Rigid-Body Motion Tolerance for Industrial Helical CT Measurements of Logs

Conference paper
First Online:
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

The major cost in sawmills is the log raw material. It is therefore important to maximize the value of the product yielded from each log. Computed Tomography (CT) has been explored as a sensing solution for determining log defects and making data-driven choices in product breakdown. However, the harsh conditions of the sawmill environment lead to limitations in data acquisition and log manipulation. This paper presents an iterative-solver CT reconstruction scheme that includes rigid-body motion compensation, greatly increasing reconstruction robustness for misalignments in the radiographic data. The motion compensation is carried out by using the known nominal distribution of density in softwood logs to approximate the geometric center of the log and its radius from the radiographs. This is then applied to an iterative reconstruction methodology based on a log-specific voxel geometry previously developed. The method is validated for synthetic phantoms, a physical phantom, as well as real log samples. Results indicate that the rigid body compensation effectively ameliorates motion blur for movement within in the detector field of view.

Keywords

Tomography Sawmill Lumber CT Wood 
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Notes

Acknowledgements

The authors sincerely thank the Natural Sciences and Engineering Research Council of Canada (NSERC) and FPInnovations, Inc., Vancouver, Canada, for their financial support of this work.

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Copyright information

© The Society for Experimental Mechanics, Inc. 2017

Authors and Affiliations

  1. 1.FPInnovations, Inc.VancouverCanada
  2. 2.Department of Mechanical EngineeringUniversity of British ColumbiaVancouverCanada

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