Magnetometer measurement error calibration method and device, medium and electronic equipment

Abstract

The embodiment of the invention discloses a magnetometer measurement error calibration method and device, a medium and electronic equipment, and relates to the technical field of spacecraft attitude control, and the method comprises the steps: carrying out the deformation of a comprehensive error model, and defining a correction coefficient according to an error deformation mathematical model; obtaining an initial value of a correction coefficient based on a least square principle; and performing Gaussian Newton iteration on the initial value to obtain a target correction coefficient and an error between a correction value of the magnetic field measurement value and a standard magnetic field. According to the method, primary calibration of the measurement error of the magnetometer is realized through the comprehensive error model, the influence of the installation position deviation of the magnetometer on calibration in secondary calibration is avoided, the initial value is provided for iteration based on the least square principle, so that the iteration can be rapidly converged, the target correction coefficient is obtained, and the calibration precision is improved. Finally, the output of the magnetometer is corrected based on the correction coefficient, the error between the output and the standard magnetic field is obtained, rapid calibration of the measurement error of the magnetometer is achieved, and the calibration level of the measurement error of the three-axis magnetometer is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of spacecraft attitude control technology, and specifically to a magnetometer measurement error calibration method, device, medium and electronic equipment. Background Art

[0002] The three-axis magnetometer is used to measure the strength and direction of the geomagnetic field. Using the IGRF geomagnetic model, the attitude information of the satellite's two axes can be derived only based on the onboard three-axis magnetometer data. Due to its small size, light weight and low power consumption, it is often used as an attitude sensor for microsatellites. However, under normal circumstances, due to the limitations of its own design and processing technology, the magnetometer has instrument errors such as zero offset error, gain coefficient error and three-axis verticality error; at the same time, due to the limited volume and high-density layout of microsatellites, the interference magnetic field generated by the ferromagnetic materials on the satellite causes hard iron error and soft iron error, which also has a huge impact on the magnetometer readings.

[0003] Therefore, the three-axis magnetometer needs to be calibrated before use. However, the calibration level in the existing technology is relatively low. On the one hand, the interference compensation of the satellite-borne magnetometer needs to be carried out in the zero magnetic space, and the residual magnetism and magnetic induction are compensated separately, the test process and equipment are complicated, and the test cost is high; some methods propose to compensate the magnetometer in the geomagnetic field, which has low accuracy and is only applicable to traditional large satellites with small magnetic induction. This method is not applicable to micro satellites. Summary of the invention

[0004] The main purpose of the present application is to provide a magnetometer measurement error calibration method, device, medium and electronic equipment, aiming to solve the problem of low calibration level of three-axis magnetometer in the prior art.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a method for calibrating a magnetometer measurement error, comprising the following steps:

[0007] According to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the environmental magnetic field value at the target point, the comprehensive error model is deformed to obtain an error deformation model; wherein the comprehensive error model is established according to the measurement error of the magnetometer;

[0008] According to the error deformation mathematical model, the correction coefficient is defined;

[0009] Based on the least squares principle, the initial value of the correction coefficient is obtained;

[0010] Using singular value decomposition, the initial value is iterated based on Gauss-Newton to obtain the target correction coefficient;

[0011] According to the target correction coefficient, the error between the correction value of the magnetic field measurement value and the standard magnetic field is obtained to realize the calibration of the measurement error of the target magnetometer.

[0012] In a possible implementation of the first aspect, according to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the ambient magnetic field value of the target point, the comprehensive error model is deformed, and before obtaining the error deformation model, the method further includes:

[0013] According to the instrument error model and the compass error model, a comprehensive error model is obtained.

[0014] In a possible implementation manner of the first aspect, before obtaining the comprehensive error model according to the instrument error model and the compass error model, the method further includes:

[0015] An instrument error model is established based on the magnetic field measurement value, the angle between the three axes, the zero offset error of the three axes, and the three-axis gain coefficient error.

[0016] In a possible implementation manner of the first aspect, before obtaining the comprehensive error model according to the instrument error model and the compass error model, the method further includes:

[0017] A compass model is established based on the environmental magnetic field value of the target point, the angle between the three axes, the gain coefficient of the soft magnetic material changing with the magnetic field, and the offset value of the hard iron to the magnetic field.

[0018] In a possible implementation of the first aspect, obtaining a comprehensive error model according to an instrument error model and a compass error model includes:

[0019] The compass error model is substituted into the instrument error model to eliminate the magnetic field measurement value and obtain a comprehensive error model.

