swing spectra;

[0072] For the outer frame, perform a 1-hour swing for each swing spectrum, record the change amount dH of the heading angle before and after each swing, and subtract the static constant error. , record the position of dHi in the table respectively, where i represents the number of the swing spectrum.

[0073] Furthermore, the specific steps of step (4) are as follows:

[0074] Calculate the integral of the positive swing angular velocity within the corresponding rate range of the swing spectrum i in step (3). ; ;

[0075] ;

[0076] Calculate the integral of the positive swing angular velocity corresponding to the angular rate lower than (j < i), and the calculation method is as follows: ; ;

[0077] ;

[0078] Calculate the corresponding scale factor asymmetry error dki as

[0079] ;

[0080] The relevant parameters of the scale factor asymmetry error at different angular rates are obtained through the above formula.

[0081] Furthermore, the specific steps of step (5) are as follows:

[0082] According to the calculation results of step (4), compensate for the asymmetry error of the scale factor of the gyroscope, and the compensation method is as follows:

[0083] ;

[0084] where is the gyro angular rate calculated in real time.

[0085] The advantages and positive effects achieved by this invention are:

[0086] 1. The design of this invention uses a turntable to simulate the actual swing. By calculating and parameter fitting the dynamic error accumulation excited by the scale factor asymmetry error during the reciprocating swing of the gyroscope, the compensation for the scale factor asymmetry error of the fiber optic gyroscope is realized. This technology has strong versatility and can be easily implemented for testing.

[0087] 2. The method designed in this invention uses dynamic swing data for calculation and compensation, which avoids the drawback of traditional testing methods that can only calculate the scaling factor asymmetry error at a few fixed rates, and achieves effective compensation at the full rate.

[0088] 3. The method designed in this invention can compensate for the angular velocity error caused by the asymmetric scaling factor error due to the periodic change of angular velocity in the fiber optic gyroscope during operation. It can effectively improve the attitude measurement accuracy under dynamic swing conditions and enhance the dynamic environment adaptability of inertial navigation products. Attached Figure Description

[0089] Figure 1 This is a flowchart illustrating the fast alignment algorithm of the present invention;

[0090] Figure 2 This is a three-dimensional schematic diagram of an installation structure for the inertial navigation device of the present invention. Detailed Implementation

[0091] The present invention will be further described below with reference to the embodiments. The following embodiments are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0092] The various experimental operations involved in the specific embodiments are all conventional techniques in the field. For parts not specifically annotated in this document, those skilled in the art can refer to various commonly used reference books, scientific and technological documents or related instructions and manuals prior to the filing date of this invention to carry out the operations.

[0093] A method for testing and compensating for the asymmetric error of the scaling factor of a fiber optic gyroscope, comprising the following steps:

[0094] (1) Rapid alignment of inertial navigation equipment;

[0095] (2) Testing the static zero bias of the azimuth gyroscope under test;

[0096] (3) Calculation of the equivalent zero bias error corresponding to the asymmetric error of the gyroscope scaling factor;

[0097] (4) Calculate the compensation model based on the swing spectrum and the equivalent zero bias error;

[0098] (5) Gyroscope scaling factor asymmetric error compensation model.

[0099] like Figure 1 As shown, the specific steps are as follows:

[0100] (1) Rapid alignment of inertial navigation equipment;

[0101] 1.1 Installation of Inertial Navigation Equipment

[0102] like Figure 2 As shown, the inertial navigation device is installed on a three-axis turntable. The X-axis, Y-axis, and Z-axis of the device correspond to the middle frame rotation axis 1, inner frame rotation axis 2, and outer frame rotation axis 3 of the three-axis turntable, respectively. The Z-axis gyroscope is the fiber optic gyroscope to be tested. After the device is installed, the turntable is powered on, each axis returns to zero, and remains stationary. After the device is powered on, the temperature of the gyroscope and accelerometer is stabilized (temperature change is less than 1°C in 1 hour) before the test begins.

