• 센서학회지
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• 제20권5호
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• pp.329-335
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• 2011

We demonstrated that high-stability thermistors can be calibrated with an uncertainty less than 1 mK, if the error due to the heat conduction is minimized. We first investigated the effect of the self-heating of typical thermistor probes to see how accurate we need to determine the effect of self-heating. We, then, calibrated thermistors and fitted the results using various modeling equations. We found out that the heat conduction is an important factor in achieving the calibration uncertainty under 1 mK for thermistors when the diameter of the probe is as thick as 10 mm. Therefore, we controlled the room temperature within $0.5^{\circ}C$ to minimize the heat conduction error during the calibration. The calibration with an uncertainty below 1 mK was possible when the stabilization time for each calibration was long enough to obtain a good thermal equilibrium.

• Journal of Astronomy and Space Sciences
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• 제24권4호
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• pp.389-396
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• 2007

The Global Navigation Satellite System (GNSS) becomes more important and is applied to various systems. Recently, the Galileo navigation system is being developed in Europe. Also, other countries like China, Japan and India are developing the global/regional navigation satellite system. As various global/regional navigation satellite systems are used, the navigation ground system gets more important for using the navigation system reasonably and efficiently. According to this trend, the technology of GNSS Ground Station (GGS) is developing in many fields. The one of purposes for this study is to develop the high precision receiver for GNSS sensor station and to provide ground infrastructure for better performance services on navigation system. In this study, we consider the configuration of GNSS Ground Station and analyze function of Monitoring and Control subsystem which is a part of GNSS Ground Station. We propose Monitoring and Control subsystem which contains the navigation software for GNSS Ground System to monitor and control equipments in GNSS Ground Station, to spread the applied field of navigation system, and to provide improved navigation information to user.

• 전기학회논문지
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• 제59권6호
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• pp.1150-1158
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• 2010

In this paper, a new reliable portable activity monitoring device implemented with the buddhist-style bowing activity and walking step detection algorithm, is presented. In order to monitor the bowing and walking activities, miniaturized 3-axis accelerometer sensor with the sensitivity of 800 mV/g was used. After initial signal conditioning, vector magnitude of accelerometer signals was calculated. Syntactic peak detection method was used in order to feature points. All signal processing algorithms were implemented in ultra-low power microcontroller MSP430 with double precision floating point arithmetic. For evaluation, 19 young man($24.22\pm5.22$ yrs) and woman($22.28\pm2.72$ yrs) were involved. The accuracy of the proposed algorithms were 98.91 %($\pm0.011$) for walking step detection and 98.25 %($\pm0.023$) for buddhist-style bowing activity. Comparing to the commercialized pedometer accuracy, 87.1 %($\pm0.058$), the proposed walking step detection algorithms show more reliable accuracy.

• 한국생산제조학회지
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• 제8권1호
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• pp.74-80
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• 1999

Recently, manufacturing work has been transformed to small scale production form with various types to act up to user's expectation from mass production with a little items required in the past. Then FMS using NC type machinaries has been applied actively also in domestic manufacturing line to meet thus tendency, but there are many machining troubles occured during work process not be settled yet. Nowdays high efficiently has been required no less than high precision in grinding work for the improvement of productivity. In this study, to represent more advance FMS can be adapted to thus situation In-process type monitoring method using AE and Current sensors is suggested to investigate the machining condition in grinding process. As results form this experimental study, it is recognized well that grinding conditions and dressing point of in time cab be estimated effectively using monitoring method suggested. Furthermore, surface shape of grinding wheel on voluntary point of in time can be predicted indirectly through the observation and comparison of AE signal waveform obtained as performance of continuous dressing work.

• 한국산업정보학회논문지
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• 제19권3호
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• pp.49-56
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• 2014

툴 프리세터는 수치제어 공작기계용 공구의 테이퍼부를 기준으로 하여 날끝 치수를 사전에 정렬하기 위한 장치로서 여기에는 접촉과 비접촉, 두 가지 방식이 있다. 광학센서 기반 비접촉 방식은 측정의 유연성과 편리함의 이점을 가지고 있다. 본 논문에서는 선형 스케일러와 머신 비전을 도입한 산업용 툴 프리세터 장비 개발을 다룬다. 측정 전에 대상 공구를 기구부에 고정시키고 광학부를 정렬한다. 공구 영상을 취득한 후 제시된 영상처리 알고리즘은선형 스케일러로부터 광학부의 이동 거리를 조합하여 공구의 정밀한 치수를 계산해낸다. 실험 결과, 본 장비의 정밀도가 ${\pm}20um$ 범위내에 있음을 검증하였다.

