Meteorological wind measurement method based on inertia/satellite/atmosphere combination

文档序号:1056174 发布日期:2020-10-13 浏览:16次 中文

阅读说明:本技术 一种基于惯性/卫星/大气组合的气象风测量方法 (Meteorological wind measurement method based on inertia/satellite/atmosphere combination ) 是由 王学运 从浩 张京娟 赵明 于 2020-06-19 设计创作,主要内容包括:本发明公开一种基于惯性/卫星/大气组合的气象风测量方法,尤其涉及风速风向的在线测量,在不改变飞行器结构外形、不增加测量装置和硬件设备的前提下,利用现有的机载惯性导航系统、卫星定位系统、大气数据系统的输出参数,得到惯性系统的加速度、角速度和姿态角,卫星测得地速、大气数据系统测得真空速,通过构建无迹卡尔曼滤波器,将风速风向测量模型和状态估计过程融合起来,实现飞行器机体周围风速风向的实时测量,并完成下一时刻风速风向的估计。本发明所提出的方法方案可以解决飞行器周围局域风速风向的实时测量和大区域连续飞行实时风速风向测量问题,为四维航迹飞行、飞机准点达到提供方法支持。(The invention discloses a meteorological wind measuring method based on inertia/satellite/atmosphere combination, in particular to on-line measurement of wind speed and direction, which obtains the acceleration, angular velocity and attitude angle of an inertia system by utilizing the output parameters of the existing airborne inertia navigation system, satellite positioning system and atmosphere data system on the premise of not changing the structural appearance of an aircraft and increasing the measuring device and hardware equipment, measures the ground speed by a satellite and measures the vacuum speed by the atmosphere data system, and integrates a wind speed and direction measuring model and a state estimation process by constructing an unscented Kalman filter to realize the real-time measurement of the wind speed and direction around the aircraft body and finish the estimation of the wind speed and direction at the next moment. The method scheme provided by the invention can solve the problems of real-time measurement of local wind speed and wind direction around the aircraft and real-time measurement of wind speed and wind direction of large-area continuous flight, and provides method support for four-dimensional flight path flight and aircraft punctuation.)

1. A meteorological wind measuring method based on inertia/satellite/atmosphere combination is characterized in that: the method comprises the following steps:

outputting parameters by using an avionics device onboard an aircraft, the parameters comprising:

(1) the inertial navigation system outputs the acceleration, the angular velocity and the attitude angle of the aircraft;

(2) the satellite positioning system outputs the ground speed of the aircraft;

(3) the air data system outputs the vacuum speed of the aircraft;

calculating a state transition matrix by using the acceleration, the angular velocity and the attitude angle output by the inertial navigation system;

solving the three-axis speed of the aircraft in the body coordinate system by using the ground speed output by the satellite positioning system through the body coordinate system and the state transfer matrix of the geographic coordinate system;

calculating the vacuum speed of the aircraft by using the vacuum speed output by the atmospheric data system;

calculating the wind speed and the wind direction around the fuselage of the aircraft by using the ground speed, the state transition matrix and the vacuum speed resolving result of the aircraft at the current moment, and accurately estimating the wind speed and the wind direction at the next moment in real time by using an unscented Kalman filter.

2. The method for measuring meteorological wind based on inertia/satellite/atmosphere combination as claimed in claim 1, wherein the acceleration, angular velocity and attitude angle of the aircraft are obtained by reading three angular velocities, three attitude angles and three linear acceleration information output by the inertial navigation system at a period △ T, and three angular velocities [ pqr ] are obtained]TRoll angular velocity p, pitch angular velocity q and yaw angular velocity r in the X-axis, Y-axis and Z-axis directions under the machine system respectively; three attitude angles phi theta phi]TRespectively a roll angle phi, a pitch angle theta and a yaw angle psi; three linear accelerations [ a ]xayaz]TRespectively is the linear acceleration a of the body in the X-axis directionxLinear acceleration a in the Y-axis directionyAnd linear acceleration a in the Z-axis directionzAnd the directions of the X axis, the Y axis and the Z axis of the body coordinate system are forward, rightward and downward respectively.

