CN118584981A - A method for controlling a cluster of fixed-wing UAVs in coordinated formation - Google Patents

Abstract

The invention relates to the technical field of unmanned aerial vehicle path planning, and provides a fixed wing unmanned aerial vehicle cluster cooperative formation control method, which comprises the following steps: determining formation roles of each fixed-wing unmanned aerial vehicle; determining formation parameters of the fixed wing unmanned aerial vehicle cluster; based on formation parameters of the fixed-wing unmanned aerial vehicle clusters and formation roles of each fixed-wing unmanned aerial vehicle, judging whether the fixed-wing unmanned aerial vehicle clusters need to be formed or not; based on formation parameters of the fixed-wing unmanned aerial vehicle clusters and formation roles of each fixed-wing unmanned aerial vehicle, carrying out cooperative formation control on the fixed-wing unmanned aerial vehicle clusters; and judging whether the fixed-wing unmanned aerial vehicle cluster finishes the cooperative formation control. The invention has reasonable and efficient design, can effectively divide the work of different roles for each fixed wing unmanned aerial vehicle in the cluster, and cooperatively solves the problem that the cluster formation of the fixed wing unmanned aerial vehicles is difficult to cooperatively control by different formation control logics of the long-wing unmanned aerial vehicles, thereby easily causing the collision of the fixed wing unmanned aerial vehicles in the cluster.

Description

A method for controlling a cluster of fixed-wing UAVs in coordinated formation

Technical Field

The present invention relates to the technical field of unmanned aerial vehicle path planning, and in particular to a method for controlling a fixed-wing unmanned aerial vehicle cluster coordinated formation.

Background Art

Drones are flexible, convenient and fast, and are widely used in civil and military fields. For example, drones are used in agriculture to spray pesticides, so that crops in the cultivated land can be fully covered with pesticides; in geographical surveying and mapping, drones are used to replace manpower to complete panoramic surveying and mapping in high-cold or high-altitude areas; drones are used in earthquake relief to search and rescue trapped people in disaster-stricken areas, etc.

Fixed-wing UAVs have broader prospects in industry, agriculture, rescue, scientific research and military due to their high maneuverability, high speed, long range and greater payload. When the mission is more complex, a single UAV may have problems such as too long mission duration, high battery consumption, insufficient remaining flight time, limited flight range and low mission robustness, and cannot complete the mission alone. Therefore, it is necessary to use multiple UAVs to form a cluster to solve practical problems through autonomous collaboration.

However, when fixed-wing UAV swarms deployed in actual scenarios perform specific tasks, they need to fly in a small-spacing formation. Coordinated control of fixed-wing UAV swarm formations to avoid collisions between fixed-wing UAVs within the formation is an important factor that needs to be considered. Existing methods do not give an appropriate response to this factor.

Summary of the invention

The present invention aims to provide a method for coordinated formation control of a fixed-wing UAV cluster, so as to solve the problem of coordinated control to avoid collision in the formation control of a fixed-wing UAV cluster.

The present invention provides a method for controlling a fixed-wing UAV cluster coordinated formation, comprising the following steps:

S1, determine the formation role of each fixed-wing UAV;

S2, determine the formation parameters of the fixed-wing UAV cluster;

S3, based on the formation parameters of the fixed-wing UAV cluster and the formation role of each fixed-wing UAV, determines whether the fixed-wing UAV cluster needs to be assembled in formation;

S4, based on the formation parameters of the fixed-wing UAV cluster and the formation role of each fixed-wing UAV, the fixed-wing UAV cluster collaborative formation control is performed;

S5, determining whether the fixed-wing UAV cluster has ended the coordinated formation control.

Furthermore, in step S1, the formation role of each fixed-wing UAV in the fixed-wing UAV cluster includes setting a number for each fixed-wing UAV before takeoff, and the fixed-wing UAV with the smallest number is the lead aircraft by default, and the remaining fixed-wing UAVs are wingmen.

Furthermore, in step S2, determining the formation parameters of the fixed-wing UAV cluster includes determining the formation of the fixed-wing UAV cluster, the horizontal spacing and height difference spacing of each wingman relative to the lead aircraft, and the real-time position of the lead aircraft.

