Inertial navigation system installation error correction method, system, and storage medium

Abstract

The present invention provides an inertial navigation system installation error correction method, system, and storage medium. The correction method includes: obtaining the measured three-component magnetic field value and attitude data of a strapdown three-component magnetic measurement system after attitude change; constructing an attitude transformation Euler angle rotation matrix and an installation error Euler angle rotation matrix; building a conversion model, and constructing a trajectory equation based on the conversion model; using the Z axis of the geographic coordinate system as a preset normal vector, and constructing an objective function of the installation error according to a number of line vectors on the trajectory equation and the preset normal vector; minimizing the objective function, obtaining the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, so as to complete the correction of the inertial navigation system installation error. The inertial navigation system installation error correction method provided by the present application is simple and accurate in calibration.

Description

Technical Field

[0001] The present invention relates to the field of measurement and calibration technology, and in particular to an inertial navigation system installation error correction method, system and storage medium. Background Art

[0002] The three-component data of the geomagnetic field obtained by the three-component magnetic measurement system can provide vector magnetic field information compared to traditional total field measurement. The vector magnetic field information contains more magnetic field characteristics and is widely used in resource exploration and positioning, underwater magnetic anomaly target positioning, underwater geomagnetic matching navigation and many other aspects.

[0003] The three-component magnetic measurement system is generally composed of an inertial navigation system, a three-axis magnetometer and a carrier rigidly connected. The inertial navigation system provides attitude data for the three-axis magnetometer. Specifically, the inertial navigation system provides attitude data to restore the three-component magnetic measurement data to a geographic coordinate. After the strapdown three-component magnetic measurement system is installed, since the three axes of the three-axis magnetometer and the inertial navigation system cannot be visualized, the mechanical installation cannot be fully aligned, resulting in the attitude provided by the inertial navigation system not matching the actual attitude of the three-axis magnetometer; since the sensitive axes of these instruments are internal, physical calibration is difficult to achieve with high precision, and there will be attitude deviation when the three-component data is converted to the geographic coordinate system, that is, there is a rotation relationship between the two coordinate systems, which can be expressed by Euler angles; theoretically, this deviation will result in errors of the order of thousands of nT, so correction is essential for obtaining accurate three-component magnetic field data.

[0004] At present, the conventional calibration method is to set a random auxiliary vector, obtain two sets of magnetic field data rotating around different axes by rotating the turntable, and use the relationship that the plane of the magnetic measurement data after the coordinate system conversion is parallel to the plane of the obtained auxiliary correction data to construct an objective function to fit and solve the installation error angle. The main limitations of the conventional calibration method are as follows: 1. The selection of auxiliary vectors will affect the accuracy of error calibration; 2. Due to the specific requirements of the experiment, experimental data is difficult to obtain, and the existing method requires multiple rotations around different axes; 3. A non-magnetic turntable is usually required, and its accuracy may affect the calibration results. 4. The experimental conditions are very high, and multiple rotations around the axis are required, and the amount of data required is large. If the strapdown magnetic measurement system does not strictly rotate around a certain axis, the correction effect will be greatly reduced, and the practicality is low. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide an inertial navigation system installation error correction method, system, storage medium and computer to solve the technical problems existing in the prior art.

[0006] The present invention provides an inertial navigation system installation error correction method, which is used to correct the installation error of a strapdown three-component magnetic measurement system formed by assembling an inertial navigation system and a three-axis magnetometer. The installation error correction method comprises:

[0007] Acquire the measured three-component magnetic field value of the three-axis magnetometer and the attitude data of the inertial navigation system after the strapdown three-component magnetic measurement system changes its attitude;

[0008] Constructing a posture transformation Euler angle rotation matrix based on the posture data, and constructing an installation error Euler angle rotation matrix;

[0009] Constructing a conversion model based on the measured three-component magnetic field value, the installation error Euler angle rotation matrix, the attitude transformation Euler angle rotation matrix, and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and constructing a trajectory equation based on the conversion model;

[0010] Taking the Z axis of the geographic coordinate system as a preset normal vector, constructing an objective function of the installation error according to a number of line vectors on the trajectory equation and the preset normal vector;

[0011] The objective function is minimized and solved to obtain attitude data deviation and standard three-component magnetic field values ​​in the area where the strapdown three-component magnetic measurement system is located, so as to complete the correction of the installation error of the inertial navigation system.

