CN114035175A - A system and method for generating false target interference situation with diffuse reflector - Google Patents

Abstract

The invention relates to a system and method for generating a false target interference situation of a diffuse reflector. In the system, the mainframe of the interference situation generation system for the false target of the diffuse reflector includes: an energy acquisition and measurement subsystem, an image acquisition subsystem and an interference situation generation subsystem; Measurement; the image acquisition subsystem displays the position of the false target image of the diffuse reflector in the field of view in real time, and adjusts the azimuth and pitch angles of the gimbal according to the position of the false target image of the diffuse reflector in the field of view, so that the false target image of the diffuse reflector is adjusted. Place it in the center of the field of view, and collect the target image; the interference situation generation subsystem uses corner detection and monocular vision pose measurement to determine the target distance and attitude angle according to the laser energy density in front of the mirror and the target image, and then generates a laser false image. Target jamming airspace situation map. The invention can realize the real-time visual evaluation of the interference airspace when the diffuse reflection board is deployed.

Description

A system and method for generating false target interference situation with diffuse reflector

technical field

The invention relates to the field of generating a false target interference situation of a diffuse reflector, in particular to a system and method for generating a false target interference situation of a diffuse reflector.

Background technique

At present, the laser angle deception jamming system is mainly equipped with laser alarms, diffuse reflectors, jamming laser transmitters and other devices. In practical applications, the diffuse reflector can be deployed around the protected target at a certain distance and angle. After the laser alarm captures the enemy's laser guidance signal, it identifies the enemy's laser guidance signal, and is emitted by the interference laser transmitter. The interference laser of a certain power reaches the false target of the diffuse reflector, and the reflected interference laser signal can interfere with the enemy's laser-guided weapon, so that it can attack the false target of the diffuse reflector, so as to achieve the purpose of protecting the real target.

When protecting key targets, not only one diffuse reflector is needed, but multiple diffuse reflectors are needed to form a closed interference airspace around the key target. At present, there is a lack of reliable interference airspace assessment methods, and it is impossible to adjust and monitor the airspace protected by the diffuse reflector in real time according to the placement position of the diffuse reflector.

Among them, "a portable laser decoy interference effect visualization test device" realizes the visualization of the test process and results by automatically searching for the coded indicating laser signal, decoding and tracking, and displaying the target location information and scene information in real time. It can not only improve the flexibility of the laser decoy interference effect test, but also accurately locate the current position of the test equipment, and can also significantly improve the intuitiveness of the test evaluation process. "An external field evaluation system for the decoupling effect of laser decoy and jamming equipment" uses the flying device to carry the components required for laser guidance, and erects the components required for laser target indication on the ground to simulate the laser semi-active guided weapons. In the attack mode of the cast, before and after the laser decoy jamming device to be evaluated is turned on, the laser reflection signal collected by the detector is calculated respectively, and the laser decoy jamming device is evaluated according to the change of the calculated position before and after the laser decoy jamming device to be evaluated is turned on. the seductive effect. It not only realizes the full coverage of the false target in the target area by the guidance field of view, but also can effectively evaluate the decoy effect of the laser decoy jamming equipment in stationary and maneuvering states. "A system for generating a situation map of laser biasing interference environment" can accurately and completely display the layout information and false information of each sub-equipment (including laser warning equipment, laser information processor, false targets, photoelectric interference vehicles, etc.) in the biasing system. Target biased posture.

However, "a portable laser decoy interference effect visualization test device" verified the influence of different laser encoded signals on the interference effect by means of hardware-in-the-loop simulation, and realized the visualization of the interference effect. However, the influence of false target placement factors on the interference effect is not considered. "A field evaluation system for the decoy effect of laser decoy jamming equipment" proposes a method for outfield evaluation of the decoy effect of laser decoy jamming equipment with a seeker mounted on a flying platform, which can overcome the problem of limited field of view in the ground test method. However, the influence on the decoy interference effect is not considered from the perspective of fake target application. "A system for generating a situation map of laser biasing interference environment" can display the number and layout parameters of each sub-equipment of the laser biasing and interference system, and generate a false target biasing situation map. However, the number and layout parameters of each sub-equipment in this scheme require manual input, and the influence of the posture of the false target layout on the actual interference effect is not considered.

