• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.5 s.176
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• pp.1155-1165
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• 2000

Due to the irregularity of walking ground and the inaccuracy in trajectory control of a leg, the mechanical shock and slip on the ground can be caused in the landing and supporting legs of a walkin g robot, and the robot may lose walking stability. Especially in a jointed-leg type walking robot, those problems are much more severe than in the pantograph type since the leg-weight of the jointed-leg type walking robot is relatively heavier than that of the pantograph type in general. In order to secure the walking stability for the jointed-leg type quadrupedal robot under development in KIST(Korea Institute of Science and Technology), a balancing algorithm consisting of the leg compliance control and the body posture control is implemented in this paper, and the effectiveness of the algorithm is verified through experiments.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.2
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• pp.95-101
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• 2018

This paper presents a collision free mobile robot navigation based on the fuzzy inference fusion model in unkonown environments using multi-ultrasonic sensor. Six ultrasonic sensors are used for the collision avoidance approach where CCD camera sensors is used for the trajectory following approach. The fuzzy system is composed of three inputs which are the six distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot's wheels, and three cost functions for the robot's movement, direction, obstacle avoidance, and rotation. For the evaluation of the proposed algorithm, we performed real experiments with mobile robot with ultrasonic sensors. The results show that the proposed algorithm is apt to identify obstacles in unknown environments to guide the robot to the goal location safely.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.4
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• pp.293-298
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• 2006

In this paper, a sensor fusion based robot navigation method for the autonomous control of a miniature human interaction robot is presented. The method of navigation blends the optimality of the Fuzzy Neural Network(FNN) based control algorithm with the capabilities in expressing knowledge and learning of the networked Intelligent Robotic Space(IRS). States of robot and IR space, for examples, the distance between the mobile robot and obstacles and the velocity of mobile robot, are used as the inputs of fuzzy logic controller. The navigation strategy is based on the combination of fuzzy rules tuned for both goal-approach and obstacle-avoidance. To identify the environments, a sensor fusion technique is introduced, where the sensory data of ultrasonic sensors and a vision sensor are fused into the identification process. Preliminary experiment and results are shown to demonstrate the merit of the introduced navigation control algorithm.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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• pp.189-197
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• 2000

This paper addresses that the autonomous mobile robot with the function of teaching a moving path by speech and avoiding a collision is developed. The use of human speech as the teaching method provides more convenient user-interface for a mobile robot. In speech recognition system a speech recognition algorithm using neural is proposed to recognize Korean syllable. For the safe navigation the autonomous mobile robot needs abilities to recognize a surrounding environment and to avoid collision with obstacles. To obtain the distance from the mobile robot to the various obstacles in surrounding environment ultrasonic sensors is used. By the navigation algorithm the robot forecasts the collision possibility with obstacles and modifies a moving path if it detects a dangerous obstacle.

• Journal of Korea Multimedia Society
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• v.25 no.6
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• pp.833-843
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• 2022

Based on the problems of untimely Expressway fire rescue and backward traditional fire rescue methods, an emergency fire fighting and inspection robot riding on expressway guardrail is designed. The overall mechanical structure design of emergency fire fighting and inspection robot riding on expressway guardrail is completed by using three-dimensional design software. The target fire detection is realized by using the target detection algorithm of Yolov5; By selecting a variety of sensors and using the control method of multi algorithm fusion, the basic function of robot on duty early warning is realized, and it has the ability of intelligent fire extinguishing. The BMS battery charging and discharging system is used to detect the real-time power of the robot. The design of the expressway emergency fire fighting and inspection robot provides a new technical means for the development of emergency fire fighting equipment, and improves the reliability and efficiency of expressway emergency fire fighting.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.1
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• pp.59-64
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• 2005

In the paper, we propose an intelligent walking algorithm of biped robot on the uneven ground and a posture stabilization algorithm against external forces. At first, the mechanics and the control system of biped robot that can walk on the uneven ground and stand external forces are designed. We propose obstacle hurdling, incline walking. and going-up stairs algorithm by using infrared sensors and FSR sensors. Also, posture stabilization algorithm against external forces is designed using FSR sensors. Infrared sensors ate used to detect the obstacles in the working environment and FSR sensors are used to obtain the ZMP of biped robot. The developed biped robot can be controlled by the remote control system using vision system and RF module. The experimental results show that the biped robot Performs obstacle avoidance, obstacle hurdling, walking on the inclined plane, and going up stairs using the proposed walking and stabilization algorithm.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.7
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• pp.651-658
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• 2011

An efficient modified $D^*$ lite algorithm is suggested, which can perform online path planning for mobile robots in dynamic indoor environment. Online path planning should plan and execute alternately in a short time, and hence it enables the robot avoid unknown dynamic obstacles which suddenly appear on robot's path. Based on $D^*$ Lite algorithm, we improved representation of edge cost, heuristic function, and priority queue management, to build a modified $D^*$ Lite algorithm. Performance of the proposed algorithm is revealed via extensive simulation study.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.565-570
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• 1994

This work deals with finding a suitable position correction algorithm of industrial robot based on measuring gaps between door and chassis. The algorithm calculates correction quantities and then must allow visually acceptable door-chassis assembly take. The algorithm simulation is performed for a simple door-chassis model, and its effectiveness is addressed in terms of the predefined total unformity, line uniformity. In addition, the error sensitivity analysis of the rotation center of door due to the mismatch of robot grasping is performed using the algorithm.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.2
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• pp.53-63
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• 2018

A novel real-time path planning algorithm suitable for implementation on a small mobile robot is introduced. The algorithm can be used as the basis for mapping unknown or partially known environments and is tested in a specially developed simulation environment in Matlab(R). Simulations results are presented demonstrating that the algorithm can readily be implemented to allow a small robot to navigate in various unknown and partially known environments. The main characteristics of the algorithm include simplicity, ease of implementation, speed, and efficiency, thereby being especially suitable for small robots. Furthermore, for partially known environments, another algorithm is proposed to predefine an optimal path taking into account information provided regarding the environment.

• Journal of Sensor Science and Technology
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• v.32 no.5
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• pp.300-306
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• 2023

A hull-cleaning robot sticks to the surface of a vessel and moves for efficient cleaning. Precise path planning and tracking using the current position is crucial. Many robots rely on the INS algorithm, but errors accumulate. To fix this, GPS, sonar, and USBL are used, though with limitations. Selecting suitable sensors for the surface operation and accurate positioning algorithm are vital. In this study, we developed a robot position estimation algorithm using the structure of a ship. Problems that arise when expanding the 2D position estimation algorithm used in existing wall structures to 3D were evaluated and methods for solving them were proposed. In addition, we aimed to improve performance by deriving singularities that exist in the robot path and proposing an error correction algorithm based on the singularities.