• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.6-8
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• 2008

Electrical machineries have been developed as following with various and high technical application in these days. Especially the robot is integrated system including mechanical structure, electronic control, and electrical technology. The robot system is not compact and has not natural motion like human, although the technology of robot has been developing continuously. The spherical wheel motor is useful electric machine for using robot joint as operation of 3-degrees of freedom. In this paper, a permanent magnet spherical wheel motor is introduced and performance characteristics are analyzed for improving of operation stability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1089-1090
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• 2010

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.97.1-97.1
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• 2008

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1667-1672
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• 2009

The spherical motor is an electric machine which is able to tilt its shaft on 3-dimensional space as using electromagnetic force. Recently a permanent magnet is remarkable material for applying electric machinery, because of high magnetic flux density. In this paper, a spherical motor, which has permanent magnet on its rotor, is researched. As known, the spherical motor has a special feature as 3 degrees of freedom (D.O.F) operation. This performance can be realized by using electromagnetic torque between coils and magnets. Therefore, in this paper, a permanent magnet spherical wheel motor is introduced and performance characteristics are analyzed for improving of operation stability.

• ETRI Journal
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• v.41 no.6
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• pp.838-849
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• 2019

We present a permanent magnet-based spherical wheel motor that can be used in omnidirectional mobility applications. The proposed motor consists of a ball-shaped rotor with a magnetic dipole and a hemispherical shell with circumferential air-core coils attached to the outer surface acting as a stator. Based on the rotational symmetry of the rotor poles and stator coils, we are able to model the rotor poles and stator coils as dipoles. A simple physical model constructed based on a torque model enables fast numerical simulations of motor dynamics. Based on these numerical simulations, we test various control schemes that enable constant-speed rotation along arbitrary axes with small rotational attitude error. Torque analysis reveals that the back electromotive force induced in the coils can be used to construct a control scheme that achieves the desired results. Numerical simulations of trajectories confirm that even without explicit methods for correcting the rotational attitude error, it is possible to drive the motor with a low attitude error (<5°) using the proposed control scheme.

• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.183-187
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• 2012

In the present study, a feasibility study on an innovative satellite attitude control actuator is performed. The actuator is specially designed to generate the reaction torque in an arbitrary axis, so that a satellite attitude can be controlled by using itself. It consists of a spherical flywheel and electromagnets for levitation and rotation control of the ball. As the earlier study, a rotating performance test on the spherical actuator is conducted in a single rotating axis and vertical levitation condition. From the test results, it can be confirmed that the maximum speed and torque of the innovative device are 7,200rpm and 0.7Nm, respectively. Using torque-voltage characteristics of the spherical motor, an open-loop control (V/f constant control) is performed, and the test results show excellent control performance in acceleration and deceleration phases.

• Journal of Advanced Navigation Technology
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• v.16 no.5
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• pp.731-737
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• 2012

In the present study, a feasibility study on an innovative satellite attitude control actuator is performed. The actuator is specially designed to generate the reaction torque in an arbitrary axis, so that a satellite attitude can be controlled by using itself. It consists of a spherical flywheel and electromagnets for levitation and rotation control of the ball. As the earlier study, a rotating performance test on the spherical actuator is conducted in a single rotating axis and vertical levitation condition. From the test results, it can be confirmed that the maximum speed and torque of the innovative device are 7,200rpm and 0.7Nm, respectively. Using a velocity-voltage characteristic curve of the spherical motor, an open-loop control (V/f constant control) is performed, and the test results show excellent control performance in acceleration and deceleration phases.

• 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 Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.463-466
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• 2017

The purpose of this paper is to develop a module capable of all-directional driving different from conventional wheeled robots, and to solve the problems of the conventional mobile robot with side driving performance degradation, It is possible to overcome the disadvantages such as an increase in the time required for the unnecessary driving. The all - direction spherical wheel drive module for driving a ball - balancing robot is required to develop a power transfer mechanism and a driving algorithm for driving the robot in all directions using three rotor casters. 3DoF (Axis) A driver with built-in forward motion algorithm is embedded in the module and a driving motor module with 3DoF (axis) for driving direction and speed is installed. The movement mechanism depends on the sum of the rotation vectors of the respective driving wheels. It is possible to create various movement directions depending on the rotation and the vector sum of two or three drive wheels. It is possible to move in different directions according to the rotation vector field of each driving wheel. When a more innovative all-round spherical wheel drive module for forward movement is developed, it can be used in the driving part of the mobile robot to improve the performance of the robot more technically, and through the forward-direction robot platform with the drive module Conventional wheeled robots can overcome the disadvantage that the continuous straightening performance is lowered due to resistance to various environments. Therefore, it is necessary to use a full-direction driving function as well as a cleaning robot and a mobile robot applicable in the Americas and Europe It will be an essential technology for guide robots, boarding robots, mobile means, etc., and will contribute to the expansion of the intelligent service robot market and future automobile market.