首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Quantitative underwater 3D motion analysis using submerged video cameras: accuracy analysis and trajectory reconstruction
Authors:Amanda P Silvatti  Pietro Cerveri  Thiago Telles  Fábio AS Dias  Guido Baroni  Ricardo ML Barros
Institution:1. Faculty of Physical Education, University of Campinas, Campinas, Brazil;2. Bioengineering Department, Politecnico di Milano, Milano, Italyamandasilvatti@yahoo.com.br;4. Bioengineering Department, Politecnico di Milano, Milano, Italy;5. Laboratoire d'Informatique Gaspard-Monge, Université Paris-Est, Paris, France
Abstract:In this study we aim at investigating the applicability of underwater 3D motion capture based on submerged video cameras in terms of 3D accuracy analysis and trajectory reconstruction. Static points with classical direct linear transform (DLT) solution, a moving wand with bundle adjustment and a moving 2D plate with Zhang's method were considered for camera calibration. As an example of the final application, we reconstructed the hand motion trajectories in different swimming styles and qualitatively compared this with Maglischo's model. Four highly trained male swimmers performed butterfly, breaststroke and freestyle tasks. The middle fingertip trajectories of both hands in the underwater phase were considered. The accuracy (mean absolute error) of the two calibration approaches (wand: 0.96 mm – 2D plate: 0.73 mm) was comparable to out of water results and highly superior to the classical DLT results (9.74 mm). Among all the swimmers, the hands' trajectories of the expert swimmer in the style were almost symmetric and in good agreement with Maglischo's model. The kinematic results highlight symmetry or asymmetry between the two hand sides, intra- and inter-subject variability in terms of the motion patterns and agreement or disagreement with the model. The two outcomes, calibration results and trajectory reconstruction, both move towards the quantitative 3D underwater motion analysis.
Keywords:3D underwater motion analysis  camera calibration  segmental kinematics
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号