Design and Implementation of PID-Based Refrigerator Temperature Control System

This paper presents the design and implementation of a PID-based refrigerator temperature control system. We begin by explaining the working principle of PID controllers and their industrial applications. The design process of the refrigerator temperature control system is detailed, describing the functionality and characteristics of each component including sensors, actuators, controllers, and power supplies. From a coding perspective, the PID algorithm implementation typically involves proportional, integral, and derivative terms calculated through discrete-time equations, with parameters tuned using methods like Ziegler-Nichols. The system performance evaluation and optimization methods are discussed to ensure stability and reliability, covering techniques such as setpoint tracking analysis and disturbance rejection testing. Finally, we present the implementation process including hardware development (using microcontrollers like Arduino or STM32), software development (featuring real-time temperature sampling and PWM output control), and system testing procedures. Through this paper, readers will understand the complete design and implementation workflow of PID-based temperature control systems, grasp fundamental control principles, and learn performance evaluation and optimization techniques applicable to embedded systems.