A method for processing the target priority of an anti-collision radar on an unmanned aerial vehicle

Abstract

The present invention discloses a method for processing the target priority of an airborne anti-collision radar for unmanned aerial vehicles, including: calculating the distance and collision risk factor between an intrusion target and the aircraft using the position and velocity of the intrusion target and the aircraft in the ECEF coordinate system, and determining the priority of the intrusion target based on this. The use of the target priority can effectively allocate radar resources and adjust the radar beam direction, enabling the radar to continuously track high-priority targets, improving the target data rate, and reducing the probability of target loss. At the same time, the track information of high-priority targets is sent to the collision avoidance system at a higher data rate to calculate the avoidance plan and preferentially avoid high-risk targets, thereby reducing the collision risk.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and particularly to a method for processing the target priority of an on-board anti-collision radar of an unmanned aerial vehicle. Background Art

[0002] In recent years, unmanned aerial vehicles have been widely used in the fields of logistics, agriculture, security, etc. However, the data sources of the on-board anti-collision equipment of civilian unmanned aerial vehicles only have the surveillance data from cooperative targets, lacking the detection data of non-cooperative targets, and it is impossible to form a complete airspace flight situation information. Moreover, the existing on-board surveillance equipment is difficult to give the priority of intrusion targets in the flight airspace of unmanned aerial vehicles, and it is impossible to give priority to avoiding high-risk targets. With a large number of unmanned aerial vehicles entering the airspace, it is difficult to carry out optimal route planning based on target position, speed, and priority information, and the risk of collision suddenly rises, seriously threatening flight safety.

[0003] Reference [1] analyzed the target radial distance threat function, speed threat function, angle threat function, and altitude threat function, weighted the threat functions according to different weights to obtain the comprehensive threat degree of the target, and obtained the target priority according to the time required for target interception. Reference [2] defined the threat degree factors of ballistic missile targets, including factors such as target speed, flight phase, distance to the destination, importance of the destination, warhead type, etc., and weighted and summed each factor according to different weighting coefficients to obtain the comprehensive priority of the target.

[0004] The target priorities in Reference [1] and Reference [2] are mainly used for the interception of targets such as fighter jets and missiles by weapon systems. The target threat degree models in the references independently divide target speed, distance, angle, altitude, etc. into several influencing factors, construct threat functions for each factor, and obtain the comprehensive threat degree of the target by weighted summation of each factor. This method lacks the interaction between parameters such as target speed, distance, angle, and altitude, and it is difficult to objectively and real-time reflect the change of the target threat level for changing and moving scenarios. The methods for generating target priorities in Reference [1] and Reference [2] are complex and each influencing factor is independent, which is not applicable to the operation scenarios of on-board anti-collision radars of unmanned aerial vehicles with rapidly changing airspace situations, a large number of intrusion targets, high real-time calculations, and high-speed moving platforms, and it is difficult to meet the requirements of airspace conflict resolution and route planning for unmanned aerial vehicles.

[0005] References

[0006] [1] Zhang Haowei, Xie Junwei, Sheng Chuan. Adaptive scheduling method of phased array radar under comprehensive priority planning [J]. Acta Armamentarii, 2016, 37(11): 2163-2169;

[0007] [2] Yang Shanchao, Tian Kangsheng, Li Hongquan, Zhou Guangtao, Liang Futai. Task Scheduling Algorithm for Anti-Missile Early Warning Phased Array Radar under Comprehensive Priority [J]. Acta Armamentarii, 2020, 41(02): 315-323. Summary of the Invention

[0008] The present invention provides a method for processing the target priority of an anti-collision radar on an unmanned aerial vehicle in view of the defects of the prior art.

[0009] In order to achieve the above invention objectives, the technical solutions adopted by the present invention are as follows:

[0010] A method for processing the target priority of an anti-collision radar on an unmanned aerial vehicle, comprising the following steps:

[0011] S1: In the three directions of X, Y, and Z in the ECEF (Earth-Centered Earth-Fixed) coordinate system, the coordinates of the own aircraft are (X s , Y s , Z s ), the speed is (v xs , v ys , v zs ), and the updated track coordinates of the intruding target are (X t , Y t , Z t ), and the speed is (v xt , v yt , v zt ).

[0012] S2: Calculate the distance R between the own aircraft and the intruding target.

[0013] S3: In the ECEF coordinate system, the risk factors of collision between the intruding target and the own aircraft in the three directions of X, Y, and Z are τ x , τ y , τ z , respectively. From τ x , τ y , τ z and R, the risk factor τ of collision between the intruding target and the own aircraft is obtained.

