A REAL-TIME OPTIMAL CONTROL ALGORITHM FOR GREENHOUSE HEATING

Abstract 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.

[1]  B. J. Bailey.  WIND DEPENDENT CONTROL OF GREENHOUSE TEMPERATURE , 1985 .

[2]  Olivier Jolliet,et al.  HORTICERN: an improved static model for predicting the energy consumption of a greenhouse , 1991 .

[3]  G. Bot.  Greenhouse climate : from physical processes to a dynamic model , 1983 .

[4]  Z. Huang,et al.  Use of time-series analysis to model and forecast wind speed , 1995 .

[5]  M. Bartholomew-Biggs.  A Globally Convergent Version of REQP for Constrained Minimization , 1988 .

[6]  A. D. Koning,et al.  Long-term temperature integration of tomato. Growth and development under alternating temperature regimes , 1990 .

[7]  G.P.A. Bot,et al.  Global comparison of three greenhouse climate models , 1985 .

[8]  I. Seginer,et al.  OPTIMUM CONTROL OF GREENHOUSE HEATING , 1989 .

[9]  R. G. Hurd,et al.  THE INFLUENCE OF DIFFERENT TEMPERATURE PATTERNS HAVING THE SAME INTEGRAL ON THE EARLINESS AND YIELD OF TOMATOES , 1984 .

[10]  D. P. Aikman,et al.  Wind-related temperature setting in glasshouses , 1989 .

[11]  A. D. Koning,et al.  Development and dry matter distribution in glasshouse tomato : a quantitative approach , 1994 .

[12]  L. S. Marsh,et al.  Economically optimum day temperatures for greenhouse hydroponic lettuce production. I. A computer model , 1991 .

[13]  L. Marsh,et al.  Optimal temperature setpoints for greenhouse lettuce , 1991 .

[14]  L. S. Marsh,et al.  ECONOMICALLY OPTIMUM DAY TEMPERATURES FOR GREENHOUSE HYDROPONIC LETTUCE PRODUCTION PART II: RESULTS AND SIMULATIONS , 1991 .

[15]  Peter C. Young,et al.  Modelling and PIP control of a glasshouse micro-climate , 1994 .

[16]  P. F. Davis,et al.  An algorithm for temperature compensation in a heated greenhouse , 1988 .