• Journal of Institute of Control, Robotics and Systems
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• v.8 no.7
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• pp.564-572
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• 2002

This article describes the ultrasonic range sensor for the recognition of the Indoor environment, especially utilizing the multiple reflection properties of the sonar usually ignored as disturbances or noises. In this paper, we endow the ultrasonic range sensor with the active motion using the stepping servomechanism in order to get the multiple reflections with environment objects. Environment features such as target type, distance and azimuth based on the scanned one frame data of that multiple reflection patterns are recognized simultaneously.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.43-47
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• 1995

The ball screw is one of the important mechanical parts for the linear motion feeding systems. The usage of the ball screw has been growing in various industrial fields such as CNC machine tool, industrial robot and automated systems. Because of ever increasing demand for ball screws, increased accuracy and quality of the ball screw is needed,especially the surface roughness of the ball contact area in order to diminish noise and vibration. Therefore to improve the surface roughness of the area,we introduced magnetic assisted polishing which is one of the new potential polishing methods. In this study, diamond slurry and iron powder was used for magnetic assisted polishing of the ball bearing surface. This polishing process was experimentally confirmed to improve the surface roughness of the ball bearing.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.161-172
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• 2017

Foot mechanisms play the role of interface between the main body of robotic systems and the ground. Biomimetic design of the foot mechanism is proposed in the paper. Specifically, multi-chained and multiple contact characteristics of general foot mechanisms are analyzed and their advantages are highlighted in terms of impulse. Using Newton-Euler based closed-form external and internal impulse models, characteristics of multiple contact cases are investigated through landing simulation of an articulated leg model with three kinds of foot. It is shown that in comparison to single chain and less articulated linkage system, multi-chain and articulated linkage system has superior characteristic in terms of impulse absorption as well as stability after collision. The effectiveness of the simulation result is verified through comparison to the simulation result of a commercialized software.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.9
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• pp.779-784
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• 2004

This paper describes a sonic polygonal multiple reflection range sensor (SPMRS), which uses multiple reflection properties usually ignored in ultrasonic sensors as disturbances or noises. Targets such as a plane, corner, edge, or cylinder in indoor environments can easily be detected by the multiple reflection patterns obtained with a SPMRS system. Target classification and feature data extraction, such as distance and azimuth to the target, are computed simultaneously by considering the geometrical relationships between the detected targets, and finally the environment model is generated by refining the detected targets. In addition, the narrow field of view of a sonar range sensor is increased and the scanning time is reduced by active motion of the SPMRS stepping servomechanism.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.65-68
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• 1996

Robotic manipulators have become increasingly important in the field of flexible automation. High speed and high-precision trajectory tracking are indispensable capabilities for their versatile application. The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. This paper presents a new approach to the design of neural control system using digital signal processors in order to improve the precision and robustness. The TMS32OC31 is used in implementing real time neural control to provide an enhanced motion control for robotic manipulators. In this control scheme, the networks introduced are neural nets with dynamic neurons, whose dynamics are distributed over all the, network nodes. The nets are trained by the distributed dynamic back propagation algorithm. The proposed neural network control scheme is simple in structure, fast in computation, and suitable for implementation of real-time, control. Performance of the neural controller is illustrated by simulation and experimental results for a SCARA robot.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1245-1248
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• 1996

This paper describes a cell programming environment that deals with problems associated with programming Flexible Manufacturing Cells(FMCs). The environment consists of the cell programming editor and the automatic generation module. In the cell programming editor, cell programmers can develop cell programs using task level description set which supports task-oriented specifications for manipulation cell activities. This approach to cell programming reduces the amount of details that cell programmers need to consider and allows them to concentrate on the most important aspects of the task at hand. The automatic generation module is used to transform task specifications into executable programs used by cell constituents. This module is based on efficient algorithm and expert systems which can be used for optimal path planning of robot operations and optimal machining parameters of machine tool operations. The development tool in designing the environment is an object-oriented approach which provides a simple to use and intuitive user interface, and allows for an easy development of object models associated with the environment.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1527-1530
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• 1996

Telerobot system is being developed for the application to nuclear power plants by Korea Atomic Energy Research Institute. Human-machine interaction and interface are very important elements of telerobotic systems. The main purpose of this study is developing a control system based on 3-D graphic techniques for the easy user interface and realistic visual I information supply. This system possesses the abilities for (1) virtual work, environment modelling and simulation, (2) kinematic animation include redundant behavior (3) interfacing with a real robot system, (4) transformation between real and virtual mode within the same graphics system. This system is especially focused on enhancing the overall efficiency and reliably of nozzle dam installation task inside water chamber of steam generator in nuclear power plant.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.11
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• pp.936-942
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• 2005

Recently the exoskeletal power assistive equipment which is a kind of wearable robot has been widely developed to help the human body motion. For the elderly people and patients, however, some limits exist due to the weight and volume of the equipments. As a feasible solution, a tendon-driven exoskeletal power assistive device fur the lower body, and caster walker are proposed in this research. Since the caster walker carries the heavy items, the weight and volume of the wearable exoskeleton are minimized. The key control is used to generate the joint torque required to assist motions such as sitting, standing and walking. Experiments were performed for several motions and the EMG sensors were used to measure the magnitude of assistance. When the motion of sitting down and standing up was compared with and without wearing the proposed device, the $25\%$ assistance was acquired.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.10-16
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• 2006

In this paper, moving a fragile object from an initial point to a specific location in the minimum time without damage is studied. In order to achieve this goal, initially, the maximum acceleration and velocity ranges are specified. These ranges can be dynamically generate on the planned path by the manipulator. The path can be altered by considering the geometrical constraints. Later, considering the impulsive force constraint on the object, the range of maximum acceleration and velocity are obtained to preserve object safety while the manipulator is carrying it along the curved path. Finally, a time-optimal trajectory is planned within the maximum allowable range of acceleration and velocity. This time-optimal trajectory planning can be applied to real applications and is suitable for both continuous and discrete paths.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1071-1076
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• 2004

It is a fuzzy controller that it is the most used method in the control of non-linear system. The most important part in the fuzzy controller is a design of fuzzy rules. Many algorithm that design fuzzy rules have proposed. And attention to the evolutionary computation is increasing in the recent days. Among them, the co-evolutionary algorithm is used in the design of optimal fuzzy rule. This paper takes advantage of a schema co-evolutionary algorithm. In order to verify the efficiency of the schema co-evolutionary algorithm, a fuzzy controller for the mobile robot control is designed by the schema co-evolutionary algorithm and it is compared with other parasitic co-evolutionary algorithm such as a virus-evolutionary genetic algorithm and a co-evolutionary method of Handa.