An unmanned aerial vehicle target positioning method, device, equipment and medium

Abstract

The embodiment of the present specification provides a kind of unmanned plane target positioning method, device, equipment and medium, wherein the method includes that unmanned plane obtains distance information and unmanned plane twice position information by laser ranging equipment to target point twice ranging;With the space position of unmanned plane as the ball center when twice ranging, the distance value to target point measured is radius, constructs two space balls, and the intersection of two space balls constitutes the intersection circle of fitting;The space surface of ground elevation is established to target point position area;According to the intersection circle of fitting and the space surface of ground elevation established, construct simultaneous geometric equation group, determine the position of target point by solving equation.The present application, realize that the attitude angle, turntable attitude angle and the like data of unmanned plane are not needed in positioning process, reduce flight load, reduce equipment cost, while also prevent the error generated in the process of measuring these data from entering positioning process, greatly improve positioning precision.

Description

Technical Field

[0001] This invention relates to the field of target positioning technology, and in particular to a method, apparatus, device and medium for unmanned aerial vehicle (UAV) target positioning. Background Technology

[0002] The single-station angle and distance measurement method for UAVs is a fundamental algorithm for UAV target localization. This method can locate ground targets with a single illumination, offering fast positioning speed and relative simplicity. However, it requires numerous parameters, is prone to errors, and places high demands on the measuring equipment. To further improve accuracy and reduce equipment requirements, the spatial multi-point intersection positioning method has emerged. This method reduces the number of parameters needed for positioning and improves the longitude accuracy by performing multiple distance measurements. Specifically, as shown below... Figure 1 The diagram illustrates the positioning principle of the UAV spatial three-point (multi-point) intersection positioning method. Each time the UAV measures the distance to the target, it generates a ternary quadratic equation with the target coordinates as parameters, based on the UAV's coordinates and the measured distance. Specifically:

[0003]

[0004] After measuring the distance to the same target three times (or more) (with the measurement points not on the same straight line), a system of three quadratic equations in three variables about the target point can be obtained. Solving this system of three quadratic equations will give the coordinates of the target point. It should be noted that the target point coordinates obtained by this method are often two values. In this case, it is necessary to eliminate one incorrect solution based on the actual situation.

[0005] However, the existing spatial multi-point intersection positioning method also has obvious drawbacks. Since this method requires three ranging and positioning operations when a single UAV performs a reconnaissance mission, it is almost impossible to achieve target tracking and positioning. At the same time, it also requires the UAV to spend more time to complete the data collection of the three ranging points. This makes the UAV's reconnaissance mission more time-consuming, less efficient, and greatly reduces the battlefield survivability.

[0006] Therefore, how to improve the survival rate and positioning speed of drones while ensuring accuracy is an urgent problem to be solved. Summary of the Invention

[0007] This specification provides one or more embodiments of a UAV target localization method, including the following steps:

[0008] The UAV uses a laser rangefinder to measure the target point twice to obtain distance information and the UAV's position information twice. Using the UAV's spatial position at each of the two measurements as the center and the distance from the UAV to the target point as the radius, two spatial spheres are constructed. The intersection of the two spatial spheres forms a fitted intersection circle. A digital elevation model is established for the target point's location area, creating a spatial surface for the ground elevation. Based on the fitted intersection circle and the established spatial surface for the ground elevation, a system of simultaneous geometric equations is constructed, and the equations are solved to determine the target point's position.

[0009] This specification provides one or more embodiments of a UAV target positioning device, including

[0010] Information receiving module: Receives distance information obtained by the UAV through two distance measurements of the target point using a laser rangefinder, and two position information obtained by the UAV through its positioning system.

[0011] The intersection circle determination module: Based on the information received by the signal receiving module, two spatial spheres are constructed, with the UAV's spatial position at the two distance measurements as the center and the distance measured by the UAV to the target point as the radius. The intersection of the two spatial spheres constitutes the fitted intersection circle.

[0012] Spatial Surface Construction Module: Creates a digital elevation model of the target point location area and establishes a spatial surface for the ground elevation;

[0013] Target point confirmation module: Based on the intersection circle fitted by the intersection circle construction module and the spatial surface of the ground elevation established by the spatial surface construction module, a system of simultaneous geometric equations is constructed, and the equations are solved to determine the location of the target point.

[0014] This specification provides one or more embodiments of a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a UAV target localization method as described above.

