1. Multiple UAV Rendezvous with Collision Avoidance
Joel George and Debasish Ghose
Guidance, Control, and Decision Systems Laboratory (GCDSL)
Department of Aerospace Engineering,
Indian Institute of Science, Bangalore
India

2. Introduction Rendezvous: meeting at a pre-planned time and place
Rendezvous of multiple UAVs
For simultaneous deployment of resources
To exchange resources or critical information
Rendezvous of multiple UAVs when some of the UAVs have to do collision avoidance maneuvers en route

3. Assumptions Kinematic UAV model
is the position, is the velocity, is the heading, and is the turn rate command of UAV
Global communication between UAVs

4. Solution Approach
Rendezvous via consensus on Estimated Time of Arrival (ETA) at target
ETA at target obtained from Dubins path to target
Arrive at a consensus on ETA by adjusting velocities

5. Solution Approach Average consensus
In principle, any consensus protocol can be used. Average consensus protocol is used for the purpose of illustration

6. Handling velocity bounds
If a UAV hits the maximum velocity bound, it stays with that velocity
If a UAV hits the minimum velocity bound, it stays with that velocity and in addition does a wandering maneuver (move away from target)

7. Wandering maneuver example
Example of a case where one UAV (red) hits upper velocity bound while other (green) hits lower velocity bound but still achieves a rendezvous

8. Rendezvous without collision avoidance
Example of rendezvous of 10 UAVs

9. Rendezvous with collision avoidance
Rendezvous of 5 UAVs with collision avoidance

10. Target tracking Target tracking with a stand-off radius
Target tracking can be achieved by a little modification in the rendezvous via consensus algorithm
Stand-off radius achieved by keeping the ETA to target constant

11. Target tracking
Tracking a stationary target

12. Target tracking
Tracking moving target

13. Remarks
The algorithm developed for rendezvous via consensus can be modified by adding a ‘bias’ to address the cooperative timing problem

14. Summary
Algorithm for multiple UAV rendezvous under collision avoidance achieved via consensus on ETA to target