• 조명전기설비학회논문지
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• 제21권3호
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• pp.11-17
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• 2007

고제철설비 같은 매우 가혹한 환경 조건에서 뜨거운 철판의 온도를 측정하는 적외선 온도측정시스템을 개발하였다. POSCO 광양제철소 철판 압연공정에서 3개원간의 현장 테스트를 수행하였다. 현장 시운전에서 개발된 시스템의 신뢰성을 확인하였다. A2TPMI 센서의 비선형 방정식을 풀기위해 커브핏 방법을 통해 보정하고, 각 레인지당 $1[^{\circ}C]$이하의 정밀도로 25[msec]처리 속도를 확보하였다. 실험에서는 POSCO에서 받은 시험성적과 USN 기반에서 폴링방식을 통한 트래픽 모니터링을 통해 효과적인 온도감시 시스템임을 확인하였다.

• 로봇학회논문지
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• 제15권1호
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• pp.39-47
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• 2020

This paper presents a control and operation system for a remotely operated vehicle (ROV). The ROV used in the study was equipped with a manipulator and is being developed for underwater exploration and autonomous underwater working. Precision position and attitude control ability is essential for underwater operation using a manipulator. For propulsion, the ROV is equipped with eight thrusters, the number of those are more than six degrees-of-freedom. Four of them are in charge of surge, sway, and yaw motion, and the other four are responsible for heave, roll, and pitch motion. Therefore, it is more efficient to integrate the management of the thrusters rather than control them individually. In this paper, a thrust allocation method for thruster management is presented, and the design of a feedback controller using sensor data is described. The software for the ROV operation consists of a robot operating system that can efficiently process data between multiple hardware platforms. Through experimental analysis, the validity of the control system performance was verified.

• International Journal of Internet, Broadcasting and Communication
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• 제7권2호
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• pp.73-78
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• 2015

Touch panel is mainly applied to pressure type touch panel but it occur a low recognition rate and error during long-term use. So, it is partly applied to capacitive touch panel to compensate for these problems but it also can occur a same problems via pollutions. Touch technology has developed a various method but it is not used because of high costs and difficult installation process. So, in this paper, we proposed an input method of touchless panel using IrDA matrix. This method is conducted using an IrDA Matrix composed of depth sensor. It is possible to offer a various contents for multi user. The proposed technology need a development of a high sensitivity sensing method and high-speed processing method of position information for Seamless operation control. And, it is required high-precision drive technology. Also, we proposed a Seamless user recognition for interactive contents service through a touchless panel using IrDA matrix.

• 전자공학회논문지T
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• 제36T권4호
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• pp.88-93
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• 1999

본 논문에서는 한방의료에서 인체 전신의 상태를 파악하는데 주요한 요소인 맥파를 과학적으로 관찰하고자 스트레인 게이지를 이용하여 맥파를 검출하는 새로운 시스템을 구성하였다. 스트레인 게이지는 센서의 변형에 대해 선형적으로 고유한 저항값이 변화되므로 손목에서 맥의 변화는 스트레인 게이지를 이용하여 맥파의 파형으로 검출할 수 있다. 맥파 검출 시스템의 구성에서 스트레인 게이지로부터 발생된 저항변화값을 검출하기 위해 정밀 브리지회로와 고감도 증폭회로를 설계, 제작하였으며 이 시스템으로 미세한 맥의 변화를 상응하는 전압파형으로 출력시킨다. 구성된 시스템을 이용하여 6인의 맥을 직접 검출하고 시간영역과 주파수 영역에서 맥의 특성을 관찰하므로써 본 연구에서 구성된 맥파 검출 시스템의 과학적인 효용성을 입증하였다.

• Journal of Positioning, Navigation, and Timing
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• 제7권3호
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• pp.165-173
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• 2018

Underwater vehicles use Inertial Navigation System (INS) with high-performance Inertial Measurement Unit (IMU) for high precision navigation. However, when underwater navigation is performed for a long time, the INS error gradually diverges, therefore, an integrated navigation method using auxiliary sensors is used to solve this problem. In terms of underwater vehicles, the vertical axis error is primarily compensated through Vertical Channel Damping (VCD) using a depth gauge, and an integrated navigation filter can be designed to perform horizontal axis error and sensor error correction using a speedometer such as Electromagnetic-Log (EM-Log). However, since EM-Log outputs the forward direction relative speed of the vehicle with respect to the sea and sea current, INS correction filter using this may cause a rather large error. Although it is possible to design proper filters if the exact model of the sea current is known, it is impossible to know the accurate model in reality. Therefore, this study proposes an INS/EM-Log integrated navigation filter with the function to estimate sea current using an Interacting Multiple Model (IMM) filters, and the performance of this filter is analyzed through a simulation performed in various environments.