Intermittent process measurement and process capability analysis using MP700 touch trigger probe on a CNC machining center

摘要

This study developed an intermittent process measurement system by integrating a MP700 touch trigger probe system with a machining center to measure a workpiece containing freeform surface and regular geometric features, and to do the statistical process control analysis. The whole measuring system, consisting of a personal computer, a CNC machining center controller, a RENISHAW MP700 touch probe system, was integrated information-technically. Measuring software was also developed to simulate the measuring path, to prevent collision, to generate the corresponding measuring NC codes and to calculate the process capability indices, such as the process capability index (Cp), the process performance index (C_(PK)) and the accuracy capability index (Ca). To evaluate the performance of the developed measuring system, a carrier combined with a freeform surface and regular geometric features, referred to in the ISO 10791-7 cutting test standard, was designed. Six pieces of the tested carriers were manufactured and inspected using the MP700 touch trigger probe to evaluate the performance of the developed measuring system. According to the measuring results, the developed measuring system was successfully and effectively used to carry out the intermittent process measurement and the statistical process analysis of the measuring results of some test carriers on the machining center.