A method and system for infrared simulation of dynamic flying targets

Abstract

This application relates to the field of target simulation technology, and in particular to a method and system for infrared simulation of dynamic flying targets. The method first calculates the three-dimensional temperature field of the target, and then uses the three-dimensional temperature field data to render and generate infrared radiation characteristic maps of different attitudes to construct a target infrared characteristic map dataset. During simulation, based on the simulation data, the infrared radiation characteristic map number for the target's corresponding attitude is calculated, and the target imaging parameters are calculated. Then, the infrared radiation characteristic map of the target's corresponding attitude is retrieved using the number, and the target image is adjusted according to the target imaging parameters and fused with the background to generate an infrared scene map. Finally, the scene map is converted into a thermal radiation signal using an infrared target simulator, and a five-axis simulation turntable is used to simulate the relative perspective between the target and the aircraft, realizing a semi-physical simulation of dynamic target relative motion detection. This application solves the problems of poor real-time performance and low fidelity in existing infrared target simulation technologies, and has the advantages of high simulation efficiency and high realism.

Description

Technical Field

[0001] This application relates to the technical field of target simulation, and in particular to a method and system for infrared simulation of dynamic flying targets. Background Technology

[0002] With the continuous development of optical infrared imaging detection technology, infrared detection methods have demonstrated significant advantages in the detection, identification, and tracking of civilian and military targets, becoming one of the key technologies in modern optical detection systems. Infrared target scene generation simulation can be widely applied in the design of flight simulators, the development of target detection and identification algorithms, and the development of infrared imaging guidance systems. However, generating high-fidelity target infrared images is difficult and costly, especially the generation of infrared images of high-speed dynamic targets, which mainly relies on simulation generation.

[0003] Existing infrared target scene generation and simulation solutions mainly include full mathematical simulation and image simulation based on existing data. Full mathematical simulation utilizes the target's radiation characteristics, atmospheric and environmental radiation characteristics, atmospheric infrared radiation transmission, and the imaging mechanism of imaging equipment to simulate infrared images. However, full mathematical simulation methods are difficult to meet the requirements of real-time dynamic simulation, and require high modeling fidelity and are computationally time-consuming. On the other hand, image simulation based on existing data mainly assigns material properties (thermal characteristics, optical parameters, spectral characteristics, etc.) to the target and background, and combines physical effects to model and reproduce the infrared imaging process. It can generate infrared images of large-scale complex scenes (such as digital earth-level scenes). However, it depends on material division and frame rate requirements, resulting in insufficient accuracy in modeling the target's thermal infrared characteristics and insufficient analysis of the influence of heat sources, affecting the accuracy of the target's infrared features and the reliability of software and hardware verification.

[0004] Hardware-in-the-loop (HIL) simulation can replace physical experiments with repeated experimental studies at a lower cost and with a higher degree of execution through theoretical analysis, ground tests, and selective physical experiments. It can obtain complete experimental data of the system under various conditions. Therefore, HIL simulation has been applied to various fields due to its unique functions and outstanding advantages.

[0005] For example, the invention patent application with publication number CN102538598A discloses an infrared target motion simulation system. It provides a target simulator with different sizes and energies, and drives the target simulator to perform individual or combined movements on the horizontal and pitch planes. It also includes a positioning fixture that supports the guidance cabin. Then, the industrial control computer completes the human-machine interaction and sends the processed control signal to the motion control system. The motion control system receives the control signal sent by the host computer, processes the control signal further, and sends it to the execution component.

[0006] However, the above simulation system has a simple structure and limited simulation dimensions. The probe is fixedly positioned and aligned with the target simulator, and there is no attitude simulation. It is only suitable for simulation of simple dynamic scenarios. Summary of the Invention

[0007] The purpose of this invention is to provide a dynamic flight target infrared simulation method and system, which partially solves or alleviates the above-mentioned shortcomings in the prior art, can meet the requirements of real-time simulation, and generates infrared target characteristic images with high fidelity, significantly improving simulation efficiency and accuracy.

[0008] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution:

[0009] A first aspect of the present invention is to provide a dynamic flight target infrared simulation method, comprising the following steps:

[0010] The three-dimensional temperature field data of the simulated target is calculated using fluid dynamics software. The three-dimensional temperature field data is quantified and rendered to obtain the infrared radiation characteristic map of the target. The corresponding infrared radiation characteristic map of the target is collected and numbered by controlling the attitude change of the simulated target, thereby forming a target infrared characteristic map dataset.

[0011] During simulation, a real-time simulator is used to calculate and output the pose data of the simulated target and the aircraft in real time. The relative angle is calculated based on the pose data of the simulated target and the aircraft, and the corresponding target infrared radiation characteristic map number is calculated using the relative angle.

[0012] Based on the pose data of the simulated target and the aircraft, the head and tail vertex coordinates of the simulated target in the camera coordinate system are calculated. Based on the preset camera imaging model, the head and tail vertex coordinates are transformed to the pixel coordinate system, and the target imaging parameters are calculated. The target imaging parameters include pixel size, imaging position and pointing angle.

