• 제어로봇시스템학회논문지
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• 제6권7호
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• pp.586-593
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• 2000

In this paper we propose a new approach to the autonomous wall-following of wheeled mobile robots using hybrid system reference motion synthesis and generation. The hybrid system approach is in-troduced to the motion control of nonholonomic mobile robots for the indoor navigation problems. In the dis-crete event system the discrete states are defined by the user-defined constraints and the reference mo-tion commands are specified in the abstracted motions. The hybrid control system applied for the non-holonomic mobile robots can combine the motion planning and autonomous navigation with obstacle avoid-ance for the indoor navigation problem. Simulation results show that hybrid system approach is an effective method for the autonomous navigation in indoor environments.

• 한국지능시스템학회논문지
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• 제23권1호
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• pp.18-23
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• 2013

In this paper we propose an image enhancement technique based on histogram specification method over local overlapping regions referred as Local Histogram Specification. First, both reference and original images are splitted into local regions that each overlaps half of its adjacent regions and general histogram specification method is used between corresponding local regions of reference and original image. However it produces noticeable boundary effects. Linear weighted image blending method is used to reduce this effect in order to make seamless image and we also proposed new technique dealing with over-enhanced contrast areas. We satisfied with our experimental results that showed better enhancement accuracy and less noise amplifications compared to other well-known image enhancement methods. We conclude that the proposed method is well suited for motion detection systems as a responsible part to overcome sudden illumination changes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.387-392
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• 1992

This paper presents a local trajectory generation method which is based on a sequence of reference posture-velocities and the efficient low level control algorithm which constructs the complete smooth curve from the trajectory specification. The reference trajectory generator(RTG) which is in between the local path planner(LPP) and the robot motion controller(RMC) generates a sequence of set-points for each path segments from the LPP and pass it to the RMC. The RMC controls the motions of vehicle which should follow the sequence. In the feedback controller of VMC, the method which compensates robot posture-velocity error correctly is used. These methods are implemented on indoor autonomous vehicle, 'ALIVE' mobile robot. The ALIVE mobile robot system is implemented on the 32bit VME bus system: the two VME CPU's are used for RTG and RMC, while the 80C196KC-based VME board is used for motor controller.

• 제어로봇시스템학회논문지
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• 제7권9호
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• pp.774-782
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• 2001

In this paper, we propose a new approach to the autonomous and high-speed indoor navigation of wheeled mobile robots using hybrid system controller. The hierarchical structure of hybrid system presented consists of high-level reasoning process and the low-level motion control process and the environmental interaction. In a discrete event system, the discrete states are defined by the user-defined constraints and the reference motion commands are specified in the abstracted motions. The hybrid control system applied for the nonholonomic mobile robots can combine the motion planning and autonomous navigation with obstacle avoidance in the indoor navigation problem. For the evaluation of the proposed algorithm, the algorithm is implemented to the two-wheel driven mobile robot system. The experimental results show that the hybrid system approach is an effective method for the autonomous navigation in indoor environments.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.210-218
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• 1998

The ATO(Automatic Train Operation) System is used for train operation instead of drivers. It is interfaced with TCMS(Train Control and Monitoring System) and ATC/TWC system in the train and wayside facilities. In this paper describes configuration of ATO, specification of ATO hardware, construction of ATO software and the algorithm fur automatic train speed regulation in the carborn ATO system. ATO Application Software is consist of ART, SPR, REG, SRV and PSM tasks. ART task is main control part of the ATO that determine ATO control, ATO mode, state transition. SPR determine speed reference according to train motion status, track data, train data and restricted train speed. REG task regulated train speed form the starting of one station to the precision stop at the other station under the result of ART and SPR tasks. In this paper, a algorithm for the train speed regulation while running is described.

• 해양환경안전학회지
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• 제19권6호
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• pp.666-673
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• 2013

본 연구는 빠른 운항 속도와 짧은 운용 시간을 요구하는 임무에 활용될 저가 소형 자율 무인잠수정에 고가 대형 관성 측정 장치를 대신하여 사용할 수 있는 저가 소형 자세 측정 장치 개발 및 성능 검증을 수행하였다. 저가 소형 자세 측정 장치 개발을 위해서 MEMS 기술을 적용한 gyro, accelerometer 및 magnetometer 채택하여 MEMS 기반 하드웨어를 제작하였으며, 좌표 변환 공식과 칼만 필터를 적용하여 자세 계산 알고리즘을 구현하였다. 또한 개발된 MEMS 기반 자세 측정 장치에 대한 기본 성능 검증을 위한 지자기센서 검증 시험, 정적 자세 시험, 차량 시험, 운동 모사 장치 시험을 수행하였으며, 각각 시험 결과를 제시하였다. 지자기센서 검증 시험 결과 외부 자기장 보정을 통하면 개발된 MEMS 기반 자세 측정 장치의 측정 결과가 외부 자기장에 강인함을 확인하였으며, 정적 자세 시험 및 차량 시험을 통하여 자세 변화가 크지 않는 환경에서 자세 측정 오차가 $0.5^{\circ}/hr$ 임을 확인하였다. 운동 모사 장치 시험을 통하여 5분 내외 자세 변화가 큰 운동 중에도 자세 측정 오차가 발산하지 않고 $1^{\circ}/hr$ 이내임을 확인하였다. 상기 시험 결과로부터 개발된 MEMS 기반 자세 측정 장치가 목표 성능인 $1^{\circ}/hr$이내 roll, pitch, yaw 오차를 보여주고 있음 확인하였으며, 이로부터 20분 내외 운용 시간 동안 정확한 자세 정보 제공 가능성을 확인할 수 있었다.