Multi-level track rapid search method based on target detection radar
Through the multi-stage track fast search method, the track determination is determined using linear frequency modulation radar and neighborhood conditions, which solves the problem of difficulty in establishing tracks in complex environments, and realizes accurate estimation and real-time processing of the end of the projectile.
Patent Information
- Application Number
- CN202510475140.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2025-07-11
AI Technical Summary
In the complex physical and electromagnetic environment, the existing target detection radar is difficult to establish a complete route at the end of the projectile in a track start and tracking algorithm, resulting in inaccurate estimation of landing parameters and false alarm missed detection.
A multi-stage track fast search method is used to set the projectile landing point space coordinates, velocity vectors and the initial range of the arrival time, and perform uniform step division. Combined with the linear frequency modulation pulse radar measurement points, the track is determined using Euclidean norms and neighborhood conditions, and gradually refine the search, and finally output the target track parameters.
It realizes accurate estimation of projectile terminal tracks in complex environments, avoids short-term data loss and interference effects, has second-level processing cycle and high robustness, and is suitable for most target detection radar systems.
Smart Images
Figure CN120294739A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of target detection radar, and particularly relates to a multi-level track fast search method based on a target detection radar, which can be used for estimating the track parameters and impact points at the end of various missiles and shells. Background Art
[0002] In the live ammunition drills and test appraisal tasks of the troops, it is necessary to detect and report the impact points and miss situations of the projectiles to complete the review and analysis of the tasks. Radar has good environmental adaptability in such tasks and is basically not affected by explosion smoke, fire, weather, etc. It is an irreplaceable mainstream target detection equipment.
[0003] Existing radar target detection measurement systems include two types: scalar and vector. Among them, the vector miss distance measurement system can measure the flight trajectory and miss vector of the projectile by detecting echo points, building tracks, and tracking the end track of the projectile. By using coordinate transformation, the distance from any point on the target to the projectile can be examined, so as to better estimate the killing effect of the projectile and accurately identify the performance of the weapon system. Therefore, vector miss distance measurement is the mainstream development direction of target detection radar.
[0004] In practical applications, target detection equipment will inevitably be affected by hull occlusion, ground clutter, sea clutter, electromagnetic environment interference, etc., resulting in a decline in radar detection ability and the generation of false alarms or missed detections. This is because the existing track initiation and tracking algorithms judge whether to start sailing through a limited number of frames of data in the data processing stage, and perform filtering and estimation with the subsequent continuous input data. The time for judging whether the tracks are associated is short, usually only in the order of dozens of milliseconds. When there are consecutive frames of target losses or excessive clutter echo points, the existing track processing algorithms are difficult to establish a complete end route of the projectile, affecting the accuracy of the final target reporting. Summary of the Invention
[0005] The purpose of the present invention is to provide a multi-level track fast search method based on a target detection radar for the technical problems existing in the target detection radar in a complex physical and electromagnetic environment, and perform multi-level fast search on all possible track routes at the end of the projectile, which can effectively solve the technical problems of incomplete echo points at the end of the projectile, difficult establishment of the end track by the existing technical methods under interference, and inaccurate estimation of the impact point parameters.
