• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.32.6-32
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• 2001

This paper describes the steering control and geomagnetism cancellation for an autonomous mobile robotusing MR sensors. The magnetic-resistive (MR) sensor obtains the vector summation of the magnetic fields from embedded magnets and the Earth. The robot is controlled by the magnetic fields from embedded magnets. So, geomagnetism is the disturbance in the steering control system. In this paper, we propose a new method of the sensor arrangement in order to remove the geomagnetism and robotbody interference. The proposed method uses two MR sensors located in a level plane and the steering controller has been developed. The controller has three input variables (dBx, dBy, dBz) using the measured magnetic field difference, and an output variable (the steering angle) ...

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.245-251
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• 2005

선박의 자동조타기에는 반드시 방위정보가 필요하며, 방위정보를 제공하는 장비로는 자이로콤파스, 지자기 콤파스 및 GPS 콤파스가 있다. 자이로콤파스는 안정된 동작을 하지만 고가형이므로 주로 대형선박에서 사용되고 있으며, 중소형 선박에서는 저가형의 지자기콤파스 및 GPS 콤파스가 사용되고 있다. 본 연구에서는 지자기콤파스와 GPS 콤파스에서 각각의 단점을 보완하는 방식으로 안정된 방위정보를 제공하는 병행알고리즘의 전자콤파스를 구현하였다.

• 센서학회지
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• 제10권5호
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• pp.329-336
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• 2001

This paper describes the steering control and geomagnetism cancellation for an autonomous vehicle using an MR sensor. The magneto-resistive (MR) sensor obtains the vector summation of the magnetic fields from embedded magnets and the Earth. The vehicle is controlled by the magnetic fields from embedded magnets. So, geomagnetism is the disturbance in the steering control system. In this paper, we propose a new method of the sensor arrangement in order to remove the geomagnetism and vehicle body interference. The proposed method uses two MR sensors located in a level plane and the steering controller has been developed. The controller has three input variables ($dB_x$, $dB_y$, $dB_z$) using the measured magnetic field difference, and an output variable (the steering angle). A simulation program was developed to acquire the data to teach the neural network, in order to test the ability of a neural network to learn the steering control process. Also, the computer simulation of the vehicle (including vehicle dynamics and steering) was used to verify the steering performance of the vehicle controller using the neural network. From the simulation and field test, good result was obtained and we confirmed the robustness of the neural network controller in a real autonomous vehicle.

• 한국측량학회지
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• 제15권2호
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• pp.175-184
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• 1997

본 논문에서는 우리 나라 1등 지자기점에서 측정된 지자기 측량성과를 지자기에 대한 기초이론을 도입하여 정리·분석하였으며 지자기의 5성분(편각 D, 복각 I, 수평분력 H, 연직분력 Z, 전자력 F)에 대한 자장분포식을 결정하였다. 또한 결정된 자장분포식으로부터 우리 나라의 지구자장 분포상태를 규명하였으며, 이로부터 우리나라 국가기본도에 표시할 각 도곽별 편각 및 자오선 수차를 제시하였다.

• 센서학회지
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• 제16권1호
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• pp.17-23
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• 2007

This paper presents a miniaturized turn-counting sensor (TCS) where the geomagnetism and high-rpm rotation of ammunition are used to detect the turn number of ammunition for applications to small-caliber turn-counting fuzes. The TCS, composed of cores and a coil, has a robust structure with no moving part for increasing the shock survivability in the gunfire environments of ${\sim}30,000$ g's. The TCS is designed on the basis of the simulation results of an electromagnetic analysis tool, $Maxwell^{(R)}$3D. In experimental study, the static TCS test using a solenoid-coil apparatus and the dynamic TCS test (firing test) have been made. The presented TCS has shown that the induction voltage of $6.5{\;}mV_{P-P}$ is generated at the magnetic flux density of 0.05 mT and the rotational velocity of 30,000 rpm. From the measured signal, the TCS has shown the SNR of 44.0 dB, the nonlinearity of 0.59 % and the frequency-normalized sensitivity of $0.26{\pm}0.01{\;}V/T{\cdot}Hz$ in the temperature range of $-30{\sim}+43^{\circ}C$. Firing test has shown that the TCS can be used as a turn-counting sensor for small-caliber ammunition, verifying the shock survivability of TCS in high-g environments.

