Analysis three dimensional kinematics of Carp tail fin

摘要

In this paper, a test based on the wavelet transform for instantaneous three dimensional (3D) Carp tail fin profile measurements and analysis the kinematics of Carp tail fin method was proposed to understand the function of the tail fin. This experiment method is used in cruising carp. Projecting a moire fringes onto a tail fin, the deformed fringe pattern containing 3D information was produced and varied with the movement of tail fin. The time-sequence deformed fringe pattern images were captured by a high speed camera. By wavelet transform profilometry, the tail fin movements were really reconstructed. On this basis, the kinematics parameter of tail fin was analyses. Experimental results indicate that the 3D profile of tail fin was varied during the tail-beat cycle. Analysis of tail kinematics suggests that, at a swimming speed 0.5Ls~(-1), the tail beat frequency is 1.42Hz and the dorsal lobe of the tail undergoes a 15.6% greater lateral excursion than does the ventral lobe. The timing of maximal lateral excursion was different at different location of tail fin.