[0013] Based on the number of the calculated target infrared radiation characteristic map, the target infrared radiation characteristic map of the corresponding attitude is read from the target infrared characteristic map dataset. The target size and orientation of the target infrared radiation characteristic map are adjusted according to the target imaging parameters to obtain the adjusted target infrared image. Then, the scene background image is read and the adjusted target infrared image is pasted into the background image according to the calculated target imaging position to form a scene map with target infrared characteristics.

[0014] The scene image with the infrared characteristics of the target is output to the infrared dynamic target simulator in real time at a fixed frequency. The infrared dynamic target simulator converts the image data into realistic infrared thermal radiation signals and uses a five-axis simulation turntable to simulate the relative perspective relationship between the target and the aircraft. Then, the motion control of the five-axis simulation turntable is used to realize the semi-physical simulation of dynamic target relative motion detection.

[0015] Furthermore, the quantization and rendering of the three-dimensional temperature field data to obtain the target infrared radiation characteristic map includes:

[0016] The radiance of each point in the three-dimensional temperature field data is calculated and quantized to the range of 0-255 to form the thermal radiation grayscale value of the simulated target, and the infrared radiation characteristic map of the target is rendered.

[0017] Furthermore, the step of acquiring and numbering the corresponding infrared radiation characteristic maps of the simulated target by controlling its attitude changes includes:

[0018] By controlling the roll angle of the simulated target around the X-axis from 0 degrees to 360 degrees, adjusted in N-degree intervals, and the yaw angle around the target's Y-axis from 0 degrees to 180 degrees, adjusted in N-degree intervals, infrared radiation characteristic maps of the simulated target under different attitudes are collected and numbered according to the attitude angle information to form a target infrared characteristic map dataset.

[0019] Furthermore, the step of acquiring and numbering the corresponding infrared radiation characteristic maps of the simulated target by controlling its attitude changes includes:

[0020] The first number is the roll angle or relative viewing angle of the simulated target, and the second number is the relative viewing angle or roll angle between the simulated target and the aircraft. The first number and the second number are separated by a hyphen.

[0021] Furthermore, the step of calculating the relative viewing angle based on the pose data of the simulated target and the aircraft, and using the relative viewing angle to calculate the corresponding target infrared radiation characteristic map number includes:

[0022] The position of the aircraft is transformed to the coordinate system of the simulated target to obtain the unit vector of the aircraft in the target coordinate system. The angle between the unit vector of the aircraft in the target coordinate system and the unit vector of the X-axis of the simulated target is calculated. The angle is used as the relative viewing angle and combined with the roll angle of the simulated target itself to solve for the number of the corresponding infrared radiation characteristic map of the target.

[0023] Furthermore, the step of calculating the head and tail vertex coordinates of the simulated target in the camera coordinate system based on the pose data of the simulated target and the aircraft, and transforming the head and tail vertex coordinates to the pixel coordinate system based on a preset camera imaging model includes:

[0024] The real-time simulator calculates and outputs the pose data of the simulated target and the aircraft in real time, setting them as three-dimensional coordinate points in the geodetic coordinate system. Based on the pose of the preset camera imaging model in the geodetic coordinate system, the transformation matrix between the camera coordinate system and the geodetic coordinate system is calculated. The head and tail vertices of the simulated target in the geodetic coordinate system are transformed to the camera coordinate system. Then, the pixel coordinates of the simulated target in the two-dimensional image are calculated based on the three-dimensional coordinates of the head and tail of the simulated target in the camera coordinate system.

[0025] Furthermore, the calculation of target imaging parameters includes:

[0026] Based on the pixel coordinates of the head vertex of the simulated target image. and tail vertex pixel coordinates Calculate the Euclidean distance between the two points as the pixel size K of the target image:

[0027] ;

[0028] Head vertex pixel coordinates and tail vertex pixel coordinates The midpoint of the line connecting the two points is used as the imaging position for target imaging. :

[0029] ;

[0030] Taking the horizontal rightward direction of the image as the 0° reference direction and the counterclockwise direction as the positive angle direction, with... As a starting point The angle between the target image's pointing direction and the direction pointed to from (w / 2, h / 2) in the image as the starting point and (w, h / 2) as the ending point is the pointing angle of the target image; where w is the image width and h is the image height.

[0031] Furthermore, adjusting the target infrared radiation characteristic map according to the target imaging parameters to obtain the adjusted target infrared image includes:

[0032] Read the target infrared radiation characteristic map with the corresponding number from the target infrared characteristic map dataset, scale the target infrared radiation characteristic map proportionally according to the calculated pixel size of the target image, use the calculated imaging position of the target image as the imaging position to be pasted into the background image, and rotate the target infrared radiation characteristic map according to the pointing angle of the target image.

[0033] Secondly, this application also discloses a dynamic flight target infrared simulation system, the system comprising:

[0034] The target infrared characteristic map dataset acquisition module is configured to use fluid software to simulate and calculate the three-dimensional temperature field data of the simulated target, quantize and render the three-dimensional temperature field data to obtain the target infrared radiation characteristic map, and collect the corresponding target infrared radiation characteristic map by controlling the attitude change of the simulated target and numbering it to form the target infrared characteristic map dataset.

