CN109459027A - It is a kind of based on polarization-ground magnetic vector tight integration air navigation aid - Google Patents

Abstract

The invention relates to a navigation method based on a tight combination of polarization-geomagnetic vectors. First, a compound eye-like polarization compass is used to intelligently extract solar vector information in a carrier coordinate system; secondly, combined with the solar astronomical almanac, solar vector information in a geographic coordinate system is obtained. , and establish the information conversion relationship of the sun vector under the ontology coordinate system and the geographic coordinate system; extract the geomagnetic vector under the ontology coordinate system and the geographic coordinate system, and establish the transformation relationship between the ontology coordinate system and the geomagnetic vector under the geographic coordinate system; Under the system, information fusion of geomagnetic vector and solar vector is carried out; finally, an integrated navigation system model based on polarization/geomagnetic vector fusion is established. Compared with the existing method, the method realizes the deep fusion of geomagnetic information and polarization information, which can improve the accuracy and stability of the system, and can be used in the fields of attitude determination and positioning of carriers, such as ships, unmanned aerial vehicles, missiles, and unmanned vehicles.

Description

A Navigation Method Based on Polarization-Geomagnetic Vector Compact Combination

technical field

The invention relates to a navigation method based on a tight combination of polarization-geomagnetic vectors, which is used for the determination and positioning of autonomous attitudes in three-dimensional space of carriers such as unmanned aerial vehicles, ships and missiles.

Background technique

At present, the working environment of carriers such as unmanned aerial vehicles, ships, and missiles is becoming more and more complex. In order to make up for the shortage of single navigation, the combined navigation of multi-sensor fusion is the development direction of future navigation. Inertial/satellite integrated navigation system is the most widely used integrated navigation system at present, but satellite navigation is susceptible to natural environment and human interference, and cannot provide accurate and reliable navigation information in the environment of rejection, interference, and confrontation. Therefore, the application of satellite navigation systems in deep space exploration, deep sea exploration and other fields has been greatly restricted. Therefore, there is an urgent need to develop an integrated navigation system that does not rely on satellite navigation.

Biomimetic polarization navigation is passive, non-radiative, well concealed, highly autonomous and not affected by electromagnetic interference. It can provide three-dimensional attitude information and position information for the carrier, which can complement the advantages of the inertial navigation system and improve the performance of the integrated navigation system. Autonomy and reliability provide new solutions. Geomagnetic navigation system is another common navigation method, which can also provide high-precision attitude and position information to compensate for the attitude and position errors of inertial navigation system. For the existing polarization/geomagnetic aided integrated navigation systems, satellite navigation systems are used, such as the authorized Chinese patent 201510312112.5, "A dual-mode bionic polarization/geomagnetic aided integrated navigation system, paper "Bionic polarized light/GPS/ Design and Implementation of Geomagnetic Integrated Navigation Method", "Research on Polarized Light/Geomagnetic/GPS/SINS Integrated Navigation Algorithm", "Research and Implementation of Multi-information Source Fusion Navigation Method Using Polarized Light, Geomagnetism and GPS", etc. The Chinese patent 201310037586.4, "Positioning system and positioning method based on polarized light bionic navigation", Chinese patent CN 103822629, "Positioning system and positioning method based on multi-directional polarized light navigation sensor", although satellite navigation is not used However, the deep fusion of geomagnetic information and polarization information is not considered, and the reliability of the system needs to be further improved.

In order to make full use of the measurement information of polarization and geomagnetism and effectively improve the accuracy and reliability of the bionic integrated navigation system, the present invention deeply integrates the information of polarization and geomagnetism vector, and establishes a navigation system model with a tight combination of polarization and geomagnetism for the first time. In the absence of satellite navigation, fully autonomous integrated navigation with bionic polarization/geomagnetic assistance is realized.

SUMMARY OF THE INVENTION

The invention discloses a navigation method based on the tight combination of polarization-geomagnetic vector. First, by designing a compound eye-like polarization compass, the sun position information under the body coordinate system is measured in real time, and combined with the astronomical almanac, the sun vector under the body coordinates and the geographic coordinates are established. Next, the information conversion relationship between the geomagnetic vector under the ontology coordinate and the geographic coordinate system is established. Under the ontology coordinate system, the geomagnetic vector and the sun vector are deeply integrated to establish a tight combination based on the polarization-geomagnetic vector. model of the navigation system.

