A non-singular linear transfer alignment method and system based on relative attitude matrix

Abstract

The application discloses a non-singular linear transfer alignment method and system based on a relative attitude matrix, belongs to the technical field of inertial navigation systems, and particularly relates to transfer alignment technology. In view of the problems that existing transfer alignment methods are prone to model singularity and alignment precision reduction when facing large installation error angles or complex dynamic environments, the application proposes the following: a strapdown inertial navigation system carrier coordinate system is acquired to determine a main inertial navigation attitude matrix; a transfer alignment error model is established by using a relative attitude matrix based on the main inertial navigation attitude matrix; flexible rod arm state information is acquired to optimize the transfer alignment error model; and transfer alignment of the strapdown inertial navigation system is realized based on the optimized transfer alignment error model. The application significantly improves alignment precision by optimizing the transfer alignment error model, and can still maintain stable and reliable alignment results under large installation error angles or complex dynamic environments, thereby enhancing the robustness and accuracy of the transfer alignment model.

Description

Technical Field

[0001] This invention relates to the field of transfer alignment technology for inertial navigation systems, specifically to a non-singular linear transfer alignment method and system based on a relative attitude matrix, applicable to high-precision transfer alignment between the main inertial navigation unit and the sub-inertial navigation unit in a strapdown inertial navigation system. Background Technology

[0002] In strapdown inertial navigation systems (DINS), precise synchronization between the high-precision master inertial navigation unit (MINS) and multiple low-precision sub-inertial navigation units (SINS) is crucial for ensuring overall system performance. The MINS provides accurate attitude, velocity, and position information; the SINS are distributed across different locations on the vehicle and require alignment correction to correct for measurement errors. The vehicle coordinate system (i-frame) describes the vehicle's motion state. The Earth coordinate system (e-frame) defines the navigation velocity.

[0003] Currently, the main challenges faced in the transfer alignment process include: Large-angle installation errors: Traditional transfer alignment methods are prone to model singularities when dealing with large installation error angles (e.g., exceeding 10 degrees), leading to a significant decrease in alignment accuracy (e.g., an increase in error of 20%-30%). This singularity mainly manifests as the mathematical model producing irreversible matrices or unsolvable equations during calculation, causing the alignment process to fail to converge or converge to erroneous results. Large-angle errors are usually caused by mechanical deviations during installation or deformation of the mechanical structure due to long-term use. To address this issue, modern alignment methods typically employ nonlinear filtering algorithms (such as extended Kalman filtering or unscented Kalman filtering) to handle large-angle errors, thereby improving the robustness and accuracy of alignment. Flexible lever arm effect: The relative displacement change between the master inertial navigation system (INS) and the sub-INS introduces additional acceleration errors, known as the flexible lever arm effect. When there is elastic deformation in the connection structure between the master and sub-INS, the sub-INS will experience additional acceleration due to the bending or vibration of the lever arm. These accelerations are not generated by the motion of the carrier itself, but by the elastic deformation of the lever arm. This effect is particularly pronounced in high-dynamic environments (such as high-speed flight or violent maneuvers), potentially increasing alignment errors by 10%-15%. To mitigate the impact of the flexible lever effect, it is typically necessary to incorporate lever compensation algorithms into the model or use a high-precision inertial measurement unit (IMU) to monitor and correct lever deformation in real time. Time-varying factors: Environmental factors such as temperature changes and material aging can cause minute deformations in the mechanical structure, increasing the difficulty of alignment. For example, temperature changes may cause the inertial navigation system (INS) mounting base to expand or contract, thereby altering the relative position and attitude between the master and slave INS. Material aging can reduce the stiffness of the connecting structure, further exacerbating the flexible lever effect. These time-varying factors accumulate over long-term operation, leading to a gradual decrease in alignment accuracy. To address this issue, the system typically requires temperature compensation mechanisms and periodic calibration procedures to ensure high alignment accuracy under different environmental conditions. Furthermore, employing highly stable materials and structural designs can also effectively reduce the impact of time-varying factors on alignment accuracy.

