CN110231025B - Dynamic orientation method and system based on strapdown polarized light compass - Google Patents

Dynamic orientation method and system based on strapdown polarized light compass Download PDF

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CN110231025B
CN110231025B CN201910597332.5A CN201910597332A CN110231025B CN 110231025 B CN110231025 B CN 110231025B CN 201910597332 A CN201910597332 A CN 201910597332A CN 110231025 B CN110231025 B CN 110231025B
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incident light
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CN110231025A (en
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何晓峰
韩国良
张礼廉
范晨
胡小平
何瑞光
屈豪
毛军
范颖
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National University of Defense Technology
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Abstract

The invention discloses a dynamic orientation method and a system based on a strapdown polarized light compass, wherein the polarized light compass is installed on a carrier in a strapdown mode and comprises a camera, a polarization piece and a wide-angle lens, an observation image is shot through the camera in the moving process of the carrier, and the heading angle of the current carrier in a navigation coordinate system is obtained by carrying out image analysis on the observation image, and the method specifically comprises the following steps: obtaining polarization information of incident light in an observation image; according to the polarization information of the incident light, combining a pitch angle and a roll angle of a camera to obtain the polarization direction of an incident light E vector; obtaining the optimal solar meridian direction according to the polarization direction of the incident light E vector; acquiring current time and position information, and acquiring a solar azimuth angle according to the astronomical calendar; and calculating the course angle of the carrier in the navigation coordinate system according to the solar azimuth angle and the optimal solar meridian direction. The heading angle of the carrier can be accurately, quickly and robustly estimated under the condition that the horizontal attitude angle of the polarized light compass changes.

Description

Dynamic orientation method and system based on strapdown polarized light compass
Technical Field
The invention relates to a method for estimating a carrier course angle, in particular to a dynamic orientation method and a system based on a strapdown polarized light compass.
Background
Heading information is of great importance in autonomous navigation processes. For a small unmanned platform, an inertial navigation system is the most common autonomous navigation mode and has the advantages of strong anti-interference performance, complete navigation information, strong real-time performance and the like, but positioning and orientation errors are accumulated along with time; the vision/inertia combination still belongs to a recursive navigation method, and can only inhibit the divergence of the course to a certain extent; magnetic compasses can provide heading information, but are susceptible to interference from ambient magnetic fields. In recent years, with the search for a mechanism of bio-navigation, bio-navigation using natural polarization has attracted much attention from researchers.
The polarized light orientation technology uses the capability of biological sensitive polarized light for reference, imitates a biological compound eye structure to measure an atmospheric polarization mode, realizes the acquisition of carrier course information, and further performs navigation and positioning, and has the advantages of strong anti-interference performance, no error accumulation along with time, wide application range and the like. The polarized light compass based on image type polarization measurement can simultaneously extract the polarization angle and the polarization degree information of the whole sky area in the view angle range. The current research on polarized light navigation mainly takes the situation that a sensor is horizontally arranged, and does not consider the horizontal attitude angle change caused by the strapdown installation of an optical compass on a carrier. Therefore, the method for accurately, quickly and robustly estimating the heading angle of the carrier under the condition that the polarized light compass is installed on the dynamic carrier in a strapdown mode has very important significance.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a dynamic orientation method and a system based on a strapdown polarized light compass.
The technical scheme is as follows:
a dynamic orientation method based on a strapdown polarized light compass is characterized in that the polarized light compass is an image type polarized light sensor and is mounted on a carrier in a strapdown mode, the polarized light compass comprises a camera, a polarizing piece and a wide-angle lens, the polarizing piece is located between the lens of the camera and the wide-angle lens, an observation image is shot through the camera in the moving process of the carrier, the observation image refers to a landscape image in a shooting view field of the camera and changes in real time along with the movement of the carrier; the course angle of the current carrier in a navigation coordinate system is obtained by carrying out image analysis on an observed image, wherein the polarizing element is a micro-array type polarizing film and specifically comprises polarizing measurement units distributed in an array manner, each polarizing measurement unit comprises polarizing films distributed in a field shape in four directions of 0 degree, 45 degrees, 90 degrees and 135 degrees, each polarizing film in each polarizing measurement unit corresponds to a pixel of a camera one by one, and each four pixels of the camera respond to a beam of incident light.
