• The Journal of Korea Robotics Society
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• v.2 no.2
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• pp.178-182
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• 2007

Precision stages are essential device for micro machines, fiber optic assembly systems, and biology instruments. In this paper, a precision inchworm type actuator for a linear stage is proposed and evaluated. An analytic method to design an inchworm type motor is proposed. Developed actuator provides fast motion compared with a commercial inchworm actuator, and can be used as an actuator for a stage in substitution for a conventional rotary actuator.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.623-625
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• 1992

This study presents a design method for linear DC motor which substituted for rotary combined with conversion apparatus and the designed motor is analyzed. To design the linear DC motor, magnetic cicuit network method is introduced and characteristics of motor at steady state are analyzed using FEM. And the transient behavior is investigated by using the finite element analysis coupling voltage equation and dynamic equation.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.3
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• pp.134-138
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• 2005

A typical conventional systems of a linear motion use rack and pinions or ball screws to convert rotary motions from DC servo motors. A linear motor has been used a several field for a MEMS technology and a aircraft carrier. We have studied a transient response of a linear actuator with a damping ratio, spring constant and a pressed power for a constant stroke control.

• Journal of Magnetics
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• v.15 no.3
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• pp.143-147
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• 2010

Rotary-type voice coil motors are widely used as actuators in hard disk drives. The recent trend toward higher density and smaller form factors in data storage devices requires performance improvement of the voice coil motor. In this study, we introduce a Halbach magnet array to the voice coil motor in order to increase the force generation. The Halbach magnetic circuit outperforms the conventional magnetic circuit due to the confined magnetic flux. To investigate the performance of the Halbach magnetic circuit, we analyze air gap flux density with the various shapes and thickness of the magnets using 3-dimensional finite element analysis. Consequently the optimum shape of the Halbach magnetic circuit is proposed. Simulations and experimental results proved effectiveness of the proposed magnet array in the voice coil motor for a commercial hard disk drive.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.440-440
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• 1999

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.636-640
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• 2003

As industrial technology was developed, necessity for small size motor was increased on various fields such as medical treatment and robotics. The motor should be simple structure, and it has easy process of manufacture to overcome the limit of miniaturization. So, "the windmill type ultrasonic motor" is enough to satisfy these conditions. In this paper, windmill type ultrasonic motor which was proposed by B.Koc and K.Uchino, was analyzed and fabricated with modified endcap shape. Displacements of arms of the proposed endcap were compared with the previous endcap, using the finite element analysis program (ANSYS). Better rotational characteristics was expected in proposed model as result of FEA. Experimentally, rotary motors of 3.5 [cm] diameter were fabricated, and the speed and torque of the motor were measured. As a result, speed and torque were changed in proportion to the electrical input voltages. And low efficiency which was different from an expectation was obtained in this motor. So, various problems should be improved for practical use.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.445-448
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• 2004

Linear motor is very rapidly substituted for rotary motor and ball screw for precision positioning applications because of its characteristics such as high speed, no backlash and simplicities. A precision positioning system which is composed of linear motion(LM) guide and linear motor is widely used since it has easy controllable property but this system has low accuracy problem caused by friction of the LM guide. In this study, a scanning type XY stage is manufactured and some experiments is performed to improve the accuracy of the stage.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.6
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• pp.333-341
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• 2003

In induction motor control systems driven by the indirect vector control scheme, the rotor speed is measured to determine the flux angle which is a key variable in the control algorithm. The most popular way to measure the angular velocity is the use of rotary encoder. Since the errorneous measurement of rotor speed results in incorrect flux angle estimate, the control input generated based on the faulty information should be far from the desired (correct) value and deteriorates the overall control performance. In this paper the effects of encoder fault on motor variables and control performance are analyzed by both theoretical approach and experimental study. A parity equation based on the Power is suggested and applied to detect the incipient fault of encoder.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.1121-1124
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• 1999

Linear motor is able to produce line movement without rotary-to-line converter at the system required line moving. Thus Linear motor has no gear, screw, belt for line movement. Therefore it has some advantage which decrease friction loss, noise, vibration, maintenance effort and prevent decay of control performance due to backlash. This paper proposes the estimation method of unknown parameters from the BLDC Linear motor and determine the PI controller gain through this estimation. Each control movement that is current, speed, position control, and PWM wave generation is performed on Processor, which is DSP(Digital Signal Processor), having high speed performance. PI theory is adopted to each for controller for control behavior More fast convergence to command position is accomplished by applying the new velocity locus which derived from position error.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.191-192
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• 2005

In this study, the ultrasonic motor which has hollowed cross type stator was designed, and the elastic body of ultrasonic motor was optimized by using a finite element analysis program(ANSYS 9.0). When the length of leg(L) of the elastic body was increased and the width of piezoceramics was decreased, the resonant frequency was increased and the displacement of contact point between the rotor and the stator was increased. However, when the length of the leg was over the 1/3 point of the width of ceramics, the displacement of the contact point was decreased, because the elastic buckle was generated in the leg.