阅读说明：本技术 一种基于偏振和太阳双矢量切换的惯性/偏振导航方法 (Inertia/polarization navigation method based on polarization and sun dual-vector switching ) 是由 郭雷 豆青风 杨健 王悦 于 2021-11-22 设计创作，主要内容包括：本发明涉及一种基于偏振和太阳双矢量切换的惯性/偏振导航方法。首先,根据惯导输出计算偏振矢量；其次,根据传感器更新测得的偏振矢量信息计算误差矢量；再者,利用误差矢量计算各个偏振传感器的信息判别因子,并且确定每个偏振传感器是否可靠；最后,若有多个传感器测量信息可靠时,进入太阳误差矢量导航模式,若只有一个传感器可靠时,则进入偏振误差矢量导航模式,两种模式均通过卡尔曼滤波方法实现状态估计并反馈,从而完成基于偏振和太阳矢量的双矢量组合导航方法。本发明根据误差矢量建立量测方程避免了矢量间的方向歧义性问题,同时设计信息判别准则判定传感器状态,双矢量导航的设计使得偏振信息得到充分利用,提高了系统的可靠性。(The invention relates to an inertia/polarization navigation method based on polarization and sun dual-vector switching. Firstly, calculating a polarization vector according to inertial navigation output; secondly, calculating an error vector according to polarization vector information updated and measured by a sensor; thirdly, calculating information discrimination factors of each polarization sensor by using the error vectors, and determining whether each polarization sensor is reliable; and finally, if the measurement information of a plurality of sensors is reliable, entering a sun error vector navigation mode, and if only one sensor is reliable, entering a polarization error vector navigation mode, wherein the two modes realize state estimation and feedback through a Kalman filtering method, thereby completing the dual-vector combined navigation method based on polarization and sun vectors. According to the method, the measurement equation is established according to the error vector, the problem of direction ambiguity among vectors is avoided, the information discrimination criterion is designed to judge the state of the sensor, the polarization information is fully utilized due to the design of dual-vector navigation, and the reliability of the system is improved.)

1. An inertia/polarization navigation method based on polarization and sun dual-vector switching is characterized by comprising the following implementation steps:

firstly, collecting inertial navigation output data and resolving to obtain longitudeLatitude and longitudeLHeight, heighthAnd attitude matrixCombined with astronomical almanac information to obtainnLower solar vectors ⁿ And then calculated to obtainbLower solar vectorCalculating according to Rayleigh scattering theory to obtain correspondenceslTheoretical polarization vector of each observation directionWherein, in the step (A),is as followsiProjection of observation vectors of the sensors under a b system;

secondly, whether the polarization sensor is updated or not is detected, and when the output data of the polarization sensor is updated, the data measured by the polarization sensor is obtainedlPolarization azimuth information output by polarization sensorBased on the polarization azimuth information and the polarization sensor coordinate systemmIs tied tobTransfer matrix of systemTo obtainlMeasuring polarization vector of polarization sensorCombined with the theoretical polarization vector in the first stepIs calculated to obtainlPolarization error vector；

Thirdly, calculating the information discrimination factor of each polarization sensor according to the polarization error vector in the second stepAccording to empirical thresholdT _p Making a criterionThe quality of the information of each polarization sensor is determined by a criterion, i.e.q _i =1 denotesiThe polarization sensor is normally usable in the direction,q _i =0 denotesiThe polarization sensor is unusually unavailable in direction;

step four, utilizing the information quality of the polarization sensor obtained in the step three, if a plurality of polarization sensor measurement information are normally available, entering a solar error vector navigation mode, and constructing a solar error vector measurement equation，Z _ps For the measurement of the sun error vector,H _ps in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _ps is measured byMeasuring noise, if only one polarization sensor measurement information is normally available, entering a polarization error vector navigation mode, and constructing a polarization error vector measurement equation，Z _pp For the purpose of polarization error vector measurement,H _pp in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _pp in order to measure noise, after the navigation mode is entered, the Kalman filtering method is adopted to realize the estimation and feedback of the system state, and the inertial navigation/polarization combined navigation is completed.

