Rapid alignment and air correction method during emergency launching

Abstract

The invention discloses a rapid alignment and air correction method during emergency launch, which comprises the following steps: in a ground analysis coarse alignment stage, a strapdown inertial navigation system performs analysis coarse alignment according to bound launch position coordinates and flight target coordinates; determining an initial horizontal attitude angle and an initial azimuth angle and calculating an initial attitude matrix for inertial navigation; in the air correction stage, the strapdown inertial navigation system carries out inertial navigation calculation; when the aircraft is in the rising section of the flight route and the satellite navigation information is valid, performing coarse correction on the strapdown inertial navigation system according to the satellite navigation information, performing fine alignment for a period of time through a Kalman filter, and correcting the attitude matrix by utilizing a fine alignment result, so as to realize integrated navigation; and in the precision verification and secondary correction stage, the aircraft verifies the precision of the inertial system in the flight process, and if the precision does not meet the requirement, secondary correction is performed on the strapdown inertial navigation system.

Description

Technical Field

[0001] The invention relates to the field of strapdown inertial navigation technology, and in particular to a rapid alignment and air correction method during emergency launch, which is suitable for rapid alignment of strapdown inertial navigation systems carried by various rocket-propelled aircraft before launch. Background Art

[0002] At present, the use of strapdown inertial navigation systems to perform attitude control and course correction on rocket-propelled aircraft can effectively increase their range and significantly improve their landing accuracy, becoming the main trend in the development of rocket-propelled aircraft.

[0003] The strapdown inertial navigation system needs to be initially aligned when working: determine the attitude matrix at the initial moment so that the mathematical platform coordinate system and the navigation coordinate system coincide. Initial alignment can be divided into coarse alignment and fine alignment according to the stage; it can be divided into static base alignment and dynamic base alignment according to the motion state of the base; it can be divided into autonomous alignment and non-autonomous alignment according to the degree of dependence on external information; the accuracy and time of initial alignment are the two most important technical indicators.

[0004] The strapdown inertial navigation system on rocket-propelled aircraft usually adopts a static base alignment scheme. The alignment process is coarse alignment first, and then fine alignment using Kalman filtering. The alignment time usually takes more than 150 seconds. As the launch reaction time requirements become shorter and shorter, the initial alignment time may only be a few seconds in emergency launch situations. The traditional strapdown inertial navigation initial alignment scheme cannot meet the system requirements; and due to the short preparation time, it cannot even provide accurate azimuth information for the inertial navigation system. Summary of the invention

[0005] The purpose of the present invention is to provide a rapid alignment and air correction method for emergency launch, so as to overcome the problems of the existing alignment method that the alignment time is long and it is difficult to meet the emergency launch requirements.

[0006] In order to achieve the above tasks, the present invention adopts the following technical solutions:

[0007] A method for rapid alignment and air correction during emergency launch, comprising:

[0008] In the ground analytical coarse alignment stage, the strapdown inertial navigation system performs analytical coarse alignment based on the bound launch position coordinates and flight target coordinates, determines the initial horizontal attitude angle and initial azimuth angle, and calculates the initial attitude matrix for inertial navigation;

[0009] In the air correction stage, the strapdown inertial navigation system performs inertial navigation solution; when the aircraft is in the ascending stage of the route and the satellite navigation information is valid, the strapdown inertial navigation system is roughly corrected according to the satellite navigation information and finely aligned for a period of time through the Kalman filter, and the attitude matrix is ​​corrected using the fine alignment result, thereby realizing integrated navigation;

[0010] During the accuracy verification and secondary correction stage, the aircraft verifies the accuracy of the strapdown inertial navigation system during flight. If the accuracy does not meet the requirements, the strapdown inertial navigation system will be corrected for the second time.

