Simple mixed ON-OFF and PI/PID controller using a microcontroller for a vacuum chamber substrate heater

摘要

A control system has evolved from a traditional approach to a fuzzy and neural network based system. The system development is intended to achieve a good response and stability. In current technology many control systems are implemented using a digital system. By using a microcontroller we have developed a simple control system based on classical control, combining an ON-OFF controller and PI (proportional integral) or PID (proportional integral derivative) controller to control a substrate heater's temperature. The system will act as an ON-OFF or PI/PID control depending on the temperature difference between the setting point and substrate heater temperature. The approach has been successfully implemented to control substrate temperature with a characteristic of a fast response at the beginning and a stable response at steady state.