2. The inertial/polarization navigation method based on polarization and sun dual-vector switching according to claim 1, wherein: in the first step, collecting inertial navigation output data and resolving to obtain longitudeLatitude and longitudeLHeight, heighthAnd attitude matrixCombined with astronomical almanac information to obtainnLower solar vectors ⁿ And then calculated to obtainbLower solar vectorCalculating according to Rayleigh scattering theory to obtain correspondenceslTheoretical polarization vector of each observation directionIs as followsiThe projection of the observation vector of each sensor under the b system is realized as follows:

navigation systems involve two coordinate systems: the navigation system, namely the N system, and the coordinate axes point to east (E), north (N) and sky (U) respectively; the carrier system, i.e. system b, the axes of which are respectively directed to the right of the carrier (x) Front (a)y) Above (z）；

Position information output by inertial navigation: longitude (G)Latitude and longitudeLHeight, heighthObtaining the altitude angle of the sun under n system according to the astronomical calendarAnd azimuth angleWhereby the sun vector under the navigation system isCombined with attitude rotation matrixTo obtainbLower solar vector；

The polarization sensor coordinate system, i.e., the m-system, is established as follows: using the zero reference direction of the polarization sensor asx _m ，y _m Form a right-handed helical rule therewith, and the rotation matrix of m to b is；

Then it is firstiThe observation vector of each polarization sensor isWherein, in the step (A),is as followsiA rotation matrix of the orientation sensors with respect to the b-system; get the theoretical biasVibration vector。

3. The inertial/polarization navigation method based on polarization and sun dual-vector switching according to claim 1, wherein: in the second step, whether the polarization sensor is updated or not is detected, and when the output data of the polarization sensor is updated, the measured data of the polarization sensor is utilized to obtainlPolarization azimuth information output by polarization sensorBased on the polarization azimuth information and the polarization sensor coordinate systemmIs tied tobTransfer matrix of systemTo obtainlMeasured polarization vector information of polarization sensorCombined with calculation of the polarization vector in the first stepCalculating to obtain the ith polarization error vectorThe method is concretely realized as follows:

definition ofiAn output azimuth angle of the polarization sensor isThen measure the polarization vectorThen the polarization error vector is。

4. The inertial/polarization navigation method based on polarization and sun dual-vector switching according to claim 1, wherein: in the third step, the information discrimination factor of each sensor is calculated according to the polarization error vector in the second stepAccording to empirical thresholdT _p Making a criterionThe quality of the information of each polarization sensor is determined by a criterion, i.e.q _i =1 denotesiThe polarization sensor is normally usable in the direction,q _i =0 denotesiThe polarization sensor is unusually unavailable in direction; the concrete implementation is as follows:

according to the theoretical polarization vector in the first stepAnd measuring the polarization vector in the second stepInformation discrimination factors can be established:

given decision thresholdT _p Then the information discrimination criterion is:

wherein the content of the first and second substances,lthe number of the observation directions of the polarization sensor,q _i =1 denotesiThe polarization sensor is normally usable in the direction,q _i =0 denotesiThe polarization sensor in the direction is unusually unusable.

5. The inertial/polarization navigation method based on polarization and sun dual-vector switching according to claim 1, wherein:

in the fourth step, the information quality of the polarization sensor obtained in the third step is utilized, if the measurement information of a plurality of sensors is normally available, the sun error vector navigation mode is entered, and a sun error vector measurement equation is constructed，Z _ps For the measurement of the sun error vector,H _ps in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _ps for measuring noise, if only one polarization sensor measurement information is normally available, entering a polarization error vector navigation mode, and constructing a polarization error vector measurement equation，Z _pp For the purpose of polarization error vector measurement,H _pp in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _pp to measure noise; after entering a navigation mode, estimating and feeding back the system state by adopting a Kalman filtering method to complete inertial navigation/polarization combined navigation; the concrete implementation is as follows:

the system state model used by the integrated navigation is a strapdown inertial navigation error state equation, which specifically comprises the following steps:

misalignment angle dynamic equation:

speed error dynamic equation:

position error dynamic equation:

drift dynamic equation:

wherein the content of the first and second substances,V ⁿ the speed of the carrier under the n system is,is the speed error;in order to be a position error,respectively latitude error, longitude error and altitude error;is the projection of the rotational angular velocity of the earth under n system,is composed ofThe error of (a) is detected,is the projection of the angular velocity of the system n relative to the terrestrial coordinate system, i.e. the system e under the system n,is composed ofThe error of (a) is detected,a rotation matrix from b to n; f ^b the acceleration is given by the equation b,respectively, constant drift of the gyroscope and the adder;is a matrix of the relationship between the position error derivative and the velocity error,is a matrix of the relationship between the position error derivative and the velocity;

the system state equation is:

wherein the content of the first and second substances,Fin order to be a state transition matrix,,Wis process noise;

according to the criterion of polarization information discrimination, if two or more polarization sensors are in normal operation, that isWherein, in the step (A),kif the number of the polarization sensors which normally work is more than or equal to 2, entering a sun error vector navigation mode; sun error vector mode of operationThe following measurement models were established:

in thatkTwo of the polarization sensors optionally calculate polarization vectors of，Then, according to the Rayleigh scattering theory,the sun error vector measurement is:

omitThe quadratic term of (2) is obtained by considering the noise of the polarization sensor, and the measurement equation of the sun error vector is as follows:

wherein the content of the first and second substances,，v _ps is white gaussian noise;

if 1 polarization sensor works normally, entering a polarization error vector navigation mode, and establishing a measurement model under the polarization error vector working mode as follows:

omitConsidering the noise of the polarization sensor, the obtained polarization error vector measurement equation is as follows:

wherein the content of the first and second substances,，v _pp to measure noise;

and the two working modes estimate and feed back the state by a Kalman filtering method to complete inertial navigation/polarization combined navigation.

Technical Field

The invention belongs to the field of integrated navigation, and relates to an inertia/polarization navigation method based on polarization and sun dual-vector switching.

Background

In recent years, polarization navigation has been rapidly developed, and with the progress of research, various polarization navigation systems have been proposed in succession, and polarization navigation models have been enriched. As a complementary navigation system of a strapdown inertial navigation system in navigation direction measurement, the polarization navigation has the unique advantage of full autonomy in attitude measurement, and the sensor measurement has no accumulated error, so the application of the polarization navigation in the field of integrated navigation is more and more extensive.

The principle of polarization navigation is from scattering propagation of sunlight after passing through the atmosphere, the distribution rule of light vectors in the atmosphere is mainly disclosed, more is the relation between the vectors, and the scattering theory can know that the polarization angle of scattered light can be accurately determined through a sensor, but the direction is unknown, so that the problem of direction ambiguity exists in the application process of polarization information.