[0011] Further, the strapdown inertial navigation system performs analytical coarse alignment according to the bound launch position coordinates and flight target coordinates, determines the initial horizontal attitude angle and the initial azimuth angle, and calculates the initial attitude matrix for inertial navigation, including:

[0012] Binding the launch position coordinates and the flight target coordinates to the strapdown inertial navigation system, wherein the launch position coordinates and the flight target coordinates both include longitude and latitude;

[0013] Collecting the outputs of the accelerometer in three directions within a first preset time and taking the averages thereof to obtain output components in the three directions, and determining the initial horizontal attitude angle, including the initial pitch angle and the initial roll angle, by using the relationship between the output components in the three directions;

[0014] Determine the initial azimuth using the launch position coordinates and the longitude and latitude of the flight target coordinates;

[0015] The initial attitude matrix is ​​determined based on an initial azimuth angle, an initial pitch angle, and an initial roll angle.

[0016] Further, the strapdown inertial navigation system performs inertial navigation solution, including updating of attitude matrix;

[0017] The quaternion method is used to update the attitude matrix. First, the equivalent angular increments in the three directions are determined based on the angular increments in the three directions within the navigation cycle output by the gyroscope. Then, the attitude quaternion is updated and normalized using the equivalent angular increments, and the attitude matrix is ​​updated using the normalized quaternion.

[0018] Further, the strapdown inertial navigation system performs inertial navigation solution, including updating of three-dimensional velocity and three-dimensional position;

[0019] When updating the three-dimensional velocity, the velocity increment of the strapdown inertial navigation system in the navigation coordinate system within a navigation cycle is calculated using the projection of the acceleration vector output by the accelerometer in the navigation coordinate system, the velocity of the strapdown inertial navigation system at the previous moment, and the projection of the gravity acceleration vector in the navigation coordinate system; based on the velocity increment and the velocity of the strapdown inertial navigation system at the previous moment, the three-dimensional velocity of the strapdown inertial navigation system at the current moment is determined;

[0020] When updating the three-dimensional position, the latitude, longitude and altitude of the strapdown inertial navigation system at the previous moment are used, combined with the speed of the strapdown inertial navigation system at the current moment and the previous moment in the navigation coordinate system, to calculate the longitude, latitude and altitude at the current moment, thereby obtaining the three-dimensional position.

[0021] Further, the rough correction of the strapdown inertial navigation system according to the satellite navigation information includes:

[0022] When the satellite navigation information is valid, the three-dimensional speed and three-dimensional position in the east, north and celestial directions in the navigation coordinate system provided in the satellite navigation information are used to directly assign and correct the three-dimensional speed and three-dimensional position of the strapdown inertial navigation system when performing inertial navigation solution; at the same time, the three-dimensional speed is used to calculate the track angle of the aircraft, and the track angle assignment is used to correct the initial azimuth, thereby making a rough correction to the inertial navigation.

[0023] Further, the precise alignment for a period of time by using a Kalman filter includes:

[0024] According to the error equation of strapdown inertial navigation system, the state equation and measurement equation of the precise alignment process are established;

[0025] A recursive equation of a discrete Kalman filter is constructed, and an iterative Kalman filter operation is performed through the recursive equation until the operation reaches a specified second preset time, thereby obtaining three misalignment angle estimates in the east, north and celestial directions after precise alignment.

[0026] Furthermore, the state equation and measurement equation of the precise alignment process are expressed as:

[0027] ;

[0028] ;

[0029] The dot above the parameter indicates the first-order derivative of the parameter. is the state variable, is the measured variable, is the state transfer matrix, and are system noise and measurement noise respectively; is the measurement matrix, It is a noise driven array;

[0030] ;

[0031] ;

[0032] in, Represents the three misalignment angle estimates of the east, north and sky directions, It indicates the velocity error in the east, north and sky directions in the navigation coordinate system. Indicates the longitude error, latitude error and altitude error, is the gyro constant drift error in the x, y, and z directions in the airborne coordinate system, is the constant zero bias error of the accelerometer in the x, y, and z directions in the airborne coordinate system.

[0033] Further, the method of using the precise alignment result to correct the attitude matrix to achieve integrated navigation includes:

[0034] The skew-symmetric matrix is ​​constructed using the three misalignment angle estimates of the east, north and sky directions after precise alignment.

