• 한국항공우주학회지
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• 제32권6호
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• pp.134-141
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• 2004

최근 중 대형 산업품에 대한 비접촉식 3차원 정밀 측정 장비가 개발되고 있다. 이러한 장비 중 하나인 데오드라이트 측정 시스템이 항공우주산업에 널리 활용되고 있다. 본 논문에서는 데오드라이트 시스템을 이용하여 근역장에서의 RF 프로브에 대한 위성체 탑재 안테나의 레인지 얼라인먼트 측정 방법을 기술하였다. Ku-band 및 Ka-band 안테나의 레인지 얼라인먼트 측정 및 조정을 측정 정밀도 ${\pm}1mm$ 및 ${\pm}0.05^{\circ}$ 이내에서 성공적으로 수행하였다.

• 대한전자공학회논문지SD
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• 제40권11호
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• pp.19-28
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• 2003

CCOTDR (complementary correlation optical time domain reflectometer)의 dynamic range는 사용된 코드의 길이와 평균 횟수에 따라 증가한다. OTDR의 전체 측정 시간이 제한된 경우에는 코드 길이를 늘이게 되면 평균 횟수를 줄여야 한다. 이와 같은 관계 때문에 코드 길이가 일정 이상 증가하면 dynamic range의 증가 정도가 어느 이상 커지지 않는다. 본 논문에서는 전체 측정 시간이 제한된 경우에 단일 펄스를 사용한 측정 방법에서 1회 측정에 걸리는 시간과 코드를 사용한 측정 방법에서 1회 측정에 걸리는 시간을 비교하였다. 이를 바탕으로 코드를 길게 해서 dynamic range를 개선시기는 데에 한계가 있음을 보였고, 길이가 짧으면서 최대 dynamic range를 달성할 수 있는 코드 길이를 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.403-405
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• 1993

The ultrasonic sensor used in autonomous mobile robot and autonomous guided vehicle(A.G.V.) is not available for long range measurement. And as the performance of autonomous mobile robot and A.G.V. improves, the importance of the range sensor for long range measurement is increasing. In this paper, we introduce the range sensor for long range measurement using milimeter wave sensor and propose the structure of that system.

• 항공우주기술
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• 제3권1호
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• pp.117-125
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• 2004

최근 중ㆍ대형 산업품에 대한 비접촉식 3차원 정밀 측정 장비가 개발되고 있다. 이러한 장비 중 하나인 데오드라이트 측정 시스템이 항공우주산업에 널리 활용되고 있다. 본 논문에서는 데오드라이트 시스템을 이용하여 근역장에서의 RF 프로브에 대한 위성체 탑재 안테나의 레인지 얼라인먼트 측정 방법을 기술하였다. Ku-band 및 Ka-band 안테나의 레인지 얼라인먼트 측정 및 조정을 측정 정확도 ±1 mm 및 ±$0.05^{circ}$도 이내에서 성공적으로 수행하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2430-2432
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• 1998

Generally, in the best-known Pulse-type type and Frequency Modulated Continuous Wave(FM/CW)-type RF range measurement systems, the nearest measurable distance between antenna of system and targets is limited to several tens of meters. Moreover, in case of high-speed targets it is more difficult to measure the distance precisely. In this paper we design our own RF(X-band) range(up to 15 meters) measurement system usi code correlation for high- speed targets. It 0 the correlation value between transmitting receiving PN (Pseudo -Noise) codes. So we determine the distance between antenna of s and targets using this correlation value. We fabricated it using MIC techniques and experimental results show that the proposed syste fully qualified for a short range measurement syste

• 동력기계공학회지
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• 제19권2호
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• pp.27-32
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• 2015

This paper describes a distance measurement system with high accuracy that utilizes a stereo-based camera and a pan-tilt unit for automatically maintaining the positional relationship between a vessel and a target on the side of a facility at a close range. The measurement system offers an advantage in that it can measure the distance to a target while tracking it. In order to improve the ability to control the position of a vessel between it and a target while maintaining the distance especially at a close range, the accuracy of the measurement system has to be improved. The accuracy of the distance measured by our system is increased with revisions of the conclusively generated data of distance measurement. We verified the accuracy of our system from an experiment, which generated results that had an accuracy of 30 mm for distances in the range between 2-8 m.