At present, inertial navigation/polarization combined navigation methods based on polarization vector measurement have been studied. The thesis "combined orientation method based on micro-inertia/polarization vision" is based on the Rayleigh scattering principle, calculates the sun vector based on the relation between the unidirectional polarization vector and the sun vector and observation vector, proposes a robust orientation method by using the least square method, and solves the orientation and positioning problems of vehicle navigation in the city together with the monocular camera measurement result; the paper "Integrated polarized diagonal sensor and MIMU with a metallic map for a urea group navigation" calculates a polarization vector by using the relationship between a unidirectional polarization vector and a sun vector, an observation vector based on the Rayleigh scattering principle, proposes a robust orientation method by using a least square method, and solves the problems of orientation and positioning of vehicle navigation in a city together with a monocular camera measurement result; the paper "An Autonomous initiative Alignment and Observation Analysis for SINS with Bio-accelerated Polarized Skylight Sensors" establishes a polarization measurement model by using solar vectors, analyzes the Observability of the SINS/POL combined navigation system, and provides theoretical guidance for polarization high-precision navigation; the chinese granted patent CN 104880191 a establishes a polarization measurement model by using the sun vector, and performs difference construction measurement between the sun vector obtained by using the almanac and the sun vector obtained by using the polarization information to complete inertial navigation/polarization combined navigation. The model design in the above document needs to introduce a vector direction determination rule, which brings extra calculation cost to the integrated navigation, and the simple polarization measurement without directivity problem is an important problem worth to be researched for improving the performance of the inertial navigation/polarization integrated navigation system. In addition, polarized light navigation is easily shielded by factors such as buildings, cloud layers and the like, the polarized information is damaged due to the shielding problem, the reliability of the inertial navigation/polarized combined navigation system can be seriously reduced by using a single polarized vector for navigation, and the realization of efficient utilization of the polarized vector information is important for the research of the inertial navigation/polarized combined navigation method.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the problems of vector direction ambiguity in polarization navigation and a switching mechanism under sensor abnormality, an inertia/polarization navigation method based on polarization and sun dual-vector switching is provided, two different normal vector polarization measurement models are established according to a cross product principle between vectors, and an information discrimination criterion is designed to intelligently select a combined navigation mode, so that high-precision reliable navigation under the condition of sensor abnormality is completed.

The technical scheme adopted by the invention for solving the technical problems is as follows: an inertia/polarization navigation method based on polarization and sun dual-vector switching comprises the following implementation steps:

firstly, collecting inertial navigation output data and resolving to obtain longitudeLatitude and longitudeLHeight, heighthAnd attitude matrixCombined with astronomical almanac information to obtainnLower solar vectors ⁿ And then calculated to obtainbLower solar vectorCalculating according to Rayleigh scattering theory to obtain correspondenceslTheoretical polarization vector of each observation directionWherein, in the step (A),is as followsiProjection of observation vectors of the sensors under a b system;

secondly, whether the polarization sensor is updated or not is detected, and when the output data of the polarization sensor is updated, the data measured by the polarization sensor is obtainedlPolarization azimuth information output by polarization sensorBased on the polarization azimuth information and the polarization sensor coordinate systemmIs tied tobTransfer matrix of systemTo obtainlPolarization vector information of polarization sensorCombined with the theoretical polarization vector in the first stepIs calculated to obtainlPolarization error vector；

Thirdly, calculating the information discrimination factor of each polarization sensor according to the polarization error vector in the second stepAccording to empirical thresholdT _p Making a criterionThe quality of the information of each polarization sensor is determined by a criterion, i.e.q _i =1 denotesiThe polarization sensor is normally usable in the direction,q _i =0 denotesiThe polarization sensor in the direction is unusually unusable.

Step four, utilizing the information quality of the polarization sensor obtained in the step three, if a plurality of sensor measurement information are normally available, entering a solar error vector navigation mode, and constructing a solar error vector measurement equation，Z _ps For the measurement of the sun error vector,H _ps in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _ps for measuring noise, if only one polarization sensor is provided, the method enters a polarization error vector navigation mode, and a polarization error vector measurement equation is constructed，Z _pp For the purpose of polarization error vector measurement,H _pp in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _pp to measure noise. After entering the navigation mode, the Kalman filtering method is adopted to realize the estimation and feedback of the system state, and the inertial navigation/polarization combined navigation is completed.

