A vector magnetometer attitude determination method, device, storage medium and electronic equipment

Abstract

The present specification discloses a method, device, storage medium and electronic device for determining the attitude of a vector magnetometer, which obtains the measured magnetic field strength of a reference magnetometer at a first position, rotates the magnetometer to be measured multiple times at a set angle, and obtains the measured magnetic field strength of the magnetometer to be measured at a second position after each rotation. An objective function is constructed based on the measured magnetic field strength of the reference magnetometer at the first position, the measured magnetic field strength of the magnetometer to be measured at the second position after each rotation, a first parameter and a second parameter. In the present specification, the first parameter is the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer when not rotated, and the second parameter is the vector magnetic field difference between the first position and the second position. By rotating the magnetometer to be measured multiple times, an equivalent relationship between the measurement results of the reference magnetometer and the coordinate system of the magnetometer to be measured is established, the first parameter is solved, and the rotation attitude of the coordinate system to be determined relative to the coordinate system of the reference magnetometer is determined.

Description

Technical Field

[0001] The present invention relates to the field of magnetic field measurement technology, and in particular to a vector magnetometer attitude determination method, device, storage medium and electronic device. Background Art

[0002] Geomagnetic navigation positioning uses the characteristics of different distribution of geomagnetic field strength with geographical spatial position to realize the positioning of moving carriers such as cars and spacecraft. The principle of geomagnetic navigation is that a vector magnetometer is installed on the moving carrier. Through the measurement results of the magnetic field strength by the vector magnetometer, the geomagnetic field characteristic data on the moving track of the moving carrier can be obtained, and matched with the pre-stored geomagnetic field model or geomagnetic reference map to determine the real-time position of the moving carrier.

[0003] In order to achieve more accurate positioning of the moving carrier, it is generally necessary to set up multiple vector magnetometers at different positions on the moving carrier, and determine the geomagnetic field characteristic data on the moving track of the moving carrier by combining the measurement results of each vector magnetometer.

[0004] The measurement result of each vector magnetometer is the vector magnetic field intensity, which is composed of the magnetic field components corresponding to the three axial directions of the vector magnetometer's own coordinate system. The direction of the vector magnetometer's own coordinate system changes accordingly with the change of the vector magnetometer's posture. Because of the differences in the positions and angles of each vector magnetometer, the postures of each vector magnetometer's own coordinate system are different. The measurement results of each vector magnetometer are values ​​in different posture coordinate systems and are not comparable.

[0005] Attitude calculation refers to solving the rotation state of an object relative to a reference magnetometer coordinate system. In order to unify the coordinate system attitude of each magnetic field measurement data, it is necessary to perform attitude calculation on each vector magnetometer. Therefore, this specification provides a vector magnetometer attitude determination method. Summary of the invention

[0006] The present specification provides a vector magnetometer attitude determination method, device, storage medium and electronic device to at least partially solve the above-mentioned problems existing in the prior art.

[0007] This manual adopts the following technical solutions:

[0008] This specification provides a vector magnetometer attitude determination method, including:

[0009] Leveling the reference magnetometer and the magnetometer to be measured to obtain the measured magnetic field strength of the reference magnetometer at the first position;

[0010] To set the angle The magnetometer to be measured is rotated multiple times to obtain the measured magnetic field strength of the magnetometer to be measured at a second position after each rotation, wherein the first position and the second position are different positions of the non-uniform background magnetic field. is the set angle for the kth rotation;

[0011] Constructing an objective function according to the magnetic field strength measured by the reference magnetometer at the first position, the magnetic field strength measured by the magnetometer to be measured at the second position after each rotation, a first parameter and a second parameter, wherein the first parameter is the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer when not rotated, and the second parameter is the vector magnetic field difference between the first position and the second position;

[0012] The value of the first parameter is obtained according to the solution result of the objective function.

[0013] Optionally, the magnetometer to be tested is placed on a turntable;

[0014] To set the angle The magnetometer to be tested is rotated multiple times, including:

[0015] Control the turntable to set the angle Multiple rotations.

[0016] Optionally, constructing an objective function according to the magnetic field strength of the reference magnetometer at the first position, the magnetic field strength of the magnetometer to be measured at the second position after each rotation, the first parameter and the second parameter specifically includes:

[0017] For each rotation, according to the first parameter and the set angle during the rotation, determine the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation;

[0018] According to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation, the measured magnetic field intensity of the magnetometer to be measured at the second position after the rotation is transformed into the coordinate system of the reference magnetometer to obtain the transformed magnetic field intensity corresponding to the rotation;

[0019] An objective function is constructed according to the transformed magnetic field strength corresponding to each rotation, the magnetic field strength of the reference magnetometer at the first position and the second parameter.

