CN105258671A - Method for improving angle measuring precision of magnetic flux gate - Google Patents

Abstract

A method for improving the angle measurement accuracy of a fluxgate, the invention relates to a method for improving the angle measurement accuracy of a fluxgate. The purpose of the present invention is to solve the problem in the prior art that the measurement accuracy of the fluxgate itself is limited, and there is also a certain error in angle measurement, resulting in low accuracy of the fluxgate angle measurement. Specifically, it is prepared according to the following steps: 1. Obtain and (α, β, γ); 2. Calculate M according to (α, β, γ); 3. According to Obtain the direction of the geomagnetic field in the ground coordinate system; 4. Calculate according to M and the direction of the geomagnetic field in the ground coordinate system Five, according to Calculate cosX, cosY, cosZ, record cosX as a ₁ , cosY as b ₁ , cosZ as c ₁ ; 6. According to Obtain cosX, cosY, cosZ, record cosX as a ₂ , cosY as b ₂ , cosZ as c ₂ ; 7. Fusion a ₁ , b ₁ , c ₁ and a ₂ , b ₂ , c ₂ to obtain Calculate the direction cosine value of the angle between the geomagnetic field and each axis of the motion platform coordinate system and fuse the direction cosine value of the magnetic field obtained directly through the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate. The invention is applied to the field of fluxgate angle measurement.

Description

A Method of Improving the Angle Measurement Accuracy of Fluxgate

technical field

The invention relates to a method for improving the angle measurement accuracy of a fluxgate.

Background technique

Fluxgate magnetometer is a sensor for measuring magnetic field, which is designed according to the principle of Faraday's electromagnetic induction, and generally uses permalloy as the magnetic core. The fluxgate magnetometer can measure the magnetic field value of three orthogonal axes, which belongs to the vector magnetometer.

In the process of aeromagnetic compensation, it is usually necessary to install a fluxgate magnetometer on the aircraft platform. Using the fluxgate magnetometer, the three axes of the fluxgate magnetometer, that is, the three axes of the aircraft platform, can be obtained. The direction cosine of the angle with the direction of the earth's magnetic field, which plays a key role in aeromagnetic compensation.

Assuming that the magnetic induction intensity collected by the fluxgate magnetometer is (B _x ,B _y ,B _z ) ^T , the direction cosine of the measured magnetic field in the coordinate system formed by the three axes of the fluxgate can be obtained by calculation:

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

However, limited by the measurement accuracy of the fluxgate itself, there is also a certain error in angle measurement, which is often prone to certain obstacles in practical applications with high precision requirements.

Contents of the invention

The purpose of the present invention is to solve the problem that the existing technology is limited by the measurement accuracy of the fluxgate itself, and there are certain errors in angle measurement, resulting in low accuracy of the fluxgate angle measurement, and proposes a method to improve the fluxgate angle measurement method of precision.

A method for improving the accuracy of fluxgate angle measurement, comprising the following steps:

Step 1. Obtain the magnetic induction intensity vector output by the fluxgate magnetometer at a certain moment The three deflection angles (α, β, γ) output by the current gyroscope;

Step 2. Calculate the rotation matrix M between the ground coordinate system and the motion platform coordinate system according to (α, β, γ) in step 1;

Step 3. According to the magnetic induction intensity vector of the geomagnetic field in the ground coordinate system Obtain the direction of the geomagnetic field in the ground coordinate system;

Step 4. According to the rotation matrix M between the ground coordinate system and the motion platform coordinate system in step 2 and the direction of the geomagnetic field in the ground coordinate system in step 3, calculate the direction of the geomagnetic field in the motion platform coordinate system

Step 5. According to the direction of the geomagnetic field calculated in step 4 in the coordinate system of the moving platform Calculate the direction cosine values cosX, cosY, and cosZ of the angles between the geomagnetic field and the axes of the moving platform coordinate system, and record cosX as a ₁ , cosY as b ₁ , and cosZ as c ₁ ;

Step 6. According to the magnetic induction intensity vector output by the fluxgate magnetometer at a certain moment obtained in step 1 Obtain the cosine values cosX, cosY, and cosZ of the direction of the magnetic field obtained directly through the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate, and record cosX as a ₂ , cosY as b ₂ , and cosZ as c ₂ ;

Step 7. Fuse a ₁ , b ₁ , c ₁ with a ₂ , b ₂ , c ₂ to obtain the direction cosine value of the angle between the geomagnetic field and the axes of the motion platform coordinate system calculated by the gyroscope. The cosine value of the direction of the magnetic field obtained by the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate.