Therefore, in view of the above-mentioned problem of the lack of a visual evaluation method for the interference effect of the false target of the diffuse reflector, the purpose is to analyze the influence of different parameters on the interference airspace of the false target of the diffuse reflector. The false target interference situation generation system can realize the real-time visual assessment of the interference airspace when the diffuse reflector is deployed.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a system and method for generating a false target interference situation of a diffuse reflector, which can realize the real-time visual evaluation of the interference airspace of the diffuse reflector during the deployment strategy.

For achieving the above object, the present invention provides the following scheme:

A diffuse reflector false target interference situation generation system, comprising: a mainframe of the diffuse reflector false target interference situation generation system, a gimbal and a tripod;

The mainframe of the diffuse reflector false target interference situation generation system is arranged on the pan/tilt; the tripod is used to support the pan/tilt;

The mainframe of the diffuse reflector false target interference situation generation system includes: an energy acquisition and measurement subsystem, an image acquisition subsystem, and an interference situation generation subsystem;

The energy collection and measurement sub-system is used to collect laser energy and measure the laser energy density in front of the mirror; the laser energy is the simulated interference laser emitted by the laser to the false target of the diffuse reflection board, and the generated diffuse reflection laser signal is transmitted into the false target through the atmosphere. Laser energy that interferes with airspace assessment systems;

The image acquisition subsystem is used to display the position of the false target image of the diffuse reflector in the field of view in real time, and adjust the azimuth angle and pitch angle of the pan/tilt according to the position of the false target image of the diffuse reflector in the field of view, so as to make the diffuse reflection The false target image of the board is placed in the center of the field of view, and the target board image is collected;

The interference situation generation subsystem is used to determine the distance and attitude angle of the target board by using corner detection and monocular vision pose measurement according to the laser energy density in front of the mirror and the target board image, and then generate a laser false target interference airspace situation map.

Optionally, the energy collection and measurement subsystem includes: a narrow-band filter, a near-infrared optical system, a photodetector, a signal processing and peak hold unit, and an energy measurement unit, which are connected in sequence.

Optionally, the image acquisition subsystem includes: a narrow-band filter, a near-infrared optical system, a near-infrared CCD device, and a real-time image acquisition component connected in sequence.

Optionally, the interference situation generation subsystem includes: a hardened computer and an integrated information processing center;

The comprehensive information processing center includes: real-time processing software, test evaluation processing software, post-processing application software and communication software.

A method for generating a false target interference situation for a diffuse reflector, applied to the system for generating a false target interference situation for a diffuse reflector, the method comprising:

Obtain the false target image of the diffuse reflector;

Adjust the azimuth angle and pitch angle of the gimbal according to the position of the false target image of the diffuse reflector in the field of view, so that the false target image of the diffuse reflector is placed in the center of the field of view, and the target image is collected; laser energy density;

According to the target plate image, use corner detection and monocular vision pose measurement to calculate the target plate distance and attitude angle;

According to the laser energy density, target distance and attitude angle, the situation map of laser false target interference airspace is generated.

Optionally, according to the target plate image, use corner point detection and monocular vision pose measurement to calculate the target plate distance and attitude angle, specifically including:

Perform global threshold segmentation and connected domain analysis on the target plate image to determine the target plate binary image;

Carry out gradient operation and Canny edge detection respectively on the binary image of the target plate;

Calculate the improved corner response function according to the binary image of the target plate after gradient operation;

Perform edge point 8-field analysis on the target board binary image after Canny edge detection;

The binary image of the target plate after the edge point 8-domain analysis and the improved corner point response function are suppressed by local non-maximum value, and then the boundary pseudo-corner points are removed, and the four corner points of the target plate are determined.

Optionally, according to the target plate image, using corner detection and monocular vision pose measurement to calculate the target plate distance and attitude angle, it also specifically includes:

确定空间中某点在世界坐标系下的坐标与对应像点在图像像素坐标系下的坐标的关系；Use the formula

Determine the relationship between the coordinates of a point in the space in the world coordinate system and the coordinates of the corresponding image point in the image pixel coordinate system;

确定旋转矩阵；Use the formula

determine the rotation matrix;

确定靶板的姿态角；Use the formula

Determine the attitude angle of the target board;

