Method for discriminating near space hypersonic target maneuver based on aerodynamic parameter identification

Abstract

The application discloses a near space hypersonic target maneuvering discrimination method based on pneumatic parameter identification, finds certain certainty law or common sense knowledge of the near space hypersonic target, makes more reasonable and accurate research and judgment on the target trajectory and maneuvering mode on the basis, and provides certain theoretical basis for rapid prediction of target attack range, reduction of detection area and early establishment of interception and attack scheme. The method comprises the following steps: firstly, the radar target tracking technology is used to realize the near space hypersonic target motion state estimation and identification of pneumatic parameters and guidance control parameters; secondly, the target motion is analyzed in the longitudinal and lateral directions, and the longitudinal gliding capacity and lateral turning capacity are analyzed according to the typical maneuvering mode types of the target; finally, the target maneuvering style is comprehensively discriminated by comprehensively combining the prior information such as enemy and our troop deployment, no-fly zone, and the maneuvering capacity of the typical near space hypersonic target.

Description

Technical Field

[0001] This invention relates to the field of near-space hypersonic target tracking, and in particular to a near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification. Background Technology

[0002] In recent years, with the rapid development of near-space hypersonic targets, the threat from aerospace has been increasing. Near-space hypersonic targets are characterized by non-ballistic maneuvering flight, low flight altitude, late radar detection time, and short detection and tracking time. Traditional defense systems struggle to detect and track these targets, and it is difficult to predict their trajectories and intercept them. These targets pose a serious challenge to the interception and strike capabilities of air defense and missile defense systems, and will have a disruptive impact on the operational modes, processes, and outcomes of future wars. Therefore, the need to develop near-space hypersonic target defense systems is becoming increasingly urgent.

[0003] Near-space hypersonic target tracking technology is a crucial component of near-space hypersonic target defense systems. In researching near-space hypersonic targets, this invention proposes a maneuver discrimination technique based on aerodynamic parameter identification. The essence of maneuver discrimination is to identify certain deterministic patterns or common-sense knowledge, and on this basis, to rationally analyze the target trajectory and maneuver patterns. The fundamental approach to improving discrimination accuracy is to extract as much prior information as possible from known intelligence such as measurement data, target characteristics, and enemy / friendly force deployments. Improved maneuver discrimination accuracy contributes to more accurate tracking of near-space hypersonic targets, while also providing a theoretical basis for rapid prediction of target strike range, narrowing the detection area, and formulating interception and strike plans as early as possible. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies and achieve precise tracking of hypersonic targets in near space, this invention adopts the following technical solution:

[0005] A near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification includes the following steps:

[0006] Step 1: Estimate and track the motion state of hypersonic targets in the airspace through radar target tracking, and identify aerodynamic parameters and guidance and control parameters;

[0007] Step 2: Perform longitudinal and lateral maneuver analysis on the target's motion, and analyze the target's longitudinal gliding ability and lateral turning ability based on the typical maneuvering patterns of this type of target;

[0008] Step 3: Based on the prior information from the basic database and the analysis results from Step 2, comprehensively determine the target's maneuvering patterns.

[0009] Further, step 1 includes the following steps:

[0010] Step 1.1: Decompose the maneuvering trajectory of the hypersonic target in the air into a longitudinal maneuvering trajectory and a lateral maneuvering trajectory, corresponding to the longitudinal acceleration a, respectively. h and lateral acceleration a x ;

[0011] Step 1.2: Track the target using radar. Based on the tracking filtering algorithm of the maneuvering reentry target model, obtain the longitudinal acceleration a. h and lateral acceleration a x The estimated value;

[0012] Step 1.3: Use the Extended Kalman Filter (EKF) algorithm to track the maneuvering reentry target.

[0013] Furthermore, the maneuvering reentry target model in step 1.2 considers the target's aerodynamic lift. In the Northeast-Eastern-Upper-Southern (ENU) coordinate system, the vector motion equation of the hypersonic target in the airspace is as follows:

[0014]

[0015] In the formula, r and Let v and v represent the target's position vector and its derivative, respectively; Let a represent the target's velocity vector and its derivative, respectively. A a represents aerodynamic acceleration. G w represents gravitational acceleration. e The angular velocity of Earth's rotation is the target velocity, and the target is only the gravitational acceleration a. G Under the influence of the force, the motion manifests as inertial ballistic reentry motion; in a A Under the influence of each component, the target possesses non-inertial ballistic reentry and maneuverability.

