African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6688

Full Length Research Paper

Modeling of the dynamics of CO2 in greenhouses: A comparative study

J. L. López-Medina1,4, J. E. Olvera-González1, D. Alaniz-Lumbreras1, J. Villa-Hernandez1, M. A. Araiza-Esquivel1, C. Olvera-Olvera, R. Guzman-Cruz3, V. Torres-Argüelles2, A. de la Isla3 and V. M. Castaño3,5*
1Facultad de Ingeniería Eléctrica, Doctorado en Ciencias de la Ingeniería, Universidad Autónoma de Zacatecas, Av. López Velarde 801, Centro, Zacatecas, Zac. 98068, México. 2Departamento de Ingeniería Industrial y Manufactura, IIT, Universidad Autónoma de Ciudad Juárez, Av. P.E. Calles 1210, Fovissste Chamizal, C.P. 32310 Juárez, Chihuahua. México.  3Universidad Autónoma de Querétaro, Campus Aeropuerto, Santiago de Querétaro, Qro., México. 4Universidad Politécnica de Sur Zacatecas, Juchipila, Zac., México. 5Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México.
Email: [email protected]

  •  Accepted: 06 November 2012
  •  Published: 20 December 2012

Abstract

Three mathematical models for the dynamic behavior of CO2 inside a greenhouse with the climatic conditions of Central Mexico were analyzed: The first was based on the physical model proposed by Tap, the second was an auto regressive model with external input (ARX) with structure of multiple inputs and single output (MISO), and the third was an artificial neural network model (ANN) with feed-forward type structure and a Levenberq-Marquardt back propagation training. The external CO2, solar radiation, external temperature, wind speed and humidity were used as input for ARX and ANN models. In the Tap model, also the windward and leeward of the greenhouse windows were considered. The results show that the neural networks had a better fit with R2 = 0.91 and mean square error (RMSE) of 16.08, whereas the ARX models had an R2 = 0.77 with an RMSE of 25.5, and the physical model had an R2 = 0.72 with an RMSE of 32.11.

 

Key words: CO2, greenhouse, ARX model, physical model, neural networks.