Tube-Based Explicit Model Predictive Control for a Tiltrotor UAV in Cargo Transportation Tasks

In this paper, we present a robust control strategy based on model predictive control (MPC) for a tiltrotor unmanned aerial vehicle in suspended load transportation tasks, from the perspective of the load. To this aim, we propose a new formulation of tube-based MPC for high-order dynamical systems, allowing its embedded implementation. The proposed formulation computes an explicit solution to the optimization problem using the nominal part of an uncertain linear parameter-varying (LPV) system, while a second control law is used to compensate for the differences between the nominal and uncertain models. To compute the feedback gain used by the second control law, we propose a novel group of LMIs based on the uncertain LPV model where the uncertainty set is represented as a zonotope. The reachable set, used in the MPC strategy, is computed as a robust positive invariant set also using zonotopes, reducing the computational cost and allowing its offline computation. Furthermore, by using t...