A method for predicting the flight trajectory of a high-speed aerial target under conditions of visor perforation.

Abstract

This invention relates to the field of civil aircraft flight safety technology, and in particular to a method for predicting the flight trajectory of a high-speed target under conditions of visor perforation. The method includes: acquiring the calculated coefficient parameter data of the target's flight dynamics model; establishing a trajectory prediction framework based on a three-degree-of-freedom target flight dynamics model and real-time target flight data; numerically simulating the flow field in the visor perforation area using fluid dynamics analysis software to acquire velocity and pressure field data; establishing an aerodynamic analysis model of the visor perforation flow field using a high-order polynomial fitting method; calculating the Mach number and pressure distribution after visor perforation; dynamically updating the aerodynamic coefficient data and aerodynamic parameter database; and introducing the velocity and pressure distribution data into the three-degree-of-freedom target flight dynamics model for registration and updating to obtain the predicted trajectory. The prediction accuracy is improved by 30%–50%, especially under high angle-of-attack conditions, reducing the prediction error from over 20% to within 5%.

Description

Technical Field

[0001] This invention relates to the field of civil aircraft flight safety technology, and in particular to a method for accurately predicting the flight trajectory of high-speed aerial targets under conditions of visor perforation. Background Technology

[0002] In the modern air safety monitoring environment, high-speed aerial targets, such as high-speed demonstrator aircraft and high-speed scientific research aircraft, are important research subjects. These targets typically possess extremely high flight speeds and maneuverability, making them extremely difficult to track. When the radome of such targets is perforated by external impacts or other factors, their aerodynamic characteristics change significantly, causing deviations from their flight paths and posing a huge challenge to tracking and monitoring.

[0003] Traditional trajectory prediction methods are typically based on aerodynamic models and kinematic equations of undamaged targets, which cannot accurately reflect the changes in aerodynamic characteristics after hood perforation, leading to significant deviations between predicted and actual trajectories. Existing trajectory prediction methods that consider damage effects mainly employ simplified linear models to handle hood perforation problems. This simplification ignores the nonlinear effects of factors such as perforation shape, size, and location on the flow field, failing to accurately describe aerodynamic characteristic changes under complex perforation conditions. Furthermore, these methods often lack real-time performance and dynamic adaptability, failing to meet the demands of rapidly changing monitoring environments.

[0004] Therefore, how to accurately predict the flight trajectory of high-speed aerial targets under the condition of visor perforation has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, this invention provides a method for predicting the flight trajectory of high-speed aerial targets under conditions of hood perforation. This method establishes a nonlinear aerodynamic analysis model of the flow field under hood perforation through fluid dynamics numerical simulation, dynamically updates the target's aerodynamic coefficients, and registers real-time flight data with the flight dynamics model to achieve accurate prediction of the flight trajectory of high-speed aerial targets under hood perforation conditions.

[0006] This invention proposes a method for predicting the flight trajectory of a high-speed aerial target under conditions of a perforated visor, comprising the following steps:

[0007] 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.

[0008] 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 perforated flow field 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.

[0009] The velocity and pressure distribution are imported into the aerodynamic data file, and the aerodynamic coefficient data is dynamically updated.

[0010] Update the aerodynamic parameter database and perform trajectory prediction;

[0011] 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.

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

[0013] Calculate the angle-of-attack-sideslip angle distribution curves at specified Mach numbers;

[0014] A three-dimensional geometric model of the hood perforation area was established using fluid dynamics analysis software. Boundary conditions and initial conditions were set, and numerical simulation calculations were performed to obtain velocity and pressure field data of the perforation area. Combined with angle of attack, sideslip angle and pressure distribution data, aerodynamic data files were generated.

[0015] For all perforations, mesh the perforation areas at all angles of attack and sideslip angles;

[0016] Select boundary values ​​for angle of attack and sideslip angle, including maximum and minimum sideslip angle, maximum and minimum angle of attack;

[0017] 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.

[0018] A continuous pressure distribution function is obtained through interpolation;

[0019] Calculate the angle of attack-side slip angle distribution curves at different Mach numbers;

[0020] 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.

[0021] Preferably, 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.

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

[0023] The target flight dynamics equations were constructed, and the flow field characteristics after the helmet was perforated were introduced. Mach number and pressure distribution were incorporated into the target flight dynamics equations.

[0024] The Mach number, angle of attack, and sideslip angle data from the calculation coefficient parameter data of the target flight dynamics model are introduced;

[0025] Calculate the current angle of attack and sideslip angle;

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

[0027] Calculate the Mach number at the angle of attack and the sideslip angle, and update the aerodynamic coefficient values.

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

[0029] 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.

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

[0031] 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.

[0032] Preferably, the method further includes the step of establishing a model of the head hood perforation damage state:

[0033] 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;

[0034] Calculate the aerodynamic pressure during flight at the current moment based on the target's current flight state parameters;

[0035] Calculate the impact force and pressure on the target's hood;

[0036] Based on the calculated impact force and pressure, calculate the current strength coefficient of the hood;

[0037] Determine the current perforation damage status of the hood and construct a hood perforation damage status model;

[0038] Repeat the above steps to calculate the hood perforation damage status of the target at different times during flight.