The present invention has the following beneficial effects

The method proposed by the present invention can calculate the cosine value of the included angle between the geomagnetic field and the axial direction of the moving platform coordinate system through the gyroscope, and integrate the value of the included angle between the geomagnetic field and the axial direction of the moving platform coordinate system directly calculated by the fluxgate magnetometer. Cosine value, thereby improving the calculation accuracy, the accuracy has increased by more than 22%. It has certain application value in aeromagnetic compensation technology, so it has certain application space in aeromagnetic survey, geological exploration, geophysical prospecting and other fields.

Description of drawings

Fig. 1 is a flowchart of the present invention;

Fig. 2 is a schematic diagram of the coordinate system of the fluxgate magnetometer, where X, Y, and Z respectively represent three coordinate axes of the fluxgate magnetometer's own coordinate system;

Figure 3 is a schematic diagram of the coordinate system of the motion platform (shown as an aircraft), which coincides with the coordinate system of the fluxgate magnetometer in Figure 1, so the coordinate axes are still represented by X, Y, and Z, and X, Y, and Z are the coordinate system of the motion platform , where He represents the geomagnetic field, φ represents the geomagnetic inclination, θ represents the geomagnetic declination, N represents the projection of the geomagnetic field on the plane where the moving platform is located, and x, y, z represent the distance between the X, Y, Z axes and the geomagnetic field, respectively. the angle between

Fig. 4 is a schematic diagram of the ground coordinate system, Xt, Yt, and Zt respectively represent three orthogonal coordinate axes of the ground coordinate system;

Fig. 5 is a group of 5081 data points obtained after the calculation of the algorithm of the present invention and the mean value schematic diagram after the difference between the real cosine value and the attitude refers to the difference between the cosine value result calculated by simply applying the gyroscope and the real cosine value result The average value of the value on the X, Y, and Z axes. Fluxgate refers to the average value of the difference between the cosine value result calculated by the fluxgate magnetometer and the real cosine value result on the X, Y, and Z axes. The value, the mean value of the difference between the cosine value result obtained after applying the WLS method (the present invention) fusion and the real cosine value result is at X, Y, the value on the three axes of Z; X_axis, Y_axis, Z_axis refer to three axes The mean of the difference between the up cosine result and the true cosine result.

detailed description

Specific embodiment one: illustrate this embodiment in conjunction with Fig. 1, a kind of method of improving fluxgate angular measurement accuracy of this embodiment is specifically prepared according to the following steps:

Step 1. Obtain the magnetic induction intensity vector output by the fluxgate magnetometer at a certain moment The three deflection angles (α, β, γ) output by the current gyroscope;

Step 2. Calculate the rotation matrix M between the ground coordinate system and the motion platform coordinate system according to (α, β, γ) in step 1;

Step 3. According to the magnetic induction intensity vector of the geomagnetic field in the ground coordinate system Obtain the direction of the geomagnetic field in the ground coordinate system;

Step 4. According to the rotation matrix M between the ground coordinate system and the motion platform coordinate system in step 2 and the direction of the geomagnetic field in the ground coordinate system in step 3, calculate the direction of the geomagnetic field in the motion platform coordinate system

Step 5. According to the direction of the geomagnetic field calculated in step 4 in the coordinate system of the moving platform Calculate the direction cosine values cosX, cosY, and cosZ of the angles between the geomagnetic field and the axes of the moving platform coordinate system, and record cosX as a ₁ , cosY as b ₁ , and cosZ as c ₁ ;

Step 6. According to the magnetic induction intensity vector output by the fluxgate magnetometer at a certain moment obtained in step 1 Obtain the cosine values cosX, cosY, and cosZ of the direction of the magnetic field obtained directly through the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate, and record cosX as a ₂ , cosY as b ₂ , and cosZ as c ₂ ;

Step 7. Fuse a ₁ , b ₁ , c ₁ with a ₂ , b ₂ , c ₂ to obtain the direction cosine value of the angle between the geomagnetic field and the axes of the motion platform coordinate system calculated by the gyroscope. The cosine value of the direction of the magnetic field obtained by the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate.

