• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.322-324
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• 2007

In this paper, an eye-in-hand visual servoing strategy for keeping feature points within the FOV(field-of-view) is proposed. We first specify the FOV constraint which must be satisfied to keep the feature points within the FOV. It is expressed as the inequality relationship between (i) the LOS(jine-of-sight) angles of the center of the feature points from the optical axis of the camera and (ii) the distance between the object and the camera. We then design a nonlinear feedback controller which decouples linearly the translational and rotational control loops. Finally, we show that appropriate choice of the controller gains assures to satisfy the FOV constraint. The main advantage of our approach over the previous ones is that the trajectory of the camera is smooth and circular-like. Furthermore, ours can be applied to the large camera displacement problem.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.543-548
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• 2000

In this study, an interactive programming method for robot in electronic part assembly task is proposed. Many of industrial robots are still taught and programmed by a teach 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 play back repetitively to perform 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 downloaded to the robot controller. This teaching process is implemented through an off-line programming software. The OLP is developed for an 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 an assembly system for soldering electronic parts on a circuit board. A six-axis articulated robot executes assembly task according to the off-line teaching in the system.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.5
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• pp.581-588
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• 2002

A fuzzy learning control algorithm is proposed in this paper. In this method, two fuzzy controllers are used as a feedback and a feedforward type. The fuzzy feedback controller can be designed using simple knowledge for the controlled system. On the other hand, the fuzzy feedforward controller has a self-organizing mechanism and therefore, it does not need any knowledge in advance. The effectiveness of the proposed algorithm is demonstrated by experiment on the position and force control problem of a parallelogram type robot manipulator with two degrees of freedom. It is shown that the rapid learning and the robustness can be achieved by adopting the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.590-596
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• 1994

In a CGL(Continuous Galvanizing Line) in steel making plants, zinc-coated steel sheets are produced. These sheets are used where long running corrosion resistivity is required. During the coating process top dross is produced, being harmful to the quality of the coating. To collect and remove this top dross, an automation system is developed consisting of a robot and its carriage system, a pot level sensor, a system controller, and specialtools. Forthe first, the level of the pot must be measured and fed back to the robot controller to avoid submersion of the robot hand in the hot pot. In this paper,acoustic and laser distance sensors are tested for the appropriate pot lvel sensor, especially the former in the view point of hot environment.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.12
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• pp.1160-1166
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• 2007

This paper presents the design and implementation of an embedded image stabilization control system for a mobile phone with a built-in camera. Image stabilization is a family of techniques for reducing image blur resulting from minute camera shake due to hand-held shooting, thereby allowing the use of shutter speeds slower than values normally required to obtain sharp images. A mechanical image stabilizer mechanism developed for a camera mobile phone is introduced and a digital control system as a part of the image stabilization system is designed and implemented on an 8-bit microcontroller with integer arithmetic in C. This paper focuses primarily on issues that need to be taken into consideration for fixed-point implementation of the digital controller. Several experimental results are presented to demonstrate the performance of the implemented image stabilization control system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.117-122
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• 1998

A servo system requires faster and more accurate dynamic reponses. Generally a PD control is mainly used to obtain the precision, and in the other hand a fuzzy control to improve the transient response and to cope with the nonlinearity of systems. Recently hybrid control, which is attempted to combine the advantages of PD control and a Fuzzy control was proposed, but this technique requires complicate design procedures. Therefore in this paper, designed on the Fuzzy controller with a various series rules, width of membership functions. And also it was showed to have the excellent adaptive performances against disturbances and the usefulness of this controller from the results of simulations.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.2995-2997
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• 1999

Recently, real-time visual tracking control for a robot manipulator is performed by using a vision feedback sensor information. In this paper, the optical flow is computed based on the eye-in-hand robot configuration. The image jacobian is employed to calculate the rotation and translation velocity of a 3D moving object. LQG visual controller generates the real-time visual trajectory. In order to improving the visual tracking performance. VSC controller is employed to control the robot manipulator. Simulation results show a better visual tracking performance than other method.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.553-554
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• 2023

본 연구에서는 손가락의 움직임을 입력받는 햅틱 컨트롤러를 이용하여 물체를 잡거나 놓는 손의 포즈를 생성하여 가상의 물체를 제어할 수 있는 방법을 제안한다. 다섯 개의 손가락을 움직일 수 있는 경우의 수는 무수히 많아서 이를 위한 모든 모션을 캡쳐하는 것은 매우 힘든 작업이고, 캡쳐한 모든 모션을 수동으로 연결시키는 것도 어려운 일이다. 제안 방법은 햅틱 컨트롤러에서 입력된 다섯 개의 신호를 인공 신경망을 사용하여 손가락의 포즈로 변경해 준다. 이를 위해 입력 신호와 매칭되는 손의 포즈를 이용하여 인공 신경망을 훈련시킨 후, 그 결과를 이용하여 사용자의 입력에 대응하는 손의 포즈를 생성한다. 결과 포즈의 사실성을 높이기 위해 모션 캡쳐 장비로부터 훈련용 데이터를 생성하였다. 본 논문의 방법은 햅틱 컨트롤러에서 동일한 입력을 받더라도 물체의 모양에 대응하는 손의 모션을 생성하는 결과를 보여준다.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.455-458
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• 1988

In this paper, a grasping force control of robot hand is presented with consideration of workpiece dynamics. It is difficult to control a manipulator without the knowledge of Its dynamics, because its handling with unknown workpiece may bring about overshoots and vibrations. Then it is necessary to adjust control gains according to the handling workpieces in order to achieve good control performances. The authors propose a new control strategy which uses adaptive observer and VSS (${\underline{V}}ariable$ ${\underline{S}}tructure$ ${\underline{S}}ystem$) controller to subdue these overshoots and vibrations. Some simulations of the proposed method are carried out for a grasping system to control the grasping force to various workpieces, whose dynamics cannot be known in advance.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.5
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• pp.177-184
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• 1986

An effective cartesian coordinate model is presented to control a robot motion along a prescribed timebased hand trajectory in cartesian coordinates and to provide an adaptive feedback design approach utilizing self-tuning control methods without requiring a detailed mathematical description of the system dynamics. Assuming that each of the hybrid variable set of velocities and forces at the cartesian coordinate level is mutually independent, the dynamic model for the cartesian coordinate control is reduced to first-order SISO models for each degree of freedom of robot hand, including a term to represent all unmodeled effects, by which the number of parameters to be identified is minimized. The self-tuners are designde to minimize a chosen performance criterion, and the computed control forces are resolved into applied joint torques by the Jacobian matrix. The robustness of the model and controller is demonstrated by comparing with the other catesian coordinate controllers.