[0020] Optionally, according to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation, transforming the measured magnetic field intensity of the magnetometer to be measured at the second position after the rotation into the coordinate system of the reference magnetometer to obtain the transformed magnetic field intensity corresponding to the rotation, specifically includes:

[0021] Determine a rotation matrix according to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation;

[0022] According to the rotation matrix, the measured magnetic field strength of the magnetometer to be measured at the second position after the rotation is transformed into the coordinate system of the reference magnetometer to obtain the transformed magnetic field strength corresponding to the rotation.

[0023] Optionally, according to the rotation matrix, transforming the measured magnetic field strength of the magnetometer to be measured at the second position after the rotation into the coordinate system of the reference magnetometer to obtain the transformed magnetic field strength corresponding to the rotation, specifically includes:

[0024] The rotation matrix is ​​multiplied by the measured magnetic field strength of the magnetometer to be measured at the second position after the rotation to obtain the transformed magnetic field strength corresponding to the rotation.

[0025] Optionally, constructing an objective function according to the transformed magnetic field intensity corresponding to each rotation, the magnetic field intensity of the reference magnetometer at the first position and the second parameter specifically includes:

[0026] For each rotation, determining an estimated magnetic field strength of the first position corresponding to the rotation according to the transformed magnetic field strength corresponding to the rotation and the second parameter;

[0027] Determine a residual corresponding to the rotation according to a difference between an estimated magnetic field strength at the first position corresponding to the rotation and a measured magnetic field strength at the first position;

[0028] The objective function is determined according to the sum of the residuals corresponding to the rotations.

[0029] Optionally, obtaining the value of the first parameter according to the solution result of the objective function specifically includes:

[0030] Iteratively optimizing the objective function with the goal of minimizing the value of the objective function;

[0031] The value of the first parameter when the iteration stopping condition is reached is determined.

[0032] This specification provides a vector magnetometer attitude determination device, the device comprising:

[0033] A reference value acquisition module is used to level the reference magnetometer and the magnetometer to be measured, and obtain the measured magnetic field strength of the reference magnetometer at the first position;

[0034] Rotate the module to set the angle The magnetometer to be measured is rotated multiple times to obtain the measured magnetic field strength of the magnetometer to be measured at a second position after each rotation, wherein the first position and the second position are different positions of the non-uniform background magnetic field. is the set angle for the kth rotation;

[0035] a function construction module, constructing an objective function according to the magnetic field strength measured by the reference magnetometer at the first position, the magnetic field strength measured by the magnetometer to be measured at the second position after each rotation, a first parameter and a second parameter, wherein the first parameter is a relative angle between a coordinate system of the magnetometer to be measured and a coordinate system of the reference magnetometer when not rotated, and the second parameter is a vector magnetic field difference between the first position and the second position;

[0036] A solution module obtains the value of the first parameter according to the solution result of the objective function.

[0037] This specification provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned vector magnetometer attitude determination method is implemented.

[0038] This specification provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned vector magnetometer attitude determination method when executing the program.

[0039] At least one of the above technical solutions adopted in this specification can achieve the following beneficial effects:

[0040] In the vector magnetometer attitude determination method provided in this specification, the measured magnetic field strength of the reference magnetometer at the first position is obtained to set the angle The magnetometer to be measured is rotated multiple times to obtain the measured magnetic field strength of the magnetometer to be measured at the second position after each rotation, wherein the first position and the second position are different positions of the non-uniform background magnetic field. is the set angle at the kth rotation. According to the measured magnetic field intensity of the reference magnetometer at the first position, the measured magnetic field intensity of the magnetometer to be measured at the second position after each rotation, the first parameter and the second parameter, an objective function is constructed. The first parameter is the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer when not rotated, and the second parameter is the vector magnetic field difference between the first position and the second position. According to the solution result of the objective function, the value of the first parameter is obtained.

[0041] In this specification, the measured magnetic field intensity of the magnetometer to be measured at the second position at each set angle is obtained by rotating the magnetometer to be measured multiple times according to the set angle, and the equivalent relationship between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer is established by defining the vector magnetic field difference as the second parameter, thereby achieving the solution of the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer when not rotated, and determining the rotation posture of the coordinate system of the magnetometer to be measured relative to the coordinate system of the reference magnetometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings described herein are used to provide a further understanding of this specification and constitute a part of this specification. The illustrative embodiments and descriptions of this specification are used to explain this specification and do not constitute an improper limitation on this specification. In the drawings:

[0043] Figure 1 A schematic diagram of a flow chart of a vector magnetometer attitude determination method in this specification;

[0044] Figure 2 This is an application scenario diagram provided in an embodiment of this specification;

[0045] Figure 3 A coordinate system transformation principle diagram provided in this specification;

[0046] Figure 4 A schematic diagram of a vector magnetometer attitude determination device provided in this specification;

[0047] Figure 5 The corresponding Figure 1 Schematic diagram of electronic equipment. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of this specification more clear, the technical solutions of this specification will be clearly and completely described below in combination with the specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] In geomagnetic navigation scenarios, multiple vector magnetometers working together can determine more accurate geomagnetic field characteristic data and more accurately locate moving carriers.

