Energy-Coupling-Based Control for Unmanned Quadrotor Transportation Systems: Exploiting Beneficial State-Coupling Effects

Cable suspension transport is a crucial method for quadrotors to transport goods and materials. During transportation, the quadrotor transport system (QTS) faces external disturbances and system uncertainties. Particularly, the underactuated nature of the system poses significant challenges to its stable operation. To solve these problems, this paper proposes a hierarchical control scheme that enhances coupling and leverages advantageous state-coupling to achieve precise positioning and eliminate payload swings for QTS. By leveraging the cascading characteristics of QTS, the design process is greatly simplified through the separate design of the torque input for the inner loop and the force input for the outer loop. Simulation results demonstrate the effective control performance of this method.