Design and development of an online process measurement system for zero defect production

Abstract

The objective of this paper is to fabricate a system for press line that allows for real-time sorting of parts with defects caused by process variation. Despite high investment and advanced technology, defects like thinning, cracks and wrinkles are still common in products in the sheet metal forming industries. Variation of the process parameter is an unavoidable reality resulting in heavy investment in process control technologies like adaptive control and closed-loop systems. The limitations of a control system mandate an inspection line post-production. With this scheme, the dependence of product quality on the effectiveness of the inspection line can be reduced. The project that was undertaken herein mainly focuses on design and fabrication of online inspection measurement system which is used to monitor the process parameters-alignment, uneven force distribution and non-uniform pneumatic pressure. Comparison of real-time values is done with ideal value of process parameters to check variation of values in the press line. The readings on GUI of MATLAB show the exact parameters of the system at particular instants through which estimation of the reason for defect and an exact number of defective pieces can be found. The experiments affirmed the importance of process parameters in the consistency of quality through the feedback from sensors. The scheme can successfully reduce both producer and consumer risk. Savings in space, time, manpower and capital in inspection system can also be achieved.