3. The method of claim 2, wherein the low speed of the aircraft is obtained by reading the three-axis ground speed [ V ] in the geographic coordinate system outputted from the onboard satellite positioning system at a period of △ TxVyVz]TIn which V isxIs the speed component, V, of the aircraft on the X axis of the geographic coordinate systemyIs the velocity component, V, of the aircraft in the Y-axis of the geographic coordinate systemzIs the speed component of the aircraft in a geographic coordinate system, wherein the X axis and the Y axis of the geographic coordinate systemThe Z-axis points north, east and ground, respectively.

4. The combined inertial/satellite/atmospheric meteorological wind measurement method of claim 3, wherein: the state transition matrix is a state transition matrix from a geographic coordinate system to a body coordinate system and is obtained through attitude angle information, the attitude angle information comprises a roll angle phi, a pitch angle theta and a yaw angle psi, and the state transition matrix is calculated

Figure FDA0002546877920000021

Figure FDA0002546877920000022

Converting triaxial ground speed [ V ] under geographic coordinate system through state transition matrixxVyVz]TSwitching to a machine system:

[wxwywz]Tthree axis wind speeds.

5. The combined inertial/satellite/atmospheric meteorological wind measurement method of claim 4, wherein: the vacuum speed of the aircraft is obtained by resolving pressure and temperature provided by a pressure sensor and a temperature sensor in an airborne atmospheric data system by combining a Bernoulli equation, and the calculation formula is as follows:

Figure FDA0002546877920000024

wherein, the delta P is dynamic pressure, the rho is air density, and the K is a correction factor;

ground speed measured by satellite positioning systemAttitude angle measured by an inertial navigation system, state transition matrix obtained by resolving attack angle α and sideslip angle β provided by an atmospheric data system, and vacuum speed measured by the atmospheric data system

Figure FDA0002546877920000026

WhereinwxIs the wind speed in the X-axis direction, wyIs the wind speed in the Y-axis direction, wzIs the wind speed in the Z-axis direction.

6. The combined inertial/satellite/atmospheric meteorological wind measurement method of claim 5, wherein: the wind direction around the aircraft body comprises a wind direction angle, the wind direction angle comprises a wind direction azimuth angle and a wind direction elevation angle, and the included angle between the wind speed and the north direction is called the wind direction azimuth angleThe included angle between the wind speed and the horizontal plane is called wind direction elevation angle

7. The combined inertial/satellite/atmospheric meteorological wind measurement method of claim 6, wherein: the method for accurately estimating the wind speed and the wind direction at the next moment in real time comprises the following specific steps: with three axes of acceleration [ a ]xayaz]TAnd angular rate [ p q r]TAs input to the system; with three-axis speed [ uv w ] of aircraft body]TRoll angle phi, pitch angle theta, yaw angle psi and IIIAxial wind velocity [ w ]xwywz]TAs the state quantity, i.e., X ═ u v w Φ θ ψ wxwywz]T(ii) a At triaxial ground speed [ V ]xVyVz]TVacuum speed VaAngle of attack α and sideslip angle β are measured as quantities, i.e., Z ═ VxVyVzVaα β]T(ii) a According to the current time tkSystem input amount at time, current time tkMeasurement information of time and current time tkObtaining t by utilizing the unscented Kalman filter according to the state quantity information of the momentk+1And the optimal estimation value of the state quantity at the moment is obtained, so that the on-line measurement and real-time accurate estimation of the wind speed and the wind direction are realized.

