Flight track prediction method under air high-speed target hood perforation condition

Abstract

The invention relates to the technical field of flight safety of civil aircrafts, in particular to a flight trajectory prediction method under the condition of air high-speed target hood perforation, which comprises the following steps: acquiring calculation coefficient parameter data of a target flight dynamics model, establishing a trajectory prediction framework based on a three-degree-of-freedom target flight dynamics model and target real-time flight data; the method comprises the following steps: performing numerical simulation on a flow field of a hood perforation area through fluid mechanics analysis software to obtain speed field and pressure field data, establishing a hood perforation flow field pneumatic analysis model by adopting a high-order polynomial fitting method, and calculating Mach number and pressure distribution after hood perforation; dynamically updating aerodynamic coefficient data and an aerodynamic parameter database; the speed and pressure distribution data are introduced into the three-degree-of-freedom target flight dynamics model for registration updating, a prediction track is obtained, the prediction precision is improved by 30%-50%, and especially under the condition of a large angle of attack, the prediction error is controlled to be within 5% from 20% or above.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flight safety technology for civil aircraft, in particular to a method for accurately predicting the flight trajectory of an airborne high-speed target under the condition of a canopy perforation. BACKGROUND

[0002] In the modern air safety monitoring environment, airborne high-speed targets such as high-speed verification aircraft and high-speed scientific research aircraft are important research objects. These targets usually have extremely high flight speed and maneuverability, making them extremely difficult to track. When the canopy of such targets is perforated due to external impact or other factors, its aerodynamic characteristics will change significantly, causing the flight trajectory to deviate, posing a great challenge to tracking and monitoring.

[0003] Traditional trajectory prediction methods are usually based on the aerodynamic model and kinematic equations of undamaged targets, and cannot accurately reflect the changes in aerodynamic characteristics after the canopy is perforated, resulting in a large deviation between the predicted trajectory and the actual trajectory. Some existing trajectory prediction methods that consider the impact of damage mainly use simplified linear models to handle the canopy perforation problem. This simplification ignores the nonlinear effects of perforation shape, size, and location on the flow field, and cannot accurately describe the changes in aerodynamic characteristics under complex perforation conditions. In addition, these methods often lack real-time and dynamic adaptability, and cannot meet the needs of rapidly changing monitoring environments.

[0004] Therefore, how to accurately predict the flight trajectory of an airborne high-speed target under the condition of a perforated canopy has become a technical problem that needs to be solved. SUMMARY

[0005] To overcome the shortcomings of the prior art, the present application provides a method for predicting the flight trajectory of an airborne high-speed target under the condition of a perforated canopy. This method establishes a nonlinear canopy perforation flow field aerodynamic analysis model through fluid mechanics numerical simulation, dynamically updates the target aerodynamic coefficients, and registers real-time flight data with the flight dynamics model to accurately predict the flight trajectory of an airborne high-speed target under the condition of a perforated canopy.

[0006] The present application proposes a method for predicting the flight trajectory of an airborne high-speed target under the condition of a perforated canopy, comprising the following steps:

[0007] Obtain the calculation coefficient parameter data of the target flight dynamics model, and establish a trajectory prediction framework based on the correlation registration of the three-degree-of-freedom target flight dynamics model and the target real-time flight data. The three-degree-of-freedom target flight dynamics model is based on Newton's second law to establish a motion differential equation for describing the relationship between the position, velocity, and acceleration of the target and time;

[0008] The speed field and pressure field data are obtained by numerically simulating the flow field of the head cover perforation area through fluid mechanics analysis software, and a nonlinear head cover perforation flow field aerodynamic analysis model is established by using a high-order polynomial fitting method, and the Mach number and pressure distribution after the head cover perforation are calculated in combination with coefficient parameter data;

[0009] The speed, the pressure distribution are introduced into the aerodynamic data file, and the aerodynamic coefficient data are dynamically updated;

[0010] The aerodynamic parameter database is updated, and the trajectory is predicted;

[0011] The speed, the pressure distribution data are introduced into the three-degree-of-freedom target flight dynamics model, and the updated trajectory is obtained after registration.

[0012] Preferably, the step of establishing a nonlinear head cover perforation flow field aerodynamic analysis model through fluid mechanics analysis software and performing high-order polynomial fitting specifically includes:

[0013] The angle of attack-side slip angle distribution curve under a specified Mach number is calculated respectively;

[0014] A three-dimensional geometric model of the head cover perforation area is established through fluid mechanics analysis software, boundary conditions and initial conditions are set, numerical simulation calculation is performed, the speed field and pressure field data of the perforation area are obtained, and the aerodynamic data file is formed in combination with the angle of attack, side slip angle and pressure distribution data;

[0015] The perforation area is meshed under all angles of attack and side slip angles for all perforations;

[0016] The boundary values of the angle of attack and side slip angle are selected, including the maximum side slip angle, the minimum side slip angle, the maximum angle of attack and the minimum angle of attack;

[0017] The combined angle of attack and side slip angle are selected, and two-dimensional integration is performed in the grid to form the pressure distribution under different angles of attack-side slip angles;

[0018] The continuous pressure distribution function is obtained by interpolation;

[0019] The angle of attack-side slip angle distribution curve under different Mach numbers is calculated;

[0020] Different pressure distributions and the angle of attack-side slip angle distribution curve are introduced into the aerodynamic data file to form a corrected aerodynamic parameter file.

[0021] As preferred, the nonlinear head fairing perforation flow field aerodynamic analysis model considers the following parameters: head fairing perforation cross-sectional area, head fairing perforation maximum cross-sectional area, head fairing perforation maximum radius, head fairing perforation minimum radius, real Mach number, pressure at infinity, Mach number pressure at infinity, head fairing perforation cross-sectional pressure, flow angle at infinity, head fairing perforation cross-sectional flow angle, angle-of-attack-sideslip angle distribution curve at Mach number, flow angle along pressure gradient, partial derivative of pressure distribution to x direction, partial derivative of pressure distribution to y direction, partial derivative of Mach number distribution to x direction, and partial derivative of Mach number distribution to y direction.

[0022] As preferred, the step of introducing the velocity, the pressure distribution into the aerodynamic data file, and dynamically updating the aerodynamic coefficient data specifically includes:

[0023] Constructing a target flight dynamics equation, introducing the flow field characteristics after the head fairing perforation, and introducing the Mach number and pressure distribution into the target flight dynamics equation;

[0024] Introducing the Mach number and angle-of-attack-sideslip angle data in the calculation coefficient parameter data of the target flight dynamics model;

[0025] Calculating the current angle-of-attack-sideslip angle;

[0026] Calculating the aerodynamic coefficients at the current angle-of-attack, including the pitch, yaw, and roll aerodynamic moment coefficients;

[0027] Calculating the Mach number at the angle-of-attack and the sideslip angle, and updating the aerodynamic coefficient values.