[0035] The infrared radiation characteristic map acquisition module is configured to use a real-time simulator to calculate and output the pose data of the simulated target and the aircraft in real time, calculate the relative angle based on the pose data of the simulated target and the aircraft, and use the relative angle to calculate the number of the corresponding infrared radiation characteristic map of the target.

[0036] The target imaging calculation module is configured to calculate the head and tail vertex coordinates of the simulated target in the camera coordinate system based on the pose data of the simulated target and the aircraft, transform the head and tail vertex coordinates to the pixel coordinate system based on a preset camera imaging model, and calculate the target imaging parameters; the target imaging parameters include pixel size, imaging position and pointing angle;

[0037] The scene image generation module is configured to read the target infrared radiation characteristic map of the corresponding posture from the target infrared radiation characteristic map dataset based on the number of the calculated target infrared radiation characteristic map, and adjust the target size and orientation of the target infrared radiation characteristic map according to the target imaging parameters to obtain the adjusted target infrared image. Then, it reads the scene background image and pastes the adjusted target infrared image into the background image according to the calculated target imaging position to form a scene image with target infrared characteristics.

[0038] The dynamic simulation module is configured to output the scene image with the infrared characteristics of the target to the infrared dynamic target simulator in real time at a fixed frequency. The infrared dynamic target simulator converts the image data into realistic infrared thermal radiation signals and uses a five-axis simulation turntable to simulate the relative viewpoint relationship between the target and the aircraft. Then, the motion control of the five-axis simulation turntable is used to realize the dynamic target relative motion simulation detection semi-physical simulation.

[0039] Furthermore, the target infrared characteristic map dataset acquisition module specifically includes:

[0040] Temperature field data calculation unit, configured to use fluid simulation software to calculate the three-dimensional temperature field data of the simulated target;

[0041] The first image processing unit is configured to quantize the three-dimensional temperature field data and render it to obtain a target infrared radiation characteristic map.

[0042] The second image processing unit is configured to control the attitude changes of the simulated target in order to acquire and number the corresponding infrared radiation characteristic maps of the target, thereby forming a target infrared characteristic map dataset.

[0043] Beneficial effects:

[0044] 1. Three-dimensional temperature field data of the target is calculated using fluid dynamics simulation software. By precisely quantifying the mapping relationship between temperature values ​​and grayscale values, high-precision infrared radiation characteristic maps are generated and rendered. A data acquisition method based on dual-angle interval sampling of roll and yaw is specifically designed to construct a full-coverage target infrared feature map dataset at fixed angles (e.g., 3°), ensuring that the thermal radiation characteristics of each attitude angle can be accurately recorded and reproduced. This data generation method overcomes the limitation of insufficient accuracy of thermal models in traditional simulations, providing a realistic and reliable data foundation for target dynamic simulation.

[0045] 2. To meet the requirements of high fidelity and real-time performance for dynamic simulation targets, this invention pre-generates a high-fidelity target infrared feature image dataset. During real-time simulation, the imaging parameters of the target are calculated using a preset camera model, and the target posture data is solved. The infrared feature map of the target posture corresponding to the acquired image library is retrieved, and its size, position, and orientation are adjusted. Combined with the background, a simulation scene map is generated in real time, which greatly improves the smoothness and realism of the simulation.

[0046] 3. This invention is the first to propose a dynamic overlay technology for infrared feature maps with transparent channels, achieving seamless fusion of the target and background through precise control of pixel transparency. A scientific background-target radiation characteristic fusion model is established, solving the common radiation characteristic mismatch problem in traditional simulations. This innovative scene generation method significantly improves the realism of the synthesized images, providing a more reliable simulation environment for testing infrared detection systems.

[0047] 4. By combining the classic pinhole camera model with target geometric features, a method for calculating imaging parameters based on the projection of the target's head and tail vertices is proposed. By accurately calculating key parameters such as the target's imaging size, position, and pointing angle in the pixel coordinate system, intelligent scaling, rotation, and position adjustment of the infrared feature map are achieved. This parameterized adjustment method effectively overcomes the distortion of thermal radiation characteristics caused by traditional image deformation, ensuring the accuracy of target infrared features at different distances and orientations. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0049] Figure 1 This is a flowchart of an embodiment of an infrared simulation method for dynamic flying targets according to this application;

[0050] Figure 2 This is a schematic diagram of the target simulation and detection hardware-in-the-loop system structure in one embodiment of this application;

[0051] Figure 3 This is a flowchart of the infrared dynamic target scene generation process in one embodiment of this application;

[0052] Figure 4 This is a schematic diagram of the target coordinate system in one embodiment of this application;

[0053] Figure 5 This is a schematic diagram of the module structure of a dynamic flight target infrared simulation system in one embodiment of this application. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0055] In this document, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" may be used interchangeably.

[0056] In this document, the terms "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] In this document, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0058] In this document, "and / or" includes any and all combinations of one or more of the listed related items.

