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

Abstract

The invention relates to the technical field of geomagnetic navigation, and discloses a vector geomagnetic calibration method and device based on multi-route data alignment, and the method comprises the steps: obtaining a plurality of first latitudes of a first route and a plurality of second latitudes of a second route, and aligning each second latitude with the first latitude, 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; acquiring a plurality of first abnormal field intensity data of the first route based on the first field intensity data, and acquiring a plurality of second abnormal field intensity data of the second route based on the second field intensity data; and obtaining a conversion matrix of the second route based on the first abnormal field intensity data, the second abnormal field intensity data and the second field intensity data, and converting the second field intensity data into calibration field intensity data of the second route according to the conversion matrix. According to the technical scheme provided by multiple embodiments of the invention, strip errors generated when the three-dimensional vector geomagnetic map is constructed can be eliminated.

Description

Technical Field

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

[0002] Currently, when collecting geomagnetic data of an aircraft, an inertial navigation system and a geomagnetic sensor are usually used to obtain geomagnetic data of different routes.

[0003] In practical applications, since the inertial navigation system will cause an initial alignment error during acquisition, and the attitude change and external environmental interference of the aircraft will cause magnetic interference errors, the geomagnetic data of different routes will show obvious jumps after being converted to the geographic coordinate system, resulting in strip errors when constructing a three-dimensional vector geomagnetic map, which affects the accuracy and reliability of geomagnetic navigation.

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

[0005] This application provides a vector geomagnetic calibration method and device based on multi-route data alignment, which can eliminate the strip errors generated when constructing a three-dimensional vector geomagnetic map from multi-route geomagnetic data.

[0006] The first aspect of this application provides a vector geomagnetic calibration method based on multi-route data alignment. The method includes: obtaining a plurality of first latitudes of a first route and a plurality of second latitudes of a second route, aligning each of the second latitudes with each of the first latitudes, and determining 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; 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; obtaining a transformation 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 calibrated field strength data of the second route according to the transformation matrix.

[0007] In a possible implementation manner, aligning each of the second latitudes with each of the first latitudes and determining a plurality of first field strength data of the first latitude and a plurality of second field strength data of the second latitude based on the alignment result includes: for any one of the first latitudes, obtaining the first field strength data of the first latitude, determining two second latitudes adjacent to the first latitude, obtaining two initial field strength data of the two second latitudes, aligning any one of the second latitudes 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 passing through the aligned second latitude based on the first latitude, the first field strength data of the first latitude, and the two adjacent second latitudes and the initial field strength data of the second latitude.

[0008] In a possible implementation manner, before obtaining a plurality of first abnormal field strength data of the first route based on the first field strength data, the method further includes: obtaining first attitude data of the first route, determining a first coordinate rotation matrix according to the first attitude data, multiplying the first field strength data by the first coordinate rotation matrix, and re-determining the first field strength data based on the result of multiplying the first coordinate rotation matrix; obtaining second attitude data of the second route, determining a second coordinate rotation matrix according to the second attitude data, multiplying the second field strength data by the second coordinate rotation matrix, and re-determining the second field strength data based on the result of multiplying the second coordinate rotation matrix.

[0009] In a possible implementation manner, 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: obtaining first main magnetic field strength data and first diurnal variation field strength data of each of the first latitudes, and obtaining second main magnetic field strength data and second diurnal variation field strength data of each of the second latitudes aligned with the first latitudes. For any one of the first latitudes, obtaining a plurality of first abnormal field data of the first route based on the first field strength data of the first latitude, the first main magnetic field strength data, and the first diurnal variation field strength data, and for any one of the aligned second latitudes, obtaining a plurality of second abnormal field strength data of the second route based on the second field strength data of the second latitude, the second main magnetic field strength data, and the second diurnal variation field strength data.

[0010] In a possible implementation manner, obtaining the first abnormal field intensity data and the second abnormal field intensity data includes: for any one of the first latitudes, generating first difference information between the first field intensity data of the first latitude and the first main magnetic field intensity data and the first diurnal variation field intensity data, and determining the first difference information as one first abnormal field data of the first flight path; and for any one of the aligned second latitudes, generating second difference information between the second field intensity data of the second latitude and the second main magnetic field intensity data and the second diurnal variation field intensity data, and determining the second difference information as one second abnormal field intensity data of the second flight path.

