Airborne chaff projectile simulation method based on three-dimensional particle special effect

Abstract

The invention discloses an airborne chaff bomb simulation method based on a three-dimensional particle effect, and the method comprises the following steps: chaff individual particle modeling: simulating the motion trail of a single chaff, the motion characteristics of chaff cloud, and the chaff electromagnetic scattering characteristic RCS based on a three-dimensional particle effect technology; complex environment modeling including a meteorological environment simulation model and an electromagnetic environment simulation model; particle effect driven simulation calculation: under the action of the chaff individual particle model and the complex environment model, firstly carrying out granulation on each chaff individual; then real-time calculation is carried out; and finally carrying out radar wave irradiation analysis. And three-dimensional dynamic visual output: realizing real-time display of distribution and interference effects of chaff bullets in different heights and environments. According to the invention, the processes of explosion, diffusion, disappearance and the like of the chaff projectile in the throwing process can be simulated in a highly vivid manner, including the motion trail, the diffusion distribution pattern, the radar scattering effect and the like of the chaff projectile.

Description

Technical Field

[0001] The invention belongs to the technical field of military simulation, and in particular relates to an airborne chaff bomb simulation method based on three-dimensional particle special effects. Background Art

[0002] In modern military simulation confrontation technology, airborne chaff bomb simulation plays an important role in interfering with enemy radars and protecting one's own fighters. The principle of interference simulation of chaff bombs is mainly based on the reflection and scattering characteristics of metal foil to electromagnetic waves, so as to destroy or weaken the enemy's simulated radar's detection or tracking of targets. Existing airborne chaff bomb simulation technology mostly uses MATLAB or C to realize the diffusion process and electromagnetic scattering characteristics of chaff bombs, and simulates electromagnetic scattering characteristics by fitting or matching the corresponding distribution model of the electromagnetic scattering characteristics of related chaff bombs measured or in papers.

[0003] These methods have the problems of insufficient authenticity and high computational complexity, and are unable to effectively simulate the diffusion of foil strips in complex environments and the electromagnetic scattering characteristics. For example, in the actual simulation process, it is necessary to consider factors such as the number of foil strips, initial velocity, acceleration, launch angle, wind direction, wind speed, air density, meteorological environment, weight gravity, air resistance, terrain, etc. in the complex external environment. Therefore, it is impossible to truly simulate realistic actual conditions in military simulation confrontation technology.

[0004] The current technology still has the following problems: (1) In traditional simulations, it is difficult to accurately simulate the stress conditions of chaff bombs in complex airflow environments. For example, the strong airflow generated by the flight of an aircraft and the difference in air density at different altitudes affect the movement of chaff. (2) The simulation of the electromagnetic scattering characteristics of chaff to radar waves is crucial. Existing simulation methods often simplify the electromagnetic scattering characteristic model, resulting in a large deviation between the simulation results and the actual situation. (3) The simulation of airborne chaff bombs requires the processing of a large number of chaff particles. Traditional algorithms are inefficient in real-time calculation of the movement and electromagnetic characteristics of a large number of chaff wires. (4) The real battlefield environment is complex and changeable, with many factors such as terrain, weather, and electromagnetic interference. Current simulations are almost impossible to fully consider the impact of these complex factors on the interference effect of chaff.

[0005] With the development of three-dimensional particle special effects technology, particle simulation can more realistically reproduce the movement and distribution effects of chaff shells, and can calculate their scattering and reflection characteristics under different environmental conditions in real time, thereby improving the accuracy and reliability of simulation. In addition, in order to meet battlefield needs, ensuring efficient calculations and rapid strategy adjustments in real-time simulation has also become an important technical requirement for improving the jamming effect of chaff shells. Therefore, in view of the accuracy, adaptability and real-time requirements of airborne chaff shell simulation, a new type of three-dimensional particle simulation technology is urgently needed to better support the jamming needs in modern air combat environments. Summary of the invention

[0006] Technical purpose: In order to solve the above technical problems, the present invention proposes an airborne chaff bomb simulation method based on three-dimensional particle special effects to improve the accuracy, adaptability and real-time performance of the simulation.