[0035] The current attitude matrix is ​​corrected by using the skew-symmetric matrix and the unit matrix to obtain a corrected attitude matrix, and the corrected attitude matrix is ​​used for inertial navigation, thereby performing combined navigation of Kalman filtering and inertial navigation.

[0036] A terminal device comprises a processor, a memory and a computer program stored in the memory; when the processor executes the computer program, the method for rapid alignment and air correction during emergency launch is implemented.

[0037] A computer-readable storage medium stores a computer program; when the computer program is executed by a processor, the method for rapid alignment and air correction during emergency launch is implemented.

[0038] Compared with the prior art, the present invention has the following technical features:

[0039] 1. Aiming at the limitation that the alignment time is only a few seconds in the case of emergency launch of rocket-propelled aircraft, the present invention adopts an analytical coarse alignment method to obtain relatively accurate initial pitch angle, initial roll angle and rough initial azimuth; provides the onboard computer with the information required for attitude control of the rocket-propelled aircraft when the satellite navigation positioning information is missing in the active flight phase; after the satellite positioning information is valid, the azimuth, speed and position information of the inertial navigation system are corrected through rough correction and fine alignment in the air and according to the fine alignment result to improve the accuracy of the inertial navigation system, and the maneuverability of the rocket-propelled aircraft is improved; in the latter part of the flight, the accuracy of the strapdown inertial navigation system is verified, and secondary correction is performed as needed. The present invention provides a complete alignment scheme under emergency launch conditions, which overcomes the shortcomings of traditional initial alignment: transmission alignment requires main inertial navigation information and a certain period of maneuvering; self-alignment requires high-precision inertial devices and a longer alignment time.

[0040] 2. The present invention utilizes the maneuvers of the rocket-propelled aircraft during air route correction to perform aerial alignment, thereby improving the observability of the azimuth misalignment angle and achieving higher alignment accuracy without requiring the rocket-propelled aircraft to perform additional special maneuvers to lose energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of a method in one embodiment of the present invention;

[0042] Figure 2 A working principle diagram of inertial navigation solution in one embodiment of the present invention;

[0043] Figure 3 is a misalignment angle estimation curve in one embodiment of the present invention. DETAILED DESCRIPTION

[0044] The present invention provides a method for rapid alignment and air correction during emergency launch, see Figure 1 , including the ground analysis and rough alignment stage, the air correction stage, the accuracy verification and the secondary correction stage;

[0045] In the ground analytical coarse alignment stage, the strapdown inertial navigation system performs analytical coarse alignment based on the bound launch position coordinates and flight target coordinates, determines the initial horizontal attitude angle and initial azimuth angle, and calculates the initial attitude matrix for inertial navigation;

[0046] In the air correction stage, the strapdown inertial navigation system performs inertial navigation solution; when the aircraft is in the ascending stage of the route and the satellite navigation information is valid, the strapdown inertial navigation system is roughly corrected according to the satellite navigation information and finely aligned for a period of time through the Kalman filter, and the attitude matrix is ​​corrected using the fine alignment result, thereby realizing integrated navigation;

[0047] During the accuracy verification and secondary correction stage, the aircraft verifies the accuracy of the strapdown inertial navigation system during flight. If the accuracy does not meet the requirements, the strapdown inertial navigation system will be corrected for the second time.

[0048] The specific implementation process of the present invention is further described in detail below with reference to the accompanying drawings.

[0049] 1. Ground analysis and coarse alignment stage.

[0050] Step 1: The strapdown inertial navigation system on the aircraft is in a stationary state and is ready for power-on.

[0051] Step 2: Bind the launch position coordinates (longitude) to the strapdown inertial navigation system ,latitude and height ) and flight target coordinates (longitude ,latitude and height ).

