Energy Harvesting Combat Boot for Satellite Positioning

Abstract

Most portable electronic devices are power-limited by battery capacity, and recharging these batteries often interrupts the user’s experience with the device. The product presented in this paper provides an alternative to powering portables by converting regular human walking motion to electricity. The device harvests electric power using air bulbs, distributed in the sole of a shoe to drive a series of micro-turbines connected to small DC motors. The number and position of air bulbs is optimized to harvest the maximum airflow from each foot-strike. The system is designed to continuously drive the micro-turbines by utilizing both outflow and inflow from the air bulbs. A prototype combat boot was fitted on the right foot of a 75 kg test subject, and produced an average continuous power on the order of 10 s of mW over a 22 Ω load during walking at 3.0 mph. This combat boot provides enough electric power to a passive GPS tracker that periodically relays geographical coordinates to a smartphone via satellite without battery replacement.

A Review of Energy Harvesting in Localization for Wireless Sensor Node Tracking

“…This method, however, has a limitation when the Tx node is covered in shadows or under a building. In [8], the proposed device harvests electric power using air bulbs installed in the sole of a shoe to trigger a series of microturbines connected to small DC motors. A 75kg test subject wore a prototype combat boot and produced an average continuous power on the order of 10s of mW while walking at 3.0mph.…”

“…Lavanya R et al (2018) adopted the thermoelectric EH source for autistic child tracking and human body temperature monitoring [12]. Meanwhile, Haluk Akay et al (2018) examined the micro-turbine embedded GPS tracker systems as EH supply [8]. They created a GPS tracker for military boot, and utilised supercapacitor and battery as dual-energy storage for the GPS tracker.…”

“…Ideally, implementing position sensor should be low in cost and the precision of distance estimation should be high in scores. GPS tracker is a simple form of positioning in direct sight [8], habitat monitoring [9], [10], medical diagnostics [11], [12], and object tracking [13], [14]. Target sensor monitoring typically involves trajectory approximation of one or more moving objects based on partial knowledge, such as GPS coordinates, acceleration, and sensor direction [6], [15].…”

Recent Advances in Human Motion Excited Energy Harvesting Systems for Wearables

“…[ 87 ] As the large impact force of foot strike may cause damage to the energy harvester, Akay et al applied air bulbs to buffer the impact and capture the kinetic energy. [ 88 ] Later, Deng et al studied a pressure‐type energy harvester to absorb the impact energy of foot strike and proposed magnetic spring to improve the durability of the device. [ 89 ] Although the power output can be significantly enhanced by rigid transducers or mechanical amplification mechanisms, the users may suffer from certain discomfort, because most of these devices cannot deform.…”

Hybrid Internal Combustion Engine Based Auxiliary Power Unit

“…It is well-evident that specific fuel consumption remains relatively constant within a 0.9 kW output power range but increased sharply when the output power was further reduced. When operated against a 60 Ah Volta lead-acid battery bank as a typical load, the APU supplies most of the time circa 0.24 kW of the DC power (floating battery charging [15,16]). According to Figure 3, specific fuel consumption of the APU @0.24 kW load was 4.7 times higher than the @>0.9 kW load range.…”