[0007] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0008] A method for simulating an airborne chaff bomb based on three-dimensional particle special effects comprises the following steps:

[0009] Modeling of individual foil strips: Based on 3D particle special effects technology, set the parameters of the individual foil strip model, and establish a parameter model including electromagnetic scattering. Set the mass, aerodynamic characteristics and flight environment-related parameter information of each foil strip, simulate the motion trajectory of a single foil strip, the motion characteristics of the foil strip cloud and the foil strip electromagnetic scattering characteristics RCS;

[0010] Complex environment modeling: including meteorological environment simulation model and electromagnetic environment simulation model. The meteorological environment simulation model is used to simulate the influence of different meteorological conditions on the movement and diffusion characteristics of foil strips; the electromagnetic environment simulation model is used to calculate the propagation path and attenuation of radar waves in complex electromagnetic environments;

[0011] Particle special effects driven simulation calculation: Under the action of the individual foil particle model and the complex environment model, each foil individual is first particleized to extract the geometric properties, physical properties and initial state parameters of the foil; then real-time calculation is performed, and the movement and diffusion characteristics of a large number of foil particles in three-dimensional space are calculated using the GPU parallel computing method to obtain the position information, attitude information and overlap information of the foil particles, and the position, speed and scattering characteristics of each particle are updated in real time; finally, radar wave irradiation analysis is performed, and the position information and attitude information of the foil particles are processed using GPU rendering to simulate the interaction between radar waves and foil clouds;

[0012] 3D dynamic visualization output: Convert the particle simulation results into 3D dynamic visualization scenes, superimpose electromagnetic scattering characteristics, and realize the real-time display of the distribution and interference effects of chaff bombs at different heights and environments.

[0013] The technical solution of the present invention is further defined as follows: the specific steps of simulating the motion trajectory of a single foil strip are:

[0014] In the geodetic coordinate system XYZ, a single foil strip is subjected to the buoyancy f along the Y axis, the gravity G along the Y axis and its velocity V. cs The air resistance F in the opposite direction cs The joint effect of

[0015] When the speed is lower than 100m / s, the air resistance is expressed as:

[0016]

[0017] When the speed is greater than 100m / s, the air resistance is expressed as:

[0018]

[0019] Where ρ = dl / 4 is the equivalent projection area of ​​the foil strip, V x 、V y 、V z represents the velocity components of the foil strip in the three coordinate axes, d is the diameter of the foil strip, l is the length of the foil strip, ρ is the air density, C x , C y , C z is the resistance coefficient, and the specific expression is:

[0020]

[0021] Where a 0 、a 1 is a constant. When the foil strip length is 5 cm, a 0 =1.8, a 1 =0.09, μ is the dynamic viscosity, μ=1.8×10 -5 ;

[0022] After the foil strips are dispersed, they show the characteristics of turbulent motion and diffusion, and their speed is the speed of the foil strip V 0 The speed of the wind V w The synthesis of

[0023]

[0024] In the formula θ 0 V 0 Angles with the X-axis and Z-axis; θ w V w Angles with the X-axis and Z-axis;

[0025] The buoyancy force on a single foil strip can be expressed as

[0026]

[0027] The self-gravity expression of the foil strip is: G = ρ b0 A v g = mg, where ρ b0 is the density of the foil strip, m is the mass of the foil strip, and g is the acceleration at different heights;

[0028] According to the above force analysis, the speed of the foil strip at time t can be expressed as

[0029]

[0030] Where ΔV x (t), ΔV y (t), ΔV z (t) is a random parameter, and the recursive expression of the displacement d(t) components on the three coordinate axes at any time t can be obtained, and the motion trajectory of a single foil strip can be obtained.

[0031]

[0032] Furthermore, the specific steps of simulating the motion characteristics of the foil cloud are:

[0033] (1) Select 19×36 foil strips at the boundary of the foil strip cloud, where V 0 , θ 0 is a fixed value, V w It is also a fixed value. and θ w = [0, 2π), divided into 19 × 36 directions by π / 18;

[0034] (2) The displacement of 19×36 foil strips at any time is calculated using a single foil strip motion model. After the displacement is converted into the position of each foil strip, the positions of these foil strips at any time are fitted using the ellipsoid surface fitting method to obtain the center of the foil strip cloud and the lengths of the three main semi-axes at any time.

[0035] (3) The movement trajectory of the chaff cloud can be obtained by connecting the centers of the chaff cloud at each moment. The displacement difference of the centers of the chaff cloud at two adjacent moments divided by the time difference can be obtained to obtain the average speed of the chaff cloud at each moment. The movement speed of the chaff cloud at each moment can be further calculated by the calculation formula of the length of each semi-axis of the chaff cloud and the volume of the ellipsoid Calculate the volume of the chaff cloud at any time.

[0036] Furthermore, when simulating the electromagnetic scattering characteristics RCS of the foil strip, a Rayleigh distribution curve is used to describe the radar reflection cross-sectional area of ​​the foil strip cloud, and the fitting formula is: Where η is the reduction coefficient caused by foil adhesion and damage, The average scattering area of ​​half-wavelength foil strips, N is the number of foil strips; σ RCS (t) is the radar reflection cross-sectional area of ​​the chaff cloud; k is a constant, reflecting the maximum value of the radar reflection cross-sectional area of ​​the chaff cloud; d is the parameter of the Rayleigh distribution, reflecting the effective duration of the chaff cloud.