[0052] Step 3: Strapdown Inertial Navigation System performs analytical coarse alignment: collect the first preset time The output of the accelerometer in the x, y, and z directions is obtained by taking the average value , Substituting into the following formula, the initial horizontal attitude angle, including the initial pitch angle and the initial roll angle for:

[0053] ;

[0054] ;

[0055] Initial azimuth It can be calculated from the launch position coordinates and the flight target coordinates by the following formula, or it can be roughly measured by geomagnetic or other sensors:

[0056] ;

[0057] Then the initial azimuth , initial pitch angle and the initial roll angle Substitute the azimuth parameter into the following formula , Pitch angle parameters , roll angle parameters The initial posture matrix can be calculated :

[0058] ;

[0059] in, It represents the onboard coordinate system of the aircraft, taking the right front upper coordinate system, and the origin of the coordinate is located at the center of mass of the strapdown inertial navigation system; n is the navigation coordinate system, taking the northeast celestial coordinate system ENU, and the origin of the coordinate is located at the center of mass of the strapdown inertial navigation system; It is the attitude matrix between the airborne coordinate system and the navigation coordinate system, and is the variable to be determined for the strapdown inertial navigation system alignment; the initial attitude matrix is ​​used for update iterations in subsequent inertial navigation processes.

[0060] 2. Air correction phase.

[0061] Step 4, the strapdown inertial navigation system performs inertial navigation solution; during the launch of the aircraft, the initial attitude matrix is ​​updated, and the three-axis angular velocity, three-axis acceleration, initial horizontal attitude angle, initial azimuth, three-dimensional velocity, three-dimensional position and other information required for inertial navigation are sent to the aircraft's onboard computer to maintain the aircraft's attitude stable after the launch.

[0062] Among them, in the initial horizontal attitude angle, the initial pitch angle and the initial roll angle are directly calculated from the output of the accelerometer, so they are relatively accurate; while the initial azimuth angle has a large error, so it is a rough alignment stage; the three-dimensional velocity and three-dimensional position are given by the solution of inertial navigation, and the solution process of the inertial navigation is as follows:

[0063] Step 4.1, use the classic quaternion method to update the attitude matrix.

[0064] a) Calculation of equivalent angular increment.

[0065] ;

[0066] In the formula, It is the navigation solution cycle; , , It is the equivalent angular increment in the x, y and z directions during the navigation solution cycle; , , They are the angular increments in the x, y, and z directions within the navigation cycle output by the gyroscope, obtained by integrating the angular velocity; is the latitude of the location of the strapdown inertial navigation system; , are the north speed and east speed in the navigation coordinate system; is the height of the strapdown inertial navigation system; is the Earth's rotation angular rate; and They are the radii of the Earth's meridian and meridian respectively.

[0067] b) Update the attitude quaternion using the equivalent angle increment and normalize it.

[0068] ;

[0069] ;

[0070] ;

[0071] ;

[0072] In the formula, are the attitude quaternions of the strapdown inertial navigation system at time k and time k+1 respectively; and are the components of the attitude quaternion before and after normalization respectively; is the equivalent angular increment , , Model; The equivalent angular increment , , Constructed matrix; for The identity matrix of .

[0073] c) Update of the attitude matrix.

[0074] ;

[0075] ;

[0076] In the formula, , , , They are the attitude quaternions at time k+1 respectively The four components of is the attitude matrix.

[0077] Step 4.2, update of three-dimensional velocity.

[0078] ;

[0079] ;

[0080] In the formula, For a navigation cycle Velocity increment of the strapdown inertial navigation system in the navigation coordinate system; It is the projection of the acceleration vector output by the accelerometer in the navigation coordinate system; is the projection of the earth's rotation angular rate in the navigation coordinate system; is the angular rate of rotation of the navigation coordinate system caused by the motion of the aircraft; is the speed of the strapdown inertial navigation system at time k-1; is the projection of the gravity acceleration vector in the navigation coordinate system; is the speed of the strapdown inertial navigation system at the current time k, which is decomposed into the navigation coordinate system to obtain its three-dimensional speed in three directions.

[0081] Step 4.3, update of three-dimensional position.

