• 한국항공우주학회지
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• 제35권4호
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• pp.316-322
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• 2007

정유압 방식 EHA는 종래의 밸브 제어 방식 전기유압 구동장치와 전혀 다른 특성을 나타낸다. 본 논문에서는 EHA의 비선형 요소를 포함한 수학적 모델을 유도하고 실험적으로 검증하였다. 이 수학적 모델을 근거로 전기 모터로 구동되는 유압 펌프, 파이프 배관 그리고 유압 실린더로 구성되는 EHA의 시물레이션 모델을 개발하여 주요 설계 인자인 모터 토크의 피크치, 펌프의 관성 모멘트 등이 제어 성능에 미치는 영향을 분석하였다. 여기에서 실험 조건은 의도적으로 과도기에서 모터 토크가 포화되도록 선정하였다. 그 결과로서 최대 속도로 동작하는 EHA의 제어 정밀도를 개선하기 위한 설계 조건을 조사하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.748-753
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• 2000

Nowadays, many studies and researches in data storage have been carried out and storage capacity is increased. But the limitation of storage capacity is happened for several problems. One of them is spot & pit size in optical and magnetic data storage and another is the resolution of actuators. The problems in spot & pit size is covered by new data storage methods- for example, NFR{Near-Field Recoding) system. But the resolution limit of an actuator doesn't follow up the development of spot & pit size. Because of them, we should improve a resolution of an actuator. Especially, in this paper an actuator is studied and designed for NFR(in using SIL(Solid Immersion Lens) system. It is a dual stage actuator, which consists of a Fine actuator and a Coarse actuator, and should desire 100nm accuracy. But, our actuator system only includes tracking mechanism execpt focusing mechanism which is controlled by slider mechanism used in HDD. Its actuating force generation method is VCM(Voice Coil Motor). The Fine actuator is composed of 4-leaf springs and a bobbin wrapped by coil. The Coarse actuator has Coils and 3-Roller bearings.

• 대한기계학회논문집
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• 제6권2호
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• pp.191-195
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• 1982

연속계의 동적 시스템을 제어하고저 할 때에는 구동장치와 측정장치를 어느 위치에 두느냐에 따라 시스템의 제어 성능이 상당히 달라지기 때문에 위치선정 문제가 매우 중요한 설계변수의 하나이다. 본 연구에서는 일반 연속계의 제어시스템을 설계하고저 할 때를 고려하여, 그들의 최적 위치를 결정할 수 있는 조건식을 최적 제어 이론을 바탕으로 유도하였다.

• 한국항공우주학회지
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• 제45권4호
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• pp.349-357
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• 2017

최근 전술유도무기 분야는 대부분 전기식 구동장치를 채용하고 있으나 주어진 공간조건과 무게 제한 아래 상대적으로 부하가 크며 작동시간이 짧고 동시에 빠른 응답성이 요구될 경우에는 무게 및 공간 조건을 맞추기 위해서 반드시 유압식 구동장치를 적용해야 할 경우가 발생한다. 본 논문에서는 소형 유압식 구동장치 시스템을 대상으로 수학적 모델링과 시뮬레이션을 수행하였다. 수학적 모델은 고압용기, 압력조절밸브, 저유기, 유압작동기로 나누어 구성하였으며 실험 결과와 비교하여 모델의 타당성을 검증하고 고찰하였다. 본 연구를 통하여 소형 유압식 구동장치 시스템 설계에 유용한 수학적 모델을 수립하였다.

• 한국군사과학기술학회지
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• 제18권3호
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• pp.213-219
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• 2015

Piezoelectric-based hydraulic actuator is a hybrid device consisting of a hydraulic pump driven by piezoelectric stacks that is coupled to a conventional hydraulic cylinder via a set of fast-acting valves. Nowadays, such hybrid actuators are being researched and developed actively in many developed countries by requirement of high performance and compact flight system. In this research, a piezoelectric hybrid actuator has been designed and tested. To achieve bi-directional capabilities in the actuator, solenoid valves were used to control the direction of output fluid. The experimental testing of the actuator in uni-directional and bi-directional modes was performed to examine performance issues related to the solenoid valves. The results showed that the bi-directional performance was slightly lower than uni-directional performance due to air bubble developed in the valve system. A new design to solve the vacuum problem has been proposed to improve the performance of the hybrid actuator.