[0011] In a possible implementation manner, the transformation matrix includes a translation matrix and a rotation matrix; obtaining the transformation matrix of the second flight path based on the first abnormal field intensity data, the second abnormal field intensity data, and the second field intensity data, and converting the second field intensity data into the calibrated field intensity data of the second flight path according to the transformation matrix includes: obtaining the translation matrix and the rotation matrix of the second flight path according to the first abnormal field intensity data, the second abnormal field intensity data, and the second field intensity data; and based on the translation matrix and the rotation matrix, converting the second field intensity data into the calibrated field intensity data.

[0012] In a possible implementation manner, based on the translation matrix and the rotation matrix, converting the second field intensity data into the calibrated field intensity data includes: varying the calibrated field intensity data based on the rotation matrix to obtain initial calibrated data, and translating the initial calibrated data using the translation matrix to obtain the calibrated field intensity data.

[0013] The second aspect of the present application provides a vector geomagnetic calibration device based on multi-flight path data alignment. The device includes: a latitude alignment unit, configured to obtain a plurality of first latitudes of a first flight path and a plurality of second latitudes of a second flight path, and align each of the second latitudes with each of the first latitudes; a data acquisition unit, configured to determine a plurality of first field intensity data of the first latitudes and a plurality of second field intensity data of the second latitudes based on the alignment result, obtain a plurality of first abnormal field intensity data of the first flight path based on the first field intensity data, and obtain a plurality of second abnormal field intensity data of the second flight path based on the second field intensity data; and a data calibration unit, configured to obtain the transformation matrix of the second flight path based on the first abnormal field intensity data, the second abnormal field intensity data, and the second field intensity data, and convert the second field intensity data into the calibrated field intensity data of the second flight path according to the transformation matrix.

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

[0015] A fourth aspect of the present application provides a computer-readable storage medium, on which computer instructions are stored. The computer instructions are used to cause 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 aligns and calibrates the geomagnetic field strength data of multiple routes according to the latitude information of the reference route to avoid data jumps and strip 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 is 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 transformation matrix, so that the field strength data of each route after transformation is as close as possible to the field strength data of the reference route, to eliminate the attitude error and magnetic interference error, and avoid strip errors when constructing a three-dimensional vector geomagnetic map due to data jumps.

[0017] It can be seen that the technical solution provided by the present application can avoid data jumps when obtaining the geomagnetic data of each route, and at the same time, eliminate the strip 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 embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a step diagram of a vector geomagnetic calibration method based on multi-route data alignment provided by an embodiment of the present application; Figure 2 It is a latitude schematic diagram of the first route and the second route provided by an embodiment of the present application; Figure 3 It is a method step diagram for obtaining the field strength data of the first abnormal field and the field strength data of the second abnormal field provided by an embodiment of the present application; Figure 4 It is a method step diagram for obtaining a transformation matrix provided by an embodiment of the present application; Figure 5 Schematic diagram of the flight path for the vector geomagnetic calibration method based on the alignment of three flight path data provided by an embodiment of the present application; Figure 6 Schematic diagram of the structure of a vector geomagnetic calibration device based on the alignment of multi-flight path data provided by an embodiment of the present application; Figure 7 Schematic diagram of the structure of a computer device provided by an embodiment of the present application. Detailed implementation manners

[0020] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0021] In addition, the descriptions involving "first", "second", etc. in the present application are only for descriptive purposes, and cannot be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the embodiments of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more. In addition, the use of "based on" or "according to" means open and inclusive, because a process, step, calculation or other action "based on" or "according to" one or more of the stated conditions or values may in practice be based on additional conditions or values beyond those stated.

[0022] With the continuous development of the modern navigation industry, three-dimensional vector geomagnetic mapping and navigation technology, as one of the important research directions in the modern navigation field, can provide rich information for the geomagnetic positioning and navigation of aircraft by collecting vector geomagnetic data of different flight paths and constructing a three-dimensional vector geomagnetic map according to the vector geomagnetic data. Generally speaking, in the absence of measurement errors, it can be considered that the magnitudes of the three-component geomagnetic fields at the same position on overlapping flight paths or adjacent flight paths with the same heading are equal or close. Therefore, vector geomagnetic information of overlapping flight paths or adjacent flight paths with the same heading is usually collected to construct a vector geomagnetic data map.

