A method for target identification and interception based on a UAV system

Abstract

The application provides a method for target identification and interception based on a UAV system, and belongs to the technical field of detection and identification. The method comprises the following steps: detecting and identifying an incoming target by using a radar airspace detection area model, and the conditions for detection and identification include that the incoming target is within the range of a radar detection boundary, the incoming target is within the azimuth angle of a radar sector, and the incoming target is within the elevation angle of a radar sector; when the radar airspace detection area model determines that the incoming target is located in the detection area through detection and identification, performing interpolation operation on the height segments of the incoming target by using a UAV system kill area model to obtain the range of the kill area; when the UAV system kill area model determines that the incoming target is located in the kill area, calculating the interception arc segment time length, the earliest encounter point of the interception arc segment and the latest encounter point of the interception arc segment by using a UAV system interception model, and performing interception based on the interception expectation.

Description

Technical Field

[0001] This invention belongs to the field of detection and identification technology, and in particular relates to a method for target identification and interception based on an unmanned aerial vehicle (UAV) system. Background Technology

[0002] Researching the issue of drone defense against attacks from adversary targets is of great significance. How to deal with incoming targets and how to achieve defense, protection, and effective interception of such targets are pressing problems that need to be solved. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes a method for target identification and interception based on an unmanned aerial vehicle (UAV) system.

[0004] The first aspect of this invention discloses a method for target identification and interception based on an unmanned aerial vehicle (UAV) system. The method includes: Step S1, detecting and identifying an incoming target using a radar airspace detection zone model, wherein the detection and identification conditions include: the incoming target is within the radar detection range; the incoming target is within the azimuth angle of a radar sector; and the incoming target is within the elevation angle of a radar sector; Step S2, when the radar airspace detection zone model determines that the incoming target is located within the detection zone through the detection and identification, interpolating the altitude segments of the incoming target using an UAV system kill zone model to obtain the kill zone range; Step S3, when the UAV system kill zone model determines that the incoming target is located within the kill zone, calculating the interception arc duration, the earliest encounter point of the interception arc, and the latest encounter point of the interception arc using the UAV system interception model, and performing interception based on the interception expectation.

[0005] According to the method of the first aspect of the present invention, the method further includes: step S0, establishing a basic coordinate system and preprocessing the elevation data, coordinate data, and attack route; wherein: a northeast-sky rectangular coordinate system is established as the basic coordinate system, with due east as the X-axis, due north as the Y-axis, and the sky as the Z-axis; the elevation data is taken from the origin of the coordinate system, the horizontal data is data sampled sequentially at 50-meter intervals eastward from the origin of the coordinate system, and the vertical data is data sampled at 50-meter intervals northward from the origin of the coordinate system; when the sampled elevation data is negative, its altitude is set to zero, and the position coordinates are discretized at 50-meter intervals to correspond to the elevation data to obtain the position coordinates and deployment location coordinates under the elevation data, which are used as the coordinate data; for the coordinates of several marker points of the attack route and their relative height to the ground, linear interpolation is performed at 50-meter intervals, and the altitude of the attack route is obtained by adding elevation data.

[0006] According to the method of the first aspect of the present invention, in step S1, the constraint condition of the radar detection far boundary is specifically described as: the UAV system's first The coordinates of the radar are , No. The coordinates of the target are The first Under line-of-sight conditions, the detection area of ​​a radar is a partially spherical region with azimuth, elevation, and radius. When obstacles obstruct the propagation of electromagnetic waves, creating a shielding angle, the radar detection area becomes an irregular partially spherical region. When the radar antenna altitude is 0, the first... The formula for calculating the shielding angle of a radar is:

[0007]

[0008] in, For the first k The altitude of the shelter For the first The radar reached the first k The straight-line distance of the shield, The equivalent radius of the Earth under the influence of Earth's curvature and atmospheric refraction;

[0009] A parallel line-of-sight determination model is established, and the occlusion angle is calculated using the Bresenham-parallel line-of-sight determination model. i The furthest detection range of the radar is R i The first i The radar unit for the first j The furthest detection range of the target is The first i The radar is at an altitude of 100 meters above the ground. H i When considering shading conditions, the first... i The furthest detection range of this radar is:

[0010]

[0011] The first i The radar and the first The distance between the targets satisfies the following equation:

[0012] .

[0013] According to the method of the first aspect of the present invention, in step S1: the first i The antenna normal of the radar is rotated clockwise relative to true north at an angle of _____. The radar sector width angle is Then the azimuth angle of the radar sector satisfies:

[0014] ,

[0015] The first i The lower limit of the sector elevation angle of the radar is The upper limit is Then the elevation angle of the radar sector satisfies:

[0016]

[0017]

[0018] The first Radar for the first The radar airspace detection area model for each target is as follows:

[0019] .

