Point Cloud Measurements on a CMM Artifact using a Laser Scanner

Abstract

Tight tolerance part inspection, whether it is an industrial application or national laboratory requirement is traditionally performed using Cartesian Coordinate Measuring Machines (CMMs). Furthermore, data collection is performed with the use of either tactile probing or dynamic scanning to ensure high-quality part inspection, with high-data density measurement sets to adequately characterize part geometries. Requirements, such as high-accuracy and high-data density, limit the class of measurement instrument which can produce satisfactory results; highaccuracy can be limited to hard-probing, while high-density may require an optical alternative. Such technologies, although excellent in their own rights, either cannot produce point-cloud data or utilize superficial coatings to ensure proper surface reflectivity. To alleviate these issues, an articulating arm CMM (AACMM) with an integrated laser scanner is used. Laser scanning allows the ability to quickly measure and create accurate, high-density point clouds without contact or surface alteration. This research investigates the accuracy, precision, and measurement capability associated with laser scanning to generate point clouds of common, unclassified CMM hemi-shell artifacts used in a nuclear weapons laboratory. These artifacts are characterized are composite geometries (i.e., hemispheres, cylinders and/or cones).