[0050] In addition, the attitude calculation of the vector magnetometer is also used in magnetic interference compensation. Magnetic interference compensation is a method to correct the measurement error of the vector magnetometer in the presence of non-geomagnetic field interference signals.

[0051] When measuring the magnetic field strength of the geomagnetic field, there may be non-geomagnetic field interference signals generated by environmental factors near the location of the vector magnetometer, such as electromagnetic radiation generated by the power supply system and communication system, and local magnetic fields generated by magnetic materials in the moving carrier. Non-geomagnetic field interference signals will cause deviations in the measurement results of the vector magnetometer, resulting in the vector magnetometer being unable to measure the accurate magnetic field strength of the geomagnetic field, and subsequently being unable to correspond to the accurate position based on the magnetic field strength of the geomagnetic field.

[0052] There is currently a magnetic interference compensation method based on machine learning, in which the training data used for machine learning is the measurement results of multiple vector magnetometers at different positions of the background magnetic field. Because the coordinate system postures of each vector magnetometer are different, the obtained measurement results cannot be directly used for the training of the machine learning model. Through the vector magnetometer posture determination method of this manual, the measurement results of each vector magnetometer can be unified into the same coordinate system.

[0053] The vector magnetometer attitude determination method of this specification can be applied to the attitude determination scenario of multiple vector magnetometers. In the attitude determination scenario of multiple vector magnetometers, first determine one vector magnetometer as a reference magnetometer, and the other vector magnetometers as magnetometers to be measured. Each time, the attitude solution is performed for the reference magnetometer and one magnetometer to be measured.

[0054] In the following description, the attitude calculation process of a reference magnetometer and a magnetometer to be measured is taken as an example to illustrate the vector magnetometer attitude determination method of this specification. The vector magnetometer in this specification can be any instrument with a vector magnetic field measurement function, such as a three-axis vector magnetometer.

[0055] The technical solutions provided by the embodiments of this specification are described in detail below in conjunction with the accompanying drawings.

[0056] Figure 1 The following is a flow chart of a method for determining the attitude of a vector magnetometer in this specification, which specifically includes the following steps:

[0057] S100: Leveling a reference magnetometer and a magnetometer to be measured, and obtaining a measured magnetic field strength of the reference magnetometer at a first position.

[0058] All steps in the vector magnetometer attitude determination method provided in this specification can be implemented by any electronic device with computing functions, such as a terminal, a server, etc. For the convenience of description, the vector magnetometer attitude determination method provided in this specification is described below with the server as the execution subject.

[0059] The background magnetic field in this manual is a non-uniform magnetic field. The reference magnetometer and the magnetometer to be tested are placed at different positions of the background magnetic field. Due to the different positions, the magnetic field strengths at their respective positions measured by each vector magnetometer are different. And because the vector magnetometers are placed separately, it is often difficult to keep the postures of the reference magnetometer and the magnetometer to be tested consistent, so the magnetic field strengths measured by the reference magnetometer and the magnetometer to be tested are the results of different coordinate system postures.

[0060] In this specification, the position of the reference magnetometer in the background magnetic field is called the first position, and the position of the magnetometer to be measured in the background magnetic field is called the second position. The relative angle of the coordinate system to be measured relative to the coordinate system of the reference magnetometer is calculated by the attitude determination method of this specification, taking the coordinate system of the reference magnetometer as a reference.

[0061] The server first needs to level the magnetometer to be tested and the reference magnetometer, that is, the z-axis of the coordinate systems of the magnetometer to be tested and the reference magnetometer are parallel to the gravity direction before performing subsequent operations. After leveling, there is a relative horizontal angle between the coordinate systems of the reference magnetometer and the magnetometer to be tested.

[0062] Next, the server obtains the magnetic field strength measured by the reference magnetometer at the first position. In this specification, the magnetic field strength measured by the reference magnetometer at the first position is denoted as , where r represents the coordinate system of the reference magnetometer.

[0063] The measured magnetic field strength is the true value of the magnetic field strength at the reference magnetometer's location. The measured magnetic field strength at the first position is the measurement result of the reference magnetometer, and in subsequent steps, it will be used as a reference value in the reference magnetometer's coordinate system to participate in the attitude solution process.