8. The combined inertial/satellite/atmospheric meteorological wind measurement method of claim 7, wherein: obtaining t by using unscented Kalman filterk+1The optimal estimation value of the state quantity at the moment is obtained, so that the on-line measurement and real-time accurate estimation of the wind speed and the wind direction are realized, and the specific method comprises the following steps: establishing an unscented Kalman filter state equation: xk=f(Xk-1,uk-1)+Wk-1Wherein X iskAnd Xk-1State vectors at times k and k-1, W, respectivelyk-1Is the state noise vector, Wk-1Three-axis speed change rate of aircraft bodyRate of change of three-axis attitude angle

Figure FDA0002546877920000034

8.1) selecting a filtering initial value:

Figure FDA0002546877920000037

wherein E refers to the mathematical expectation, X0For the initial value of the state vector,

Figure FDA0002546877920000038

8.2) calculating the sigma sample point at the k-1 moment:

Figure FDA0002546877920000041

Figure FDA0002546877920000043

where n is the state dimension and λ is α2(n+κ)-n,α∈[10-4,1],κ=3-n;

8.3) determining the weight:

Figure FDA0002546877920000046

wherein, W0 (m)And Wi (m)Is the weight of the ith sigma point state vector, W0 (c)And Wi (c)The weight of the covariance matrix of the ith sigma point-like state vector is β, which is a state distribution parameter, β is 2;

8.4) calculating a one-step prediction model value at the k moment:

to predict the state vector, Pk/k-1To predict the covariance matrix of the state vector, Qk-1A noise matrix of a last state vector;

8.5) computing one-step predicted sample points at time k

Figure FDA00025468779200000411

Figure FDA00025468779200000412

Figure FDA00025468779200000413

8.6) measurement update:

Figure FDA0002546877920000051

Figure FDA0002546877920000053

wherein the content of the first and second substances,in order to predict the observation vector(s),

Figure FDA0002546877920000059

8.7) updating the filtering:

Figure FDA0002546877920000055

Figure FDA0002546877920000056

wherein, KkIn order to be a matrix of gains, the gain matrix,to estimate the state vector, PkIs a covariance matrix for estimating the state vector.

9. The combined inertial/satellite/atmospheric meteorological wind measurement method of claim 8, wherein: in the unscented Kalman filter, a roll angle phi, a pitch angle theta and a yaw angle psi of a state quantity are provided by an inertial navigation system, the triaxial speed of a body system is provided by a satellite positioning system, a three-dimensional wind speed initial value is provided by an external anemoscope, the three-dimensional wind speed change rate initial value is zero, the system initial state quantity is formed, and an initial state estimation error variance matrix P is formed0Initial value Q of system noise variance array0Sum measure noise variance matrix R0The initial values of the matrix are directly input from the outside of the system, and the noise matrix Q of the systemkInitial value Q of system noise variance matrix0Determining and measuring a noise matrix Rk+1By measuring the initial value R of the noise variance matrix0And (4) determining.

10. The combined inertial/satellite/atmospheric meteorological wind measurement method of claim 9, wherein: knowing t from said state quantitiesk+1And (3) taking the obtained three-dimensional wind speed to an included angle formula of the wind speed and the north direction and an included angle formula of the wind speed and the horizontal plane to obtain a wind direction angle.

Disclosure of Invention

The invention aims to make up for the defects of the existing method and provides a meteorological wind measuring method based on inertia/satellite/atmosphere combination.

The invention is realized by the following method scheme:

a meteorological wind measurement method based on inertia/satellite/atmosphere combination, which utilizes parameters output by an airborne avionics device of an aircraft, and comprises the following steps:

acceleration, angular velocity and attitude angle output by the inertial system;

the ground speed output by the satellite positioning system;

the vacuum speed output by the atmospheric data system;

calculating a state transition matrix according to output information of the inertial navigation system;

and solving the three-axis speed of the aircraft under the body coordinate system by the ground speed output by the satellite positioning system through the state transfer matrix of the body coordinate system and the geographic coordinate system.

And measuring data by an atmospheric data system, and calculating the vacuum speed of the aircraft.

