A multi-target recognition method based on real-time data analysis

Abstract

The application provides a multi-target identification method based on real-time data analysis. In some flight test tasks, there are several flight targets flying simultaneously in the air, and there are many measurement devices on the ground simultaneously tracking and measuring the flight targets. The task of some precise measurement devices only needs to capture, track and measure one flight target. Since the multiple flight targets have intersection in time and space, the precise measurement devices inevitably have identification and tracking confusion. The reasons for the identification confusion of the flight targets tracked and locked by the measurement devices under the background of multi-target flight are discussed. The internal relationship between the data of the same target obtained by the measurement devices is discussed by using mathematical methods. The process of the spatial coordinates of the flight target changing with time is further revealed, and the properties of the trajectory, data continuity and smooth curve are established. A mathematical model for the measurement devices to avoid identification confusion of the flight targets in a short time is established.

Description

Technical Field

[0001] This invention relates to the field of multi-target recognition technology, and more specifically, to a multi-target recognition method based on real-time data analysis. Background Technology

[0002] In some flight test missions, multiple aerial targets often fly simultaneously, and ground-based measurement equipment tracks and measures these targets in real time. If the targets are concentrated in the same area, their position coordinates change in real time, and their flight angles and altitudes are similar, which may cause the measurement equipment to misidentify and track them. This phenomenon has been encountered multiple times in test missions, seriously interfering with the accuracy of measurement data and directly affecting real-time track display and subsequent data processing. Therefore, we propose an improvement to this problem, namely a multi-target identification method based on real-time data analysis. Summary of the Invention

[0003] The purpose of this invention is to address the problems raised in the existing background technology. To achieve the above-mentioned objective, this invention provides the following technical solution: a multi-target identification method based on real-time data analysis, wherein the measuring device is set to detect targets up to the current time t. n It has received n consecutive measurements (t1,x1,y1,z1), (t2,x2,y2,z2), ..., (t...) of its stable, tracked flight target. n ,x n ,y n ,z n ), the next moment t n+1 The received measurement value is (t) n+1 ,x n+1 ,y n+1 ,z n+1 If a t is fitted based on several known points... n+1 Point of time Then you can consider using t n+1 The difference between the measured value and the fitted value at a given time is used to determine whether the measured value is the flight target that the measuring device has been tracking. The mathematical formula used for this determination can be described as the form of equation (1):

[0004]

[0005] In the formula, v n For t n The speed of the flying target at any given time, α is a manually set weight constant used to control the size of the ratio; if the value of α is appropriately set, if equation (1) holds, it is considered to be data from the same flying target; if equation (1) does not hold, it is considered not to be data from the same flying target, and the fitted value is... As a guide for the measuring device to recapture the target data.

[0006] As a preferred technical solution of the present invention, the above analysis is based on a three-dimensional coordinate system. Direct application to actual calculations is complex; therefore, the three-dimensional problem can be first transformed into a two-dimensional problem. Time t is a variable describing the motion and change of things. Introducing t as an independent variable, and considering the three coordinate variables in the three-dimensional spatial coordinate system as functions of time t, the three-dimensional coordinate variables... It is decomposed into 3 two-dimensional coordinate variables The function can be expressed as equation (2);

[0007] x = f x (t), y = f y (t), z=f z (t) (2)

[0008] Based on the known measurement data, the corresponding approximate function, i.e. the fitting function, can be obtained. The function can be expressed as equation (3).

