Particle motion tracking utilizing a high-resolution digital CCD camera

Digital imaging acquisition and processing is applied for the tracking of a two-dimensional assembly of disks. The disks are used to assemble models f or studying granular material behavior for which the kinematics of the indi vidual particles, and hence the disks' trajectory during motion, are of car dinal importance. Large particle size is dictated by photoelastic interpart icle interaction analysis. Therefore, a sufficiently large representative n umber of particles results in a large physical model. The system requirements of a sizable physical model comprised of a large nu mber of particles, and simultaneous precise tracking of all particles, are achieved through the use of high-resolution digital CCD camera and semi-aut omatic image processing and analysis algorithms. The physical system setup, image acquisition procedure, calibration, accura cy, and algorithms of analysis are described. The system's performance is d emonstrated through test results describing the displacement field along wi th the motion and interaction of individual particles. The system's advantages in providing detailed tracking of a large number of particles with minimal labor are unmatched by any other technique. The dat a obtained by such systems allow a better understanding of particulate medi a behavior with the ability to examine and calibrate numerical models on an individual grain basis.