The technical solution of the present invention is: a navigation method based on the tight combination of polarization-geomagnetic vector, the implementation steps are as follows:

Step (1), a compound-eye-like polarized compass composed of a polarized navigation sensor, obtains the sun vector in the real-time detection body coordinate system

Step (2), combine the solar astronomical calendar to obtain the solar vector under the geographic system Combined with the sun vector under the body coordinates obtained in step (1), establish the conversion relationship between the geographic coordinate system and the sun vector under the body coordinate system

Step (3), in the ontology coordinate system and the geographic coordinate system, obtain the geomagnetic vector respectively and Establish the transformation relationship between the geomagnetic vector under the geographic coordinate system and the ontology coordinate system

Step (4), in the body coordinate system, perform information fusion on the geomagnetic vector and the sun vector

In step (5), combined with step (4), a navigation system model based on the tight combination of polarization-geomagnetic vector is established.

In the step (1), a compound eye-like polarized compass composed of a polarized navigation sensor is used to acquire and detect the sun vector in the body coordinate system in real time. The specific implementation is as follows:

The compound-eye-like polarization compass is composed of three polarization sensors, which are marked as M ₁ , M ₂ , and M ₃ respectively. The observation direction of M ₁ is the zenith direction, and M ₂ and M ₃ are symmetrically installed at M ₁ for measurement. Be n, establish the coordinate system Mxyz with M ₁ as the benchmark, the x-axis is the direction of the carrier body axis, the z-axis points to the zenith, and the y-axis is determined by the right-hand rule;

In the body coordinate system, the azimuth of the sun Azimuth of polarization that can be measured by the M ₁ sensor And the azimuth angle ψ provided by the geomagnetic sensor is calculated to get:

The polarization degree measurement values d ₁ , d ₂ , and d ₃ of the three polarization sensors are obtained in real time. Based on the Rayleigh scattering theory, the polarization degree of the observation point is related to the scattering angle as follows:

Among them, d _max ∈[max{d ₁ ,d ₂ ,d ₃ },1), θ ₁ , θ ₂ , θ ₃ are the angles between the observation directions of M ₁ , M ₂ , M ₃ and the sun vector,

According to the compound eye-like polarization compass structure, the relationship between θ ₁ , θ ₂ , and θ ₃ can be expressed as:

cosθ ₂ +cosθ ₃ =2cosηcosθ ₁ (3)

According to formulas (2)-(3), the maximum polarization degree d _max in the whole sky can be obtained;

In the geographic coordinate system, according to the maximum polarization degree d _max in the whole space, the polarization observation angle θ ₁ of the main polarization sensor M ₁ is obtained:

Among them, the θ ₁ direction can be judged by an external light intensity sensor or a gravity sensor;

According to the installation method of the M ₁ sensor and the observed sun altitude The relationship between the scattering angle θ ₁ and the observed solar altitude angle in the body coordinate system for:

In the module coordinate system, the sun vector can be expressed as:

make

The step (2) obtains the solar vector under the geographic system according to the solar astronomical almanac Combined with the sun vector under the ontology coordinates obtained in step (1), establish the conversion relationship between the ontology coordinate system and the sun vector under the geographic coordinates The specific implementation is as follows:

According to the geographic location and local time of the carrier, the solar azimuth angle and solar altitude angle under the geographic coordinate system are obtained through the solar astronomical almanac, which are expressed as:

Among them, L is the geographic latitude, δ is the solar declination, and Ω is the solar hour angle;

According to formula (6), the sun vector in the geographic system is obtained,

make

According to the attitude transformation relationship between the ontology coordinate system and the geographic coordinate system, the transformation relationship between the ontology coordinate system and the sun vector under the geographic coordinate system is established:

in, is the attitude transformation matrix between the body coordinate system and the geographic coordinate system;

Among them, θ, γ, ψ are the pitch angle, roll angle and heading angle of the carrier, respectively,

The attitude error angle of the system is defined as follows:

φ=[φ _x φ _y φ _z ] ^T (9)

Then the transformation relationship of the sun vector in the ontology coordinate system and the geographic coordinate system can be expressed as:

in is the nominal matrix, which can be obtained from the carrier attitude angle, specifically expressed as:

In the step (3), under the ontology coordinate system and the geographic coordinate system, the geomagnetic vector is obtained respectively and Establish the transformation relationship between the body coordinate system and the geomagnetic vector in the geographic coordinate system The specific implementation is as follows:

