A vector geomagnetic calibration method and device based on multi-route data alignment

Abstract

The present application relates to the field of geomagnetic navigation technology and discloses a vector geomagnetic calibration method and device based on multi-route data alignment, wherein the method includes: obtaining multiple first latitudes of a first route and multiple second latitudes of a second route, aligning each second latitude with the first latitude, and determining multiple first field strength data of the first latitude and multiple second field strength data of the second latitude based on the alignment results; obtaining multiple first abnormal field strength data of the first route based on the first field strength data, and obtaining multiple second abnormal field strength data of the second route based on the second field strength data; obtaining a conversion matrix for the second route based on the first abnormal field strength data, the second abnormal field strength data, and the second field strength data, and converting the second field strength data into calibration field strength data for the second route according to the conversion matrix. The technical solutions provided in multiple embodiments of the present application can eliminate the striping error generated when constructing a three-dimensional vector geomagnetic map.

Description

Technical Field

[0001] The present application relates to the technical field of geomagnetic data calibration, and in particular to a vector geomagnetic calibration method and device based on multi-route data alignment. Background Art

[0002] Currently, when collecting geomagnetic data of aircraft, inertial navigation systems and geomagnetic sensors are usually used to obtain geomagnetic data of different routes.

[0003] In practical applications, the inertial navigation system will cause initial alignment errors during acquisition, and the aircraft's attitude changes and external environmental interference will cause magnetic interference errors. As a result, the geomagnetic data of different routes will show obvious jumps after being converted to the geographic coordinate system, resulting in stripe errors when constructing the three-dimensional vector geomagnetic map, affecting the accuracy and reliability of geomagnetic navigation.

[0004] In view of this, how to eliminate the stripe error generated when constructing a three-dimensional vector geomagnetic map is an urgent problem to be solved. Summary of the Invention

[0005] The present application provides a vector geomagnetic calibration method and device based on multi-route data alignment, which can eliminate the striping error caused by constructing a three-dimensional vector geomagnetic map using multi-route geomagnetic data.

[0006] The first aspect of the present application provides a vector geomagnetic calibration method based on multi-route data alignment, the method comprising: obtaining multiple first latitudes of a first route and multiple second latitudes of a second route, aligning each second latitude with each first latitude, and determining multiple first field strength data of the first latitude and multiple second field strength data of the second latitude based on the alignment result; obtaining multiple first abnormal field strength data of the first route based on the first field strength data, and obtaining multiple second abnormal field strength data of the second route based on the second field strength data; obtaining a conversion matrix of the second route based on the first abnormal field strength data, the second abnormal field strength data and the second field strength data, and converting the second field strength data into calibration field strength data of the second route according to the conversion matrix.

[0007] In one possible embodiment, aligning each second latitude with each first latitude, and determining multiple first field strength data of the first latitude and multiple second field strength data of the second latitude based on the alignment result includes: for any first latitude, obtaining the first field strength data of the first latitude, and determining two second latitudes adjacent to the first latitude, obtaining two initial field strength data of the two second latitudes, aligning any second latitude adjacent to the first latitude with the first latitude so that the second latitude is parallel to the first latitude, and determining the second field strength data of the second route at the aligned second latitude based on the first field strength data of the first latitude and the first latitude and the initial field strength data of the two adjacent second latitudes and the second latitude.

[0008] In a possible embodiment, before obtaining multiple first abnormal field strength data of the first route based on the first field strength data, the method also includes: obtaining first posture data of the first route, determining a first coordinate rotation matrix based on the first posture data, multiplying the first field strength data by the first coordinate rotation matrix, and redetermining the first field strength data based on the multiplication result of the first coordinate rotation matrix; obtaining second posture data of the second route, determining a second coordinate rotation matrix based on the second posture data, multiplying the second field strength data by the second coordinate rotation matrix, and redetermining the second field strength data based on the multiplication result of the second coordinate rotation matrix.

[0009] In a possible embodiment, obtaining multiple first abnormal field strength data of the first route based on the first field strength data, and obtaining multiple second abnormal field strength data of the second route based on the second field strength data includes: obtaining the first main magnetic field strength data and the first daily varying field strength data of each first latitude, and obtaining the second main magnetic field strength data and the second daily varying field strength data of each second latitude aligned with the first latitude; for any first latitude, obtaining multiple first abnormal field data of the first route based on the first field strength data, the first main magnetic field strength data and the first daily varying field strength data of the first latitude; and for any aligned second latitude, obtaining multiple second abnormal field strength data of the second route based on the second field strength data, the second main magnetic field strength data and the second daily varying field strength data of the second latitude.