[0004] Therefore, how to solve the problems caused by installation errors, flexible lever effect and time-varying factors, thereby improving alignment accuracy and system robustness, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a non-singular linear transfer alignment method and system based on the relative attitude matrix, which solves the problems caused by installation errors, additional acceleration sensitivity caused by flexible levers, and time-varying factors, thereby improving alignment accuracy and system robustness.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A non-singular linear transfer alignment method based on a relative attitude matrix includes the following steps:

[0008] Obtain the coordinate system of the strapdown inertial navigation system carrier and determine the main inertial navigation attitude matrix; based on the main inertial navigation attitude matrix, establish a transfer alignment error model using the relative attitude matrix; obtain the flexible arm state information and optimize the transfer alignment error model; realize the transfer alignment of the strapdown inertial navigation system based on the optimized transfer alignment error model.

[0009] Furthermore, obtaining the coordinate system of the strapdown inertial navigation system carrier and determining the main inertial navigation attitude matrix includes:

[0010] When the strapdown inertial navigation system is stationary, gravity and the geomagnetic field are used as references to calculate the initial attitude matrix;

[0011] When the strapdown inertial navigation system is in motion, it acquires angular velocity data and updates the attitude matrix using differential equations based on the angular velocity data, thereby determining the main inertial navigation attitude matrix.

[0012] Furthermore, when the strapdown inertial navigation system is in motion, it acquires angular velocity data and uses differential equations based on this data. To update the pose matrix, where, This is the angular velocity vector transformed into the navigation coordinate system, where (·×) represents the rotational effect. The main inertial navigation attitude matrix, This is the updated master inertial navigation attitude matrix.

[0013] Furthermore, based on the master inertial navigation attitude matrix, a transfer alignment error model is established using the relative attitude matrix, including:

[0014]

[0015] In the formula, This is the updated master inertial navigation attitude matrix. For the sub-inertial navigation attitude matrix, The relative attitude matrix;

[0016] For relative attitude matrix When performing chain decomposition and considering time-varying deformation angles, the relative attitude matrix... Given a time-varying matrix, chain decomposition yields:

[0017]

[0018] In the formula, m0 and s0 represent the inertial coordinate systems obtained by solidifying the principal and child inertial conductor coordinate systems at the initial moment, respectively;

[0019] Among them, the time-varying attitude matrix and The angular velocities output by the primary and secondary inertial gyroscopes are obtained by integrating the attitude matrix differential equation:

[0020]

[0021] In the formula, Main inertial angular velocity, For the sub-inertial angular velocity;

[0022] By listing the attitude matrix and error angle as state variables, a non-singular linear propagation alignment error model is established under any installation error angle:

[0023]

[0024] In the formula, Time-varying attitude matrix The error, This is the error angle.

[0025] Furthermore, the state information of the flexible lever arm is obtained, and the model for transferring alignment errors is optimized, including:

[0026] Establish a vector representation from inertial coordinate system i to sub-inertial navigation coordinate system s;

[0027] Establish a vector representation from the navigation coordinate system e to the sub-inertial navigation coordinate system s;

[0028] While considering the time-varying nature of the flexible lever arm, the vector representation is differentiated;

[0029] Define the velocity in each coordinate system and establish the velocity-vector relationship;

[0030] Establish a velocity error model based on velocity and vector relationships;

[0031] Based on the velocity error model, the linear differential equation of velocity in the final navigation coordinate system is obtained, which is the optimized transfer alignment error model.

[0032] Furthermore, the vector representation from the inertial coordinate system i to the sub-inertial navigation coordinate system s is established as follows:

[0033]

[0034] In the formula, This represents the vector from inertial coordinate system i to principal inertial navigation coordinate system m; This represents the vector from the main inertial navigation coordinate system m to the sub-inertial navigation coordinate system s; This represents the rotation matrix from the principal inertial coordinate system m to the inertial coordinate system i; This represents the vector from inertial coordinate system i to sub-inertial navigation coordinate system s.

