Press-rotation electromagnetic generator for a self-powered positioning system

Mechanical structures and energy harvesting technologies have the potential to solve the problems of short battery life and environmental pollution caused by positioning devices. A self-powered positioning system driven by a press-rotation electromagnetic generator (PR-EMG) is proposed in this paper. The mechanical energy generated by human motion is collected by the PR-EMG, which can provide continuous power to the positioning module and reduce maintenance costs. The PR-EMG has a two-stage amplification structure that can convert low-frequency vertical displacement into high-frequency rotational motion. Two springs are used to provide load-bearing capacity and shock resistance for the PR-EMG. The effects of external excitation frequency, spring stiffness, and pressing stroke on the output voltage performance of the PR-EMG are analyzed. The results show that the output power generated by pressing the full stroke is more than twice that of pressing the half stroke. With an external excitation frequency of 1 Hz and a spring stiffness of 0.170 N/mm, the peak power of a single module is 171 mW. To ensure the stable operation of the self-powered positioning system, the system integrates a rectifier circuit and an energy storage unit to provide continuous power to the positioning and Bluetooth modules. Field tests conducted at campus security locations demonstrated that the PR-EMG has excellent positioning performance and enables unattended monitoring of entry and exit activities. Self-powered positioning systems based on electromagnetic power generation have good output power and are expected to be applied in mine rescue, urban security, ecological monitoring and other fields.