[0037] Furthermore, in the particle special effect driven simulation calculation step, the step of extracting the initial loading parameters of the foil strip particles is:

[0038] The initial position of the chaff particles is determined by the launch position of the chaff launcher and the launch mechanism. The launch position of the chaff launcher is a spatial coordinate point, which determines the starting spatial position of the chaff particles, and the launch mechanism will further affect the specific distribution of the initial position of the particles around this coordinate point.

[0039] The initial velocity of the chaff particles is determined by the chaff launch speed and launch angle. The chaff launch speed determines the speed of the initial movement of the particles, while the launch angle determines the direction of the initial movement of the particles.

[0040] The acceleration of the foil particles is determined by gravity and air resistance.

[0041] Furthermore, in the particle special effect driven simulation calculation step, after the radar wave irradiates the foil cloud, its distribution and posture are calculated according to the position information and overlapping information of the foil particles, and the scattering situation is analyzed in real time.

[0042] Furthermore, in the three-dimensional dynamic visualization output step, the movement and scattering effects of the particle special effects are intuitively presented based on a graphics rendering method. In this process, each particle is given corresponding visual effects such as color and transparency according to the properties of the particles.

[0043] Furthermore, different brightness is set for the particles according to the radar wave scattering intensity. Flake particles with high radar wave scattering intensity appear as brighter points in the visualization effect, while those with low scattering intensity appear relatively darker. This difference in brightness enables the observer to clearly see the interference of the chaff cloud on the radar wave. At the same time, the aggregation and dynamic diffusion of the chaff cloud are simulated. The aggregation effect of the chaff cloud can be reflected by the change in the distance between particles and the change in particle density. When the particles are close to each other and the density increases, the aggregation effect is presented; the dynamic diffusion is simulated by the particles moving continuously to the surrounding space over time, and the distance between the particles gradually increases. The simulation of these effects can enhance the realism of the visualization, making the observer feel as if they are in a real scene of the interaction between the chaff cloud and the radar wave.

[0044] Beneficial effects:

[0045] The method of the present invention aims to solve the problem of how to accurately simulate the combined effects of multiple forces such as aerodynamics, gravity, and electromagnetic force on foil strips based on particle special effects, and its motion trajectory complies with real physical laws, including the diffusion characteristics of foil strips under maneuvers such as aircraft acceleration, turning, and diving; at the same time, particle special effects are used to accurately simulate the radar wave scattering characteristics of foil strips in different shapes, lengths, materials, and different distribution densities, including considering the scattering response of multi-band radar wave irradiation foil strip bombs, so as to accurately present the changes in echo signals; and while ensuring the simulation accuracy, the method of parallel computing is used to reduce the computing resource usage, improve the real-time performance of large-scale particle simulation, and enable the simulation to run quickly and accurately under the limited hardware resource environment of the computer system; in addition, the method of using particle special effects to incorporate complex environmental factors into the simulation model, such as the interaction between terrain such as mountains and sea surfaces on radar wave reflection and foil strip bomb scattering, and the influence of meteorological conditions such as rain, snow, fog, etc. on electromagnetic signal propagation and foil strip performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a flowchart of an embodiment of the present invention;

[0047] Figure 2 This is a simulation of the chaff bomb launch in an environment without external meteorological conditions according to an embodiment of the present invention;

[0048] Figure 3 This is a simulation of chaff bomb launch in a rainy environment according to an embodiment of the present invention;

[0049] Figure 4 The RCS distribution of a single chaff bomb in an embodiment of the present invention;

[0050] Figure 5 This is the target echo situation of the embodiment of the present invention;

[0051] Figure 6 The simulation of chaff bomb launch in a rainy environment after parameter setting of the embodiment of the present invention;

[0052] Figure 7 The RCS distribution of a single chaff bomb after parameter setting in the embodiment of the present invention;

[0053] Figure 8 The simulation result of the chaff target echo after the parameters of the embodiment of the present invention are set;

[0054] Fig. 9 The simulation rate of the rear chaff bomb is set by the parameters of the embodiment of the present invention. DETAILED DESCRIPTION

[0055] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0056] Embodiment 1

[0057] A method for simulating an airborne chaff bomb based on three-dimensional particle special effects comprises the following steps:

[0058] 1. Modeling of individual foil strip particles: Based on three-dimensional particle special effects technology, set the parameters of the individual foil strip model, and establish a parameter model including electromagnetic scattering. Set the mass, aerodynamic characteristics and flight environment-related parameter information of each individual foil strip to simulate the motion trajectory of a single foil strip, the motion characteristics of the foil strip cloud and the electromagnetic scattering characteristics RCS of the foil strip.

[0059] Set the individual model parameters of the foil strip, including the length, width, thickness, and material (such as aluminum foil, aluminized glass fiber, etc.) of the foil strip. According to the above parameters, establish a scattering model of electromagnetic parameters, set the mass of each individual foil strip and the relevant parameter information required for aerodynamics, and simulate the movement characteristics and electromagnetic scattering characteristics of a single individual foil strip in different aerial environments.

