Unmanned aerial vehicle formation anti-collision method

Abstract

The invention relates to an unmanned aerial vehicle formation anti-collision method, which comprises the steps of 1, acquiring surrounding situation information of a local vehicle in real time, performing horizontal and vertical conflict detection on surrounding aircrafts, and screening out invading aircrafts possibly colliding with the local vehicle; step 2, sorting according to the threat degree of the invading aircraft to the local aircraft; 3, according to the relative positions of the invading aircrafts and the local aircraft, the avoidance situation is judged, according to the avoidance principle, an avoidance strategy set of the local aircraft for the invading aircrafts is selected from the strategy complete set, and the avoidance strategy sets corresponding to the invading aircrafts are synthesized to obtain an anti-collision strategy set T; step 4, solving a minimum strategy set Tfinal capable of being executed by the anti-collision strategy set T; 5, if the minimum strategy set Tfinal is non-null, the local machine executes the strategies in the minimum strategy set Tfinal, and if the minimum strategy set Tfinal is non-null, the local machine executes the strategies in the minimum strategy set Tfinal; and if the minimum strategy set Tfinal is empty, the avoidance strategy set corresponding to the invading aircraft with the lowest threat degree to the aircraft is removed from the anti-collision strategy set T, and the fourth step to the fifth step are carried out again.

Description

Technical Field

[0001] The present application belongs to the technical field of UAV formation collision avoidance design, and specifically relates to a UAV formation collision avoidance method. Background Art

[0002] With the development of drone technology, air traffic is becoming increasingly congested. Airspace itself is a limited resource. Under certain interval standards and air traffic control rules, it is an inevitable trend for drones and civil aircraft to share airspace.

[0003] Existing UAV collision avoidance technologies, such as artificial potential field method, geometric analysis method and probability-based prediction methods, do not take into account the situation of sharing airspace with civil aircraft, resulting in the algorithms being incompatible with civil aviation flight guidelines, which leads to three problems. First, the UAV collision avoidance algorithm makes its behavior unpredictable, resulting in air traffic control personnel being unable to know the flight position of the UAV after the collision avoidance is initiated, and thus unable to guide civil aircraft to perform reasonable avoidance; second, there is no human control on the UAV, and the ground control station personnel intervene and control the UAV flight through the link, but the ground control station personnel usually do not belong to the civil aviation system, so the air traffic control personnel cannot communicate with the ground control station personnel in time, resulting in time delays. This time delay increases the risk of collision between the UAV and the civil aircraft; third, the data link connecting the ground control station and the UAV is unstable. If the UAV encounters a civil aircraft and the data link fails, the UAV is in an uncontrolled state, which can easily lead to serious consequences.

[0004] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0005] The purpose of this application is to provide a UAV formation collision avoidance method to overcome or alleviate at least one of the known technical deficiencies.

[0006] The technical solution of this application is:

[0007] A UAV formation collision avoidance method, comprising:

[0008] Step 1: Obtain the situation information around the aircraft in real time, and perform horizontal and vertical conflict detection on surrounding aircraft to screen out intruding aircraft that may collide with the aircraft;

[0009] Step 2: Sort the invading aircraft according to their threat level to the aircraft itself;

[0010] Step 3: According to the relative position of the invading aircraft and the aircraft itself, the avoidance situation is determined. According to the avoidance principle, the avoidance strategy set of the aircraft itself to the invading aircraft is selected from the entire strategy set. The avoidance strategy sets corresponding to each invading aircraft are integrated to obtain the collision avoidance strategy set T;

[0011] Step 4: Find the minimum strategy set T that can be executed by the anti-collision strategy set T final ;

[0012] Minimum strategy set T final is the intersection of each avoidance strategy set in the collision avoidance strategy set T;

[0013] Step 5: If the minimum strategy set T final If it is non-empty, the local machine executes the minimum strategy set T final Medium strategy;

[0014] If the minimum strategy set T final If it is empty, remove the avoidance strategy set corresponding to the intruding aircraft that poses the lowest threat to the aircraft from the anti-collision strategy set T, and repeat steps 4 to 5.

[0015] Optionally, in the above-mentioned UAV formation collision avoidance method, in step 1:

[0016] Define aircraft A as the aircraft itself, which is considered stationary, and aircraft B as the surrounding aircraft;

[0017] In d min ≤R, calculate the time T taken by machine B to reach the horizontal projection monitoring area of ​​machine A au1 :

[0018]

[0019] in,

[0020] d min For A machine The distance is the relative motion speed of machine A and machine B on the XY plane; and are the components of the speed of machine A and machine B on the XY plane;

[0021] AB is the distance between machine A and machine B, θ is the oblique angle between machine A and machine B;

[0022] R is 50 km;

[0023] exist Calculate the time T taken by machine B to reach the vertical projection monitoring area of ​​machine A. au2 :

[0024]

[0025] in,

[0026] is the relative motion speed of machine A and machine B on the YZ plane; and is the component of the speed of machine A and machine B in the Z-axis direction;

[0027] are the direction vectors of machine A and machine B;

[0028] If (T au1 <20)∩(T au2 <20), then aircraft B is considered to be an intruder aircraft that may collide with aircraft A.

