• Journal of Institute of Control, Robotics and Systems
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• v.15 no.1
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• pp.105-110
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• 2009

In this paper, we proposed a navigation algorithm of the mobile robot for obstacle avoidance using a circular path planning method. The proposed method makes circular paths in order to avoid obstacles in the front side of the mobile robot. An optimal path for approaching to the target is selected and the linear and angular speeds for stable moving of the mobile robot are controlled. Obstacles are detected by image processing which reduce image data obtained from a web camera. Performance of the proposed algorithm is shown by experiments with application to the Pioneer-2DX mobile robot.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.550-552
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• 1998

스포츠 비디오는 역동적인 특성과 비정형적인 구조를 가지고 있으므로 뉴스와 같은 정형적인 비디오와는 달리 분석이 쉽지 않다. 본 논문에서는 이러한 어려움을 극복하기 위하여 축구 경기에서 하이라이트를 추출하여 색인하고 이에 대하여 선수 위치 추적, 파노라마 영상 구성, 경기장 모델 상에서의 선수 이동 궤적 도시 등을 수행하는 방법을 제안한다. 이를 위하여 제한된 색상의 HSV 영상을 구성하여 골대와 선수 위치를 추적하고, 움직임 벡터를 추출하여 카메라 동작을 분석하였으며 경기장 모델 구성을 위해 경기장 내의 특징점을 추출하여 투영 변환을 수행하였다. 실험 결과를 통해서 제안된 방법이 축구 경기 비디오 분석에 효율적으로 이용될 수 있음을 확인할 수 있다.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.212-223
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• 1995

To improve the efficiency of a power transmission system with slip elements, power split/circulation system is applied. The performance of a power split/circulation system varies widely by the change of the followings; the layout of system, the type and gear ratio of planetary gear, the performance of slip element, etc. Therefore, when one designs such a power transmission system or when one determines the economic/power mode of system, a certain performance prediction method is needed. In this study, the internal power flow pattern of a power split/circulation system is theoretically analyzed on several transmission systems. And an effective performance prediction method(so called performance locus diagram) is presented. By this method, the effects of design factors can be easily understood and the qualitative performances of system can be clearly evaluated.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.9
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• pp.845-853
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• 2012

We propose time-optimal cornering motion trajectory planning and control algorithms for differential wheeled mobile robot with motor actuating voltage constraint, under piecewise constant control input condition. For time-optimal cornering trajectory generation, 1) we considered mobile robot's dynamics including actuator motors, 2) divided the cornering trajectory into one liner section, followed by two cornering section with angular acceleration and deceleration, and finally one liner section, and 3) formulated an efficient trajectory generation algorithm satisfying the bang-bang control principle. Also we proposed an efficient trajectory control algorithm and implemented with an X-bot to prove the performance.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.3
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• pp.98-102
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• 2011

This paper proposes a method of a touch-based remote control and sensor information acquisition of a mobile robot using a smart phone. An application in a smart phone processes the acquired sensor information and conducts autonomous navigation. By touching the screen of the smart phone, a series of points obtained from designated curve traces are analyzed and provide control of a robot. This study develops a mobile application that acquires and handles data from a mobile robot and sends appropriate action commands through remote control using Bluetooth communication with a smart phone. The utility and performance of the proposed control scheme have been successfully verified through experimental tasks using an actual smart phone and a mobile robot.

• Journal of Digital Convergence
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• v.3 no.1
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• pp.149-163
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• 2005

Researches for NN(nearest neighbor) query which is often used in LBS system, have been worked. However. Conventional NN query processing techniques are usually meaningless in moving object management system for LBS since their results may be invalidated as soon as the query and data objects move. To solve these problems, in this paper we propose a new nearest neighbor query processing technique, called CTNN, which is possible to meet continuous trajectory nearest neighbor query processing. The proposed technique consists of Approximate CTNN technique which has quick response time, and Exact CTNN technique which makes it possible to search accurately nearest neighbor objects. Experimental results using GSTD datasets shows that the Exact CTNN technique has high accuracy, but has a little low performance for response time. They also shows that the Approximate CTNN technique has low accuracy comparing with the Exact CTNN, but has high response time.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.8
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• pp.351-357
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• 2005

This paper presents vibration minimization of a PMLSM driven feed-slide by using optimized smooth velocity curve with finite jerk. First of all, the PMLSM was designed and made to reduce detent force. Next, a PMLSM driven feed-slide system was mathematically modeled as a 4-degree-of-freedom lumped parameter model. The key idea of our vibration minimization method is to find out the most appropriate smooth velocity(feedrate) curve with finite jerk. The validity of our proposed method has been verified by comparing computer simulation results of the feed-slide model with experimental ones.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2473-2475
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• 2001

In trajectory tracking methods, the error values of current position and velocity are compensated to follow the given reference path and velocity. The path tracking for a wheeled mobile robot is treated in this paper. It is very difficult to implement stable trajectory tracking algorithms because mobile robots have kinematically non-holonomic constraints. For solving this problem, a velocity controller is presented in this paper. This velocity controller is designed by a PID controller which could be easily employed. In this case, velocity errors caused by system uncertainties or internal and external disturbances could exist. A neural network is used for compensating the velocity errors. Input variables of this neural network compensator are defined by differences between the velocities of the posture controller and the real velocities of the mobile robot. Simulation results show the effectiveness of the proposed controller.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.9
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• pp.1827-1833
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• 2009

This paper deals with the trajectory tracking control of wheeled mobile robots with input constraint. The proposed method converts the trajectory tracking problem to the system stability problem using the control inputs composed of feedforward and feedback terms, and then, by using Taylor series, nonlinear terms in origin system are transformed into polynomial equations. The composed system model can make it possible to obtain the control inputs using numerical tool named as SOSTOOL. From the simulation results, the mobile robot can track the reference trajectory well and can have faster convergence rate of the trajectory errors than the existing nonlinear control method. By using the proposed method, we can easily obtain the control input for nonlinear systems with input constraint.

• Information and Communications Magazine
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• v.30 no.10
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• pp.3-9
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• 2013

최근 텔레매틱스 기술은 운전자와 차량, 차량과 외부의 정보들을 이용하여 다른 산업과의 융합이 급속히 진행되고 있으며, 다양한 서비스에 대한 요구 역시 점차 증가하는 추세이다. 최근에는 차량의 위치 및 궤적 데이터 정보 서비스뿐만 아니라 차량을 통한 차별화된 고객별 영업, 마케팅 및 서비스 제공에 대한 VRM(Vehicle Relationship Management)이 대두되고 있다. VRM은 차량의 주행 정보, 과거 이동정보, 운전자의 정보 등과 같은 차량에 관련된 다양한 정보에서 특정 규칙과 패턴을 추출한 후에 그것에 알맞게 영업, 서비스 생산, 마케팅 전략을 수립 및 적용할 수 있도록 해주는 것으로 CRM과 유사하다고 할 수 있다. 따라서 본 논문에서는 기존의 CRM의 성공 요인에 대한 선행 연구를 검토해 VRM의 전략적 관점에서 프로세스에 준거하여 고객자산가치관리와 VRM의 핵심기능인 고객자산가치 관리역량을 통해 차량의 주행정보, 차량 정검 정보, 운전자의 정보 등과 같은 차량에 관련된 모든 정보를 VRM 프레임워크가 갖추어야 할 요소를 도출하고 차량 기반 고객관계 프레임워크 모델을 제시해보고자 한다.