[0060] 1. The specific steps of simulating the motion trajectory of a single foil strip are:

[0061] In the geodetic coordinate system XYZ, a single foil strip is subjected to the buoyancy f along the Y axis, the gravity G along the Y axis and its velocity V. cs The air resistance F in the opposite direction cs The joint effect of

[0062] When the speed is lower than 100m / s, the air resistance is expressed as:

[0063]

[0064] When the speed is greater than 100m / s, the air resistance is expressed as:

[0065]

[0066] Where ρ = dl / 4 is the equivalent projection area of ​​the foil strip, V x 、V y 、V z represents the velocity components of the foil strip in the three coordinate axes, d is the diameter of the foil strip, l is the length of the foil strip, ρ is the air density, C x , C y , C z is the resistance coefficient, and the specific expression is:

[0067]

[0068] Where a 0 、a 1 is a constant. When the foil strip length is 5 cm, a 0 =1.8, a 1 =0.09, μ is the dynamic viscosity, μ=1.8×10-5 ;

[0069] After the foil strips are dispersed, they show the characteristics of turbulent motion and diffusion, and their speed is the speed of the foil strip V 0 The speed of the wind V w The synthesis of

[0070]

[0071] In the formula θ 0 V 0 Angles with the X-axis and Z-axis; θ w V w Angles with the X-axis and Z-axis;

[0072] The buoyancy force on a single foil strip can be expressed as

[0073]

[0074] In addition to the above forces, the foil strip's own gravity is expressed as: G = ρ b0 A v g = mg, where ρ b0 is the density of the foil strip, m is the mass of the foil strip, and g is the acceleration at different heights;

[0075] According to the above force analysis, the speed of the foil strip at time t can be expressed as

[0076]

[0077] Where ΔV x (t), ΔV y (t), ΔV z (t) is a random parameter, and the recursive expression of the displacement d(t) components on the three coordinate axes at any time t can be obtained, and the motion trajectory of a single foil strip can be obtained.

[0078]

[0079] 2. The specific steps of simulating the motion characteristics of the foil cloud are:

[0080] (1) When the chaff is initially released from the airborne chaff bomb, the chaff moves in turbulent diffusion, so the individual chaff is thrown in all directions. Since there is a lot of mass mixing and exchange between the two average streamlines in turbulence, the low-speed chaff is accelerated by the high-speed chaff mixed with it, and the high-speed chaff is decelerated in turn. Therefore, the chaff with the largest initial velocity is always at the boundary of the chaff cloud. Therefore, 19×36 chaff strips are selected at the boundary of the chaff cloud, where V 0 , θ 0is a fixed value, V w It is also a fixed value. and θ w = [0, 2π), divided into 19 × 36 directions by π / 18;

[0081] (2) The single foil strip motion model is used to calculate the displacement of 19×36 foil strips at any time. After converting the displacement into the position of each foil strip, the ellipsoid surface fitting method is used to fit the positions of these foil strips at any time to obtain the center of the foil strip cloud and the lengths of the three main semi-axes at any time.

[0082] (3) Connecting the centers of the chaff cloud at each moment can obtain the motion trajectory of the chaff cloud. The displacement difference of the centers of the chaff cloud at two adjacent moments divided by the time difference can obtain the average speed of the chaff cloud at each moment. The motion speed of the chaff cloud at each moment can be further calculated. The calculation formula of the length of each semi-axis of the chaff cloud and the volume of the ellipsoid is The volume of the chaff cloud at any time can be calculated.

[0083] 3. Simulation of electromagnetic scattering characteristics: Based on the material and shape of the foil strip, multi-band electromagnetic simulation is used to calculate the scattering cross section of the foil strip under the action of radar waves of different wavelengths, and a particle model of electromagnetic response is generated;

[0084] In the early stage of the chaff bomb explosion, the chaff has not been fully dispersed, and the shielding effect in the cloud is more obvious. As the chaff quickly disperses, the RCS increases rapidly until it reaches the maximum value. When the spatial volume of the chaff cloud is so large that part of the chaff cloud is beyond the radar beam, the RCS will decrease as the volume increases. The Rayleigh distribution curve is used in the simulation to describe the radar reflection cross-sectional area of ​​the chaff cloud, and its fitting formula is

[0085] σ RCS (t) = ktexp(-t 2 / d 2 ) / d 2

[0086]

[0087] η is the reduction coefficient caused by foil adhesion and damage (0-1), The average scattering area of ​​half-wavelength foil strips, N is the number of foil strips. RCS (t) is the radar cross-sectional area of ​​the chaff cloud; k is a constant, reflecting the maximum value of the radar cross-sectional area of ​​the chaff cloud; d is the parameter of the Rayleigh distribution, reflecting the effective duration of the chaff cloud. Parameter k is related to the maximum RCS that the chaff bomb can reach, and is generally required to be 3 to 5 times the aircraft RCS.