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

[0040] Based on the research results of the physical characteristics of the target hood perforation, the hood perforation damage parameters are defined;

[0041] Determine the damage status of the headgear at different points under different damage parameters;

[0042] Based on the perforation type and damage parameters of the target's hood, a structural model of the target hood is constructed;

[0043] The types of perforation include two types of damage: punching perforation and shearing tear.

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

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

[0046] Based on the target's current flight state and theoretical flight trajectory, calculate the target's current force conditions and aerodynamic load coefficients;

[0047] 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.

[0048] Based on the current hood perforation damage state and aerodynamic load coefficient, calculate the target aerodynamic load considering the hood perforation state.

[0049] Calculate the aerodynamic parameters of the target considering the hood perforation state, and correct the target's flight trajectory;

[0050] 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.

[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 under high angle 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 1This is a flowchart of a method for predicting the flight trajectory of a high-speed aerial target under conditions of visor perforation, according to the present invention;

[0065] Figure 2 This is a flowchart illustrating the construction of the nonlinear hood perforation flow field aerodynamic analysis model in this invention;

[0066] Figure 3 This is a schematic diagram of the mesh division of the perforated area in this invention;

[0067] Figure 4 This is a flowchart of the dynamic update process of aerodynamic coefficients in this invention;

[0068] Figure 5 This is a flowchart of the headgear perforation damage state model construction process in this invention;

[0069] Figure 6 This is a comparison diagram of the effects of different perforation shapes on pressure distribution in this invention. Detailed Implementation

[0070] Please refer to Figures 1-6 The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0071] like Figure 1 As shown, this invention provides a method for predicting the flight trajectory of a high-speed aerial target under conditions of a perforated visor, comprising the following steps:

[0072] First, the calculated coefficient parameter data of the target flight dynamics model are acquired, and a trajectory prediction framework based on the correlation registration between the three-degree-of-freedom target flight dynamics model and the target's real-time flight data is established. In a preferred embodiment of the invention, the acquired coefficient parameter data includes aerodynamic coefficients, inertial parameters, control surface effectiveness, etc. These parameters are typically obtained through wind tunnel testing, historical data analysis, or theoretical calculations. For example, for a typical high-speed scientific research aircraft, it may be necessary to acquire aerodynamic coefficient data with a Mach number range of 3.0 to 8.0 and an angle of attack range of -5° to 20°. The three-degree-of-freedom target flight dynamics model considers the translational degrees of freedom of the target in three-dimensional space, and establishes the differential equations of motion using Newton's second law to describe the changes in the target's position, velocity, and acceleration over time.

[0073] The trajectory prediction framework established in this invention can be represented as:

[0074] ,

[0075] ,

[0076] in, This is a position vector, representing the target's coordinate position in three-dimensional space, in meters (m). This is a velocity vector, representing the target's velocity in three-dimensional space, with units of m / s; This is the derivative of the position vector with respect to time, i.e., the velocity vector, with units of m / s; This is the derivative of the velocity vector with respect to time, i.e., the acceleration vector, with units of m / s². The target mass is expressed in kg. The net force acting on the target, expressed in N; Aerodynamic force, generated by the interaction between the target and the air, is measured in N; Gravity is the force generated by Earth's gravitational pull, and its unit is N; Control force, generated by the target control system, such as rudder deflection, is measured in N.

[0077] Real-time flight data includes, but is not limited to, Mach number, atmospheric pressure, altitude, angle of attack, roll angle, yaw angle, pitch angle, target pitch deflection, target roll deflection, and target yaw deflection. This data is typically obtained through sensors on the target or external observation systems. In practical applications, the data acquisition frequency is usually between 10 and 100 Hz to ensure the capture of rapid changes in the target's motion. 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 in the perforated area of ​​the hood was numerically simulated using fluid dynamics analysis software to obtain velocity and pressure field data. A high-order polynomial fitting method was then used to establish a nonlinear aerodynamic analysis model of the flow field through the perforated hood. Combined with coefficient parameter data, the Mach number and pressure distribution after the hood was perforated were calculated. Figure 2 As shown, this step is the core innovation of the present invention, which solves the problem that traditional linear models cannot accurately describe the impact of headgear perforation.

[0079] In one embodiment of the invention, a three-dimensional geometric model of the perforated region of the hood is established using commercial fluid dynamics analysis software (such as ANSYS Fluent, STAR-CCM+, or OpenFOAM), including the target shape and detailed geometry of the perforations. Appropriate boundary conditions are set, including the incoming Mach number, incoming static pressure, and incoming static temperature, and a suitable turbulence model (such as the SST k-ω model or the Spalart-Allmaras model) is selected for numerical simulation. Detailed flow field information of the perforated region, including velocity, pressure, density, and temperature fields, is obtained by solving the Navier-Stokes equations.

[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 the 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; , The order of the polynomial determines the fitting accuracy; it is typically 3-5 and is dimensionless.