Further, in step S3, determining whether the fixed-wing UAV cluster needs to be assembled in formation includes:

According to the formation parameters of the fixed-wing UAV cluster, the number of each fixed-wing UAV, the horizontal and height difference distance between each wingman and the lead aircraft, and the real-time position of the lead aircraft, the expected position of each wingman relative to the lead aircraft is determined; when the distance between a wingman and the expected position exceeds the distance threshold, the wingmen will assemble in formation.

Further, the formation assembly includes roll angle control, speed control and altitude control;

The roll angle control formula for wingman formation assembly is as follows:

in: is the wingman roll angle; is the north component of the vector from the wingman’s current position to the desired position, is the east component of the vector from the wingman's current position to the desired position; The desired track angle for the wingman; is the current track angle of the wingman; is the expected track angular velocity of the wingman; is the angular velocity conversion gain; Ground speed for the wingman; is the acceleration due to gravity; Sat() indicates the limited output; is the minimum roll angle of the wingman, is the maximum roll angle of the wingman;

The speed control formula for wingman formation assembly is as follows:

in, is the wingman speed, is the minimum speed of the wingman, is the maximum speed of the wingman; Take the absolute value of the deviation between the wingman's expected track angle and the wingman's current track angle;

The altitude control formula for wingman formation assembly is:

in, is the wingman altitude, is the height of the long aircraft, The number of the lead aircraft in the current formation. The number of the wingman in the current formation. It is the height difference between the lead aircraft and the wingman.

Furthermore, in step S4, the fixed-wing UAV cluster coordinated formation control includes lead aircraft formation control and wingman formation control.

Furthermore, only speed control is required in the lead aircraft formation control; the speed control formula for the lead aircraft formation control is:

in, Long machine speed, The default expected speed of the long-distance aircraft. is the minimum speed of the long machine, is the maximum speed of the long-haul aircraft, is the number of wingmen in the fixed-wing UAV cluster, is the formation waiting distance of the i -th wingman, is the long machine speed gain, It is the limit value of the wingman's standby distance.

Furthermore, the wingman formation control includes roll angle control, speed control and altitude control;

The roll angle control formula for wingman formation control is:

in; is the roll angle of the wingman formation control, is the minimum roll angle of the wingman formation control, The maximum roll angle of the wingman formation control; The waiting distance for the wingman formation. It is the side deviation distance of the wingman formation; is the foresight distance; is the current track angle of the lead aircraft; is the current track angle of the wingman; The desired track angle for the wingman; is the expected track angular velocity of the wingman; is the angular velocity conversion gain; is the desired roll angle; is the roll angle limit; is the flight path angular velocity of the lead aircraft; the ground speed of the lead aircraft and wingman ground speed The wingman's roll angle at the same time Roll angle with the lead aircraft same; is the acceleration due to gravity;

The speed control formula for wingman formation control is as follows:

in, is the wingman speed; is the desired velocity vector of the wingman in an ideal situation; and The actual flight path direction of the wingman and the speed of the leader are the control gains. The deviation is ;

The altitude control formula for wingman formation control is:

in, is the wingman altitude, is the height of the long aircraft, The number of the lead aircraft in the current formation. The number of the wingman in the current formation. It is the height difference between the lead aircraft and the wingman.

Furthermore, in step S5, determining whether the collaborative formation control of the fixed-wing UAV cluster has ended includes: determining whether the collaborative formation control of the fixed-wing UAV cluster in step S4 has ended based on control feedback information; if the collaborative formation control of the fixed-wing UAV cluster in step S4 has not ended, then returning to execute step S2 after a period of time; otherwise, ending the control process of the fixed-wing UAV cluster collaborative formation control method.

In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

The fixed-wing UAV cluster collaborative formation control method provided by the present invention is reasonably designed and efficient, and can effectively divide different roles for each fixed-wing UAV in the cluster. Through the different formation control logics of the leader and wingman, the problem of the difficulty in collaborative control of the fixed-wing UAV cluster formation, which easily causes collisions between the fixed-wing UAVs in the cluster, is collaboratively solved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a method for controlling a fixed-wing UAV cluster coordinated formation according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the relative positions of the lead aircraft and the wingman in an embodiment of the present invention.

FIG. 3 is a schematic diagram of the wingman formation assembly in an embodiment of the present invention.

