A method for compensating dynamic errors of an accelerometer assembly of a laser inertial navigation system

Abstract

The application discloses a kind of methods for laser inertial navigation system accelerometer assembly measurement dynamic error compensation, comprising: design inertial navigation calibration software, accelerometer assembly sensitive axis torsional elastic deformation angle model and measurement dynamic error model are established in software;After inertial navigation static initial alignment process is completed, do linear motion and angular motion coupling motion, collect gyroscope accelerometer calibration data, input inertial navigation calibration software, complete calibration parameter identification including accelerometer assembly dynamic error model parameter;According to accelerometer assembly dynamic error model parameter, dynamic error real-time compensation value is calculated, multiplied by sampling period to obtain dynamic velocity increment error compensation, deducts accelerometer velocity increment dynamic velocity increment error compensation, completes accelerometer measurement dynamic error online compensation.The application designs a kind of accelerometer assembly dynamic error compensation model, realizes laser inertial navigation accelerometer assembly dynamic error high-precision compensation.

Description

Technical Field

[0001] This invention relates to the field of inertial navigation, and more particularly to a method for dynamic error compensation in accelerometer components of laser inertial navigation systems. Background Technology

[0002] Calibration of the inertial measurement unit (IMU) component in laser inertial navigation is a key technology in the field of high-precision laser inertial navigation. Conventional laser inertial navigation calibration only focuses on the calibration of the constant zero bias and scale coefficients of inertial devices. However, in reality, under linear and angular motion environments, the coupling of linear and angular motion generates torsional torque, causing the sensitive axis of the IMU component to twist, i.e., elastic deformation, which in turn creates an equivalent installation deviation, resulting in dynamic measurement errors of the IMU component. The IMU component includes gyroscope components and accelerometer components. This patent addresses the dynamic error compensation problem of the accelerometer component, urgently proposing a method for modeling and compensating the dynamic measurement errors of the accelerometer component to improve the navigation accuracy of laser inertial navigation in highly dynamic environments such as rotation modulation, which has significant engineering implications. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for dynamic error compensation of accelerometer components in laser inertial navigation systems, addressing the deficiencies in the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is: This invention provides a method for dynamic error compensation in accelerometer components of a laser inertial navigation system, the method comprising the following steps: Inertial navigation calibration software was designed, which established a torsional elastic deformation angle model and a measurement dynamic error model for the sensitive axis of the accelerometer component. The inertial navigation calibration software takes the gyroscope measurement angle increment and the accelerometer measurement velocity increment as inputs to realize the calculation of initial alignment, attitude update, velocity update and position update of the inertial navigation system, as well as the Kalman filter estimation of the dynamic error of the accelerometer component. After the inertial navigation system completes the initial alignment process at rest, it performs coupled linear and angular motion, collects gyro accelerometer calibration data, inputs it into the inertial navigation calibration software, and completes the identification of calibration parameters, including the dynamic error model parameters of the accelerometer components. Based on the identified dynamic error model parameters of the accelerometer component, the real-time compensation value of the dynamic error is calculated. Multiplying this value by the sampling period yields the dynamic velocity increment error compensation amount. Subtracting the dynamic velocity increment error compensation amount from the accelerometer velocity increment completes the online compensation of the dynamic error of the accelerometer measurement. The compensated accelerometer velocity increment is then used for subsequent navigation update calculations.

[0005] Furthermore, the method for establishing the torsional elastic deformation angle model of the accelerometer component's sensing axis in this invention includes: Under online motion and angular motion conditions, the torsional elastic deformation angle of the sensitive axis of the accelerometer assembly It is the input ratio The function;

[0006] Input ratio Measured by the accelerometer assembly:

[0007]

[0008] The superscript b indicates that the vector is the vector projection in the accelerometer component coordinate system b. The specific differential is denoted as ,Right now:

[0009]

[0010] yes and The function, namely the torsional elastic deformation angle model of the accelerometer component's sensing axis:

[0011]

[0012] in , These are the parameters of the model to be calibrated and identified.

[0013] Furthermore, the method for establishing the dynamic error model of the accelerometer assembly measurement in the present invention includes: Let the dynamic error of the accelerometer assembly be . Elastic deformation angle For small angles, then by The resulting measurement error in the accelerometer is:

[0014]

[0015] Substituting the formula for the torsional elastic deformation angle model of the accelerometer component's sensing axis, we get:

[0016] remember

[0017] in

[0018]

[0019] Based on matrix multiplication and identity transformations, the dynamic error model of the accelerometer assembly measurement is obtained as follows:

[0020]

[0021] In the formula,

[0022]

[0023] matrix .

