Multivariable cycle-to-cycle of an injection molding process

Abstract

Cycle-to-Cycle (CtC) feedback control has been studied extensively with increasing demands on the precision and quality of manufactured parts. Single input-Single output has been studied as the basis of CtC feedback control. In the manufacturing sector, processes consist of many input parameters and critical outputs. Multivariate CtC seeks to extend the findings of SISO CtC to more accurately reflect real world processes. Multiple input-Multiple output CtC feedback control is applied to an injection molding process to verify the effects on quality of the parts produced. A design of experiment is used to determine the gains of the process, regression models are developed and integral feedback control is applied. The process is actively driven to meet specific target outputs. Minimal mean errors and variance ratios ranging from 0.14 to 0.57 are observed indicating an improvement in quality.