Online real-time wind repair attack angle calculation method based on forecast wind field

Abstract

The invention discloses an online real-time wind repair attack angle calculation method based on a forecast wind field, and the method comprises the steps: obtaining real-time wind field information, including wind speed and wind direction, according to the flight height of an aircraft in a flight process, and obtaining the projection of a wind vector in a transmitting coordinate system through calculation; the speed of an aircraft body is obtained through navigation information on the aircraft, and the airspeed vector and the airspeed of a launching coordinate system are obtained based on the speed of the aircraft body and the projection of a wind vector on the launching coordinate system, so that a load attack angle and a sideslip angle are obtained. According to the method, a traditional wind field-based off-line attack angle calculation mode of the carrier rocket is converted into an on-line real-time calculation mode combined with navigation information in flight, and the method is an innovative and practical engineering design method with an obvious effect.

Description

Technical Field

[0001] The present invention relates to the field of aircraft control, and particularly to an online real-time wind correction angle of attack calculation method based on a predicted wind field. Background Art

[0002] In a launch mission of a launch vehicle, in order to reduce the wind angle of attack during flight, the traditional method is to adopt a pre-launch ballistic wind correction technology. Based on the predicted wind field obtained before launch, the wind correction ballistic program angle is calculated offline based on a standard ballistic, and then loaded onto the rocket for flight use. This offline calculation method increases the pre-launch design workload. At the same time, in terms of the calculation accuracy of the angle of attack, the offline method applies the rocket flight speed information of the standard ballistic, which is different from the speed information of the rocket's real-time flight navigation, and this will bring a certain deviation to the actual angle of attack calculation, resulting in a loss of calculation accuracy. Summary of the Invention

[0003] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, providing an online real-time wind correction angle of attack calculation method based on a predicted wind field, and solving the problem of how to calculate the wind correction angle of attack online in real time.

[0004] The technical solution of the present invention is: an online real-time wind correction angle of attack calculation method based on a predicted wind field, including:

[0005] During the flight process, according to the flight altitude of the aircraft, real-time wind field information including wind speed and wind direction is obtained, and the projection of the wind vector in the launch coordinate system is calculated;

[0006] The aircraft body speed is obtained through the navigation information on the aircraft. Based on the aircraft body speed and the projection of the wind vector in the launch coordinate system, the airspeed vector and airspeed magnitude in the launch coordinate system are obtained, thereby obtaining the payload angle of attack and sideslip angle.

[0007] Further, the projection of the wind vector in the launch coordinate system is:

[0008]

[0009] In the formula, G E is the conversion matrix from the geocentric coordinate system to the launch coordinate system, E T is the conversion matrix from the local horizontal coordinate system to the geocentric coordinate system, and are the wind speed and wind direction interpolated according to the flight altitude of the aircraft respectively;

[0010] The airspeed vector in the launch coordinate system is:

[0011]

[0012] In the formula, is the speed of the aircraft body obtained from the navigation information on the aircraft;

[0013] The magnitude of the airspeed is:

[0014]

[0015] Furthermore, the angle of attack and sideslip angle of the payload are calculated as follows:

[0016] Calculate the projection of the airspeed vector in the rocket body coordinate system:

[0017]

[0018] In the formula, B G is the transformation matrix from the launch coordinate system to the rocket body coordinate system;

[0019] Calculate the angle of attack α a and sideslip angle β a :

[0020]

[0021] Furthermore, the flight altitude is calculated as follows:

[0022] Calculate the magnitude r of the vector radius r from the aircraft position to the center of the earth:

[0023]

[0024] In the formula, is the projection of the vector radius r from the aircraft position to the center of the earth in the launch inertial system;

[0025] Calculate the geocentric latitude φ of the point under the rocket:

[0026]

[0027] ω ex 、ω ey 、ω ez are the projections of the earth's angular velocity ω e on the corresponding coordinate axes of the launch inertial coordinate system;

[0028] Calculate the magnitude R of the geocentric vector radius of the point under the rocket:

[0029]

[0030] e is the flattening of the earth, and a e is the average radius of the earth's equator;

[0031] Calculate the flight altitude H:

[0032] H = r - R.

