Field-of-view splicing method for distributed photoelectric tracking system

Abstract

The present application relates to the technical field of unmanned aerial vehicle, and discloses a field splicing method of distributed photoelectric tracking system, first, a frequency spectrum monitor is used to find an unmanned aerial vehicle target and send the azimuth and distance data of the target to a target detection unit, after the target is found by the target detection unit, the target is automatically or manually locked, and the information of the locked target is transmitted to a target tracking unit, the target tracking unit extracts features in the area around the original position of the target in the last frame, finds the position with the highest matching degree of the target features and takes the position as the new position of the target, then adjusts the camera to the new position, automatically or manually controls the linked interference device, and transmits satellite navigation and remote control interference signals to the target area until the unmanned aerial vehicle is driven away. The present application solves the problem of too large target position error of the frequency spectrum monitor, and has accurate positioning, and meets the real-time and success rate requirements of target search.

Description

Field stitching method for distributed photoelectric tracking systems Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, specifically to a field-of-view stitching method for a distributed photoelectric tracking system. Background Technology

[0002] In recent years, the civilian drone market has experienced explosive growth. Beyond traditional applications such as entertainment and aerial photography, specialized applications in fields like agricultural plant protection, power line inspection, disaster relief, intelligent logistics, geographic surveying, and formation flying have gradually become the new norm. At the same time, due to the lack of effective regulatory measures for low-altitude, slow-moving, and small aircraft, drones have frequently caused serious incidents such as disrupting air traffic, disturbing public order, remotely spying and stealing secrets, and carrying out terrorist attacks, becoming a new type of security threat to society.

[0003] While various detection and countermeasure technologies exist for drones, each has its limitations, necessitating a combination of methods for effective drone control. Currently, most methods rely on spectrum analyzers for locating unauthorized drones. However, the azimuth error provided by spectrum analyzers is significantly greater than the telephoto field of view of electro-optical tracking systems. When operating in a traditional one-to-one radar-based manner, the search time for moving targets is limited, accuracy is low, and the success rate is low. Therefore, a highly efficient field-of-view stitching method for distributed electro-optical tracking systems is needed. Summary of the Invention

[0004] The purpose of this invention is to provide a field-of-view stitching method for a distributed photoelectric tracking system. This invention solves the problem of excessive target position error in spectrum analyzers, achieving precise positioning and meeting the requirements for real-time performance and success rate in target search.

[0005] This invention is implemented as follows:

[0006] This invention provides a field-of-view stitching method for a distributed photoelectric tracking system, specifically including a spectrum monitor, a camera carrying a target detection unit and a target tracking unit, and a pan-tilt unit carrying an interference device and the aforementioned camera; specifically, it is executed according to the following steps:

[0007] S1: The spectrum monitor detects the UAV target and sends the target's azimuth and distance data to the target detection unit. After the target detection unit detects the target, it automatically or manually locks onto the target and transmits the target locking information to the target tracking unit.

[0008] S2: The target tracking unit extracts features in the area around the original position of the target in the previous frame, finds the position with the highest feature matching degree with the target, and uses it as the new position of the target.

[0009] S2.1 Multiple photoelectric tracking units are evenly deployed on the circumference monitored and scanned by the spectrum monitor, and the possible locations of the target given by the spectrum monitor are searched simultaneously in different areas.

[0010] S 2.2 The field of view tracked by multiple photoelectric tracking units is stitched together and calculated to determine the position of the monitored UAV; the number of photoelectric tracking units is not less than two.

[0011] S3: Then adjust the camera to a new position and automatically or manually control the linked jamming device to send satellite navigation and remote control jamming signals to the target area until the drone is driven away.

[0012] Furthermore, step S3 is specifically performed as follows:

[0013] First, acquire the target distance and azimuth angle {L,a} data tracked by each photoelectric tracking unit;

[0014] S 3.1 : Obtain the azimuth angles between each point E and the target F, and solve for the azimuth angles {a} between each E and F;

[0015] S 3.2 Given {R,L,a}, find the distance and direction deviation {D,b} from each point E to F.

