Robust Parameter Control based on Selecting Online Controllable Variables

Robust parameter design (RPD) is considered as a cost effective tool for reducing process variability. Robust parameter control, integrating RPD with automatic process control, will performance better than the traditional RPD approach. This paper proposed a strategy of robust process control based on selecting online controllable variables with consideration of generalized quality cost, which includes quality loss and manufacturing cost. Firstly, online controllable variables were selected and offline controllable variables were optimized in the design stage by minimizing the expectation of quality loss. Then, online controllable variables were adjusted during production according to the measurement of noise variables. Finally, the illustrative example showed that the proposed approach achieved lower quality cost.