[0059] In this article, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0060] Figure 1 The flowchart of a dynamic flight target infrared simulation method according to this application is shown. The method specifically includes the following steps:

[0061] S1 uses fluid simulation software to calculate the three-dimensional temperature field data of the simulated target; the three-dimensional temperature field data is quantized and rendered (using the pyvista library of Python to render the temperature field data into a point cloud) to obtain the infrared radiation characteristic map of the target. By controlling the attitude change of the simulated target, the corresponding infrared radiation characteristic map of the target is collected and numbered to form the target infrared characteristic map dataset (i.e., multi-attitude infrared feature map dataset).

[0062] During S2 simulation, a real-time simulator is used to calculate and output the pose data of the simulated target and the aircraft in real time. The relative angle is calculated based on the pose data of the simulated target and the aircraft (specifically, the pose data can be obtained by a scene generation computer and the relative angle can be calculated). The corresponding target infrared radiation characteristic map number is calculated using the relative angle.

[0063] S3 calculates the head and tail vertex coordinates of the simulated target in the camera coordinate system based on the pose data of the simulated target and the aircraft. Based on the preset camera imaging model, it transforms the head and tail vertex coordinates to the pixel coordinate system and calculates the target imaging parameters, including pixel size, imaging position and pointing angle.

[0064] S4 reads the target infrared radiation characteristic map of the corresponding attitude from the target infrared radiation characteristic map dataset based on the number of the calculated target infrared radiation characteristic map, and adjusts the target size and orientation of the target infrared radiation characteristic map according to the target imaging parameters to obtain the adjusted target infrared image. Then, it reads the scene background image and pastes the adjusted target infrared image into the background image according to the calculated target imaging position to form a scene map with target infrared characteristics.

[0065] The S5 outputs a scene image with the infrared characteristics of the target to the infrared dynamic target simulator in real time at a fixed frequency. The infrared dynamic target simulator converts the image data into realistic infrared thermal radiation signals and uses a five-axis simulation turntable to simulate the relative perspective relationship between the target and the aircraft. Then, the motion control of the five-axis simulation turntable is used to realize the semi-physical simulation of dynamic target relative motion detection.

[0066] This embodiment focuses on the semi-physical simulation of infrared dynamic scenes for aerial targets. First, high-fidelity infrared feature maps of the simulated target (i.e., the dynamic target) at different attitudes are created using temperature field data. These maps are then numbered according to attitude angle information, resulting in a dataset of infrared feature images of the simulated target at different attitudes. During simulation, the imaging parameters of the simulated target are calculated using a camera imaging model based on the simulation data. The infrared radiation characteristic maps from the corresponding attitude characteristic map dataset are then retrieved and adjusted according to the calculated parameters to simulate arbitrary target size and attitude. Finally, the infrared images of the simulated target and background at different distances and attitudes at any given time are obtained through background image fusion. The real-time generated sequence of target infrared simulation images is then output to the infrared dynamic target simulator for dynamic simulation of the target's infrared characteristics.

[0067] In one specific embodiment, quantizing and rendering the three-dimensional temperature field data to obtain the target infrared radiation characteristic map includes:

[0068] The temperature value of each point in the three-dimensional temperature field data is converted and quantized to the range of 0-255 to form the thermal radiation grayscale value of the simulated target, and then rendered to obtain the infrared radiation characteristic map of the target. In the three-dimensional temperature field data, each point [x,y,z,c] of the simulated target contains the three-dimensional position x, y, z and the current temperature value c.

[0069] In one specific embodiment, the acquisition and numbering of corresponding infrared radiation characteristic maps of the simulated target by controlling the attitude changes of the simulated target includes:

[0070] By controlling the roll angle of the simulated target around the X-axis from 0 degrees to 360 degrees, and adjusting it at intervals of N degrees (e.g., 3 degrees), and simultaneously adjusting the yaw angle around the Y-axis from 0 degrees to 180 degrees, at intervals of N degrees (e.g., 3 degrees), infrared radiation characteristic maps of the simulated target under different attitudes are collected and numbered according to the attitude angle information to form a target infrared characteristic map dataset.

[0071] In one specific embodiment, the acquisition and numbering of corresponding infrared radiation characteristic maps of the simulated target by controlling the attitude changes of the simulated target includes:

[0072] The first digit of the number is the roll angle of the simulated target, and the second digit is the relative angle between the simulated target and the aircraft, separated by a hyphen. Alternatively, in some embodiments, the first digit may be the relative angle between the simulated target and the aircraft, and the second digit may be the roll angle of the simulated target, separated by a hyphen.

[0073] In one specific embodiment, the relative viewing angle is calculated based on the pose data of the simulated target and the aircraft. The corresponding target infrared radiation characteristic map number is obtained by using the relative viewing angle.

[0074] The position of the aircraft is transformed to the coordinate system of the simulated target to obtain the unit vector of the aircraft in the target coordinate system. The angle between the unit vector of the aircraft in the target coordinate system and the unit vector of the X-axis of the simulated target is calculated. The angle is used as the relative viewing angle and combined with the roll angle of the simulated target itself to solve for the corresponding target infrared radiation characteristic map number.