[0010] In one possible embodiment, obtaining the first abnormal field strength data and the second abnormal field strength data includes: for any first latitude, generating first difference information between the first field strength data at the first latitude and the first main magnetic field strength data and the first daily variable field strength data, determining the first difference information as a first abnormal field data for the first route, and for any aligned second latitude, generating second difference information between the second field strength data at the second latitude and the second main magnetic field strength data and the second daily variable field strength data, and determining the second difference information as a second abnormal field strength data for the second route.

[0011] In one possible embodiment, the conversion matrix includes a translation matrix and a rotation matrix; obtaining the conversion matrix of the second route based on the first abnormal field strength data, the second abnormal field strength data and the second field strength data, and converting the second field strength data into the calibration field strength data of the second route according to the conversion matrix includes: obtaining the translation matrix and the rotation matrix of the second route according to the first abnormal field strength data, the second abnormal field strength data and the second field strength data; and converting the second field strength data into the calibration field strength data based on the translation matrix and the rotation matrix.

[0012] In one possible embodiment, based on the translation matrix and the rotation matrix, converting the second field strength data into the calibration field strength data includes: changing the calibration field strength data based on the rotation matrix to obtain initial calibration data, and translating the initial calibration data using the translation matrix to obtain the calibration field strength data.

[0013] The second aspect of the present application provides a vector geomagnetic calibration device based on multi-route data alignment, the device comprising: a latitude alignment unit, for acquiring multiple first latitudes of a first route and multiple second latitudes of a second route, and aligning each second latitude with each first latitude; a data acquisition unit, for determining multiple first field strength data of the first latitude and multiple second field strength data of the second latitude based on the alignment result, and acquiring multiple first abnormal field strength data of the first route based on the first field strength data, and acquiring multiple second abnormal field strength data of the second route based on the second field strength data; a data calibration unit, for acquiring a conversion matrix of the second route based on the first abnormal field strength data, the second abnormal field strength data and the second field strength data, and converting the second field strength data into calibration field strength data of the second route according to the conversion matrix.

[0014] The third aspect of the present application provides a computer device, including a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform a vector geomagnetic calibration method based on multi-route data alignment as described in the first aspect.

[0015] The fourth aspect of the present application provides a computer-readable storage medium having computer instructions stored thereon, wherein the computer instructions are used to enable a computer to execute a vector geomagnetic calibration method based on multi-route data alignment as described in the first aspect.

[0016] The technical solution provided by one or more embodiments of the present application is to align and calibrate the geomagnetic field strength data of multiple routes according to the latitude information of the reference route to avoid data jumps and striping errors. Specifically, a reference route is determined, the measurement points of different routes are aligned according to the latitude information of the reference route, and the geomagnetic data are calibrated at the same or similar latitudes. The position deviation and attitude deviation of the geomagnetic data of each route are corrected by solving the conversion matrix, so that the field strength data of each route after conversion is as close as possible to the field strength data of the reference route, so as to eliminate attitude errors and magnetic interference errors, and avoid data jumps that cause striping errors when constructing a three-dimensional vector geomagnetic map.

[0017] It can be seen that the technical solution provided by this application can reduce data jumps when obtaining geomagnetic data of each route, and at the same time, eliminate the striping errors that may occur when constructing a three-dimensional vector geomagnetic map based on the field strength data of each route. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A step diagram of a vector geomagnetic calibration method based on multi-route data alignment provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the latitudes of the first route and the second route provided in one embodiment of the present application;

[0021] Figure 3 A diagram showing the steps of a method for obtaining first abnormal field strength data and second abnormal field strength data provided by one embodiment of the present application;

[0022] Figure 4 A diagram showing the steps of a method for obtaining a conversion matrix provided in one embodiment of the present application;

[0023] Figure 5 A schematic diagram of a route for a vector geomagnetic calibration method based on alignment of three route data provided by an embodiment of the present application;

[0024] Figure 6 A schematic structural diagram of a vector geomagnetic calibration device based on multi-route data alignment provided by one embodiment of the present application;

[0025] Figure 7 A schematic diagram of the structure of a computer device provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0026] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0027] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more. In addition, the use of "based on" or "according to" means openness and inclusiveness, because the process, steps, calculations or other actions "based on" or "according to" one or more of the conditions or values ​​can be based on additional conditions or values ​​beyond the described values ​​in practice.

[0028] With the continuous development of the modern navigation industry, three-dimensional vector geomagnetic mapping and navigation technology has become one of the important research directions in the field of modern navigation. By collecting vector geomagnetic data from different routes and constructing three-dimensional vector geomagnetic maps based on this vector geomagnetic data, rich information can be provided for aircraft geomagnetic positioning and navigation. Generally speaking, in the absence of measurement errors, it can be assumed that the three-component geomagnetic field at the same location on overlapping routes or adjacent routes with the same heading is equal or similar in magnitude. Therefore, vector geomagnetic information is usually collected from overlapping routes or adjacent routes with the same heading to construct vector geomagnetic data maps.