[0024] Furthermore, the Kalman filter estimation method for the dynamic error of the accelerometer assembly in the method of the present invention includes: Based on the optimal estimation method of Kalman filtering, the dynamic error parameters of the accelerometer component are measured. and The calibration and identification, with and The state of the element-extended Kalman filter system is given by the following differential equations:

[0025]

[0026]

[0027] The system equations related to the extended state variables are:

[0028] .

[0029] Furthermore, in the method of this invention, the state variables of the Kalman filter are commonly used in the field of inertial navigation, including: platform misalignment angle error, velocity error, latitude and longitude error, gyroscope zero bias error, accelerometer zero bias error, gyroscope calibration coefficient error, and accelerometer calibration coefficient error; the system equation is constructed based on the strapdown inertial navigation error equation, and the measurement equation is constructed with the position and velocity under the static base as the observations. Kalman filtering time update and measurement update are performed to achieve optimal estimation of state variable parameters.

[0030] Furthermore, the method for online compensation of dynamic errors in accelerometer measurement in this invention includes: Based on the identified model parameters and The dynamic error of the accelerometer assembly measurement is calculated using the formula of the dynamic error model of the accelerometer assembly measurement. The formula of the dynamic error model of the accelerometer assembly measurement is rewritten as follows:

[0031]

[0032]

[0033] The online compensation method for dynamic measurement error of accelerometer components is as follows:

[0034] in, The accelerometer specific force measurement after dynamic error correction is used for numerical integration calculation of inertial navigation velocity to improve the accuracy of laser inertial navigation velocity.

[0035] This invention provides a system for dynamic error compensation in accelerometer components of a laser inertial navigation system, comprising: The inertial navigation calibration software unit is used to establish the torsional elastic deformation angle model and measurement dynamic error model of the sensitive axis of the accelerometer component in the software. The inertial navigation calibration software takes the gyroscope measurement angle increment and the accelerometer measurement velocity increment as input to realize the calculation of initial alignment, attitude update, velocity update and position update of the inertial navigation system, as well as the Kalman filter estimation of the dynamic error of the accelerometer component. The parameter calibration and identification unit is used to perform coupled linear and angular motion after the inertial navigation system has completed the initial alignment process while stationary, collect gyro accelerometer calibration data, input it into the inertial navigation calibration software, and complete the identification of calibration parameters, including the dynamic error model parameters of the accelerometer components. The online error compensation unit is used to calculate the real-time dynamic error compensation value based on the identified dynamic error model parameters of the accelerometer component, multiply it by the sampling period to obtain the dynamic velocity increment error compensation amount, subtract the dynamic velocity increment error compensation amount from the accelerometer velocity increment, and complete the online compensation of the dynamic error of the accelerometer measurement. The compensated accelerometer velocity increment is used for subsequent navigation update calculations.

[0036] The beneficial effects of this invention are: This invention provides a method for dynamic error compensation of accelerometer components in laser inertial navigation systems. The method is based on the dynamic error effect of elastic deformation of the sensitive axis of the laser inertial navigation accelerometer component, and designs a dynamic error compensation model for the accelerometer component to achieve high-precision compensation of dynamic errors of the laser inertial navigation accelerometer component.

[0037] Compared with traditional calibration techniques, this invention takes into account the dynamic error caused by the torsional elastic deformation of the sensitive axis of the accelerometer component under the coupled environment of linear and angular motion. By modeling, calibrating and identifying the dynamic error of accelerometer measurement and compensating it online, the speed accuracy of laser inertial navigation is improved, which has significant engineering practical value. Attached Figure Description

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1This is a flowchart illustrating the implementation of the dynamic error compensation method for the laser inertial accelerometer assembly according to an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] Example 1 The method for modeling and compensating dynamic measurement errors of a laser inertial navigation accelerometer assembly according to an embodiment of the present invention includes the following steps: Step a) Establish the torsional elastic deformation angle model of the accelerometer component's sensing axis. Under online motion and angular motion conditions, the torsional elastic deformation angle of the sensitive axis of the accelerometer assembly It is the input ratio The function.

[0041] Input ratio Measured by the accelerometer assembly:

[0042] (1)

[0043] The superscript b indicates that the vector is the vector projection in the accelerometer component coordinate system b.

[0044] The specific differential is denoted as ,

[0045] (2)

[0046] Elastic deformation angle Recorded as:

[0047] (3)

[0048] yes and The function, that is:

[0049] (4)

[0050] In the above formula: ,

[0051] Equation (4) is the elastic deformation angle model of the accelerometer assembly, where , These are the parameters of the model to be calibrated and identified.

[0052] Step b) Establish a dynamic error model for accelerometer assembly measurements. Let the dynamic error of the accelerometer assembly be . Elastic deformation angle For small angles, then by The resulting measurement error in the accelerometer is:

[0053] (5)

[0054] Substituting equation (4) into equation (5), we get: (6)

[0055] remember (7)

[0056] in (8)

[0057] (9)

[0058] Based on matrix multiplication, by performing identity transformations on equations (8) and (9), the dynamic error model of the accelerometer assembly measurement is obtained as follows: (10)

[0059] (11)

[0060] In the formula,

[0061]

[0062] matrix The results are obtained by calculation based on equations (10) and (11) respectively.

