Product Evaluation In Elliptical Helical Pipe Bending

International Journal of Computer Trends and Technology (IJCTT)          
© - October Issue 2013 by IJCTT Journal
Volume-4 Issue-10                           
Year of Publication : 2013
Authors :Wasantha Samarathunga , Masatoshi Seki , Hidenobu Saito , Ken Ichiryu , Yasuhiro Ohyama


Wasantha Samarathunga , Masatoshi Seki , Hidenobu Saito , Ken Ichiryu , Yasuhiro Ohyama"Product Evaluation In Elliptical Helical Pipe Bending "International Journal of Computer Trends and Technology (IJCTT),V4(10):3701-3705 October Issue 2013 .ISSN Published by Seventh Sense Research Group.

Abstract:-  This research proposes a computation approach to address the evaluation of end product machining accuracy in elliptical surfaced helical pipe bending using 6dof parallel manipulator as a pipe bender. The target end product is wearable metal muscle supporters used in build-to-order welfare product manufacturing. This paper proposes a product testing model that mainly corrects the surface direction estimation errors of existing least squares ellipse fittings, followed by arc length and central angle evaluations. This post-machining modelling requires combination of reverse rotations and translations to a specific location before accuracy evaluation takes place, i.e. the reverse comparing to pre-machining product modelling. This specific location not only allows us to compute surface direction but also the amount of excessive surface twisting as a rotation angle about a specified axis, i.e. quantification of surface torsion. At first we experimented three ellipse fitting methods such as, two least-squares fitting methods with Bookstein constraint and Trace constraint, and one non-linear least squares method using Gauss-Newton algorithm. From fitting results, we found that using Trace constraint is more reliable and designed a correction filter for surface torsion observation. Finally we apply 2D total least squares line fitting method with a rectification filter for surface direction detection.


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Keywords :— 6DOF Parallel Manipulator, Elliptical Helical Bending, Least-Squares Fitting, Surface Torsion Observation, Surface Direction Detection