[0012] Optionally, the expression of the posture transformation Euler angle rotation matrix is:

[0013]

[0014]

[0015]

[0016]

[0017] In the formula, is the Euler angle rotation matrix for posture transformation, , , are respectively the heading angle, pitch angle, and roll angle in the attitude data;

[0018] The expression of the installation error Euler angle rotation matrix is:

[0019]

[0020]

[0021]

[0022]

[0023] In the formula, is the installation error Euler angle rotation matrix, is the heading angle deviation, is the pitch angle deviation, is the roll angle deviation.

[0024] Optionally, the expression of the conversion model is:

[0025] In the formula, is the measured three-component magnetic field value, is the joint rotation matrix, is the Euler angle rotation matrix for posture transformation, is the standard three-component magnetic field value;

[0026] The expression of the trajectory equation is:

[0027] 。

[0028] Optionally, the step of taking the Z axis of the geographic coordinate system as a preset normal vector and constructing an objective function of the installation error according to a plurality of line vectors on the trajectory equation and the preset normal vector is:

[0029] Acquire at least three trajectory points on the trajectory equation, and construct a trajectory plane based on the at least three trajectory points;

[0030] Performing pairwise differences on the trajectory points on the trajectory plane to obtain a number of line vectors on the trajectory plane;

[0031] The preset normal vector is respectively subjected to vector product operations with a number of the line vectors and the sum is calculated to construct an objective function of the installation error.

[0032] Optionally, the objective function is expressed as:

[0033]

[0034] In the formula, is the preset normal vector, is the first Line vectors, is the trajectory plane Track points, is the number of trajectory points selected in the trajectory plane.

[0035] Optionally, the step of minimizing the objective function, obtaining the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and completing the correction of the inertial navigation system installation error includes:

[0036] Minimizing the objective function, when the objective function reaches a minimum value, the trajectory plane is perpendicular to the Z axis of the geographic coordinate system;

[0037] Solving and calculating the corresponding installation error Euler angle rotation matrix based on the minimum value of the objective function;

[0038] Performing several posture adjustments on the strapdown three-component magnetic measurement system to solve several corresponding installation error Euler angle rotation matrices;

[0039] Using a nonlinear least square method to optimize the parameters of a plurality of the installation error Euler angle rotation matrices, and performing coincidence restoration on the installation error Euler angle rotation matrices after the parameter optimization;

[0040] The standard three-component magnetic field value and the heading angle deviation between the inertial navigation system and the three-axis magnetometer are obtained according to the result after the overlap restoration. , Pitch angle deviation , Roll angle deviation , in order to complete the correction of the installation error of the inertial navigation system.

[0041] The present invention also provides an inertial navigation system installation error correction system, comprising:

[0042] The first acquisition module is used to obtain the measured three-component magnetic field value of the three-axis magnetometer and the attitude data of the inertial navigation system after the strapdown three-component magnetic measurement system changes its attitude;

[0043] A first construction module is used to construct a posture transformation Euler angle rotation matrix based on the posture data and to construct an installation error Euler angle rotation matrix;

[0044] A second construction module is used to construct a conversion model based on the measured three-component magnetic field value, the installation error Euler angle rotation matrix, the attitude transformation Euler angle rotation matrix and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and construct a trajectory equation based on the conversion model;

[0045] A third construction module is used to use the Z axis of the geographic coordinate system as a preset normal vector and construct an objective function of the installation error according to a plurality of line vectors on the trajectory equation and the preset normal vector;

[0046] The correction module is used to minimize the objective function, obtain the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, so as to complete the correction of the installation error of the inertial navigation system.

[0047] The present invention also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned inertial navigation system installation error correction method is implemented.

[0048] The present invention also proposes a computer, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned inertial navigation system installation error correction method when executing the computer program.