[0085] Based on experience, for common circular or elliptical perforations, a third-order polynomial ( This usually provides sufficient fitting accuracy, with errors controlled within 5%; however, for irregularly shaped perforations, such as star-shaped or crack-shaped perforations, higher-order polynomials (such as...) may be required. This allows for the capture of complex airflow variations, keeping errors within an acceptable range (typically less than 10%). For example, when irregular, tear-like perforations form on the nose cone of a hypersonic civilian aircraft, fifth-order polynomial fitting can reduce the average error in pressure distribution prediction from 25% to 7% using conventional methods.

[0086] like Figure 3 As shown, this invention performs mesh generation within the perforation region at all angles of attack and sideslip angles for all perforations. Preferably, a non-uniform mesh is used, with higher mesh density in areas of rapid airflow change, such as the perforation edges, and relatively sparse mesh in areas of gentle change. This improves computational efficiency while maintaining computational accuracy. For typical hypersonic civilian aircraft canopy perforation problems, a mesh element count between 500 and 2000 is reasonable, depending on the complexity of the perforation and the required computational accuracy. For example, for a circular perforation with a diameter of 10 mm, approximately 800 mesh elements typically provide good computational accuracy; while for complex, irregular perforations, 1500 or more mesh elements may be needed to accurately capture flow field changes.

[0087] This invention selects boundary values ​​for the angle of attack and sideslip angle, including the maximum value of the sideslip angle ( ), minimum sideslip angle ( ), maximum angle of attack ( ) and minimum angle of attack ( In practical applications, these boundary values ​​are typically determined based on the target's flight characteristics. For example, for a typical hypersonic civilian aircraft, the angle of attack range might be between -10° and 30°, and the sideslip angle range between -15° and 15°. For specific missions, these ranges may be further narrowed to improve computational efficiency. For instance, for a hypersonic cruise civilian aircraft designed with a cruise angle of attack of 3°, it might only be necessary 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 practical flight conditions.

[0088] After selecting the combined angle of attack and sideslip angle, this invention performs two-dimensional integration within the grid to form the pressure distribution under different angles of attack and sideslip angles. The two-dimensional integration uses the Gaussian integration method, and its form is as follows:

[0089] ,

[0090] in, Indicates in the region Perform double integration on the above; The integral region is a two-dimensional plane, i.e., the perforated region, and the unit is m², representing the area element. This represents the summation operation; , The number of integration points in the x and y directions is dimensionless and represents the number of discrete points selected in each direction. , The weighting coefficients of the Gaussian integral are dimensionless and predetermined according to the theory of Gaussian integrals. Coordinates The pressure value at that location, in Pa; For the first The x-direction integration point and the th x-direction integration point The coordinates are formed by integrating points along the y-direction, with units of meters (m). Typically, for moderately complex perforations, a [missing information - likely a specific method or technique] is used. The high number of integration points allows for better computational accuracy, keeping integration errors within 2%. For example, using 5×5 Gaussian integration points to calculate an elliptical perforation on the nose cone of a hypersonic civilian aircraft can accurately obtain the pressure distribution under different combinations of angles of attack and sideslip angles, providing a reliable basis for subsequent aerodynamic characteristic analysis.

[0091] By interpolation, this invention obtains a continuous pressure distribution function. Preferably, cubic spline interpolation is used to ensure that the interpolation function is continuously differentiable at the nodes, thereby more accurately reflecting 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 that require the continuity of high-order derivatives.

[0092] Then, the present invention calculates the angle-of-attack-sideslip angle distribution curves at different Mach numbers, and imports the different pressure distributions and angle-of-attack-sideslip angle distribution curves into an 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 operating 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 dedicated hypersonic civilian aircraft, more attention may be paid to data in the range of Ma=4.0 to 8.0. In this case, more densely packed Mach number points such as Ma=4.0, 5.0, 6.0, 7.0, and 8.0 can be selected to ensure more accurate interpolation results within this working range.

[0093] Next, this invention incorporates velocity and pressure distribution into the aerodynamic data file, dynamically updating the aerodynamic coefficient data. For example... Figure 4 As shown, this step includes the following specific steps:

[0094] First, the target flight dynamics equations are constructed, incorporating the flow field characteristics after the visor is perforated, and including Mach number and pressure distribution in the equations. These equations are based on Newton's second law and consider the effects of various forces, including aerodynamic forces and gravity. After the visor is perforated, the flow field characteristics change significantly, especially the non-uniform pressure distribution, which leads to additional forces and moments, affecting the target's flight trajectory. For example, if a perforation occurs on the right side of the visor of a hypersonic civilian aircraft, the local pressure on the right side will be significantly higher than on the left, generating an additional yaw moment. If not compensated for in time, this could cause the civilian aircraft to deviate from its intended course.

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

[0096] Next, calculate the angle of attack at the current moment ( ), sideslip angle ( The angle of attack is defined as the angle between the velocity vector and the longitudinal axis of the aircraft, while the sideslip angle is defined as the angle between the projection of the velocity vector outside the plane of symmetry of the aircraft and the longitudinal axis of the aircraft. 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 civilian aircraft performs a maneuver, the angle of attack may increase rapidly from 2° to 15°. In this case, it is necessary to calculate the new angle of attack value in real time to update the aerodynamic coefficients.