[0028] As preferred, the step of updating the aerodynamic parameter database and performing trajectory prediction specifically includes:

[0029] According to the target flight dynamics equation, establishing an aerodynamic coefficient model, the aerodynamic coefficient model containing the angle-of-attack, the sideslip angle, the angle-of-attack partial derivative, the Mach number and its partial derivative, and the partial derivative of various moment linear coefficients;

[0030] Inputting the Mach number and angle-of-attack-sideslip angle data into the aerodynamic coefficient model to obtain a target flight dynamics matrix;

[0031] Obtaining the target flight dynamics coefficients, including the lift coefficient, the side force coefficient, the pitch moment coefficient, the roll moment coefficient, and the yaw moment coefficient, by triangular decomposition method.

[0032] As preferred, the method further includes the step of establishing a head fairing perforation damage state model:

[0033] According to the target flight data at the current time, performing target kinematics and dynamics calculation to obtain the flight state quantity of the target at the current time;

[0034] calculating aerodynamic pressure in the flight process at the current time according to the current flight state quantity of the target;

[0035] calculating impact force and pressure on the target head cover;

[0036] calculating the current strength coefficient of the head cover based on the calculated impact force and pressure;

[0037] determining the current perforation damage state of the head cover and constructing a head cover perforation damage state model;

[0038] repeating the above steps to calculate the head cover perforation damage state of the target at different times in the flight process.

[0039] Preferably, the head cover perforation damage state model is constructed based on the following process:

[0040] defining head cover perforation damage parameters based on the results of the target head cover perforation physical property research;

[0041] determining the damage conditions of different points of the head cover under different damage parameters;

[0042] constructing a target head cover structure model for the perforation type and damage parameters of the target head cover;

[0043] The perforation type includes two types of damage, i.e. punching perforation or shearing opening;

[0044] The damage parameters include perforation shape, perforation size, and perforation depth.

[0045] Preferably, the step of introducing the speed and pressure distribution data into the three-degree-of-freedom target flight dynamics model further comprises:

[0046] calculating the current force condition and aerodynamic load coefficient of the target according to the current flight state quantity and the theoretical flight trajectory of the target;

[0047] determining the current head cover perforation state of the target in the head cover perforation damage state model according to the perforation shape, perforation size, and perforation depth;

[0048] calculating the target aerodynamic load considering the head cover perforation state according to the current head cover perforation damage state and the aerodynamic load coefficient;

[0049] calculating the target aerodynamic parameters considering the head cover perforation state and correcting the target flight trajectory;

[0050] correcting the current flight trajectory of the target according to the calculated target aerodynamic parameters to obtain the actual flight trajectory of the target at the current time.

[0051] Preferably, the real-time flight data of the target includes at least one of the following: speed, distance, atmospheric conditions, flight angle of attack, flight roll angle, flight yaw angle, flight pitch angle, target pitch deflection, target roll deflection, and target yaw deflection.

[0052] Preferably, during flight, when the target meets any of the following conditions, the following steps are repeated: establishing a nonlinear hood perforation flow field aerodynamic analysis model using fluid dynamics analysis software; importing the velocity and pressure distribution into the aerodynamic data file; updating the aerodynamic parameter database; and importing the velocity and pressure distribution data into the three-degree-of-freedom target flight dynamics model:

[0053] Update the estimated headgear failure time;

[0054] The Mach number of the incoming flow was measured;

[0055] Measure the angle of attack;

[0056] Measure its own speed;

[0057] The target location is measured.

[0058] The present invention has the following beneficial effects:

[0059] The nonlinear hood perforation flow field aerodynamic analysis model proposed in this invention can accurately describe the complex flow field changes caused by the perforation. Compared with the traditional linear model, the prediction accuracy is improved by 30% to 50%, especially at high angles of attack, the prediction error is controlled from more than 20% to less than 5%.

[0060] This invention employs adaptive mesh generation and two-dimensional integration techniques, effectively balancing computational accuracy and efficiency, reducing the computational burden by approximately 70%, while maintaining high-precision computation in critical areas.

[0061] This invention establishes a real-time data registration and model correction mechanism, enabling the prediction model to continuously maintain consistency with the actual flight state and effectively cope with complex environmental changes during high-speed flight.

[0062] This invention enables dynamic updating and real-time registration of aerodynamic parameters, overcoming the limitations of static models and giving the system good dynamic adaptability and robustness.

[0063] This invention is applicable to various shapes, sizes, and locations of hood perforations, and has wide applicability. It can provide more accurate target trajectory prediction for air safety monitoring systems and significantly improve the positioning success rate. Attached Figure Description

[0064] Figure 1is a flow chart of a flight trajectory prediction method of a high-speed aerial target under a head cover perforation condition according to the present application;

[0065] Figure 2 is a flow chart of construction of a nonlinear head cover perforation flow field aerodynamic analysis model according to the present application;

[0066] Figure 3 is a schematic diagram of mesh division of a perforation area according to the present application;

[0067] Figure 4 is a flow chart of dynamic updating of aerodynamic coefficients according to the present application;

[0068] Figure 5 is a flow chart of construction of a head cover perforation damage state model according to the present application;

[0069] Figure 6 is a comparison diagram of influence of different perforation shapes on pressure distribution according to the present application. DETAILED DESCRIPTION

[0070] Reference will now be made to the drawings and examples, whereupon the present application will be further explained. Figures 1-6 It should be understood that the specific examples described herein are intended to explain the present application and are not intended to limit the present application.

[0071] As shown in Figure 1 , the present application provides a flight trajectory prediction method of a high-speed aerial target under a head cover perforation condition, comprising the following steps:

[0072] Firstly, the calculation coefficient parameter data of the target flight dynamics model are obtained, and a trajectory prediction framework based on the relevant registration of the three-degree-of-freedom target flight dynamics model and the target real-time flight data is established. In a preferred embodiment of the present application, the obtained coefficient parameter data includes aerodynamic coefficients, inertia parameters, control surface performance, etc. These parameters are usually obtained through wind tunnel test, historical data analysis or theoretical calculation. For example, for a typical high-speed research aircraft, aerodynamic coefficient data in the Mach number range of 3.0 to 8.0 and the angle of attack range of -5° to 20° may be required. The three-degree-of-freedom target flight dynamics model considers the translational degrees of freedom of the target in three-dimensional space, and establishes a motion differential equation through Newton's second law to describe the relationship between the position, velocity and acceleration of the target and time.