[0064] S102: At a set angle The magnetometer to be measured is rotated multiple times to obtain the measured magnetic field strength of the magnetometer to be measured at a second position after each rotation, wherein the first position and the second position are different positions of the non-uniform background magnetic field. is the set angle for the kth rotation.

[0065] The coordinate system of the vector magnetometer is its own internal body coordinate system, and moves with the movement of the vector magnetometer. In this specification, the coordinate system of the magnetometer to be measured is rotated by controlling the magnetometer to be measured to rotate.

[0066] The server can directly control the rotation of the magnetometer to be tested through the control component installed on the magnetometer to be tested. Alternatively, if the magnetometer to be tested is placed on a turntable, the server can control the rotation of the turntable so that the turntable drives the magnetometer to be tested to rotate. When the magnetometer to be tested is placed on a turntable, the turntable can be a high-precision turntable. The server can achieve more subtle angle rotation control through the high-precision turntable, thereby obtaining more accurate measurement data of the magnetometer to be tested at different set angles.

[0067] Figure 2 This is an application scenario diagram provided in an embodiment of this specification. Figure 2The cube on the left represents the magnetometer to be tested, the cube on the right represents the reference magnetometer, and the cylinder below the cube on the left represents the turntable. The coordinate system of the magnetometer to be tested is represented as , the coordinate system of the reference magnetometer is expressed as .from Figure 2 It can be seen that when the postures of the magnetometer to be measured and the reference magnetometer are inconsistent, there is also an angle difference between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer.

[0068] Server to set angle The magnetometer to be measured is rotated multiple times to obtain the measured magnetic field strength of the magnetometer to be measured at the second position after each rotation. is the set angle for the kth rotation. The set angles for each rotation can be set at equal intervals or randomly, as long as the set angles for each rotation are different.

[0069] In particular, the set angle may take a value of 0, that is, during a certain rotation process, the server may not perform any operation and directly obtain the measured magnetic field strength of the magnetometer to be measured at the second position.

[0070] S104: constructing an objective function according to the magnetic field strength measured by the reference magnetometer at the first position, the magnetic field strength measured by the magnetometer to be measured at the second position after each rotation, a first parameter and a second parameter, wherein the first parameter is a relative angle between a coordinate system of the magnetometer to be measured and a coordinate system of the reference magnetometer when not rotated, and the second parameter is a vector magnetic field difference between the first position and the second position.

[0071] In this specification, the reference magnetometer and the magnetometer to be measured are located on the same horizontal plane, that is, there is a relative angle in the horizontal direction between the coordinate system of the reference magnetometer and the coordinate system of the magnetometer to be measured, and the relative angle is the angle difference between the coordinate system of the reference magnetometer and the coordinate system of the magnetometer to be measured when not rotated, and is the data to be solved for attitude solution in this specification. Therefore, this relative angle is defined as the first parameter in this specification.

[0072] The background magnetic field is a constant magnetic field and does not change with time. Therefore, the difference between the magnetic field strength at the location of the reference magnetometer and the magnetic field strength at the location of the measured magnetometer, that is, the vector magnetic field difference between the first position and the second position, does not change, and the vector magnetic field difference is a constant value. In this specification, in order to solve the first parameter, the vector magnetic field difference between the first position and the second position is used as the second parameter to construct an equivalent relationship between the reference magnetometer coordinate system and the measured magnetic field and coordinate system.

[0073] The vector magnetic field difference is the difference between two vector magnetic field intensities, so the second parameter is composed of magnetic components in the directions of three coordinate axes. For the convenience of description, the vector magnetic field difference is recorded as ,but .

[0074] It should be understood that the two magnetic field intensities must be values ​​in the same coordinate system to be subtracted. Because the coordinate system posture of the reference magnetometer is used as the reference in this specification, the second parameter in this specification, the vector magnetic field difference, is the magnetic field difference between the first position and the second position in the coordinate system of the reference magnetometer.

[0075] In this specification, by controlling the magnetometer to be measured to rotate multiple times, the measurement results of the magnetometer to be measured at each set angle are obtained, and the constraint relationship between multiple first parameters and second parameters can be obtained, thereby converting the solution problem of the first parameters and the second parameters into a parameter optimization problem, and solving the first parameters and the second parameters.

[0076] The server constructs an objective function according to the magnetic field strength measured by the reference magnetometer at the first position, the magnetic field strength measured by the magnetometer to be measured at the second position after each rotation, the first parameter and the second parameter.

[0077] First, for each rotation, the server determines the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation according to the first parameter and the set angle during the rotation.