[0023] In practical applications, vector geomagnetic data of each flight path 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. Exemplarily, if the initial pitch angle error is 0.1°, the position error may reach hundreds of meters after flying for 1 hour. The attitude error causes obvious jumps when converting the vector geomagnetic data of different flight paths into the geographic coordinate system. At this time, obvious strip errors will exist when constructing a three-dimensional vector geomagnetic map. Moreover, magnetic interference errors will occur when the aircraft attitude changes rapidly. In addition, due to the metal structures, electronic devices or external electromagnetic fields around the aircraft, the measurement of the geomagnetic sensor will also be interfered, resulting in magnetic interference errors, thus exacerbating the data jump.

[0024] Furthermore, when obvious strip errors exist in the constructed three-dimensional vector geomagnetic map, the geomagnetic data in some areas will be discontinuous or mutated. The navigation system may misidentify the position, resulting in a decrease in navigation accuracy, which may pose a safety hazard when the aircraft based on geomagnetic navigation conducts path planning. In view of this, how to eliminate the strip errors generated when constructing a three-dimensional vector geomagnetic map to ensure the high precision and robustness of geomagnetic navigation is an urgent problem to be solved.

[0025] In view of this, one or more embodiments of the present application provide a vector geomagnetic calibration method and device based on multi-flight path data alignment, which can solve the above problems and eliminate the strip errors generated when constructing a three-dimensional vector geomagnetic map.

[0026] Please refer to Figure 1 , one embodiment of the present application provides a vector geomagnetic calibration method based on multi-flight path data alignment. The method may include the following steps: S1: Obtain a plurality of first latitudes of a first flight path and a plurality of second latitudes of a second flight path, 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.

[0027] The above-mentioned first flight path and the above-mentioned second flight path are adjacent flight paths or overlapping flight paths in the same heading. It is generally considered that the magnitudes of the three-component geomagnetic fields at the same position on the overlapping flight paths or adjacent flight paths in the same heading are equal or close. A vector geomagnetic map is constructed by collecting the geomagnetic elements of the above-mentioned first flight path and the above-mentioned second flight path. The above-mentioned geomagnetic elements include a plurality of physical quantities representing the direction and magnitude of the earth's magnetic field. As one of the geomagnetic elements, the measured field strength data is usually represented in the form of a vector.

[0028] In this embodiment, when collecting vector geomagnetic data, it is necessary to obtain the latitude information of the first flight path and the second flight path. Specifically, the above-mentioned first flight path and second flight path usually consist of a series of measurement points, and each measurement point has its corresponding latitude information. The latitude information of each measurement point on the first flight path is taken as the first latitude, and the latitude information of each measurement point on the second flight path is taken as the second latitude, so as to obtain a plurality of first latitudes and a plurality of second latitudes.

[0029] In this embodiment, since the different positions of the above-mentioned first flight path and the second flight path will bring certain magnetic field change effects, it is necessary to align the field strength data of the first flight path and the second flight path to the same latitude. Specifically, each of the first latitudes is taken as the reference latitude, and for any second latitude, it is aligned with one of the first latitudes of the first flight path, so that the above-mentioned second latitude is as close as possible to the position of the above-mentioned first latitude. Among them, by aligning the measurement points of different flight paths according to the latitude information, it can be ensured that the geomagnetic data is calibrated at the same or similar latitudes.

[0030] Further, after aligning the second latitudes of the second flight path with the first latitudes of the first flight path, the field strength data of the measurement points represented by the first flight path at each latitude is obtained. For each of the first latitudes, the total field strength data of the first flight path at the above-mentioned first latitude is measured as the first field strength data, and for each of the second latitudes after alignment, the total field strength data of the second flight path at the above-mentioned second latitude is measured as the second field strength data.

[0031] S3: Obtain a plurality of first abnormal field strength data of the first flight path based on the first field strength data, and obtain a plurality of second abnormal field strength data of the second flight path based on the second field strength data.

[0032] The measured first field strength data and second field strength data usually include main magnetic field strength data, daily variation field strength data, and abnormal variation field strength data. Among them, the abnormal field strength data is local and irregular in space, and can be understood as the magnetic field anomaly caused by local geological structures, human activities, or other environmental factors. Therefore, the difference in abnormal field strength data between different flight paths is relatively small.

