Adaptive Disturbance Observers for Building Thermal Model

Abstract

Space cooling in buildings is influenced by thermal dynamics, which in turn is affected by ambient conditions, solar radiation, occupancy, stray heating and various other disturbances that are time-varying and nonlinear. This investigation presents an adaptive disturbance observer for estimating the thermal states of the building depending on the disturbance influences. In our approach, the building is modelled as an electrical equivalent circuit and the disturbance influences are modelled as exogenous inputs. Then an adaptive observer is designed for estimating the disturbances and providing accurate state estimates. Further, we also provide the conditions in which the adaptive observer provides an estimate of the disturbance. The proposed approach is illustrated on a test building with an air conditioner controlled using a thermostat. Our studies showed that the proposed observer provided accurate estimation of temperature depending on the disturbances.