[0078] Because the coordinate system of the magnetometer to be measured moves with the magnetometer to be measured, when the magnetometer to be measured is rotated, the relative angle between the coordinate system of the reference magnetometer and the coordinate system of the magnetometer to be measured also changes.

[0079] by represents the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer when not rotated, then the angle is set Rotate the magnetometer to be measured, and the relative angle between the coordinate system of the reference magnetometer and the coordinate system of the magnetometer to be measured becomes .

[0080] Secondly, the server transforms the measured magnetic field intensity of the magnetometer to be tested at the second position after the rotation into the coordinate system of the reference magnetometer according to the relative angle between the coordinate system of the magnetometer to be tested and the coordinate system of the reference magnetometer after the rotation, and obtains the transformed magnetic field intensity corresponding to the rotation.

[0081] Specifically, the server determines a rotation matrix according to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation. According to the rotation matrix, the measured magnetic field intensity of the magnetometer to be measured at the second position after the rotation is transformed into the coordinate system of the reference magnetometer to obtain the transformed magnetic field intensity corresponding to the rotation.

[0082] Because the coordinate system of the magnetometer to be tested and the coordinate system of the reference magnetometer are located in the same horizontal plane, for the kth rotation, the coordinate system of the reference magnetometer is equivalent to the relative angle of rotation of the coordinate system of the magnetometer to be tested around the z-axis of the coordinate system of the magnetometer to be tested. Then the rotation matrix from the coordinate system of the magnetometer to be measured to the coordinate system of the reference magnetometer is for .

[0083] The server multiplies the rotation matrix by the magnetic field strength measured by the magnetometer to be measured at the second position after the rotation to obtain the transformed magnetic field strength corresponding to the rotation.

[0084] At setting angle Under the condition that the magnetic field strength at the second position measured by the magnetometer to be measured is the measurement result in the coordinate system of the magnetometer to be measured, the magnetic field strength at the second position is converted to the coordinate system of the reference magnetometer, which can be expressed by the following formula:

[0085]

[0086] Wherein, c represents the coordinate system of the magnetometer to be measured, r represents the coordinate system of the reference magnetometer, cr represents the coordinate system of the magnetometer to be measured transformed to the coordinate system of the reference magnetometer, Indicates that the angle is set The measurement results of the magnetometer to be tested are as follows: represents the transformed magnetic field intensity corresponding to the kth rotation.

[0087] Then, the server constructs the objective function according to the transformed magnetic field intensity corresponding to each rotation, the magnetic field intensity of the reference magnetometer at the first position and the second parameter.

[0088] Specifically, the server determines the estimated magnetic field strength of the first position corresponding to each rotation according to the transformed magnetic field strength corresponding to the rotation and the second parameter, and constructs an objective function according to the estimated magnetic field strength of the first position corresponding to each rotation and the measured magnetic field strength of the first position.

[0089] The server determines the magnetic field strength at the location of the reference magnetometer according to the sum of the transformed magnetic field strength corresponding to the rotation and the second parameter as the estimated magnetic field strength at the first location corresponding to the rotation.

[0090] The estimated magnetic field strength at the first position corresponding to the rotation includes the first parameter and the second parameter. The server can use the first parameter and the second parameter as the quantity to be solved x, then Among them, because It consists of the magnetic components of three coordinate axes, and x is a four-dimensional vector.

[0091] Setting Angle The corresponding estimated magnetic field strength can be expressed as follows:

[0092]

[0093] in, represents the estimated magnetic field strength corresponding to the kth rotation, that is, the estimated value of the magnetic field strength at the first position where the reference magnetometer is located based on the measured magnetic field strength and the second parameter of the magnetometer to be tested at the second position after the kth rotation.

[0094] After each rotation, an estimated value of the magnetic field strength at the second position of the reference magnetometer can be calculated based on the measured magnetic field strength at the second position of the magnetometer to be tested. That is, the number of set angles is equal to the number of determined estimated magnetic field strengths.

[0095] Theoretically, the estimated magnetic field strength corresponding to each rotation at the first position should be equal to the measured magnetic field strength of the reference magnetometer at the first position. Based on this principle, the server determines the objective function according to the estimated magnetic field strength and the measured magnetic field strength corresponding to each set angle.

[0096] Specifically, the server determines the residual corresponding to the kth rotation according to the difference between the estimated magnetic field strength at the first position corresponding to the kth rotation and the measured magnetic field strength at the first position, and determines the objective function according to the sum of the residuals corresponding to each rotation.

[0097] The objective function can be expressed as follows:

[0098]

[0099] Wherein, N represents the total number of set angles.

[0100] S106: Obtaining a value of the first parameter according to a solution result of the objective function.

