Integrated Process Control by Combining Controllers and Monitoring Charts

Integrated processes between automatic process control (APC) and statistical process control (SPC) have been of interest to researchers in the process control area as both are complementary to each other and share the common objective of reduction of process variation. In this paper, a control system with damping property functions is designed as an integral controller and is combined with SPC charts in order to reduce process variability. The proposed controller is compared with other existing and widely-used controllers including minimum mean square error controllers and proportional, integral and derivative controllers under the integration of APC and SPC. The results show that indeed a damping controller with optimum parameters results in a more significant. reduction in process variation than the widely-used ones. Numerical examples are given to demonstrate the applicability of the proposed controller.