[0029] Optionally, in the above-mentioned UAV formation collision avoidance method, in step 2:

[0030] Take T au1 , T au2 The smaller value is used as the Tau value of the invading aircraft. The smaller the Tau value, the higher the threat level to the aircraft.

[0031] Optionally, in the above-mentioned UAV formation collision avoidance method, in step three, the avoidance strategy set includes strategy 0: turn right, strategy 1: turn left, strategy 2: descend, strategy 3: climb, strategy 4: deceleration, strategy 5: acceleration, strategy 6: deceleration, turn right, strategy 7: deceleration, turn left, strategy 8: deceleration, climb, strategy 9: deceleration, descend, strategy 10: acceleration, climb, strategy 11: acceleration, descend, strategy 12: climb, turn right, strategy 13: descend, turn right, strategy 14: climb, turn left, strategy 15: descend, turn left.

[0032] Optionally, in the above-mentioned UAV formation collision avoidance method, in step 3, the avoidance situation includes:

[0033] Avoidance scenario 1: The intruder aircraft meets the own aircraft head-on at the same altitude, -190°≤θ≤-170°, -260m≤Z≤260m, where θ is the difference in heading angle between the intruder aircraft and the own aircraft, and Z is the difference in altitude between the intruder aircraft and the own aircraft. The avoidance strategy set of the own aircraft against the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 6, strategy 12, and strategy 13;

[0034] Avoidance situation 2: The intruding aircraft meets the own aircraft at the same altitude and in the same direction, the own aircraft is behind, -10°≤θ≤10°, -260m≤Z≤260m, and the avoidance strategy set of the own aircraft to the intruding aircraft is selected from the full set of strategies as strategy 0, strategy 3, strategy 6, strategy 8, strategy 12, and strategy 13;

[0035] Avoidance scenario 3: Description: The intruder aircraft meets the own aircraft at the same altitude, the own aircraft is in front, -10°≤θ≤10°, -260m≤Z≤260m, and the avoidance strategy set for the intruder aircraft is selected from the full strategy set as strategy 0, strategy 3, strategy 6, strategy 8, strategy 12, strategy 13;

[0036] Avoidance situation 4: The intruding aircraft crosses with the own aircraft at the same altitude, -90°≤θ≤-10°, -260m≤Z≤260m, and the speed direction points to the own aircraft. The avoidance strategy set of the own aircraft to the intruding aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 3, strategy 10, strategy 12, strategy 14, strategy 6, strategy 7, and strategy 8;

[0037] Avoidance scenario 5: The invading aircraft crosses the own aircraft at the same altitude, -170°≤θ≤-90°, -260m≤Z≤260m, and the speed direction points to the own aircraft. The avoidance strategy set for the invading aircraft is selected from the full set of strategies: Strategy 1, Strategy 3, Strategy 14, Strategy 10, Strategy 7, Strategy 8, and Strategy 12.

[0038] Optionally, in the above-mentioned UAV formation collision avoidance method, in step 3, the avoidance situation also includes:

[0039] Avoidance scenario 6: Description: The intruder aircraft crosses with the own aircraft at the same altitude, 10°≤θ≤90°, -260m≤Z≤260m, and the speed direction points to the own aircraft. The avoidance strategy set of the own aircraft for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 2, strategy 11, strategy 13, strategy 15, strategy 6, strategy 7, and strategy 9;

[0040] Avoidance situation 7: The intruder aircraft crosses the own aircraft at the same altitude, -270°≤θ≤-190°, -260m≤Z≤260m, and the speed direction points to the own aircraft. The avoidance strategy set of the own aircraft for the intruder aircraft is selected from the full set of strategies: strategy 0, strategy 2, strategy 13, strategy 6, strategy 9, strategy 11, strategy 15;

[0041] Avoidance situation 8: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -180°≤θ≤0°, -260m≤Z≤260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 2, strategy 11, strategy 13, strategy 15 strategy 6, strategy 7, strategy 9;

[0042] Avoidance situation 9: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -90°≤θ≤-10°, Z≥260m, and the avoidance strategy set of the own aircraft against the intruder aircraft is selected from the full set of strategies: strategy 1, strategy 2, strategy 15, strategy 7, strategy 9, strategy 11;

[0043] Avoidance situation 10: The invading aircraft is above the own aircraft and its speed is pointing to the own aircraft, -180°≤θ≤-90°, Z≥260m. The avoidance strategy set for the invading aircraft is selected from the full set of strategies: strategy 0, strategy 2, strategy 6, strategy 9, strategy 13, and strategy 11.

