• 제목/요약/키워드: longitudinal distance

검색결과 267건 처리시간 0.035초

Extraction of Distance Information with Nonlinear Correlation of Photon-Counting Integral Imaging

  • Yeom, Seokwon
    • Journal of the Optical Society of Korea
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    • 제20권5호
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    • pp.579-585
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    • 2016
  • Integral imaging combined with photon-counting detection has been researched for three-dimensional information sensing under low-light-level conditions. This paper addresses the extraction of distance information with photon-counting integral imaging. The longitudinal distance to the object is obtained utilizing photon-counting elemental images. The pixel disparity is estimated by maximizing the nonlinear correlation of photocounts. The first- and second-order statistical properties of the nonlinear correlation are theoretically derived. In the experiments, these properties are verified by varying the mean number of photocounts in the scene. The average distance is compared to that from the intensity information, showing the robustness of the proposed system even at low photocounts.

Convergence rate of a test statistics observed by the longitudinal data with long memory

  • Kim, Yoon Tae;Park, Hyun Suk
    • Communications for Statistical Applications and Methods
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    • 제24권5호
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    • pp.481-492
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    • 2017
  • This paper investigates a convergence rate of a test statistics given by two scale sampling method based on $A\ddot{i}t$-Sahalia and Jacod (Annals of Statistics, 37, 184-222, 2009). This statistics tests for longitudinal data having the existence of long memory dependence driven by fractional Brownian motion with Hurst parameter $H{\in}(1/2,\;1)$. We obtain an upper bound in the Kolmogorov distance for normal approximation of this test statistic. As a main tool for our works, the recent results in Nourdin and Peccati (Probability Theory and Related Fields, 145, 75-118, 2009; Annals of Probability, 37, 2231-2261, 2009) will be used. These results are obtained by employing techniques based on the combination between Malliavin calculus and Stein's method for normal approximation.

관측자를 이용한 직진 주행 차량의 적응 제어 (Observer Based Adaptive Control of Longitudinal Motion of Vehicles)

  • 김응석;김동헌;양해원
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권3호
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    • pp.130-135
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    • 2001
  • In this paper, an observer-based adaptive controller is proposed to control the longitudinal motion of vehicles. The standard gradient method will be used to estimate the vehicle parameters, mass, time constant, etc. The nonlinear model between the driving force and the vehicle acceleration will be chosen to design the state observer for the vehicle velocity and acceleration. It will be shown that the proposed observer is exponentially stable, and that the adaptive controller proposed on this paper is stable. It will be proved that the errors of the relative distance, velocity and acceleration converge to zero asymptotically fast, and that the overall system is also asymptotically stable. The simulation results are presented to investigate the effectiveness of the proposed method.

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지능형 자율주행 제어 알고리즘 개발 및 시험차량 성능평가 (Development of an Intelligent Autonomous Control Algorithm and Test Vehicle Performance Verification)

  • 김원균;이경수
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.861-866
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    • 2007
  • 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)

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Iosipescu Shear Test를 이용한 고분자 복합재료의 종방향 전단계수 연구 (Effective Longitudinal Shear Modulus of Polymeric Composite Using Iosipescu Shear Test)

  • 정태헌;권용수;이유태;이동주
    • 한국산업융합학회 논문집
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    • 제3권1호
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    • pp.61-67
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    • 2000
  • Effective shear modulus of continuous fiber reinforced polymeric composites is measured using a modified Iosipescu Shear Test(IST) and compared with data obtained by finite element analyses that a concept of unit cell is. It is found that the numerical results of the longitudinal shear modulus give a good agreement with experimental data at lower fiber volume fraction. In this paper, both the distance and stress transfer between the fibers are discussed as the major factors.