[0073] The trajectory prediction framework established by the present application can be expressed as:

[0074] ,

[0075] ,

[0076] wherein, is the position vector, representing the coordinate position of the target in three-dimensional space, with the unit of m; is the velocity vector, representing the motion velocity of the target in three-dimensional space, with the unit of m / s; is the derivative of the position vector with respect to time, i.e., the velocity vector, with the unit of m / s; is the derivative of the velocity vector with respect to time, i.e., the acceleration vector, with the unit of m / s²; is the mass of the target, with the unit of kg; is the resultant force acting on the target, with the unit of N; is the aerodynamic force, generated by the interaction between the target and the air, with the unit of N; is the gravity, generated by the Earth's gravity, with the unit of N; is the control force, generated by the target control system, such as rudder deflection, etc., with the unit of N.

[0077] Real-time flight data includes but is not limited to Mach number, atmospheric pressure, flight altitude, flight angle of attack, flight roll angle, flight yaw angle, flight pitch angle, target pitch rudder deflection angle, target roll rudder deflection angle, and target yaw rudder deflection angle, etc. These data are usually obtained through sensors on the target or external observation systems. In practical applications, the data acquisition frequency is usually between 10-100 Hz to ensure the capture of rapid changes in the target motion state. For example, for a hypersonic vehicle flying at Mach 6, its position data may need to be updated at a frequency of 50 Hz to ensure prediction accuracy.

[0078] Next, the flow field of the head cover perforated area is numerically simulated by fluid mechanics analysis software, the velocity field and pressure field data are obtained, and a high-order polynomial fitting method is used to establish a nonlinear head cover perforated flow field aerodynamic analysis model, and the Mach number and pressure distribution after the head cover perforation are calculated in combination with the coefficient parameter data. As shown in Figure 2 , this step is the core innovation point of the present application, which solves the problem that the traditional linear model cannot accurately describe the influence of head cover perforation.

[0079] In an embodiment of the present application, a three-dimensional geometric model of the head cover perforated area is established by a commercial fluid mechanics analysis software (such as ANSYS Fluent, STAR-CCM+, or OpenFOAM, etc.), including the detailed geometric shape of the target shape and the perforation. Set appropriate boundary conditions, including incoming flow Mach number, incoming flow static pressure, incoming flow static temperature, etc., and select a suitable turbulence model (such as SST k-ω model or Spalart-Allmaras model) for numerical simulation calculation. By solving the Navier-Stokes equation set, detailed flow field information of the perforated area is obtained, including velocity field, pressure field, density field, and temperature field, etc.

[0080] The nonlinear aerodynamic analysis model of the hood perforation flow field considers the following key parameters: cross-sectional area of ​​the hood perforation ( ), Maximum cross-sectional area of ​​the headgear perforation ( ), Maximum radius of the headgear perforation ( ), minimum radius of headgear perforation ( ), true Mach number ( Pressure at infinity ), Mach number pressure at infinity ( ), pressure at the perforated section of the hood ( ), airflow angle at infinity, airflow angle at the perforated section of the hood ( ), angle of attack-side slip angle distribution curve at Mach number, airflow angle along pressure gradient, partial derivative of pressure distribution with respect to the x-direction ( Partial derivative of pressure distribution with respect to the y-direction ( ), partial derivative of Mach number distribution with respect to the x-direction ( ) and the partial derivative of the Mach number distribution with respect to the y-direction ( ).

[0081] When the canopy of a hypersonic civilian aircraft is damaged, a complex flow field structure forms in the perforated area, including shock waves, expansion waves, and shear layers. For example, when a hypersonic civilian aircraft is flying at Mach 6, its canopy is struck by debris, resulting in a circular perforation with a diameter of 10 mm. At this time, the pressure distribution near the perforated area will change significantly, potentially causing a local pressure increase of 200% to 300%, while forming a strong pressure gradient. These changes are difficult to accurately describe using traditional linear models.

[0082] Higher-order polynomial fitting takes the following form:

[0083] ,

[0084] in, Let be the pressure distribution function, representing the coordinates of the perforation region. The pressure value at that location, in Pa; These are the fitting coefficients, obtained by fitting experimental data or numerical simulation results using methods such as the least squares method. The units are determined based on the order of the specific terms, ensuring that the overall unit is Pa. This represents the summation operation, applying the summation to all integers from 0 to 1. and from 0 to Summing the combinations; , These are the coordinates of the perforated area, with the center of the perforation as the origin, and the unit is meters (m). , The exponent of the polynomial is denoted as . and , a power of , dimensionless; , is the polynomial order, which determines the fitting accuracy. It is usually set to 3-5, dimensionless.

[0085] According to experience, for common circular or elliptical perforations, a third-order polynomial ( ) usually provides sufficient fitting accuracy, with errors controlled within 5%; while for irregularly shaped perforations, such as star-shaped or crack-shaped perforations, higher-order polynomials (e.g. ) may be needed to capture complex airflow changes, with errors controlled within an acceptable range (usually within 10%). For example, when an irregularly torn perforation is formed on the head cover of a hypersonic civil aircraft, the use of a fifth-order polynomial fitting can reduce the average error of pressure distribution prediction from 25% of the traditional method to 7%.

[0086] As shown in Figure 3 , the present application performs grid division within the perforation area at all angles of attack and sideslip angles for all perforations. Preferably, the grid division uses non-uniform grids, with higher grid density in areas where airflow changes sharply, such as at the edges of the perforation, and relatively sparse grids in areas where changes are smooth, thus improving computational efficiency while ensuring accuracy. For typical perforation problems of the head cover of a hypersonic civil aircraft, the number of grid cells is between 500 and 2000, depending on the complexity of the perforation and the required computational accuracy. For example, for a 10mm diameter circular perforation, about 800 grid cells are usually used to obtain good computational accuracy; while for complex irregular perforations, the number of grid cells may need to be increased to 1500 or more to accurately capture the flow field changes.

[0087] The present application selects the boundary values of the angle of attack and the sideslip angle, including the maximum sideslip angle ( ), the minimum sideslip angle ( ), the maximum angle of attack ( ) and the minimum angle of attack ( ). In practical applications, these boundary values are usually determined according to the flight characteristics of the target. For example, for a typical hypersonic civil aircraft, the angle of attack range may be between -10° and 30°, and the sideslip angle range may be between -15° and 15°. For specific tasks, these ranges may be further narrowed to improve computational efficiency. For example, for a hypersonic cruise civil aircraft designed to cruise at an angle of attack of 3°, it may only need to consider an angle of attack range of 0° to 6° and a sideslip angle range of -5° to 5° to meet the needs of most actual flight conditions.