[0015] This specification provides one or more embodiments of a computer-readable storage medium storing a computer program that, when executed by a processor, implements a UAV target localization method as described above. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in one or more embodiments of this specification or in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram illustrating a scenario of the prior art UAV spatial three-point (multi-point) intersection positioning method provided in this specification;

[0018] Figure 2 A flowchart illustrating a UAV target localization method provided for one or more embodiments of this specification;

[0019] Figure 3 A schematic cross-sectional view of a two-point positioning method for a UAV target positioning method provided in one or more embodiments of this specification.

[0020] Figure 4 A schematic diagram of the spatial sphere intersection of a UAV target localization method provided in one or more embodiments of this specification;

[0021] Figure 5 A schematic diagram illustrating the solution of the minimum distance from any point in space to the intersection circle in a UAV target localization method provided in one or more embodiments of this specification;

[0022] Figure 6 A schematic diagram illustrating the principle of a UAV target localization method for progressively approximating and optimizing target point localization results, provided in one or more embodiments of this specification;

[0023] Figure 7 GPS positioning map in an experiment of a UAV target positioning method provided in one or more embodiments of this specification;

[0024] Figure 8 This specification provides an image of the UAV target localization result in an experiment, which is part of one or more embodiments of a UAV target localization method.

[0025] Figure 9 A schematic diagram of the structure of a UAV target positioning device provided in one or more embodiments of this specification;

[0026] Figure 10 This is a schematic diagram of the structure of a computer device provided for one or more embodiments of this specification. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification 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 this specification, and not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this document.

[0028] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0029] Method Implementation Examples

[0030] According to embodiments of the present invention, a method for locating unmanned aerial vehicle (UAV) targets is provided, such as... Figure 2 The diagram shown is a flowchart of a UAV target localization method according to this embodiment. The UAV target localization method according to this embodiment includes the following steps:

[0031] Step S1: The UAV uses a laser rangefinder to measure the distance to the target point twice to obtain distance information, and the UAV uses the positioning system to measure the position information twice.

[0032] Step S2: Using the information obtained in step S1, construct two spatial spheres with the UAV's spatial position during the two distance measurements as the center and the distance from the UAV to the target point as the radius. The intersection of the two spatial spheres forms a fitted intersection circle. In this embodiment, the two spatial spheres and the intersection circle are established using a geometric method. The data of the two spatial spheres have been measured, and the intersection circle of the two spatial spheres is an auxiliary graphic for solving the target point.

[0033] Step S3: Establish a digital elevation model for the target point location area and create a spatial surface for the ground elevation;

[0034] Step S4: Based on the intersection circle fitted in Step S2 and the spatial surface of the ground elevation established in Step S3, construct a system of simultaneous geometric equations, solve the equations to determine the location of the target point.

[0035] In this embodiment, the drone or computer can obtain the elevation information of the target point through satellite imagery or high-precision differential GPS;

[0036] Compared with the single-station angle and distance measurement method of UAV, the positioning method based on the spatial two-point intersection method of digital elevation model does not require the collection of UAV attitude angles, turntable attitude angles and other data during the positioning process. This reduces the flight load, lowers equipment costs, and also prevents errors generated during the measurement of these data from entering the positioning process, thus greatly improving positioning accuracy.

[0037] Compared with the UAV spatial three-point (multi-point) intersection method, the spatial two-point intersection method based on the digital elevation model also uses the UAV's positioning information and the target's ranging information for calculation. Theoretically, it can achieve similar accuracy. However, the spatial two-point intersection method based on the digital elevation model reduces one ranging point in the positioning process, requiring only two sampling points to achieve accurate positioning. This greatly improves the battlefield survivability of the carrier aircraft, while also improving the efficiency of UAV positioning and enabling real-time positioning of two aircraft.

[0038] In this embodiment, as Figure 3 As shown, two spatial spheres are established using distance information obtained from two distance measurements of the target point by a UAV. Two ternary quadratic equations can be determined using geometric methods. Combined with the establishment of a digital elevation model function through an elevation model, a system of simultaneous geometric equations is constructed. Solving the equations determines the coordinates of the target point, as detailed below:

[0039] like Figure 3 Point A represents the UAV's position during the first ranging measurement (x1, y1, z1) (Geometric rectangular coordinates are (x1, y1, z1)), and r1 is the ranging value. Point B represents the UAV's position during the second ranging measurement (x2, y2, z2) (Geometric rectangular coordinates are (x2, y2, z2)), and r2 is the ranging value. Therefore, the target point coordinates (x0, y0, z0) satisfy the following formula:

[0040]