[0035] Furthermore, the vector representation from the navigation coordinate system e to the sub-inertial navigation coordinate system s is established as follows:

[0036]

[0037] In the formula, This represents the vector from the navigation coordinate system e to the main inertial navigation coordinate system m. This represents the rotation matrix from the master inertial navigation coordinate system m to the navigation coordinate system e; The vector representing the distance from the primary inertial navigation coordinate system m to the secondary inertial navigation coordinate system s; The vector from the navigation coordinate system e to the sub-inertial navigation coordinate system s.

[0038] Furthermore, based on the velocity error model, the final linear differential equation of velocity in the navigation coordinate system is expressed as:

[0039]

[0040] In the formula, This represents the rate of change of the velocity error in the navigation coordinate system e; This represents the rate of change of velocity of the sub-inertial navigation coordinate system s in the navigation coordinate system e; This represents the rate of change of velocity of the sub-inertial coordinate system s in the inertial coordinate system i; Represents the relative attitude matrix The estimated value in navigation coordinate system e; This represents the estimated force vector value in the navigation coordinate system e; Represents the relative attitude matrix The actual value in navigation coordinate system e; φ represents the true force vector in the navigation coordinate system e; I3 represents the attitude error angle; (·×) represents the antisymmetric matrix operator.

[0041] A non-singular linear transfer alignment system based on a relative attitude matrix includes:

[0042] Initialization module: used to obtain the coordinate system of the strapdown inertial navigation system and determine the attitude matrix of the main inertial navigation system;

[0043] Model building module: used to build a model for propagating alignment errors based on the master inertial navigation attitude matrix and using the relative attitude matrix;

[0044] Model optimization module: used to acquire the state information of the flexible lever arm and optimize the model for transferring alignment errors;

[0045] Transfer alignment module: used to achieve transfer alignment of strapdown inertial navigation systems based on an optimized transfer alignment error model.

[0046] As can be seen from the above technical solution, compared with the prior art, this invention discloses a non-singular linear transfer alignment method and system based on a relative attitude matrix. Starting from obtaining the carrier coordinate system, it progressively advances to establishing a transfer alignment error model, then optimizes the model to account for the flexible lever effect, and finally achieves accurate transfer alignment. Each step is closely linked, forming a complete process, ensuring the logic and coherence of the solution. Furthermore, by introducing advanced mathematical modeling and a real-time error compensation mechanism, the alignment accuracy and reliability of the strapdown inertial navigation system are significantly improved, demonstrating broad application prospects and practical value. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0049] Figure 2 This is a schematic diagram of the system structure of the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] The purpose of this invention is to provide a non-singular linear transfer alignment method and system based on a relative attitude matrix. The method includes: acquiring the coordinate system of the strapdown inertial navigation system (SINS) carrier and determining the master inertial navigation system's attitude matrix; establishing a transfer alignment error model using a relative attitude matrix based on the master inertial navigation system's attitude matrix; acquiring the flexible arm's state information and optimizing the transfer alignment error model; and achieving transfer alignment of the SINS based on the optimized transfer alignment error model. This invention addresses problems caused by installation errors, sensitivity to additional acceleration due to the flexible arm, and time-varying factors, providing a solution for improving alignment accuracy and system robustness.

[0052] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] See Figure 1 This invention discloses a non-singular linear transfer alignment method based on a relative attitude matrix, comprising the following steps:

[0054] Obtain the coordinate system of the strapdown inertial navigation system carrier and determine the main inertial navigation attitude matrix; based on the main inertial navigation attitude matrix, establish a transfer alignment error model using the relative attitude matrix; obtain the flexible arm state information and optimize the transfer alignment error model; realize the transfer alignment of the strapdown inertial navigation system based on the optimized transfer alignment error model.

[0055] Specifically, this invention significantly improves alignment accuracy by optimizing the transfer alignment error model, and maintains stable and reliable alignment results even under large installation error angles or complex dynamic environments, thereby enhancing the robustness and accuracy of the transfer alignment model.

