• Journal of Institute of Control, Robotics and Systems
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• v.14 no.11
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• pp.1146-1154
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• 2008

This paper presents a method for the acceleration analysis of multi-legged walking robots in consideration of the frictional ground contact. This method is based on both unified dynamic equation for finding the acceleration of a robot's body and constraint equation for satisfying no-slip condition. After the dynamic equation representing relationship between actuator torques and body acceleration, is derived from the force and acceleration relationship between foot and body's gravity center, the constraint equation is formulated to reconfigure the maximum torque boundaries satisfying no-slip condition from given original actuator torque boundaries. From application of the reconfigured torques to the dynamic equation, interested acceleration boundaries are obtained. The approach based on above two equations, is adapted to the changes of degree-of-freedoms of legs as well as friction of ground. And the method provides the maximum translational and rotational acceleration boundaries of body's center that are achievable in every direction without occurring slipping at the contact points or saturating all actuators. Given the torque limits in infinite normsense, the resultant accelerations are derived as a polytope. From the proposed method, we obtained achievable acceleration boundaries of 4-legged and 6-legged walking robot system successfully.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.4
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• pp.206-211
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• 2017

The most of the elders or patients that use common walkers do not have enough physical strength in the legs and cannot walk for a long time where they want to go. So it is necessary to take rests and highly required to develop a multi-function walker that can guide walking safely for weak elders or patients with IT application products at the same time. This study is focused on the walkers for elders with bent back and the design to grant new values for elders to overcome limitations of existing walkers.

• Journal of the Korea Furniture Society
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• v.21 no.2
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• pp.167-187
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• 2010

In this paper, the research is carried out about a couch, a horse foot chair, a horse foot table, and a multi-leg table among the furniture of Koguryeo. The couch had been widely used from the Chinese Han Dynasty, and the couch of the Koguryeo was influenced by that of Han. The couch of Koguryeo was a piece of furniture which was used not only for sitting purposes but also for symbolizing status ranking. The horse foot chair is a chair whose leg is finished with a horse foot shape, and is a relic which shows an aspect of the art exchange between the East and the West, appearing in Egypt and Mesopotamia, having influence on chairs of Greece and Rome, and being introduced into Koguryeo and Japan by way of the countries bordering on Western China and China. The horse foot chair was used by the royalty, the aristocracy and the priesthood, and use of the chair at that time reflects the effect of Buddhist culture. The horse foot table is a piece of furniture whose leg is finished with a horse foot shape as in the horse foot chair, and there are many instances that it is used together with the horse foot chair. The multi-leg table is configured to have a square plate, plural legs and footstool, and is used by the upper classes, being also influenced by China. In this paper, the study about the furniture of Koguryeo, which has not been closely considered up to now, is performed, and is important as a study about origin of Korean furniture. In the future, the research about succession of the furniture of Koguryo to that of Koryeo period should be carried out, and much more research material be investigated.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2132-2137
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• 2005

This paper is concerned with computer simulations of a biped robot walking in dynamic gaits. To this end, a three-dimensional robot is considered possessing a torso and two identical legs of a kinematically ingenious design. Specific walking patterns are off-line generated meeting stability based on the ZMP condition. Subsequently, to verify whether the robot can walk as planned, a multi-body dynamics CAE code has been applied to the corresponding joint motions determined by inverse kinematics. In this manner, complex mass effects could be accurately evaluated for the robot model. As a result, key parameters to successful gaits are identified including inherent characteristics as well. Also, joint actuator capacities are found required to carry out those gaits.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.6 s.249
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• pp.643-652
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• 2006

This paper is concerned with computer simulations of a biped robot walking in static and dynamic gaits. To this end, a three-dimensional robot is considered possessing a torso and two identical legs of a typical design. For such limbs, a set of inverse kinematic solutions is analytically derived between the torso and the feet. Specific walking patterns are off-line generated meeting stability based on the VPCG or ZMP condition. Subsequently, to verify whether the robot can walk as planned in the presence of mass and ground effects, a multi-body dynamics CAE code has been applied to the resulting joint motions determined by inverse kinematics. As a result, the key parameters to successful gaits could be identified including inherent characteristics as well. Upon comparisons between the two types of gaits, dynamic gaits are concluded more desirable for larger humaniods.

