PRECISION ALIGNMENT TECHNIQUE FOR PARTS HAVING THIN FEATURES USING MEASUREMENT FEEDBACK ITERATIVE METHOD IN CAD CAI ENVIRONMENT/

In this paper, a new technique of CAD/CAI integration is proposed for the three-dimensional (3D) curved parts having very thin and sharp geo metry. The technique begins with feature reconstruction of turbine bla des which have 3D combined geometry, such as splines, and thin circles . The alignment procedures consist of two phases: rough phase and fine phase alignments. The rough phase alignment is based on the conventio nal six points probing on the clear cut surfaces, and the fine phase a lignment is based on the initial measurement for the 3D curved parts, using an iterative least squares technique based on the measurement fe edback. As the results of the alignment, the CNC code of measurement o peration is generated in DMIS file format, thus dimensional inspection of complicated parts having thin sections is completed. The developed inspection technique has been applied to practical procedures of blad e manufacturing, and demonstrated high performance.