[0016] Further, in step 1.2, at time k, the aerodynamic parameters estimated by the Maneuvering Reentry Target Model (MaRV) tracking algorithm are:

[0017]

[0018] Among them, C L and C D These are the lift coefficient and drag coefficient, respectively; α is the angle of attack. and Let a represent the drag parameter, turning force parameter, and climb force parameter of each coordinate component in the half-velocity coordinate system at time k, respectively; Equation (2) shows that the aerodynamic parameter a M It is independent of changes in atmospheric density ρ, can directly characterize the anisotropic maneuvers of the target, and has clear physical meaning: and These correspond to the target's horizontal left and right turn maneuvers, respectively. and Corresponding to the target's climb and dive maneuvers respectively, using aerodynamic parameter a M Replace aerodynamic acceleration a A The model parameters can be adjusted directly based on the target's maneuvering characteristics, which helps improve observation accuracy; α represents the angle of attack and σ represents the bank angle, both of which are guidance control parameters. The angle of attack α affects the aerodynamic acceleration α during flight by influencing the aerodynamic coefficient. A The change in angle of attack directly affects the aerodynamics of the hypersonic glide vehicle; the inclination angle σ is a key control parameter that directly affects the track inclination and heading angle during flight, and indirectly affects the target's position and speed; S represents the reference area, and m represents the vehicle's mass.

[0019] Furthermore, in step 1.2, different maneuvering modes are identified by analyzing the relationship between maneuvering acceleration and control parameters; at time k, the position and velocity coordinates estimated by the Maneuvering Reentry Target Model (MaRV) tracking algorithm are respectively... and Estimates of longitudinal and lateral acceleration are obtained. and

[0020]

[0021] This represents the x, y, and z components of the estimated position at time k. This represents the estimated velocity components along the xyz axes at time k;

[0022] according to and Based on the relationship, an estimated value of the yaw angle is obtained.

[0023]

[0024] At this point, the target state vector x is composed of the target state components and aerodynamic parameters:

[0025]

[0026] In the formula, x, y, and z represent the coordinates of the target on the x, y, and z axes in the northeast-northeast coordinate system, respectively. and Let a and b represent the derivatives of the target's coordinates on the x, y, and z axes in the northeast-northeast coordinate system, respectively. v a t and a c These represent the drag, turning force, and climb force parameters of each coordinate component in the half-velocity coordinate system, respectively.

[0027] The equations of motion for the aerodynamic parameters are expressed using a white noise model as follows:

[0028]

[0029] in, w represents the derivative of the aerodynamic parameter. a =[w v w t w c ] T w a It is a column vector, w v w t and w c These represent the drag, turning force, and climb force parameters of each coordinate component under the white noise model, respectively.

[0030] The nonlinear state transition function f(x) of the Maneuvering Reentry Target Model (MaRV) in the Northeast-Eastern-Sky (ENU) coordinate system is expressed as:

[0031]

[0032] In the formula, μ is the Earth's gravitational constant; the aerodynamic accelerations in three directions under the radar station's northeast-northeast coordinate system (ENU); r is the distance from the Earth's center; R e A is the Earth's radius; x A y and A z They represent respectively;

[0033] The Maneuvering Reentry Target Model (MaRV) is highly nonlinear. To apply this model, the Jacobian matrix corresponding to f(x) is given:

[0034]

[0035] In the formula, g represents the gravitational acceleration vector; r and v represent the target's position vector and velocity vector, respectively; I 3×3 Represents the identity matrix; This represents the aerodynamic acceleration in the ENU coordinate system.

[0036] Furthermore, in step 2, for a longitudinally maneuvering trajectory, a hypersonic target in the airspace is mainly affected by aerodynamic lift and gravity, and the magnitude of the longitudinal maneuvering acceleration a h Represented as:

[0037]

[0038] In the formula, a h The acceleration is expressed as the velocity from the Earth's center of gravity towards the spacecraft's center of mass; L represents the aerodynamic lift acceleration; σ is the roll angle; gr γ represents the gravitational acceleration; V is the spacecraft velocity; r is the distance from the Earth's center; and γ is the velocity tilt angle. The three terms on the right-hand side of the formula represent the vertical component of lift acceleration, gravitational acceleration, and centrifugal acceleration, respectively.

