Closed-Loop Feedback Control of Production Part Errors

This paper presents a new supervisory controller, designed to meet or exceed the tight quality specifications required of high-volume production parts. The process optimizing controller takes Co-ordinate Measuring Machine (CMM) data collected on Statistical Process Control (SPC) samples. It analyses the data and updates the program on a Computer Numerically Controlled (CNC) milling machine to optimize the overall production process. Part specifications, including dimensions between cast and machined features, are controlled through feedback. The controller improved process capability (Cp ), and by targeting the mean on the nominal dimension it significantly improved the capability index (Cpk ).Copyright © 2002 by ASME