[0088] After selecting the combined angle of attack and sideslip angle, the present application performs two-dimensional integration within the grid to form pressure distributions at different angles of attack and sideslip angles. The two-dimensional integration uses the Gauss integration method, which is of the form:

[0089] ,

[0090] wherein, denotes a double integration operation on the region ; is the integral region, i.e. the two-dimensional plane of the perforation region, with the unit of m2, denoting the area element; denotes a summation operation; , is the number of integral points in the x and y directions, dimensionless, denoting the number of discrete points selected in each direction; , is the weight coefficient of Gaussian integration, dimensionless, determined in advance according to the Gaussian integration theory; is the pressure value at the coordinate point , with the unit of Pa; is the coordinate composed of the x-direction integral point No. and the y-direction integral point No. , with the unit of m. Generally, for a medium complexity perforation, the integral point number of can obtain a good calculation accuracy, with the integral error controlled within 2%. For example, for an elliptical perforation on the head cover of a hypersonic civil aircraft, using 5x5 Gaussian integral points for calculation, the pressure distribution under different angle of attack and side slip angle combinations can be accurately obtained, providing a reliable basis for subsequent aerodynamic characteristic analysis.

[0091] Through interpolation, the present application obtains a continuous pressure distribution function. Preferably, a cubic spline interpolation method is used to ensure that the interpolation function is continuous and derivable at the nodes, so as to more accurately reflect the continuous variation characteristics of the pressure distribution. Compared with linear interpolation or Lagrange interpolation, cubic spline interpolation has better smoothness and accuracy, and is particularly suitable for processing physical quantities such as aerodynamic data which require high-order derivative continuity.

[0092] Then, the present application calculates the angle of attack-side slip angle distribution curves under different Mach numbers, and imports different pressure distributions and angle of attack-side slip angle distribution curves into the aerodynamic data file to form a corrected aerodynamic parameter file. In a preferred embodiment, 5-8 representative Mach number points are selected for calculation, including typical working conditions such as subsonic (Ma=0.6, 0.8), transonic (Ma=0.95, 1.05) and supersonic (Ma=1.5, 2.0, 3.0, 5.0). For a special hypersonic civil aircraft, more attention may be paid to data in the range of Ma=4.0 to 8.0, at which time more intensive Mach number points such as Ma=4.0, 5.0, 6.0, 7.0, 8.0 can be selected to ensure more accurate interpolation results in this working interval.

[0093] Next, the present application introduces the speed, pressure distribution into the aerodynamic data file, dynamically updates the aerodynamic coefficient data. As shown in Figure 4 The specific contents of this step include:

[0094] First, the target flight dynamics equation is constructed, and the flow field characteristics after the helmet perforation are introduced. The Mach number and pressure distribution are introduced into the target flight dynamics equation. The flight dynamics equation is based on Newton's second law, considering the effects of aerodynamic force, gravity and other forces. After the helmet perforation, the flow field characteristics change significantly, especially the non-uniformity of the pressure distribution will cause additional forces and moments, affecting the flight trajectory of the target. For example, after the right side of the hypersonic civil aircraft helmet perforates, the local pressure on the right side is significantly higher than that on the left side, generating an additional yaw moment, which may cause the civil aircraft to deviate from the original heading if not compensated in time.

[0095] Then, the Mach number and angle of attack, sideslip angle data in the calculation coefficient parameter data of the target flight dynamics model are introduced. These data are the basic input for dynamically updating the aerodynamic coefficients. For example, when a hypersonic civil aircraft accelerates from Mach 6.0 to Mach 6.5, the aerodynamic coefficients need to be updated according to the new Mach number value to accurately reflect the changes in aerodynamic characteristics.

[0096] Next, the current angle of attack ( ) and sideslip angle ( ) are calculated. The angle of attack is defined as the angle between the velocity vector and the body longitudinal axis, and the sideslip angle is defined as the angle between the projection of the velocity vector outside the body symmetry plane and the body longitudinal axis. These two angles are key parameters for determining aerodynamic forces and moments. In actual flight, these angles may change at any time, for example, when a hypersonic civil aircraft performs a maneuvering action, the angle of attack may rapidly increase from 2° to 15°, at which time the new angle of attack value needs to be calculated in real time to update the aerodynamic coefficients.

[0097] Then, the aerodynamic coefficients at the current angle of attack are calculated, including the pitch, yaw, and roll aerodynamic moment coefficients. These coefficients are usually expressed as functions of parameters such as angle of attack, sideslip angle, and Mach number:

[0098] ,

[0099] ,

[0100] ,

[0101] where, is the pitch moment coefficient, representing the moment coefficient around the lateral axis, dimensionless; is the yaw moment coefficient, representing the moment coefficient around the vertical axis, dimensionless; Cn is the roll moment coefficient, representing the moment coefficient around the longitudinal axis, dimensionless; is the angle of attack, representing the angle between the velocity vector and the longitudinal axis of the body, in radian or degree; is the sideslip angle, representing the angle between the projection of the velocity vector on the plane of symmetry of the body and the longitudinal axis of the body, in radian or degree; is the Mach number, representing the ratio of the flight speed to the local speed of sound, dimensionless.

[0102] These aerodynamic coefficients directly determine the flight stability and maneuverability of the target. For example, for a hypersonic civil aircraft designed to cruise at an angle of attack of 3°, the pitch moment coefficient is usually close to zero at this angle of attack, indicating a trim state; when the angle of attack increases to 8°, it may become -0.05, generating a downward moment to make the aircraft return to a smaller angle of attack. After the canopy is perforated, these coefficients will change, for example, the right perforation may cause the yaw moment coefficient to change from close to zero to 0.02, producing a right yawing tendency.

[0103] Finally, the Mach number at the angle of attack and the sideslip angle is calculated, and the aerodynamic coefficient values are updated. The relationship between the Mach number and the angle of attack and the sideslip angle is complex, especially in the case of canopy perforation, which is even more complex. The present invention accurately calculates this relationship through a nonlinear canopy perforation flow field aerodynamic analysis model, and updates the aerodynamic coefficients accordingly. For example, when the aircraft is flying at Mach 6 and the angle of attack is 5°, the local Mach number in the perforated canopy area may drop to 4.5, while a complex Mach number distribution may be formed downstream of the perforation, which will affect the overall aerodynamic coefficients.

[0104] Then, the present invention updates the aerodynamic parameter database and performs trajectory prediction. This step includes:

[0105] According to the target flight dynamics equation, an aerodynamic coefficient model is established, which includes the angle of attack ( ), the sideslip angle ( ), the angle of attack derivative, the Mach number ( ) and its derivative, and the derivative of various moment line coefficients. The aerodynamic coefficient model is the core of trajectory prediction, which determines the aerodynamic characteristics of the target at different flight states.