[0039] When the longitudinal force approximately satisfies the equilibrium condition, i.e., a h ≈0, the hypersonic target in the air performs balanced gliding flight, and the trajectory pattern is Qian Xuesen trajectory; when the force does not meet the conditions for balanced gliding, due to the change of lift acceleration L with air density, the target will perform jump gliding flight by decaying and oscillating along the balanced gliding trajectory, and the trajectory pattern is Sanger trajectory.

[0040] Furthermore, during the jump, when γ < 0, the target is in the downward phase of the jump; when γ > 0, the target is in the upward phase of the jump. As the flight progresses, the target's altitude gradually decreases, the air density gradually increases, and the lift acceleration L also increases accordingly. In this situation, as L increases and the velocity V decreases, the rate of change of the velocity tilt angle increases. It will gradually increase; the target will jump more frequently;

[0041] Under the influence of aerodynamic drag, the target's kinetic energy gradually decreases, and the longitudinal jump amplitude also gradually decreases; the flight trajectory approximately exhibits a damped change with an increasing frequency and a decreasing amplitude and mean.

[0042] Furthermore, in step 2, at time k, if the longitudinal motion acceleration... Maintain at 0±1m / s 2 If the speed is within (m / s²), the target is judged to be gliding in a balanced manner; if If the oscillations are periodic, it can be determined that the target is jumping and gliding.

[0043] Jump-glide trajectory analysis determines whether the target is in the ascent or descent phase by estimating the distance from the Earth's center and... Determining the periodic change segments.

[0044] Furthermore, in step 2, in lateral maneuver mode, hypersonic targets in the airspace generally achieve lateral maneuvering by changing the sign of the tilt angle guidance command and using left and right tilting, thus bypassing enemy detection areas or obstacles to achieve maneuver evasion. The lateral acceleration satisfies a x satisfy:

[0045]

[0046] Among them, a xχ represents the centripetal acceleration of the aircraft during lateral turning; χ is the velocity azimuth angle; by tilting the projectile, the tilt angle σ gradually increases, and the aircraft uses the lateral component of lift acceleration Lsinσ to provide centripetal acceleration to achieve lateral turning.

[0047] Total lift F on the target L satisfy:

[0048]

[0049] Therefore, the lateral turning radius R m satisfy:

[0050]

[0051] R m The basic parameters of the aircraft (mass m, reference area S) M Lift coefficient C L And related to the tilt angle ν, due to m and S M For constant values, and atmospheric density ρ and C L As a slow variable, the change in maneuverability mainly depends on the change in ν;

[0052] In the initial stages of flight, the higher altitude results in thinner air, increasing ρ and C. L Both are relatively small, resulting in a larger turning radius and lower maneuverability at this stage; in the later stages of flight, due to the decrease in flight altitude, ρ and C... L As the radius gradually increases, the turning radius gradually decreases, and the maneuverability also increases.

[0053] Furthermore, in step 2, at time k, the target turning state is analyzed; according to The sign is used to determine if Then the target turns left horizontally; if The target is horizontally turned right; if The target is in a straight flight state;

[0054] For a turning target, estimate the turning radius; in the lateral acceleration estimate... Based on this, the estimated turning radius for:

[0055]

[0056] This represents the estimated velocity component along the xyz axes at time k.

[0057] The advantages and beneficial effects of this invention are as follows:

[0058] The proposed method for identifying near-space hypersonic target maneuvers based on aerodynamic parameter identification uses longitudinal acceleration estimation to determine the target's longitudinal ballistic pattern and skip-glide period. It can also effectively determine the target's lateral maneuvers, enabling the identification of straight flight, left turns, and right turns, as well as the estimated turning radius. This further improves the tracking accuracy of near-space hypersonic targets and provides a theoretical basis for rapid prediction of target strike range, narrowing the detection area, and formulating interception and strike plans as early as possible. Attached Figure Description

[0059] Figure 1 This is a flowchart of a near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification in an embodiment of the present invention.