[0033] In this embodiment, based on the first field strength data and the second field strength data, the abnormal field strength data of each flight path can be calculated by obtaining the main magnetic field strength data and the daily variation field strength data. The main magnetic field strength data is the main part of the geomagnetic field and has long-term stability. The daily variation field strength data is the short-term variation caused by solar activities and has obvious time variation characteristics. Therefore, the main magnetic field strength data and the daily variation field strength data are relatively easy to obtain. Based on the main magnetic field strength data and the daily variation field strength data of the first flight path and the second flight path, the difference is taken between each first field strength data and each second field strength data, and multiple first abnormal field strength data and multiple second abnormal field strength data of the first flight path can be obtained.

[0034] Optionally, the abnormal field strength data can also be extracted from the total field strength data through a filtering and separation algorithm. Exemplarily, the above filtering algorithm can adopt the Fourier transform algorithm or the Kalman filtering algorithm, and the above separation algorithm can adopt the independent component analysis algorithm or the principal component analysis algorithm. By decomposing the above first field strength data and second field strength data into components of different frequencies, the frequency range where the abnormal field strength data is located is identified and extracted through the filtering algorithm, and the abnormal field strength data is further separated through the separation algorithm.

[0035] S5: Obtain the transformation matrix of the second flight path 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 calibrated field strength data of the second flight path according to the transformation matrix.

[0036] The above transformation matrix is used to correct the position deviation and attitude deviation when obtaining geomagnetic data between the first flight path and the second flight path, so as to eliminate the attitude error and magnetic interference error, avoid data jumps, and thus avoid stripe errors when generating a three-dimensional vector geomagnetic map.

[0037] Optionally, the least squares method can be used to solve the transformation matrix, and the best fitting parameters of the second field strength data are found by minimizing the error between the first abnormal field data and the second abnormal field data, which can include a rotation matrix and a translation matrix, and the above rotation matrix and translation matrix are used as the transformation matrix. Exemplarily, the transformation matrix can also be solved based on methods for finding the optimal solution such as iterative algorithms, genetic algorithms, etc. or based on constructing a neural network model through deep learning.

[0038] In this embodiment, by solving the transformation matrix, the attitude error and magnetic interference error of the magnetic field vector of the second flight path relative to the first flight path can be corrected. Specifically, the transformation matrix is solved according to the first abnormal field data, the second abnormal field data and the second field strength data. After the above second field strength data is transformed by the transformation matrix, it is as close as possible to the first field strength data of the first flight path, and the transformed second field strength data is used as the calibrated field strength data of the second flight path after vector geomagnetic calibration.

[0039] The technical solution provided by this embodiment aligns and calibrates the geomagnetic field strength data of the first flight path and the second flight path according to the latitude information to avoid data jumps and strip errors. Specifically, by aligning the measurement points of different flight paths according to the latitude information, calibrating the geomagnetic data at the same or similar latitudes, and correcting the position deviation and attitude deviation of the geomagnetic data of the first flight path and the second flight path by solving the transformation matrix, the converted second field strength data is made as close as possible to the first field strength data of the first flight path, so as to eliminate the attitude error and magnetic interference error and avoid strip errors caused by data jumps when constructing a three-dimensional vector geomagnetic map.

[0040] In one embodiment, on the basis of step S1, aligning each of the second latitudes with each of the first latitudes, and determining 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 includes: For any one of the first latitudes, 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 one of the second latitudes 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 latitude, the first field strength data of the first latitude, and the two adjacent second latitudes and the initial field strength data of the second latitudes, determine the second field strength data of the second flight path at the aligned second latitude.

[0041] Specifically, the above-mentioned second field strength data can be represented in the following manner: , where is the second field strength data, is a first latitude, is an adjacent second latitude, is the other adjacent second latitude, is the corresponding initial field strength data, is the corresponding initial field strength data.

[0042] Please refer to Figure 2 , in this embodiment, taking each of the first latitudes of the first flight path as a reference, align each of the second latitudes of the second flight path with each of the first latitudes. Specifically, for any one first latitude , determine the second latitudes and the second latitude adjacent to the first latitude, and obtain the initial field strength data at the and Initial field strength data at latitude For any second latitude, using the above-mentioned second latitude as an example, the aligned field strength data is calculated by linear interpolation, and the aligned field strength data is used as the second field strength data. It should be noted that the above-mentioned second latitudes that need to be aligned are data points within the latitude range of the first latitude of the first flight path.

[0043] In another embodiment, the first latitudes and the second latitudes can also be aligned by means of multiple spline curve interpolations. After determining the second latitude and the corresponding initial field strength data , by constructing a cubic spline interpolation function, the corresponding second field strength data is calculated according to the first latitude .

