A method for calculating the dynamic electromagnetic scattering characteristics of aircraft based on control surface deflection

Abstract

This invention discloses a method for calculating the dynamic electromagnetic scattering characteristics of aircraft based on control surface deflection, belonging to the technical field of aircraft electromagnetic scattering characteristic calculation. The method acquires the control surface deflection angle, flight trajectory, and attitude changes during flight in real time, corrects the radar wave incident angle, and generates a dynamic hybrid mesh matrix to accurately reflect the geometric deformation caused by control surface deflection. A hybrid method combining physical optics (PO) and physical diffraction theory (PTD) is employed to calculate the dynamic RCS results, thereby capturing the real-time impact of control surface motion on electromagnetic scattering characteristics. This invention solves the problem of RCS prediction distortion caused by neglecting rapid control surface deflection in traditional static or quasi-static models, significantly improving the realism and accuracy of dynamic RCS calculation for maneuvering aircraft. It is applicable to stealth aircraft design, dynamic RCS evaluation, and radar target identification.

Description

Technical Field

[0001] This invention belongs to the field of aircraft electromagnetic scattering characteristic calculation technology, specifically relating to a method for calculating the dynamic electromagnetic scattering characteristics of aircraft based on control surface deflection. Background Technology

[0002] The radar cross section (RCS) of an aircraft is a key indicator for stealth design and radar target identification. Traditional RCS calculation methods are usually based on static or quasi-static models, assuming that the target attitude is fixed or changes slowly, and do not consider the dynamic deflection of movable components such as control surfaces during flight. However, in actual maneuvering flight, control surfaces (such as ailerons, rudders, and elevators) will deflect rapidly and significantly due to flight control commands, causing significant changes in the local geometry, edge scattering, and obstruction relationships of the aircraft, thereby affecting the distribution and intensity of the overall RCS.

[0003] Existing dynamic RCS calculation methods primarily focus on overall aircraft attitude changes (such as pitch, roll, and yaw), while treating control surface deflection separately from attitude changes. This fails to establish a refined electromagnetic scattering model of the control surface as an independent moving part. This simplification leads to significant discrepancies between the predicted RCS for aircraft undergoing violent maneuvers (such as evasive or attack maneuvers) and actual conditions, reducing the reference value of simulation data. Furthermore, traditional methods often employ rigid body assumptions, making it impossible to update the geometric deformation caused by control surface deflection in real time and accurately capture the dynamic changes of local scattering centers.

[0004] To address the aforementioned issues, there is an urgent need for a dynamic RCS calculation method that can couple flight control commands, control surface deflection states, and electromagnetic scattering characteristics, in order to achieve high-precision real-time assessment of the stealth performance of maneuvering aircraft. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection. Based on the control surface deflection angle output by the flight control model, a dynamic mesh model reflecting the actual deflection state of the control surfaces is updated in real time, and the incident angle of radar waves is corrected according to the flight state. Furthermore, based on high-frequency electromagnetic calculation methods, it accurately reflects the real-time impact of control surface deflection on stealth characteristics, providing a theoretical basis for the dynamic RCS calculation of aircraft.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection, the method comprising:

[0008] Step S1: Obtain the control surface deflection angle, flight trajectory, and attitude changes during the flight of the aircraft;

[0009] Step S2: Calculate the incident direction of the radar wave in the global coordinate system based on the flight trajectory, and correct the incident angle of the radar wave;

[0010] Step S3: Based on the aircraft's baseline geometric model, dynamically adjust the geometric position and orientation of the control surfaces according to the control surface deflection angle to generate a dynamically updated hybrid mesh matrix in real time;

[0011] Step S4: Using the corrected radar wave incident angle and dynamic hybrid grid matrix as input, electromagnetic scattering calculation is performed using physical optics combined with physical diffraction theory, and the dynamic RCS result considering the real-time deflection state of the control surface is output.

[0012] In a second aspect, the present invention provides an electronic device, comprising: one or more processors; and a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection.

[0013] Thirdly, the present invention provides a computer-readable storage medium storing executable instructions thereon, which, when executed by a processor, enable the processor to implement the aforementioned method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection.

[0014] The beneficial effects of this invention are as follows:

[0015] Dynamic and refined modeling: By calculating the control surface deflection angle in real time and combining it with changes in flight attitude, the aircraft's geometric model is dynamically updated, accurately reflecting the local deformation and occlusion relationship caused by control surface deflection, thus solving the defect that traditional static or quasi-static models cannot capture the effects of rapid maneuvering.

[0016] Closed-loop calculation process: Flight control commands, six-degree-of-freedom models, dynamic mesh generation, radar incident angle correction and RCS calculation are integrated into a unified framework to form a complete dynamic closed-loop system, which significantly improves the realism and timeliness of RCS calculation during maneuvers.