The method specifically comprises the following steps:
step 101, obtaining polarization information of incident light in an observation image from the observation image, measuring the light intensity of the incident light penetrating through a polaroid by using a polarized light compass, and calculating the polarization angle and the polarization degree of the incident light based on the light intensity information:
the partially polarized light is represented by a STOKES vector, which contains four parameters S ═ S0,S1,S2,S3]Wherein S is0Denotes the total light intensity, S1Is a polarized light component in the 0 DEG direction, S2Is a polarization component in the 45 DEG direction, S3Is a circularly polarized component, and since the circularly polarized component is negligible in most cases, S is considered in polarization detection3And ≡ 0, the light intensity after the polarized light passes through the polarizing plate with the theta direction is as follows:
Figure BDA0002118027080000021
when θ is taken as 0 °, 45 °, 90 ° and 135 °, respectively, the intensities I (0 °), I (45 °), I (90 °), and I (135 °) of incident light when the incident light passes through the corresponding polarizing plate are measured by a polarizing compass, so that the STOKES vector can be found by the following equation:
Figure BDA0002118027080000022
S1＝I(0°)-I(90°)
S2＝I(45°)-I(135°)
further obtaining polarization information of incident light including a polarization angle and a polarization degree:
Figure BDA0002118027080000031
Figure BDA0002118027080000032
in the formula, DoLP represents the degree of polarization of incident light, and AoP represents the polarization angle of incident light.
102, obtaining the polarization direction of an incident light E vector according to the polarization information of the incident light by combining the pitch angle and the roll angle of the camera, wherein the pitch angle and the roll angle of the camera are obtained by micro inertial navigation:
obtaining a vector
Figure BDA0002118027080000033
The expression in the camera coordinate system is:
Figure BDA0002118027080000034
wherein point O represents the origin of the camera coordinate system and the horizontal reference coordinate system; the point P is an observation point and represents the intersection point of incident light and the celestial sphere, and the observation point P corresponding to each incident light beam and the central pixel (x) of one polarization measurement unit in the observation imagep,yp) Corresponding, therefore, at the focal length f of the known cameracUnder the premise of (1), the zenith angle gamma of the observation point P under the camera coordinate systemcAnd an azimuth angle alphacComprises the following steps:
Figure BDA0002118027080000035
Figure BDA0002118027080000036
in the formula (x)c,yc) Coordinates representing an optical axis of the camera in the observation image;
obtaining a vector
Figure BDA0002118027080000037
The expression in the horizontal reference coordinate system is:
Figure BDA0002118027080000038
wherein,
Figure BDA0002118027080000039
delta and theta are respectively a rolling angle and a pitching angle of the camera;
the polarization direction φ of the incident light E vector is obtained as:
Figure BDA00021180270800000310
in the formula,
Figure BDA0002118027080000041
and
Figure BDA0002118027080000042
are respectively vectors
Figure BDA0002118027080000043
The first element and the second element of (1).
Step 103, obtaining the optimal solar meridian direction according to the polarization direction of the incident light E vector:
obtaining an E vector of the incident light in an incident light coordinate system as follows:
Figure BDA0002118027080000044
obtaining an E vector of the incident light under a horizontal parameter coordinate system, wherein the E vector is as follows:
Figure BDA0002118027080000045
Figure BDA0002118027080000046
wherein gamma represents the zenith angle of the observation point P in the horizontal reference coordinate system, and alpha represents the azimuth angle of the observation point P in the horizontal reference coordinate system;
obtaining the position (x) of the zenith point in the observation imagezenithYzenith), where the zenith point is the observation point directly above the carrier, and is given by (x)zenith,yzenith) As a center, a Rayleigh scattering model is established in a circular area with the radius of L:
the zenith angle of the observation point P in the horizontal reference coordinate system is gamma, and the zenith angle is obtained by the following formula:
Figure BDA0002118027080000047
wherein
Figure BDA0002118027080000048
As vectors
Figure BDA0002118027080000049
The pixel point corresponding to the minimum zenith angle | γ | | | value is the position of the zenith in the polarized image, and can be obtained by the following formula:
Figure BDA00021180270800000410
according to the rayleigh scattering model, the direction of the E vector of the scattered light is perpendicular to the scattering surface, i.e. the E vector is perpendicular to the sun direction vector S, which can be estimated from two uncorrelated E vectors, defined,
Figure BDA00021180270800000411
n is the number of effective pixels, and can be obtained as follows:
ETs＝0
wherein,
Figure BDA00021180270800000412
s is a sun direction vector;
the optimal estimation of the sun vector can be represented as an optimization problem as follows:
Figure BDA0002118027080000051
wherein with EETThe eigenvector corresponding to the minimum eigenvalue is the optimal estimation of the sun vector, and the EE is obtained through Singular Value Decomposition (SVD) of ETThe eigenvectors and eigenvalues of;
let eλIs EETThe minimum eigenvalue corresponds to the eigenvector, and then the projection of the sun vector direction in the horizontal direction, i.e. the best sun meridian direction alphasComprises the following steps:
Figure BDA0002118027080000052
wherein e isλ1And eλ2Are respectively a vector eλA first element and a second element.
