• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.57-62
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• 2003

This paper describes the design and simulation of a multivariable optimal control system for the combined speed, heading and depth control of a Semi-Autonomous Underwater Vehicle (SAUV) developed in Korea Ocean Research and Development Institute (KRODI). The SAUV is a test-bed for the evaluation of the navigation and manipulator technologies developed for a mine disposal vehicle (MDV) in military use and for a light working underwater vehicle in scientific use. The vehicle was designed to control its cruising speed, heading and depth with 4 horizontal thrusters installed at the rear of the hull. Therefore, the decoupled control methods are limited to apply to the SAUV because the thrust forces are highly coupled with the surging, yawing, and pitching motion of the vehicle. The multivariable Linear Quadratic (LQ) control method is chosen to control steering and diving in variable speed motion automatically. A series of simulation is carried out with fully nonlinear six degree of freedom dynamic model to validate the controller.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2921-2927
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• 2011

Modal Shift from road to rail has been adapted in several countries as one of effective ways of reducing $CO_2$ emissions caused by transport. Generally, effect analysis of $CO_2$ reduction toward modal shift is calculated mainly from use stage and less consideration from other stages of life cycle, even though, in some case of modal shift needs that new line construction or new vehicle manufacturing. In this study, modal shift effect analysis is performed with considering construction, manufacturing vehicle and use stage. As a result we can get total $CO_2$ reduction effect using life cycle thinking and check the necessity of including other life cycle stage not only considering use stage. In conclusion, there is no $CO_2$ reduction effect if the reduction amount of $CO_2$ in use stage is not bigger than allocated annual amount of $CO_2$ in construction and manufacturing vehicle stage. According to this fact, analysing $CO_2$ reduction effect of Modal Shift should be considered not only the use stage.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.487-490
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• 2003

In this research, we will devise an obstacle avoidance algorithm for a previously unmanned vehicle. Whole systems consist mainly of the vehicle system and the control system. The two systems are separated; this system can communicate with the vehicle system and the control system through wireless RF (Radio Frequency) modules. These modules use wireless communication. And the vehicle system is operated on PIC Micro Controller. Obstacle avoidance method for unmanned vehicle is based on the Virtual Force Field (VFF) method. An obstacle exerts repulsive forces and the lane center point applies an attractive force to the unmanned vehicle. A resultant force vector, comprising of the sum of a target directed attractive force and repulsive forces from an obstacle, is calculated for a given unmanned vehicle position. With resultant force acting on the unmanned vehicle, the vehicle's new driving direction is calculated, the vehicle makes steering adjustments, and this algorithm is repeated.

• 지식경영연구
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• 제23권1호
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• pp.111-131
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• 2022

모빌리티(mobility) 서비스는 정보통신기술(ICT)를 활용하여 이동 수단에 대한 수요자와 공급자를 연계시켜 주는 서비스로서, 현재의 교통시스템에서 사용자가 느끼는 불편을 감소시키고 환경적인 지속가능성 증대를 지향하는 서비스이다. 최근 그 사용이 점차 증가하고 있으며 학계 및 산업계의 관심이 커지고 있다. 본 연구는 국내 차량 모빌리티 서비스 이용의도 증가와 관련된 주요 영향요인들을 도출하고, 그 영향력에 대해 서비스 유형별(차량호출 vs. 차량공유 서비스) 그룹과 세대별(MZ세대 vs. X세대) 그룹 간 비교 분석을 실시하였다. 비교 연구 결과, 서비스 유형 그룹 간 사용자 혜택의 차이가 나타났고, 세대 그룹 간 사용자 혜택 및 모빌리티 플랫폼에 대한 태도의 차이가 나타났다. 이러한 비교 연구를 통해, 차량 모빌리티 서비스의 이용 세대별, 서비스 종류별로 이용의도 증가에 영향을 미치는 핵심적인 요인이 무엇이고 어떠한 차이점이 있는지를 검증하고, 주 이용자 타깃층과 서비스 종류에 따라 차량 모빌리티 서비스 활성화를 위해 지식 경영 측면에서 고려해야 할 주요 시사점을 제시하고자 한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.308-313
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• 2005

An urban railway vehicle has a characteristics such as that a lot of passenger use it and the major of passenger is standee. The ride comfort of standee is greatly influenced by the lateral dynamic characteristics of vehicle. So the lateral vibration is important factor for the improvement of ride comfort. In this study, vibration test of railway vehicle is carried out under the same condition of field driving to find out the major factor of vibration. By considering the test results under the various driving condition, the vibrational characteristics of vehicle is verified.