[0029] In practical applications, vector geomagnetic data of each route is usually collected through an inertial navigation system and a geomagnetic sensor. However, the inertial navigation system may cause attitude errors when determining the initial attitude of the carrier. For example, if the initial pitch angle error is 0.1°, it may cause a position error of hundreds of meters after one hour of flight. The attitude error causes the vector geomagnetic data of different routes to be converted to a geographic coordinate system. There is a significant jump when the three-dimensional vector geomagnetic map is constructed. At this time, there will be obvious stripe errors. And when the attitude of the aircraft changes rapidly, magnetic interference errors will be generated. In addition, the metal structures, electronic equipment or external electromagnetic fields around the aircraft will also interfere with the measurement of the geomagnetic sensor, resulting in magnetic interference errors, thereby exacerbating data jumps.

[0030] Furthermore, when the constructed 3D vector geomagnetic map contains significant banding errors, the geomagnetic data in some areas may be discontinuous or abrupt, which can cause the navigation system to misidentify the location, resulting in reduced navigation accuracy and potentially posing a safety hazard to aircraft using geomagnetic navigation during path planning. Therefore, eliminating the banding errors generated when constructing 3D vector geomagnetic maps to ensure high accuracy and robustness of geomagnetic navigation is an urgent problem to be solved.

[0031] In view of this, one or more embodiments of the present application provide a vector geomagnetic calibration method and device based on multi-route data alignment, which can solve the above problems and eliminate the striping errors generated when constructing a three-dimensional vector geomagnetic map.

[0032] See also Figure 1 In one embodiment of the present application, a vector geomagnetic calibration method based on multi-route data alignment is provided. The method may include the following steps:

[0033] S1: Acquire multiple first latitudes of a first route and multiple second latitudes of a second route, align each of the second latitudes with each of the first latitudes, and determine multiple first field strength data of the first latitudes and multiple second field strength data of the second latitudes based on the alignment result.

[0034] The first and second routes are adjacent or overlapping routes with the same heading. It is generally assumed that the three-component geomagnetic field at the same location on overlapping or adjacent routes with the same heading is equal or similar in magnitude. A vector geomagnetic map is constructed by collecting geomagnetic elements from the first and second routes. The geomagnetic elements include multiple physical quantities representing the direction and magnitude of the Earth's magnetic field. As one of the geomagnetic elements, field strength data is typically represented in vector form.

[0035] In this embodiment, when collecting vector geomagnetic data, it is necessary to obtain the latitude information of the first and second routes. Specifically, the first and second routes are typically composed of a series of measurement points, each of which has corresponding latitude information. The latitude information of each measurement point on the first route is used as the first latitude, and the latitude information of each measurement point on the second route is used as the second latitude, thereby obtaining multiple first latitudes and multiple second latitudes.

[0036] In this embodiment, because the different locations of the first and second routes will result in certain magnetic field variations, it is necessary to align the field strength data for the first and second routes to the same latitude. Specifically, each first latitude is used as a reference latitude, and any second latitude is aligned with one of the first latitudes of the first route, so that the second latitude is as close as possible to the first latitude. By aligning the measurement points of different routes based on latitude information, it is possible to ensure that the geomagnetic data is calibrated at the same or similar latitudes.

[0037] Furthermore, after aligning the second latitude of the second route with the first latitude of the first route, field strength data for the measurement points represented by the first route at each latitude is obtained. For each first latitude, the total field strength data for the first route at the first latitude is measured as the first field strength data, and for each aligned second latitude, the total field strength data for the second route at the second latitude is measured as the second field strength data.

[0038] S3: Acquire a plurality of first abnormal field strength data of the first route based on the first field strength data, and acquire a plurality of second abnormal field strength data of the second route based on the second field strength data.

[0039] The first and second measured field strength data typically include main magnetic field strength data, daily variable field strength data, and abnormal variable field strength data. Abnormal field strength data is spatially localized and irregular, and can be understood as magnetic field anomalies caused by local geological structures, human activities, or other environmental factors. Therefore, the differences in abnormal field strength data between different routes are relatively small.

[0040] In this embodiment, the abnormal field strength data of each route can be calculated by obtaining the main magnetic field strength data and the diurnal field strength data based on the first field strength data and the second field strength data. The main magnetic field strength data is the main part of the geomagnetic field and has long-term stability. The diurnal field strength data is a short-term change caused by solar activity and has obvious time-varying characteristics. Therefore, the main magnetic field strength data and the diurnal field strength data are relatively easy to obtain. Based on the main magnetic field strength data and the diurnal field strength data of the first route and the second route, each first field strength data and each second field strength data are respectively subtracted to obtain multiple first abnormal field strength data and multiple second abnormal field strength data of the first route.

