• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.874-876
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• 1995

Force and compliance control has been used in the control of legged walking vehicles to achieve superior terrain adaptability on rough terrains. The compliance control requires distribution of the vehicle load over the supporting legs. However, the constraint equations for ground reaction forces of supporting legs are generally underdetermined, allowing an infinite number of solutions. Thus, it is possible to apply an optimization criteria in solving the force setpoint problem. It has been observed that the previous force setpoint optimization methods sometimes cause a system stability problem and/or the load distribution among supporting legs is not well balanced due to a memory effect on the solution trajectory, This paper presents an iterative force setpoint method to solve this problem using an interpolation technique. By simulation it was shown that an excessive load unbalance among supporting legs and the memory effect in the force trajectory are alleviated much with the proposed method.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.1 no.1
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• pp.7-11
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• 2007

A compass device which indicates the right direction using the recorded voice was developed to assist the people who are blind when they are walking and moving to somewhere. The developed voice compass consists of a sensing module which recognizes the terrestrial magnetism with magnetic sensor, voice recorder IC, speaker and microprocessor which controlled all the components. It has 32 directions resolution and can continuously indicates the progressing direction with established time interval for the user convenience. It can help walking of the blind people and designed to be used in various sports and leisure. The performance of the developed device was verified by experiment with person who are blind.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.6
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• pp.673-678
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• 2011

This paper analyzes the standing balance of four-legged robots which are useful for delivering objects or investigating of information. For this, we specify an effective model of general four-legged robots and propose a boundary condition based on the standing stability of the four-legged walking. To verify such a standing balance, we consider some exemplary free motions at the standing mode of the robot and discuss on the robot's balance margin. The analysis specified in this paper will be applicable for effective balancing control of various quadruped robotic walking.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.6
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• pp.376-382
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• 2005

In this paper, practical biped humanoid robot is presented, designed, and modeled by fuzzy system. The humanoid robot is a popular research area in robotics because of the high adaptability of a walking robot in an unstructured environment. But owing to the lots of circumstances which have to be taken into account it is difficult to generate stable and natural walking motion in various environments. As a significant criterion for the stability of the walk, ZMP (zero moment point) has been used. If the ZMP during walking can be measured, it is possible for a biped humanoid robot to realize stable walking by a control method that makes use of the measured ZMP. In this study, measuring the ZMP trajectories in real time situations throughout the whole walking phase on the flat floor and slope are conducted. And the obtained ZMP data are modeled by fuzzy system to explain empirical laws of the humanoid robot. By the simulation results, the fuzzy system can be effectively used to model practical humanoid robot and the acquired trajectories will be applied to the humanoid robot for the human-like walking motions.

• Journal of Biomedical Engineering Research
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• v.15 no.2
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• pp.167-174
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• 1994

In this paper, a DSP and microcomputer-based EMG controlled functional electrical stimulation (FES) system, for restoring walking of paraplegics at the patients' own command, is presented. The above-lesion EMG is a time-varying nonstationary signal and its autoregressive (AR) parameters are identified by the nonstationary identification algorithm using a DSP chip. The identified AR parameters are used for the cloassification of the function and the control of the movement. The below-lesion response-EMG signal is used as a measure of muscle fatigue. This FES system is designed to measure muscle fatigue and control the stimulation intensity according to the amplitude of the response-EMG signal. While the automatic electrical intensity control is obtained by identifying the movement, the proposed FES system is suitable for the automatic control of paraplegic walking.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1587-1596
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• 2016

This paper presents an interactive locomotion controller using motion capture data and inverted pendulum model. Most of the data-driven character controller using motion capture data have two kinds of limitation. First, it needs many example motion capture data to generate realistic motion. Second, it is difficult to make natural-looking motion when characters navigate dynamic terrain. In this paper, we present a technique that uses dimension reduction technique to motion capture data together with the Gaussian process dynamical model (GPDM), and interpolates the low-dimensional data to make final motion. With the low-dimensional data, we can make realistic walking motion with few example motion capture data. In addition, we apply the inverted pendulum model (IPM) to calculate the root trajectory considering the real-time user input upon the dynamic terrain. Our method can be used in game, virtual training, and many real-time applications.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.510-512
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• 2015