[0088] 2. Complex environment modeling: including meteorological environment simulation model and electromagnetic environment simulation model. The meteorological environment simulation model is used to simulate the influence of different meteorological conditions on the movement and diffusion characteristics of foil strips; the electromagnetic environment simulation model is used to calculate the propagation path and attenuation of radar waves in a complex electromagnetic environment.

[0089] 1. Meteorological environment simulation construction: including factors such as wind speed, wind direction, temperature, humidity, meteorological environment (rain, snow, fog, etc.). For different meteorological conditions, different calculation models are used to simulate the impact of meteorology on the movement and diffusion characteristics of foil strips. For example, under the influence of wind, the foil strip particles and force conditions are calculated according to the wind speed and direction, and their movement trajectory is changed; in an environment with a large humidity ring, the impact of water vapor on radar wave propagation is considered. When the pressure remains unchanged, according to ρ=PM / RT, the temperature directly affects the air density ρ, which in turn affects the buoyancy of the foil strip.

[0090] 2. Electromagnetic environment simulation construction: Considering the electromagnetic characteristics of enemy radars, such as enemy radar frequency, power, beam width and other parameters, as well as the electromagnetic radiation characteristics of one's own electronic equipment, establish a radio wave propagation model and calculate the propagation path and attenuation of radar waves in a complex electromagnetic environment.

[0091] According to different environments, fine-tune the relevant parameters of the movement and diffusion of the relevant foil cloud to achieve a simulation effect that is more in line with reality.

[0092] 3. Particle special effects driven simulation calculation: Under the action of the individual particle model of the foil strip and the complex environment model, each individual foil strip is first particleized to extract the geometric properties, physical properties and initial state parameters of the foil strip; then real-time calculation is performed, and the movement and diffusion characteristics of a large number of foil strip particles in three-dimensional space are calculated using the GPU parallel computing method to obtain the position information, attitude information and overlap information of the foil strip particles, and the position, speed and scattering characteristics of each particle are updated in real time; finally, radar wave irradiation analysis is performed, and the position information and attitude information of the foil strip particles are processed using GPU rendering to simulate the interaction between radar waves and foil strip clouds.

[0093] In the particle special effect driven simulation calculation step, the step of extracting the initial loading parameters of the foil strip particles is:

[0094] 1. When constructing three-dimensional particle effects, we must first represent them in particles. Here, each individual foil strip is precisely regarded as a particle with a variety of specific properties. The setting of these properties is very detailed and comprehensive, covering many aspects such as the geometric and physical properties of the foil strip. Among them, the geometric properties of the foil strip include parameters in dimensions such as length, width, and thickness. These parameters clearly define the basic shape and size of the foil strip particles. The material physical parameters are based on the essence of the material, such as the material density and elastic coefficient of the foil strip. These parameters will affect the interaction between the foil strip particles and the external environment (such as air resistance, etc.) in subsequent calculations.

[0095] At the same time, the initial state parameters of the particles are also crucial. The initial position of the particles is jointly determined by the launch position of the chaff launcher and the launch mechanism. The launch position of the chaff launcher is a spatial coordinate point, which determines the starting spatial position of the chaff particle, and the launch mechanism will further affect the specific distribution of the initial position of the particles around this coordinate point. In terms of initial velocity, it is calculated based on the chaff launch speed and launch angle. The chaff launch speed determines the speed of the initial movement of the particles, while the launch angle determines the direction of the initial movement of the particles. In addition, acceleration is determined by gravity and air resistance. Gravity is a constant influencing factor that always exerts a downward force on the chaff particles; air resistance will change according to the motion state of the particles (such as speed, posture, etc.). These kinematic parameters together constitute the basic motion characteristics of the chaff particles in the initial state.

[0096] Struct SingleChaff{

[0097] double nLength;

[0098] double nWidth;

[0099] double nThick;

[0100] int nTexture;

[0101] double nInitDist;

[0102] float nInitSpeed;

[0103] float nAccleRate;}

[0104] In the particle special effect driven simulation calculation step, after the radar wave irradiates the foil cloud, the distribution and posture of the foil particles are calculated according to the position information and overlapping information of the foil particles, and the scattering situation is analyzed in real time.

[0105] 2. Next is the real-time calculation process, which is achieved by GPU parallel computing. Since the movement and diffusion characteristics of a large number of foil particles need to be calculated in three-dimensional space, GPU parallel computing can greatly improve the computing efficiency. Specifically, the particle computing tasks are reasonably distributed to multiple computing units. This distribution method is like breaking down a huge task into many small tasks, each computing unit is responsible for a part of it, and then calculating at the same time, which significantly improves the computing speed.