Further, in the first step, the longitude obtained by resolving the acquired inertial navigation output dataLatitude and longitudeLHeight, heighthAnd attitude matrixCombined with astronomical almanac information to obtainnLower solar vectors ⁿ And then calculated to obtainbLower solar vectorCalculating according to Rayleigh scattering theory to obtain correspondenceslTheoretical polarization vector of each observation directionWherein, in the step (A),is as followsiThe projection of the observation vector of each sensor under the b system is realized as follows:

navigation systems involve two coordinate systems: the navigation system, namely the N system, and the coordinate axes point to east (E), north (N) and sky (U) respectively; the carrier system, i.e. system b, the axes of which are respectively directed to the right of the carrier (x) Front (a)y) Above (z）；

Position information output by inertial navigation: longitude (G)Latitude and longitudeLHeight, heighthObtaining the altitude angle of the sun under n system according to the astronomical calendarAnd azimuth angleWhereby the sun vector under the navigation system isCombined with attitude rotation matrixTo obtainbLower solar vector。

Polarization sensor coordinate system, i.e. m-systemThe establishment is as follows: using the zero reference direction of the sensor asx _m ，y _m Form a right-handed helical rule therewith, and the rotation matrix of m to b is。

Then it is firstiThe observation vector of each polarization sensor isWherein, in the step (A),is as followsiA rotation matrix of the individual directional polarization sensors with respect to the b-system.

Furthermore, whether the polarization sensor is updated or not is detected in the second step, and when the output data of the polarization sensor is updated, the data measured by the sensor is obtainedlPolarization azimuth information output by polarization sensorBased on the polarization azimuth information and the polarization sensor coordinate systemmIs tied tobTransfer matrix of systemTo obtainlMeasured polarization vector information of polarization sensorCombined with the theoretical polarization vector in the first stepIs calculated to obtainlPolarization error vector. The concrete implementation is as follows:

definition ofiAn output azimuth angle of the polarization sensor isThen measure the polarization vectorThen the polarization error vector is。

Further, in the third step, the information discrimination factors of each polarization sensor are calculated according to the polarization error vector in the second stepAccording to empirical thresholdT _p Making a criterionThe quality of the information of each polarization sensor is determined by a criterion, i.e.q _i =1 denotesiThe polarization sensor is normally usable in the direction,q _i =0 denotesiThe polarization sensor in the direction is not available abnormally, and the method is realized as follows:

according to the theoretical polarization vector in the first stepAnd measuring the polarization vector in the second stepInformation discrimination factors can be established:

given decision thresholdT _p Then the information discrimination criterion is:

wherein the content of the first and second substances,lthe number of the observation directions of the polarization sensor,q _i =1 denotesiThe polarization sensor is normally usable in the direction,q _i =0 denotesiThe polarization sensor in the direction is unusually unusable.

Further, in the fourth step, the information quality of the polarization sensor obtained in the third step is utilized, if the measurement information of a plurality of sensors is normally available, the solar error vector navigation mode is entered, and a solar error vector measurement equation is constructed，Z _ps For the measurement of the sun error vector,H _ps in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _ps for measuring noise, if only one polarization sensor measurement information is normally available, entering a polarization error vector navigation mode, and constructing a polarization error vector measurement equation，Z _pp For the purpose of polarization error vector measurement,H _pp in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _pp to measure noise; after entering the navigation mode, the Kalman filtering method is adopted to realize the estimation and feedback of the system state, and the inertial navigation/polarization combined navigation is completed. The concrete implementation is as follows:

the system state model used by the integrated navigation is a strapdown inertial navigation error state equation, which specifically comprises the following steps:

misalignment angle dynamic equation:

speed error dynamic equation:

position error dynamic equation:

drift dynamic equation:

wherein the content of the first and second substances,V ⁿ the speed of the carrier under the n system is,is the speed error;in order to be a position error,respectively latitude error, longitude error and altitude error;is the projection of the rotational angular velocity of the earth under n system,is composed ofThe error of (a) is detected,is the projection of the angular velocity of n relative to e system (terrestrial coordinate system) under n system,is composed ofThe error of (a) is detected,a rotation matrix from b to n;f ^b the acceleration is given by the equation b,respectively, constant drift of the gyroscope and the adder;is a matrix of the relationship between the position error derivative and the velocity error,is a matrix of the relationship between the position error derivative and the velocity;

the system state equation is:

wherein the content of the first and second substances,Fin order to be a state transition matrix,,Wis process noise.