Calculating the wind speed and the wind direction around the aircraft body according to the ground speed, the state transition matrix and the vacuum speed calculation result of the aircraft at the current moment, and accurately estimating the wind speed and the wind direction at the next moment in real time through an unscented Kalman filter.

Comprises the following steps:

in the first step, three angular velocities, three attitude angles and three linear acceleration information output by the inertial navigation system are read in a period △ T, and the three angular velocities [ p q r [ ]]TRoll angular velocity p, pitch angular velocity q and yaw angular velocity r in the X-axis, Y-axis and Z-axis directions under the machine system respectively; three attitude angles phi theta phi]TRespectively a roll angle phi, a pitch angle theta and a yaw angle psi; three linear accelerations [ a ]xayaz]TRespectively is the linear acceleration a of the body in the X-axis directionxLinear acceleration a in the Y-axis directionyAnd linear acceleration a in the Z-axis directionzAnd the directions of the X axis, the Y axis and the Z axis of the body coordinate system are forward, rightward and downward respectively.

Secondly, reading the three-axis ground speed [ V ] under the geographic coordinate system output by the airborne satellite positioning system in a period △ TxVyVz]TIn which V isxFor the speed component, V, of the aircraft on the X-axis of the geographic coordinate systemyFor the speed component, V, of the aircraft in the Y-axis of the geographic coordinate systemzIs the speed component of the aircraft in a geographic coordinate system, wherein the X-axis, Y-axis and Z-axis of the geographic coordinate system are respectively oriented in the north direction, east direction and ground direction.

Thirdly, the state transition matrix is a state transition matrix from the geographic coordinate system to the body coordinate system and is obtained through attitude angle information, the attitude angle information comprises a roll angle phi, a pitch angle theta and a yaw angle psi, and the state transition matrix is calculated

Figure BDA0002546877930000021

Figure BDA0002546877930000022

Fourthly, the three-axis ground speed [ V ] under the geographic coordinate system can be realized through the state transition matrixxVyVz]TSwitching to a machine system:

Figure BDA0002546877930000023

[wxwywz]Tthree axis wind speeds.

Fifthly, the airborne vacuum speed is generally obtained by resolving pressure and temperature provided by a pressure sensor and a temperature sensor in an airborne atmospheric data system by combining a Bernoulli equation, and the calculation formula is as follows:

wherein, Δ P is dynamic pressure, ρ is air density, and K is a correction factor.

Sixthly, measuring the ground speed by using a satellite positioning system

Figure BDA0002546877930000025

Attitude angle measured by an inertial navigation system, attitude transition matrix obtained by resolving an attack angle α and a sideslip angle β provided by an atmospheric data system, and vacuum speed measured by the atmospheric data system

Figure BDA0002546877930000031

Obtaining:

Figure BDA0002546877930000032

whereinwxIs the wind speed in the X-axis direction, wyIs the wind speed in the Y-axis direction, wzIs ZWind speed in the axial direction.

Seventhly, measuring a wind field around the aircraft to obtain a wind direction angle, wherein the wind direction angle comprises a wind direction azimuth angle and a wind direction elevation angle, and an included angle between the wind speed and the north direction is called the wind direction azimuth angleThe included angle between the wind speed and the horizontal plane is called wind direction elevation angle

Figure BDA0002546877930000035

Eighthly, using the three-axis acceleration [ a ] measured by the inertial measurement unit of the inertial navigation systemxayaz]TAnd angular rate [ pqr]TAs input to the system; selecting three-axis speed [ uv w ] of aircraft body]TRoll angle phi, pitch angle theta, yaw angle psi and triaxial wind speed wxwywz]TAs the state quantity, i.e., X ═ u v w Φ θ ψ wxwywz]TAnd establishing an unscented Kalman filter state equation: xk=f(Xk-1,uk-1)+Wk-1Wherein X iskAnd Xk-1State vectors at times k and k-1, W, respectivelyk-1Is the state noise vector, Wk-1Three-axis speed change rate of aircraft body