[0009]

[0010] With x = f x Taking (t) as an example, when t = t n+1 hour, Therefore t n+1 The difference between the measured value and the fitted value in the x-direction can be expressed as equation (4);

[0011]

[0012] Similarly, find t n+1 The component differences Δy and Δz in the y and z directions at time t are used to obtain the measurement equipment's speed at time t. n+1 The formula for determining whether the measurement data at any given time is the target being tracked is (5);

[0013]

[0014] As a preferred technical solution of the present invention, a fitting function for the flight target is obtained through known measurement data, and t is obtained based on the fitting function. n+1 A fitting point at time Measuring equipment at t n+1 The flight target position point acquired at each moment is P(x) n+1 ,y n+1 ,z n+1 The distance between P and Q is d; if P is within a circle centered at Q, α·v n (t n+1 -t nIf the target is within a sphere with radius P, then the judgment point P is the coordinate value of the flight target originally tracked by the measuring equipment; otherwise, the judgment point P is an outlier point, such as... Figure 3 The midpoint P' has already exceeded the boundaries of the sphere. At this point, As guiding data for measuring equipment.

[0015] As a preferred technical solution of the present invention, it includes a method for finding the fitting function, specifically including two methods: Lagrange interpolation and Hermite interpolation. The former is simpler to calculate but has lower accuracy, while the latter has a more complex calculation process but higher accuracy. The function f is then solved. x Fitting function of (t) For the purpose of analysis.

[0016] As a preferred technical solution of the present invention, the Lagrange interpolation is known and the current time t is known. n Three consecutive points (t) within and adjacent to each other. n-2 ,x n-2 ), (t n-1 ,x n-1 ), (t n ,x n Then you can get

[0017]

[0018] in,

[0019]

[0020]

[0021]

[0022] If the data acquisition period of the measuring device is T, then the above calculation of the time difference can be simplified to:

[0023]

[0024] As a preferred technical solution of the present invention, Hermite interpolation is used to solve the function H using the Hermite interpolation method. x (t), due to the habit of description, will Noted as H x (t), taken from the current time t n Three consecutive points (t) that are adjacent to each other. n-2 ,x n-2 ), (t n-1 ,x n-1 ), (t n ,x nFor the sake of brevity and convenience, they are respectively denoted as (t) -1 ,x -1 Given (t0, x0) and (t1, x1), then H x (t) can be expressed as a cubic Hermite interpolation polynomial of equation (8);

[0025]

[0026] in,

[0027]

[0028]

[0029]

[0030]

[0031] It should be noted that Δt0 and Δt1 represent the time difference between two adjacent data nodes. If the working cycle of the measuring device is T, then Δt i It is an integer multiple of T, see equation (7); It is the speed of the flying target, v i The projection onto the plane xot The size is Δt during this time period. i The average speed within the time interval is chosen because the time interval is very short, and the flight speed is relatively stable after the aircraft takes off and enters the predetermined path. Replace the function derivative value at the node

[0032] As a preferred technical solution of this invention, a computer-based algorithm for Hermite interpolation is used. During the actual flight of an aircraft, time is a continuously increasing quantity. To simplify the calculation process and considering the short time required for each interpolation calculation, relative time can be used for calculation, with the relative time redefined after each calculation. In each calculation, the time of the first node is set to 0, and the times of the second and third nodes are the sum of the time intervals between two data points, i.e., integer numbers of device cycles. This time interval can be calculated separately from two consecutive received data frames. This can be expressed mathematically as follows: considering a four-dimensional coordinate point (x...) in space... i ,y i ,z i ,t i In each calculation, the three consecutive interpolation nodes can take the following values: (x －1 ,y －1 ,z －1,0), (x0,y0,z0,mT), (x1,y1,z1,mT+nT), where m and n are integers, and T represents the equipment cycle; t i The value of is the number of device cycles between two data frames, i.e., t0 = mT, t1 = mT + nT.

[0033] As a preferred technical solution of the present invention, let the next measurement coordinate point received by the measuring device at time t1, which needs to be determined whether it is the tracking target, be (x c ,y c ,z c ,t c ), and its corresponding extrapolation point is (x * ,y * ,z * ,t c ), then t c =kT (k is an integer), the algorithm can be simply described as follows: Set α, and the program performs necessary initialization.

