CN103017768A - System and method for three-dimensional attitude determination for aircraft - Google Patents

Abstract

The invention provides a system and a method for three-dimensional attitude determination for an aircraft. The system comprises an observation module, a model establishment module, a data query module, a data processing module, and an attitude solution module, wherein the observation module is used for measuring the light vibration directions of skylights in two mutually vertical directions in real time and automatically by virtue of a sky scattered light polarization character measurement system; the model establishment module is connected with the observation module and used for establishing the body coordinate system and the equatorial coordinate system of the aircraft in a computer; the data query module is connected with the observation module and used for obtaining the declination and the Greenwich hour angle of the sun at an observation time; the data processing module is connected with the observation module, the model establishment module and the data query module, and used for performing transformation processing on the data obtained by the observation module and the data query module in the established model coordinate system; and the attitude solution module is connected with the data processing module and used for establishing an equation set by virtue of the data output by the data processing module, solving and outputting a result.

Description

A kind of aircraft three-dimensional posture fixing system and method

Technical field

The invention belongs to field of navigation technology, be specifically related to a kind of aircraft three-dimensional posture fixing method based on the skylight polarization characteristic.

Background technology

Sunshine is natural light, it itself not polarized light, sunshine is in the propagation in atmosphere process, be subject to the scattering of atmospheric molecule or other particles, only become and upwards vibrate dominant polarized light in some direction vibrations or one party, when atmosphere comparatively cleaned, Rayleigh scattering accounted for leading, and the light of scattering outgoing mainly is linearly polarized light.

Polarization characteristic can be described with degree of polarization and polarization azimuth.Studies show that polarization characteristic and the position of sun of sky are closely related, the plane that the electric vector vibration direction of day aerial certain observation station consists of perpendicular to the aerial observation station in the sun, ground observation point and sky.

Someone proposes a kind of polarisation distribution based on skylight and the relation between the solar direction obtains the position on naval vessel and the method for course information, but, when it had only considered that the naval vessel navigates by water on the sea level, pedestal kept the situation of level, thereby had limited to greatly the range of application of this kind method.Someone proposes to utilize sky polarized light distribution pattern to determine the method for navigational system course angle, the method is by setting up sky polarized light distributed model, determined the navigation reference line and in conjunction with astronomical navigation method, determine the relative position of the sun, then obtain course angle, but for the movable body that needs navigate, do not possess the vision system of responsive polarization, thereby can't determine the reference line that navigates, also just can't utilize smoothly this kind method to finish navigation task.For this problem, someone proposes to pass through hardware design, try to achieve the meridianal position angle of current location and the sun, for real-time navigation is carried out in the vehicles such as boats and ships, aircraft, vehicle and robot and moving object, but only provided near the navigation accuracy of the sun middle day, the navigation accuracy of the sun in other position has not been described in detail.Also the someone has proposed a kind of technology of polarotactic navigation under water based on ocean scatter light polarization characteristic, but the foundation of its navigation coordinate system is to make the pedestal maintenance level of surveying, and in the actual navigation procedure, because the attitude of aircraft changes, pedestal is difficult to the maintenance level, thereby has limited the practical application of this kind method.

Summary of the invention

The object of the present invention is to provide a kind of aircraft three-dimensional posture fixing system, solve the aircraft navigation that prior art exists and decide in real time the appearance hard problem.

Another object of the present invention is to provide a kind of aircraft three-dimensional posture fixing method.

The object of the present invention is achieved like this, and a kind of aircraft three-dimensional posture fixing system comprises:

The observation module, utilize sky scattering light polarization measuring system real-time, measure the optical vibration direction of the skylight of two mutual vertical direction automatically;

Model building module, model building module links to each other with described observation module, sets up the body coordinate system of aircraft in computing machine, the equatorial system of coordinates;

The data query module, the data query module links to each other with the observation module, is used for obtaining observation constantly declination and the Greenwich hour angle of the sun.

Data processing module, data processing module links to each other with observation module, model building module, data query module, is used for the data of observing module and data query module obtain are carried out conversion processing in the model coordinate systems of setting up.

Attitude is found the solution module, and attitude is found the solution module and linked to each other with data processing module, and the data of utilizing data processing module to transfer out are set up system of equations, finds the solution and Output rusults.

Another object of the present invention is achieved in that a kind of aircraft three-dimensional posture fixing method, comprising:

The observation module, utilize sky scattering light polarization measuring system real-time, measure the optical vibration direction of the skylight of two mutual vertical direction automatically;

Model building module, model building module links to each other with the observation module, sets up the body coordinate system of aircraft in computing machine, the equatorial system of coordinates;

The data query module, the data query module links to each other with the observation module, is used for obtaining observation constantly declination and the Greenwich hour angle of the sun.

