A hybrid precise calibration method for a strapdown inertial navigation system

Abstract

The application discloses a kind of strapdown inertial navigation system mixed type accurate calibration method, it is related to inertial navigation technical field.The application is first by the data acquisition of multiple attitude of inertial measurement unit, the accurate scale coefficient and installation error angle coefficient of gyroscope component and the coarse scale coefficient of accelerometer component are calculated;Afterwards, the rotation order of system level calibration 18 position is collected data, the zero offset of gyroscope component and accelerometer component is estimated to obtain respective zero offset, and the scale coefficient error and installation error angle of accelerometer component are estimated, so that the installation error angle and accurate scale coefficient of accelerometer component are obtained.The application uses mixed type calibration, compared with single calibration mode, the reliability is high, and the dependence on turntable precision is reduced;Compared with traditional system level calibration, since the grouping of estimation error parameters, the estimation result converges faster and is more accurate.

Description

Technical Field

[0001] This invention belongs to the field of inertial navigation technology, specifically referring to a hybrid precision calibration method for strapdown inertial navigation systems. Background Technology

[0002] Calibration compensation technology has always been a hot research topic in the field of inertial navigation. As core components of the inertial navigation system, the output values ​​of gyroscopes and accelerometers always deviate from the actual angular velocity and specific force sensitive to the IMU due to various error factors. The purpose of IMU calibration is to determine the calibration factors, installation errors, constant drift, and other relatively fixed error parameters of the inertial measurement unit, and then compensate for them in the output of the inertial measurement unit to minimize these deviations and improve navigation accuracy.

[0003] Currently, the mainstream calibration methods include discrete calibration, system-level calibration, and fitting calibration. Discrete calibration is simple and easy to implement, but it is highly dependent on the accuracy of the test turntable. Fitting calibration and system-level calibration estimate the calibration error in reverse based on the error propagation characteristics of the inertial navigation system, but require the design of complex rotation paths to solve the problem of error parameter coupling. Relatively speaking, fitting calibration requires attitude information provided by the turntable, making it more dependent on the turntable and requiring more complex rotation paths. Hybrid calibration combines two or more calibration methods, calibrating error parameters in groups, thus possessing the characteristics of low turntable dependence, short calibration time, and high calibration accuracy. It is more suitable for dynamic navigation and positioning and calibration under high-maneuverability swaying conditions, and is currently a research hotspot. Summary of the Invention

[0004] In view of this, the present invention proposes a hybrid precision calibration method for strapdown inertial navigation systems, which can achieve higher accuracy and faster convergence in system calibration.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A hybrid precision calibration method for a strapdown inertial navigation system includes the following steps:

[0007] Step 1: Install the inertial measurement unit on the three-axis turntable and turn on the system power to preheat the system;

[0008] Step 2: Rotate the inertial measurement unit to 6 different attitudes in sequence. For each attitude, first collect the first static output raw data of the accelerometer component in the inertial measurement unit; then rotate the three-axis turntable clockwise and counterclockwise at the same rotational angular velocity n times, and collect the clockwise and counterclockwise rotation output raw data of the gyroscope component in the inertial measurement unit.

[0009] Step 3: For each posture, integrate the original clockwise and counterclockwise rotation output data of the gyroscope component separately, and record the difference between the integral values ​​of the clockwise and counterclockwise rotation output data under the same posture. Combine this with the total clockwise and counterclockwise rotation angle of the three-axis turntable to calculate the joint matrix S of the gyroscope component's scaling coefficient and installation error angle. Mg :

[0010] S Mg =[S gx ,S gy ,S gz ,α yz ,α zy ,α zx ] T

[0011] Among them, S gx S gy With S gz These are the scaling coefficients of the gyroscope component in the x, y, and z axes, respectively. yz Let a be the installation error angle of the gyroscope component's z-axis relative to the y-axis. zy Let a be the installation error angle of the y-axis relative to the z-axis of the gyroscope assembly. zx The x-axis of the gyroscope assembly is the installation error angle relative to the z-axis.

[0012] Step 4: After the three-axis turntable stops rotating, acquire the second static output raw data of the accelerometer assembly, select the scaling acceleration β, and calculate the coarse scaling coefficient S of the accelerometer assembly based on the scaling acceleration β and the first and second static output raw data of the accelerometer assembly. Ma :

[0013] S Ma =[S ax S ay S az ] T

[0014] Among them, S ax S ay With S az These are the coarse scaling coefficients of the accelerometer assembly in the x, y, and z axes, respectively.

