• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.694-697
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• 2005

This paper presents a novel movable microneedle that becomes active when necessary to use. Conventional researches have been focused on the fabrication of microneedles and the interface with fluidic chip [1,2]. Therefore, we proposed an active microneedle to sample body fluids or deliver drugs in a controlled amount by actuating the needles. This allows us to keep the needles in operation only when necessary so that both the body skin and the needles can be protected from undesirable external disturbance while no operation.

• 한국정밀공학회지
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• 제14권7호
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• pp.73-81
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• 1997

An new class of robust position/force hybrid control law is proposed for uncertain robot manipulators. The uncertainty is nonlinear and (plssibly fast) time-varying. Therefore, the uncertain factors such as imper- fect modeling, friction, payload change, and external disturbance are all addressed. Based on the possible bound of the uncertainty, the controller is constructed and the stability study based on Lyapunov function is presented. To show that the proposed control laws are indeed applicable, the theoretical result is applied to a SCARA-type robot manipulator and simulation result is presented.

• 제어로봇시스템학회논문지
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• 제18권7호
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• pp.627-631
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• 2012

Observable mathematical model of DDM (Direct Dirve Motor) was suggested. The motor that operates the object system directly is called DDM. DDM has many strong points, however, it has a significant disadvantage, that it is more sensitive to the external force than the motor with reduction gear. In other word, if the force is applied, air gap of the motor can be perturbed. This causes not only difficulty in motor control but also even more serious problem, such as the breakdown of motor. However, if the air gap variation can be estimated, it can help prevent these problems. DDM should be modeled to estimate the air gap variation. The type of researched DDM is PMSM (Permanent Magnet Synchronous Motor) and precedent model of PMSM includes only characteristics of electro-magnetic system and rotational motion. However, suggested model should also include characteristics of translational motion of rotor to estimate the air gap variation. Also, this model should satisfy observability condition, because state observer is designed based on this model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.392-395
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• 2003

In the maritime container terminal, LMTT (Linear Motor-based Transfer Technology) is horizontal transfer system for the yard automation, which has been proposed to take the place of AGV (Automated Guided Vehicle). The system is based on PMLSM (Permanent Magnetic Linear Synchronous Motor) that is consists of stator modules on the rail and shuttle car (mover). Because of large variant of mover's weight by loading and unloading containers, the difference of each characteristic of stator modules, and a stator module's trouble etc., LMCPS (Linear Motor Conveyance Positioning System) is considered as that the system is changed its model suddenly and variously. In this paper, we will introduce the soft-computing method of a multi-step prediction control for LMCPS using DR-FNN (Dynamically-constructed Recurrent Fuzzy Neural Network). The proposed control system is used two networks for multi-step prediction. Consequently, the system has an ability to adapt for external disturbance, cogging force, force ripple, and sudden changes of itself.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.307-310
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• 2003

In the maritime container terminal, LMTT(Linear Motor-based Transfer Technology) is horizontal transfer system for the yard automation, which has been proposed to take the place of AGV(Automated Guided Vehicle). The system is based on PMLSM (Permanent Magnetic Linear Synchronous Motor) that is consists of stator modules on the rail and shuttle car (mover). Because of large variant of mover's weight by loading and unloading containers, the difference of each characteristic of stator modules, and a stator module's trouble etc., LMCPS (Linear Motor Conveyance Positioning System) is considered as that the system is changed its model suddenly and variously. In this paper, we will introduce the soft-computing method of a multi-step prediction control for LMCPS using DR-FNN (Dynamically-constructed Recurrent Fuzzy Neural Network). The proposed control system is used two networks for multi-step prediction. Consequently, the system has an ability to adapt for external disturbance, cogging force, force ripple, and sudden changes of itself.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권12호
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• pp.592-600
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• 2005

In this paper, a low loss magnetic levitation(Maglev) system is suggested and tested. The suggested Maglev system includes four hybrid magnets which consist of permanent magnet and coil. In the steady state, the levitated module system can be supported by attraction force generated by permanent magnet. The coil current controls only dynamic loads due to external disturbances. The module systems are designed by using finite element method(FEM) software tools such as MAXWELL and ANSYS. Also, digital control systems are designed to keep the magnet airgap at a constant value. The control systems include a VME(versa module europa)-based CPU(central processing unit) board, AD(analog to digital) board, PWM(pulse width modulation) board, 4-quadrant chopper, and sensors. In order to estimate the vertical velocity of the magnet, we use second order state observer with acceleration and gap signals as input and output signals, respectively. The characteristics of the suggested low loss Maglev system are demonstrated by experimental results showing coil current of 0A in the steady state of 3m airgap and performance specifications are satisfied for reference gap and force disturbance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2206-2208
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• 2003