Data processing module, data processing module links to each other with observation module, model building module, data query module, is used for the data of observing module and data query module obtain are carried out conversion processing in the model coordinate systems of setting up.

Attitude is found the solution module, and attitude is found the solution module and linked to each other with data processing module, and the data of utilizing data processing module to transfer out are set up system of equations, finds the solution and Output rusults;

Comprise the steps:

Step 1 is set up the body coordinate system of aircraft in computing machine, utilize sky scattering light polarization measuring system real-time, obtain the optical vibration direction of the skylight of two mutual vertical direction automatically;

Step 2 is set up the equatorial system of coordinates optical vibration direction that obtains in the step 1 is passed to computing machine automatically in computing machine, utilize the rotating coordinate system formula that the direction of vibration of two-beam is transformed in the equatorial system of coordinates; The position relationship that utilizes two direction of polarized light and the sun calculates the direction of the sun under the line in the coordinate system;

Step 3 to be surveyed the constantly declination of the sun, and the longitude and latitude of Green visual angle and aircraft is expressed the direction of the sun;

Step 4: utilize in step 2 and the step 3 solar direction of gained to set up system of equations;

Step 5: the data transmission that obtains in the step 3 is carried out last numerical solution in the system of equations of step 4 gained.

Further, step 1 comprises:

1) set up aircraft body navigation coordinate system, on celestial sphere, S is the sun, D ₁, D ₂Two groups of orthogonal detection directions on surface level time for aircraft, D ' ₁And D ' ₂Be two vertical skylight detection directions of reality, respectively along Y " ' axle and Z " ' axle; Gained coordinate axis after X " ' axle is X " rotates with pedestal; N' is the real north of aircraft local (φ, λ), and E is the due east direction, P ₁For at D ₁' the skylight optical vibration direction that orientation detection arrives, P ₂For at D ₂' skylight optical vibration direction that orientation detection arrives, TC is the true heading of aircraft; Ignore the impact of earth radius, take in the earth's core as true origin, set up coordinate system XYZ, X ' Y ' Z ', X " Y " Z " and X " ' Y " ' Z " ', wherein X-axis is along the due east direction, and Y-axis is along real north, and Z, Z ' axle be vertical shaft direction up during along the aircraft level; X, X', X " the prow direction of axle along the horizontal right flank direction of aircraft Y ' axle along aircraft; " axle is along D for Y ₁Direction, " axle is along D for Z ₂Direction, " ' axle is along D ' for Y ₁Direction, " ' axle is along D ' for Z ₂Direction;

2) real-time monitored is carried out in the skylight optical vibration direction of two vertical direction, and hourly observation constantly; At the fixing swivel mount with demarcating pointer of polaroid, so that rotatory polarization sheet and do the surface level reference, the effect of polaroid and swivel mount is the polarizing angle that produces three different directions, by the measurement to the light intensity of the polarizing angle of these three different directions, just can obtain the direction of vibration of the polarized light of this direction.

Further, step 2 comprises:

1) the measured polarized light direction of vibration of two orthogonal two detection directions is transformed to X " Y " Z " in;

When the angle of pitch is that x and roll angle are when being ψ.Can there be following transition matrix to carry out conversion, transforms to X " Y " Z " coordinate system.

$M={\mathrm{<figure-callout\; id="1"\; label="M"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">M</figure-callout>}}_1*{\mathrm{<figure-callout\; id="2"\; label="M"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">M</figure-callout>}}_2=$

$\left[\begin{array}{ccc}\cos \mathrm{\&psi;}& \frac{\sqrt{2}}{2}\sin \mathrm{\&psi;}& \frac{\sqrt{2}}{2}\sin \mathrm{\&psi;}\\ \frac{-(\sqrt{2}\sin \mathrm{\&psi;}*(\cos \mathrm{\&chi;}-\sin \mathrm{\&chi;}))}{2}& \cos \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}+1}{2}\right)-\sin \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}-1}{2}\right)& \cos \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}-\frac{1}{2})-\sin \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}+\frac{1}{2})\\ \frac{-(\sqrt{2}\sin \mathrm{\&psi;}*(\cos \mathrm{\&chi;}+\sin \mathrm{\&chi;}))}{2}& \cos \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}-1}{2}\right)+\sin \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}+1}{2}\right)& \cos \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}+\frac{1}{2})+\sin \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}-\frac{1}{2})\end{array}\right]---\left(6\right)$

2) at X " ' Y " ' Z " in ' coordinate system, P ₁And P ₂The unit vector of direction can be expressed as:

${\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">P</figure-callout>}}_1=\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_1\\ 0\\ \cos {\mathrm{\&theta;}}_2\end{array}\right]---\left(7\right)$

${\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">P</figure-callout>}}_2=\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_2\\ \cos {\mathrm{\&theta;}}_2\\ 0\end{array}\right]---\left(8\right)$

With P ₁And P ₂The unit vector of direction from X " Y " ' Z " ' transform to X " Y " Z " again by following matrix X " Y " Z " be transformed into the xyz coordinate system, transition matrix is:

$S=\left[\begin{array}{ccc}\cos \mathrm{\&beta;}& -\cos \mathrm{\&alpha;}\sin \mathrm{\&beta;}& \sin \mathrm{\&alpha;}\sin \mathrm{\&beta;}\\ \sin \mathrm{\&beta;}\cos \mathrm{\&gamma;}& \cos \mathrm{\&gamma;}\cos \mathrm{\&beta;}\cos \mathrm{\&alpha;}-\sin \mathrm{\&gamma;}\sin \mathrm{\&alpha;}& -\cos \mathrm{\&gamma;}\cos \mathrm{\&beta;}\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;}\cos \mathrm{\&alpha;}\\ \sin \mathrm{\&alpha;}\sin \mathrm{\&gamma;}& \sin \mathrm{\&alpha;}\cos \mathrm{\&beta;}\cos \mathrm{\&gamma;}+\sin \mathrm{\&alpha;}\cos \mathrm{\&gamma;}& \cos \mathrm{\&alpha;}\cos \mathrm{\&gamma;}-\sin \mathrm{\&alpha;}\cos \mathrm{\&beta;}\sin \mathrm{\&gamma;}\end{array}\right]---\left(9\right)$

α=π/4 wherein, β=2 π-TC, γ=-φ.

Then by S transition matrix, just P ₁And P ₂The unit vector of direction is expressed as in the xyz coordinate system:

${\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">P</figure-callout>}}_1=S\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_1\\ 0\\ \cos {\mathrm{\&theta;}}_1\end{array}\right]---\left(10\right)$

${\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">P</figure-callout>}}_2=S\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_2\\ \cos {\mathrm{\&theta;}}_2\\ 0\end{array}\right]---\left(11\right)$

3) solar direction P can be expressed as:

P＝P ₁×P ₂ (12)

Further, step 3 comprises:

1) moment that will record first is converted to universal time; If the time of recording is Beijing time, and Beijing time is in the Dong Ba district, so T _G(universal time)=T(Beijing time)-8h;

2) constantly table look-up by integral point first, then utilize the hour angle in the subordinate list, the declination interpolation table is asked minute, the interpolate value in second; Hour angle=integral point is worth constantly+and every minute and second interpolate value+hour angle is overproof; Declination=integral point is worth+every minute and second interpolate value+declination difference constantly; Annotate: the declination interpolate value gets the positive and negative identical of positive and negative and declination difference;

3) set up the equatorial system of coordinates; Coordinate system xyz, wherein the x axle is along the due east direction, the y axle is along earth's axis directed north direction, the z axle pass (0, λ) point;

4) can check in declination (δ), the Greenwich hour angle (t) of surveying the moment sun by " celestial navigation is gone through ", then in the xyz coordinate system, can represent that solar direction is:

$P^{\&prime;}=\left[\begin{array}{c}\cos \left(\mathrm{\&delta;}\right)\sin (t-\mathrm{\&lambda;})\\ \sin \left(\mathrm{\&delta;}\right)\\ \cos \left(\mathrm{\&delta;}\right)\cos (t-\mathrm{\&lambda;})\end{array}\right]---\left(13\right)$

Further, in the step 4, because P' and P represent same direction, then have:

P×P′=0 (14)

Further, in the step 5, simultaneous (6) (7) (8) (9) (11) (12) (13) (14) formula can be tried to achieve 3 d pose roll angle ψ, angle of pitch x and the crab angle TC of aircraft.

The present invention utilizes the polarization characteristic of skylight and the relation of solar direction, has proposed a kind of implementation method of 3 d pose of definite aircraft (such as aircraft) newly.The method can be measured the skylight optical vibration direction on two vertical direction automatically simultaneously, and set up corresponding navigation model, utilize the rotation between the different coordinates to change, crab angle, the angle of pitch, the roll angle of aircraft are provided in real time automatically, what solved aircraft navigation decides the appearance problem in real time, has practicality.

Description of drawings

Fig. 1 is Rayleigh particle scattering model.