[0020] In a possible implementation of the first aspect, according to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the ambient magnetic field value of the target point, the comprehensive error model is deformed, and before obtaining the error deformation model, the method further includes:

[0021] Determine the center point of the star's magnetic axis as the target point.

[0022] In a possible implementation of the first aspect, singular value decomposition is used to perform Gauss-Newton iteration on the initial value to obtain a target correction coefficient, including:

[0023] The initial value is iterated based on Gauss-Newton using singular value decomposition until the root mean square change of the eigenvector is less than the change threshold or the number of iterations reaches the target number, thereby obtaining the target correction coefficient; wherein the eigenvector is obtained based on the correction coefficient.

[0024] In a second aspect, an embodiment of the present application provides a magnetometer measurement error calibration device, comprising:

[0025] The deformation module is used to deform the comprehensive error model according to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the environmental magnetic field value of the target point to obtain an error deformation model; wherein the comprehensive error model is established according to the measurement error of the magnetometer;

[0026] A definition module, the definition module is used to define a correction coefficient according to an error deformation mathematical model;

[0027] An acquisition module, which is used to obtain an initial value of a correction coefficient based on a least squares principle;

[0028] Iteration module, which is used to perform Gauss-Newton iteration on the initial value by using singular value decomposition to obtain the target correction coefficient;

[0029] The calibration module is used to obtain the error between the correction value of the magnetic field measurement value and the standard magnetic field according to the target correction coefficient, so as to calibrate the measurement error of the target magnetometer.

[0030] In a third aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program. When the computer program is loaded and executed by a processor, the magnetometer measurement error calibration method provided in any one of the first aspects above is implemented.

[0031] In a fourth aspect, an embodiment of the present application provides an electronic device, including a processor and a memory, wherein:

[0032] The memory is used to store computer programs;

[0033] The processor is used to load and execute a computer program so that the electronic device executes the magnetometer measurement error calibration method provided in any one of the first aspects above.

[0034] Compared with the prior art, the beneficial effects of this application are:

[0035] The present application provides a method, device, medium and electronic device for calibrating the measurement error of a magnetometer. The method comprises: deforming a comprehensive error model according to a linear relationship between a magnetic field measurement value of a target magnetometer at a target point and an environmental magnetic field value of the target point to obtain an error deformation model; wherein the comprehensive error model is established according to the measurement error of the magnetometer; a correction coefficient is defined according to the error deformation mathematical model; an initial value of the correction coefficient is obtained based on the least squares principle; the initial value is iterated based on Gauss-Newton using singular value decomposition to obtain a target correction coefficient; and according to the target correction coefficient, an error between a corrected value of the magnetic field measurement value and a standard magnetic field is obtained to calibrate the measurement error of the target magnetometer. The present application realizes a primary calibration of the magnetometer measurement error through a comprehensive error model, avoids the influence of the magnetometer installation position deviation on the calibration during the secondary calibration process, defines a correction coefficient through mathematical modeling, and then provides an initial value for the Gauss-Newton iteration based on the least squares principle, so that the iteration can converge quickly, thereby obtaining the target correction coefficient, and finally, based on the correction coefficient, the output of the magnetometer is corrected in turn, and the error between the corrected output value and the standard magnetic field is obtained, thereby realizing the rapid calibration of the magnetometer measurement error and effectively improving the calibration level of the three-axis magnetometer measurement error. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure of an electronic device of a hardware operating environment involved in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of a flow chart of a magnetometer measurement error calibration method provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the angles between three axes in the magnetometer measurement error calibration method provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of a flow chart of a magnetometer measurement error calibration method provided in an embodiment of the present application in one implementation manner;

[0040] Figure 5 The comprehensive error of the output value of the three-axis magnetometer before correction in the magnetometer measurement error calibration method provided in the embodiment of the present application;

[0041] Figure 6 It is the comprehensive error of the output value of the three-axis magnetometer after correction in the magnetometer measurement error calibration method provided in the embodiment of the present application;

[0042] Figure 7 A schematic diagram of a module of a magnetometer measurement error calibration device provided in an embodiment of the present application;

[0043] Markings in the figure: 101 - processor, 102 - communication bus, 103 - network interface, 104 - user interface, 105 - memory. DETAILED DESCRIPTION

