Humidity control in greenhouse

I completed this project with two other students as my final project of my second year of preparatory class. The goal of the project was to investigate how to maintain optimal humidity levels in a greenhouse for plant growth and health by studying ambient humidity. To do this, we selected two humidity sensors with different technologies: a resistive hygrometer and a capacitive hygrometer. We also conducted experiments to evaluate the accuracy and reliability of these sensors.

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I first examined the impact of temperature on humidity measurement by enclosing a sample in a cloche and repeating the experiment in both humid and dry environments. This allowed me to plot the humidity as a function of temperature and compare the results to the dry air chart.

We also designed a system that controls humidity by spraying water based on the humidity level. To do this, we used a strain gauge to measure the deformation caused by the weight of water in a tank, and used this information to control the amount of water sprayed.

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I also used Matlab Simulink to simulate this system. With this tool, I was able to select a suitable controller for the motor to meet the specified requirements for speed and accuracy.

Finally, we built the simulink model of our humidity controller.

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With this model, we can choose a corrector to have an error rate of negligible and the necessary speed.

To summarize, this project allowed me to learn how to create a controller using Arduino and how to write code for it. I also gained experience in comparing experimental results to theoretical ones, and learned how to design both simulated and experimental projects and evaluate the accuracy of the experimental results.