ISHS Acta Horticulturae 406: II IFAC/ISHS Workshop :Mathematical & Control Applications in Agriculture & Horticulture
IDENTIFICATION AND CONTROL OF AIR TEMPERATURE IN GREENHOUSE SYSTEMS |
| Authors: | H. Nishina, Y. Hashimoto, A. Matsumoto |
| Abstract:
In this study, the authors analyzed the air temperature inside greenhouse by means of system identification and investigated the applicability of system identification. Furthermore, as a control system for the air temperature inside greenhouse, an optimal regulator with observer was designed and the control performance was examined. The experiment of system identification was carried out in a vinyl house. The authors identified a system with an input of the incident radiation outside greenhouse and an output of the air temperature inside greenhouse by assuming MA (moving average) model and ARMA (auto-regressive moving average) model. The relationship between order and error in the identification of the system was also investigated. Identification of a system where the inside air temperature is determined by both the outside radiation and the on-off of ventilating fan was also carried out. The experiment of control of the air temperature inside greenhouse was carried out in a small model greenhouse with a water-to-air heat exchanger for heating/cooling. Observer was calculated from the estimated parameters of ARMA model. An optimal regulator was designed based on solution of Riccati equation and state feedback gain. The control performance was examined experimentally with some different values of weighting factor used in LQ (linear quadratic) control design. | |
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