A method for processing cooperative multi-drone collision avoidance

Abstract

The present invention belongs to the field of aerial collision avoidance technology and discloses a cooperative multi-unmanned aerial vehicle (UAV) collision avoidance processing method. The method includes: S1, determining a collision avoidance strategy for the UAV and each threat aircraft; S2, determining the priority of the threat aircraft based on the S-mode addresses of the threat aircraft; S3, forming a threat queue based on the order of appearance and priority; S4, if the UAV's orientation relative to the primary comparison aircraft and the second threat aircraft is the same, checking the next threat aircraft in the threat queue; if the UAV's orientation relative to the primary comparison aircraft and the next threat aircraft is different, simulation evaluation is performed on the UAV, the primary comparison aircraft, and the next threat aircraft until all threat aircraft in the threat queue have been processed; S5, obtaining a final collision strategy based on the results of the simulation evaluation of all threat aircraft. The method has low reliance on computing resources and excellent real-time performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of air collision avoidance, and in particular relates to a method for processing cooperative multi-UAV collision avoidance. Background Art

[0002] With the rapid development of general aviation and drones, the number of small aircraft, including military and civilian drones, is increasing. The risk of flight conflicts is increasing, and a mature collision avoidance system is urgently needed to address this issue. Multi-drone conflict resolution technology remains a key issue that has yet to be fully resolved.

[0003] At present, most multi-aircraft collision avoidance methods use global optimization processing methods such as artificial potential fields, genetic algorithms, and ant colonies. Global processing methods can obtain the global optimal solution, but they are time-consuming and require high computing resources. The processing is not real-time enough and does not match the current airspace density. Summary of the Invention

[0004] The purpose of this invention is to address the problems mentioned in the background and propose a method for processing cooperative multi-drone collision avoidance. By adopting a decentralized processing method, the threat aircraft are compared in pairs, and the entire multi-drone conflict is pre-processed. After that, the optimization results obtained from each group of comparisons are finally optimized to obtain the final collision avoidance strategy.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions to achieve it.

[0006] A method for processing cooperative multi-UAV collision avoidance, the method comprising:

[0007] S1, determining a collision avoidance strategy between the own aircraft and each threat aircraft; the threat aircraft are all aircraft within a preset range centered on the own aircraft;

[0008] S2, determines the priority of the threat aircraft based on the size of the threat aircraft's Mode S address;

[0009] S3: Sort the threat aircraft according to their appearance time and priority to form a threat queue;

[0010] S4: Use the first threat aircraft in the threat queue as the primary comparison aircraft. If the own aircraft's heading relative to the primary comparison aircraft and the second threat aircraft are the same, proceed to check the next threat aircraft in the threat queue. If the own aircraft's heading relative to the primary comparison aircraft and the next threat aircraft are different, simulate and evaluate the own aircraft, the primary comparison aircraft, and the next threat aircraft until all threat aircraft in the threat queue have been processed.

[0011] S5, based on the results of simulation and evaluation of all threat aircraft, obtain the final collision strategy.

[0012] The characteristics and further improvements of the technical solution of the present invention are:

[0013] (1) S1 specifically refers to the aircraft's collision avoidance strategy for each threatening aircraft, including the direction and intensity of the maneuver;

[0014] S11, calculate the time τ when the aircraft reaches the closest point of approach, and obtain the expected relative vertical speed: ΔV = H need / τ, the intensity of the machine's action is: V self =V other +ΔV, the closest point refers to the point where the other aircraft has the smallest distance from the aircraft when passing by;

[0015] Among them: H need is the vertical safety interval threshold, V self V is the expected vertical velocity of the aircraft, i.e. the intensity of the action; other The vertical speed of the threatening aircraft;

[0016] S12: For a new threat aircraft, simulate climbing and descending using the desired vertical rate obtained for own aircraft to obtain the climbing and descending altitude intervals. The direction of own aircraft's maneuver is selected in the direction with the larger altitude interval.

[0017] For existing threat aircraft, check whether the direction needs to be reversed. If not, continue to maintain the current direction. If necessary, change the current direction of the aircraft relative to the threat aircraft.

[0018] (2) In S12, for a new threatening aircraft, if the selected direction has an altitude intersection and the altitude interval in the other direction meets the preset vertical interval, then the other direction is selected.

