• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.134.2-134
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• 2001

This paper treats the implementation of a statically stable control system for a biped walking robot with 10 degrees-of-freedom. Statically stable walking of a biped robot can be realized by keeping the center of mass (COM) inside the sole of the supporting foot (or feet) during single-support or double-support phases. We predetermined five static positions for walking based on the COM method. The positions can be represented by the length of the gait, the width between the feet, the height of the foot and two parameters in the hip movement. With the five parameters, we calculated the position trajectory. And we got the angular trajectories of 10 joints from the posit ion trajectory using the position tracking control and neural network. By tracking the angular trajectories, the robot can walk maintaining stability. We implemented walking of a biped robot throught the above ...

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.43-43
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• 2000

In this paper, we introduce a case study of developing a miniature humanoid robot that has 16 degrees of freedom and is able to perform statically stable walking. The developed humanoid robot is 37cm tall and weighs 1,200g. RC servo motors are used as actuators. The robot can walk forward and turn to any direction on even surface. It equipped with a small digital camera, so it can transmit vision data to a remote host computer via wireless modem. The robot can be operated in two modes; One is a remote-controlled mode, in which the robot behaves according to the command given by a human operator through the user-interface program running on a remote host computer, the other is a stand-alone mode, in which the robot behaves autonomously according to the pre-programmed strategy. The user-interface program also contains a robot graphic simulator that is used to produce and verify the robot's gait motion. In our walking algorithm, the ankle joint is mainly used lot balancing the robot. The experimental results shows that the developed robot can perform statically stable walking on even surface.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.105.2-105
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• 2002

$\textbullet$ Statically stable walk with COG(center of gravity) $\textbullet$ Dynamically stable walk with ZMP(zero moment point) $\textbullet$ Dynamically adaptational stable walk with FRI(foot ratation indicator) $\textbullet$ Simplified inverted pendulum model approach $\textbullet$ Analysis posture of biped's foot as passive joint $\textbullet$ Stability compensation method of FRI against falling down $\textbullet$ Simulation of ZMP and FRI to real biped robot IWR-III

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.5
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• pp.420-426
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• 2001

In this paper, we introduce a case study of developing a miniature humanoid robot that has 16 degrees of freedom and is able to perform statically stable walking. The developed humanoid robot is 37cm tall and weighs 1,200g. RC servo motors are used as actuators. The robot can walk forward and turn to any direction on an even surface. It equipped with a small digital camera, so it can transmit vision data to a remote host computer via wireless modem. The robot can be operated in two modes: One is a remote-controlled mode, in which the robot behaves according to the command given by a human operator through the user-interface program running on a remote host computer, the other is a stand-alone mode, in which the robot behaves autonomously according the pre-programmed strategy. The user-interface program also contains a robot graphic simulator that is used to produce and verify the robot\`s gait motion. In our walking algorithm, the ankle joint is mainly used for balancing the robot. The experimental results shows that the developed robot can perform statically stable walking on an even surface.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.162.2-162
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• 2001

This paper presents the stability analysis of a biped robot IWR-III. We use a foot-rotation indicator(FRI) concept to reveal the degree of stability. The foot rotation can be a barometer of postural instability, which should be carefully treated in implementing a dynamically stable walk and avoided altogether in performing a statically stable walk. The conventionally mentioned zero moment point(ZMP) criterion may not be sufficient to express the stability of a biped robot. ZMP equation needs an assumption that the supporting foot is fixed firmly to the ground during the walking. Therefore, applying the FRI concept is more desirable when a biped robot is falling down ...

• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.18-24
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• 2003

Center of buoyancy moves along with pitch attitude variation, which causes Helium gas inclination. In this paper, movement of center of buoyancy and corresponding variation of longitudinal static stability were observed. The effect of separating wall, which is placed in the envelop to minimize movement of center of buoyancy was also investigated. Installation of separating wall was proved to be essential for current design, because movement of center of buoyancy aggravates longitudinal static stability. Investigation of longitudinal static stability for various speeds reveals a 50m airship is statically stable only in a low speed regime.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.4
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• pp.142-147
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• 2007

When the aircraft is developed, several flight tests are performed including stability and controllability, performance and systems, above all the most important part of the flight test is stability test. Stability test is divided into two parts, static stability and dynamic stability. Static stability of the aircraft is typically defined in terms of its initial tendency to return to equilibrium after a disturbance and not included time concept. One of static stability, longitudinal static stability, was addressed here. The longitudinal static stability was studied from the basic theory to the flight test method and also explained data reduction method throughout the flight test. Finally showed how to meet the specifications such as ROC, FAR and MIL-specifications.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.7
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• pp.787-793
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• 1999

A self-sensing magnetic suspension system utilizing a LC resonant circuit is proposed by using the characteristic that the inductance of the magnetic system is varied with respect to the air gap displacement. An external capacitor is added into the electric system to make the levitation system be statically stable system, which much relieves the control effort required to stabilize the magnetic suspension system of haying an intrinsic unstable nature. For the realization of the self- sensing magnetically levitated system, an amplitude modulation / demodulation method is used with a positive position feedback controller Experimental results are presented to validate the proposed method.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.523-528
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• 2000

In this paper, the new type biped walking robot which is composed of the minimum number or links just for walking and its appropriate gaits are proposed. The proposed new gaits for this robot are four-crossing, crawling, standing and turning gait. In designing the biped robot we propose the Performance Index which means the needed torque per a moving distance and generate foot trajectories by $3^{rd}$ order spline Interpolation. Among those, numerically we find the optimal conditions which minimize the Performance Index. Dynamically stable walking of the biped robot is realized by satisfying the stability condition of ZMP(zero moment point), which is related to maintaining the ZMP within the region of the supporting foot during the s1n91e leg support phase. We determine the region of mass center from the stability condition of ZMP and plan references which track the mass conte. trajectory of constant velocity. Finally we implement the gaits statically tracking the planned trajectories using PD control method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.572-577
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• 1996

Stereolithography is a process used to rapidly produce stereolithographic parts directly from three dimensional CAD models. However, design methodologies necessary to create components to be built by stereolithography are different from those required by conventional machining processes. A case in point is the nescessity of support structures, which are used to support a component during the building the build but are removed once building and curing are complete. Support structures are required to anchor the component to the platform and to prevent sagging or disortion. This paper deals with the specially maintained SupportMap data structure to find some region which need support structures. Interferences between support structures and parts, as well as among support structures are checked and statically stable regions are searched to remove the surplus support structures. Cross shaped tooth profiles are designed for easy eliminating the support structures.