Decentralized unmanned aerial vehicle conflict resolution method, equipment and unmanned aerial vehicle

Abstract

The invention discloses a decentration type unmanned aerial vehicle conflict resolution method and device and an unmanned aerial vehicle. The method comprises the following steps: acquiring state information of the unmanned aerial vehicle and state information of other unmanned aerial vehicles; detecting whether there is a conflict with other unmanned aerial vehicles according to the obtained state information; the conflict condition comprises an existing conflict and a potential conflict; based on a preset consensus rule, performing security separation analysis according to the state information and the conflict condition, generating a maneuvering strategy of the unmanned aerial vehicle, and adjusting the speed and / or course of the unmanned aerial vehicle according to the maneuvering strategy; wherein, when the maneuvering strategy is generated, a set route of the unmanned aerial vehicle is considered, and the deviation between the actual flight route of the unmanned aerial vehicle and the set route is minimized. When the maneuvering strategy of the unmanned aerial vehicle is generated, the set route of the unmanned aerial vehicle is considered, the deviation between the actual flight route and the set route of the unmanned aerial vehicle is minimized, the influence on tasks executed by the unmanned aerial vehicle and additional consumption are reduced, and the method can be widely applied to the technical field of unmanned aerial vehicles.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and in particular to a decentralized unmanned aerial vehicle conflict resolution method, device and unmanned aerial vehicle. Background Art

[0002] At present, drones are not only used in the military field, but also widely used in civilian fields such as cargo transportation, healthcare, traffic monitoring and smart agriculture. In addition, drones are also believed to play an important role in the construction of future 6G networks and smart cities. In these potential application scenarios, a large number of drones will fly densely in the airspace. Therefore, air traffic safety has gradually become the focus of people's attention. How to ensure that drones fly in an orderly manner while maintaining a safe distance from other drones is one of the urgent problems to be solved, which has also promoted many studies on conflict resolution. Considering the problem that the centralized optimization coordination method is difficult to apply when the number of drones flying in a local environment is large, the existing technology proposes a decentralized drone conflict resolution method oriented to task requirements.

[0003] Existing decentralized conflict resolution methods include artificial potential field methods, optimization-based methods, and geometric navigation methods. Artificial potential field methods can generate smooth and safe paths for UAVs in real time, but there are problems such as being easily trapped in local minima. Optimization-based methods can perform long-term conflict-free path planning for UAVs, but these methods have difficulty handling sudden conflicts. Geometric navigation-based methods, such as the speed barrier method and the collision cone method, can quickly find solutions based on the instantaneous geometric characteristics of the upcoming conflict without the need for a lot of prediction and analysis, and are therefore more suitable for short-term conflict resolution problems. However, existing methods still have some limitations. When calculating conflict avoidance strategies for UAVs involved in conflicts, the established tasks of the UAVs are ignored, making it difficult for the UAVs to quickly return to the established route. Another problem is that when UAVs face multiple conflicts, existing methods do not distinguish between conflicts, making it difficult for the generated strategies to avoid critical conflicts that have a greater impact on flight safety. In addition, although existing methods consider modifying the magnitude and direction of the UAV velocity vector to cover all possible maneuvering strategies, they do not consider the different preferences of UAVs for heading and speed adjustments when performing different tasks. Summary of the invention

[0004] In order to solve at least one of the technical problems existing in the prior art to a certain extent, the purpose of the present invention is to provide a decentralized UAV conflict resolution method, device and UAV oriented to task requirements.

[0005] The first technical solution adopted by the present invention is:

[0006] A decentralized UAV conflict resolution method, applied to a UAV, comprises the following steps:

[0007] Obtaining its own status information and the status information of other drones; the status information includes position information and speed information;

[0008] Detecting whether there is a conflict with other UAVs based on the acquired status information; the conflict situation includes existing conflicts and potential conflicts;

[0009] Based on the preset consensus rules, a safety separation analysis is performed according to the state information and conflict conditions, a maneuvering strategy of the UAV is generated, and the speed and / or heading of the UAV is adjusted according to the maneuvering strategy;

[0010] Among them, the established route of the UAV is taken into account when generating the maneuvering strategy, so as to minimize the deviation between the actual flight route of the UAV and the established route.

[0011] Furthermore, the detecting whether there is a conflict with other drones according to the acquired status information includes:

[0012] Each drone is defined with a p i (t) is the center and the radius is r i The circular safety area D i (p i (t),r i );

[0013] Assume that the two interacting drones are denoted as A i and A j , its current position and velocity are the position and velocity at t = 0; when t = 0, A i Relative to A j The position is denoted as p ij (0); A j Relative to A i The current speed is v ji ;

[0014] Assuming that each UAV involved in the conflict will adopt a strategy of adjusting its heading and speed, A i The heading adjustment and speed adjustment are and Δv i , A j The heading adjustment and speed adjustment are and Δv j , then A j Relative to A i The new velocity is v′ ji ;

[0015] To analyze A i and A j The relationship between iThe relative safety area is defined as in D ij The two tangent lines of form a collision cone through the origin of the coordinate system. To avoid collision, v′ ji Should be outside the collision cone, the constraints are expressed as:

[0016]

[0017] In the formula, k ji is v′ ji The slope of and Yes ij (0) weight;

[0018] The existing conflict is defined as: ji The direction is in the safe area D ij If the two UAVs involved in the conflict do not adopt appropriate strategies to adjust their heading and speed, then A j will enter a safe area at some point in the future;

[0019] The potential conflict is defined as: ji The current direction of the drone is not within the collision cone, however, if the drones involved in the conflict do not adopt appropriate strategies to change their heading and speed, it may cause v ji Re-enter the collision cone within time τ.

