A multi-unmanned aerial vehicle simultaneous arrival control method based on cooperative margin

Abstract

The application discloses a kind of based on the multi-unmanned plane simultaneous arrival control method of coordination margin, it is related to unmanned plane cooperative control technical field, it is related to unmanned plane cooperative control technical field, comprising: S1, definition contains distance margin and speed margin's coordination margin, the coordination margin is through time-remaining distance t-S Graphical method describes the reason and boundary condition that cannot be realized in the coordination of the process of multiple unmanned planes coordination arrival;S2, at any time t , each unmanned plane is arranged as S 1, S 2,…, S n , and maximum coordination margin is used for multiple unmanned planes in the scene of maintaining coordination control under disturbance. The control method of the application takes "maximum coordination margin" as the optimization goal, which is not a passive response to disturbance, but actively configures the system state to enhance robustness, so as to adapt to complex and variable environment.

Description

Technical Field

[0001] This invention relates to the field of collaborative control technology for unmanned aerial vehicles (UAVs). More specifically, this invention relates to a method for controlling the simultaneous arrival of multiple UAVs based on collaborative margin. Background Technology

[0002] The simultaneous arrival of unmanned aerial vehicles (UAVs) is a typical scenario for multi-UAV collaborative applications, with significant implications in both military and civilian sectors. In the military field, by deploying a large number of low-cost UAVs simultaneously from different directions and altitudes to attack a high-value target (such as air defense radar, command centers, or warships), the interception capabilities of the enemy's air defense system can be overwhelmed instantly. Even if some UAVs are shot down, the remaining ones can successfully penetrate defenses, ensuring mission completion. Furthermore, the simultaneous arrival of multiple UAVs is also a crucial component of distributed collaborative reconnaissance and collaborative jamming tactics. In the civilian sector, simultaneous UAV arrival technology provides vital support for applications such as collaborative mapping and 3D modeling, emergency response, and search and rescue.

[0003] The synchronous arrival of drones mainly involves two technical aspects: 1) Dynamic path planning: Under environmental and collaborative constraints, a path is planned for each drone to avoid threats and reach the target at a specific angle; at the same time, online replanning can be performed when the constraints change. 2) Collaborative guidance and control: By collaboratively adjusting the speed and heading of each drone, it can strictly follow its own planned path and reach the target point simultaneously at the final moment.

[0004] The common practice in existing technologies is to use path planning to plan a path that meets the constraints for each UAV and assign a uniform flight speed to each UAV based on the path length. However, this method has inherent drawbacks: first, the path length estimation itself has errors; second, disturbances during flight (such as atmospheric turbulence and wind fields) can lead to path following errors. These two unavoidable errors make it difficult for pure path planning methods to achieve accurate simultaneous arrival.

[0005] To address this, cooperative guidance and control must be introduced based on path planning to compensate for errors and achieve precise control. Although much research has advanced cooperative guidance, it still suffers from a common drawback: its guidance strategy typically pre-sets a fixed coordination time for the UAV and keeps it flying at a relatively constant speed. Since fixed-wing UAVs have upper and lower speed limits, using this method, the UAV almost exhausts all its adjustment margin in the terminal phase of flight. In the event of an emergency (such as temporary obstacle avoidance), the fixed-wing UAV cannot wait in place like a rotary-wing UAV. In this situation, the system may completely lose its coordination time window, ultimately failing to achieve coordinated arrival.

[0006] In response, when multiple UAVs fly along a planned path, their guidance and control strategies should incorporate a proactive design concept, leaving as much room for coordinated adjustments as possible to cope with unforeseen circumstances when multiple UAVs approach the target area. This would address the technical challenge that existing UAV coordinated arrival control methods are prone to losing the coordination window due to limited adjustment capabilities when encountering unforeseen circumstances, thus preventing the implementation of coordinated arrival applications. Summary of the Invention

[0007] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0008] To achieve these objectives and other advantages of the present invention, a multi-UAV simultaneous arrival control method based on cooperative margin is provided, comprising:

[0009] S1. Define a collaborative margin that includes distance margin and speed margin, wherein the collaborative margin is calculated as time-remaining distance. tS The graphical method describes the reasons and boundary conditions under which cooperative arrival cannot be achieved in the process of multi-UAV collaboration;

