• Smart Structures and Systems
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• v.11 no.6
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• pp.623-635
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• 2013

This paper investigates application of a control algorithm called model predictive sliding mode control (MPSMC) to active vibration suppression of a cantilevered aluminum beam. MPSMC is a relatively new control algorithm where model predictive control is employed to enhance sliding mode control by enforcing the system to reach the sliding surface in an optimal manner. In previous studies, it was shown that MPSMC can be applied to reduce hysteretic effects of piezoelectric actuators in dynamic displacement tracking applications. In the current study, a cantilevered beam with unknown mass distribution is selected as an experimental test bed in order to verify the robustness of MPSMC in active vibration control applications. Experimental results show that MPSMC can reduce vibration of an aluminum cantilevered beam at least by 29% regardless of modified mass distribution.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.7
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• pp.903-908
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• 1999

In this paper, it is proposed the phase shifter array active system to receive digital satellite broadcasting for vehicle. To receive satellite broadcasting data in vehicle, it is inevitable to have active antenna system, which traces the satellite in real time. Also if it is used in vehicle, it must be thin and light structure. To develop this type of antenna system, several techniques should be integrated properly. These are the design and manufacturing technique of high gain antenna, algorithm for tracking satellite and its manufacturing technique, controller design and manufacturing technique, system integration technique and so on. The validity of the proposed AVDBS system was confirmed by simulation and experimental results.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.4
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• pp.51-59
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• 2012

Recently, the study about object tracking using image processing has been active in the field of security and surveillance. Existing security and surveillance systems using multiple cameras have been operating independently. Thus, the chase was difficult when the tracking object move to other monitored areas. In this paper, we propose the way to change the control of camera automatically following the moving direction of objects in multiple cameras. The proposed method detects the object and tracks the object using color information and direction information of object. The color information obtains using the hue and the direction information obtains using the optical flow. At this time, the optical flow is detected for the entire image area of an object that is not applied only to reduce the computational complexity makes it possible to track in real time. In addition, it can be solved to inconvenience of security surveillance system to use existing camera by tracking an object automatically.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.9 s.339
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• pp.35-40
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• 2005

A digitally controlled phase-locked loop (DCPLL) is described. The DCPLL has basically the same structure as a conventional analog PLL except for a tracking analog-to-digital converter (ADC). The tracking ADC generates the control signal for voltage controlled oscillator. Since the DCPLL employs neither digitally controlled oscillator nor time-to-digital converter-the key building blocks of digital PLL (DPLL), there is no need for the 03de-off between jitter, power consumption and silicon area. The DCPLL was implemented in a $0.18\mu$m CMOS process and the active area is 1mm $\times$0.35 mm The DCPLL consumes S9mW during the normal opuation and $984\{mu}W$ during the power-down mode from a 1.8V supply. The DCPLL shows 16.8ps ms jitter.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.264-270
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• 2012

e-Training focusing on the experience and practice accelerates actual-active learning and enforces the learning effects against the existing theory based education. The most typical hans-on training system is augmented reality. Especially, in the training field installed augmented reality system, the automobile maintenance trainee experiences effective training with the immediate information, which is indicating the location of parts and the procedure of repairing. The tracking is the core technology of the augmented reality system. The performance of augmented reality system depends on the tracking technology. Therefore, this paper suggests the tracking technology which is proper to the e-Training augmented reality service technology for the car mechanics.