[0075] In one specific embodiment, the head and tail vertex coordinates of the simulated target in the camera coordinate system are calculated based on the pose data of the simulated target and the aircraft. The transformation of the head and tail vertex coordinates to the pixel coordinate system based on the preset camera imaging model includes:

[0076] The real-time simulator calculates and outputs the pose data of the simulated target and the aircraft in real time, setting them as three-dimensional coordinate points in the geodetic coordinate system. Based on the pose of the preset camera imaging model in the geodetic coordinate system, the transformation matrix between the camera coordinate system and the geodetic coordinate system is calculated. The head and tail vertices of the simulated target in the geodetic coordinate system are transformed to the camera coordinate system. Then, the pixel coordinates of the simulated target in the two-dimensional image are calculated based on the three-dimensional coordinates of the head and tail of the simulated target in the camera coordinate system.

[0077] In one specific embodiment, the target imaging parameters include pixel size, imaging position, and pointing angle.

[0078] In one specific embodiment, calculating the target imaging parameters includes:

[0079] Based on the pixel coordinates of the head vertex of the simulated target image. and tail vertex pixel coordinates Calculate the Euclidean distance between the two points as the pixel size K of the target image:

[0080] ;

[0081] Head vertex pixel coordinates and tail vertex pixel coordinates The midpoint of the line connecting the two points is used as the imaging position for target imaging. :

[0082] ;

[0083] Taking the horizontal rightward direction of the image as the 0° reference direction and the counterclockwise direction as the positive angle direction, with... As a starting point The angle between the target image's pointing direction and the direction pointed to from (w / 2, h / 2) in the image as the starting point and (w, h / 2) as the ending point is the pointing angle of the target image; where w is the image width and h is the image height.

[0084] In one specific embodiment, adjusting the target infrared radiation characteristic map according to the target imaging parameters to obtain the adjusted target infrared image includes:

[0085] Read the target infrared radiation characteristic map with the corresponding number from the target infrared characteristic map dataset, scale the target infrared radiation characteristic map proportionally according to the pixel size of the calculated target image, use the image position of the calculated target image as the image position to be pasted into the background image, and rotate the target infrared image according to the pointing angle of the target image.

[0086] In a specific embodiment, the following will describe in detail a dynamic flight target infrared simulation method and system of this application:

[0087] In this embodiment, the dynamic flight target infrared simulation method relies on, for example, Figure 2 The target simulation detection semi-physical simulation system shown is used to achieve this. The system includes an infrared dynamic target simulator, an infrared target detector, a five-axis simulation turntable, a scene generation computer, an external mission computer, a flight control computer, and a real-time simulation computer.

[0088] The system comprises several components: a real-time simulator that calculates and outputs real-time position and attitude data of the simulated target and the aircraft, using a five-axis simulation turntable to simulate the relative positional relationship between the target and the aircraft; an infrared dynamic target simulator fixedly mounted on the outer two axes of the five-axis simulation turntable to provide target detection information to the infrared target detectors on the inner three axes; a scene generation computer that generates dynamic target images from the aircraft's perspective in real time and transmits them to the infrared dynamic target simulator for infrared dynamic target scene simulation; an external mission computer that provides computational resources for target detection; and a flight control computer that provides flight guidance and control for the aircraft in the hardware-in-the-loop simulation.

[0089] In the simulation, the infrared dynamic target simulator is used to simulate the infrared optical characteristics of moving infrared targets. The input infrared target image is generated in real time by a scene generation computer. The scene generation computer calculates and updates the target's view relative to the aircraft in real time based on the output of the real-time simulator, thus forming a dynamic target scene. The infrared dynamic target scene generation process in the scene generation computer is as follows: Figure 3 As shown.

[0090] First, before simulation, the infrared characteristic maps of the target under different postures are calculated and a target infrared characteristic map dataset is collected. Then, the three-dimensional temperature field data of the target is simulated and calculated using fluid software. Each point [x,y,z,c] of the target contains three-dimensional position and temperature value information of the current point. The temperature value of each point is converted and quantized to the range of 0-255 to form the thermal radiation grayscale value of the target, thereby rendering the infrared radiation characteristic map of the target.

[0091] By controlling different target postures, different infrared characteristic maps of the target are generated. During acquisition, a certain imaging distance is set with a pure black background, and the image resolution is set to (w, h) so that the target is imaged in the exact center of the image. The target imaging pixel size is a fixed value. .

[0092] Reference Figure 4 The target coordinate system simulates the target's attitude changes by rotating the target around the x-axis from 0 degrees to 360 degrees in 3-degree intervals. Simultaneously, the target's yaw attitude around the y-axis changes from 0 degrees to 180 degrees in 3-degree intervals, and the infrared characteristic image of the target in the current attitude is saved. The image name is numbered according to the current target attitude angle information. For example, the first number represents the target's roll angle value, separated by a hyphen "-", and the second number represents the target's line-of-sight angle value. In this way, infrared image datasets with different target characteristics are collected.