최근 IT 기술의 발전으로 가장 보편화 되고 있는 첨단기기는 스마트폰이다. 길을 걸으며 스마트폰을 사용하는 사람들이 늘어나고 이러한 행위는 보행자 자신의 안전에도 크게 위협적인 요소가 될 수도 있지만 자칫 주변 사람들에게까지 돌이킬 수 없는 결과를 초래할 수도 있다. 본 논문에서는 사람들의 안전한 생활을 위한 지능형 신발을 설계한다. 설계한 신발은 사람들에게 편리하고 유용한 장애물 감지 및 알림 시스템을 설계하기 위해 초음파 센서와 진동 센서 그리고 LED를 이용한다. 또한 모바일 어플리케이션(Mobile application)을 개발하여 활용도를 높인다. 초음파 센서는 마이크로 프로세서에서 장애물과의 거리를 계산한다. 진동 센서는 초음파 센서에서 계산한 거리가 특정거리(IM-4M) 이내이면 신호를 받아 진동 센서 혹은 LED가 동작해 사람에게 장애물이 있다고 알려준다. 모바일 어플리케이션(Mobile application)은 신발이 스마트폰과 일정거리 이상 멀어져 블루투스(Bluetooth)가 끊기면 알림을 해줌으로써 분실 방지를 해주고. 신발의 각 기능들을 제어하도록 해준다. 또 장애물과의 거리가 얼마나 남았는지를 확인할 수 있는 기능도 있다. 따라서 본 논문에서 제안하는 장애물 감지 및 알림 기능은 사람들에게 안전을 보장해주고 저비용으로 구현 가능한 장점이 있다.

• The Journal of Korea Robotics Society
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• v.18 no.2
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• pp.172-181
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• 2023

This paper presents research on the stability of control for a quadruped robot with two different leg structure designs. The focus of the research is on the design and analysis of the leg structures in terms of their impact on the stability and robustness of the robot's motion. First, a static analysis was performed in the simulation to compare the structural strength of the legs when the same force was applied. Secondly, two quadruped robots were built, each equipped with differently designed legs, and performed trot gait walking in the real world. And the states of the robots and the torques of each joint were analyzed and compared. In conclusion, based on the results of structural analysis in simulation and the actual walking experiments with the robots, it was demonstrated that the legs designed to be structurally robust improved the control stability of the quadruped robot.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.153-154
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• 2020

기존 VR컨트롤러는 현손에 별도의 컨트롤러를 들고 조작해야만 해왔다. 이는 현실감을 느끼기 위한 시각적인 요소를 충족시켰음에도 몰입도를 떨어뜨리는 요소이다. 본 연구에서는 현실감을 더욱 증가 시키는 것을 전제로 뇌파를 이용한 VR컨트롤러 기술을 적용하고자 한다. 현재 대중화 되어 있는 VR 장치들을 보면 움직이는 의자, 보행을 위한 장치, 캐릭터 조종을 위한 손에 쥐는 컨트롤러 등을 사용하고 있다. 이러한 장치들은 가상현실을 더욱 현실처럼 느끼기 위한 보조적인 장치들이지만 장치를 설치하기 위한 공간을 많이 차지하기 때문에 일반 가정에서는 잘 사용하지 않는다. 또한 손에 있는 컨트롤러로 가상 현실속의 동작을 구현하다 보니 아무리 내 눈앞에 보이더라도 '단순한 게임이다'라는 생각을 가지고 있어 몰입도가 떨어질 수밖에 없다. 본 논문은 이러한 문제점들을 개선하기 위해 기존의 VR컨트롤러 대신 뇌파입력을 적용한 '머신러닝을 통한 뇌파 VR컨트롤러' 기술을 제안한다. 기존의 VR컨트롤러와는 다르게 빅 데이터 처리기술인 머신러닝을 이용하여 뇌파 데이터를 처리하고 그 데이터들과 입력되는 뇌파 값을 비교하여 가상현실 속의 캐릭터의 동작을 제어할 수 있다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.673-674
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• 2023

도로교통의 안전 확보와 사고 예방을 목적으로 운전자나 보행자에게 필요한 정보를 제공하기 위해 경찰청에서 규격 또는 지침으로 제정하여 노변에 설치되는 교통안전시설 장치는 교통신호정보를 받기 위한 통신선과 함께 장치 구동을 위한 전원선을 개별로 시공해야 하기에 시공 비용의 절감과 함께 다종·다형의 장치에 대하여 통합적인 관제, 확장성, 유연성에 대응할 필요성이 제기되고 있다. 이에 본 논문에서는 이더넷 통신을 기반으로 전원 공급이 하나의 케이블로 가능한 이더넷 전원장치(PoE) 기술과 IoT 프로토콜인 MQTT를 이용하여 다종·다형의 교통안전시설 장치를 통합관제하고, 확장성과 유연성을 가지는 교통안전시설 장치 통합 시스템을 제안한다.