Fig. 2 is Horizon geometric coordinate system;

Fig. 3 is the measuring method synoptic diagram of partial poolarized light optical vibration direction;

Fig. 4 is skylight optical vibration direction measurement mechanism synoptic diagram:

Fig. 5 is aircraft body navigation coordinate system;

Fig. 6 is the equatorial system of coordinates;

Fig. 7 is the implementation structural representation of the aircraft attitude determination system based on the skylight polarization characteristic of the present invention.

In the accompanying drawing, 1. observation module, 2. model building module, 3. data query module, 4. data processing module, 5. attitude is found the solution module.

Embodiment

The present invention is described in detail below in conjunction with the drawings and specific embodiments.

A kind of aircraft three-dimensional posture fixing system and method comprises:

Observation module 1, utilize sky scattering light polarization measuring system real-time, measure the optical vibration direction of the skylight of two mutual vertical direction automatically;

Model building module 2, model building module 2 links to each other with described observation module 1, sets up the body coordinate system of aircraft in computing machine, the equatorial system of coordinates;

Data query module 3, data query module 3 links to each other with observation module 1, is used for obtaining observation constantly declination and the Greenwich hour angle of the sun.

Data processing module 4, data processing module 4 links to each other with observation module 1, model building module 2, data query module 4, is used for the data of observing module 1 and data query module 4 obtain are carried out conversion processing in the model coordinate systems of setting up.

Attitude is found the solution module 5, and attitude is found the solution module 5 and linked to each other with data processing module 4, and the data of utilizing data processing module 4 to transfer out are set up system of equations, finds the solution and Output rusults.

Comprise the steps:

Step 1 is set up the body coordinate system of aircraft in computing machine, utilize sky scattering measurement of polarization characteristic system real-time, obtain the optical vibration direction of the skylight of two mutual vertical direction automatically;

Step 2 is set up the equatorial system of coordinates with (optical vibration direction that obtains in the step 1) passes to computing machine automatically, utilizes the rotating coordinate system formula that the direction of vibration of two-beam is transformed in the equatorial system of coordinates in computing machine; The position relationship that utilizes two direction of polarized light and the sun calculates the direction of the sun under the line in the coordinate system;

Step 3 to be surveyed the constantly declination of the sun, and the longitude and latitude of Green visual angle and aircraft is expressed the direction of the sun;

Step 4: utilize the solar direction of gained in step (2) and the step (3) to set up system of equations;

Step 5: the data transmission that obtains in the step 3 is carried out last numerical solution in the system of equations of step 4 gained.

Further, step 1 comprises:

1) such as Fig. 5, set up aircraft body navigation coordinate system, on celestial sphere, S is the sun, D ₁, D ₂Two groups of orthogonal detection directions on surface level time for aircraft, D ' ₁And D ' ₂Be two vertical skylight detection directions of reality, respectively along Y " ' axle and Z " ' axle.Gained coordinate axis after X " ' axle is X " rotates with pedestal.N' is the real north of aircraft local (φ, λ), and E is the due east direction, P ₁For at D ₁' the skylight optical vibration direction that orientation detection arrives, P ₂For at D ₂' skylight optical vibration direction that orientation detection arrives, TC is the true heading of aircraft.Ignore the impact of earth radius, take in the earth's core as true origin, set up coordinate system XYZ, X'Y'Z', X " Y " Z " and X " ' Y " ' Z " ', wherein X-axis is along the due east direction, and Y-axis is along real north, and Z, Z ' axle be vertical shaft direction up during along the aircraft level; X, X ', X " the prow direction of axle along the horizontal right flank direction of aircraft Y ' axle along aircraft; " axle is along D for Y ₁Direction, " axle is along D for Z ₂Direction, " ' axle is along D ' for Y ₂Direction, " ' axle is along D ' for Z ₂Direction.

2) the skylight optical vibration direction of two vertical direction carried out real-time monitored, and hourly observation constantly.As shown in Figure 3, at the fixing swivel mount with demarcating pointer of polaroid, so that rotatory polarization sheet and do the surface level reference, the effect of polaroid and swivel mount is the polarizing angle that produces three different directions, by the measurement to the light intensity of the polarizing angle of these three different directions, just can obtain the direction of vibration of the polarized light of this direction.

Further, step 2 comprises:

1) the measured polarized light direction of vibration of two orthogonal two detection directions is transformed to X " Y " Z " in;

When the angle of pitch is that x and roll angle are when being ψ.Can there be following transition matrix to carry out conversion, transforms to X " Y " Z " coordinate system.