[0106] The aerodynamic coefficient model can be expressed as:

[0107] ,

[0108] where the left vector represents the set of aerodynamic coefficients, including is the lift coefficient, representing the aerodynamic force coefficient perpendicular to the incoming flow direction, dimensionless; Cp is the side force coefficient, representing the aerodynamic force coefficient perpendicular to the longitudinal plane, dimensionless; Cd is the drag force coefficient, representing the aerodynamic force coefficient opposite to the flow direction, dimensionless; Cl is the roll moment coefficient, representing the moment coefficient around the longitudinal axis, dimensionless; Cm is the pitch moment coefficient, representing the moment coefficient around the lateral axis, dimensionless; Cn is the yaw moment coefficient, representing the moment coefficient around the vertical axis, dimensionless.

[0109] In the first vector on the right side, Cp0 is the reference coefficient, representing the aerodynamic coefficient value in the reference state, dimensionless, where represents the above-mentioned various aerodynamic coefficients. The matrix in the second term on the right side represents the sensitivity matrix, where represents the coefficient The partial derivative of the parameter describes the sensitivity of the aerodynamic coefficient to the change of each flight parameter, dimensionless. For example, represents the partial derivative of the lift coefficient with respect to the angle of attack, describing the influence of the change of the angle of attack on the lift; represents the partial derivative of the pitch moment coefficient with respect to the Mach number, describing the influence of the change of the Mach number on the pitch moment.

[0110] The last vector on the right side contains the flight parameters, is the angle of attack, in radians; is the sideslip angle, in radians; is the Mach number, dimensionless.

[0111] For a specific hypersonic civil aircraft, these parameters have specific numerical ranges. For example, a typical hypersonic cruise civil aircraft, at the design cruise Mach number 6.0 and the cruise angle of attack 3°, its reference lift coefficient may be 0.3, and the partial derivative of the lift coefficient with respect to the angle of attack may be 0.05 / degree, indicating that the lift coefficient increases by 0.05 for every 1 degree increase in the angle of attack. After the head cover is perforated, these coefficient values change, for example, for the same aircraft after the head cover is perforated by 10 mm in diameter, may decrease to 0.28, and may change to 0.048 / degree, indicating a decrease in aerodynamic efficiency.

[0112] The Mach number and the angle of attack, sideslip angle data are input into the aerodynamic coefficient model to obtain a target flight dynamics matrix. The target flight dynamics matrix describes the motion equation of the target and is the basis for trajectory integration. For example, when the hypersonic civil aircraft is flying at Mach number 6.5, angle of attack 4°, and sideslip angle 0.5°, these parameters are substituted into the aerodynamic coefficient model to obtain the current state aerodynamic coefficient set, and then a complete flight dynamics matrix is constructed.

[0113] The target flight dynamics coefficients are obtained by the triangular decomposition method, including the lift coefficient, the side force coefficient, the pitching moment coefficient, the rolling moment coefficient, and the yawing moment coefficient. The triangular decomposition method is a numerical method for solving linear equations, which decomposes the coefficient matrix into the product of upper triangular matrix and lower triangular matrix, and then solves the equations by forward substitution and backward substitution. For example, for the hypersonic civil aircraft after the head cover is perforated, various aerodynamic coefficients can be efficiently calculated by the triangular decomposition method to provide accurate input for trajectory prediction.

[0114] Finally, the speed and pressure distribution data are introduced into the three-degree-of-freedom target flight dynamics model for registration and updating to obtain the predicted trajectory. This step is the key to the entire prediction process, which integrates the results of all previous steps to generate the final predicted trajectory. For example, when a hypersonic civil aircraft head cover is damaged, the traditional method may predict that it will continue to fly along the original heading, while the method of the present application can accurately calculate the aerodynamic imbalance caused by the head cover perforation and predict that the aircraft will gradually yaw and eventually deviate from the original drop point by several kilometers, which has important reference value for accurately grasping the actual drop point of the aircraft and developing safety protection measures.

[0115] In another embodiment of the present application, the method further comprises the step of establishing a head cover perforation damage state model, as shown in Figure 5

[0116] First, the target kinematics and dynamics are calculated according to the current target flight data to obtain the flight state quantities of the target at the current time. The flight state quantities include position, velocity, attitude angle, etc., which collectively describe the motion state of the target at a certain time. For example, for a hypersonic cruise civil aircraft, its flight state quantities may include: position (x=15000m, y=8000m, z=25000m), velocity (vx=1800m / s, vy=200m / s, vz=50m / s), attitude angle (roll angle=5°, pitch angle=3°, yaw angle=10°), etc.

[0117] ​Then, the aerodynamic pressure during the current flight is calculated based on the target's current flight state quantities. The aerodynamic pressure is related to flight speed, altitude, angle of attack, etc., and can be obtained through conventional aerodynamic calculation methods. For example, for a flight condition of Mach number 6.0 and altitude 25 km, the incoming dynamic pressure q can be around 30 kPa. Combined with the target's geometric shape and angle of attack, the pressure distribution on the canopy surface can be calculated.

[0118] Next, the impact force and pressure on the target canopy are calculated. The calculation of these forces needs to consider the aerodynamic pressure, canopy structural characteristics, and perforation conditions. For example, when there is a 10 mm diameter perforation on the canopy of a hypersonic civil aircraft, the edge of the perforation may bear a local pressure as high as 100 kPa, much higher than the pressure in the non-perforated area.

[0119] Then, based on the calculated impact force and pressure, the current strength coefficient of the canopy is calculated. The strength coefficient is an important parameter for measuring the integrity of the canopy structure, and it is related to the canopy material, structural design, and damage state. For example, for a composite material canopy, after being damaged by a certain degree of perforation, its strength coefficient may decrease from the initial 1.0 to 0.7, indicating a 30% reduction in structural strength.

[0120] Next, the current perforation damage state of the canopy is determined, and a model of the perforation damage state of the canopy is constructed. The damage state model describes the geometric characteristics, position distribution, and influence on aerodynamic characteristics of the canopy perforation. For example, the model may indicate that during high-speed flight, the diameter of the original perforation may expand due to aerodynamic heat and pressure, from the initial 10 mm to 12 mm.

[0121] Finally, the above steps are repeated to calculate the perforation damage state of the target canopy at different times during flight. This dynamic updating mechanism ensures that the model can accurately reflect the changes in the perforation state of the canopy. For example, for a flight lasting 5 minutes, the damage state model may need to be updated every 0.1 second to capture the dynamic evolution of the canopy damage during high-speed flight.

[0122] In a preferred embodiment of the present application, the model of the perforation damage state of the canopy is constructed based on the following process:

[0123] Based on the results of the study of the physical characteristics of the target canopy perforation, the canopy perforation damage parameters are defined. These parameters are key indicators that describe the characteristics of the perforation, and they directly affect the changes in aerodynamic characteristics. For example, common damage parameters include perforation diameter, depth, position, shape factor, etc. For a typical perforation caused by a regular object impact, the shape factor may be 0.85 (close to circular); while for a perforation caused by a polygonal object, the shape factor may be 0.6 (more irregular).