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

[0098] ,

[0099] ,

[0100] ,

[0101] in, is the pitch moment coefficient, representing the moment coefficient about the horizontal axis, which is dimensionless; The yaw moment coefficient represents the moment coefficient about the vertical axis and is dimensionless. is the rolling moment coefficient, representing the moment coefficient about the longitudinal axis, which is dimensionless; Angle of attack, representing the angle between the velocity vector and the longitudinal axis of the aircraft, is expressed in radians or degrees. The sideslip angle represents the angle between the projection of the velocity vector outside the plane of symmetry of the aircraft and the longitudinal axis of the aircraft, and is expressed in radians or degrees. Mach number, representing the ratio of flight speed to the local speed of sound, is dimensionless.

[0102] These aerodynamic coefficients directly determine the target's flight stability and maneuverability. For example, for a hypersonic civilian aircraft designed for a cruise angle of attack of 3°, the pitch moment coefficient at that angle of attack is typically close to zero, indicating a trim state; however, when the angle of attack increases to 8°, It might change to -0.05, generating a downward moment that returns the aircraft to a smaller angle of attack. When the visor is perforated, these coefficients change; for example, a perforation on the right side could cause the yaw moment coefficient to change from near zero to 0.02, resulting in a tendency to yaw to the right.

[0103] Finally, the Mach number at the angle of attack and sideslip angle is calculated, and the aerodynamic coefficient values ​​are updated. A complex nonlinear relationship exists between the Mach number and the angle of attack and sideslip angle, especially when the visor is perforated. This invention accurately calculates this relationship using a nonlinear aerodynamic analysis model of the flow field through the perforated visor, and updates the aerodynamic coefficients accordingly. For example, when the aircraft flies at Mach 6 at an angle of attack of 5°, the local Mach number in the perforated region of the visor may drop to 4.5, while a complex Mach number distribution may form downstream of the perforation. These changes will affect the overall aerodynamic coefficients.

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

[0105] Based on the target flight dynamics equations, an aerodynamic coefficient model is established, which includes the angle of attack (...). ), sideslip angle ( ), angle of attack partial derivative, Mach number ( The aerodynamic coefficient model, including its partial derivatives and the partial derivatives of various moment coefficients, is the core of trajectory prediction, determining the aerodynamic characteristics of the target under different flight conditions.

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

[0107] ,

[0108] Wherein, the left-hand vector represents the set of aerodynamic coefficients, including is the lift coefficient, representing the aerodynamic coefficient perpendicular to the direction of the incoming flow, and is dimensionless; is the lateral force coefficient, representing the aerodynamic force coefficient perpendicular to the longitudinal plane, and is dimensionless; is the drag coefficient, representing the aerodynamic coefficient opposite to the direction of the incoming flow, and is dimensionless; is the rolling moment coefficient, representing the moment coefficient about the longitudinal axis, which is dimensionless; is the pitch moment coefficient, representing the moment coefficient about the horizontal axis, which is dimensionless; yaw moment coefficient, representing the moment coefficient about the vertical axis, is dimensionless.

[0109] In the first vector on the right, The reference coefficient represents the aerodynamic coefficient value under reference conditions; it is dimensionless. This represents the various aerodynamic coefficients mentioned above. The matrix in the second term on the right represents the sensitivity matrix, where... Represents coefficients For parameters The partial derivatives of the aerodynamic coefficients describe the sensitivity of the aerodynamic coefficients to changes in various flight parameters, and are dimensionless. For example, This represents the partial derivative of the lift coefficient with respect to the angle of attack, describing the effect of changes in the angle of attack on lift. This represents the partial derivative of the pitch moment coefficient with respect to the Mach number, describing the effect of changes in the Mach number on the pitch moment.

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

[0111] For specific hypersonic civilian aircraft, these parameters have specific numerical ranges. For example, a typical hypersonic cruise civilian aircraft, under the conditions of a design cruise Mach number of 6.0 and a cruise angle of attack of 3°, has a base lift coefficient. It could be 0.3, the partial derivative of the lift coefficient with respect to the angle of attack. It might be 0.05 / degree, meaning that for every 1 degree increase in angle of attack, the lift coefficient increases by 0.05. These coefficient values ​​will change after the radome is perforated. For example, for the same aircraft, after a 10mm diameter perforation in the radome... It may drop to 0.28, while It may become 0.048 / degree, indicating a decrease in aerodynamic efficiency.

[0112] By inputting Mach number, angle of attack, and sideslip angle data into the aerodynamic coefficient model, the target's flight dynamics matrix is ​​obtained. This matrix describes the target's equations of motion and forms the basis for trajectory integration. For example, when a hypersonic civilian aircraft flies at Mach 6.5, an angle of attack of 4°, and a sideslip angle of 0.5°, substituting these parameters into the aerodynamic coefficient model yields the set of aerodynamic coefficients for the current state, thus constructing a complete flight dynamics matrix.