[0049] Compared with the prior art, the invention has the following beneficial effects: the inertial navigation system installation error correction method provided by the present application utilizes the data of the magnetic measurement system collected under random posture to replace the existing specific rotation mode, constructs an objective function based on the Euler rotation characteristic according to a specific axis, and estimates the installation error parameters, the parameters are represented by Euler angles and a correction operation is performed, and after eliminating the error of mechanical installation, the geomagnetic three-component values ​​in the geographic coordinate system of the current position can be restored; no turntable or auxiliary vector is required to eliminate the introduced error, and after forming a strapdown three-component measurement system, any posture synchronous measurement of the inertial navigation system and the three-axis fluxgate data in multiple heading angle directions can be performed to complete the fitting calculation, and compared with the prior method, the data tolerance is high, and the three-axis magnetometer self-error calibration can be performed after the strapdown three-component magnetic measurement system is installed, and the installation error correction is directly performed using the same set of data, and there is no need to obtain data through two experiments, the process is simple, easy to implement in engineering, and the accuracy is high, and it is suitable for large-scale promotion.

[0050] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A flowchart of an inertial navigation system installation error correction method in a first embodiment of the present invention;

[0052] Figure 2 A schematic diagram of the coordinate system deviation in the first embodiment of the present invention;

[0053] Figure 3 A schematic diagram of trajectory points before and after correction in the first embodiment of the present invention;

[0054] Figure 4 It is a schematic diagram of the simulation of the magnetic field in the X direction before and after correction in the first embodiment of the present invention;

[0055] Figure 5A schematic diagram of the Y-direction magnetic field simulation before and after correction in the first embodiment of the present invention;

[0056] Figure 6 A schematic diagram of the magnetic field simulation in the Z direction before and after correction in the first embodiment of the present invention;

[0057] Figure 7 FIG. 4 is a structural block diagram of a computer in a fourth embodiment of the present invention.

[0058] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0059] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0061] Embodiment 1

[0062] See also Figure 1 , shown is an inertial navigation system installation error correction method in the first embodiment of the present invention, which is used to correct the installation error of a strapdown three-component magnetic measurement system formed by assembling an inertial navigation system and a three-axis magnetometer. The inertial navigation system installation error correction method specifically includes steps S10 to S50:

[0063] S10, obtaining the measured three-component magnetic field value of the three-axis magnetometer and the attitude data of the inertial navigation system after the strapdown three-component magnetic measurement system changes its attitude;

[0064] In the specific implementation, a non-magnetic plate can be selected, the inertial navigation system and the three-axis magnetometer can be rigidly fixed on the plate and roughly aligned; the attitude data of the inertial navigation system can be obtained, and the attitude data mainly includes the heading angle , Pitch angle , Roll Angle ,The attitude change of the strapdown three-component magnetic measurement system will cause the attitude change of the ,sensitive axis of the three-axis magnetometer, which in turn causes the measurement value of the ,three-axis magnetometer and the attitude data of the inertial navigation system to change.

[0065] S20, constructing a posture transformation Euler angle rotation matrix based on the posture data, and constructing an installation error Euler angle rotation matrix;

[0066] The expression of the posture transformation Euler angle rotation matrix is:

[0067]

[0068]

[0069]

[0070]

[0071] In the formula, is the Euler angle rotation matrix for posture transformation, , , are respectively the heading angle, pitch angle, and roll angle in the attitude data;

[0072] The expression of the installation error Euler angle rotation matrix is:

[0073]

[0074]

[0075]

[0076]

[0077] In the formula, is the installation error Euler angle rotation matrix, is the heading angle deviation, is the pitch angle deviation, is the roll angle deviation.

[0078] S30, constructing a conversion model based on the measured three-component magnetic field value, the installation error Euler angle rotation matrix, the attitude transformation Euler angle rotation matrix, and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and constructing a trajectory equation based on the conversion model;

[0079] Optionally, in this implementation, if the installation error is not considered, the three-component data of the three-axis magnetometer can be obtained theoretically by converting the attitude angle of the inertial navigation system to the geographic coordinate system in reverse order of ZXY:

[0080]

[0081] In the formula, each parameter is similar to the above parameters and will not be repeated here;

[0082] Due to the existence of installation errors, there is a deviation between the attitude data provided by the inertial navigation system and the actual data of the three-axis magnetometer, mainly including: heading angle deviation , pitch angle deviation and roll angle deviation The deviation between the inertial navigation system coordinate system and the three-axis magnetometer coordinate system after installation is as follows: Figure 2 As shown, the heading angle deviation , pitch angle deviation and roll angle deviation After the system is installed, it is a fixed value. Therefore, in this embodiment, it is necessary to solve the heading angle deviation , pitch angle deviation and roll angle deviation To perform error calibration and improve the measurement accuracy of the strapdown three-component magnetic measurement system.

