A multi-UAV tight formation flight controller

This paper studies a control mode of multiple UAVs flying in a close-coupled formation for the purposes of fuel reduction and then proposes a two-loop controller design methodology based on a two-time scale design approach: one is a Sliding Mode Controller in outer-loop to track relative position commands and generate body-axis rate commands for the inner loop, the other is a Self-Adaptive Controller in inner-loop to produce desired angular rotations of aircraft, which uses aileron, elevator, and rudder control surfaces to complete the maneuver. Simulation results of multi-UAV formation demonstrate that the proposed controller design enables the follower UAVs to hold a desired position in the leader UAV's vortex field.