Decentralized collision avoidance for uavs

Abstract

A method includes recording, by a first UAV, a current position of the first UAV, comparing, the current position of the first UAV to a current flight plan of the first UAV, and geocasting a first track declaration message. The method may further include receiving, by the first UAV, a second track declaration message generated by a second UAV, detecting a potential collision with the second UAV and executing a collision avoidance maneuver by the first UAV.

1 . A method comprising:
 geocasting, by each of a plurality of UAVs, a track declaration message for each of the plurality of UAVs, wherein each of the track declaration message comprises a current position and current flight plan for the each of the plurality of UAVs;   receiving, by the each of the plurality of UAVs, the track declaration message from at least one other of the plurality of UAVs;   simulating, by the each of the plurality of UAVs, flight[s] paths of each of the plurality of UAVs based on the receiving step to determine whether there is a potential collision;   executing, by one of the plurality of UAVs, a first collision avoidance maneuver if there is a potential collision, wherein the first collision avoidance maneuver is determined based on the simulating step, and wherein the one of the plurality of UAVs is determined by a UAV whose potential collision is associated with a closest elapsed time measurement to t 0 ; and   geocasting, by the one of the plurality of UAVs, an updated track declaration message identifying an updated flight plan of the one of the plurality of UAVs based on the first collision avoidance maneuver.   
     
     
         2 . The method of  claim 1  further comprising calculating, by the each of the plurality of the UAVs, a radius of uncertainty for the current position of the each of the plurality of the UAV's, and the track declaration messages includes the current position in view of the radius of uncertainty. 
     
     
         3 . The method of  claim 1  further comprising determining, by each of the plurality of the UAVs, a time period since the geocasting step was last executed, and if the time period exceeds a threshold time period, then geocasting an updated track declaration message. 
     
     
         4 . The method of  claim 1  further comprising changing, by one of the plurality of UAVs, the current flight plan to an updated flight plan and geocasting, by the one of the plurality of UAVs, an updated geocast track declaration message identifying the updated flight plan. 
     
     
         5 . The method of  claim 4  further comprising, detecting, by a second of the plurality of UAVs, a potential collision with another of the plurality of UAVs and executing, by the second of the plurality of UAVs, a second collision avoidance maneuver. 
     
     
         6 . The method of  claim 5  wherein the one of the plurality of UAVs creates a first set of collision avoidance maneuvers and the second of the plurality of UAVs creates a second set of collision avoidance maneuvers and wherein the first collision avoidance maneuver is selected randomly from the first set of collision avoidance maneuvers and the second collision avoidance maneuver is selected from the second set of collision avoidance maneuvers. 
     
     
         7 . The method of  claim 6  wherein the first of the plurality of UAVs creates a first set of collision avoidance maneuvers and wherein the first collision avoidance maneuver is selected randomly from the first set of collision avoidance maneuvers. 
     
     
         8 . The method of  claim 7  wherein the first collision avoidance maneuver comprises one of hovering by the first UAV, bending the current flight track of the first UAV, or adjusting the altitude of the current flight track of the first UAV to create an updated flight plan. 
     
     
         9 . A method comprising:
 receiving, by a first UAV from a ground control station, a track declaration message generated by a second UVA and a track declaration message generated by a third UAV;   simulating, by the first UAV, a first flight path of the first UAV wherein each point on the simulated first flight path is associated with an elapsed time measurement between to and to;   detecting, by the first UAV, a potential collision with one of the second UAV or third UAV based on the simulating step;   executing, by the first UAV, a first collision avoidance maneuver in response to the detecting step, wherein the first collision avoidance maneuver comprises one of hovering by the first UAV, bending the current flight track of the first UAV, or adjusting the altitude of the current flight track of the first UAV to avoid colliding with the second UAV having a simulated collision time is closest to t 0 .   
     
     
         10 . The method of  claim 9 , further comprising simulating, by the first UAV, the first collision avoidance maneuver and determining whether the first collision avoidance maneuver will be effective in avoiding the potential collision prior to the executing step. 
     
     
         11 . The method of  claim 9  further comprising determining, by the first UAV, a first set of collision avoidance maneuvers and wherein the first collision avoidance maneuver is randomly selected from the first set of collision avoidance maneuvers. 
     
     
         12 . The method of  claim 9  further comprising, transmitting by the first UAV to the ground control station, a second track declaration message identifying the current position of the first UAV and an updated flight plan of the first UAV based on the first collision avoidance maneuver. 
     
     
         13 . A system comprising:
 a first UAV and a second UAV, each of the first UAV and the second UAV having a capability to send and receive geocast messages and messages to and from a ground control station, the first UAV having a first processor and a first memory coupled with the first processor, the first memory having stored thereon executable instructions that when executed by the first processor cause the first processor to effectuate operations comprising:   sending, to the ground control station, a first track declaration message;   receiving, a second track declaration message from the ground control station, generated by the second UAV;   determining if a flight track of the first UAV may have a collision based on a flight track of the second UAV;   creating a collision avoidance maneuver;   simulating an alternative flight track based on the collision avoidance maneuver; and   executing the collision avoidance maneuver if the simulating step indicates that the alternative flight track will avoid the collision.   
     
     
         14 . The system of  claim 13  wherein the operations further comprise sending the alternative flight track to the ground control station. 
     
     
         15 . The system of  claim 13  further comprising generating a set of collision avoidance maneuvers and the collision avoidance maneuver is randomly selected from the set of collision avoidance maneuvers. 
     
     
         16 . The system of  claim 13  wherein the collision avoidance maneuver is one of hovering, bending the flight track, or changing the altitude of the flight track of the first UAV. 
     
     
         17 . The system of  claim 13  further comprising:
 the second UAV having a second processor and a second memory coupled with the second processor, the second memory having stored thereon executable instructions that when executed by the second processor cause the second processor to effectuate operations comprising: 
 transmitting to the ground control station, the second track declaration message; 
 receiving the first track declaration message from the ground control station generated by the first UAV; 
 determining if a flight track of the first UAV may have a collision based on the flight track of the second UAV; 
 creating a second collision avoidance maneuver to be performed by the second UAV; 
 simulating a second alternative flight track of the second UAV based on the second collision avoidance maneuver; and 
 executing the second collision avoidance maneuver if the simulating step indicates that the second alternative flight track will avoid the collision. 
 
     
     
         18 . The system of  claim 17  wherein the operations further comprise sending the alternative flight track to the ground control station. 
     
     
         19 . The system of  claim 17  further comprising generating a set of collision avoidance maneuvers and wherein the collision avoidance maneuver is randomly selected from the set of collision avoidance maneuvers. 
     
     
         20 . The system of  claim 17  wherein the collision avoidance maneuver is one of hovering, bending the flight track, or changing the altitude of the flight track of the first UAV.