[0010] S2. At the initial moment, the drone with the longest remaining distance in the cluster is set to start at the fastest speed. V max The drone with the shortest remaining distance should fly at the slowest speed. V min Flight, then the two drones will be in tS The intersection points in the diagram are defined as priority arrival points. P ;

[0011] S3, at any time t Real-time determination of the remaining distance between each drone and the priority arrival point P. S i And sort them in descending order. S i The arrangement is updated in real time. S 1, S 2,…, S n Simultaneously, the drone numbers are updated in real time as the remaining distance of the drones changes. U 1, U 2,…, U n ;

[0012] S4, Determine S1-S n >S cord If the conditions are met, the margin cooperative control mode will be used in scenarios where multiple UAVs maintain cooperative control under disturbances, and the control method of the margin cooperative control mode will be characterized by the following formula:

[0013]

[0014] In the above formula, T P 、S P These are the coordinates of the points that are the first point to reach, P. t For a moment, V ci The flight speed of each UAV in the margin cooperative control mode, S cord To avoid oscillations in the drone's speed command, a judgment threshold is set when switching between the margin cooperative control model and the non-margin cooperative mode.

[0015] Otherwise, if S1-Sn≤S cord Under certain conditions, when the non-marginalized cooperative mode is enabled, the flight speed of each drone will be... V i Characterized according to the following formula:

[0016]

[0017] in, V leader This indicates the flight speed of the drone after it arrives at the priority arrival point P and is selected as the lead drone based on its sequence number. S leader This represents the remaining path estimate for the selected drone as the lead aircraft. k s This is the gain coefficient.

[0018] Preferably, in S1, the cooperative path margin is based on the distance margin. S mar It is characterized by the following formula:

[0019]

[0020] In the above formula, Is tS In the picture, from T u dot V max Draw a straight line with the slope of the current timeline. t The remaining distance after the intersection, and T u For drones S 1. According to V min The time it takes for the flight to reach the target point.

[0021] Preferably, in S1, the cooperative speed margin is based on the speed margin. Vmar It is characterized by the following formula:

[0022]

[0023] In the above formula, Is tS In the picture, from S 1 o'clock T u The slope of the line.

[0024] Preferably, in S2, maximizing the cooperative margin means that, when the upper and lower boundaries of the UAV's velocity remain unchanged, the cooperative margin should be maximized. S n As large as possible, and S 1 should be as small as possible, so that S mar and V mar maximize.

[0025] The present invention has at least the following beneficial effects:

[0026] Firstly, by introducing collaborative margin (distance margin and velocity margin), this invention provides for the first time a clear quantitative indicator for the robustness of multi-UAV collaborative systems, making the system's ability to withstand emergencies measurable and predictable.

[0027] Secondly, unlike traditional methods that passively respond to disturbances, this invention proactively enhances the inherent robustness of the system before disturbances occur by actively adjusting the control strategy (maximizing cooperative margin), thus preventing problems before they arise.

[0028] Third, this invention is based on the geometric and kinematic relationships at the system level and does not depend on a specific UAV dynamics model. Therefore, it has good versatility and adaptability and can be applied to various types of fixed-wing UAV swarms, making it more versatile.

[0029] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the definition of collaborative margin in the time-remaining path graph in this invention;

[0031] Figure 2 This is a graphical illustration of the application of the collaborative margin in this invention.

[0032] Figure 3 To verify Example 1, a partial schematic diagram of the path of multiple UAVs cooperating in flight using existing technology;

[0033] Figure 4 To verify Example 1, a schematic diagram showing the distance from the target point when multiple UAVs are flying collaboratively using existing technology;

[0034] Figure 5 To verify Example 1, a schematic diagram of the drone speed during multi-drone cooperative flight using existing technology is provided.

[0035] Figure 6 To verify Example 1, a schematic diagram of the distance margin during multi-UAV cooperative flight using existing technology is provided.

[0036] Figure 7 To verify Example 1, a partial path diagram of multiple UAVs flying together is shown when the cooperative margin control of the present invention is used;

[0037] Figure 8 To verify Example 1, a schematic diagram showing the distance from the target point when multiple UAVs are flying collaboratively using the cooperative margin control of the present invention;

[0038] Figure 9 To verify Example 1, a schematic diagram of the drone speed during multi-drone cooperative flight using the cooperative margin control of the present invention is shown.

[0039] Figure 10 To verify Example 1, a schematic diagram of the distance margin during multi-UAV cooperative flight is provided.

