• 대한임베디드공학회논문지
• /
• 제10권5호
• /
• pp.325-333
• /
• 2015

Vision based night-time vehicle detection has been an emerging research field in various advanced driver assistance systems(ADAS) and automotive vehicle as well as automatic head-lamp control. In this paper, we propose night-time vehicle detection method based on multi-class support vector machine(SVM) that consists of thresholding, labeling, feature extraction, and multi-class SVM. Vehicle light candidate blobs are extracted by local mean based thresholding following by labeling process. Seven geometric and stochastic features are extracted from each candidate through the feature extraction step. Each candidate blob is classified into vehicle light or not by multi-class SVM. Four different multi-class SVM including one-against-all(OAA), one-against-one(OAO), top-down tree structured and bottom-up tree structured SVM classifiers are implemented and evaluated in terms of vehicle detection performances. Through the simulations tested on road video sequences, we prove that top-down tree structured and bottom-up tree structured SVM have relatively better performances than the others.

• 유공압시스템학회논문집
• /
• 제4권3호
• /
• pp.13-21
• /
• 2007

A forklift is a motive machine powered by LPG, diesel engine or electric motors. The internal combustion engine type forklift is equipped with automatic transmission to meet the required drive load as well as the easy operation of the vehicle. This paper deals with the shift control and endurance test controller which is developed for the functional test of the newly designed automatic transmission on a dynamometer test bench. Its major function is to control the proportional solenoid currents, which is directly related to clutch pressures, for the given reference current trajectory during shift and sequential operation of shift schedule designed for the durability test at each gear. It also has the ability to monitor all the necessary test data through RS232 communication and log them to disk files. The current controller of embedded system is designed from the identified dynamics of solenoid coil and the current reference can be easily modified with a user interface software on PC so as to match the shift data by experiments.

• Journal of Advanced Marine Engineering and Technology
• /
• 제33권8호
• /
• pp.1203-1211
• /
• 2009

무인잠수정의 동역학은 추진체의 동력학에 의해 큰 영향을 받는다. 무인잠수정의 호버링 또는 저속 상태의 움직임을 제어하는 것은 자동 도킹 혹은 잠수정의 매니퓰레이터의 제어에 있어서 매우 중요하다. 모터기반의 추진체 동역학은 비선형적이며 불확실한 매개변수를 가지고 있다. 결국, 추진기와 동적 커플링을 이루는 무인잠수정의 운동역학도 매우 비선형적이며 불확실한 매개변수를 가지고 있기 때문에 강인제어기가 무인잠수정의 모션제어에 있어서 효과적이라고 할 수 있다. 따라서 본 논문에서는 전기 추진체에 의해 추진되는 무인잠수정의 저속 또는 호버링 상태를 제어하기 위한 강인제어 기법을 보인다. 또한, 비선형성과 불확실한 매개변수가 결합된 무인잠수정의 상태도 강인제어를 이용하여 동시에 제어한다. 강인제어 방법 중에서 슬라이딩 모드 제어기를 설계하여 추진체와 무인잠수정의 불확실한 변수와 비선형성들을 보상하며 원하는 위치를 유지하는 제어방법을 제안하였다. 모의실험을 통하여 제안한 슬라이딩 모드 제어기는 선형제어기인 PD제어기 보다 성능이 우수함을 확인할 수 있었다.

• 한국정보통신학회논문지
• /
• 제14권9호
• /
• pp.1993-1998
• /
• 2010

본 연구에서는 모바일 텔레매틱스와 수송기계 텔레매틱스를 융합한 모바일차량 텔레매틱스 (Mobile In Vehicle: MIV) 를 이용하여 수송기계를 무선으로 제어하고 차량항법이 가능한 범용 통합 제어모듈을 개발하였다. 근거리에 있는 차량을 목적지까지 무인 제어가 가능하도록 제어모듈을 구현하고 이를 하드웨어 시뮬레이션을 통해 검증하였으며, 특히 무선 제어 기술을 위해 Wi-Fi, TCP/IP 및 3G 통신망에서 제어가 가능하도록 범용 통합제어 모듈로 설계되어 원거리에 있는 수송기계의 각종 정보를 수집하고 각종 편의기능 확인 및 제어가 가능하도록 하였다. 본 연구에서 개발된 수송기계 무선제어 기술은 현재까지 특정 통신망에서만 사용 가능한 단순 제어모듈과 다르게 다양한 통신망에서 사용이 가능하여 범용화를 이룬 효율적인 모듈로서 향후 다양한 수송기계 제어 편의기능 개발에 유용하게 적용이 가능할 것이다.