[0020] Furthermore, in order to discuss k ji The feasible solution range of , according to formula (1), defines formula (2):

[0021]

[0022] The root of formula (2) determines k ji Two thresholds of; Assuming that the two drones maintain safe separation at time t = 0, there exists Make the roots of equation (2) real numbers:

[0023]

[0024] in In formula (1), k ji The feasible solution range is given by and Decision; j Rotate the local coordinate system with A as the origin. i and A j The direction of the line between them is taken as the new Y axis, then k ji The feasible solution range is:

[0025]

[0026] Each conflicting constraint is represented by and Decide:

[0027] 1) In an existing conflict, v ji is within the collision cone, so and The constraints identified are all existing constraints;

[0028] 2) In potential conflicts, according to v ji There are three possible situations for the direction of v: ji If it is in area 1, The constraints determined are the existing constraints, and The constraints identified are potential constraints; if v ji If it is in area 2, The constraints determined are potential constraints, and The constraints determined are existing constraints; if v ji If it is in area 3, and The constraints identified are all potential constraints;

[0029] Depend on and The determined constraints cannot be satisfied at the same time. The conflicting drones will choose the constraints according to the right strategy, i.e. A i and A j Select by Determine the constraints.

[0030] Furthermore, the area 1, area 2 and area 3 are determined by:

[0031] straight line Divide the plane into two half planes, one of which contains the conflict area and the other does not contain the conflict area. The half plane that does not contain the conflict area is recorded as area 2.

[0032] straight line Divide the plane into two half planes, one of which contains the conflict area and the other does not contain the conflict area. The half plane that does not contain the conflict area is recorded as area 1.

[0033] The overlapping area of ​​area 1 and area 2 is recorded as area 3.

[0034] Furthermore, the safety separation analysis is performed according to the state information and the conflict situation to generate the maneuver strategy of the UAV, including:

[0035] In order to analyze the pairwise conflicting constraints, k ji Expands to:

[0036]

[0037] Rewrite formula (3) into the following form:

[0038]

[0039] Define two new variables:

[0040]

[0041] In the formula, v i For drone A i The current speed, v j For drone A j The current speed; Φ i ′ is drone A i The current heading, Φ j ′ is drone A j Current heading;

[0042] Transform formula (4) into and The linear relationship between:

[0043]

[0044] This results in a two-dimensional rectangular coordinate system exist In the example, the conflict-free region is represented as FR ij ; For existing constraints, the initial point For potential constraints, The minimum distance between the available vector and the boundary of the conflict-free zone express;

[0045] The mapping position of the new state of the UAV involved in the pairwise conflict after taking the maneuver is recorded as from arrive The vector is defined as

[0046] In the existing constraints, in order to ensure A i and A j The safe separation between in u m The projection in the direction should be greater than ‖u m ‖; On the contrary, in the potential constraint, in u m The projection in the direction should be smaller than ‖um ‖; Due to the kinematic constraints of the drone, Can't Any value above;

[0047] 1) Existing constraints: Assumption exist The component on the axis is exist The component on the axis is The possible value range of and Δv i The maneuver constraint determines The possible value range of and Δv j The maneuver constraint determines that; for the existing constraints, there is according to and The possible value range of , and the three cases with existing constraints are analyzed as follows:

[0048] a) Case 1: but The constraints are defined as:

[0049]

[0050] b) Case 2: but The minimum value should be taken so that A i There are more optional maneuver strategies; The constraints are defined as:

[0051]

[0052] c) Case 3: To ensure A i and A j The safety interval between j Should take more responsibility to make up for A i Maneuverability restriction; when A i When performing maximum maneuver, When the maximum value is reached, Should be less than Rather than less than This new state will fall into a conflict-free zone; It is expressed as:

[0053]

[0054] In the formula, The constraints are defined as follows:

[0055]

[0056] 2) Potential constraints: For potential constraints, there are according to and The possible value range of , the two cases of potential constraints are analyzed as follows:

[0057] a) Case 1: Despite the possibility of re-entering the conflict zone, considering A j You may encounter multiple conflicts at the same time, so you should try to make A j The maneuverable range of The constraints can be defined as:

[0058]

[0059] b) Case 2: To ensure in u m The projection in the direction is less than ‖u m ‖, The constraints can be defined as:

[0060]

[0061] In the formula,

[0062] Obtained according to the constraint range constraints and generate the UAV’s maneuver strategy.

[0063] Furthermore, the predetermined route of the UAV is taken into consideration when generating the maneuvering strategy so as to minimize the deviation between the actual flight route of the UAV and the predetermined route, including:

[0064] Adjustments in speed and / or heading will result in A j Deviate from the original flight path and after the conflict is resolved, j The speed of A is restored to its original speed, and j Return to the scheduled route;

[0065] Under the premise of satisfying safety interval constraints and maneuvering constraints, in order to ensure air traffic efficiency, the goal of collaborative conflict resolution is to minimize the additional flight cost. The objective function is defined as:

[0066]

[0067] In the formula, K1 and K2 are weights; v j A j The current speed, v j,oA j The initial velocity; is the return angle.

[0068] Furthermore, the decentralized UAV conflict resolution method further comprises the following steps:

[0069] When a drone faces multiple conflict situations, it calculates the urgency of each conflict situation, and judges and prioritizes conflicts that have a greater impact on its flight safety based on the urgency.

