Laser guiding device for unmanned aerial vehicle targetTechnical Field
The invention relates to the field of photoelectric measurement and tracking, in particular to a laser guiding device for an unmanned aerial vehicle target.
Background
The unmanned aerial vehicle is increasingly widely applied to the battlefield at present and becomes an important component of modern war. Unmanned aerial vehicles are widely used for reconnaissance, striking and harassment, and are difficult to intercept due to the characteristics of small target, high speed and the like of the unmanned aerial vehicle.
The countermeasures of the current unmanned aerial vehicle mainly comprise laser weapons, microwave weapons, antiaircraft gun interception, electromagnetic interference, unmanned aerial vehicle interception, shotgun shooting and the like. For example, chinese patent CN 219790359U discloses an automatic laser guiding device, which drives a laser head to perform pitching motion by using a worm gear, and because the worm gear structure usually has a certain transmission gap, the response accuracy and the position control accuracy of the device are affected, so the pointing accuracy of the laser guiding device is lower. For example, chinese patent CN 221992538U discloses a laser interference anti-unmanned aerial vehicle device, and specifically discloses a laser interference anti-unmanned aerial vehicle device which comprises a base, a horizontal rotary table and a vertical rotary table, wherein the horizontal rotary table is arranged on the base, the horizontal rotary table can rotate on a horizontal plane, the vertical rotary table is provided with a detection radar, a laser emitter, a camera and a laser range finder, and the detection radar detects that the rotary table rotates after an unmanned aerial vehicle target so that the laser emitter aims at the target to emit laser to interfere the unmanned aerial vehicle. The striking precision of the method is completely dependent on the precision of the turntable motor, and the high-precision motor can be realized at high cost.
Therefore, how to reduce the manufacturing cost of the laser guiding device, accurately identify, accurately track and strike the unmanned aerial vehicle, and realize the intelligent unmanned aerial vehicle defense without unattended operation is the technical problem to be solved by the invention.
Disclosure of Invention
The invention aims to provide a laser guiding device aiming at an unmanned aerial vehicle target.
The aim of the invention can be achieved by the following technical scheme:
a laser guidance device for an unmanned aerial vehicle target, comprising:
a base and a rotating motor arranged on the base;
the rotating platform is arranged on the base, and the lower surface of the rotating platform is connected to an output shaft of the rotating motor;
The radar module is arranged on the upper surface of the rotary platform;
the support and the pitching motor are arranged on the support, and the support is arranged on the upper surface of the rotary platform;
The electronic zoom system comprises a working platform, a triple rotation prism system and an electronic zoom camera, wherein the triple rotation prism system and the electronic zoom camera are arranged in parallel and in the same direction on the working platform, the working platform is connected with an output shaft of a pitching motor, and the output shaft of the pitching motor and the output shaft of the rotating motor are vertically arranged;
The upper computer is respectively connected with the rotating motor, the pitching motor, the radar module, the electronic zoom camera and the rotating triple prism system and is configured to execute the following steps:
s1, acquiring data acquired by a radar module, and analyzing to obtain a low-altitude small-sized flying target;
s2, controlling a rotating motor and a pitching motor to act based on the obtained low-altitude small-sized flying target so as to enable the triple prism system and the electronic zoom camera to face the direction of the low-altitude small-sized flying target;
S3, zooming by the electronic zoom camera based on the distance of the low-altitude small-sized flying object and shooting to obtain a photo of the low-altitude small-sized flying object;
Step S4, identifying an object in the photo based on a target detection algorithm, if the identified object contains an unmanned plane, executing step S5, otherwise, selecting a next low-altitude small-sized flying target and returning to step S2;
S5, acquiring a central pixel coordinate of a target boundary frame, converting the pixel coordinate into an image coordinate under an image coordinate system according to a camera imaging model and camera calibration parameters, and calculating a direction vector of a target according to focal length information;
s6, acquiring a coordinate conversion relation from a camera coordinate system to a prism coordinate system according to camera-prism calibration parameters, and converting a target direction vector under the camera coordinate system into a target vector serving as a reverse solution of a prism under the prism coordinate system;
and S7, controlling the axicon system to emit laser according to the target vector of the inverse solution of the axicon.