[0093] During simulation, the scene generation computer reads the position, pitch, yaw, and roll attitude data of the target and aircraft from the real-time simulator in real time via fiber optics. This data is used to calculate the attitude identification information and geometric information of the target imaging. First, the relative viewing angle is calculated based on the position and attitude data of the target and aircraft. Then, the aircraft position is transformed to the target coordinate system to obtain the unit vector of the aircraft in the target coordinate system. Calculate the unit vector The angle between the target and the unit vector (1,0,0) on the X-axis Then utilize the target's own roll angle and included angle Calculate the target infrared feature map number at this time, combine the target infrared feature image name according to the number, and then read the image with the corresponding name from the dataset to obtain the infrared feature map of the target under this view.

[0094] In the target imaging simulation calculation, the classic pinhole camera model is used to model the camera, simulating and calculating the geometric parameters of the target image, such as size, position, and orientation. During the calculation, a geodetic coordinate system, a camera coordinate system, and a pixel coordinate system are constructed. The resolution of the simulated camera output image is set to (w, h), and certain intrinsic camera parameters, including focal length f and unit pixel size, are set. and Center pixel and During simulation, the target position output by the real-time simulator is a three-dimensional spatial coordinate point in the geodetic coordinate system, with its head and tail vertices... and tail apex The simulated camera's pose in the center is driven by the aircraft pose output by the real-time simulator. Based on the camera's pose in the geodetic coordinate system, the transformation matrix between the camera coordinate system and the geodetic coordinate system is calculated. And set the head and tail vertices of the target in the geodetic coordinate system. and tail apex Transformed to camera coordinate system as follows and Then, based on the corresponding 3D coordinates of the target's head and tail in the camera coordinate system, the pixel coordinates of the target in the 2D image are calculated. and The method for calculating the coordinates from a spatial point to a two-dimensional pixel point is as follows:

[0095]

[0096] In the formula, f is the camera focal length, and Unit pixel size and Center point pixel coordinates, The distance from the target to the camera.

[0097] The pixel coordinates of the head and tail vertices of the target were obtained through calculation. and Then, calculate the pixel size K of the image in the target image and the center position of the image. And the pointing angle of the image. The distance between the two points is calculated based on the pixel values ​​of the head and tail vertices of the target in the image, and is taken as the target imaging pixel size. The target's imaging location is and Midpoint between two points The imaging direction of the target in the image is defined with 0° to the right as positive, counterclockwise as positive, and clockwise as negative. starting point The angle between the endpoint pointing and the image (with (w / 2, h / 2) as the starting point and (w, h / 2) as the endpoint pointing is the target imaging direction. .

[0098] The calculated target imaging geometry information is used to map and transform the obtained target infrared feature map. First, a transparent layer is added to the read target infrared feature map according to the pixel values ​​in the image, where pixels with a value of 0 represent full transparency and pixels with a value of 255 represent opacity. This results in an infrared feature map of the target with a transparent layer. The target imaging size is then calculated. Target size compared to the original feature map Instead of obtaining the target scaling value (scale) and then scaling the infrared feature map of the target with the transparent layer proportionally, the target is then rotated according to the obtained imaging direction after scaling. The scaled target feature map is then aligned with the calculated target imaging direction. The value is rotated. The scene background image is read, and the target imaging position is calculated. The target's characteristic image, scaled and rotated with a transparent layer, is pasted onto the background image, making the target appear within the background image. At the target location, a scene image with the infrared characteristics of the target is formed. Finally, the synthesized scene image is output to the target simulator in real time at a fixed frequency (100Hz to ensure program stability) for target simulation. This process of updating the scene target image is repeated until the simulation ends.

[0099] By generating dynamic target infrared scenes based on target infrared feature maps, the simulation meets the requirements of real-time simulation and has high-fidelity infrared target characteristics. At the same time, the five-axis turntable is used to simulate the relative positional relationship between the detector and the target, resulting in high control precision. The five-axis turntable introduces the infrared target detector and the target simulator into the hardware-in-the-loop simulation, thereby improving the reliability of the simulation.

[0100] Further reference Figure 5 As an implementation of the above-described method, this application provides an embodiment of a dynamic flight target infrared simulation method system, which is similar to... Figure 1 Corresponding to the method embodiments shown, this device can be specifically applied to various electronic devices.

[0101] refer to Figure 5 A dynamic flight target infrared simulation system, comprising:

[0102] The target infrared characteristic map dataset acquisition module 101 is configured to use fluid software to simulate and calculate the three-dimensional temperature field data of the simulated target, quantify and render the three-dimensional temperature field data to obtain the target infrared radiation characteristic map, and collect the corresponding infrared radiation characteristic map by controlling the attitude change of the simulated target and numbering it to form the target infrared characteristic map dataset.

[0103] The infrared radiation characteristic map acquisition module 102 is configured to use a real-time simulator to calculate and output the pose data of the simulated target and the aircraft in real time, calculate the relative angle based on the pose data of the simulated target and the aircraft, and use the relative angle to calculate the number of the corresponding infrared radiation characteristic map of the target.

[0104] The target imaging calculation module 103 is configured to calculate the head and tail vertex coordinates of the simulated target in the camera coordinate system based on the pose data of the simulated target and the aircraft, transform the head and tail vertex coordinates to the pixel coordinate system based on a preset camera imaging model, and calculate the target imaging parameters.