[0070] Furthermore, when the UAV faces multiple conflict situations, the urgency of each conflict situation is calculated, and conflicts with a greater impact on its flight safety are judged and handled preferentially according to the urgency, including:

[0071] For A j Every pairwise conflict encountered generates a The constraint is expressed as:

[0072]

[0073] Where, FS j|i express feasible solutions in pairwise conflicts;

[0074] When A j Multiple conflicts are encountered at the same time, and A j In each pairwise conflict, determine the constraints on the maneuvers; for multiple conflicts, The constraints can be expressed as:

[0075]

[0076] In the formula, C j Yes and A j a collection of conflicting drones;

[0077] When faced with multiple conflicts, The feasible solution area is A j The intersection of the feasible solution regions corresponding to each conflict encountered; if there is a conflict involving A j The two pairwise conflicting feasible solution domains of are disjoint, that is, When A j It will be impossible to determine a viable maneuver strategy;

[0078] Calculate the urgency of each conflict pair according to the preset index, sort the conflicts according to the urgency, and delete the constraints generated by the conflicts with the lowest urgency one by one until A j The feasible solution domain of is no longer an empty set.

[0079] The second technical solution adopted by the present invention is:

[0080] An electronic device comprises a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement a decentralized UAV conflict resolution method as described above.

[0081] The third technical solution adopted by the present invention is:

[0082] A drone comprises the electronic device as described above.

[0083] The fourth technical solution adopted by the present invention is:

[0084] A computer-readable storage medium stores at least one instruction, at least one program, a code set or an instruction set, wherein the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by a processor to implement a decentralized UAV conflict resolution method as described above.

[0085] The fifth technical solution adopted by the present invention is:

[0086] A computer program product or a computer program includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the above method.

[0087] The beneficial effect of the present invention is that the present invention takes into account the established route of the drone when generating the maneuvering strategy of the drone, thereby minimizing the deviation between the actual flight route of the drone and the established route, reducing the impact on the tasks performed by the drone and the additional consumption. In addition, for the situation where the drone faces multiple conflicts, the concept of conflict urgency is proposed, so that each drone can independently judge and give priority to the conflicts that have a greater impact on its flight safety. In addition, the proposed method combines speed maneuvering and heading maneuvering strategies, and can generate different conflict avoidance maneuvering strategies for drones according to their different preferences, providing drones with more flexible maneuvering options and enhancing the adaptability and practicality of the proposed method. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the embodiments of the present invention or the drawings of related technical solutions in the prior art are introduced below. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0089] Figure 1 is a schematic diagram of a UAV safety separation constraint based on a collision cone in an embodiment of the present invention; wherein, Figure 1 (a) shows the layout of two interacting drones. Figure 1 (b) shows the relative speed v of the drone ji Should be outside the collision cone (grey area);

[0090] Figure 2 is a schematic diagram of a local coordinate system after rotation in an embodiment of the present invention;

[0091] Figure 3 is a schematic diagram of different types of conflicts and constraints in an embodiment of the present invention; wherein, Figure 3 (a) shows existing conflicts (indicated by red arrows) and potential conflicts (indicated by blue arrows). Figure 3 (b) shows that the type of constraint is determined by v at t = 0. ji Decide;

[0092] Figure 4 is a schematic diagram of existing constraints and potential constraints represented in a mapping coordinate system in an embodiment of the present invention;

[0093] Figure 5 In the embodiment of the present invention, when A i When the required maneuver cannot be achieved, A j Schematic diagram of those who should take more responsibility for conflict resolution;

[0094] Figure 6 A in the embodiment of the present invention j exist Schematic diagram of the feasible solution region on the plane;

[0095] Figure 7 In the embodiment of the present invention, during the flight, A j Schematic diagram of multiple conflicts that may occur simultaneously with different neighbors;

[0096] Figure 8 is a schematic diagram of the urgency of pairwise conflicts in an embodiment of the present invention (red arrows indicate existing conflicts, and blue arrows indicate potential conflicts);

[0097] Fig. 9is a schematic diagram of an additional flight distance caused by heading maneuvering in an embodiment of the present invention;

[0098] Fig.10 is a flow chart of a decentralized conflict resolution algorithm in an embodiment of the present invention;

[0099] Fig.11 It is a flowchart of the steps of a decentralized UAV conflict resolution method in an embodiment of the present invention. DETAILED DESCRIPTION

[0100] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limitations of the present invention. For the step numbers in the following embodiments, they are only provided for the convenience of explanation, and the order between the steps is not limited in any way, and the execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0101] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0102] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0103] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0104] Example 1

[0105] like Fig.10 and Fig.11 As shown, this embodiment provides a decentralized UAV conflict resolution method, which is applied to a UAV and includes the following steps:

[0106] S1. Obtaining the status information of the drone and other drones; the status information includes position information and speed information;

[0107] S2. Detecting whether there is a conflict with other UAVs based on the acquired status information; the conflict situation includes existing conflicts and potential conflicts;

[0108] S3. Perform safety separation analysis based on status information and conflict situations. When the drone faces multiple conflict situations, calculate the urgency of each conflict situation, and judge and prioritize conflicts that have a greater impact on its flight safety based on the urgency.

[0109] S4, generating the maneuver strategy of the UAV based on the safety separation constraints obtained through analysis and the preset consensus rules;

[0110] S5. Adjust the speed and / or heading of the UAV according to the maneuvering strategy; wherein, when generating the maneuvering strategy, the predetermined route of the UAV is taken into consideration so as to minimize the deviation between the actual flight route of the UAV and the predetermined route.

