Dr. Hesham A. Hegazi

A LEAST-SQUARES FITTING APPROACH FOR THE REVERSE

ENGINEERING OF FREE FORM SURFACES

Shalaby, M.M.*, Metwalli, S.M.**, Nassef, A.O.***,

Hegazi, H.A.**** and Ashraf A.M.*****

* M. Sc. Candidate, Faculty of Engineering, Cairo Univeristy, Egypt. e-mail: [email protected] ** Professor of Machine Design, Faculty of Engineering, Cairo Univeristy, Egypt. e-mail: [email protected] *** Assistant Professor, Faculty of Engineering, Cairo Univeristy, Egypt. e-mail: [email protected] **** Ph.D. Candidate, Faculty of Engineering, Cairo Univeristy, Egypt. e-mail: [email protected] ***** M. Sc. Candidate, Faculty of Engineering, Cairo Univeristy, Egypt. e-mail: [email protected]

ABSTRACT

Creating geometric models of existing objects for which no such models are available is desirable in many areas of industry. Reverse engineering transforms real parts into engineering models. This paper presents an approach for reverse engineering of free form curves and surfaces. Real parts were captured using 3D laser digitizer. The least squares approach is used for fitting the captured data to get their geometric models. The new geometric model can be exported to CAD/CAM software for implementing any changes and for getting CNC codes for production.

KEY WORDS

CAD, geometric modeling, reverse engineering, scanning, B-spline function