$M={\mathrm{<figure-callout\; id="1"\; label="M"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">M</figure-callout>}}_1*{\mathrm{<figure-callout\; id="2"\; label="M"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">M</figure-callout>}}_2=$

$\left[\begin{array}{ccc}\cos \mathrm{\&psi;}& \frac{\sqrt{2}}{2}\sin \mathrm{\&psi;}& \frac{\sqrt{2}}{2}\sin \mathrm{\&psi;}\\ \frac{-(\sqrt{2}\sin \mathrm{\&psi;}*(\cos \mathrm{\&chi;}-\sin \mathrm{\&chi;}))}{2}& \cos \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}+1}{2}\right)-\sin \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}-1}{2}\right)& \cos \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}-\frac{1}{2})-\sin \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}+\frac{1}{2})\\ \frac{-(\sqrt{2}\sin \mathrm{\&psi;}*(\cos \mathrm{\&chi;}+\sin \mathrm{\&chi;}))}{2}& \cos \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}-1}{2}\right)+\sin \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}+1}{2}\right)& \cos \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}+\frac{1}{2})+\sin \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}-\frac{1}{2})\end{array}\right]---\left(6\right)$

2) at X " ' Y " ' Z " in ' coordinate system, P ₁And P ₂The unit vector of direction can be expressed as:

${\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">P</figure-callout>}}_1=\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_1\\ 0\\ \cos {\mathrm{\&theta;}}_2\end{array}\right]---\left(7\right)$ ${\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">P</figure-callout>}}_2=\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_2\\ \cos {\mathrm{\&theta;}}_2\\ 0\end{array}\right]---\left(8\right)$

With P ₁And P ₂The unit vector of direction from X " Y " ' Z " ' transform to X " Y " Z " again by following matrix X " Y " Z " be transformed into the xyz coordinate system, transition matrix is:

$S=\left[\begin{array}{ccc}\cos \mathrm{\&beta;}& -\cos \mathrm{\&alpha;}\sin \mathrm{\&beta;}& \sin \mathrm{\&alpha;}\sin \mathrm{\&beta;}\\ \sin \mathrm{\&beta;}\cos \mathrm{\&gamma;}& \cos \mathrm{\&gamma;}\cos \mathrm{\&beta;}\cos \mathrm{\&alpha;}-\sin \mathrm{\&gamma;}\sin \mathrm{\&alpha;}& -\cos \mathrm{\&gamma;}\cos \mathrm{\&beta;}\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;}\cos \mathrm{\&alpha;}\\ \sin \mathrm{\&alpha;}\sin \mathrm{\&gamma;}& \sin \mathrm{\&alpha;}\cos \mathrm{\&beta;}\cos \mathrm{\&gamma;}+\sin \mathrm{\&alpha;}\cos \mathrm{\&gamma;}& \cos \mathrm{\&alpha;}\cos \mathrm{\&gamma;}-\sin \mathrm{\&alpha;}\cos \mathrm{\&beta;}\sin \mathrm{\&gamma;}\end{array}\right]---\left(9\right)$

α=π/4 wherein, β=2 π-TC, γ=-φ.

Then by S transition matrix, just P ₁And P ₂The unit vector of direction is expressed as in the xyz coordinate system:

${\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">P</figure-callout>}}_1=S\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_1\\ 0\\ \cos {\mathrm{\&theta;}}_1\end{array}\right]---\left(10\right)$ ${\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">P</figure-callout>}}_2=S\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_2\\ \cos {\mathrm{\&theta;}}_2\\ 0\end{array}\right]---\left(11\right)$

3) solar direction P can be expressed as:

P=P ₁×P ₂ (12)

Further, step 3 comprises:

1) moment that will record first is converted to universal time.If the time of recording is Beijing time, and Beijing time is in the Dong Ba district, so T _G(universal time)=T(Beijing time)-8h;

2) constantly table look-up by integral point first, then utilize the hour angle in the subordinate list, the declination interpolation table is asked minute, the interpolate value in second.Hour angle=integral point is worth constantly+and every minute and second interpolate value+hour angle is overproof.Declination=integral point is worth+every minute and second interpolate value+declination difference constantly.Annotate: the declination interpolate value gets the positive and negative identical of positive and negative and declination difference;

3) as shown in Figure 6, set up the equatorial system of coordinates.Coordinate system xyz, wherein the x axle is along the due east direction, the y axle is along earth's axis directed north direction, the z axle pass (0, λ) point;

4) can check in declination (δ), the Greenwich hour angle (t) of surveying the moment sun by " celestial navigation is gone through ", then in the xyz coordinate system, can represent that solar direction is:

$P^{\&prime;}=\left[\begin{array}{c}\cos \left(\mathrm{\&delta;}\right)\sin (t-\mathrm{\&lambda;})\\ \sin \left(\mathrm{\&delta;}\right)\\ \cos \left(\mathrm{\&delta;}\right)\cos (t-\mathrm{\&lambda;})\end{array}\right]---\left(13\right)$