[0019] (3) In S12, for the existing threat aircraft, check whether the direction needs to be reversed. Specifically, the altitude interval of the reversed direction opposite to the current direction is obtained at the vertical speed desired by the aircraft. If the altitude interval of the reversed direction is greater than the altitude interval threshold, the aircraft's direction with respect to the threat aircraft is reversed.

[0020] (4) In S2, the priority is determined according to the size of the S-mode address of the threat aircraft. The smaller the S-mode address, the higher the priority.

[0021] (5) S3 is specifically: Sort by the time when the threat aircraft appear, with the one that appears earlier being ranked first. If multiple threat aircraft appear at the same time, sort by priority, with the one with the higher priority being ranked first.

[0022] (6) In S4, when the own aircraft's orientation towards the primary comparison aircraft and the next threat aircraft is different, simulated evaluations are performed for the own aircraft, the primary comparison aircraft, and the next threat aircraft, specifically:

[0023] S41: If the own aircraft has the highest priority, it will perform a heading reversal simulation on the primary comparison aircraft and the next threat aircraft respectively to obtain the altitude interval after the reversal simulation.

[0024] If the reversal altitude interval of the basic comparison aircraft is large and the reversal altitude interval is greater than the altitude interval threshold, the aircraft's heading will be reversed with respect to the basic comparison aircraft; if the reversal altitude interval of the next threat aircraft is large and the reversal altitude interval is greater than the altitude interval threshold, the aircraft's heading will be reversed with respect to the next threat aircraft;

[0025] If the reversal altitude intervals between the primary comparison aircraft and the next threat aircraft are both less than the altitude interval threshold, the aircraft will perform a level flight simulation to obtain its own level flight intervals for the primary comparison aircraft and the next threat aircraft. If both level flight intervals are less than the level flight interval threshold, the aircraft may choose to fly level.

[0026] If the level flight separation also does not meet the level flight threshold requirement, the aircraft will simulate increasing the vertical speed rate for the higher priority threat aircraft to obtain an altitude separation with an increased vertical speed rate. If the altitude separation can meet the altitude separation threshold, the aircraft will change its heading relative to the other threat aircraft.

[0027] S42: If the own aircraft's priority is between the primary comparison aircraft and another threat aircraft, the own aircraft performs a heading reversal simulation on the threat aircraft with a lower priority than the own aircraft. If the reversal altitude interval is greater than the altitude threshold, the own aircraft performs a heading reversal on the threat aircraft.

[0028] If the altitude separation is less than the altitude threshold, the aircraft will attempt to perform level flight simulations on both threat aircraft to obtain their level flight separations. If both level flight separations are greater than the level flight separation threshold, the aircraft will choose level flight.

[0029] If the level flight separation also fails to meet the threshold requirement, the aircraft will simulate increasing the vertical speed rate for the threat aircraft with a lower priority than itself to obtain an altitude separation with an increased vertical speed rate. If the altitude separation meets the altitude separation threshold, the aircraft will change its heading relative to the threat aircraft.

[0030] S43: If the priority of this unit is the lowest, no change is made.

[0031] (7) Level flight simulation is as follows:

[0032] First, simulate the vertical separation distance generated by the aircraft climbing or descending from the aircraft's current vertical speed to the target vertical speed of 0 ft / s when the aircraft is climbing or descending normally in the cruise phase for the basic comparison aircraft, and take the smallest absolute value as MALT1;

[0033] Then simulate the vertical separation distance generated by the aircraft climbing or descending from its current vertical rate to the target vertical rate of 0 ft / s when the aircraft is climbing or descending normally in the cruise phase. The smallest absolute value is taken as MALT2.

[0034] If the minimum vertical distances MALT1 and MALT2 generated by level flight are both greater than the level flight reversal threshold, level flight is possible.

[0035] (8) Increased vertical velocity simulation includes:

[0036] The aircraft's vertical speed is increased from its current speed to 1.5 times the current speed at takeoff climb, resulting in an altitude separation with increased vertical speed.

[0037] (9) S5 is specifically:

[0038] Determine where all threat aircraft will pass over your aircraft based on your aircraft's current heading. If all threat aircraft pass over your aircraft, your aircraft's final heading will be descending. If all threat aircraft pass under your aircraft, your aircraft's final heading will be climbing. If threat aircraft pass both above and below your aircraft, your aircraft will choose level flight.

[0039] This invention decentralizes the global problem, pre-processing threatening aircraft in pairs. The final recommendation is then obtained by simply optimizing the optimization results obtained from each pair. This approach requires little computing resources and offers excellent real-time performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The figure shows the process of a cooperative multi-UAV collision avoidance method. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is described in detail below with reference to the accompanying drawings.

