Title: A hybrid method of reconstructing 3D airfoil profile from incomplete and corrupted optical scans

Authors: X.Q. Chen, Danwei Wang, H.Z. Li

Addresses: Department of Mechanical Engineering, The University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand. ' School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, 639798, Singapore. ' Singapore Institute of Manufacturing Technology, Nanyang Drive, 638075, Singapore

Abstract: In overhauling turbine blades and vanes, the automated machining system must be able to adapt to distorted airfoil surfaces to avoid undercuts or overcuts. Thus 3D profile measurement and reconstruction is required to plan the tool path according to the individual part geometry. In deploying optical sensors for 3D profile measurement, specular reflection on turbine airfoil surface causes loss of measurement data and noisy signals in optical scans. A hybrid method that combines piecewise cubic Hermite interpolation with linear compensation has been developed to reconstruct the surface, with errors less than 30 µm.

Keywords: optical measurement; adaptive machining; turbine airfoils; 3D airfoil profile; Hermite interpolation; profile reconstruction; incomplete scans; corrupted scans; optical scaning; distorted surfaces; airfoil surfaces; turbine blades; turbine vanes; optical sensors; linear compensation.

DOI: 10.1504/IJMMS.2009.024347

International Journal of Mechatronics and Manufacturing Systems, 2009 Vol.2 No.1/2, pp.39 - 57

Published online: 01 Apr 2009 *

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