[0020] According to the method of the first aspect of the present invention, in step S2: the vertical kill zone constraint condition is, the first j The location of the incoming target within the vertical kill zone satisfy:

[0021]

[0022] in, From point O, the location of the radar of the UAV system, to the first... j The distance from the incoming target landing on the near-end boundary arc. From point O, the location of the radar of the UAV system, to the first... j The distance from the incoming target landing on the far boundary arc;

[0023] The horizontal kill zone constraint is that, within the horizontal kill zone, the incoming target's trajectory lies within the maximum way angle range:

[0024]

[0025] in, For the first i The radar unit for the first j The clockwise angle between the incoming target and the target For the first i The radar unit for the first j The maximum half-angle of the incoming target;

[0026] The kill zone model of the UAV system, established by the horizontal kill zone and the vertical kill surface, is as follows:

[0027] .

[0028] According to the method of the first aspect of the present invention, in step S2, PCHIP-third-order Hermite interpolation is used for fitting, and the fitting polynomial is:

[0029]

[0030] Among them, the fixed and Two points, and This is the corresponding derivative.

[0031] According to the method of the first aspect of the present invention, in step S3: i The first unmanned aerial vehicle system and the first j The interception arc duration for each incoming target is The earliest encounter time of the intercepting arc is The latest encounter time of the interception arc is The duration of the interception arc can then be expressed as:

[0032]

[0033] The first j The coordinates of the incoming target when it enters the outer boundary of the kill zone are: The time is The time when the far boundary of the kill zone is The moment when leaving the near-boundary of the kill zone is The detection area detected the first j The time of the attacking target is The reaction time of the unmanned aerial vehicle system is ;

[0034] The earliest encounter point of the intercepting arc segment can be determined in two cases:

[0035] Scenario 1: When the starting point of the interception arc of the UAV system is the farthest boundary of the kill zone, the flight time of the intercepted object to reach the far boundary of the kill zone does not exceed the time it takes for the incoming target to reach the far boundary of the kill zone; the first... j The first incoming target i The distance between the drone systems is The speed of the interceptor is V The time required for the interceptor to enter the far boundary of the kill zone is The time it takes for the incoming target to reach the far boundary of the kill zone is Satisfying the equation The earliest encounter time of the intercepting arc segment is... ;

[0036] Scenario 2: When the earliest encounter point of the interception arc is located within the kill zone, and the flight time of the interceptor to the far boundary of the kill zone exceeds the time it takes for the incoming target to reach the far boundary of the kill zone, the interception is carried out within the kill zone. When the incoming target and the interceptor encounter each other within the kill zone, the distance from the unmanned aerial vehicle system is... The earliest encounter time of the intercepting arc segment is expressed as: ;

[0037] If the incoming target flies to the vicinity of the kill zone before the interceptor reaches the kill zone, the interception fails and there is no earliest encounter point of the interception arc.

[0038] According to the method of the first aspect of the present invention, in step S3, if the latest encounter point of the interception arc is located on the near boundary of the kill zone, then the latest encounter point of the interception arc is the time when the incoming target reaches the near boundary of the kill zone, and has The unmanned aerial vehicle (UAV) system interception model is as follows:

[0039]

[0040] When the interception arc exists, interception is performed within the airspace of the kill zone; when the interception arc does not exist, it indicates that the attacking target has already flown out of the kill zone before the interceptor enters the kill zone, and interception is impossible.

[0041] According to the method of the first aspect of the present invention, in step S3, the first i The weapon base of each unmanned aerial vehicle system is The probability of killing is The expected interception is: The expected interception rate of all drone systems is: The greater the interception expectation of the UAV system, the greater its interception effectiveness.

[0042] In the above method, it is proposed to deploy an unmanned aerial vehicle (UAV) system to carry out defense work with the support of ground-based radar information; establish a radar airspace detection zone model, an UAV system kill zone model, and an UAV system interception model required in the physical interception process; and determine the maximum interception expectation of the UAV system for a given attack route based on whether the effective interception conditions are met, thereby achieving effective interception. Attached Figure Description

[0043] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the northeast-central rectangular coordinate system according to an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of elevation and site coordinate preprocessing according to an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of linear interpolation preprocessing for the attack route according to an embodiment of the present invention;

[0047] Figure 4 This is a schematic diagram illustrating the effect of the shielding angle on the target detection range of the radar according to an embodiment of the present invention;

[0048] Figure 5 This is a schematic diagram of a parallel visibility judgment model according to an embodiment of the present invention;

[0049] Figure 6 This is a schematic diagram illustrating the principle of the Bresenham algorithm according to an embodiment of the present invention;

[0050] Figure 7 This is a schematic diagram of the azimuth angle according to an embodiment of the present invention;

[0051] Figure 8 This is a schematic diagram of the spatial shape of the kill zone according to an embodiment of the present invention;

[0052] Figure 9 This is a schematic diagram of the vertical kill zone according to an embodiment of the present invention;

[0053] Figure 10 This is a schematic diagram of the horizontal kill zone according to an embodiment of the present invention;

[0054] Figure 11 This is a schematic diagram of the third-order polynomial interpolation fitting of the far boundary of the power zone of a Type I UAV according to an embodiment of the present invention;