为靶标相对于相机的俯仰角，

为相对相机的方位角，f_x，f_y为相机在u轴和v轴上的归一化焦距，(u₀,v₀)为图像成像中心在图像像素坐标系下的坐标，(X_W,Y_W,Z_W)为空间点在世界坐标系下的坐标，(u,v)为成像点在图像像素坐标系下的坐标，M₁是相机的内参数矩阵，是空间点在相机坐标系和对应像点在图像像素坐标系之间的转换矩阵，在相机参数不变的情况下，M₁是不变的，M₂是相机的外参数矩阵，表示空间点在相机坐标系和世界坐标系之间的旋转和平移关系，随世界坐标系的位姿变化而变化，R为旋转矩阵，θ_z为靶标相对相机的滚动角，T＝(T_x,T_y,T_z)^T为一个3×1的平移矩阵，T_x,T_y,T_z分别为在x,y,z方向上世界坐标系原点相对相机坐标系原点的平移量，r₀～r₈为系数。in,

is the pitch angle of the target relative to the camera,

is the azimuth angle relative to the camera, f _x , f _y are the normalized focal lengths of the camera on the u-axis and v-axis, (u ₀ , v ₀ ) are the coordinates of the image imaging center in the image pixel coordinate system, (X _W , Y _W , Z _W ) are the coordinates of the space point in the world coordinate system, (u, v) are the coordinates of the imaging point in the image pixel coordinate system, M ₁ is the internal parameter matrix of the camera, which is the coordinate of the space point in the camera The transformation matrix between the image pixel coordinate system and the corresponding image point between the image pixel coordinate system. When the camera parameters are unchanged, M ₁ is unchanged, and M ₂ is the external parameter matrix of the camera, indicating that the space point is in the camera coordinate system and the world. The rotation and translation relationship between coordinate systems changes with the pose of the world coordinate system, R is the rotation matrix, θ _z is the roll angle of the target relative to the camera, T=(T _x ,T _y ,T _z ) ^T is A 3×1 translation matrix, T _x , T _y , and T _z are the translations of the origin of the world coordinate system relative to the origin of the camera coordinate system in the x, y, and z directions, respectively, and r ₀ to r ₈ are coefficients.

Optionally, according to the target plate image, using corner detection and monocular vision pose measurement to calculate the target plate distance and attitude angle, it also specifically includes:

确定相机相对于靶板的距离；Use the formula

Determine the distance of the camera relative to the target board;

为假目标相对系统设备的法向角。Among them, L is the distance of the camera relative to the target plate, E _t is the single pulse energy of the interference laser, τ _t is the transmittance of the laser interference source transmitting optical system, τ _r is the transmittance of the seeker receiving system, ρ is The hemispherical reflectivity of the diffuse false target, θ _r is the angle between the reflected light and the normal line of the diffuse reflector, E _r is the laser energy density threshold received by the seeker, u _a is the attenuation constant of the atmosphere, and R ₁ is the interference laser The distance from the diffuse reflector, E is the laser energy density,

It is the normal angle of the false target relative to the system equipment.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The system and method for generating a false target interference situation of a diffuse reflector provided by the invention adopts an integrated structure design method, has a compact design and a reasonable layout, and is characterized in that the equipment is light in weight, convenient to carry and easy to assemble. The invention can automatically calculate the distance, attitude and other parameters of the false target, and then establish the effective interference airspace model of the false target according to different weather conditions and the position, distance and attitude angle of the false target, and draw the airspace situation diagram of the false target interference of the laser, so as to prevent the protection of the false target. The interference effect of false targets in the area is analyzed and evaluated to provide information support for the layout of false targets.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

Figure 1 is a schematic diagram of a laser semi-active guided weapon attack;

Figure 2 is a schematic diagram of the working principle of laser angle deception jamming;

3 is a schematic structural diagram of a system for generating a false target interference situation with a diffuse reflector provided by the present invention;

4 is a schematic flowchart of a method for generating a false target interference situation of a diffuse reflector provided by the present invention;

Figure 5 is a schematic diagram of the improved Harris algorithm to detect the corners of the target plate;

Figure 6 is a schematic diagram of the world coordinate system;

FIG. 7 is a schematic diagram of false target interference airspace.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a system and method for generating a false target interference situation of a diffuse reflector, which can realize the real-time visual evaluation of the interference airspace of the diffuse reflector during the deployment strategy.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Laser-guided weapons use a laser to emit a laser beam to irradiate the target. The laser receiver mounted on the projectile receives the irradiated laser signal or the laser signal reflected by the target. The guidance system calculates the degree to which the projectile deviates from the irradiation or reflected laser beam. Adjust the flight trajectory so that the warhead advances along the irradiated or reflected laser, and finally hits the target. Laser guidance can effectively improve the guidance accuracy, so it is widely used in the guidance of missiles and bombs. At present, laser semi-active guided weapons are widely used. Its working principle is shown in Figure 1.