Step 104, acquiring current time and position information, and acquiring a solar azimuth angle according to the astronomical calendar;
step 105, calculating a course angle of the carrier in the navigation coordinate system according to the solar azimuth angle and the optimal solar meridian direction:
Figure BDA0002118027080000053
in the formula,
Figure BDA0002118027080000054
is the heading angle of the carrier in the navigation coordinate system,
Figure BDA0002118027080000055
is the sun azimuth, αsThe best solar meridian direction.
A dynamic orientation system based on a strapdown polarized light compass comprises a memory and a processor, wherein the memory stores a computer program, and the processor realizes the steps of the method when executing the computer program.
According to the dynamic orientation method system based on the strap-down type polarized light compass, the polarized light compass is mounted on the carrier in a strap-down mode, so that the shooting angle of a camera in the polarized light compass changes along with the movement of the carrier, observation images of different shooting angles are further obtained, the polarization direction of an incident light E vector is obtained in the subsequent image analysis process by combining the pitch angle and the roll angle of the camera, the optimal solar meridian direction is further obtained through the polarization direction of the incident light E vector, the heading angle of the carrier in a navigation coordinate system is finally obtained, and the carrier angle can be accurately, quickly and robustly estimated under the condition that the horizontal attitude angle of the polarized light compass changes.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
FIG. 1 is a schematic flow diagram of the process of the present invention;
FIG. 2 is a schematic diagram of the composition and structure of a polarized light compass;
FIG. 3 is a schematic view of a camera coordinate system and a horizontal reference coordinate system when the light compass is tilted;
fig. 4 is a schematic diagram of a first-order rayleigh scattering model.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.
In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; the connection can be mechanical connection, electrical connection, physical connection or wireless communication connection; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.
As shown in fig. 1, the dynamic orientation method based on the strapdown polarized light compass is that the polarized light compass is mounted on a carrier in a strapdown manner, and includes an image-based polarized light sensor and micro inertial navigation; the polarized light compass comprises a CCD camera, a polarizing piece and a wide-angle lens, wherein the polarizing piece is positioned between the lens of the CCD camera and the wide-angle lens and is used for shooting an observation image through the CCD camera in the moving process of the carrier; the micro inertial navigation system is connected with the CCD camera and used for obtaining a pitch angle and a roll angle of the CCD camera, namely a horizontal attitude angle.
The course angle of the current carrier in a navigation coordinate system is obtained by carrying out image analysis on an observed image, wherein the polarizing element is a micro-array type polarizing film and specifically comprises polarizing measurement units distributed in an array manner, each polarizing measurement unit comprises polarizing films distributed in a field shape in four directions of 0 degree, 45 degrees, 90 degrees and 135 degrees, each polarizing film in each polarizing measurement unit corresponds to a pixel of the CCD camera one by one, and each four pixels of the CCD camera respond to a beam of incident light.
The process of observing image analysis specifically comprises the following steps:
step 101, obtaining polarization information of incident light in an observation image from the observation image, measuring the light intensity of the incident light penetrating through a polaroid by using a polarized light compass, and calculating the polarization angle and the polarization degree of the incident light based on the light intensity information:
the partially polarized light is represented by a STOKES vector, which contains four parameters S ═ S0,S1,S2,S3]Wherein S is0Denotes the total light intensity, S1Is a polarized light component in the 0 DEG direction, S2Is a polarization component in the 45 DEG direction, S3Is a circularly polarized component, and since the circularly polarized component is negligible in most cases, S is considered in polarization detection3And ≡ 0, the light intensity after the polarized light passes through the polarizing plate with the theta direction is as follows:
Figure BDA0002118027080000071
when θ is taken as 0 °, 45 °, 90 ° and 135 °, respectively, the intensities I (0 °), I (45 °), I (90 °), and I (135 °) of incident light when the incident light passes through the corresponding polarizing plate are measured by a polarizing compass, so that the STOKES vector can be found by the following equation:
Figure BDA0002118027080000081
S1＝I(0°)-I(90°)
S2＝I(45°)-I(135°)
further obtaining polarization information of incident light including a polarization angle and a polarization degree:
Figure BDA0002118027080000082
Figure BDA0002118027080000083
in the formula, DoLP represents the degree of polarization of incident light, and AoP represents the polarization angle of incident light.
