Grey modeling and control of a thermal barrel in plastic molding processes

We propose a self-tuning controller with a grey system for online process control. The self-tuning mechanism is designed based on a group of input-output data obtained from the process. The grey system in the tuning mechanism is utilized to reduce the random variation of the input-output data. The self-tuning mechanism is integrated into an internal model control, and the developed control system is applied to control the temperature distribution in a thermal barrel of plastic molding processes. From the experimental result, we conclude that the usage of the grey system can filter out the noise in the process and reduce the number of input-output data required in the tuning mechanism.