According to the criterion of polarization information discrimination, if two or more polarization sensors are in normal operation, that is(kNot less than 2), wherein,kand if the number of the polarization sensors which normally work is more than or equal to 2, the sun error vector navigation mode is entered. The measurement model under the sun error vector working mode is established as follows:

in thatkTwo of the polarization sensors optionally calculate polarization vectors of，According to Rayleigh scattering theoryIn view of the above, it is believed that,the sun error vector measurement is:

omitThe quadratic term of (2) is obtained by considering the noise of the polarization sensor, and the measurement equation of the sun error vector is as follows:

wherein the content of the first and second substances,，v _ps to measure noise.

If 1 polarization sensor works normally, entering a polarization error vector navigation mode, and establishing a measurement model under the polarization error vector working mode as follows:

omitConsidering the noise of the polarization sensor, the obtained polarization error vector measurement equation is as follows:

wherein the content of the first and second substances,，v _pp is measured byMeasuring noise;

and the two working modes estimate and feed back the state by a Kalman filtering method to complete inertial navigation/polarization combined navigation.

Compared with the prior art, the invention has the following advantages:

(1) the existing three-dimensional polarization measurement model has the vector direction ambiguity problem and needs to be determined by a design judgment criterion.

(2) The invention designs the information discrimination criterion by utilizing the resource utilization characteristics of the two built models, provides a sensor model switching mechanism under the abnormal condition of the sensor, and improves the reliability under the abnormal condition of the sensor information.

Drawings

FIG. 1 is a flow chart of an inertial/polarization navigation method based on dual-vector switching of polarization and sun according to the present invention;

FIG. 2 is a schematic representation of Rayleigh scattering geometry.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying 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, rather than all embodiments, and all other embodiments obtained by a person skilled in the art based on the embodiments of the present invention belong to the protection scope of the present invention without creative efforts.

The method of the invention is concretely realized as follows:

firstly, collecting inertial navigation output data and resolving to obtain longitudeLatitude and longitudeLHeight, heighthAnd attitude matrixCombined with astronomical almanac information to obtainnLower solar vectors ⁿ And then calculated to obtainbLower solar vectorCalculating according to Rayleigh scattering theory to obtain correspondenceslTheoretical polarization vector of each observation directionWherein, in the step (A),is as followsiProjection of observation vectors of the sensors under a b system; the concrete implementation is as follows:

navigation systems involve two coordinate systems: the navigation system, namely the N system, and the coordinate axes point to east (E), north (N) and sky (U) respectively; the carrier system, i.e. system b, the axes of which are respectively directed to the right of the carrier (x) Front (a)y) Above (z）。

Position information output by inertial navigation: longitude (G)Latitude and longitudeLHeight, heighthObtaining the altitude angle of the sun under n system according to the astronomical calendarAnd azimuth angleWhereby the sun vector under the navigation system isCombined with attitude rotation matrixObtain the sun vector under system。

The polarization sensor coordinate system, i.e., the m-system, is established as follows: to be provided withZero reference direction of the polarization sensor isx _m ，y _m Form a right-handed helical rule therewith, and the rotation matrix of m to b is。

Then it is firstiThe observation vector of each polarization sensor isWherein, in the step (A),is as followsiA rotation matrix of the individual directional polarization sensors with respect to the b-system; obtaining a theoretical polarization vector；