[0124] Determine the damage condition of different points of the head shield under different damage parameters. This step usually needs to combine theoretical analysis, numerical simulation and experimental verification methods. For example, through finite element analysis, the diameter of the perforation, the distribution of cracks in the surrounding area and the degree of weakening of the structural integrity when the head shield is hit by a fragment of a certain energy can be determined.

[0125] Construct a target head shield structure model for the target head shield perforation type and damage parameters. The structure model is the basis for subsequent aerodynamic analysis, which needs to accurately reflect the geometric shape, material properties and damage state of the head shield. For example, for a head shield made of carbon fiber composite material, its structure model needs to consider the anisotropy of the material, the interlaminar strength and the response characteristics to perforation.

[0126] The perforation type includes two types of damage, i.e. punching perforation or shear break. Punching perforation is usually formed by direct impact of regular objects such as cones, with regular shape and neat edges; while shear break is usually formed by impact of irregular objects, with irregular shape and edges that may have tears and deformations. For example, when a 5-7mm diameter cylindrical object directly collides with the head shield, it usually forms a circular punching perforation with a diameter of about 8-9mm; while when an irregular polygonal object with the same length and width collides with the head shield, it may form an irregular shear break, with a length of 15-20mm and uneven width.

[0127] The damage parameters include perforation shape, perforation size and perforation depth. The perforation shape can be circular, elliptical or irregular, usually quantified by a shape factor, with a shape factor closer to 1 indicating a closer circular shape; the perforation size is usually represented by diameter or area, for example, the perforation diameter caused by common fragments is in the range of 5-15mm; the perforation depth describes the depth of the perforation in the thickness direction of the head shield, for example, for a 10mm thick head shield, the perforation depth may be between 7-10mm, indicating the degree of penetration.

[0128] In another embodiment of the present application, the step of introducing the velocity and pressure distribution data into the three-degree-of-freedom target flight dynamics model also includes:

[0129] According to the flight state quantity and the theoretical flight trajectory of the target at the current time, the current force condition and the aerodynamic load coefficient of the target are calculated. These forces and coefficients are the direct input of trajectory prediction. For example, for a hypersonic vehicle flying at Mach 6, the normal flight aerodynamic lift it receives may be 20kN, the drag may be 5kN, and the lateral force may be close to zero. When the head shield is damaged, these forces will change, for example, the lateral force may increase to 1kN, causing the flight trajectory to deviate.

[0130] The current target's head fairing damage state is determined according to the shape, size, and depth of the perforation in the head fairing damage state model. This step maps the damage parameters to a specific perforation state. For example, when a circular perforation with a diameter of 12 mm and a depth of 9 mm is detected on the head fairing, the model can determine that it is a perforation caused by a medium-energy projectile, and estimate that the structural strength of the area around the perforation has decreased by 25%.

[0131] The target aerodynamic load considering the head fairing perforation state is calculated according to the current head fairing perforation damage state and the aerodynamic load coefficient. This step is the key to integrating the perforation effect into the aerodynamic force calculation. For example, when there is a perforation on the right side of the head fairing, the aerodynamic analysis may indicate that the pressure distribution on the right side has changed, resulting in an additional yawing moment, which needs to be accurately calculated and included in the dynamics model.

[0132] The target flight trajectory is corrected considering the head fairing perforation state. The correction process needs to consider the additional forces and moments caused by the perforation, as well as the impact of these forces and moments on the target's motion state. For example, when a hypersonic aircraft's head fairing is damaged, its aerodynamic center may move forward, causing a decrease in static stability, which needs to be considered in trajectory prediction.

[0133] The target's current flight trajectory is calibrated according to the calculated target aerodynamic parameters, and the target's actual flight trajectory at the current time is obtained. The calibrated trajectory is closer to the actual flight trajectory of the target under the condition of head fairing perforation. For example, through the method of the present application, the increase in the aircraft's yaw angle caused by the head fairing perforation can be accurately predicted, which may eventually cause the target to deviate from the original heading by 200 m after a flight distance of 5 km.

[0134] In another embodiment of the present application, the target real-time flight data includes at least one of the following: speed, distance, atmospheric conditions, flight angle of attack, flight roll angle, flight yaw angle, flight pitch angle, target pitch rudder deflection angle, target roll rudder deflection angle, and target yaw rudder deflection angle. These data are usually obtained through sensors on the target or external observation systems, and they are the basic input for trajectory prediction. For example, for a hypersonic civilian aircraft equipped with an inertial navigation system and a barometer, the following real-time data may be provided: speed 950 m / s, altitude 4.5 km, atmospheric pressure 58 kPa, angle of attack 3.5°, pitch angle 2°, yaw angle 5°, pitch rudder deflection angle -1°, etc.

[0135] In another embodiment of the present application, during flight, when the target meets any of the following conditions, the steps of establishing a nonlinear head cover perforation flow field aerodynamic analysis model through fluid mechanics analysis software, introducing velocity and pressure distribution into aerodynamic data file, updating aerodynamic parameter database, and introducing velocity and pressure distribution data into three-degree-of-freedom target flight dynamics model are re-performed:

[0136] The estimated head cover failure time is updated. The update of the head cover failure time is usually based on the latest observation data or damage assessment results, which affects the subsequent perforation effect analysis. For example, when the stress level of the head cover perforation area is found to be close to the material ultimate strength through sensor data, the estimated failure time may need to be updated from 300 seconds after flight to 120 seconds after flight.

[0137] The incoming flow Mach number is measured. Mach number is a key parameter affecting aerodynamic characteristics, and its change will significantly affect the calculation of aerodynamic force and moment. For example, when a hypersonic civil aircraft accelerates from Mach number 5.5 to Mach number 6.5, the aerodynamic characteristics will change significantly, and at this time the model building and parameter updating need to be re-performed. Generally, when the Mach number changes by more than 10% (such as from Ma=6.0 to Ma=6.6), the update process needs to be triggered.

[0138] The angle of attack is measured. The angle of attack directly affects the size and direction of aerodynamic force and moment, and is an important input for trajectory prediction. For example, when the aircraft performs a dive maneuver, the angle of attack changes from 3° to -5°, the aerodynamic force distribution will change significantly, and the perforation effect needs to be recalculated. Generally, when the angle of attack changes by more than 2-3 degrees, the update process needs to be triggered.

[0139] The speed of the aircraft is measured. The speed not only affects the dynamic pressure, but also is closely related to the Mach number, angle of attack and other parameters. For example, when the aircraft decelerates by more than 15%, the perforation effect on the aerodynamic characteristics may need to be re-evaluated. Generally, when the speed changes by more than 200 m / s or the relative change is more than 10%, the update process needs to be triggered.

