A real-time optimal control algorithm for greenhouse heating

A real-time control algorithm for generating optimal heating setpoints has been implemented and tested on a commercial greenhouse nursery with a tomato crop. The algorithm is based on a model of the greenhouse energy requirements and on a numerical method for optimisation, and uses weather forecasts supplied by the Meteorological Office. The algorithm resides on a PC which communicates with a commercial greenhouse computer system and which receives weather forecasts remotely via a modem. The overall system (including the transmission of weather forecasts) has been configured in such a way as to require the least additional intervention from the grower to what is normally required in operating greenhouse computer systems. The grower is required only to define the constraints on the heating setpoints.