Specific embodiment two: the difference between this embodiment and specific embodiment one is: the magnetic induction intensity vector output by the fluxgate magnetometer at a certain moment is obtained in the step one The three deflection angles (α, β, γ) output by the current gyroscope; the specific process is:

When the moving platform (usually in the process of aeromagnetic measurement, the platform is a fixed-wing aircraft) equipped with a fluxgate magnetometer and a gyroscope moves to a certain state, the fluxgate magnetometer will measure its position The magnetic induction intensity of , and the corresponding measurement results are given in vector form, set as Among them, B _x , By _y , and B _z represent the position of each axis in the three-dimensional coordinate system constructed with the position of the fluxgate magnetometer as the center and its (fluxgate magnetometer) own orthogonal direction as the axis. Magnetic induction; T is matrix transposition; the coordinate system is shown in Figure 2. Since the fluxgate magnetometer is installed on the moving platform, the three axes of the fluxgate magnetometer are consistent with the three axes of the moving platform coordinate system, and the moving platform coordinate system As shown in Figure 3 (illustrated with an airplane). When the motion platform does not perform deflection maneuvers, the coordinate system of the motion platform and the ground coordinate system (as shown in Figure 4) are coincident, assuming that at this moment, the motion platform makes a maneuver, and the gyroscope generates a motion of the motion platform relative to the ground. The deflection angle of the coordinate system is set to (α, β, γ), where α represents the rotation angle of the motion platform around the Z-axis of the ground coordinate system, β represents the rotation angle of the motion platform around the Y-axis of the ground coordinate system, and γ represents the rotation angle of the motion platform around the ground coordinate system. The angle by which the X-axis of the ground coordinate system is rotated.

Other steps and parameters are the same as those in Embodiment 1.

Specific embodiment three: the difference between this embodiment and specific embodiment one or two is that in the step two, the rotation between the ground coordinate system and the motion platform coordinate system is calculated according to (α, β, γ) in step one Matrix M; the specific process is:

In step 1, when the motion platform makes a maneuver, the coordinate system of the motion platform will deflect relative to the ground coordinate system;

According to the theory of flight dynamics, the moving platform rotates around its (moving platform coordinate system) Z axis by an angle of α, and the rotation matrix M(α) between the moving platform coordinate system and the ground coordinate system is expressed as:

${\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; =</span>\left[\begin{array}{ccc}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}& \mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}& \mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

The motion platform rotates an angle of β around its (motion platform coordinate system) Y axis, and the rotation matrix M(β) between the motion platform coordinate system and the ground coordinate system is expressed as:

${\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}<span\; class="notranslate">\; =</span>\left[\begin{array}{ccc}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}\end{array}\right]<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

The motion platform rotates an angle of γ around its (motion platform coordinate system) X axis, and the rotation matrix M(γ) between the motion platform coordinate system and the ground coordinate system is expressed as:

${\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}<span\; class="notranslate">\; =</span>\left[\begin{array}{ccc}\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&gamma;</span>}& \mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&gamma;</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}& \mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; \&gamma;</span>}\end{array}\right]<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Therefore, when the motion platform performs maneuvers of (α, β, γ), the rotation matrix M between the motion platform coordinate system and the ground platform coordinate system can be expressed as:

M = M _γ M _β M _α (7).

Other steps and parameters are the same as those in Embodiment 1 or Embodiment 2.

Specific embodiment four: this embodiment is different from one of the specific embodiments one to three: in the step three, according to the magnetic induction intensity vector of the geomagnetic field under the ground coordinate system Obtain the direction of the geomagnetic field in the ground coordinate system; the specific process is:

At this stage, the model of the earth's magnetic field has been relatively perfect. The geomagnetic inclination φ and geomagnetic declination θ at the location of the moving platform can be considered known, so the magnetic induction vector of the geomagnetic field in the ground coordinate system can be obtained for:

$\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; h</span>}\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&phi;</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&phi;</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&phi;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

Among them, |He| represents the scalar magnitude of the magnetic induction intensity of the geomagnetic field, which is measured by a total field magnetometer (such as an atomic magnetometer) also installed on the moving platform; where He represents the geomagnetic field, φ represents the geomagnetic inclination angle, and θ represents the geomagnetic field The declination, (cosφcosθ, cosφsinθ, sinφ) indicates the direction of the geomagnetic field in the ground coordinate system.