[0060] Figure 2 This is a schematic diagram of aerodynamic acceleration in a half-velocity coordinate system in an embodiment of the present invention.

[0061] Figure 3a This is a model diagram of the angle of attack control quantity during ballistic simulation in an embodiment of the present invention.

[0062] Figure 3b This is a model diagram of the tilt angle control quantity during ballistic simulation in an embodiment of the present invention.

[0063] Figure 4 This is a schematic diagram of the longitudinal gliding trajectory of a hypersonic target in the airspace, as described in an embodiment of the present invention.

[0064] Figure 5 This is a schematic diagram of the lateral maneuvering mode of a hypersonic target in the airspace in an embodiment of the present invention.

[0065] Figure 6a These are height curves of two types of ballistic scenarios generated in the simulation experiment of this invention.

[0066] Figure 6b These are latitude and longitude curves of two types of ballistic scenarios generated in the simulation experiment of this invention.

[0067] Figure 6c These are velocity curves for two types of ballistic scenarios generated in the simulation experiment of this invention.

[0068] Figure 6d The images show the trajectory diagrams of two types of ballistic scenarios in the ENU coordinate system of the radar station generated during the simulation experiment of this invention.

[0069] Figure 7a This is a simulation experiment diagram showing the estimated height and longitudinal acceleration of target trajectory 1 in this invention.

[0070] Figure 7bThis is a simulation experiment diagram showing the estimated height and longitudinal acceleration of target ballistics 2 in an embodiment of the present invention.

[0071] Figure 8a This is a simulation experiment diagram of the target's lateral acceleration estimation in an embodiment of the present invention.

[0072] Figure 8b This is a simulation experiment diagram of the target tilt angle estimation in an embodiment of the present invention.

[0073] Figure 8c This is a simulation experiment diagram of the target turning radius estimation in this embodiment of the invention. Detailed Implementation

[0074] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0075] like Figure 1 As shown, a near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification includes the following steps:

[0076] Step 1: Estimate and track the motion state of hypersonic targets in the airspace through radar target tracking, and identify aerodynamic parameters and guidance and control parameters;

[0077] The specific steps are as follows:

[0078] Step 1.1: Decompose the maneuvering trajectory of the hypersonic target in the air into a longitudinal maneuvering trajectory and a lateral maneuvering trajectory. The two maneuvering trajectories correspond to longitudinal acceleration a, respectively. h and lateral acceleration a x ;

[0079] Step 1.2: Track the target using radar. Based on the tracking filtering algorithm of the maneuvering reentry target model, obtain the longitudinal acceleration a. h and lateral acceleration a x The estimated value;

[0080] The maneuvering reentry target model considers the target's aerodynamic lift. In the Northeast-Heaven (ENU) coordinate system, the vector motion equations of a hypersonic target in the airspace are:

[0081]

[0082] In the formula, r and Let v and v represent the target's position vector and its derivative, respectively; Let a represent the target's velocity vector and its derivative, respectively. A a represents aerodynamic acceleration. G w represents gravitational acceleration. eThe angular velocity of Earth's rotation is the target velocity, and the target is only the gravitational acceleration a. G Under the influence of the force, the motion manifests as inertial ballistic reentry motion; in a A Under the influence of each component, the target possesses non-inertial ballistic reentry and maneuverability, such as Figure 2 As shown;

[0083] At time k, the aerodynamic parameters estimated by the Maneuvering Reentry Target Model (MaRV) tracking algorithm are:

[0084]

[0085] Among them, C L and C D These are the lift coefficient and drag coefficient, respectively; α is the angle of attack. and Let a represent the drag parameter, turning force parameter, and climb force parameter of each coordinate component in the half-velocity coordinate system at time k, respectively; Equation (2) shows that the aerodynamic parameter a M It is independent of changes in atmospheric density ρ, can directly characterize the anisotropic maneuvers of the target, and has clear physical meaning: and These correspond to the target's horizontal left and right turn maneuvers, respectively. and Corresponding to the target's climb and dive maneuvers respectively, using aerodynamic parameter a M Replace aerodynamic acceleration a A The model parameters can be adjusted directly based on the target's maneuvering characteristics, which helps improve observation accuracy; α represents the angle of attack and σ represents the bank angle, both of which are guidance control parameters. The angle of attack α affects the aerodynamic acceleration α during flight by influencing the aerodynamic coefficient. A Changes in the angle of attack directly affect the aerodynamics of a hypersonic glide vehicle; the inclination angle σ is a key control parameter, directly affecting the track inclination and heading angles during flight, and indirectly affecting the target's position and speed, such as... Figure 3a , Figure 3b As shown; S represents the reference area, and m represents the mass of the aircraft;