The axicon system includes:
The laser transmitter is fixed on the working platform through a laser transmitter bracket;
the laser device comprises a prism shell, a first prism, a second prism and a third prism, wherein the first prism, the second prism and the third prism are all rotary prisms and are sequentially arranged along the output direction of a laser emitter;
the first prism motor, the second prism motor and the third prism motor are respectively connected with the first prism, the second prism and the third prism through corresponding transmission mechanisms so as to respectively drive the first prism, the second prism and the third prism to rotate.
The triple prism system further comprises a first motor encoder, a second motor encoder and a third motor encoder, wherein the first motor encoder, the second motor encoder and the third motor encoder are correspondingly connected with the first prism motor, the second prism motor and the third prism motor respectively to detect the rotation angle.
The transmission mechanism is a worm and gear mechanism.
In the step S5, the conversion relationship of converting the pixel coordinates into the image coordinates in the image coordinate system is as follows:
x=(u-cx)·dx,y＝(v-cy)·dy
Wherein x is the abscissa of the image coordinate in the image coordinate system, y is the ordinate of the image coordinate in the image coordinate system, u is the abscissa of the pixel coordinate system, v is the ordinate of the pixel coordinate system, cx is the abscissa of the pixel coordinate of the projection of the optical center on the pixel plane, cy is the ordinate of the pixel coordinate of the projection of the optical center on the pixel plane, dx is the actual physical width of the unit pixel, and dy is the actual physical height of the unit pixel.
The direction vector of the target obtained in the step S5 is:
v is a direction vector of a target, and f is the current focal length of the electronic zoom camera.
The step S7 includes:
S7-1, according to a target vector reversely solved by the triple prism, solving the rotation angles of the first prism, the second prism and the third prism required by the laser emitted by the prism axis to be directed to the target vector, and respectively controlling the first prism motor, the second prism motor and the third prism motor to drive the first prism, the second prism and the third prism to rotate to corresponding angles;
And S7-2, the laser transmitter transmits high-energy laser, and the high-energy laser sequentially passes through the first prism, the second prism and the third prism and then points to the target unmanned aerial vehicle, so that the unmanned aerial vehicle is damaged.
The inclined plane of first prism sets up towards laser emitter, and the plane sets up towards the second prism, the plane of second prism sets up towards first prism, and the inclined plane sets up towards the third prism, the inclined plane of third prism is towards the second prism.
The vector of the high-energy laser after being deflected by the prism is as follows:
wherein Ai is the unit direction vector of the refracted ray, Ni is the refractive index of the refractive medium, Ni-1 is the refractive index of the incident medium, Ai-1 is the unit direction vector of the incident ray, and N is the unit vector of the interface normal.
The radar module comprises a radar and a radar fixing upright post for fixing the radar, the axis of the radar fixing upright post is parallel to the axis of the output shaft of the rotating motor, and the height of the radar is larger than that of the triple prism system and the electronic zoom camera.
Compared with the prior art, the invention has the following beneficial effects:
1. The three-dimensional optical tracking system has high pointing precision, the three-dimensional optical tracking system converts mechanical tracking into optical tracking, and meanwhile, due to the system characteristic of the three-dimensional optical tracking system, a large reduction ratio relationship exists between the rotation angle of the prism and the deflection angle of the light beam, and under the condition of limited motor conditions, higher pointing precision can still be achieved.
2. Compared with a rotary biprism system, the system has no blind area, all targets in the field of view can realize laser pointing through prism deflection, the situation that the targets are lost is avoided, the track of the biprism has singularity, and the problem is solved by the prior scholars.