[0034] 1. Input (t) i ,x i (i = -1, 0, 1), x c / / Coordinate system XOT

[0035] (1) Place

[0036]

[0037]

[0038]

[0039]

[0040] (2)

[0041] (3)

[0042] 2. Input (t) i ,y i (i = -1, 0, 1), y c / / Coordinate system YOT

[0043] (1) Place

[0044] Calculate h0, h1, H0, and H1 based on 1-(1).

[0045] (2)

[0046] (3)

[0047] 3. Input (t) i ,z i (i = -1, 0, 1), z c / / Coordinate system ZOT

[0048] (1) Place

[0049] Calculate h0, h1, H0, and H1 based on 1-(1).

[0050] (2)

[0051] (3)

[0052] Determine the size of d and M.

[0053] Compared with existing technologies, the beneficial effects of this invention are as follows: In the solution of this invention, by analyzing the inherent logical relationships of the measurement data and identifying the functional relationships between various parameters from a mathematical perspective, a mathematical model is established to determine whether target identification is erroneous through data analysis and processing, based on the possible reasons why measurement equipment may mistrack flight targets in multi-target flight tests. This method has a high degree of consistency between the data processing and the real flight target in a short period of time, and is highly targeted and practical. However, as the interval time increases, the accuracy of the fitting points decreases rapidly. At this point, external guidance can be considered for discrimination and identification. Attached Figure Description

[0054] Figure 1 This is a schematic diagram illustrating the identification and tracking errors of the measuring device provided by the present invention.

[0055] Figure 2 This invention provides a schematic diagram illustrating the relationship between the target trajectory and measurement data.

[0056] Figure 3 This invention provides a schematic diagram of the data used to identify mistracking.

[0057] Figure 4 A schematic diagram illustrating the velocity change of the target provided by this invention;

[0058] Figure 5 The diagram illustrates the interval time and derivative provided by this 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.

[0060] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0061] Example 1: Please refer to Figure 1-5 This is a multi-target identification method based on real-time data analysis. The flight trajectory of a flying target is a continuous, smooth curve, and the spatial coordinates of the flying target measured by the measuring equipment are points periodically collected along this curve. Conversely, the line connecting the set of measurement values ​​of the flying target approximates a continuous, smooth curve, rather than exhibiting jagged edges. For example... Figure 2 As shown, the measurement data are approximate values ​​of the actual position of the flying target. Due to differences in the technical specifications of the measurement equipment, the measured values ​​will inevitably fluctuate within a controllable range near the actual position. However, due to the combined effects of factors such as the performance status of the measurement equipment, disturbance conditions, and weather conditions, the measured values ​​may exhibit missing points or outliers in certain areas. The measurement equipment is set to measure up to the current time t. n It has received n consecutive measurements (t1,x1,y1,z1), (t2,x2,y2,z2), ..., (t...) of its stable, tracked flight target. n ,x n ,y n ,z n ), the next moment t n+1 The received measurement value is (t) n+1 ,x n+1 ,y n+1 ,z n+1 If a t is fitted based on several known points... n+1 Point of time Then you can consider using t n+1 The difference between the measured value and the fitted value at a given time is used to determine whether the measured value is the flight target that the measuring device has been tracking. The mathematical formula used for this determination can be described as the form of equation (1):

[0062]

[0063] In the formula, v n For t nThe speed of the flying target at any given time, α is a manually set weight constant used to control the size of the ratio; if the value of α is appropriately set, if equation (1) holds, it is considered to be data from the same flying target; if equation (1) does not hold, it is considered not to be data from the same flying target, and the fitted value is... As a guide for the measuring device to recapture the target data.

[0064] The above analysis is based on a three-dimensional coordinate system. Directly applying it to practical calculations is quite complex. Therefore, we can first transform the three-dimensional problem into a two-dimensional problem. Time *t* is a variable describing the motion and change of things. Introducing *t* as an independent variable, we can consider the three coordinate variables in the three-dimensional spatial coordinate system as functions of time *t*. Thus, the three-dimensional coordinate variables... It is decomposed into 3 two-dimensional coordinate variables The function can be expressed as equation (2);

[0065] x = f x (t), y = f y (t), z=f z (t) (2)

[0066] Based on the known measurement data, the corresponding approximate function, i.e. the fitting function, can be obtained. The function can be expressed as equation (3).