[0086] Different maneuver modes are identified by analyzing the relationship between maneuver acceleration and control parameters;

[0087] At time k, the position and velocity coordinates estimated by the Maneuvering Reentry Target Model (MaRV) tracking algorithm are respectively... and Estimates of longitudinal and lateral acceleration are obtained. and

[0088]

[0089] This represents the x, y, and z components of the estimated position at time k. This represents the estimated velocity components along the x, y, and z axes at time k;

[0090] according to and Based on the relationship, an estimated value of the yaw angle is obtained.

[0091]

[0092] At this point, the target state vector x is composed of the target state components and aerodynamic parameters:

[0093]

[0094] In the formula, x, y, and z represent the coordinates of the target on the x, y, and z axes in the northeast-northeast coordinate system, respectively. and Let a and b represent the derivatives of the target's coordinates on the x, y, and z axes in the northeast-northeast coordinate system, respectively. v a t and a c These represent the drag, turning force, and climb force parameters of each coordinate component in the half-velocity coordinate system, respectively.

[0095] The equations of motion for the aerodynamic parameters are expressed using a white noise model as follows:

[0096]

[0097] in, w represents the derivative of the aerodynamic parameter. a =[w v w t w c ] T w a It is a column vector, w v w t and w c These represent the drag, turning force, and climb force parameters of each coordinate component under the white noise model, respectively.

[0098] The nonlinear state transition function f(x) of the Maneuvering Reentry Target Model (MaRV) in the Northeast-Eastern-Sky (ENU) coordinate system is expressed as:

[0099]

[0100] In the formula, μ is the Earth's gravitational constant; the aerodynamic accelerations in three directions under the radar station's northeast-northeast coordinate system (ENU); r is the distance from the Earth's center; R e A is the Earth's radius; xA y and A z They represent respectively;

[0101] The Maneuvering Reentry Target Model (MaRV) is highly nonlinear. To apply this model, the Jacobian matrix corresponding to f(x) is given:

[0102]

[0103] In the formula, g represents the gravitational acceleration vector; r and v represent the target's position vector and velocity vector, respectively; I 3×3 Represents the identity matrix; This represents aerodynamic acceleration in the ENU coordinate system;

[0104] Step 1.3: Use the Extended Kalman Filter (EKF) algorithm to track the maneuvering reentry target;

[0105] The EKF algorithm uses Taylor polynomial expansion to approximate a nonlinear problem into a linear problem, resulting in a suboptimal nonlinear filtering algorithm; this invention uses the first-order EKF algorithm.

[0106] Step 2: Perform longitudinal and lateral maneuver analysis on the target's motion, and analyze its longitudinal gliding ability and lateral turning ability based on the typical maneuvering patterns of this type of target;

[0107] The specific steps are as follows:

[0108] For longitudinally maneuvering trajectories, hypersonic targets at close range are primarily affected by aerodynamic lift and gravity, with the magnitude of the longitudinal maneuvering acceleration being 'a'. h Represented as:

[0109]

[0110] In the formula, a h The acceleration is expressed as the velocity from the Earth's center of gravity towards the spacecraft's center of mass; L represents the aerodynamic lift acceleration; σ is the roll angle; g r γ represents the gravitational acceleration; V is the velocity of the aircraft; r is the distance from the Earth's center; γ is the velocity tilt angle. The three terms on the right side of equation (9) represent the vertical component of lift acceleration, gravitational acceleration, and centrifugal acceleration, respectively.

[0111] like Figure 4 As shown, when the longitudinal force approximately satisfies the equilibrium condition, i.e., a h ≈0, the hypersonic target in the air is in a balanced gliding flight, and the trajectory is the Qian Xuesen trajectory; when the force does not meet the balanced gliding conditions, due to the change of lift acceleration L with air density, the target will perform a jump gliding flight along the balanced gliding trajectory with decay and oscillation, and the trajectory is the Sanger trajectory.

