A review study on the design and control of optimised greenhouse environments

Effective air circulation is crucial for plant growth, requiring adequate airflow and environmental stability. This study utilized Computational Fluid Dynamics (CFD) to analyze airflow patterns in a controlled testing chamber, focusing on how miniature fan placement affects airflow direction and temperature distribution. Ten case studies were conducted, with the CFD model validated against experimental data collected from six monitoring locations on the plant growth table. Model validation was performed using statistical analyses including coefficient of determination (R2), root mean square error (RMSE), and mean absolute error (MAE). The validation results showed strong agreement between simulated and experimental data, with R2 values of 0.92 for temperature and 0.89 for airflow velocity. Statistical analysis showed significant differences in both airflow and temperature models at the 0.05 level, with the CFD model validation yielding an RMSE of 2.02 and an average absolute error of 1.17. Among the tested configurations, case M1 achieved the highest air velocity (0.317 m/s) and lowest temperature (27.03 °C), compared to M2 (0.255 m/s, 27.17 °C) and M3 (0.164 m/s, 27.18 °C). The temperature variations between cases significantly impacted cold storage efficiency, with case M1’s superior airflow distribution providing more uniform cooling. These findings offer practical guidelines for optimizing ventilation system design in medicinal plant cultivation facilities, particularly in maintaining ideal storage conditions through strategic fan placement and airflow management.

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A Comparative Analysis of Sliding Mode and Fuzzy Sliding Mode Controllers for Climate Control Application of a Greenhouse Flower Garden

Yetayew,

Tamir,

Hailu

2024

JERA

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This paper describes a comparative performance analysis of sliding mode and fuzzy sliding mode controllers for climate control application of a greenhouse flower garden. Various internal and external climate related factors affect the overall growth and health of flowers that needs robust controllers to control the humidity and temperature of the greenhouse flower garden. Review of related works show that for non-linear systems, sliding mode controllers can provide robust performance even though chattering is a major drawback of the controller. A number of approaches are used to solve the chattering problem of sliding mode controllers such as hybrid uses of other controllers along with sliding mode controller. In this paper, sliding mode controller and fuzzy sliding mode controllers are designed and implemented for the specified control application based on the linearized and decoupled model of the system. The performance evaluation has been done for the control problems of reference tracking and disturbance rejection with time domain performance measures of percentage overshoot, settling time and rise time. Accordingly, the overall system has been implemented in MATLAB/Simulink and the simulations for the control problems have been done. Thus, FSMC has got rise time of 5.89min, 10.59min settling time and almost negligible percentage overshoot for indoor temperature at 27°C and humidity at 22g/m3. And for humidity control, the FSMC has got 5.44min settling time and nearly zero percentage overshoot for set point tracking problem. For the disturbance of solar radiation, decrease in outside temperature and fixed set point of 27°C and humidity of 22g/m3, FSMC outperforms SMC. In summary, both quantitative and qualitative results analysis results reveal that fuzzy sliding mode controller (FSMC) outperforms sliding mode controller (SMC) for the indoor temperature and humidity control tasks of both set point tracking and disturbance rejection problems.

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A review study on the design and control of optimised greenhouse environments

Cited by 3 publications

References 57 publications

Impact of Setpoint Control on Indoor Greenhouse Climate Modeling

Impact of Setpoint Control on Indoor Greenhouse Climate Modeling

Modeling Airflow and Temperature in a Sealed Cold Storage System for Medicinal Plant Cultivation Using Computational Fluid Dynamics (CFD)

A Comparative Analysis of Sliding Mode and Fuzzy Sliding Mode Controllers for Climate Control Application of a Greenhouse Flower Garden

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