FIG. 4 is a schematic diagram of the control of the lead aircraft formation in an embodiment of the present invention.

FIG. 5 is a schematic diagram of wingman formation control in an embodiment of the present invention.

DETAILED DESCRIPTION

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Example

As shown in FIG1 , this embodiment proposes a method for controlling a fixed-wing UAV cluster coordinated formation, comprising the following steps:

S1, determine the formation role of each fixed-wing UAV in the fixed-wing UAV cluster;

As shown in FIG. 2 , the preferred embodiment of the present invention is to determine the formation role of each fixed-wing UAV in the fixed-wing UAV cluster, including setting a number for each fixed-wing UAV before takeoff, and taking the fixed-wing UAV with the smallest number as the lead aircraft by default, and the remaining fixed-wing UAVs as wingmen.

S2, determine the formation parameters of the fixed-wing UAV cluster;

As shown in FIG. 2 , in the preferred embodiment of this invention, determining the formation parameters of the fixed-wing UAV cluster includes determining the formation shape of the fixed-wing UAV cluster, the horizontal spacing and height difference spacing of each wingman relative to the lead aircraft, and the real-time position of the lead aircraft and other parameters.

S3, based on the formation parameters of the fixed-wing UAV cluster and the formation role of each fixed-wing UAV, determines whether the fixed-wing UAV cluster needs to be assembled in formation;

As shown in FIG3 , in the preferred embodiment of this invention, determining whether the fixed-wing UAV cluster needs to be assembled in formation includes:

According to the formation parameters of the fixed-wing UAV cluster, the number of each fixed-wing UAV, the horizontal and height difference distance between each wingman and the lead aircraft, and the real-time position of the lead aircraft, the expected position of each wingman relative to the lead aircraft is determined; when a wingman is too far away from the expected position (exceeding the distance threshold, such as 1000 meters), the wingmen will form a formation to quickly approach the expected position. At this time, the control amount of the wingman is independent of the track angle direction of the lead aircraft.

Furthermore, the formation assembly includes roll angle control, speed control and altitude control.

As shown in Figure 3, the roll angle control formula for the wingman to perform formation assembly is as follows:

in: is the wingman roll angle; is the north component of the vector from the wingman’s current position to the desired position, is the east component of the vector from the wingman's current position to the desired position; The desired track angle for the wingman; is the current track angle of the wingman; is the expected track angular velocity of the wingman; is the angular velocity conversion gain, which can be taken as 1.0; Ground speed for the wingman; is the acceleration due to gravity; Sat() indicates the limited output; is the minimum roll angle of the wingman, is the maximum roll angle of the wingman.

The speed control formula for wingman formation assembly is as follows:

in, is the wingman speed, is the minimum speed of the wingman, is the maximum speed of the wingman; is the absolute value of the deviation between the wingman’s expected track angle and the wingman’s current track angle. Less than When the aircraft is in the desired position, it accelerates to the desired position; otherwise, it goes in the reverse state and flies at the minimum speed.

The altitude control formula for wingman formation assembly is:

in, is the wingman altitude, is the height of the long aircraft, The number of the lead aircraft in the current formation. The number of the wingman in the current formation. It is the height difference between the lead aircraft and the wingman.

S4, coordinated formation control of fixed-wing UAV cluster based on the formation parameters of the fixed-wing UAV cluster and the formation role of each fixed-wing UAV;

Preferably, the fixed-wing UAV cluster coordinated formation control includes lead aircraft formation control and wingman formation control.

Furthermore, the leader aircraft will fly autonomously according to the route waypoints during formation flight, and the leader aircraft only needs to perform speed control during formation control. If the leader aircraft flies at the lowest or highest speed, the wingman aircraft lacks speed adjustment space, and appropriate intervention in the leader aircraft's speed can greatly shorten the formation time. Therefore, the leader aircraft uses the fixed speed attribute set at the waypoint as the speed control benchmark. The leader aircraft collects the formation waiting distance of each wingman aircraft and adjusts the flight speed of the leader aircraft according to the average waiting distance of the wingman aircraft that lags behind or exceeds the expected position as a whole.

As shown in Figure 4, the speed control formula for the lead aircraft formation control is:

in, Long machine speed, The default expected speed of the long-distance aircraft. is the minimum speed of the long machine, is the maximum speed of the long-haul aircraft, is the number of wingmen in the fixed-wing UAV cluster, is the formation waiting distance of the i -th wingman, is the long machine speed gain, which can be set to 1. The distance limit for the wingman to wait for flight can be 1000m.

