Two dimensional model of CMM probing system

A coordinate measuring machine (CMM) as an automation technology is playing the key role in the modern industry to improve the measurement accuracy. Accurate probing that is computer controlled is the current trend for the next generation of coordinate metrology. However, the CMM probing system is limited by its dynamic root errors that may markedly affect its response characteristics. In this paper, dynamic response errors of CMM measurements have been analyzed. The adopted probe stylus sizes throughout the course of measurements are found to cause some waviness errors during CMM operations due to each of the prescribed angle of the probe tip contact point with the specimen surface and the radius of the stylus tip. Variations in the geometry of the stylus have their consequent effects on its inherent intrinsic dynamic characteristics that in turn would cause relevant systematic root errors in the resulted measurements. Unforeseeable geometrical errors of a CMM using a ductile touch-trigger probing system have been characterized theoretically. These results are analyzed in order to investigate the effect of the dynamic root errors in the light of six probe stylus tip of the situation into account when assessing the accuracy of the CMM measurements. Analytical approaches have been applied on a developed two dimensional model (2DM) of stylus tip to demonstrate the capability of such approaches of emphasizing the root error concept using the strategy of CMM ductile trigger type of probe.