Further, in the step 4, because P ' and P represent same direction, then have:

P×P'=0 (14)

Further, in the step 5, simultaneous (6) (7) (8) (9) (11) (12) (13) (14) formula can be tried to achieve the 3 d pose roll angle ψ of aircraft, angle of pitch x and crab angle TC;

1) polarization characteristic of sunshine in atmosphere

Sunshine is natural light, it itself not polarized light, sunshine is in the propagation in atmosphere process, be subject to the scattering of atmospheric molecule or other particles, only become and upwards vibrate dominant polarized light in some direction vibrations or one party, when atmosphere comparatively cleaned, Rayleigh scattering accounted for leading, and the light of scattering outgoing mainly is linearly polarized light;

Polarization characteristic can be described with degree of polarization and polarization azimuth.The natural light that the sun sends can be decomposed into two linear polarization components of quadrature, horizontal component

And vertical component

Such as Fig. 1, incide on the Rayleigh particle, the electric field after particle scattering is

With

With Parallel to each other, scatteringangleθ is defined as the angle of incident light direction and observed ray, with I _r, I ₁Expression is vertical and be parallel to the scattering plane polarization strength component of (referring to incident wave and scattering wave plane) respectively.For Rayleigh scattering, be under the condition of natural light at incident light, degree of polarization can be expressed as

$P\left(\mathrm{\&theta;}\right)=\frac{1-{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&theta;}}{1+{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&theta;}}$ $P_{\max }=\frac{{\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2\mathrm{\&theta;}}{1+{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA00002467094400042.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&theta;}}{P}_{\max }$

（1）

P _MaxCan surely provide with all-sky polarization imaging instrumentation;

2) degree of polarization of skylight and polarization azimuth calculate

Studies show that polarization characteristic and the position of sun of sky are closely related, the plane that the electric vector vibration direction of day aerial certain observation station consists of perpendicular to the aerial observation station in the sun, ground observation point and sky;

Set up Horizon geometric coordinate system such as Fig. 2, observer's loca is the O point, and the sun and O point line and air sphere intersect at the S point, and the Z point represents zenith point, and the P point is observed ray and atmospherical intersection point; θ is the angle of incident light direction OS and observed ray OP; h _sThe elevation angle of the sun; A _sThe position angle of the sun; h _pIt is the elevation angle of the aerial observation point P in sphere sky; A _pPosition angle for observation point P; The coordinate Due South is representing 0 ° at position angle, and positive west represents 90 ° at position angle;

In spherical triangle ZPS, known by the cosine law of spherical triangle:

cosθ=cos(π/2-h _p)cos(π/2-h _s)

（2）

+sin(π/2-h _p)sin(π/2-h _s)cos(A _s-A _p)

That is: cos θ=sinh _pSinh _s+ cosh _pCosh _sCos (A _s-A _p) (3)

Sine by spherical triangle can be tried to achieve:

$\cos \mathrm{\&phi;}=\frac{\sin (A_s-A_p)}{\sin \mathrm{\&theta;}}\&CenterDot;\cos h_s---\left(4\right)$

Can be calculated degree of polarization P and the polarization azimuth φ of day aerial observed ray light beam by (1), (3) and (4) formula.

Fig. 4 is skylight optical vibration direction measurement mechanism synoptic diagram: will observe pedestal be fixed on the aircraft fuselage, two detection directions are positioned at the phase cross surface of the aircraft longitudinal axis and vertical shaft, and the base plane normal is symmetrical relatively.

Claims (7)

1. an aircraft three-dimensional posture fixing system is characterized in that, comprising:

Observation module (1), utilize sky scattering light polarization measuring system real-time, measure the optical vibration direction of the skylight of two mutual vertical direction automatically;

Model building module (2), model building module (2) links to each other with observation module (1), sets up the body coordinate system of aircraft in computing machine, the equatorial system of coordinates;

Data query module (3), data query module (3) links to each other with observation module (1), is used for obtaining observation constantly declination and the Greenwich hour angle of the sun;

Data processing module (4), data processing module (4) links to each other with observation module (1), model building module (2), data query module (4), is used for the data of observing module (1) and data query module (4) obtain are carried out conversion processing in the model coordinate systems of setting up;

Attitude is found the solution module (5), and attitude is found the solution module (5) and linked to each other with data processing module (4), and the data of utilizing data processing module (4) to transfer out are set up system of equations, finds the solution and Output rusults.