[0112] During the jump, when γ < 0, the target is in the downward phase of the jump; when γ > 0, the target is in the upward phase of the jump. As the flight progresses, the target's altitude gradually decreases, air density gradually increases, and lift acceleration L also increases accordingly. Under these conditions, as L increases and velocity V decreases, the rate of change of velocity tilt angle increases. It will gradually increase; the target jumps will become more frequent.

[0113] Under the influence of aerodynamic drag, the target's kinetic energy gradually decreases, and the longitudinal jump amplitude also gradually decreases; the flight trajectory approximately exhibits a damped change with an increasing frequency and a decreasing amplitude and mean.

[0114] At time k, longitudinal acceleration It can be estimated from formula (3) that if If the value remains around 0, the target can be identified as a balanced glider; if... If the oscillations are periodic, it can be determined that the target is jumping and gliding;

[0115] Jump-glide trajectory analysis determines whether the target is in the ascent or descent phase by estimating the distance from the Earth's center and... Determining the periodic change segments;

[0116] like Figure 5 As shown, in lateral maneuver mode, hypersonic targets in the airspace generally achieve lateral maneuvering by changing the sign of the tilt angle guidance command and using left and right tilting motions to bypass enemy detection areas or obstacles, thus achieving the purpose of maneuvering evasion. The lateral acceleration satisfies a x satisfy:

[0117]

[0118] Among them, a x χ represents the centripetal acceleration of the aircraft during lateral turning; χ is the velocity azimuth angle; by tilting the projectile, the tilt angle σ gradually increases, and the aircraft uses the lateral component of lift acceleration Lsinσ to provide centripetal acceleration to achieve lateral turning.

[0119] Total lift force F on the target L satisfy:

[0120]

[0121] Therefore, the lateral turning radius R m satisfy:

[0122]

[0123] From equation (12), we know that R m The basic parameters of the aircraft (mass m, reference area S)M Lift coefficient C L And related to the tilt angle ν, due to m and S M For constant values, and atmospheric density ρ and C L As a slow variable, the change in maneuverability mainly depends on the change in ν;

[0124] In the initial stages of flight, the higher altitude results in thinner air, increasing ρ and C. L Both are relatively small, resulting in a larger turning radius and lower maneuverability at this stage; in the later stages of flight, due to the decrease in flight altitude, ρ and C... L As the radius gradually increases, the turning radius gradually decreases, and the maneuverability also increases.

[0125] Analysis of the target turning state at time k; based on The sign is used to determine if Then the target turns left horizontally; if The target is horizontally turned right; if The target is in a straight flight state;

[0126] For a turning target, estimate the turning radius; obtain the estimated lateral acceleration value from equation (3). Based on this, the estimated turning radius for:

[0127]

[0128] Step 3: Comprehensive Judgment; Based on the basic database information, such as prior information on enemy and friendly troop deployments, no-fly zones, and the maneuverability of typical hypersonic targets in the vicinity, and combined with the analysis results of Step 2, the maneuvering patterns of the targets are comprehensively judged.

[0129] The effects of this invention can be further illustrated by the following simulation experiments;

[0130] The experiment used the CAV-H aerodynamic parameter model to generate two types of trajectories for the HTV-2 target, and simulated the proposed maneuver discrimination scheme. The simulation environment was set as follows: the initial geodetic coordinates of the target were (27°E, 26°N), the initial altitude was 45km, the initial velocity was 3000m / s, the initial velocity tilt angle was 0°, the heading angle was -65°, and the simulation time was 500s; the radar's geodetic coordinates were (114°E, 30°N), the platform altitude was 30km, and the sampling period T = 1s; trajectory 1 was a constant angle of attack and tilt angle model; trajectory 2 adopted the following... Figure 3a Figure 3b The control model shown. Figures 6a to 6dFor the two trajectories, under longitudinal maneuvering, trajectory 1 is approximately balanced gliding; trajectory 2 is skip gliding; under lateral maneuvering, trajectory 1 is approximately straight flying; trajectory 2 performs a right turn maneuver from 1 to 91 seconds and a left turn maneuver from 92 seconds to 500 seconds.