[0106] According to the calculation results of the above step (1), the position information, attitude information and related foil overlap information of each simulated foil strip can be obtained. The foil strip position information accurately describes the coordinate position of the foil strip particles in three-dimensional space, and this position changes over time because the particles are moving. The attitude information reflects the state of the foil strip particles, such as whether the foil strip is placed horizontally, vertically or tilted at a certain angle. The foil strip overlap information reflects whether there is any intersection or overlap between different foil strip particles, which has an important impact on the subsequent physical simulation and visualization effect.

[0107] In addition, the position, velocity, scattering characteristics and other parameter information of each particle are updated in real time based on the physical simulation and environmental model. The physical simulation takes into account the various forces acting on the particles (such as gravity, air resistance, etc.), so as to accurately calculate the changes in the particle position and velocity; the environmental model takes into account the influence of surrounding environmental factors (such as the influence of temperature, humidity, etc. on air resistance) on the particle scattering characteristics, so that the various parameters of the particles can reflect the real physical phenomena in real time.

[0108] At the code level, taking CUDA as an example, the following is a simplified pseudocode:

[0109] __global__void CalParticle(Particle*particles,int numParticles){

[0110] int idx=blockIdx.x*blockDim.x+threadIdx.x;

[0111] if(idx <numParticles){

[0112] Particle p=particles[idx];

[0113] p.velocity.x+=p.acceleration.x+dt;

[0114] p.velocity.y+=p.acceleration.y+dt;

[0115] p.velocity.z+=p.acceleration.z+dt;

[0116] p.position.x+=p.velocity.x+dt;

[0117] p.position.y+=p.velocity.y+dt;

[0118] p.position.z+=p.velocity.z+dt;

[0119] particles[idx] = p;

[0120] }.

[0121] 3. After the radar wave irradiates the chaff cloud, the scattering situation is analyzed in real time according to the distribution of the chaff wires and their posture. The distribution of the chaff wires depends on the previously calculated chaff wire position information and overlap information, and different distribution situations will lead to differences in radar wave scattering. Through this analysis, a detailed description of the distribution of the chaff wires can be given, such as the density of the chaff wires in space, the shape of the distribution, etc. At the same time, the scattering center is calculated in real time based on this information. The scattering center is an important concept to describe the scattering effect of the chaff cloud on radar waves, and its calculation results will directly affect the evaluation of the radar wave interference effect.

[0122] 4. Three-dimensional dynamic visualization output: Convert the particle simulation results into a three-dimensional dynamic visualization scene, superimpose the electromagnetic scattering characteristics, and realize the real-time display of the distribution and interference effect of chaff bombs at different heights and environments.

[0123] In the three-dimensional dynamic visualization output step, the movement and scattering effects of the particle special effects are intuitively presented based on a graphics rendering method. In this process, each particle is given corresponding visual effects such as color and transparency according to the properties of the particles.

[0124] Finally, the visualization rendering stage is used. Based on the graphics rendering method, the movement and scattering effects of the particle special effects are intuitively presented. In this process, each particle is given corresponding visual effects such as color and transparency according to the properties of the particles. For example, different brightness is set for the particles according to the scattering intensity of the radar wave. Foil particles with high radar wave scattering intensity appear as brighter points in the visualization effect, while those with low scattering intensity are relatively darker. This difference in brightness enables the observer to see very clearly the interference of the foil cloud on the radar wave. At the same time, the aggregation and dynamic diffusion of the foil cloud are simulated. The aggregation effect of the foil cloud can be reflected by the change in the distance between particles and the change in particle density. When the particles are close to each other and the density increases, the aggregation effect is presented; the dynamic diffusion is simulated by the particles moving continuously to the surrounding space over time, and the distance between the particles gradually increases. The simulation of these effects can enhance the realism of the visualization, making the observer feel as if they are in a scene where the real foil cloud interacts with the radar wave.

[0125] The actual working process of this embodiment is shown in the attached Figure 1 As shown in the figure, the simulation of chaff bomb launch in the absence of external weather conditions is as follows Figure 2 As shown in the figure, the simulation of chaff bomb launch in rainy environment is as follows Figure 3 As shown, the RCS distribution of a single chaff bomb is as follows Figure 4 As shown in Figure 2, the target echo is as follows: Figure 5 As shown, the specific workflow is:

[0126] Start simulation: Start the entire simulation process.

[0127] Set external environment information: Enter external environment parameters, such as terrain and environmental information.

[0128] Load radar waveform file: Import radar waveform data required for simulation.

[0129] Set chaff shell parameters: configure the number of chaff shell release groups, release interval and other parameters.

[0130] Simulate the diffusion range: calculate the diffusion effect of chaff bombs in the environment.