Furthermore, the wingman follows the lead aircraft, and the wingman formation control includes two parts: trajectory tracking control of the wingman and the lead aircraft and attitude tracking control of the wingman and the lead aircraft. The former is suitable for following the straight segment trajectory, and the latter is suitable for following the lead aircraft in turns and maintaining the distance when following the lead aircraft in turns. The two are combined to form the wingman tracking control law, which generates the roll angle control, speed control and altitude control of the wingman formation control.

The schematic diagram of wingman formation control is shown in Figure 5. The waiting distance for the wingman formation. is the wingman formation's side deviation distance. The purpose of wingman formation control is to make .

Roll angle control for wingman formation control:

Wingman formation control is the forward-looking distance, which is equivalent to the lateral control gain. The longer the distance, the smaller the gain. The parameter value is also related to the flight speed. The higher the speed, the better the formation assembly. The larger the value, the smaller the speed change. In this embodiment, a fixed value is taken. . is the current track angle of the lead aircraft, is the current track angle of the wingman, is the desired flight path angle of the wingman, is the wingman's expected track angular velocity, is the angular velocity conversion gain, which can be 1.0. is the desired roll angle, is the roll angle limit, here we take .

Attitude tracking control wingman follows the lead aircraft's roll angle , ignoring the roll angle of the long aircraft For values less than 1°, is the flight path angular velocity of the lead aircraft, and the ground speed of the lead aircraft and wingman ground speed At the same time, the wingman's roll angle Roll angle with the lead aircraft same, is the acceleration due to gravity.

The two channels are combined to form the final roll angle control formula for wingman formation control as follows:

Roll angle for wingman formation control.

Speed control for wingman formation control:

Assume that the desired velocity vector of the wingman in an ideal situation is , in the lead aircraft's track coordinate system, The expression is as follows:

in, and For control gain, both can be set to 1; the actual track direction of the wingman is The deviation is , that is, the track angle deviation between the wingman and the leader. Therefore, the speed control formula for wingman formation control is as follows:

in, is the wingman speed.

Consistent with the wingman formation assembly, the altitude control formula for wingman formation control is:

in, is the wingman altitude, is the height of the long aircraft, The number of the lead aircraft in the current formation. The number of the wingman in the current formation. It is the height difference between the lead aircraft and the wingman.

S5, determining whether the fixed-wing UAV cluster has ended the coordinated formation control.

Preferably, in this embodiment, determining whether the collaborative formation control of the fixed-wing UAV cluster has ended includes: determining whether the collaborative formation control of the fixed-wing UAV cluster in step S4 has ended based on control feedback information; if the collaborative formation control of the fixed-wing UAV cluster in step S4 has not ended, then returning to execute step S2 after a period of time; otherwise, ending the control process of the fixed-wing UAV cluster collaborative formation control method.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (9)