[0067]

[0068] With x = f x Taking (t) as an example, when t = t n+1 hour, Therefore t n+1 The difference between the measured value and the fitted value in the x-direction can be expressed as equation (4);

[0069]

[0070] Similarly, find t n+1 The component differences Δy and Δz in the y and z directions at time t are used to obtain the measurement equipment's speed at time t. n+1 The formula for determining whether the measurement data at any given time is the target being tracked is (5);

[0071]

[0072] The fitting function of the flight target is obtained by using known measurement data, and t is obtained from the fitting function. n+1 A fitting point at time Measuring equipment at t n+1 The flight target position point acquired at each moment is P(x) n+1 ,y n+1 ,z n+1The distance between P and Q is d; if P is within a circle centered at Q, α·v n (t n+1 -t n If the target is within a sphere with radius P, then the judgment point P is the coordinate value of the flight target originally tracked by the measuring equipment; otherwise, the judgment point P is an outlier point, such as... Figure 3 The midpoint P' has already exceeded the boundaries of the sphere. At this point, As guiding data for measuring equipment.

[0073] This includes methods for finding the fitting function, specifically Lagrange interpolation and Hermite interpolation. The former is simpler to calculate but has lower accuracy, while the latter is more complex but has higher accuracy. The solution is the function f. x Fitting function of (t) For the purpose of analysis.

[0074] Lagrange interpolation is known from the current time t. n Three consecutive points (t) that are adjacent to each other. n-2 ,x n-2 ), (t n-1 ,x n-1 ), (t n ,x n Then you can get

[0075]

[0076] in,

[0077]

[0078]

[0079]

[0080] If the data acquisition period of the measuring device is T, then the above calculation of the time difference can be simplified to:

[0081]

[0082] Hermite interpolation, solving for function H using the Hermite interpolation method. x (t), due to the habit of description, will Noted as H x (t), taken from the current time t n Three consecutive points (t) that are adjacent to each other. n-2 ,x n-2 ), (t n-1 ,x n-1 ), (tn ,x n For the sake of brevity and convenience, they are respectively denoted as (t) -1 ,x -1 Given (t0, x0) and (t1, x1), then H x (t) can be expressed as a cubic Hermite interpolation polynomial of equation (8);

[0083]

[0084] in,

[0085]

[0086]

[0087]

[0088]

[0089] It should be noted that Δt0 and Δt1 represent the time difference between two adjacent data nodes. If the working cycle of the measuring device is T, then Δt i It is an integer multiple of T, see equation (7); It is the speed of the flying target, v i The projection onto the plane xot The size is Δt during this time period. i The average speed within the time interval is considered because the time interval is very short, and the flight speed is relatively stable after the aircraft takes off and enters the predetermined path. i x Replace the function derivative value at the node

[0090] The Hermite interpolation algorithm is a computer-based solution. During actual flight, time is a continuously increasing quantity. To simplify the calculation process and considering the short duration of each interpolation calculation, relative time can be used. The relative time is redefined after each calculation. In each calculation, the time of the first node is set to 0, and the times of the second and third nodes are the sum of the time intervals between two data points, i.e., integer numbers of device cycles. This time interval can be calculated separately from two consecutive received data frames. This can be expressed mathematically as follows, considering a four-dimensional coordinate point (x...). i ,y i ,z i ,t i In each calculation, the three consecutive interpolation nodes can take the following values: (x －1 ,y －1 ,z －1,0), (x0,y0,z0,mT), (x1,y1,z1,mT+nT), where m and n are integers, and T represents the equipment cycle; t i The value of is the number of device cycles between two data frames, i.e., t0 = mT, t1 = mT + nT.