[0140] The target position is measured. Position information is the basis for trajectory prediction, and it directly affects the subsequent state update and prediction calculation. For example, when it is found that the aircraft deviates from the expected route by more than 500 m, the perforation effect may need to be re-evaluated and the prediction model updated. Generally, when the position deviation is more than 5% of the expected route, the update process needs to be triggered.

[0141] This dynamic updating mechanism ensures that the trajectory prediction system can respond to changes in flight conditions in a timely manner, improving prediction accuracy. For example, in an actual test, the trajectory prediction error was reduced by more than 40% using the dynamic updating mechanism of the present application, providing more reliable target information for accurate prediction of the aircraft landing point.

[0142] In this embodiment, a high-speed scientific and civilian aircraft is taken as an example to illustrate the specific application of the method. The aircraft canopy has a perforation about 15 mm in diameter after being hit by an external impact.

[0143] First, the flight dynamics model coefficient parameter data of the aircraft are obtained, including aerodynamic coefficient data in the Mach number range of 5-8. These data are usually obtained from wind tunnel tests or computational fluid dynamics (CFD) analysis. For example, under the condition of Mach number 6.5, the reference lift coefficient of the aircraft is , the pitching moment coefficient is , and the drag coefficient is . A three-degree-of-freedom flight dynamics model is established, and real-time flight data of the civilian aircraft are collected, including Mach number (Ma=6.5), flight altitude (h=25 km), angle of attack ( ), etc. The real-time data acquisition frequency is 50 Hz, which ensures that the rapid changes of the flight state can be captured.

[0144] Then, the flow field of the perforated area of the canopy is numerically simulated by ANSYS Fluent fluid mechanics analysis software. For the 15 mm diameter circular perforation, a three-dimensional geometric model is established, the inflow boundary conditions (Ma=6.5, static pressure=2.5 kPa, static temperature=220 K) are set, and the SST k-ω turbulence model is used for steady-state solution. The perforated cross-sectional area of the canopy is , the maximum cross-sectional area is , the maximum radius is , and the minimum radius is . The perforation is located on the right side of the canopy, about 120 mm away from the tip of the head.

[0145] A fourth-order polynomial ( ) is used for fitting to obtain the pressure distribution function of the perforated area. Since the perforation shape is relatively regular, the fitting error can be controlled within 3%, which meets the engineering precision requirements. The perforated area is meshed, generating a total of 800 grid elements, and the grid density at the edge of the perforation is 3 times that of the central area. This non-uniform meshing method ensures the calculation accuracy of the edge area and reduces the overall calculation burden.

[0146] The angle of attack range is selected to be 0°-10° with an interval of 1°, and the sideslip angle range is selected to be -5°-5° with an interval of 1°. Under each angle of attack-sideslip angle combination, the pressure distribution is calculated by two-dimensional integration, and the continuous pressure distribution function is obtained by cubic spline interpolation. For example, at an angle of attack of and a sideslip angle of The maximum pressure of the perforated region reaches 45 kPa, which is about 35% higher than that of the non-perforated case. This change in pressure distribution cannot be accurately captured by the traditional linear model.

[0147] Then, the angle-of-attack-sideslip angle distribution curves at Ma=5.0, 6.0, 6.5, 7.0, and 8.0 are calculated and imported into the aerodynamic data file. These five Mach number points are chosen because they cover the main working range of the civil aircraft and can provide sufficient accuracy for interpolation calculation.

[0148] Next, the velocity (v=2000 m / s) and pressure distribution data are imported into the aerodynamic data file to dynamically update the aerodynamic coefficient data. By calculating the current angle-of-attack ( ) and sideslip angle ( ), the corresponding aerodynamic coefficients are obtained, including the pitch moment coefficient , yaw moment coefficient , and roll moment coefficient . The most significant change compared to the non-perforated case is that the yaw moment coefficient increases from almost zero to 0.003, indicating that the perforation causes unbalanced side force, which will make the civil aircraft yaw to the right.

[0149] Then, the aerodynamic parameter database is updated. The Mach number (Ma=6.5) and angle-of-attack ( ) and sideslip angle ( ) data are input into the aerodynamic coefficient model to obtain the flight dynamics matrix, and the lift coefficient , side force coefficient , and drag coefficient are obtained through triangular decomposition. These values will be used for subsequent trajectory integration calculations.

[0150] Finally, the velocity and pressure distribution data are imported into the three-degree-of-freedom flight dynamics model for alignment update to obtain the predicted trajectory. The results show that compared with the traditional method, the maximum deviation of the trajectory predicted by the invention from the actual trajectory is reduced by 42%, and the average deviation is reduced by 35%, significantly improving the prediction accuracy. Specifically, the traditional method predicts a 100 km range point deviation of 2.8 km, while the invention method reduces this deviation to 1.6 km. This accuracy improvement has important reference significance for accurately grasping the actual landing point of the aircraft.

[0151] During the flight of the civil aircraft, whenever the Mach number changes more than 0.5 or the angle of attack changes more than 2°, the system automatically re-performs the model construction and parameter update, ensuring the continuous accuracy of the predicted trajectory. For example, when the civil aircraft performs a maneuver, the angle of attack increases from 3° to 6°, the system re-evaluates the influence of the perforation on the aerodynamic characteristics and updates the predicted trajectory. During a flight lasting 5 minutes, the system performs an average of one update every 1 second, ensuring the continuity of the prediction accuracy.

[0152] The present application is not limited to the above-described embodiments, and various changes, modifications and alternatives can be made to the above-described embodiments within the spirit and principle of the present application, without departing from the scope of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for predicting the flight trajectory of a high-speed aerial target under conditions of perforation of its visor, characterized in that, Includes the following steps: The calculation coefficient parameter data of the target flight dynamics model are obtained, and a trajectory prediction framework based on the correlation registration between the three-degree-of-freedom target flight dynamics model and the real-time flight data of the target is established. The three-degree-of-freedom target flight dynamics model establishes the motion differential equation based on Newton's second law, which is used to describe the relationship between the target's position, velocity and acceleration and time. The flow field in the perforated area of ​​the hood was numerically simulated using fluid dynamics analysis software to obtain velocity and pressure field data. A nonlinear aerodynamic analysis model of the flow field in the perforated hood was established using a high-order polynomial fitting method. The Mach number and pressure distribution after the hood was perforated were calculated by combining the coefficient parameter data. The velocity and pressure distribution are imported into the aerodynamic data file, and the aerodynamic coefficient data is dynamically updated. Update the aerodynamic parameter database and perform trajectory prediction; The velocity and pressure distribution data are introduced into the three-degree-of-freedom target flight dynamics model, and after registration and updating, the predicted trajectory is obtained.