[0113] The triangular decomposition method is used to obtain the target's flight dynamics coefficients, including lift coefficient, side force coefficient, pitch moment coefficient, roll moment coefficient, and yaw moment coefficient. The triangular decomposition method is an efficient numerical method for solving linear equations. It decomposes the coefficient matrix into the product of upper and lower triangular matrices, and then solves the equations through forward and backward substitutions. For example, for hypersonic civilian aircraft with perforated pylons, the triangular decomposition method can efficiently calculate various aerodynamic coefficients, providing accurate input for trajectory prediction.

[0114] Finally, this invention incorporates velocity and pressure distribution data into a three-degree-of-freedom target flight dynamics model, performs registration updates, and obtains the predicted trajectory. This step is crucial to the entire prediction process, integrating the results of all preceding steps to generate the final predicted trajectory. For example, when the canopy of a hypersonic civilian aircraft is damaged, traditional methods might predict that it will continue flying along its original course. However, the method of this invention can accurately calculate the aerodynamic imbalance caused by the canopy perforation, predicting that the aircraft will gradually yaw and eventually deviate from its original landing point by several kilometers. This has significant reference value for accurately determining the actual landing point of the aircraft and formulating safety protection measures.

[0115] In another embodiment of the invention, the method further includes the step of establishing a model of the hood perforation damage state, such as... Figure 5 As shown:

[0116] First, kinematic and dynamic calculations are performed on the target's flight data at the current moment to derive its current flight state parameters. These parameters include position, velocity, and attitude angles, which together describe the target's motion state at a given moment. For example, for a hypersonic cruise civilian aircraft, its flight state parameters might include: position (x=15000m, y=8000m, z=25000m), velocity (vx=1800m / s, vy=200m / s, vz=50m / s), and attitude angles (roll angle=5°, pitch angle=3°, yaw angle=10°), etc.

[0117] Then, the aerodynamic pressure during the current flight moment is calculated based on the target's current flight state parameters. Aerodynamic pressure is related to parameters such as flight speed, altitude, and angle of attack, and can be obtained using conventional aerodynamic calculation methods. For example, for flight conditions of Mach 6.0 and an altitude of 25 km, the flow pressure q might be around 30 kPa. Combining the target's geometry and angle of attack, the pressure distribution on the helmet surface can be calculated.

[0118] Next, the impact force and pressure on the target pylon are calculated. These force calculations need to take into account aerodynamic pressure, pylon structural characteristics, and perforation conditions. For example, when there is a 10mm diameter perforation on the pylon of a hypersonic civilian aircraft, the edge of the perforation may experience local pressures as high as 100kPa, which is much higher than the pressure in areas without perforations.

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

[0120] Next, the current perforation damage state of the hood is determined, and a hood perforation damage state model is constructed. The damage state model describes the geometric characteristics, location distribution, and impact on aerodynamic properties of the hood perforations. For example, the model may show that during high-speed flight, the diameter of the original perforation may increase from the initial 10 mm to 12 mm due to aerodynamic heat and pressure.

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

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

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

[0124] Determine the damage at different points on the helmet under various damage parameters. This step typically requires a combination of theoretical analysis, numerical simulation, and experimental verification. For example, finite element analysis can determine the perforation diameter, crack distribution in the surrounding area, and the degree of structural integrity reduction when the helmet is struck by a fragment of a specific energy.

[0125] Based on the perforation type and damage parameters of the target hood, a structural model of the hood is constructed. The structural model is the foundation for subsequent aerodynamic analysis; it needs to accurately reflect the hood's geometry, material properties, and damage state. For example, for a hood made of carbon fiber composite material, its structural model needs to consider the material's anisotropy, interlaminar strength, and response characteristics to perforation.

[0126] The types of perforation include two types of damage: punching perforations and shear tears. Punching perforations are usually formed by direct impact from regular objects such as cones, resulting in a relatively regular shape and clean edges. Shear tears, on the other hand, are usually formed by impact from irregularly shaped objects, resulting in an irregular shape and possible tearing and deformation at the edges. For example, when a cylindrical object with a diameter of 5-7 mm directly impacts the hood, it will usually form a circular punching perforation with a diameter of about 8-9 mm; while when an irregular polygonal object of the same length and width impacts the hood, it may form an irregular shear tear, which can reach a length of 15-20 mm and has an uneven width.

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

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

[0129] Based on the target's current flight state and theoretical flight trajectory, the current forces and aerodynamic load coefficients are calculated. These forces and coefficients are direct inputs for trajectory prediction. For example, for a hypersonic vehicle flying at Mach 6, the aerodynamic lift during normal flight might be 20 kN, the drag 5 kN, and the lateral force close to zero. When the radome is damaged, these forces will change; for example, the lateral force might increase to 1 kN, causing the flight trajectory to deviate.

[0130] Based on the perforation shape, size, and depth, the current perforation state of the target's hood is determined in the hood perforation damage state model. This step establishes a mapping relationship between damage parameters and specific perforation states. For example, when a circular perforation with a diameter of 12 mm and a depth of 9 mm is detected on the hood, the model can determine that this is a perforation caused by a medium-energy projectile, and accordingly estimate that the structural strength of the area surrounding the perforation is reduced by 25%.