Other steps and parameters are the same as those in Embodiments 1 to 3.

Specific embodiment five: the difference between this embodiment and one of the specific embodiments one to four is: in the step 4, according to the rotation matrix M between the ground coordinate system and the motion platform coordinate system in the step 2 and the geomagnetic field in the step 3 Direction in the ground coordinate system, calculate the direction of the geomagnetic field in the coordinate system of the moving platform (In order to match the calculation form of the rotating platform, it is written in the form of a column vector): the specific process is:

$\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; m</span>}\left(\begin{array}{c}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&phi;</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}\\ \mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; \&phi;</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}\\ \mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&phi;</span>}\end{array}\right)<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

Other steps and parameters are the same as in one of the specific embodiments 1 to 4.

Specific embodiment six: the difference between this embodiment and one of specific embodiments one to five is: the direction of the geomagnetic field calculated according to step four in the step five under the coordinate system of the moving platform Calculate the direction cosine values cosX, cosY, and cosZ of the angles between the geomagnetic field and the axes of the moving platform coordinate system, and record cosX as a ₁ , cosY as b ₁ , and cosZ as c ₁ ;

The specific process is:

The direction cosine value of the angle between the geomagnetic field and the coordinate system of each axis of the moving platform is expressed as:

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\frac{{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}{<span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; =</span>\frac{{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}{<span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 11</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; =</span>\frac{{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; z</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}{<span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; z</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 12</span>}<span\; class="notranslate">\; )</span>$

in, Respectively represent the X, Y, and Z coordinate axis directions of the motion platform, and obviously, cosX is the cosine value of the angle between the geomagnetic field and the X-axis coordinate system of the moving platform, cosY is the cosine value of the angle between the geomagnetic field and the Y-axis coordinate system of the moving platform, cosZ is the difference between the geomagnetic field and the Z-axis coordinate system of the moving platform The cosine of the included angle;

Note that cosX calculated in step 5 is a ₁ , cosY is b ₁ , and cosZ is c ₁ .

Other steps and parameters are the same as one of the specific embodiments 1 to 5.

Specific embodiment seven: the difference between this embodiment and one of the specific embodiments one to six is: in the step six, according to the magnetic induction vector output by the fluxgate magnetometer at a certain moment obtained in the step one Obtain the cosine values cosX, cosY, and cosZ of the direction of the magnetic field obtained directly through the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate, and record cosX as a ₂ , cosY as b ₂ , and cosZ as c ₂ ; specifically The process is:

According to the magnetic induction intensity vector measured by the fluxgate magnetometer obtained in step 1 Obtain the cosine values cosX, cosY, cosZ of the direction of the magnetic field obtained directly through the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate,

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In the formula, cosX is the direction cosine of the coordinate system formed by the magnetic field obtained directly through the fluxgate magnetometer on the X-axis of the fluxgate; The direction cosine of the coordinate system; cosZ is the direction cosine of the coordinate system formed by the magnetic field obtained directly through the fluxgate magnetometer on the Z axis of the fluxgate;

Record cosX as a ₂ , cosY as b ₂ , and cosZ as c ₂ :

In order to distinguish the calculation result in step 5 from the calculation result obtained directly through the fluxgate magnetometer, record the three direction cosines calculated in step 5 as a ₁ , b ₁ , c ₁ ; record directly through the fluxgate The direction cosines obtained by the magnetometer are a ₂ , b ₂ , c ₂ (according to the magnetic induction vector measured by the fluxgate magnetometer obtained in step 1 It can be obtained by combining formulas 1, 2, and 3).

Other steps and parameters are the same as one of the specific embodiments 1 to 6.