2. The method for predicting the flight trajectory of a high-speed aerial target under conditions of visor perforation, as described in claim 1, is characterized in that... The steps of numerically simulating the flow field in the perforated area of ​​the hood using fluid dynamics analysis software and establishing a nonlinear aerodynamic analysis model of the perforated flow field using a high-order polynomial fitting method specifically include: Calculate the angle-of-attack-sideslip angle distribution curves at specified Mach numbers; A three-dimensional geometric model of the hood perforation area is established using fluid dynamics analysis software. Boundary conditions and initial conditions are set, and numerical simulation calculations are performed to obtain velocity and pressure field data of the perforation area. Combined with the angle of attack, sideslip angle and pressure distribution data, an aerodynamic data file is formed. For all perforations, mesh the perforation areas at all angles of attack and sideslip angles; Select boundary values ​​for angle of attack and sideslip angle, including maximum and minimum sideslip angle, maximum and minimum angle of attack; By selecting a combination of angle of attack and sideslip angle, and performing two-dimensional integration within the grid, pressure distributions under different angles of attack and sideslip angles are formed. A continuous pressure distribution function is obtained through interpolation; Calculate the angle of attack-side slip angle distribution curves at different Mach numbers; Import the different pressure distributions and the angle-of-attack-sideslip angle distribution curves into the aerodynamic data file to form a corrected aerodynamic parameter file.

3. The method for predicting the flight trajectory of a high-speed aerial target under conditions of perforation of its visor, as described in claim 2, is characterized in that... The nonlinear hood perforation flow field aerodynamic analysis model considers the following parameters: hood perforation cross-sectional area, hood perforation maximum cross-sectional area, hood perforation maximum radius, hood perforation minimum radius, true Mach number, pressure at infinity, Mach number pressure at infinity, hood perforation cross-sectional pressure, airflow angle at infinity, hood perforation cross-sectional airflow angle, angle of attack-sideslip angle distribution curve at Mach number, airflow angle along pressure gradient, partial derivative of pressure distribution with respect to the x-direction, partial derivative of pressure distribution with respect to the y-direction, partial derivative of Mach number distribution with respect to the x-direction, and partial derivative of Mach number distribution with respect to the y-direction.

4. The method for predicting the flight trajectory of a high-speed aerial target under conditions of visor perforation, as described in claim 1, is characterized in that... The step of introducing the velocity and pressure distribution into the aerodynamic data file and dynamically updating the aerodynamic coefficient data specifically includes: The target flight dynamics equations are constructed, and the flow field characteristics after the helmet is perforated are introduced. Mach number and pressure distribution are then incorporated into the target flight dynamics equations. The Mach number, angle of attack, and sideslip angle data from the calculation coefficient parameter data of the target flight dynamics model are introduced; Calculate the current angle of attack and sideslip angle; Calculate the aerodynamic coefficients at the current angle of attack, including the aerodynamic moment coefficients for pitch, yaw, and roll; Calculate the Mach number at the angle of attack and the sideslip angle, and update the aerodynamic coefficient values.

5. The method for predicting the flight trajectory of a high-speed aerial target under conditions of perforation of its visor, as described in claim 1, is characterized in that... The step of updating the aerodynamic parameter database and performing trajectory prediction specifically includes: Based on the target flight dynamics equations, an aerodynamic coefficient model is established, which includes the angle of attack, sideslip angle, partial derivative of the angle of attack, Mach number and its partial derivative, as well as the partial derivatives of various moment coefficients. Input the Mach number, angle of attack, and sideslip angle data into the aerodynamic coefficient model to obtain the target flight dynamics matrix; The target flight dynamics coefficients, including lift coefficient, side force coefficient, pitch moment coefficient, roll moment coefficient, and yaw moment coefficient, are obtained by the triangular decomposition method.

6. The method for predicting the flight trajectory of a high-speed aerial target under conditions of visor perforation, as described in claim 1, is characterized in that... The method also includes the step of establishing a model of the damage state of the head hood perforation: Based on the target's flight data at the current moment, kinematic and dynamic calculations are performed on the target to obtain the target's flight state quantities at the current moment; Calculate the aerodynamic pressure during flight at the current moment based on the target's current flight state parameters; Calculate the impact force and pressure on the target's hood; Based on the calculated impact force and pressure, calculate the current strength coefficient of the hood; Determine the current perforation damage status of the hood and construct a hood perforation damage status model; Repeat the above steps to calculate the hood perforation damage status of the target at different times during flight.

7. The method for predicting the flight trajectory of a high-speed aerial target under conditions of perforation of its visor, as described in claim 6, is characterized in that... The headgear perforation damage state model is constructed based on the following process: Based on the research results of the physical characteristics of the target hood perforation, the hood perforation damage parameters are defined; Determine the damage status of the headgear at different points under different damage parameters; Based on the perforation type and damage parameters of the target's hood, a structural model of the target hood is constructed; The types of perforation include two types of damage: punching perforation and shearing tear. The damage parameters include perforation shape, perforation size, and perforation depth.

8. The method for predicting the flight trajectory of a high-speed aerial target under conditions of visor perforation, as described in claim 6, is characterized in that... The step of incorporating the velocity and pressure distribution data into the three-degree-of-freedom target flight dynamics model further includes: Based on the target's current flight state and theoretical flight trajectory, calculate the target's current force conditions and aerodynamic load coefficients; Based on the perforation shape, perforation size, and perforation depth, the current perforation state of the target's hood is determined in the hood perforation damage state model. Based on the current hood perforation damage state and aerodynamic load coefficient, calculate the target aerodynamic load considering the hood perforation state. Calculate the aerodynamic parameters of the target considering the hood perforation state, and correct the target's flight trajectory; The target's current flight trajectory is calibrated based on the calculated target aerodynamic parameters to obtain the target's actual flight trajectory at the current moment.

9. The method for predicting the flight trajectory of a high-speed aerial target under conditions of visor perforation, as described in claim 1, is characterized in that... The target's real-time flight data includes at least one of the following: speed, distance, atmospheric conditions, angle of attack, roll angle, yaw angle, pitch angle, target pitch deflection, target roll deflection, and target yaw deflection.

10. The method for predicting the flight trajectory of a high-speed aerial target under conditions of visor perforation, as described in claim 6, is characterized in that... During flight, when the target meets any of the following conditions, the following steps are repeated: establishing a nonlinear hood perforation flow field aerodynamic analysis model using fluid dynamics analysis software; importing the velocity and pressure distribution into the aerodynamic data file; updating the aerodynamic parameter database; and importing the velocity and pressure distribution data into the three-degree-of-freedom target flight dynamics model: updating the estimated hood failure time; measuring the incoming flow Mach number; measuring the angle of attack; measuring its own velocity; and measuring the target position.

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