Review. Advantages and disadvantages of control theories applied in greenhouse climate control systems

Duarte-Galvan, Carlos; Torres-Pacheco, Irineo; Guevara-González, Ramón Gerardo; Romero-Troncoso, René de Jesús; Contreras-Medina, Luis Miguel; Rios-Alcaraz, M. A.; Millán-Almaraz, Jesús Roberto

doi:10.5424/sjar/2012104-487-11

Cited by 39 publications

(15 citation statements)

References 56 publications

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“…To improve the control accuracy and reduce the energy cost, computerized greenhouse climate control based on sensing technologies was introduced. The existing computerized control strategies can be categorized into two branches: conventional control and generalized optimal control (Duarte-Galvan et al, 2012 ). Conventional control can be regarded as the early development stage of computerized control strategies.…”

Section: Introductionmentioning

confidence: 99%

A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth

Qiu¹,

Zheng

Wang

et al. 2017

Front. Plant Sci.

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State observer is an essential component in computerized control loops for greenhouse-crop systems. However, the current accomplishments of observer modeling for greenhouse-crop systems mainly focus on mass/energy balance, ignoring physiological responses of crops. As a result, state observers for crop physiological responses are rarely developed, and control operations are typically made based on experience rather than actual crop requirements. In addition, existing observer models require a large number of parameters, leading to heavy computational load and poor application feasibility. To address these problems, we present a new state observer modeling strategy that takes both environmental information and crop physiological responses into consideration during the observer modeling process. Using greenhouse cucumber seedlings as an instance, we sample 10 physiological parameters of cucumber seedlings at different time point during the exponential growth stage, and employ them to build growth state observers together with 8 environmental parameters. Support vector machine (SVM) acts as the mathematical tool for observer modeling. Canonical correlation analysis (CCA) is used to select the dominant environmental and physiological parameters in the modeling process. With the dominant parameters, simplified observer models are built and tested. We conduct contrast experiments with different input parameter combinations on simplified and un-simplified observers. Experimental results indicate that physiological information can improve the prediction accuracies of the growth state observers. Furthermore, the simplified observer models can give equivalent or even better performance than the un-simplified ones, which verifies the feasibility of CCA. The current study can enable state observers to reflect crop requirements and make them feasible for applications with simplified shapes, which is significant for developing intelligent greenhouse control systems for modern greenhouse production.

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Section: Introductionmentioning

confidence: 99%

A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth

Qiu¹,

Zheng

Wang

et al. 2017

Front. Plant Sci.

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“…Nowadays, agriculture is changing in response to the requirements of modern society, where ensuring food supply through practices such as water conservation, reduction of agrochemicals and the required planted surface, which guarantees high quality crops are in demand (Duarte-Galvan et al, 2012). The necessary prerequisite needed to ensure what was previously said is the use of well-functioning agricultural machines and mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Reliability of agriculture universal joint shafts based on temperature measuring in universal joint bearing assemblies

Asonja¹,

Desnica

2014

Span. j. agric. res.

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This paper presents a research into reliability calculations of agriculture double universal joint shafts based on temperature measuring in cardan-type universal joint bearing assemblies. Special laboratory equipment was developed for this research which is presented in the paper. The objective of this research was to test the real life span of universal joint shafts in the laboratory and in field, to obtain the results which can be used to improve the reliability of universal joint shafts. If the presented research were used along with maintenance measures recommended in the paper and with proper use, the level of reliability of the shafts would be 2.1 times higher. The presented results of the research showed that needle bearings, i.e. bearing assemblies of the joints, are the most critical elements on universal joint shafts and are possible causes of their lower reliability. The second universal joint is the part with the lowest reliability in the observed technical system.

