• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.283-289
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• 2014

Purpose: This study was carried out to evaluate the labor requirement and the cost-reducing effects of the pick-up type pulse crop harvester compared with those of conventional harvesting for soybeans and red beans. Methods: The labor requirement and the cost to gather, thresh, and clean for conventional harvesting operations were surveyed; those for the pick-up type pulse crop harvester were estimated for soybeans and red beans. The annual capacity of the harvester and the break-even area of the two harvesting methods were also estimated. Results: For soybean harvesting, the labor requirement of 0.57 hour-persons/10 a for the pick-up type pulse crop harvester reflects a 91.9% reduction in the labor requirement of 7.00 hour-persons/10 a for conventional harvesting. Machinery costs of 51,300 won/10 a for the harvester were estimated for an annual harvesting area of 52.5 ha/year, representing a reduction of 33.3% from the 78,700 won/10 a cost of conventional harvesting. A break-even area of 28.4 ha was estimated for the two harvestings. For red bean harvesting, the labor requirement of 0.57 hour-persons/10 a for the harvester reflects a 92.6% reduction in the labor requirement of 7.66 hour-persons/10 a for conventional harvesting. For an annual harvesting area of 52.5 ha/year, annual capacity of 52.5 ha/year and machinery costs of 51,700 won/10 a were estimated for the harvester, reflecting a reduction of 44.7% in the cost of 93,500 won/10 a for conventional harvesting. A break-even area of 23.1 ha was estimated for the two harvestings. A governmental subsidy for purchasing the harvester could contribute to reducing the break-even area and harvesting costs. Conclusions: The pick-up type pulse crop harvester for soybean and red bean harvesting could reduce the labor requirement and costs of conventional harvesting, and a governmental subsidy for purchasing the harvester will improve the economics of the harvester for efficient mechanical harvesting.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3506-3511
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• 2007

The energy harvesting using smart materials has been extensively investigated to supply electric power to wireless sensor systems. In this paper, the energy harvesting using eddy current was studied with the integrated magnetic cantilever beam system. If a large conductive metal plate moves through a magnetic field which intersects perpendicularly to the sheet, the magnetic field will induce small rings of current which will actually create internal magnetic fields opposing the change. This eddy current that was induced in the coiled conductive sheet from the mechanical vibration was converted to chemical energy by charging batteries. The experimental results show that the eddy current generated the electric power up to max 31.2mW. Additionally the vibration reduction of the mechanical cantilever beam was observed by the energy dissipation in the electro-magnetic coupled system. The present result shows that the vibration level of the first natural frequency was reduced up to 7.7dB

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2048-2053
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• 2011

The aim of this paper is to propose an energy harvesting system by converting mechanical energy of revolving door into electrical energy. The method of energy harvesting system is discussed on two methods: one is the energy-harvester using gear shaft coupling system, and the other is the energy-harvester using spiral spring system. The former is generated by coupling the shaft of rotating door with generator system, while the latter is generated by connecting end-effector of door with the string of generator system. We present the experimental results for two developed energy-harvester. Finally, a comparison between these results is presented to show the validity of energy-harvester.

• Advances in aircraft and spacecraft science
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• v.8 no.1
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• pp.17-30
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• 2021

This is an investigation for a more electric regional aircraft, considering the ATR 72 aircraft as an example and the electrification of its four double slotted flaps, which were estimated to require an energy of 540 Wh for takeoff and 1780 Wh for landing, with a maximum power requirement of 35.6 kW during landing. An analysis and evaluation of three energy harvesting systems has been carried out, which led to the recommendation of a combination of a piezoelectric and a thermoelectric harvesting system providing 65% and 17%, respectively, of the required energy for the actuators of the four flaps. The remaining energy may be provided by a solar energy harvesting photovoltaic system, which was calculated to have a maximum capacity of 12.8 kWh at maximum solar irradiance. It was estimated that a supercapacitor of 232 kg could provide the energy storage and power required for the four flaps, which proved to be 59% of the required weight of a lithium iron phosphate (LFP) battery while the supercapacitor also constitutes a safer option.

• Smart Structures and Systems
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• v.21 no.3
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• pp.287-303
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• 2018

Applications of energy harvesting from mechanical vibrations is becoming popular but the full potential of such applications is yet to be explored. This paper addresses this issue by considering an application of energy harvesting for the dual objective of serving as an indicator of structural health monitoring (SHM) and extent of control. Variation of harvested energy from an undamaged baseline is employed for this purpose and the concept is illustrated by implementing it for active vibrations of a pipe structure. Theoretical and experimental analyses are carried out to determine the energy harvesting potential from undamaged and damaged conditions. The use of energy harvesting as indicator for control is subsequently investigated, considering the effect of the introduction of a tuned mass damper (TMD). It is found that energy harvesting can be used for the detection and monitoring of the location and magnitude of damage occurring within a pipe structure. Additionally, the harvested energy acts as an indicator of the extent of reduction of vibration of pipes when a TMD is attached. This paper extends the range of applications of energy harvesting devices for the monitoring of built infrastructure and illustrates the vast potential of energy harvesters as smart sensors.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.31-34
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• 2013

Based on the structural analysis of cantilever and the piezoelectric effect, we propose a new design of piezoelectric cantilever to harvest maximum vibration energy. Geometric parameters of piezoelectric cantilever are optimized according to two different types of cantilever structure. The main factors that affect the harvesting performance of the cantilever was the shape of the cantilever and the load at the free end. The amount of charge is affected by piezoelectric constant and mechanical strain of the cantilever.

