• The Journal of Korea Robotics Society
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• v.17 no.4
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• pp.431-437
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• 2022

This paper deals with a study on the automatic depalletizing robot for parcels loaded in rolltainer of domestic postal distribution centers. Specifically, we proposed a robot system that detect parcels loaded in a rolltainer with a 3D camera and perform de-palletizing using a cooperative robot. In addition, we developed the task flow chart for parcel de-palletizing and the method of retreat motion generation in the case of collision with rolltainer. Then, we implemented the proposed methods to the robot's controller by developing robot program. The proposed robot system was installed at the Anyang Post Distribution Center and field tests were completed. Field tests have shown that the robotic system has a success rate of over 90% for depalletizing task. And it was confirmed that the average tact time per parcel was 7.3 seconds.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.65-68
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• 1999

In this study, an off-line automatic teaching method using vision information for robotic assembly task is proposed. Many of industrial robots are still taught and programmed by a teaching pendant. The robot is guided by a human operator to the desired application locations. These motions are recorded and are later edited, within the robotic language using in the robot controller, and played back repetitively to perform the robot task. This conventional teaching method is time-consuming and somewhat dangerous. In the proposed method, the operator teaches the desired locations on the image acquired through CCD camera mounted on the robot hand. The robotic language program is automatically generated and transferred to the robot controller. This teaching process is implemented through an off-line programming(OLP) software. The OLP is developed for the robotic assembly system used in this study. In order to transform the location on image coordinates into robot coordinates, a calibration process is established. The proposed teaching method is implemented and evaluated on the assembly system for soldering electronic parts on a circuit board. A six-axis articulated robot executes assembly task according to the off-line automatic teaching.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.10
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• pp.37-45
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• 1992

For a precise manipulator control in the presence of environmental uncertainties, it has long been recognized that the robot should be controlled in a task-referenced space. In this respect, an effective visual servo control system for robot manipulators based on neural networks is proposed. In the proposed control system, a Backpropagation neural network is used first to learn the mapping relationship between the robot's joint space and the video image space. However, in the real control loop, this network is not used in itself, but its first and second derivatives are used to generate servo commands for the robot. Second, and Adaline neural network is used to identify the approximately linear dynamics of the robot and also to generate the proper joint torque commands. Computer simulation has been performed demonstrating the proposed method's superior performance. Futrhermore, the proposed scheme can be effectively utilized in a robot skill acquisition system where the robot can be taught by watching a human behavioral task.

• The Journal of Korea Robotics Society
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• v.2 no.2
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• pp.129-136
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• 2007

This paper introduces a position-based robust visual servoing method which is developed for operation of a human-like robot with two arms. The proposed visual servoing method utilizes SIFT algorithm for object detection and CAMSHIFT algorithm for object tracking. While the conventional CAMSHIFT has been used mainly for object tracking in a 2D image plane, we extend its usage for object tracking in 3D space, by combining the results of CAMSHIFT for two image plane of a stereo camera. This approach shows a robust and dependable result. Once the robot's task is defined based on the extracted 3D information, the robot is commanded to carry out the task. We conduct several position-based visual servoing tasks and compare performances under different conditions. The results show that the proposed visual tracking algorithm is simple but very effective for position-based visual servoing.

• Journal of the Ergonomics Society of Korea
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• v.7 no.1
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• pp.31-37
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• 1988

This paper designs, in the teleoperation task, the world coordinate system by the functional analysis of each of the robot joint so that the human operator performs easily the task. Also, it constructs the heuristic rules of the equal motion line coordinates for the position and the posture control of the robot within the knowledge base so that the robot hand reaches-possibly in any position of the robot's work space. As shown in the result of the experiments. the coordinate reading is easy because the work station is displayed to the high resolution by using the superimposer of the motion analysing computer system. Also. the task burden of the human operator reduces and the error recovery time reduces because the coordinates of the object is obtained just by touch using the digitizer.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.3
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• pp.247-255
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• 1989

This paper proposes an error model with integral action and a pole-place-ment self-tuning controller for robot manipulators in task coordinates. The controller can reject the offset due to any load disturbance without a detailed description of the robot dynamics. The error model parameters are estimated by the recursive least square identification algorithms, and controller parameters are determined by the pole-placement method. A computer simulation study has been conducted to demonstrate the performance of the proposed control system in task coordinates for a 3-joint and 2-link spatial robot manipulator with payload.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.7
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• pp.656-662
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• 2008

A cost-function based on manipulability and compatibility is designed to determine assembly motions of two cooperating manipulators. Assembly motions are planned along the direction maximizing performance indices to improve control performance of the two manipulators. This paper proposes bimanual task compatibility by defining cost functions. The proposed cost functions are applied and compared to the bimanual assembly task. The problem is formulated as a constrained optimization considering assembly constraints, position of the workpieces, and kinematics and redundancy of the bimanual robot. The proposed approach is evaluated with simulation of a peg-in-hole assembly with an L-shaped peg and two 3-dof manipulators.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.8
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• pp.570-578
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• 1988

In order for a robot to carry out a precise assembly task with compliant motion, a force/torque sensor is needed. The output of the cross-bar structured force / torque sensor which is used in a peg-in-hole insertion task and attached to a SCARA type robot, is analzed. First, the relationship between the sensor outputs and the force / torque components obtained by the outputs is investigated. Second, in a peg-in-hole insertion task, the sensor outputs changing with the contact position of the peg and the hole, are analyzed. Also, the relative position of the peg and the hole is obtained from the sensor outputs. The peg-in-hole insertion task is successfully executed, using a SCARA type robot with a wrist force / torque sensor manufactured in our laboratory and the compliance algorithm from the results of this paper.

• Therapeutic Science for Rehabilitation
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• v.7 no.4
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• pp.79-91
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• 2018

Objective : The purpose of this study was to investigate the short-term effect of robot-assisted therapy to improve upper extremity function in subacute stroke. Method : This study was a retrospective study using the medical record. The subjects were 20 patients who were diagnosis with stroke within 6 months. All patients received general rehabilitation intervention during the experimental period and robot-assisted therapy and task-oriented training. Robot assisted therapy was composed of 1 sessions, 1hour per person and task-oriented training was same. For result analysis, descriptive statistics, paired t-test were used. Results : After intervention, all participants got 3D motion analysis about reaching. For the result, there was statistically significant improvement in smoothness in robot assisted therapy(p<.05). there was no statistically significant difference between robot assisted therapy and task-oriented training in speed, time. In this result, we knew the robot assisted therapy can short term effect in elbow joint during arm reaching. Conclusion : Robot assisted therapy is considered as alternative choice in clinical occupational therapy for improving upper extremity function in subacute stage stroke patients.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1832-1835
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• 1997

Off-line programming systems are widely spread in assembly lines of minute electronic products to huge offshore structures. Any OLP system has to be calibrated before the on-line robot tasks are performed because there are inherent differences between the CAD model on OLP and the real robot workspace. This paper uses simple geometric expressions to propose a calibration method applicable to an OLP for SCARA robots. A positioning task on the two-dimensional horizontal surface was used in the error analysis of a SCARA robot and the anaysis shows that the inaccuracy results from the two error sources non-zero offset angles of two rotational joints at the zero return and differences in link lengths. Pen marks on a sheet of plotting paper are used to determine the accurate data on the joint centers and link dimensions. The calculated offset angles and link lengths are fed back to the OLP for the calibration of the CAD model of the robot and task environments.