[0101] The server may use an iterative optimization method to minimize the value of the objective function, that is, to make the estimated magnetic field strength of the first position calculated for each rotation close to the measured magnetic field strength of the reference magnetometer at the first position, and then the x value when the iterative customization condition is reached is the solution result of the objective function. The solution result is the value of the first parameter and the second parameter determined at the last iteration. The iterative stop condition may be a preset maximum number of iterations or the minimization accuracy of the objective function.

[0102] Specifically, the server iteratively optimizes the objective function with the minimum value of the objective function as the goal, and obtains the values ​​of the first parameter and the second parameter. The first parameter and the second parameter are the quantity to be solved x, and the quantity to be solved x can be expressed as: .

[0103] The specific optimization algorithm used in this specification is not limited, and it can be any nonlinear iterative optimization algorithm, such as Gauss-Newton, Levenberg Marquardt, etc.

[0104] exist Figure 1 In the vector magnetometer attitude determination method shown, the measured magnetic field intensity of the measured magnetometer at the second position at each set angle is obtained by rotating the measured magnetometer for multiple times according to the set angle, and the equivalent relationship between the coordinate system of the measured magnetometer and the coordinate system of the reference magnetometer is established by defining the vector magnetic field difference as the second parameter, thereby solving the relative angle between the coordinate system of the measured magnetometer and the coordinate system of the reference magnetometer when not rotated, and determining the rotation attitude of the coordinate system of the measured magnetometer relative to the coordinate system of the reference magnetometer.

[0105] The construction principle of the objective function in this specification is explained below.

[0106] Still It represents the angular difference between the coordinate system of the reference magnetometer and the coordinate system of the magnetometer to be measured when it is not rotated. represents the magnetic field vector difference between the first position and the second position, r represents the coordinate system of the reference magnetometer, c represents the coordinate system of the magnetometer to be measured, cr represents the conversion of the coordinate system of the magnetometer to be measured to the coordinate system of the reference magnetometer, represents the magnetic field strength measured by the magnetometer at the second position during the kth rotation, represents the transformed magnetic field intensity corresponding to the kth rotation, Represents the magnetic field strength measured by the reference magnetometer at the first position.

[0107] Figure 3 This is a coordinate system transformation principle diagram provided in this manual, such as Figure 3 As shown, for a vector , the vector The actual spatial position of does not change, but due to the rotation of the coordinate system, the vector The coordinates in different coordinate systems are expressed differently. Figure 3 middle, express Projection vector on the xOy coordinate plane.

[0108] In the coordinate system of the reference magnetometer, the vector The coordinates of , in the undetermined coordinate system, the vector The coordinates of There is a relative angle between the reference magnetometer coordinate system and the coordinate system to be determined. .

[0109] Depend on Figure 3 The geometric relationship shown in the figure can be obtained as follows:

[0110]

[0111] in, Indicates the setting angle The corresponding rotation matrix Therefore, when the angle is set to When ,like , the following relationship exists:

[0112]

[0113] Because the magnetic field vector difference between the magnetic field strength at the reference magnetometer and the magnetic field strength at the location of the magnetometer to be measured is , as the second parameter. Then for the set angle , .

[0114] Each setting angle , corresponding to a constraint condition on the first parameter and the second parameter, each constraint condition can be expressed as follows:

[0115]

[0116] In particular, the can be 0, then the corresponding constraint is .

[0117] The amount to be solved , according to the constraints, the estimated magnetic field strength can be determined The calculation formula is .

[0118] The above is the vector magnetometer attitude determination method provided in this specification. Based on the same idea, this specification also provides a corresponding vector magnetometer attitude determination device, such as Figure 4 shown.

[0119] Figure 4 A schematic diagram of a vector magnetometer attitude determination device provided in this specification specifically includes:

[0120] The reference value acquisition module 200 is used to level the reference magnetometer and the magnetometer to be measured, and obtain the measured magnetic field strength of the reference magnetometer at the first position;

[0121] Rotation module 202, used to set the angle The magnetometer to be measured is rotated multiple times to obtain the measured magnetic field strength of the magnetometer to be measured at a second position after each rotation, wherein the first position and the second position are different positions of the non-uniform background magnetic field. is the set angle for the kth rotation;

[0122] A function construction module 204 is used to construct an objective function according to the magnetic field strength measured by the reference magnetometer at the first position, the magnetic field strength measured by the magnetometer to be measured at the second position after each rotation, a first parameter and a second parameter, wherein the first parameter is a relative angle between a coordinate system of the magnetometer to be measured and a coordinate system of the reference magnetometer when not rotated, and the second parameter is a vector magnetic field difference between the first position and the second position;

[0123] The solution module 206 is used to obtain the value of the first parameter according to the solution result of the objective function.