3. The real-time performance is good, the real-time performance of the target tracking is strongly related to the real-time performance of the visual detection end by adopting a mode of coarse tracking and fine tracking, the real-time performance is strong by adopting the latest version of the YOLO target detection algorithm, the faster detection speed can be achieved by adopting the GPU with stronger performance, and the higher real-time performance requirement is met.
4. Visual feedback the visual detection system can perform fine adjustment on the laser guiding device according to camera observation in real time, so as to realize visual closed loop.
5. The detection accuracy is high, the radar can detect low-altitude targets near the device, but can not distinguish whether the targets are unmanned aerial vehicles or not, the visual detection system can judge whether the targets in the field of view are unmanned aerial vehicles or not through reasoning of the model, the situation of false impact is avoided, the visual detection algorithm detects on the image level, and the detection accuracy of the pixel level can be achieved.
Drawings
Fig. 1 is an isometric view of the present invention.
Fig. 2 is a top view of the present invention.
Fig. 3 is a cross-sectional view of a axicon system.
Fig. 4 is a schematic diagram of the axicon system of the present invention controlling beam deflection.
Fig. 5 is a flow chart of the operation of the present invention.
Fig. 6 is a diagram of a detection effect of the unmanned aerial vehicle.
10, A radar, 20, an electronic zoom camera, 30, a triple prism system, 40, a rotary platform, 50, a laser transmitter, 31, a first prism motor, 32, a second prism motor, 33, a third prism motor, 34, a first motor encoder, 35, a second motor encoder, 36, a third motor encoder, 37, a first prism, 38, a second prism, 39, a third prism, 41, a rotary motor, 42, a pitching motor, 43, a working platform, 51, a laser transmitter bracket, 52 and an optical fiber.
Detailed Description
The invention will now be described in detail with reference to the drawings and specific examples. The present embodiment is implemented on the premise of the technical scheme of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following examples.
A laser guidance device for an unmanned aerial vehicle target, as shown in fig. 1to 2, comprising:
A base and a rotary motor 41 provided on the base;
A rotary platform 40 provided on the base, the lower surface of which is connected to an output shaft of the rotary motor 41;
The radar module is arranged on the upper surface of the rotary platform 40;
a bracket and a pitching motor 42 arranged on the bracket, wherein the bracket is arranged on the upper surface of the rotary platform 40;
The electronic zoom camera comprises a working platform 43, a triple-prism system 30 and an electronic zoom camera 20, wherein the triple-prism system 30 and the electronic zoom camera 20 are arranged in parallel and in the same direction on the working platform 43, the working platform 43 is connected with an output shaft of a pitching motor 42, and the output shaft of the pitching motor 42 is vertically arranged with an output shaft of the rotating motor 41;
an upper computer respectively connected with the rotating motor 41, the pitching motor 42, the radar module, the electronic zoom camera 20 and the prism system 30,
In this embodiment, as shown in fig. 2 and 3, the axicon system 30 includes:
a laser transmitter 50 fixed to the work platform 43 by a laser transmitter mount 51;
the laser transmitter comprises a prism shell, a first prism 37, a second prism 38 and a third prism 39 which are arranged in the shell, wherein the first prism 37, the second prism 38 and the third prism 39 are all rotary prisms and are sequentially arranged along the output direction of the laser transmitter;
The first, second and third prism motors 31, 32 and 33 are connected to the first, second and third prisms 37, 38 and 39 through corresponding transmission mechanisms, respectively, to drive the first, second and third prisms 37, 38 and 39 to rotate, respectively.
Further, in the present embodiment, the triple prism system 30 further includes a first motor encoder 34, a second motor encoder 35, and a third motor encoder 36, and the first motor encoder 34, the second motor encoder 35, and the third motor encoder 36 are correspondingly connected to the first prism motor 31, the second prism motor 32, and the third prism motor 33, respectively, to detect the rotation angle, so that the feedback control of the first prism 37, the second prism 38, and the third prism 39 can be realized.
In this embodiment, the transmission mechanism is a worm gear mechanism, which has higher durability, and of course, in the embodiment, other control schemes may be adopted.