[0015] Step 5: Rotate the three-axis turntable according to the rotation sequence of the 18 positions calibrated at the system level. Perform navigation calculations based on the output data of the gyroscope and accelerometer components, and determine its state variable X. INS for:

[0016] X INS =[φ E φ N φ U δVE δV N δV U δLδλδh] T

[0017] Where, φ E φ N φ U These represent the attitude errors of the inertial measurement unit in the east, north, and sky directions, respectively; δV E δV N δV U δL, δλ, and δh represent the velocity errors of the inertial measurement unit in the east, north, and sky directions, respectively; δL, δλ, and δh represent the latitude error, accuracy error, and altitude error of the inertial measurement unit, respectively.

[0018] Step 6: During the navigation calculation process, the zero bias X of the gyroscope component is calculated using the Kalman filter method. g The scaling factor error of the accelerometer assembly, the installation error angle and the zero offset X a Make an estimate:

[0019] X g =[b gx b gy b gy ] T

[0020] X a =[S' ax S' ay S′ az θ xy θ xz θ yx θ yz θ zx θ zy b ax b ay b az ] T

[0021] Among them, S' ax S' ay With S' az These represent the scaling coefficient errors of the accelerometer assembly in the xyz directions, and θ. xy θ is the installation error angle of the y-axis relative to the x-axis of the accelerometer assembly. xz θ is the installation error angle of the accelerometer assembly relative to the x-axis. yx θ is the installation error angle of the accelerometer assembly relative to the y-axis. yz θ is the installation error angle of the accelerometer assembly relative to the y-axis. zx θ is the installation error angle of the accelerometer assembly relative to the z-axis.zy b is the installation error angle of the y-axis relative to the z-axis of the accelerometer assembly. gx b gy b gz These represent the zero bias of the gyroscope component in the x, y, and z axes, respectively; b ax b ay b az These represent the zero offset of the accelerometer assembly in the x, y, and z axes, respectively.

[0022] Step 7: Correct the coarse scaling coefficient of the accelerometer assembly based on the estimated scaling coefficient error.

[0023] Furthermore, the six different postures in step 2 include:

[0024] First attitude: The x-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Second attitude: The y-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Third attitude: The z-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Fourth attitude: Both the x-axis and y-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable; Fifth attitude: Both the x-axis and z-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable; Sixth attitude: Both the y-axis and z-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable.

[0025] Furthermore, in step 3, the scaling coefficients of the gyroscope component and the joint matrix S of the installation error angle... Mg The calculation method is as follows:

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032] Where 4nπ is the total clockwise and counterclockwise rotation angle of the three-axis turntable. and These represent the original data output by the gyroscope component during clockwise rotation and counterclockwise rotation, respectively, for the i-th orientation, where i = 1, 2, 3...6; t cw The rotation time is clockwise or counterclockwise; and These represent the clockwise and counterclockwise rotations of the gyroscope component in the i-th orientation, with clockwise rotation outputting the original data and counterclockwise rotation outputting the integral values ​​of the original data, respectively.

[0033] The scaling coefficient and installation error angle joint matrix S of the gyroscope component are calculated using the above six formulas. Mg .

[0034] Furthermore, in step 4, the coarse scaling coefficient S of the accelerometer assembly... Ma The calculation method is as follows:

[0035] ||β|| 2 -||S Ma (A1)|| 2 =0

[0036] ||β|| 2 -||S Ma (A2)|| 2 =0

[0037] ||β|| 2 -||S Ma (A3)|| 2 =0

[0038] ||β|| 2 -||S Ma (A4)|| 2 =0

[0039] ||β|| 2 -||S Ma (A5)|| 2 =0

[0040] ||β|| 2 -||S Ma (A6)|| 2 =0

[0041] Among them, A i The average value of the first and second static output raw data of the accelerometer component at the i-th pose.

[0042] The coarse scale coefficient S of the accelerometer is calculated using the above six formulas. Ma .