[0016] S 3.3 Choose the smallest point E as the starting point and F as the center point;

[0017] S 3.4 Send {b, g, D} to device at point E;

[0018] S 3.5 : Determine if E is the last point; if so, end the process.

[0019] S 3.6 Otherwise, based on the known {R,L,b,g}, solve for the edge points {a+t,Dn};

[0020] S 3.7 Switch to the next point E and adjust the a value of the edge point relative to E;

[0021] S 3.8 Given {R,L,a}, solve for the center point {D,b}, then return to step S. 3.4 .

[0022] Furthermore, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a main controller, implements the system and method as described in any of the above claims.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] It solves the problem of excessive target position error in spectrum analyzers, achieving accurate positioning and meeting the requirements for real-time target search and success rate. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 is a system schematic diagram of the present invention;

[0027] Figure 2 is a schematic diagram of the target tracking unit of the present invention;

[0028] Figure 3 is a flowchart of the method of the present invention;

[0029] Figure 4 is an example diagram of an embodiment of the present invention. Detailed Implementation

[0030] 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 a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please refer to Figure 1. The distributed photoelectric tracking system specifically includes a spectrum monitor, a camera carrying the target detection unit and the target tracking unit, and a pan-tilt unit carrying the jamming device and the aforementioned camera; the specific steps are as follows:

[0032] S1: The spectrum monitor detects the UAV target and sends the target's azimuth and distance data to the target detection unit. After the target detection unit detects the target, it automatically or manually locks onto the target and transmits the target locking information to the target tracking unit.

[0033] S2: The target tracking unit extracts features in the area around the original position of the target in the previous frame, finds the position with the highest feature matching degree with the target, and uses it as the new position of the target.

[0034] S 2.1 Multiple photoelectric tracking units are evenly deployed on the circumference monitored and scanned by the spectrum monitor, and the possible locations of the target given by the spectrum monitor are searched simultaneously in different areas.

[0035] S 2.2 The field of view tracked by multiple photoelectric tracking units is stitched together and calculated to determine the position of the monitored UAV; the number of photoelectric tracking units is not less than two.

[0036] S3: Then adjust the camera to a new position and automatically or manually control the linked jamming device to send satellite navigation and remote control jamming signals to the target area until the drone is driven away.

[0037] As shown in Figure 2, firstly, the target distance and azimuth angle {L,a} data tracked by each photoelectric tracking unit are obtained;

[0038] S 3.1 : Obtain the azimuth angles between each point E and the target F, and solve for the azimuth angles {a} between each E and F;

[0039] S 3.2 Given {R,L,a}, find the distance and direction deviation {D,b} from each point E to F.

[0040] S 3.3 Choose the smallest point E as the starting point and F as the center point;

[0041] S 3.4 Send {b, g, D} to device at point E;

[0042] S 3.5 : Determine if E is the last point; if so, end the process.

[0043] S 3.6 Otherwise, based on the known {R,L,b,g}, solve for the edge points {a+t,Dn};

[0044] S 3.7 Switch to the next point E and adjust the a value of the edge point relative to E;

[0045] S 3.8 Given {R,L,a}, solve for the center point {D,b}, then return to step S. 3.4 .

[0046] As shown in Figure 2, where O: origin of the coordinate system; L: distance of the target position from the origin; center point: intersection of the optical axis of the photoelectric system and the circumference of L; edge point: intersection of the edge of the field of view of the photoelectric system and the circumference of L; F and Fn: target point, center point, or edge point; E: position of the photoelectric tracking system; R: distance of the photoelectric tracking system from the origin; a: angle between the photoelectric system and the target relative to the origin; b: azimuth deviation angle of the target relative to the photoelectric system; g: half of the horizontal field of view angle of the photoelectric system; t: deviation angle of F or Fn; D and Dn: distance between F or Fn and the photoelectric system.