[0006] The technical problems proposed by the present invention are solved as follows:
[0007] A multi-level track fast search method based on a target detection radar includes the following steps:
[0008] Set the initial ranges of the spatial coordinates of the projectile impact point, the velocity vector at the projectile's end, and the time when the projectile reaches the impact point respectively, and perform uniform step division to obtain the initial value sets of the spatial coordinates of the projectile impact point, the velocity vector at the projectile's end, and the time when the projectile reaches the impact point;
[0009] Step 1: Combine the elements in the value sets of the spatial coordinates of the projectile impact point, the velocity vector at the projectile's end, and the time when the projectile reaches the impact point to obtain all possible value sets of the straight-line trajectory at the projectile's end; all elements in the all possible value sets of the straight-line trajectory at the projectile's end are assumed straight-line trajectories at the projectile's end; denote the straight-line trajectory at the projectile's end as z = [r T , u T , t] T , where r = [r X , r Y , r Z T represents the spatial coordinates of the projectile impact point, r X , r Y and r Z represent the spatial coordinates of the projectile impact point in the x, y, and z directions respectively, and the superscript T represents the transpose, represents the velocity vector at the projectile's end, u, and θ represent the modulus, azimuth angle, and elevation angle of the velocity at the projectile's end respectively, and t is the time when the projectile reaches the impact point;
[0010] Under the assumption of the straight-line trajectory z at the projectile's end, the spatial coordinates p(n|z) of the projectile at time t n are expressed as:
[0011] p(n|z) = r + (t n - t)v
[0012] where v = [v X , v Y , v Z T , v X , v Y and v Z represent the components of the velocity at the projectile's end in the x, y, and z directions respectively;
[0013] Step 2: Denote the measured coordinate of the projectile detected by the linear frequency modulation pulse radar at time t n as p(n) = [x n , y n , z n T , x n , y n and z n are x n The coordinate values of the measurement points of the projectile in the x, y, and z directions at a certain moment;
[0014] Under the assumption of the trajectory z, the actual space coordinate q(n) of the projectile is calculated as:
[0015]
[0016] where f is the carrier frequency, K is the linear frequency modulation slope, and |||| represents the Euclidean norm;
[0017] Step 3: Denote the azimuth angle and elevation angle of the actual space coordinate q(n) of the projectile relative to the space coordinate r of the projectile landing point as and θ0 respectively; if the following conditions are simultaneously satisfied:
[0018]
[0019] where, and Δθ are the azimuth search neighborhood size and elevation search neighborhood size respectively, then it is determined that q(n) and p(n|z) are in the same angle search unit;
[0020] Step 4: Denote the distances between the actual space coordinate q(n) of the projectile and the space coordinate p(n|z) of the projectile at time t n relative to the space coordinate r of the projectile landing point as r0 and r respectively. If the following conditions are satisfied:
[0021] |r - r0| ≤ max{|t n - t|Δv, vΔt}
[0022] where Δv and Δt are the velocity search interval and the landing point time search interval respectively, then it is determined that q(n) and p(n|z) are in the same distance search unit, max represents taking the maximum value, and || represents taking the absolute value;
[0023] Step 5: When the actual space coordinate q(n) of the projectile and the space coordinate p(n|z) of the projectile at time t n are in the same angle search unit and distance search unit, it can be determined that the coordinate p(n) of the corresponding projectile coordinate measurement point is on the straight line trajectory z at the end of the projectile; during the processing period from detecting the projectile to the projectile landing, count the number of the coordinate p(n) of the projectile coordinate measurement point on the straight line trajectory z at the end of the projectile, denoted as M(z);
[0024] Step 6: For all possible value sets {z k} of the straight line trajectory at the end of the projectile, k = 1, 2,..., K, where K is the total number of the straight line trajectories at the end of the projectile, and z k is the k-th straight line trajectory at the end of the projectile, perform Steps 1 to 5 for search traversal, and take all M(z k)>The straight-line trajectory z at the end of the projectile of M0 k is the detected target trajectory, where M0 is the set threshold of the number of point traces;
[0025] Step 7: Conduct a finer uniform division within the stepping range to which the detected target trajectory belongs, update the set of values of the projectile landing point space coordinates, the projectile end velocity, and the moment when the projectile reaches the landing point, and execute Steps 1 to 6 to find more accurate target trajectory parameters;
[0026] Step 8: Repeat Steps 1 to 7, and stop the loop when the accuracy of the target trajectory parameters meets the set requirements, and output the final target trajectory parameters.
[0027] The beneficial effects of the present invention are:
[0028] (1) The processing period of the method of the present invention can be flexibly selected, and the maximum reaches the second level, which can effectively avoid the problems of broken track and inaccurate parameter estimation caused by the loss of target data in a short time for the existing algorithms, and has high robustness and anti-interference ability;
[0029] (2) The search space of the trajectory parameters of the method of the present invention can be divided into multiple levels from coarse to fine, and only the neighborhood of the trajectory parameters of the detected target is searched more finely, effectively solving the problems of excessive computational resource requirements and long computational time caused by a large parameter search space;
[0030] (3) The method of the present invention performs data processing at the radar backend without additional modification to the front end of the radar system, and the algorithm has wide applicability and can be widely used in most target detection radars. Description of the Drawings
[0031] Figure 1 is a schematic flow chart of the method of the present invention;
[0032] Figure 2 is a graph of the trajectory search result of the method of the embodiment under clutter interference conditions, where (a) is a three-dimensional graph, (b) is a top view, (c) is a side view of the x-y plane, and (d) is a side view of the y-z plane;
[0033] Figure 3 is a graph of the trajectory search result of the method of the embodiment under the condition of missing point traces, (a) is a three-dimensional graph, (b) is a top view, (c) is a side view of the x-y plane, and (d) is a side view of the y-z plane. Detailed Embodiment
[0034] The present invention will be further described below in conjunction with the drawings and embodiments.