Secondly, whether the polarization sensor is updated or not is detected, and when the output data of the polarization sensor is updated, the data measured by the polarization sensor is obtainedlPolarization azimuth information output by polarization sensorBased on the polarization azimuth information and the polarization sensor coordinate systemmIs tied tobTransfer matrix of systemTo obtainlMeasured polarization vector information of polarization sensorCombined with the theoretical polarization vector in the first stepIs calculated to obtainlPolarization error vectorThe method is concretely realized as follows:

definition ofiAn output azimuth angle of the polarization sensor isThen measure the polarization vectorThen the polarization error vector is。

Thirdly, calculating the information discrimination factor of each sensor according to the polarization error vector in the second stepAccording to empirical thresholdT _p Making a criterionThe quality of the information of each polarization sensor is determined by a criterion, i.e.q _i =1 denotesiThe polarization sensor is normally usable in the direction,q _i =0 denotesiThe polarization sensor in the direction is unusually unusable. The concrete implementation is as follows:

according to the theoretical polarization vector in the first stepAnd measuring the polarization vector in the second stepInformation discrimination factors can be established:

given decision thresholdT _p Then the information discrimination criterion is:

wherein the content of the first and second substances,lthe number of the observation directions of the polarization sensor,q _i =1 denotesiThe polarization sensor is normally usable in the direction,q _i =0 denotesiThe polarization sensor in the direction is unusually unusable.

Step four, utilizing the information quality result of the polarization sensor obtained in the step three, if a plurality of sensor measurement information are normally available, entering a solar error vector navigation mode, and constructing a solar error vector measurement equation，Z _ps For the measurement of the sun error vector,H _ps in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _ps for measuring noise, if only one polarization sensor measurement information is normally available, entering a polarization error vector navigation mode, and constructing a polarization error vector measurement equation，Z _pp For the purpose of polarization error vector measurement,H _pp in order to measure the matrix, the measurement matrix is,Xis a vector of the states of the system,v _pp to measure noise; after entering the navigation mode, the Kalman filtering method is adopted to realize the estimation and feedback of the system state, and the inertial navigation/polarization combined navigation is completed. The concrete implementation is as follows:

the system state model used by the integrated navigation is a strapdown inertial navigation error state equation, which specifically comprises the following steps:

misalignment angle dynamic equation:

speed error dynamic equation:

position error dynamic equation:

drift dynamic equation:

wherein the content of the first and second substances,V ⁿ the speed of the carrier under the n system is,is the speed error;in order to be a position error,respectively latitude error, longitude error and altitude error;is the projection of the rotational angular velocity of the earth under n system,is composed ofThe error of (a) is detected,is the projection of the angular velocity of n relative to e system (terrestrial coordinate system) under n system,is composed ofThe error of (a) is detected,a rotation matrix from b to n;f ^b the acceleration is given by the equation b,respectively, constant drift of the gyroscope and the adding meter;is a matrix of the relationship between the position error derivative and the velocity error,is a matrix of the relationship between the position error derivative and the velocity;

the system state equation is:

wherein the content of the first and second substances, Fin order to be a state transition matrix,,Wis process noise;

according to the judgment criterion of the polarization information, if two or more polarization sensors work normally,(knot less than 2), wherein,kif the number of the polarization sensors which normally work is more than or equal to 2, entering a sun error vector navigation mode; the measurement model under the sun error vector working mode is established as follows:

in thatkOptionally two of the polarization sensors measure polarization vectors of，Then, according to the Rayleigh scattering theory,the sun error vector measurement is:

omitThe quadratic term of (2) is obtained by considering the noise of the polarization sensor, and the measurement equation of the sun error vector is as follows:

wherein the content of the first and second substances,，v _ps to measure noise;

if 1 polarization sensor works normally, entering a polarization error vector navigation mode, and establishing a measurement model under the polarization error vector working mode as follows:

omitConsidering the noise of the polarization sensor, the obtained polarization error vector measurement equation is as follows:

wherein the content of the first and second substances,，v _pp to measure noise;

and the two working modes estimate and feed back the state by a Kalman filtering method to complete inertial navigation/polarization combined navigation.