The laser angle deception jamming is an effective means to combat laser semi-active weapons. The principle is that the laser warning machine sensitively intercepts the enemy's laser guidance signal and issues an alarm, inputs the guidance pulse signal to the information processor for decoding, and parses the laser signal. Wavelength, pulse width, frequency, coding pattern and other parameter information, and then the laser jammer is set according to the decoded parameters, and the jamming laser with advanced time is launched to the false target, and the diffusely reflected laser jamming signal is used to guide the enemy's guided weapons. , and its working principle is shown in Figure 2.

3 is a schematic structural diagram of a system for generating a false target interference situation with a diffuse reflector provided by the present invention. As shown in FIG. 3 , a system for generating a false target interference situation with a diffuse reflector provided by the present invention includes: a diffuse reflector Fake target jamming situation generation system host, gimbal and tripod;

The mainframe of the diffuse reflector false target interference situation generation system is arranged on the pan/tilt; the tripod is used to support the pan/tilt;

The mainframe of the diffuse reflector false target interference situation generation system includes: an energy acquisition and measurement subsystem, an image acquisition subsystem, and an interference situation generation subsystem;

The energy collection and measurement sub-system is used to collect laser energy and measure the laser energy density in front of the mirror; the laser energy is the simulated interference laser emitted by the laser to the false target of the diffuse reflection board, and the generated diffuse reflection laser signal is transmitted into the false target through the atmosphere. Laser energy that interferes with airspace assessment systems;

The image acquisition subsystem is used to display the position of the false target image of the diffuse reflector in the field of view in real time, and adjust the azimuth angle and pitch angle of the pan/tilt according to the position of the false target image of the diffuse reflector in the field of view, so as to make the diffuse reflection The false target image of the board is placed in the center of the field of view, and the target board image is collected;

The interference situation generation subsystem is used to determine the distance and attitude angle of the target board by using corner detection and monocular vision pose measurement according to the laser energy density in front of the mirror and the target board image, and then generate a laser false target interference airspace situation map.

The evaluation of the interference airspace for diffuse reflectors is characterized by the interference distance. When the interference signal irradiates the false target of the diffuse reflector, the energy of the reflected signal exhibits a cosine attenuation as the angle between the reflection direction and the normal direction of the diffuse reflector increases. To achieve effective interference, the distance at this time is the interference distance, and the combination of interference distances at different angles is the interference airspace.

The energy collection and measurement subsystem includes: a narrow-band filter, a near-infrared optical system, a photodetector, a signal processing and peak holding unit, and an energy measurement unit, which are connected in sequence.

The narrow-band filter is used to filter multi-band light, and the central light wavelength is 1.064 μm; the near-infrared optical system is mainly used to optically amplify the optical signal of the diffuse reflection of the laser spot; the photodetector converts the optical signal into a pulse current; the signal The processing and peak holding unit amplifies, samples, and holds the peak value of the pulse current signal output by the photodetector; the energy measuring unit measures the energy density value of the laser signal.

During the experiment, the laser emits simulated interference laser to the false target of the diffuse reflection board, and the diffuse reflection laser signal is transmitted through the atmosphere into the false target interference airspace evaluation system. The energy measurement subsystem collects the laser energy and measures the laser energy density in front of the system mirror. When the interference laser energy density measurement is performed under the conditions of strong sunlight and backlight, it is necessary to install a light shield before the energy measurement optical system.

The image acquisition subsystem includes: narrow-band filters, a near-infrared optical system, a near-infrared CCD device and an image real-time acquisition component, which are connected in sequence.

The narrow-band filter is used to filter multi-band light; the near-infrared optical system is mainly used for optical amplification of the target image; the near-infrared CCD device has high sensitivity in the near-infrared band; the real-time image acquisition component is mainly used to collect diffuse reflection Board fake target video image.

During the test, the system can display the position of the false target of the diffuse reflector in the field of view in real time, and can adjust the azimuth and pitch angles of the gimbal according to the video image, so that the system can be aligned with the false target of the diffuse reflector. After aligning the false target of the diffuse reflector, a single frame image of the diffuse reflector can be collected. Subsequent processing of the diffuse reflector image can calculate the distance and attitude angle of the diffuse reflector relative to the evaluation system, providing data for subsequent interference airspace evaluation.

The interference situation generation subsystem includes: a hardened computer and a comprehensive information processing center;

The comprehensive information processing center includes: real-time processing software, test evaluation processing software, post-processing application software and communication software.