Further, in this embodiment, the axis of the laser transmitter 50 coincides with the axicon axis. The radar is responsible for actively detecting low-altitude flying objects around the device, providing the approximate azimuth, pitch, and distance of the object from the device. The upper computer is responsible for resolving data detected by the radar, and controlling the rotation of the rotary platform and the working platform, so that the camera platform is aligned to the approximate direction of the target. The electronic zoom camera adjusts the focal length according to the approximate distance of the target so that the unmanned aerial vehicle target can appear clearly in the field of view. And the upper computer detects the unmanned aerial vehicle target in the camera view field according to a single-stage target detection algorithm, and determines the pixel coordinate of the center of the target boundary frame. And converting the target pixel coordinates into image coordinate system coordinates according to the camera imaging model, and obtaining a direction vector of the target in the camera coordinate system according to the current focal length of the camera and the coordinates in the target image coordinate system. And converting the target direction vector under the camera coordinate system into the triangular prism coordinate system according to the rotation and translation matrix. According to the reverse solution of the triple prism, the angle at which the prism should rotate is solved, and the upper computer controls the three motors to drive the prism to rotate to the corresponding angle, so that accurate guiding of laser is realized.
In addition, in the embodiment, the electronic zoom camera is an infrared day-night high-definition fog-penetrating long-focus camera, the unique optical technology can provide fine color images in the daytime and fine black-and-white images at night, and targets of the unmanned aerial vehicle can be clearly imaged in a long-distance range so as to support detection and identification of target detection algorithms.
In the embodiment, the upper computer deploys sensor control software, an unmanned aerial vehicle target detection algorithm and an autonomous decision algorithm, scene information is obtained through radar and visual sensor information fusion, target information is obtained through unmanned aerial vehicle target detection algorithm reasoning, and a motor is automatically controlled through a PID control algorithm.
In addition, in the embodiment, the target detection algorithm is a single-stage target detection latest YOLO algorithm, and the algorithm further improves the real-time performance and accuracy of target detection on the basis of the previous series, for example, under the test of 4060GPU, the detection speed of one image containing the unmanned aerial vehicle target is between 5 ms and 10ms, the reasoning time is short, and the real-time tracking requirement is met.
In the embodiment, the triple prism system converts the traditional mechanical tracking into the optical tracking, and a larger reduction ratio relationship exists between the rotation angle of the prism and the deflection angle of the light beam, so that the light beam pointing error is greatly reduced, and the accurate pointing of the light beam with low cost is possible. The rotating triple prism system has no scanning blind area problem of the rotating double prism system, can perform blind area-free scanning on targets in the video field range, and avoids the problem of target follow-up loss.
As shown in fig. 5, the upper computer is configured to perform the steps of:
Step S1, acquiring data acquired by a radar module, wherein the radar measures the distance, speed and direction of a low-altitude target by transmitting electromagnetic waves and receiving signals reflected back from surrounding objects;
Step S2, controlling the rotating motor 41 and the pitching motor 42 to act based on the obtained low-altitude small-sized flying target so as to enable the three-dimensional rotating prism system 30 and the electronic zoom camera 20 to face the low-altitude small-sized flying target;
Step S3, the electronic zoom camera 20 zooms and takes a picture of the low-altitude miniature flying object based on the distance of the low-altitude miniature flying object;
Step S4, identifying an object in the photo based on a target detection algorithm, if the identified object contains an unmanned plane, executing step S5, otherwise, selecting a next low-altitude small-sized flying target and returning to step S2;
S5, acquiring a central pixel coordinate of a target boundary frame, converting the pixel coordinate into an image coordinate under an image coordinate system according to a camera imaging model and camera calibration parameters, and calculating a direction vector of a target according to focal length information;
In this embodiment, in step S5, the conversion relationship of converting the pixel coordinates into the image coordinates in the image coordinate system is:
x=u-cx·dx,y＝v-cy·dy
Wherein x is the abscissa of the image coordinate in the image coordinate system, y is the ordinate of the image coordinate in the image coordinate system, u is the abscissa of the pixel coordinate system, v is the ordinate of the pixel coordinate system, cx is the abscissa of the pixel coordinate of the projection of the optical center on the pixel plane, cy is the ordinate of the pixel coordinate of the projection of the optical center on the pixel plane, dx is the actual physical width of the unit pixel, and dy is the actual physical height of the unit pixel.