[0082] ;

[0083] ;

[0084] ;

[0085] In the formula, , are the latitudes of the strapdown inertial navigation system at the current time k and time k-1 respectively; , are the longitudes of the strapdown inertial navigation system at the current time k and time k-1 respectively; , are the altitudes of the strapdown inertial navigation system at the current time k and time k-1 respectively; It is the navigation solution cycle; , , are the north, east and celestial velocities of the strapdown inertial navigation system at the current time k in the navigation coordinate system; , , are the north, east and celestial velocities of the strapdown inertial navigation system at time k-1 in the navigation coordinate system, , They represent the meridian radius and the meridian radius respectively.

[0086] The schematic diagram of inertial navigation solution is as attached. Figure 2 shown.

[0087] Step 5, rough correction in the air: When the aircraft is in the ascending stage after launch, the satellite receiver continues to locate the aircraft. When the satellite navigation information is valid, the three-dimensional speed in the east, north and sky directions in the navigation coordinate system provided in the satellite navigation information is used. , , and three-dimensional position (longitude ,latitude and height ), directly assign values ​​to correct the three-dimensional velocity and three-dimensional position of the strapdown inertial navigation system during inertial navigation calculation; at the same time, use and Calculate the flight path angle of the aircraft , and using the track angle Assign a value to correct the initial azimuth, thereby making a rough correction to the inertial navigation.

[0088] .

[0089] Step 6: Use Kalman filter to perform a second preset time The precise alignment within 10000mA is performed, and the estimated misalignment angles in the east, north and sky directions are obtained. It is worth noting that: in order to improve the observability of the misalignment angle, the aircraft needs to maneuver for a certain period of time. At this time, due to the large error in the previous orientation, there is a certain error between the aircraft's flight route and the theoretical route, and the aircraft needs to perform appropriate maneuvers to correct the flight route.

[0090] Step 6.1, based on the error equation of the strapdown inertial navigation system, establish the state equation and measurement equation of the precise alignment process:

[0091] ;

[0092] ;

[0093] The dot above the parameter indicates the first-order derivative of the parameter. is the state variable, is the measured variable, is the state transfer matrix, and are system noise and measurement noise respectively; is the measurement matrix, The noise driven array.

[0094] ;

[0095] in, Represents the three misalignment angle estimates of the east, north and sky directions, It indicates the velocity error in the east, north and sky directions in the navigation coordinate system. Indicates the longitude error, latitude error and altitude error, is the gyro constant drift error in the x, y, and z directions in the airborne coordinate system, is the constant zero bias error of the accelerometer in the x, y, and z directions in the airborne coordinate system.

[0096] ;

[0097] in, , , It indicates the three-dimensional speed in the east, north and sky directions in the navigation coordinate system provided by the satellite navigation information. , , Represents the longitude, latitude and altitude provided in satellite navigation information. , , is the three-dimensional velocity in the east, north and sky directions calculated by the strapdown inertial navigation system. , , The longitude, latitude and altitude calculated by the strapdown inertial navigation system.

[0098] for dimensional state transfer matrix, which can be written as:

[0099] ;

[0100] in, express The zero matrix of is the attitude matrix.

[0101] ;

[0102] In the formula, , are the projection components of the earth's rotation angular velocity vector in the celestial direction and the northern direction respectively; is the radius of the Earth; is the latitude of the location of the strapdown inertial navigation system; , is the projection component of the three-axis specific force of the accelerometer in the east, north and sky directions; is the attitude matrix.

[0103] Step 6.2, construct the recursive equation of the discrete Kalman filter, and perform iterative Kalman filter operation through the recursive equation until the operation reaches the specified second preset time , and obtain the three misalignment angle estimates after precise alignment .

[0104] Step 7: In-flight fine-tuning: Using the estimated misalignment angle Attitude matrix of strapdown inertial navigation system Correction is made and the corrected attitude matrix is ​​used for inertial navigation, thereby performing combined navigation of Kalman filtering and inertial navigation.

[0105] Pose Matrix The correction method is:

[0106] ;

[0107] ;

[0108] in, To use the misalignment angle estimate Constructed skew-symmetric matrix; is the corrected attitude matrix; is the identity matrix; is the current posture matrix.