Obtain the geomagnetic vector under the geographic coordinate system, and obtain the geomagnetic vector under the geographic coordinate system, which is expressed as:

The geomagnetic vector in the body coordinate system can be obtained directly through the geomagnetic sensor, which is expressed as:

Establish the transformation relationship between the body coordinate system and the geomagnetic vector in the geographic coordinate system:

In the step (4), in the body coordinate system, the geomagnetic vector and sun vector Deep information fusion The specific implementation is as follows:

The sun vector of the body coordinate system obtained according to step (2) and step (3) and geomagnetic vector The cross product of formula (6) and formula (12) is processed to obtain the fusion of polarization and geomagnetic vector in the ontology coordinate system:

Combining formulas (10) and (13), formula (15) can be expressed as:

in:

The step (5), combined with the step (4), establishes a navigation system model based on the tight combination of the polarization-geomagnetic vector, and the specific implementation is as follows:

By formula (15), the integrated navigation system model based on polarization-geomagnetic vector fusion is obtained:

The principle of the invention is as follows: measuring the sun position information through the imitation compound eye polarization compass, and combining with the solar astronomical almanac to establish the transmission relationship between the body coordinates and the sun vector information under the geographic coordinate system. According to the geomagnetic vector obtained by the geomagnetic sensor in the body coordinate system, the conversion relationship between the body coordinate system and the geomagnetic vector in the geographic coordinate system is established, and in the body coordinate system, the information depth fusion of the geomagnetic vector and the polarization vector is completed. - Navigation system model with tight combination of geomagnetic vector.

The advantages of the present invention compared with the prior art are:

(1) The present invention does not rely on satellite navigation signals, and can perform information fusion of the polarization vector and the geomagnetic vector through the observation of the atmospheric polarization field and the geomagnetic field to jointly compensate for the attitude and position measurement errors of inertial navigation, and has strong autonomy, Robustness and reliability;

(2) The present invention adopts the idea of tightly combining the polarization navigation system and the geomagnetic navigation system, and establishes a polarization-geomagnetic integrated navigation system model by introducing the attitude measurement error of inertial navigation, which can improve the observability of the system model.

(3) The present invention uses polarization degree information to determine the orientation of the sun. Compared with the traditional method, this method is not affected by the transmission of the polarization azimuth angle error, which can improve the accuracy of the solar height observation, and then improve the accuracy of the sun height observation based on the tight combination of polarization and geomagnetism. Navigation system performance.

Description of drawings

Fig. 1 is the flow chart of a kind of navigation method based on polarization-geomagnetic vector tight combination of the present invention;

FIG. 2 is a schematic diagram of the structure of the imitation compound eye polarized compass according to the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

As shown in Figure 1, the specific implementation steps of a navigation method based on the tight combination of polarization-geomagnetic vector of the present invention are as follows:

1. The compound-eye-like polarization compass composed of polarization navigation sensors can obtain the sun vector in the coordinate system of the detection module in real time The schematic diagram of the structure of the imitation compound eye polarization compass is shown in Figure 2. The imitation compound eye polarization compass consists of three polarization sensors, which are respectively recorded as M ₁ , M ₂ and M ₃ , where the observation direction of M ₁ is the zenith direction, and the observation direction of M ₂ and M ₃ Symmetrically installed at M1 for measurement, the installation angles are all η, the coordinate system Mxyz is established based on M1, the _{x -} axis is the direction of the carrier body axis, the z-axis points to the zenith, and the y-axis is determined by the right-hand rule.

In the body coordinate system, the azimuth of the sun Azimuth of polarization that can be measured by the M ₁ sensor And the azimuth angle ψ provided by the geomagnetic sensor is calculated to get:

The polarization degree measurement values d ₁ , d ₂ , and d ₃ of the three polarization sensors are obtained in real time. Based on the Rayleigh scattering theory, the polarization degree of the observation point is related to the scattering angle as follows:

Wherein, d _max ∈[max{d ₁ ,d ₂ ,d ₃ },1), θ ₁ , θ ₂ , θ ₃ are the angles between the observation directions of M ₁ , M ₂ , M ₃ and the sun vector;

According to the compound eye-like polarization compass structure, the relationship between θ ₁ , θ ₂ , and θ ₃ can be expressed as:

cosθ ₂ +cosθ ₃ =2cosηcosθ ₁ (3)

According to formulas (2)-(3), the maximum polarization degree d _max in the whole sky can be obtained;