[0035] This embodiment provides a multi-level trajectory fast search method based on a target detection radar, and its schematic flow chart is as Figure 1As shown in the figure, it includes the following steps:
[0036] Set the initial ranges of the projectile landing point spatial coordinates, the projectile's terminal velocity vector, and the time when the projectile reaches the landing point respectively, and perform uniform step division to obtain the initial value sets of the projectile landing point spatial coordinates, the projectile's terminal velocity vector, and the time when the projectile reaches the landing point;
[0037] Step 1: Combine the elements in the value sets of the projectile landing point spatial coordinates, the projectile's terminal velocity vector, and the time when the projectile reaches the landing point to obtain all possible value sets of the projectile's terminal straight-line trajectory; the elements in all possible value sets of the projectile's terminal straight-line trajectory are assumed projectile terminal straight-line trajectories; denote the projectile's terminal straight-line trajectory as z = [r T , u T , t] T , where r = [r X , r Y , r Z T represents the projectile landing point spatial coordinates, r X , r Y , and r Z respectively represent the spatial coordinates of the projectile landing point in the x, y, and z directions, and the superscript T represents the transpose, represents the projectile's terminal velocity vector, u, , and θ respectively represent the modulus, azimuth angle, and pitch angle of the projectile's terminal velocity, and t is the time when the projectile reaches the landing point;
[0038] Under the assumption of the projectile's terminal straight-line trajectory z, the projectile spatial coordinate p(n|z) at time t n is expressed as:
[0039] p(n|z) = r + (t n - t)v
[0040] where v = [v X , v Y , v Z T , v X , v Y , and v Z respectively represent the components of the projectile's terminal velocity in the x, y, and z directions;
[0041] Step 2: Denote the coordinate measurement point coordinates of the projectile detected by the linear frequency modulation pulse radar at time t n as p(n) = [x n , y n , z n T , x n , y n , and z n are respectively at tn The coordinate values of the measurement points of the projectile in the x, y, and z directions at a certain moment;
[0042] Under the assumption of the track z, the actual space coordinates q(n) of the projectile are calculated as:
[0043]
[0044] where f is the carrier frequency, K is the linear frequency modulation slope, and |||| represents the Euclidean norm.
[0045] Step 3: Denote the azimuth angle and elevation angle of the actual space coordinates q(n) of the projectile relative to the space coordinates r of the projectile landing point as and θ0 respectively. Set the azimuth search neighborhood size and elevation search neighborhood size as and Δθ (the value is set according to the minimum interval between any two velocity vectors u in the azimuth and elevation directions in the set of possible values). If the following conditions are simultaneously satisfied:
[0046]
[0047] Then it is determined that q(n) and p(n|z) are in the same angle search unit.
[0048] Step 4: Denote the distances of the actual space coordinates q(n) of the projectile and the space coordinates p(n|z) of the projectile at time t n relative to the space coordinates r of the projectile landing point as r0 and r respectively. Set the velocity search interval as Δv (the value is set according to the minimum interval of the modulus values of any two velocity vectors u in the set of possible values), and set the landing time search interval as Δt (the value is set according to the minimum interval between any two landing times t in the set of possible values). If the following conditions are satisfied:
[0049] |r - r0| ≤ max{|t n - t|Δv, vΔt}
[0050] Then it is determined that q(n) and p(n|z) are in the same distance search unit, max represents taking the maximum value, and || represents taking the absolute value.