[0044] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0045] See attached Figure 1 , attached Figure 1 This is a schematic diagram of the structure of an electronic device of the hardware operating environment involved in the embodiment of the present application. The electronic device may include: a processor 101, such as a central processing unit (CPU), a communication bus 102, a user interface 104, a network interface 103, and a memory 105. Among them, the communication bus 102 is used to realize the connection and communication between these components. The user interface 104 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the user interface 104 may also include a standard wired interface and a wireless interface. The network interface 103 may optionally include a standard wired interface and a wireless interface (such as a wireless fidelity (WIreless-FIdelity, WI-FI) interface). The memory 105 may optionally be a storage device independent of the aforementioned processor 101. The memory 105 may be a high-speed random access memory (RAM) memory, or it may be a stable non-volatile memory (NVM), such as at least one disk storage; the processor 101 may be a general-purpose processor, including a central processing unit, a network processor, etc., or it may be a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component.

[0046] Those skilled in the art will appreciate that Figure 1 The structure shown in the figure does not constitute a limitation on the electronic device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0047] As attached Figure 1 As shown, the memory 105 as a storage medium may include an operating system, a network communication module, a user interface module, and a magnetometer measurement error calibration device.

[0048] In the attached Figure 1In the electronic device shown, the network interface 103 is mainly used for data communication with a network server; the user interface 104 is mainly used for data interaction with a user; the processor 101 and the memory 105 in the present application can be set in the electronic device, and the electronic device calls the magnetometer measurement error calibration device stored in the memory 105 through the processor 101, and executes the magnetometer measurement error calibration method provided in the embodiment of the present application.

[0049] See attached Figure 2 Based on the hardware device of the aforementioned embodiment, an embodiment of the present application provides a magnetometer measurement error calibration method, comprising the following steps:

[0050] S10: deforming the comprehensive error model according to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the environmental magnetic field value of the target point to obtain an error deformation model; wherein the comprehensive error model is established according to the measurement error of the magnetometer.

[0051] In the specific implementation process, the target magnetometer is the three-axis magnetometer that needs to be calibrated for measurement error; the comprehensive error model is the mathematical model directly established based on the measurement error of the magnetometer; the target point is the point inside the star body, usually the center point of the star's magnetic axis, and the initial environmental magnetic field value of this point is recorded as B o , affected by the residual magnetism of the star, the actual magnetic field value at the target point inside the star is recorded as B t , the magnetic field value measured by the magnetometer is recorded as B m .

[0052] Measurement errors can be divided into instrument errors and compass errors, so the comprehensive error model can be expressed as obtained based on the instrument error model and the compass error model.

[0053] Instrument errors mainly include zero offset error, gain coefficient error and three-axis verticality error. Zero offset error is a short-term constant error caused by the internal residual magnetism of the magnetometer and the circuit signal processing loss. It is an additive error, equivalent to the translation transformation of the true value of the magnetic field; the gain coefficient error is the proportional error between the magnetic field of each axis and the output voltage caused by the internal amplification circuit and bridge resistance error of the magnetoresistive sensor, which is manifested as a scaling transformation of the true value; the three-axis verticality error is an error caused by the non-orthogonality of the measuring axes due to processing errors, which can be regarded as a rotation transformation of the geomagnetic vector.

[0054] Compass error refers to the error caused by the three-axis magnetometer under the influence of the environmental magnetic field. Compass error mainly includes: hard iron error, soft iron error and three-axis alignment error. Hard iron error is the time-invariant magnetic field interference caused by hard iron materials in or around the star, which is an additive error; soft iron error is the time-varying magnetic field interference caused by ferromagnetic materials under the influence of the changing magnetic field vector, which can be approximately considered to be linearly related to the magnetic field; three-axis alignment error is the offset of the magnetic sensitive axis and the measurement coordinate system due to the installation error of the magnetic sensor, which is equivalent to the coordinate rotation transformation of the magnetic field.

[0055] In one embodiment, before obtaining the comprehensive error model according to the instrument error model and the compass error model, the method further includes:

[0056] An instrument error model is established based on the magnetic field measurement value, the angle between the three axes, the zero offset error of the three axes, and the three-axis gain coefficient error.

