• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.5
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• pp.577-582
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• 2004

This paper describes position estimation algorithm using neural network for the navigation of the vision-based Wheeled Mobile Robot (WMR) in a corridor with taking ceiling lamps as landmark. From images of a corridor the lamp's line on the ceiling in corridor has a specific slope to the lateral position of the WMR. The vanishing point produced by the lamp's line also has a specific position to the orientation of WMR. The ceiling lamps has a limited size and shape like a circle in image. Simple image processing algorithms are used to extract lamps from the corridor image. Then the lamp's line and vanishing point's position are defined and calculated at known position of WMR in a corridor To estimate the lateral position and orientation of WMR from an image, the relationship between the position of WMR and the features of ceiling lamps have to be defined. Data set between position of WMR and features of lamps are configured. Neural network are composed and teamed with data set. Back propagation algorithm(BPN) is used for learning. And it is applied in navigation of WMR in a corridor.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.237-240
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• 1997

The design of underwater inspection robot system is presented. This robot system is designed for wall inspection in the nuclear plant facility. This paper describes the major components of the robot and its structures. This robot system is consisted of three parts : mechanical electrical and sensing pail. The main problem of designing mechanical part is to select the mechanism of driving. In this system the propeller driving mechanism is selected which can be move the robot continuously. For reducing the size of robot, we designed the CPU and motor controller board. The sensor system is consisted of two parts. One is environment monitoring part and the other is robot localization system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.415-415
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• 2000

The functions of a mobile robot such as obstacle knowledge and collision avoidance for in-door cleaning are necessary features, as has been much studied in the field of industrial automatic guided vehicle or general mobile robot. A mobile robot, in order to avoid collision with obstacles, has to gather data with environment knowledge sensors and recognize environment and the shape of obstacles from the data. In the study, a wall-following algorithm was suggested as a autonomous moving algorithm in which a mobile robot can recognize obstacles in indoor like environment and do cleaning work in effect. The system suggested in the study is for cleaning of nuclear material dusts generated in the process of nuclear fuel manufacturing and decontamination of devices in disorder which is performed in M6 radioactive ray shield hot-cell in IMEF(Irradiated Material Examination Facility) in the Korea Atomic Energy Research Institute.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2337-2340
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• 2002

This paper presents the method of AGV(Automatic guided vehicle)'s moving environment(plane, corner, edge) recognition using SONAR sensor configuration. As for the SONAR sensor, the Crosstalk effect has been generally considered as an inevitable noisy phenomenon in the indoor environment. However, this effect can be used as a clue for classifying and localizing targets in the indoor environment if those can be controlled and used well. EERUF(error eliminate rapid ultrasonic firing) is a method for firing multiple ultrasonic sensors in mobile robot application and multi-echo mode of POLARIOD Device can reduce the Crosstalk effect. Here, Crosstalk effect was reduced using EERUF and applied to the AGV with a simple wall-following algorithm in the indoor environment. This method was tesed by a typical AGV with multi SONAR sensors in the laboratory environment.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.7
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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.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3105-3107
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• 1999

In this paper, we propose a new approach to autonomous wall-following of wheeled mobile robots using hybrid control system. The hybrid control approach IS introduced to the motion control of nonholonomic mobile robots in the Indoor navigation problems. In hybrid control architecture, 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 to motion planning and autonomous navigation with obstacle avoidance In indoor navigation problem. Simulation results show that it is an effective method for the autonomous navigation in indoor environments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5450-5456
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• 2011

In order to build a ship, painting on ship cargo tank is one of the most dangerous parts as it involves working in high altitudes and a closed ship cargo tank. Therefore, researchers have been developing devices that will enable mobile robots to operate on vertical walls. The wall-climbing robots have been widely used to attach on the wall such as suction types. These types can be utilized regardless of the wall material. However, it is required to adhere and control the suction cups. To moderate this drawbacks, this paper proposes an automatic painting robot that uses a permanent magnet mobile robot. Using the magnetic characteristics, this robot can move on the boat vertically and horizontally even while hanging on the ceiling of the ship cargo tank. Also, we made a prototype to test adhesive force of the permanent magnet wheel and mobile robot as well as the towing capacity and auto-piloting ability.

• Journal of the Korean Society for Railway
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• v.18 no.6
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• pp.522-532
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• 2015

In the present study, a tunnel type soundproof wall with partial opening is proposed to reduce the environmental noise caused by railway vehicles traveling on bridges, which affects residents of high-rise apartment buildings; the study also attempts to minimize load due to wind and the weight of the wall. Applying the principles of computational fluid dynamics and structural mechanics, and the ray tracing method, a reduction in noise as well as of the overall weight of the soundproof walls is estimated. Analysis results show that the proposed soundproof wall with a partial opening weighs less, while reducing the wind loading by up to 30%. To prevent direct propagation of sound through openings in the wall, an acoustic louver, which is a type of silencer, could be considered for the opening. In order to achieve a similar noise effect with existing insulation material, the fluid flow and the insulation effect of the acoustic louver are analyzed. As the considered opening is in the range of 30~40% of the total length of the soundproof wall, the noise effect and wind load are reduced by 10dB and 25% respectively. Consequently, opening some part of tunnel type soundproof walls and installing louvers on the wall openings can have the effects of weight-reduction and reduced wind load. If a partial opening is applied with proper sound material application, a gain of an additional 5~10dB of noise reduction can be achieved.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.447-456
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• 1997

When the disabled is operating a rehabilitation assisting system with a joystick by himself, unlike in the case of a normal person, tremor with joystick control or instant miscontrol can often occur. If these misoperations should be directly relayed to the system, shaking or malfunction of the mobile rehabilitation assisting system might be the result. The safety of the disabled is of prime concern. To solve this problem, that is, to prevent the miscontrol of the disabled operator and avoid crashes into his or her surroundings, we propose the force-reflection locomotion algorithm with the joystick. This method uses ultrasonic sensors to measure the distance between the object and mobile robot. Based on the reception of sensory data, the necessary torque is applied via the joystick to the attatched motor. To confirm the effectiveness of the proposed method, the subjects on the reflected force by the dynamic characteristics of the joystick and the reflected force by the distance information are tested Even though there are some differences in human dexterity, we confirmed the fact that the information from the obstacles was relayed to the operator via the joystick and resulted in an improved operational performance and safety level with regard to those obstacles.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.113-115
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• 2011

본 논문은 레이저 내비게이션(laser navigation)의 위치측정을 위한 반사체 매칭(matching) 기법을 제안한다. 레이저 내비게이션은 레이저 헤더가 360도로 회전하면서 벽면에 부착되어 있는 반사체의 위치를 측정하는 장치이다. 기존의 레이저 내비게이션을 이용한 매칭방법은 계측된 반사체들을 이미 알고 있는 실제 반사체의 각각에 평행 이동시켜 회전 하면서 매칭하는 방법이었다. 하지만 기존의 방법은 연산량이 많아 AGV의 위치를 측정하기 위해 많은 시간을 요구한다. 따라서 본 논문에서는 기존 문제를 해결하기 위해, 실제 반사체들의 위치를 AGV의 위치로 가정하고 실제 반사체들을 회전하여 계측된 반사체를 매칭하는 방법을 제안한다. 실험은 레이저 내비게이션이 설치된 실제 AGV를 5회 회전 주행시켜 반사체를 계측 받고 제안된 방법으로 위치측정한 결과를 분석하였다. 실험 결과, 제안된 방법은 적은 연산으로 정확히 반사체를 매칭 할 수 있음을 확인하였다.