Un esperimento meccanico ed uno elettrico sul caos deterministico

The inverted torsional pendulum (often used as a tool to study non-linear oscillations and the transition to deterministic chaos) is here compared to an electric non-linear oscillator which shows a quite similar dynamic behaviour: the motion equation of the second system is exactly described by the Duffing equation, which is only approximated by the first one. Both systems are analysed experimentally and through numerical simulations. We show the evolution to the chaotic behaviour in both systems by observing, with a proper choice of the parameters in forced oscillations, the phenomenon of period-doubling and the Poincaré maps (measured and simulated). A detailed description of the experimental setup is reported for both devices.