Control of chaos via OGY method on a bistable energy harvester

Abstract

The current paper aims to use methods of control of chaos to stabilize the chaotic behavior of a nonlinear piezo-electric energy harvester, making its power generation more fruitful, both for signal improvement and for the amplitude of the generated power. We have implemented the "discrete" OGY method of chaos control on the dynamical model of the harvester's system. The methodology (following the OGY method) is based on detecting recurrent points in a Poincaré section, through the development of the dynamical system, and, once the desired orbit is detected (if it exists within the analysis time) the system applies small control forces to maintain the system in this trajectory. Depending on the constraint imposed on the recurring points, stabilization can occur for orbits of not only one period, but also of multiple periods, with different geometries in the phase space, which may take more or less time to stabilize. The results obtained so far are promising. Stabilized orbits generally have a higher energy yield than that of the free system (which may be chaotic or not). Depending on the constraint imposed, the system can be stabilized in larger or smaller orbits of one or multiple periods. In some cases, stabilization may occur for orbits that have an energy efficiency lower than that of the chaotic system, but other orbits, for the same system conditions, achieve a higher yield.