Development of Thermal Control Algorithm for the Splash Water Chamber based on Expert System

The PID controller used to regulate the internal temperature of a splash water chamber has only one modeling and control gain set. In addition, it is very difficult to control the temperature within a splash water chamber because of hardware design problems. The heater can be finely controlled by changing the output amount from 0 to 100% through the PWM method. However, the chiller cannot be connected to the output of the PID controller due to hardware compatibility issues. Therefore, the chiller is not finely controllable and only has output levels of 100%, 60% and 40%. Therefore, the control system is designed to control the temperature using the heater only after setting the output level of the chiller. This type of design causes problems such as not reaching the desired temperature, exceeding the settling time, and creating overshoots. In this paper, an expert system is introduced to develop a control algorithm to solve the above-mentioned problems. The expert system to be developed consists of supervisory rules and reasoning rules; based on these rules, the output level of the chiller is switched to achieve the desired performance such as fast settling to the target temperature and elimination of overshoot. To validate the feasibility of the proposed method, several experiments are performed and the results are provided. © ICROS 2022.