The comprehensive information processing center mainly completes the measurement of the energy density in front of the laser mirror, the calculation of the distance and attitude parameters of the false target of the diffuse reflector, the generation of the effective interference airspace data and the generation of the effective airspace situation map. The interference situation generation system has the advantages of strong real-time performance, good visualization effect, and easy operation. It can more intuitively reflect the interference effect of the false target of the diffuse reflector, and quickly evaluate the protection situation in the defense zone.

FIG. 4 is a schematic flowchart of a method for generating a false target interference situation of a diffuse reflector provided by the present invention. As shown in FIG. 4 , a method for generating a false target interference situation of a diffuse reflector provided by the present invention is applied to the A system for generating a false target interference situation for a diffuse reflector, the method comprising:

Obtain the false target image of the diffuse reflector;

Adjust the azimuth angle and pitch angle of the gimbal according to the position of the false target image of the diffuse reflector in the field of view, so that the false target image of the diffuse reflector is placed in the center of the field of view, and the target image is collected; laser energy density;

According to the target plate image, use corner detection and monocular vision pose measurement to calculate the target plate distance and attitude angle;

According to the laser energy density, target distance and attitude angle, the situation map of laser false target interference airspace is generated.

When measuring the distance and attitude of the target board, it is necessary to know the coordinate information of at least four feature points on the target board. The target used in the protection is a square target, so the four corners of the target can be detected as the feature points of the target. However, the traditional Harris corner detection algorithm has shortcomings such as low precision and false corners when detecting corners. The invention proposes a target board corner detection algorithm based on the improved Harris algorithm, which can quickly and accurately realize the target board. The detection of four corner points and the removal of false corner points can meet the system requirements. The steps of detecting the corner points of the target board by the improved Harris algorithm proposed by the present invention are shown in FIG. 5 .

As shown in Figure 5, according to the target plate image, corner detection and monocular vision pose measurement are used to calculate the target plate distance and attitude angle, specifically including:

Perform global threshold segmentation and connected domain analysis on the target plate image to determine the target plate binary image;

Carry out gradient operation and Canny edge detection respectively on the binary image of the target plate;

Calculate the improved corner response function according to the binary image of the target plate after gradient operation;

Perform edge point 8-field analysis on the target board binary image after Canny edge detection;

The binary image of the target plate after the edge point 8-domain analysis and the improved corner point response function are suppressed by local non-maximum value, and then the boundary pseudo-corner points are removed, and the four corner points of the target plate are determined.

The target board distance and attitude angle are calculated by using corner detection and monocular vision pose measurement according to the target board image, specifically:

确定空间中某点在世界坐标系下的坐标与对应像点在图像像素坐标系下的坐标的关系；Use the formula

Determine the relationship between the coordinates of a point in the space in the world coordinate system and the coordinates of the corresponding image point in the image pixel coordinate system;

确定旋转矩阵；Use the formula

determine the rotation matrix;

确定靶板的姿态角；Use the formula

Determine the attitude angle of the target board;

为靶标相对于相机的俯仰角，

为相对相机的方位角，f_x，f_y为相机在u轴和v轴上的归一化焦距，(u₀,v₀)为图像成像中心在图像像素坐标系下的坐标，(X_W,Y_W,Z_W)为空间点在世界坐标系下的坐标，(u,v)为成像点在图像像素坐标系下的坐标，M₁是相机的内参数矩阵，是空间点在相机坐标系和对应像点在图像像素坐标系之间的转换矩阵，在相机参数不变的情况下，M₁是不变的，M₂是相机的外参数矩阵，表示空间点在相机坐标系和世界坐标系之间的旋转和平移关系，随世界坐标系的位姿变化而变化，R为旋转矩阵，θ_z为靶标相对相机的滚动角，T＝(T_x,T_y,T_z)^T为一个3×1的平移矩阵，T_x,T_y,T_z分别为在x,y,z方向上世界坐标系原点相对相机坐标系原点的平移量，r₀～r₈为系数。in,

is the pitch angle of the target relative to the camera,

is the azimuth angle relative to the camera, f _x , f _y are the normalized focal lengths of the camera on the u-axis and v-axis, (u ₀ , v ₀ ) are the coordinates of the image imaging center in the image pixel coordinate system, (X _W , Y _W , Z _W ) are the coordinates of the space point in the world coordinate system, (u, v) are the coordinates of the imaging point in the image pixel coordinate system, M ₁ is the internal parameter matrix of the camera, which is the coordinate of the space point in the camera The transformation matrix between the image pixel coordinate system and the corresponding image point between the image pixel coordinate system. When the camera parameters are unchanged, M ₁ is unchanged, and M ₂ is the external parameter matrix of the camera, indicating that the space point is in the camera coordinate system and the world. The rotation and translation relationship between the coordinate systems changes with the pose of the world coordinate system, R is the rotation matrix, θ _z is the roll angle of the target relative to the camera, T=(T _x ,T _y ,T _z ) ^T is A 3×1 translation matrix, T _x , T _y , and T _z are the translations of the origin of the world coordinate system relative to the origin of the camera coordinate system in the x, y, and z directions, respectively, and r ₀ to r ₈ are coefficients.