[0109] It should be noted that, in this stage, the process of correcting the three-dimensional velocity and three-dimensional position during inertial navigation using the three-dimensional velocity and three-dimensional position information in the navigation coordinate system provided in the satellite navigation information in step 5 is continuously executed.

[0110] 3. Second correction stage of accuracy verification.

[0111] Step 8, after the strapdown inertial navigation system has been fine-tuned in the air, the Kalman filter is reset and the integrated navigation solution is performed; during the integrated navigation process, the accuracy of the strapdown inertial navigation system is verified. If the accuracy does not meet the requirements, the strapdown inertial navigation system can be corrected twice according to the methods of steps 6 and 7 to improve the accuracy.

[0112] In order to verify the effect of the present invention, the following simulation test is carried out:

[0113] 1) Take a low-to-medium precision strapdown inertial navigation system, whose gyroscope bias is 0.5° / h and accelerometer bias is 0.2mg.

[0114] 2) After power-on, static alignment is performed for 3 seconds before switching to inertial navigation; after rough correction in the air, the initial azimuth error is about 2°, and the initial pitch angle and initial roll angle errors are about 0.1°.

[0115] 3) During the flight, from 5s to 15s, the aircraft has accelerations of 0.3g and 0.25g in the horizontal direction, and flies in a straight line at a constant speed during the rest of the time; the precise alignment time is 60s, and the alignment results are as follows: Figure 3 shown.

[0116] from Figure 3 It can be seen that the misalignment angles in the east, north and celestial directions converge quickly. The estimated errors in the east and north directions are about 0.01°, and the estimated error in the celestial direction misalignment angle is about 0.03°. The estimation effect is good.

[0117] It is worth noting that the convergence speed of the directional misalignment angle is greatly affected by the horizontal acceleration. Therefore, in practical applications, the precise alignment time and horizontal acceleration should be reasonably arranged according to the maneuverability of the aircraft and the flight time to achieve an ideal estimation effect.

[0118] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for rapid alignment and air correction during emergency launch, characterized in that: include: In the ground analytical coarse alignment stage, the strapdown inertial navigation system performs analytical coarse alignment based on the bound launch position coordinates and flight target coordinates, determines the initial horizontal attitude angle and initial azimuth angle, and calculates the initial attitude matrix for inertial navigation; During the air correction phase, the strapdown inertial navigation system performs inertial navigation solutions; When the aircraft is in the ascending phase of the route and the satellite navigation information is valid, the strapdown inertial navigation system is roughly corrected according to the satellite navigation information and finely aligned for a period of time through the Kalman filter, and the attitude matrix is ​​corrected using the fine alignment result, thereby realizing integrated navigation; During the accuracy verification and secondary correction stage, the aircraft verifies the accuracy of the strapdown inertial navigation system during flight. If the accuracy does not meet the requirements, the strapdown inertial navigation system will be corrected for the second time.

2. The method for rapid alignment and air correction during emergency launch according to claim 1, characterized in that: The strapdown inertial navigation system performs analytical coarse alignment according to the bound launch position coordinates and flight target coordinates, determines the initial horizontal attitude angle and the initial azimuth angle, and calculates the initial attitude matrix for inertial navigation, including: Binding the launch position coordinates and the flight target coordinates to the strapdown inertial navigation system, wherein the launch position coordinates and the flight target coordinates both include longitude and latitude; Collecting the outputs of the accelerometer in three directions within a first preset time and taking the averages thereof to obtain output components in the three directions, and determining the initial horizontal attitude angle, including the initial pitch angle and the initial roll angle, by using the relationship between the output components in the three directions; Determine the initial azimuth using the launch position coordinates and the longitude and latitude of the flight target coordinates; The initial attitude matrix is ​​determined based on an initial azimuth angle, an initial pitch angle, and an initial roll angle.

3. The method for rapid alignment and air correction during emergency launch according to claim 1, characterized in that: The strapdown inertial navigation system performs inertial navigation solution, including updating of attitude matrix; The quaternion method is used to update the attitude matrix. First, the equivalent angular increments in the three directions are determined based on the angular increments in the three directions within the navigation cycle output by the gyroscope. Then, the attitude quaternion is updated and normalized using the equivalent angular increments, and the attitude matrix is ​​updated using the normalized quaternion.