[0047] The parameters {R,L,a,b,g,t,D,Dn} have the following relationships as shown in equations (1)-(4):

[0048] R*sin(a)=D*sin(ba; (1)

[0049] R*cos(a)+D*cos(ba)=L; (2)

[0050] R*sin(a+t)=Dn*sin((b+g)-(a+t)); (3)

[0051] R*cos(a+t)+Dn*cos((b+g)-(a+t))=L; (4)

[0052] Based on the above relationships, after transformation, {b,D} can be obtained from {R,L,a}, and the specific calculation formulas are shown in equations (5)-(6):

[0053] b=a+2*atan((R*cos(a)-L+(L^2-2*cos(a)*L*R+R^2)^(1 / 2)) / (2*R*cos(a / 2)*sin(a / 2))); (5)

[0054] D=(L^2-2*cos(a)*L*R+R^2)^(1 / 2); (6)

[0055] Using the same method, after b deflects by an angle g, {t,Dn} can be obtained from {R,L,b,g}. The specific calculation formulas are as follows, as shown in equations (7)-(8):

[0056] t=2*atan((L*tan(b / 2+g / 2)^2-L+(L^2+2*L^2*tan(b / 2+g / 2)^2+L^2*tan(b / 2 +g / 2)^4-4*R^2*tan(b / 2+g / 2)^2)^(1 / 2)) / (2*tan(b / 2+g / 2)*(L+R)))-a; (7)

[0057] Dn=(2^(1 / 2)*((R^2*cos(2*b+2*g)+2*L^2-R^2) / cos(b / 2+g / 2)^4)^(1 / 2)) / 4-R*cos(b+g)+(2^(1 / 2)*cos(b+g)*((R^2*co s(2*b+2*g)+2*L^2-R^2) / cos(b / 2+g / 2)^4)^(1 / 2)) / 4; (8)

[0058] In this embodiment, as shown in Figure 4, three photoelectric devices, E1, E2, and E3, are evenly distributed on a 10m circle. The horizontal field of view of the photoelectric system is 4°. The spectrum monitor indicates that the target is located in the direction of the 20° angle between E1 and the origin, 1000m away, with an azimuth error of ±5°.

[0059] Step 1: Find the shortest distances between E1, E2, E3 and the target F1;

[0060] E1: R=10, L=1000, a=20*pi() / 180 {b, D}={20.1968, 990.6090}

[0061] E2:R=10,L=1000,a=140*pi() / 180 {b,D}={140.3655,1.0077e+03}

[0062] E3:R=10,L=1000,a=260*pi() / 180 {b,D}={259.4367,1.0018e+03}

[0063] Step 2: Solve for the left and right boundaries F2 and F3 of the shortest distance E1 field of view;

[0064] F1:R=10,L=1000,a=20*pi() / 180{b,D}={20.1968,990.6090}

[0065] F2: R=10, L=1000, b=20.1968*pi() / 180, g=-2*pi() / 180{an,Dn}={ 18.0179 ,990.4952}

[0066] F3: R=10, L=1000, b=20.1968*pi() / 180, g=2*pi() / 180{an,Dn}={ 21.9803 ,990.7339}

[0067] Step 3: Solve for the field center F4 and boundary F5 of E2;

[0068] F2:R=10,L=1000,a=(18.0179+120)*pi() / 180{b,D}={138.3983,1.0075e+03}

[0069] F4: R=10, L=1000, b=138.3983*pi() / 180, g=-2*pi() / 180{an,Dn}={136.0032,1.0072e+03}

[0070] F5: R=10, L=1000, b=138.3983*pi() / 180, g=-4*pi() / 180{an,Dn}={ 133.9889 ,1.0070e+03}

[0071] Step 4: Solve for the field center F6 and boundary F7 of E3;

[0072] F3: R=10, L=1000, a=(21.9803+240)*pi() / 180{b,D}={ 2 61.4138,1.0014e+03}

[0073] F6: R=10, L=1000, b=261.4138*pi() / 180, g=2*pi() / 180{an,Dn}={-96.0170,1.0011e+03}

[0074] F7: R=10, L=1000, b=261.4138*pi() / 180, g=4*pi() / 180{an,Dn}={- 94.0151 ,1.0007e+03}

[0075] Result: The stitched field of view ∠F7OF5=360° - ∠E2OE3 - ∠F5OE2 - ∠E3OF7

[0076] = 360° - 120° - 133.9889° - 94.0151°

[0077] =11.966°

[0078] In this embodiment, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a main controller, implements the system and method as described in any of the above claims.

