• Journal of Institute of Control, Robotics and Systems
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• v.22 no.4
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• pp.281-287
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• 2016

In this paper, we propose a novel compact surveillance throwing robot which has an omnidirectional shock absorption mechanism and an active control part of wheel treads to stabilize the dynamic posture of a miniature sphere type throwing robot. This throwing robot, which weighs 1.14kg and is 110mm in height, is designed in a spherical shape to be easily grabbed for throwing. Also, the omnidirectional shock absorbing aspect is designed using several leaf springs connected with inner and outer wheels. The wheel treads control part consists of a link mechanism. Through the field experiments, this robot is validated to withstand higher than 17Ns of omnidirectional impulse and increase the stabilized max speed three times from 11 rad/s to 33rad/s by increasing wheel treads.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.4
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• pp.361-366
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• 2015

In this paper, we propose a novel surveillance throwing robot which is compact, light-weight and has an efficient shock absorption mechanism. The throwing robot is designed in a spherical shape to be easily grabbed by a hand for throwing. Also, a motor-wheel linking mechanism is designed to be robustly protected from shocks upon landing. The proposed robot has a weight of 2.2kg and the diameter of its wheels is 150 mm. Through the field experiments, the designed robot is validated to withstand higher than 13Ns of impulse.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.138-140
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• 2007

These days, robot-industry development requires a new motor technology. Robot system is more complex than the other machine ones. They need the simplicity and light weight as robot systems. Moreover, They have to become a high energy efficiency machine. For these reasons, in this paper, the 3-degrees of freedom permanent-magnet spherical motor is proposed instead of existing ones. The proposed motor model is analyzed by using FEA(Finite Element Analysis), for comparing the results, torque of the motor is simulated by derived torque function.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.4
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• pp.30-37
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• 2010

This paper deals with attitude determination and parameter estimation problems for a lunar module. For this we first derive equations of motion for the lunar module by considering allocation locations (configurations) of reaction thruster and a reaction wheel assembly. The lunar module is assumed as a rigid body. In order to include the effect of fuel sloshing on the dynamics of the lunar module, we model it as a spherical pendulum for a simple analysis. For estimating angular rates and moment of inertia of the module, we employ an extended Kalman filter and the least mean square algorithms, respectively. Finally we construct a dynamical model for the lunar module by combining all these elements.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.477-482
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• 1998

In the aquaculture industry, a photobioreactor (Pbr) with high productivity is a prerequisite for mass production of Chlorella sp., a feeding fry for Rotifer (Brachinous plicatilis). To enhance the productivity of Chlorella sp., model Pbrs such as Cylinder type, Spherical surface type, Half-spherical surface type, Plate type, Raceway pond type and Water-wheel type Pbr with different values of surface area exposed to light/culture volume (S/V) were manufactured, and the maximum specific growth rate (${\mu}_{max}$) and productivity of Chlorella vulgaris 211-11b at $25^{\circ}C$, pH 7.0 and 12,000 lux were compared each other. The ${\mu}_{max}$ and productivity were not proportional to S/V. Among the 6 model Pbrs, Half-spherical surface type Pbr showed the highest ${\mu}_{max}$ and productivity as 2.206 ($day^{-1}$) and 0.247($g^{{\ell}-1}day^{-1}$).

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.347-360
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• 2008

In this paper, a Hardware-In-the-Loop simulator to simulate attitude control of space craft using momentum wheels is developed. The simulator consists of a spherical air bearing system allowing rotation and tilt in all three axes, three momentum wheels for actuation, and an AHRS (Attitude Heading Reference System). The simulator processes various types of data in PC104 and wirelessly communicates with a host PC using TCP/IP protocol. A simple low-cost momentum wheel assembly set and its drive electronics are also developed. Several experiments are performed to test the performance of the momentum wheels. For the control performance test of the simulator, a PID controller is implemented. The results of experimental demonstrations confirm the feasibility and validity of the Hardware-In-the-Loop simulator developed in the current study.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.2
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• pp.1-9
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• 2006

As consumers in optics, electronics, aerospace and electronics industry grow, the demand for ultra-precision aspheric surface lens increases higher. To enhance the precision and productivity of ultra precision aspheric surface micro lens, the development of ultra-precision grinding system and process for the aspheric surface micro lens are described. In the work reported in this paper, an ultra-precision grinding system for manufacturing the aspheric surface micro lens was developed by considering the factors affecting the ground surface roughness and profile accuracy. This paper deals with mirror grinding of an aspheric surface micro lens by resin bonded diamond wheel and spherical lens of BK7. The optimization of grinding conditions on ground surface roughness and profiles accuracy is investigated using the design of experiments.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.635-640
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• 2000

This paper presents the analysis method of the instantaneous screw axis using line geometry in bump and rebound motion of 5-SS multi-link suspensions. Instantaneous screw axis is based on screw motion, and screw motion of zero pitch can be expressed as $Pl{\ddot{u}}cker$ line coordinates of line geometry instead of screw coordinates. In screw coordinates, twist and wrench are described by components of instantaneous screw axis. For instantaneous motion of wheel assembly, the principle of virtual work with twist and wrench is applied to 5-SS multi-link suspension, and it makes 5 linear equations. Therefore, it is possible to find instantaneous screw axis by solving these equations. This analysis by line geometry demands geometric values only, such as the locations of spherical joints in the case of multi-link suspensions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.561-562
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• 2006

To enhance the precision and productivity of ultra precision aspheric surface micro lens, the development of ultra-precision grinding system and process for the aspheric surface micro lens are described. In the work reported in this paper, an ultra-precision grinding system for manufacturing the aspheric surface micro lens was developed by considering the factors affecting the grinding surface roughness and profile accuracy. This paper deals with mirror grinding of an aspheric surface micro lens by resin bonded diamond wheel and spherical lens of BK7. The optimization of grinding conditions on ground surface roughness and profiles accuracy is investigated using the design of experiments.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.636-646
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• 2017

This thesis aims to create a new technique by applying traditional ceramics technique. As a matter of fact, on the toremi plate of the sieve-frame skein technique, the weld on which various patterns are squeezed, is attached to the cylinder made of clay on the spinning wheel. And it is the concept that maximizes aesthetic beauty by expressing distorted pattern and free dismantling of existing pattern by pushing it out from inside by the turn of electric spinning wheel for the first time.The main point of view of this aesthetic source is that most of the surface of the ceramics is a spherical curved surface and looks distorted like an indicator drawn on a globe. The researcher created a dynamic and humorous technique of expression through the free dismantling of the squashed shapes and the distorted patterns and called it the bating sealing weld outer wall extension technique.