Robust Control for a Slung-Mass Quadcopter Under Abrupt Velocity Changes

This paper addresses the robust control for a slung-mass quadrotor under abrupt velocity changes. The proposed algorithm is based on a sliding mode controller applied to the quadrotor translational dynamics considering the slung-mass angle as feedback. A Lyapunov candidate function is used to demonstrate system stability. Numerical simulations are performed to demonstrate stability in hover, forward flight, and under abrupt velocity changes. Experimental tests show that the proposed approach is also robust for stabilizing the aerial vehicle against disturbances caused by slung-load oscillations and wind gusts in outdoor environments by stopping the forward velocity from 29 km/h to hover by compensating within 1 s for the slung-mass oscillations.