[0131] Based on the current hood perforation damage state and aerodynamic load coefficients, calculate the target aerodynamic load considering the hood perforation state. This step is crucial for integrating the perforation effect into the aerodynamic calculation. For example, when there is a perforation on the right side of the hood, aerodynamic analysis may indicate a change in the pressure distribution on the right side, resulting in an additional yaw moment. This moment needs to be accurately calculated and incorporated into the dynamic model.

[0132] The aerodynamic parameters of the target, considering the puncture of the visor, are calculated to correct the target's flight trajectory. The correction process needs to account for the additional forces and moments caused by the puncture, and their impact on the target's motion. For example, when the visor of a hypersonic vehicle is damaged, its aerodynamic center may shift forward, leading to a decrease in static stability, which needs to be considered in trajectory prediction.

[0133] The target's current flight trajectory is calibrated based on the calculated aerodynamic parameters, yielding the target's actual flight trajectory at that moment. The calibrated trajectory more closely approximates the target's actual flight trajectory under hood perforation conditions. For example, using the method of this invention, the increase in aircraft yaw angle caused by hood perforation can be accurately predicted, potentially causing the target to deviate from its original course by 200m after a flight distance of 5km.

[0134] In another embodiment of the invention, the real-time flight data of the target 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. This data is typically acquired through sensors on the target or external observation systems, and it serves as the fundamental 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 might 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 deflection -1°, etc.

[0135] In another embodiment of the present invention, during flight, when the target meets any of the following conditions, the steps of establishing a nonlinear hood perforation flow field aerodynamic analysis model using fluid dynamics analysis software, importing velocity and pressure distribution into the aerodynamic data file, updating the aerodynamic parameter database, and importing velocity and pressure distribution data into the three-degree-of-freedom target flight dynamics model are repeated:

[0136] The estimated hood failure time needs to be updated. Updates to the hood failure time are typically based on the latest observational data or damage assessment results, and they affect subsequent perforation effect analysis. For example, if sensor data reveals that the stress level in the perforated area of ​​the hood is close to the material's ultimate strength, the estimated failure time may need to be updated from 300 seconds after flight to 120 seconds after flight.

[0137] The incoming Mach number is measured. Mach number is a key parameter affecting aerodynamic characteristics, and its changes significantly impact the calculation of aerodynamic forces and moments. For example, when a hypersonic civilian aircraft accelerates from Mach 5.5 to Mach 6.5, its aerodynamic characteristics change significantly, requiring a remodeling and parameter update. Typically, an update process is triggered when the Mach number change exceeds 10% (e.g., from Ma=6.0 to Ma=6.6).

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

[0139] The aircraft's own velocity is measured. Velocity not only affects the magnitude of dynamic pressure but is also closely related to parameters such as Mach number and angle of attack. For example, when an aircraft decelerates by more than 15%, it may be necessary to reassess the impact of perforations on aerodynamic characteristics. Typically, an update process needs to be triggered when the velocity change exceeds 200 m / s or the relative change exceeds 10%.

[0140] The target position is measured. Position information is fundamental to trajectory prediction, directly impacting subsequent state updates and prediction calculations. For example, if an aircraft is found to have deviated from its expected flight path by more than 500 meters, it may be necessary to reassess the impact of the perforation and update the prediction model. Typically, an update process is triggered when the position deviation exceeds 5% of the expected flight path.

[0141] This dynamic update mechanism ensures that the trajectory prediction system can respond promptly to changes in flight conditions, improving prediction accuracy. For example, in a practical test, using the dynamic update mechanism of this invention, the trajectory prediction error was reduced by more than 40%, providing more reliable target information for accurately predicting the aircraft's landing point.

[0142] In this embodiment, a high-speed scientific research civilian aircraft is used as an example to illustrate the specific application of the method of the present invention. The aircraft's helmet radome developed a perforation with a diameter of approximately 15 mm after being subjected to an external impact.

[0143] First, obtain the calculation coefficient parameter data for the aircraft's flight dynamics model, including aerodynamic coefficient data in the Mach number range of 5-8. This data typically comes from wind tunnel testing or computational fluid dynamics (CFD) analysis. For example, the baseline lift coefficient of the aircraft at Mach number 6.5. Pitch moment coefficient drag coefficient A three-degree-of-freedom flight dynamics model was established, and real-time flight data of the civil aircraft was collected, including Mach number (Ma=6.5), flight altitude (h=25km), and angle of attack ( ). (etc.) The real-time data acquisition frequency is 50Hz to ensure that rapid changes in flight status can be captured.

[0144] Then, the flow field in the perforated area of ​​the hood was numerically simulated using ANSYS Fluent fluid dynamics analysis software. For the 15mm diameter circular perforation, a three-dimensional geometric model was established, and the incoming flow boundary conditions were set (Ma=6.5, static pressure=2.5kPa, static temperature=220K). The SST k-ω turbulence model was used for steady-state solution. The cross-sectional area of ​​the hood perforation was calculated. Maximum cross-sectional area Maximum radius , minimum radius The perforation is located on the right side of the hood, approximately 120mm from the tip of the head.