[0056] In one specific embodiment, obtaining the carrier coordinate system of the strapdown inertial navigation system and determining the main inertial navigation attitude matrix includes:

[0057] When the strapdown inertial navigation system is stationary, gravity and the geomagnetic field are used as references to calculate the initial attitude matrix;

[0058] When the strapdown inertial navigation system is in motion, it acquires angular velocity data and updates the attitude matrix using differential equations based on the angular velocity data, thereby determining the main inertial navigation attitude matrix.

[0059] In one specific embodiment, when the strapdown inertial navigation system carrier is in motion, angular velocity data is acquired, and the attitude matrix is ​​updated using a differential equation based on the angular velocity data. The expression is as follows:

[0060]

[0061] In the formula, This is the angular velocity vector transformed into the navigation coordinate system (the rotational velocity of the vehicle coordinate system relative to the reference coordinate system). (·×) is a matrix that transforms the angular velocity vector ω into an antisymmetric matrix (also called a cross product matrix) to represent the rotational effect. The main inertial navigation attitude matrix, This is the updated master inertial navigation attitude matrix.

[0062] Specifically, when a strapdown inertial navigation system is started, a precise initial alignment process is required to determine the initial attitude of the MINS. This is typically accomplished through static or dynamic initialization methods.

[0063] When the carrier is stationary, the initial attitude matrix is ​​calculated using gravity and the geomagnetic field as references.

[0064] If the carrier is in motion, more complex dynamic initialization can be performed using auxiliary information such as GPS and visual sensors.

[0065] In one specific embodiment, based on the master inertial navigation attitude matrix, a transfer alignment error model is established using a relative attitude matrix, including:

[0066]

[0067] In the formula, This is the updated master inertial navigation attitude matrix. For the sub-inertial navigation attitude matrix, The relative attitude matrix;

[0068] Specifically, relative attitude matrix The relative attitude between the main inertial navigation coordinate system m and the sub-inertial navigation coordinate system s is described;

[0069] Specifically, to extract the attitude error as a state variable from the relative attitude matrix, a chain decomposition method can be used. In particular, when considering time-varying deformation angles, the relative attitude matrix can be decomposed into a constant part and a time-varying part.

[0070] For relative attitude matrix When performing chain decomposition and considering time-varying deformation angles, the relative attitude matrix... Given a time-varying matrix, chain decomposition yields:

[0071]

[0072] In the formula, is a constant attitude matrix, where m0 and s0 represent the inertial coordinate systems obtained by freezing the principal and child inertial conductor coordinate systems at the initial moment, respectively;

[0073] Among them, the time-varying attitude matrix and The angular velocities output by the primary and secondary inertial gyroscopes are obtained by integrating the attitude matrix differential equation:

[0074]

[0075] In the formula, Main inertial angular velocity, For the sub-inertial angular velocity;

[0076] Specifically, because the accuracy of the sub-inertial navigation system is relatively low, It contains errors, that is... lead to It also contains errors, denoted as Its error angle φ s It can be modeled as a linear differential equation, that is, the attitude matrix and error angle are listed as state variables, and a non-singular linear propagation alignment error model is established under any installation error angle:

[0077]

[0078] In the formula, is the sub-inertial angular velocity. The error, Time-varying attitude matrix The error, φ s This is the error angle.

[0079] Specifically, the relative attitude matrix is ​​decomposed into a constant part and a time-varying part using a chain decomposition method. The attitude matrix is ​​updated using the angular velocity output from the gyroscope. The error of the sub-inertial navigation angular velocity is considered and modeled as a linear differential equation. Through these steps, the state information of the flexible arm can be effectively obtained, and the model for propagating alignment errors can be optimized.

[0080] In one specific embodiment, obtaining the flexible lever state information and optimizing the transmission alignment error model includes:

[0081] Establish the vector representation from inertial coordinate system i to sub-inertial navigation coordinate system s:

[0082]

[0083] In the formula, This represents the vector from inertial coordinate system i to principal inertial navigation coordinate system m; This represents the vector from the main inertial navigation coordinate system m to the sub-inertial navigation coordinate system s; This represents the rotation matrix from the principal inertial coordinate system m to the inertial coordinate system i; This represents the vector from inertial coordinate system i to sub-inertial navigation coordinate system s.