Figure BDA0002546877930000036

Rate of change of three-axis attitude angleAnd three axis wind speed rate of changeCausing; selecting the three-axis ground speed [ V ] measured by a satellite positioning systemxVyVz]TVacuum speed VaAngle of attack α and sideslip angle β are measured as quantities, i.e., Z ═ VxVyVzVaα β]TAnd establishing an unscented Kalman filter measurement equation Zk=h(Xk)+VkMeasuring the noise VkCaused by measurement noise of a satellite positioning system and an atmospheric data system; obtaining the current time t according to the first stepkThe system input quantity of the time is obtained according to the second step and the fifth stepkThe measurement information of the time is obtained according to the fourth step and the fifth stepkObtaining t by utilizing the unscented Kalman filter according to the state quantity information of the momentk+1And the optimal estimation value of the state quantity at the moment is obtained, so that the on-line measurement and real-time accurate estimation of the wind speed and the wind direction are realized.

And ninthly, performing unscented Kalman filtering:

8.1) selecting a filtering initial value:

wherein E refers to the mathematical expectation, X0For the initial value of the state vector,

Figure BDA00025468779300000311

is the mean of the initial values of the state vector, P0Covariance matrix as initial value of state vector

8.2) calculating the sigma sample point at the k-1 moment:

Figure BDA0002546877930000041

Figure BDA0002546877930000042

Figure BDA0002546877930000043

where n is the state dimension and λ is α2(n+κ)-n,α∈[10-4,1],κ=3-n;

8.3) determining the weight:

wherein the content of the first and second substances,and Wi (m)The weight of the ith sigma point state vector,

Figure BDA0002546877930000048

and Wi (c)The weight of the covariance matrix of the ith sigma point-like state vector is β, which is a state distribution parameter, β is 2;

8.4) calculating a one-step prediction model value at the k moment:

Figure BDA0002546877930000049

Figure BDA00025468779300000411

Figure BDA00025468779300000412

to predict the state vector, Pk/k-1To predict the covariance matrix of the state vector, Qk-1A noise matrix of a last state vector;

8.5) calculating one-step predicted sample point at time k:

Figure BDA00025468779300000413

Figure BDA00025468779300000415

8.6) measurement update:

Figure BDA0002546877930000053

wherein the content of the first and second substances,in order to predict the observation vector(s),

Figure BDA0002546877930000055

is a covariance matrix of the prediction vector and the observation vector,to predict covariance matrix of observations and state vectors, RkTo observe the noise matrix;

8.7) Filter update

Figure BDA0002546877930000057

Figure BDA0002546877930000059

Wherein, KkIn order to be a matrix of gains, the gain matrix,to estimate the state vector, PkIs a covariance matrix for estimating the state vector.

Tenth, in the unscented kalman filter, the roll angle phi, the pitch angle theta and the yaw angle psi of the state quantity are provided by an inertial navigation system, the three-axis speed of the body system is provided by a satellite positioning system, an external anemoscope provides a three-dimensional wind speed initial value, the three-dimensional wind speed change rate initial value is zero, the system initial state quantity is formed, and an initial state estimation error variance matrix P is formed0Initial value Q of system noise variance array0Measuring the noise variance matrix R0The initial values of the matrix are directly input from the outside of the system, and the noise matrix Q of the systemkInitial value Q of systematic noise variance array0Determining and measuring a noise matrix Rk+1By measuring the initial value R of the noise variance matrix0And (4) determining.

The tenth step, the last three items of the state quantity can be used to obtain tk+1And (5) taking the obtained three-dimensional wind speed to the seventh step to obtain the corresponding wind direction angle.