• Journal of Biosystems Engineering
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• v.40 no.1
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• pp.28-34
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• 2015

Purpose: This study aimed to install an RTK-GPS (Real Time Kinematic-Global Positioning System) and IMU (Inertial Measurement Unit) on a tractor used in a farm to measure positions, pasture topography, posture angles, and vibration accelerations, translate the information into maps using the GIS, analyze the characteristics of grass harvesting work, and establish new technologies and construction standards for pasture infrastructure improvement based on the analyzed data. Method: Tractor's roll, pitch, and yaw angles and vibration accelerations along the three axes during grass harvesting were measured and a GIS map prepared from the data. A VRS/RTK-GPS (MS750, Trimble, USA) tractor position measuring system and an IMU (JCS-7401A, JAE, JAPAN) tractor vibration acceleration measuring systems were mounted on top of a tractor and below the operator's seat to obtain acceleration in the direction of progression, transverse acceleration, and vertical acceleration at 10Hz. In addition, information on regions with bad workability was obtained from an operator performing grass harvesting and compared with information on changes in tractor posture angles and vibration acceleration. Results: Roll and pitch angles based on the y-axis, the direction of forward movements of tractor coordinate systems, changed by at least $9-13^{\circ}$ and $8-11^{\circ}$ respectively, leading to changes in working postures in the central and northern parts of the pasture that were designated as regions with bad workability during grass harvesting. These changes were larger than those in other regions. The synthesized vectors of the vibration accelerations along the y-axis, the x-axis (transverse direction), and the z-axis (vertical direction) were higher in the central and northwestern parts of the pasture at 3.0-4.5 m/s2 compared with other regions. Conclusions: The GIS map developed using information on posture angles and vibration accelerations by position in the pasture is considered sufficiently utilizable as data for selection of construction locations for pasture infrastructure improvement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.69-74
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• 2015

Recently, energy harvesting technology is increasing due to the fossil fuel shortages. Energy harvesting is generating electrical energy from wasted energies as sunlight, wind, waves, pressure, and vibration etc. Energy harvesting is one of the alternatives of fossil fuel. One of the energy harvesting technologies, the piezoelectric energy harvesting has been actively studied. Piezoelectric generating uses a positive piezoelectric effect which produces electrical energy when mechanical vibration is applied to the piezoelectric device. Piezoelectric energy harvesting has an advantage in that it is relatively not affected by weather, area and place. Also, stable and sustainable energy generation is possible. However, the output power is relatively low, so in this paper, newly designed honeycomb shaped piezoelectric energy harvesting device for increasing a generating efficiency. The output characteristics of the piezoelectric harvesting device were analyzed according to the change of parameters by using the finite element method analysis program. One model which has high output voltage was selected and a prototype of the honeycomb shaped piezoelectric harvesting device was fabricated. Experimental results from the fabricated device were compared to the analyzed results. After the AC-DC converting, the power of one honeycomb shaped piezoelectric energy harvesting device was measured 2.3[mW] at road resistance 5.1[$K{\Omega}$]. And output power was increased the number of harvesting device when piezoelectric energy harvesting device were connected in series and parallel.

• Smart Structures and Systems
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• v.32 no.6
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• pp.383-391
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• 2023

Energy harvesting in trams may become a prevalent source of passive energy generation due to the high density of vibrational energy, and this may help power structural health monitoring systems for the trams. This paper presents a broadband vibrational energy harvesting device design that utilizes a varied frequency from a tram vehicle using a 2 DOF vibrational system combined with electromagnetic energy conversion. This paper will demonstrate stepwise optimization processes to determine mechanical parameters for frequency tuning to adjust to the trams' operational conditions, and electromagnetic parameters for the whole system design to maximize power output. The initial optimization will determine 5 important design parameters in a 2 DOF vibrational system, namely the masses (m₁, m₂ (and spring constants (k₁, k₂, k₃). The second step will use these parameters as initial guesses for the second optimization which will maintain the ratios of these parameters and present electrical parameters to maximize the power output from this system. The obtained values indicated a successful demonstration of design optimization as the average power generated increased from 1.475 mW to 17.44 mW (around 12 times).

• Journal of Biosystems Engineering
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• v.24 no.1
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• pp.1-8
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• 1999

In this study, the physical properties of live garlic at the harvesting season were measured and analyzed as a fundamental study for developing a garlic harvester. A universal testing machine and a machine vision system were used to obtain mechanical and morphological properties of live garlic, respectively. The moisture content of live garlic at the harvesting season was 50% higher than that of dried garlic. The root of live garlic elongated greatly with respect to the applied tensile force. The relationship between the projected area and the weight of a bulb of live garlic was linear. Such a feature would be applied to develop an effective garlic harvester or garlic quality grader. Other useful physical properties of live garlic at the harvesting season were represented in the study.