Research on a magnetic rolling pendulum-based multi-stable electromagnetic generator with dual-path transition mechanism

A magnetic rolling pendulum-based multi-stable electromagnetic generator (MRP-MEMG) is designed and investigated in this paper for low-frequency energy harvesting. The multiple stable equilibrium positions are realized by coupling the magnetic repulsion and gravitational forces. The circumferential configuration of the proposed system provides a special dual-path transition mechanism, which realizes additional transition pathways between potential wells through alternative energy barriers. This mechanism enables larger displacement response and enhanced kinetic energy accumulation, thereby improving the dynamical and electrical performances compared to conventional multi-stable generators. The dynamical and electrical models of the system are theoretically derived, along with nonlinear magnetic force and magnetic flux analyses. The prototype of the MRP-MEMG is fabricated for parameter identification and experimental work, which confirms the effectiveness of the theoretical models. The rich dynamical behaviors of the system and parametric influences on the system’s energy harvesting performance are analyzed through numerical simulations, and a comparative discussion with a conventional quad-stable energy harvester is provided. Energy harvesting experiments are further conducted to evaluate the energy harvesting potential of the MRP-MEMG. It is found that a peak output power of 66.23 mW is achieved across a single coil under a harmonic excitation with amplitude of 2.5 g and frequency of 8.5 Hz. This work presents a novel multi-stable architecture with dual-path transition mechanism, and provides guidelines for the design and optimization of the proposed MRP-MEMG, which has considerable potential for practical application in low-frequency vibration energy harvesting.