[0083] In this implementation, the attitude change of the inertial navigation system and the three-axis magnetometer is equivalent to the superposition of two rotation matrices. .

[0084] Therefore, the expression of the actual measurement data conversion model of the three-axis magnetometer is:

[0085] In the formula, is the measured three-component magnetic field value, is the Euler angle rotation matrix for posture transformation, is the standard three-component magnetic field value; Although it is also a fixed value, it varies from place to place. is not the same. When the strapdown three-component magnetic measurement system moves, the new position With the original position are not the same, so it is determined in the area where the strapdown three-component magnetic measurement system is located, and its corresponding It also needs to be solved.

[0086] based on The inverse transformation of the expression can be obtained:

[0087]

[0088] Set up the track: .

[0089] S40, using the Z axis of the geographic coordinate system as a preset normal vector, and constructing an objective function of the installation error according to a plurality of line vectors on the trajectory equation and the preset normal vector;

[0090] The step of using the Z axis of the geographic coordinate system as a preset normal vector and constructing an objective function of the installation error according to a number of line vectors on the trajectory equation and the preset normal vector is:

[0091] Acquire at least three trajectory points on the trajectory equation, and construct a trajectory plane based on the at least three trajectory points;

[0092] Performing pairwise differences on the trajectory points on the trajectory plane to obtain a number of line vectors on the trajectory plane;

[0093] The preset normal vector is respectively subjected to vector product operations with a number of the line vectors and the sum is calculated to construct an objective function of the installation error.

[0094] The expression of the objective function is:

[0095]

[0096] In the formula, is the preset normal vector, is the first Line vectors, is the trajectory plane Track points, is the number of trajectory points selected in the trajectory plane.

[0097] S50, minimizing the objective function to obtain attitude data deviation and standard three-component magnetic field values ​​in the area where the strapdown three-component magnetic measurement system is located, so as to correct the installation error of the inertial navigation system.

[0098] The step of minimizing the objective function, obtaining the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and completing the correction of the inertial navigation system installation error includes:

[0099] Minimizing the objective function, when the objective function reaches a minimum value, the trajectory plane is perpendicular to the Z axis of the geographic coordinate system;

[0100] Solving and calculating the corresponding installation error Euler angle rotation matrix based on the minimum value of the objective function;

[0101] Performing several posture adjustments on the strapdown three-component magnetic measurement system to solve several corresponding installation error Euler angle rotation matrices;

[0102] Using a nonlinear least square method to optimize the parameters of a plurality of the installation error Euler angle rotation matrices, and performing coincidence restoration on the installation error Euler angle rotation matrices after the parameter optimization;

[0103] The standard three-component magnetic field value and the heading angle deviation between the inertial navigation system and the three-axis magnetometer are obtained according to the result after the overlap restoration. , Pitch angle deviation , Roll angle deviation , in order to complete the correction of the installation error of the inertial navigation system.

[0104] In the specific implementation, the Z axis of the geographic coordinate system is used as the preset normal vector. Select three track points on , , , construct line vectors by pairwise differences;

[0105]

[0106]

[0107] By constructing a differential data set model, the available data set is expanded and the common mode error is reduced; the minimum value of the above objective function is zero, and the objective function takes the minimum value, that is: =0 .

[0108] When the objective function takes the minimum value, it means that the preset normal vector Z axis is perpendicular to all line vectors of the trajectory plane. It can be understood that the vector perpendicular to the plane is also perpendicular to all lines on the plane; therefore, the Z axis is also perpendicular to the trajectory plane, and the trajectory is the trajectory of rotation around the Z axis; solve the minimum value of the objective function. Theoretically, when all error coefficients are accurately solved, the error is zero; this condition can be used to calculate the installation error Euler angle rotation matrix included , and then make several posture adjustments to solve the corresponding , using the nonlinear least squares (NLS) function Optimize the parameters, solve the installation error expressed by Euler angle between the three-axis magnetometer coordinate system and the inertial navigation system coordinate system, perform conversion and overlap restoration, and then solve the heading angle deviation in turn , Pitch angle deviation , Roll angle deviation , joint rotation matrix , the standard three-component magnetic field value at the current position , so as to achieve the installation error correction effect, such as Figure 3 As shown, the trajectory point , , Forming a track is the trajectory surface before correction, and the trajectory point , , The trajectory formed is the corrected trajectory surface.

