• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.523-526
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• 1996

In this paper, robot endeffector tracking using sensory information from structured laser pattern diode, is described. In order to track robot endeffector robustly irrespective of translation, scaling and rotation of robot working tool, structured laser pattern is used as track feature. Structured laser patterns of crosshair, concentric circles, dot matrix, and parallel lines are illuminated to robot endeffector. Illuminated laser patterns are held invariently and coherently irrespective of various motions of robot endeffector. Extracting and tracking these invariant structured laser patterns as track feature, the whole system keeps tracking of the robot endeffector robustly and effectively provided that structured laser pattern is always assumed to aim at robot endeffector.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.130.1-130
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• 2001

In this paper, a motion control algorithm is developed using a fuzzy control and the optimization of performance function, which makes a robot arm avoid an unexpected obstacle when the end-effector of the robot arm is moving to the goal position. During the motion, if there exists no obstacle, the end-effector of the robot arm moves along the pre-defined path. But if there exists an obstacle and close to the robot arm, the fuzzy motion controller is activated to adjust the path of the end-effector of the robot arm. Then, the robot arm takes the optimal posture for collision avoidance with the obstacle. To show the feasibility of the developed algorithm, numerical simulations are carried out with changing both the positions and sizes of obstacles. It was concluded ...

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.511-516
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• 1991

A new end-effector has been devised and the problems resulted from using it with SCARA robots are discussed. The end effector has two modules: one composed of two ultrasonic motors and two encoders for controlling each finger, and the other module composed of two ultrasonic motors and two encoders for controlling the wrist. The wrist module adds two degrees of freedom to the SCARA type robot, which generally has four degrees of freedom. With independent finger actuation and touch sensors, the gripper under computer control can feedback information about part size and part presence. Ultrasonic motors with high torque and slow motion characteristics are used. The principle of ultrasonic motors is explained and the servo characteristics of ultrasonic motors are studied. They are controlled by the general motion controller (Hewlett Packard HCTL-1000) which is linked to an IBM-PC AT.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.3
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• pp.173-180
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• 2015

In this paper, we propose a new precise control technology of robotic gripper for assembling and handling of part. When a robot manipulator interacts mechanically with its environment to perform tasks such as assembly or edge-finishing, the end-effector is thereby constrained by the environment. Therefore grasping force control is very important, since it increases safety due to monitoring of contact force. A comparison of various force control architecture is reported. Different force control methods can often be configured to achieve similar results for a given task, and the choice of control algorithm depends strongly on the application or on the characteristics of a particular robot. In the research, the adjustable gripping force can be controlled and improved the accuracy using the artificial intelligence techniques.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.12
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• pp.165-172
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• 1995

Many algorithms to enhance a speed performance of a robot have been studied, but it's rare to consider disign aspect of a robot arm for time optimal problem. In this paper, section demensions of a robot arm and a velocity profile of an end-effector were optimally designed to minimize the cycle time. Capacity of actuators, deflections of end-effector, and a fundamental natural frequency of the robot arm were constrained in optimal design. For a given path with a trapezoidal velocity profile, torques of each joint were calculated using the inverse kinematics and dynamics. For the SCARA type robot which is mainly used for assembly tasks, the time optimal design of each robot arm id presented with the above constraints.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.22-26
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• 1999

In general, three are many degrees of freedom (DOF) in industrial robots. That can generate several special end-effector's positions and orientations. For that reason, industrial robots are used in a wide scope of industrial applications such as welding, spray painting, deburring, and so on. In this research, new method is presented which safely maintain the desired constant end-effector's orientation and minimize the numbers of segments in path. These algorithms may apply to welding, painting, and assembling. The simulation study of straight line and circular motions in arc-welding operations is carried out to show the sure proof of these algorithms.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.6
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• pp.98-104
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• 2002

In this study, we have developed an algorithm by attaching a camera at the end-effector of industrial six-axis robot in order to determine position and orientation of the camera system from cartesian coordinates. Cartesian coordinate as a starting point to evaluate for suggested algorithm, it was easy to confront increase of orientation vector for a linear line point that connects two points from coordinate space applied by recursive least square method which includes previous data result and new data result according to increase of image point. Therefore, when the camera attached to the end-effector has been applied to production location, with a calibration mask that has more than eight points arranged, this simulation approved that it is possible to determine position and orientation of cartesian coordinates of camera system even without a special measuring equipment.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2468-2470
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• 2003

비주얼 서보잉이란 로봇팔 등과 같은 제어기의 폐루프에서 입력단에 영상을 이용하는 것이다. 영상에 나타난 정보는 특징점을 통해 얻을 수 있으며, 매시간 이 특징점의 위치를 추적함으로써 제어기의 출력값을 결정한다. Optical flow를 이용하는 가나데 특징점 추적기는 특징점 추적기 중에서 성능이 우수하다고 알려져 있다. 본 논문에서는 가나데 특징점 추적기를 이용하여 실시간으로 로봇팔을 제어하고 결과를 분석하도록 한다. 실험에 이용되는 로봇팔은 전체 6축이며 기존의 5축 상용로봇의 end-effector에 ccd카메라를 좌우로 회전가능하도록 기구부를 추가하였다. 6DOF를 갖도륵 변형된 로봇팔을 기구적으로 분석하고 자코비안을 획득한 후, 로봇팔의 end-effector에 설치된 카메라를 통하여 특정 영상이 얻어지도록 로봇의 end-effector의 속도를 생성해내고, 자코비안의 역행렬을 통해 로봇의 각 관절을 제어하는 과정을 기술하고 분석한다.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.7
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• pp.92-100
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• 2004

A service robot is expected to be useful in indoor environment such as a hotel, a hospital and so on. However, many service robots are driven by wheels so that they cannot climb stairs to move to other floors. If the robot cannot use elevators. In this paper, the mobile manipulator system was developed, which can operate numeral buttons on the operating panel in the elevator. To perform this task, the robot is composed of an image recognition module, an ultrasonic sensor module and a manipulator. The robot can recognize numeral buttons and an end-effector in manipulator by the vision system. The Learning vector quantization (LVQ) algorithm is used to recognize the number on the button. The barcode mark on the end-effector is used to recognize the end-effector. The manipulator can push numeral buttons using informations captured by the vision system. The proposed method is evaluated by experiments.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.559-562
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• 2003

본 논문에서는 실시간 마커프리 모션캡쳐 시스템으로 캡쳐된 동작자의 Root와 End-effector 위치 데이터를 이용하여 가상 캐릭터의 동작을 생성하는 방법에 0해 기술한다. 동작자의 신체중심이 되는 Root와 머리, 손, 발과 같은 End-effector의 위치 데이터는 동작자의 전방 좌, 우에 위치한 동기화된 2대의 컬러 CCD 카메라를 이용하여 3차원 위치를 캡쳐한다. 영상으로부터 추출되지 않은 중간관절의 위치를 생성하기 위해 Root와 End-effector의 3차원 위치값들을 IK( Inverse Kinematics) 알고리듬에 적용하고, 생성된 위치값들에 다양한 신체의 제약조건을 고려하여 정밀하게 계산한다. 이러한 과정을 거치므로 서 20개 관절의 위치값을 생성할 수 있으며, 생성된 관절의 위치값을 가상 캐릭터에 적용하므로 서 캐릭터의 움직임을 실시간으로 생성할 수 있다.