[0131] like Figure 7a , Figure 7b As shown, the longitudinal acceleration estimate of trajectory 1 does not jump significantly and is closer to 0 than that of trajectory 2. Therefore, trajectory 1 conforms to an approximately balanced gliding trajectory. The variation pattern of the longitudinal acceleration estimate of trajectory 2 is consistent with that of the jump gliding trajectory, and the variation period of the longitudinal acceleration is consistent with the longitudinal jump period.

[0132] like Figures 8a to 8c As shown, the estimated lateral acceleration and bank angle of trajectory 1 match the true values. Since the acceleration tends to 0, trajectory 1 is approximately a straight flight without turning maneuvers. The estimated lateral acceleration and bank angle of trajectory 2 are basically consistent with the true values. There is an estimation delay of approximately 20 seconds when the sign changes. From the sign of the lateral acceleration, it can be seen that the target on trajectory 2 makes a right turn maneuver from 0s to 113s and a left turn maneuver from 114s to 500s. Figure 8c It can be seen that as the target altitude decreases, the turning radius of the ballistic target gradually decreases; this also explains... Figure 6b The phenomenon that the turning effect is more pronounced in the late stage of the ballistic trajectory 2.

[0133] In summary, the aerodynamic parameter identification method proposed in this invention can determine the target's longitudinal ballistic pattern and jump-glide period by estimating longitudinal acceleration; it can also effectively determine the target's lateral maneuvering, enabling the differentiation between straight flight, left turns, and right turns, as well as the estimated turning radius; this further improves the tracking accuracy of hypersonic targets in the airspace, and provides a theoretical basis for rapid prediction of target strike range, narrowing the detection area, and formulating interception and strike plans as early as possible.

[0134] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for identifying the maneuvering of hypersonic targets in near space based on aerodynamic parameter identification, characterized in that... Includes the following steps: Step 1: Estimate and track the motion state of hypersonic targets in the airspace using radar target tracking, and identify aerodynamic and guidance control parameters; including the following steps: Step 1.1: Decompose the maneuvering trajectory of the hypersonic target in the air into a longitudinal maneuvering trajectory and a lateral maneuvering trajectory, corresponding to the longitudinal acceleration respectively. and lateral acceleration ; Step 1.2: Track the target using radar and obtain the longitudinal acceleration based on the tracking algorithm of the maneuvering reentry target model. and lateral acceleration The estimated value; At time t, the aerodynamic parameters estimated by the maneuvering reentry target model tracking algorithm are: : in, and These are the lift coefficient and the drag coefficient, respectively. It's an angle of attack; , and They represent The drag parameters, turning force parameters, and climb force parameters of each coordinate component in the half-velocity coordinate system at time t; and These correspond to the target's horizontal left and right turn maneuvers, respectively. and These correspond to the target's climb and dive maneuvers, respectively. Indicates angle of attack and Indicates the tilt angle, all of which are guidance control parameters; Indicates the reference area. Indicates the mass of the aircraft; pass At time t, the position and velocity coordinates estimated by the maneuvering reentry target model tracking algorithm are respectively and This yields estimates of longitudinal and lateral acceleration. and : , , This represents the x, y, and z components of the estimated position at time k. , , This represents the estimated velocity components along the x, y, and z axes at time k; according to and Based on the relationship, an estimated value of the yaw angle is obtained. : At this time, the target state vector It is composed of the target state components and aerodynamic parameters: In the formula, x, y, and z represent the coordinates of the target on the x, y, and z axes in the northeast-northeast coordinate system, respectively. , and Let x, y, and z represent the derivatives of the target's coordinates on the x, y, and z axes in the northeast-northeast coordinate system. , and These represent the drag, turning force, and climb force parameters of each coordinate component in the half-velocity coordinate system, respectively. The equations of motion for the aerodynamic parameters are expressed using a white noise model as follows: in, Represents the derivative of aerodynamic parameters. , It is a column vector. , and These represent the drag, turning force, and climb force parameters of each coordinate component under the white noise model, respectively. Nonlinear state transition function of the maneuvering reentry target model in the northeast-sky coordinate system Represented as: In the formula, It is the Earth's gravitational constant; , and These represent the aerodynamic accelerations in three directions under the northeast-northeast coordinate system: It is the distance from the Earth's center; The radius of the Earth; The corresponding Jacobian matrix: In the formula, Represents the gravitational acceleration vector; and These represent the target's position vector and velocity vector, respectively. Represents the identity matrix; express Aerodynamic acceleration in a coordinate system; Step 1.3: Use the extended Kalman filter algorithm to track the maneuvering reentry target; Step 2: Perform longitudinal and lateral maneuver analysis on the target's motion, and analyze the target's longitudinal gliding ability and lateral turning ability based on the typical maneuvering patterns of this type of target; Step 3: Based on the prior information from the basic database and the analysis results from Step 2, comprehensively determine the target's maneuvering patterns.