[0057] In the specific implementation process, the target point is recorded as point O, assuming that there is no influence of the star, and the initial environmental magnetic field value B o , true magnetic field value B t , the magnetic field measurement value is recorded as B m , which can be decomposed into three-axis components as follows:

[0058]

[0059] The instrument error model is as follows. The final degree of the magnetometer can be expressed as the actual magnetic field B at point O under the influence of the star. t Several transformations of :

[0060]

[0061] Where k x1 , k y1 , k z1 is the gain coefficient error of the three axes, α, β, and γ are the angles between the three axes, and their specific definitions are as shown in the attached Figure 3 As shown, O-XYZ represents the magnetometer three-axis coordinate system, OX O Y O Z O represents the orthogonal coordinate system, b x1 、b y1 、b z1 are the zero offset errors of the three axes respectively, and (X1, Y1, Z1) are the corresponding errors between the magnetometer three-axis coordinate system and the orthogonal coordinate system.

[0062] In one embodiment, before obtaining the comprehensive error model according to the instrument error model and the compass error model, the method further includes:

[0063] A compass model is established based on the environmental magnetic field value of the target point, the angle between the three axes, the gain coefficient of the soft magnetic material changing with the magnetic field, and the offset value of the hard iron to the magnetic field.

[0064] In the specific implementation process, the relationship between the initial environmental magnetic field value and the actual value of the magnetic center point is established, and the Radian error model is as follows:

[0065]

[0066] Where k x2 , k y2 , k z2 are the gain coefficient of soft magnetic material with changing magnetic field, b x2 、b y2 、b z2 are the offsets of the magnetic field value caused by hard iron, and α′, β′, and γ′ are the angles between the three axes.

[0067] In one embodiment, a comprehensive error model is obtained according to the instrument error model and the compass error model, including:

[0068] The compass error model is substituted into the instrument error model to eliminate the magnetic field measurement value and obtain a comprehensive error model.

[0069] In the specific implementation process, it can be seen from the instrument error model and the compass error model that the initial environmental magnetic field value B o Under the interference of hard iron and soft iron errors in the satellite, the real satellite magnetic field B is formed at the center point of magnetic measurement. t At the same time, the actual magnetic field inside the star is affected by the error of the magnetometer instrument, forming the final magnetometer reading B m After substituting the compass error model into the instrument error model for simplification, the actual value B in the star caused by the ferromagnetic material of the star is eliminated. t , thereby establishing the relationship between the initial ambient magnetic field and the final reading, and forming a comprehensive error model of the magnetometer.

[0070] The mathematical modeling of the comprehensive error model is as follows:

[0071]

[0072] Consider the matrices of a and b as a whole, that is:

[0073] B m =a·B o +b

[0074] It is not difficult to see that the magnetic field measurement value B m and the ambient magnetic field value B o It is a linear relationship, and the formula contains 12 unknown quantities. At the same time, according to the linear relationship between the two, the above formula can be rewritten as:

[0075]

[0076] Right now:

[0077]

[0078] The model rewritten by the transformation is the error deformation model.

[0079] S20: Define a correction coefficient according to the error deformation mathematical model.

[0080] In the specific implementation process, the coefficients represent 12 unknowns, that is, A in the above formula 4×3 , rewrite it and define the correction factor X:

[0081] X=[A1 A2 A3 A4 A5 A6 A7 A8 A9 b1 b2 b3]

[0082] The comprehensive error model is regarded as a function f of the correction coefficient X, and Y is the measured magnetometer reading B m , then the F function can be defined as:

[0083] F(X)=f(X)-Y=0

[0084] The estimated value of the function at X Perform a Taylor series expansion:

[0085]

[0086] In the formula is the Jacobian matrix of the parameter to be estimated, representing the partial derivative of the function F with respect to the parameter to be estimated, ε is a small high-order quantity, and δX is a small quantity of the correction coefficient X.

[0087] S30: Based on the least squares principle, an initial value of the correction coefficient is obtained.

[0088] In the specific implementation process, the key condition for the rapid convergence of Gauss-Newton iteration is to find a suitable initial estimate. When the number of measurement groups is n, the least squares principle is used to calculate:

[0089]

[0090] In the formula, is the covariance matrix, b n×3 is the residual between the measured value and the estimated value, and then the state estimate is continuously updated through iteration.

[0091] S40: Using singular value decomposition, perform Gauss-Newton iteration on the initial value to obtain a target correction coefficient.