[0145] Using a fourth-order polynomial ( A fitting function was used to obtain the pressure distribution function of the perforated region. Since the perforation shape is relatively regular, a fourth-order polynomial could control the fitting error within 3%, meeting engineering accuracy requirements. The perforated region was meshed, generating 800 mesh elements, with the mesh density at the perforation edges being three times that of the central region. This non-uniform meshing method ensured computational accuracy in the edge regions while reducing the overall computational burden.

[0146] Angle of attack was selected from 0° to 10°, with 1° intervals; sideslip angle was selected from -5° to 5°, with 1° intervals. For each angle of attack-side slip angle combination, pressure distribution was calculated using two-dimensional integration, and a continuous pressure distribution function was obtained through cubic spline interpolation. For example, at an angle of attack... Sideslip angle Under these conditions, the maximum pressure in the perforated area reaches 45 kPa, which is about 35% higher than that in the case without perforation. This change in pressure distribution cannot be accurately captured by traditional linear models.

[0147] Then, the angle-of-attack-sideslip angle distribution curves at five Mach numbers (Ma=5.0, 6.0, 6.5, 7.0, and 8.0) were calculated, and these data were imported into the aerodynamic data file. These five Mach numbers were chosen because they cover the main operating range of the civil aircraft and provide sufficient accuracy for interpolation calculations.

[0148] Next, the velocity (v=2000m / s) and pressure distribution data are imported into the aerodynamic data file, and the aerodynamic coefficient data are dynamically updated. The angle of attack at the current moment is calculated. ), sideslip angle ( The corresponding aerodynamic coefficients, including the pitching moment coefficient, are obtained. Yaw moment coefficient Rolling torque coefficient The most significant change compared to the unperforated case is that the yaw moment coefficient increased from almost zero to 0.003, indicating that the perforation caused an unbalanced lateral force that would cause the civil aircraft to yaw to the right.

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

[0150] Finally, the velocity and pressure distribution data were incorporated into a three-degree-of-freedom flight dynamics model for registration and updating to obtain the predicted trajectory. The results show that, compared to traditional methods, the maximum deviation between the predicted trajectory and the actual trajectory is reduced by 42%, and the average deviation is reduced by 35%, significantly improving prediction accuracy. Specifically, the traditional method predicts a 2.8km deviation at the 100km range point, while the method of this invention reduces this deviation to 1.6km. This improvement in accuracy is of significant reference value for accurately determining the actual landing point of the aircraft.

[0151] During the flight of a civil aircraft, whenever the Mach number changes by more than 0.5 or the angle of attack changes by more than 2°, the system automatically rebuilds the model and updates the parameters to ensure the continuous accuracy of the predicted trajectory. For example, when a civil aircraft performs a maneuver and the angle of attack increases from 3° to 6°, the system reassesses the impact of the perforation on aerodynamic characteristics and updates the predicted trajectory. During a 5-minute flight, the system updates on average once every second, ensuring the continuity of prediction accuracy.

[0152] This invention is not limited to the above embodiments. Within the spirit and principles of this invention, various changes, modifications and substitutions can be made to the above embodiments without departing from the scope of this invention, which is defined by the appended claims and their equivalents.

Claims

1. A method for predicting the flight trajectory of an aerial high-speed target under the condition of head cover perforation, characterized in that, The method comprises the following steps: 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, wherein the three-degree-of-freedom target flight dynamics model is based on the 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; Numerically simulate the flow field of the head cover perforation area by using a fluid mechanics analysis software, obtain the velocity field and pressure field data, and establish a nonlinear head cover perforation flow field aerodynamic analysis model by using a high-order polynomial fitting method, and calculate the Mach number and pressure distribution after the head cover perforation in combination with the coefficient parameter data; Introduce the velocity and the pressure distribution into an aerodynamic data file, and dynamically update the aerodynamic coefficient data; Update the aerodynamic parameter database, and perform trajectory prediction; Introduce the velocity and the pressure distribution into the three-degree-of-freedom target flight dynamics model, perform registration and update, and obtain a predicted trajectory.

2. The method according to claim 1, wherein, The step of numerically simulating the flow field of the head cover perforation area by using a fluid mechanics analysis software, and establishing a nonlinear head cover perforation flow field aerodynamic analysis model by using a high-order polynomial fitting method specifically comprises: Calculate the angle of attack-side slip angle distribution curve under a specified Mach number respectively; Establish a three-dimensional geometric model of the head cover perforation area by using a fluid mechanics analysis software, set boundary conditions and initial conditions, perform numerical simulation calculation, obtain the velocity field and pressure field data of the perforation area, and form an aerodynamic data file in combination with the angle of attack, the side slip angle and the pressure distribution data; Divide the grid in the perforation area under all angles of attack and side slip angles for all perforations; Select the boundary values of the angle of attack and the side slip angle, including the maximum side slip angle, the minimum side slip angle, the maximum angle of attack and the minimum angle of attack; Select the combined angle of attack and side slip angle, and perform two-dimensional integration in the grid to form the pressure distribution under different angles of attack-side slip angles; Obtain a continuous pressure distribution function through interpolation; Calculate the angle of attack-side slip angle distribution curve under different Mach numbers; Introduce different pressure distributions and the angle of attack-side slip angle distribution curve into the aerodynamic data file to form a corrected aerodynamic parameter file.