[0041] At this point, the spatial sphere containing the target point can be determined. This sphere, along with the digital elevation model function (f(x0,y0)=z0) (i.e., the spatial surface of the aforementioned ground elevation), is used to solve for the target point. The simultaneous equations are as follows:

[0042]

[0043] Then, by eliminating incorrect solutions based on the relative position of the target point to the UAV, the coordinates of the target point are obtained. The rectangular coordinates are then converted to latitude and longitude using a formula:

[0044]

[0045] Where b is the minor semi-axis of the Earth ellipse, a is the major semi-axis of the Earth ellipse, e is the first eccentricity of the Earth reference ellipse, e′ is the second eccentricity of the Earth ellipse, and R... N Let U be the radius of curvature of the zonal loop, and U be an auxiliary quantity.

[0046]

[0047] In this embodiment, the specific solution process for the target point in steps S2-S4 includes the following steps:

[0048] S101. Establish the equations for the two spatial spheres. Read the digital elevation model information. The equations are established as follows:

[0049]

[0050] S102, such as Figure 4 As shown, the center and radius of a spatial sphere are determined using spatial geometry, specifically as follows:

[0051] Subtracting the equations of the two spheres yields the plane containing the line of intersection of the two spheres. The equation of this plane is:

[0052] a*x0+b*y0+c*z0+d=0 (6)

[0053] The values ​​of a, b, c, and d are as follows:

[0054]

[0055] By spatial geometry, we can deduce that the line connecting the centers of the two spheres must pass through the center of the circle of intersection of the two spheres and be perpendicular to the plane containing the circle of intersection. The equation of the line connecting the centers of the two spheres is:

[0056]

[0057] Where the values ​​of m, n, and p are respectively:

[0058]

[0059] Solve the system of equations for the straight line and the plane containing the intersection of the two spheres to find the center (x0, y0, z0) of the circle of intersection. The results are as follows:

[0060]

[0061] Where j is the auxiliary computational quantity, its expression is:

[0062]

[0063] According to the Pythagorean theorem, the radius R of the intersection circle is:

[0064] R 2 =r2 2 -((x2-x1) 2 +(y2-y1) 2 +(z2-z1) 2 (12) Given the coordinates of the center and radius of the intersection circle, the equation of the intersection circle of the two spheres is:

[0065] (x0-x) 2 +(y0-y) 2 +(z0-z) 2 =R2 (13)

[0066] S103. Using the coordinates of the center and radius of the intersection circle, derive the minimum value of d′ from any point Q in space to the intersection circle based on geometric relationships:

[0067]

[0068] Where D is the distance from any point in space to the plane containing the intersection circle, and the expression for D is:

[0069]

[0070] S104. Using the iterative method, substitute the discrete points in the digital elevation model library into the above formula to determine the minimum D value, and then determine the coordinates of the target point.

[0071] In this preferred embodiment, the target point location can be determined by the above method. However, since the accuracy of coordinate positioning is greatly affected by the digital elevation model database, the accuracy of the digital elevation model database (and the interval or resolution of sampling points) will directly affect the target accuracy calculated by this positioning method. In order to solve this problem, this embodiment optimizes the calculation result of equation (15), and specifically includes the following steps:

[0072] S5. By using the successive approximation method, taking the target point coordinates determined in step S4 as the origin, the true value is gradually approximated in the three coordinate axis directions with a predetermined step size, and finally the optimized target point coordinates are determined, as follows: Figure 6 As shown, this optimization algorithm can overcome the limitations of the data elevation model library to a certain extent and improve the target positioning accuracy.

[0073] The following specific experimental case illustrates the practical value of the method in this embodiment.

[0074] This experiment utilized an unmanned aerial vehicle (UAV) equipped with a laser ranging device to conduct a field test near Yuanshi Airport. Data collection was completed, and the positioning accuracy was compared with that of the traditional video image positioning method, verifying the practical feasibility and application value of this positioning method.

[0075] First, a digital elevation model was established. Since there was no digital elevation model that met the experimental conditions, a digital elevation model was established in an area with a length and width of 50 meters within Yuanshi Airport in this experiment. Sampling points were set at 5-meter intervals. The geodetic rectangular coordinate values ​​of 100 sampling points were recorded using the GPS function of a mobile phone and written into the file "Yuanshi Airport Digital Elevation Model.txt".

[0076] Next, establish target points. Within the digital elevation model of Yuanshi Airport, set 10 conspicuous yellow target points as ground target reconnaissance points, and use a mobile phone GPS to record the true coordinates of the yellow target points, such as... Figure 7 .

