지능형 자율주행 제어 알고리즘 개발 및 시험차량 성능평가

김원균,이경수 대한기계학회 2007 環境管理學會誌 Vol.2007 No.5

This paper presents development of a vehicle lateral and longitudinal control for autonomous driving control and test results obtained using an electric vehicle. Sliding control theory has been used to develop a vehicle speed and distance control algorithm. The longitudinal control algorithm that maintains safety and comfort of the vehicle consists of a cruise and STOP&GO control depending on traffic conditions. Desired steering angle is determined through the lateral position error and the yaw angle error based on preview optimal control. Motor control inputs have been directly derived from the sliding control law. The performance of the autonomous driving control which is integrated with a lateral and longitudinal control is investigated by computer simulations and driving test using an electric vehicle. Electric vehicle system consists of DC driving motor, an electric power steering system, main controller (Autobox)

원격탐사자료와 수치표고모형을 이용한 옥천대 남서경계부의 선구조 분석 연구

김원균,이윤수,원중선,민경덕,이영훈,Kim, Won Kyun,Lee, Youn Soo,Won, Joong-Sun,Min, Kyung Duck,Lee, Younghoon 대한자원환경지질학회 1997 자원환경지질 Vol.30 No.5

In order to examine the primary trends and characteristics of geological lineaments along the southwestern boundary of Okcheon zone, we carried out the analysis of geological lineament trends over six selected sub-areas using Landsat-5 TM images and digital elevation model. The trends of lineaments is determined by a minimum variance method, and the resulting geological lineament map can be obtained through generalized Hough transform. We have corrected look direction biases reduces the interpretability of remotely sensed image. An approach of histogram modification is also adopted to extract drainage pattern specifically in alluvial plains. The lineament extracting method adopted in this study is very effective to analyze geological lineaments, and that helps estimate geological trends associated various with the tectonic events. In six sub-areas, the general trends of lineaments are characterized NW, NNW, NS-NNE, and NE directions. NW trends in Cretaceous volcanic rocks and Jurassic granite areas may represent tension joints that developed by rejuvenated end of the Early Cretaceous left-lateral strike-slip motion along the Honam Shear Zone, while NE and NS-NNE trends correspond to fault directions which are parallel to the above Shear Zone. NE and NW trends in Granitic Gneiss are parallel to the direction of schitosity, and NS-NNE and NE trends are interpreted the lineation by compressive force which acted by right-lateral strike-slip fault from late Triassic to Jurassic. And in foliated Granite, NE and NNE trends are coincided with directions of ductile foliation and Honam Shear Zone, and NW-NNW trends may be interpreted direction of another compressional foliation (Triassic to Early Jurassic) or end of the Early Cretaceous tensional joints. We interpreted NS-NNE direction lineation is related with the rejuvenated Chugaryung Fault System.

디지털 통신 시스템에서 데이터-재순환 LMS 알고리즘을 이용한 신호 간섭 제어

김원균,나상동 한국통신학회 1999 韓國通信學會論文誌 Vol.24 No.9

본 논문에서, LMS 알고리즘의 수렴 속도를 향상시키기 위한 효율적인 신호간섭 제어기법을 제안한다. 수신 데이터를 재활용하여 심볼 시간 주기에 계수들을 곱함으로써 적응되는 제안된 알고리즘의 수렴특성이 수렴 속도의 향상을 이론적으로 증명하기 위해 분석한다. 스텝-크기 매개변수 $\mu$가 증가됨에 따라 알고리즘의 수렴 속도가 제어된다. 또한, 스텝-크기 매개변수 $\mu$의 증가는 실험적으로 계산된 학습 곡선에서 분산을 감소시키는 효과를 갖는다. 고유치 확산을 증가시킴에 따라 적응 등화기의 수렴속도를 천천히 제어하고 평균 자승 에러의 안정-상태 값을 증가시키는 효과를 나타내며 데이터-재사용 LMS 기술이 수렴속도를 (B+1)배만큼 증가시켜 필터 알고리즘에서 신호간섭제어의 우수성을 입증한다. In this paper, an efficient signal interference control technique to improve the convergence speed of LMS algorithm is introduced. The convergence characteristics of the proposed algorithm, whose coefficients are multiply adapted in a symbol time period by recycling the received data, are analyzed to prove theoretically the improvement of convergence speed. According as the step-size parameter $\mu$ is increased, the rate of convergence of the algorithm is controlled. Also, a increase in the step-size parameter $\mu$ has the effect of reducing the variation in the experimentally computed learning curve. Increasing the eigenvalue spread has the effect of controlling down the rate of convergence of the adaptive equalizer and also increasing the steady-state value of the mean squared error and also demonstrate the superiority of signal interference control to the filter algorithm increasing convergence speed by (B+1) times due to the data-recycling LMS technique.