[0091] Let the next measurement coordinate point received by the measuring device at time t1, which needs to be determined to be the target being tracked, be (x... c ,y c ,z c ,t c ), and its corresponding extrapolation point is (x * ,y * ,z * ,t c ), then t c =kT (k is an integer), the algorithm can be simply described as follows: Set α, and the program performs necessary initialization.

[0092] 1. Input (t) i ,x i (i = -1, 0, 1), x c / / Coordinate system XOT

[0093] (1) Place

[0094]

[0095]

[0096]

[0097]

[0098] (2)

[0099] (3)

[0100] 2. Input (t) i ,y i (i = -1, 0, 1), y c / / Coordinate system YOT

[0101] (1) Place

[0102] Calculate h0, h1, H0, and H1 based on 1-(1).

[0103] (2)

[0104] (3)

[0105] 3. Input (t) i ,z i (i = -1, 0, 1), z c / / Coordinate system ZOT

[0106] (1) Place Calculate h0, h1, H0, and H1 based on 1-(1).

[0107] (2)

[0108] (3) Determine the size of d and M.

[0109] Based on the judgment results, appropriate processing is performed, and preparation is made for the next judgment. In the specific program writing, much work is still required, such as the selection of interpolation nodes, separating and calculating the time interval from two frames of data, etc. These steps depend on the specific situation; the above is only a program outline. This paper explores the reasons why measurement equipment may mistrack flight targets in multi-target flight tests. By analyzing the inherent logical relationships of the measurement data, the functional relationships between various parameters are found from a mathematical perspective, and a mathematical model is established to determine whether target identification is erroneous through data analysis and processing. This method has a high degree of consistency between data processing and real flight targets in a short time, and is highly targeted and practical. However, as the interval time increases, the accuracy of the fitting points decreases rapidly. At this point, external guidance can be considered for discrimination and identification.

[0110] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A multi-target recognition method based on real-time data analysis, characterized in that, Set the measuring device up to the current time t n It has received n consecutive measurements (t1,x1,y1,z1), (t2,x2,y2,z2), ..., (t...) from the flight target it is steadily tracking. n ,x n ,y n ,z n ), the next moment t n+1 The received measurement value is (t) n+1 ,x n+1 ,y n+1 ,z n+1 ); Fit a t based on several known points n+1 Point of time via t n+1 The difference between the measured value and the fitted value at a given time is used to determine whether the measured value is the flight target that the measuring device has been tracking. The mathematical formula used for this determination can be described as the form of equation (1): In the formula, v n For t n The speed of the flying target at any given time, α is a manually set weight constant used to control the size of the ratio; if the value of α is appropriately set, if equation (1) holds, it is considered to be data from the same flying target; if equation (1) does not hold, it is considered not to be data from the same flying target, and the fitted value is... As a guide for the measuring device to recapture the target.

2. The multi-target recognition method based on real-time data analysis according to claim 1, characterized in that, Introducing t as an independent variable, and considering the three coordinate variables in the three-dimensional coordinate system as functions of time t, then the three-dimensional coordinate variables... It is decomposed into 3 two-dimensional coordinate variables The function is expressed in equation (2); x=f x (t),y=f y (t),z=f z (t) (2) The corresponding approximate function, i.e. the fitting function, is obtained based on the known measurement data. The function is expressed in the form of equation (3). With x = f x Taking (t) as an example, when t = t n+1 hour, Therefore t n+1 The difference between the measured value and the fitted value in the x-direction at time is expressed as equation (4); Similarly, find t n+1 The component differences Δy and Δz in the y and z directions at time t are used to obtain the measurement equipment's speed at time t. n+1 The formula for determining whether the measurement data at a given time is the target being tracked:

3. The multi-target recognition method based on real-time data analysis according to claim 2, characterized in that, The fitting function of the flight target is obtained by using known measurement data, and t is obtained from the fitting function. n+1 A fitting point at time 1 Measuring equipment at t n+1 The flight target position point acquired at each moment is P(x) n+1 ,y n+1 ,z n+1 The distance between P and Q is d; if P is within a circle centered at Q, α·v n (t n+1 -t n If the radius is 1, then the judgment point P is the coordinate value of the flight target originally tracked by the measuring equipment; Otherwise, determine if point P is an outlier. For example, if point P' is outside the sphere, then... As guiding data for measuring equipment.