In the geographic coordinate system, according to the maximum polarization degree d _max in the whole space, the observation angle θ ₁ of the main polarization sensor M ₁ is obtained:

Among them, the θ ₁ direction can be judged by an external light intensity sensor or a gravity sensor;

According to the installation method of the M ₁ sensor and the observed sun altitude The relationship between the scattering angle θ ₁ and the observed solar altitude angle in the body coordinate system for:

In the body coordinate system, the sun vector can be expressed as,

make

2. Combine the solar astronomical calendar to get the sun vector in the geographic system Establish the conversion relationship between the geographic coordinate system and the sun vector in the ontology coordinate According to the geographic location and local time of the carrier, the solar azimuth angle and solar altitude angle under the geographic coordinate system are obtained through the solar astronomical almanac, which are expressed as:

Among them, L is the geographic latitude, δ is the solar declination, and Ω is the solar hour angle;

According to formula (6), the sun vector in the geographic system is obtained,

make

According to the attitude transformation relationship between the ontology coordinate system and the geographic coordinate system, the transformation relationship between the ontology coordinate system and the sun vector under the geographic coordinate system is established:

in, is the attitude transformation matrix between the body coordinate system and the geographic coordinate system,

Among them, θ, γ, ψ are the pitch angle, roll angle and heading angle of the carrier, respectively,

The attitude error angle of the system is defined as follows:

φ=[φ _x φ _y φ _z ] ^T (9)

Then the transformation relationship of the sun vector in the ontology coordinate system and the geographic coordinate system can be expressed as:

in is the nominal matrix, which can be obtained from the carrier attitude angle, specifically expressed as:

3. In the ontology coordinate system and the geographic coordinate system, respectively obtain the geomagnetic vector and Establish the transformation relationship between the body coordinate system and the geomagnetic vector in the geographic coordinate system:

Obtain the geomagnetic vector under the geographic coordinate system, and obtain the geomagnetic vector under the geographic coordinate system, which is expressed as:

The geomagnetic vector in the body coordinate system can be obtained directly through the geomagnetic sensor, which is expressed as:

Establish the transformation relationship between the body coordinate system and the geomagnetic vector in the geographic coordinate system:

4. In the body coordinate system, the geomagnetic vector and sun vector Deep information fusion

The sun vector of the body coordinate system obtained according to step (2) and step (3) and geomagnetic vector The cross product of formula (6) and formula (12) is processed to obtain the fusion of polarization and geomagnetic vector in the ontology coordinate system:

Combining formulas (10) and (13), formula (15) can be expressed as:

in

5. Combined with step (4), a navigation system model based on the tight combination of polarization/geomagnetic vector is established:

By formula (15), the integrated navigation system model based on polarization/geomagnetic vector fusion is obtained:

Claims (6)

1. A navigation method based on polarization-geomagnetic vector tight combination is characterized in that: the method comprises the following implementation steps:

step (1), a compound eye-imitating polarization compass composed of polarization navigation sensors acquires and detects the sun vector under a body coordinate system in real time

Step (2) obtaining a sun vector under a geographic system according to the solar astronomical calendarCombining the sun vector under the body coordinate obtained in the step (1), establishing a conversion relation between the body coordinate system and the sun vector under the geographic coordinate system

Step (3) respectively obtaining geomagnetic vectors under the body coordinate system and the geographic coordinate systemAndestablishing a conversion relation of the geomagnetic vectors in the body coordinate system and the geographic coordinate system

Step (4) under the body coordinate system, geomagnetic vector is alignedAnd sun vectorPerforming information depth fusion

And (5) combining the step (4) to establish a navigation system model based on the tight combination of the polarization-geomagnetic vector.

2. The navigation method according to claim 1, wherein the navigation method based on the close combination of polarization-geomagnetic vectors is characterized in that: the step (1) is to obtain and detect the sun vector under the body coordinate system in real time by a compound eye-imitating polarization compass formed by a polarization navigation sensorThe concrete implementation is as follows:

the compound eye-imitating polarization compass consists of three polarization sensors, which are respectively marked as M₁、M₂、M₃Wherein M is₁The observation direction is the zenith direction, M₂And M₃Are respectively symmetrically arranged at M₁Measurement, installation angle is η, in M₁Establishing a coordinate system Mxyz for the reference, wherein the x axis is the body axis direction of the carrier, the z axis points to the zenith, and the y axis is determined by a right-hand rule;

