Synergism of high and low level systems for the efficient management of greenhouses

Sigrimis, NA; Arvanitis, KG; Pasgianos, GD

dc.contributor.author	Sigrimis, NA	en
dc.contributor.author	Arvanitis, KG	en
dc.contributor.author	Pasgianos, GD	en
dc.date.accessioned	2014-03-01T01:15:54Z
dc.date.available	2014-03-01T01:15:54Z
dc.date.issued	2000	en
dc.identifier.issn	0168-1699	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13814
dc.subject	computer control	en
dc.subject	fuzzy systems	en
dc.subject	knowledge based control	en
dc.subject	proportional-integral-derivative (PID) central	en
dc.subject	Smith predictor	en
dc.subject.classification	Agriculture, Multidisciplinary	en
dc.subject.classification	Computer Science, Interdisciplinary Applications	en
dc.title	Synergism of high and low level systems for the efficient management of greenhouses	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0168-1699(00)00134-4	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0168-1699(00)00134-4	en
heal.language	English	en
heal.publicationDate	2000	en
heal.abstract	The advantages of using artificial intelligence (AI) decision support tools in synergism with low level process controllers or schedulers are investigated in this paper. The development of a modern control and management system for greenhouses used recent advances in software design, and development tools, to provide an open system for rapid program development. To effectively integrate expert system applications in a control and management system, an environment was built that supports all required interfaces between Al applications and the greenhouse management system (GMS). This environment incorporates a native fuzzy knowledge based system (KBS) and a number of procedural control functions, in the GMS, that can effectively interact. The programmable logic controller (PLC) houses all well-known control function blocks, in library form, callable to implement various control loop designs. Functions that have not been foreseen in the PLC control library can be instantly implemented using the open KBS system. The innovative addition of integral initial conditions on a proportional-integral-derivative (PID) controller, for repetitive load switching applications, is an example, demonstrated in this paper. The usefulness of other control blocks such as a self-adjusting Smith predictor is also tested for a real application of a mixing process with long dead time. Synergism of fuzzy decisions and fuzzy controllers, at the supervisory level, with low level process regulators provide adaptive systems, which can optimize both long-term objectives and the short time dynamic responses. (C) 2000 Elsevier Science B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCI LTD	en
heal.journalName	COMPUTERS AND ELECTRONICS IN AGRICULTURE	en
dc.identifier.doi	10.1016/S0168-1699(00)00134-4	en
dc.identifier.isi	ISI:000089439300003	en
dc.identifier.volume	29	en
dc.identifier.issue	1-2	en
dc.identifier.spage	21	en
dc.identifier.epage	39	en