[0103] 1.2 Alignment Method for Quick Alignment

[0104] Rapid alignment employs a fixed coordinate system alignment method. The purpose of alignment is to determine the orientation cosine matrix of the inertial navigation equipment. The basic method of the scheme uses an inertial coordinate system as a reference. Two inertial coordinate systems are initially fixed: the initial navigation system n0 and the carrier system b0. Then, the angular motion quaternion of the carrier relative to the inertial coordinate system is updated. The transformation matrix of the two fixed inertial coordinate systems is obtained using the transformation relationship between gravity and the carrier's linear motion. From this, the transformation matrix is ​​calculated. .

[0105] First, decompose the azimuth cosine matrix into:

[0106] ;

[0107] in, This represents the direction cosine matrix from the carrier coordinate system to the Earth's geographic coordinate system. The direction cosine matrix represents the distance from the geographic coordinate system at the moment of freezing to the geographic coordinate system at the current moment. This represents the direction cosine matrix from the carrier coordinate system at the time of solidification to the geographic coordinate system at the time of solidification. This represents the transformation matrix from the carrier coordinate system at the current moment to the carrier coordinate system at the solidification moment.

[0108] It can be broken down into:

[0109] ;

[0110] in This is the direction cosine matrix from the geocentric coordinate system to the geographic coordinate system. Let be the direction cosine matrix from the geocentric coordinate system at the time of solidification to the geocentric coordinate system at the current time. Let be the direction cosine matrix from the geographic coordinate system at the time of freezing to the geocentric coordinate system at the time of freezing.

[0111] The cosine matrix in each direction is expanded as follows:

[0112] ;

[0113] ;

[0114] ;

[0115] in, and To align the initial longitude and latitude; and For alignment The longitude and latitude of the time, where t is the alignment time.

[0116] The calculation method uses attitude quaternions to update and obtain the differential equation:

[0117] ;

[0118] in, To and The corresponding quaternion representation, Let k-1 be the quaternion representation of the carrier's attitude. This is a quaternion representation of the carrier's attitude change from time k-1 to the current time.

[0119] The corresponding equivalent rotation vector matrix is .

[0120] ;

[0121] in This refers to the increment of angular displacement directly measured by the gyroscope.

[0122] According to the rules of vector coordinate system transformation, establish and... The relevant transformation equation is:

[0123] ;

[0124] The matrix in the formula expands to:

[0125] ;

[0126] ;

[0127] in, The acceleration measured by the accelerometer This represents the gravitational acceleration in the local geographic coordinate system.

[0128] The above equation can be derived by reverse deduction. The calculation formula is as follows:

[0129] ;

[0130] Finally according to The direction cosine matrix of the current carrier attitude can then be calculated.

[0131] Depend on The matrix elements are used to extract the attitude angle in real time, as shown in the following formula:

[0132] ;

[0133] ;

[0134] ;

[0135] Where P is the pitch angle, R is the roll angle, and H is the heading angle.

[0136] (2) Testing the static zero bias of the azimuth gyroscope under test;

[0137] Based on the alignment result of step (1), adjust the inner frame and middle frame of the three-axis turntable to -R and -P angles respectively, so that the horizontal attitude angle of the system is zero, and record the heading angle at this time as . .

[0138] Navigation updates are performed using the common attitude, velocity, and position update algorithms for inertial navigation systems at a frequency of 200Hz. After each 5ms inertial navigation update calculation, the inertial navigation update velocity is set to zero, and the position is set to the local position. After 1 hour of inertial navigation algorithm updates, the current heading angle is recorded as H. 1. .

[0139] The specific calculation process is as follows:

[0140] A solution cycle is defined as The time interval is ;

[0141] Record The carrier posture of time is Corresponding The quaternion at time is The quaternion attitude update formula is:

[0142]

[0143] in, and These represent the rotation angles of the navigation coordinate system and the vehicle coordinate system relative to inertial space, respectively. The corresponding equivalent rotation vectors need to be calculated separately. This represents a recording point at a specific moment. This indicates the previous record point at a given moment;

[0144] for The update requires the use of Integrate to obtain the equivalent rotation vector. .

[0145] ;

[0146] The matrix in the formula expands to:

[0147] ;

[0148] and The corresponding equivalent rotation vector is The calculation method is as follows:

[0149] ;

[0150] Since the speed and position are set to zero speed and local position, their update process can be ignored.

