上海科技大学知识管理系统

This paper introduces a transient-motion-powered IoT sensor node, which is called ViPSN-E. It can carry out motion detection and wireless communication by making good use of the energy harvested from an instantaneous unidirectional motion. The mechanical energy harvester is composed of a piezoelectric cantilever and a pair of repelling magnets, which realize the plucking excitation under low-speed movement. Different from the system under periodic excitation, whose energy can be continuously accumulated over time, a single plucking motion only inputs a limited amount of energy to the system. An asymmetric structure is designed for identifying the open-door and close-door paths based on the differences between the amounts of their harvested energy. The working mechanism of the magnetic plucking motion is analyzed considering the potential wells variation during the open-door and close-door movements. On the other hand, efficient conversion and utilization of the limited amount of energy are challenging. The prototyped ViPSN-E includes an efficient power management unit, therefore can make good use of the energy harvested from each transient plucking motion. Only one plucking can fulfill the tasks of temperature sensing, motion direction detection, and several rounds of wireless transmissions. The harvested energy and consumption of the IoT node are analyzed to validate the feasibility of this design. The proposed ViPSN-E provides valuable guidance towards the design of self-powered ubiquitous motion-sensing systems.
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