[0014] S4: From the target distance R and the collision risk factor τ, the target track priority is obtained. The target priority set is divided into three categories: high-priority targets, medium-priority targets, and low-priority targets, and the priorities of the targets are classified accordingly:

[0015] When the collision risk factor τ = 0, the target is classified as a high-priority target;

[0016] When the collision risk factor τ > 0, the target is classified as a medium-priority target;

[0017] When the collision risk factor τ < 0, the target is classified as a low-priority target.

[0018] Further, the coordinates of the host in S1 are (X s , Y s , Z s ), the speed is (v xs , v ys , v zs ), and the updated track coordinates of the intrusion target are (X t , Y t , Z t ), the speed is (v xt , v yt , v zt )

[0019] The distance between the host and the intrusion target is R:

[0020]

[0021] Further, the collision risk factors in the X, Y, and Z directions in S2 are τ x , τ y , τ z The calculation formulas are as follows:

[0022]

[0023]

[0024]

[0025] Further, the calculation of the risk factor τ in S3 is as follows:

[0026] When R ≤ 1219m:

[0027] τ = 0

[0028] When R > 1219m and at least one of τ x , τ y , τ z is less than zero:

[0029] τ = min(τ x , τ y , τ z )

[0030] When R > 1219m and τ x , τ y , τ z are all greater than or equal to zero:

[0031] τ = max(τ x , τ y , τz )

[0032] Where min(·) is the minimum value function and max(·) is the maximum value function.

[0033] Furthermore, the steps for obtaining the priority of the target track in S4 are as follows:

[0034] S41: Obtain the track update values of all intruding aircraft at the current moment. Suppose there are n track position updates, and the coordinates are (X t1 , Y t1 , Z t1 ), (X t2 , Y t2 , Z t2 ), …, (X tn , Y tn , Z tn ), and their speeds are (v xt1 , v yt1 , v zt1 ), (v xt2 , v yt2 , v zt2 ), …, (v xtn , v ytn , v ztn );

[0035] S42: Obtain the coordinates (X s , Y s , Z s ) and speed (v xs , v ys , v zs ) of the own aircraft at the current moment;

[0036] S43: For the k-th track, k = 1, 2, …, n, calculate the distance and collision factor according to the following process:

[0037] S44: Calculate the distance R between the own aircraft and the intrusion target k

[0038] S45: If R k ≤ 1219 m:

[0039] τ k = 0

[0040] If R k > 1219 m, calculate the risk factors τ xk , τ yk , τ zk in the X, Y, and Z directions;

[0041] If R k > 1219 m and τxk , τ yk , τ zk At least one value is less than zero:

[0042] τ k = min(τ xk , τ yk , τ zk )

[0043] If R k > 1219 m and τ xk , τ yk , τ zk are all greater than or equal to zero:

[0044] τ k = max(τ xk , τ yk , τ zk )

[0045] S46: Repeat steps S43 to S45 to obtain the distances and collision factors of all n targets.

[0046] S47: The target priority set is divided into three categories: high-priority targets, medium-priority targets, and low-priority targets, and the priorities of the targets are classified accordingly:

[0047] When the collision factor τ k of the k-th target is 0, this target is classified as a high-priority target;

[0048] When the collision factor τ k of the k-th target is > 0, this target is classified as a medium-priority target;

[0049] When the collision factor τ k of the k-th target is < 0, this target is classified as a low-priority target.

[0050] S48: For the targets within the three target sets of high-priority, medium-priority, and low-priority, further sort them according to the distance R and collision factor τ of the targets.

[0051] S49: Form the priority numbers of the tracks of each invading target. The smaller the number, the higher the priority, and output the priority numbers together with the target track information.

[0052] Furthermore, the calculation formula of R k in S44 is as follows:

[0053]

[0054] Furthermore, the calculation formulas of τ xk , τ yk , τ zk in S45 are as follows:

[0055]

[0056]

[0057]

[0058] Furthermore, the internal target sorting in S48 for the high-priority set is as follows:

[0059] For all the targets within the high-priority set, they are sorted according to the distance between the local device and the targets. The smaller the distance, the higher the priority. Suppose there are h targets in the high-priority set, and the priority sorting result is shown in Table 1.