[0033] The present invention also provides an online real-time wind correction angle calculation system based on a predicted wind field, including:

[0034] A first module, configured to obtain real-time wind field information including wind speed and wind direction according to the flight altitude of the aircraft during flight, and calculate the projection of the wind vector in the launch coordinate system;

[0035] A second module, configured to obtain the aircraft body speed through the navigation information on the aircraft, and based on the aircraft body speed and the projection of the wind vector in the launch coordinate system, obtain the airspeed vector and the airspeed magnitude in the launch coordinate system, so as to obtain the payload angle of attack and the sideslip angle.

[0036] Further, in the first module, the calculation method of the projection of the wind vector in the launch coordinate system is:

[0037]

[0038] In the formula, G E is the conversion matrix from the geocentric coordinate system to the launch coordinate system, E T is the conversion matrix from the local horizontal coordinate system to the geocentric coordinate system, and are the wind speed and wind direction interpolated according to the flight altitude of the aircraft respectively;

[0039] The calculation method of the airspeed vector in the launch coordinate system is:

[0040]

[0041] In the formula, is the aircraft body speed obtained through the navigation information on the aircraft;

[0042] The calculation method of the airspeed magnitude is:

[0043]

[0044] Further, in the second module, the calculation method of the payload angle of attack and the sideslip angle is:

[0045] Calculate the projection of the airspeed vector in the rocket body coordinate system:

[0046]

[0047] In the formula, B G is the conversion matrix from the launch coordinate system to the rocket body coordinate system;

[0048] Calculate the payload angle of attack α a , sideslip angle β a :

[0049]

[0050] Further, in the first module, the calculation method of the flight altitude is as follows:

[0051] Calculate the modulus r of the radius vector r from the position of the aircraft to the center of the earth:

[0052]

[0053] In the formula, The projection of the radius vector r from the position of the aircraft to the center of the earth in the launch inertial system;

[0054] Calculate the geocentric latitude φ of the point under the arrow:

[0055]

[0056] ω ex and ω ey and ω ez are the projections of the earth's angular velocity ω e on the corresponding coordinate axes of the launch inertial coordinate system; calculate the modulus R of the radius vector from the point under the arrow to the center of the earth:

[0057]

[0058] e is the flattening of the earth, and a e is the average radius of the earth's equator;

[0059] Calculate the flight altitude H:

[0060] H = r - R.

[0061] The present invention also provides a computer program product, and when the computer program product is executed by a processor, the steps of the method are implemented.

[0062] The present invention also provides a computing terminal, characterized in that: it is deployed on an aircraft and includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the method are implemented.

[0063] The advantages of the present invention compared with the prior art are as follows:

[0064] The present invention binds the measured wind field of "flight altitude - wind speed - wind direction" of the rocket launch window to the flight software of the aircraft. During flight, real-time wind field information is obtained based on the flight altitude, and the projection of the wind vector in the launch coordinate system is calculated; the body velocity is obtained through the on-board navigation information, and the airspeed vector and airspeed magnitude in the launch coordinate system considering actual disturbances and deviations are obtained, so as to obtain the angle of attack and sideslip angle of the payload, providing support for directly controlling the angle of attack in the aerodynamic load sensitive area. The present invention converts the traditional off-line calculation mode of the angle of attack based on the wind field of the launch vehicle into an on-line real-time calculation mode combining navigation information during flight, which is an innovative, practical and effective engineering design method. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a flowchart in an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0066] In order to better understand the technical solution of the present invention, the specific embodiments of the present invention will be specifically described below in conjunction with the drawings.

[0067] The first step: Calculate the transformation matrix B from the launch coordinate system to the body coordinate system G , the transformation matrix G from the launch inertial coordinate system to the launch coordinate system A , the transformation matrix B from the launch inertial coordinate system to the body coordinate system A ;

[0068] The transformation matrix B from the launch coordinate system to the body coordinate system G

[0069]

[0070] Among them, are the pitch, yaw, and roll attitude angles of the launch system, and the relationship with the attitude angles of the launch inertial system is as follows

[0071]

[0072] Among them, A 0 is the launch azimuth angle; B 0 is the geographical latitude of the launch point; ω e = 7.292115×10 -5 rad / s is the magnitude of the earth's angular velocity of rotation; t is the flight time (takeoff is 0s).