Embodiment 8: The difference between this embodiment and one of Embodiments 1 to 7 is that in step 7, a ₁ , b ₁ , c ₁ and a ₂ , b ₂ , c ₂ are fused to obtain The direction cosine value of the angle between the geomagnetic field and the coordinate system of the moving platform is fused directly with the direction cosine value of the magnetic field obtained by the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate; the specific process is:

According to the method of information fusion estimation, assuming that the measurement error variance of the gyroscope is σ ₁ ² , and the measurement error variance of the fluxgate magnetometer is σ ₂ ² , then the fusion result of the two is:

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\frac{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\frac{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 13</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; =</span>\frac{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\frac{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 14</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; cos</span>}\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; =</span>\frac{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\frac{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 15</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; .</span>$

Other steps and parameters are the same as one of the specific embodiments 1 to 7.

Adopt the following examples to verify the beneficial effects of the present invention:

Embodiment one:

A method for improving the accuracy of fluxgate angle measurement in this embodiment is specifically prepared according to the following steps:

Step 1. Obtain the vector magnetic induction intensity output by the fluxgate magnetometer at a certain moment (unit: nT) and the three deflection angles (α, β, γ) output by the current gyroscope = (359.563, 0.607, 7.125) (unit: degree);

Step 2. According to (α, β, γ) in step 1, calculate the rotation matrix between the ground coordinate system and the motion platform coordinate system $m=\left(\begin{array}{ccc}0.9999& -0.0033& -0.0118\\ 0.0047& 0.9919& 0.1273\\ 0.0113& -0.1274& 0.9918\end{array}\right);$

Step 3. According to the magnetic induction intensity vector of the geomagnetic field in the ground coordinate system Obtain the direction of the geomagnetic field in the ground coordinate system (0.5244,-0.0622,0.8492);

Step 4. According to the rotation matrix M between the ground coordinate system and the motion platform coordinate system in step 2 and the direction of the geomagnetic field in the ground coordinate system in step 3, calculate the direction of the geomagnetic field in the motion platform coordinate system $\stackrel{\&Right\; Arrow;}{h}=(0.5145,0.0489,0.8561);$

Step 5. According to the direction of the geomagnetic field calculated in step 4 in the coordinate system of the moving platform Calculate the direction cosine value cosX=0.5145, cosY=0.0489, cosZ=0.8561 of the angle between the geomagnetic field and each axis of the moving platform coordinate system, record cosX as a ₁ , cosY as b ₁ , and cosZ as c ₁ ;

Step 6. According to the magnetic induction vector measured by the fluxgate magnetometer obtained in step 1 Obtain the cosine value cosX=0.5074, cosY=0.0647, cosZ=0.8593 of the direction cosine value cosX=0.5074, cosY=0.0647, cosZ=0.8593 of the magnetic field obtained directly by the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate, record cosX as a ₂ , cosY as b ₂ , cosZ is c ₂ ;

Step 7. Fuse a ₁ , b ₁ , c ₁ with a ₂ , b ₂ , c ₂ to obtain the direction cosine value of the angle between the geomagnetic field and the axes of the motion platform coordinate system calculated by the gyroscope. The cosine values of the direction of the magnetic field obtained by the fluxgate magnetometer in the coordinate system formed by the three axes of the fluxgate are cosX=0.5115, cosY=0.0519, and cosZ=0.8577.

Fig. 5 is a group of 5081 data points after the result obtained after the algorithm operation of the present invention and the mean value after the real cosine value is done difference:

Respectively represent the mean value of the difference between the cosine value result calculated by simply applying the gyroscope and the real cosine value result on the three axes of X, Y, and Z, and the cosine value result calculated by simply applying the fluxgate magnetometer and the real cosine value result The value of the mean value of the difference on the three axes of X, Y, and Z, and the mean value of the difference between the cosine value result obtained after applying the WLS method and the real cosine value result on the three axes of X, Y, and Z.

The present invention can also have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations are all Should belong to the scope of protection of the appended claims of the present invention.