[0044] In this embodiment, by aligning the data of the second flight path with the data of the first flight path in terms of latitude, it is ensured that the two sets of data correspond one by one in latitude. For adjacent flight paths with the same heading, the geomagnetic distribution of the adjacent data of the adjacent flight paths is made smoother, thereby providing reference data for the subsequent calibration of the field strength data to construct a smoothly transitional three-dimensional vector geomagnetic map and solve the problem of strip error. It should be noted that the alignment and calibration of the flight path data of multiple flights can also be performed according to the recursive method.

[0045] In one embodiment, before step S3, the above-mentioned first field strength data and the above-mentioned second field strength data also need to be converted from the vehicle coordinate system to the geographic coordinate system to eliminate the influence of the aircraft attitude on the data. In addition, if no conversion is performed, the measurement data under different attitudes cannot be compared or fused in the same geographic coordinate system.

[0046] In this embodiment, the method for converting the above-mentioned second field strength data from the vehicle coordinate system to the geographic coordinate system includes: obtaining the first attitude data of the first flight path, determining the first coordinate rotation matrix according to the first attitude data, multiplying the first field strength data by the first coordinate rotation matrix, and re-determining the first field strength data based on the result of multiplying by the first coordinate rotation matrix; obtaining the second attitude data of the second flight path, determining the second coordinate rotation matrix according to the second attitude data, multiplying the second field strength data by the second coordinate rotation matrix, and re-determining the second field strength data based on the result of multiplying by the second coordinate rotation matrix.

[0047] The above carrier coordinate system is a local coordinate system referenced to the aircraft or measurement carrier, with the forward, left, and upward directions of the aircraft on the first flight path and the second flight path as the x, y, and z axes respectively. The above geographic coordinate system is a geographic coordinate system based on geographic directions, such as the northeast celestial coordinate system, pointing to the geographic east, geographic north, and the vertical direction pointing to the center of the earth respectively. The above attitude data includes the pitch angle, roll angle, and heading angle of the aircraft, which can be directly measured by an inertial navigation system.

[0048] In this embodiment, by constructing the coordinate rotation matrices of the first flight path and the second flight path, the field strength data is subjected to coordinate transformation. Specifically, the first attitude data of the first flight path is obtained, including the pitch angle, roll angle, and heading angle at each first latitude of the first flight path, and the second attitude data of the second flight path is obtained, including the pitch angle, roll angle, and heading angle at each second latitude of the second flight path. Based on the above first attitude data and the above second attitude data, the first coordinate rotation matrix of the first flight path and the second coordinate rotation matrix of the second flight path are constructed.

[0049] Exemplarily, taking the first coordinate rotation matrix of the first flight path as an example, the above first coordinate rotation matrix , where is the rotation matrix for rotation about the z-axis, representing the rotation matrix of the heading angle, is the rotation matrix for rotation about the x-axis, representing the rotation matrix of the roll angle, is the rotation matrix for rotation about the y-axis, representing the rotation matrix of the pitch angle. Similarly, the above second coordinate rotation matrix , where is the rotation matrix for rotation about the z-axis, representing the rotation matrix of the heading angle, is the rotation matrix for rotation about the x-axis, representing the rotation matrix of the roll angle, is the rotation matrix for rotation about the y-axis, representing the rotation matrix of the pitch angle.

[0050] Please refer to Figure 3 , in one embodiment, on the basis of step S3, obtaining the multiple first abnormal field strength data of the first flight path based on the first field strength data, and obtaining the multiple second abnormal field strength data of the second flight path based on the second field strength data includes the following steps: S31: Obtain the first main magnetic field strength data and the first daily variation field strength data of each of the first latitudes, and obtain the second main magnetic field strength data and the second daily variation field strength data of each of the second latitudes aligned with the first latitudes.

[0051] S33: For any one of the first latitudes, based on the first magnetic field strength data, the first main magnetic field strength data, and the first daily variation magnetic field strength data of the first latitude, obtain multiple first abnormal field data of the first route; and for any aligned second latitude, based on the second magnetic field strength data, the second main magnetic field strength data, and the second daily variation magnetic field strength data of the second latitude, obtain multiple second abnormal field strength data of the second route.