포텐셜필드의 스텍트럼대비법을 이용한 의성소분지의 지구조 연구

김원균 대한자원환경지질학회 2000 자원환경지질 Vol.33 No.3

We use spectral correlation method to analyze gravity and magnetic anomalies of Euiseong Sub-basin for distribution of rock facies and gelogic structures. The analysis reveals distinct polarity between gravity and magnetic anomaly correlation ; intermediate to mafic intrusives, extrusives, and the Tertiary basin shows positive gravity (+G) and positive magnetic (+M) correlation. Granitic gneiss and felsic volcanics negative gravity 9-G) and negative magnetic (-M) correlation. The Palgongsan granite, felsic to mafic extrusives and Mesozoic granites are characterized by -G and + M correlation. +G and -M correlations in the sedimentary formations are interpreted by uplift of pre-Cretaceous basement rocks . The + G and + M correlation characteristics in northeastern part of Euiseong Sub-basin including the Tertiary sedimentary basin result from the uplift of crustal materials. Major axes of spectrally correlated amomalies have mostly NW-SE or NE-SW directions. The former is due to the intrusives along strike-slip faults, and the latter which is observed in sedimentary formations is related to geological structures of basement associated new insight into the boundary between Euiseong and Milyang Sub-basin.

항공자력의 Analytical 이상을 이용한 의송소분지의 지구조 연구

김원균 대한자원환경지질학회 2000 자원환경지질 Vol.33 No.3

The structure of Euiseong Sub-basin and boundary of sub-basins were examined by analytical aeromagentci anomaly data. Magnetic lineaments have trends of NE-SW, NWW-SEE and NEE-SWW. The NE-SW lineaments in the sedimentary formations and pre-Cretaceous basement are assoicated with the direction of expansion of basin and the lineaments in the volcanic rocks and intrusives indicate the direction of structural weakness ones such as fault, which were major gateways of igneous activities. Euiseong Subbasin is bounded by pre-existing Andong Fault, pre-Cretaceous basement in the west, NE-SW lineament from Jyungsan to Angang, and NW-SE lineament connecting southwestern boundary of Palgongsan Granite and Jeokje Fault. In particular , the NW-SE lineament , which caused upheavel of pre-Cretaceous rocks, on Jeokje Fault is inferred as a boundary between Euiseong and Milyang Sub-basins.

적응 등화기에서 데이터-재사용 LMS 알고리즘을 이용한 신호 간섭 제어

김원균,김동국,곽종서,나상동 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.2

적응 등화기에서 LMS 알고리즘의 수렴 속도를 개선하기 위한 데이터 재순환 버퍼 구조를 제안한다. 폐기된 수신 데이터를 재활용함으로서 심볼 시간 주기에 적응 등화기의 에러를 이용한 가중치 갱신을 통해 제안된 알고리즘의 수렴특성을 분석하여 수렴 속도가 향상됨을 보인다. 컴퓨터 시뮬레이션 결과를 통해 스텝-크기 매개변수 μ가 증가됨에 따라 알고리즘의 수렴 속도가 상응하게 감소하고 또한, 스텝 크기 매개변수 μ의 증가는 실험적으로 계산된 학습 곡선에서 평균 자승 에러를 감소시키는 효과를 갖는다. 고유치 확산을 감소시킴에 따라 적응 등화기의 수렴속도를 천천히 감소시키고 평균 자승 에러의 안정-상태 값을 증가시키는 효과를 나타낸다. 따라서, 제안된 데이터 재순환 버퍼를 이용한 LMS 알고리즘의 수렴 특성을 개선시키고 계산의 복잡도를 증가시키지 않으면서 수렴속도를 (B+1)배만큼 증가시킨다는 것을 보인다. 컴퓨터 시뮬레이션 결과는 최악의 스텝 크기 매개변수와 고유치 확산 영역에 따른 평균 자승 에러를 분석하고 필터 알고리즘에서 신호간섭제어가 우수함을 입증한다. Data-recycling buffer structure to improve the convergence speed of LMS algorithm in adaptive equalizer is proposed. The improvement of convergence speed is shown by analyzing convergence characteristics of the proposed algorithm through updating weight using the error of adaptive equalizer when coefficients are multiply adapted in a symbol time period. As the step-size parameter μ is increased, the rate of convergence of the algorithm is correspondingly decreased through computer simulation result. Also, increasing the step-size parameter μ has the effect of reducing the variation in the experimentally computed learning curve. Reducing the eigenvalue spread has the effect of slowing down the rate of convergence of the adaptive equalizer and also increasing the steady-state value of the average squared error. Accordingly, the analysis shows that convergence speed can increase by (B+1) times, where B is the number of recycled data, as improving of convergence characteristics using the data-recycling buffer and not increasing complex of computation. The results of the computer simulation demonstrate analyzing mean squared error in accordance with the worst step-size parameter and eigenvalue spread and the superiority of signal interference control in the filter algorithm.