[0060] Table 1 Internal target priority sorting in the high-priority set

[0061] Target distance R <![CDATA[R h1 > <![CDATA[R h2 > … <![CDATA[R hh > Target priority number 1 2 … h

[0062] Where:

[0063] 0m < R h1 ≤ R h2 ≤... ≤ R hh ≤ 1219m.

[0064] Furthermore, the internal target sorting in S48 for the medium-priority set is as follows:

[0065] For all the targets within the medium-priority set, they are sorted according to the collision factor. The smaller the collision factor value, the higher the priority. Suppose there are m targets in the medium-priority set, and the priority sorting result is shown in Table 2.

[0066] Table 2 Internal target priority sorting in the medium-priority set

[0067] Target collision factor τ <![CDATA[τ m1 > <![CDATA[τ m2 > … <![CDATA[τ mm > Target priority number h+1 h+2 … h + m

[0068] Where:

[0069] 0 < τ m1 ≤ τ m2 ≤... ≤ τ ml .

[0070] Furthermore, the internal target sorting in S48 for the low-priority set:

[0071] For all the targets within the low-priority set, they are sorted according to the collision factor. The smaller the collision factor value, the lower the priority, that is, the smaller the absolute value of the collision factor, the higher the priority. Suppose there are l targets in the low-priority set, and the priority sorting result is shown in Table 3.

[0072] Table 3 Internal target priority sorting in the low-priority set

[0073] Target collision factor τ <![CDATA[τ l1 > <![CDATA[τ l2 > … <![CDATA[τ ll > Target priority number h + m + 1 h + m + 2 … h + m + l

[0074] Wherein:

[0075] τ ll ≤τ ll-1 ≤...≤τ l2 ≤τ l1 <0

[0076] n = h + m + l.

[0077] Compared with the prior art, the advantages of the present invention are as follows:

[0078] It can effectively distinguish the priority levels of each intrusion target, and use this as a reference to adjust the radar beam direction, so that the radar can continuously track high-priority targets, improve the target data rate, and reduce the probability of target loss. At the same time, the track information of high-priority targets is sent to the collision avoidance system at a higher data rate to calculate the avoidance plan, and high-risk targets are preferentially avoided to reduce the collision risk. Description of the Drawings

[0079] Figure 1 It is a schematic diagram of the positions and velocities of the host and intrusion targets in the ECEF coordinate system according to an embodiment of the present invention. Detailed Embodiments

[0080] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention by way of examples based on the drawings.

[0081] In the ECEF coordinate system, the coordinates of the host are (X s , Y s , Z s ), and the velocity is (v xs , v ys , v zs ). The updated target track coordinates are (X t , Y t , Z t ), and the velocity is (v xt , v yt , v zt ), as shown in Figure 1 . The velocity of the target moving along the positive direction of the coordinate axis is positive, and the velocity of the target moving along the negative direction of the coordinate axis is negative. For example, if the target moves from the origin along the positive x-axis, v xt is positive, and if it moves along the negative x-axis, v xt is negative.

[0082] The distance between the host and the intrusion target is R:

[0083]

[0084] In the ECEF coordinate system, the risk factors of the intrusion target colliding with the host in the X, Y, and Z directions are τ x , τ y , τ z .

[0085]

[0086]

[0087]

[0088] From τ x , τ y , τ z and R, the risk factor τ of the intrusion target colliding with the host is obtained.

[0089] (1) When R ≤ 1219 m:

[0090] τ = 0

[0091] (2) When R > 1219 m and at least one of τ x , τ y , τ z is less than zero:

[0092] τ = min(τ x , τ y , τ z )

[0093] (3) When R > 1219 m and τ x , τ y , τ z are all greater than or equal to zero:

[0094] τ = max(τ x , τ y , τ z )

[0095] Where min(·) is the minimum value function and max(·) is the maximum value function.

[0096] From the target distance R and the collision risk factor τ, the target track priority is obtained. The specific processing flow of the target track priority is as follows:

[0097] (1) Obtain the track update values of all intruding aircraft at the current moment. Suppose there are n track position updates, and the coordinates are (X t1 , Y t1 , Z t1 ), (X t2 , Y t2 , Z t2 ), …, (Xtn , Y tn , Z tn ), whose speeds are respectively (v xt1 , v yt1 , v zt1 );

[0098] (v xt2 , v yt2 , v zt2 ), …, (v xtn , v ytn , v ztn );

[0099] (2) Obtain the coordinates (X s , Y s , Z s ) and speed (v xs , v ys , v zs ) of the local machine at the current moment;