[0105] The scene image generation module 104 is configured to read the infrared radiation characteristic map of the corresponding attitude from the target infrared characteristic map dataset based on the pose data of the simulated target and the aircraft, and adjust the infrared radiation characteristic map according to the target imaging parameters to obtain the adjusted target infrared image. Then, it reads the scene background image and pastes the adjusted target infrared image into the background image to form a scene image with the target infrared characteristics.

[0106] The dynamic simulation module 105 is configured to output the scene image with the infrared characteristics of the target to the infrared dynamic target simulator in real time at a fixed frequency. The infrared dynamic target simulator converts the image data into realistic infrared thermal radiation signals and uses a five-axis simulation turntable to simulate the relative viewing angle between the target and the aircraft. Then, the motion control of the five-axis simulation turntable is used to perform dynamic simulation of the target.

[0107] In a specific embodiment, the target infrared characteristic map dataset acquisition module 101 specifically includes: a temperature field data calculation unit, configured to use fluid software to simulate and calculate the three-dimensional temperature field data of the simulated target; a first image processing unit, configured to quantize and render the three-dimensional temperature field data to obtain the target infrared radiation characteristic map; and a second image processing unit, configured to control the attitude change of the simulated target to collect the corresponding infrared radiation characteristic map and number it, thereby forming a target infrared characteristic map dataset.

[0108] In another aspect, this application also provides a computer-readable storage medium, which may be included in the electronic device described in the above embodiments; or it may exist independently and not assembled into the electronic device. The aforementioned computer-readable storage medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the following... Figure 1 The method shown.

[0109] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0110] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a computer terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0111] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A dynamic flight target infrared simulation method, characterized in that, Includes the following steps: The three-dimensional temperature field data of the simulated target is calculated using fluid dynamics software. The three-dimensional temperature field data is quantified and rendered to obtain the infrared radiation characteristic map of the target. The corresponding infrared radiation characteristic map of the target is collected and numbered by controlling the attitude change of the simulated target, thereby forming a target infrared characteristic map dataset. During simulation, a real-time simulator is used to calculate and output the pose data of the simulated target and the aircraft in real time. The relative angle is calculated based on the pose data of the simulated target and the aircraft, and the corresponding target infrared radiation characteristic map number is calculated using the relative angle. Based on the pose data of the simulated target and the aircraft, the head and tail vertex coordinates of the simulated target in the camera coordinate system are calculated. Based on the preset camera imaging model, the head and tail vertex coordinates are transformed to the pixel coordinate system, and the target imaging parameters are calculated. The target imaging parameters include pixel size, imaging position and pointing angle. Based on the number of the calculated target infrared radiation characteristic map, the target infrared radiation characteristic map of the corresponding attitude is read from the target infrared characteristic map dataset. The target size and orientation of the target infrared radiation characteristic map are adjusted according to the target imaging parameters to obtain the adjusted target infrared image. Then, the scene background image is read and the adjusted target infrared image is pasted into the background image according to the calculated target imaging position to form a scene map with target infrared characteristics. The scene image with the infrared characteristics of the target is output to the infrared dynamic target simulator in real time at a fixed frequency. The infrared dynamic target simulator converts the image data into realistic infrared thermal radiation signals and uses a five-axis simulation turntable to simulate the relative perspective relationship between the target and the aircraft. Then, the motion control of the five-axis simulation turntable is used to realize the semi-physical simulation of dynamic target relative motion detection.

2. The method for simulating the infrared motion of a dynamic flying target according to claim 1, characterized in that... The process of quantizing and rendering the three-dimensional temperature field data to obtain the target infrared radiation characteristic map includes: The radiance of each point in the three-dimensional temperature field data is calculated and quantized to the range of 0-255 to form the thermal radiation grayscale value of the simulated target, and the infrared radiation characteristic map of the target is rendered.

3. The method for simulating the infrared motion of a dynamic flying target according to claim 1, characterized in that: The step of acquiring and numbering the corresponding infrared radiation characteristic maps of the simulated target by controlling its attitude changes includes: By controlling the roll angle of the simulated target around the X-axis from 0 degrees to 360 degrees, adjusted in N-degree intervals, and the yaw angle around the target's Y-axis from 0 degrees to 180 degrees, adjusted in N-degree intervals, infrared radiation characteristic maps of the simulated target under different attitudes are collected and numbered according to the attitude angle information to form a target infrared characteristic map dataset.

4. The dynamic flight target infrared simulation method according to claim 3, characterized in that: The step of acquiring and numbering the corresponding infrared radiation characteristic maps of the simulated target by controlling its attitude changes includes: The first number is the roll angle or relative viewing angle of the simulated target, and the second number is the relative viewing angle or roll angle between the simulated target and the aircraft. The first number and the second number are separated by a hyphen.