102, obtaining the polarization direction of an incident light E vector according to the polarization information of the incident light by combining the pitch angle and the roll angle of the CCD camera:
as shown in fig. 2, first, the following right-hand rectangular coordinate system is defined:
camera coordinate system (OX)cYcZc): o is the center of the image plane, XcAxis and YcThe axes being respectively in the transverse and longitudinal directions, Z, of the CCD cameracThe axis being the optical axis of the carrier, Z if the CCD camera is placed horizontallycThe axis points in the zenith direction;
horizontal reference frame (OX)lYlZl)：ZlThe axis pointing in the zenith direction, XlThe shaft rotates in sequence to form a pitch angle and a roll angle and then forms a sum with XcThe axes being coincident, YlAnd XlAxis and ZlRight-hand rectangular coordinate system formed by shaftsIf the CCD camera is horizontally placed, XlAxis and YlThe axes are respectively connected with XcAxis and YcThe axes are coincident when the CCD camera is along ZlAs the shaft rotates, the horizontal reference frame rotates by a corresponding angle.
Incident light coordinate system (PX)iYiZi): z thereofiThe axis pointing in the observation direction, XiThe axis lying in the vertical plane (OPP') of the observation direction, YiAxis and XiAxis and ZiRight-handed rectangular coordinate system (Y) formed by shaftsiThe shaft is not labeled);
assuming that the observer is at position O, the observation point in the sky is P, representing the intersection of the incident light and the celestial sphere. The zenith angle and the azimuth angle of the observation point P under the carrier coordinate system are respectively gamma and alpha, and the E vector polarization direction of the incident light is phi.
Vector corresponding to observation point P in camera coordinate system relative to horizontal reference coordinate system
Figure BDA0002118027080000084
The representation in the camera coordinate system is:
Figure BDA0002118027080000091
wherein point O represents the origin of the camera coordinate system and the horizontal reference coordinate system; the point P is an observation point, and the observation point P corresponding to each incident light beam and the central pixel (x) of one polarization measurement unit in the observation imagep,yp) Corresponding, therefore, to the focal length f of the known CCD cameracUnder the premise of (1), the zenith angle gamma of the observation point P under the camera coordinate systemcAnd an azimuth angle alphacComprises the following steps:
Figure BDA0002118027080000092
Figure BDA0002118027080000093
in the formula (x)c,yc) Coordinates representing an optical axis of the camera in the observation image;
obtaining a vector
Figure BDA0002118027080000094
The expression in the horizontal reference coordinate system is:
Figure BDA0002118027080000095
wherein,
Figure BDA0002118027080000096
delta and theta are respectively a rolling angle and a pitching angle of the camera;
the polarization direction φ of the incident light E vector is obtained as:
Figure BDA0002118027080000097
in the formula,
Figure BDA0002118027080000098
and
Figure BDA0002118027080000099
are respectively vectors
Figure BDA00021180270800000910
The first element and the second element of (1).