Claims (8)

1. A method for improving the angle measurement precision of a fluxgate is characterized in that the method for improving the angle measurement precision of the fluxgate is specifically carried out according to the following steps:

step one, obtaining a magnetic induction intensity vector output by a fluxgate magnetometer at a certain momentThree angles of deflection (α, γ) from the current gyroscope output;

step two, calculating a rotation matrix M between the ground coordinate system and the motion platform coordinate system according to the (alpha, beta, gamma) in the step one;

step three, according to the magnetic induction intensity vector of the geomagnetic field in the ground coordinate systemObtaining the direction of the geomagnetic field under a ground coordinate system;

step four, calculating the direction of the geomagnetic field under the coordinate system of the motion platform according to the rotation matrix M between the coordinate system of the ground and the coordinate system of the motion platform in the step two and the direction of the geomagnetic field under the coordinate system of the ground in the step three

Step five, calculating the direction of the geomagnetic field under the coordinate system of the motion platform according to the step fourCalculating direction cosine values cosX, cosY and cosZ of included angles between the geomagnetic field and each axis of the coordinate system of the motion platform, and recording cosX as a₁cosY is b₁cosZ is c₁；

Step six, obtaining the magnetic induction intensity vector output by the fluxgate magnetometer at a certain moment according to the step oneObtaining the cosine values cosX, cosY and cosZ of the magnetic field obtained by the fluxgate magnetometer in the direction of the coordinate system formed by the three fluxgate axes, and recording cosX as a₂cosY is b₂cosZ is c₂；

Step seven, fusing a₁，b₁，c₁And a₂，b₂，c₂And obtaining the direction cosine value of an included angle between the geomagnetic field and each axis of the motion platform coordinate system calculated by the gyroscope, and the direction cosine value of the coordinate system formed by the three axes of the fluxgate of the magnetic field directly obtained by the fluxgate magnetometer.

2. The method for improving the angle measurement accuracy of the fluxgate of claim 1, wherein: in the first step, the magnetic induction intensity vector output by the fluxgate magnetometer at a certain moment is obtainedThree deflection angles (α, gamma) with the current gyroscope output, the specific process is as follows:

when the motion platform carrying the fluxgate magnetometer and the gyroscope at the same time moves to a certain state, the fluxgate magnetometer can measure the magnetic induction intensity of the position where the fluxgate magnetometer is positioned, and a corresponding measurement result is given in a vector form and is set asWherein B is_x、B_y、B_zThe method comprises the steps of respectively representing magnetic induction intensity of each axial direction in a three-dimensional coordinate system which is constructed by taking the position of a fluxgate magnetometer as the center and taking the orthogonal direction of the fluxgate magnetometer as the axial direction, and T is a matrix transpose, wherein the fluxgate magnetometer is installed on a moving platform, three axes of the fluxgate magnetometer are consistent with three axes of the moving platform coordinate system, the moving platform coordinate system is coincident with a ground coordinate system under the condition that the moving platform does not perform deflection maneuver, and if the moving platform performs the maneuver at the moment, the gyroscope generates a deflection angle of the moving platform relative to the ground coordinate system, the deflection angle is set to be (α, gamma), wherein α represents the rotation angle of the moving platform around the Z axis of the ground coordinate system, β represents the rotation angle of the moving platform around the Y axis of the ground coordinate system, and gamma represents the rotation angle of.

3. The method for improving the angle measurement accuracy of the fluxgate of claim 2, wherein: in the second step, a rotation matrix M between the ground coordinate system and the motion platform coordinate system is calculated according to the (alpha, beta, gamma) in the first step; the specific process is as follows:

in the first step, when the motion platform is maneuvering, the motion platform coordinate system deflects relative to the ground coordinate system;

according to the theory of flight dynamics, the motion platform rotates around the Z axis by an angle of alpha, and a rotation matrix M (alpha) between a coordinate system of the motion platform and a ground coordinate system is expressed as follows:

$M_{\mathrm{\&alpha;}}=\left[\begin{array}{ccc}cos\mathrm{\&alpha;}& sin\mathrm{\&alpha;}& 0\\ -sin\mathrm{\&alpha;}& cos\mathrm{\&alpha;}& 0\\ 0& 0& 1\end{array}\right]---\left(4\right)$

the rotation matrix M (beta) between the coordinate system of the motion platform and the coordinate system of the ground is expressed as follows:

