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Energy Harvesting from Upper-Limb Pulling Motions for Miniaturized Human-Powered Generators.

Yeo J, Ryu MH, Yang Y - Sensors (Basel) (2015)

Bottom Line: This study proposes a portable human-powered generator which is designed to obtain mechanical energy from an upper limb pulling motion for improved human motion economy as well as efficient human-mechanical power transfer.Its small form factor (50 mm × 32 mm × 43.5 mm, 0.05 kg) and the substantial electricity produced verify the effectiveness of the proposed method in the utilization of human power.It is expected that the developed generator could provide a mobile power supply.

View Article: PubMed Central - PubMed

Affiliation: Healthcare Engineering, Chonbuk National University, Deokjin-dong Jeonju 664-14, Korea. yeojjin85@jbnu.ac.kr.

ABSTRACT
The human-powered self-generator provides the best solution for individuals who need an instantaneous power supply for travel, outdoor, and emergency use, since it is less dependent on weather conditions and occupies less space than other renewable power supplies. However, many commercial portable self-generators that employ hand-cranking are not used as much as expected in daily lives although they have enough output capacity due to their intensive workload. This study proposes a portable human-powered generator which is designed to obtain mechanical energy from an upper limb pulling motion for improved human motion economy as well as efficient human-mechanical power transfer. A coreless axial-flux permanent magnet machine (APMM) and a flywheel magnet rotor were used in conjunction with a one-way clutched power transmission system in order to obtain effective power from the pulling motion. The developed prototype showed an average energy conversion efficiency of 30.98% and an average output power of 0.32 W with a maximum of 1.89 W. Its small form factor (50 mm × 32 mm × 43.5 mm, 0.05 kg) and the substantial electricity produced verify the effectiveness of the proposed method in the utilization of human power. It is expected that the developed generator could provide a mobile power supply.

No MeSH data available.


Related in: MedlinePlus

The recorded waveforms of pulling force and output voltage.
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sensors-15-15853-f008: The recorded waveforms of pulling force and output voltage.

Mentions: Figure 8 shows the recorded waveforms of input force and output voltage for 10 consecutive pulling cycles. A pulling force with a maximum of 30 N was applied to the string with a rate of 0.56 cycles/s. The generated voltage showed a maximum of 16 Vpp with the matching resistive load. The mechanical input work was calculated from the measured time profiles of the force and the displacement of string by using Equation (9). Since the repetitive voltage waveforms are in accordance with the revolution of the rotor, the displacement could be accurately obtained by examining the number of voltage peaks, gear ratio, and bobbin radius as follows. The 12 magnets positioned on the rotor with alternating polarities generate six positive voltage peaks when the rotor revolves one time. If the bobbin revolves one time, the rotor is turned 33 times by the gear ratio (1:33). Thus, 198 positive voltage peaks occur when the bobbin revolves one time. Since the circumference of the bobbin adopted in our prototype energy harvester is about 35.5 mm, a gap between two adjacent positive voltage peaks in electrical output waveform, which is defined as peak distance, dDp, corresponds to 0.18 mm displacement of pulled string, Then, the displacement dSs, within specific period of time can be obtained by measuring dDp as shown in Equation (11):(11)dSs=0.18⋅dDp


Energy Harvesting from Upper-Limb Pulling Motions for Miniaturized Human-Powered Generators.

Yeo J, Ryu MH, Yang Y - Sensors (Basel) (2015)

The recorded waveforms of pulling force and output voltage.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541857&req=5

sensors-15-15853-f008: The recorded waveforms of pulling force and output voltage.
Mentions: Figure 8 shows the recorded waveforms of input force and output voltage for 10 consecutive pulling cycles. A pulling force with a maximum of 30 N was applied to the string with a rate of 0.56 cycles/s. The generated voltage showed a maximum of 16 Vpp with the matching resistive load. The mechanical input work was calculated from the measured time profiles of the force and the displacement of string by using Equation (9). Since the repetitive voltage waveforms are in accordance with the revolution of the rotor, the displacement could be accurately obtained by examining the number of voltage peaks, gear ratio, and bobbin radius as follows. The 12 magnets positioned on the rotor with alternating polarities generate six positive voltage peaks when the rotor revolves one time. If the bobbin revolves one time, the rotor is turned 33 times by the gear ratio (1:33). Thus, 198 positive voltage peaks occur when the bobbin revolves one time. Since the circumference of the bobbin adopted in our prototype energy harvester is about 35.5 mm, a gap between two adjacent positive voltage peaks in electrical output waveform, which is defined as peak distance, dDp, corresponds to 0.18 mm displacement of pulled string, Then, the displacement dSs, within specific period of time can be obtained by measuring dDp as shown in Equation (11):(11)dSs=0.18⋅dDp

Bottom Line: This study proposes a portable human-powered generator which is designed to obtain mechanical energy from an upper limb pulling motion for improved human motion economy as well as efficient human-mechanical power transfer.Its small form factor (50 mm × 32 mm × 43.5 mm, 0.05 kg) and the substantial electricity produced verify the effectiveness of the proposed method in the utilization of human power.It is expected that the developed generator could provide a mobile power supply.

View Article: PubMed Central - PubMed

Affiliation: Healthcare Engineering, Chonbuk National University, Deokjin-dong Jeonju 664-14, Korea. yeojjin85@jbnu.ac.kr.

ABSTRACT
The human-powered self-generator provides the best solution for individuals who need an instantaneous power supply for travel, outdoor, and emergency use, since it is less dependent on weather conditions and occupies less space than other renewable power supplies. However, many commercial portable self-generators that employ hand-cranking are not used as much as expected in daily lives although they have enough output capacity due to their intensive workload. This study proposes a portable human-powered generator which is designed to obtain mechanical energy from an upper limb pulling motion for improved human motion economy as well as efficient human-mechanical power transfer. A coreless axial-flux permanent magnet machine (APMM) and a flywheel magnet rotor were used in conjunction with a one-way clutched power transmission system in order to obtain effective power from the pulling motion. The developed prototype showed an average energy conversion efficiency of 30.98% and an average output power of 0.32 W with a maximum of 1.89 W. Its small form factor (50 mm × 32 mm × 43.5 mm, 0.05 kg) and the substantial electricity produced verify the effectiveness of the proposed method in the utilization of human power. It is expected that the developed generator could provide a mobile power supply.

No MeSH data available.


Related in: MedlinePlus