• 수산해양기술연구
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• 제35권3호
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• pp.215-226
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• 1999

The experimented rangefinder consist of sets of V/A-Code GPS and sets of L1 C/A-code & carrier phase receivers connected by two spread spectrum radio modems in order to measure relative range and bearing between two ship antennas by real time, comparing and analyzing accuracy of both GPS receivers at the fix point on the land by means of executing zero baseline test by C/A code and by carrier phase as well as measuring distance range 5m, 10m, 15m between each other receivers. The results from the measurement of relative range and bearing are as follows as ;1. According to the results from zero baseline test, the average error by C/A-code receiver is less than 0.1m, which proves theories from published books but when each GPS receivers track different satellites, the range accuracy error becomes up to 100m by means of S/A. Because of this sudden wide range error, rangefinder is not appropriate at relative range measurement without additional modification of the algorism of the GPS receiver itself.2. According to relative range measurement by Carrier Phase and zero baseline test at static condition, the range error is less than 3.5cm in case that it passes more than 5 minutes after GPS sets can track simultaneously more than 6 satellites. Its main reason is understood that the phase center of antenna is bigger than geodetic antenna.3. When range measurement of two receivers from 5m, to 10m to 15m, the each range error is 0.340m, 0.190m, 0.011m and each standard variation is 0.0973m, 0.0884m, 0.0790m. The range error and standard variation are in inverse proportion to distance between two receivers. 4. L1 Carrier Phase GPS generally needs 5 minutes to fix and during this ambiguity search, the relative range and bearing angle is shown to be various.

• 대한한의학회지
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• 제38권1호
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• pp.56-71
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• 2017

Objectives: The purpose of this study was to review the article using an IMU(Inertial Measurement Unit) for measuring the cervical range of motion and to evaluate the feasibility of using an IMU for measuring the cervical range of motion. Method: Scopus was used to search for the articles relating to the inclusion criteria. Which is measuring the cervical range of motion using an IMU. A total of 15 articles were selected through discussion. Degree and the reliability of the cervical range of motion and the validity of the data within the articles were extracted. Results: The measurement of the cervical range of motion using an IMU were $92.25^{\circ}$ to $138.2^{\circ}$, $122.4^{\circ}$ to $154.9^{\circ}$, $73.75^{\circ}$ to $93.1^{\circ}$ on the sagittal plane, transverse plane, and coronal plane respectively. 38 of the 43 values showed good reliability. They were larger than 0.75. 5 of the 43 values showed reliability less than 0.75. They were measured by smart phone. 16 of the 21 values showed good validity. The remaining 5 were measured by smart phone. The lower reliability and validity of smart phone were related to the protocol. The IMU can measure the coupling motion and may be used in various situations. Conclusion: The IMU may become a gold standard for measuring the cervical range of motion. The IMU measured not only the cervical range of motion but also the coupling motion. Furthermore, IMU may be used in various situations. Therefore, IMU must be considered a valuable measurement device.

• 한국안전학회지
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• 제14권1호
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• pp.66-72
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• 1999

Local heating transportation pipe has sensor and return lines to detect water-leakage. There are impulse and resistance comparison measurement types for a water-leakage detection. The impulse type shows large detection error within a measurement range. Since the resistance comparison type can find a comparative accurate single water-leakage point in the measurement range of heating pipe, it has been used to detect water-leakages these days. However if the multi water-leakages are happened in the measurement range of transportation pipe. the resistance comparison type shows a detection error point by the parallel resistance between a detection sensor line and ground. But the detection error will be minimized by the divided transportation pipe loops. In this research, it suggests the design of remote controlled detection system which can divide a large pipe loop and a possible single water-leakage measurement process in each divided loops.

• 한국군사과학기술학회지
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• 제11권4호
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• pp.116-123
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• 2008

In this paper we study the performance of the measurement time-delay estimation of tightly-coupled GPS/INS(Global positioning system/Inertial Navigation system) system. Generally, the heading error estimation performance of loosely-coupled GPS/INS system using GPS's Navigation Solution is poor. In the case of tightly-coupled GPS/INS system using pseudo-range and pseudo-range rate, the heading error estimation performance is better. However, the time-delay error on the measurement(pseudo-range rate) make the heading error estimation performance degraded. So that, we propose the time-delay model on the measurement and compose the time-delay estimator. And we confirm that the heading error estimation performance in the case of measurement time-delay existence is similar with the case of no-delay by Monte-Carlo simulation.