[0055] Figure 12 This is a schematic diagram of the nearest neighbor step interpolation fitting of the far boundary of the power zone of a Type I UAV according to an embodiment of the present invention;

[0056] Figure 13 A schematic diagram of PCHP interpolation fitting for the far boundary of the power zone of a Type I UAV according to an embodiment of the present invention;

[0057] Figure 14 This is a schematic diagram of the detection, launch, and interception arc segments according to an embodiment of the present invention;

[0058] Figure 15 This is a schematic diagram illustrating the effective launch conditions of an unmanned aerial vehicle (UAV) system according to an embodiment of the present invention. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0060] The first aspect of this invention discloses a method for target identification and interception based on an unmanned aerial vehicle (UAV) system. The method includes: Step S1, detecting and identifying an incoming target using a radar airspace detection zone model, wherein the detection and identification conditions include: the incoming target is within the radar detection range; the incoming target is within the azimuth angle of a radar sector; and the incoming target is within the elevation angle of a radar sector; Step S2, when the radar airspace detection zone model determines that the incoming target is located within the detection zone through the detection and identification, interpolating the altitude segments of the incoming target using an UAV system kill zone model to obtain the kill zone range; Step S3, when the UAV system kill zone model determines that the incoming target is located within the kill zone, calculating the interception arc duration, the earliest encounter point of the interception arc, and the latest encounter point of the interception arc using the UAV system interception model, and performing interception based on the interception expectation.

[0061] In a preferred embodiment, the method further includes: step S0, establishing a basic coordinate system and preprocessing the elevation data, coordinate data, and attack route; wherein: a northeast-sky rectangular coordinate system is established as the basic coordinate system, with due east as the X-axis, due north as the Y-axis, and the sky as the Z-axis; the elevation data is taken from the origin of the coordinate system, the horizontal data is data sampled sequentially at 50-meter intervals eastward from the origin of the coordinate system, and the vertical data is data sampled at 50-meter intervals northward from the origin of the coordinate system; when the sampled elevation data is negative, its altitude is set to zero, and the position coordinates are discretized at 50-meter intervals to correspond to the elevation data, so as to obtain the position coordinates and deployment location coordinates under the elevation data, which are used as the coordinate data; for the coordinates of several marker points of the attack route and their relative height to the ground, linear interpolation is performed at 50-meter intervals, and the altitude of the attack route is obtained by adding elevation data.

[0062] In a preferred embodiment, in step S1, the constraint condition of the radar detection far boundary is specifically described as: the UAV system's first... The coordinates of the radar are , No. The coordinates of the target are The first Under line-of-sight conditions, the detection area of ​​a radar is a partially spherical region with azimuth, elevation, and radius. When obstacles obstruct the propagation of electromagnetic waves, creating a shielding angle, the radar detection area becomes an irregular partially spherical region. When the radar antenna altitude is 0, the first... The formula for calculating the shielding angle of a radar is:

[0063]

[0064] in, For the first k The altitude of the shelter For the first The radar reached the first k The straight-line distance of the shield, The equivalent radius of the Earth under the influence of Earth's curvature and atmospheric refraction;

[0065] A parallel line-of-sight determination model is established, and the occlusion angle is calculated using the Bresenham-parallel line-of-sight determination model. i The furthest detection range of the radar is R i The first i The radar unit for the first j The furthest detection range of the target is The height of the i-th radar above the ground is H i When considering shading conditions, the first... i The furthest detection range of this radar is:

[0066]

[0067] The first i The radar and the first The distance between the targets satisfies the following equation:

[0068] .

[0069] In a preferred embodiment, in step S1: the antenna normal direction of the i-th radar rotates clockwise relative to true north by an angle of _____. The radar sector width angle is Then the azimuth angle of the radar sector satisfies:

[0070] ,

[0071] The first i The lower limit of the sector elevation angle of the radar is The upper limit is Then the elevation angle of the radar sector satisfies:

[0072]

[0073]

[0074] The first Radar for the first The radar airspace detection area model for each target is as follows:

[0075] .

[0076] In a preferred embodiment, in step S2: the vertical kill zone constraint condition is, the first... j The location of the incoming target within the vertical kill zone satisfy:

[0077]

[0078] in, From point O, the location of the radar of the UAV system, to the first... j The distance from the incoming target landing on the near-end boundary arc. From point O, the location of the radar of the UAV system, to the first... j The distance from the incoming target landing on the far boundary arc;

[0079] The horizontal kill zone constraint is that, within the horizontal kill zone, the incoming target's trajectory lies within the maximum way angle range:

[0080]

[0081] in, For the first i The radar unit for the first j The clockwise angle between the incoming target and the target For the first i The radar unit for the first j The maximum half-angle of the incoming target;

[0082] The kill zone model of the UAV system, established by the horizontal kill zone and the vertical kill surface, is as follows:

[0083] .

[0084] In a preferred embodiment, in step S2, PCHIP-third-order Hermite interpolation is used for fitting, and the fitting polynomial is:

[0085]

[0086] Among them, the fixed and Two points, and This is the corresponding derivative.