• Journal of The Geomorphological Association of Korea
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• v.25 no.3
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• pp.89-103
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• 2018

This study presents results of analysis on fault-related landforms and the Quaternary fluvial landforms, which are important evidences for active faulting by identifying surface deformation, around the Ulsan Fault Zone. In addition, this study suggests lineament map and inferred active fault-line map based on analyzing linearity and continuity of these landforms and by compiling location information of existing active faults. We convince that quantitative tectonic-geomorphological analysis are an effective method for active faults tracking, in particular, considering the conditions of relatively low seismicity and surface ruptured-events in the Korean Peninsula compared to plate boundary active areas. However, research on active fault in South Korea is just an infant stage since the 1990s and requires accumulation of research achievements on development and application of various fault analysis techniques, analysing and standardizing linear structures.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.464-467
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• 1995

Autonomous Mobile Robot(AMR) is a field of study which is under active research along with rapid development of the engineering technology. The main reasons for the high interest in AMR are because of its ability to change work space freely and its capability to replace human being for difficult and dangerous jobs. Also the fact that AMR provides a variety of research fields, such as path planning, navigation algorithm, sensor fusion, image processing, and controller design is part of the reason for its popularity. But relatively few researches are concerned with controller. So in this paper, a control strategy of mobile robot with nonholonomic constraint for tracking ordered discontinuous motion is proposed. The proposed control strategy has been designed as a state feedback shape to allow the AMR to obtain continuous velocity and track the path which is composed of discontinuous motions. In order to design such controller, 3 states have been reduced to 2 states through coordinate projection. These ideas are tested for validity through simulation and simulation result is compared with experiments result.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.1
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• pp.17-26
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• 2005

An optical phase tracking technique for an extrinsic Fabry-Perot interferometer (EFPI) is proposed in order to overcome interferometric non-linearity. Basic idea is utilizing strain-rate information, which cannot be easily obtained from an EFPI sensor itself. The proposed phase tracking system consists of a patch-type EFPI sensor and a simple on-line phase tracking logic. The patch-type EFPI sensor comprises an EFPI and a piezoelectric patch. An EFPI sensor itself has non-linear behavior due to the interferometric characteristics, and a piezoelectric material has hysteresis. However, the composed patch-type EFPI sensor system overcomes the problems that can arise when they are used individually. The dynamic characteristics of the proposed phase tracking system were investigated, and then the patch-type EFPI sensor system was applied to the active suppression of flutter, dynamic aeroelastic instability, of a swept-back composite plate structure. The proposed system has effectively reduced the amplitude of the flutter mode, and increased flutter speed.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.6
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• pp.608-614
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• 2008

This paper describes a location tracking system to guide landing process of an Unmanned Helicopter(UMH) exploiting MIT Cricket nodes. For automatic landing of a UMH, a precise positioning system is indispensable. However, GPS(Global Positioning System) is inadequate for tracking the three dimensional position of a UMH because of large positioning errors. The Cricket systems use Time-Difference-of-Arrival(TDoA) method with ultrasonic and RF(Radio Frequency) signals to measure distances. They operate in passive mode in that a listener attached to a moving device receives distance signals from several beacons located at fixed points on ground. Inevitably, this passive type of implementation causes large disturbances in measuring distances between beacons and the listener due to wind blow from propeller and turbulence of UMH body. To cope with this problem, we proposed active type of implementation for positioning a UMH. In this implementation, a beacon is set up at UMH body and four listeners are located at ground area at least where the UMH will land. A pair of Ultrasonic and RF signals from the beacon arrives at several listeners to calculate the position of the UMH. The distance signals among listeners are synchronized with a counter value appended to each distance signals from the beacon.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.456-463
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• 2004

Non-intrusive methods based on active remote IR illumination for eye tracking is important for many applications of vision-based man-machine interaction. One problem that has plagued those methods is their sensitivity to lighting condition change. This tends to significantly limit their scope of application. In this paper, we present a new real-time eye detection and tacking methodology that works under variable and realistic lighting conditions. Based on combining the bright-Pupil effect resulted from IR light and the conventional appearance-based object recognition technique, our method can robustly track eyes when the pupils ale not very bright due to significant external illumination interferences. The appearance model is incorporated in both eyes detection and tacking via the use of support vector machine and the mean shift tracking. Additional improvement is achieved from modifying the image acquisition apparatus including the illuminator and the camera.