[0063] Step c) Calibrate and identify the dynamic error model parameters of the accelerometer assembly. Based on the optimal estimation method of Kalman filtering, the dynamic error parameters of the accelerometer component are measured. and The calibration and identification. and The state of the element-extended Kalman filter system is given by the following differential equations:

[0064] (12)

[0065] (13)

[0066] The system equations related to the extended state variables are: (14)

[0067] (15)

[0068] Other Kalman filter state variables are commonly used in the field of inertial navigation, including: platform misalignment angle error, velocity error, latitude and longitude error, gyroscope zero bias error, accelerometer zero bias error, gyroscope calibration coefficient error, accelerometer calibration coefficient error, etc. The system equation is constructed based on the strapdown inertial navigation error equation, and the measurement equation is constructed with the position and velocity under the static base as the observations. Kalman filter time update and measurement update are performed to achieve optimal estimation of state variable parameters.

[0069] Step d) Based on the model parameters identified by the model and calibration, compensate online for the dynamic measurement error of the accelerometer component. Based on the identified model parameters and The dynamic error of the accelerometer assembly is calculated using equations (10) and (11). Equations (10) and (11) are then rewritten as follows:

[0070]

[0071]

[0072] The online compensation method for dynamic measurement error of accelerometer components is as follows: (16)

[0073] The accelerometer specific force measurement after dynamic error correction is used for numerical integration calculation of inertial navigation velocity to improve the accuracy of laser inertial navigation velocity.

[0074] Example 2 The dynamic error compensation method for laser inertial navigation accelerometer components in this invention, according to steps a) to c) of the above embodiments, completes the inertial navigation calibration software that includes Kalman filter estimation of the dynamic error of the accelerometer components. Gyro accelerometer calibration data under coupled linear and angular motion conditions are collected, and the designed inertial navigation calibration software is used to identify calibration parameters, including the dynamic error model parameters of the accelerometer components. According to step d), online compensation for the dynamic measurement error of the accelerometer components based on the model and parameters is implemented in the real-time inertial navigation application software. The implementation process is as follows: Figure 1 As shown, the specific implementation method is as follows: Step 1: Based on steps a) to c) of the above technical solution, complete the design of inertial navigation calibration software that includes Kalman filter estimation of the dynamic error of the accelerometer component. The inertial navigation calibration software takes the gyroscope measurement angle increment and the accelerometer measurement velocity increment as inputs to realize the calculation of initial alignment, attitude update, velocity update and position update of the inertial navigation system, as well as the Kalman filter estimation of the dynamic error of the accelerometer component included in the technical solution. The data input and navigation calculation frequency is 200Hz. It is obtained by multiplying the velocity increment by the sampling period. Depend on The difference is obtained.

[0075] Step 2: After the inertial navigation system completes the initial alignment process at rest, it performs coupled linear and angular motion, collects gyro accelerometer calibration data, inputs it into the inertial navigation calibration software, and completes the identification of calibration parameters, including the dynamic error model parameters of the accelerometer components. Step 3: In the real-time application software coding of inertial navigation, based on step d) and the identified dynamic error model parameters of the accelerometer component, calculate the real-time compensation value for dynamic error. and Multiplying the value by the sampling period yields the dynamic velocity increment error compensation. Subtracting this compensation from the accelerometer velocity increment completes the online compensation for dynamic errors in accelerometer measurements. The compensated accelerometer velocity increment is then used for subsequent navigation update calculations.

[0076] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0077] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for dynamic error compensation in accelerometer assembly measurements of a laser inertial navigation system, characterized in that, The method includes the following steps: Inertial navigation calibration software was designed, which established a torsional elastic deformation angle model and a measurement dynamic error model for the sensitive axis of the accelerometer component. The inertial navigation calibration software takes the gyroscope measurement angle increment and the accelerometer measurement velocity increment as inputs to realize the calculation of initial alignment, attitude update, velocity update and position update of the inertial navigation system, as well as the Kalman filter estimation of the dynamic error of the accelerometer component. After the inertial navigation system completes the initial alignment process at rest, it performs coupled linear and angular motion, collects gyro accelerometer calibration data, inputs it into the inertial navigation calibration software, and completes the identification of calibration parameters, including the dynamic error model parameters of the accelerometer components. Based on the identified dynamic error model parameters of the accelerometer component, the real-time compensation value of the dynamic error is calculated, multiplied by the sampling period to obtain the dynamic velocity increment error compensation amount, and the dynamic velocity increment error compensation amount is subtracted from the accelerometer velocity increment to complete the online compensation of the dynamic error of the accelerometer measurement. The compensated accelerometer velocity increment is used for subsequent navigation update calculation. The method for establishing the torsional elastic deformation angle model of the accelerometer component's sensing shaft includes: Under online motion and angular motion conditions, the torsional elastic deformation angle of the sensitive axis of the accelerometer assembly It is the input ratio The function; Input ratio Measured by the accelerometer assembly: The superscript b indicates that the vector is the vector projection in the accelerometer component coordinate system b. The specific differential is denoted as ,Right now: yes and The function, namely the torsional elastic deformation angle model of the accelerometer component's sensing axis: in , These are the parameters of the model to be calibrated and identified.