2. an aircraft three-dimensional posture fixing method is characterized in that, comprising:

Observation module (1), utilize sky scattering light polarization measuring system real-time, measure the optical vibration direction of the skylight of two mutual vertical direction automatically;

Model building module (2), model building module (2) links to each other with observation module (1), sets up the body coordinate system of aircraft in computing machine, the equatorial system of coordinates;

Data query module (3), data query module (3) links to each other with observation module (1), is used for obtaining observation constantly declination and the Greenwich hour angle of the sun;

Data processing module (4), data processing module (4) links to each other with observation module (1), model building module (2), data query module (4), is used for the data of observing module (1) and data query module (4) obtain are carried out conversion processing in the model coordinate systems of setting up;

Attitude is found the solution module (5), and attitude is found the solution module (5) and linked to each other with data processing module (4), and the data of utilizing data processing module (4) to transfer out are set up system of equations, finds the solution and Output rusults;

Comprise the steps:

Step 1 is set up the body coordinate system of aircraft in computing machine, utilize sky scattering light polarization measuring system real-time, obtain the optical vibration direction of the skylight of two mutual vertical direction automatically;

Step 2 is set up the equatorial system of coordinates optical vibration direction that obtains in the step 1 is passed to computing machine automatically in computing machine, utilize the rotating coordinate system formula that the direction of vibration of two-beam is transformed in the equatorial system of coordinates; The position relationship that utilizes two direction of polarized light and the sun calculates the direction of the sun under the line in the coordinate system;

Step 3 to be surveyed the constantly declination of the sun, and the longitude and latitude of Green visual angle and aircraft is expressed the direction of the sun;

Step 4: utilize in step 2 and the step 3 solar direction of gained to set up system of equations;

Step 5: the data transmission that obtains in the step 3 is carried out last numerical solution in the system of equations of step 4 gained.

3. aircraft three-dimensional posture fixing method as claimed in claim 2 is characterized in that step 1 comprises:

1) set up aircraft body navigation coordinate system, on celestial sphere, S is the sun, D ₁, D ₂Two groups of orthogonal detection directions on surface level time for aircraft, D ' ₁And D ' ₂Be two vertical skylight detection directions of reality, respectively along Y " ' axle and Z " ' axle; Gained coordinate axis after X " ' axle is X " rotates with pedestal; N ' is the real north of aircraft local (φ, λ), and E is the due east direction, P ₁For at D ₁' the skylight optical vibration direction that orientation detection arrives, P ₂For at D ₂' skylight optical vibration direction that orientation detection arrives, TC is the true heading of aircraft; Ignore the impact of earth radius, take in the earth's core as true origin, set up coordinate system XYZ, X'Y'Z', X " Y " Z " and X " ' Y " ' Z " ', wherein X-axis is along the due east direction, and Y-axis is along real north, and Z, Z ' axle be vertical shaft direction up during along the aircraft level; X, X', X " the prow direction of axle along the horizontal right flank direction of aircraft Y ' axle along aircraft; " axle is along D for Y ₁Direction, " axle is along D for Z ₂Direction, " ' axle is along D ' for Y ₁Direction, " ' axle is along D ' for Z ₂Direction;

2) real-time monitored is carried out in the skylight optical vibration direction of two vertical direction, and hourly observation constantly; At the fixing swivel mount with demarcating pointer of polaroid, so that rotatory polarization sheet and do the surface level reference, the effect of polaroid and swivel mount is the polarizing angle that produces three different directions, by the measurement to the light intensity of the polarizing angle of these three different directions, just can obtain the direction of vibration of the polarized light of this direction.

4. aircraft three-dimensional posture fixing method as claimed in claim 3 is characterized in that step 2 comprises:

1) the measured polarized light direction of vibration of two orthogonal two detection directions is transformed to X " Y " Z " in;

When the angle of pitch is x and roll angle when being ψ, can carry out conversion by following transition matrix, transform to X " Y " Z " coordinate system;

$M=M_1*M_2=$

$\left[\begin{array}{ccc}\cos \mathrm{\&psi;}& \frac{\sqrt{2}}{2}\sin \mathrm{\&psi;}& \frac{\sqrt{2}}{2}\sin \mathrm{\&psi;}\\ \frac{-(\sqrt{2}\sin \mathrm{\&psi;}*(\cos \mathrm{\&chi;}-\sin \mathrm{\&chi;}))}{2}& \cos \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}+1}{2}\right)-\sin \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}-1}{2}\right)& \cos \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}-\frac{1}{2})-\sin \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}+\frac{1}{2})\\ \frac{-(\sqrt{2}\sin \mathrm{\&psi;}*(\cos \mathrm{\&chi;}+\sin \mathrm{\&chi;}))}{2}& \cos \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}-1}{2}\right)+\sin \mathrm{\&chi;}*\left(\frac{\cos \mathrm{\&psi;}+1}{2}\right)& \cos \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}+\frac{1}{2})+\sin \mathrm{\&chi;}*(\frac{\cos \mathrm{\&psi;}}{2}-\frac{1}{2})\end{array}\right]---\left(6\right)$