The invention has the advantages that: according to the invention, no additional airborne avionics equipment is required to be added, the structural appearance of the aircraft is not required to be changed, the real-time wind speed and wind direction around the aircraft are obtained by resolving by utilizing the output of the existing inertial navigation system, the existing satellite positioning system and the existing atmospheric data system, the large-area continuous wind measurement on the flight track can be realized, and the method has great significance for four-dimensional track flight and the accurate point arrival of the aircraft.

Drawings

FIG. 1 is a schematic block diagram of a method for measuring meteorological wind based on a combination of inertia/satellite/atmosphere;

FIG. 2 is a schematic diagram of a measurement method of a meteorological wind measurement method based on a combination of inertia/satellite/atmosphere;

FIG. 3 is a forward wind speed estimate and a true error plot from a combined inertial/satellite/atmospheric meteorological wind measurement method in one embodiment;

FIG. 4 is a plot of estimated right-hand wind speed and true error based on a combined inertial/satellite/atmospheric meteorological wind measurement method in one embodiment;

FIG. 5 is a graph of estimated values and true errors of the wind speed in the sky based on a combined inertial/satellite/atmospheric meteorological wind measurement method in one embodiment;

FIG. 6 is a wind direction azimuth plot of a combined inertial/satellite/atmospheric weather wind measurement method according to one embodiment;

FIG. 7 is a wind direction altitude and altitude graph obtained by a meteorological wind measurement method based on a combination of inertia/satellite/atmosphere in one embodiment.

Detailed Description

For a more clear explanation of the present application, the following description is further provided in conjunction with the embodiments and the accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. It is to be understood by persons of ordinary skill in the art that the following descriptions are intended to be illustrative, but not limiting, and are not intended to limit the scope of the present disclosure.

It is clear that the above examples are given solely for the purpose of illustrating the present invention in a clear and non limitative way, and that on the basis of the above description, other variants and modifications are possible for a person skilled in the art of the method, and that not all embodiments are exhaustive, and that all obvious variants and modifications are still within the scope of the invention, as they are introduced in the method variant of the present application.

In one embodiment, referring to fig. 1, the present invention utilizes the output parameters of the existing airborne inertial navigation system, satellite positioning system, and atmospheric data system to realize the on-line measurement of wind speed and direction at the current moment and the real-time accurate estimation of wind speed and direction at the next moment by designing the kalman filter.

In order to realize the on-line measurement and estimation of wind speed and wind direction, the following steps are required:

firstly, acquiring output information of an inertial navigation system, and reading three angular velocities, three attitude angles and three linear acceleration information output by the inertial navigation system at a period △ T, wherein the three angular velocities are [ p q r ]]TRoll angular velocity p, pitch angular velocity q and yaw angular velocity r in the X-axis, Y-axis and Z-axis directions under the machine system respectively; three attitude angles phi theta phi]TRespectively a roll angle phi, a pitch angle theta and a yaw angle psi; three linear accelerations [ a ]xayaz]TRespectively is the linear acceleration a of the body in the X-axis directionxLinear acceleration a in the Y-axis directionyAnd linear acceleration a in the Z-axis directionzAnd the directions of the X axis, the Y axis and the Z axis of the body coordinate system are forward, rightward and downward respectively.

Secondly, obtaining the output information of the satellite positioning system, and reading the triaxial ground speed [ V ] under the geographic coordinate system output by the airborne satellite positioning system according to the period delta TxVyVz]TIn which V isxFor the speed component, V, of the aircraft on the X-axis of the geographic coordinate systemyFor the speed component, V, of the aircraft in the Y-axis of the geographic coordinate systemzIs the speed component of the aircraft in a geographic coordinate system, wherein the X-axis, Y-axis and Z-axis of the geographic coordinate system are respectively oriented in the north direction, east direction and ground direction.

Thirdly, obtaining a state transition matrix of the system, wherein the state transition matrix is a state transition matrix from a geographic coordinate system to a body coordinate system, obtaining the state transition matrix through attitude angle information, the attitude angle information comprises a roll angle phi, a pitch angle theta and a yaw angle psi, and calculating the state transition matrix

Fourthly, the three-axis ground speed [ V ] under the geographic coordinate system can be realized through the state transition matrixxVyVz]TSwitching to a machine system:

[wxwywz]Tthree axis wind speeds.

