Dynamic Referencing in 3D Optical Metrology for Higher Accuracy in Shop Floor Conditions

This paper describes the principles of dynamic refe rencing for optical CMMs and demonstrates the advan tages of this new functionality in terms of measurement a ccuracy in shop floor conditions. Recent optical triangulation–based CMMs are now able to simultaneo usly measure multiple 3D points. With the help of markers placed on the part being measured, it is no w p ssible to continuously monitor any deviations f rom the reference part. In this way, the machine reference and part reference become one and the same and rema in locked on the part throughout the measuring process . This significantly improves the accuracy of porta ble CMMs operating in challenging shop floor environmen ts that are subject to intense vibrations, thus eli minating the need to acquire expensive heavy equipment to en sur measurement accuracy. This article describes t h vibration conditions common in factory environments as well as the experiments we designed to reproduc e these disturbances and assess their impact on measurement processes using a portable CMM. We conclude with examples from real-life situations.