A model-free control strategy for an experimental greenhouse with an application to fault accommodation

Writing down mathematical models of agricultural greenhouses and regulating them via advanced controllers are challenging tasks since strong perturbations, like meteorological variations, have to be taken into account. This is why we are developing here a new model-free control approach and the corresponding intelligent controllers, where the need of a good model disappears. This setting, which has been introduced quite recently and is easy to implement, is already successful in many engineering domains. Tests on a concrete greenhouse and comparisons with Boolean controllers are reported. They not only demonstrate an excellent climate control, where the reference may be modified in a straightforward way, but also an efficient fault accommodation with respect to the actuators

Model-free control and fault accommodation for an experimental greenhouse

International audienceThe greenhouse climate control is important in modern agriculture. It is also rather difficult to design: as a matter of fact writing down a "good" mathematical model, which takes into account strong meteorological disturbances, might be an impossible task. The control is here synthesized via a new "model-free" setting, which yields an "intelligent" proportional feedback controller, the tuning of which is straightforward, and even simpler than the intelligent proportional-integral controller, which was already utilized in a previous publication. Our control strategy is successfully tested via an experimental greenhouse. The comparison with the classic Boolean approach, which is popular among manufacturers, demonstrates the superiority of our viewpoint, which permits moreover an efficient actuator fault accommodation. It might be the first model-free fault-tolerant control, which works satisfactorily in practice

On the model-free control of an experimental greenhouse

International audienceIn spite of a large technical literature, an efficient climate control of a greenhouse remains a very difficult task. Indeed, this process is a complex nonlinear system with strong meteorological disturbances. The newly introduced ''model-free control'' setting is employed here. It is easy to implement, and has already shown excellent performances in many other concrete domains. Successful experimental tests are presented and discussed. They are compared to a Boolean approach, which is often utilized in practice

Моделювання системи управління параметрами мікроклімату з нечітким регулюванням

В статті приведені результати досліджень автоматизованої системи контролю та регулювання параметрів мікроклімату цехового приміщення, що включає нечіткий регулятор.В статье приведены результаты исследований автоматизированной системы контроля и регулирования параметров микроклимата включающий нечеткий регулятор.The results of research of the automated control system and regulation of microclimate parameters including a fuzzy controller

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

Multi-Objective Control Optimization for Greenhouse Environment Using Evolutionary Algorithms

This paper investigates the issue of tuning the Proportional Integral and Derivative (PID) controller parameters for a greenhouse climate control system using an Evolutionary Algorithm (EA) based on multiple performance measures such as good static-dynamic performance specifications and the smooth process of control. A model of nonlinear thermodynamic laws between numerous system variables affecting the greenhouse climate is formulated. The proposed tuning scheme is tested for greenhouse climate control by minimizing the integrated time square error (ITSE) and the control increment or rate in a simulation experiment. The results show that by tuning the gain parameters the controllers can achieve good control performance through step responses such as small overshoot, fast settling time, and less rise time and steady state error. Besides, it can be applied to tuning the system with different properties, such as strong interactions among variables, nonlinearities and conflicting performance criteria. The results implicate that it is a quite effective and promising tuning method using multi-objective optimization algorithms in the complex greenhouse production

Controlled atmosphere and dynamic controlled atmosphere for Fuzzy logic-based banana storage: Atmosfera controlada e atmosfera controlada dinâmica baseadas em lógica Fuzzy para o armazenamento de bananas