[0111] The embodiment of the present invention proposes a geometry-based decentralized collaborative conflict resolution method, which establishes consensus rules (such as right-side strategies and constraint decoupling rules) between drones, so that each drone can independently determine the feasible maneuvering range of the conflict involved. The established route of the drone is taken into account when generating the drone's maneuvering strategy, so that the deviation between the actual flight route of the drone and the established route is minimized, reducing the impact on the tasks performed by the drone and additional consumption. For situations where drones face multiple conflicts, the concept of conflict urgency is proposed, so that each drone can independently judge and give priority to conflicts that have a greater impact on its flight safety. In addition, the proposed method combines speed maneuvering and heading maneuvering strategies, and can generate different conflict avoidance maneuvering strategies for drones according to their different preferences, providing drones with more flexible maneuvering options and enhancing the adaptability and practicality of the proposed method.

[0112] The above method is explained in detail below with reference to the accompanying drawings and specific implementation methods.

[0113] (1) UAV kinematic model

[0114] Assume that N drones are flying simultaneously in a two-dimensional plane space, and the i-th drone is denoted as A i , i∈{1,2,…,N}. A i The kinematic model of can be described using a rectangular coordinate system, where vector variables are in bold:

[0115]

[0116] in Indicates Ai At the time t, x i (t) and y i (t) are p i (t) Components on the X and Y axes. i (t) represents A i The velocity at time t, v i (t), i.e., velocity v i (t), whose value range is limited to arrive Φ i (t) is the heading angle of the UAV, indicating v i (t) Direction in a two-dimensional plane. a i (t) and ω i (t) are A i Acceleration and angular velocity at time t. and

[0117] The method of this embodiment controls the heading and speed of the UAV, namely A i Φ i (t) and v i (t) to resolve the conflict. i The heading adjustment and speed adjustment are recorded as and Δv i Combined with the maximum angular velocity and the acceleration limit, we can reasonably estimate the maximum steering angle that the drone can achieve within the time window t∈[0,τ] and speed range right and Δv i The constraints are defined as follows:

[0118]

[0119] (2) Inter-machine conflict analysis

[0120] In order to ensure the safety of the drone during flight, this embodiment defines a p i (t) is the center and the radius is r i The circular safety area D i (p i (t),r i ). i Yes A i The fixed parameters are given by A i Determined by the platform specifications.

[0121] like Figure 1 As shown in (a), the two interacting drones are denoted as A andi and A j , its current position and velocity are the position and velocity at t = 0. Figure 1 In the local coordinate system shown in (b), A j The position of is the origin of the local coordinate system. i Relative to A j The position is denoted as p ij (0).

[0122] p ij (0) = [x i (0)-x j (0) y i (0)-y j (0)] T (3)

[0123] Figure 1 (b) shows A i and A j The pairwise conflict between A j Relative to A i The current speed is v ji =v j (0)-v i (0). In order to maintain a safe interval, each UAV involved in the conflict will adopt a strategy of adjusting its heading and speed. Assume A i The heading adjustment and speed adjustment are and Δv i , A j The heading adjustment and speed adjustment are and Δv j , then A j Relative to A i The new velocity can be expressed as formula (4). To simplify the expression, we use v i and v j Instead of v i (0) and v j (0), using Φ i and Φ j Replace Φ i (0) and Φ j (0).

[0124]

[0125] To analyze A i and A j The relationship between will be located in A i The relative safety area is defined as in D ijThe two tangent lines of form a collision cone through the origin of the coordinate system. To avoid collision, v′ ji Should be outside the collision cone. The constraint is expressed as:

[0126]

[0127] Among them, k ji is v′ ji The slope of and Yes ij (0). In order to discuss k ji The feasible solution range of can be defined according to formula (5) as formula (6):

[0128]

[0129] The root of formula (6) determines k ji Assume that the two drones maintain safe separation at time t = 0, that is, there exists Make the roots of equation (6) real numbers.

[0130]

[0131] in In formula (5), k ji The feasible solution range is given by and Decision. j Rotate the local coordinate system with A as the origin. i and A j The direction of the line between them is taken as the new Y axis, then k ji The feasible solution range is:

[0132]

[0133] It is worth noting that the constraint condition of formula (8) is a necessary and sufficient condition of formula (5), but it does not make v j j i Necessary and sufficient conditions to stay outside the collision cone. Figure 2 As shown, if v′ ji The heading is within the shaded area with an angle of θ, that is, the relative velocity is directed so that A i and A j In this case, v′ ji It does not satisfy formula (5), but it can still ensure A i and A j Keep a safe distance between them.

[0134] The method of this embodiment considers two different conflicts. The first is called existing conflict. Figure 3 As shown in (a), v ji The heading is in the safe area D ij In this case, if the two UAVs involved in the conflict do not adopt appropriate strategies to adjust their headings and speeds, then A j Will enter the safe zone at some point in the future.

[0135] The second type is called potential conflict, which should be considered when multiple drones collide at the same time. Figure 3 As shown in (a), v ji The current heading of the drone may not be within the collision cone. However, if the drones involved in the conflict adopt inappropriate strategies to change heading and speed, it may cause v ji reenter the collision cone within time τ, which means they will no longer remain safely separated.

[0136] In order to analyze the pairwise conflicting constraints, k ji Expand to formula (9):

[0137]

[0138] Formula (9) can be rewritten as follows:

[0139]

[0140] in

[0141] Each conflict will generate two different constraints, respectively and The method of this embodiment considers two different types of constraints, namely existing constraints and potential constraints. Taking the decision constraint as an example, explain the difference between these two types of constraints.

