• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1598-1602
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• 2003

The parallel-type mechanism provides more accurate and stiff motion than the serial-type mechanism. However, in case of using the haptic device, the performance of the force reflection can be deteriorated due to the singular points existing in workspace. In this paper, we propose a redundantly actuated parallel 3-DOF haptic device, which is singularity-free in the workspace and has an improved force reflection capability. In addition, we propose a new force distribution algorithm, which can reflect force of both high and low resolution, using two sets of actuator with different size. Redundant actuators are attached to the base frame in order to minimize the inertia of the system. Moreover, a wire and gear reduction system is employed to achieve high force reflection along with soft feeling. We confirm the performance of the force reflection capability throughout simulation.

• 제어로봇시스템학회논문지
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• 제16권9호
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• pp.846-851
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• 2010

In this paper, we newly propose a novel control strategy of a three joints-robot finger for the purpose of artificial hands. The robot finger is specifically modeled by using a 3D CAD program (CATIA), considering human fingers, and then the proposed control method is verified through the dynamic simulation tool (Simulink and Recurdyn R2). Each slider is individually controlled to be located at the optimal positions where the maximal joint torque can be generated. To prove the effectiveness of the proposed control method, we devise two cases for the reference position of sliders. By comparing the control performance of two cases, the validity of the proposed control method will be verified.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.463-463
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• 2000

A dual-stage positioner for fast and fine robotic manipulations is presented. By adopting the merits of both coarse and fine actuator, a desirable system having the capacity of large workspace with high resolution of motion is enabled. We have constructed an ultra precision XY positioner with dual-stage mechanism where the PZT driven fine stage is mounted on the motor driven XY positioner and applied it to fine tracking controls and micro-tele operations as a slave manipulator. We describe essential merits of the compound actuation mechanism and some control strategies to successfully utilize it with proper servo system design. Through experimental results, the effectiveness of the coarse/fine manipulation by the dual-stage positioner will be shown.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.78-79
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• 2018

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.48-51
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• 1996

A 5-bar structure with redundant actuators is proposed as a finger mechanism. It is shown that one additional redundant actuator greatly enhances the load handling capacity of the system. The actuator location should be carefully decided to maximize the performance enhancement. Furthermore, we develop stiffness and frequency control algorithms based on the internal loading created by redundant actuation. The effectiveness of these algorithms have been demonstrated by simulations.

• 한국항공우주학회지
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• 제33권12호
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• pp.48-53
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• 2005

본 논문에서 LIPCA(Lightweight Piezoceramic Composite Actuator)를 이용한 날갯짓(flapping) 기구의 개발에 관한 최근의 연구진척 사항을 제시하였다. 날갯짓 기구는 여러 개의 연결막대를 이용하여 LIPCA의 제한된 작동변위를 커다란 날갯짓 각(flapping angle)이 발생하도록 증폭시켰으며, 패더링 메커니즘(feathering mechanism)을 적용하여 날갯짓과 동시에 날개에 비틀림이 발생하도록 설계되었다. 이 날갯짓 기구의 고유 날갯짓 주파수는 약 9Hz로, 이때 최대의 날갯짓 각이 발생하였다. 제작된 날갯짓 기구의 작동성능을 평가하기 위하여 날갯짓 주파수를 4Hz에서 15Hz까지 변화시키면서 발생되는 양력과 추력을 측정하였으며, 최대 양력과 최대 추력은 고유 날갯짓 주파수 부근에서 계측되었다.

• 한국추진공학회지
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• 제19권2호
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• pp.17-28
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• 2015

본 논문에서는 ON/OFF 작동과 같이 단순화된 구동 메커니즘을 가지면서도 구동 명령 한계가 있는 시스템의 구동 위치 제어 기법 설계를 수행하였다. 가장 먼저 구동기 시험데이터를 이용하여 고려되는 구동기의 PWM 명령을 입력으로 하는 비선형/선형 구동 동역학 모델링을 수행 하였다. 선형화된 모델을 이용하여 목표로 하는 제어 성능 요구조건을 만족시키기 위한 고전적인 PI 제어기법을 설계하였으며, PWM 제어명령 한계에 따른 제어 성능 감소를 해소하기 위한 제어 알고리즘을 제안하여 유효 제어 범위 내에서 설계된 제어 성능이 구현되도록 하였다. 최종적으로 제어 시뮬레이션을 통해 설계 방법을 검증하고 해당 제어기법 적용에 따른 성능 개선 정도를 평가하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.51.4-51
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• 2002

$\textbullet$ A noval haptic mouse system is developed for human computer interface. $\textbullet$ Five bar mechanism is adapted for 2 dof force feedback with virtual environment. $\textbullet$ Double prismatic joint type mechanism is adapted to reflect 1 dof grabbing force feedback. $\textbullet$ Cable driven mechansim is used for actuation to reduce backlash and endow backdrivability. $\textbullet$ Virtual wall perception experiment is conducted to obtain force specification for haptic mouse. $\textbullet$ Average mouse workspace is measured using magnetic position tracker.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1405-1406
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• 2010

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1993-2001
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• 2006

The piezoelectric bimorph film, which, as an actuator, can generate more effective displacement than the usual PVDF film, is used to control the turbulent boundary-layer flow. The change of wall pressures inside the turbulent boundary layer is observed by using the multi-channel microphone array flush-mounted on the surface when actuation at the non-dimensional frequency $f_b^+$:=0.008 and 0.028 is applied to the turbulent boundary layer. The wall pressure characteristics by the actuation to produce local displacement are more dominantly influenced by the size of the actuator module than the actuation frequency. The movement of large-scale turbulent structures to the upper layer is found to be the main mechanism of the reduction in the wall- pressure energy spectrum when the 700$700{\nu}/u_{\tau}$-long bimorph film is periodically actuated at the non- dimensional frequency $f_b^+$:=0.008 and 0.028. The biomorph actuator is triggered with the time delay for the active forcing at a single frequency when a 1/8' pressure-type, pin-holed microphone sensor detects the large-amplitude pressure event by the turbulent spot. The wall-pressure energy in the late-transitional boundary layer is partially reduced near the convection wavenumber by the open-loop control based on the large amplitude event.