• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술대회 논문집 전문대학교육위원
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• pp.38-41
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• 2003

An Autonomous Mobile Robot(AMR) performs duty by sensing a recognized situation and controlling suitably. The existing algorithm has some advantages that it is possible to express the obstacle exactly and the robot is sensitive to the change of environment. However, this algorithm needs to control repeatedly according to the modelling and working environment that requires a great quantity of calculations. In this paper, We supplement shortcoming and designed direction algorithm of AMR using fuzzy controller. Fuzzy controller does not derive special quality spinning expression for system, and uses rules by value expressed by language. It is used extensively to non-linear, plant which mathematical modelling is difficult etc... Fuzzy control algorithm of AMR that is used by this research applies obstacle position, distance of obstacle, Progress direction of robot, speed of robot, Perception area of sensor, etc... by fuzzy control and decide steering angle of robot.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.166-171
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• 1989

In the view of the fact that mobile robot in nuclear facilities should be able to turn in narrow space, go over obstacles, and climb stairs for the inspection and maintenance, a robot, named as KAEROT, is developed. It adopts 2DWIS (2-Driving Wheels, 1-Steering) and has three planetary wheels that are composed of two star-like arms and three small wheels. The experiments were carried out in two locomotion methods; (1) by controlling the rear wheel speed as a function of steering angle, and (2) by using inclination and stair-detection sensor to control the position of planetary and small wheel. The developed robot moved on the floor with stability. Results from the experiment on the rectangular obstacle as well as the computer simulation showed a feasibility on the stairs.

• 한국군사과학기술학회지
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• 제12권5호
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• pp.636-643
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• 2009

NHC means that the velocity of the vehicle in the plane perpendicular to the forward direction is almost zero. The main error source of NHC is the mounting misalignment which is the difference between the body frame of a land vehicle and the sensor frame of an inertial measurement unit. This paper suggests new NHC algorithm that can reduce position errors by real-time estimation of mounting misalignment. Then NHC/ZUPT integrated land navigation system is designed and its performances are analyzed by simulations with van test data. Simulation results show that the proposed NHC/ZUPT land navigation system improves navigation accuracy regardless of misalignment angle and is very useful when SDINS operates stand-alone for land vehicle navigation with large mounting misalignment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.905-908
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• 1988

In recent, Kalman filter technique has been much used as one of technique for tracking of the moving target. But some problem are still remained to be resolved. For example, when Kalman filter technique is applied to nonlinear system, the technique is nonoptimal estimator. Therefore, extended Kalman filter is proposed to reduce modeling error for nonlinear system. In this study, an extended Kalman filter in Cartesian coordinates is described for moving target, when the radar sensor measures range, azimuth and elevation angle in polar coordinates. And an approximate gain computation algorithm is proposed. In this approach, Kalman gains are computed for three uncoupled filter and multiplied by a Jacobian transformation determined from the measured target position and orientation.

• 제어로봇시스템학회논문지
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• 제12권9호
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• pp.850-855
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• 2006

This is concerned with the development and design of automatic maneuvering system using Differential Global Positioning System(DGPS). To achievement of autonomous maneuvering controller for giant ship, first, we investigated automatic maneuvering controller using DGPS in motor car. The sensors are configured with DGPS and digital compass. We calculated velocity and steering angle of motor car based on sensor signal. To design the controller, we derived the bicycle model and developed critically damped controller. The critically damped controller can be tracing previously appointed position in the fastest time. We are used a laptop computer to realize and the control algorithm is programmed by visual basic software. The obtained experimental results from developed system show unmanned motor car is good tracing planed positions. Hence, the system is looking forward to use the autonomous maneuvering control fur giant ship.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.418-421
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• 2006

현재 국내 외에서 GIS(Gas Insulated Switchgear)용 광 CT(optical current transformer)가 활발히 연구 개발되고 있다. 이러한 광 CT는 전력선에 발생하는 자기장에 의해 레이저 빛의 파장 각도가 변하는 현상인 Faraday Effect를 기련 원리로 한 전류측정용 기기이다. 본 논문에서는 GIS용 광 CT 개발을 목적으로 한 기초적 연구로써 자기장이 발생하는 전력선에 장착되는 센서부가 도선을 중심으로 해서 어떻게 위치하느냐에 따른 광 CT의 출력신호를 측정하여 연구하였다.

• Journal of Power Electronics
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• 제11권3호
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• pp.285-293
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• 2011

This paper proposes two SRM driving systems using a variable dc-link voltage controlled by a single-phase inverter. Two SRM converter topologies of a half bridge type and a full bridge type are proposed according to the power circuits of an inverter. The phase current can be controlled by means of a PWM controller at the inverter, and the turn-on/off angle at the phase switches can be controlled by a position sensor at the converter in the drive system. The inverter acts as a peak-current limiter if the transient current exceeds its maximum value. SRMs using the proposed topologies maintain high efficiency due to energy regeneration after the turn-off of power switches. The operational modes of the proposed topologies are verified by simulation and experimental results.