3. The method of claim 2, wherein the method is characterized by: The nonlinear head cover perforation flow field aerodynamic analysis model considers the following parameters: head cover perforation cross-sectional area, head cover perforation maximum cross-sectional area, head cover perforation maximum radius, head cover perforation minimum radius, real Mach number, infinite distance pressure, infinite distance Mach number pressure, head cover perforation cross-sectional pressure, infinite distance airflow angle, head cover perforation cross-sectional airflow angle, angle of attack-side slip angle distribution curve under a Mach number, airflow angle along the pressure gradient, partial derivative of the pressure distribution to the x direction, partial derivative of the pressure distribution to the y direction, partial derivative of the Mach number distribution to the x direction, and partial derivative of the Mach number distribution to the y direction.

4. The method of claim 1, wherein, The step of introducing the velocity and the pressure distribution into an aerodynamic data file, and dynamically updating the aerodynamic coefficient data specifically comprises: Build a target flight dynamics equation, introduce the flow field characteristics after the head cover perforation, introduce the Mach number and the pressure distribution into the target flight dynamics equation; Mach number and angle of attack, side slip angle data in the calculation coefficient parameter data of the target flight dynamics model are introduced; The current angle of attack and side slip angle are calculated; The aerodynamic coefficients at the current angle of attack are calculated, including the aerodynamic moment coefficients of pitch, yaw and roll; The Mach number under the angle of attack and the side slip angle is calculated, and the aerodynamic coefficient value is updated.

5. The method of claim 1, wherein, The updating of the aerodynamic parameter database and the trajectory prediction step specifically includes: According to the target flight dynamics equation, an aerodynamic coefficient model is established, which includes the angle of attack, side slip angle, angle of attack partial derivative, Mach number and its partial derivative, and the partial derivative of various moment linear coefficients; Mach number and angle of attack, side slip angle data are input into the aerodynamic coefficient model to obtain the target flight dynamics matrix; The target flight dynamics coefficients are obtained by triangular decomposition method, including lift coefficient, side force coefficient, pitch moment coefficient, roll moment coefficient and yaw moment coefficient.

6. The method of claim 1, wherein, The method further includes the step of establishing a head cover perforation damage state model: According to the target flight data at the current time, the target kinematics and dynamics are calculated to obtain the flight state quantity of the target at the current time; According to the target flight state quantity at the current time, the aerodynamic pressure during the flight at the current time is calculated; The impact force and pressure on the target head cover are calculated; Based on the calculated impact force and pressure, the current strength coefficient of the head cover is calculated; The perforation damage state of the current head cover is determined, and the head cover perforation damage state model is constructed; The above steps are repeated to calculate the head cover perforation damage state of the target at different times during the flight.

7. The method of claim 6, wherein the method is a method of predicting a flight trajectory of an airborne high-speed target under a head cover perforation condition, characterized by, The head cover perforation damage state model is constructed based on the following process: Based on the research results of the physical characteristics of the target head cover perforation, the head cover perforation damage parameters are defined; The damage conditions of the head cover at different points under different damage parameters are determined; According to the perforation type and damage parameters of the target head cover, the target head cover structure model is constructed; The perforation type includes two types of damage, i.e. punching perforation and shear opening; The damage parameters include perforation shape, perforation size and perforation depth.

8. The method of claim 6, wherein the method is a method of predicting a flight trajectory of an airborne high-speed target under a head cover perforation condition, characterized by, The step of introducing the speed and pressure distribution data into the three-degree-of-freedom target flight dynamics model further includes: 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; According to the perforation shape, perforation size and perforation depth, the current head cover perforation state of the target is determined in the head cover perforation damage state model; According to the current head cover perforation damage state and the aerodynamic load coefficient, the target aerodynamic load considering the head cover perforation state is calculated; The target aerodynamic parameters considering the head cover perforation state are calculated, and the target flight trajectory is corrected; According to the calculated target aerodynamic parameters, the target flight trajectory at the current time is calibrated to obtain the actual flight trajectory of the target at the current time.

9. The method of claim 1, wherein the method is a method of predicting a flight trajectory of an overhead high-speed target head cover perforation condition, characterized by, 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.

10. The method of claim 6, wherein the method is a method of predicting a flight trajectory of an overhead high-speed target head cover perforation condition, characterized by, During the flight, when the target meets any one of the following conditions, the steps of establishing a nonlinear head cover perforation flow field aerodynamic analysis model by fluid mechanics analysis software, introducing the velocity and pressure distribution into the aerodynamic data file, updating the aerodynamic parameter database, and introducing the velocity and pressure distribution into the three-degree-of-freedom target flight dynamics model are re-performed: updating the estimated head cover failure time; measuring the incoming flow Mach number; measuring the angle of attack; measuring the own speed; measuring the target position.

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