$M_{\mathrm{\&beta;}}=\left[\begin{array}{ccc}cos\mathrm{\&beta;}& 0& -sin\mathrm{\&beta;}\\ 0& 1& 0\\ sin\mathrm{\&beta;}& 0& \cos \mathrm{\&beta;}\end{array}\right]---\left(5\right)$

the motion platform rotates around the X axis by an angle of gamma, and a rotation matrix M (gamma) between a motion platform coordinate system and a ground coordinate system is expressed as follows:

$M_{\mathrm{\&gamma;}}=\left[\begin{array}{ccc}1& 0& 0\\ 0& cos\mathrm{\&gamma;}& sin\mathrm{\&gamma;}\\ 0& -sin\mathrm{\&alpha;}& \cos \mathrm{\&gamma;}\end{array}\right]---\left(6\right)$

thus, when the motion platform is maneuvered by an amount (α, β, γ), the rotation matrix M between the motion platform coordinate system to the ground platform coordinate system can be expressed as:

M＝M_γM_βM_α(7)。

4. the method for improving the angle measurement accuracy of the fluxgate of claim 3, wherein: in the third step, the magnetic induction intensity vector of the geomagnetic field under the ground coordinate system is usedObtaining the direction of the geomagnetic field under a ground coordinate system; the specific process is as follows:

magnetic induction intensity vector of geomagnetic field in ground coordinate systemComprises the following steps:

$\stackrel{\&RightArrow;}{He}=\left|He\right|(cos\mathrm{\&phi;}cos\mathrm{\&theta;},cos\mathrm{\&phi;}sin\mathrm{\&theta;},sin\mathrm{\&phi;})---\left(8\right)$

wherein, | He | represents the scalar magnitude of the geomagnetic field magnetic induction intensity, and is measured by a total field magnetometer arranged on the motion platform; wherein He represents the geomagnetic field, phi represents the geomagnetic inclination angle, theta represents the geomagnetic declination angle, and (cos phi cos theta, cos phi sin theta, sin phi) represents the direction of the geomagnetic field in the ground coordinate system.

5. The method for improving the angle measurement accuracy of the fluxgate as set forth in claim 4, wherein: in the fourth step, the direction of the geomagnetic field under the coordinate system of the motion platform is calculated according to the rotation matrix M between the coordinate system of the ground and the coordinate system of the motion platform in the second step and the direction of the geomagnetic field under the coordinate system of the ground in the third stepThe specific process is as follows:

$\stackrel{\&RightArrow;}{h}=M\left(\begin{array}{c}cos\mathrm{\&phi;}cos\mathrm{\&theta;}\\ cos\mathrm{\&phi;}sin\mathrm{\&theta;}\\ \sin \mathrm{\&phi;}\end{array}\right)---\left(9\right).$

6. the method for improving the angle measurement accuracy of the fluxgate of claim 5, wherein: in the step five, the direction of the geomagnetic field under the coordinate system of the motion platform is calculated according to the step fourCalculating direction cosine values cosX, cosY and cosZ of included angles between the geomagnetic field and each axis of the coordinate system of the motion platform, and recording cosX as a₁cosY is b₁cosZ is c₁；

The specific process is as follows:

the direction cosine value of the included angle between the geomagnetic field and each axis coordinate system of the motion platform is expressed as follows:

$\cos X=\frac{{\stackrel{\&RightArrow;}{e}}_x\&CenterDot;\stackrel{\&RightArrow;}{h}}{\left|{\stackrel{\&RightArrow;}{e}}_x\right|\left|\stackrel{\&RightArrow;}{h}\right|}---\left(10\right)$

$\cos Y=\frac{{\stackrel{\&RightArrow;}{e}}_y\&CenterDot;\stackrel{\&RightArrow;}{h}}{\left|{\stackrel{\&RightArrow;}{e}}_y\right|\left|\stackrel{\&RightArrow;}{h}\right|}---\left(11\right)$

