• Journal of Electrical Engineering and Technology
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• 제11권5호
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• pp.1116-1127
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• 2016

• 한국정밀공학회지
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• 제13권7호
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• pp.78-89
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• 1996

This paper discusses automation of a small-scale hydraulic shovel and its trajectory control. To move an end-effect (grinder) along a desired trajectory, the controller uses PID(proportional-integral- defferential) control and internal pressure of hydraulic cylinder. To apply PID control in the present hydraulic system, the system model is derived physically and its system parameters are obtained by actual measurement. To show the effectiveness of the PID controller and propriety of system model, the computer simulations and experiments are performed. These results of the simulations and experiments indicate that the PID trajectory control of robotic deburring by hydraulic shovel is very effective.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.331-332
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• 2007

In this paper we analyze whether recent Radio Frequence Identification technology can be used to improve the localization of mobile robot in their environment. This system make use of power control because Tag with Reader distance measurement. We are accurately the low at former time than the environment. A distance measurement is rather correct. This system used 900MHz Frequencies.

• 인터넷정보학회논문지
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• 제25권1호
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• pp.17-27
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• 2024

수산자원의 남획, 기후변화 및 어업종별 경쟁 조업 등으로 어업생산량은 지속적으로 감소하고 있다. 이러한 문제점을 개선하고자 개별어종에 대해 연간 어획량을 설정하여, 그 한도 내에서만 어획을 허용하는 수산자원 관리제도인 TAC(총허용어획량 제도)를 제정하였다. TAC 제도의 일환으로 육상 조사원이 위판장 어종의 체장, 체고를 측정하여 무게를 산출하여 TAC 소진량을 산출한다. 하지만 육상 조사원의 숙련도에 따라 취득 데이터의 정확도가 상이하고 노동 집약적 업무로 인해 지속가능 하지 못하다. 이러한 문제점을 개선하고자 본 논문에서는 물제와의 거리를 측정할 수 있는 스마트 패드의 카메라를 이용하여 TAC 관리 여덟 어종의 체장, 체고를 측정하고 무게를 산출하고 자동화하는 어종 인식 및 체장 측정 시스템을 제안하고자 한다. 이를 통해 현행 노동 집약적 업무의 스마트화와 데이터 누락을 최소화하여 TAC 제도 확립을 기대할 수 있다.

• Smart Structures and Systems
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• 제14권3호
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• pp.327-345
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• 2014

This paper presents a composite control strategy for the active suppression of vibration due to the unknown disturbances, such as external excitation, harmonic effects and control spillover, as well as high-frequency accelerometer measurement noise in the all-clamped stiffened plate. The proposed composite control action based on the modal approach, consists of two contributions including feedback part and feedforward part. The feedback part is the well-known PID controller, which is widely used to increase the structure damping and improve its dynamic performance close to the resonance frequencies. In order to get better performance for vibration suppression, the weight matrixes is optimized by chaos sequence. Then an improved disturbance observer (IDOB) as the feedforward compensation part is developed to enhance the vibration suppression performance of PID under various disturbances and uncertainties. The proposed IDOB can simultaneously estimate the various disturbances dynamically as well as measurement noise acting on the system and suppress them by feedforward compensation design. A rigorous analysis is also given to show why the IDOB can effectively suppress the unknown disturbances and measurement noise. In order to verify the proposed composite control algorithm (IDOB-PID), the dSPACE real-time simulation platform is used and an experimental platform for the all-clamped stiffened plate active vibration control system is set up. The experimental results demonstrate the effectiveness, practicality and strong anti-disturbances ability of the proposed control strategy.

• 한국정밀공학회지
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• 제12권6호
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• pp.72-79
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• 1995

The purpose of this paper is to develop an automatic measuring system based on the digital image processing which can be applied to the in-process measurment of the characteristics of the thin thickness. The derivative operators is used for edge detection in gray level image. This concept can be easily illustrated with the aid of object shows an image of a simple light object on a dark background, the gray level profile along a horizontal scan line of the image, and the first and second derivatives of the profile. The first derivative of an edge modeled in this manner is 0 in all regions of constant gray level, and assumes a constant value during a gray level transition. The experimental results indicate that the developed automatic inspection system can be applied in real situation.