[0100] (3) For the k-th track (k = 1, 2,..., n), calculate the distance and collision factor according to the following process:

[0101] (a) Calculate the distance between the local machine and the intrusion target as R k :

[0102]

[0103] (b) If R k ≤1219 m:

[0104] τ k = 0

[0105] (c) If R k > 1219 m, calculate τ xk , τ yk , τ zk :

[0106]

[0107]

[0108]

[0109] (d) If R k > 1219 m and at least one of τ xk , τ yk , τ zk is less than zero:

[0110] τ k = min(τ xk , τyk , τ zk )

[0111] (e) If R k > 1219 m and τ xk , τ yk , τ zk are all greater than or equal to zero:

[0112] τ k = max(τ xk , τ yk , τ zk )

[0113] (4) Repeat step (3) to obtain the distances and collision factors of all n targets.

[0114] (5) The target priority set is divided into three categories: high-priority targets, medium-priority targets, and low-priority targets, and the priorities of the targets are classified accordingly:

[0115] When the collision factor τ of the kth target k = 0, this target is classified as a high-priority target;

[0116] When the collision factor τ of the kth target k > 0, this target is classified as a medium-priority target;

[0117] When the collision factor τ of the kth target k < 0, this target is classified as a low-priority target.

[0118] (6) For the targets within the three target sets of high-priority, medium-priority, and low-priority, further sort them according to the distance R and collision factor τ of the targets.

[0119] Sorting of targets within the high-priority set

[0120] For all targets within the high-priority set, sort them according to the distance between the local machine and the targets. The smaller the distance, the higher the priority. Suppose there are h targets in the high-priority set, and the priority sorting result is shown in Table 1.

[0121] Table 1 Priority sorting of targets within the high-priority set

[0122] Target distance R <![CDATA[R h1 > <![CDATA[R h2 > … <![CDATA[R hh > Target priority number 1 2 … h

[0123] Among them:

[0124] 0 m < R h1 ≤ R h2 ≤... ≤ R hh ≤ 1219 m

[0125] Sorting of targets within the medium-priority set

[0126] For all the targets within the medium-priority set, sort them according to the collision factor. The smaller the value of the collision factor, the higher the priority. Suppose there are m targets in the medium-priority set, and the priority sorting results are shown in Table 2.

[0127] Table 2 Priority sorting of targets within the medium-priority set

[0128] Target collision factor τ <![CDATA[τ m1 > <![CDATA[τ m2 > … <![CDATA[τ mm > Target priority number h+1 h+2 … h + m

[0129] Where:

[0130] 0 < τ m1 ≤ τ m2 ≤... ≤ τ ml

[0131] Sorting of targets within the low-priority set

[0132] For all the targets within the low-priority set, sort them according to the collision factor. The smaller the value of the collision factor, the lower the priority, that is, the smaller the absolute value of the collision factor, the higher the priority. Suppose there are l targets in the low-priority set, and the priority sorting results are shown in Table 3.

[0133] Table 3 Priority sorting of targets within the low-priority set

[0134] Target collision factor τ <![CDATA[τ l1 > <![CDATA[τ l2 > … <![CDATA[τ ll > Target priority number h + m + 1 h + m + 2 … h + m + l

[0135] Where:

[0136] τ ll ≤ τ ll-1 ≤... ≤ τ l2 ≤ τ l1 <0

[0137] n = h + m + l

[0138] (7) Form the priority numbers of the tracks of each intrusion target. The smaller the number, the higher the priority, and output the priority numbers together with the target track information.

[0139] The method according to the present invention described above can be implemented in hardware, firmware, or be implemented as software or computer code that can be stored in a recording medium (such as a CD ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or be implemented as computer code originally stored in a remote recording medium or a non-transitory machine-readable medium and to be downloaded through a network and stored in a local recording medium, so that the method described herein can be stored as such software processing on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as an ASIC or FPGA). It will be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component (e.g., RAM, ROM, flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the processing method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the processing shown herein, the execution of the code converts the general-purpose computer into a dedicated computer for executing the processing shown herein.

[0140] Those of ordinary skill in the art will realize that the embodiments described herein are for helping the reader understand the implementation methods of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those of ordinary skill in the art can make various other specific deformations and combinations that do not depart from the essence of the present invention based on the technical revelations disclosed in the present invention, and these deformations and combinations are still within the protection scope of the present invention.

