Distributed Model Predictive Control for UAVs Collaborative Payload Transport

We consider the problem of collaborative transport of a payload using several quadrotor vehicles. The payload is assumed to be a rigid body and is attached to the vehicles with rigid rods. The model of the system is presented and is employed to formulate a Model Predictive Controller. The centralized MPC formulation differs from others in the literature in the way the linearized model of the system is employed about a non-equilibrium state-input pair. We then present a decentralized formulation of MPC by distributing the computations among the vehicles. Simulations of both versions of the controller are carried out for a four-quadrotor system carrying out a transport maneuver of a box payload, for a cost penalizing the deviations of the vehicles from the desired trajectory and the attitude perturbations of the payload. The results confirm that the decentralized controller can yield a comparable performance to the centralized MPC implementation, for the same computation time of the two algorithms.