[0043] Furthermore, the rotation order of the system-level scale 18 position in step 5 is as follows:

[0044]

[0045] Furthermore, the state equation of the Kalman filtering method in step 6 is as follows:

[0046]

[0047] in,

[0048]

[0049] Indicates A skew-symmetric matrix composed of elements. Indicates A skew-symmetric matrix composed of elements;

[0050] Let be the projection of the rotational angular velocity of the navigation frame relative to the inertial frame onto the navigation frame. Let f be the attitude matrix. b This refers to the acceleration of the inertial measurement unit;

[0051]

[0052] R N R is the principal radius of curvature of the circle. M L is the principal curvature radius of the meridian, L is the latitude of the inertial measurement unit, and h is the height of the inertial measurement unit.

[0053]

[0054] Ω is the Earth's angular velocity of rotation, V E V represents the eastward velocity of the inertial measurement unit. N This represents the northward velocity of the inertial measurement unit;

[0055]

[0056] and I1 and I2 are the integral values ​​of the rotation output data of the gyroscope component in the x, y, and z axes, respectively; I3 and I4 are the two-dimensional and three-dimensional identity matrices, respectively.

[0057]

[0058] Indicates A skew-symmetric matrix composed of elements. Indicates A skew-symmetric matrix composed of elements;

[0059] This is the projection of the Earth's rotational angular velocity onto the navigation system. The projection of the angular velocity of the inertial measurement unit onto the navigation frame. This refers to the ground velocity of the inertial measurement unit;

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] u = [w g w a ] T

[0066] w g For the measurement noise of the gyroscope component, w a This refers to the measurement noise of the accelerometer assembly.

[0067] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0068] 1. The hybrid calibration method used in this invention has higher reliability and reduces dependence on turntable accuracy compared to a single calibration method.

[0069] 2. Due to the grouping of estimation error parameters, the estimation results of this invention converge faster and are more accurate, and are more suitable for calibration under dynamic navigation and positioning and high maneuvering conditions. Attached Figure Description

[0070] Figure 1 This is a flowchart illustrating a hybrid precision calibration method for a strapdown inertial navigation system according to an embodiment of the present invention.

[0071] Figure 2 These are the six different postures in the embodiments of the present invention. Detailed Implementation

[0072] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0073] A hybrid precision calibration method for strapdown inertial navigation systems, such as Figure 1 As shown, it includes the following steps:

[0074] Step 1: Install the inertial measurement unit on the three-axis turntable and turn on the system power to preheat the system;

[0075] Step 2: Rotate the inertial measurement unit to 6 different attitudes in sequence. For each attitude, first collect the first static output raw data of the accelerometer component in the inertial measurement unit; then rotate the three-axis turntable clockwise and counterclockwise at the same rotational angular velocity n times, and collect the clockwise and counterclockwise rotation output raw data of the gyroscope component in the inertial measurement unit.

[0076] Step 3: For each posture, integrate the original clockwise and counterclockwise rotation output data of the gyroscope component separately, and record the difference between the integral values ​​of the clockwise and counterclockwise rotation output data under the same posture. Combine this with the total clockwise and counterclockwise rotation angle of the three-axis turntable to calculate the joint matrix S of the gyroscope component's scaling coefficient and installation error angle. Mg :

[0077] S Mg =[S gx ,S gy ,S gz ,α yz ,α zy ,α zx ] T

[0078] Among them, S gx S gy With S gz These are the scaling coefficients of the gyroscope component in the x, y, and z axes, respectively. yz Let a be the installation error angle of the gyroscope component's z-axis relative to the y-axis. zy Let a be the installation error angle of the y-axis relative to the z-axis of the gyroscope assembly. zx The x-axis of the gyroscope assembly is the installation error angle relative to the z-axis.

[0079] Step 4: After the three-axis turntable stops rotating, acquire the second static output raw data of the accelerometer assembly, select the scaling acceleration β, and calculate the coarse scaling coefficient S of the accelerometer assembly based on the scaling acceleration β and the first and second static output raw data of the accelerometer assembly. Ma :

[0080] S Ma =[S ax S ay S az ] T

[0081] Among them, S ax S ay With S az These are the coarse scaling coefficients of the accelerometer assembly in the x, y, and z axes, respectively.

[0082] Step 5: Rotate the three-axis turntable according to the rotation sequence of the 18 positions calibrated at the system level. Perform navigation calculations based on the output data of the gyroscope and accelerometer components, and determine its state variable X. INS for:

[0083] X INS =[φ E φN φ U δV E δV N δV U δLδλδh] T

[0084] Where, φ E φ N φ U These represent the attitude errors of the inertial measurement unit in the east, north, and sky directions, respectively; δV E δV N δV U δL, δλ, and δh represent the velocity errors of the inertial measurement unit in the east, north, and sky directions, respectively; δL, δλ, and δh represent the latitude error, accuracy error, and altitude error of the inertial measurement unit, respectively.

