Influence of human factor in the AACMM performance: a new evaluation methodology

Abstract

One of the main principles of metrology, when talking about instrument calibration, concern to the idea of reproducing the actual measurement process during calibration (same instrument handling, environment, measurement parameters, etc.) in order to obtain suitable information. In spite of that, this principle is being currently neglected in Articulated Arm Coordinate Measuring Machine (AACMM) evaluation and/or calibration procedures. These procedures are carried out in manufacturer facilities under unknown conditions and measurement parameters instead of “in-situ” procedures with similar measurement parameters. Thereby, reported accuracy has little to do with AACMM common use and, therefore, with its reliability. This work presents a new evaluation methodology for both AACMM and operator performance. To do so, a survey of main measurement parameters (operator, contact force, type of feature) is carried out by mean of contact force sensor on the AACMM probe and geometric gauges. ANOVA have been used for the study of these parameters and its impact on AACMM performance. Additionally, a new evaluation methodology capable of quantifying AACMM, operator and its measuring technique contribution to measurement uncertainty has been developed. It is supported by a feature-base gauge that has been specifically designed for this task.