1. A method for controlling a fixed-wing UAV cluster coordinated formation, characterized in that it comprises the following steps: S1, determine the formation role of each fixed-wing UAV; S2, determine the formation parameters of the fixed-wing UAV cluster; S3, based on the formation parameters of the fixed-wing UAV cluster and the formation role of each fixed-wing UAV, determines whether the fixed-wing UAV cluster needs to be assembled in formation; S4, based on the formation parameters of the fixed-wing UAV cluster and the formation role of each fixed-wing UAV, the fixed-wing UAV cluster collaborative formation control is performed; S5, determining whether the fixed-wing UAV cluster has ended the coordinated formation control. 2. The method for controlling a cluster of fixed-wing UAVs in collaborative formation according to claim 1 is characterized in that, in step S1, the formation role of each fixed-wing UAV in the cluster of fixed-wing UAVs includes setting a number for each fixed-wing UAV before takeoff, and the fixed-wing UAV with the smallest number is the lead aircraft by default, and the remaining fixed-wing UAVs are wingmen. 3. The fixed-wing UAV cluster collaborative formation control method according to claim 2 is characterized in that, in step S2, determining the formation parameters of the fixed-wing UAV cluster includes determining the formation formation of the fixed-wing UAV cluster, the horizontal spacing and height difference spacing of each wingman relative to the lead aircraft, and the real-time position of the lead aircraft. 4. The method for controlling the coordinated formation of a fixed-wing UAV cluster according to claim 3, wherein in step S3, determining whether the fixed-wing UAV cluster needs to be assembled in formation comprises: According to the formation parameters of the fixed-wing UAV cluster, the number of each fixed-wing UAV, the horizontal and height difference distance between each wingman and the lead aircraft, and the real-time position of the lead aircraft, the expected position of each wingman relative to the lead aircraft is determined; when the distance between a wingman and the expected position exceeds the distance threshold, the wingmen will assemble in formation. 5. The method for controlling a cluster of fixed-wing UAVs in a coordinated formation according to claim 4, wherein the formation assembly includes roll angle control, speed control and altitude control; The roll angle control formula for wingman formation assembly is as follows: in: is the wingman roll angle; is the north component of the vector from the wingman’s current position to the desired position, is the east component of the vector from the wingman's current position to the desired position; The desired track angle for the wingman; is the current track angle of the wingman; is the expected track angular velocity of the wingman; is the angular velocity conversion gain; Ground speed for the wingman; is the acceleration due to gravity; Sat() indicates the limited output; is the minimum roll angle of the wingman, is the maximum roll angle of the wingman; The speed control formula for wingman formation assembly is as follows: in, is the wingman speed, is the minimum speed of the wingman, is the maximum speed of the wingman; Take the absolute value of the deviation between the wingman's expected track angle and the wingman's current track angle; The altitude control formula for wingman formation assembly is: in, is the wingman altitude, is the height of the long aircraft, The number of the lead aircraft in the current formation. The number of the wingman in the current formation. It is the height difference between the lead aircraft and the wingman. 6. The fixed-wing UAV cluster collaborative formation control method according to claim 5 is characterized in that, in step S4, the fixed-wing UAV cluster collaborative formation control includes lead aircraft formation control and wingman formation control. 7. The method for controlling a cluster of fixed-wing UAVs in coordinated formation according to claim 6, wherein only speed control is required in the control of the lead aircraft formation; the speed control formula of the lead aircraft formation control is: in, Long machine speed, The default expected speed of the long-distance aircraft. is the minimum speed of the long machine, is the maximum speed of the long-haul aircraft, is the number of wingmen in the fixed-wing UAV cluster, is the formation waiting distance of the i -th wingman, is the long machine speed gain, It is the limit value of the wingman's standby distance. 8. The fixed-wing UAV swarm coordinated formation control method according to claim 7, characterized in that the wingman formation control includes roll angle control, speed control and altitude control; The roll angle control formula for wingman formation control is: in, is the roll angle of the wingman formation control, is the minimum roll angle of the wingman formation control, The maximum roll angle of the wingman formation control; The waiting distance for the wingman formation. It is the side deviation distance of the wingman formation; is the foresight distance; is the current track angle of the lead aircraft; is the current track angle of the wingman; The desired track angle for the wingman; is the expected track angular velocity of the wingman; is the angular velocity conversion gain; is the desired roll angle; is the roll angle limit; is the flight path angular velocity of the lead aircraft; the ground speed of the lead aircraft and wingman ground speed The wingman's roll angle at the same time Roll angle with the lead aircraft same; is the acceleration due to gravity; The speed control formula for wingman formation control is as follows: in, is the wingman speed; is the desired velocity vector of the wingman in an ideal situation; and The actual flight path direction of the wingman and the speed of the leader are the control gains. The deviation is ; The altitude control formula for wingman formation control is: in, is the wingman altitude, is the height of the long aircraft, The number of the lead aircraft in the current formation. The number of the wingman in the current formation. It is the height difference between the lead aircraft and the wingman. 9. The fixed-wing UAV cluster collaborative formation control method according to claim 1 is characterized in that, in step S5, judging whether the fixed-wing UAV cluster has ended the collaborative formation control includes: judging whether the fixed-wing UAV cluster collaborative formation control in step S4 has been completed based on control feedback information; if the fixed-wing UAV cluster collaborative formation control in step S4 has not been completed, then returning to execute step S2 after a period of time; otherwise, ending the control process of the fixed-wing UAV cluster collaborative formation control method.