[0084] Establish a vector representation from the navigation coordinate system e to the sub-inertial navigation coordinate system s:

[0085]

[0086] In the formula, This represents the vector from the navigation coordinate system e to the main inertial navigation coordinate system m. This represents the rotation matrix from the master inertial navigation coordinate system m to the navigation coordinate system e; The vector representing the distance from the primary inertial navigation coordinate system m to the secondary inertial navigation coordinate system s; The vector from the navigation coordinate system e to the sub-inertial navigation coordinate system s.

[0087] While considering the time-varying nature of the flexible arm, the derivative of the vector representation is obtained as follows:

[0088]

[0089] And define the lever arm velocity in the i-frame as:

[0090]

[0091] Similarly, we can conclude that:

[0092]

[0093] because and The projected coordinate system in the image is consistent with the reference coordinate system, so it can be denoted as... and in, and This is called absolute velocity. and This is called the navigation velocity in the e-frame, or relative velocity. In summary, the linear differential equation for velocity in the navigation coordinate system can be obtained as follows:

[0094] Represented as:

[0095]

[0096] In the formula, This represents the rate of change of the velocity error in the navigation coordinate system e; This represents the rate of change of velocity of the sub-inertial navigation coordinate system s in the navigation coordinate system e; This represents the rate of change of velocity of the sub-inertial coordinate system s in the inertial coordinate system i; Represents the relative attitude matrix The estimated value in navigation coordinate system e; This represents the estimated force vector value in the navigation coordinate system e; Represents the relative attitude matrix The actual value in navigation coordinate system e; φ represents the true force vector in the navigation coordinate system e; I3 represents the attitude error angle; (·×) represents the antisymmetric matrix operator.

[0097] Specifically, this embodiment first defines the velocities in each coordinate system:

[0098] The velocity of the sub-inertial navigation system in inertial coordinate system i;

[0099] The velocity of the sub-inertial navigation system in navigation coordinate system e.

[0100] Based on vector relationships and the definition of velocity, we can obtain:

[0101]

[0102]

[0103] Furthermore, in order to establish a speed error model, this embodiment needs to consider the rate of change of speed error. That is, the velocity error of the sub-inertial navigation system in the navigation coordinate system e. The velocity error model can be expressed as:

[0104]

[0105] Expanding further, we get:

[0106]

[0107] in, This is an estimate of the relative attitude matrix in the navigation coordinate system e; This is the estimated force vector value in the navigation coordinate system e; This represents the true value of the relative attitude matrix in the navigation coordinate system e; Let be the actual force vector in the navigation coordinate system e.

[0108] The final linear differential equation for velocity in the navigation coordinate system can be expressed as:

[0109]

[0110] After simplification, we get:

[0111]

[0112] Specifically, through the above steps, the present invention can systematically derive the linear differential equation of velocity in the navigation coordinate system, which can be used to optimize the model for transferring alignment errors.

[0113] In one specific embodiment, by implementing all the above steps, the accuracy, stability, and reliability of the model are ensured. This includes:

[0114] First, the coordinate system of the strapdown inertial navigation system (SINS) is obtained to determine the initial position and attitude of the main inertial navigation system (MINS) and the sub-inertial navigation system (SINS). Specifically, a high-precision initialization process, such as static or dynamic initialization, is used to determine the initial state of the carrier coordinate system i and the navigation coordinate system e. Then, the initial position and attitude of the main inertial navigation system m and the sub-inertial navigation system s are determined.

[0115] Then, the master inertial navigation attitude matrix is ​​determined. An accurate master inertial navigation attitude matrix is ​​obtained by measuring angular velocity using a high-precision gyroscope and updating the attitude matrix using differential equations. Kalman filtering or other estimation methods are combined with external observations provided by auxiliary sensors (such as accelerometers, magnetometers, and GPS) for error compensation and correction. This ensures real-time updates of the attitude matrix to reflect the most accurate attitude information.