• 한국산학기술학회논문지
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• 제19권3호
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• pp.624-629
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• 2018

본 논문은 NDIR(Non Dispersive Infra Red) 방식을 적용하여 $CO_2$ 및 $CH_4$의 두 가지 가스를 하나의 휴대용 장치에서 측정이 가능하도록 제작된 복합 가스 측정 장치에 대한 연구이다. 측정 장치의 구성은 적외선램프에서 적외선이 방출되면 방출된 파장이 광학창을 거치면서 흡수로 인하여 빛이 줄어들게 되고 이 감소량(흡수도)을 검출기에서 검출하고 이를 전기적 신호로 변환 증폭하여(3.5V~6V) 정확한 측정이 가능함을 보여준다. 기존의 Single Sensor 방식은 적외선에서 특수파장을 흡수하여 상대 측정량을 검출하는 방식으로 가스의 경우 $4.26{\mu}m$파장의 빛만을 검출하여 측정하는 방식으로 센서의 값을 보정할 수 있는 기준센서가 없어 오차가 발생하는 문제가 발생하였다. 본 연구에 적용된 Dual Sensor 방식은 다른 가스의 영향을 받지 않는 $3.91{\mu}m$의 기준치와 가스의 $4.26{\mu}m$의 두 파장을 검출하여 비교측정 함으로써 오차가 적어 신뢰도가 높은 방식으로, 휴대형으로 소형화하여 저 전력화가 가능하며, $CO_2$ 및 $CH_4$의 2가지 가스농도를 복합적으로 측정 할 수 있다는 특징이 있다. 측정 범위는 $CO_2$의 경우 0ppm~5,000ppm이고 $CH_4$의 경우는 0~5%의 부피 농도로 실내 공기량 1,000ppm을 측정 할 수 있도록 제작되어 휴대용이나 주택의 Home automation과 연동하여 소화연동이 가능함으로 화재예방에 매우 효과적일 것으로 확인하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.591-594
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• 2002

This paper presents a systematic method of probing channel characteristics and communication reliabilities of home power line communication network applied to the Internet accessed control of home appliances. The effects of the three performance deteriorating factors, i.e., additive noise, channel attenuation, and intersymbol interference, can be systematically measured by applying the channel probing waveform in the frequency range from 100㎑ to 450㎑. Probability of bit error is derived with the probed channel parameters of the signal attenuation, noise and signal-to-interference ratio read in the frequency domain. The agreement between the derived probability of bit ewer and the measured probability of bit error support the validity of the proposed approach of probing home power line channel characteristics. The experimental results performed with the constructed test-bed applying the Proposed channel probing method and the operation reliability measurement of the overall networked system also support the feasibility of commercially deploying the PLC modem installed home appliances and their services for the Internet accessed home automation in densely populated residential apartment complexes.

• 한국생산제조학회지
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• 제19권5호
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• pp.672-677
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• 2010

The goal of this study is to simplify the measurement process of the flat zone length produced by a flexible disk grinding system for the process automation. The image of workpiece in the grinding process is obtained, and the cutting speed and the feeding speed are controlled carefully to maximize the flat zone length. The gradient, the inflection point and the length of the line in the image are calculated, and the length is also measured by using a projector. Processing conditions and inversely proportional to flat zone length was changing. The flat zone length is estimated by Neural network algorithm considering the process conditions with the estimated error range as 0.06~3.61%, the Neural network algorithm for the grinding process estimation is found to be useful for building the process automation database.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권9호
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• pp.3635-3654
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• 2015

With the rapid development of smart devices and mobile Internet, the video application plays an increasingly important role on mobile devices. Understanding user behavior patterns is critical for optimized operation of mobile live streaming systems. On the other hand, volume based billing models on cloud services make it easier for video service providers to scale their services as well as to reduce the waste from oversized service capacities. In this paper, the watching behaviors of a commercial mobile live streaming system are studied in a content-centric manner. Our analysis captures the intrinsic correlation existing between popularity and watching intensity of programs due to the synchronized watching behaviors with program schedule. The watching pattern is further used to estimate traffic volume generated by the program, which is useful on data volume capacity reservation and billing strategy selection in cloud services. The traffic range of programs is estimated based on a naive popularity prediction. In cross validation, the traffic ranges of around 94% of programs are successfully estimated. In high popularity programs (>20000 viewers), the overestimated traffic is less than 15% of real happened traffic when using upper bound to estimate program traffic.