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Full-Text Articles in Mechanical Engineering
Nonlinear Energy Harvesting Under White Noise, Qifan He
Nonlinear Energy Harvesting Under White Noise, Qifan He
All Theses
While purposeful introduction of stiffness nonlinearities into the dynamics of energy harvesters is aimed at enhancing performance under non-stationary and random excitations, most of the conclusions reported in the current literature are based on the steady-state response which assumes a harmonic fixed-frequency excitation. As a result, we still do not have a clear understanding of how the nature of the excitation influences the output power, or what role stiffness nonlinearities play in the transduction of energy harvesters under random excitations. To fill this gap in the current knowledge, this thesis investigates the response of nonlinear mono- and bi-stable energy harvesters …
An Electromagnetic Energy Harvester For Powering Consumer Electronics, Xiyuan Liu
An Electromagnetic Energy Harvester For Powering Consumer Electronics, Xiyuan Liu
All Theses
This thesis introduces an electromagnetic vibratory energy harvester to power consumer electronics by generating electricity from the strides taken during walking or jogging. The harvester consists of a magnetic pendulum oscillating between two fixed magnets. The pendulum behaves similar to a rotor in a DC generator, while the fixed magnets, which are poled opposite to the pendulum, provide magnetic restoring forces similar to mechanical springs. When attached to a person's arm, the swinging motion subjects the magnetic pendulum to base excitations. Consequently, the pendulum oscillates near a stator which has three poles of wound copper coils. The motion of the …
Implementation Of Delayed-Feedback Controllers On Continuous Systems And Analysis Of Their Response Under Primary Resonance Excitations, Yousef Qaroush
Implementation Of Delayed-Feedback Controllers On Continuous Systems And Analysis Of Their Response Under Primary Resonance Excitations, Yousef Qaroush
All Dissertations
During the last three decades, a considerable amount of research has been directed toward understanding the influence of time delays on the stability and stabilization
of dynamical systems. From a control perspective, these delays can either have a compounding and destabilizing effect, or can actually improve controllers'
performance. In the latter case, additional time delay is carefully and deliberately introduced into the feedback loop so as to augment inherent system delays and
produce larger damping for smaller control efforts. While delayed-feedback algorithms have been successfully implemented on discrete dynamical systems with
limited degrees of freedom, a critical issue appears in …