[0151] Based on the navigation calculation with an update frequency of 1 hour, the static zero position of the gyroscope under test can be obtained as follows:

[0152] ;

[0153] In the formula: This is a static constant error. To quickly align and level the heading angle on the turntable, The heading angle of the vehicle after 1 hour of navigation.

[0154] (3) Calculation of the equivalent zero bias error corresponding to the asymmetric error of the gyroscope scaling factor;

[0155] Static constant error under static bench conditions of the computing system Based on this, the additional error caused by different swing spectra is calculated. Repeat the process of steps (1) and (2), and change the static holding for 1h after alignment and leveling in step 2 to keeping the inner frame of the middle frame locked, and refer to the parameters of the dynamic test swing spectrum in Table 1 below for operation;

[0156] Table 1 Dynamic Test Swing Spectrum

[0157]

[0158] For the outer frame, oscillate for 1 hour each time according to one of the oscillation spectra in Table 1, and record the change in heading angle dH before and after each oscillation, and subtract the static constant error. The positions of dHi in the table are recorded respectively, where i represents the number of the swing spectrum.

[0159] Let Ai be the amplitude of the corresponding swing spectrum i, and Ti be the period of the corresponding swing spectrum i. This represents the maximum angular rate of the corresponding oscillation spectrum. Based on the range of angular rates that the equipment needs to compensate for, design oscillations of different amplitudes.

[0160] (4) Calculate the compensation model based on the swing spectrum and the equivalent zero bias error;

[0161] 4.1 In calculation step (3), the calculation method for the compensation model parameters corresponding to the swing spectrum 1 in Table 1 is as follows:

[0162] The integral of the positive angular velocity in the 1-hour reciprocating oscillation corresponding to the oscillation of oscillation spectrum 1 is:

[0163] ;

[0164] in, The swing amplitude corresponding to swing spectrum 1. A11 represents the swing period corresponding to swing spectrum 1, and A11 represents the swing angle accumulated by the positive angular velocity after 1 hour of swinging according to swing spectrum 1.

[0165] The corresponding scaling factor asymmetry error is:

[0166] ;

[0167] That is, in The scaling factor asymmetry error within the range is ;

[0168] 4.2 In calculation step (3), the corresponding compensation model parameters for the swing spectrum 2 in Table 2 are:

[0169] When calculating the swing spectrum 2, the corresponding velocity range of the swing spectrum 2 Integral quantity of the positive angular velocity of the swing within The calculation method is as follows:

[0170] ;

[0171] in, The swing amplitude corresponding to swing spectrum 2. A22 represents the swing period corresponding to swing spectrum 2, and A22 represents the swing angle accumulated by the positive angular velocity after 1 hour of swinging according to swing spectrum 2.

[0172] Calculate the corresponding rate range in the gyroscope data from the swing spectrum 1 during the swing spectrum 2 swing. Integral quantity of the positive angular velocity of the swing within The calculation method is as follows:

[0173] ;

[0174] Calculate based on the above equation. , When swinging according to swing spectrum 2, the maximum angular velocity corresponding to swing spectrum 1 is reached. The point in time.

[0175] ;

[0176] The corresponding scaling factor asymmetry error is calculated as follows:

[0177] ;

[0178] 4.3 In calculation step (3), the corresponding compensation model parameters for the swing spectrum 2 in Table 2 are:

[0179] When calculating the swing spectrum 3, the corresponding velocity range of the swing spectrum 3 Integral quantity of the positive angular velocity of the swing within The calculation method is as follows:

[0180] ;

[0181] in, The swing amplitude corresponding to swing spectrum 3. A33 represents the swing period corresponding to swing spectrum 3, and A33 represents the swing angle accumulated by the positive angular velocity after 1 hour of swinging according to swing spectrum 3.

[0182] Calculation below The different oscillation spectra below the speed correspond to the integral angle experienced by the speed, and the angular velocity range is within Integral quantity of the positive angular velocity of the swing within The calculation method is as follows:

[0183] ;

[0184] in, When swinging according to swing spectrum 3, the maximum angular velocity corresponding to swing spectrum 2 is reached. The point in time.