2. The near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification according to claim 1, characterized in that: The vector motion equations of the hypersonic target in the airspace of the maneuvering reentry target model in step 1.2, in the northeast-northeast coordinate system, are as follows: In the formula, and Let these represent the target's position vector and its derivative, respectively. and Let these represent the target's velocity vector and its derivative, respectively. Indicates aerodynamic acceleration. Represents gravitational acceleration; This is the Earth's rotational angular velocity.

3. The near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification according to claim 1, characterized in that: In step 2, for the longitudinal maneuver trajectory, the magnitude of the longitudinal acceleration... Represented as: In the formula, This represents the aerodynamic lift acceleration value; It is the tilt angle; This represents the value of gravitational acceleration. For the speed of the aircraft; It is the distance from the Earth's center; The velocity inclination angle; When the longitudinal force approximately satisfies the equilibrium condition, that is A hypersonic target in the air performs a balanced gliding flight, and its trajectory follows the Qian Xuesen trajectory. When the forces do not meet the conditions for balanced gliding, due to lift acceleration... As air density changes, the target will glide and oscillate along a balanced gliding trajectory, exhibiting a jump-gliding flight pattern known as the Sanger trajectory.

4. The near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification according to claim 3, characterized in that: During the jump, when At that time, the target is in the downward phase of the jump; when At this point, the target is in the upward phase of the jump; as the flight progresses, the target's altitude gradually decreases, air density gradually increases, and lift acceleration gradually increases. It will also increase accordingly; in this case, as Increase and speed Decrease, rate of change of velocity tilt angle It will gradually increase; the target will jump more frequently; Under the influence of aerodynamic drag, the target's kinetic energy gradually decreases, and the longitudinal jump amplitude also gradually decreases; the flight trajectory approximately exhibits a damped change with an increasing frequency and a decreasing amplitude and mean.

5. The near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification according to claim 1, characterized in that: In step 2, At time , if longitudinal acceleration Maintain at 0±1m / s 2 If within this range, the target is judged to be gliding in a balanced manner; if If the oscillations are periodic, it can be determined that the target is jumping and gliding. Jump-glide trajectory analysis determines whether the target is in the ascent or descent phase by estimating the distance from the Earth's center and... Determining the periodic change segments.

6. The near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification according to claim 1, characterized in that: In step 2, under lateral maneuvering mode, the lateral acceleration satisfies satisfy: in, The velocity azimuth angle; the tilt angle is determined by tilting the projectile. As it gradually increases, the lateral component of the lift acceleration utilized by the aircraft... Provides centripetal acceleration to achieve lateral turning; Total lift on the target satisfy: Therefore, the lateral turning radius satisfy: With the mass of the aircraft Reference area Lift coefficient and tilt angle Related, due to and It is a constant value, and the atmospheric density is... and As a slow variable, changes in maneuverability mainly depend on Changes; During the initial stages of flight, the higher altitude results in thinner air. and The turning radius is relatively large and maneuverability is relatively low at this stage; in the later stages of flight, due to the decrease in flight altitude, and As the radius gradually increases, the turning radius gradually decreases, and the maneuverability also increases.

7. The near-space hypersonic target maneuver discrimination method based on aerodynamic parameter identification according to claim 1, characterized in that: In step 2, At any given moment, the target's turning state is analyzed; based on The sign is used to determine if Then the target turns left horizontally; if The target is to make a horizontal right turn maneuver; if If so, the target is in a straight flight state; For a turning target, estimate the turning radius; in the lateral acceleration estimate... Based on this, the estimated turning radius for: , , This represents the estimated velocity component along the xyz axes at time k.

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