  This paper describes a hierarchical control scheme for interconnected
systems. The higher layer of the control structure is designed with robust
Model Predictive Control (MPC) based on a reduced order dynamic model of the
overall system and is aimed at optimizing long-term performance, while at the
lower layer local regulators acting at a higher frequency are designed for the
full order models of the subsystems to refine the control action. A simulation
experiment concerning the control of the temperature inside a building is
reported to witness the potentialities of the proposed approach.
