• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.491-496
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• 1992

An analytic solution approach to the time-varying obstacle avoidance problem is pursued. We formulate the problem in robot joint space(JS), and introduce the view-time concept to deal with the time-varying obstacles. The view-time is a set of continuous times in which a time-varying obstacle is viewed and approximated by an equivalent stationary obstacle. The equivalent stationary obstacle is transformed into the JS obstacle. In JS, the path and trajectory avoiding the JS obstacle is planned.

• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.184-191
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• 2007

Autonomous navigation of mobile robot requires a ranging system for measurement of distance to environmental objects. It is obvious that the wider and the faster distance measurement gives a mobile robot more freedom in trajectory planning and control. The active omni-directional ranging system proposed in this paper is capable of obtaining the distance for all 3600 directions in real-time because of the omni-directional mirror and the structured light. Distance computation including the sensitivity analysis and the experiments on the omni-directional ranging are presented to verify the effectiveness of the proposed system.

• 제어로봇시스템학회논문지
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• 제14권6호
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• pp.573-579
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• 2008

This paper introduces a new approach to develop a fast gait for quadruped robot using GP(genetic programming). Planning gaits for legged robots is a challenging task that requires optimizing parameters in a highly irregular and multidimensional space. Several recent approaches have focused on using GA(genetic algorithm) to generate gait automatically and shown significant improvement over previous results. Most of current GA based approaches used pre-selected parameters, but it is difficult to select the appropriate parameters for the optimization of gait. To overcome these problems, we proposed an efficient approach which optimizes joint angle trajectories using genetic programming. Our GP based method has obtained much better results than GA based approaches for experiments of Sony AIBO ERS-7 in Webots environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.552-554
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• 1998

This paper deals with the gait generation of IWR-III using a kick action to have a walking pattern like human. For this, trajectory planning with the consideration of kick action is done in each walking step, and the coordinate transformation is done for simplifying the kinematics. Balancing motion is analyzed by FDM during the walking, By combining 4-types of pre-defined steps, multi-step walking is done. Using numerical simulator, dynamic analysis, ZMP analysis and system stability is confirmed. Walking motion is visualized by 3D- graphic simulator. As a result, trunk ahead motion effect and impactless smooth walking is implemented by experiment. Finally walking with kick action is implemented the IWR-III system.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2018년도 제57차 동계학술대회논문집 26권1호
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• pp.53-54
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• 2018

본 논문은 ROS 프레임워크를 기반으로 4-자유도를 가진 로봇 팔의 Pick-and-Place 동작 제어를 구현하고, 틱택토 게임에 적용한 사례를 제시한다. 로봇 팔의 Pick-and-Place 동작 제어는 움직임 궤적 계획, 충돌 회피 그리고 역기구학 모델링 연산들과 이를 이용한 복잡한 제어 과정을 요구한다. ROS 프레임워크는 간단한 인터페이스 통해 로봇 팔의 동작을 용이하게 제어할 수 있도록 일련의 연산들과 제어 동작을 통합하여 MoveIt 패키지를 제공하고 있으며, 본 논문은 이 패키지를 기반으로 4-자유도의 로봇 팔에 대한 동작 제어 모듈을 구현하였다. 또한 이를 틱택토 게임에 적용하여 로봇 팔을 적절히 제어함을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.519-524
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• 1998

This paper presents a robust control scheme of free-joint manipulators to overcome actuator failures and uncertain-ties in Cartesian space where tasks are planned. The control scheme has the adaptation law for the upper bound on the norm of uncertainties through the Lyapunov function approach. To solve the dynamic singularity problem in the controller, the singular and nonsingular regions are investigated based on a computer simulation. Then a singularity-free Cartesian trajectory planning is achieved in order to guarantee the availability of the control scheme. To illustrate the validity of the proposed control scheme, simulation results for a three-link planar robot arm with a free joint are shown.

• 전자공학회논문지B
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• 제33B권9호
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• pp.13-23
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• 1996

When artificial potential field approach is used to avoid obstacle, the problem can be occurred in case that manipulator selects the path which across over an obstacle among paths. In thiscase manipulator can't reach the desired goal form obstacle. This problem is a case of structual local minimum. so this paper proposes the method to solve structual local minimum in this case. The method is that the manipulator goes via temporary goal. This paper proposes that visual region concept to select the temporary goal. The temporary goal is selected on the border of the visual region. To prove its effectiveness, two simulation examples are done by two link manipulator in two dimension and by three link manipulator in three dimension.

• 대한전기학회논문지
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• 제36권2호
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• pp.129-139
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• 1987

In this paper the programming language for Hero-1 robot is developed using Apple II micro computer. The language is composed of main monitor mode, editing mode, execution mode, and debugging mode. The main monitor mode is a main flow of the whole language system and controls starting and terminating procedures of operating the controller, and monitors the others. The editing mode has capability to make a user's maniqulation program. Trajectory planning algorithms(point-to-point motion and linear approximate motion)have been realized in the robot language, and in the case of point-to-point motion, inverse kinematics have been solved for the desired point.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.456-459
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• 2003

This paper deal with the biped walking stability by inverted pendulum type balancing joints. This model is hard to interpretation for the nonlinearity caused by upper direction movement then conventional model which have roll and prismatic joints. We can interpret this model by a linear approximation or interpolation method. This paper use a linear approximation method that can decide a movement of upper direction. Inverted pendulum type balancing joints have a advantage of less movement for keep stability and similar with human than conventional model and this model can be used for humanoid robot. We can see a stability of biped by ZMP(Zero Moment Point). Genetic algorithm is used for trajectory planning that is important for stable walking of biped.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2001년도 추계학술발표대회 개요집
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• pp.121-124
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• 2001

The main characteristic of the Electron Beam Welding technique is its high energy density which produces thin and deep welds with very little distortion. High accelerated electrons, focused in a beam of 0.5 ∼ 2mm diameter, produce narrow welds with deep penetration. The result is a small HAZ as well as a low and uniform distortion which is predictible within very narrow limits. But the small diameter of the EB increases the requirements for the equipment control system for centering the beam on the welding joint in order to avoid any lack of fusion. Therefore, in this paper, we introduce the system developed at our company and the quality of welding zone, the detail function of system.