[0040] Figure 11 To verify Example 2, a partial schematic diagram of the path of multiple UAVs cooperating in flight when using existing technology;

[0041] Figure 12 To verify Example 2, a schematic diagram showing the distance from the target point when multiple UAVs are flying collaboratively using existing technology;

[0042] Figure 13 To verify Example 2, a schematic diagram of the drone speed during multi-drone cooperative flight using existing technology is provided.

[0043] Figure 14 To verify Example 2, a schematic diagram of the speed margin during multi-UAV cooperative flight using existing technology is provided.

[0044] Figure 15 To verify Example 2, a partial schematic diagram of the path of multiple UAVs flying together when using the cooperative margin control of the present invention is shown.

[0045] Figure 16 To verify Example 2, a schematic diagram showing the distance from the target point when multiple UAVs are flying collaboratively using the cooperative margin control of the present invention;

[0046] Figure 17 To verify Example 2, a schematic diagram of the drone speed during multi-drone cooperative flight using the cooperative margin control of the present invention is shown.

[0047] Figure 18 To verify Example 2, a speed margin diagram is shown when multiple UAVs are flying together using the cooperative margin control of the present invention. Detailed Implementation

[0048] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0049] The essence of multi-UAV cooperative arrival failure is that the system loses its redundancy to maintain time consistency under disturbance. To address this, this invention proposes the concept of "cooperation margin," an indicator used to quantitatively characterize the ability of a multi-UAV system to maintain cooperative arrival under disturbance. The cooperation margin can be specifically defined as distance margin and velocity margin.

[0050] As shown in Figure 1, this invention uses the time-remaining distance graphical method to describe the definition of cooperation margin in the multi-UAV cooperative process. That is, at any given time... t Arrange the drones in descending order of remaining path length. S 1 , S 2 , ..., S n , Figure 1 The slope of the median segment represents the drone's flight speed. Therefore, the time it takes for the drone traveling the longest distance to reach the target point at the fastest speed is defined as... T l The time it takes for the drone to reach the target point at the slowest speed over the shortest distance is defined as... T u .when When it was established, a time coordination window existed, enabling multiple drones to coordinate.

[0051] from T u dot Vmax Draw a straight line with the slope of the current timeline. t Intersect, and define the corresponding remaining distance as If the longest distance is at this time S 1 The corresponding drone path has increased to At this point, the multi-UAV system is in a critical state where coordination is possible. arrive S 1 The distance is defined as the cooperative path margin of a multi-UAV system. Smar Its expression can be written as:

[0052]

[0053] Its significance is that when the drone with the longest range faces a sudden threat area, the resulting distance increase exceeds [a certain value]. S mar Even if each drone flies at its maximum speed, multiple drones cannot achieve a coordinated state if the path cannot be changed.

[0054] Furthermore, in Figure 1, from S 1 Draw a line from a dot. T u The line (yellow dashed line) indicates that if this drone encounters a headwind of a certain strength, its maximum flight speed will be reduced from the range indicated by the blue line. V max Reduce to At this point, the multi-drone system is also in a critical state of coordination. If the maximum speed is further reduced, the multi-drone system will be unable to achieve coordinated arrival. V max arrive The change in is defined as the cooperative velocity margin, and its expression is: V mar It can be written as:

[0055]

[0056] Its significance is that when the drone with the longest distance faces a sudden headwind, the reduction in its maximum speed exceeds [a certain amount]. V mar Even if each drone flies at its maximum speed, multiple drones cannot achieve a coordinated state if the path cannot be changed.

[0057] As can be seen from the above scheme, the present invention achieves the quantification of collaborative margin control by proposing the concept of "collaborative margin", which can reveal the intrinsic mechanism of collaborative failure caused by typical sudden situations, and quantitatively characterize the system's ability boundary and margin to maintain collaborative achievement in the current state.

[0058] Example:

[0059] The definition of cooperative margin explains the reasons and boundary conditions under which multi-UAV systems cannot achieve cooperative arrival when encountering emergencies. Therefore, based on the theory of cooperative margin, we can further analyze and determine how to design a cooperative control method for multiple UAVs to improve their ability to cope with emergencies. This embodiment proposes an improved simultaneous arrival control method based on cooperative margin. From the expression of cooperative path margin, it can be seen that when the upper and lower boundaries of the UAV's velocity do not change, the target path margin should be...S n As large as possible, and S 1. As small as possible, it can make S mar At its maximum, because fixed-wing drones have a lower speed limit, and S n and S The expression for the remaining path length is 1, which decreases with the drone's flight speed as the slope.