[0041] Optionally, abnormal field strength data can be extracted from the total field strength data using filtering and separation algorithms. For example, the filtering algorithm can employ a Fourier transform algorithm or a Kalman filter algorithm, and the separation algorithm can employ an independent component analysis algorithm or a principal component analysis algorithm. By decomposing the first and second field strength data into components of different frequencies, the filtering algorithm is used to identify and extract the frequency range in which the abnormal field strength data resides, and the separation algorithm is used to further separate the abnormal field strength data.

[0042] S5: Acquire a conversion matrix for the second route based on the first abnormal field strength data, the second abnormal field strength data, and the second field strength data, and convert the second field strength data into calibrated field strength data for the second route according to the conversion matrix.

[0043] The above conversion matrix is ​​used to correct the position deviation and attitude deviation of the first route and the second route when acquiring geomagnetic data, so as to eliminate attitude error and magnetic interference error, avoid data jump, and thus avoid stripe error in the three-dimensional vector geomagnetic map.

[0044] Optionally, a least squares method can be used to solve the transformation matrix, and the optimal fitting parameters for the second field strength data can be found by minimizing the error between the first abnormal field data and the second abnormal field data. This can include a rotation matrix and a translation matrix, with the rotation matrix and translation matrix serving as the transformation matrix. Exemplarily, the transformation matrix can also be solved by searching for an optimal solution using an iterative algorithm, a genetic algorithm, or by constructing a neural network model based on deep learning.

[0045] In this embodiment, the attitude error and magnetic interference error of the magnetic field vector of the second route relative to the first route can be corrected by solving a conversion matrix. Specifically, the conversion matrix is ​​solved based on the first abnormal field data, the second abnormal field data, and the second field strength data. After the second field strength data is transformed using the conversion matrix, it is made as close as possible to the first field strength data of the first route. The transformed second field strength data is used as the calibration field strength data for the second route after vector geomagnetic calibration.

[0046] The technical solution provided in this embodiment aligns and calibrates the geomagnetic field strength data of the first and second routes according to latitude information to avoid data jumps and striping errors. Specifically, the measurement points of different routes are aligned according to latitude information, the geomagnetic data are calibrated at the same or similar latitudes, and the position deviation and attitude deviation of the geomagnetic data of the first and second routes are corrected by solving the conversion matrix. The converted second field strength data is made as close as possible to the first field strength data of the first route, thereby eliminating attitude errors and magnetic interference errors and avoiding striping errors caused by data jumps when constructing a three-dimensional vector geomagnetic map.

[0047] In one embodiment, based on step S1, aligning each second latitude with each first latitude, and determining a plurality of first field intensity data of the first latitude and a plurality of second field intensity data of the second latitude based on the alignment result includes:

[0048] For any first latitude, obtain the first field strength data of the first latitude, and determine two second latitudes adjacent to the first latitude, and obtain two initial field strength data of the two second latitudes; align any second latitude adjacent to the first latitude with the first latitude so that the second latitude is parallel to the first latitude, and based on the first field strength data of the first latitude and the first latitude and the initial field strength data of the two adjacent second latitudes and the second latitude, determine the second field strength data of the second route at the aligned second latitude.

[0049] Specifically, the second field strength data can be expressed in the following manner: ,in, is the second field strength data, is a first latitude, For An adjacent second latitude, is another adjacent second latitude, for The corresponding initial field strength data, for The corresponding initial field strength data.

[0050] See also Figure 2 In this embodiment, the first latitudes of the first route are used as a reference to align the second latitudes of the second route with the first latitudes. , determine a second latitude adjacent to the first latitude and the second latitude , and obtain the second route Initial field strength data at latitude and Initial field strength data at latitude For any second latitude, the above second latitude For example, the aligned The field strength data of It should be noted that the second latitudes that need to be aligned are data points within the latitude range of the first latitude of the first route.

[0051] In another embodiment, each first latitude can be aligned with each second latitude by multiple spline curve interpolation. and the corresponding initial field strength data Then, by constructing the cubic spline difference function, according to the first latitude Calculate the corresponding second field strength data .

[0052] In this embodiment, the data for the second route is aligned with the data for the first route in latitude to ensure a one-to-one correspondence between the two sets of data. For adjacent routes with the same heading, the geomagnetic distribution of the adjacent data for the adjacent routes is smoothed, providing reference data for the subsequent calibration of the field strength data, thereby constructing a smooth transition three-dimensional vector geomagnetic map and resolving the issue of striping errors. It should be noted that the alignment and calibration of route data for multiple flights can also be performed recursively.

