Symmetric send-on-delta PI control of a greenhouse system

This paper deals with a symmetric send-on-delta PI control strategy for controlling the internal temperature of a greenhouse. It is shown that, by properly designing the control system, the disturbances represented by the soil temperature, the solar radiation, the wind velocity, and the outside temperature can be effectively compensated with a limited number of events. The role of the design parameters is outlined and simulation results demonstrate the efficacy of the methodology by comparing it with previously proposed techniques.