[0087] In a preferred embodiment, in step S3: the first i The first unmanned aerial vehicle system and the first j The interception arc duration for each incoming target is The earliest encounter time of the intercepting arc is The latest encounter time of the interception arc is The duration of the interception arc can then be expressed as:

[0088]

[0089] The first j The coordinates of the incoming target when it enters the outer boundary of the kill zone are: The time is The time when the far boundary of the kill zone is The moment when leaving the near-boundary of the kill zone is The detection area detected the first j The time of the attacking target is The reaction time of the unmanned aerial vehicle system is ;

[0090] The earliest encounter point of the intercepting arc segment can be determined in two cases:

[0091] Scenario 1: When the starting point of the interception arc of the UAV system is the farthest boundary of the kill zone, the flight time of the intercepted object to reach the far boundary of the kill zone does not exceed the time it takes for the incoming target to reach the far boundary of the kill zone; the first... j The first incoming target i The distance between the drone systems is The speed of the interceptor is V The time required for the interceptor to enter the far boundary of the kill zone is The time it takes for the incoming target to reach the far boundary of the kill zone is Satisfying the equation The earliest encounter time of the intercepting arc segment is... ;

[0092] Scenario 2: When the earliest encounter point of the interception arc is located within the kill zone, and the flight time of the interceptor to the far boundary of the kill zone exceeds the time it takes for the incoming target to reach the far boundary of the kill zone, the interception is carried out within the kill zone. When the incoming target and the interceptor encounter each other within the kill zone, the distance from the unmanned aerial vehicle system is... The earliest encounter time of the intercepting arc segment is expressed as: ;

[0093] If the incoming target flies to the vicinity of the kill zone before the interceptor reaches the kill zone, the interception fails and there is no earliest encounter point of the interception arc.

[0094] In a preferred embodiment, in step S3, if the latest encounter point of the interception arc is located near the kill zone boundary, then the latest encounter point of the interception arc is the time when the incoming target reaches the kill zone boundary, and there is... The unmanned aerial vehicle (UAV) system interception model is as follows:

[0095]

[0096] When the interception arc exists, interception is performed within the airspace of the kill zone; when the interception arc does not exist, it indicates that the attacking target has already flown out of the kill zone before the interceptor enters the kill zone, and interception is impossible.

[0097] In a preferred embodiment, in step S3, the weapon base number of the i-th UAV system is... The probability of killing is The expected interception is: The expected interception rate of all drone systems is: The greater the interception expectation of the UAV system, the greater its interception effectiveness.

[0098] Specifically, studying the problem of UAV defense against enemy target attacks is of great significance. To counter attacks from Blue Force targets on its defended targets, the Red Force plans to deploy 12 sets of 5 types of UAV systems to conduct air defense operations with the support of ground-based radar information. Topographical elevation data of the proposed deployment area and relevant information for 100 reserve positions are provided. For each defended target, assuming the Blue Force target attacks from a 90-degree range between due east and due south, a corresponding strategy for the Red Force's UAV system deployment is proposed. First, a radar airspace detection zone model, a UAV system kill zone model, and a UAV system interception model are established for the physical interception process. Based on whether the effective interception conditions are met, the maximum expected interception of the UAV systems on several fixed positions against a given attack route is determined to achieve effective interception.

[0099] Specifically, based on the coordinate system and topographic elevation data, a northeast-sky rectangular coordinate system is established, with due east as the X-axis, due north as the Y-axis, and sky as the Z-axis, as follows: Figure 1 As shown.

[0100] Specifically, elevation and coordinate data preprocessing is performed. Topographic elevation data is taken from the coordinate origin. Lateral data is obtained by sampling eastward from the origin at 50-meter intervals, and longitudinal data is obtained by sampling northward at 50-meter intervals. When the data is negative, the elevation is set to zero. The site coordinates are discretized in 50-meter intervals and mapped to the elevation data to obtain the site coordinates and deployment coordinates under the elevation data. Figure 2 As shown.

[0101] Specifically, the attack route preprocessing involves 20 marker points along the attack route, along with their relative elevations to the ground. To accurately calculate the shielding angle of the position, the marker points are linearly interpolated at 50-meter intervals, and elevation information is added to obtain the altitude of the attack route. Figure 3 As shown.

[0102] I. Radar Airspace Detection Zone Model

[0103] For a guidance radar to detect a cruise missile target, the following conditions must be met: first, the incoming target must be within the radar's detection range; second, the incoming target must be within the radar sector's azimuth angle; and third, the incoming target must be within the radar sector's elevation angle. The establishment of the radar detection area model mainly revolves around these three points.