[0131] Particle special effects simulation driver: simulate particle diffusion behavior based on particle special effects.

[0132] Calculate RCS information for each step: Calculate the radar cross-section (RCS) information for each simulation step after diffusion.

[0133] Effect presentation: Display simulation effects.

[0134] Diffusion judgment: judge whether the diffusion is finished.

[0135] Simulation end: When the diffusion reaches the set conditions, the simulation ends.

[0136] In this embodiment, the parameters are set as follows: Enemy radar electromagnetic characteristic parameter information: frequency 9000MHz, pulse width: 10us, pulse repetition period: 100us, beam width: 10 degrees. Chaff bomb launch information: number of chaff wires 500,000, number of launch groups 5 groups, launch interval 1 second, chaff bomb duration 5 seconds, chaff bomb launch initial velocity 25 meters per second, launch azimuth 180 degrees, launch pitch 0 degrees. External environment information: altitude 1000 meters, wind speed 5 meters per second, wind direction 0 degrees, temperature 20 degrees Celsius, air density 0.4 kilograms per cubic meter. Carrier movement speed: 200 meters per second. After the parameters are set, the simulation results are as follows Figures 6 to 9 shown.

[0137] The simulation technology of airborne chaff bombs based on three-dimensional particle special effects in this embodiment can simulate the explosion, diffusion, disappearance and other processes of chaff bombs in a highly realistic manner, including the movement trajectory of the chaff bombs, the diffusion distribution form and the radar scattering effect, etc. At the same time, it can reflect the actual combat scene, and can set the factors affecting the diffusion of chaff bombs (such as wind speed, wind direction, etc.) according to the preset model in the particle special effects, and can calculate the information of the chaff bombs after launch in real time according to the flight attitude of the carrier aircraft and the launch position information. In the air electronic warfare simulation technology, it can simulate different geographical environments, different launch information and different meteorological environments in a short time by adjusting parameters, which accelerates the efficiency of electronic warfare simulation.

[0138] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A method for simulating airborne chaff bombs based on three-dimensional particle effects, characterized in that: The following steps are included: Modeling of individual foil strips: Based on 3D particle special effects technology, set the parameters of the individual foil strip model, and establish a parameter model including electromagnetic scattering. Set the mass, aerodynamic characteristics and flight environment-related parameter information of each foil strip, simulate the motion trajectory of a single foil strip, the motion characteristics of the foil strip cloud and the foil strip electromagnetic scattering characteristics RCS; Complex environment modeling: including meteorological environment simulation model and electromagnetic environment simulation model. The meteorological environment simulation model is used to simulate the influence of different meteorological conditions on the movement and diffusion characteristics of foil strips; the electromagnetic environment simulation model is used to calculate the propagation path and attenuation of radar waves in complex electromagnetic environments; Particle special effects driven simulation calculation: Under the action of the individual foil particle model and the complex environment model, each foil individual is first particleized to extract the geometric properties, physical properties and initial state parameters of the foil; then real-time calculation is performed, and the movement and diffusion characteristics of a large number of foil particles in three-dimensional space are calculated using the GPU parallel computing method to obtain the position information, attitude information and overlap information of the foil particles, and the position, speed and scattering characteristics of each particle are updated in real time; finally, radar wave irradiation analysis is performed, and the position information and attitude information of the foil particles are processed using GPU rendering to simulate the interaction between radar waves and foil clouds; 3D dynamic visualization output: Convert the particle simulation results into 3D dynamic visualization scenes, superimpose electromagnetic scattering characteristics, and realize the real-time display of the distribution and interference effects of chaff bombs at different heights and environments.

2. The method for simulating an airborne chaff bomb based on three-dimensional particle effects according to claim 1, characterized in that: The specific steps of simulating the motion trajectory of a single foil strip are: In the geodetic coordinate system XYZ, a single foil strip is subjected to the buoyancy f along the Y axis, the gravity G along the Y axis and its velocity V. cs The air resistance F in the opposite direction cs The joint effect of When the speed is lower than 100m / s, the air resistance is expressed as: When the speed is greater than 100m / s, the air resistance is expressed as: Where ρ = dl / 4 is the equivalent projection area of ​​the foil strip, V x 、V y 、V z represents the velocity components of the foil strip in the three coordinate axes, d is the diameter of the foil strip, l is the length of the foil strip, ρ is the air density, C x , C y , C z is the resistance coefficient, and the specific expression is: Where a0 and a1 are constants. When the foil strip length is 5 cm, a0 = 1.8, a1 = 0.