[0185] Corresponding angular velocity range Integral quantity of the positive angular velocity of the swing within The calculation method is as follows:

[0186] ;

[0187] in, When swinging according to swing spectrum 3, the maximum angular velocity corresponding to swing spectrum 1 is reached. The point in time.

[0188] The corresponding scaling factor asymmetry error is calculated as follows:

[0189] ;

[0190] The calculation formula for the scale factor asymmetry error corresponding to the spectrum of other wobbles is similar to that of wobble 3. The formula is directly given as follows. The method for calculating the gyro scale factor asymmetry error dKi corresponding to wobble i is as follows:

[0191] When calculating the wobble spectrum i, the wobble positive angular velocity integration within the rate range corresponding to the wobble spectrum i ;

[0192] ;

[0193] Calculate the integration of the positive angular velocity of the wobble corresponding to the angular rate lower than ; the corresponding (j < i) wobble positive angular velocity integration , and the calculation method is as follows:

[0194] ;

[0195] Calculate the corresponding scale factor asymmetry error dki as:

[0196] ;

[0197] The above has obtained the relevant parameters of the scale factor asymmetry error at different angular rates.

[0198] (5) Gyro scale factor asymmetric error compensation model.

[0199] According to the calculation results of step (4), the asymmetry error of the gyro scale factor can be compensated, and the compensation method is as follows:

[0200]

[0201] Where is the gyro angular rate calculated in real time.

[0202] Using the method of the present invention, the heading holding accuracy in the pure inertial working mode of the fiber optic gyro inertial navigation system is tested. After static zero bias error compensation, the dynamic wobble test accuracy is tested, and the real-time comparison effect is shown in Table 2:

[0203] ​​​​​​​

Claims

1. A method for testing and compensating for the asymmetric error of the scaling factor of a fiber optic gyroscope, characterized in that: The steps are as follows: (1) Rapid alignment of inertial navigation equipment; The inertial navigation device was installed on a three-axis turntable. After installation, the turntable was powered on, each axis was returned to zero and kept stationary. After the temperature of the gyroscope and accelerometer stabilized, the test was started. The orientation cosine matrix of the inertial navigation device is determined using a solidified coordinate system alignment method. Using the inertial coordinate system as a reference, two inertial coordinate systems are initially fixed: the initial navigation system n0 and the carrier system b0. Then, the quaternion of the angular motion of the carrier relative to the inertial coordinate system is updated. The transformation matrix of the two fixed inertial coordinate systems is obtained using the transformation relationship between gravity and the carrier's linear motion. From this, the transformation is deduced... ; (2) Testing the static zero bias of the azimuth gyroscope under test; Based on the alignment result of step (1), adjust the inner frame and middle frame of the three-axis turntable to -R and -P angles respectively, so that the horizontal attitude angle of the system is zero, and record the heading angle as H at this time. 0； Navigation updates are performed using the common attitude, velocity, and position update algorithms for inertial navigation systems at a frequency of 200Hz. After each 5ms inertial navigation update calculation, the inertial navigation update velocity is set to zero, and the position is set to the local position. After 1 hour of inertial navigation algorithm updates, the current heading angle is recorded as H. 1； (3) Calculation of the equivalent zero bias error corresponding to the asymmetric error of the gyroscope scaling factor; Static constant error under static bench conditions of the computing system Based on this, the additional error caused by different swing spectra is calculated and tested; (4) Calculate the compensation model based on the swing spectrum and the equivalent zero bias error; In step (3), the compensation model parameters corresponding to different swing spectra are calculated; (5) Asymmetric error compensation model for gyroscope scaling factor; Based on the calculation results of step (4), the asymmetry error of the scaling factor of the gyroscope is compensated; The specific steps of step (4) are as follows: In calculation step (3), for different swing spectra i, the corresponding velocity range of swing spectra i Integral quantity of the positive angular velocity of the swing within ; ； The calculated angular rate is lower than corresponding positive angular velocity integral of swaying (j < i) , and the calculation method is as follows: ； Calculate the corresponding scaling factor asymmetry error dki as follows: ； The relevant parameters of the scaling factor asymmetry error under different angular rates were obtained using the above formula; Step (5) The specific steps are as follows: Based on the calculation results of step (4), the asymmetry error of the scaling factor of the gyroscope is compensated. The compensation method is as follows: ； in This refers to the gyroscope angular rate calculated in real time.