[0116] Secondly, based on the master inertial navigation system's attitude matrix, a transfer alignment error model is established using a relative attitude matrix. This model can handle installation error angles of arbitrary sizes while ensuring non-singularity. Specifically, a relative attitude matrix is ​​defined to describe the relative attitude between the master and sub-inertial navigation systems. The relative attitude matrix is ​​decomposed into a chain reaction, dividing it into a constant part and a time-varying part. The error angle of the attitude matrix is ​​listed as one of the state variables, and a linear differential equation is established to ensure the non-singularity of the model.

[0117] The state information of the flexible arm is acquired again, and the alignment error model is optimized. Considering the existence and dynamic changes of the flexible arm, the velocity error equation is optimized. Specifically, the representation of the vector from the main inertial navigation system to the sub-inertial navigation system in inertial coordinate system i is defined. The time-varying nature of the flexible arm is considered, and the arm velocity is defined. A linear differential equation for velocity in the navigation coordinate system is constructed, and the velocity vector of the sub-inertial navigation system is updated in real time by combining the definition of navigation velocity and the velocity error equation. This also includes acquiring information affecting the deformation of the mechanical structure through environmental monitoring equipment (such as temperature sensors) and developing a real-time monitoring system for compensation.

[0118] Finally, the transfer alignment of the strapdown inertial navigation system is realized based on the optimized transfer alignment error model. The optimized transfer alignment error model is applied to improve the alignment accuracy and robustness of the strapdown inertial navigation system.

[0119] On the other hand, see Figure 2 The present invention also discloses a non-singular linear transfer alignment system based on a relative attitude matrix, comprising:

[0120] Initialization module: Obtains the coordinate system of the strapdown inertial navigation system and determines the attitude matrix of the main inertial navigation system;

[0121] Model building module: Based on the master inertial navigation attitude matrix, a model for transferring alignment error is established using the relative attitude matrix;

[0122] Model optimization module: Acquires the state information of the flexible lever arm and optimizes the model for transmitting alignment errors;

[0123] Transfer alignment module: Implements transfer alignment of the strapdown inertial navigation system based on the optimized transfer alignment error model.

[0124] This invention enhances the robustness and accuracy of the transfer alignment model, ensuring stable and reliable alignment results even in the face of large installation error angles or complex dynamic environments; it improves the accuracy of velocity error estimation, providing an effective solution, especially for the additional challenges brought about by flexible connection structures; it simplifies algorithm design, reduces computational complexity, and facilitates rapid deployment and implementation in engineering practice; it enhances the overall system's anti-interference capability and long-term stability, providing a solid foundation for multi-sensor fusion.

[0125] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0126] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A non-singular linear transfer alignment method based on a relative attitude matrix, characterized in that, Includes the following steps: Obtain the coordinate system of the strapdown inertial navigation system carrier and determine the main inertial navigation attitude matrix; Based on the main inertial navigation attitude matrix, a transfer alignment error model is established using the relative attitude matrix; the flexible lever state information is obtained, and the transfer alignment error model is optimized; the transfer alignment of the strapdown inertial navigation system is realized based on the optimized transfer alignment error model. The step of acquiring the flexible lever state information and optimizing the transmission alignment error model includes: Establish a vector representation from inertial coordinate system i to sub-inertial navigation coordinate system s; Establish a vector representation from the navigation coordinate system e to the sub-inertial navigation coordinate system s; While considering the time-varying nature of the flexible lever arm, the vector representation is differentiated; Define the velocity in each coordinate system and establish the velocity-vector relationship; Establish a velocity error model based on velocity and vector relationships; Based on the velocity error model, the linear differential equation of velocity in the final navigation coordinate system is obtained, which is the optimized transfer alignment error model.

2. The non-singular linear transfer alignment method based on a relative attitude matrix according to claim 1, characterized in that, The process of obtaining the carrier coordinate system of the strapdown inertial navigation system and determining the main inertial navigation attitude matrix includes: When the strapdown inertial navigation system is stationary, gravity and the geomagnetic field are used as references to calculate the initial attitude matrix; When the strapdown inertial navigation system is in motion, it acquires angular velocity data and updates the attitude matrix using differential equations based on the angular velocity data, thereby determining the main inertial navigation attitude matrix.