[0085] Step 6: During the navigation calculation process, the zero bias X of the gyroscope component is calculated using the Kalman filter method. g The scaling factor error of the accelerometer assembly, the installation error angle and the zero offset X a Make an estimate:

[0086] X g =[b gx b gy b gy ] T

[0087] X a =[S' ax S' ay S' az θ xy θ xz θ yx θ yz θ zx θ zy b ax b ay b az ] T

[0088] Among them, S' ax S' ay With S' az These represent the scaling coefficient errors of the accelerometer assembly in the xyz directions, and θ. xy θ is the installation error angle of the y-axis relative to the x-axis of the accelerometer assembly. xz θ is the installation error angle of the accelerometer assembly relative to the x-axis. yx θ is the installation error angle of the accelerometer assembly relative to the y-axis. yz θ is the installation error angle of the accelerometer assembly relative to the y-axis. zxθ is the installation error angle of the accelerometer assembly relative to the z-axis. zy b is the installation error angle of the y-axis relative to the z-axis of the accelerometer assembly. gx b gy b gz These represent the zero bias of the gyroscope component in the x, y, and z axes, respectively; b ax b ay b az These represent the zero offset of the accelerometer assembly in the x, y, and z axes, respectively.

[0089] Step 7: Correct the coarse scaling coefficient of the accelerometer assembly based on the estimated scaling coefficient error.

[0090] Furthermore, such as Figure 2 As shown, the six different postures in step 2 include:

[0091] First attitude: The x-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Second attitude: The y-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Third attitude: The z-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Fourth attitude: Both the x-axis and y-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable; Fifth attitude: Both the x-axis and z-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable; Sixth attitude: Both the y-axis and z-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable.

[0092] Furthermore, in step 3, the scaling coefficients of the gyroscope component and the joint matrix S of the installation error angle... Mg The calculation method is as follows:

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099] Where 4nπ is the total clockwise and counterclockwise rotation angle of the three-axis turntable. and These represent the original data output by the gyroscope component during clockwise rotation and counterclockwise rotation, respectively, for the i-th orientation, where i = 1, 2, 3...6; t cwThe rotation time is clockwise or counterclockwise; and These represent the clockwise and counterclockwise rotations of the gyroscope component in the i-th orientation, with clockwise rotation outputting the original data and counterclockwise rotation outputting the integral values ​​of the original data, respectively.

[0100] The scaling coefficient and installation error angle joint matrix S of the gyroscope component are calculated using the above six formulas. Mg .

[0101] Furthermore, in step 4, the coarse scaling coefficient S of the accelerometer assembly... Ma The calculation method is as follows:

[0102] ||β|| 2 -||S Ma (A1)|| 2 =0

[0103] ||β|| 2 -||S Ma (A2)|| 2 =0

[0104] ||β|| 2 -||S Ma (A3)|| 2 =0

[0105] ||β|| 2 -||S Ma (A4)|| 2 =0

[0106] ||β|| 2 -||S Ma (A5)|| 2 =0

[0107] ||β|| 2 -||S Ma (A6)|| 2 =0

[0108] Among them, A i The average value of the first and second static output raw data of the accelerometer component at the i-th pose.

[0109] The coarse scale coefficient S of the accelerometer is calculated using the above six formulas. Ma .

[0110] Furthermore, the rotation order of the system-level scale 18 position in step 5 is as follows:

[0111]

[0112] Furthermore, the state equation of the Kalman filtering method in step 6 is as follows:

[0113]

[0114] in,

[0115]

[0116] Indicates A skew-symmetric matrix composed of elements. Indicates A skew-symmetric matrix composed of elements;

[0117] Let be the projection of the rotational angular velocity of the navigation frame relative to the inertial frame onto the navigation frame. Let f be the attitude matrix. b This refers to the acceleration of the inertial measurement unit;

[0118]

[0119] R N R is the principal radius of curvature of the circle. M L is the principal curvature radius of the meridian, L is the latitude of the inertial measurement unit, and h is the height of the inertial measurement unit.