LMTT(Linear Motor-based Transfer Technology) is horizontal transfer system in the maritime container terminal for the port automation. The system is modeled PMLSM(Permanent Magnetic Linear Synchronous Motor) that is consists of stator modules on the rail and shuttle car(mover). Because of large variant of movers weight by loading and unloading containers, the difference of each characteristic of stator modules, and a stator module's default etc., LMCS(Linear Motor Conveyance System) is considered as that the system is changed its model suddenly and variously. In this paper, we will introduce the soft-computing method of a multi-step prediction control for LMCS using DR-FNN(Dynamically Constructed Recurrent Fuzzy Neural Network). The proposed control system is used two networks for multi-step prediction. Consequently, the system has an ability to adapt for external disturbance, cogging force, force ripple, and sudden changes of itself.

• 한국기계가공학회지
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• 제20권11호
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• pp.43-51
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• 2021

A robust tracking controller design was developed for a rotary motion control system. The friction force versus the angular velocity was measured and modeled as a combination of linear and nonlinear components. By adding a model-based friction compensator to a nominal proportional-integral-derivative controller, it was possible to build a simulated control system model that agreed well with the experimental results. A zero-phase error tracking controller was selected as the feedforward tracking controller and implemented based on the estimated closed-loop transfer function. To provide robustness against external disturbances and modeling uncertainties, a disturbance observer was added in the position feedback loop. The performance improvement of the overall tracking controller structure was verified through simulations and experiments.

• 대한기계학회논문집A
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• 제34권12호
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• pp.1925-1930
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• 2010

겐트리형 리니어 모터의 주행 축은 동기화가 필수적이며 그렇지 못할 경우에는 위치의 어긋남이나 불안정한 동작으로 인해 동기오차가 발생하며 이는 고속 고정밀 선형운동에 악영향을 미친다. 또한 두 리니어모터의 축은 로터리 모터와 달리 동력 전달장치를 제거함으로 인해 모델의 불확실성이나 외란에 민감할 뿐만 아니라 마찰과 리플의 특성에 쉽게 영향을 받는다. 본 논문은 겐트리형 리니어 모터의 주행 축을 대상으로 위치제어에 악영향을 주는 대표적인 비선형 함수인 마찰력과 리플력을 추정하여 보상하며 두 축간의 동기오차를 줄이기 위해 동기제어 알고리즘을 설계하였다. 제안된 비선형 적응제어기는 모의실험을 통하여 성능을 검증하였다.

• 대한기계학회논문집A
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• 제34권3호
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• pp.369-374
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• 2010

리니어 모터는 동력전달장치가 필요 없는 직접구동 방식으로 접촉 식의 비선형 효과를 크게 줄일 수 있고 구조 또한 간단하다. 그러나 리니어 모터는 동력전달장치를 제거함으로 인해 파라미터 변화와 외란 등에 둔감한 동력전달장치의 장점을 잃게 되어 모델의 불확실성이나 외란에 민감할 뿐만 아니라 마찰과 리플의 특성에 쉽게 영향을 받는다. 본 논문은 리니어 모터의 두 축을 대상으로 위치제어에 악영향을 주는 대표적인 비선형 함수인 마찰력과 리플력을 추정하여 이를 보상하며 개선된 교차 축 연동제어기를 통해 축 간의 윤곽정밀도를 향상시켰다. 기존의 연구된 제어기들은 위치추종과 윤곽추종을 위해 개별적인 제어기를 설계하였으나 제안된 제어기는 하나의 안정한 제어기로 두 축의 위치정밀도와 윤곽정밀도를 동시에 향상시켰다. 제안된 비선형 적응제어기는 모의실험을 통하여 기존의 제안된 교차 축 연동제어기와 비교검증을 함으로써 제안된 제어시스템의 성능을 검증하였다.