[0044] Optionally, in the above-mentioned UAV formation collision avoidance method, in step 3, the avoidance situation also includes:

[0045] Avoidance situation 11: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -90°≤θ≤-10°, Z≥260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 2, strategy 13, strategy 15, strategy 6, strategy 7, strategy 9, strategy 11;

[0046] Avoidance situation 12: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -10°≤θ≤10°, 0°≤θ≤90°, Z≥260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 3, strategy 10, strategy 12, strategy 14, strategy 6, strategy 7, strategy 8;

[0047] Avoidance situation 13: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -100°≤θ≤-80°, Z≥260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies as strategy 1, strategy 3, strategy 14, strategy 7, strategy 8, and strategy 10;

[0048] Avoidance situation 14: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -270°≤θ≤-180°, Z≥260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies: strategy 0, strategy 3, strategy 12, strategy 6, strategy 8, strategy 10;

[0049] Avoidance situation 15: The invading aircraft is above the own aircraft and its speed is pointing to the own aircraft, -270°≤θ≤-190°, Z≥260m. The avoidance strategy set for the invading aircraft is selected from the full set of strategies: strategy 0, strategy 1, strategy 3, strategy 12, strategy 14, strategy 6, strategy 7, strategy 8, strategy 10.

[0050] Optionally, in the above-mentioned UAV formation collision avoidance method, in step 4, the minimum strategy set T final is the intersection of each avoidance strategy set in the collision avoidance strategy set T. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a schematic diagram of a UAV formation collision avoidance method provided in an embodiment of the present application;

[0052] Figure 2 is a schematic diagram of a distance ball model provided in an embodiment of the present application;

[0053] Figure 3 is a schematic diagram of a time ball model and its monitoring area provided in an embodiment of the present application;

[0054] Figure 4 is a schematic diagram of coordinate system definition provided in an embodiment of the present application;

[0055] Figure 5 is a schematic diagram of avoidance situation 1 provided in an embodiment of the present application;

[0056] Figure 6 is a schematic diagram of avoidance situation 2 provided in an embodiment of the present application;

[0057] Figure 7 is a schematic diagram of avoidance scenario 3 provided in an embodiment of the present application;

[0058] Figure 8 is a schematic diagram of avoidance situation 4 provided in an embodiment of the present application;

[0059] Fig. 9 is a schematic diagram of avoidance situation 5 provided in an embodiment of the present application;

[0060] Fig.10 is a schematic diagram of avoidance situation 6 provided in an embodiment of the present application;

[0061] Fig.11 is a schematic diagram of avoidance situation 7 provided in an embodiment of the present application;

[0062] Fig.12 is a schematic diagram of avoidance situation 8 provided in an embodiment of the present application;

[0063] Fig.13 is a schematic diagram of avoidance situation 8 provided in an embodiment of the present application;

[0064] Fig.14 is a schematic diagram of avoidance situation 9 provided in an embodiment of the present application;

[0065] Fig.15 is a schematic diagram of an avoidance situation 10 provided in an embodiment of the present application;

[0066] Fig.16 is a schematic diagram of an avoidance situation 11 provided in an embodiment of the present application;

[0067] Fig.17 is a schematic diagram of an avoidance situation 12 provided in an embodiment of the present application;

[0068] Fig.18 is a schematic diagram of an avoidance situation 12 provided in an embodiment of the present application;

[0069] Fig.19 is a schematic diagram of avoidance situation 13 provided in an embodiment of the present application;

[0070] Fig. 20 is a schematic diagram of an avoidance situation 14 provided in an embodiment of the present application;

[0071] Fig.21 It is a schematic diagram of avoidance situation 15 provided in an embodiment of the present application.

[0072] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0073] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0074] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0075] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0076] An unmanned aerial vehicle formation collision avoidance method mainly includes two parts: safety conflict detection and collision avoidance strategy design. The safety conflict detection defines the concept of a distance ball model, defines the time ball model and the concept of a monitoring area according to the safety reserve time, and designs horizontal and vertical safety conflict detection algorithms based on the distance ball and time ball models. Once it is detected that the collision avoidance conditions between the aircraft and other aircraft are met, the collision avoidance strategy is started. The collision avoidance strategy defines 15 situations based on the different positions and speed directions of the invading aircraft relative to the aircraft, covering all possible collision scenarios, and designs different strategy sets for each scenario. All strategies are compatible with the "Basic Flight Rules of the People's Republic of China", which can solve the need for simultaneous avoidance of aircraft isomorphic to the formation and civil aircraft when the unmanned aerial vehicles are in non-dense formation, making the unmanned aerial vehicle avoidance action predictable, while meeting the civil aviation standards, and reducing the safety risk of unmanned aerial vehicles and civil aircraft flying in the same airspace.

[0077] A UAV formation collision avoidance method, such as Figure 1 As shown, the following steps are included.

[0078] Step 1: Obtain the situation information around the aircraft in real time, and perform horizontal and vertical conflict detection on surrounding aircraft to screen out invading aircraft that may collide with the aircraft.

[0079] Define the three-dimensional area with a radius of 150m with the aircraft as the center as the distance sphere, such as Figure 2 As shown, the distance ball represents the size of the aircraft. If another aircraft invades the distance ball, it is considered that the other aircraft has collided with the aircraft.

