Inspection of size and geometrical tolerances of 3D objects by contact, optical and laser systems

Inspection of size and geometrical tolerances of 3D objects by contact, optical and laser systems P.O. Chelishchev, S.A. Kolyubin, K. Sørby (Trondheim) The paper includes state-of-the-art of multi-axis coordinate measurement systems and an experimental work on testing some of the methods with artefacts. There are many types of measurements systems for inspection of dimensions and geometrical tolerances of machined parts available today on the market. The main goal of the paper is to define the best method or combination of them to minimize any possible deviation in manufacturing process and ensure that measured components will provide a successful assembly. The first part provides of a brief overview about measurement systems, which are based on mechanical or optical principles. International Standards (ISO) concerning Geometry Product Specification (GPS) is discussed. Both possibilities of control such as offline and online are taken into account. The advantages and particular limits are considered. Detailed information about the functional principles of photogrammetry instrument, laser interferometer and electronic distance measurement instrument is provided. In addition, a possibility of using a combination of two measurement systems as an in-process gaging control for machine tool center is considered. The second part contains experimental results from tests with NIKON photogrammetry instrument, Leica laser tracker, and Leitz coordinate measuring machine (CMM). Problem examinations and partial simplification are applied and described. The measurement uncertainties and traceability of tested methods are evaluated. An analysis of measured data is provided in table and vector diagram. The GPS inspection has been created by use of PC-DMIS and Spatial Analyzer software.