[0092] In the specific implementation process, singular value decomposition is used to o The generalized inverse of After initial value correction, we get:

[0093]

[0094] Count the number of iterations as k, then:

[0095]

[0096] In the formula, represents the estimated value of X after K-1 iterations, represents the estimated value of X after k iterations.

[0097] In one embodiment, singular value decomposition is used to perform Gauss-Newton iteration on the initial value to obtain the target correction coefficient, including:

[0098] The initial value is iterated based on Gauss-Newton using singular value decomposition until the root mean square change of the eigenvector is less than the change threshold or the number of iterations reaches the target number, thereby obtaining the target correction coefficient; wherein the eigenvector is obtained based on the correction coefficient.

[0099] In the specific implementation process, another key condition of Gauss-Newton iteration is the number of iterations, which defines the root mean square RMS of vector b. b for:

[0100]

[0101] Where n is the number of measurement groups and i is the number of iterations.

[0102] When RMS b When the size change is less than the change threshold, the above iteration is considered complete. The change threshold is usually 10 -4 , the algorithm sets the maximum number of iterations, such as 10, to prevent the algorithm from not converging.

[0103] S50: According to the target correction coefficient, the error between the correction value of the magnetic field measurement value and the standard magnetic field is obtained to calibrate the measurement error of the target magnetometer.

[0104] In the specific implementation process, after obtaining the final correction coefficient, the output value of the corrected magnetometer is calculated, and the error between it and the standard magnetic field is output to achieve the calibration of the target magnetometer measurement error. In the selection of data points, the embodiment of the present application uses a high-precision Helmholtz coil to generate a standard magnetic field, and the coil generates magnetic field values ​​in each vector direction, so that the points taken can be distributed as evenly as possible within the range of the magnetometer.

[0105] In this embodiment, a primary calibration of the magnetometer measurement error is achieved through a comprehensive error model to avoid the influence of the magnetometer installation position deviation on the calibration during the secondary calibration process. A correction coefficient is defined by mathematical modeling, and then an initial value is provided for the Gauss-Newton iteration based on the least squares principle so that the iteration can converge quickly to obtain the target correction coefficient. Finally, the output of the magnetometer is corrected in turn based on the correction coefficient, and the error between the corrected output value and the standard magnetic field is obtained, thereby achieving rapid calibration of the magnetometer measurement error and effectively improving the calibration level of the three-axis magnetometer measurement error.

[0106] As attached Figure 4 As shown in the attached Figure 4 The present application is further described below in the following embodiments:

[0107] First, the standard magnetic field [X ix Y iy Z iz ] and magnetometer to test magnetic field [X x Y y Z z ] Perform a least squares fit and calculate the RMS of each iteration b , in RMS b Size change is less than 10 -4 The correction coefficient X is output, and then the output value of the corrected magnetometer is calculated, and the error between it and the standard magnetic field is output, and then the algorithm ends. The specific results are verified as follows:

[0108] The magnetometer installed in the CubeSat is calibrated in a standard magnetic shielding room. A three-axis Helmholtz coil is built in the shielding room. The uniform magnetic field area is 200×200×200mm, and the total magnetic field variation in the area is less than 5nT, which meets the calibration requirements of the magnetoresistive magnetometer.

[0109] First, the accuracy of the uncalibrated magnetometer is evaluated. In order to comprehensively evaluate the reading of the magnetometer under the combined effect of the geomagnetic field and the interfering magnetic field, this application uses a three-axis magnetic simulator to generate a total of 729 measurement points uniformly distributed in the measurement space from zero magnetic field to the geomagnetic field scalar. The specific method is to change the X, Y, and Z axes within the range of ±40000nT with a step size of 10000nT. There are 9 permutations and combinations. 3 There are 729 possibilities in total. These points can fully reflect the error changes of the magnetometer in different magnetic field environments.

[0110] Compare the actual magnetic field value generated with the output value of the magnetometer before calibration. The results are shown in the attached figure. Figure 5As shown in the figure, due to the influence of the residual magnetism on the satellite, there is a huge difference between the reading of the magnetometer and the magnetic field value applied by the magnetic simulator. The maximum error exceeds 10000nT, and the accuracy cannot meet the attitude measurement requirements of the CubeSat.

