• ICROS
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• v.17 no.2
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• pp.27-35
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• 2011

This paper presents the state of the art of control strategies for bilateral teleoperation systems under time delays. In the bilateral teleoperation that has force feedback, the time delay in the communication channel is the main source of instability. To cope with this problem. a number of control methods have been proposed. Among many control strategies. key aspects of the recent passivity-based methods are mainly summarized for approaches with wave variables. PO/PC (passivity observer/passivity controller), simple PD, and energy bounds.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.5
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• pp.519-526
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• 1990

In this paper we propose the resolved motion controller using a neural network for a robot manipulator. Neural identifier designed by a neural network is trained by using a feedback force as an error signal. The identifier approximates the output of a unknown nonlinear system by monitoring both the input and the output of this system. If the neural network is sufficiently trained well, it does not require either strict modelling of the manipulator or precise parameter estimation. The effectiveness of the proposed controller is demonstrated by computer simulation using a two-link planar robot.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.1134-1135
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• 2014

힘반영 원격제어시스템의 시간지연 문제로 발생하는 마스터제어기와 슬레이브 로봇 매니퓰레이터의 발산 운동에 대한 완화를 위하여, 원격작업에 필요한 시나리오를 통해 작업환경들을 프로파일로 제공하여 힘반영에 도움을 받는 방법에 대하여 기술한다. 이 방법은 원전과 같이 제한된 시간 내에 작업을 종료해야하는 환경에서 유용하게 사용될 수 있다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.499-502
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• 2003

VR(virtual reality, 가상 현실) 환경이 대중화 되면서, VR 환경 하에서 사용자가 반력(force feedback)을 느끼게 하는 방법들에 대한 연구가 활발해 지고 있다. 이러한 반력의 사용에 있어, 반력을 지원하는 하드웨어, 소프트웨어들이 필수적이고, 기존의 탁상형 고정식인 반력 게임컨트롤러 뿐만 아니라, 게임 플레이어가 보다 향상된 체감효과를 통해 현실감을 경험할 수 있도록 다양한 햅틱 장치를 필요로 한다. 본 연구에서는 신체에 착용하여 체감을 느낄 수 있도록 특별 제작된 (custom) 햅틱 수트 (haptic suit)를 다룬다. 이를 위한 게임 인터페이스를 제시하여, 게임 컨텐츠에 실재감을 부여할 수 있는 반력을 편집하고, 재생할 수 있는 효과 생성기를 제시한다.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.382-382
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• 2000

The external force disturbance is the one of the main causes that deteriorate the performance of the magnetic suspension. Thus, this paper develops a fuzzy estimator for gain scheduling control of magnetic suspension systems suffering from the unknown disturbance. The proposed fuzzy estimator computes the disturbance injected to the plant and the gain scheduled controller generates the corresponding stabilizing control input associated with the estimated disturbance. In the simulation results we confirm the novelty of the proposed control scheme comparing with the other method using a feedback linearization.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.1
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• pp.23-31
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• 2002

We proposed a concept of a desktop micro device factory for visually servoed teleoperated microassembly assisted by a virtual reality (VR) interface. It is composed of two micromanipulators equipped with micro tools operating under a light microscope. First a manipulator, control method for the micro object to follow a planned trajectory in pushing operation is proposed undo. vision based-position control. Then, we present the cooperation control strategy of the micro handling operation under vision-based force control integrating a sensor fusion framework approach. A guiding-system based on virtual micro-world exactly reconstructed from the CAD-CAM databases of the real environment being considered is presented for the imprecisely calibrated micro world. Finally, some experimental results of microassembly tasks performed on millimeter-sized components are provided.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.3
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• pp.190-194
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• 2013

This paper presents experimental results of the attitude control for a two-rotor system with 3-DOF(degree-of-freedom). Two DC motors are equipped at the two ends of a rectangular beam to generate lift force and the relation between motor voltage and lift force is found experimentally. And inertial sensors are mounted at the center of the beam to measure the roll angle and a complementary filter is designed to get the angle during DC motors driving. A controller with nonlinear compensation, integrator and state feedback to achieve asymptotic tracking for a step input and reject input disturbance is designed and experimented.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.882-885
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• 2003

In this paper, we describe a haptic jacket and wheel as a haptic interface to enhance VR game realism. Building upon the VR game system using this devices, our haptic interface technique allows the user to intuitive interact on game contents, and then to sense the game event properties such as walking, attacking, driving and fire in a natural way. In addition, we extended the initial haptic model to support haptic decoration and dynamic interactions due to the added game event in a real time display. An application example presented here is a VR Dino-Attack game. This game supports interactions among dynamic and our intuitive haptic interface. Modeling physic interactions involves precise collision detection, real-time force computation, and high control-loop bandwidth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.383-386
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• 2005

An integrated analytical model which should have essential dynamics on the longitudinal railway vehicle is developed. The model consists of translational movement, rotational movement, brake actuator, adhesion force between rail and wheel, and brake friction force between wheel and pad. Thus, during the deceleration for stopping, a feedback controller controlling the brake cylinder pressure is designed to improve ride quality and to release friction problems. Through the developed model, the feasibility of controlling the cylinder pressure is verified for the better performances during braking.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1106-1111
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• 2007

This paper is focused on design of a new active control engine mount (ACM), which is compact in size and cost effective. The ACM, consisting of an electrodynamic actuator as the active element, flat springs and a sliding ball joint, is different in structure from the previous ACM designs based on the conventional hydraulic engine mount. Dynamic characteristics of the proposed ACM are extensively investigated before a prototype ACM, which meets the design specifications, is built in the laboratory. For cost effectiveness, a feed-forward control algorithm without a feedback sensor is used for reduction of the transmitted force through the ACM from the engine. The prototype ACM is then harmonic-tested with a rubber testing machine for verification of its control performance as well as adequacy of modeling. Experimental results show that the proposed ACM is capable of reducing the transmitted force by 20 dB up to the frequency range of 60 Hz.