[0120]

[0121] Ω is the Earth's angular velocity of rotation, V E V represents the eastward velocity of the inertial measurement unit. N This represents the northward velocity of the inertial measurement unit;

[0122]

[0123] and I1 and I2 are the integral values ​​of the rotation output data of the gyroscope component in the x, y, and z axes, respectively; I3 and I4 are the two-dimensional and three-dimensional identity matrices, respectively.

[0124]

[0125] Indicates A skew-symmetric matrix composed of elements. Indicates A skew-symmetric matrix composed of elements;

[0126] This is the projection of the Earth's rotational angular velocity onto the navigation system. The projection of the angular velocity of the inertial measurement unit onto the navigation frame. This refers to the ground velocity of the inertial measurement unit;

[0127]

[0128]

[0129]

[0130]

[0131]

[0132] u = [w g w a ] T

[0133] w g For the measurement noise of the gyroscope component, w a This refers to the measurement noise of the accelerometer assembly.

[0134] In summary, this invention employs a hybrid calibration method, which offers higher reliability and reduced dependence on turntable accuracy compared to a single calibration method. Compared to traditional system-level calibration, the estimation results converge faster and are more accurate due to the grouping of estimated error parameters, making it more suitable for calibration under dynamic navigation and positioning conditions and high-maneuverability oscillations.

[0135] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the structure and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A hybrid precision calibration method for a strapdown inertial navigation system, characterized in that, Includes the following steps: Step 1: Install the inertial measurement unit on the three-axis turntable and turn on the system power to preheat the system; Step 2: Rotate the inertial measurement unit to 6 different attitudes in sequence. For each attitude, first collect the first static output raw data of the accelerometer component in the inertial measurement unit; then rotate the three-axis turntable clockwise and counterclockwise at the same rotational angular velocity n times, and collect the clockwise and counterclockwise rotation output raw data of the gyroscope component in the inertial measurement unit. Step 3: For each posture, integrate the original clockwise and counterclockwise rotation output data of the gyroscope component separately, and record the difference between the integral values ​​of the clockwise and counterclockwise rotation output data under the same posture. Combine this with the total clockwise and counterclockwise rotation angle of the three-axis turntable to calculate the joint matrix S of the gyroscope component's scaling coefficient and installation error angle. Mg : S Mg =[S gx ,S gy ,S gz ,a yz ,a zy ,a zx ] T Among them, S gx S gy With S gz These are the scaling coefficients of the gyroscope component in the x, y, and z axes, respectively. yz Let a be the installation error angle of the gyroscope component's z-axis relative to the y-axis. zy Let a be the installation error angle of the y-axis relative to the z-axis of the gyroscope assembly. zx The x-axis of the gyroscope assembly is the installation error angle relative to the z-axis. Step 4: After the three-axis turntable stops rotating, acquire the second static output raw data of the accelerometer assembly, select the scaling acceleration β, and calculate the coarse scaling coefficient S of the accelerometer assembly based on the scaling acceleration β and the first and second static output raw data of the accelerometer assembly. Ma : S Ma =[S ax S ay S az ] T Among them, S ax S ay With S az These are the coarse scaling coefficients of the accelerometer assembly in the x, y, and z axes, respectively. Step 5: Rotate the three-axis turntable according to the rotation sequence of the 18 positions calibrated at the system level. Perform navigation calculations based on the output data of the gyroscope and accelerometer components, and determine its state variable X. INS for: X INS =[φ E f N f U δV E δV N δV U δL δλ δh] T Where, φ E φ N φ U These represent the attitude errors of the inertial measurement unit in the east, north, and sky directions, respectively; δV E δV N δV U δL, δλ, and δh represent the velocity errors of the inertial measurement unit in the east, north, and sky directions, respectively; δL, δλ, and δh represent the latitude error, accuracy error, and altitude error of the inertial measurement unit, respectively. Step 6: During the navigation calculation process, the zero bias X of the gyroscope component is calculated using the Kalman filter method. g The scaling factor error of the accelerometer assembly, the installation error angle and the zero offset X a Make an estimate: X g =[b gx b gy b gy ] T X a =[S' ax S' ay S' az i xy i xz i yx i yz i zx i zy b ax b ay b az ] T Among them, S' ax S' ay With S' az These represent the scaling coefficient errors of the accelerometer assembly in the xyz directions, and θ. xy θ is the installation error angle of the y-axis relative to the x-axis of the accelerometer assembly. xz θ is the installation error angle of the accelerometer assembly relative to the x-axis. yx θ is the installation error angle of the accelerometer assembly relative to the y-axis. yz θ is the installation error angle of the accelerometer assembly relative to the y-axis. zx θ is the installation error angle of the accelerometer assembly relative to the z-axis. zy b is the installation error angle of the y-axis relative to the z-axis of the accelerometer assembly. gx b gy b gz These represent the zero bias of the gyroscope component in the x, y, and z axes, respectively; b ax b ay b az These represent the zero offset of the accelerometer assembly in the x, y, and z axes, respectively. Step 7: Correct the coarse scaling coefficient of the accelerometer assembly based on the estimated scaling coefficient error.