• 천문학논총
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• 제15권spc2호
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• pp.15-20
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• 2000

The geomagnetic measurements on the Korean Territory began in 1918 in the Incheon (Zinsen in Japanese pronunciation) Observatory of which the annual means of total magnetic field intensity, declination, and inclination still remain for 1918-1944. From 1970s, the National Geography Institute (NGI) and the Radio Research Laboratory (RRL) have tried independently to measure the geomagnetic field continuously. The RRL as the result of such efforts has installed 3 geomagnetic observatories, the first in Icheon and the second in Yongin in 1996, and the third in Jeju in 1997. From 1992, the Korea Institute of Geology, Mining and Materials (KIGAM) has tried also to measure the geomagnetism and as the result they have installed 2 geomagnetic observatories, one in Daejeon in 1998 and the other in Gyeongju in 2000. Nowadays, the RRL and the KIGAM collect the measured data into their own main computers by telecommunication in real time. The two institutions will cooperate in near future to link the two geomagnetic data bases so that the whole set of geomagnetic data measured on Korean Territory could be provided to the end users in Korea.

• Journal of Astronomy and Space Sciences
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• 제8권1호
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• pp.85-98
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• 1991

지구의 남극과 북극 주위를 저고도로 돌고 있는 소형 과학위성의 자세 조정을 위해 지구자기장을 이용하였다. 이것을 위해 소형 과학위성의 Telemetry 자료를 분석하였다. 위성에 장치된 3축 magnetometer에서 자기장 성분의 크기와 변동량을 측정하여 위성의 회전상태를 알아내는 방법이 제시되었다. 위성이 회전축에 대하여 대칭형인 경우 특정한 위치에서의 자세판단이 가능하다. 현재 자세와 원하는 자세를 비교했을 때 나타나는 차이를 각 축에 대한 회전속도의 조절로 제거할 수 있는 방법을 연구하였다. 여기에서는 자세 측정으로부터 얻은 자료를 가지고 magnetorquer에 공급되어야 할 전류의 크기(혹은 유지시간)를 계산하는 기본 알고리즘을 연구하였고 직접 프로그램으로 작성해서 수행시켜 보았다. 이러한 자세제어 방법은 위성이 초기 tumbling 운동을 할 때와 Gravity gradient boom에 의한 수동제어가 이루어진 후에 적용할 수 있다.

• 한국측량학회지
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• 제32권3호
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• pp.253-259
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• 2014

There has been a need for replacing human labors with a robot in such dangerous and hard jobs of various construction sites. For that reason, many researches have been made about the high quality robot, which performs its duty instead of human labors. This study is about auto surveying system development based on VRS-GPS which enables autodriving in dangerous areas where it's difficult for humans to measure directly. This study is about the auto-surveying system development, based on VRS-GPS, which enables auto-drive in dangerous areas, whereas difficult for humans to measure directly. The GPS is made with GRXI and SHC250 controllers of the SOKKIA company. The auto surveying system is composed of DPS module, geomagnetism sensor, bluetooth, gimbals, IMU, etc to automatic drive via enter into a route of position. The developed auto surveying system has installed the carmeras for front and vertical axis as well as systems to grasp situation of surveying with smartphone in real time. The result from analysed RMSE of auto surveying system and VRS-GPS surveying is 0.0169m of X-axis and 0.0246m of Y-axis.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.353-360
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• 2007

KIGAM has installed a FLARE+ continuous geomagnetic observation system in 1998 in Daejeon of which the IAGA identification code is DZN. The coordinates of the absolute measurement plinth precisely determined by the PDGPS(Post-Processing Differential Global Positioning System) is (127-21-37.19E, 36-22-43.96N, 45.93 m) in WGS84 for the horizontal and from the geoid surface for the vertical. Periodically we have conducted the absolute geomagnetic measurement on the plinth above. We have processed the continuous time-variation 3-axis geomagnetic data measured on arbitrary sensors' coordinates in the observatory and absolute geomagnetic data together to get as the results the time-variation H(orizontal), D(eclination), Z(vertical down), F(scalar calculated from 3 components) and P(Proton Precession Magnetometer Data). We have compared our own data with those calculated from the 10th generation IGRF(International Geomagnetic Reference Field). All the measured data in the DZN Observatory can be acquired through the website http://geomag.kigam.re.kr.

• 동굴
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• 제79호
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• pp.41-46
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• 2007

지구자기장의 성인에 대하여 고찰하고 기존 학설에 대한 신 모델을 제안하였다. 지자기 성인의 가장 유력한 이론적 모델은 열전류와 열화학적 전류에 의한 자기장 형성이다. 하지만, 이 모델은 매우 한정적 조건을 바탕으로 설명하고 있으며, 동시에 지자기의 분산과 세기의 상쇄 요인을 내포하고 있기 때문에 설득력이 저하된다. 그러나 본 제안의 가설에서 주장하는 이온층 전류에 의한 지자기의 성인은 그와 같은 분산 요인이 있을 수 없으며, 그 결과로 나타나는 지자기의 새기와 방향도 일정하게 형성됨이 해석 가능하기 때문에 타당성과 설득력이 높은 완벽한 이론이다. 따라서 이온층 전류에 의한 보다 안정적인 지자기성인의 전자기학적 신 모델을 제안한다.