• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.6
• /
• pp.139-144
• /
• 2012

In the automobile industry, the various efforts to lower their industrial cost and enhance fuel efficiency have been made through process improvement or weight saving of automobile parts. Gear is one of significant parts of transmission, which is made by cast iron or alloy steel. It is expensive due to complex processing, inferior materials and large machining allowance. In this study, alternative gear cars oil which is based on fluid applications materials is produced by reducing surface induction hardening and carburizing hardened in production. And then, wear characteristic and mechanical properties such as hardness of the sintered alloy which is used as a substitute for small machining allowance is investigated.

• Journal of the Optical Society of Korea
• /
• v.19 no.2
• /
• pp.154-158
• /
• 2015

We experimentally demonstrated a novel wavelength-swept laser using a cascaded Raman gain around 1310 nm. A 1064/1310 wavelength division multiplexing (WDM) coupler and coupled fiber Bragg gratings mirrors at 1064, 1117, 1175, 1240 nm are effectively used to increase the power efficiency in a laser ring cavity with highly non-linear fiber (HNLF) of 2 km. Linear wavelength sweeping is demonstrated with the 100 Hz triangular driving signal to fiber Fabry-Perot tunable filter (FFP-TF) around the 1310 nm region. The measured sweeping range and output power were 27 nm and 2.1 mW, respectively, which are suitable for optical coherence tomography (OCT) imaging.

• Proceedings of the IEEK Conference
• /
• 2007.07a
• /
• pp.311-312
• /
• 2007

This dissertation proposes a global search and a local search method to track the object in real-time. The global search recognizes a target object among the candidate objects through the entire image search, and the local search recognizes and track only the target object through the block search. This dissertation uses the object color and feature information to achieve fast object recognition. Finally we conducted an experiment for the object tracking system based on a pan/tilt structure.

• Proceedings of the KIPE Conference
• /
• 2001.07a
• /
• pp.459-463
• /
• 2001

Since recent inverters are formed IGBT VVVF inverter its switching speed has been increased relative to the conventional inverters and the motor design based on the switching surge voltage at the inverter output is very important factor. Therefore, motor and inverter should be designed to have the optimal characteristics by considering the mutually limited conditions. On this research the design technology characteristics for inverter driving traction moor is compared to the products in Korea and the analysis is performed. Thus, it is intend to re-estimate the technology level and introduce the products by HHI, which is driving on Seoul subway line 6 since December, 2000.

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.16-18
• /
• 2007

In this paper, an advanced DTC(Direct Torque Control) scheme for PMSM(Permanent Magnet Synchronous Motor) is presented. The proposed DTC method uses a conventional torque estimator and torque error. But the switching signal is generated by PWM method according to the switching rules and torque error. A simple calculation of PMW without any complex determination of space vector can assure the constant switching frequency with an excellent control performance. The proposed torque control scheme for PMSM is verified by computer simulation.

• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1917-1919
• /
• 2003

본 연구에서는 바이오 및 환경 분야에 적용 가능한 미세 유체소자 제작에 있어서 4" 유리 / 유리 웨이퍼접합을 시도하였으며, 접합결과 90%이상의 접합면적을 보였다. 접합된 샘플을 산 및 알카리 조건에 따른 인장시험결과 모든 조건에서 약 $2kgf/mm^2$ 이상의 접합강도를 보였으며 파괴는 접합면이 아닌 모재에서 발생되었다. 또한 미세유체소자 제작에 있어서 초음파를 이용하여 유리를 가공하였으며, 폭 $300{\mu}m$, 깊이 $200{\mu}m$의 미세채널을 제작하였다.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.4
• /
• pp.766-772
• /
• 2013

Modeling and control of radial force in the double stator type bearingless switched reluctance motor (BLSRM) is researched. The rotational torque is controlled independently from the radial force control. And the radial force is constant which is independent from the rotor position. In order to realize steady suspension, analytical models of torque and radial force for the proposed structure are derived. Meanwhile, in order to realize steady suspension, control scheme for proposed BLSRM is proposed. In the control method, the radial force can be controlled in arbitrary direction and magnitude by selecting some combinations of radial force windings. The validities of structure and control method are verified by the experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.12
• /
• pp.1866-1872
• /
• 2017

This paper presents the design of in-wheel type Switched Reluctance Motor (SRM) which can be used as both traction motor and power pickup device in a wireless charging system of electric vehicles. The SRM acts as a traction drive in driving mode and a power receiver in charging mode to avoid any additional weights. Double stator axial field SRM is used due to its structure that can be mounted inside the wheel. The charging circuit is integrated with the asymmetric converter and phase windings of SRM, reducing the cost and size of the system. Magnetic resonance is implemented to increase the efficiency. Simulations done in Maxwell and Simplorer verify the effectiveness of the proposed system.

• Proceedings of the KIPE Conference
• /
• 2014.07a
• /
• pp.251-252
• /
• 2014

본 논문은 직접토크 제어에서 토크와 자속 오차에 따라 결정된 전압 벡터가 가지고 있는 자속 및 토크 출력 특성을 전압의 d-q 해석을 통해서 분석하고, 6섹터 방식과 12섹터 방식에서 각 전압에 의해 발생되는 토크 및 자속 특성을 회전자 위치에 따라 해석하였다. 또한, 전압벡터의 전압특성을 모의하기 위한 근사 전압함수를 제시하고, 근사전압함수를 통해 직접토크 제어 방식에서의 자속 및 토크 제어의 성능향상이 가능함을 실험을 통해 검증하였다.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.217-218
• /
• 2015

본 논문에선 BLDCM(Brushless DC Motor)의 전류(轉流)구간에서 발생하는 토크리플을 저감시키기 위해 BLDCM의 역기 전력 모델을 이용하여 상승하는 전류와 하강하는 전류의 기울기가 같아지도록 PWM의 턴-온 시간을 실시간으로 제어하는 방식을 제안한다. 제안된 방식에서는 상이 전환되는 구간에서 상전류의 변화량이 스위칭 시간에 따른 인가전압과 전동기 모델방정식 및 예측되는 역기전력 모델에 의해 예측되어지며, 인가하는 전압의 크기는 PWM의 턴-온 시간에 따라 변하게 되므로, 두 전류의 변화량이 같아지도록 하는 스위칭 시간을 계산하여 적용하는 방식이다. 제안된 방식의 유효성은 실제 BLDCM에 대한 시뮬레이션을 통하여 증명하였다.