Adaptive Control of Quadrotor Aerial Transportation Systems with Constraint and Uncertain Dynamics

Recently, quadrotor aerial transportation systems have become an important area for applications of unmanned aerial vehicles. Accurate position tracking and pendulum angle control are critical for transport systems. This paper proposes a new sliding mode control strategy that can accurately control the positions of an aerial transportation system under the presence of unknown disturbances and a constraint on payload swing angle. The approach uses a new disturbance observer to accurately estimate the disturbances in the system and combines sliding mode control with an adaptively constructed control variable to ensure the constraint on payload swing angle is satisfied. Stability analysis shows that control error is guaranteed to converge to zero while the constraint is satisfied. Simulation results show that the proposed control strategy effectively improves the control accuracy and robustness of the position control of quadrotor aerial transportation systems.