• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권2호
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• pp.244-250
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• 2003

In this paper, the relationship between a slave robot and the uncertain remote environment is modeled as the impedance to generate the virtual force to feed back to the operator. For the control of a tele-operated mobile robot equipped with camera, the tele-operated mobile robot take pictures of remote environment and sends the visual information back to the operator over the Internet. Because of the limitation of communication bandwidth and narrow view-angles of camera, it is not possible to watch the environment clearly, especially shadow and curved areas. To overcome this problem, the virtual force is generated according to both the distance between the obstacle and robot and the approaching velocity of the obstacle. This virtual force is transferred back to the master over the Internet and the master(two degrees of freedom joystick), which can generate force, enables a human operator to estimate the position of obstacle in the remote environment. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. This force reflection improves the performance of a tele-operated mobile robot significantly.

• 로봇학회논문지
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• 제4권2호
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• pp.105-111
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• 2009

In this paper, we provide experimental results and verification for obstacle avoidance algorithm 'ELA(Emergency Level Around)', which is applicable to rescue robots. ELA is a low level intelligence-based obstacle avoidance algorithm, so can be used in fast mobile robots requiringhigh speed in operation with little computational load. Constructed system for experiments consist of laptop, sensors, peripheral devices and mobile robot platform VSTR(Variable Single-tracked Robot) to realize predetermined scenarios. Finally, experiment was conducted in indoor surroundings including miscellaneous things as well as dark environment to show fitness and robustness of ELA for rescue, and it is shown that VSTR navigates endowed area well with real-time obstacle avoidance based on ELA. Therefore, it is concluded that ELA can be a candidate algorithm to increase mobility of rescue robots in real situation.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권5호
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• pp.307-314
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• 2005

In this paper, we propose a predictive system for the avoidance of the moving obstacle. In the dynamic environment, robots should travel to the target point without collision with the moving obstacle. For this, we need the prediction of the position and velocity of the moving obstacle. So, we use the Kalman filer algorithm for the prediction. And for the application of the Kalman filter algorithm about the real time travel, we obtain the position of the obstacle which has the future time using Fuzzy system. Through the computer simulation studies, we show the effectiveness of the proposed navigational algorithm for autonomous mobile robots.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.643-648
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• 1989

This paper presents a theoretic study and computer simulation of models and approaches for dynamical obstacle avoidance by mobile robots. The movement of obstacles in unknown environment is described by any one or a combination of three models. The control strategy of the mobile robots is formulated based on one of three approaches. A trajectory-guided control strategy for dynamical obstacle avoidance has been developed. The method greatly simplifies the control process of mobile robots, and is computationally attractive.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.796-799
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• 1999

In this paper, we propose an inference method for understanding intention of obstacle for collision avoidance using the grid-type map. In order to represent the environment using ultrasonic sensors, the grid-type map is first constructed. Then we detect the obstacle and infer the intention for collision avoidance using the CLA(Centroid of Largest Area) point of the grid-type map. To verify the proposed method, some experiments are performed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.939-940
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• 2006

Many researches on path planning and obstacle avoidance for the fundamentals of mobile robot have been done. In this paper, we propose the algorithm of path planning and obstacle avoidance for mobile robot. We call the proposed method Random Access Sequence(RAS) method. RAS method using obstacle information from variable sensors is useful to get minimum path length to goal.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2856-2858
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• 2000

This paper proposes a scan code method for obstacle avoidance of mobile robot. Obstacles detected in a circular window are converted to scan codes and then to the steering angle. The safe rotating radius is obtained by the scan code to avoid the collision between robot and obstacle and. the minimum distance for rotation is calculated. Effectiveness of the method is illustrated through simulations, and the results show that the proposed method can be efficiently implemented to an unknown environment.

• 한국산업정보학회논문지
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• 제22권5호
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• pp.25-30
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• 2017

본 논문에서는 초음파 센서를 이용한 저비용 장애물 인식 장치를 개발한다. 개발된 장애물 인식 장치는 시각 장애인들이 보행시 장애물을 인식하는 데 쓰일 수 있도록 한다. 장애물의 인식 여부는 내장된 모터의 진동을 통하여 시각 장애인들에게 인식이 가능하도록 한다. 뿐만 아니라 장애물의 거리에 따라 대상자에게 장애물 인식 유무에 대해 시간차를 두고 고지하여 대상자가 장애물에 대해 적절한 반응을 수행할 수 있도록 한다. 마이크로 컨트롤러 제어를 통한 펄스 신호를 이용하여 장애물에 대한 반사파를 통해 장애물의 존재 유무와 거리를 탐지하며 펄스 신호를 이용한 반사파 탐지는 반복 수행을 통해 인식률을 높인다. 개발된 장애물 인식 장치는 $30^{\circ}$ 내외의 전방 탐지각을 나타내고, 2cm-30cm의 탐지거리를 가지며 일상적인 보행 조건에서 동작이 가능함을 실험을 통해 입증하였다.

• 전기학회논문지
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• 제62권12호
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• pp.1813-1819
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• 2013

Existing level crossing obstacle detecting system was installed using a laser beam. Level crossing obstacle detecting system using a laser beam that has been a problem in relation to safety and maintainability failure according to weather conditions. We proposed laser radar level crossing obstacle detecting system as a way to overcome problem, and we developed an algorithm for this. Level crossing obstacle detecting system using a laser radar sensor algorithm is robust to external environment and a shadow zone does not exist. Sensor part of the laser radar level crossing obstacle detecting system of these is made up by the image processing unit and laser radar sensor, it operations by receiving train entering information from the control unit. In this paper, we proposed a detecting algorithm with calculation of the size of the laser radar sensor. Based on this, we were performance test on the basis of the scenario by making a prototype. In the future, laser radar level crossing obstacle detecting system to ensure the safety and reliability through the field test.

• 한국지능시스템학회논문지
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• 제19권4호
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• pp.451-456
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• 2009

본 논문에서는 Virtual Mass-Spring-Damper 모델을 사용하여 이동로봇과 주위 물체와의 관계를 모델링하고 장애물의 충돌벡터를 검출하여 가상의 척력을 발생시키는 가상 임피던스 방법을 제안하였다. 이를 위하여 원격지 슬래이브 로봇의 주위 환경 정보 즉, 이동 로봇과 장애물과의 거리 및 접근 속도 등의 정보를 조작자에게 입체적으로 전달하기 위해 조이스틱의 각축에 연결된 모터를 이용하여 힘을 발생시킬 수 있도록 한다. 제안한 방법의 실제 로봇적용에 앞서 이동로봇의 장애물 회피 시뮬레이션을 통하여 알고리즘을 검증하였다.