2. The method for dynamic error compensation of accelerometer components in a laser inertial navigation system according to claim 1, characterized in that, The methods for establishing the dynamic error model of the accelerometer assembly measurement include: Let the dynamic error of the accelerometer assembly be . Elastic deformation angle For small angles, then by The resulting measurement error in the accelerometer is: Substituting the formula for the torsional elastic deformation angle model of the accelerometer component's sensing axis, we get: remember in Based on matrix multiplication and identity transformations, the dynamic error model of the accelerometer assembly measurement is obtained as follows: In the formula, matrix .

3. The method for dynamic error compensation of accelerometer components in a laser inertial navigation system according to claim 2, characterized in that, The Kalman filter estimation method for the dynamic error of the accelerometer assembly in this method includes: Based on the optimal estimation method of Kalman filtering, the dynamic error parameters of the accelerometer component are measured. and The calibration and identification, with and The state of the element-extended Kalman filter system is given by the following differential equations: The system equations related to the extended state variables are: 。 4. The method for dynamic error compensation of accelerometer components in a laser inertial navigation system according to claim 3, characterized in that, In this method, the state variables of the Kalman filter are commonly used in the field of inertial navigation, including: platform misalignment angle error, velocity error, latitude and longitude error, gyroscope zero bias error, accelerometer zero bias error, gyroscope calibration coefficient error, and accelerometer calibration coefficient error. The system equation is constructed based on the strapdown inertial navigation error equation, and the measurement equation is constructed with the position and velocity under the static base as the observations. Kalman filtering time update and measurement update are performed to achieve optimal estimation of state variable parameters.

5. The method for dynamic error compensation of accelerometer components in a laser inertial navigation system according to claim 3, characterized in that, The methods for online compensation of dynamic errors in accelerometer measurements include: Based on the identified model parameters and The dynamic error of the accelerometer assembly measurement is calculated using the formula of the dynamic error model of the accelerometer assembly measurement. The formula of the dynamic error model of the accelerometer assembly measurement is rewritten as follows: The online compensation method for dynamic measurement error of accelerometer components is as follows: in, The accelerometer specific force measurement after dynamic error correction is used for numerical integration calculation of inertial navigation velocity to improve the accuracy of laser inertial navigation velocity.

6. A system for dynamic error compensation in accelerometer assembly measurements of a laser inertial navigation system, characterized in that, include: The inertial navigation calibration software unit is used to establish the torsional elastic deformation angle model and measurement dynamic error model of the sensitive axis of the accelerometer component in the software. The inertial navigation calibration software takes the gyroscope measurement angle increment and the accelerometer measurement velocity increment as input to realize the calculation of initial alignment, attitude update, velocity update and position update of the inertial navigation system, as well as the Kalman filter estimation of the dynamic error of the accelerometer component. The parameter calibration and identification unit is used to perform coupled linear and angular motion after the inertial navigation system has completed the initial alignment process while stationary, collect gyro accelerometer calibration data, input it into the inertial navigation calibration software, and complete the identification of calibration parameters, including the dynamic error model parameters of the accelerometer components. The online error compensation unit is used to calculate the real-time dynamic error compensation value based on the identified dynamic error model parameters of the accelerometer component, multiply it by the sampling period to obtain the dynamic velocity increment error compensation amount, subtract the dynamic velocity increment error compensation amount from the accelerometer velocity increment, and complete the online compensation of the dynamic error of the accelerometer measurement. The compensated accelerometer velocity increment is used for subsequent navigation update calculation. The method for establishing the torsional elastic deformation angle model of the accelerometer component's sensing axis in this system includes: Under online motion and angular motion conditions, the torsional elastic deformation angle of the sensitive axis of the accelerometer assembly It is the input ratio The function; Input ratio Measured by the accelerometer assembly: The superscript b indicates that the vector is the vector projection in the accelerometer component coordinate system b. The specific differential is denoted as ,Right now: yes and The function, namely the torsional elastic deformation angle model of the accelerometer component's sensing axis: in , These are the parameters of the model to be calibrated and identified.

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