09. μ is the dynamic viscosity. In air, μ = 1.8 × 10 -5 ; After the foil strips are dispersed, they show the characteristics of turbulent motion and diffusion, and their speed is the speed of the foil strips V0 and the speed of the wind V w The synthesis of In the formula θ0 is the angle between V0 and the X-axis and Z-axis; θ w V w Angles with the X-axis and Z-axis; The buoyancy force on a single foil strip can be expressed as The self-gravity expression of the foil strip is: G = ρ b0 A v g = mg, where ρ b0 is the density of the foil strip, m is the mass of the foil strip, and g is the acceleration at different heights; According to the above force analysis, the speed of the foil strip at time t can be expressed as Where ΔV x (t), ΔV y (t), ΔV z (t) is a random parameter, and the recursive expression of the displacement d(t) components on the three coordinate axes at any time t can be obtained, and the motion trajectory of a single foil strip can be obtained.

3. A method for simulating an airborne chaff bomb based on three-dimensional particle effects according to claim 2, characterized in that: The specific steps of simulating the motion characteristics of the chaff cloud are: (1) Select 19×36 foil strips at the boundary of the foil strip cloud, where V0, θ0 is a constant value, V w It is also a fixed value. and θ w = [0, 2π), divided into 19 × 36 directions by π / 18; (2) The displacement of 19×36 foil strips at any time is calculated using a single foil strip motion model. After the displacement is converted into the position of each foil strip, the positions of these foil strips at any time are fitted using the ellipsoid surface fitting method to obtain the center of the foil strip cloud and the lengths of the three main semi-axes at any time. (3) The movement trajectory of the chaff cloud can be obtained by connecting the centers of the chaff cloud at each moment. The displacement difference of the centers of the chaff cloud at two adjacent moments divided by the time difference can be obtained to obtain the average speed of the chaff cloud at each moment. The movement speed of the chaff cloud at each moment can be further calculated by the calculation formula of the length of each semi-axis of the chaff cloud and the volume of the ellipsoid Calculate the volume of the chaff cloud at any time.

4. The method for simulating an airborne chaff bomb based on three-dimensional particle effects according to claim 2, characterized in that: When simulating the electromagnetic scattering characteristics RCS of the foil strip, the Rayleigh distribution curve is used to describe the radar of the foil strip cloud. σ RCS (t)=ktexp(-t 2 / d 2 ) / d 2 Reflection cross-sectional area, the fitting formula is: Where η is the reduction coefficient caused by foil adhesion and damage, The average scattering area of ​​half-wavelength foil strips, N is the number of foil strips; σ RCS (t) is the radar reflection cross-sectional area of ​​the chaff cloud; k is a constant, reflecting the maximum value of the radar reflection cross-sectional area of ​​the chaff cloud; d is the parameter of the Rayleigh distribution, reflecting the effective duration of the chaff cloud.

5. The method for simulating an airborne chaff bomb based on three-dimensional particle effects according to claim 1, characterized in that: In the particle special effect driven simulation calculation step, the step of extracting the initial loading parameters of the foil strip particles is: The initial position of the chaff particles is determined by the launch position of the chaff launcher and the launch mechanism. The launch position of the chaff launcher is a spatial coordinate point, which determines the starting spatial position of the chaff particles, and the launch mechanism will further affect the specific distribution of the initial position of the particles around this coordinate point. The initial velocity of the chaff particles is determined by the chaff launch speed and launch angle. The chaff launch speed determines the speed of the initial movement of the particles, while the launch angle determines the direction of the initial movement of the particles. The acceleration of the foil particles is determined by gravity and air resistance.

6. The method for simulating an airborne chaff bomb based on three-dimensional particle effects according to claim 1, characterized in that: In the particle special effect driven simulation calculation step, after the radar wave irradiates the foil cloud, the distribution and posture of the foil particles are calculated according to the position information and overlapping information of the foil particles, and the scattering situation is analyzed in real time.

7. The method for simulating an airborne chaff bomb based on three-dimensional particle effects according to claim 1, characterized in that: In the three-dimensional dynamic visualization output step, the movement and scattering effects of the particle special effects are intuitively presented based on a graphics rendering method. In this process, each particle is given corresponding visual effects such as color and transparency according to the properties of the particles.

8. The method for simulating an airborne chaff bomb based on three-dimensional particle effects according to claim 7, characterized in that: Different brightness levels are set for particles according to the radar wave scattering intensity. Flake particles with high radar wave scattering intensity appear as brighter points in the visualization, while those with low scattering intensity appear relatively darker. This difference in brightness enables the observer to clearly see the interference of the chaff cloud on the radar waves. At the same time, the aggregation and dynamic diffusion of the chaff cloud are simulated. The aggregation effect of the chaff cloud can be reflected by the change in the distance between particles and the change in the particle density. When the particles are close to each other and the density increases, the aggregation effect is presented; dynamic diffusion is simulated by the particles moving continuously into the surrounding space over time, and the distance between the particles gradually increases. The simulation of these effects can enhance the realism of the visualization, making the observer feel as if they are in a real scene of the interaction between the chaff cloud and the radar wave.

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