[0052] Specifically, based on step S33, for any one of the first latitudes, subtract the first magnetic field strength data, the first main magnetic field strength data, and the first daily variation magnetic field strength data of the first latitude to obtain first difference information of the first latitude, and determine the first difference information as multiple first abnormal field data of the first route; and for any aligned second latitude, subtract the second magnetic field strength data, the second main magnetic field strength data, and the second daily variation magnetic field strength data of the second latitude to obtain second difference information of the second latitude, and determine the second difference information as multiple second abnormal field strength data of the second route.

[0053] In this embodiment, the above first magnetic field strength data or the second magnetic field strength data is the total magnetic 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 variation magnetic field strength data, and the abnormal variation magnetic field strength data. When the total magnetic field strength data, the main magnetic field strength data, and the daily variation magnetic field strength data of each route are measured, the abnormal variation magnetic field strength data of each route can be calculated. Since the difference in the abnormal field strength data between different routes is small, the magnetic field strength data can be calibrated based on the analysis of the abnormal field data.

[0054] Exemplarily, taking the first abnormal field strength data of a first latitude as an example, the above first abnormal field strength data is obtained by subtracting the first magnetic field strength data , the first main magnetic field strength data , and the first daily variation magnetic field strength data under the current first latitude, where the first abnormal field strength data .

[0055] Exemplarily, taking the first abnormal field strength data of a second latitude as an example, the above first abnormal field strength data is obtained by subtracting the first magnetic field strength data , the first main magnetic field strength data , and the first daily variation magnetic field strength data under the current first latitude, where the first abnormal field strength data .

[0056] Please refer to Figure 4 , in one embodiment, based on step S5, the transformation matrix includes a translation matrix and a rotation matrix; obtaining the transformation matrix of the second flight path 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 calibrated field strength data of the second flight path according to the transformation matrix includes: S51: Obtain the translation matrix and the rotation matrix of the second flight path according to the first abnormal field strength data, the second abnormal field strength data, and the second field strength data; S53: And based on the translation matrix and the rotation matrix, convert the second field strength data into the calibrated field strength data.

[0057] The above translation matrix is used to eliminate the position deviation between the first flight path and the second flight path, thereby eliminating the magnetic interference error. The above magnetic interference error mainly results from the magnetic interference of the vehicle itself, causing the vector geomagnetic data measured by the geomagnetic sensor to deviate.

[0058] The above rotation matrix is used to eliminate the attitude deviation between the first flight path and the second flight path, thereby eliminating the attitude error. The above attitude error mainly results from different attitude angles between different flight paths, causing the vector geomagnetic data measured to have an attitude error.

[0059] In this embodiment, the rotation matrix and the translation matrix can be calculated by the least squares method according to the first abnormal field strength data, the second abnormal field strength data, and the second field strength data. Specifically, the above translation matrix and rotation matrix can be obtained in the following manner: , by correcting the direction deviation and attitude deviation of the magnetic field vector of the second flight path, thereby eliminating the attitude error and the magnetic interference error, and constructing a relatively smooth three-dimensional vector geomagnetic map, so that the above three-dimensional vector geomagnetic map has no strip error.

[0060] In this embodiment, according to the small difference in the abnormal field strength data between different flight paths, it can be considered that is approximately equal to , since , determine , where 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 and the translation matrix are calculated according to the least squares method.

[0061] In this embodiment, the second field strength data is processed according to the translation matrix and the rotation matrix to obtain the calibrated field strength data of the second flight path. Specifically, the calibrated field strength data is transformed based on the rotation matrix to obtain the initial calibration data, and the initial calibration data is translated using the translation matrix to obtain the calibrated field strength data.

[0062] Exemplarily, the second field strength data is transformed by left multiplying the rotation matrix and adding the translation matrix. The above initial calibration data and calibrated field strength data are represented as follows: , , where is the initial calibration data, is the calibrated field strength data, is the rotation matrix, is the second field strength data, is the translation matrix. Multiply the second field strength data by the rotation matrix on the left to obtain the initial calibration data , and add the translation matrix to the initial calibration data to obtain the calibrated field strength data of the second flight path .

[0063] In this embodiment, by solving the transformation matrix including the translation matrix and the rotation matrix, the position deviation and attitude deviation of the magnetic field vector of the second flight path relative to the first flight path can be corrected. Specifically, the translation matrix and the rotation matrix are calculated according to 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 flight path is left multiplied by the rotation matrix and added with the translation matrix to calibrate the above second field strength data to obtain the calibrated field strength data of the second flight path.