in the body coordinate system, the sun azimuth angleCan pass through M₁Polarization azimuth angle measured by sensorAnd the azimuth angle psi provided by the geomagnetic sensor is calculated to obtain:

real-time obtaining polarization degree measured values d of three polarization sensors₁，d₂，d₃Based on Rayleigh scattering theory, the polarization degree of an observation point has the following relation with a scattering angle:

wherein d is_max∈[max{d₁,d₂,d₃},1)，θ₁，θ₂，θ₃Is M₁、M₂、M₃Observing an included angle between the direction and the sun vector;

according to the structure of a compound eye-imitating polarizing compass₁，θ₂，θ₃The relationship between can be expressed as:

cosθ₂+cosθ₃＝2cosηcosθ₁(3)

according to the formulas (2) to (3), the maximum polarization degree d of the whole day domain can be obtained_max，

According to the maximum polarization degree d of the full airspace under the geographic coordinate system_maxObtaining the main polarization sensor M₁Observation angle of (theta)₁：

Wherein, theta₁The direction can be judged by an external light intensity sensor or a gravity sensor;

according to M₁Sensor mounting method and sun altitude observation angleAngle of scattering theta₁The relation between the solar altitude and the solar altitude is obtained under the body coordinate systemComprises the following steps:

in the body coordinate system, the sun vector can be expressed as:

order to

3. The navigation method according to claim 1, wherein the navigation method based on the close combination of polarization-geomagnetic vectors is characterized in that: the step (2) obtains the sun vector under the geographic system according to the solar astronomical calendarCombining the sun vector under the body coordinate obtained in the step (1), establishing a conversion relation between the body coordinate system and the sun vector under the geographic coordinateThe concrete implementation is as follows:

according to the geographical position of the carrier and the local time, the solar azimuth angle and the solar altitude angle under the geographical coordinate system are obtained through the solar almanac and are respectively expressed as follows:

wherein L is geographical latitude, delta is solar declination, omega is solar hour angle,

obtaining the sun vector under the geographic system according to the formula (6),

order to

According to the attitude transformation relation between the body coordinate system and the geographic coordinate system, establishing the transformation relation of the sun vectors under the body coordinate system and the geographic coordinate system:

wherein,is the attitude transformation matrix between the body coordinate system and the geographic coordinate system,

wherein, theta, gamma and psi are carrier pitch angle, roll angle and course angle respectively;

the attitude error angle of the system is defined as follows:

φ＝[φ_xφ_yφ_z]^T(9)

the conversion relationship between the body coordinate system and the sun vector under the geographic coordinate system can be expressed as:

whereinThe nominal matrix can be obtained by carrier attitude angles, and is specifically represented as:

4. the navigation method according to claim 1, wherein the navigation method based on the close combination of polarization-geomagnetic vectors is characterized in that: the step (3) is to respectively obtain the geomagnetic vector under the body coordinate system and the geographic coordinate systemAndestablishing a conversion relation of the geomagnetic vectors in the body coordinate system and the geographic coordinate systemThe concrete implementation is as follows:

solving the geomagnetic vector under the geographic coordinate system to obtain the geomagnetic vector under the geographic coordinate system, which is expressed as:

the geomagnetic vector under the body coordinate system can be directly obtained through the geomagnetic sensor, and is represented as:

establishing a transformation relation of the geomagnetic vectors in the body coordinate system and the geographic coordinate system:

5. the navigation method according to claim 1, wherein the navigation method based on the close combination of polarization-geomagnetic vectors is characterized in that: the step (4) is to measure the geomagnetic vector under the body coordinate systemAnd sun vectorPerforming information depth fusionThe concrete implementation is as follows:

the sun vector of the body coordinate system obtained according to the step (2) and the step (3)And geomagnetic vectorThe cross multiplication processing is carried out on the formula (6) and the formula (12) to obtain a bodyAnd (3) carrying out polarization and geomagnetic vector fusion under a coordinate system:

combining equations (10) and (13), equation (15) can be expressed as:

wherein:

6. the navigation method according to claim 1, wherein the navigation method based on the close combination of polarization-geomagnetic vectors is characterized in that: the step (5) is combined with the step (4) to establish a navigation system model based on the tight combination of polarization-geomagnetic vectors, and the method is specifically realized as follows:

obtaining a combined navigation system model based on polarization-geomagnetic vector fusion through formula (15):