in,

The target plate used is a 1m×1m square diffuse reflector. The origin of the world coordinate system O _W is set at the centroid of the diffuse reflector. The four corners of the target are feature points, and the plane where the four feature points are located is O _W -X _W Y _W plane, when the target plate is placed, the X _W axis is in the target plate plane and parallel to the horizontal plane to the right, Y _W is in the target plate plane and perpendicular to the horizontal plane, and the Z _W axis is perpendicular to the other two coordinate axes and obey the right-hand rule. The relationship between the world coordinate system and the four feature points is shown in Figure 6.

The coordinates of a point in the space in the camera coordinate system have the following relationship with the coordinates in the pixel coordinate system:

remember

In the formula, i=1, 2, 3, 4 are the numbers of the four feature points, u _i , v _i are the coordinates of the image points corresponding to the four feature points in the pixel coordinate system, X _Ci , Y _Ci , Z _Ci are The coordinates of the four feature points in the camera coordinate system.

Since the four feature points are the four corner points on the square, they are recorded here:

The above formula gets:

Converted to matrix form as:

The solution is:

Obtained from the orthogonality of the rotation matrix:

Therefore, all elements of the rotation matrix R can be represented by (k _xi , k _yi )| _i= 1˜4.

以及相对相机的方位角

可以表示为：According to the rotation matrix of Eq., the pitch angle of the target plate

and the azimuth relative to the camera

It can be expressed as:

The roll angle of the target plate rotating around the Z _W axis has no effect on its interference airspace, so θ _z is not solved here.

After solving the attitude angle of the target board, it is also necessary to solve the distance of the target board. _The principle of the solution is as follows: the coordinates of the image points corresponding to the two lateral corner points P1 and P4 _of the target board in the image pixel coordinate system are respectively are (u ₁ , v ₁ ) and (u ₄ , v ₄ ), then the dimensions of the corresponding line segment P ₁ P ₄ in the image physical coordinate system are:

(u ₁ -u ₄ )d _x (9)

则靶板横向的边长P₁P₄在成像时的有效长度为：The target plate is rotated around the Y _W axis

Then the effective length of the lateral side length P ₁ P ₄ of the target plate during imaging is:

By perspective projection principle:

Therefore, the displacement T _Z of the target plate relative to the camera in the Z _C axis direction is:

T _X , T _Y can be calculated by formula (9), so the distance L of the camera relative to the target board is:

为漫反射板假目标相对于设备法向角的俯仰分量，θ_i为入射光与漫反射板法线的夹角，θ_rp为漫反射板的法线和激光制导武器来袭方向夹角的俯仰分量，θ为激光制导武器来袭方向与地面的夹角(威胁角)。In the process of evaluating the false target interference airspace, the interference distance is a very important indicator. The laser transmitter transmits a laser interference signal to the false target of the diffuse reflector, and the energy of the laser interference signal reflected by the false target of the diffuse reflector exhibits a cosine attenuation as the angle between the reflection direction and the normal direction of the false target of the diffuse reflector increases. . When the reflected energy at a certain angle is attenuated to the same as the minimum acceptable power of the seeker, the distance at this time is the interference distance. The space filled with scattered laser light can be drawn through the reflection model of the diffuse reflector and the atmospheric scattering model corresponding to the weather, as shown in Figure 7. Figure 7

is the pitch component of the false target of the diffuse reflector relative to the normal angle of the device, θ _i is the angle between the incident light and the normal of the diffuse reflector, θ _rp is the angle between the normal of the diffuse reflector and the incoming direction of the laser-guided weapon The pitch component, θ is the angle between the incoming direction of the laser-guided weapon and the ground (threat angle).