[0042] The embodiment of the present invention provides a method for processing cooperative multi-drone collision avoidance, such as Figure 1 As shown, the method includes:

[0043] S1, determining a collision avoidance strategy between the own aircraft and each threat aircraft; the threat aircraft are all aircraft within a preset range centered on the own aircraft;

[0044] S2, determines the priority of the threat aircraft based on the size of the threat aircraft's Mode S address;

[0045] S3: Sort the threat aircraft according to their appearance time and priority to form a threat queue;

[0046] S4: Use the first threat aircraft in the threat queue as the primary comparison aircraft. If the own aircraft's heading relative to the primary comparison aircraft and the second threat aircraft are the same, proceed to check the next threat aircraft in the threat queue. If the own aircraft's heading relative to the primary comparison aircraft and the next threat aircraft are different, simulate and evaluate the own aircraft, the primary comparison aircraft, and the next threat aircraft until all threat aircraft in the threat queue have been processed.

[0047] S5, based on the results of simulation and evaluation of all threat aircraft, obtain the final collision strategy.

[0048] S1 specifically includes: the aircraft's collision avoidance strategy for each threatening aircraft, including the direction and intensity of the action;

[0049] S11, calculate the time τ when the aircraft reaches the closest point of approach, and obtain the expected relative vertical speed: ΔV = H need / τ, the intensity of the machine's action is: V self =V other +ΔV, the closest point refers to the point where the other aircraft has the smallest distance from the aircraft when passing by;

[0050] Among them: H need is the vertical safety interval threshold, V self V is the expected vertical velocity of the aircraft, i.e. the intensity of the action; other The vertical speed of the threatening aircraft;

[0051] S12: For a new threat aircraft, simulate climbing and descending using the desired vertical rate obtained for own aircraft to obtain the climbing and descending altitude intervals. The direction of own aircraft's maneuver is selected in the direction with the larger altitude interval.

[0052] For existing threat aircraft, check whether the direction needs to be reversed. If not, continue to maintain the current direction. If necessary, change the current direction of the aircraft relative to the threat aircraft.

[0053] In S12, for a new threatening aircraft, if the selected direction has an altitude intersection and the altitude interval in the other direction meets the preset vertical interval, then the other direction is selected.

[0054] In S12, for the existing threat aircraft, check whether the direction needs to be reversed. Specifically, the altitude interval of the reversal is obtained at the vertical speed expected by the aircraft, which is opposite to the current direction. If the reversal altitude interval is greater than the altitude interval threshold, the aircraft's direction relative to the threat aircraft is reversed.

[0055] In S2, the priority is determined based on the size of the S-mode address of the threat aircraft. The smaller the S-mode address, the higher the priority.

[0056] S3 is specifically: sorting by the time when the threat aircraft appear, with the earlier one appearing first. If multiple threat aircraft appear at the same time, sorting by priority, with the higher priority one appearing first.

[0057] In S4, when the own aircraft's orientation towards the primary comparison aircraft and the next threat aircraft is different, a simulation assessment is performed for the own aircraft, the primary comparison aircraft, and the next threat aircraft. Specifically:

[0058] S41: If the own aircraft has the highest priority, it will perform a heading reversal simulation on the primary comparison aircraft and the next threat aircraft respectively to obtain the altitude interval after the reversal simulation.

[0059] If the reversal altitude interval of the basic comparison aircraft is large and the reversal altitude interval is greater than the altitude interval threshold, the aircraft's heading will be reversed with respect to the basic comparison aircraft; if the reversal altitude interval of the next threat aircraft is large and the reversal altitude interval is greater than the altitude interval threshold, the aircraft's heading will be reversed with respect to the next threat aircraft;

[0060] If the reversal altitude intervals between the primary comparison aircraft and the next threat aircraft are both less than the altitude interval threshold, the aircraft will perform a level flight simulation to obtain its own level flight intervals for the primary comparison aircraft and the next threat aircraft. If both level flight intervals are less than the level flight interval threshold, the aircraft may choose to fly level.

[0061] If the level flight separation also does not meet the level flight threshold requirement, the aircraft will simulate increasing the vertical speed rate for the higher priority threat aircraft to obtain an altitude separation with an increased vertical speed rate. If the altitude separation can meet the altitude separation threshold, the aircraft will change its heading relative to the other threat aircraft.

