• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.63.6-63
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• 2001

For robot navigation and visual reconstruction , structure from motion (SFM) is an active issue in computer vision community and its properties are also becoming well understood. As a drawback in SFM, it is well known that the SFM methods, using small motion model such as optical flow and direct method, have inevitably motion ambiguity between translation and rotation, which is called bas-relief ambiguity. In this paper based on the robust direct method using stereo image sequence, we present a new method for improving those ambiguities. Basically, the direct method uses nearly all image pixels for estimating motion parameters and depths, and global optimization techniques are adopted for finding its solution ...

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.97.6-97
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• 2002

In this paper, we present an arrayed flexible tactile sensor, which can detect contact normal forces as well as positions. The tactile sensor is developed using Polyvinylidene Fluoride (PVDF) that is known as piezoelectric polymer, and the surface electrode is fabricated using silk-screening technique with silver. We develop a charge amplifier in order to amplify the small signal from the sensor, and a fast signal processing unit by using a DSP chip. The developed tactile sensor is physically flexible and it can be deformed three-dimensionally to any shape so that it can be placed on anywhere on the curved surface. In the future, the developed sensor is applied to a dexterous robotic hand...$\textbullet$ Tactile sensing, PVDF, Robot hand

• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.327-335
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• 2000

The spent fuel rod extracting machine is automatically operated in high radioactive environment, so high reliability of operation is required. In this paper, to enhance the reliability of this machine by providing a close monitoring capability. a real time graphic simulation method is suggested. This method utilizes conventional IGRIP (Interactive Graphics Robot Instruction Program) 3D graphic simulation tool to visualize and simulate the 3D graphic model of this machine. Also, the dedicated protocol is defined for transmission of the operational data of the machine. The real time graphic simulation is realized by developing the socket module between a graphic workstation and a machine control computer through the TCP/IP network and by dividing the 3D graphic simulation GSL(Graphic Simulation Language) program as a small sized sub routine. The suggested method is implemented while automatically operating the rod extracting machine. The result of implementation shows that the real time 3D graphic simulation is well synchronized with the actual machine according to the operational data.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.3
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• pp.250-256
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• 2015

We present a novel method to model the body posture of a worm for vision-based automatic monitoring and analysis. The worm considered in this study is a Caenorhabditis elegans (C. elegans), which is popularly used for research in biological science and engineering. We model the posture by an open chain of a few curved or rigid line segments, in contrast to previously published approaches wherein a large number of small rigid elements are connected for the modeling. Each link segment is represented by only two parameters: an arc angle and an arc length for a curved segment, or an orientation angle and a link length for a straight line segment. Links in the proposed method can be readily related using the Denavit-Hartenberg convention due to similarities to the kinematics of an articulated manipulator. Our method was tested with real worm images, and accurate results were obtained.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.1
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• pp.64-70
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• 2008

Thanks to the breakthroughs in micro fabrication technology, numerous concepts of micro aerospace systems including micro aerial vehicle, nano satellite and micro robot have been proposed. In order to activate these mobile micro systems, high density power in a small scale power source is required. However, we still do not have micro power source that has energy density that can support these systems. In the present article, status of micro power sources are described and alternatives that have been derived from the past experience are proposed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.553-558
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• 1994

In this paper, we present a new approach for the automation of deburring process. An algorithm for teaching skills of a human expert to a robot manipulator is developed. This approach makes use of TSK fuzzy model that can express a highly nonlinear functional relation with small number of rules. Burr features such as height, width, area, cutting area are extracted from image processing by use of the vision system. Cutting depth, repeative number and normal cutting force are chosen as control signals representing actions of the human expert. It is verified that our processed fuzzy model can accurately express the skills of human experts for the deburring process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.469-470
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• 2006

Piezoelectric transformers based on lead zirconate titanate(PZT) have been received considerable interest because of their wide potential applications in transformer, oscillator, resonance sensor, actuator, acoustic transducer, as well as active slider for hard disk drives. However, for the applications which need a small power supply such as thin and flat displays, micro-robot, micro-system, it is especially necessary to integrate the passive components because they typically need more than 2/3 of the space of the conventional circuit. So, we have fabricated the piezoelectric micro-transformer to supply energy for micro-systems using PZT thin films and MEMS technologies.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.6
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• pp.602-608
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• 2014

Mixed-model production lines are often used in manufacturing systems. In production lines, different product types are simultaneously manufactured by processing small batches. This paper describes a new welding assembly technology involving the development of experimental models for a mixed-model production line in an automobile company. Due to the extensive number of models, the design of a welding assembly system is complicated. Performance evaluation is an important phase in the design of welding assembly lines in a mixed-model production environment. In this study, a new welding assembly technology for a mixed-model production method was used to weld the package tray and dash panel of a vehicle.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.1
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• pp.40-47
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• 2010

This paper presents a simultaneous localization and mapping (SLAM) of an indoor hallway environment using Rao-Blackwellized particle filter (RBPF) along with a line segment as a landmark. Based on the fact that fluent line features can be extracted around the ceiling and side walls of hallway using vision sensor, a horizontal line segment is extracted from an edge image using Hough transform and is also tracked continuously by an optical flow method. A successive observation of a line segment gives initial state of the line in 3D space. For data association, registered feature and observed feature are matched in image space through a degree of overlap, an orientation of line, and a distance between two lines. Experiments show that a compact environmental map can be constructed with small number of horizontal line features in real-time.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.139-142
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• 2004

As fiber reinforced composite materials are widely used in aircraft, space structures and robot arms, the study on the non-destructive testing methods of the composite materials has become an important research area for improving their reliability and safety. In this paper, the AE signal analyzer with the resonance circuit to extract the specified frequency of the acoustic emission signal were designed and fabricated. The noise levels of the fabricated AE signal analyzer by the disturbance such as impact or mechanical vibration had a very small value comparable to those of the conventional AE signal analyzer. Also, the crack detection capabilities of the fabricated AE signal analyzer under the static and dynamic tensile test were evaluated and compared with the conventional AE signal analyzer.