The interference distance of the diffuse reflector is:

The target board distance and attitude angle are calculated by using corner detection and monocular vision pose measurement according to the target board image, specifically:

确定相机相对于靶板的距离；Use the formula

Determine the distance of the camera relative to the target board;

为假目标相对系统设备的法向角。Among them, L is the distance of the camera relative to the target plate, E _t is the single pulse energy of the interference laser, τ _t is the transmittance of the laser interference source transmitting optical system, τ _r is the transmittance of the seeker receiving system, ρ is The hemispherical reflectivity of the diffuse false target, θ _r is the angle between the reflected light and the normal line of the diffuse reflector, E _r is the laser energy density threshold received by the seeker, u _a is the attenuation constant of the atmosphere, and R ₁ is the interference laser The distance from the diffuse reflector, E is the laser energy density,

It is the normal angle of the false target relative to the system equipment.

The relationship between the interference distance R and the data measured by this system at different reflection angles:

The reflection angle θ _r has an azimuth angle component θ _ra and a pitch angle component θ _rp in space. The value range of θ _ra is the hemispherical space corresponding to the forward direction of the false target, namely [-90°, 90°]. The value of _θrp is:

相等，则式(16)可以表示为：Assuming that the laser is incident on the false target parallel to the ground, then the incident angle θ _i and

Equation (16) can be expressed as:

From this, the laser interference airspace under different threat angles and inclination angles of the diffuse reflector can be obtained, as expressed by Equation (18).

According to the characteristics of the cosine function, the equation (17) is brought into (18) to obtain:

为轴，在反射角方位分量取[-90°，90°]时干扰距离取值所组成的闭环曲线。如已知单个漫反射板假目标相对设备法向角以及法向角的方位和俯仰分量，就可以得到其在不同威胁角下的不同方位上的干扰距离，不同方位距离数据合成单个假目标的干扰空域，多个假目标干扰空域合成得到多假目标干扰空域态势图。Assuming that the azimuth angle of the diffuse reflector read by the rotation of the gimbal is θ _a , the interference airspace of the diffuse reflector at a certain threat angle is

is a closed-loop curve composed of the interference distance when the azimuth component of the reflection angle is [-90°, 90°]. If the normal angle of a single diffuse reflector false target relative to the device and the azimuth and pitch components of the normal angle are known, its interference distances in different azimuths under different threat angles can be obtained, and the azimuth distance data of different azimuth distances can be synthesized for a single false target. In the interference airspace, multiple false target interference airspaces are synthesized to obtain a multi-false target interference airspace situation map.

According to the incoming threat information of semi-active laser-guided weapons, the reflection characteristics of the diffuse reflector, and the test principle of the laser scattering characteristics of the false target, combined with the environmental characteristics of the protected target, it can analyze the placement position of the false target of the diffuse reflector. The orientation of the diffuse reflection surface and the specific requirements for the placement of multiple false targets. In practical applications, if individual false targets are hit, the laser interference airspace test and evaluation system can be used to evaluate the interference effect of the remaining targets in a timely and effective manner, analyze and judge the protection situation in the protection area, and make allocation decisions for interference resources. Provide technical support for the use of false targets.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

In this paper, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; meanwhile, for those skilled in the art, according to the present invention There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (8)