And fifthly, acquiring output data of the airborne atmospheric data system, wherein the airborne vacuum speed is generally obtained by resolving pressure and temperature provided by a pressure sensor and a temperature sensor in the airborne atmospheric data system by combining a Bernoulli equation, and the calculation formula is as follows:

Figure BDA0002546877930000074

wherein, Δ P is dynamic pressure, ρ is air density, and K is a correction factor.

Sixthly, measuring the ground speed by using a satellite positioning system

Figure BDA0002546877930000075

Attitude angle measured by an inertial navigation system, attitude transition matrix obtained by resolving an attack angle α and a sideslip angle β provided by an atmospheric data system, and vacuum speed measured by the atmospheric data systemObtaining:

whereinwxIs the wind speed in the X-axis direction, wyIs the wind speed in the Y-axis direction, wzIs the wind speed in the Z-axis direction.

Seventhly, obtaining the three-axis wind speed from the sixth step and substituting the three-axis wind speed into the wind directionCornerWind direction high and low angle

Figure BDA0002546877930000083

And obtaining the wind direction angle of the corresponding point.

Eighthly, using the three-axis acceleration [ a ] measured by the inertial measurement unit of the inertial navigation systemxayaz]TAnd angular rate [ pqr]TAs input to the system; selecting three-axis speed [ uv w ] of aircraft body]TRoll angle phi, pitch angle theta, yaw angle psi and triaxial wind speed wxwywz]TAs the state quantity, i.e., X ═ u v w Φ θ ψ wxwywz]TAnd establishing an unscented Kalman filter state equation: xk=f(Xk-1,uk-1)+Wk-1Wherein X iskAnd Xk-1State vectors at times k and k-1, W, respectivelyk-1Is the state noise vector, Wk-1Three-axis speed change rate of aircraft body

Figure BDA0002546877930000084

Rate of change of three-axis attitude angleAnd three axis wind speed rate of change

Figure BDA0002546877930000086

Causing; selecting the three-axis ground speed [ V ] measured by a satellite positioning systemxVyVz]TVacuum speed VaAngle of attack α and sideslip angle β are measured as quantities, i.e., Z ═ VxVyVzVaα β]TAnd establishing an unscented Kalman filter measurement equation Zk=h(Xk)+VkMeasuring the noise VkCaused by measurement noise of a satellite positioning system and an atmospheric data system; obtaining the current time t according to the first stepkThe system input amount of the time is based on the secondStep five, obtaining the current time tkThe measurement information of the time is obtained according to the fourth step and the fifth stepkObtaining t by utilizing the unscented Kalman filter according to the state quantity information of the momentk+1And the optimal estimation value of the state quantity at the moment is obtained, so that the on-line measurement and real-time accurate estimation of the wind speed and the wind direction are realized.

And ninthly, performing unscented Kalman filtering:

8.1) selecting a filtering initial value:

Figure BDA0002546877930000087

wherein E refers to the mathematical expectation, X0For the initial value of the state vector,is the mean of the initial values of the state vector, P0Covariance matrix as initial value of state vector

8.2) calculating the sigma sample point at the k-1 moment:

Figure BDA00025468779300000811

where n is the state dimension and λ is α2(n+κ)-n,α∈[10-4,1],κ=3-n;

8.3) determining the weight:

Figure BDA0002546877930000094

wherein the content of the first and second substances,and Wi (m)The weight of the ith sigma point state vector,

Figure BDA0002546877930000096

and Wi (c)The weight of the covariance matrix of the ith sigma point-like state vector is β, which is a state distribution parameter, β is 2;

8.4) calculating a one-step prediction model value at the k moment:

Figure BDA0002546877930000097

Figure BDA0002546877930000098

Figure BDA0002546877930000099

Figure BDA00025468779300000910

to predict the state vector, Pk/k-1To predict the covariance matrix of the state vector, Qk-1A noise matrix of a last state vector;

8.5) calculating one-step predicted sample point at time k:

Figure BDA00025468779300000911

8.6) measurement update:

Figure BDA00025468779300000916

wherein the content of the first and second substances,in order to predict the observation vector(s),

Figure BDA0002546877930000103

is a covariance matrix of the prediction vector and the observation vector,

Figure BDA0002546877930000104

to predict covariance matrix of observations and state vectors, RkTo observe the noise matrix;

8.7) Filter update

Figure BDA0002546877930000106

Figure BDA0002546877930000107

Wherein, KkIn order to be a matrix of gains, the gain matrix,

Figure BDA0002546877930000108

to estimate the state vector, PkIs a covariance matrix for estimating the state vector.

Tenth, in the unscented kalman filter, the roll angle phi, the pitch angle theta and the yaw angle psi of the state quantity are provided by an inertial navigation system, the three-axis speed of the body system is provided by a satellite positioning system, an external anemoscope provides a three-dimensional wind speed initial value, the three-dimensional wind speed change rate initial value is zero, the system initial state quantity is formed, and an initial state estimation error variance matrix P is formed0Initial value Q of system noise variance array0Measuring the noise variance matrix R0The initial values of the matrix are directly input from the outside of the system, and the noise matrix Q of the systemkInitial value Q of systematic noise variance array0Determining and measuring a noise matrix Rk+1By measuring the initial value R of the noise variance matrix0And (4) determining.

The tenth step, the last three items of the state quantity can be used to obtain tk+1The three-dimensional wind speed at the moment is taken to the seventh step to obtain tk+1The wind direction angle corresponding to the moment.

Therefore, the online measurement of the wind speed and the wind direction around the aircraft body and the real-time accurate estimation of the wind speed and the wind direction are completed.

FIG. 1 is a basic principle block diagram of the method, and an unscented Kalman filter is used for resolving and obtaining real-time wind speed and wind direction around an aircraft body and a wind speed and wind direction estimated value at the next moment by utilizing the outputs of an airborne inertial navigation system, a satellite positioning system and an atmospheric data system. Solid arrows between the various modules represent the basic logical connections.

FIG. 2 is a further refinement of the principle in FIG. 1, which represents a specific flow of a meteorological wind measurement method based on a combination of inertia/satellite/atmosphere, and more clearly shows the data source, data transmission and wind speed and direction calculation of the system.

FIG. 3 is a graph of forward wind speed estimate and true error in seconds on the horizontal axis and in meters/second on the vertical axis for forward error in meters/second for wind speed estimate and true wind speed in the range of [ -0.4m/s,0.4m/s ] obtained in an embodiment of the method of the present invention.

FIG. 4 is a plot of the estimated and true values of the right wind speed in seconds on the horizontal axis and the error in meters/second on the right hand axis in the range of [ -0.5m/s,0.5m/s ] on the vertical axis for the estimated and true values of the wind speed obtained in an embodiment of the method of the present invention.

FIG. 5 is a graph of estimated and true values of the wind speed in the direction of the day in seconds on the horizontal axis and the error in the direction of the day in meters per second on the vertical axis for the estimated and true values of the wind speed in the range of [ -0.4m/s,0.4m/s ] in one embodiment of the method of the present invention.

FIG. 6 is a plot of wind direction azimuth angle in seconds on the horizontal axis and wind direction azimuth angle in degrees on the vertical axis for a range of [6, 16 ] obtained in one embodiment of the method of the present invention.

FIG. 7 is a graph of wind direction elevation angles obtained in an embodiment of the method of the present invention, with time in seconds on the horizontal axis and wind direction elevation angle values in degrees on the vertical axis, in the range of [17, 27 ].

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