IOT Based Automatic Environmental Control System for an Outdoor Oyster Mushroom Growing Unit

Abstract

The thesis proposes the design and implementation of a low-cost, robust, and water-efficient autonomous smart Internet of Things (IoT) based automatic climate control system for an outdoor oyster mushroom growing unit. The system aims to monitor, control, and maintain temperature and humidity with respect to ambient conditions. newline newlineThe IoT-based control system utilizes an IoT prototype and an Evaporative Cooling System (ECS). The IoT node consists of two DHT22 sensors, an ESP32 controller, and actuators such as a water pump and a cooling fan. These components work together to provide appropriate air circulation and maintain temperature and humidity within the mushroom growing unit. The system incorporates a fuzzy inference system (FIS) integrated into the ESP32 controller using Arduino C to calculate the switching on/off time of the water pump and cooling fan based on the current temperature and humidity readings with respect to ambient temperature and ambient humidity respectively. newline newlineA working prototype of the system was developed and implemented, and it operated continuously for seventeen days, collecting and storing data online. The results showed that the FIS-based IoT prototype effectively maintained the internal temperature below 27 °C and humidity above 70%. However, it was noted that the water consumption was 172 liters per day to maintain the required humidity. newline newlineTo optimize water usage, an Irrigation Interval-based FIS algorithm was proposed and implemented. This algorithm utilized three sensing interval policies to sense the humidity of the mushroom unit based on FIS-calculated water pump time and current humidity. The optimized IoT prototype with the Irrigation Interval-based FIS algorithm reduced water consumption to 34 liters per day while maintaining the desired indoor humidity and temperature. Furthermore, experimental data were used to design and simulate an Adaptive Neuro-Fuzzy Inference System (ANFIS) controller for the mushroom growing unit using MATLAB/Simulink.