|Title||Double closed-loop optimal control of greenhouse cultivation|
|Author(s)||Xu, Dan; Du, Shangfeng; Willigenburg, Gerard van|
|Source||Control Engineering Practice 85 (2019). - ISSN 0967-0661 - p. 90 - 99.|
Mathematical and Statistical Methods - Biometris
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||Double closed-loop - Greenhouse cultivation - LED lighting - Optimal control - Time-scale decomposition|
Two time-scale receding horizon optimal control (TTRHOC) of greenhouse cultivation is investigated. Recent developments enable closure of the outer-loop of this control system because they facilitate on-line recomputation of the optimal control of the slow dynamics on a daily basis. This paper quantifies the benefits obtained from having an outer closed-loop that counteracts errors and changes concerning predictions of crop growth, long-term weather, revenues obtained from selling crops and costs to control greenhouse climate. As a special, important case LED lighting is considered which increases both crop growth and profit. Having an outer closed-loop is especially beneficial in this case.