• 한국지능시스템학회논문지
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• 제20권1호
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• pp.54-59
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• 2010

본 논문은 AGV(autonomous guided vehicle)의 센서융합을 통한 위치측정(localization)과 라인 트레킹(line tracking) 방법인 AGV의 유도 시스템(guidance system)에 관한 연구이다. 기존에 AGV는 유도 되어진 선만을 주행 가능한 시스템이었고, 그러한 유도 시스템에 대표적인 방법으로는 자기-자이로 유도(magnet-gyro guidance) 방식과 유선 유도(wire guidance) 방식이 있었다. 하지만 이들은 설치 및 유지보수에 대한 비용이 높고, 작업 환경의 변화에 따른 시스템의 변경이 어렵다는 단점이 있다. 이러한 문제점을 해결하기 위해, 본 논문에서는 레이저 내비게이션과 자이로, 엔코더를 함께 이용하여 외란에 강인하고 작업 환경 및 작업의 내용에 따른 주행 경로 변경이 유연한 위치측정 시스템을 구현하였다. 또한 유도선이 없는 레이저 내비게이션의 라인 트레킹을 위해서 프로그램 상에 가상의 유도선을 설정하고, 경유 노드를 생성하여 AGV와 노드 사이의 각도 차를 바탕으로 주행 제어기(driving controller)를 설계하였다. 실험은 직접 제작한 AGV를 이용하였으며, 동일한 작업공간에서 반복적으로 라인 트래킹 실험을 하였다. 실험 결과, 설정된 주행선의 경로와 실제 AGV 사이의 최대 오차가 49.93mm 이내였으며, 제안한 시스템이 AGV의 라인 트레킹에 효율적임을 확인할 수 있었다.

• 대한조선학회논문집
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• 제50권3호
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• pp.190-198
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• 2013

In order to predict acoustic pressure distributions by exterior incident wave at Cylindrical Hydrophone Array (CHA) sensor's positions, acoustic pressure analysis is performed by using beam tracing method. Beam tracing method is well-known of reliable pressure analysis methods at high-frequency range. When an acoustic noise source is located at the center of rectangular room, acoustic pressure analysis is performed by using both beam tracing method and Power Flow Boundary Element Method (PFBEM). By comparing with results of beam tracing method and those of PFBEM, the accuracy of beam tracing method is verified. We develop the CHA pressure analysis program by verified beam tracing method. The developed software is composed of model input, sensor array creator, analysis option, solver and post-processor. We can choose a model option of 2D or 3D. The sensor array generator is connected to a sonar which is composed of center position, bottom, top and angle between sensors. We also can choose an analysis option such as analysis frequency, beam number, reflect number, etc. The solver module calculates the ray paths, acoustic pressure and result of generating beams. We apply the program to 2D and 3D CHA models, and their results are reliable.

• 자연과학논문집
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• 제5권1호
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• pp.87-93
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• 1992

비구조적인 환경에서 평면패렛을 포크리프트로 로딩하거나 보조필드 재료운송시스템 로보트를 제안한다. 시스템은 패렛의 위치와 방향을 정의하고 패렛의 2개의 구멍의 위치를 결정하기 위해서 결합된 어쿠스틱과 비쥬얼 센싱 데이타를 사용한다. 그 결과 포크리프트를 패렛의 2개의 구멍에 접근하고 운송하기 위해서 패렛을 인게즈한다. 재료운송시스템의 복잡성을 줄이기 위해서 2차원 포라로이드 울트라소닉 센서와 2차원 압티컬 카메라 비쥬얼 센서데이타를 통합하는 시스템을 개발한다. 2개의 다른 소스에서 얻은 데이타는 서로서로 보완하고 재료운송 시스템로보트를 제어하기 위한 효율적인 알고리즘에 사용한다. 2개의 선형스켄닝으로 부터 얻은 레인지 데이타는 least-mean square 방법을 사용하여 패렛의 팬과 틸트각도를 결정하기 위해서 사용한다. 그리고 에지탐지와 Hough 트랜스폼기술을 사용하여 스윙각도와 패렛의 인게이지먼트 위치를 결정하기 위해서 비쥬얼 데이타를 사용한다. 팬과 틸트각도를 결정하기 위해서 발생하는 제안을 논의한다. 개발된 시스템은 하드웨어와 소프트웨어 구현하여 평가하고 실험적인 결과도 나타낸다.