• 제어로봇시스템학회논문지
• /
• 제15권7호
• /
• pp.700-710
• /
• 2009

A computer vision technique of estimating the location of an unmanned ground vehicle is proposed. Identifying the location of the unmaned vehicle is very important task for automatic navigation of the vehicle. Conventional positioning sensors may fail to work properly in some real situations due to internal and external interferences. Given a DSM(Digital Surface Map), location of the vehicle can be estimated by the registration of the DSM and multiview range images obtained at the vehicle. Registration of the DSM and range images yields the 3D transformation from the coordinates of the range sensor to the reference coordinates of the DSM. To estimate the vehicle position, we first register a range image to the DSM coarsely and then refine the result. For coarse registration, we employ a fast random sample matching method. After the initial position is estimated and refined, all subsequent range images are registered by applying a pair-wise registration technique between range images. To reduce the accumulation error of pair-wise registration, we periodically refine the registration between range images and the DSM. Virtual environment is established to perform several experiments using a virtual vehicle. Range images are created based on the DSM by modeling a real 3D sensor. The vehicle moves along three different path while acquiring range images. Experimental results show that registration error is about under 1.3m in average.

• 산업경영시스템학회지
• /
• 제20권43호
• /
• pp.287-297
• /
• 1997

This research is concerned with operation control problem for an automated manufacturing system which consists of two machine centers and a single automatic guided vehicle. The objective is to develop and evaluate heuristic scheduling procedures that minimize maximum completion time to be included travel time of AGV. A new heuristic algorithm is proposed and a numerical example illustrates the proposed algorithm. The heuristic algorithm is implemented for various cases by SLAM II. The results show that the proposed algorithm provides better solutions than the previous algorithms.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 추계학술대회 논문집
• /
• pp.1163-1168
• /
• 2008

Automatic Train Protection(ATP) System is developed by ETCS(European Train Control System) CONSORTIUM for unify Europe railway system. ATP system is composed of Eurobalise and EuroATC. Nowadays, Korea construct ATP system in conventional line and new electrical locomotives also install ATP system. It is important to verify quality which form checklist during Factory Acceptance Test at beyond the seas. In this paper, review the process, test item, norm and checklist for the Balise Transmission Module, Compact Antenna Unit, Vehicle Control Unit and Communication Controller at the Plymouth Bombardier and Vasteras enics factory.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제8권3호
• /
• pp.243-251
• /
• 2016

Autonomous Underwater Vehicles (AUVs) generally work in complex marine environments. Any fault in AUVs may cause significant losses. Thus, system reliability and automatic fault diagnosis are important. To address the actuator failure of AUVs, a fault diagnosis method based on the Gaussian particle filter is proposed in this study. Six free-space motion equation mathematical models are established in accordance with the actuator configuration of AUVs. The value of the control (moment) loss parameter is adopted on the basis of these models to represent underwater vehicle malfunction, and an actuator failure model is established. An improved Gaussian particle filtering algorithm is proposed and is used to estimate the AUV failure model and motion state. Bayes algorithm is employed to perform robot fault detection. The sliding window method is adopted for fault magnitude estimation. The feasibility and validity of the proposed method are verified through simulation experiments and experimental data.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1994년도 추계학술대회 논문집
• /
• pp.472-477
• /
• 1994

The lockup clutch is embeded on torque converter of automatic transmission to prevent the efficiency deterioration of torque converter in high speed. For improving fuel consumption rate, it is desirable to engage the lockup clutch earlier. But, it results in degrading shift quality, due to the transient torque. The transient clutch pressure which affects the shifting quality, should be controlled properly. In this study, to solve the problem, it is analysed the hydraulic circuit of lockup system including line pressure regulating circuit, established the nonlinear model, and designed the PID controller. The line pressure is supplied to the lockup clutch through the lockup control valve by switching the lockup solenoid valve on. In order to control the transient pressure actively, it is needed to control the lockup solenoid valve by closed loop control. The lockup solenoid valve is 2-way on-off valve, and is adequate for PWM control. To reduce the pressure chattering, the carrier frequency is increased. Target pressure profile is computed from optimized velocity difference profile throuth dynamic equation of vehicle system.

• 한국해양공학회지
• /
• 제13권2호통권32호
• /
• pp.74-82
• /
• 1999

Nowadays, the crank shaft motor vehicle has become essential as the important component. The machining precision was asked for manufacturing the shaft. They could be unstable in the quality by the conventional are welding. Both in-process quailty control and high reliability of the weld are the major concerns in applying friction wlding to the economical and qualified mass-production. No reliable nondestructive monitoring method is avaliable at present to determine the real-time evaluation of automatic production quality control for bar-to-bar friction welding of the crank shaft of O.D 24mm for motor vehicle. This paper, so that, presents the experimental examinations and statistical quantitative analysis of the correlation between the cumulative counts of acoustic emission(AE) during plastic deformation periods of the welding and the tensile strength and other properties of the bar-to-bar welded joints of O.D. 24mm shaft as well as the various welding variables, as a new approach which attempts finally to develop real-time quality monitoring system for friction welding, resulting in practical possiblility of real-time quality control more than 100% joint efficiency showing good weld with no micro structural defects.