[0111] The integrated error correction algorithm of the microsatellite magnetometer based on the Gauss-Newton iteration algorithm is used to perform integrated error correction on the magnetometer output. The above measured raw data is fitted with the actual applied magnetic field, and the values ​​of the 12 unknowns in the correction coefficient equation are determined. After the correction coefficient is obtained, the original value is corrected on site and the corrected value is output. Then, the error between the corrected value and the actual applied magnetic field is evaluated. The size of the integrated error is shown in the attached figure. Figure 6 shown.

[0112] By attaching Figure 5 and attached Figure 6 By comparison, it can be found that after correction, the root mean square error of the magnetometer's measurement value under the influence of the residual magnetism on the satellite has dropped by two orders of magnitude, successfully correcting the influence of most interfering magnetic fields and sensor manufacturing errors, and the accuracy has reached within 200nT, which can meet the needs of on-satellite magnetic field measurement. The error values ​​before and after correction are shown in Table 1 below:

[0113] Table 1 Magnetometer error values ​​before and after correction

[0114]

[0115] See attached Figure 7 Based on the same inventive concept as in the above-mentioned embodiment, the embodiment of the present application further provides a magnetometer measurement error calibration device, comprising:

[0116] The deformation module is used to deform the comprehensive error model according to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the environmental magnetic field value of the target point to obtain an error deformation model; wherein the comprehensive error model is established according to the measurement error of the magnetometer;

[0117] A definition module, the definition module is used to define a correction coefficient according to an error deformation mathematical model;

[0118] An acquisition module, which is used to obtain an initial value of a correction coefficient based on a least squares principle;

[0119] Iteration module, which is used to perform Gauss-Newton iteration on the initial value by using singular value decomposition to obtain the target correction coefficient;

[0120] The calibration module is used to obtain the error between the correction value of the magnetic field measurement value and the standard magnetic field according to the target correction coefficient, so as to calibrate the measurement error of the target magnetometer.

[0121] Those skilled in the art should understand that the division of the various modules in the embodiment is only a division of logical functions, and can be fully or partially integrated into one or more actual carriers in actual application, and these modules can be all implemented in the form of software called by the processing unit, or all implemented in the form of hardware, or implemented in the form of a combination of software and hardware. It should be noted that the modules in the magnetometer measurement error calibration device in this embodiment correspond one-to-one to the steps in the magnetometer measurement error calibration method in the aforementioned embodiment. Therefore, the specific implementation of this embodiment can refer to the implementation of the aforementioned magnetometer measurement error calibration method, which will not be repeated here.

[0122] Based on the same inventive concept as in the aforementioned embodiment, an embodiment of the present application further provides a computer-readable storage medium storing a computer program. When the computer program is loaded and executed by a processor, a magnetometer measurement error calibration method as provided in the embodiment of the present application is implemented.

[0123] Based on the same inventive concept as in the above-mentioned embodiment, an embodiment of the present application further provides an electronic device, including a processor and a memory, wherein:

[0124] The memory is used to store computer programs;

[0125] The processor is used to load and execute a computer program so that the electronic device executes the magnetometer measurement error calibration method provided in the embodiment of the present application.

[0126] In some embodiments, the computer readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or various devices including one or any combination of the above memories. The computer may be various computing devices including intelligent terminals and servers.

[0127] In some embodiments, executable instructions may be in the form of a program, software, software module, script or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine or other unit suitable for use in a computing environment.

[0128] As an example, executable instructions may, but need not, correspond to a file in a file system, may be stored as part of a file that stores other programs or data, such as in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or code portions).

[0129] By way of example, executable instructions may be deployed to be executed on one computing device, or on multiple computing devices located at one site, or on multiple computing devices distributed across multiple sites and interconnected by a communication network.

[0130] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0131] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0132] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory / random access memory, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a multimedia terminal device (which can be a mobile phone, a computer, a television receiver, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0133] In summary, the present application provides a magnetometer measurement error calibration method, device, medium and electronic device, the method comprising: deforming a comprehensive error model according to a linear relationship between a magnetic field measurement value of a target magnetometer at a target point and an ambient magnetic field value of the target point to obtain an error deformation model; wherein the comprehensive error model is established according to the measurement error of the magnetometer; a correction coefficient is defined according to the error deformation mathematical model; an initial value of the correction coefficient is obtained based on the least squares principle; the initial value is iterated based on Gauss-Newton using singular value decomposition to obtain a target correction coefficient; according to the target correction coefficient, an error between a corrected value of the magnetic field measurement value and a standard magnetic field is obtained to achieve calibration of the target magnetometer measurement error. The present application realizes a primary calibration of the magnetometer measurement error through a comprehensive error model, avoids the influence of the magnetometer installation position deviation on the calibration during the secondary calibration process, defines a correction coefficient through mathematical modeling, and then provides an initial value for the Gauss-Newton iteration based on the least squares principle, so that the iteration can converge quickly, thereby obtaining the target correction coefficient, and finally, based on the correction coefficient, the output of the magnetometer is corrected in turn, and the error between the corrected output value and the standard magnetic field is obtained, thereby realizing the rapid calibration of the magnetometer measurement error and effectively improving the calibration level of the three-axis magnetometer measurement error.