3. The non-singular linear transfer alignment method based on a relative attitude matrix according to claim 2, characterized in that, When the strapdown inertial navigation system is in motion, it acquires angular velocity data and uses differential equations based on this data. To update the pose matrix, where, It is the angular velocity vector transformed into the navigation coordinate system. ) indicates rotational action. The main inertial navigation attitude matrix, This is the updated master inertial navigation attitude matrix.

4. The non-singular linear transfer alignment method based on a relative attitude matrix according to claim 1, characterized in that, Based on the master inertial navigation attitude matrix, a model for transferring alignment error is established using the relative attitude matrix, including: In the formula, This is the updated master inertial navigation attitude matrix. For the sub-inertial navigation attitude matrix, The relative attitude matrix; For relative attitude matrix When performing chain decomposition and considering time-varying deformation angles, the relative attitude matrix... Given a time-varying matrix, chain decomposition yields: In the formula, and These represent the inertial coordinate systems obtained by solidifying the principal and child inertial conductor coordinate systems at the initial moment, respectively. Among them, the time-varying attitude matrix and The angular velocities output by the primary and secondary inertial gyroscopes are obtained by integrating the attitude matrix differential equation: In the formula, Main inertial angular velocity, For the sub-inertial angular velocity; By listing the attitude matrix and error angle as state variables, a non-singular linear propagation alignment error model is established under any installation error angle: in, Time-varying attitude matrix The error, This is the error angle.

5. The non-singular linear transfer alignment method based on a relative attitude matrix according to claim 1, characterized in that, The vector representation of the distance from the inertial coordinate system i to the sub-inertial navigation coordinate system s is established as follows: In the formula, This represents the vector from inertial coordinate system i to principal inertial navigation coordinate system m; This represents the vector from the main inertial navigation coordinate system m to the sub-inertial navigation coordinate system s; This represents the rotation matrix from the principal inertial coordinate system m to the inertial coordinate system i; This represents the vector from inertial coordinate system i to sub-inertial navigation coordinate system s.

6. The non-singular linear transfer alignment method based on a relative attitude matrix according to claim 5, characterized in that, The vector representation of the distance from the navigation coordinate system e to the sub-inertial navigation coordinate system s is established as follows: In the formula, This represents the vector from the navigation coordinate system e to the main inertial navigation coordinate system m. This represents the rotation matrix from the master inertial navigation coordinate system m to the navigation coordinate system e; The vector representing the distance from the primary inertial navigation coordinate system m to the secondary inertial navigation coordinate system s; The vector from the navigation coordinate system e to the sub-inertial navigation coordinate system s.

7. The non-singular linear transfer alignment method based on a relative attitude matrix according to claim 6, characterized in that, Based on the velocity error model, the final linear differential equation of velocity in the navigation coordinate system is expressed as: In the formula, This represents the rate of change of the velocity error in the navigation coordinate system e; This represents the rate of change of velocity of the sub-inertial navigation coordinate system s in the navigation coordinate system e; This represents the rate of change of velocity of the sub-inertial coordinate system s in the inertial coordinate system i; Represents the relative attitude matrix The estimated value in navigation coordinate system e; This represents the estimated force vector value in the navigation coordinate system e; Represents the relative attitude matrix The actual value in navigation coordinate system e; This represents the actual force vector in the navigation coordinate system e; Indicates the attitude error angle; Represents a 3x3 identity matrix; ) represents the antisymmetric matrix operator.

8. The system of the non-singular linear transfer alignment method based on the relative attitude matrix according to any one of claims 1-7, characterized in that, include: Initialization module: used to obtain the coordinate system of the strapdown inertial navigation system and determine the attitude matrix of the main inertial navigation system; Model building module: used to build a model for propagating alignment errors based on the master inertial navigation attitude matrix and using the relative attitude matrix; Model optimization module: used to acquire the state information of the flexible lever arm and optimize the model for transferring alignment errors; Transfer alignment module: used to achieve transfer alignment of strapdown inertial navigation systems based on an optimized transfer alignment error model.

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