[0053] In one embodiment, before step S3, the first field strength data and the second field strength data need to be converted from the carrier coordinate system to the geographic coordinate system to eliminate the influence of the aircraft attitude on the data. In addition, if the conversion is not performed, the measurement data under different attitudes cannot be compared or fused in the same geographic coordinate system.

[0054] In this embodiment, the method for converting the above-mentioned second field strength data from the carrier coordinate system to the geographic coordinate system includes: obtaining the first posture data of the first route, determining the first coordinate rotation matrix based on the first posture data, multiplying the first field strength data by the first coordinate rotation matrix, and redetermining the first field strength data based on the multiplication result of the first coordinate rotation matrix; obtaining the second posture data of the second route, determining the second coordinate rotation matrix based on the second posture data, multiplying the second field strength data by the second coordinate rotation matrix, and redetermining the second field strength data based on the multiplication result of the second coordinate rotation matrix.

[0055] The aforementioned carrier coordinate system is a local coordinate system referenced by the aircraft or measurement carrier, with the x, y, and z axes denoted as the forward, left, and upward directions of the aircraft for the first and second routes, respectively. The aforementioned geographic coordinate system is a geographic coordinate system based on geographic directions, such as the northeast celestial coordinate system, which points to geographic east, geographic north, and the vertical direction toward the center of the Earth, respectively. The aforementioned attitude data, including the aircraft's pitch, roll, and heading angles, can be directly measured by an inertial navigation system.

[0056] In this embodiment, the field strength data is transformed by constructing coordinate rotation matrices for the first and second routes. Specifically, first attitude data for the first route is obtained, including the pitch angle, roll angle, and heading angle at each first latitude of the first route, and second attitude data for the second route is obtained, including the pitch angle, roll angle, and heading angle at each second latitude of the second route. Based on the first and second attitude data, a first coordinate rotation matrix for the first route and a second coordinate rotation matrix for the second route are constructed.

[0057] For example, taking the first coordinate rotation matrix of the first route as an example, the first coordinate rotation matrix ,in, is the rotation matrix around the z-axis, representing the rotation matrix of the heading angle. is the rotation matrix around the x-axis, which represents the rotation matrix of the roll angle. is the rotation matrix around the y-axis, representing the rotation matrix of the pitch angle. Similarly, the second coordinate rotation matrix ,in, is the rotation matrix around the z-axis, representing the rotation matrix of the heading angle. is the rotation matrix around the x-axis, which represents the rotation matrix of the roll angle. is the rotation matrix around the y-axis, representing the rotation matrix of the pitch angle.

[0058] See also Figure 3 In one embodiment, based on step S3, obtaining a plurality of first abnormal field strength data of the first route based on the first field strength data, and obtaining a plurality of second abnormal field strength data of the second route based on the second field strength data includes the following steps:

[0059] S31: Acquire the first main magnetic field strength data and the first diurnal field strength data at each of the first latitudes, and acquire the second main magnetic field strength data and the second diurnal field strength data at each of the second latitudes aligned with the first latitudes.

[0060] S33: For any of the first latitudes, based on the first field strength data, the first main magnetic field strength data and the first daily variable field strength data of the first latitude, obtain multiple first abnormal field data of the first route; and for any of the aligned second latitudes, based on the second field strength data, the second main magnetic field strength data and the second daily variable field strength data of the second latitude, obtain multiple second abnormal field strength data of the second route.

[0061] Specifically, on the basis of step S33, for any first latitude, the first field strength data at the first latitude is subtracted from the first main magnetic field strength data and the first daily variable field strength data to obtain the first difference information of the first latitude, and the first difference information is determined as a plurality of first abnormal field data of the first route, and for any aligned second latitude, the second field strength data at the second latitude is subtracted from the second main magnetic field strength data and the second daily variable field strength data to obtain the second difference information of the second latitude, and the second difference information is determined as a plurality of second abnormal field strength data of the second route.

[0062] In this embodiment, the first field strength data or the second field strength data are the total field strength data of the first route or the second route at a certain measurement point, including the main magnetic field strength data, the daily variable field strength data, and the abnormal variable field strength data. When the total field strength data, the main magnetic field strength data, and the daily variable field strength data of each route are measured, the abnormal variable field strength data of each route can be calculated. Since the difference in abnormal field strength data between different routes is small, the field strength data can be calibrated based on the analysis of the abnormal field data.

[0063] For example, the first abnormal field strength data at a first latitude For example, the above first abnormal field strength data The first field strength data at the current first latitude , the first main magnetic field strength data And the first day's variable field strength data The difference is obtained, where the first abnormal field strength data .

[0064] For example, the first abnormal field strength data at a second latitude For example, the above first abnormal field strength data The first field strength data at the current first latitude , the first main magnetic field strength data And the first day's variable field strength data The difference is obtained, where the first abnormal field strength data .