[0104] 1. Radar detection far-boundary constraints

[0105] Let the unmanned aerial vehicle system be the first The coordinates of the radar are , No. The coordinates of the target are , No. Under line-of-sight conditions, the detection area of ​​a radar is a partially spherical shape with a certain azimuth, elevation, and radius. When there are obstacles or obstructions around the radar, the propagation of electromagnetic waves is blocked, thus reducing the radar's detection range and creating an obstruction angle. In this case, the radar's detection area becomes an irregular partially spherical shape. For example... Figure 4 As shown, when the radar antenna altitude is 0, the first... The formula for calculating the shielding angle of a radar is: ,in For the first k The altitude of the shelter, For the first The radar reached the first k The straight-line distance of the shield, The equivalent radius of the Earth after taking into account the effects of Earth's curvature and atmospheric refraction.

[0106] Considering the incoming target's flight path is a low-altitude penetration along the river valley and the large amount of data (including a 50m×50m grid DEM, 100 alternative positions, and a 6000×6000 base map with different height subdivisions), directly calculating the shielding angle using formulas is computationally too intensive and impractical. Therefore, an optimized algorithm is needed to calculate the shielding angle. The following sections optimize the two calculation steps: visibility assessment and elevation interpolation.

[0107] 1.1 Establishing a parallel line-of-sight judgment model

[0108] Based on matrix elevation data, a parallel data processing approach is adopted to prune the model. A profile is constructed along the elevation judgment line segment and the Z-axis, and this profile is divided into different subsets. Multiple computing nodes of the computer simultaneously read these subsets and concurrently execute the Bresenham line-of-sight analysis algorithm. The elevation angle calculation results are returned to the main thread, which then determines the i-th radar based on the results returned by each process. With the j One goal Line-of-sight status of waypoints. If any subprocess determines that there is no line of sight at the elevation angle, then... and If two points are not mutually visible, they are mutually visible; otherwise, they are mutually visible. A cross-sectional diagram of the parallel visibility judgment model for any two points is shown below. Figure 5 As shown, line segment lie in The projection of the plane into the first quadrant, for and , The equation of the plane projection line is .

[0109]

[0110] First, let's discuss In this situation, when along When the axial direction increases by 1 unit length, that is Then along Increased Each unit. Due to the computer's rasterization processing of the terrain, there are actual errors in the location of the points. , .

[0111] like Figure 6 As shown, at this time ,and In a grid terrain, only one option is possible. or The basis for selection is the Rounding to the nearest whole number, the piecewise function is:

[0112]

[0113] Subdivision The new error generated is set as The expression is: To eliminate floating-point operations, both sides of the error formula are multiplied by . ,make The following relationships exist: .

[0114] 1.2 Solving using the Bresenham-parallel line-of-sight decision model

[0115] No. i Radar and the first j When determining the line of sight between points on a target trajectory, identify the coordinates of the points that need to be judged for general recognition, and connect the two points according to... Each axis is subdivided into 1-unit segments, forming a set of discrete points along the track. Since there is no elevation information for these discrete points, the Bresenham algorithm is used to assign elevation values ​​to each point. Line-of-sight is then determined for this set of discrete points to solve the problem. No. 1 position Dispersion point of the track The situation can be transformed into a solution. , Connection at Points on the projection line segment of the plane right Angle of elevation The elevation angle can be determined from the aforementioned model as follows: ;in, To elevate the radar, Let k be the elevation of the k-th point on the projected line segment. For the elevation of the position, for For the end of the connection The angle of elevation.

[0116] Whether the line of sight is equivalent to discrete points Is it smaller than the end of the connection? . In the function, The function remains constant and monotonically increases within the range of its outermost elevation angle. and Size comparison can be converted to Comparison: Finally, if any point on the line connecting the two points forms an elevation angle with the radar that is greater than the elevation angle at the end of the line, then it is determined that there is no line of sight. In the parallel search, this situation will terminate the program, and pruning will optimize the time complexity.

[0117] Let the first i The furthest detection range of the radar is Ri , No. i Radar for the first j The furthest detection range of the target is , No. i The radar is at an altitude of 100 meters above the ground. H i When considering shading, the first i The maximum detection range of this radar should be:

[0118]

[0119] No. i Radar and the first The distance between the targets satisfies the following equation:

[0120]

[0121] 2. Radar detection azimuth constraints

[0122] Let the first i The antenna normal of the radar is rotated clockwise relative to true north at an angle of _____. The radar sector width angle is .like Figure 7 As shown, the azimuth angle satisfies and .

[0123] 3. Radar detection elevation angle constraints

[0124] The lower limit of the sector elevation angle of the i-th radar is The upper limit is Then the pitch angle satisfies:

[0125]

[0126]

[0127] In summary, constructing the first Radar for the first The radar detection model for each target is as follows:

[0128]

[0129] By solving the model, the first... Radar for the first The radar detection area of ​​a target is defined within which the radar can detect incoming target information and prepare for the next step, such as whether to enter the kill zone and intercept the target.

