Cooperative and hierarchical fuzzy MPC for building heating control

A combined cooperative and hierarchical control structure utilizing Fuzzy Model Predictive Control (FMPC) for building heating is introduced. The structure comprises three types of Model Predictive Controllers (MPC): For different independent zones of the building FMPCs optimize the fast acting input variable fan coils (FC) while a global linear MPC optimizes the slowly acting thermally activated building systems (TABS). Cooperation between these two groups of controllers is guaranteed by an inter-sample iteration. This cooperative structure acts as master in a hierarchical structure, where the slave is a mixed-inter MPC (MI-MPC) in the supply level. While the cooperative structure ensures user comfort in the building, the MI-MPC optimizes monetary costs of heat supply. This structure allows for decoupled and independent modeling of FMPCs, simple incorporation of the coupling input TABS, and decoupled design of the supply level control. A discussion on stability and sub-optimality of the control structure is given. A simulation of a large office building incorporating disturbances of ambient temperature, radiance, and occupancy demonstrates the performance of the proposed concept.