[0124] Optionally, the magnetometer to be measured is placed on a turntable, and the rotation module 202 is specifically used to control the turntable to set an angle. Multiple rotations.

[0125] Optionally, the function construction module 204 is specifically used to determine, for each rotation, the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation according to the first parameter and the set angle during the rotation; according to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation, transform the measured magnetic field intensity of the magnetometer to be measured at the second position after the rotation into the coordinate system of the reference magnetometer to obtain the transformed magnetic field intensity corresponding to the rotation; and construct the objective function according to the transformed magnetic field intensity corresponding to each rotation, the magnetic field intensity of the reference magnetometer at the first position and the second parameter.

[0126] Optionally, the function construction module 204 is specifically used to determine a rotation matrix according to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation, and transform the measured magnetic field intensity of the magnetometer to be measured at the second position after the rotation into the coordinate system of the reference magnetometer according to the rotation matrix to obtain the transformed magnetic field intensity corresponding to the rotation.

[0127] Optionally, the function construction module 204 is specifically configured to multiply the rotation matrix by the magnetic field strength measured by the magnetometer to be measured at the second position after the rotation to obtain the transformed magnetic field strength corresponding to the rotation.

[0128] Optionally, the function construction module 204 is specifically used to determine, for each rotation, the estimated magnetic field strength of the first position corresponding to the rotation based on the transformed magnetic field strength corresponding to the rotation and the second parameter, determine the residual corresponding to the rotation based on the difference between the estimated magnetic field strength of the first position corresponding to the rotation and the measured magnetic field strength at the first position, and determine the objective function based on the sum of the residuals corresponding to the rotations.

[0129] Optionally, the solving module 206 is specifically configured to iteratively optimize the objective function with the goal of minimizing the value of the objective function, and determine the value of the first parameter when an iteration stop condition is met.

[0130] This specification also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 A vector magnetometer attitude determination method is provided.

[0131] This manual also provides Figure 5 The schematic structure diagram of the electronic device shown in FIG. Figure 5 As mentioned above, at the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 Of course, in addition to the software implementation, this specification does not exclude other implementations, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0132] For the improvement of a technology, it can be clearly distinguished whether it is a hardware improvement (for example, improvement of the circuit structure of diodes, transistors, switches, etc.) or a software improvement (improvement of the method flow). However, with the development of technology, many improvements of the method flow today can be regarded as direct improvements of the hardware circuit structure. Designers almost always obtain the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow cannot be implemented with a hardware entity module. For example, a programmable logic device (PLD) (such as a field programmable gate array (FPGA)) is such an integrated circuit whose logical function is determined by the user's programming of the device. Designers can "integrate" a digital system on a PLD by programming themselves, without having to ask chip manufacturers to design and make dedicated integrated circuit chips. Moreover, nowadays, instead of manually making integrated circuit chips, this kind of programming is mostly implemented by "logic compiler" software, which is similar to the software compiler used when developing and writing programs, and the original code before compilation must also be written in a specific programming language, which is called hardware description language (HDL). There is not only one kind of HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should also know that it is only necessary to program the method flow slightly in the above-mentioned hardware description languages ​​and program it into the integrated circuit, and then it is easy to obtain the hardware circuit that implements the logic method flow.

[0133] The controller may be implemented in any suitable manner, for example, the controller may take the form of a microprocessor or processor and a computer-readable medium storing a computer-readable program code (e.g., software or firmware) executable by the (micro)processor, a logic gate, a switch, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller, examples of which include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320, and the memory controller may also be implemented as part of the control logic of the memory. It is also known to those skilled in the art that, in addition to implementing the controller in a purely computer-readable program code manner, the controller may be implemented in the form of a logic gate, a switch, an application-specific integrated circuit, a programmable logic controller, and an embedded microcontroller by logically programming the method steps. Therefore, such a controller may be considered as a hardware component, and the devices for implementing various functions included therein may also be considered as structures within the hardware component. Or even, the devices for implementing various functions may be considered as both software modules for implementing the method and structures within the hardware component.

[0134] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with 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 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.

[0135] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0136] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt 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 codes.

[0137] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes 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 generate 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.

[0138] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate 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 A function specified in one or more boxes.

[0139] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0140] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0141] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0142] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0143] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0144] It should be understood by those skilled in the art that the embodiments of this specification may be provided as methods, systems or computer program products. Therefore, this specification may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, this specification may 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.

[0145] This specification may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. This specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0146] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0147] The above description is only an embodiment of this specification and is not intended to limit this specification. For those skilled in the art, this specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification should be included in the scope of the claims of this application.

