Design and Experimental Evaluation of an IoT-Based Smart Greenhouse System With Enhanced Closed-Loop PID Control and Cloud Integration

Abstract

This paper presents the design, implementation, and experimental evaluation of a smart greenhouse system based on the Internet of Things (IoT), integrating real-time monitoring, closed-loop control, and data synchronization on a cloud platform. Unlike traditional systems that use threshold or open-loop control, the proposed method employs an advanced PID controller implemented on the low-cost ESP8266 platform to regulate greenhouse temperature. A first-order thermal model is constructed based on the principle of energy balance to support the controller design. The system integrates environmental measurement components, actuator control, Firebase cloud storage, and a mobile application for remote monitoring and control. Experiments are conducted under various environmental conditions to evaluate control performance using metrics such as response time, settling time, and overshoot. The results show that the system achieves a response time of 31-52 seconds, a settling time of 44-56 seconds, and an overshoot of less than 1% under stable conditions. A comparative analysis with existing IoT greenhouse systems indicates that the proposed method offers superior advantages in control accuracy, system integration, and quantitative assessment capabilities. The results affirm that the proposed architecture is a reliable and scalable platform for smart agricultural applications.