Optimal greenhouse cultivation control: survey and perspectives

Abstract: A survey is presented of the literature on greenhouse climate control, positioning the various solutions and paradigms in the framework of optimal control. A separation of timescales allows the separation of the economic optimal control problem of greenhouse cultivation into an off-line problem at the tactical level, and an on-line problem at the operational level. This paradigm is used to classify the literature into three categories: focus on operational control, focus on the tactical level, and truly integrated control. Integrated optimal control warrants the best economical result, and provides a systematic way to design control systems for the innovative greenhouses of the future. Research issues and perspectives are listed as well

Linear matrix inequalities tool to design predictive model control for greenhouse climate

Modeling and regulating the internal climate of a greenhouse have been a challenge as it is a complex and time variant system. The main goal is to regulate the internal climate considering the difference between nighttime and diurnal phases of the day. To depict the comportment of the greenhouse, a multi model approach based on two multivariable black box models have been proposed representing the diurnal and nighttime phases of the day. The least-squares method is utilized to identify the parameters of these two models based on an experimental collected data. We have shown that these two models are more representative than one model to describe the dynamic behavior of the greenhouse. The second contribution is to control the internal temperature and hygrometry respecting constraints on actuators and controlled variables. For this purpose, a constrained model predictive control scheme based on the multi-modeling approach have been developed. The optimization problem of the control law is transformed to a convex optimization problem includes linear matrix inequalities (LMI). The simulation results show that the adopted control method of indoor climate allows rapid and precise tracking of set points and rejects effectively the external disturbances affecting the greenhouse

The workings of Autonomous Greenhouses

Tato rešeršní bakalářská práce si klade za cíl zkoncentrovat znalosti z rozsáhlé literatury zabývající se autonomními skleníky a tématy s nimi spojenými. První část práce je zaměřena na základní pojmy spojené s autonomními skleníky. V druhé části je vysvětleno množství pojmů spojených s logickým aparátem a principy logiky v těchto sklenících využívaných. Dále se práce zabývá fyzickými aparáty inteligentních skleníků, především aktuátory. Nakonec soutěžemi úzce spojenými s touto problematikou, s důrazem na soutěžní podmínky a logiku.This research work aims to concentrate information from extensive literature dealing with autonomous greenhouse related topics. The first part of the work is focused on basic concepts related to autonomous greenhouses. The second part explains an amount of concepts defining the logical apparatus and logical principles used in autonomous greenhouse design. Furthermore, this work deals with the physical aparatus of intelligent greenhouses, primarily its actuators. Finally it deals with autonomous greenhouse competitions, with focus on their conditions and logic.

RESOURCE AND ENVIRONMENTAL CONSTRAINTS ON SUSTAINABLE GROWTH IN AGRICULTURAL PRODUCTION: REPORT ON A DIALOGUE

Environmental Economics and Policy, Farm Management,

Energy Efficiency in Buildings: Both New and Rehabilitated

Buildings are one of the main causes of the emission of greenhouse gases in the world. Europe alone is responsible for more than 30% of emissions, or about 900 million tons of CO2 per year. Heating and air conditioning are the main cause of greenhouse gas emissions in buildings. Most buildings currently in use were built with poor energy efficiency criteria or, depending on the country and the date of construction, none at all. Therefore, regardless of whether construction regulations are becoming stricter, the real challenge nowadays is the energy rehabilitation of existing buildings. It is currently a priority to reduce (or, ideally, eliminate) the waste of energy in buildings and, at the same time, supply the necessary energy through renewable sources. The first can be achieved by improving the architectural design, construction methods, and materials used, as well as the efficiency of the facilities and systems; the second can be achieved through the integration of renewable energy (wind, solar, geothermal, etc.) in buildings. In any case, regardless of whether the energy used is renewable or not, the efficiency must always be taken into account. The most profitable and clean energy is that which is not consumed