• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.38-38
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• 2004

본 연구에서는 미세 물체를 조작하기 위해 젓가락 구조론 가진 3 텅스텐 젓가락형 그립퍼(이후 텅스텐 그립퍼로 명명)와 2 하이브리드 젓가락형 그립퍼(이후 하이브리드형 그립퍼로 명명)를 설계하고 제작하여 장단점을 비교 분석한다. 두 가지 그립퍼의 미세 핑거(Micro fingers)들은 모두 압전 다중 벤더(Piezoelectric Multilayer bender)와 스택(Stack) 구동기로 구동되었다. 그 중 압전 다중벤더는 물체를 잡을 때 굽힘(Bending) 운동을 만들고 스택은 팁간의 끝점이 일치하지 않을 매 일치되도록 잡는 방향과 수직한 방향으로 구동된다.(중략)

• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.127-132
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• 2003

In this paper. the pneumatic service robot with a hybrid type is developed. A pneumatic has the advantages of good compliance , high Payload-to-weight and payload-to-volume ratios. high speed and force capabilities. Using pneumatic actuators. which have low stiffness. the service robot can guarantee safety. By suggesting a new serial-parallel hybrid type for the service robot which separates into Positioning motion and orienting motion, we can achieve large workspace and high strength-to-moving-weight ratio at the same time. A sliding mode controller can be designed for tracking the desired output using the Lyapunov stability theory and structural properties of pneumatic servo systems. Through many experiments of circular trajectory. the Pneumatic service robot is evaluated and verified.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.782-787
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• 2002

In optical disk drives (ODD), the demands of high data density and high speed have been increasing rapidly to achieve high data capacity and data transfer rate. The short wavelength laser, High NA objective lens, and high track following performance are needed to raise data density and data rate. For high-performance actuator, the improvement of linearity and acceleration become more important. Also, 3-axis actuator for active tilt compensation is introduced to overcome the decrease in disk tilt tolerance which is induced by short wavelength laser. In this paper, a hybrid type 3-axis actuator is presented and a new yoke structure, which can reduce the interaction between yoke and moving magnet, is designed to keep the efficiency of magnetic circuit. Experimental results show the validity of the yoke in the hybrid type actuator.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.1
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• pp.46-55
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• 2006

This paper presents the control method for the hybrid actuator comprising a DC motor and an MR brake. Generally, a DC motor as an active actuator has a small power to weight ratio and goes unstable with higher force control gain due to its saturation limit. In order to cope with this instability and make the transparency higher, this paper proposes a hybrid actuator which consists of a DC motor and an MR brake as a passive actuator and its force control method based on network theory. A DC motor actively produces the output corresponding to the signs of the input currents. On the other hand, an MR brake passively resists against the external load independent of the sign changes of the input currents. This characteristics is widely known as 'passive' This paper suggests a force control method based on passivity concept in network theory for the hybrid actuator and verified its performance and stability through the experiments.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.447-449
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• 2006

본 논문에서는 변압기를 이용한 새로운 PDP용 전력회수회로를 제안한다. 2권선형 변압기를 이용하여 패널에 저장된 에너지를 전원으로 회생시켜 방전 이외의 용량성 부하로 기인하는 전력손실을 최소화 한다. 제안된 회로는 주스위치의 영전압 스위칭과 보조 스위치의 영전류 스위칭이 가능하고 변압기를 이용하기 때문에 권선비에 의한 자유로운 공진에너지 조절이 가능한 장점을 갖는다. 변압기 이용으로 인해 영전압 및 고속구동을 위한 천이시간 증가시 전류주입모드와 전압인가모드를 동시에 사용할 수 있는 장점을 갖는다. 제안된 회로의 성능과 하이브리드 모드 구동시에 나타나는 장점을 42인치 PDP적용실험을 통해 검증해본다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.2
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• pp.211-217
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• 2015

Emission gas regulations and constantly increasing fuel costs call for the worldwide use of environmentally friendly and energy-efficient machines in industry. To meet these requirements, a hybrid excavator prototype has been developed that incorporates an electric swing motor, engine assist motor, and ultra-capacitor module into a conventional hydraulic excavator of the 22-ton class. This paper mainly describes a few techniques to optimize its energy efficiency. These include 1) controlling the engine speed in proportion to the load torque, 2) controlling the pump displacement when driving the electric swing system, 3) managing the ultra-capacitor voltage to minimize the electrical energy loss, and 4) reducing the cooling fan speed to improve the energy efficiency of the system.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.25-28
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• 2011

본 논문에서는 스마트폰과 같은 모바일 단말기 자체에서 동작하는 경량화된 영한 하이브리드 모바일 번역 엔진을 설계 및 구현하였다. 번역 엔진은 자연스러운 번역과 높은 번역 품질을 위해 번역 메모리(Translation Memory)와 규칙기반의 번역 엔진으로 이중화를 하였다. PC에 비해 하드웨어 제약이 심한 스마트폰 자체에서 구동이 원활하도록 주메모리의 사용을 줄이고 분석 시간 단축을 위하여 핵심 번역 엔진을 포함한 번역 지식 DB가 외장메모리에서 구동되도록 하였다. 실험결과 번역 품질은 BLEU와 NIST 평가치를 기준으로 서버 기반의 구글번역기 대비 70.0%로 사용자의 의미전달이 가능한 실용적인 수준으로 평가되었다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.970-971
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• 2008

본 논문은 하이브리드 전기자동차를 위한 에어컨 압축기용 구동 드라이브에 대해 연구하였다. 전기자동차의 경우 열악한 환경에서 구동되기 때문에 센서리스 타입은 필수적이며, 고효율화와 고집적화를 위해서 매입형 영구자석 전동기 IPMSM (Interior Permanent Magnet Synchronizing Motor)을 사용하였다. 본 논문에서 사용된 IPMSM은 비정현적인 역기전력과 입력전류를 가지기 때문에 기존 IPMSM의 센서리스 방식은 불가능하다. 이를 해결하기 위해 최소차원의 관측기를 구성하고 속도함수에 의한 가변차단주파수에 의한 강인한 필터회로를 이용한 새로운 제어 알고리즘을 제안하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.4
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• pp.291-298
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• 2013

In this paper a new hybrid-type control system is proposed which reduces the pump speed of an electro-hydraulic actuator consisting of a pressure-compensated variable displacement piston pump and a valve-controlled hydraulic cylinder, whenever the flow rate demand is low. In order to avoid interfering with the pressure regulator which also has an effect on swash plate angle, the pump speed is changed in proportion to the mean value of the speed component of position commands. Additionally a pressure switch is employed to prevent the system pressure from getting lower than a reference value. Based on computer simulation & experimental results, it is shown that the hybrid control can save the idling power up to 44% at a stand-by mode by reducing the pump speed from 1,800 rpm to 600 rpm without affecting the dynamic response of the electro-hydraulic actuator.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.122-128
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• 2009

A bimodal low-floor tram is designed to provide the flexibility of bus and the punctuality of trains together to the passengers. The propulsion equipment of the bimodal tram is a series hybrid type using a set of CNG engine generator and Li-polymer battery. The present paper describes the specifications of the propulsion system in the bimodal tram which was drawn by a desirable driving cycle. In addition, it shows how the propulsion system of the bimodal tram can be controlled. With using a computer simulation tool of hybrid vehicles, ADVISOR, the performance of the bimodal tram was verified.