[0051] Step 5: When the actual space coordinates q(n) of the projectile and the space coordinates p(n|z) of the projectile at time t n are in the same angle search unit and distance search unit, it can be determined that the corresponding coordinate p(n) of the projectile measurement point is on the straight-line track z at the end of the projectile; within the processing period from detecting the projectile to the projectile landing, count the number of the coordinate p(n) of the projectile measurement point on the straight-line track z at the end of the projectile, denoted as M(z).
[0052] Step 6: For all possible value sets {z k} of the straight-line trajectory at the end of the projectile, where k = 1, 2, …, K and K is the total number of straight-line trajectories at the end of the projectile, and z k is the seventh straight-line trajectory at the end of the projectile, perform Steps 1 to 5 for search and traversal, and select all straight-line trajectories z k of the projectile at the end that satisfy M(z k ) > M0 as the detected target trajectories, where M0 is the set point-trace quantity threshold.
[0053] Step 7: Conduct a finer uniform division within the stepping range to which the detected target trajectory belongs, update the value sets of the spatial coordinates of the projectile landing point, the velocity at the end of the projectile, and the time when the projectile reaches the landing point, and execute Steps 1 to 6 to find more accurate target trajectory parameters;
[0054] Step 8: Repeat Steps 1 to 7, and stop the loop when the accuracy of the target trajectory parameters meets the set requirements, and output the final target trajectory parameters.
[0055] Set the parameter search range in the trajectory z as -1000m ≤ r X , r Y ≤ 1000m, -50m ≤ r Z ≤ 50m, 100m / s ≤ v ≤ 300m / s, -90° ≤ θ < 0°, 0 ≤ t ≤ 2s; the first-level parameter search intervals in each range are 500m, 25m, 50m / s, 90°, 22.5°, 0.5s respectively, the second-level parameter search intervals are 100m, 5m, 10m / s, 18°, 4.5°, 0.1s respectively, the third-level parameter search intervals are 20m, 1m, 2m / s, 3.6°, 0.9°, 0.02s respectively, and the point-trace threshold number is taken as 20.
[0056] Perform three-level trajectory search on the simulated input measurement point-traces within 2s of the two landings according to the above parameters, and the obtained results are shown in Figure 2 and Figure 3 respectively. Figure 2 is the trajectory search result diagram of the method described in the embodiment under clutter interference conditions, where (a) is a three-dimensional diagram, (b) is a top view, (c) is a side view of the x-y plane, and (d) is a side view of the y-z plane. Figure 3 is the trajectory search result diagram of the method described in the embodiment under the condition of missing point-traces, where (a) is a three-dimensional diagram, (b) is a top view, (c) is a side view of the x-y plane, and (d) is a side view of the y-z plane.
[0057] Among them, Figure 2 shows that the blue point-traces contain a large number of interfering point-traces generated by explosion fragments, Figure 3The blue dots show the missing dots caused by occlusion, and the red dots are the dot sequences reconstructed by the method described in this embodiment after the track parameters are searched. It can be seen that the method proposed by the present invention can accurately estimate the projectile track parameters in both cases, and can effectively reduce the influence of interference and missing dots on the track parameter estimation. The running time of the method described in the present invention on a general notebook computer platform for these two processing cycles is less than 2 s, which meets the requirements of continuous real-time operation and has good engineering application value.
[0058] In summary, from the processing results, the method provided by the present invention has practical value.