Correspondingly, the direction vector of the obtained target is:
Where v is the direction vector of the target and f is the current focal length of the electronic zoom camera 20.
S6, acquiring a coordinate conversion relation from a camera coordinate system to a prism coordinate system according to camera-prism calibration parameters, and converting a target direction vector under the camera coordinate system into a target vector serving as a reverse solution of a prism under the prism coordinate system;
step S7, controlling the axicon system 30 to emit laser according to the target vector of the inverse solution of the axicon, specifically including:
Step S7-1, according to the target vector reversely solved by the triple prism, calculating the rotation angles of the first prism 37, the second prism 38 and the third prism 39 required by the laser emitted by the prism axis to be directed to the target vector, and respectively controlling the first prism motor 31, the second prism motor 32 and the third prism motor 33 to drive the first prism 37, the second prism 38 and the third prism 39 to rotate to corresponding angles;
In step S7-2, the laser emitter emits high-energy laser, and the high-energy laser sequentially passes through the first prism 37, the second prism 38 and the third prism 39 and then is directed to the target unmanned aerial vehicle, so that the unmanned aerial vehicle is damaged.
The inclined surface of the first prism 37 is disposed toward the laser emitter, the plane is disposed toward the second prism 38, the plane of the second prism 38 is disposed toward the first prism 37, the inclined surface is disposed toward the third prism 39, and the inclined surface of the third prism 39 is disposed toward the second prism 38.
The vector of the high-energy laser after being deflected by the prism is as follows:
wherein Ai is the unit direction vector of the refracted ray, Ni is the refractive index of the refractive medium, Ni-1 is the refractive index of the incident medium, Ai-1 is the unit direction vector of the incident ray, and N is the unit vector of the interface normal.
Further, in particular, in the present embodiment, the radar module includes the radar 10 and the radar fixing post for fixing the radar 10, the axis of the radar fixing post and the axis of the output shaft of the rotary electric machine 41 are parallel, and the height of the radar 10 is greater than the heights of the prism system 30 and the electronic zoom camera 20, thereby reducing interference with the radar.
As shown in fig. 3, the laser transmitter 50 is disposed at the rear end of the axicon system with its axis coincident with the axicon axis. The laser transmitter 50 emits a high-energy laser beam, as shown in fig. 5, and the laser beam is deflected by the first prism 37, the second prism 38 and the third prism 39, so that the target of the unmanned aerial vehicle is precisely pointed, and the unmanned aerial vehicle is irradiated to damage the target.
In the embodiment, the device is a comprehensive system for low-altitude target detection and damage, integrates the functions of target detection, target identification and classification, accurate pointing and high-energy laser striking, and has the advantages of multi-sensor fusion, high-accuracy pointing and real-time feedback, intelligent target identification, all-weather monitoring, high-energy laser damage and the like. The system utilizes the radar 10 to detect low-altitude targets, calculates the target azimuth through an upper computer, adjusts the orientation of the camera 20 and the prism 30, combines the electronic zoom camera 20 to realize clear imaging of the targets, and adopts the latest version YOLO algorithm to recognize and classify the targets in real time. When the target is confirmed to be an unmanned plane, the system realizes high-precision pointing of laser through the rotating triangular prism and utilizes the laser to perform damage striking on the target. The system can work around the clock in the daytime and at night, and has quick response and high-precision pointing capability.
The above functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. The storage medium includes a U disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, an optical disk, or other various media capable of storing program codes.