1. a diffuse reflection board false target interference situation generation system, is characterized in that, comprises: diffuse reflection board false target interference situation generation system mainframe, pan-tilt and tripod; The mainframe of the diffuse reflector false target interference situation generation system is arranged on the pan/tilt; the tripod is used to support the pan/tilt; The mainframe of the diffuse reflector false target interference situation generation system includes: an energy acquisition and measurement subsystem, an image acquisition subsystem, and an interference situation generation subsystem; The energy collection and measurement sub-system is used to collect laser energy and measure the laser energy density in front of the mirror; the laser energy is the simulated interference laser emitted by the laser to the false target of the diffuse reflection board, and the generated diffuse reflection laser signal is transmitted into the false target through the atmosphere. Laser energy that interferes with airspace assessment systems; The image acquisition subsystem is used to display the position of the false target image of the diffuse reflector in the field of view in real time, and adjust the azimuth angle and pitch angle of the pan/tilt according to the position of the false target image of the diffuse reflector in the field of view, so as to make the diffuse reflection The false target image of the board is placed in the center of the field of view, and the target board image is collected; The interference situation generation subsystem is used to determine the distance and attitude angle of the target board by using corner detection and monocular vision pose measurement according to the laser energy density in front of the mirror and the target board image, and then generate a laser false target interference airspace situation map. 2. a kind of diffuse reflector false target jamming situation generation system according to claim 1, is characterized in that, described energy collection and measurement sub-system comprises: narrow-band filter, near-infrared optical system, photoelectric detection that are connected in sequence device, signal processing and peak hold unit and energy measurement unit. 3. a kind of diffuse reflection plate false target interference situation generation system according to claim 1, is characterized in that, described image acquisition subsystem comprises: narrow-band filter, near-infrared optical system, near-infrared CCD device connected in sequence and image real-time acquisition components. 4. a kind of diffuse reflector false target interference situation generation system according to claim 1, is characterized in that, described interference situation generation sub-system comprises: reinforcement computer and comprehensive information processing center; The comprehensive information processing center includes: real-time processing software, test evaluation processing software, post-processing application software and communication software. 5. A method for generating a false target interference situation for a diffuse reflector, characterized in that it is applied to a system for generating a false target interference situation for a diffuse reflector described in any one of claims 1-4, the method comprising: Obtain the false target image of the diffuse reflector; Adjust the azimuth angle and pitch angle of the gimbal according to the position of the false target image of the diffuse reflector in the field of view, and then place the false target image of the diffuse reflector in the center of the field of view to collect the target image; and measure the corresponding time laser energy density; According to the target plate image, use corner detection and monocular vision pose measurement to calculate the target plate distance and attitude angle; According to the laser energy density, target distance and attitude angle, the situation map of laser false target interference airspace is generated. 6 . The method for generating a false target interference situation of a diffuse reflector according to claim 5 , wherein the target distance is calculated by using corner detection and monocular vision pose measurement according to the target image. 7 . and attitude angle, including: Perform global threshold segmentation and connected domain analysis on the target plate image to determine the target plate binary image; Carry out gradient operation and Canny edge detection respectively on the binary image of the target plate; Calculate the improved corner response function according to the binary image of the target plate after gradient operation; Perform edge point 8-field analysis on the target board binary image after Canny edge detection; The binary image of the target plate after the edge point 8-domain analysis and the improved corner point response function are suppressed by local non-maximum value, and then the boundary pseudo-corner points are removed, and the four corner points of the target plate are determined. 7 . The method for generating a false target interference situation of a diffuse reflector according to claim 6 , wherein the target distance is calculated by using corner detection and monocular vision pose measurement according to the target image. 8 . and attitude angle, including: Use the formula

Determine the relationship between the coordinates of a point in the space in the world coordinate system and the coordinates of the corresponding image point in the image pixel coordinate system; Use the formula

determine the rotation matrix; Use the formula

Determine the attitude angle of the target board; in,

is the pitch angle of the target relative to the camera,

is the azimuth angle relative to the camera, f _x , f _y are the normalized focal lengths of the camera on the u-axis and v-axis, (u ₀ , v ₀ ) are the coordinates of the image imaging center in the image pixel coordinate system, (X _W , Y _W , Z _W ) are the coordinates of the space point in the world coordinate system, (u, v) are the coordinates of the imaging point in the image pixel coordinate system, M ₁ is the internal parameter matrix of the camera, which is the coordinate of the space point in the camera The transformation matrix between the image pixel coordinate system and the corresponding image point between the image pixel coordinate system. When the camera parameters are unchanged, M ₁ is unchanged, and M ₂ is the external parameter matrix of the camera, indicating that the space point is in the camera coordinate system and the world. The rotation and translation relationship between coordinate systems changes with the pose of the world coordinate system, R is the rotation matrix, θ _z is the roll angle of the target relative to the camera, T=(T _x ,T _y ,T _z ) ^T is A 3×1 translation matrix, T _x , T _y , and T _z are the translations of the origin of the world coordinate system relative to the origin of the camera coordinate system in the x, y, and z directions, respectively, and r ₀ to r ₈ are coefficients. 8 . The method for generating a false target interference situation of a diffuse reflector according to claim 7 , wherein the target distance is calculated by using corner detection and monocular vision pose measurement according to the target image. 9 . and attitude angle, including: Use the formula

Determine the distance of the camera relative to the target board; Among them, L is the distance of the camera relative to the target plate, E _t is the single pulse energy of the interference laser, τ _t is the transmittance of the laser interference source transmitting optical system, τ _r is the transmittance of the seeker receiving system, ρ is The hemispherical reflectivity of the diffuse false target, θ _r is the angle between the reflected light and the normal line of the diffuse reflector, E _r is the laser energy density threshold received by the seeker, u _a is the attenuation constant of the atmosphere, and R ₁ is the interference laser The distance from the diffuse reflector, E is the laser energy density,

It is the normal angle of the false target relative to the system equipment.

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