• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1075-1080
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• 2006

본 연구에서는 영화나 게임 등에서 사용되는 인간형 관절체의 움직임을 만들어내기 위하여 동역학 시뮬레이션을 이용하는 방법을 제안한다. 동역학을 이용하여 동작을 생성하는 방법은 실제 배우가 연기하기 힘들어서 동작 포착을 활용할 수 없는 경우, 키프레임 방식에 비해 보다 사실적이고 효과적으로 동작을 만들어 내는 장점이 있다. 하지만 시간이 많이 소요되고 결과 동작을 예측하거나 제어하기 힘들기 때문에 지금까지 활용도가 낮았다. 본 연구에서 제안하는 방법은 복잡한 최적화나 컨트롤러 모델링과정 없이 동작 포착 데이터를 이용한 비례 미분 제어기를 통해서 포착된 동작과 유사한 패턴을 가지는 관절 제어기를 만들어낸다. 특히, 내부 관절 제어기뿐만 아니라 최상위 관절에 작용하는 가장제어기를 생성하여 포착된 동작의 관절 궤적을 보다 효과적으로 흉내 낼 수 있게 한다. 생성된 제어기의 매개변수를 조정함으로써 여러 가지 효과를 만들어 낼 수 있으며, 동시에 다양한 동작 패턴도 적용 가능하다. 마지막으로 제어기를 통해 시뮬레이션 되는 동작과 원래 동작 포착된 결과를 혼합하거나 보간함으로써 최종 동작을 생성한다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1831_1832
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• 2009

본 논문에서는 유연관절 로봇 팔 제어를 위한 토크센서 기반의 외란에 강인한 제어기 설계를 다루고 있다. 로봇은 관절의 토크센서를 통해 관절에서 발생하는 토크의 측정이 가능하며 외란에 강인한 제어기 설계를 위해 외란 관측기가 적용 되었다. 외란관측기는 시스템에 작용하고 있는 외란을 상쇄하는 역할을 한다. 본 논문에서 설계된 제어기의 성능은 컴퓨터 모의실험을 통하여 확인하도록 한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.3
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• pp.236-242
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• 2009

When two-link flexible arm is rotated about an joint axis, transverse vibration may occur. In this paper, vibration dynamics of flexible robot arm is modeled by using Bernoulli-Euler beam theory and Lagrange equation. Using the fact that matrix $\dot{D}$-2C is skew symmetric, new controllers which have a simplified structure with less computational burden is proposed. Lyapunov stability theory is applied to achieve a stable deterministic nonlinear controller for the regulation of joint angle.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.1
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• pp.46-50
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• 2013

This paper proposes an adaptive fault accommodation control approach for flexible-joint (FJ) robots with multiple actuator faults. It is assumed that the value and occurrence time of multiple actuator faults are unknown. An adaptive fault accommodation control scheme with prescribed performance bounds, which characterize the convergence rate and maximum overshoot of tracking errors, is designed to accommodate the actuator faults. From the Lyapunov stability theorem, it is proved that all signals of the closed-loop system are semi-globally uniformly ultimately bounded and tracking errors are preserved within prescribed performance bounds regardless of actuator faults.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.317-325
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• 2011

This study aims to develop the stance-control typed 4-bar linkage orthotic knee joint that replace the locked orthotic knee joint for the disabled with poliomyelitis and muscle weakness of lower limb. Unlike the existing stance-control orthotic knee joint, there are no needs of electric power, connecting circuit, bulky compomnets, etc, because this 4-bar linkage orthotic knee joint is controled by geometric locking. To evaluate the 4-bar linkage orthotic knee joint, a subject participated in this study who has been diagnosed with lower limb poliomyelitis and have used locked type orthotic knee joint. In the results of analysis of subject's gait using 3-dimentional motion analysis system, this 4-bar linkage orthotic knee joint provide the stability during stance phase and knee flexion during swing phase.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1203-1211
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• 2017

This paper proposes a robust controller for flexible joint robots to achieve tracking performance and to improve robustness against both matched and mismatched disturbances. The proposed controller consists of a disturbance observer(DOB), passivity-based controller, and integral sliding mode controller(ISMC) in a backstepping manner. The DOB compensates the mismatched disturbance in the link-side and formulates the reference input for the motor-side controller. Interconnection and damping assignment passivity-based controller (IDA-PBC) performs tracking control of motor-side, and it is integrated to nominal control of ISMC to guarantee the over-all stability of the nominal system, while, matched disturbances are decoupled by the discontinuous control of ISMC. In the design of the link-side controller, PD type impedance controller is designed with DOB and this leads the continuous control input which is suitable to the reference input for the motor-side.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.4
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• pp.1-12
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• 2004

This paper presents an adaptive fuzzy backstepping (AFB) controller for a single-link flexible joint robot in the Presence of Parametric uncertainties and external disturbances. Adaptive fuzzy logic systems are used as universal approximators to counteract the model uncertainties coming from robot dynamics and to compensate for the nonlinearities coming from adaptive backstepping method. The approach suggested herein does not require neither an additional supervisory nor a robustifying controller and guarantees that tracking error is uniformly ultimately bounded (UUB) within a sufficiently small residual set. Finally, a simulation result is given to demonstrate the robust tracking performance of proposed design method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.1
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• pp.31-38
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• 1999

In this paper, we proposed a fuzzy sliding mode controller for a robot manipulator with passive joints. A robot manipulator with passive joints which is not equipped with actuators is a kind of underactuated systerms. The control of underactuated manipulators is more difficult than that of fully-actuated ones. Though the sliding mode control technique has a robust charocteristics to prrarreter uncertainties and external disturbances, the chattering phenomena becorne one of the major problems in application to the real plant. plant.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.5
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• pp.640-647
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• 2007

This paper presents a joint controller for a humanoid robot based on genetic algorithm. h humanoid robot has basically instability during walking because it isn't fixed on the ground. Moreover nonlinearities of the joints increase its instability. If one of them isn't satisfied, the robot may fall down at the ground during walking. To attack one of those problems, joint controller is proposed. It can perform tracking control preciously and reduce the effect of nonlinearities by gear, limitation of the input voltage, coulomb friction and so on. This controller is based on fuzzy-sliding mode controller (FSMC) and compensator and control gains are searched by a proposed genetic algorithm. It can reduce the effect by nonlinearities. Also, to improve the tracking performance, the proposed controller has motion controller. From the given controller, a humanoid robot can moved more preciously. Here, all the processes are investigated through simulations and it is verified experimentally in a real joint system for a humanoid robot.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.2
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• pp.92-100
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• 1992

플렉시블한 관절을 가지고 있는 로보트에 대하여 계단(step) 혹은 경사(ramp) 함수로 기준입력이 주어졌을 때, 모델의 불확실성이나 외란 아래에서 추적오차가 없는 디지찰 제어기법을 제시하고 실제로 실험을 통하여 제어기를 MC 68000으로 구현함으로써 제안한 제어 알고리즘의 유용성을 보였다. 제어기 설계에 있 어서 고려한 사항들은 비선형 마찰력, 중력에 의한 외란, 구동기와 부하사이의 뒤틀림 스프링 효과, 구리고 측 정할 수 없는 상태변수들이다. 또한 미분불가능한 쿨롱마찰로 인하여 전체 시스템이 이산/연속 혼성 시스템이 되어 출력에서 나타나는 리미트 싸이클을 해석/추정하기 위하여 혼성 시스템에서의 기술함수(Describing Function) 법을 제시하였다.