• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.279-280
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• 2011

2바퀴이상의 로봇은 중심점을 기준으로 안정화가 이루어진다. 그러나 2바퀴이하의 로봇으로 수직 자세를 유지하기 위해서는 로봇자체를 기울여 중심점을 이동하므로 수평을 유지할 수 있다. 그러나 이러한 중심점의 이동은 속도나 방향성분이 같이 출력되므로 정확한 센서의 계산이 요구되고 정밀한 제어를 필요로 한다. 또한 많은 구조물로 인해 장애물 인식 및 자율주행 알고리즘 등이 필요하며 장시간 정보획득과 무인기 연동을 위한 빠른 움직임을 가져야한다. 위의 2조건을 만족하기 위한 구성으로 최근들어 두 바퀴를 가지는 모바일 역진자 로봇에 대한 연구가 활발히 이루어지고 있다. 이는 서비스 및 주행 로봇의 알고리즘이 휴머노이드에서 모바일 역진자 로봇으로 변화되었기 때문이다. 모바일 역진자 로봇은 휴머노이드에 비하여 사용되는 모터의 수가 적고 균형을 잡으려면 관절마다 값비싼 고성능 모터가 필요하며 이를 가동하려면 전력도 많이 소모되며 대용량 배터리를 장착할 수밖에 없게 된다. 반면 바퀴로 움직이는 로봇은 전력이 적게 들고 이동도 쉽다. 따라서 본 연구에서는 IMU를 이용한 간단하면서도 정확한 센서의 연산 방법과 이를 이용한 자세제어 방법을 연구한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1160-1165
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• 2004

The purpose of this study was to calculate three dimensional angular displacements, moments and joint reaction forces of the ankle joint during the waist pulling, and to assess the ankle joint reaction forces according to different perturbation modes and different levels of perturbation magnitude. Ankle joint model was assumed 3-D ball and socket joint which is capable of three rotational movements. We used 6 cameras, force plate and waist pulling system. Two different waist pulling systems were adopted for forward sway with three magnitudes each. From motion data and ground reaction forces, we could calculate 3-D angular displacements, moments and joint reaction forces during the recovery of postural balance control. From the experiment using falling mass perturbation, joint moments were larger than those from the experiment using air cylinder pulling system with milder perturbation. However, JRF were similar nevertheless the difference in joint moment. From this finding, we could conjecture that the human body employs different strategies to protect joints by decreasing joint reaction forces, like using the joint movement of flexion or extension or compensating joint reaction force with surrounding soft tissues. Therefore, biomechanical analysis of human ankle joint presented in this study is considered useful for understanding balance control and ankle injury mechanism.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.400-405
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• 2023

Currently, inverted pendulums are being studied in many fields, including posture control of missiles, rockets, etc, and bipedal robots. In this study, the vertical posture control of the pendulum was studied by constructing a rotary inverted pendulum using a 256-pulse rotary encoder and a DC motor. In the case of nonlinear systems, complex algorithms and controllers are required, but a control method using the classic and relatively simple PID(Proportional Integral Derivation) algorithm was applied to the rotating inverted pendulum system, and a simple but desired method was studied. The rotating inverted pendulum system used in this study is a nonlinear and unstable system, and a PID controller using Microchip's dsPIC30F4013 embedded processor was designed and implemented in linear modeling. Usually, PID controllers are designed by combining one or two or more types, and have the advantage of having a simple structure compared to excellent control performance and that control gain adjustment is relatively easy compared to other controllers. In this study, the physical structure of the system was analyzed using mathematical methods and control for vertical balance of a rotating inverted pendulum was realized through modeling. In addition, the feasibility of controlling with a PID controller using a rotating inverted pendulum was verified through simulation and experiment.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.120-130
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• 2014

The purpose of this study was to evaluate the effects of line dance activity on the balance factors during static standing to reveal the exercise intervention for fall prevention. A 15-week line dance programme was applied to 16 elderly females who aged more than 65 years in the community. Balance ability during static standing was evaluated by the range of center of pressure(cop), the velocity of cop, and sway area that calculated on the basis of ground reaction force data, forces, and moments. The range and velocity of cop in the anterio-posterior were significantly reduced after line dance(p<.01, p<.05, respectively), but change in those of cop in the medio-lateral was not found. It was demonstrated that 16-week line dance activities allow more effective in anterio-posterior stability and sway area of static standing. It was suggested that the effect of fall prevention exercise should be studied more associate with fall from vestibular and sensory system as future study.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.904-911
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• 2001

