Nonlinear Motion Control for a Quadrotor Transporting a Cable-Suspended Payload

In this paper, we focus on the velocity control problem for a quadrotor with a cable-suspended payload (QCSP). A dynamic model of QCSP is proposed by the Lagrangian approach. The air resistance of the payload, which usually alters the dynamic of a QCSP significantly, but has received less attention in existing works, are considered in the model building. Based on such a dynamical model, a novel nonlinear cascade controller, which supports the application of gyroscope, is proposed to realize accurate and stable velocity control for the payload of a QCSP with exponential stability and reduce the coupling disturbance when multi-axis tilt happens in the transportation process. The cascade controller includes three sub-controllers: an attitude sub-controller for the quadrotor, a swing angle sub-controller, and a velocity sub-controller for the payload. Numerical simulations implemented in a Matlab
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SimMechanics
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and experiments performed on a newly designed experimental platform are carried out to demonstrate the effectiveness of the modeling and the designed controller.