[0080] Define Tau as the reserved time, which is the time required for the distance ball from the invading aircraft to the own aircraft. With the own aircraft as the center, the three-dimensional area within the range of Tau < 40s is the alert area, and the three-dimensional area within the range of Tau < 20s is the warning area. The time ball is obtained, such as Figure 3 shown.

[0081] Define the three-dimensional spherical area with the aircraft as the center and a radius of R = 50km as the monitoring area, such as Figure 3 As shown, the aircraft only takes collision avoidance measures against intruding aircraft in the surveillance area.

[0082] With the aircraft as the center, establish the Northeast Sky three-dimensional coordinate system, with the positive direction of the X axis pointing to the east, the positive direction of the Y axis pointing to the north, and the positive direction of the Z axis pointing to the sky. Figure 4 shown.

[0083] Perform horizontal conflict detection on surrounding aircraft. Please refer to the following for details:

[0084] On the XY plane, aircraft A is the aircraft itself and is considered stationary, and aircraft B is the surrounding aircraft. The two aircraft move at a relative speed. near:

[0085]

[0086] in,

[0087] and are the components of the speed of machine A and machine B on the XY plane.

[0088] Definition min For A machine If the distance d min ≤R, it is considered that there is a horizontal collision risk, and the time T taken by machine B to reach the horizontal projection monitoring area of ​​machine A is calculated. au1 :

[0089]

[0090] in,

[0091] AB is the distance between machine A and machine B, and θ is the oblique angle between machine A and machine B.

[0092] Perform vertical conflict detection on surrounding aircraft. Please refer to the following for details:

[0093] On the YZ plane, aircraft A is the aircraft itself and is considered stationary, and aircraft B is the surrounding aircraft. The two aircraft move at a relative speed. near:

[0094]

[0095] in,

[0096] and It is the component of the speed of machine A and machine B in the Z-axis direction.

[0097] like The vector angle is less than 90, where is the direction vector of machine A and machine B, then it is considered that there is a vertical collision risk, and the time T taken by machine B to reach the vertical projection monitoring area of ​​machine A is calculated. au2 :

[0098]

[0099] If (T au1 <20)∩(T au2 <20), then aircraft B is considered to be an intruder aircraft that may collide with aircraft A.

[0100] Step 2: Sort the invading aircraft according to their threat level to the aircraft itself.

[0101] Take T au1 、T au2The smaller value is used as the Tau value of the invading aircraft. The smaller the Tau value, the higher the threat level to the aircraft.

[0102] Step 3: According to the relative position of the invading aircraft and the aircraft, the avoidance situation is determined. According to the avoidance principle, the avoidance strategy set of the aircraft to the invading aircraft is selected from the entire strategy set. The avoidance strategy sets corresponding to each invading aircraft are integrated to obtain the collision avoidance strategy set T.

[0103] The aircraft avoids collisions mainly by changing altitude (climbing, descending), speed (accelerating, decelerating) and heading (turning left and right). The above three operations are combined to form the following avoidance strategy set:

[0104] Strategy 0: turn right, strategy 1: turn left, strategy 2: descend, strategy 3: climb, strategy 4: decelerate, strategy 5: accelerate, strategy 6: decelerate, turn right, strategy 7: decelerate, turn left, strategy 8: decelerate, climb, strategy 9: decelerate, descend, strategy 10: accelerate, climb, strategy 11: accelerate, descend, strategy 12: climb, turn right, strategy 13: descend, turn right, strategy 14: climb, turn left, strategy 15: descend, turn left, as shown in the following table:

[0105] All possible scenarios that the drone may encounter are classified according to the quadrant in which the invading aircraft is located and its speed direction. At the same time, the basic flight rules of the People's Republic of China are used as the design constraints to form avoidance principles for each type of scenario. Based on the avoidance principles, a special strategy set is designed for each type of scenario.

[0106] For each invading aircraft, the quadrant in which the invading aircraft is located relative to the own aircraft is determined based on its relative position to the own aircraft. Combined with the speed of the invading aircraft and the speed of the own aircraft, corresponding avoidance situations are used to form an avoidance strategy set Ti for each invading aircraft. If there are N invading aircraft, the corresponding avoidance strategy set T = {T1, T2, ...Tn}.

[0107] There are fifteen avoidance situations:

[0108] Avoidance Scenario 1:

[0109] Description: The intruder aircraft meets the own aircraft head-on at the same altitude, -190°≤θ≤-170°, -260m≤Z≤260m, where θ is the difference in heading angle between the intruder aircraft and the own aircraft, and Z is the difference in altitude between the intruder aircraft and the own aircraft, such as Figure 5 shown.

[0110] Avoidance principle: When meeting head-on at the same height, avoid to the right.

[0111] From the full set of strategies, the evasion strategy set for the aircraft is selected as strategy 0, strategy 6, strategy 12, and strategy 13, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 6 - √ - - - √ Strategy 12 - - √ - - √ Strategy 13 - - - √ - √

[0112] Avoidance Scenario 2:

[0113] Description: The intruder aircraft meets the own aircraft at the same altitude and in the same direction. The own aircraft is behind, -10°≤θ≤10°, -260m≤Z≤260m, such as Figure 6 shown.