Claims

1. A vector magnetometer attitude determination method, characterized in that: include: Leveling the reference magnetometer and the magnetometer to be measured to obtain the measured magnetic field strength of the reference magnetometer at the first position; To set the angle The magnetometer to be measured is rotated multiple times to obtain the measured magnetic field strength of the magnetometer to be measured at a second position after each rotation, wherein the first position and the second position are different positions of the non-uniform background magnetic field. is the set angle for the kth rotation; Constructing an objective function according to the magnetic field strength measured by the reference magnetometer at the first position, the magnetic field strength measured by the magnetometer to be measured at the second position after each rotation, a first parameter and a second parameter, wherein the first parameter is the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer when not rotated, and the second parameter is the vector magnetic field difference between the first position and the second position; The value of the first parameter is obtained according to the solution result of the objective function.

2. The method according to claim 1, characterized in that The magnetometer to be tested is placed on a turntable; To set the angle The magnetometer to be tested is rotated multiple times, including: Control the turntable to set the angle Multiple rotations.

3. The method according to claim 1, characterized in that Constructing an objective function according to the magnetic field strength of the reference magnetometer at the first position, the magnetic field strength of the magnetometer to be measured at the second position after each rotation, the first parameter and the second parameter, specifically comprising: For each rotation, according to the first parameter and the set angle during the rotation, determine the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation; According to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation, the measured magnetic field intensity of the magnetometer to be measured at the second position after the rotation is transformed into the coordinate system of the reference magnetometer to obtain the transformed magnetic field intensity corresponding to the rotation; An objective function is constructed according to the transformed magnetic field strength corresponding to each rotation, the magnetic field strength of the reference magnetometer at the first position and the second parameter.

4. The method according to claim 3, characterized in that According to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation, the measured magnetic field intensity of the magnetometer to be measured at the second position after the rotation is transformed into the coordinate system of the reference magnetometer to obtain the transformed magnetic field intensity corresponding to the rotation, specifically including: Determine a rotation matrix according to the relative angle between the coordinate system of the magnetometer to be measured and the coordinate system of the reference magnetometer after the rotation; According to the rotation matrix, the measured magnetic field strength of the magnetometer to be measured at the second position after the rotation is transformed into the coordinate system of the reference magnetometer to obtain the transformed magnetic field strength corresponding to the rotation.

5. The method according to claim 4, characterized in that According to the rotation matrix, transforming the measured magnetic field strength of the magnetometer to be measured at the second position after the rotation into the coordinate system of the reference magnetometer to obtain the transformed magnetic field strength corresponding to the rotation, specifically includes: The rotation matrix is ​​multiplied by the measured magnetic field strength of the magnetometer to be measured at the second position after the rotation to obtain the transformed magnetic field strength corresponding to the rotation.

6. The method according to claim 3, characterized in that According to the transformed magnetic field intensity corresponding to each rotation, the magnetic field intensity of the reference magnetometer at the first position and the second parameter, an objective function is constructed, specifically including: For each rotation, determining an estimated magnetic field strength of the first position corresponding to the rotation according to the transformed magnetic field strength corresponding to the rotation and the second parameter; Determine a residual corresponding to the rotation according to a difference between an estimated magnetic field strength at the first position corresponding to the rotation and a measured magnetic field strength at the first position; The objective function is determined according to the sum of the residuals corresponding to the rotations.

7. The method according to claim 1, characterized in that Obtaining the value of the first parameter according to the solution result of the objective function specifically includes: Iteratively optimizing the objective function with the goal of minimizing the value of the objective function; The value of the first parameter when the iteration stopping condition is reached is determined.

8. A vector magnetometer attitude determination device, characterized in that: include: A reference value acquisition module is used to level the reference magnetometer and the magnetometer to be measured, and obtain the measured magnetic field strength of the reference magnetometer at the first position; Rotate the module to set the angle The magnetometer to be measured is rotated multiple times to obtain the measured magnetic field strength of the magnetometer to be measured at a second position after each rotation, wherein the first position and the second position are different positions of the non-uniform background magnetic field. is the set angle for the kth rotation; a function construction module, constructing an objective function according to the magnetic field strength measured by the reference magnetometer at the first position, the magnetic field strength measured by the magnetometer to be measured at the second position after each rotation, a first parameter and a second parameter, wherein the first parameter is a relative angle between a coordinate system of the magnetometer to be measured and a coordinate system of the reference magnetometer when not rotated, and the second parameter is a vector magnetic field difference between the first position and the second position; A solution module obtains the value of the first parameter according to the solution result of the objective function.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method described in any one of claims 1 to 7 is implemented.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method described in any one of claims 1 to 7 is implemented.

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