[0142] like Figure 3 As shown in (b), the straight line The plane is divided into two half planes, one of which contains the conflict area and the other does not contain the conflict area. The half plane containing the conflict area is called the unsafe area, and the half plane not containing the conflict area is called the safe area. If v at t = 0 ji Located in an unsafe area, then The determined constraints are the existing constraints, which can be expressed as:

[0143]

[0144] If v ji In the safe area, then The determined constraints are potential constraints, which can be expressed as:

[0145]

[0146] Similarly, by The determined constraints can also be analyzed in the same way and are omitted here. and The identified constraints can be summarized as follows:

[0147]

[0148] and

[0149]

[0150] By analyzing the constraints (11) and (12), we can find that the type of constraint is determined by the relative velocity v at t = 0. ji In existing conflicts, ji is within the collision cone, so and The constraints determined are all existing constraints.

[0151] In potential conflicts, according to v ji There are three possible situations for the direction of Figure 3 As shown in (b), if v ji If it is in area 1, then The constraints determined are the existing constraints, and The constraints identified are potential constraints. If v ji If it is in area 2, The constraints determined are potential constraints, and The constraints determined are existing constraints. If v ji If it is in area 3, and The constraints identified are all potential constraints.

[0152] (3) Decentralized conflict resolution method based on spatial mapping

[0153] In this section, the UAV safety separation constraints based on the spatial mapping method are analyzed and the nonlinear constraints are linearized. Then, based on the linearized constraints, a decentralized conflict resolution method combining speed and heading adjustment is proposed.

[0154] 3.1) Linearization of safety separation constraints through spatial mapping

[0155] To ensure A i and A jThe heading adjustment and speed adjustment should satisfy the nonlinear inequality constraints of (13) or (14). However, it is difficult to establish a consensus rule that can decouple the conflict resolution responsibilities of the UAVs involved in the conflict based on nonlinear constraints. According to the structure of the inequality constraints, two new variables are defined:

[0156]

[0157] Where b = 1 or 2. Formula (10) can be transformed into and The linear relationship between:

[0158]

[0159] This results in a two-dimensional rectangular coordinate system It should be noted that and The two determined constraints cannot be satisfied at the same time. Therefore, when a conflict is detected, the two drones should reach a consensus to determine which constraint to satisfy. The method of this embodiment selects the constraint according to the right strategy, that is, A i and A j Will choose by Determine the safety separation constraints. Combined with the previous analysis, it can be inferred that when v ji When located in the conflict zone and zone 1, The constraint type is an existing constraint. ji When it is located in area 2 and area 3, The constraints identified are potential constraints. This strategy is very effective for conflict scenarios with multiple drones. If all drones find solutions to avoid conflicts according to the right strategy, they will all pass safely from the right side of the other drone, thus ensuring the orderly flight of the drones.

[0160] Next, we will discuss The safety separation constraint is determined in the rectangular coordinate system. Figure 4 As shown, the initial state of a pair of UAVs that produce pairwise conflicts is mapped to a point in the coordinate system, namely Figure 4 The red dashed rectangle in the middle represents the maneuverability constraints of the drone pair.

[0161]

[0162] exist In the figure, the non-conflict area and the conflict area are represented by straight lines. The conflict-free region is denoted as FR ij For existing constraints, the initial point For potential constraints, The minimum distance between the available vector and the boundary of the conflict-free zone express:

[0163]

[0164] The mapping position of the new state of the UAV involved in the pairwise conflict after taking the maneuver is recorded as from arrive The vector is defined as In the existing constraints, in order to ensure A i and A j The safe separation between in u m The projection in the direction should be greater than ‖u m ‖. On the contrary, in the potential constraint, in u m The projection in the direction should be smaller than ‖u m ‖. Due to the kinematic constraints of the drone, Can't Therefore, we further discuss the safety separation constraint:

[0165] 1) Existing constraints: Assumption exist The component on the axis is exist The component on the axis is It can be expressed as:

[0166]

[0167] The possible value range of and Δv i The maneuver constraint determines The possible value range of and Δv j The maneuver constraints determine the and The value range of is expressed as:

[0168]

[0169] According to equations (13) and (14), there must be Therefore, for the existing constraints, there is according to The possible value range of , and the three cases with existing constraints are analyzed as follows:

[0170] Case 1: but The constraints are defined as:

[0171]

[0172] Case 2: but The minimum value should be taken so that A i There are more optional maneuver strategies. The constraints are defined as:

[0173]

[0174] Case 3: To ensure A i and A j The safety interval between j Should take more responsibility to make up for A i Maneuverability restrictions. Figure 5 As shown, when A i When performing maximum maneuver, When the maximum value is reached, Should be less than Rather than less than This new state will fall into the conflict-free area. According to the geometric relationship, It can be expressed as:

[0175]

[0176] in The constraints are defined as follows:

[0177]

[0178] 2) Potential constraints: For potential constraints, there are according to and The possible value range of , the two cases of potential constraints are analyzed as follows:

[0179] Case 1: Despite the possibility of re-entering the conflict zone, considering A j You may encounter multiple conflicts at the same time, so you should try to make A j The maneuverable range is maximized. Therefore, The constraints can be defined as:

[0180]

[0181] Case 2: To ensure in u m The projection in the direction is less than ‖u m ‖, The constraints can be defined as:

[0182]

[0183] With the general The constraints are limited to In contrast, the constraints in (26) can expand A j The maneuverable range of A j Have more maneuver options when facing multiple conflicts.

[0184] 3.2) Constraints for safe separation of multiple drones

[0185] By discussing the constraints in different situations, we can The constraints are determined Constraints, so A j Substituting (19) into the above constraints, we can get the conflict resolution responsibilities under different conditions. At the same time, since A i Maneuver strategy In the same way, we analyzed A i and A j There are pairwise conflicts between Can meet the guarantee A i and A j Safety separation constraints. j Every pairwise conflict encountered generates a The constraint can be expressed as:

[0186]

[0187] Among them FS j|i express The feasible solution domain in pairwise conflicts. Figure 6 As shown, FS j|i Represents a nonlinear inequality constraint in The feasible region on the plane.

