• International Journal of Control, Automation, and Systems
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• v.4 no.2
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• pp.217-226
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• 2006

Grasping and manipulation by hands can be considered as one of inevitable functions to achieve the performances desired in humanoid operations. When a humanoid robot manipulates an object by his hands, each finger should be well-controlled to accomplish a precise manipulation of the object grasped. So, the trajectory of each joint required for a precise finger motion is fundamentally necessary to be planned stably. In this sense, this paper proposes an effective joint motion planning method for humanoid fingers. The proposed method newly employs a bio-mimetic concept for joint motion planning. A suitable model that describes an interphalangeal coordination in a human finger is suggested and incorporated into the proposed joint motion planning method. The feature of the proposed method is illustrated by simulation results. As a result, the proposed method is useful for a facilitative finger motion. It can be applied to improve the control performance of humanoid fingers or prosthetic fingers.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2486-2491
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• 2003

This paper presents a method to segment object ID marks on poor quality images under uncontrolled lighting conditions of FA inspection process. The method is based on multiple templates and normalized gray-level correlation (NGC) method. We propose a multiple template method, called as ATM (Active Template Model) which uses combinational relation of multiple templates from model templates to match and segment several characters of the inspection images. Conventional Snakes algorithm provides a good methodology to model the functional of ATM. To increase the computation speed to segment the ID mark regions, we introduce the Dynamic Programming based algorithm. Experimental results using images from real FA environment are presented.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.571-574
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• 2005

In this paper, we propose an efficient image segmentation technique for large-sized monochrome images using a hybrid approach which combines threshold and region-based techniques. First, an image is partitioned into fixed-size blocks and for each block the representative intensity is determined by averaging pixel intensities within the block. Next, the neighborhood blocks that have similar characteristics with respect to a specific threshold are merged in order to form candidate regions. Finally, those candidate regions are refined to get final target object regions by merging regions considering the spatial locality and certain criteria. We have performed experiments on images selected from various domains and showed that our technique was able to extract target object regions appropriately from most images.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.257-260
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• 2011

본 논문에서는 비디오 데이터로부터 물체의 초기 움직임 영역을 자동으로 검출하는 방법을 소개한다. 제안하는 시스템은 먼저 입력 영상을 받아들인 후 인접된 영상으로부터 일정 크기의 정방향의 블록 단위로 움직임을 나타내는 모션 벡터를 추출한다. 그리고 추출된 모션벡터를 아웃라이어를 제거하는 강건 예측 알고리즘에 적용하여 배경에 해당하는 모션벡터와 잡음 및 움직이는 물체에 해당하는 모션벡터를 구분한다. 그런 다음, 군집화 알고리즘을 적용하여 이동하는 물체를 나타내는 모션벡터를 군집화하고, 군집화된 모션벡터에 해당하는 영역의 크기가 일정 수치 값 이상일 때 움직이는 물체가 감지되었다고 판단한다. 본 논문의 실험에서는 제안된 물체의 움직임 감지 방법이 기존의 방법에 비해 성능이 보다 우수함을 보인다.

• Journal of Mechanical Science and Technology
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• v.14 no.7
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• pp.782-788
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• 2000

In this paper, we present a new approach to visual feedback control using image-based visual servoing with stereo vision. In order to control the position and orientation of a robot with respect to an object, a new technique is proposed using binocular stereo vision. The stereo vision enables us to calculate an exact image Jacobian not only around a desired location but also at other locations. The suggested technique can guide a robot manipulator to the desired location without providing a priori knowledge such as the relative distance to the desired location or the model of an object even when the initial positioning error is large. This paper describes a model of stereo vision and how to generate feedback commands. The performance of the proposed visual servoing system is illustrated by experimental results and compared with conventional control methods for an assembly robot.

• Journal of Engineering Education Research
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• v.5 no.2
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• pp.10-21
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• 2002

In the knowledge based society, the development of creative human resources is one of the core factors for securing a national competition power. Especially in the software industries, the development of human resources who can solve a problem creatively by applying object oriented programming technique which is a update Programming technology is required. In this paper, we designed a lecture plan and produced it into a course contents which could be run on a online learning system. The teaching focuses of the developed course are the development of problem solving ability and object oriented design and programming ability through Java.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.197-198
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• 2012

본 논문에서는 입력되는 스테레오 영상에서 3차원 깊이 정보를 이용하여 객체를 보다 정확하게 분리하는 알고리즘을 제안한다. 제안된 알고리즘은 먼저 촬영된 장면의 왼쪽과 오른쪽 영상으로부터 스테레오 정합 기법을 이용하여 영상의 각 화소에 대한 3차원의 깊이 정보를 추출한다. 그런 다음, 추출된 깊이 정보를 강인하게 이진화하여 배경 영역을 제외하고 전경에 해당하는 객체만을 분리한다. 성능평가를 위한 실험에서는 본 논문에서 제안된 방법을 여러 가지 영상에 적용하여 테스트를 해 보았으며, 제안된 방법이 기존의 2차원 기반의 객체 분리 방법에 비해 보다 강건하고 정확하게 객체를 분리함을 확인하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.10
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• pp.886-890
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• 2013

In this paper, a 3D coordinates acquisition method for a mechanical assembly is developed by using multiview X-ray images. The multi-view X-ray images of an object are obtained by a rotary table. From the rotation transformation, it is possible to obtain the 3D coordinates of corresponding edge points on multi-view X-ray images by triangulation. The edge detection algorithm in this paper is based on the attenuation characteristic of the X-ray. The 3D coordinates of the object points are represented on a graphic display, which is used for the inspection of a mechanical assembly.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1740-1743
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• 2002

This paper presents the basic concept of a Solid Freeform Fabrication System using a rapid prototyping procedure. The system can fabricate a ceramic model by laser cutting, accumulating, laminating and sintering of each slice. The system is mainly equipped with a laser apparatus, an x-y table, a material transfer system, and an electric oven. The system could fabricate a small object with smooth surface within comparatively short period of time. The system has also shown its effectiveness in terms of the direct application of the object without the secondary mechanical process. The fabricated sample could directly be applied and used to fairly wide practical areas.

• Journal of the Semiconductor & Display Technology
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• v.10 no.1
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• pp.83-89
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• 2011

In the case of the tracking system with an active camera, it is very difficult to guarantee real-time processing due to the attribute of vision system which handles large amounts of data at once and has time delay to process. The reliability of the processed result is also badly influenced by the slow sampling time and uncertainty caused by the image processing. In this paper, we figure out dynamic characteristics of pixels reflected on the image plane and derive the mathematical model of the vision tracking system which includes the actuating part and the image processing part. Based on this model, we find a controller that stabilizes the system and enhances the tracking performance to track a target rapidly. The centroid is used as the position index of moving object and the DC motor in the actuating part is controlled to keep the identified centroid at the center point of the image plane.