The insertion of New Information and Communication Technologies is increasingly present in the most diverse fields of knowledge, among them agriculture. This insertion results in what is called precision agriculture. Postharvest of bananas requires the application of new technologies to increase storage time and reduce losses. Bananas are highly perishable.  Losses in postharvest may vary from 20% to 80% of the crop. Therefore, the purpose of this article is to present the impact of applying new information and communication technologies in the quality and time of conservation of bananas in control atmosphere. To meet the goals, five treatments in the cold storage process of bananas, refrigerated environment, static controlled atmosphere (2% of O2 and 7% of CO2), dynamic controlled atmosphere with static respiratory quotient, dynamic controlled atmosphere with dynamic respiratory quotient, and controlled atmosphere with intelligent control (2% of O2 and 7% of CO2) were applied. These five treatments were implemented based on a computing embedded system, sensors and actuators. The intelligent control system used was built with Fuzzy logic techniques. The system controls the respiration gases of bananas and a cold chamber controls the temperature. To validate the research, the storage of pome banana was evaluated in all the treatments to compare the fruit technical requisites and quality. As results we can see the expressive increase of storage time of bananas with the keep of fruit quality. The treatment system with dynamic and intelligent atmosphere control was also seen (2% of O2 and 7% of CO2) as the most efficient, reaching a storage for 45 days and thus proving that new technologies promotes precision agriculture

A Compatible Control Algorithm for Greenhouse Environment Control Based on MOCC Strategy

Conventional methods used for solving greenhouse environment multi-objective conflict control problems lay excessive emphasis on control performance and have inadequate consideration for both energy consumption and special requirements for plant growth. The resulting solution will cause higher energy cost. However, during the long period of work and practice, we find that it may be more reasonable to adopt interval or region control objectives instead of point control objectives. In this paper, we propose a modified compatible control algorithm, and employ Multi-Objective Compatible Control (MOCC) strategy and an extant greenhouse model to achieve greenhouse climate control based on feedback control architecture. A series of simulation experiments through various comparative studies are presented to validate the feasibility of the proposed algorithm. The results are encouraging and suggest the energy-saving application to real-world engineering problems in greenhouse production. It may be valuable and helpful to formulate environmental control strategies, and to achieve high control precision and low energy cost for real-world engineering application in greenhouse production. Moreover, the proposed approach has also potential to be useful for other practical control optimization problems with the features like the greenhouse environment control system

Sistem Kendali Temperatur, Kelembaban Tanah, Dan Cahaya Otomatis Menggunakan Raspberry Pi Pada Smart Greenhouse

Conventional greenhouse technology replaced by the development of smart greenhouses. In this greenhouse there is an automatic control system. Measured factors of plant growth can be controlled such as temperature, soil moisture and sunlight. Weather which often cannot be predicted causes these factors to interfere with plant growth. In this study a system for controlling temperature, soil moisture and light was made to suit the needs of plants. As a control method using the fuzzy method. This method is suitable to be applied to the control system. In detecting temperature using a DHT11 sensor, detection of soil moisture uses the YL-69 sensor and light detection using an LDR type sensor. Raspberry Pi is the main brain in this control system. The Raspberry used is the Raspberry Pi 3 Model B + which has better than the previous version. The fuzzy method designed is processed into the Raspberry Pi to produce fan output and water pumps. In the lighting system, the light will turn on if sunlight is less than the plant's needs. In the system created this has been going well. This control system is able to measure the degree of temperature, soil moisture level, and light, and control the system according to predetermined parameter

GREENHOUSE REMOTE MONITORING & CONTROL SYSTEM

Continuous control and monitoring of the greenhouse factors can be considered as a pivotal part in the production practices. The rate of crop’s growth highly influenced by the surrounding optimal climate conditions, but in order to do so, they required sets of expensive and complex equipment. Conventional systems used an excessive work to link and dispense the transducers and their control systems. One of the reasons why it’s expensive is the requirement of the systems of having a wide range of power wires and data cables to and from the sensors to control systems. Plus, for users such as growers and planters for businesses are having difficulties to monitor and control its system from any remote location with the system applied only allowed to be control from the control room and et cetera. To overcome these drawbacks, this proposal intends to describe how the innovative greenhouse control system can be characterized as an event-based system, where every control actions are primarily deliberated compared to the events formed by instabilities from surrounding elements. Proposed control system offers a costs-saving solution with low maintenance required, as well as producing a great performance results. This solution also with eliminate the over-dependability of the industry to the human workforce today