[0188] During the flight, A j There may be multiple conflicts at the same time, and A j The constraints on the maneuvers can be determined in each pairwise conflict. For multiple conflicts, The constraints can be expressed as:

[0189]

[0190] Among them, C j Yes and A j A collection of drones in conflict. Figure 6 As shown, when faced with multiple conflicts, The feasible solution area is A j The intersection of the feasible solution regions corresponding to each conflict encountered.

[0191] In the case of intensive conflict, there may be j The two pairwise conflicting feasible solution domains of are disjoint, that is, like Figure 7 As shown, A j There will be multiple neighbors approaching from different directions, and the constraints for resolving each pair of conflicts are contradictory. j It will be impossible to determine a viable maneuver strategy.

[0192] Therefore, corresponding mechanisms should be designed to deal with this situation. The research of Ballerini et al. shows that in the collective behavior of bird flocks, the interaction between members depends on the topological distance, and each bird interacts with a fixed number of neighbors on average, rather than all neighbors within a fixed metric distance. Inspired by this theory, this embodiment proposes to sort adjacent drones while considering the danger of conflict and give priority to more urgent conflicts. This embodiment defines the urgency of each pair of conflicts. When a drone encounters multiple pairs of conflicts, it sorts them according to the urgency. If A j If the feasible solution domain of A is empty, the constraints generated by conflicts with lower urgency will be removed one by one until A j The feasible solution domain of is no longer an empty set. Therefore, each drone can perform conflict avoidance maneuvers while considering more urgent conflicts.

[0193] This embodiment defines several indicators to measure the urgency of each conflict. Figure 8 As shown, the future A i and A j The minimum distance between is defined as i The position to v ji The vertical distance of the defined straight line. The smaller the minimum distance between two drones, the greater the maneuver they should take to avoid each other. Since the maneuverability of drones is limited, they need more time to complete larger maneuvers. Therefore, this embodiment uses the minimum distance as one of the criteria.

[0194] In addition, the current distance between the two drones will also affect the urgency of the pairwise conflict between them. If the distance between the two drones is far, the sudden maneuver of one or both drones will not cause them to lose the safety interval immediately. However, when the two drones are close, even if the safety distance can be maintained according to the current state of motion, a small maneuver of one drone may cause the two drones to lose the safety interval immediately. Therefore, the current distance between the two drones is also used to measure the urgency of the pairwise conflict.

[0195] Finally, the relative motion state between the two drones also affects the urgency of the pairwise conflict. When two drones approach each other quickly, the time to take maneuvers to avoid each other will be reduced. The predicted approach time of each pairwise conflict is defined as the third indicator of conflict urgency. j When encountering an existing conflict with its neighbors, the predicted approach time is A j The time to enter a relatively safe area. When they encounter a potential conflict, the predicted approach time is A i and A j The time when the distance between them reaches the minimum.

[0196] from Figure 8 It can be seen that the distance between the conflicting pairs of drones and the magnitude and direction of their relative speed will affect the predicted approach time. Specifically, the closer the distance, the greater the relative speed, and the closer the direction of the relative speed is to A. j The closer the connection between them and their neighbors, the shorter the predicted approach time will be. This means that the conflict is more urgent. In order to unify the measurement, the conflict urgency between two drones is defined as:

[0197]

[0198] where α * >0 is the weight. The parameter definition in formula (29) is as follows Figure 8 As shown. ij A i With A j The predicted minimum distance between To predict the approach time. ij In the composition of , the first term considers the influence of the minimum distance, the second term considers the influence of the current distance between the two drones, and the third term considers the influence of the predicted approach time. Note that DR ij The smaller the value of, the higher the urgency of the conflict.

[0199] Since in calculating DR ij The quantities used are scalar, so velocities of equal magnitude but opposite directions will calculate to the same DR ij Therefore, when the relative speed vji When it is in the lower half plane, The urgency of the conflict should be reduced when v ji When in zone 3, DR ij is set to 1000. In addition, since this embodiment adopts the right-side strategy, the DR of the pairwise conflicts in the left half plane with relative velocity ij This should be set to a small value because conflicts can become unresolvable if they are not resolved first.

[0200] 3.3) Decentralized conflict resolution algorithm

[0201] In Section 3.2 above, the safety separation constraints of multiple UAVs and the method for selecting the constraints have been defined. In addition to satisfying the constraints to ensure safe separation from other UAVs, A j The maneuver strategy should also satisfy the maneuver constraint conditions defined in equation (2). j The maneuver limit is denoted as ML j . The maneuver constraint condition is recorded as:

[0202]

[0203] Under the premise of satisfying safety interval constraints and maneuvering constraints, in order to ensure air traffic efficiency, the goal of collaborative conflict resolution is to minimize the additional flight cost. The objective function is defined as:

[0204] Where K * >0 is the weight. The objective function considers two aspects of the flight cost. The first is the deviation between the adjusted speed and the initial speed, where v j A j The current speed, v j,o A j The initial speed of A. j Ahead or behind schedule, so after the conflict is resolved, A j The speed should be restored to the original speed. The second is the deviation between the heading adjustment and the return angle, where is the return angle, so that A j Return to the scheduled route. Fig. 9 As shown, the heading maneuver will result in A j Deviate from the planned flight path and generate additional flight distance. j A temporary target will be selected on the predetermined path. j The heading should be as close as possible to the direction of the temporary target so that A j By setting different weights, Aj The selected maneuvering strategy is biased towards heading maneuvering or speed maneuvering.

