Comfort control in residential housing using predictive controllers

Generalised predictive control (GPC) is an effective strategy for high performance applications, with good temporal and frequency properties. This paper presents an application of GPC to climate control in buildings, with particular attention on strict temperature setpoint specifications. Specifically, the future temperature setpoint (which is step-like) is prespecified or known and the objective is to attain leading edge temperatures (positive increase) to within ±0.5°C at the specified time. The controller must also regulate the temperature to within ±0.5°C throughout the duration of the setpoint pulse and turn off the heater coincident with the trailing edge of the step change. The controller developed consists of a standard RST regulator derived from GPC and an empirical anticipative rule which shifts the future setpoint backward in time in order to launch the heater sufficiently in the past to attain the leading edge setpoint value. The regulator is initialized only at start up; no switching in or out of controllers is needed. The validity and workability of such a predictive structure for thermal control in buildings is finally pointed out with the results of the predictive controller in the CLIM 2000 environment, coupled with an automatic design of the tuning parameters for a simplified implementation