A generalised featured-based inspection framework for dimensional inspection of individual machined parts

Inspection and dimensional measurement of machined parts plays a vital role in manufacturing. Machined parts are inspected to much tighter tolerances in order to achieve the highest quality finished products. The dimensional inspection process of discrete components has been developed and automated with time and has come a long way, from the early use of gauge blocks, dial indicators, micrometers to today's computer controlled coordinate measuring machines (CMMs) with touch trigger probes. Despite this rapid advancement, bespoke inspection methods are used for dimensional measurement of machined parts either on a CMM or a CNC machining centre have touch trigger probes. A generalised dimensional inspection framework is required and to achieve this STEP and STEP-NC standards provide a convenient plate-form. In this paper the concept of a framework which gives a generalised feature-based inspection and measurement plan for prismatic machined parts based on STEP and STEP-NC is presented. This generalised STEP-NC compliant inspection plan could be a direct input to an intelligent controller of a CNC machining centre through an interface or can be interpreted into an inspection code for a CMM. The inspection framework uses the information regarding manufacturing features of a machined part and touch probing as given in ISO14649 (STEP-NC).