Video-based Analysis and Damping Identification of a Ball Absorber on a Circular Rail Track

Abstract

This paper investigates the dynamic behaviour of a rolling ball absorber moving along a circular track whose surface is formed by a pair of rails. The rail geometry constrains the motion of the ball to a planar trajectory. Experimental measurements of free oscillations are recorded using a video camera and subsequently processed by a presented algorithm. The output of the algorithm is the angular displacement of the absorber ball as a function of time. The free-vibration response is further analysed by fitting a numerical simulation to the experimentally obtained time history. The equations of motion are derived for a physical model consistent with the experimental setup and include a combination of viscous damping and rolling resistance to describe energy dissipation. The fitting procedure aims to identify an optimal combination of viscous and rolling damping coefficients that yields the best agreement between the numerical simulation and the experimental response.