[0077] Next, a drone equipped with a laser platform was used to measure the distance to ten target points in the air. Two distance measurements were taken at each target point, and the aircraft coordinates and distance values ​​were recorded for each measurement. The experimental data after the distance measurement experiment was completed is shown in Appendix 5. Figure 8 .

[0078] Finally, the computer calculates and determines the coordinates of ten target points through the above calculation steps, and obtains the comparison results of the two positioning methods, as shown in Appendix 1 at the end of the article.

[0079] The rectangular coordinates were converted to geodetic latitude and longitude to obtain experimental comparison results, as shown in Appendix II at the end of this article, which compares the positioning coordinates and deviations of the two positioning methods.

[0080] Experimental conclusion:

[0081] Experimental data shows that the spatial two-point intersection method based on digital elevation models has good practical application value:

[0082] 1. Compared with the current spatial three-point (multi-point) intersection positioning method, the two-point intersection method based on digital elevation model can calculate the altitude of the target point, which is more practical.

[0083] 2. In terms of accuracy, the accuracy of the spatial two-point intersection method based on the digital elevation model is greatly affected by the terrain. In this experiment, the accuracy is generally slightly higher than that of the spatial three-point (multi-point) intersection positioning method. In areas with large undulations, the accuracy is lower than that of the video image positioning method, but it can still achieve the practical purpose.

[0084] Device Examples

[0085] According to embodiments of the present invention, a target positioning device for unmanned aerial vehicles (UAVs) is provided, such as... Figure 9 As shown, the UAV target positioning device according to an embodiment of the present invention includes

[0086] Information receiving module: Receives distance information obtained by the UAV through two distance measurements of the target point using a laser rangefinder, as well as two position information measured by the UAV through its positioning system.

[0087] The intersection circle determination module: Based on the information received by the signal receiving module, two spatial spheres are constructed, with the UAV's spatial position at the two distance measurements as the center and the distance measured by the UAV to the target point as the radius. The intersection of the two spatial spheres constitutes the fitted intersection circle.

[0088] Spatial Surface Construction Module: Creates a digital elevation model of the target point location area and establishes a spatial surface for the ground elevation;

[0089] Target point confirmation module: Based on the intersection circle fitted by the intersection circle construction module and the spatial surface of the ground elevation established by the spatial surface construction module, a system of simultaneous geometric equations is constructed, and the equations are solved to determine the location of the target point.

[0090] Specifically, in this embodiment, the target point confirmation module uses two spatial spheres established by the intersection circle determination module. Through geometric methods, it determines two ternary quadratic equations. Combined with a digital elevation model function established through an elevation model, a system of simultaneous geometric equations is constructed. Solving these equations determines the coordinates of the target point. The specific calculation is as follows:

[0091] like Figure 3 Point A represents the UAV's position during the first ranging measurement (x1, y1, z1) (Geometric rectangular coordinates are (x1, y1, z1)), and r1 is the ranging value. Point B represents the UAV's position during the second ranging measurement (x2, y2, z2) (Geometric rectangular coordinates are (x2, y2, z2)), and r2 is the ranging value. Therefore, the target point coordinates (x0, y0, z0) satisfy the following formula:

[0092]

[0093] At this point, the spatial sphere containing the target point can be determined. The target point can then be solved simultaneously with the digital elevation model function (f(x0,y0)=z0). The simultaneous equations are as follows:

[0094]

[0095] Then, by eliminating incorrect solutions based on the relative position of the target point to the UAV, the coordinates of the target point are obtained. The rectangular coordinates are then converted to latitude and longitude using a formula:

[0096]

[0097] Where b is the minor semi-axis of the Earth ellipse, a is the major semi-axis of the Earth ellipse, e is the first eccentricity of the Earth reference ellipse, e′ is the second eccentricity of the Earth ellipse, and R... N Let U be the radius of curvature of the zonal loop, and U be an auxiliary quantity.