[0060] To make S mar maximum, S n The corresponding drone, i.e., the drone with the shortest path, flies at the minimum speed. S The drone corresponding to 1, i.e., the drone with the longest path, flies at its maximum speed. From the expression for cooperative speed margin, it can be seen that when the upper and lower boundaries of the drone's speed do not change, it should be... S n As large as possible, and S 1 As small as possible, it can make V mar This requirement is consistent with the requirement to maximize the margin of collaborative paths.

[0061] Based on the above analysis, in a multi-drone system, the drone with the longest remaining distance should fly at its fastest speed, and the drone with the shortest remaining distance should fly at its slowest speed. These two drones... tS There will be an intersection point in the diagram, which is defined as the priority arrival point. P As shown in Figure 2. For UAVs other than those following the shortest and longest remaining paths, their distance change curves must not exceed [a certain value] before reaching the priority arrival point. S 1 PS n If the triangular region enclosed (orange area in the diagram) is exceeded, the cooperative margin of the UAV system will be lower than the maximum cooperative margin. Therefore, for other UAVs, the optimal speed control is... S 1 and S n The corresponding drones arrive at the priority arrival point at the same time, meaning the system reaches the remaining distance in the fastest time. Once the drones reach the priority arrival point, the multi-drone system can proceed according to the pre-set numbering sequence. U 1, U 2,…, U nThe drone with the highest sequence number is selected as the lead drone, and the other drones maintain a coordinated state with the lead drone. At this point, the coordination margin of the multi-drone system changes consistently. Simultaneously, to avoid repeated acceleration and deceleration of the drones due to repeated switching between the two control modes, a threshold S for mode switching needs to be set. cord Typically, the maximum distance between drones in front and behind each other during coordinated formation flying of multiple drones is chosen as the switching threshold, and the estimated value of the remaining longest distance S1 and the shortest distance Sn is used as the basis for mode switching.

[0062] In summary, when the condition S1-Sn>Scord is satisfied, the improved multi-UAV cooperative control method based on maximizing cooperative margin is defined as a margin cooperative control mode, and the control mode of the margin cooperative control mode is characterized by the following formula:

[0063]

[0064] In the above formula, T P 、S P These are the coordinates of the points that are the first point to reach, P. t For a moment, V ci The flight speed of each UAV in the margin cooperative control mode, S cord To avoid oscillations in the drone's speed command, a judgment threshold is set when switching between the margin cooperative control model and the non-margin cooperative mode.

[0065] Given that S1-Sn≤S cord Under certain conditions, when the non-marginalized cooperative mode is enabled, the flight speed of each drone will be... V i Characterized according to the following formula:

[0066]

[0067] in, V leader This indicates the flight speed of the drone after it arrives at the priority arrival point P and is selected as the lead drone based on its sequence number. S leader This represents the remaining path estimate for the selected drone as the lead aircraft. k s This is the gain coefficient.

[0068] As can be seen from the above description, after proposing the concept of "cooperative margin" and its quantification method, this invention improves the method of UAV cooperative control by aiming at "maximizing cooperative margin". It breaks through the limitations of traditional "precise arrival" control and is committed to maximizing the robustness and adaptive adjustment capability of the system in the face of sudden situations at the end while ensuring the final arrival accuracy, thereby significantly improving the success rate of multi-UAV cooperative missions in complex environments.

[0069] Verification Example 1:

[0070] Application verification in scenarios facing sudden threats, such as Figure 3 As shown ( Figure 3 The orange area within the red line represents the sudden, temporary threat zone. When the drone approaches its final target, a new threat zone is detected, and the replanned path is approximately 10 km longer than the original path. At this point, the distance margin using existing methods is only... Figure 6 The 6.7km shown is insufficient to handle a path increase of 10km, even for the longest-distance drones. Figure 5 Flying at the maximum speed shown, when drone 2 and drone 3 arrive at the same time, drone 1 still has a distance of... Figure 4 The distance shown is incomplete.

[0071] Using the method of this invention, in the first half of the cooperative flight, the multiple unmanned aerial vehicle systems achieve synchronous arrival control in a manner that maximizes margin (e.g., Figure 9 As shown in the figure, at the same moment when path increase occurs, the cooperative path margin of the multi-UAV system is still as... Figure 10 The 20km range shown is sufficient to handle a 10km increase in path length, ultimately allowing multiple drones to operate as follows: Figure 7 He Ru Figure 8 As shown, they arrived at the target point simultaneously.