2. The hybrid precision calibration method for a strapdown inertial navigation system according to claim 1, characterized in that, The six different postures in step 2 include: First attitude: The x-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Second attitude: The y-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Third attitude: The z-axis of the inertial measurement unit coincides with the rotation axis of the three-axis turntable; Fourth attitude: Both the x-axis and y-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable; Fifth attitude: Both the x-axis and z-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable; Sixth attitude: Both the y-axis and z-axis of the inertial measurement unit are at 45° to the rotation axis of the three-axis turntable.

3. The hybrid precision calibration method for a strapdown inertial navigation system according to claim 2, characterized in that, In step 3, the joint matrix S of the scaling coefficients and installation error angles of the gyroscope component Mg The calculation method is as follows: Where 4nπ is the total clockwise and counterclockwise rotation angle of the three-axis turntable. and These represent the original data output by the gyroscope component during clockwise rotation and counterclockwise rotation, respectively, for the i-th orientation, where i = 1, 2, 3...6; t cw The rotation time is clockwise or counterclockwise; and These represent the clockwise and counterclockwise rotations of the gyroscope component in the i-th orientation, with clockwise rotation outputting the original data and counterclockwise rotation outputting the integral values ​​of the original data, respectively. The scaling coefficient and installation error angle joint matrix S of the gyroscope component are calculated using the above six formulas. Mg .

4. The hybrid precision calibration method for a strapdown inertial navigation system according to claim 3, characterized in that, The coarse scaling coefficient S of the accelerometer assembly in step 4 Ma The calculation method is as follows: ||β|| 2 -||S Ma (A1)|| 2 =0 ||β|| 2 -||S Ma (A2)|| 2 =0 ||b|| 2 -||S Ma (A3)|| 2 =0 ||β|| 2 -||S Ma (A4)|| 2 =0 ||b|| 2 -||S Ma (A5)|| 2 =0 ||β|| 2 -||S Ma (A6)|| 2 =0 Among them, A i The average value of the first and second static output raw data of the accelerometer component at the i-th pose. The coarse scale coefficient S of the accelerometer is calculated using the above six formulas. Ma .

5. The hybrid precision calibration method for a strapdown inertial navigation system according to claim 4, characterized in that, The rotation sequence of the system-level calibration position 18 in step 5 is as follows:

6. The hybrid precision calibration method for a strapdown inertial navigation system according to claim 5, characterized in that, The state equation for the Kalman filter method in step 6 is as follows: in, Indicates A skew-symmetric matrix composed of elements. Indicates A skew-symmetric matrix composed of elements; Let be the projection of the rotational angular velocity of the navigation frame relative to the inertial frame onto the navigation frame. Let f be the attitude matrix. b This refers to the acceleration of the inertial measurement unit; R N R is the principal radius of curvature of the circle. M L is the principal curvature radius of the meridian, L is the latitude of the inertial measurement unit, and h is the height of the inertial measurement unit. Ω is the Earth's angular velocity of rotation, V E V represents the eastward velocity of the inertial measurement unit. N This represents the northward velocity of the inertial measurement unit; and I1 and I2 are the integral values ​​of the rotation output data of the gyroscope component in the x, y, and z axes, respectively; I3 and I4 are the two-dimensional and three-dimensional identity matrices, respectively. Indicates A skew-symmetric matrix composed of elements. Indicates A skew-symmetric matrix composed of elements; This is the projection of the Earth's rotational angular velocity onto the navigation system. The projection of the angular velocity of the inertial measurement unit onto the navigation frame. This refers to the ground velocity of the inertial measurement unit; u=[w g w a ] T w g For the measurement noise of the gyroscope component, w a This refers to the measurement noise of the accelerometer assembly.

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