[0065] See also Figure 4 In one embodiment, based on step S5, the conversion matrix includes a translation matrix and a rotation matrix; obtaining the conversion matrix for the second route based on the first abnormal field strength data, the second abnormal field strength data, and the second field strength data, and converting the second field strength data into calibration field strength data for the second route according to the conversion matrix includes:

[0066] S51: Acquire the translation matrix and the rotation matrix of the second route according to the first abnormal field strength data, the second abnormal field strength data, and the second field strength data;

[0067] S53: Based on the translation matrix and the rotation matrix, convert the second field intensity data into the calibration field intensity data.

[0068] The translation matrix is ​​used to eliminate the position deviation between the first route and the second route, thereby eliminating the magnetic interference error. The magnetic interference error is mainly caused by the magnetic interference of the aircraft itself, which causes the vector geomagnetic data measured by the geomagnetic sensor to be offset.

[0069] The rotation matrix is ​​used to eliminate the attitude deviation between the first and second routes, thereby eliminating the attitude error. The attitude error is mainly caused by the different attitude angles between different routes, which leads to attitude errors in the measured vector geomagnetic data.

[0070] In this embodiment, the rotation matrix and the translation matrix can be calculated using the least squares method based on the first abnormal field strength data, the second abnormal field strength data, and the second field strength data. Specifically, the translation matrix and the rotation matrix can be obtained according to the following method: By correcting the direction deviation and attitude deviation of the magnetic field vector of the second route, the attitude error and magnetic interference error are eliminated, and a relatively smooth three-dimensional vector geomagnetic map is constructed so that the above three-dimensional vector geomagnetic map has no stripe error.

[0071] In this embodiment, the difference in the abnormal field strength data between different routes is small, so it can be considered that Approximately equal to ,because ,Sure ,in, is the rotation matrix, is the translation matrix, is the second field strength data, is the first abnormal field strength data, is the second abnormal field strength data. Further, the rotation matrix is ​​calculated by the least square method and translation matrices .

[0072] In this embodiment, the second field strength data is processed based on the translation matrix and the rotation matrix to obtain calibrated field strength data for the calibrated second route. Specifically, the calibrated field strength data is transformed based on the rotation matrix to obtain initial calibration data, and the initial calibration data is translated using the translation matrix to obtain the calibrated field strength data.

[0073] Exemplarily, the second field strength data is transformed by left-multiplying the rotation matrix and adding the translation matrix. The above-mentioned initial calibration data and calibration field strength data are represented as follows: , ,in, is the initial calibration data, To calibrate the field strength data, is the rotation matrix, is the second field strength data, is the translation matrix. Left multiply the rotation matrix , to obtain the initial calibration data , the initial calibration data Add the translation matrix , to obtain the calibrated field strength data of the calibrated second route .

[0074] In this embodiment, the position deviation and attitude deviation of the magnetic field vector of the second route relative to the first route can be corrected by solving a transformation matrix including a translation matrix and a rotation matrix. Specifically, the translation matrix and the rotation matrix are calculated based on the second abnormal field strength data, the first abnormal field strength data, and the second field strength data. The second field strength data of the second route is multiplied on the left by the rotation matrix and added to the translation matrix to calibrate the second field strength data, thereby obtaining the calibrated field strength data for the second route.

[0075] The technical solution provided in this embodiment calculates a translation matrix and a rotation matrix by analyzing the changes in the first and second abnormal field strength data to align the geomagnetic data of different routes. The translation matrix can eliminate magnetic interference errors in the field strength data between different routes, and the rotation matrix can eliminate attitude errors in the field strength data between different routes. This effectively reduces the jumps and discontinuities between the geomagnetic data of different routes, constructs a smooth transition three-dimensional vector geomagnetic map, and solves the problem of striping errors.

[0076] Please refer to Figure 5 This application provides an embodiment of the above-mentioned vector geomagnetic calibration method based on multi-route data alignment. The embodiment includes three routes, L1, L2, and L3. The geomagnetic data of the three routes are calibrated according to the following steps:

[0077] Step 1: Use the latitude information of the first flight as the reference latitude information to obtain the second latitude information and second field strength data of the second flight , and obtain the third latitude information and third field strength data of the third flight .

[0078] Step 2: Align the third latitude information of the third flight according to the second latitude information, based on the third field strength data of the third flight and the second field strength data Calculate the first rotation matrix and the first translation matrix ,according to Calculate the third field strength data for the third flight based on the calibration of the second flight .

[0079] Step 3: Obtain the first field strength data of the first flight, based on the second field strength data of the second flight and the first field strength data of the first flight Calculate the first rotation matrix and the first translation matrix ,according to Calculate the second field strength data for the second flight based on the calibration of the first flight , and according to Calculate the third field strength data for the third flight based on the calibration of the first flight .

