• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.932-937
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• 2003

In this paper, we will explain about the unmanned vehicle control and modeling for combined obstacle avoidance and lane tracking. First, obstacle avoidance is considered as one of the important technologies in the unmanned vehicle. It is consisted by two parts: the first part includes the longitudinal control system for the acceleration and deceleration and the second part is the lateral control system for the steering control. Each system uses to the obstacle avoidance during the vehicle moving. Therefore, we propose the method of vehicle control, modeling and obstacle avoidance. Second, we describe a method of lane tracking by means of vision system. It is important in the unmanned vehicle and mobile robot system. In this paper, we deal with lane tracking and image processing method and it is including lane detection method, image processing algorithm and filtering method.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.809-817
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• 2008

This paper describes an obstacle detecting system of an unmanned ground vehicle (UGV). The unmanned ground vehicle is consists of several systems such as vehicle control system, navigation system, obstacle detecting system and integration system. Among these systems, the obstacle detecting system is a driving assistance system of UGV. Through the UGV is driving, the system detects obstacles such as cars, human, tree, curb and hills and then send information of obstacles position to integration system for safety driving. In this research, the obstacle detecting system is composed of 5 laser scanners and develop algorithms of detecting obstacles, curb, uphill and downhill road.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.2
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• pp.114-123
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• 2017

This paper introduces a novel obstacle-climbing robot that moves on the facade of buildings and its climbing mechanism. A winch system set on the top of the building makes the vertical motion of the robot while it climbs obstacles that protrude from the wall surface. The obstacle-climbing robot suggested in this research is composed of a main platform and three modular climbing units. Various sensors installed on each climbing unit detect the obstacles, and the robot controller coordinates the three units and the winch to climb the obstacles using the obstacle-climbing mechanism. To evaluate the performance of the developed robot prototype, a test bed, which consists of an artificial wall and an obstacle, was manufactured. The obstacle size and the time required to climb the obstacle were selected as the performance indices, and extensive experiments were carried out. As a result, it was confirmed that the obstacle-climbing robot can climb various-sized obstacles with a reasonable speed while it moves on the wall surface.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1055-1062
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• 1996

A method for automatically driving paddy vehicles, such as rice transplanters, etc., straight ahead in a paddy field was investigated . The direction of such vehicles must be precisely controlled to do the operations as straight. However, the alignment of the from wheels becomes distorted due to the unevenness of the ground, preventing the vehicle form going straight. If the proper alignment of the front wheels is maintained , the vehicle can be driven straight ahead greater precision. To investigate the influence of the ground uneveness, the behavior of a paddy vehicle running over an obstacle was quantified. The left wheel ran over an obstacle on a flat concrete road surfaced. When the steering wheel was free, the front wheels were forced toward the left when vehicle went up the obstacle and toward the right when the vehicle went down it. The torsion of the wheel when the vehicle went down the obstacle was larger than that when it went up ,so it turned right 5 degrees. Sinc hydraulic control steering decreased the steering angle , it turned right 3 degrees. These results suggest that a vehicle can be driven straight ahead with high precision when the steering angle is changed in response to the direction and inclination of the vehicle . Such results were obtained in a paddy field tests.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.169-176
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• 2013

To generate the walking path of a humanoid robot in an unknown environment, the shapes of obstacles around the robot should be detected accurately. However, doing so incurs a very large computational cost. Therefore this study proposes a method to classify the obstacle shape into three types: a shape small enough for the robot to go over, a shape planar enough for the robot foot to make contact with, and an uncertain shape that must be avoided by the robot. To classify the obstacle shape, first, the range and the number of the obstacles is detected. If an obstacle can make contact with the robot foot, the shape of an obstacle is accurately derived. If an obstacle has uncertain shape or small size, the shape of an obstacle is not detected to minimize the computational load. Experimental results show that the proposed algorithm efficiently classifies the shapes of obstacles around the robot in real time with low computational load.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.5
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• pp.25-30
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• 2017

In this Paper, we Propose the Low-cost Obstacle Recognition System Utilizing the Ultrasonic Sensor. Developed Obstacle Recognition System can be used to Aid the Visually Impaired Person. The Existence of the Obstacle is Notified to the Person through the Embodied Electronic Vibration Motor. The Timing Difference from the Recognition to the Notification Indicates the Distance to the Obstacle. Pulsed Ultrasonic Signal Controlled by MCU is Utilized and the Reflected Pulse through the Obstacle gives the Developed System the Existence of the Obstacle and the Distance to the Object. Pulse is sent Repetitively to Improve the Detection Accuracy. Developed Apparatus gives 30 Degree of Detection Angle and 2cm-30cm of the Detection Range when the Apparatus is Tested under Normal Walking Environment.

• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.54-61
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• 2008

Experimental investigations were performed to assess the influences of different multiple obstacles on flame propagation in a rectangular confinement. Three different multiple obstacles were used: circular, triangular and square cross-sections with blockage ratios of 15% and 30%. The same method described in Park et al. [13] to investigate the interaction between the propagating flame and the obstacle was applied. Before the freely propagating flame impinged on the obstacle, the flame propagation speed remains close to the laminar burning velocity, regardless of the obstacles used. The reported data revealed that the trend in increase of the local flame propagation speed is a result of the interaction between the obstacle and the propagating flame front behind the obstacle. The local speed was found to increase from a circular to a triangular and a square obstacle. The mean flame speed was found to be less dependent on both the obstacle types and the different blockage ratios used.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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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.

• Journal of Biomedical Engineering Research
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• v.29 no.5
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• pp.384-391
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• 2008

For use in the guide system for the people who are visually impaired, an obstacle searching device using synchronous ultrasonic wave emission was proposed and developed. Generally, the conventional obstacle detection methods use the ultrasonic distance measuring device with successive scan method. However, the scan method causes a theoretical error and it couldn't estimate accurate obstacle distances. The proposed synchronous firing method use the plural number of ultrasonic sensors which emit ultrasonic wave simultaneously and estimate the distance to the closest obstacle relatively accurately. We analytically analyzed the errors of the conventional and proposed methods and compared the quantitative differences of the errors. The differences verified by obstacle search experiments. Using the proposed ultrasonic wave synchronous firing method, 3 dimensional obstacle location estimating device was designed and implemented. The results of the 3 dimensional obstacle detecting experiments showed the proposed method had good performances and it would be sufficiently use in the guide system for the people who are visually impaired.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.10
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• pp.928-933
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• 2012

In this paper, the IR and compass sensors for the underwater system were used. The walls of the water tank have been recognized and avoided treating the walls as obstacles by the bio-mimetic underwater robot. This paper is consists of two parts: 1.The hardware part for the IR and compass sensors and 2.The software part for obstacle avoidance algorithm while the bio-mimetic robot is swimming with the obstacle recognition. Firstly, the hardware part controls through the RS-485 communications between a microcontroller and the bio-mimetic underwater robot. The software part is simulated for obstacle recognition and collision avoidance based upon the data from IR and compass sensors. Actually, the bio-mimetic underwater robot recognizes where is the obstacle as well as where is the bio-mimetic robot itself while it is moving in the water. While the underwater robot is moving at a constant speed recognizing the wall of water tank as an obstacle, an obstacle avoidance algorithm is applied for the wall following swimming based upon the IR and compass sensor data. As the results of this research, it is concluded that the bio-mimetic underwater robot can follow the wall of the water tank efficiently, while it is avoiding collision to the wall.