[0073] The transformation matrix G from the launch inertial coordinate system to the launch coordinate system A

[0074] G A = A T BA,

[0075] Among them,

[0076] The transformation matrix B from the launch inertial coordinate system to the rocket body coordinate system A

[0077]

[0078] Step 2: Calculate the projection of the geocentric radius vector r of the vehicle position in the launch inertial system The steps are as follows:

[0079] (a) Calculate the geocentric latitude φ of the launch point 0 :

[0080]

[0081] Among them, y tmp = x tmp (1 - e) 2 tanB 0 ; a e = 6378140m is the average radius of the Earth's equator; e = 1 / 298.257 is the flattening of the Earth; H 0 is the elevation of the launch point, B 0 is the geodetic latitude of the launch point.

[0082] (b) Calculate the modulus R of the geocentric vector of the launch point 0 :

[0083]

[0084] (c) Calculate the projection of the geocentric vector R of the launch point on the launch inertial coordinate system (R 0 , R 0x , R 0y , R 0z ) T :

[0085]

[0086] Among them, μ 0 = B 0 - φ 0 is the difference between the geodetic latitude and the geocentric latitude of the launch point.

[0087] (d) Calculate the projection of the radius vector r between the vehicle position and the geocenter in the launch inertial system

[0088]

[0089] Among them, (X a , Y a , Z a )T is the position of the aircraft in the launch inertial system.

[0090] Step 3: Calculate the flight altitude H:

[0091] (a) Calculate the modulus r of the radius vector r from the position of the aircraft to the center of the earth:

[0092]

[0093] (b) Calculate the geocentric latitude φ of the subsatellite point:

[0094]

[0095] (c) Calculate the modulus R of the geocentric radius vector of the subsatellite point:

[0096]

[0097] (d) Calculate the flight altitude H:

[0098] H = r - R.

[0099] Step 4: Calculate the transformation matrix G from the geocentric coordinate system E to the launch coordinate system G E , and the transformation matrix E from the local horizontal coordinate system T to the geocentric coordinate system E T , the specific steps include:

[0100] (a) Calculate the transformation matrix G from the geocentric coordinate system E to the launch coordinate system G E :

[0101]

[0102] (b) Projection of the radius vector r from the position of the aircraft to the center of the earth in the geocentric coordinate system E

[0103]

[0104] (c) Calculate the geodetic longitude λ of the subsatellite point

[0105]

[0106] (d) Calculate the transformation matrix E from the local horizontal coordinate system T to the geocentric coordinate system E T

[0107]

[0108] Step 5: Calculate the airspeed vector in the launch system and the airspeed magnitude V aero ;

[0109] Calculate the projection of the wind vector in the launch coordinate system:

[0110]

[0111] Among them, and are the wind speed and wind direction interpolated by height.

[0112] The airspeed vector in the launch coordinate system is

[0113]

[0114] The magnitude of the airspeed is

[0115]

[0116] Step 6: Calculate the load angle of attack α a , sideslip angle β a , and the specific steps are as follows:

[0117] (a) Calculate the projection of the airspeed vector in the rocket body system

[0118]

[0119] (b) Calculate the load angle of attack α a , sideslip angle β a

[0120]

[0121] It can be understood that the present invention is described by way of examples. Those skilled in the art know that without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and examples. Additionally, under the teaching of the present invention, these features and examples can be modified to adapt to specific situations without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific examples disclosed herein, and embodiments that can fall within the scope of the claims of this application all belong to the scope protected by the present invention.

[0122] The content not detailedly described in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. An online real-time wind correction angle of attack calculation method based on forecast wind field, characterized in that: include: During the flight, the real-time wind field information, including wind speed and wind direction, is obtained according to the flight altitude of the aircraft, and the projection of the wind vector in the launch coordinate system is calculated; The aircraft body speed is obtained through the navigation information on the aircraft. Based on the projection of the aircraft body speed and wind vector on the launch coordinate system, the launch coordinate system airspeed vector and airspeed magnitude are obtained, thereby obtaining the load angle of attack and sideslip angle.