• Structural Monitoring and Maintenance
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• 제6권4호
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• pp.317-346
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• 2019

Performance assessment of pavements proves useful, in terms of handling the ride quality, controlling the travel time of vehicles and adequate maintenance of pavements. Roughness profiles provide a good measure of the deteriorating condition of the pavement. For the accurate estimates of pavement roughness from dynamic vehicle responses, vehicle parameters should be known accurately. Information on vehicle parameters is uncertain, due to the wear and tear over time. Hence, condition monitoring of pavement requires the identification of pavement roughness along with vehicle parameters. The present study proposes a scheme which estimates the roughness profile of the pavement with the use of accurate estimates of vehicle parameters computed in parallel. Pavement model used in this study is a two-layer Euler-Bernoulli beam resting on a nonlinear Pasternak foundation. The asphalt topping of the pavement in the top layer is modeled as viscoelastic, and the base course bottom layer is modeled as elastic. The viscoelastic response of the top layer is modeled with the help of the Burgers model. The vehicle model considered in this study is a half car model, fitted with accelerometers at specified points. The identification of the coupled system of vehicle-pavement interaction employs a coupled scheme of an unbiased minimum variance estimator and an optimization scheme. The partitioning of observed noisy quantities to be used in the two schemes is investigated in detail before the analysis. The unbiased minimum variance estimator (MVE) make use of a linear state-space formulation including roughness, to overcome the linearization difficulties as in conventional nonlinear filters. MVE gives estimates for the unknown input and fed into the optimization scheme to yield estimates of vehicle parameters. The issue of ill-posedness of the problem is dealt with by introducing a regularization equivalent term in the objective function, specifically where a large number of parameters are to be estimated. Effect of different objective functions is also studied. The outcome of this research is an overall measure of pavement condition.

• 한국컴퓨터정보학회논문지
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• 제21권3호
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• pp.9-15
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• 2016

In this paper, DC-PLC typed one-wire controller was designed and manufactured especially for In-vehicle safe devices. One-wire by DC-PLC scheme is to be used as a power supply and ground to process the sensor data and to operate the vehicle actuators. To avoid complicate wires, we use the conventional wires without installing extra communication lines. The data collected from the sensors are transmitted to the main controller, processed by programming, and run the actuators corresponding to the commands sending to vehicle control board. The proposed method shows that only One-wire without requiring several wires make In-vehicle control devices simple and reduce the damage due to the loss of the wiring.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.204-209
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• 2003

Recently, The TCN(Train Communication Network} as the distributed control systems for electric vehicles, which is the international standard of the intra vehicle communication, actively recognizes variations and supports reconfiguration of the train network when a vehicle is separated or recombined. The technique of reconfiguration to take variety and interoperability of a vehicle constitution is used when the vehicle constitution is changed. At the time, each node making up vehicle network shares the information about the variation of vehicle constitutions and the state of nodes. In the hierarchical TCN structure, an exchange of data becomes available as a work to transmit information between components is performed at the node playing a role of gateway. This paper proposes a protocol to transmit the information of the train reconfiguration. The protocol gives an application to renew a list for transmitting information and to perform the transmission that can guarantee periodic and non-periodic data transmission between nodes when the network nodes changed by a variation of the network state are reconfigured. If use this protocol, can use functions that are offered in the electric railcar at the same time that composition of vehicles is completed without delay. And when driver of the electric railcar inspect before running of vehicles, can confirm state of vehicles visually through monitor in driver's room.

• 전기전자학회논문지
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• 제23권1호
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• pp.235-241
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• 2019

본 논문에서는 농업 기계 시스템에서 사용하기 위한 딥러닝 알고리즘 기반의 프레임 내의 관심 영역 유사성을 이용한 새로운 후방 접근 차량 검출 알고리즘을 제안한다. 농업 기계 시스템은 후방에서 접근하는 차량만 검출해야 한다. 지나가는 자동차가 검출되면 혼란을 야기할 수 있다. 논문에서는 차량 검출을 위해 딥러닝에서 뛰어난 검출률을 나타내는 Faster R-CNN 모델을 사용하였다. 딥러닝은 뒤에서 접근하는 차량뿐만 아니라 지나가는 차량도 검출하므로 긍정오류 차량을 배제해야 한다. 본 논문에서 이를 해결하기 위해 검출된 프레임에서 관심 영역에 대한 유사성과 평균 에러를 피라미드 형태로 이용하여 접근하는 자동차만 검출하는 알고리즘을 제안하였다. 실험을 통하여 제안된 방법이 평균 98.8%의 높은 검출률을 나타내었다.

• 전자공학회논문지
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• 제51권9호
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• pp.208-214
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• 2014

차선유지 제어시스템, 적응식순항 제어시스템과 같은 첨단운전 지원시스템은 기본적으로 차량의 거동 정보를 기반으로 구동되지만, 최근 도로의 기하학적 정보를 추가적으로 활용하는 연구가 활발히 진행되고 있다. 특히, 도로의 종단경사는 차량의 가감속 제어 및 항법알고리즘 구현에 있어 필수적인 정보로서 DGPS-RTK와 같은 고가의 장비로 직접 측정하는 방법과 디지털 맵에 저장된 속성정보를 활용하는 방식이 제안되고 있으나, 상용화 관점에서는 아직 많은 문제점이 존재한다. 따라서, 본 논문에서는 추가 센서의 장착없이 연속형 확장칼만필터를 활용하여 차량의 동특성과 도로종단경사를 효율적으로 추정하는 알고리즘을 제안한다. 도로종단경사를 포함하는 3자유도 차량동역학 모델과 차량의 내부 네트워크롤 통해 수집할 수 있는 차량의 상태정보를 기반으로 확장칼만필터를 설계하여 차량의 동특성과 도로종단경사를 추정한다. 제안된 알고리즘은 시뮬레이션과 실차실험을 통해 그 성능을 검증하였다.