Step 103, obtaining the optimal solar meridian direction according to the polarization direction of the incident light E vector:
as shown in FIG. 3, the position of the sun on the celestial sphere is S, and the zenith angle of the sun is γSSolar azimuth angle alpha under carrier coordinate systemSIn the figure, the N axis is the true north of geography, and the solar azimuth angle under the navigation coordinate system is
Figure BDA00021180270800000911
Obtaining an E vector of the incident light in an incident light coordinate system as follows:
Figure BDA00021180270800000912
obtaining an E vector of the incident light under a horizontal parameter coordinate system, wherein the E vector is as follows:
Figure BDA0002118027080000101
Figure BDA0002118027080000102
wherein gamma represents the zenith angle of the observation point P in the horizontal reference coordinate system, and alpha represents the azimuth angle of the observation point P in the horizontal reference coordinate system;
obtaining the position (x) of the zenith point in the observation imagezenith,yzenith) Wherein the zenith point is an observation point right above the carrier and is (x)zenith,yzenith) As a center, a Rayleigh scattering model is established in a circular area with the radius of L:
the zenith angle of the observation point P in the horizontal reference coordinate system is gamma, and the zenith angle is obtained by the following formula:
Figure BDA0002118027080000103
wherein
Figure BDA0002118027080000104
As vectors
Figure BDA0002118027080000105
The pixel point corresponding to the minimum zenith angle | γ | | | value is the position of the zenith in the polarized image, and can be obtained by the following formula:
Figure BDA0002118027080000106
according to the rayleigh scattering model, the direction of the E vector of the scattered light is perpendicular to the scattering surface, i.e. the E vector is perpendicular to the sun direction vector S, which can be estimated from two uncorrelated E vectors, defined,
Figure BDA0002118027080000107
n is the number of effective pixels, and can be obtained as follows:
ETs＝0
wherein,
Figure BDA0002118027080000108
s is a sun direction vector;
the optimal estimation of the sun vector can be represented as an optimization problem as follows:
Figure BDA0002118027080000109
wherein with EETThe eigenvector corresponding to the minimum eigenvalue is the optimal estimation of the sun vector, and the EE is obtained through Singular Value Decomposition (SVD) of ETThe eigenvectors and eigenvalues of;
let eλIs EETThe minimum eigenvalue corresponds to the eigenvector, and then the projection of the sun vector direction in the horizontal direction, i.e. the best sun meridian direction alphasComprises the following steps:
Figure BDA0002118027080000111
wherein e isλ1And eλ2Are respectively a vector eλA first element and a second element.
Step 104, acquiring current time and position information, and acquiring a solar azimuth angle according to the astronomical calendar;
step 105, calculating a course angle of the carrier in the navigation coordinate system according to the solar azimuth angle and the optimal solar meridian direction:
Figure BDA0002118027080000112
in the formula,
Figure BDA0002118027080000113
is the heading angle of the carrier in the navigation coordinate system,
Figure BDA0002118027080000114
is the sun azimuth, αsThe best solar meridian direction.
Step 104 and step 105 are conventional operations, and therefore are not described in detail in this embodiment.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (7)

1. The dynamic orientation method based on the strapdown polarized light compass is characterized in that the polarized light compass comprises an image type polarized light sensor and is mounted on a carrier in a strapdown mode, the polarized light compass comprises a camera, a polarizing piece and a wide-angle lens, the polarizing piece is located between the lens of the camera and the wide-angle lens, an observation image is shot through the camera in the moving process of the carrier, the heading angle of the current carrier in a navigation coordinate system is obtained by carrying out image analysis on the observation image, and the polarized light compass further comprises a micro inertial navigation device connected with the camera and used for obtaining the roll angle and the pitch angle of the camera, and specifically comprises the following steps:
step 101, obtaining polarization information of incident light in an observation image from the observation image;
102, obtaining the polarization direction of an incident light E vector according to the polarization information of the incident light by combining a pitch angle and a roll angle of a camera, and specifically comprising the following steps:
obtaining a vector
Figure FDA0002936794400000011
The expression in the camera coordinate system is:
Figure FDA0002936794400000012
wherein point O represents the origin of the camera coordinate system and the horizontal reference coordinate system; the point P is an observation point and represents the intersection point of incident light and the celestial sphere, and the observation point P corresponding to each incident light beam and the central pixel (x) of one polarization measurement unit in the observation imagep,yp) Corresponding, therefore, at the focal length f of the known cameracUnder the premise of (1), the zenith angle gamma of the observation point P under the camera coordinate systemcAnd an azimuth angle alphacComprises the following steps:
Figure FDA0002936794400000013
Figure FDA0002936794400000014
in the formula (x)c,yc) Coordinates representing an optical axis of the camera in the observation image;
obtaining a vector
Figure FDA0002936794400000015
The expression under the horizontal reference coordinate system is:
Figure FDA0002936794400000016
wherein,
Figure FDA0002936794400000021
delta and theta are respectively a rolling angle and a pitching angle of the camera;
the polarization direction φ of the incident light E vector is obtained as:
Figure FDA0002936794400000022
in the formula,
Figure FDA0002936794400000023
and
Figure FDA0002936794400000024
are respectively as
Figure FDA0002936794400000025
The first element and the second element of (a);
103, obtaining the optimal solar meridian direction according to the polarization direction of the incident light E vector;
step 104, acquiring current time and position information, and acquiring a solar azimuth angle according to the astronomical calendar;
and 105, calculating the course angle of the carrier in the navigation coordinate system according to the solar azimuth angle and the optimal solar meridian direction.