2) at X " ' Y " ' Z " in ' coordinate system, P ₁And P ₂The unit vector of direction can be expressed as:

$P_1=\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_1\\ 0\\ \cos {\mathrm{\&theta;}}_2\end{array}\right]---\left(7\right)$

$P_2=\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_2\\ \cos {\mathrm{\&theta;}}_2\\ 0\end{array}\right]---\left(8\right)$

With P ₁And P ₂The unit vector of direction from X " Y " ' Z " ' transform to X " Y " Z " again by following matrix X " Y " Z " be transformed into the xyz coordinate system, transition matrix is:

$S=\left[\begin{array}{ccc}\cos \mathrm{\&beta;}& -\cos \mathrm{\&alpha;}\sin \mathrm{\&beta;}& \sin \mathrm{\&alpha;}\sin \mathrm{\&beta;}\\ \sin \mathrm{\&beta;}\cos \mathrm{\&gamma;}& \cos \mathrm{\&gamma;}\cos \mathrm{\&beta;}\cos \mathrm{\&alpha;}-\sin \mathrm{\&gamma;}\sin \mathrm{\&alpha;}& -\cos \mathrm{\&gamma;}\cos \mathrm{\&beta;}\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;}\cos \mathrm{\&alpha;}\\ \sin \mathrm{\&alpha;}\sin \mathrm{\&gamma;}& \sin \mathrm{\&alpha;}\cos \mathrm{\&beta;}\cos \mathrm{\&gamma;}+\sin \mathrm{\&alpha;}\cos \mathrm{\&gamma;}& \cos \mathrm{\&alpha;}\cos \mathrm{\&gamma;}-\sin \mathrm{\&alpha;}\cos \mathrm{\&beta;}\sin \mathrm{\&gamma;}\end{array}\right]---\left(9\right)$

α=π/4 wherein, β=2 π-TC, γ=-φ;

Then by S transition matrix, just P ₁And P ₂The unit vector of direction is expressed as in the xyz coordinate system:

$P_1=S\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_1\\ 0\\ \cos {\mathrm{\&theta;}}_1\end{array}\right]---\left(10\right)$

$P_2=S\left[\begin{array}{c}\sin {\mathrm{\&theta;}}_2\\ \cos {\mathrm{\&theta;}}_2\\ 0\end{array}\right]---\left(11\right)$

3) solar direction P can be expressed as:

P＝P ₁×P ₂ (12)

5. aircraft three-dimensional posture fixing method as claimed in claim 4 is characterized in that step 3 comprises:

1) moment that will record first is converted to universal time; If the time of recording is Beijing time, and Beijing time is in the Dong Ba district, so T _G(universal time)=T(Beijing time)-8h;

2) constantly table look-up by integral point first, then utilize the hour angle in the subordinate list, the declination interpolation table is asked minute, the interpolate value in second; Hour angle=integral point is worth constantly+and every minute and second interpolate value+hour angle is overproof; Declination=integral point is worth+every minute and second interpolate value+declination difference constantly; The declination interpolate value gets the positive and negative identical of positive and negative and declination difference;

3) set up the equatorial system of coordinates; Coordinate system xyz, wherein the x axle is along the due east direction, the y axle is along earth's axis directed north direction, the z axle pass (0, λ) point;

4) can check in declination (δ), the Greenwich hour angle (t) of surveying the moment sun by " celestial navigation is gone through ", then in the xyz coordinate system, can represent that solar direction is:

$P^{\&prime;}=\left[\begin{array}{c}\cos \left(\mathrm{\&delta;}\right)\sin (t-\mathrm{\&lambda;})\\ \sin \left(\mathrm{\&delta;}\right)\\ \cos \left(\mathrm{\&delta;}\right)\cos (t-\mathrm{\&lambda;})\end{array}\right]---\left(13\right)$

6. aircraft three-dimensional posture fixing method as claimed in claim 5 is characterized in that, in the step 4, because P ' and P represent same direction, then has:

P×P′=0 (14)

7. aircraft three-dimensional posture fixing method as claimed in claim 6 is characterized in that, in the step 5, simultaneous (6) (7) (8) (9) (11) (12) (13) (14) formula can be tried to achieve 3 d pose roll angle ψ, angle of pitch x and the crab angle TC of aircraft.

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