ON-OFF 소스를 이용한 트래픽 모델링과 통계적 다중화의 성능분석 ( Traffic Modeling by using ON-OFF Source and Performance Analysis of Statistical Multiplexing )

김원균,이하철,이병섭 한국통신학회 1996 한국통신학회 학술대회논문집 Vol.15 No.3

MPEG-2에서 H.264로 변환하기 위한 고속 모드 결정 기법

김원균,박경준,유종민,정제창,Kim, Won-Kyun,Park, Kyung-Jun,You, Jong-Min,Jeong, Je-Chang 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.3C

본 논문에서는 MPEG-2로 부호화된 비디오 스트림에서 H.264부호화 표준으로 변환하기 위한 저 복잡도 모드 결정 기법을 제안한다. 제안하는 MPEG-2에서 H.264로의 트랜스코더는 MPEG-2 복호화부와 H.264 부호화부로 구성되어 있으며, MPEG-2 복호화부에서 얻을 수 있는 현재 매크로블록외 정보를 이용해서 H.264에서 I프레임과 P프레임의 매크로블록 모드를 적응적으로 선택함으로써 전체 트랜스코더의 복잡도를 감소시킨다. 제안하는 트랜스 코더를 시퀀스에 적용한 결과 주목할 만한 화질열화나 비트율의 증가 없이 $30\sim60%$정도 복잡도가 감소된 것으로 나타난다. In this paper, we present a efficient transcoding method from MPEG-2 to H.264. The proposed transcoder is the transcoding method for spatial domain which consists of MPEG-2 decoder part and H.264 encoding part. In transcoder, we can get useful information to estimate less probable modes from MPEG-2 decoder. Using this information, H.264 encoder chooses the macroblock mode of I-frame and P-frame adaptively to reduce the whole complexity of the transcoder. Our experimental result shows that the proposed algorithm can archive about $30\sim60%$ computational saving without significant degradation of visual quality and increasing of bit rate.

독도 및 그 주변 해산 중력 이상의 지구조적 해석

김원균,김창환,박찬홍,한현철,권문상,민경덕,김백수,최영섭 대한자원환경지질학회 2000 자원환경지질 Vol.33 No.6

Shipborne gravity data are analyzed to investigate crustal structure under Dok Island and its surrounding seamounts located in border of Ulleung Basin and Oki Bank in the East Sea. Relatively low free-air gravity anomaly compared with the volume of seamounts may be explainable by isostatic compensation. From 1 st to 3rd Dokdo Seamounts, the decrease of free-air and Bouguer gravity anomalies implies the different degree of isostatic compensation, crustal thickness or/and density contrast. 3-D gravity modelling shows that seamounts have the mirror roots for regional Airy isostatic compensation, and from Ulleung Basin to Oki Bank, Moho discontinuity deepens and the density of crust is decreases. The results infer that study area is transitional zone from thin oceanic to thick continental crust. The depth of Moho discontinuity is about 15∼16 km, which may be interpreted as an uplifting of Mantle to shallow depth comparing with other borders of the Ulleung Basin.

DRIVE CONTROL SYSTEM DESIGN FOR STABILITY AND MANEUVERABILITY OF A 6WD/6WS VEHICLE

김원균,J. Y. KANG,이경수 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.1

This paper describes a drive controller designed to improve the lateral vehicle stability and maneuverability of a 6-wheel drive / 6-wheel steering (6WD/6WS) vehicle. The drive controller consists of upper and lower level controllers. The upper level controller is based on sliding control theory and determines both front and middle steering angle, additional net yaw moment, and longitudinal net force according to the reference velocity and steering angle of a manual drive, remotely controlled, autonomous controller. The lower level controller takes the desired longitudinal net force, yaw moment, and tire force information as inputs and determines the additional front steering angle and distributed longitudinal tire force on each wheel. This controller is based on optimal distribution control and takes into consideration the friction circle related to the vertical tire force and friction coefficient acting on the road and tire. Distributed longitudinal/lateral tire forces are determined as proportion to the size of the friction circle according to changes in driving conditions. The response of the 6WD/6WS vehicle implemented with this drive controller has been evaluated via computer simulations conducted using the Matlab/Simulink dynamic model. Computer simulations of an open loop under turning conditions and a closed-loop driver model subjected to double lane change have been conducted to demonstrate the improved performance of the proposed drive controller over that of a conventional DYC.