[0062] S42: If the own aircraft's priority is between the primary comparison aircraft and another threat aircraft, the own aircraft performs a heading reversal simulation on the threat aircraft with a lower priority than the own aircraft. If the reversal altitude interval is greater than the altitude threshold, the own aircraft performs a heading reversal on the threat aircraft.

[0063] If the altitude separation is less than the altitude threshold, the aircraft will attempt to perform level flight simulations on both threat aircraft to obtain their level flight separations. If both level flight separations are greater than the level flight separation threshold, the aircraft will choose level flight.

[0064] If the level flight separation also fails to meet the threshold requirement, the aircraft will simulate increasing the vertical speed rate for the threat aircraft with a lower priority than itself to obtain an altitude separation with an increased vertical speed rate. If the altitude separation meets the altitude separation threshold, the aircraft will change its heading relative to the threat aircraft.

[0065] S43: If the priority of this unit is the lowest, no change is made.

[0066] The specific level flight simulation is as follows:

[0067] First, simulate the vertical separation distance generated by the aircraft climbing or descending from the aircraft's current vertical speed to the target vertical speed of 0 ft / s when the aircraft is climbing or descending normally in the cruise phase for the basic comparison aircraft, and take the smallest absolute value as MALT1;

[0068] Then simulate the vertical separation distance generated by the aircraft climbing or descending from its current vertical rate to the target vertical rate of 0 ft / s when the aircraft is climbing or descending normally in the cruise phase. The smallest absolute value is taken as MALT2.

[0069] If the minimum vertical distances MALT1 and MALT2 generated by level flight are both greater than the level flight reversal threshold, level flight is possible.

[0070] Increased vertical speed simulation includes:

[0071] The aircraft's vertical speed is increased from its current speed to 1.5 times the current speed at takeoff climb, resulting in an altitude separation with increased vertical speed.

[0072] S5 is specifically:

[0073] Determine where all threat aircraft will pass over your aircraft based on your aircraft's current heading. If all threat aircraft pass over your aircraft, your aircraft's final heading will be descending. If all threat aircraft pass under your aircraft, your aircraft's final heading will be climbing. If threat aircraft pass both above and below your aircraft, your aircraft will choose level flight.

[0074] This invention decentralizes the global problem, pre-processing threatening aircraft in pairs. The final recommendation is then obtained by simply optimizing the optimization results obtained from each pair. This approach requires little computing resources and offers excellent real-time performance.

Claims

1. A method for processing cooperative multi-UAV collision avoidance, characterized in that: The method comprises: S1, determining a collision avoidance strategy between the own aircraft and each threat aircraft; the threat aircraft are all aircraft within a preset range centered on the own aircraft; S2, determines the priority of the threat aircraft based on the size of the threat aircraft's Mode S address; S3: Sort threat aircraft by appearance time and priority to form a threat queue. Specifically, S3 sorts threat aircraft by appearance time, with earlier appearances coming first. If multiple threat aircraft appear simultaneously, they are sorted by priority, with higher priority aircraft coming first. S4: Use the first threat aircraft in the threat queue as the primary comparison aircraft. If the own aircraft's heading relative to the primary comparison aircraft and the second threat aircraft are the same, proceed to check the next threat aircraft in the threat queue. If the own aircraft's heading relative to the primary comparison aircraft and the next threat aircraft are different, simulate and evaluate the own aircraft, the primary comparison aircraft, and the next threat aircraft until all threat aircraft in the threat queue have been processed. S41: If the own aircraft has the highest priority, it will perform a heading reversal simulation on the primary comparison aircraft and the next threat aircraft respectively to obtain the altitude interval after the reversal simulation. If the reversal altitude interval of the basic comparison aircraft is large and the reversal altitude interval is greater than the altitude interval threshold, the aircraft's heading will be reversed with respect to the basic comparison aircraft; if the reversal altitude interval of the next threat aircraft is large and the reversal altitude interval is greater than the altitude interval threshold, the aircraft's heading will be reversed with respect to the next threat aircraft; If the reversal altitude intervals between the primary comparison aircraft and the next threat aircraft are both less than the altitude interval threshold, the aircraft will perform a level flight simulation to obtain its own level flight intervals for the primary comparison aircraft and the next threat aircraft. If both level flight intervals are less than the level flight interval threshold, the aircraft may choose to fly level. If the level flight separation also does not meet the level flight threshold requirement, the aircraft will simulate increasing the vertical speed rate for the higher priority threat aircraft to obtain an altitude separation with an increased vertical speed rate. If the altitude separation can meet the altitude separation threshold, the aircraft will change its heading relative to the other threat aircraft. S42: If the own aircraft's priority is between the primary comparison aircraft and another threat aircraft, the own aircraft performs a heading reversal simulation on the threat aircraft with a lower priority than the own aircraft. If the reversal altitude interval is greater than the altitude threshold, the own aircraft performs a heading reversal on the threat aircraft. If the altitude separation is less than the altitude threshold, the aircraft will attempt to perform level flight simulations on both threat aircraft to obtain their level flight separations. If both level flight separations are greater than the level flight separation threshold, the aircraft will choose level flight. If the level flight separation also fails to meet the threshold requirement, the aircraft will simulate increasing the vertical speed rate for the threat aircraft with a lower priority than itself to obtain an altitude separation with an increased vertical speed rate. If the altitude separation meets the altitude separation threshold, the aircraft will change its heading relative to the threat aircraft. S43, if the priority of this machine is the lowest, no change is made; S5, based on the results of simulation and evaluation of all threat aircraft, obtain the final collision strategy.