[0114] Avoidance principle: When two aircraft meet at the same altitude, the rear aircraft avoids to the right and climbs, while the front aircraft avoids to the left and descends.

[0115] The avoidance strategy set for the aircraft to the intruder is selected from the full set of strategies as strategy 0, strategy 3, strategy 6, strategy 8, strategy 12, and strategy 13, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 3 - - √ - - - Strategy 6 - √ - - - √ Strategy 8 - √ √ - - - Strategy 12 - - √ - - √ Strategy 13 - - - √ - √

[0116] Avoidance Scenario 3:

[0117] Description: The intruder aircraft meets the own aircraft at the same altitude, the own aircraft is in front, -10°≤θ≤10°, -260m≤Z≤260m, such as Figure 7 shown.

[0118] Avoidance principle: When two aircraft meet at the same altitude, the rear aircraft avoids to the right and climbs, while the front aircraft avoids to the left and descends.

[0119] The avoidance strategy set for the aircraft to the intruder is selected from the full set of strategies as strategy 0, strategy 3, strategy 6, strategy 8, strategy 12, and strategy 13, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 1 - - - - √ - Strategy 2 - - - √ - - Strategy 11 √ - - √ - - Strategy 14 - - √ - √ - Strategy 15 - - - √ √ -

[0120] Avoidance Scenario 4:

[0121] Description: The intruder aircraft crosses the own aircraft at the same altitude, -90°≤θ≤-10°, -260m≤Z≤260m, and the speed direction points to the own aircraft, such as Figure 8 shown.

[0122] Avoidance principle: When two aircraft cross each other at the same altitude, if the other aircraft is on the left, your aircraft should lower its altitude; if the other aircraft is on the right, your aircraft should climb its altitude.

[0123] The avoidance strategy set for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 3, strategy 10, strategy 12, strategy 14, strategy 6, strategy 7, and strategy 8, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 1 - - - - √ - Strategy 3 - - √ - - - Strategy 10 √ - √ - - - Strategy 12 - - √ - - √ Strategy 14 - - √ - √ - Strategy 6 - √ - - - √ Strategy 7 - √ - - √ - Strategy 8 - √ √ - - -

[0124] Avoidance Scenario 5:

[0125] Description: The intruder aircraft crosses the own aircraft at the same altitude, -170°≤θ≤-90°, -260m≤Z≤260m, and the speed direction points to the own aircraft, such as Fig. 9 shown.

[0126] Avoidance principle: When two aircraft cross each other at the same altitude, if the other aircraft is on the left, your aircraft should lower its altitude; if the other aircraft is on the right, your aircraft should climb its altitude.

[0127] The avoidance strategy set for the intruder aircraft is selected from the entire strategy set as strategy 1, strategy 3, strategy 14, strategy 10, strategy 7, strategy 8, and strategy 12, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 1 - - - - √ - Strategy 3 - - √ - - - Strategy 14 - - √ - √ - Strategy 10 √ - √ - - - Strategy 7 - √ - - √ - Strategy 8 - √ √ - - - Strategy 12 - - √ - - √

[0128] Avoidance Situation 6:

[0129] Description: The intruder aircraft crosses the own aircraft at the same altitude, 10°≤θ≤90°, -260m≤Z≤260m, and the speed direction points to the own aircraft, such as Fig.10 shown.

[0130] Avoidance principle: When two aircraft cross each other at the same altitude, if the other aircraft is on the left, your aircraft should lower its altitude; if the other aircraft is on the right, your aircraft should climb its altitude.

[0131] The avoidance strategy set for the intruder aircraft is selected from the entire strategy set as strategy 0, strategy 1, strategy 2, strategy 11, strategy 13, strategy 15, strategy 6, strategy 7, and strategy 9, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 1 - - - - √ - Strategy 2 - - - √ - - Strategy 11 √ - - √ - - Strategy 13 - - - √ - √ Strategy 15 - - - √ √ - Strategy 6 - √ - - - √ Strategy 7 - √ - - √ - Strategy 9 - √ - √ - -

[0132] Avoidance Situation 7:

[0133] Description: The intruder aircraft crosses the own aircraft at the same altitude, -270°≤θ≤-190°, -260m≤Z≤260m, and the speed direction points to the own aircraft, such as Fig.11 shown.

[0134] Avoidance principle: When two aircraft cross each other at the same altitude, if the other aircraft is on the left, your aircraft should lower its altitude; if the other aircraft is on the right, your aircraft should climb its altitude.

[0135] The avoidance strategy set for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 2, strategy 13, strategy 6, strategy 9, strategy 11, and strategy 15, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 2 - - - √ - - Strategy 13 - - - √ - √ Strategy 6 - √ - - - √ Strategy 9 - √ - √ - - Strategy 11 √ - - √ - - Strategy 15 - - - √ √ -

[0136] Avoidance Situation 8:

[0137] Description: The invading aircraft is above the own aircraft, and its speed is pointing towards the own aircraft, -180°≤θ≤0°, -260m≤Z≤260m, such as Fig.12 , 13 shown.