[0064] The technical solution provided in this embodiment can calculate the translation matrix and the rotation matrix by analyzing the changes in the first abnormal field strength data and the second abnormal field strength data to align the geomagnetic data of different flight paths. The magnetic interference error of the field strength data between different flight paths can be eliminated by the translation matrix, and the attitude error of the field strength data between different flight paths can be eliminated by the rotation matrix, effectively weakening the jump and discontinuity phenomena between the geomagnetic data of different flight paths, constructing a three-dimensional vector geomagnetic map with smooth transition, and solving the strip error problem.

[0065] Please refer to Figure 5 , this application provides an embodiment applying the above vector geomagnetic calibration method based on multi-flight path data alignment. This embodiment includes flight paths of three sorties L1, L2, and L3. The calibration of the geomagnetic data of the three sorties of flight paths is carried out according to the following steps: Step 1: Use the latitude information of the first flight as the reference latitude information to obtain the second latitude information and the second field strength data of the second flight , and obtain the third latitude information and the third field strength data of the third flight .

[0066] Step 2: Align the third latitude information of the third flight according to the second latitude information first, and 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 , and according to calculate the third field strength data of the third flight calibrated based on the second flight .

[0067] Step 3: Obtain the first field strength data of the first flight, and 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 , and according to calculate the second field strength data of the second flight calibrated based on the first flight , and according to calculate the third field strength data of the third flight calibrated based on the first flight .

[0068] In this embodiment, for the third field strength data of the third flight, first calibrate the data of the third flight with the data of the second flight, and then calibrate the calibrated data with the first flight. Similarly, when there are more than three flight routes, align the data of all flight routes with the first flight by means of recursion, thereby completing the calibration of all route data and constructing a three-dimensional vector geomagnetic map with smooth transition to avoid strip errors affecting the navigation accuracy.

[0069] Please refer to Figure 6 , this application also provides a vector geomagnetic calibration device based on multi-route data alignment, and the device includes: Latitude alignment unit 100, configured to obtain multiple first latitudes of the first route and multiple second latitudes of the second route, and align each of the second latitudes with each of the first latitudes; Data acquisition unit 200, configured to 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, obtain multiple first abnormal field strength data of the first route based on the first field strength data, and obtain multiple second abnormal field strength data of the second route based on the second field strength data; The data calibration unit 300 is configured to obtain a transformation matrix of the second flight path 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 of the second flight path according to the transformation matrix.

[0070] In one embodiment, the latitude alignment unit 100 is specifically configured to, for any one of the first latitudes, determine two second latitudes adjacent to the first latitude, and align any one of the second latitudes adjacent to the first latitude with the first latitude, so that the second latitude is parallel to the first latitude.

[0071] In one embodiment, the data acquisition unit 200 is specifically configured to, for any one of the first latitudes, acquire first field strength data of the first latitude, and acquire two initial field strength data of two second latitudes adjacent to the first latitude, and determine second field strength data of the second flight path at the aligned second latitude based on the two initial field strength data.

[0072] In one embodiment, the data acquisition unit 200 is further configured to acquire first main magnetic field strength data and first daily variation field strength data of each of the first latitudes, and acquire second main magnetic field strength data and second daily variation field strength data of each of the second latitudes aligned with the first latitudes. For any one of the first latitudes and the aligned second latitude, subtract the first main magnetic field strength data and the first daily variation field strength data from the first field strength data of the first latitude to obtain a plurality of first abnormal field data of the first flight path, and subtract the second main magnetic field strength data and the second daily variation field strength data from the second field strength data of the second latitude to obtain a plurality of second abnormal field strength data of the second flight path.

[0073] In one embodiment, the data calibration unit 300 is specifically configured to obtain the translation matrix and the rotation matrix of the second flight path according to 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 calibrated field strength data based on the translation matrix and the rotation matrix.

[0074] The further function descriptions of the above-mentioned modules and units are the same as those in the corresponding embodiments above, and will not be repeated here.

[0075] The vector geomagnetic calibration device based on multi - route data alignment in the embodiments of the present application is presented in the form of functional units. Here, the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and a memory that execute one or more software or fixed programs, or other devices that can provide the above - mentioned functions.

[0076] Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of a computer device provided by the embodiments of the present application. As Figure 7 shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high - speed interfaces and low - speed interfaces. Each component communicates with each other using different buses and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed within the computer device, including instructions stored in the memory or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some alternative embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a set of blade servers, or a multi - processor system). Figure 7 In

[0077] this example, one processor 10 is taken.