[0109] Further, in this embodiment, the inertial navigation system installation error correction method provided by the present invention is simulated by MATLAB function, and the simulation data is set as follows: the geomagnetic field is stable in a short time, assuming that the background geomagnetic field ; The magnetic field measurement value is in nT; The heading angle a is taken as 361 random numbers between 0 and 360º, the pitch angle b is taken as 361 random numbers between -180º and 180º, and the roll angle c is taken as 361 random numbers between -180º and 180º; The installation error is set as: At the same time, in order to simulate the real environment, Gaussian white noise with a mean of 0 and a variance of 1 is added In the simulation results, the maximum deviation between the estimated value of the installation error and the set value is 0.0003. Figures 4 to 6 As shown, after error correction, the three-component magnetic field values ​​on the X, Y, and Z axes of the geographic coordinate system dropped from 22139nT, 13881nT, and 19619nT to 3.14nT, 3.1nT, and 3.15nT, respectively.

[0110] In summary, the inertial navigation system installation error correction method provided by the present application utilizes the data of the magnetic measurement system collected under random postures to replace the existing specific rotation mode, constructs an objective function based on the Euler rotation characteristics according to a specific axis, and estimates the installation error parameters. The parameters are expressed in Euler angles and correction operations are performed. After eliminating the error of mechanical installation, the three-component value of the geomagnetic field in the geographic coordinate system of the current position can be restored; no turntable or auxiliary vector is required to eliminate the introduced error, and after forming a strapdown three-component measurement system, any posture synchronous measurement of the inertial navigation system and the three-axis fluxgate data in multiple heading angle directions can be performed to complete the fitting calculation. Compared with the existing method, it has high data tolerance, and the three-axis magnetometer itself can be calibrated after the strapdown three-component magnetic measurement system is installed, and the installation error correction is directly performed using the same set of data, without the need to obtain data twice through experiments, the process is simple, easy to implement in engineering, and has high accuracy.

[0111] Embodiment 2

[0112] This embodiment provides an inertial navigation system installation error correction system, including:

[0113] The first acquisition module is used to obtain the measured three-component magnetic field value of the three-axis magnetometer and the attitude data of the inertial navigation system after the strapdown three-component magnetic measurement system changes its attitude;

[0114] A first construction module is used to construct a posture transformation Euler angle rotation matrix based on the posture data and to construct an installation error Euler angle rotation matrix;

[0115] A second construction module is used to construct a conversion model based on the measured three-component magnetic field value, the installation error Euler angle rotation matrix, the attitude transformation Euler angle rotation matrix and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and construct a trajectory equation based on the conversion model;

[0116] A third construction module is used to use the Z axis of the geographic coordinate system as a preset normal vector and construct an objective function of the installation error according to a plurality of line vectors on the trajectory equation and the preset normal vector;

[0117] The correction module is used to minimize the objective function, obtain the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, so as to complete the correction of the installation error of the inertial navigation system.

[0118] The expression of the posture transformation Euler angle rotation matrix is:

[0119]

[0120]

[0121]

[0122]

[0123] In the formula, is the Euler angle rotation matrix for posture transformation, , , are respectively the heading angle, pitch angle, and roll angle in the attitude data;

[0124] The expression of the installation error Euler angle rotation matrix is:

[0125]

[0126]

[0127]

[0128]

[0129] In the formula, is the installation error Euler angle rotation matrix, is the heading angle deviation, is the pitch angle deviation, is the roll angle deviation.

[0130] The expression of the conversion model is:

[0131] In the formula, is the measured three-component magnetic field value, is the joint rotation matrix, is the Euler angle rotation matrix for posture transformation, is the standard three-component magnetic field value;

[0132] The expression of the trajectory equation is:

[0133] 。

[0134] The step of using the Z axis of the geographic coordinate system as a preset normal vector and constructing an objective function of the installation error according to a number of line vectors on the trajectory equation and the preset normal vector is:

[0135] Acquire at least three trajectory points on the trajectory equation, and construct a trajectory plane based on the at least three trajectory points;

[0136] Performing pairwise differences on the trajectory points on the trajectory plane to obtain a number of line vectors on the trajectory plane;

[0137] The preset normal vector is respectively subjected to vector product operations with a number of the line vectors and the sum is calculated to construct an objective function of the installation error.