2. The method for cooperative multi-UAV collision avoidance according to claim 1, characterized in that: S1 specifically includes: the aircraft's collision avoidance strategy for each threatening aircraft, including the direction and intensity of the action; S11, calculate the time τ when the aircraft reaches the closest point of approach, and obtain the expected relative vertical speed: ΔV = H need / τ, the intensity of the machine's action is: V self =V other +ΔV, the closest point refers to the point where the other aircraft has the smallest distance from the aircraft when passing by; Among them: H need is the vertical safety interval threshold, V self is the expected vertical velocity of the aircraft, i.e. the intensity of the action; v other The vertical speed of the threatening aircraft; S12: For a new threat aircraft, simulate climbing and descending using the desired vertical rate obtained for own aircraft to obtain the climbing and descending altitude intervals. The direction of own aircraft's maneuver is selected in the direction with the larger altitude interval. For existing threat aircraft, check whether the direction needs to be reversed. If not, continue to maintain the current direction. If necessary, change the current direction of the aircraft relative to the threat aircraft.

3. The method for cooperative multi-UAV collision avoidance according to claim 2, characterized in that: In S12, for a new threatening aircraft, if the selected direction has an altitude intersection and the altitude interval in the other direction meets the preset vertical interval, then the other direction is selected.

4. The method for cooperative multi-UAV collision avoidance according to claim 2, characterized in that: In S12, for the existing threat aircraft, check whether the direction needs to be reversed. Specifically, the altitude interval of the reversal is obtained at the vertical speed expected by the aircraft, which is opposite to the current direction. If the reversal altitude interval is greater than the altitude interval threshold, the aircraft's direction relative to the threat aircraft is reversed.

5. The method for cooperative multi-UAV collision avoidance according to claim 1, characterized in that: In S2, the priority is determined based on the size of the S-mode address of the threat aircraft. The smaller the S-mode address, the higher the priority.

6. The method for cooperative multi-UAV collision avoidance according to claim 1, characterized in that: The specific level flight simulation is as follows: First, simulate the vertical separation distance generated by the aircraft climbing or descending from the aircraft's current vertical speed to the target vertical speed of 0 ft / s when the aircraft is climbing or descending normally in the cruise phase for the basic comparison aircraft, and take the smallest absolute value as MALT1; Then simulate the vertical separation distance generated by the aircraft climbing or descending from its current vertical rate to the target vertical rate of 0 ft / s when the aircraft is climbing or descending normally in the cruise phase. The smallest absolute value is taken as MALT2. If the minimum vertical distances MALT1 and MALT2 generated by level flight are both greater than the level flight reversal threshold, level flight is possible.

7. The method for cooperative multi-UAV collision avoidance according to claim 1, characterized in that: Increased vertical speed simulation includes: The aircraft's vertical speed is increased from its current speed to 1.5 times the current speed at takeoff climb, resulting in an altitude separation with increased vertical speed.

8. The method for cooperative multi-UAV collision avoidance according to claim 1, characterized in that: S5 is specifically: Determine where all threat aircraft will pass over your aircraft based on your aircraft's current heading. If all threat aircraft pass over your aircraft, your aircraft's final heading will be descending. If all threat aircraft pass under your aircraft, your aircraft's final heading will be climbing. If threat aircraft pass both above and below your aircraft, your aircraft will choose level flight.

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