[0205] By solving the following problem, we can get A j The optimal conflict avoidance strategy for

[0206]

[0207] Example 2

[0208] An embodiment of the present invention further provides an electronic device, the electronic device comprising a processor and a memory, the memory storing at least one instruction, at least one program, a code set or an instruction set, the at least one instruction, the at least one program, the code set or the instruction set being loaded and executed by the processor to implement the following Fig.11 A decentralized UAV conflict resolution method shown in FIG.

[0209] It is understood that the memory may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory may be used to store instructions, programs, codes, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function, instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data created according to the use of the server, etc.

[0210] The processor may include one or more processing cores. The processor uses various interfaces and lines to connect the various parts of the entire server, and executes various functions of the server and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory, and calling data stored in the memory. Optionally, the processor can be implemented in at least one hardware form of digital signal processing (DSP), field programmable gate array (FPGA), and programmable logic array (PLA). The processor can integrate one or a combination of a central processing unit (CPU) and a modem. Among them, the CPU mainly processes the operating system and application programs; the modem is used to process wireless communications. It can be understood that the above-mentioned modem may not be integrated into the processor, but implemented separately through a chip.

[0211] Since the electronic device is an electronic device corresponding to a decentralized UAV conflict resolution method in an embodiment of the present invention, and the principle of solving the problem by the electronic device is similar to that of the method, the implementation of the electronic device can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0212] Example 3

[0213] This embodiment provides a drone, which is equipped with a device for performing the following steps: Fig.11 The electronic device of the method shown. Specifically, the drone can be a fixed-wing drone or a rotary-wing aircraft, or other drones.

[0214] Example 4

[0215] The embodiment of the present invention further provides a computer-readable storage medium, wherein the storage medium stores at least one instruction, at least one program, code set or instruction set, and the at least one instruction, the at least one program, the code set or instruction set is loaded and executed by a processor to implement the following Fig.11 A decentralized UAV conflict resolution method is shown.

[0216] Those skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable rewritable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0217] Since the storage medium is a storage medium corresponding to a decentralized UAV conflict resolution method in an embodiment of the present invention, and the principle of solving the problem by the storage medium is similar to that of the method, the implementation of the storage medium can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0218] Example 5

[0219] In some possible implementations, various aspects of the method of the embodiments of the present invention may also be implemented in the form of a program product, which includes a program code. When the program product is run on a computer device, the program code is used to enable the computer device to execute the steps of a decentralized UAV conflict resolution method according to various exemplary embodiments of the present application described above in this specification. Among them, the executable computer program code or "code" used to execute various embodiments can be written in a high-level programming language such as C, C++, C#, Smalltalk, Java, JavaScript, Visual Basic, structured query language (e.g., Transact-SQL), Perl, or in various other programming languages.

[0220] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0221] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0222] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A decentralized UAV conflict resolution method, characterized in that: Applied to UAV, it includes the following steps: Get its own status information and other drones' status information; Detecting whether there is a conflict with other UAVs based on the acquired status information; the conflict situation includes existing conflicts and potential conflicts; Based on the preset consensus rules, a safety separation analysis is performed according to the state information and conflict conditions, a maneuvering strategy of the UAV is generated, and the speed and / or heading of the UAV is adjusted according to the maneuvering strategy; Among them, the established route of the UAV is taken into account when generating the maneuvering strategy, so as to minimize the deviation between the actual flight route of the UAV and the established route.

2. A decentralized UAV conflict resolution method according to claim 1, characterized in that: The detecting whether there is a conflict with other drones according to the obtained status information includes: Each drone is defined with a p i (t) is the center and the radius is r i The circular safety area D i (p i (t),r i ); Assume that the two interacting drones are denoted as A i and A j , its current position and velocity are the position and velocity at t = 0; when t = 0, A i Relative to A j The position is denoted as p ij (0); A j Relative to A i The current speed is v ji ; Assuming that each UAV involved in the conflict will adopt a strategy of adjusting its heading and speed, A i The heading adjustment and speed adjustment are and Δv i , A j The heading adjustment and speed adjustment are and Δv j , then A j Relative to A i The new velocity is v′ ji ; To analyze A i and A j The relationship between will be located in A i The relative safety area is defined as in D ij The two tangent lines of v form a collision cone through the coordinate origin. To avoid collision, v k ' i Should be outside the collision cone, the constraints are expressed as: In the formula, k ji Yes j ' i The slope of and Yes ij (0) weight; The existing conflict is defined as: ji The direction is in the safe area D ij If the two UAVs involved in the conflict do not adopt appropriate strategies to adjust their heading and speed, then A j will enter a safe area at some point in the future; The potential conflict is defined as: ji The current direction of the drone is not within the collision cone, however, if the drones involved in the conflict do not adopt appropriate strategies to change their heading and speed, it may cause v ji Re-enter the collision cone within time τ.

3. A decentralized UAV conflict resolution method according to claim 2, characterized in that: To discuss k ji The feasible solution range of , according to formula (1), defines formula (2): The root of formula (2) determines k ji Two thresholds of; Assuming that the two drones maintain safe separation at time t = 0, there exists Make the roots of equation (2) real numbers: in In formula (1), k ji The feasible solution range of and Decision; j Rotate the local coordinate system with A as the origin. i and A j The direction of the line between them is taken as the new Y axis, then k ji The feasible solution range is: Each conflicting constraint is represented by and Decide: 1) In an existing conflict, v ji is within the collision cone, so and The constraints identified are all existing constraints; 2) In potential conflicts, according to v ji There are three possible situations for the direction of v: ji If it is in area 1, then The constraints determined are the existing constraints, and The constraints identified are potential constraints; if v ji If it is in area 2, The constraints determined are potential constraints, and The constraints determined are existing constraints; if v ji If it is in area 3, and The constraints identified are all potential constraints; Depend on and The determined constraints cannot be satisfied at the same time. The conflicting drones will choose the constraints according to the right strategy, i.e. A i and A j Select by Determine the constraints.