[0017] High-efficiency and high-precision calculation: A hybrid algorithm combining physical optics (PO) and physical diffraction theory (PTD) is adopted. While ensuring computational efficiency, it effectively characterizes the scattering contribution of local structures such as the edge and sharp corner of the control surface, thereby improving the prediction accuracy of dynamic RCS.

[0018] Wide applicability: Applicable to dynamic RCS evaluation of various stealth aircraft, especially valuable for electromagnetic scattering characteristic analysis in violent maneuvering scenarios (such as evasion and attack), and can provide reliable data support for stealth design optimization and radar target identification. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection, according to the present invention.

[0020] Figure 2 This is a schematic diagram illustrating the relative positional relationship between the aircraft and the ground radar in the embodiment.

[0021] Figure 3 This is a schematic diagram of the flight trajectory when the rudder deflects in the embodiment;

[0022] Figure 4 This is a schematic diagram of the radar incident angle after correction when the rudder deflects in the embodiment;

[0023] Figure 5 This is a schematic diagram of the aircraft's baseline geometric model in the embodiment;

[0024] Figure 6 This is a schematic diagram of rudder deflection in the embodiment;

[0025] Figure 7 This is a schematic diagram of the dynamic RCS calculation results when the rudder deflects in the embodiment. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] This invention provides a method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection. It utilizes a six-degree-of-freedom model of the aircraft and a controller model to obtain real-time control surface deflection angles, flight trajectory, and attitude angles according to control commands. The relative position between the aircraft and the radar is obtained based on the flight trajectory, thus correcting the radar incident angle. A dynamic mesh matrix is ​​established based on the control surface deflection angles and attitude angles. A combined high-frequency algorithm of PO+PTD is used to calculate the dynamic RCS under control surface deflection conditions. The process is as follows: Figure 1 As shown, the specific steps include:

[0028] Step S1: Obtain the control surface deflection angle, flight trajectory, and attitude changes during the flight of the aircraft.

[0029] Aircraft control is achieved by altering several control variables, such as the deflection angles of the ailerons, elevators, and rudder, and the position of the throttle. The flight controller model generates the necessary control variables based on received control commands, inputs these variables into a six-degree-of-freedom model, and calculates the aircraft's motion parameters, such as control surface deflection angles, flight trajectory, speed, and attitude angles. This invention employs the classic PID control method to design the closed-loop control law, ensuring accurate maneuverability.

[0030] Step S2: Calculate the incident direction of the radar wave in the global coordinate system based on the flight trajectory, and correct the incident angle of the radar wave.

[0031] Because the aircraft's position changes in real time during maneuvering, the change in the relative positional relationship between the aircraft and the radar leads to a change in the radar's incident angle. Based on the flight trajectory obtained in step S1, the relative positional relationship between the aircraft and the ground radar is determined, such as... Figure 2 As shown. Assume the radar position in the ground coordinate system is... The real-time position of the aircraft obtained from step S1 is Calculate the incident direction of the radar wave in the global coordinate system to obtain the corrected radar incident angle in the global coordinate system:

[0032] ,

[0033] ,

[0034] in: , , , , , These represent the components of the relative distance between the radar and the aircraft on the x, y, and z axes, respectively. Indicates the radar line-of-sight azimuth angle. This refers to the radar line-of-sight elevation angle.

[0035] When the rudder is deflected, the flight path is as follows: Figure 3 As shown, if the ground radar position is (-10000, 0, 0), then the corrected radar incident angle is as follows. Figure 4 As shown.

[0036] Step S3: Based on the aircraft's baseline geometric model, dynamically adjust the geometric position and orientation of the control surfaces according to the control surface deflection angle to generate a dynamically updated hybrid mesh matrix in real time.

[0037] Establish the baseline geometric model of the aircraft, such as Figure 5 As shown, the aircraft includes the fuselage and all control surfaces (ailerons, rudder, elevator). During maneuvers, the aircraft's dynamic mesh model is as follows:

[0038] ,

[0039] ,

[0040] Where t is time, The grid coordinate matrix of the aircraft. This refers to an aircraft model. , This represents the grid coordinate matrix of the first and second ailerons on both sides. , This represents the model of the first and second ailerons on both sides. , This represents the grid coordinate matrix of the first and second rudders on both sides. , This represents the first and second rudder models. , This represents the grid coordinate matrix of the first and second elevators on both sides. , This represents the models of the first elevator and the second elevator. Represents the fuselage grid coordinate matrix. This refers to a model of the fuselage. express The surface scattering area. Based on the rudder deflection angle obtained in step S1. The geometric position and orientation of the corresponding control surfaces are dynamically adjusted, and the overall mesh is transformed according to the attitude angle information to update the hybrid mesh matrix describing the shape of the aircraft in real time. For the aileron deflection angle, For elevator deflection angle, This represents the rudder deflection angle. Use a unit vector. Indicates the axis of rotation. These represent the components of the unit vector along the x, y, and z axes, respectively. The angle at which the moving part rotates about this axis of rotation... The rotation matrix is:

[0041] ,

[0042] Taking the rudder as an example, when the rudder veers to the left, as... Figure 6 As shown, the deflection angle is The unit vector of the rotation axis is The coordinates of the endpoints of the rotation axis are Then the mesh matrix model of the left first rudder is updated as follows:

[0043] ,

[0044] ,

[0045] ,

[0046] ,

[0047] The superscript corresponds to the current transformation operation. The initial mesh coordinate matrix is ​​translated and rotated along the x, y, and z axes respectively. The rotated matrix is ​​then moved back to the endpoints of the rotation axes. The transformation method for the remaining control surface mesh matrices is the same as that for the rudder. If the relative attitude of the fuselage does not change when the control surfaces deflect, then:

[0048] ,

[0049] When an aircraft performs integrated maneuvers, multiple control surfaces deflect simultaneously according to control commands, and the flight attitude changes over time. Therefore, a comprehensive transformation of the aircraft's grid is required. This represents the rotation matrix during attitude transformation of the aircraft. The transformation matrices for rotation around the x-axis, y-axis, and z-axis are respectively... , , The dynamic hybrid mesh matrix of the aircraft is then:

[0050] ,

[0051] .

[0052] Step S4: Using the corrected radar wave incident angle and dynamic hybrid grid matrix as input, electromagnetic scattering calculation is performed using physical optics combined with physical diffraction theory, and the dynamic RCS result considering the real-time deflection state of the control surface is output.

[0053] In electromagnetic scattering problems, the high-frequency method approximates the far-field and tangential planes, neglecting the weak coupling effects of scattering on the target's local structure. This method has the advantages of low computational cost and high computational efficiency, and can well meet the requirements for analyzing the electromagnetic scattering characteristics of electrically large targets.

[0054] The physical optics method, based on the Stratton-Chu scattering field integral equation and the high-frequency field locality principle, neglects the mutual influence of different parts of the target and approximates the incident field to determine the surface induced current. Considering the design of the receiving antenna and phase factors, the RCS calculation formula is as follows:

[0055] ,

[0056] in, For the wavenumber in free space, Permeability, Angular frequency, This represents the distance from the source point to the field point. The source point coordinate vector, For integral surfaces, The direction of the electric field at the receiving antenna. The normal vector outside the surface element. In terms of radiation direction. The magnetic field strength at the point of incidence. The incident electric field strength is... This represents the surface scattering area of ​​the aircraft.

[0057] Because physical optics methods do not consider the effects of target edges, apexes, corners, and other edges, their computational accuracy is significantly reduced. To compensate for this deficiency, it is necessary to solve the physical theory of diffraction, that is, to solve for the diffraction coefficients using the typical solution of wedge scattering. PTD represents the scattered field as the sum of the physical optics contribution and the edge contribution, and extracts the edge contribution using the rigorous solution of the two-dimensional wedge problem.

[0058] Based on PTD, the RCS contribution of single-edge diffraction can be derived as follows:

[0059] ,

[0060] in, The length of the edge. The vector representing the center position of the edge. The unit vector is the edge normal. The oblique angle of the edge. The angle between the electromagnetic wave and the edge. , All are physical diffraction coefficients. The direction of the incident electric field, The direction of the incident magnetic field, The direction of the electric field at the receiving antenna. The direction of the magnetic field at the receiving antenna. For the wavenumber in free space, The unit vector is the direction of incidence.

[0061] The electromagnetic scattering characteristics of a target originate from the combined contributions of surface elements and edges. If M surface elements and N edges within the target are illuminated, then the total RCS of the target is:

[0062] ,

[0063] Using the corrected radar incident angle obtained in step S2 and the dynamic grid matrix obtained in step S3 as inputs, the dynamic RCS result considering the real-time control surface deflection state is calculated based on the above formula. Taking the rudder as an example, when the control surface deflects by 30°, and the radar frequency is set to 10GHz, the dynamic RCS calculation result under horizontal polarization is as follows: Figure 7 As shown, the mean values ​​of static and dynamic RCS calculations are -8.7943 dB and 5.8802 dB, respectively, with the peak RCS increase reaching 25 dB. The change in the local shape of the aircraft caused by rudder deflection affects the overall RCS result, showing a significant increase in some orientations. The dynamic calculation method based on rudder deflection can more realistically reflect the stealth characteristics during maneuvers.