• Korean Journal of Veterinary Service
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• v.27 no.1
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• pp.63-73
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• 2004

The present experiment was carried out to study the pathogenesis of Newcastle disease(ND), ND virus (NDV) antigens and genes in various organs from NDV inoculated chickens were detected by immunohistochemistry and RT-PCR. Immunohistochemically, NDV antigens were detected in the spleen, thymus, cecal tonsil, proventriculus, trachea and lungs at 12 hour post-inoculation (hpi). Viral antigens were localized mainly in the cytoplasm of lymphocytes and macrophages. After 48 hpi, clinical findings of the affected chickens were open-mouth breathing, conjunctivitis, watery diarrhea and edema around the eye and neck. After 72 hpi, chickens showed muscular tremor, paralysis of the legs and wings, and coma. Histopathological results consist of multi-focal necrosis with hemorrhages in lymphoid aggregates of the intestinal tracts, necrosis of the lymphoid tissues, neuronal degeneration and necrosis, and perivascular cuffing. Using RT-PCR, virus genes were detected in the spleen and proventriculus at 48 hpi, and in the brain at 60 hpi.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.534-538
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• 2017

There are three types of robots that move on the ground classified as drivetrain. Wheels, tracks and Legs. Wheels and tracks are much easier to construct and control, but they have problems passing through obstacles like people. This paper discusses the design of line tracing using Theo Jansen, one of multi-legged walking mechanism. In order to increase the moving speed, the Jansen mechanism is designed by maximizing the objective variable as GL (Ground Length), GAC (Ground Angle Coefficient). In this project, only three sensors were attached and Arduino was used for optimal control of the motor using the sensor values.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.89.2-89.2
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• 2011

The geometry of an MC (magnetic cloud) in the interplanetary space can be estimated by the magnetic flux rope model. But the single point observation in the interplanetary space near the Earth is scanty to comprehend the global configuration of MC because the MC is considered a huge loop extending from the Sun with both legs rooted on the Sun. If the MC is observed at two different locations sufficiently far away from each other, it may provide the global configuration of the MC. In this study, we model the MC which is observed two different locations using a simple straight cylinder model. The MC model fit parameters are the flux rope axis orientation (${\Theta}$, ${\phi}$), the intensity of the magnetic field at the flux rope axis ($B_0$), the radius of the MC ($R_0$), and the impact parameter (p), etc. With the MC model fit parameters we look into the difference between two observed MC geometries and also calculate the magnetic flux and helicity of the MC.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.1
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• pp.92-106
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• 1990

Active compliance is often used in the control of robot manipulators for the implementation of complex tasks such as assembly, multi-finger fine motion, legged-vehicle adaptive control,etc. This technique balances the interactive force between the manipulator tip and its working environment with its position and velocity errors to achieve the operation of a damped spring. This paper investigates the effecft of passive compliance on system stability with regard to force feedback implementation for actively compliant motion. Usually it is understood that accurate position control require a stiff system. However, theoretical examination of control experiments on a legged suspension vehicle suggests that, if the control includes discrete-time force feedback, some passive compliance is necessssary at the legs of the vehicle for system stability. This can be an important factor to bl considered in manipulator design and control. A theoretical analysis, numerical simulation, and experimental result, confirming the above conclusion, are introduced in this paper.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.429-433
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• 2016

Moving robot is divided 2 kinds; one is the robot using wheels and the other has leg structure. On plat terrain, the former is better than the latter because it has fast speed and simple method to control. But on non-plat terrain, the situation is reversed. The robot using legs has slow speed but it has advantage to adjust various environments. This robot is expected to contribute to human in many fields such as rescue and exploration and so on. So walking robot is worth enough to research. In this paper, we present the design of 4-legged walking robot based on Jansen mechanism using m-Sketch and Edison Designer.