4. A decentralized UAV conflict resolution method according to claim 3, characterized in that: The area 1, area 2 and area 3 are determined by: straight line Divide the plane into two half planes, one of which contains the conflict area and the other does not contain the conflict area. The half plane that does not contain the conflict area is recorded as area 2. straight line Divide the plane into two half planes, one of which contains the conflict area and the other does not contain the conflict area. The half plane that does not contain the conflict area is recorded as area 1. The overlapping area of ​​area 1 and area 2 is recorded as area 3.

5. A decentralized UAV conflict resolution method according to claim 3, characterized in that: The safety separation analysis is performed based on the state information and the conflict situation to generate the maneuver strategy of the UAV, including: In order to analyze the pairwise conflicting constraints, k ji Expands to: Rewrite formula (3) into the following form: Define two new variables: In the formula, v i For drone A i The current speed, v j For drone A j The current speed of i ′ is drone A i The current heading, Φ j ′ is drone A j Current heading; Transform formula (4) into and The linear relationship between: This results in a two-dimensional rectangular coordinate system exist In the example, the conflict-free region is represented as FR ij ; For existing constraints, the initial point For potential constraints, The minimum distance between the available vector and the boundary of the conflict-free zone express; The mapping position of the new state of the UAV involved in the pairwise conflict after taking the maneuver is recorded as from arrive The vector is defined as In the existing constraints, in order to ensure A i and A j The safe separation between in u m The projection in the direction should be greater than ‖u m ‖; On the contrary, in the potential constraint, in u m The projection in the direction should be smaller than ‖u m ‖; Due to the kinematic constraints of the drone, Can't Any value above; 1) Existing constraints: Assumption exist The component on the axis is exist The component on the axis is The possible value range of and Δv i The maneuver constraint determines The possible value range of and Δv j The maneuver constraint determines that; for the existing constraints, there is according to and The possible value range of , and the three cases with existing constraints are analyzed as follows: a) Case 1: but The constraints are defined as: b) Case 2: but The minimum value should be taken so that A i There are more optional maneuver strategies; The constraints are defined as: c) Case 3: To ensure A i and A j The safety interval between j Should take more responsibility to make up for A i Maneuverability restriction; when A i When performing maximum maneuver, When the maximum value is reached, Should be less than Rather than less than This new state will fall into a conflict-free zone; It is expressed as: In the formula, The constraints are defined as follows: 2) Potential constraints: For potential constraints, there are according to and The possible value range of , the two cases of potential constraints are analyzed as follows: a) Case 1: Despite the possibility of re-entering the conflict zone, considering A j You may encounter multiple conflicts at the same time, so you should try to make A j The maneuverable range of The constraints can be defined as: b) Case 2: To ensure in u m The projection in the direction is less than ‖u m ‖, The constraints can be defined as: In the formula, Obtained according to the constraint range constraints and generate the UAV’s maneuver strategy.

6. A decentralized UAV conflict resolution method according to claim 1, characterized in that: The method of taking into account the predetermined flight path of the UAV when generating the maneuvering strategy so as to minimize the deviation between the actual flight path of the UAV and the predetermined flight path includes: Adjustments in speed and / or heading will result in A j Deviate from the original flight path and after the conflict is resolved, j The speed of A is restored to its original speed, and j Return to the scheduled route; Under the premise of satisfying safety interval constraints and maneuvering constraints, in order to ensure air traffic efficiency, the goal of collaborative conflict resolution is to minimize the additional flight cost. The objective function is defined as: In the formula, K1 and K2 are weights; v j A j The current speed, v j,o A j The initial velocity; is the return angle.

7. A decentralized UAV conflict resolution method according to claim 1, characterized in that: The decentralized UAV conflict resolution method further comprises the following steps: When a drone faces multiple conflict situations, it calculates the urgency of each conflict situation, and judges and prioritizes conflicts that have a greater impact on its flight safety based on the urgency.

8. A decentralized UAV conflict resolution method according to claim 7, characterized in that: When the drone faces multiple conflict situations, the urgency of each conflict situation is calculated, and conflicts with greater impact on its flight safety are judged and handled with priority according to the urgency, including: For A j Every pairwise conflict encountered generates a The constraint is expressed as: Where, FS j|i express feasible solutions in pairwise conflicts; When A j Multiple conflicts are encountered at the same time, and A j In each pairwise conflict, determine the constraints on the maneuvers; for multiple conflicts, The constraints are expressed as: In the formula, C j Yes and A j a collection of conflicting drones; When faced with multiple conflicts, The feasible solution area is A j The intersection of the feasible solution regions corresponding to each conflict encountered; if there is a conflict involving A j The two pairwise conflicting feasible solution domains of are disjoint, that is, When A j It will be impossible to determine a viable maneuver strategy; Calculate the urgency of each conflict pair according to the preset index, sort the conflicts according to the urgency, and delete the constraints generated by the conflicts with the lowest urgency one by one until A j The feasible solution domain of is no longer an empty set.

9. An electronic device, characterized in that: The electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the method described in any one of claims 1 to 8.

10. A drone, characterized in that: Comprising an electronic device as claimed in claim 9.

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