[0130] II. Kill Zone Model of Unmanned Aerial Vehicle System

[0131] 1. Kill Zone of Unmanned Aerial Vehicle (UAV) System

[0132] The kill zone of an unmanned aerial vehicle (UAV) system is a three-dimensional spatial area within which the probability of the UAV encountering and killing an incoming target is no less than a certain given value. For example... Figure 8 As shown, O is the location of the UAV's radar. A spatial rectangular coordinate system xyz is established, where the Oy axis points parallel to and opposite to the horizontal projection of the incoming target's flight path. The entire kill zone is a three-dimensional area enclosed by the surfaces ABFE, CDMN, ABCD, EFLK, and LKMN.

[0133] 2. Establishment of the kill zone model for unmanned aerial vehicle (UAV) systems

[0134] Projecting the kill zone onto the yOz plane yields its vertical cross-sectional view, as shown below. Figure 9 As shown, the vertical kill zone is a plane bounded by AB, BC, CD, ED, and AE. The maximum altitude of the kill zone refers to its absolute elevation. Minimum kill zone height refers to the height of the incoming target relative to the ground; The maximum elevation angle of the kill zone. BC is defined as the far boundary of the vertical kill zone, and ED as the near boundary of the vertical kill zone.

[0135] 2.1 Vertical kill zone constraints

[0136] No. j The location of the incoming target within the vertical kill zone The following constraints must be met.

[0137]

[0138] in From point O to the 1st j The distance from the incoming target landing on the arc ED. From point O to the 1st j The incoming target landed at the distance of arc BC.

[0139] 2.2 Horizontal kill zone constraints

[0140] As shown in Figure 7, when the height is H0, the kill zone is projected onto the xOy plane to obtain the horizontal kill zone, which is a plane bounded by ML, LK, KN, and NM. For the first i Radar for the first j The clockwise angle between the incoming targets (shown on the diagram). For the first i Radar for the first j The maximum half-angle of the approaching target, where LK is the far boundary of the horizontal kill zone and NM is the near boundary of the horizontal kill zone.

[0141] Within the horizontal kill zone, the incoming target's trajectory must be within the maximum flight angle range, i.e.:

[0142]

[0143] In summary, a kill zone model for the UAV system is established based on the horizontal kill zone and the vertical kill surface:

[0144]

[0145] 3. Kill Zone Interpolation Model for Unmanned Aerial Vehicle Systems

[0146] Given a limited number of values ​​for the furthest boundary points of the UAV kill zone, general interpolation functions may overfit. Using a step function, combined with complex terrain data, will significantly reduce the accuracy of kill zone calculations. If a third-order ordinary polynomial is used for fitting, the curve deviates greatly from the original data, and the limited number of discrete points makes calculation impossible. Figure 11 As shown, the third-order polynomial interpolation fitting of the far boundary of the power zone of the Type I UAV (the cruise missile in the figure is modified to be an incoming target); and as shown... Figure 12 As shown, the nearest neighbor step interpolation fitting of the far boundary of the power zone of Type I UAV (the cruise missile in the figure is changed to the incoming target).

[0147] To reduce the error between the fitted interpolation curve and the actual kill radius of the UAV, PCHIP-third-order Hermite interpolation is used here, and its fitting polynomial is as follows:

[0148]

[0149] Among them, the fixed and Two points, and The corresponding derivative is used for specific iterative calculations in the program. The fitting result matches the actual growth trend, and the final result is as follows: Figure 13 The diagram shown is an interpolation fitting curve of the far boundary of the kill zone of the UAV system, specifically the PCHP interpolation fitting curve of the far boundary of the power zone of the Type I UAV (the cruise missile is replaced with an incoming target in the diagram). Based on the kill zone assessment, the UAV system will initiate an interception operation when the incoming target enters the kill zone.

[0150] III. Unmanned Aerial Vehicle (UAV) System Interception Model

[0151] 1. No slave system interception process

[0152] The interception process of an unmanned aerial vehicle (UAV) system against an incoming target can be divided into three phases: detection, launch, and interception. Detection Phase: In this phase, the target can be detected and tracked by the weapon system's radar, as shown by the green arc in the diagram. This is affected by radar detection capabilities, radar sector, weapon system deployment location, the incoming target's trajectory, and radar cross-section. Launch Phase: When the incoming target is in this phase, the UAV launches an interceptor missile. After flying for a period of time, the interceptor missile can encounter the incoming target within the kill zone, such as... Figure 11 The blue arc represents the interception arc: On this arc, the interceptor missile can encounter the incoming target, but it is also constrained by the detection arc and the launch arc, such as... Figure 14 As shown.

[0153] For an unmanned aerial vehicle (UAV) system to intercept an incoming target, three conditions must be met: ① The incoming target must enter the UAV system's detection zone; ② The incoming target must enter the UAV system's kill zone; ③ After a period of flight, the interceptor missile must be simultaneously within the kill zone of the incoming target, i.e., an interception arc must exist.

[0154] 2. Establishment of Unmanned Aerial Vehicle (UAV) System Interception Model

[0155] Let the interception arc duration between the i-th UAV system and the j-th incoming target be . The earliest encounter time of the intercepting arc is The latest encounter time of the intercepting arc is The duration of the interception arc can then be expressed as .