[0138] The expression of the objective function is:

[0139]

[0140] In the formula, is the preset normal vector, is the first Line vectors, is the trajectory plane Track points, is the number of trajectory points selected in the trajectory plane.

[0141] The step of minimizing the objective function, obtaining the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and completing the correction of the inertial navigation system installation error includes:

[0142] Minimizing the objective function, when the objective function reaches a minimum value, the trajectory plane is perpendicular to the Z axis of the geographic coordinate system;

[0143] Solving and calculating the corresponding installation error Euler angle rotation matrix based on the minimum value of the objective function;

[0144] Performing several posture adjustments on the strapdown three-component magnetic measurement system to solve several corresponding installation error Euler angle rotation matrices;

[0145] Using a nonlinear least square method to optimize the parameters of a plurality of the installation error Euler angle rotation matrices, and performing coincidence restoration on the installation error Euler angle rotation matrices after the parameter optimization;

[0146] The standard three-component magnetic field value and the heading angle deviation between the inertial navigation system and the three-axis magnetometer are obtained according to the result after the overlap restoration. , Pitch angle deviation , Roll angle deviation , in order to complete the correction of the installation error of the inertial navigation system.

[0147] Embodiment 3

[0148] This embodiment provides a storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned inertial navigation system installation error correction method is implemented.

[0149] Embodiment 4

[0150] The present invention also provides a computer, see Figure 7 , shown is a computer in an embodiment of the present invention, including a memory 10, a processor 20, and a computer program 30 stored in the memory 10 and executable on the processor 20. When the processor 20 executes the computer program 30, the above-mentioned inertial navigation system installation error correction method is implemented.

[0151] The memory 10 includes at least one type of storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory, etc.), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 10 may be an internal storage unit of a computer, such as a hard disk of the computer. In other embodiments, the memory 10 may also be an external storage device, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card, etc. Further, the memory 10 may also include both an internal storage unit of the computer and an external storage device. The memory 10 may be used not only to store application software and various types of data installed in the computer, but also to temporarily store data that has been output or is to be output.

[0152] Among them, in some embodiments, the processor 20 can be an electronic control unit (Electronic Control Unit, abbreviated as ECU, also known as a vehicle computer), a central processing unit (Central Processing Unit, CPU), a controller, a microcontroller, a microprocessor or other data processing chip, used to run the program code stored in the memory 10 or process data, such as executing access restriction programs, etc.

[0153] It should be pointed out that Figure 7 The structure shown does not constitute a limitation on the computer. In other embodiments, the computer may include fewer or more components than shown in the figure, or combine certain components, or arrange the components differently.

[0154] Those skilled in the art will appreciate that the logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For purposes of this specification, "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0155] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0156] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or a combination thereof: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0157] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0158] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for correcting the installation error of an inertial navigation system, used to correct the installation error of a strapdown three-component magnetic measurement system formed by assembling an inertial navigation system and a three-axis magnetometer, characterized in that: The installation error correction method comprises: Obtain the measured three-component magnetic field value of the three-axis magnetometer and the attitude data of the inertial navigation system after the strapdown three-component magnetic measurement system changes its attitude, the attitude data including: heading angle , Pitch angle , Roll Angle ; Constructing a posture transformation Euler angle rotation matrix based on the posture data, and constructing an installation error Euler angle rotation matrix; Constructing a conversion model based on the measured three-component magnetic field value, the installation error Euler angle rotation matrix, the attitude transformation Euler angle rotation matrix, and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and constructing a trajectory equation based on the conversion model; Taking the Z axis of the geographic coordinate system as a preset normal vector, constructing an objective function of the installation error according to a number of line vectors on the trajectory equation and the preset normal vector; Minimize the objective function to obtain the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, so as to complete the correction of the inertial navigation system installation error. The inertial navigation system installation error includes: heading angle deviation , Pitch angle deviation , Roll angle deviation ; The step of using the Z axis of the geographic coordinate system as a preset normal vector and constructing an objective function of the installation error according to a number of line vectors on the trajectory equation and the preset normal vector is: Acquire at least three trajectory points on the trajectory equation, and construct a trajectory plane based on the at least three trajectory points; Performing pairwise differences on the trajectory points on the trajectory plane to obtain a number of line vectors on the trajectory plane; Performing vector product operations on the preset normal vector and the plurality of line vectors respectively and summing the calculated values ​​to construct an objective function of the installation error; The expression of the objective function is: In the formula, is the preset normal vector, is the first Line vectors, is the trajectory plane Track points, is the number of trajectory points selected in the trajectory plane.