2. The online real-time wind correction angle of attack calculation method based on the forecast wind field according to claim 1 is characterized by: The projection of the wind vector in the launch coordinate system is: In the formula, G E is the transformation matrix from the geocentric coordinate system to the launch coordinate system, E T is the transformation matrix from the local horizontal coordinate system to the geocentric coordinate system, and They are the wind speed and wind direction interpolated according to the flight altitude of the aircraft; The launch coordinate system airspeed vector is: In the formula, is the speed of the aircraft body obtained through the navigation information on the aircraft; The airspeed is:

3. The online real-time wind correction angle of attack calculation method based on the forecast wind field according to claim 2 is characterized in that: The load attack angle and sideslip angle are calculated as follows: Calculate the projection of the airspeed vector on the arrow system: In the formula, B G is the transformation matrix from the launch coordinate system to the rocket body coordinate system; Calculate the load attack angle α a , sideslip angle β a :

4. The online real-time wind correction angle of attack calculation method based on the forecast wind field according to claim 1 is characterized in that: The flight altitude is calculated as follows: Calculate the modulus r of the radius vector r between the aircraft position and the center of the earth: In the formula, The projection of the earth's center vector r at the aircraft position in the launch inertial system; Calculate the geocentric latitude φ of the point under the arrow: ω ex ,ω ey ,ω ez is the Earth's rotation angular velocity ω e Projection on the corresponding coordinate axes of the launch inertial coordinate system; Calculate the modulus R of the earth's center of gravity at the point under the arrow: e is the Earth's flattening, a e is the mean radius of the Earth at the equator; Calculate the flight altitude H: H=rR.

5. An online real-time wind correction angle of attack calculation system based on wind field forecast, characterized in that: include: The first module is used to obtain real-time wind field information, including wind speed and wind direction, according to the flight altitude of the aircraft during flight, and calculate the projection of the wind vector in the launch coordinate system; The second module is used to obtain the aircraft body speed through the navigation information on the aircraft, and obtain the launch coordinate system airspeed vector and airspeed magnitude based on the projection of the aircraft body speed and wind vector in the launch coordinate system, thereby obtaining the load attack angle and sideslip angle.

6. The online real-time wind correction angle of attack calculation method based on the forecast wind field according to claim 5 is characterized by: In the first module, the projection of the wind vector in the launch coordinate system is calculated as follows: In the formula, G E is the transformation matrix from the geocentric coordinate system to the launch coordinate system, E T is the transformation matrix from the local horizontal coordinate system to the geocentric coordinate system, and They are the wind speed and wind direction interpolated according to the flight altitude of the aircraft; The airspeed vector of the launch coordinate system is calculated as: In the formula, is the speed of the aircraft body obtained through the navigation information on the aircraft; The airspeed is calculated as:

7. The online real-time wind correction angle of attack calculation method based on the forecast wind field according to claim 5 is characterized in that: In the second module, the load attack angle and sideslip angle are calculated as follows: Calculate the projection of the airspeed vector on the arrow system: In the formula, B G is the transformation matrix from the launch coordinate system to the rocket body coordinate system; Calculate the load attack angle α a , sideslip angle β a :

8. The online real-time wind correction angle of attack calculation method based on the forecast wind field according to claim 5 is characterized by: In the first module, the flight altitude is calculated as follows: Calculate the modulus r of the radius vector r between the aircraft position and the center of the earth: In the formula, The projection of the earth's center vector r at the aircraft position in the launch inertial system; Calculate the geocentric latitude φ of the point under the arrow: ω ex ,ω ey ,ω ez is the Earth's rotation angular velocity ω e Projection on the corresponding coordinate axes of the launch inertial coordinate system; Calculate the modulus R of the earth's center of gravity at the point under the arrow: e is the Earth's flattening, a e is the mean radius of the Earth at the equator; Calculate the flight altitude H: H=rR.

9. A computer program product, characterized in that: When the computer program product is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

10. A computing terminal, characterized in that: The method is deployed on an aircraft and includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

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