[0080] In this embodiment, the third field strength data for the third flight is first aligned with the data for the second flight, and then aligned with the data for the first flight. Similarly, when there are more than three flight routes, the data for all flights are recursively aligned with the data for the first flight, completing the alignment of all route data and constructing a smooth three-dimensional vector geomagnetic map to avoid banding errors that affect navigation accuracy.

[0081] See also Figure 6 The present application also provides a vector geomagnetic calibration device based on multi-route data alignment, the device comprising:

[0082] A latitude alignment unit 100 is configured to obtain a plurality of first latitudes of a first route and a plurality of second latitudes of a second route, and align each of the second latitudes with each of the first latitudes;

[0083] The data acquisition unit 200 determines a plurality of first field strength data at the first latitude and a plurality of second field strength data at the second latitude based on the alignment result, and acquires a plurality of first abnormal field strength data for the first route based on the first field strength data, and acquires a plurality of second abnormal field strength data for the second route based on the second field strength data;

[0084] The data calibration unit 300 is used to obtain the conversion matrix of the second route based on the first abnormal field strength data, the second abnormal field strength data and the second field strength data, and convert the second field strength data into calibration field strength data of the second route according to the conversion matrix.

[0085] In one embodiment, the latitude alignment unit 100 is specifically configured to determine, for any first latitude, two second latitudes adjacent to the first latitude, and align any second latitude adjacent to the first latitude with the first latitude so that the second latitude is parallel to the first latitude.

[0086] In one embodiment, the data acquisition unit 200 is specifically used to obtain the first field strength data of the first latitude for any first latitude, and obtain two initial field strength data of two second latitudes adjacent to the first latitude, and determine the second field strength data of the second route at the aligned second latitude based on the two initial field strength data.

[0087] In one embodiment, the data acquisition unit 200 is also used to obtain the first main magnetic field strength data and the first daily varying field strength data of each first latitude, and to obtain the second main magnetic field strength data and the second daily varying field strength data of each second latitude aligned with the first latitude. For any first latitude and the aligned second latitude, the first field strength data of the first latitude is subtracted from the first main magnetic field strength data and the first daily varying field strength data to obtain multiple first abnormal field data of the first route, and the second field strength data of the second latitude is subtracted from the second main magnetic field strength data and the second daily varying field strength data to obtain multiple second abnormal field strength data of the second route.

[0088] In one embodiment, the data calibration unit 300 is specifically used to obtain the translation matrix and the rotation matrix of the second route based on the first abnormal field strength data, the second abnormal field strength data and the second field strength data, and convert the second field strength data into the calibration field strength data based on the translation matrix and the rotation matrix.

[0089] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0090] In an embodiment of the present application, a vector geomagnetic calibration device based on multi-route data alignment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, or other devices that can provide the above functions.

[0091] See also Figure 7 , Figure 7 This is a schematic diagram of the structure of a computer device provided in an embodiment of the present application. Figure 7 As shown, the computer device includes: one or more processors 10, memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 7 A processor 10 is taken as an example.

[0092] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0093] The memory 20 stores instructions that can be executed by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0094] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0095] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0096] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0097] The embodiments of the present application also provide a computer-readable storage medium. The above-mentioned method according to the embodiment of the present application can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0098] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

[0099] The devices or units described in the above embodiments may be implemented by computer chips or entities, or by products having certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0100] For the convenience of description, the above devices are described as being divided into various units according to their functions. Of course, when implementing this application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0101] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods or apparatuses. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0102] The present application is described with reference to the flowcharts and / or block diagrams of the methods or apparatuses according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0103] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0105] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0106] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences from other embodiments. In particular, the device embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0107] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

[0108] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A vector geomagnetic calibration method based on multi-route data alignment, characterized in that: The method comprises: Acquire a plurality of first latitudes of a first route and a plurality of second latitudes of a second route, align each of the second latitudes with each of the first latitudes, and determine a plurality of first field strength data of the first latitudes and a plurality of second field strength data of the second latitudes based on the alignment result; Acquire a plurality of first abnormal field strength data of the first route based on the first field strength data, and acquire a plurality of second abnormal field strength data of the second route based on the second field strength data; Acquire a conversion matrix for the second route based on the first abnormal field strength data, the second abnormal field strength data, and the second field strength data, and convert the second field strength data into calibrated field strength data for the second route according to the conversion matrix; The step of aligning each of the second latitudes with each of the first latitudes and determining, based on the alignment result, a plurality of first field intensity data at the first latitudes and a plurality of second field intensity data at the second latitudes comprises: For any first latitude, obtaining first field strength data of the first latitude, and determining two second latitudes adjacent to the first latitude, and obtaining two initial field strength data of the two second latitudes; aligning any second latitude adjacent to the first latitude with the first latitude so that the second latitude is parallel to the first latitude; Based on the first latitude and the first field strength data at the first latitude and the initial field strength data at the two adjacent second latitudes and the second latitude, the second field strength data at the aligned second latitude of the second route is determined.