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Sensitivity Enhancement of Methyl-TROSY by Longitudinal 1H Relaxation Optimization

  • Lee, Dong-Han;Vijayan, Vinesh;Montaville, Pierre;Becker, Stefan;Griesinger, Christian
    • 한국자기공명학회논문지
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    • 제13권1호
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    • pp.15-26
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    • 2009
  • The NMR detection of methyl groups is of keen interest because they provide the long-range distance information required to establish global folds of high molecular weight proteins. Using longitudinal $^1H$ relaxation optimization, we achieve a gain in sensitivity of approximately 1.6-fold in the methyl-TROSY and its NOESY experiments for the 38 kDa protein mitogen activated protein kinase p38 in its fully protonated and $^{13}C$ and $^{15}N$ labeled state.

직진 주행 차량의 강인 적응제어기 설계 (Design of Robust Adaptive Controllers for Longitudinal Motion of Vehicles)

  • 김동헌;김응석;김홍필;양해원
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.113-113
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    • 2000
  • A robust adaptive technique for the longitudinal control of a platoon of automated vehicles is presented. A nonlinear model is used to represent the vehicle dynamics of each vehicle within the platoon. The external disturbance such as wind gust and a disturbance term due to engine transmission variations and so on are considered. The state observer is used to avoid direct measurement of the relative velocity or acceleration between the controlled and leading vehicles or the controlled vehicle's acceleration. It is shown that platoon stability can be recovered in operation even if a speed dependent spacing policy is adopted, which incorporates a constant time headway in addition to the constant distance. The simulation results demonstrate excellent tracking even in the presence of disturbances.

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차량 집단 주행 시스템을 위한 임피던스 제어 (Impedance Control for a Vehicle Platoon System)

  • 이수영
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권6호
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    • pp.295-301
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    • 2001
  • In this paper, an impedance control using a serial chain of spring-damper system is proposed for a vehicle platoon. For safety of the vehicle platoon, it is required to regulated the distance between each vehicle at a preassigned value even in case of vehicle model error, or moise in the measurement signal. Since the spring-damper system is physically stable and widely used to represent the interaction with the uncertain environments, it is appropriate to the longitudinal control of the vehicle platoon. By considering the nonholonomic characteristics of the vehicle motion, the lateral control and the longitudinal control of the vehicle paltoon are unified in the proposed algorithm. Computer simulation is carried out to verify the robustness against the uncertainties such as the vehicle model error and the measurement noise.

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지능 직선주행 제어기 설계에 관한 연구 (A Study on the Intelligent Cruise Controller Design)

  • 이욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 B
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    • pp.666-668
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    • 1998
  • An adaptive nonlinear observer-based longitudinal control law for vehicles is presented in this paper. It is assumed that for vehicle i knows only the distance between vehicle i and the preceding vehicle, i-1. An adaptive nonlinear state observer for vehicle i is developed to estimate the velocity and acceleration of the preceding vehicle, i-1. The communication of the position, velocity, and acceleration information is not used in the proposed method. It will be shown by mathematical analysis that the longitudinal control of vehicle can be implemented without an communication of the informations. It will be proven that the observation errors of the nonlinear states converge to zero asymptotically. To show the effectiveness of the proposed method, the simulation results are presented for the longitudinal control of the vehicle.

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적응순향 제어(ACC) 차량의 제어 알고리즘 및 실시간 수치실험 프로그램 개발 (Development of Control Algorithm and Real Time Numerical Simulation Program for Adaptive Cruise Control Vehicles)

  • 원문철;강연준;강병배
    • 한국자동차공학회논문집
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    • 제7권7호
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    • pp.202-213
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    • 1999
  • Adaptive Cruise Control (ACC) is one of key features on intelligent Transportation System(ITS). In ACC, the steering is done by a driver, but the engine throttle valve and the brake are controlled electronically. The relative velocity and distance from the preceeding vehicle are measured by radars or image processing units and relevant vehicular spacing is maintained in ACC control systems. In this study, vehicle longitudinal dynamics are modeled to simulate vehicle longitudinal maneuver and to design longtitudinal controllers for ACC vehicles. The control algorithm is designed based on the modeled vehicle longitudinal dynamics using a non-linear sliding mode control method. To verity the performance of the control algorithm, a real time numerical simulation program is developed on a Silicon Graphics workstation using C-language . A real time graphic program is alos develpe and integrated with the numerical simulation program.

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