[0138] Avoidance principle: When aircraft at different altitudes meet each other, the low-altitude aircraft shall not climb and the high-altitude aircraft shall not descend.

[0139] The avoidance strategy set for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 2, strategy 11, strategy 13, strategy 15, strategy 6, strategy 7, and strategy 9, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 1 - - - - √ - Strategy 2 - - - √ - - Strategy 11 √ - - √ - - Strategy 13 - - - √ - √ Strategy 15 - - - √ √ - Strategy 6 - √ - - - √ Strategy 7 - √ - - √ - Strategy 9 - √ - √ - -

[0140] Avoidance Situation 9:

[0141] Description: The intruder aircraft is above the aircraft, and its speed is pointing towards the aircraft, -90°≤θ≤-10°, Z≥260m, such as Fig.14 shown.

[0142] Avoidance principle: When aircraft at different altitudes meet each other, the low-altitude aircraft shall not climb and the high-altitude aircraft shall not descend.

[0143] The avoidance strategy set for the intruder aircraft is selected from the entire strategy set as strategy 1, strategy 2, strategy 15, strategy 7, strategy 9, and strategy 11, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 1 - - - - √ - Strategy 2 - - - √ - - Strategy 15 - - - √ √ - Strategy 7 - √ - - √ - Strategy 9 - √ - √ - - Strategy 11 √ - - √ - -

[0144] Avoidance Situation 10:

[0145] Description: The invading aircraft is above the own aircraft, and its speed is pointing towards the own aircraft, -180°≤θ≤-90°, Z≥260m, such as Fig.15 shown.

[0146] Avoidance principle: When aircraft at different altitudes meet each other, the low-altitude aircraft shall not climb and the high-altitude aircraft shall not descend.

[0147] The avoidance strategy set for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 2, strategy 6, strategy 9, strategy 13, and strategy 11, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 2 - - - √ - - Strategy 6 - √ - - - √ Strategy 9 - √ - √ - - Strategy 13 - - - √ - √ Strategy 11 √ - - √ - -

[0148] Avoidance Situation 11:

[0149] Description: The intruder aircraft is above the aircraft, and its speed is pointing towards the aircraft, -90°≤θ≤-10°, Z≥260m, such as Fig.16 shown.

[0150] Avoidance principle: When aircraft at different altitudes meet each other, the low-altitude aircraft shall not climb and the high-altitude aircraft shall not descend.

[0151] The avoidance strategy set for the intruder aircraft is selected from the entire strategy set as strategy 0, strategy 1, strategy 2, strategy 13, strategy 15, strategy 6, strategy 7, strategy 9, and strategy 11, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 1 - - - - √ - Strategy 2 - - - √ - - Strategy 13 - - - √ - √ Strategy 15 - - - √ √ - Strategy 6 - √ - - - √ Strategy 7 - √ - - √ - Strategy 9 - √ - √ - - Strategy 11 √ - - √ - -

[0152] Avoidance Situation 12:

[0153] Description: The invading aircraft is above the own aircraft, and its speed is pointing to the own aircraft, -10°≤θ≤10°, 0°≤θ≤90°, Z≥260m, such as Fig.17 , 18 shown.

[0154] Avoidance principle: When aircraft at different altitudes meet each other, the low-altitude aircraft shall not climb and the high-altitude aircraft shall not descend.

[0155] The avoidance strategy set for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 3, strategy 10, strategy 12, strategy 14, strategy 6, strategy 7, and strategy 8, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 1 - - - - √ - Strategy 3 - - √ - - - Strategy 10 √ - √ - - - Strategy 12 - - √ - - √ Strategy 14 - - √ - √ - Strategy 6 - √ - - - √ Strategy 7 - √ - - √ - Strategy 8 - √ √ - - -

[0156] Avoidance Situation 13:

[0157] Description: The invading aircraft is above the own aircraft, and its speed is pointing to the own aircraft, -100°≤θ≤-80°, Z≥260m, such as Fig.19 shown.

[0158] Avoidance principle: When aircraft at different altitudes meet each other, the low-altitude aircraft shall not climb and the high-altitude aircraft shall not descend.

[0159] The avoidance strategy set for the intruder aircraft is selected from the full set of strategies as strategy 1, strategy 3, strategy 14, strategy 7, strategy 8, and strategy 10, as shown in the following table:

[0160] Avoidance Situation 14:

[0161] Description: The invading aircraft is above the own aircraft, and its speed is pointing towards the own aircraft, -270°≤θ≤-180°, Z≥260m, such as Fig. 20 shown.

[0162] Avoidance principle: When aircraft at different altitudes meet each other, the low-altitude aircraft shall not climb and the high-altitude aircraft shall not descend.

