Study of Virtual Features in the Performance of Coordinate Measuring Arms

Coordinate Measuring Arms (AACMMs or CMAs) made up their own type of dimensional measurement machines due to their unique characteristics: structural redundancy, portability and manual control. Therefore, specific evaluation methodologies have been developed in order to guarantee their measurement reliability and traceability. Despite the fact that some AACMM evaluation parameters and test have been defined, current methodologies are based on CMM previous experience and they have to be adapted to AACMM characteristics. Virtual features, made of kinematic seats, have been proved as a singular and useful feature for AACMM measurement as well as a suitable method for a fast and low cost evaluation. In order to simplify these features and processes the required input for evaluation has been reduced to 3 points or kinematic seats, which define a virtual circle. This work studies the suitability of these virtual features at the same time that reduces the evaluation time and gauge cost. (C) 2014 The Authors. Published by Elsevier Ltd.