• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1757-1762
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• 2003

For coping with various ship types easily, welding automation using CAD/CAM is demanded and and developed. In this paper we propose a dedicated CAM system which generates MACRO files to control robot manipulators. The paper contains CAD interface, virtual simulation, macro generation and job schedulling. At first, it defines and extracts weldline from CAD data, and generates proper MACRO programs. And it obtains optimum job schedules. This system removes the manual work, and consequently reduces the overall lead time. And it reduces costs and time for developing robot welding programs. This can be expanded to virtual factory simulation technology. Moreover, it is possible to apply this system for automation of Cutting and Painting

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.677-680
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• 2002

The biggest obstacle in utilizing Telerobotics is that an exclusive line is necessary to connect the distant place and manipulator for the purpose of remote control. Moreover, installment of an exclusive line Is limited to relatively short distance, as the installment entails more difficulties with longer distance and increasing installment cost. The purpose of this paper is to suggest a methodology of factory automation by using Lab VIEW to control and monitor actuators, which are the basis of controlling manipulators, form distant places.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.504-509
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• 1990

This paper presents a decentralized adaptive control scheme for multi-Joint robot manipulators based on the independent joint control scheme. The control object is to achieve accurate tracking of desired Joint trajectories. The proposed control scheme does not use the complex manipulator dynamic model, and each joint is controlled simple by a feedback controller which ensure stable and also a position-velocity-acceleration feedforward controller and also auxiliary signal, with adjustable gains. Simulation results are given for a two-link manipulator under independent control, proposed decentralized adaptive control of manipulator is feasible. In spite of a pay load variation and strong static and dynamic couplings that exist between the joints.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.1063-1072
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• 1996

Fruit harvesting robots should have more diversity and flexibility in the working conditions and environments than industrial robots. This paper presents an efficient optimization algorithm for redundant manipulators to avoid obstacles using dynamic performance criteria, while the optimization schemes of the previous studies used the performance criteria using kinematic approach. Feasibility and effectiveness of this algorithm were tested through simulations on a 3-degrees-of-freedom manipulator made for this study. Only the position of the end-effector was controlled , which requires only three degrees of freedom. Remaining joints, except for the wrist roll joint, which does not contribute to the end-effector linear velocity, provide two degrees of redundancy. The algorithm was effective to avoid obstacles in the workspace even through the collision occurred in extended workspace, and it was found be to a useful design tool which gives more flexibility to design conditions nd to find the mechanical constraints for fruit harvesting robots.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.422-422
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• 2000

Parallel manipulators have been used to a variety of applications, including the motion simulators and mechanism for precise machining. A Stewart-Gough type parallel manipulator is composed of six linear joints which have wider contact areas than revolute ones, so linear joints are more affected by frictional force. First, the reference trajectories are computed from the model of the parallel manipulator assuming that it is subject to only the gravitational force and no friction exists. In the actual operation where friction exists, the control inputs, which correspond to the friction forces, are obtained by forcing the actual joint variables to follow these trojectories by proper control. It is shown that control performance can be improved when the friction compensation based on this information is added to the controller for position control of the moving plate of a parallel manipulator.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.445-445
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• 2000

This paper proposes the MIMO indirect adaptive fuzzy controller to control the two-link manipulators. The input-output linearization technique, equivalent control input plus integral term, augmented error model and recursive least square adaptive law are used fer the controller. The linear type of fuzzifier-defuzzifier fuzzy logic system used for nonlinear function makes easy to farm the error model and able to follow the adaptive system approach. Such that control approach, the control system is not required joint speed and accerelation measurement and easy to implement and tune. The simulation results showed that the proposed controller has good control performance, stability, very small tracking error, decoupling, fast convergence, robust to parameter variation and load.

• 로봇학회논문지
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• 제3권1호
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• pp.9-15
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• 2008

Unlike robotic systems, humans excel at a variety of tasks by utilizing their intrinsic impedance, force sensation, and tactile contact clues. By examining human strategy in arm impedance control, we may be able to teach robotic manipulators human''s superior motor skills in contact tasks. This paper develops a novel method for estimating and predicting the human joint impedance using the electromyogram(EMG) signals and limb position measurements. The EMG signal is the summation of MUAPs (motor unit action potentials). Determination of the relationship between the EMG signals and joint stiffness is difficult, due to irregularities and uncertainties of the EMG signals. In this research, an artificial neural network(ANN) model was developed to model the relation between the EMG and joint stiffness. The proposed method estimates and predicts the multi joint stiffness without complex calculation and specialized apparatus. The feasibility of the developed model was confirmed by experiments and simulations.

• Applied Microscopy
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• 제42권4호
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• pp.223-227
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• 2012

Focused Ion Beam (FIB) systems have incorporated versatile nanomanipulators with inherent sophisticated machining capability to characterize the electrical properties of highly miniature components of electronic devices. Carbon fibers were chosen as a model system to test the applicability of nanomanipulators to microscale electronic materials, with special emphasis on the direct current current-voltage characterizations in terms of electrode configuration. The presence of contact resistance affects the electrical characterization. This resistance originates from either i) the so-called "spreading resistance" due to the geometrical constriction near the electrode - material interface or ii) resistive surface layers. An appropriate electrode strategy is proposed herein for the use of FIB-based manipulators.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1996년도 특별강연 및 춘계학술발표 개요집
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• pp.96-98
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• 1996

Welding of corner area across the edge is a difficult problem in robotized arc welding system, especially when continuously-welded leakage-proof product is required. This paper presents the methodology of cooperation plan of an arc welding robot and 1 or 2 axis welding manipulators for corner area welding. Welding trajectory for the robot is generated using clothoid curves; symmetrical double clothoid curve or unsymmetrical clothoid curve depending on the nature of the workpiece. The clothoid curve is first formulated for the case of linear type positioning table and then applied to the case of rotary type manipulator. The methodology is then illustrated for practical downhand welding situations.

• International Journal of Precision Engineering and Manufacturing
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• 제6권2호
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• pp.61-71
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• 2005

The study reported deals with investigating the feasibility of control strategy for a serial rigid link manipulator that applies impulsive torques at the joints. The strategy is illustrated for a planar three rigid link manipulator. An impulse-based concept which uses successive torque impulses on rigid link as the controller for motion correction was introduced. This control strategy was tested over the entire trajectory to demonstrate that the tracking error could be reduced effectively. The best condition for minimizing the tracking error with the least impulse input at each joint is investigated by considering one design and one operating parameter. The first was the damping in the system, and the second was the sampling time during operation. The results show that this approach can provide useful guidance for the design and control of robot manipulators that require minimum impulse feedback for accurate tracking.