2. The method according to claim 1, characterized in that Before acquiring a plurality of first abnormal field strength data of the first route based on the first field strength data, the method further includes: Acquiring first attitude data of the first route, determining a first coordinate rotation matrix based on the first attitude data, multiplying the first field intensity data by the first coordinate rotation matrix, and re-determining the first field intensity data based on a result of the multiplication of the first coordinate rotation matrix; Obtain second posture data of the second route, determine a second coordinate rotation matrix based on the second posture data, multiply the second field intensity data by the second coordinate rotation matrix, and re-determine the second field intensity data based on the multiplication result of the second coordinate rotation matrix.

3. The method according to claim 1, characterized in that Acquiring a plurality of first abnormal field strength data of the first route based on the first field strength data, and acquiring a plurality of second abnormal field strength data of the second route based on the second field strength data includes: Acquire first main magnetic field strength data and first diurnal variable field strength data at each of the first latitudes, and acquire second main magnetic field strength data and second diurnal variable field strength data at each of the second latitudes aligned with the first latitudes; For any of the first latitudes, acquiring a plurality of first abnormal field data of the first route based on the first field strength data, the first main magnetic field strength data, and the first diurnal field strength data at the first latitude; And for any aligned second latitude, based on the second field strength data of the second latitude, the second main magnetic field strength data and the second daily varying field strength data, multiple second abnormal field strength data of the second route are obtained.

4. The method according to claim 3, characterized in that Acquiring the first abnormal field strength data and the second abnormal field strength data includes: For any of the first latitudes, generating first difference information between the first field strength data at the first latitude and the first main magnetic field strength data and the first daily variable field strength data, and determining the first difference information as a first abnormal field data of the first route; And for any aligned second latitude, generate second difference information between the second field strength data of the second latitude and the second main magnetic field strength data and the second daily variable field strength data, and determine the second difference information as a second abnormal field strength data of the second route.

5. The method according to claim 1, wherein The conversion matrix includes a translation matrix and a rotation matrix; obtaining the conversion matrix of the second route based on the first abnormal field strength data, the second abnormal field strength data, and the second field strength data, and converting the second field strength data into calibration field strength data for the second route according to the conversion matrix includes: acquiring the translation matrix and the rotation matrix of the second route according to the first abnormal field strength data, the second abnormal field strength data, and the second field strength data; And based on the translation matrix and the rotation matrix, the second field intensity data is converted into the calibration field intensity data.

6. The method according to claim 5, characterized in that Converting the second field intensity data into the calibration field intensity data based on the translation matrix and the rotation matrix includes: Changing the second field strength data based on the rotation matrix to obtain initial calibration data; The initial calibration data is translated using a translation matrix to obtain the calibration field strength data.

7. A vector geomagnetic calibration device based on multi-route data alignment, characterized in that: The device comprises: a latitude alignment unit, configured to obtain a plurality of first latitudes of the first route and a plurality of second latitudes of the second route, and align each of the second latitudes with each of the first latitudes; a data acquisition unit, determining a plurality of first field strength data at the first latitude and a plurality of second field strength data at the second latitude based on the alignment result, and acquiring a plurality of first abnormal field strength data for the first route based on the first field strength data, and acquiring a plurality of second abnormal field strength data for the second route based on the second field strength data; a data calibration unit, configured to obtain a conversion matrix for the second route based on the first abnormal field strength data, the second abnormal field strength data, and the second field strength data, and convert the second field strength data into calibrated field strength data for the second route according to the conversion matrix; The step of aligning each of the second latitudes with each of the first latitudes and determining, based on the alignment result, a plurality of first field intensity data at the first latitudes and a plurality of second field intensity data at the second latitudes comprises: For any first latitude, obtaining first field strength data of the first latitude, and determining two second latitudes adjacent to the first latitude, and obtaining two initial field strength data of the two second latitudes; aligning any second latitude adjacent to the first latitude with the first latitude so that the second latitude is parallel to the first latitude; Based on the first latitude and the first field strength data at the first latitude and the initial field strength data at the two adjacent second latitudes and the second latitude, the second field strength data at the aligned second latitude of the second route is determined.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the vector geomagnetic calibration method based on multi-route data alignment according to any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute a vector geomagnetic calibration method based on multi-route data alignment according to any one of claims 1 to 6.

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