A Fiducial-Aided Reconfigurable Artefact for the Estimation of Volumetric Errors of Multi-axis Ultra-Precision Machine Tools

Abstract

In this paper, a fiducial-aided reconfigurable artefact is presented for estimating volumetric errors of a multi-axis machine tools. The artefact makes use of an adjustable number of standard balls as fiducials to build a 3D artefact which has been calibrated on a coordinate measuring machine (CMM). This 3D artefact shows its reconfigurability in its number of fiducials and their locations according to the characteristics of workpieces and machine tools. The developed kinematics of the machine tool was employed to identify the volumetric errors in the working space by comparing the information acquired by the on-machine metrology with that by the CMM. Experimental studies are conducted on a five-axis ultra-precision machine tools mounted with the 3D artefact composed of five standard spheres. Factors including the gravity effect and measurement repeatability are examined for the optimization of the geometry of the artefact. The results show that the developed 3D artefact is able to provide information of the volume occupied by the workpiece.

Estimación de incertidumbre de medida bajo condiciones “on shop floor” en centro de mecanizado de 5 ejes

“…Sin embargo, no todo son ventajas. Al realizar tanto las operaciones de mecanizado como las de medición en la misma MH, ambos se ven afectados por los mismos errores geométricos originados en la propia MH, lo que complica su detección y posterior compensación [5]. Para evitar esta limitación Schmitt et al [6] plantean dos alternativas: realizar una calibración volumétrica del equipo o la implementación de un sistema metrológico externo que controle la posición de la punta de herramienta de la MH en todo momento.…”