Claims
1. A multi-level track fast search method based on a target detection radar, characterized in that, Including the following steps: Respectively set the initial ranges of the projectile landing point space coordinates, the projectile terminal velocity vector, and the time when the projectile reaches the landing point, and perform uniform step division to obtain the initial value sets of the projectile landing point space coordinates, the projectile terminal velocity vector, and the time when the projectile reaches the landing point; Step 1: Combine the elements in the value sets of the spatial coordinates of the projectile impact point, the velocity vector at the projectile's end, and the time when the projectile reaches the impact point to obtain all possible value sets of the straight-line trajectory at the projectile's end; the elements in all possible value sets of the straight-line trajectory at the projectile's end are assumed straight-line trajectories at the projectile's end; denote the straight-line trajectory at the projectile's end as z = [r T , u T , t] T , where r = [r X , r Y , r Z T represents the spatial coordinates of the projectile impact point, r X , r Y and r Z respectively represent the spatial coordinates of the projectile impact point in the x, y, and z directions, the superscript T represents the transpose, represents the velocity vector at the projectile's end, v, and θ respectively represent the modulus, azimuth angle, and elevation angle of the velocity at the projectile's end, and t is the time when the projectile reaches the impact point; t n The spatial coordinates p(n|z) of the projectile at a given time are expressed as: p(n|z) = r+(t n -t)v where v = [v X , v Y , v Z T , v X , v Y and v Z represent the components of the velocity at the end of the projectile in the x, y, and z directions, respectively; Step 2: Denote the coordinates of the projectile coordinate measurement point detected by the chirp radar at time t n as p(n) = [x n , y n , z n T , where x n , y n and z n are the coordinate values of the measurement points of the projectile in the x, y, and z directions at time t n respectively; calculate the actual spatial coordinates q(n) of the projectile; Step 3: Determine whether the actual spatial coordinates q(n) of the projectile and the spatial coordinates p(n|z) of the projectile at time t are within the same angular search unit; n Step 4: Determine whether the actual spatial coordinates q(n) of the projectile and the spatial coordinates p(n|z) of the projectile at time t are within the same distance search unit; n Step 5: When the actual spatial coordinate q(n) of the projectile and the spatial coordinate p(n|z) of the projectile at time t are in the same angular search unit and distance search unit, it is determined that the coordinate p(n) of the corresponding projectile coordinate measurement point is on the straight-line track z at the end of the projectile; within the processing period from the detection of the projectile to its landing, count the number of coordinates p(n) of the projectile coordinate measurement points on the straight-line track z at the end of the projectile, denoted as M(z); n When the actual spatial coordinate q(n) of the projectile and the spatial coordinate p(n|z) of the projectile at time t are in the same angular search unit and distance search unit, it is determined that the coordinate p(n) of the corresponding projectile coordinate measurement point is on the straight-line track z at the end of the projectile; within the processing period from the detection of the projectile to its landing, count the number of coordinates p(n) of the projectile coordinate measurement points on the straight-line track z at the end of the projectile, denoted as M(z); Step 6: For all possible value sets {z of the straight-line trajectory at the end of the projectile k}, where k = 1, 2, …, K and K is the total number of straight-line trajectories at the end of the projectile, and z k is the seventh straight-line trajectory at the end of the projectile, perform Steps 1 to 5 for search and traversal, and select all straight-line trajectories z k at the end of the projectile that satisfy M(z k ) > M0 as the detected target trajectories, where M0 is the set threshold of the number of point traces; Step 7: Perform a finer uniform division within the step range to which the detected target trajectory belongs, update the value sets of the projectile landing point space coordinates, the projectile terminal velocity, and the time when the projectile reaches the landing point, execute Steps 1 to 6, and find more accurate target trajectory parameters; Step 8: Repeat Steps 1 to 7, stop the loop when the accuracy of the target trajectory parameters meets the set requirements, and output the final target trajectory parameters.
2. The multi-level track fast search method based on a target detection radar according to claim 1, wherein In Step 2, the actual space coordinate q(n) of the projectile is calculated as: where f is the carrier frequency, K is the linear frequency modulation slope, and |||| represents the Euclidean norm.
3. The multi-level track fast search method based on a target detection radar according to claim 1, wherein, The specific process of Step 3 is: Let the azimuth angle and elevation angle of the actual space coordinate q(n) of the projectile relative to the space coordinate r of the projectile impact point be and θ0 respectively; if the following conditions are simultaneously satisfied: wherein, and Δθ are the azimuth search neighborhood size and the elevation search neighborhood size respectively, then it is determined that q(n) and p(n|z) are in the same angular search unit.
4. The multi-level track fast search method based on a target detection radar according to claim 1, wherein, The specific process of Step 4 is: Record the actual spatial coordinates q(n) and t of the projectile n The distances between the spatial coordinates p(n|z) of the projectile at time t and the spatial coordinates r of the projectile's landing point are r0 and r respectively. If the following conditions are met: |r - r0| ≤ max{|t n - t|Δv, vΔt} where Δv and Δt are the velocity search interval and the landing point time search interval respectively, then it is determined that q(n) and p(n|z) are in the same distance search unit, max represents taking the maximum value, and || represents taking the absolute value.