4. The multi-target recognition method based on real-time data analysis according to claim 3, characterized in that, This includes methods for finding the fitting function, specifically Lagrange interpolation and Hermite interpolation, to solve for the function f. x Fitting function of (t) For the purpose of analysis.

5. The multi-target recognition method based on real-time data analysis according to claim 4, characterized in that, The Lagrange interpolation value is known at the current time t. n Three consecutive points (t) that are adjacent to each other. n-2 ,x n-2 ), (t n-1 ,x n-1 ), (t n ,x n ), then we get in, If the data acquisition period of the measuring device is T, then the above time difference calculation simplifies to:

6. The multi-target recognition method based on real-time data analysis according to claim 5, characterized in that, Hermite interpolation, solving for function H using the Hermite interpolation method. x (t), due to the habit of description, will Noted as H x (t), taken from the current time t n Three consecutive points (t) that are adjacent to each other. n-2 ,x n-2 ), (t n-1 ,x n-1 ), (t n ,x n For the sake of brevity and convenience, they are respectively denoted as (t) -1 ,x -1 Given (t0, x0) and (t1, x1), then H x (t) can be expressed as a cubic Hermite interpolation polynomial of equation (8); in, It should be noted that Δt0 and Δt1 represent the time difference between two adjacent data nodes. If the working cycle of the measuring device is T, then Δt i It is an integer multiple of T, see equation (7); It is the speed of the flying target, v i The projection onto the plane xot The size is Δt during this time period. i The average speed within the time interval is chosen because the time interval is very short, and the flight speed is relatively stable after the aircraft takes off and enters the predetermined path. Replace the function derivative value x` at the node i .

7. The multi-target recognition method based on real-time data analysis according to claim 6, characterized in that, The Hermite interpolation algorithm is a computer-based solution. During actual flight, time is a continuously increasing quantity. To simplify the calculation process and considering the short duration of each interpolation calculation, relative time is used, and the relative time is redefined after each calculation. In each calculation, the time of the first node is set to 0, and the times of the second and third nodes are the sum of the time intervals between two data points, i.e., integer numbers of device cycles. This time interval is calculated separately from two consecutive received data frames. This can be expressed mathematically as follows, considering a four-dimensional coordinate point (x...). i ,y i ,z i ,t i In each calculation, the three consecutive interpolation nodes take the following values: (x －1 ,y －1 ,z －1 ,0), (x0,y0,z0,mT), (x1,y1,z1,mT+nT), where m and n are integers, and T represents the equipment cycle; t i The value of is the number of device cycles between two data frames, i.e., t0 = mT, t1 = mT + nT.

8. The multi-target recognition method based on real-time data analysis according to claim 7, characterized in that, Let the next measurement coordinate point received by the measuring device at time t1, which needs to be determined to be the target being tracked, be (x... c ,y c ,z c ,t c ), and its corresponding extrapolation point is (x * ,y * ,z * ,t c ), then t c =kT (k is an integer), the algorithm is simply described as follows: Set α, and the program performs necessary initialization.

1. Input (t) i ,x i (i = -1, 0, 1), x c / / Coordinate system XOT (1) Place (2) (3) 2. Input (t) i ,y i (i = -1, 0, 1), y c / / Coordinate system YOT (1) Place Calculate h0, h1, H0, and H1 based on 1-(1). (2) (3) 3. Input (t) i ,z i (i = -1, 0, 1), z c / / Coordinate system ZOT (1) Place Calculate h0, h1, H0, and H1 based on 1-(1). (2) (3) Determine the size of d and M.

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