[0134] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for calibrating a magnetometer measurement error, characterized in that: The following steps are involved: According to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the environmental magnetic field value of the target point, the comprehensive error model is deformed to obtain an error deformation model; wherein the comprehensive error model is established according to the measurement error of the magnetometer; According to the error deformation mathematical model, a correction coefficient is defined; Based on the least squares principle, obtaining an initial value of the correction coefficient; Using singular value decomposition, performing Gauss-Newton iteration on the initial value to obtain a target correction coefficient; According to the target correction coefficient, the error between the correction value of the magnetic field measurement value and the standard magnetic field is obtained to achieve calibration of the target magnetometer measurement error.

2. The magnetometer measurement error calibration method according to claim 1, characterized in that: Before deforming the comprehensive error model according to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the environmental magnetic field value of the target point to obtain the error deformation model, the method further includes: The comprehensive error model is obtained according to the instrument error model and the compass error model.

3. The magnetometer measurement error calibration method according to claim 2, characterized in that: Before obtaining the comprehensive error model according to the instrument error model and the compass error model, the method further includes: The instrument error model is established according to the magnetic field measurement value, the angle between the three axes, the zero offset error of the three axes and the three-axis gain coefficient error.

4. The magnetometer measurement error calibration method according to claim 2, characterized in that: Before obtaining the comprehensive error model according to the instrument error model and the compass error model, the method further includes: The compass model is established according to the environmental magnetic field value of the target point, the angle between the three axes, the gain coefficient of the soft magnetic material changing with the magnetic field, and the offset value of the hard iron to the magnetic field.

5. The magnetometer measurement error calibration method according to claim 2, characterized in that: The step of obtaining the comprehensive error model according to the instrument error model and the compass error model comprises: The compass error model is substituted into the instrument error model to eliminate the magnetic field measurement value and obtain the comprehensive error model.

6. The magnetometer measurement error calibration method according to claim 1, characterized in that: Before deforming the comprehensive error model according to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the environmental magnetic field value of the target point to obtain the error deformation model, the method further includes: The center point of the magnetic axis of the star is determined as the target point.

7. The magnetometer measurement error calibration method according to claim 1, characterized in that: The method of using singular value decomposition to perform Gauss-Newton iteration on the initial value to obtain a target correction coefficient includes: The initial value is iterated based on Gauss-Newton by using singular value decomposition until the root mean square change of the eigenvector is less than the change threshold or the number of iterations reaches the target number, thereby obtaining a target correction coefficient; wherein the eigenvector is obtained based on the correction coefficient.

8. A magnetometer measurement error calibration device, characterized in that: include: A deformation module, the deformation module is used to deform the comprehensive error model according to the linear relationship between the magnetic field measurement value of the target magnetometer at the target point and the environmental magnetic field value of the target point to obtain an error deformation model; wherein the comprehensive error model is established according to the measurement error of the magnetometer; A definition module, the definition module is used to define a correction coefficient according to the error deformation mathematical model; An acquisition module, the acquisition module is used to obtain an initial value of the correction coefficient based on the least squares principle; An iteration module, wherein the iteration module is used to perform Gauss-Newton iteration on the initial value by using singular value decomposition to obtain a target correction coefficient; A calibration module is used to obtain the error between the correction value of the magnetic field measurement value and the standard magnetic field according to the target correction coefficient, so as to calibrate the measurement error of the target magnetometer.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is loaded and executed by the processor, the magnetometer measurement error calibration method according to any one of claims 1 to 7 is implemented.

10. An electronic device, characterized in that: comprising a processor and a memory, wherein: The memory is used to store computer programs; The processor is used to load and execute the computer program so that the electronic device executes the magnetometer measurement error calibration method according to any one of claims 1 to 7.

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