An online controller redesign based fault-tolerant strategy for thermal comfort in a multi-zone building

Variable air volume (VAV) boxes are used in multi-zone buildings, which varies the volume of constant temperature air separately supplied by an air-handling unit to meet challenging thermal load demands of individual zones. A fault appearing in the VAV damper severely affects the control performance and consequently, the energy efficiency of the overall system. To address this issue, we present a novel online redesign based fault-tolerant control strategy in this paper for a VAV thermal system in a multi-zone building. The novelty of the proposed strategy is that no a priori information about the process is used in real-time. In fact, no online identification of the thermal dynamical model of the building process or estimation of its operating status (healthy or faulty) is done. The design of the fault accommodation scheme is solely based on the real-time trajectories generated by the process. In order to demonstrate the effectiveness of the developed strategy, we consider a case-study of three-zones in a one-story building.