[0078] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above - mentioned embodiments.

[0079] The memory 20 may include a program storage area and a data storage area. Among them, 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 according to 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-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some alternative embodiments, the memory 20 may optionally include a memory remotely provided with respect to the processor 10, and these remote memories may be connected to the computer device through 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.

[0080] The memory 20 may include a volatile memory, for example, a random access memory; the memory may also include a non-volatile memory, for example, a flash memory, a hard disk, or a solid-state drive; the memory 20 may further include a combination of the above types of memories.

[0081] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0082] The embodiments of the present application also provide a computer-readable storage medium. The methods according to the embodiments of the present application may be implemented in hardware, firmware, or may be implemented as computer code that can be recorded on a storage medium, or may be implemented as computer code originally stored in a remote storage medium or a non-transitory machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the methods described herein may be stored in such software processes on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium may be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid-state drive, etc.; further, the storage medium may also include a combination of the above types of memories. 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, and when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the methods shown in the above embodiments are implemented.

[0083] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations all fall within the scope defined by the appended claims.

[0084] The devices or units illustrated in the above embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer can be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, 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.

[0085] For the convenience of description, when describing the above devices, they are divided into various units according to their functions and described separately. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0086] Those skilled in the art should understand that the embodiments of the present application can be provided as a method or a device. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0087] The present application is described with reference to the flowcharts and / or block diagrams of the methods or devices according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows 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 the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0088] These computer program instructions can 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, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0089] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are performed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide for implementing the functions in the processFigure 1 one process or multiple processes and / or boxes Figure 1 steps of functions specified in one box or multiple boxes.

[0090] It should also be noted that the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, commodity or device including the said element.

[0091] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and reference can be made to the relevant parts of the method embodiments for the relevant content.

[0092] The above are only the embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

[0093] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations 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; A conversion matrix of the second route is acquired based on the first abnormal field strength data, the second abnormal field strength data and the second field strength data, and the second field strength data is converted into calibration field strength data of the second route according to the conversion matrix.

2. The method according to claim 1, characterized in that Aligning each of the second latitudes with each of the first latitudes, and determining a plurality of first field intensity data of the first latitudes and a plurality of second field intensity data of the second latitudes based on the alignment result comprises: For any of the first latitudes, first field strength data of the first latitude is acquired, and two second latitudes adjacent to the first latitude are determined, and two initial field strength data of the two second latitudes are acquired; 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 two adjacent second latitudes and the initial field strength data at the second latitude, the second field strength data of the second route at the aligned second latitude is determined.

3. 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: Acquire first attitude data of the first route, determine a first coordinate rotation matrix according to the first attitude data, multiply the first field intensity data by the first coordinate rotation matrix, and redetermine the first field intensity data based on a result of the multiplication of the first coordinate rotation matrix; Acquire second posture data of the second route, determine a second coordinate rotation matrix according to 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.

4. 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 comprises: Acquire first main magnetic field strength data and first daily variable field strength data at each of the first latitudes, and acquire second main magnetic field strength data and second daily variable field strength data at each of the second latitudes aligned with the first latitudes; 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 at the first latitude, a plurality of first abnormal field data of the first route are acquired; 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.

5. The method according to claim 4, characterized in that Acquiring the first abnormal field strength data and the second abnormal field strength data comprises: For any of the first latitudes, generate 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 determine 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 at 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.

6. The method according to claim 1, characterized in that The conversion matrix includes a translation matrix and a rotation matrix; acquiring 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: 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; And based on the translation matrix and the rotation matrix, the second field intensity data is converted into the calibration field intensity data.

7. The method according to claim 6, characterized in that Based on the translation matrix and the rotation matrix, converting the second field intensity data into the calibration field intensity data comprises: Changing the calibration 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.

8. A vector geomagnetic calibration device based on multi-route data alignment, characterized in that: The device comprises: a latitude alignment unit, configured to acquire 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, which determines a plurality of first field strength data of the first latitude and a plurality of second field strength data of the second latitude based on the alignment result, and acquires a plurality of first abnormal field strength data of the first route based on the first field strength data, and acquires a plurality of second abnormal field strength data of the second route based on the second field strength data; A data calibration unit is used 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 calibration field strength data for the second route according to the conversion matrix.

9. 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 as described in any one of claims 1 to 7 by executing the computer instructions.

10. 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 as described in any one of claims 1 to 7.

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