[0098]

[0099] In this embodiment, the target point confirmation module's specific calculation process includes the following steps:

[0100] A101. After initializing the known quantities, establish the equations for the two spatial spheres, read the digital elevation model information, and establish the equations as follows:

[0101]

[0102] A102, such as Figure 4As shown, the center and radius of a spatial sphere are determined using spatial geometry, specifically as follows:

[0103] Subtracting the equations of the two spheres yields the plane containing the line of intersection of the two spheres. The equation of this plane is:

[0104] a*x0+b*y0+c*z0+d=0 (21) where the values ​​of a, b, c, and d are respectively:

[0105]

[0106] By spatial geometry, we can deduce that the line connecting the centers of the two spheres must pass through the center of the circle of intersection of the two spheres and be perpendicular to the plane containing the circle of intersection. The equation of the line connecting the centers of the two spheres is:

[0107]

[0108] Where the values ​​of m, n, and p are respectively:

[0109]

[0110] Solve the system of equations for the straight line and the plane containing the intersection of the two spheres to find the center (x0, y0, z0) of the circle of intersection. The results are as follows:

[0111]

[0112] Where j is the auxiliary computational quantity, its expression is:

[0113]

[0114] According to the Pythagorean theorem, the radius R of the intersection circle is:

[0115] R 2 =r2 2 -((x2-x1) 2 +(y2-y1) 2 +(z2-z1) 2 (27) Given the coordinates of the center and radius of the intersection circle, the equation of the intersection circle of the two spheres is:

[0116] (x0-x) 2 +(y0-y) 2 +(z0-z) 2 =R 2 (28)

[0117] A103. Using the coordinates of the center and radius of the intersection circle, derive the minimum value of d′ from any point Q in space to the intersection circle based on geometric relationships:

[0118]

[0119] Where D is the distance from any point in space to the plane containing the intersection circle, and the expression for D is:

[0120]

[0121] A104. Using the iterative method, substitute the discrete points in the digital elevation model library into the above formula to determine the minimum D value, and then determine the coordinates of the target point.

[0122] In this preferred embodiment, the target point location is determined through the above calculations. However, since the accuracy of coordinate positioning is greatly affected by the digital elevation model database, the accuracy of the digital elevation model database directly affects the target accuracy calculated by this positioning method. To solve this problem, the device in this embodiment further includes...

[0123] Target point positioning optimization module: By using the stepwise approximation method, taking the target point coordinates determined by the target point confirmation module as the origin, the module gradually approximates the true value in the three coordinate axis directions with a predetermined step size, and finally determines the optimized target point coordinates. Using this optimization algorithm, the limitations of the data elevation model library are eliminated to a certain extent, and the target positioning accuracy is improved.

[0124] like Figure 10 As shown, the present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it implements the UAV target localization method in the above embodiments, or when the computer program is executed by a processor, it implements the UAV target localization method in the above embodiments. When the computer program is executed by the processor, it implements the following method steps:

[0125] Step S1: The UAV uses a laser rangefinder to measure the target point twice to obtain distance information and the UAV's position information twice;

[0126] Step S2: Using the information obtained in step S1, construct two spatial spheres with the UAV's spatial position during the two distance measurements as the center and the distance measured by the UAV to the target point as the radius. The intersection of the two spatial spheres forms the fitted intersection circle.

[0127] Step S3: Establish a digital elevation model for the target point location area and create a spatial surface for the ground elevation;

[0128] Step S4: Based on the intersection circle fitted in Step S2 and the spatial surface of the ground elevation established in Step S3, construct a system of simultaneous geometric equations, solve the equations to determine the location of the target point.

[0129] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0130] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for apparatus or system embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The apparatus and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0132] Appendix 1: Results of the Positioning Experiment

[0133]

[0134]

[0135] Appendix 2: Results and Deviations of the Two Positioning Methods

[0136]

[0137]

[0138]

Claims

1. A method for locating a target using an unmanned aerial vehicle (UAV), characterized in that, Includes the following steps: The UAV obtains distance information by measuring the target point twice using a laser rangefinder and also measures its spatial position twice using its positioning system. Two spatial spheres are constructed, each with its spatial position at the time of the two measurements as the center and the measured distance to the target point as the radius. The intersection of these two spheres forms a fitted intersection circle. A digital elevation model is established for the target point's location region, creating a spatial surface for the ground elevation. A system of simultaneous geometric equations is constructed based on the fitted intersection circle and the established spatial surface for the ground elevation. Solving these equations determines the target point's location. The steps involved in constructing and solving the system of simultaneous geometric equations based on the fitted intersection circle and the established spatial surface for the ground elevation to determine the target point's location include: Based on the coordinates of the center and radius of the circle of intersection, the equation of the circle of intersection of the two spheres is determined as follows: ； in,( , , () represents the coordinates of the center of the intersection circle; Based on the coordinates of the center and radius of the intersection circle, and using geometric relationships, derive the minimum value from any point Q in space to the intersection circle as follows: : ； Where D is the distance from any point in space to the plane containing the intersection circle, and the expression for D is: ； Then, using the iterative method, the discrete points in the digital elevation model library are substituted into the above formula to determine the minimum D value, which is to determine the coordinates of the target point.