Claims

1. A method for processing target priorities of an on-board anti-collision radar of an unmanned aerial vehicle, characterized in that Including the following steps: S1: In the ECEF coordinate system, in the X, Y, and Z directions, the coordinates of the host are (X s , Y s , Z s ), the speed is (v xs , v ys , v zs ), and the updated coordinates of the intruding target's track are (X t , Y t , Z t ), and the speed is (v xt , v yt , v zt ); S2: Calculate the distance R between the local machine and the intrusion target: S3: In the ECEF coordinate system, the risk factors of collision between the intrusion target and the host in the X, Y, and Z directions are τ x , τ y , and τ z ; From τ x , τ y , τ z and R, the risk factor τ of collision between the intrusion target and the host is obtained; τ x 、 τ y 、 τ z The calculation formula is as follows: The calculation of the risk factor τ is as follows: When R ≤ 1219m: τ = 0 When R > 1219 m and at least one of τ x , τ y , τ z is less than zero: τ = min(τ x , τ y , τ z ) When R > 1219 m and τ x , τ y , τ z are all greater than or equal to zero: τ = max(τ x , τ y , τ z ) where min(·) is the minimum value function and max(·) is the maximum value function; S4: Obtain the target track priority from the target distance R and the collision risk factor τ. The target priority set is divided into three categories: high-priority targets, medium-priority targets, and low-priority targets, and the priorities of the targets are classified accordingly; The steps for obtaining the target track priority are as follows: S41: Obtain the track update values of all intruding aircraft at the current moment. Suppose there are n track position updates, and the coordinates are respectively (X t1 , Y t1 , Z t1 ), (X t2 , Y t2 , Z t2 ), …, (X tn , Y tn , Z tn ), and their speeds are respectively (v xt1 , v yt1 , v zt1 ), (v xt2 , v yt2 , v zt2 ), …, (v xtn , v ytn , v ztn ); S42: Obtain the coordinates (X s , Y s , Z s ) and speed (v xs , v ys , v zs ) of the local machine at the current moment; S43: For the k-th track, k = 1, 2,..., n, calculate the distance and collision factor according to the following process: S44: Calculate the distance R between the local device and the intrusion target k ; S45: If R k ≤ 1219 m: τ k = 0 If R k > 1219 m, calculate the risk factors τ xk , τ yk , τ zk ; If R k > 1219 m and τ xk , τ yk , τ zk at least one value is less than zero: τ k = min(τ xk , τ yk , τ zk ) If R k > 1219 m and τ xk , τ yk , τ zk are all greater than or equal to zero: τ k = max(τ xk , τ yk , τ zk ) S46: Repeat steps S43 to S45 to obtain the distance and collision factors of all n targets; S47: The target priority set is divided into three categories: high-priority targets, medium-priority targets, and low-priority targets, and the priorities of the targets are classified accordingly: When the k-th target collision factor τ k = 0, this target is classified as a high-priority target; When the k-th target collision factor τ k > 0, the target is classified as a medium-priority target; When the k-th target collision factor τ k < 0, this target is classified as a low-priority target; S48: For the targets within the high-priority, medium-priority, and low-priority target sets, further sort them according to the target distance R and the collision factor τ; S49: Form the priority numbers of each intrusion target track. The smaller the number, the higher the priority, and output the priority number together with the target track information.

2. A method for processing the target priority of an airborne anti-collision radar of a drone according to claim 1, characterized in that: R in S44 k The calculation formula is as follows:

3. A method for processing the target priority of an anti-collision radar on an unmanned aerial vehicle according to claim 1, characterized in that: τ in S45 xk , τ yk , τ zk The calculation formulas are as follows:

4. A method for processing the target priority of an airborne anti-collision radar of a drone according to claim 1, characterized in that: The sorting of the targets within the high-priority set in S48 is as follows: For all the targets within the high-priority set, sort them according to the distance between the local machine and the target. The smaller the distance, the higher the priority.

5. A method for processing the target priority of an airborne anti-collision radar of a drone according to claim 4, characterized in that: The sorting of the targets within the medium-priority set in S48 is as follows: For all the targets within the medium-priority set, sort them according to the collision factor. The smaller the value of the collision factor, the higher the priority.

6. A method for processing the target priority of an airborne anti-collision radar of a drone according to claim 4, characterized in that: The sorting of the targets within the low-priority set in S48: For all the targets within the low-priority set, sort them according to the collision factor. The smaller the value of the collision factor, the lower the priority, that is, the smaller the absolute value of the collision factor, the higher the priority.

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