5. The dynamic flight target infrared simulation method according to claim 4, characterized in that: The step of calculating the relative viewing angle based on the pose data of the simulated target and the aircraft, and using the relative viewing angle to calculate the corresponding target infrared radiation characteristic map number, includes: The position of the aircraft is transformed to the coordinate system of the simulated target to obtain the unit vector of the aircraft in the target coordinate system. The angle between the unit vector of the aircraft in the target coordinate system and the unit vector of the X-axis of the simulated target is calculated. The angle is used as the relative viewing angle and combined with the roll angle of the simulated target itself to solve for the number of the corresponding infrared radiation characteristic map of the target.

6. The method for simulating the infrared motion of a dynamic flying target according to claim 1, characterized in that: The step of calculating the head and tail vertex coordinates of the simulated target in the camera coordinate system based on the pose data of the simulated target and the aircraft, and transforming the head and tail vertex coordinates to the pixel coordinate system based on a preset camera imaging model includes: The real-time simulator calculates and outputs the pose data of the simulated target and the aircraft in real time, setting them as three-dimensional coordinate points in the geodetic coordinate system. Based on the pose of the preset camera imaging model in the geodetic coordinate system, the transformation matrix between the camera coordinate system and the geodetic coordinate system is calculated. The head and tail vertices of the simulated target in the geodetic coordinate system are transformed to the camera coordinate system. Then, the pixel coordinates of the simulated target in the two-dimensional image are calculated based on the three-dimensional coordinates of the head and tail of the simulated target in the camera coordinate system.

7. The method for simulating the infrared motion of a dynamic flying target according to claim 6, characterized in that: The calculation of target imaging parameters includes: Based on the pixel coordinates of the head vertex of the simulated target image. and tail vertex pixel coordinates Calculate the Euclidean distance between the two points as the pixel size K of the target image: ； Head vertex pixel coordinates and tail vertex pixel coordinates The midpoint of the line connecting the two points is used as the imaging position for target imaging. : ； Taking the horizontal rightward direction of the image as the 0° reference direction and the counterclockwise direction as the positive angle direction, with... As a starting point The angle between the target image's pointing direction and the direction pointed to from (w / 2, h / 2) in the image as the starting point and (w, h / 2) as the ending point is the pointing angle of the target image; where w is the image width and h is the image height.

8. The method for simulating the infrared motion of a dynamic flying target according to claim 7, characterized in that: The step of adjusting the infrared radiation characteristic map of the target according to the target imaging parameters to obtain the adjusted infrared image of the target includes: Read the target infrared radiation characteristic map with the corresponding number from the target infrared characteristic map dataset, scale the target infrared radiation characteristic map proportionally according to the calculated pixel size of the target image, use the calculated imaging position of the target image as the imaging position to be pasted into the background image, and rotate the target infrared radiation characteristic map according to the pointing angle of the target image.

9. A dynamic flight target infrared simulation system, characterized in that, include: The target infrared characteristic map dataset acquisition module is configured to use fluid software to simulate and calculate the three-dimensional temperature field data of the simulated target, quantize and render the three-dimensional temperature field data to obtain the target infrared radiation characteristic map, and collect the corresponding target infrared radiation characteristic map by controlling the attitude change of the simulated target and numbering it to form the target infrared characteristic map dataset. The infrared radiation characteristic map acquisition module is configured to use a real-time simulator to calculate and output the pose data of the simulated target and the aircraft in real time, calculate the relative angle based on the pose data of the simulated target and the aircraft, and use the relative angle to calculate the number of the corresponding infrared radiation characteristic map of the target. The target imaging calculation module is configured to calculate the head and tail vertex coordinates of the simulated target in the camera coordinate system based on the pose data of the simulated target and the aircraft, transform the head and tail vertex coordinates to the pixel coordinate system based on a preset camera imaging model, and calculate the target imaging parameters; the target imaging parameters include pixel size, imaging position and pointing angle; The scene image generation module is configured to read the target infrared radiation characteristic map of the corresponding posture from the target infrared radiation characteristic map dataset based on the number of the calculated target infrared radiation characteristic map, and adjust the target size and orientation of the target infrared radiation characteristic map according to the target imaging parameters to obtain the adjusted target infrared image. Then, it reads the scene background image and pastes the adjusted target infrared image into the background image according to the calculated target imaging position to form a scene image with target infrared characteristics. The dynamic simulation module is configured to output the scene image with the infrared characteristics of the target to the infrared dynamic target simulator in real time at a fixed frequency. The infrared dynamic target simulator converts the image data into realistic infrared thermal radiation signals and uses a five-axis simulation turntable to simulate the relative viewpoint relationship between the target and the aircraft. Then, the motion control of the five-axis simulation turntable is used to realize the dynamic target relative motion simulation detection semi-physical simulation.

10. A dynamic flight target infrared simulation system according to claim 9, characterized in that, The target infrared characteristic map dataset acquisition module specifically includes: Temperature field data calculation unit, configured to use fluid simulation software to calculate the three-dimensional temperature field data of the simulated target; The first image processing unit is configured to quantize the three-dimensional temperature field data and render it to obtain a target infrared radiation characteristic map. The second image processing unit is configured to control the attitude changes of the simulated target in order to acquire and number the corresponding infrared radiation characteristic maps of the target, thereby forming a target infrared characteristic map dataset.

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