• 항공우주기술
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• 제4권1호
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• pp.162-170
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• 2005

KSLV-I의 킥모터의 추력벡터제어용 구동장치 시스템은 전기-유압식 서보 구동장치 형상으로 설계되었으며 가동노즐을 구동하는 구동장치, 유압동력을 생성하는 유압동력 생성장치, 유압동력을 구동장치에 전달해 주는 유압동력분배장치와 관성항법장치에서 입력되는 제어신호에 따라 구동장치를 제어하는 제어장치 등으로 구성되어있다. 그중에서 유압동력을 생성하는 장치는 전기모터를 이용하여 유압펌프를 구동하는 EMDP(Electric Motor Driven Pump) 방식을 채택하고 있다. 일반적으로 전기모터는 구동이 편리한 브러시 방식의 직류모터(BDC 모터)를 사용하는데 일정 고도이상에서는 사용이 용이하지 않다. 그래서 고고도에서 사용하기 위해 브러시없는 직류모터(BLDC 모터)를 이용하여 유압펌프를 구동하는 시스템을 개발하고 있다. 본 논문에서는 브러시없는 직류모터를 구동하기 위한 제어기 설계에 대하여 자세히 설명하고자 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.852-855
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• 2008

In this paper, we proposed a new type's PZT actuator using surface acoustic wave. This actuator uses Rayleigh wave as an operational traveling wave. For the development of the actuator, each components of surface acoustic wave motor like PZT substrate, slider and IDT was studied theoretically and fabricated. For the measurement of transfer function of PZT substrate and operation of surface acoustic wave motor, network analyzer and 13.56MHz RF generator were used. Also the model which expresses the driving characteristic best was suggested and simulation was executed for the suggested model. And the future research works for improvement of SAW actuator was suggested.

• 한국자동차공학회논문집
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• 제2권4호
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• pp.27-38
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• 1994

In this paper, a simplified model of a hydraulic actuator system for a low-band type active suspension system is derived. To reduce the order of model, time constants of each chamber in hydraulic system are neglected except that of an accumulator. And the dynamics of a spool in the pressure control valve is regarded as a first-order system. The step response and the frequency response of the simplified second-order simulation model exhibit a good agreement with those of the actual system as well as those of the tenth-order simulation model. It is possible to simplify the tenth-order model to the second-order one. The low-band type active suspension model is built up by combining of a quarter car model test rig to testify the validity of the simplified model. The experimental results of suspension characteristics show that the simplified second-order hydraulic actuator model is reasonable to describe the dynamics of the actual hydraulic actuator system for a low-band type active suspension system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.65-69
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• 2004

The small form factor optical data storage devices are developing rapidly nowadays. Since it is designed for portable and compatibility with flash memory, its components such as disk, head, focusing actuator, and spindle motor should be assembled within 5 m thickness. The thickness of focusing actuator is within 2 mm and the total working range is $+/-100{\mu}m$, with the resolution of less than $1{\mu}m$. Since the thickness is limited tightly, it is hard to place the yoke that closes the magnetic circuit and hard to make strong flux density without yoke. Therefore, Halbach array is adopted to increase the magnetic flux of one side without yoke. The proposed Halbach array type focusing actuator has the advantage of thin actuation structure with sacrificing less flux density than conventional magnetic array. The optical head unit is moved on the swing arm type tracking actuator. Focusing coil is attached to swing arm, and Halbach magnet array is positioned at the bottom of deck along the tracking line, and focusing actuator exerts force by the Fleming's left hand rule. The working range and resolution of focusing actuator are analyzed with FEM and experiment.

• 한국정밀공학회지
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• 제33권10호
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• pp.829-835
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• 2016

Electro-Mechanical Actuator installed on the aircraft plays a key role in an aircraft's flight control through flight control computer. Reliable prediction of the actuator is important for the aircraft. To estimate the lifetime of a product, it is necessary to test full target life. However, it is very difficult to perform it due to the long life time of actuator but short period of development time with increasing cost. Therefore, accelerated life test has been used to reduce the test time for various reasons such as reducing product's development cycle and cost. In this paper, to predict the lifetime of the actuator, we analyzed the flight profile of aircraft and adapted the method of accelerated life test in order to accelerate failure modes that might occur under user conditions. We also set up an endurance test equipment for validating the demanded lifetime of an actuator and performed accelerated life test.