2. The dynamic orientation method based on the strapdown polarized light compass according to claim 1, wherein the polarizer is a micro-array polarizer, and specifically comprises polarization measurement units distributed in an array, each polarization measurement unit comprises polarizers distributed in a field shape in four directions of 0 °, 45 °, 90 ° and 135 °, and each polarizer in each polarization measurement unit corresponds to a pixel of the camera, wherein each four pixels of the camera respond to a beam of incident light.
3. The dynamic orientation method based on the strapdown polarized light compass according to claim 2, wherein the step 101 specifically comprises:
the partially polarized light is represented by a STOKES vector, which contains four parameters S ═ S0,S1,S2,S3]Wherein S is0Denotes the total light intensity, S1Is a polarized light component in the 0 DEG direction, S2Is a polarization component in the 45 DEG direction, S3Is a circularly polarized component, and the circularly polarized component is ignored to make S3And ≡ 0, the light intensity after the polarized light passes through the polarizing plate with the theta direction is as follows:
Figure FDA0002936794400000026
when θ takes 0 °, 45 °, 90 ° and 135 °, respectively, the intensities I (0 °), I (45 °), I (90 °), and I (135 °) of incident light when the incident light transmits through the corresponding polarizing plate are measured by a polarizing compass, so that the STOKES vector is found by the following equation:
Figure FDA0002936794400000031
S1＝I(0°)-I(90°)
S2＝I(45°)-I(135°)
further obtaining polarization information of incident light:
Figure FDA0002936794400000032
Figure FDA0002936794400000033
in the formula, DoLP represents the degree of polarization of incident light, and AoP represents the polarization angle of incident light.
4. The dynamic orientation method based on the strapdown polarized light compass according to claim 1, wherein the step 103 specifically comprises:
obtaining an E vector of the incident light in an incident light coordinate system as follows:
Figure FDA0002936794400000034
obtaining an E vector of the incident light under a horizontal parameter coordinate system, wherein the E vector is as follows:
Figure FDA0002936794400000035
Figure FDA0002936794400000036
wherein gamma represents the zenith angle of the observation point P in the horizontal reference coordinate system, and alpha represents the azimuth angle of the observation point P in the horizontal reference coordinate system;
obtaining the position (x) of the zenith point in the observation imagezenith,yzenith) Wherein the zenith point is an observation point right above the carrier and is (x)zenith,yzenith) As a center, a Rayleigh scattering model is established in a circular area with the radius of L, and the Rayleigh scattering model is obtained:
ETs＝0
wherein,
Figure FDA0002936794400000041
n is the number of effective pixel points; s is a sun direction vector;
obtaining an optimal estimate of the sun vector:
Figure FDA0002936794400000042
wherein with EETThe eigenvector corresponding to the minimum eigenvalue is the optimal estimation of the sun vector;
obtaining the best solar meridian direction alphas：
Figure FDA0002936794400000043
Wherein e isλ1And eλ2Are respectively eλOf a first element and a second element, eλIs EETThe minimum feature value corresponds to the feature vector.
5. Method for dynamic orientation based on strapdown polarized light compass according to claim 4, wherein the position (x) of the zenith point in the observation imagezenith,yzenith) The calculation process comprises the following steps:
the zenith angle of the observation point P in the horizontal reference coordinate system is gamma, and the zenith angle is obtained by the following formula:
Figure FDA0002936794400000044
wherein
Figure FDA0002936794400000045
Is composed of
Figure FDA0002936794400000046
The pixel point corresponding to the minimum zenith angle | γ | value is the position of the zenith in the polarized image, and is obtained by the following formula:
Figure FDA0002936794400000047
6. the method of claim 1, wherein the calculation of the yaw angle in step 105 is as follows:
Figure FDA0002936794400000048
in the formula,
Figure FDA0002936794400000049
is the heading angle of the carrier in the navigation coordinate system,
Figure FDA00029367944000000410
is the sun azimuth, αsThe best solar meridian direction.
7. A dynamic orientation system based on a strapdown polarized light compass, comprising a memory and a processor, the memory storing a computer program, characterized in that the processor realizes the steps of the method according to any of claims 1 to 6 when executing the computer program.
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* Cited by examiner, † Cited by third party
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* Cited by examiner, † Cited by third party
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