2. The UAV target localization method as described in claim 1, characterized in that, The specific steps involved in constructing a system of simultaneous geometric equations and solving the equations to determine the coordinates of the target point are as follows: Based on the position of the drone during the first ranging ( x 1, y 1, z 1), r 1 represents the ranging value, indicating the drone's position during the second ranging measurement. x 2, y 2, z 2) r 2 represents the distance measurement value, used to determine the coordinates of the target point. , , The following equation must be satisfied: Solving for the target point by combining the solution with the digital elevation model function, the digital elevation model function is: The simultaneous equations are as follows: Next, by eliminating incorrect solutions based on the relative position of the target point to the UAV, the coordinates of the target point are obtained. Then, the rectangular coordinates are converted to latitude and longitude using a formula: in, b This is the minor semi-axis of the Earth's ellipse. a This is the semi-major axis of the Earth's ellipse. e The first eccentricity of the Earth's reference ellipse. This is the second eccentricity of the Earth's ellipse. R N The radius of curvature of the circle is denoted as . U For auxiliary quantities:

3. The UAV target localization method as described in claim 1, characterized in that, It also includes the following steps: By using the successive approximation method, taking the determined target point coordinates as the origin, the true value is gradually approximated in the three coordinate axis directions with a predetermined step size, and finally the optimized target point coordinates are determined.

4. A target positioning device for unmanned aerial vehicles (UAVs), characterized in that, include Information receiving module: Receives distance information obtained by the UAV through two distance measurements of the target point using a laser rangefinder, and automatically measures the spatial position information twice through the UAV positioning system; The intersection circle determination module: Based on the information received by the signal receiving module, two spatial spheres are constructed, with the UAV's spatial position at the two distance measurements as the center and the distance measured by the UAV to the target point as the radius. The intersection of the two spatial spheres constitutes the fitted intersection circle. Spatial Surface Construction Module: Creates a digital elevation model of the target point location area and establishes a spatial surface for the ground elevation; Target point confirmation module: Based on the intersection circle fitted by the intersection circle construction module and the spatial surface of ground elevation established by the spatial surface construction module, a system of simultaneous geometric equations is constructed. Solving the equations determines the location of the target point. The specific solution process is as follows: Based on the coordinates of the center and radius of the circle of intersection, the equation of the circle of intersection of the two spheres is determined as follows: ； in,( , , () represents the coordinates of the center of the intersection circle; Based on the coordinates of the center and radius of the intersection circle, and using geometric relationships, derive the minimum value from any point Q in space to the intersection circle as follows: : ； Where D is the distance from any point in space to the plane containing the intersection circle, and the expression for D is: ； Then, using the iterative method, the discrete points in the digital elevation model library are substituted into the above formula to determine the minimum D value, which is to determine the coordinates of the target point.

5. The UAV target positioning device as described in claim 4, characterized in that, The target point confirmation module specifically calculates the following: Based on the position of the drone during the first ranging ( x 1, y 1, z 1), r 1 represents the ranging value, indicating the drone's position during the second ranging measurement. x 2, y 2, z 2) r 2 represents the distance measurement value, used to determine the coordinates of the target point. x c , y c , z c The following equation must be satisfied: Solving for the target point by combining the solution with the digital elevation model function, the digital elevation model function is: The simultaneous equations are as follows: Next, by eliminating incorrect solutions based on the relative position of the target point to the UAV, the coordinates of the target point are obtained. Then, the rectangular coordinates are converted to latitude and longitude using a formula: in, b This is the minor semi-axis of the Earth's ellipse. a This is the semi-major axis of the Earth's ellipse. e The first eccentricity of the Earth's reference ellipse. This is the second eccentricity of the Earth's ellipse. R N The radius of curvature of the circle is denoted as . U For auxiliary quantities:

6. The UAV target positioning device as described in claim 4, characterized in that, Also includes Target point localization optimization module: By using the stepwise approximation method, taking the target point coordinates determined by the target point confirmation module as the origin, the module gradually approximates the true value in the three coordinate axis directions with a predetermined step size, and finally determines the optimized target point coordinates.

7. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements a UAV target localization method as described in any one of claims 1 to 3.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a UAV target localization method as described in any one of claims 1 to 3.

Images