Energy harvesting from chaos in base excited double pendulum

This study focusses on exploiting the dynamics of a base excited double pendulum to generate electricity in small scale. The system consists of two pendulum attached in series with rigid massless links. The mass of the double pendulum is assumed to be concentrated at the bobs. A magnet is rigidly attached to the tip of second (lower) pendulum. A series of equally spaced coils are placed near the arc of the trajectory of the magnet. Small amplitude oscillations result in fluctuating magnetic field, generating electricity in the coils. The harvested power is significantly increased when the magnet undergoes chaotic motion. Parametric studies are carried out to optimize the system and excitation parameters that lead to enhancing the harvested energy. The proof-of-concept has been demonstrated through experiments. This involved recording the motion of the bobs, subsequent video processing, followed by time series analyses to establish the chaotic dynamics and correlating the dynamical behavior with the harvested energy. The experimental observations reveal good qualitative match with the numerical simulations. (C) 2019 Elsevier Ltd. All rights reserved.