Complex Geometry Instrumentation and Standards Project

This project will promote innovation and a reduction of time to market by developing calibration capabilities and standards for measuring geometrically complex surfaces. Complex surfaces are increasingly employed in advanced manufacturing, especially for large components. Such structures are found in dynamic structures such as airframes, turbine blades, propellers, and ship hulls where these surfaces are responsible must minimize drag. Small deviations in manufacturing quality or mechanical alignment can significantly disturb their function and cause inefficiencies that consume large quantities of energy. Traditional metrology instruments used to measure these structures, such as large CMMs are immobile, represent a large fixed capital investment, and are slow at collecting the large number of data points needed to fully characterize these complex surfaces. Recent developments in electro-optical instrumentation eliminate these drawbacks and greatly increase throughput with lower labor costs. This objective targets advancing this technology by providing access to high accuracy calibrations and standards within three years.

The principal goal of this project is to create a calibration facility that can accommodate a wide range of scanning instrumentation. The activity bifurcates into a calibration of the instrument’s ranging technology (i.e. the instrument’s metric of length) and a calibration of the full 3D measuring capability. The ranging calibration facility is under construction in the NIST tape tunnel and includes a range for cooperative targets (e.g. retroreflectors) and spherical noncooperative targets. The 3D geometry calibration facility will include both fixed “monument” artifacts, and repositionable portable artifacts (e.g. large bars). The project will also develop new standards for scanning instruments through the newly formed ASTM E57 committee.

Challenge/Problem Addressed: Complex surfaces are increasingly employed in manufacturing, especially for large components. The U.S. is a major supplier of technologies that meet this need; these systems include laser trackers, LADAR (Laser Detection and Ranging), and CMMs used laser probes. Currently there are few calibration facilities and no national or international standards for this class of metrology instruments.

• Completed both the International Standard on coordinate metrology ISO 10360.2 (2009) and harmonized the U.S. with the international community by the development and publication of ASME B89.4.10360-2 (2008) Acceptance test and re-verification test for coordinate measuring machines (CMMs)
• First official NIST laser tracker calibration per the ASME B89.4.19 standard, 2009
• First official NIST articulated arm CMM calibration per ASME B89.4.22, 2009.