4. The method for rapid alignment and air correction during emergency launch according to claim 1, characterized in that: The strapdown inertial navigation system performs inertial navigation solution, including updating of three-dimensional velocity and three-dimensional position; When updating the three-dimensional velocity, the velocity increment of the strapdown inertial navigation system in the navigation coordinate system within one navigation cycle is calculated by using the projection of the acceleration vector output by the accelerometer in the navigation coordinate system, the velocity of the strapdown inertial navigation system at the previous moment, and the projection of the gravity acceleration vector in the navigation coordinate system; Determine the three-dimensional speed of the strapdown inertial navigation system at the current moment based on the speed increment and the speed of the strapdown inertial navigation system at the previous moment; When updating the three-dimensional position, the latitude, longitude and altitude of the strapdown inertial navigation system at the previous moment are used, combined with the speed of the strapdown inertial navigation system at the current moment and the previous moment in the navigation coordinate system, to calculate the longitude, latitude and altitude at the current moment, thereby obtaining the three-dimensional position.

5. The method for rapid alignment and air correction during emergency launch according to claim 1, characterized in that: The method of roughly correcting the strapdown inertial navigation system according to the satellite navigation information comprises: When the satellite navigation information is valid, the three-dimensional speed and three-dimensional position in the east, north and celestial directions in the navigation coordinate system provided in the satellite navigation information are used to directly assign and correct the three-dimensional speed and three-dimensional position of the strapdown inertial navigation system when performing inertial navigation solution; at the same time, the three-dimensional speed is used to calculate the track angle of the aircraft, and the track angle assignment is used to correct the initial azimuth, thereby making a rough correction to the inertial navigation.

6. The method for rapid alignment and air correction during emergency launch according to claim 1, characterized in that: The fine alignment for a period of time by using the Kalman filter includes: According to the error equation of strapdown inertial navigation system, the state equation and measurement equation of the precise alignment process are established; A recursive equation of a discrete Kalman filter is constructed, and an iterative Kalman filter operation is performed through the recursive equation until the operation reaches a specified second preset time, thereby obtaining three misalignment angle estimates in the east, north and celestial directions after precise alignment.

7. The method for rapid alignment and air correction during emergency launch according to claim 6, characterized in that: The state equation and measurement equation of the precise alignment process are expressed as: ； ； The dot above the parameter indicates the first-order derivative of the parameter. is the state variable, is the measured variable, is the state transfer matrix, and are system noise and measurement noise respectively; is the measurement matrix, It is a noise driven array; ； ； in, Represents the three misalignment angle estimates of the east, north and sky directions, It indicates the velocity error in the east, north and sky directions in the navigation coordinate system. Indicates the longitude error, latitude error and altitude error, is the gyro constant drift error in the x, y, and z directions in the airborne coordinate system, is the constant zero bias error of the accelerometer in the x, y, and z directions in the airborne coordinate system.

8. The method for rapid alignment and air correction during emergency launch according to claim 6, characterized in that: The method of using the precise alignment result to correct the attitude matrix to achieve integrated navigation includes: The skew-symmetric matrix is ​​constructed using the three misalignment angle estimates of the east, north and sky directions after precise alignment. The current attitude matrix is ​​corrected by using the skew-symmetric matrix and the unit matrix to obtain a corrected attitude matrix, and the corrected attitude matrix is ​​used for inertial navigation, thereby performing combined navigation of Kalman filtering and inertial navigation.

9. A terminal device comprising a processor, a memory and a computer program stored in the memory; characterized in that: When the processor executes the computer program, the method for rapid alignment and air correction during emergency launch according to any one of claims 1-8 is implemented.

10. A computer-readable storage medium, wherein a computer program is stored in the medium; characterized in that: When the computer program is executed by a processor, the method for rapid alignment and air correction during emergency launch according to any one of claims 1 to 8 is implemented.

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