A broomstick swinging biped acrobatic controller is designed and simulated to show capability of the system of controllers: virtual model controller is employed for the robot\`s posture balancing control while a higher level fuzzy controller modulate the one of the virtual model controller\`s parameter for the pendulum swinging motion generation. The robot is of 7 degree-of-freedom, 8-link planar bipedal robot having two slim legs and a body. Each leg consists of a hip joint, a knee joint, an ankle joint and the body has a free joint at the top in the head at which a freely rotating broomstick is attached. We assume that the goal for the acrobat robot is to maintain a body balance in the sagittal plane while swinging up the freely up the freely rotating pendulum. We also assume that the actuators in the joints are all ideal torque generators. The proposed system of controllers satisfies the goal and the simulation results are presented.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.210-217
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• 2014

This paper presents experimental studies on controlling one-wheel robot, GYROBO. The previous one has the problem of falling down because the inside gimbal leans against one direction to make it balancing. This structural problem has been solved by redesigning the system. Gains obtained through experimental tasks are used as a gain scheduling method so that GYROBO is more stabilized. A line trajectory following control task is performed to test the driving control as well.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.276-279
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• 1997

A simple bio-feedback system was developed to monitor and to analyze patient's postural balance. Two load celIs were used to measure the weight of each side. A specially designed electronic circuit was made to pick up the weight signals and to feed into the data acquisition system. Clinical trials were also made on 20-30 year-old normal subjects and nine hemiplegia patients who had the potential instability in weight bearing. A Microsoft window-based software collected and analyzed the postural balance data. Normal subjects showed only 5% deviations of their body weight. However, hemipegic patients had significant weight shifts toward the healthy limb. With the present system, patients can also exercise their balance and weight bearing. The present system should be of convenience to monitor in real-time and analyze the postural balance control of hemiplegic patients.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.357-358
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• 2008

본 논문은 GPS를 이용한 무인 비행체의 자율비행에 관한 연구를 다루었다. 비행체의 종류는 크게 고정익기와 회전익기로 나뉘는데 본 연구에서는 회전익기의 형태를 가진 Quarter Vehicle을 사용하였다. Quarter Vehicle은 4개의 프로펠러에 의한 양력과 회전 반발력으로 비행을 한다. 이때의 양력은 수평면에 대해 수직으로 추력을 발생시키므로 다른 비행체보다 불안정하며 이를 안정하게 제어하기 위해 관성 센서를 적용하여 균형을 유지한다. 본 연구에서는 UAV의 자세와 균형을 안정적으로 유지하기 위해 관성센서를 적용하였으며 GPS를 활용하여 독립적인 자율비행이 가능하도록 하였다. 정확한 위치정보를 제공하는 GPS는 3개 이상의 위성으로부터 시간 및 위치 정보를 받아 좌표를 계산하고 비행체의 위치, 속도 및 방향을 결정하여 자율 비행이 가능하도록 한다. 또한 초형 지자기센서를 비행체에 적용하여 GPS의 방향 정보를 보완하도록 하였다. 본 논문에서는 무인 비행체의 자율비행의 기초가 되는 위치좌표 계산을 위한 GPS의 적용 방법과 비행경로계획 알고리즘을 제시 한다.

• Journal of Biomedical Engineering Research
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• v.17 no.4
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• pp.417-426
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• 1996

In this paper, we report the effects of visual stimulation patterns in the postural balance control. We used the motor-driven cloth panel and HMD(Head Mounted Display) to evaluate the effect of visual stimulation patterns in the postural balance control. We also investigated the usefulness of HMD in the postural balance rehabilitation training system from the view of reducing the scale of experimental system. Our results showed that a vertical-strip visual pattern was more effective than the others in the postural balance control. It was also indicated that HMD might be applied to clinical use as a new postural balance training system.

• Journal of Biomedical Engineering Research
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• v.18 no.2
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• pp.157-166
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• 1997

Postural balancing in human is known to be maintained by the complex mechanism coupled with cerebellum, equilibrium organ of ear, proprioception and other various organs. We developed a Computerized Balance Evaluation and Training system(COBET system) to evaluate postural control and to rehabilitate geriatrics and disabled patient. In addition, 55 normal adult were tested to investigate the influencing factors on balancing posture. For the analysis of static postural sway, areas of the moving center of pressure were calculated under 8 different positions of subjects. And subjects were also asked to follow the visual targets on monitor for the evaluation of the dynamic postural sway. In comparison of the first and the second sets of tests, there was test-retest reliability($\textit{p}$< 0.05). The controllability of the static pmtwn sway was decreased as the ages of subjects increase. When the ages of subject are over 60, the controllability was significantly decrease4 The dynamic postural sway was significantly greater in the age groups of 7th and 8th decade than the younger groups. It is concluded that COBET system is a reliable system in the evaluation of postural sway. The COBET system is considered to be a valuable training modality for the disabled patients as well as the elderly.