[0163] The avoidance strategy set for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 3, strategy 12, strategy 6, strategy 8, and strategy 10, as shown in the following table: accelerate slow down Climb decline Turn left Turn right Strategy 0 - - - - - √ Strategy 3 - - √ - - - Strategy 12 - - √ - - √ Strategy 6 - √ - - - √ Strategy 8 - √ √ - - - Strategy 10 √ - √ - - -

[0164] Avoidance Situation 15:

[0165] Description: The invading aircraft is above the own aircraft, and its speed is pointing towards the own aircraft, -270°≤θ≤-190°, Z≥260m, such as Fig.21 shown.

[0166] Avoidance principle: When aircraft at different altitudes meet each other, the low-altitude aircraft shall not climb and the high-altitude aircraft shall not descend.

[0167] The avoidance strategy set for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 3, strategy 12, strategy 14, strategy 6, strategy 7, strategy 8, and strategy 10, as shown in the following table:

[0168] Step 4: Find the minimum strategy set T that can be executed by the anti-collision strategy set T final .

[0169] Minimum strategy set T final is the intersection of each avoidance strategy set in the collision avoidance strategy set T.

[0170] Step 5: If the minimum strategy set T final If it is non-empty, the local machine executes the minimum strategy set T final Medium strategy.

[0171] If the minimum strategy set T final If it is empty, remove the avoidance strategy set corresponding to the intruding aircraft that poses the lowest threat to the aircraft from the anti-collision strategy set T, and repeat steps 4 to 5.

[0172] The UAV formation collision avoidance method disclosed in the above embodiment classifies all situations in which the UAV may encounter an invading aircraft, and designs a collision avoidance rule based on the "Basic Flight Rules of the People's Republic of China" for each category, so that the UAV can avoid both homogeneous aircraft in the formation and civil aircraft, making the evasive behavior of the UAV in an uncontrolled situation predictable and compatible with the flight rules of civil aircraft, which not only reduces the safety hazard of collision between the two aircraft, but also improves the utilization rate of limited airspace resources, so that the existing air traffic management system can meet the needs of manned and unmanned development and greatly improve the efficiency of air transportation.

[0173] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A UAV formation collision avoidance method, characterized in that: include: Step 1: Obtain the situation information around the aircraft in real time, and perform horizontal and vertical conflict detection on surrounding aircraft to screen out intruding aircraft that may collide with the aircraft; Step 2: Sort the invading aircraft according to their threat level to the aircraft itself; Step 3: According to the relative position of the invading aircraft and the aircraft itself, the avoidance situation is determined. According to the avoidance principle, the avoidance strategy set of the aircraft itself to the invading aircraft is selected from the entire strategy set. The avoidance strategy sets corresponding to each invading aircraft are integrated to obtain the collision avoidance strategy set T; Step 4: Find the minimum strategy set T that can be executed by the anti-collision strategy set T final ; Step 5: If the minimum strategy set T final If it is non-empty, the local machine executes the minimum strategy set T final Medium strategy; If the minimum strategy set T final If it is empty, remove the avoidance strategy set corresponding to the intruding aircraft that poses the lowest threat to the aircraft from the anti-collision strategy set T, and repeat steps 4 to 5.

2. The UAV formation collision avoidance method according to claim 1, characterized in that: In step one: Define aircraft A as the aircraft itself, which is considered stationary, and aircraft B as the surrounding aircraft; In d min ≤R, calculate the time T taken by machine B to reach the horizontal projection monitoring area of ​​machine A au1 : in, d min For A machine The distance is the relative motion speed of machine A and machine B on the XY plane; and are the components of the speed of machine A and machine B on the XY plane; AB is the distance between machine A and machine B, θ is the oblique angle between machine A and machine B; R is 50 km; exist Calculate the time T taken by machine B to reach the vertical projection monitoring area of ​​machine A. au2 : in, is the relative motion speed of machine A and machine B on the YZ plane; and is the component of the speed of machine A and machine B in the Z-axis direction; are the direction vectors of machine A and machine B; If (T au1 <20)∩(T au2 <20), then aircraft B is considered to be an intruder aircraft that may collide with aircraft A.

3. The UAV formation collision avoidance method according to claim 2, characterized in that: In step 2: Take T au1 , T au2 The smaller value is used as the Tau value of the invading aircraft. The smaller the Tau value, the higher the threat level to the aircraft.

4. The UAV formation collision avoidance method according to claim 3, characterized in that: In step three, the avoidance strategy set includes strategy 0: turn right, strategy 1: turn left, strategy 2: descend, strategy 3: climb, strategy 4: decelerate, strategy 5: accelerate, strategy 6: decelerate and turn right, strategy 7: decelerate and turn left, strategy 8: decelerate and climb, strategy 9: decelerate and descend, strategy 10: accelerate and climb, strategy 11: accelerate and descend, strategy 12: climb and turn right, strategy 13: descend and turn right, strategy 14: climb and turn left, strategy 15: descend and turn left.

