• The Journal of Korea Robotics Society
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• v.7 no.2
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• pp.83-91
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• 2012

In this paper, we propose a cable climbing robot which can climb up and down the cables in the bridges. The robot mechanism consists of three parts: a wheel based driving mechanism, adhesion mechanism, and safe landing mechanism. The wheel based driving mechanism is driven by tooth clutches and motors. The adhesion mechanism plays the role of maintaining adhesion force by a combination of pantograph, ball screw, and springs even when the power is lost. The safe landing mechanism is developed for guaranteeing the safety of the robot during operations on cables. It can make the robot fall down with reduced speed by dissipating the gravitational forces. The robot mechanism is designed and manufactured for validating its effectiveness.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.347-351
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• 2014

Planetary exploration rovers are likely to make a trip on a winding and sloping road of irregular surfaces to the destination in order to accomplish scientific missions. One of the key technologies for rovers is a suspension for traveling and performing exploration missions; the suspension is an essential area of technology for a stable movement of a rover. In this study, an 8-wheel suspension is designed to enable efficient climbing of slopes on a passage to the destination. For the two front wheels among the eight wheels, the moment at the pivot connecting two wheels is derived when the distance between the wheels and the torque of wheels are same. A test experiment was performed to compare the magnitude of moment according to the change in tilt angle and the position of the pivot. Finally, a suspension design considering the position of the pivot was proposed to enhance the hill-climbing performance.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.10
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• pp.915-920
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• 2013

Payload capacity and transition ability are essential for climbing robots to apply the robots to various applications such as inspection and exploration. This paper presents a new climbing robotic platform with multi-link structure of track-wheel modules to enhance payload capacity and transition ability, and its tracking controller design and experimental results. The compliances between track-wheel modules achieve stable internal and external transitions while the large adhesion area of the track-wheel module enhances the payload capacity of the robot. Kinematic model-based tracking controller is designed and implemented for autonomous internal transition, and the gains of the controller are optimized by experimental design. Experiments on the automatic internal transitions are performed and the results guarantee autonomous internal transition with little tracking error.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.119-120
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• 2007

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.81-84
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• 2007

바퀴구동형 로봇 메카니즘은 다양한 서비스 로봇에 활용되고 있는데, 이 로봇을 위하여 가장 기본적으로 요구되는 성능중의 하나는 등반능력과 관련된 구동모터의 사양을 결정하는 문제를 들 수 있다. 본 논문에서는 이러한 바퀴구동형 로봇 메카니즘의 등반능력을 고려하고, 경사면을 원활하게 주행하기 위한 필요조건을 제시하고자 한다. 결과적으로, 이러한 조건은 이동로봇 메카니즘의 설계에 유용하게 활용될 수 있을 것으로 기대한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.5
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• pp.478-485
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• 2015

Availability of the climbing angle information is crucial for the intelligent vehicle system. However, the climbing angle information can't be measured with the sensor mounted on the vehicle. In this paper, climbing angle estimation system is proposed. First, longitudinal acceleration obtained from gyro-sensor is compared with the actual longitudinal acceleration of the vehicle. If the vehicle is in yawing motion, actual longitudinal acceleration can't be approximated from time derivative of wheel speed, because lateral velocity and yaw rate affect actual longitudinal acceleration. Wheel speed and yaw rate can be obtained from the sensors mounted on the vehicle, but lateral velocity can't be measured from the sensor. Therefore, lateral velocity is estimated using unknown input observer with nonlinear tire model. Simulation results show that the compensated results using lateral velocity and yaw rate show better performance than uncompensated results.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.10
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• pp.1067-1072
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• 2014

The ability to overcome obstacles is necessary for field robots for various applications including the ability to climb stairs. While much research has been performed focusing on overcoming obstacles, the resulting robots do not have sufficient ability to overcome obstacles such as stairs. In this research, the purpose is to overcome relatively large obstacles by flipping locomotion through the modification of the stair climbing robotic platform of the previous research. We propose two scenarios to overcome large obstacles: a rear wheel driving system and an elevation system using a ball screw. The research is performed based on static analyses on obstacle-climbing. As the simulation results indicate, we determined the optimal posture of the robot for climbing obstacles for rear wheel driving. Also, an elevation system is analyzed for obstacle climbing. Between the two scenarios an elevation system is determined to reduce the operating torque of the actuator, and the prototype was recently assembled. The climbing ability of the robotic platform is verified. We expect the application area for this robotic platform will be in accident areas of nuclear power plants.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.548-553
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• 2002

Most tasks of the large vertical or ceiling structures have been carried out by human power. Those tasks require us much operation costs and times, safety devices, etc. So the need of automation for those tasks have been rising. That automation needs a wall-climbing mobile vehicle. Most former researches are things about attachment devices and moving mechanisms. A wall-climbing mobile vehicle must be designed by a method different from the case of the vehicle of the horizontal environment. That is because gravity acts as a negative role on the stability of a wall-climbing vehicle. In this thesis, the particular shape characteristics of a wall-climbing mobile vehicle are derived by the wall-environment modeling. In addition, some design constraints of the permanent magnetic wheel as an attachment device was studied. According to those requirements and constraints, one specific wall-climbing mobile vehicle was designed and some experiments were made on the attachment ability of that vehicle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.445-446
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• 2011

• Journal of the Korean Society for Precision Engineering
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• v.19 no.1
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• pp.143-149
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• 2002

Robot are necessary to automate the work on a vertical plane of work piece to produce a large structure like a ship, so that a permanent magnet wheel has been attempted to be used for a mobile robot. Its adhesive power was enhanced by restricting the occurrence direction of magnetic flow. Furthermore a method which weakened the adhesive force was developed for easy detachement of the wheel by changing magnetic flow with metal pin. To measure the characteristics of the adhesive and detaching farces, a load call and a gaussmeter were used. The result showed that the adhesive power was reduced to 1/3 of normal state by using 4 inducing pins.