[0079] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. In the above embodiments of the present invention, the descriptions of each embodiment have their own emphasis, and for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A field-of-view stitching method for a distributed photoelectric tracking system, characterized in that, The distributed photoelectric tracking system specifically includes a spectrum monitor, a camera carrying a target detection unit and a target tracking unit, and a gimbal carrying an interference device and the aforementioned camera; it is specifically executed according to the following steps: S1: The spectrum monitor detects the UAV target and sends the target's azimuth and distance data to the target detection unit. After the target is detected by the target detection unit, it automatically or manually locks onto the target and transmits the locked target information to the target tracking unit; S2: The target tracking unit extracts features from the region surrounding the original target position in the previous frame, finds the position with the highest feature matching degree with the target, and uses it as the new position of the target; 2.1 Multiple target tracking units are evenly deployed on the circumference of the spectrum monitor's scan area, simultaneously searching for possible target locations indicated by the spectrum monitor in different regions; S 2.2 : Stitch together the fields of view tracked by multiple target tracking units to determine the position of the monitored UAV; S3: Then, adjust the camera to a new position and automatically or manually control the linked jamming device to transmit satellite navigation and remote control jamming signals to the target area until the drone is driven away; in step S... 2.2 Specifically, the process is as follows: S2021: First, acquire the target distance and azimuth angle {L,a} data tracked by each target tracking unit; S2022: Obtain the azimuth angle between each point E and the target F, and solve for the azimuth angle {a} between each E and F; S2023: Given {R,L,a}, solve for the distance and direction deviation {D,b} from each point E to F; S2024: Select the point E with the smallest distance as the starting point and F as the center point; S2025: ... Point E sends {b, g, D}; S2026: Determine if E is the last point; if yes, end; S2027: Otherwise, based on the known {R, L, b, g}, solve for the edge point {a+t, Dn}; S2028: Switch to the next point E and adjust the edge point's a value for E; S2029: Given {R, L, a}, solve for the center point {D, b}, then return to step S2025; For the view tracked by multiple target tracking units... The specific calculation formula for splicing the field is: t=2*atan((L*tan(b / 2+g / 2)^2-L+(L^2+2*L^2*tan(b / 2+g / 2)^2+L^2*tan(b / 2+g / 2)^4-4*R^2*tan(b / 2+g / 2)^2)^(1 / 2)) / (2*tan(b / 2+g / 2)*(L+R)))-a;Dn=(2^(1 / 2) *((R^2*cos(2*b+2*g)+2*L^2-R^2) / cos(b / 2+g / 2)^4)^(1 / 2)) / 4-R*cos(b+g)+(2^(1 / 2)*cos(b+g)*((R^2*cos(2*b+2*g)+2*L^2-R^2) / cos(b / 2+g / 2)^4)^(1 / 2)) / 4; where L: the distance between the target position and the origin; Center point: The intersection of the optical axis of the photoelectric tracking system and the L-shaped circle; Edge point: The intersection of the edge of the field of view of the photoelectric tracking system and the L-shaped circle; F: Target center point; Fn: Edge point; E: Position of the photoelectric tracking system; R: Distance of the photoelectric tracking system from the origin; a: Angle between the photoelectric tracking system and the target relative to the origin; b: Target's azimuth deviation angle from the photoelectric tracking system; g: Half of the horizontal field of view of the photoelectric tracking system; t: the deviation angle of F; D: Distance between F and the photoelectric tracking system; Dn: Distance between Fn and the photoelectric tracking system.

2. The field-of-view stitching method for a distributed photoelectric tracking system according to claim 1, characterized in that, In step S 2.2 In this context, there are at least two target tracking units.

3. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the main controller, it implements the method as described in any one of claims 1-2 above.

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