5. The UAV formation collision avoidance method according to claim 4, characterized in that: In step 3, avoidance situations include: Avoidance scenario 1: The intruder aircraft meets the own aircraft head-on at the same altitude, -190°≤θ≤-170°, -260m≤Z≤260m, where θ is the difference in heading angle between the intruder aircraft and the own aircraft, and Z is the difference in altitude between the intruder aircraft and the own aircraft. The avoidance strategy set of the own aircraft against the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 6, strategy 12, and strategy 13; Avoidance situation 2: The intruding aircraft meets the own aircraft at the same altitude and in the same direction, the own aircraft is behind, -10°≤θ≤10°, -260m≤Z≤260m, and the avoidance strategy set of the own aircraft to the intruding aircraft is selected from the full set of strategies as strategy 0, strategy 3, strategy 6, strategy 8, strategy 12, and strategy 13; Avoidance scenario 3: Description: The intruder aircraft meets the own aircraft at the same altitude, the own aircraft is in front, -10°≤θ≤10°, -260m≤Z≤260m, and the avoidance strategy set for the intruder aircraft is selected from the full strategy set as strategy 0, strategy 3, strategy 6, strategy 8, strategy 12, strategy 13; Avoidance situation 4: The intruding aircraft crosses with the own aircraft at the same altitude, -90°≤θ≤-10°, -260m≤Z≤260m, and the speed direction points to the own aircraft. The avoidance strategy set of the own aircraft to the intruding aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 3, strategy 10, strategy 12, strategy 14, strategy 6, strategy 7, and strategy 8; Avoidance scenario 5: The invading aircraft crosses the own aircraft at the same altitude, -170°≤θ≤-90°, -260m≤Z≤260m, and the speed direction points to the own aircraft. The avoidance strategy set for the invading aircraft is selected from the full set of strategies: Strategy 1, Strategy 3, Strategy 14, Strategy 10, Strategy 7, Strategy 8, and Strategy 12.

6. The UAV formation collision avoidance method according to claim 5, characterized in that: In step 3, avoidance situations also include: Avoidance scenario 6: Description: The intruder aircraft crosses with the own aircraft at the same altitude, 10°≤θ≤90°, -260m≤Z≤260m, and the speed direction points to the own aircraft. The avoidance strategy set of the own aircraft for the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 2, strategy 11, strategy 13, strategy 15, strategy 6, strategy 7, and strategy 9; Avoidance situation 7: The intruder aircraft crosses the own aircraft at the same altitude, -270°≤θ≤-190°, -260m≤Z≤260m, and the speed direction points to the own aircraft. The avoidance strategy set of the own aircraft for the intruder aircraft is selected from the full set of strategies: strategy 0, strategy 2, strategy 13, strategy 6, strategy 9, strategy 11, strategy 15; Avoidance situation 8: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -180°≤θ≤0°, -260m≤Z≤260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 2, strategy 11, strategy 13, strategy 15 strategy 6, strategy 7, strategy 9; Avoidance situation 9: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -90°≤θ≤-10°, Z≥260m, and the avoidance strategy set of the own aircraft against the intruder aircraft is selected from the full set of strategies: strategy 1, strategy 2, strategy 15, strategy 7, strategy 9, strategy 11; Avoidance situation 10: The invading aircraft is above the own aircraft and its speed is pointing to the own aircraft, -180°≤θ≤-90°, Z≥260m. The avoidance strategy set for the invading aircraft is selected from the full set of strategies: strategy 0, strategy 2, strategy 6, strategy 9, strategy 13, and strategy 11.

7. The UAV formation collision avoidance method according to claim 6, characterized in that: In step 3, avoidance situations also include: Avoidance situation 11: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -90°≤θ≤-10°, Z≥260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 2, strategy 13, strategy 15, strategy 6, strategy 7, strategy 9, strategy 11; Avoidance situation 12: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -10°≤θ≤10°, 0°≤θ≤90°, Z≥260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies as strategy 0, strategy 1, strategy 3, strategy 10, strategy 12, strategy 14, strategy 6, strategy 7, strategy 8; Avoidance situation 13: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -100°≤θ≤-80°, Z≥260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies as strategy 1, strategy 3, strategy 14, strategy 7, strategy 8, and strategy 10; Avoidance situation 14: The intruder aircraft is above the own aircraft and its speed is pointing to the own aircraft, -270°≤θ≤-180°, Z≥260m, and the avoidance strategy set of the own aircraft to the intruder aircraft is selected from the full set of strategies: strategy 0, strategy 3, strategy 12, strategy 6, strategy 8, strategy 10; Avoidance situation 15: The invading aircraft is above the own aircraft and its speed is pointing to the own aircraft, -270°≤θ≤-190°, Z≥260m. The avoidance strategy set for the invading aircraft is selected from the full set of strategies: strategy 0, strategy 1, strategy 3, strategy 12, strategy 14, strategy 6, strategy 7, strategy 8, strategy 10.

8. The UAV formation collision avoidance method according to claim 7, characterized in that: In step 4, the minimum strategy set T final is the intersection of each avoidance strategy set in the collision avoidance strategy set T.

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