[0156] 2.1 Earliest encounter point of the intercepting arc

[0157] Let the first j The coordinates of the incoming target when it enters the outer boundary of the kill zone are: The time it takes for it to reach the outer edge of the kill zone is The time when the kill zone reaches its far boundary is The moment when leaving the near-boundary of the kill zone is , For radar i The time of detecting the incoming target j, This refers to the reaction time of the unmanned aerial vehicle (UAV) system.

[0158] The earliest encounter point of the intercepting arc can be divided into two cases.

[0159] Scenario 1: When the radar's detection maximum boundary is large enough, allowing sufficient time for UAV interception, the starting point of the UAV system's interception arc is considered the maximum boundary of the kill zone. In this case, the flight time of the interceptor missile to reach the far boundary of the kill zone is less than or equal to the time it takes for the incoming target to reach the far boundary of the kill zone. Because of the... j The first incoming target iThe distance between two unmanned aerial vehicle systems can be expressed as The interceptor missile's speed is V The time required for the interceptor missile to enter the far boundary of the kill zone can be expressed as: The time it takes for the incoming target to reach the outer edge of the kill zone is Satisfying the equation At this point, the earliest encounter time of the intercepting arc is... .

[0160] Scenario 2: When the time allotted for drone interception is insufficient, the earliest encounter point of the interception arc is located inside the kill zone. In this case, the flight time of the interceptor missile to the far boundary of the kill zone is greater than the time it takes for the incoming target to reach the far boundary of the kill zone. Therefore, the interception occurs inside the kill zone, satisfying the following conditions:

[0161]

[0162] When the incoming target and the interceptor missile encounter each other within the kill zone, the distance to the drone can be expressed as: The earliest encounter time of the intercepting arc can be expressed as: If the interceptor missile has not yet reached the kill zone by the time the incoming target reaches the near boundary, the interception will fail, and there will be no earliest encounter point in the interception arc.

[0163] 2.2 Latest Encounter Point of the Interception Arc

[0164] The latest encounter point of the interception arc is located on the near boundary of the kill zone. Therefore, the latest encounter point of the interception arc is the moment when the incoming target reaches the near boundary of the kill zone. In summary, the unmanned aerial vehicle (UAV) system interception model is as follows:

[0165]

[0166] When an interception arc exists, it can be assumed that interception can be carried out within the kill zone. When no interception arc exists, it can be assumed that the incoming target has already flown out of the kill zone before the interceptor missile enters the kill zone, and interception is impossible.

[0167] 3. Expected Model for Air Defense Deployment to Intercept Incoming Targets

[0168] The effectiveness of each unmanned aerial vehicle (UAV) system in countering incoming targets is primarily determined by factors such as whether launch conditions are met, the kill probability of each UAV system, the number of missiles available, and the missile interception method. The basic process for determining effective launch is as follows: Figure 15As shown. The launch conditions are: the incoming target's flight path and the UAV system's deployment location are known. When the incoming target enters the kill zone within the detection airspace and an interception arc exists, the UAV system meets the launch conditions. Based on this, the success of the UAV system's interception can be measured by the maximum interception expectation. The interception expectation is determined by the kill probability of each UAV system, the number of missiles, the missile interception method, etc. Let the first... i The weapon base of the unmanned aerial vehicle system is The probability of killing is Using the "2-block 1" interception method, the expected interception rate of this system can be expressed as:

[0169]

[0170] The interception expectation of all unmanned aerial vehicle systems in the entire position can be expressed as: The higher the interception expectation of the drone system, the greater the interception effectiveness of the system; conversely, the lower the interception effectiveness, the less effective the system is.

[0171] 4. Interception Model Solving Algorithm

[0172] Step 1: Calculate the detection area. (1) Solve for the shielding angle and set the initial error value. ;Find the next point on the grid ,like , ,otherwise (2) Reading point Calculate the equivalent value of the elevation angle based on the ground elevation. ,like Larger than a line segment Elevation angle of the line If the error is not clear, return "no view"; otherwise, proceed to the next step. (3) Update the error value. ,like ,but ,otherwise Execute step 2 until The end. (To) Situation, exchange and ,consider (4) Based on the detection area model, obtain the detection area of ​​each segment of the incoming target's flight path relative to the first five positions.

[0173] Step 2: When the incoming target is within the detection airspace, the kill zone is calculated using the kill zone interpolation model. Interpolation is performed on the target height segments to obtain the kill zone range. It is then determined whether the incoming flight path has entered the kill zone range, and based on this, a judgment can be made on whether it can be effectively intercepted.

[0174] Step 3: Using the UAV system interception model, calculate the interception arc duration. If there is an interception arc duration, it is considered that an interception zone exists. Solve for the interception expectation. The larger the interception expectation, the better the interception effect.

[0175] In summary, the technical approach proposed in this invention involves deploying an unmanned aerial vehicle (UAV) system to conduct defense operations with the support of ground-based radar information; establishing radar airspace detection zone models, UAV kill zone models, and UAV interception models required for the physical interception process; and determining the maximum interception expectation of the UAV system for a given attack route based on whether the effective interception conditions are met, thereby achieving effective interception.