$\cos Z=\frac{{\stackrel{\&RightArrow;}{e}}_z\&CenterDot;\stackrel{\&RightArrow;}{h}}{\left|{\stackrel{\&RightArrow;}{e}}_z\right|\left|\stackrel{\&RightArrow;}{h}\right|}---\left(12\right)$

wherein,respectively representing the directions of X, Y and Z coordinate axes of the motion platform, cosX is a cosine value of an included angle between the geomagnetic field and an X-axis coordinate system of the motion platform, cosY is a cosine value of an included angle between the geomagnetic field and a Y-axis coordinate system of the motion platform, and cosZ is a cosine value of an included angle between the geomagnetic field and a Z-axis coordinate system of the motion platform;

recording cosX calculated in the step five as a₁cosY is b₁cosZ is c₁。

7. The method for improving the angle measurement accuracy of the fluxgate of claim 6, wherein: in the sixth step, the magnetic induction intensity vector output by the fluxgate magnetometer at a certain moment is obtained according to the first stepObtaining the cosine values cosX, cosY and cosZ of the magnetic field obtained by the fluxgate magnetometer in the direction of the coordinate system formed by the three fluxgate axes, and recording cosX as a₂cosY is b₂cosZ is c₂(ii) a The specific process is as follows:

according to the magnetic induction intensity vector measured by the fluxgate magnetometer obtained in the step oneObtaining cosine values cosX, cosY and cosZ of the magnetic field obtained by the fluxgate magnetometer in the direction of a coordinate system formed by three fluxgate axes,

$\cos X=\frac{B_x}{\sqrt{{B_x}^2+{B_y}^2+{B_z}^2}}---\left(1\right)$

$\cos Y=\frac{B_y}{\sqrt{{B_x}^2+{B_y}^2+{B_z}^2}}---\left(2\right)$

$\cos Z=\frac{B_z}{\sqrt{{B_x}^2+{B_y}^2+{B_z}^2}}---\left(3\right)$

in the formula, cosX is the direction cosine of a magnetic field obtained directly through a fluxgate magnetometer in a coordinate system formed by a fluxgate X axis; cosY is the direction cosine of a magnetic field obtained directly through a fluxgate magnetometer in a coordinate system formed by a fluxgate Y axis; cosZ is the direction cosine of a magnetic field obtained directly through a fluxgate magnetometer in a coordinate system formed by a fluxgate Z axis;

notation cosX as a₂cosY is b₂cosZ is c₂。

8. The method for improving the angle measurement accuracy of the fluxgate of claim 7, wherein: in the seventh step, a is fused₁，b₁，c₁And a₂，b₂，c₂Obtaining a direction cosine value of an included angle between the geomagnetic field and each axis of the motion platform coordinate system calculated by the gyroscope, and a direction cosine value of a coordinate system formed by the three axes of the fluxgate of the magnetic field directly obtained by the fluxgate magnetometer; the specific process is as follows:

according to the method of information fusion estimation, the measurement error variance of a gyroscope is assumed to be sigma₁ ²The variance of the measurement error of the fluxgate magnetometer is σ₂ ²If the two are merged, the result is:

$\cos X+\cos X=\frac{{{\mathrm{\&sigma;}}_2}^2}{{{\mathrm{\&sigma;}}_1}^2+{{\mathrm{\&sigma;}}_2}^2}{a}_1+\frac{{{\mathrm{\&sigma;}}_1}^2}{{{\mathrm{\&sigma;}}_1}^2+{{\mathrm{\&sigma;}}_2}^2}{a}_2---\left(13\right)$

$\cos Y+\cos Y=\frac{{{\mathrm{\&sigma;}}_2}^2}{{{\mathrm{\&sigma;}}_1}^2+{{\mathrm{\&sigma;}}_2}^2}{b}_1+\frac{{{\mathrm{\&sigma;}}_1}^2}{{{\mathrm{\&sigma;}}_1}^2+{{\mathrm{\&sigma;}}_2}^2}{b}_2---\left(14\right)$

$\cos Z+\cos Z=\frac{{{\mathrm{\&sigma;}}_2}^2}{{{\mathrm{\&sigma;}}_1}^2+{{\mathrm{\&sigma;}}_2}^2}{c}_1+\frac{{{\mathrm{\&sigma;}}_1}^2}{{{\mathrm{\&sigma;}}_1}^2+{{\mathrm{\&sigma;}}_2}^2}{c}_2---\left(15\right).$