Fast tomographic inspection of cylindrical objects

TL;DR

This paper introduces a fast, cylindrical-coordinate-based X-ray CT method optimized for industrial parts with axial symmetry, enabling quick, in-line quality inspection through reduced reconstruction time and adaptable initial volume estimation.

Contribution

It develops a novel reconstruction approach leveraging cylindrical coordinates and pre-computed initial volumes for efficient, flexible analysis of symmetric objects in industrial CT applications.

Findings

Reduced reconstruction time via sampling grid aligned with the object

Effective use of algebraic reconstruction with pre-computed initial volumes

Feasibility demonstrated by reusing existing ray-tracers in Cartesian grid code

Abstract

This paper presents a method for improved analysis of objects with an axial symmetry using X-ray Computed Tomography (CT). Cylindrical coordinates about an axis fixed to the object form the most natural base to check certain characteristics of objects that contain such symmetry, as often occurs with industrial parts. The sampling grid corresponds with the object, allowing for down-sampling hence reducing the reconstruction time. This is necessary for in-line applications and fast quality inspection. With algebraic reconstruction it permits the use of a pre-computed initial volume perfectly suited to fit a series of scans where same-type objects can have different positions and orientations, as often encountered in an industrial setting. Weighted back-projection can also be included when some regions are more likely subject to change, to improve stability. Building on a Cartesian grid reconstruction code, the feasibility of reusing the existing ray-tracers is checked against other researches in the same field.