Abstract

This thesis deals with control problem of designing low computationally demanding robust model predictive controllers (MPC) for constrained systems subject to states/input limitations and bounded disturbances. In particular, the proposed solutions are based on a dual-mode control paradigm known as Set-Theoretic MPC (ST-MPC). This control schemes are particularly appealing for their capability of reducing the typical computation burden of robust MPC controllers. The latter is obtained by moving most of the required computations into an off-line phase, while leaving a simple and real-time affordable computational algorithm in the on-line phase. In this work, such a paradigm has been properly extended to deal with regulation and tracking problems appearing in two different control applications, namely transient stability regulation in smart grid and reference tracking in multi autonomous vehicles.

In the transient stability control problem, we consider an operative scenario where a physical fault or a cyber-attack produces an impulsive state perturbation, and a controller must be designed to robustly recover, in a finite-time, transient stability despite initial perturbation and uncertainties. In such scenario, first we have used the standard feedback linearizion technicalities to linearize the smart grid model, then, we have applied a set-theoretic MPC scheme to robustly regulate the state trajectory towards the transient stability region. Moreover, to validate the proposed theory, a simulation campaign has been performed to contrast the proposed solution with a state-of-the-art competitor. Simulation results has shown that the proposed strategy outperforms the competitor scheme both in terms of settling time and robustness.

In the multi-vehicle control problem, we exploit set-theoretic arguments to solve the reference tracking problem when the vehicles have different dynamics and/or constraints and/or disturbance, and each vehicle must follow uncoordinated reference trajectories. More in specific, we propose a novel control architecture where robust collision-free reference tracking is ensured by jointly using the set-theoretic control scheme and graph theory. To better clarify the potential and effectiveness of the proposed architecture, a simulation example involving 5 heterogeneous vehicles has been conducted.