2. The method for correcting installation errors of an inertial navigation system according to claim 1, characterized in that: The expression of the posture transformation Euler angle rotation matrix is: In the formula, is the Euler angle rotation matrix for the attitude transformation, , , are respectively the heading angle, pitch angle, and roll angle in the attitude data; The expression of the installation error Euler angle rotation matrix is: In the formula, is the installation error Euler angle rotation matrix, is the heading angle deviation, is the pitch angle deviation, is the roll angle deviation.

3. The method for correcting installation errors of an inertial navigation system according to claim 2, characterized in that: The expression of the conversion model is: In the formula, is the measured three-component magnetic field value, is the joint rotation matrix, is the Euler angle rotation matrix for the attitude transformation, is the installation error Euler angle rotation matrix, is the standard three-component magnetic field value; The expression of the trajectory equation is: 。 4. The method for correcting installation errors of an inertial navigation system according to claim 1, characterized in that: The step of minimizing the objective function, obtaining the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and completing the correction of the inertial navigation system installation error includes: Minimizing the objective function, when the objective function reaches a minimum value, the trajectory plane is perpendicular to the Z axis of the geographic coordinate system; Solving and calculating the corresponding installation error Euler angle rotation matrix based on the minimum value of the objective function; Performing several posture adjustments on the strapdown three-component magnetic measurement system to solve several corresponding installation error Euler angle rotation matrices; Using a nonlinear least square method to optimize the parameters of a plurality of the installation error Euler angle rotation matrices, and performing coincidence restoration on the installation error Euler angle rotation matrices after the parameter optimization; The standard three-component magnetic field value and the heading angle deviation between the inertial navigation system and the three-axis magnetometer are obtained according to the result after the overlap restoration. , Pitch angle deviation , Roll angle deviation , in order to complete the correction of the installation error of the inertial navigation system.

5. An inertial navigation system installation error correction system, characterized in that: include: The first acquisition module is used to obtain the measured three-component magnetic field value of the three-axis magnetometer and the attitude data of the inertial navigation system after the strapdown three-component magnetic measurement system changes its attitude. The attitude data includes: heading angle , Pitch angle , Roll Angle ; A first construction module is used to construct a posture transformation Euler angle rotation matrix based on the posture data and to construct an installation error Euler angle rotation matrix; A second construction module is used to construct a conversion model based on the measured three-component magnetic field value, the installation error Euler angle rotation matrix, the attitude transformation Euler angle rotation matrix and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, and construct a trajectory equation based on the conversion model; A third construction module is used to use the Z axis of the geographic coordinate system as a preset normal vector and construct an objective function of the installation error according to a plurality of line vectors on the trajectory equation and the preset normal vector; The correction module is used to minimize the objective function, obtain the attitude data deviation and the standard three-component magnetic field value of the area where the strapdown three-component magnetic measurement system is located, so as to complete the correction of the inertial navigation system installation error. The inertial navigation system installation error includes: heading angle deviation , Pitch angle deviation , Roll angle deviation ; The step of using the Z axis of the geographic coordinate system as a preset normal vector and constructing an objective function of the installation error according to a number of line vectors on the trajectory equation and the preset normal vector is: Acquire at least three trajectory points on the trajectory equation, and construct a trajectory plane based on the at least three trajectory points; Performing pairwise differences on the trajectory points on the trajectory plane to obtain a number of line vectors on the trajectory plane; Performing vector product operations on the preset normal vector and the plurality of line vectors respectively and summing the calculated values ​​to construct an objective function of the installation error; The expression of the objective function is: In the formula, is the preset normal vector, is the first Line vectors, is the trajectory plane Track points, is the number of trajectory points selected in the trajectory plane.

6. A storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the inertial navigation system installation error correction method as described in any one of claims 1 to 4 is implemented.

7. A computer comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the inertial navigation system installation error correction method as described in any one of claims 1 to 4 is implemented.

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