The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	Computation of collision parameters of spheres by computer vision
Author:	Sen, Sumit
View Online:	njit-etd1992-109 (x, 77 pages ~ 3.4 MB pdf)
Department:	Department of Mechanical and Industrial Engineering
Degree:	Master of Science
Program:	Mechanical Engineering
Document Type:	Thesis
Advisory Committee:	Dave, Rajesh N. (Committee chair) Rosato, Anthony D. (Committee member) Fischer, Ian Sanford (Committee member)
Date:	1992-10
Keywords:	Collisions (Physics) Computer vision Motion -- Analysis -- Automation
Availability:	Unrestricted
Abstract:	Collision parameter evaluation of rigid spherical particles requires estimation of pre- and post-impact position, velocity and angular velocity vectors of colliding particles. A three dimensional experimental technique is devised where the instantaneous position and orientation of the particles are determined by analyzing frames obtained through high speed video imaging system. Since the image obtained is two dimensional, a mirror setting is designed to capture two orthogonal views of collision in order to estimate motion in depth. The translational velocity vector is determined from the position information extracted through application of available image analysis techniques over two time frames of digitized image. The angle and the axis of rotation between two time frames is determined by tracking a few randomly marked feature points on the spheres. In order to reduce the effect of error involved in the coordinate measurement in rotation estimation, a least square fitting of the set of three dimensional feature points is employed. The technique performed satifactorily in rotation vector estimation. The method developed here is applied to a set of experimental data for computation of collision parameters. Preliminary results indicate a need for improving the accuracy of position measurement.