[0064] In a second aspect, the present invention provides an electronic device, comprising: one or more processors; and a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection.

[0065] Thirdly, the present invention provides a computer-readable storage medium storing executable instructions thereon, which, when executed by a processor, enable the processor to implement the aforementioned method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection.

[0066] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection, characterized in that, The method includes: Step S1: Obtain the control surface deflection angle, flight trajectory, and attitude changes during the flight of the aircraft; Step S2: Calculate the incident direction of the radar wave in the global coordinate system based on the flight trajectory, and correct the incident angle of the radar wave; Step S3: Based on the aircraft's baseline geometric model, dynamically adjust the geometric position and orientation of the control surfaces according to the control surface deflection angles to generate a dynamically updated dynamic hybrid mesh matrix in real time; this includes: based on the aircraft's baseline geometric model, calculating the rotation matrix of each control surface and updating its spatial position and orientation according to the real-time acquired control surface deflection angle data, generating dynamic mesh data containing the deflected control surfaces; combining the aircraft's real-time attitude angle data, performing an overall coordinate transformation on the dynamic mesh data to generate a dynamic hybrid mesh matrix reflecting the control surface deflection and flight attitude changes, providing a real-time geometric model for electromagnetic scattering calculations; the dynamic hybrid mesh matrix is: ， ， In the formula, t is time. The grid coordinate matrix of the aircraft. Represents an aircraft model. Represents the fuselage grid coordinate matrix. Indicates a fuselage model. , This represents the grid coordinate matrix of the first and second ailerons. , This represents the model of the first and second ailerons. , This represents the grid coordinate matrix of the first and second rudder. , This represents the first and second rudder models. , This represents the grid coordinate matrix of the first elevator and the second elevator. , This represents the models of the first elevator and the second elevator. This represents the rotation matrix used by the aircraft during attitude changes. This represents the rotation matrix about the x-axis. For the roll angle of the aircraft, This represents the rotation matrix around the y-axis. The pitch angle of the aircraft. This represents the rotation matrix about the z-axis. This refers to the aircraft's yaw angle; Step S4: Using the corrected radar wave incident angle and dynamic hybrid grid matrix as input, electromagnetic scattering calculation is performed using physical optics combined with physical diffraction theory, and the dynamic RCS result considering the real-time deflection state of the control surface is output.

2. The method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection according to claim 1, characterized in that, In step S1, the control surface deflection angle, flight trajectory and attitude angle are calculated in real time through the six-degree-of-freedom model of the aircraft and the controller model. The controller model uses the PID control method to generate control commands.

3. The method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection according to claim 1, characterized in that, In step S2, when correcting the radar wave incident angle, the radar wave incident direction in the global coordinate system is calculated based on the relative positional relationship between the aircraft and the radar, and the azimuth and pitch angles are updated in real time.

4. The method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection according to claim 1, characterized in that, Step S4 includes: using the corrected radar wave incident angle and dynamic hybrid grid matrix as input, calculating the scattering contribution of the surface elements of the aircraft using the physical optics method; calculating the diffraction contribution of the edge edges of the aircraft using the physical diffraction theory, where the edge edges include the edge structures formed after the control surface deflection; superimposing the surface element scattering contribution and the edge diffraction contribution, and outputting the dynamic RCS calculation result considering the real-time deflection state of the control surface.

5. The method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection according to claim 4, characterized in that, The formula for calculating the RCS of the scattering contribution of surface elements on an aircraft using the physical optics method is as follows: ， in, For the wavenumber in free space, Permeability, Angular frequency, This represents the distance from the source point to the field point. The source point coordinate vector, For integral surfaces, The direction of the electric field at the receiving antenna. The normal vector outside the surface element. In terms of radiation direction. The magnetic field strength at the point of incidence. The incident electric field strength is... This represents the surface scattering area of ​​the aircraft.

6. The method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection according to claim 5, characterized in that, The RCS of the diffraction contribution of the aircraft's edge, calculated using physical diffraction theory, is as follows: ， in, The length of the edge. The vector representing the center position of the edge. The unit vector is the edge normal. The oblique angle of the edge. The angle between the electromagnetic wave and the edge. , All are physical diffraction coefficients. The direction of the incident electric field, The direction of the incident magnetic field, The direction of the electric field at the receiving antenna. The direction of the magnetic field at the receiving antenna. For the wavenumber in free space, The unit vector is the direction of incidence.

7. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When one or more programs are executed by the one or more processors, the one or more processors implement the method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, It stores executable instructions, which, when executed by a processor, enable the processor to implement the method for calculating the dynamic electromagnetic scattering characteristics of an aircraft based on control surface deflection as described in any one of claims 1-6.

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