[0072] Verification Example 2:

[0073] In application verification facing a sudden headwind scenario, when Drone 1 approached the final target, it encountered... Figure 11 The headwind of 10 m / s shown decreases the usable speed range. At this moment, the speed margin of existing methods is only as follows: Figure 14 The speed of 8.1 m / s shown is insufficient to cope with a sudden headwind of 10 m / s. Ultimately, when drone 2 and drone 3... Figure 12 He Ru Figure 13 When they arrived at the same time, drone 1 still had some distance to cover, meaning that the three drones failed to reach the target point simultaneously.

[0074] Using the method of this invention, in the first half of the coordinated flight (such as...) Figure 17As shown in the figure, the multi-drone system achieves synchronous arrival control in a manner that maximizes margin. Even when encountering the same sudden headwind situation, the coordinated speed margin of the multi-drone system remains as good as before. Figure 18 The 20m / s speed shown is sufficient to handle headwinds of 10m / s, ultimately allowing multiple drones to... Figure 15 He Ru Figure 16 As shown, they arrived at the target point simultaneously.

[0075] The above solution is merely an illustration of a preferred example and is not limited thereto. When implementing this invention, appropriate substitutions and / or modifications can be made according to the user's needs.

[0076] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Other modifications can be readily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A method for controlling the simultaneous arrival of multiple unmanned aerial vehicles (UAVs) based on cooperative margin, characterized in that, including: S1. Define a collaborative margin that includes distance margin and speed margin, wherein the collaborative margin is calculated as time-remaining distance. t-S The graphical method describes the reasons and boundary conditions for the failure of coordinated arrival in the process of multi-UAV cooperation; S2. At the initial moment, the drone with the longest remaining distance in the cluster is set to start at the fastest speed. V max The drone with the shortest remaining distance should fly at the slowest speed. V min Flight, then the two drones will be in t-S The intersection points in the diagram are defined as priority arrival points. P ; S3, at any time t Real-time determination of each drone and its priority arrival point P remaining distance S i And in descending order S i Arranged as S 1, S 2,…, S n Simultaneously, the drone numbers are updated in real time as the remaining distance of the drones changes. U 1, U 2,…, U n ; S4, Judgment S 1 - S n > S cord If the conditions are met, the margin cooperative control mode will be used in scenarios where multiple UAVs maintain cooperative control under disturbances, and the control method of the margin cooperative control mode will be characterized by the following formula: In the above formula, ( T P , S P () is the priority arrival point P coordinates t For a moment, V ci The flight speed of each UAV in the margin cooperative control mode, S cord To avoid oscillations in the drone's speed command, a judgment threshold is set when switching between the margin cooperative control model and the non-margin cooperative mode. Otherwise, in order to satisfy S 1 - S n ≤ S cord Under certain conditions, when the non-marginalized cooperative mode is enabled, the flight speed of each drone will be... V i Characterized according to the following formula: in, V leader This indicates that after a drone reaches its priority arrival point, the drone with the highest sequence number is selected as the lead drone, and the lead drone's flight speed is... S leader This represents the remaining path estimate for the selected drone as the lead aircraft. k s This is the gain coefficient.

2. The multi-UAV simultaneous arrival control method based on cooperative margin as described in claim 1, characterized in that, In S1, cooperative path margin based on distance margin S mar It is characterized by the following formula: In the above formula, Is t-S In the picture, from T u dot V max Draw a straight line with the slope of the current timeline. t The remaining distance after the intersection, and T u For drones S 1. According to V min The time it takes for the flight to reach the target point.

3. The multi-UAV simultaneous arrival control method based on cooperative margin as described in claim 2, characterized in that, In S1, cooperative speed margin based on speed margin V mar It is characterized by the following formula: In the above formula, Is t-S In the picture, from S 1 o'clock T u The slope of the line.

4. The multi-UAV simultaneous arrival control method based on cooperative margin as described in claim 3, characterized in that, In S2, maximizing the cooperative margin means that, without changing the upper and lower boundaries of the UAV's velocity, the cooperative margin should be maximized. S n As large as possible, and S 1 should be as small as possible, so that S mar and V mar maximize.

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