• 전기학회논문지
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• 제63권2호
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• pp.272-276
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• 2014

In this paper, cable drive mechanism is proposed to implement high reduction gear ratio. Cable drive mechanism has great advantages such as light weight, high degree of freedom about design aspect and zero backlashes. However, it is restrictively utilized for robotic applications because it is difficult to implement high reduction gear ratio more than 10 to 1. Proposed mechanism enables multi-level reductions by adopting seamless winding method (SWM) which links the previous output axis and the next input axis. Consequently, this reduces the mechanical complexity significantly and enables high reduction with only one single wire cable. 3D CAD design was provided and prototype was manufactured.

• 전력전자학회논문지
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• 제8권3호
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• pp.221-229
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• 2003

IPMSM은 고효율, 고성능으로 전동기로서 전기 자동차의 적용분야에 적용되고 있다. 본 논문에서는 전기자동차의 구동을 위하여 PMSM의 약계자 영역에서 최대 토크제어를 제시한다. 최대 토크동작을 위하여 최적 d축 전류를 결정하고 이 전류를 각 제어모드에서 사용한다. 최대 토크를 발생하기 위하여 전류 조절기의 출력인 인버터의 출력 전압은 DC 링크전압을 최대로 이용한다. 제안한 IPMSM 최대 토크제어의 특성을 제시하고 타당성을 입증한다.

• 한국기계가공학회지
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• 제11권5호
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• pp.42-47
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• 2012

Construction equipment is heavily loaded during normal operation. In recent years, there is a trend that lower gear noise levels are demanded for drivers to avoid annoyance and fatigue during operation. For articulated hauler's final drive, meshing transmission error(T.E.) is the excitation that leads the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in the whole gearbox. This paper presents a method for the analysis of the tooth profile modification, and the prediction of transmission error under the loaded torques for the spur gear pair of the articulated hauler's final drive. And the transmission error, transmission error harmonics and contact stress are also calculated and compared before and after tooth modification under one torque. The simulation result shows that the transmission error and contact stress under the loads can be minimized by the appropriate tooth profile modification.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.359.1-359
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• 2002

Servo performance of a disk drive is greatly affected by the mechanical resonance frequencies of the head gimbal assembly(HGA). It is important (actor to allow broader bandwidth for servo system in improving overall drive performance. In this paper, an optimal design for ODD suspension is attempted to increase resonance frequencies. It was decided that the first resonant frequency in tracking direction was higher than 5㎑. (omitted)

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.493-496
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• 1997

This paper constructed the experimental system which is able to drive in series or separately excited by switching of the field winding, using a DC motor and obtained the characteristics of efficiency with speed and torque of each motor's type through the experiment. From this result controlled drive which is able to series DCM or separately excited DCM in the optimal point of efficiency as finding the types of motor having maximum efficiency with torque and speed. By performing high efficiency tracking drive, it is expected that energy consumption of power source with limited energy density would be reduced, and so utility efficiency would be improved.

• Journal of Power Electronics
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• 제9권2호
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• pp.259-266
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• 2009

In order to increase the power density of power converters, reduction of the switching losses at high-frequency switching conditions is one of the most important issues. This paper presents a new gate drive circuit that enables the reduction of switching losses in both the Power MOSFET and the IGBT. A distinctive feature of this method is that both the turn-on loss and the turn-off loss are decreased simultaneously without using a conventional ZVS circuit, such as the quasi-resonant adjunctive circuit. Experimental results of the switching loss of both the Power MOSFET and the IGBT are shown. In addition, an energy recovery circuit suitable for use in IGBTs that can be realized by modifying the proposed gate drive circuit is also proposed. The effectiveness of both the proposed circuits was confirmed experimentally by the buck-chopper circuit.

• 한국공작기계학회논문집
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• 제13권2호
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• pp.88-93
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• 2004

The main objective of the research is to Propose an algorithm that to estimate the screwing torque from parameters of DC motor current without using any stain gage and torque cell. The auto screw drive system is divided into two parts, one is the DC motor ind the other is mechanical part in which the friction torque and damping ratio are a function of rotational of spindle electro motive force constant. The torque is estimated from the friction torque. The research is concerned with applying the method to an auto screw drive and the advantages and limitations are also discussed in this paper.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.220-223
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• 2005

In this paper, a novel sensorless brushless DC (BLDC) motor drive method using the fuzzy back-EMF observer is proposed to improve the performance of conventional sensorless drive methods. Most existing back-EMF sensing methods need additional circuit and have a low performance intransient state or low speed range. Therefore, this paper proposes the fuzzy back-EMF observer and an algorithm using this observer to estimate a speed and a position of the rotor. The robustness of the proposed algorithm is proved through the simulation compared with other sensorless drive methods.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.79-82
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• 2004

The rotor drive system in rotor-craft carries out power transmission from powerplant to rotors and the drive shafts are fallen into misaligned condition by the vibration of engine and shafts and the deformation of supporting structures. The high performance flexible coupling accommodates these misalignments of drive shafts. In this study, we compare the performance of the metalic flexible coupling with the composite flexible coupling through analytic method to develop the high performance flexible coupling used in the rotor drive system of UAV tilt-rotor.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권8호
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• pp.482-491
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• 2003

In this paper are presented kinematic and dynamic modeling and path-tracking of four-wheeled mobile robots with 2 d.o.f haying the limited drive-torques. Controllability of wheeled-mobile robots is revealed by the kinematic model. Instantaneously coincident coordinate system, force/torque propagation and Newton's equilibrium law are used to drive the dynamic model. When drive-torques generated by inverse dynamics exceed the limitation, we make wheeled-mobile robots follow the reference path by modifying the planned reference trajectory with time-scaling. The controller is introduced to compensate for error owing to modeling uncertainty and measurement noise. And simulation results prove that method proposed by this paper is efficient.