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“…CEA, as the name implies, has benefits over other forms of farming because of the added ability to "control" the system. Several parameters can be controlled with sensors and mechanical hardware including air flow, temperature, relative humidity, CO 2 levels, water delivery and quality, pH and electrical conductivity (EC) (Coelho et al, 2005;Panwar et al, 2011;Duarte-Galvan et al, 2012). Having this added level of control potentially results in substantial yield increase and overall quality, as well as less water and fertilizer consumption (Duarte-Galvan et al, 2012).…”

Section: Introduction To Ceamentioning

confidence: 99%

“…Several parameters can be controlled with sensors and mechanical hardware including air flow, temperature, relative humidity, CO 2 levels, water delivery and quality, pH and electrical conductivity (EC) (Coelho et al, 2005;Panwar et al, 2011;Duarte-Galvan et al, 2012). Having this added level of control potentially results in substantial yield increase and overall quality, as well as less water and fertilizer consumption (Duarte-Galvan et al, 2012). Being able to control and manipulate environmental and chemical parameters have resulted in new discoveries in terms of ideal growing conditions for different plant cultivars, making CEA operations increasingly popular in universities and R&D sectors.…”

Section: Introduction To Ceamentioning

confidence: 99%

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Effect of Aquaponic vs. Hydroponic Nutrient Solution, Led Light Intensity and Photoperiod on Indoor Plant Growth of Butterhead, Romaine and Kale (L. sativa, B. oleracea)

Foster

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Effect of Aquaponic vs. Hydroponic Nutrient Solution, LED Light Intensity and Photoperiod on Indoor Plant Growth of Butterhead, Romaine and Kale (L. sativa, B. oleracea) Sean Foster Vertical farming has been proposed as a solution for providing food security for an increasing, urbanized human population. Light-emitting diode (LED) technology has become increasingly affordable and efficient, making it an ideal choice as artificial lighting for indoor farms. Still largely undiscovered parameters are the optimal plant varieties and types of production systems for plant growth, profit, and human nutrition. Aquaponics may be able to provide sustainable animal protein for vertical farms, increasing their ability to provide more substantial nutrition to consumers. This research aimed to better understand vertical farming as a food production system, and to determine if aquaponics can be an appropriate and applicable fit for it. The experiment was a randomized, factorial design with three independent variables: (1) LED photoperiod interval (2) LED-plant distance, and (3) nutrient solution, as well as several dependent variables to assess both plant yield and quality. A 4-tiered shelving unit was constructed for nutrient film technique (NFT) plant production, and treatments were assigned to each row: (1) LED experiment: Row A, 12/12hr reduced photoperiod with adjustable LEDs 4in. above plant surface; Row B, 2/1hr altered photoperiod interval relative to the control; Row C (control), 16/8hr "standard" photoperiod. (2) Nutrient experiment: Row C, aquaponic nutrient solution; Row H, hydroponic nutrient solution. Rows C and H had matched photoperiod and light intensity. Kale from Row A had significantly lower fresh and dry plant yield relative to the control, Row C (p<0.05). Hydroponic romaine, Row H, had significantly higher plant yield relative to aquaponics, Row C (p<0.05). Butterhead yields were not significantly different in any treatments (p>0.05). Future research may implement a larger sample size of only one plant variety, harvest plants earlier, limit light intensity variation, effectively "balance" the aquaponics system, and have more measures of plant "quality." v ACKNOWLEDGMENTS I would first like to thank my advisor, Dr. Greg Schwartz, for his support and guidance throughout the project; you were the best mentor I could have ever asked for. I also thank my committee members Dr. Peter Livingston and Dr. Sara Kuwahara for their insight and help in designing and executing my experiment. To Megan, Jack, and about a dozen other students who helped me count and measure leaves for hours…you saved my life. Professor Smith and Lindsey, thank you so much for helping me organize and analyze all of my data. I would also like to acknowledge the Cal Poly BRAE department, which provided so many resources for construction, operation and maintenance of the system for the experiment. The Fruit Grower's Laboratory (FGL) in San Luis Obispo was extremely generous in doing all water quality and tissue samples pro bono, all in the name...

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Review. Advantages and disadvantages of control theories applied in greenhouse climate control systems

Cited by 39 publications

References 56 publications

A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth

A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth

Reliability of agriculture universal joint shafts based on temperature measuring in universal joint bearing assemblies

Effect of Aquaponic vs. Hydroponic Nutrient Solution, Led Light Intensity and Photoperiod on Indoor Plant Growth of Butterhead, Romaine and Kale (L. sativa, B. oleracea)

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