[0176] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for target identification and interception based on an unmanned aerial vehicle (UAV) system, characterized in that, The method includes: Step S1: Detect and identify incoming targets using a radar airspace detection area model. The conditions for detection and identification include: the incoming target is within the radar detection range; the incoming target is within the azimuth angle of the radar sector; and the incoming target is within the elevation angle of the radar sector. Step S2: When the radar airspace detection area model determines that the incoming target is located within the detection area through the detection and identification, the UAV system kill zone model is used to perform interpolation calculations on the height segments of the incoming target to obtain the kill zone range. Step S3: When the UAV system kill zone model determines that the incoming target is within the kill zone, the UAV system interception model is used to calculate the interception arc duration, the earliest encounter point of the interception arc, and the latest encounter point of the interception arc, and the interception is performed based on the interception expectation. In step S1, the constraint condition for the radar detection far boundary is specifically described as follows: The unmanned aerial vehicle system The coordinates of the radar are , No. The coordinates of the target are The first Under line-of-sight conditions, the detection area of ​​a radar is a partially spherical region with azimuth, elevation, and radius. When obstacles obstruct the propagation of electromagnetic waves, creating a shielding angle, the radar detection area becomes an irregular partially spherical region. When the radar antenna altitude is 0, the first... The formula for calculating the shielding angle of a radar is: in, For the first k The altitude of the shelter For the first The radar reached the first k The straight-line distance of the shield, The equivalent radius of the Earth under the influence of Earth's curvature and atmospheric refraction; A parallel line-of-sight determination model is established, and the occlusion angle is calculated using the Bresenham-parallel line-of-sight determination model. i The furthest detection range of the radar is R i The first i The radar unit for the first j The furthest detection range of the target is The first i The radar is at an altitude of 100 meters above the ground. H i When considering shading conditions, the first... i The furthest detection range of this radar is: The first i The radar and the first The distance between the targets satisfies the following equation: 。 2. The method for target identification and interception based on an unmanned aerial vehicle (UAV) system according to claim 1, characterized in that, The method further includes: step S0, establishing a basic coordinate system and preprocessing the elevation data, coordinate data, and attack route; wherein: A rectangular coordinate system with the northeast and central axes is established as the basic coordinate system, with due east as the X-axis, due north as the Y-axis, and the sky as the Z-axis. The elevation data is taken from the origin of the coordinate system. The horizontal data is obtained by sampling data at 50-meter intervals eastward from the origin of the coordinate system, and the vertical data is obtained by sampling data at 50-meter intervals northward from the origin of the coordinate system. When the sampled elevation data is negative, its altitude is set to zero, and the position coordinates are discretized to the elevation data at 50-meter intervals to obtain the position coordinates and deployment location coordinates under the elevation data, which are used as the coordinate data. For the coordinates of several marked points along the attack route and their relative height to the ground, linear interpolation is performed at 50-meter intervals, and the altitude of the attack route is obtained by adding elevation data.

3. The method for target identification and interception based on an unmanned aerial vehicle (UAV) system according to claim 2, characterized in that, In step S1: The first i The antenna normal of the radar is rotated clockwise relative to true north at an angle of _____. The radar sector width angle is Then the azimuth angle of the radar sector satisfies: ， The first i The lower limit of the sector elevation angle of the radar is The upper limit is Then the elevation angle of the radar sector satisfies: The first Radar for the first The radar airspace detection area model for each target is as follows: 。 4. The method for target identification and interception based on an unmanned aerial vehicle (UAV) system according to claim 3, characterized in that, In step S2: The vertical kill zone constraint is, the first j The location of the incoming target within the vertical kill zone satisfy: in, From point O, the location of the radar of the UAV system, to the first... j The distance from the incoming target landing on the near-end boundary arc. From point O, the location of the radar of the UAV system, to the first... j The distance from the incoming target landing on the far boundary arc; The horizontal kill zone constraint is that, within the horizontal kill zone, the incoming target's trajectory lies within the maximum way angle range: in, For the first i The radar unit for the first j The clockwise angle between the incoming target and the target For the first i The radar unit for the first j The maximum half-angle of the incoming target; The kill zone model of the UAV system, established by the horizontal kill zone and the vertical kill zone, is as follows: 。 5. The method for target identification and interception based on an unmanned aerial vehicle (UAV) system according to claim 4, characterized in that, In step S2, PCHIP-third-order Hermite interpolation is used for fitting, and the fitting polynomial is: Among them, the fixed and Two points, and This is the corresponding derivative.

6. The method for target identification and interception based on an unmanned aerial vehicle (UAV) system according to claim 5, characterized in that, In step S3, the first i The weapon base of each unmanned aerial vehicle system is The probability of killing is The expected interception is: , The expected interception rate for all drone systems is: , The greater the interception expectation of the drone system, the greater its interception effectiveness.

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