2. The method according to claim 1, characterized in that: The specific steps of step (1) are as follows: (1.1) Installation of inertial navigation equipment The inertial navigation device was mounted on a three-axis turntable. The X, Y, and Z axes of the device corresponded to the middle frame, inner frame, and outer frame of the turntable, respectively. The Z-axis gyroscope was the fiber optic gyroscope to be tested. After the device was installed, the turntable was powered on, and each axis was returned to zero and kept stationary. After the device was powered on, the temperature of the gyroscope and accelerometer was allowed to stabilize. After 1 hour, when the temperature change was less than 1°C, the test was started. (1.2) Alignment method for rapid alignment First, decompose the azimuth cosine matrix into: ； in, This represents the direction cosine matrix from the carrier coordinate system to the Earth's geographic coordinate system. The direction cosine matrix represents the distance from the geographic coordinate system at the moment of freezing to the geographic coordinate system at the current moment. This represents the direction cosine matrix from the carrier coordinate system at the time of solidification to the geographic coordinate system at the time of solidification. The transformation matrix represents the transformation from the carrier coordinate system at the current moment to the carrier coordinate system at the solidification moment; It can be broken down into: ； in This is the direction cosine matrix from the geocentric coordinate system to the geographic coordinate system. Let be the direction cosine matrix from the geocentric coordinate system at the time of solidification to the geocentric coordinate system at the current time. The direction cosine matrix is ​​the distance from the geographic coordinate system at the time of freezing to the geocentric coordinate system at the time of freezing. The cosine matrix in each direction is expanded as follows: ； ； ； in, and To align the initial longitude and latitude; and For alignment The longitude and latitude of the moment, where t is the alignment time; The calculation method uses attitude quaternions to update and obtain the differential equation: ； in, To and The corresponding quaternion representation, Let k-1 be the quaternion representation of the carrier's attitude. The quaternion representation of the carrier attitude change from time k-1 to the current time; The corresponding equivalent rotation vector matrix is ; ； in The increment of angular displacement is obtained by direct measurement of the gyroscope. According to the rules of vector coordinate system transformation, establish and... The relevant transformation equation is: ； The matrix in the formula expands to: ； ； in, The acceleration measured by the accelerometer The gravitational acceleration is in the local geographic coordinate system. The above equation can be derived by reverse deduction. The calculation formula is as follows: ； Finally according to The direction cosine matrix of the current carrier attitude can then be calculated; Depend on The matrix elements are used to extract the attitude angle in real time, as shown in the following formula: ； ； ； Where P is the pitch angle, R is the roll angle, and H is the heading angle.

3. The method according to claim 1, characterized in that: The specific steps for step (2) are as follows: A solution cycle is defined as The time interval is ; Record The carrier posture of time is Corresponding The quaternion at time is The quaternion attitude update formula is: ； in, and These represent the rotation angles of the navigation coordinate system and the vehicle coordinate system relative to inertial space, respectively. The corresponding equivalent rotation vectors need to be calculated separately. This represents a recording point at a specific moment. This indicates the previous record point at a given moment; for The update requires the use of Integrate to obtain the equivalent rotation vector. ; ； The matrix in the formula expands to: ； and The corresponding equivalent rotation vector is The calculation method is as follows: ； Since the speed and position are set to zero speed and local position, their update process can be ignored; Based on the navigation calculation with an update frequency of 1 hour, the static zero position of the gyroscope under test can be obtained as follows: ； In the formula: This is a static constant error. To quickly align and level the heading angle on the turntable, The heading angle of the vehicle after 1 hour of navigation.

4. The method according to claim 1, characterized in that: The specific steps for step (3) are as follows: Repeat steps (1) and (2), changing the static holding for 1 hour after alignment and leveling in step 2 to keeping the inner frame of the middle frame locked, and operate according to the parameters of different dynamic test swing spectra; For the outer frame, one swing spectrum is performed each time, and the swing is carried out for 1 hour. The change in heading angle dH before and after each swing is recorded, and the static constant error is subtracted. The positions of dHi in the table are recorded respectively, where i represents the number of the swing spectrum.

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