• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.2
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• pp.59-66
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• 2007

Voice coil actuator is used linear motion system that requires precision positioning control. In order to control precision positioning of voice coil actuator, relation model between duty ratio and moving displacement of voice coil actuator is needed. This paper present a duty ratio - displacement model in PWM control of voice coil actuator. Transfer function of voice coil actuator is obtained by combining voice coil motor's equation of motion with the equation of circuit and characteristic of voice coil motor. Consider to initial condition of velocity and current, transfer function is transformed mathematical model. The induced model can predict output displacement, velocity and current according to duty ratio and amplitude. The model is verified by experimental tests such as velocity and displacement response of voice coil motor. Simulated results have tracking errors of less than 10 percent of experimental results.

• Proceedings of the KIEE Conference
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• summer
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• pp.1034-1036
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• 2004

The most basic form of a direct-drive linear motor is the voice coil motor(VCM). The voice coil motor employs a stationary permanent magnet field assembly in conjunction with a moving coil winding assembly to produce a force proportional to the current applied to the coil. Voice coil motor provide motion capable of extremely fine position sensitivity, limited only by the feedback sensor used to close the control loop. This paper presents dual-servo voice coil motor for improvement of driving range and position resolution. The voice coil motor is a cylindrical shape to improve reliability of a nanoindenter.

• 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 Society of Precision Engineering Conference
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• 2005.10a
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• pp.375-378
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• 2005

Voice Coil Motor is used linear motion actuator system that require precision positioning control. In order to control precision positioning of voice coil motor, Mathematical model of voice coil motor is needed. Mathematical model is obtained by combining voice coil motor's equation of motion with the equation of circuit and characteristic of voice coil motor. The induced model can predict output displacement according to duty ratio and amplitude. The model is verified by experimental test. Simulated results have tracking errors of less than 10 percent of experimental results.

• Journal of Drive and Control
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• v.9 no.4
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• pp.1-7
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• 2012

The voice coil linear force motor is a kind of a direct drive motion device that uses a permanent magnetic field and coil winding to produce force. In order to design a voice coil linear force motor, an exact calculations of the required force, the flux density in air gap and the flux pathway are needed. A conventional method can be used usually to calculate the flux density in air gap, but with this method it is needed to find a magnetic circuit revision constant. In this paper a voice coil linear force motor is designed by conventional design method and analyzed by 3D simulation program "Flux". For the prototype linear force motor, the results of the calculated by conventional design method and the analyzed by 3D simulation program are compared with the test result. Finally it is showed that the magnetic circuit revision constant which is found by comparing of the analyzed and the measured data can be used for the design of the voice coil type linear force motor to minimize the trial and error.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.95-96
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.57-58
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• 2006

A Simulation model is developed to minimize the path tracking errors when the non-circular cutting is done by a VCM(voice coil motor) driven tool. The relationship between PWM(Pulse Width Modulation) duty ratio and velocity of voice coil motor is theoretically derived from combining the circuit equation for the coils and the motion equation for the magnetic rod of the voice coil motor. The path tracking errors are showed differently according to the rotational speed, the number of segments and the control period in digital control. Given a required accuracy in the non-circular cutting, the optimal values for those parameters are determined based on the developed simulation model.

• Journal of Magnetics
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• v.21 no.3
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• pp.348-355
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• 2016

Precision motion stages used in the manufacturing process of flat-panel displays have inevitably low settling performance due to their huge mass and bulky structures. In order to improve the settling performance, several methods of frame vibration compensation have been developed so far. These methods are used to cancel the vibration by imposing a counter force or modifying the resonance mode of the frame of the stage. To compensate the frame vibration, high force actuators are required. In this paper, a mighty voice coil actuator is proposed to generate the counter force against the frame vibration. The proposed voice coil actuator has an axis-symmetric rectangular structure to achieve a large force with simple and low cost fabrication. Also, the voice coil actuator allows radial clearance up to ${\pm}4mm$. Using an optimized design process and a magnetic circuit model, the power consumption is minimized while the required force is obtained. With a power of 322 W, the VCA has been designed to have a maximum force of 574 N with a force constant of 164 N/A. Experimental results verified the force constant of the fabricated voice coil actuator is well matched with the designed value.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2006.06a
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• pp.129-134
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• 2006

In this paper, actuator based on voice coil motor is designed and estimated to check the capability whether that system is in design specification or not. Design specification is moving range as $20{\times}20mm^2$ a along XY-axis in plane and maximizes bandwidth for high speed. The type of voice coil motor is selected with regarding design specification and minimizes the size of actuator. Flux density of designed voice coil motor is simulated. And PI controller is designed to maximize bandwidth of actuator. Finally, characteristic of designed actuator is simulated and that result reveals the validity of presented design.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.278-280
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• 1998

A voice-coil-type LOA consists of the NdFeB permanent magnets with high specific energy as the stator, a coil-wrapped nonmagnetic hollow rectangular structure, and an iron core as a pathway for magnetic flux. When applying a voice-coil-type LOA to the control system, we have to obtain the control parameters and circuit parameters, such as mass, coil inductance, coil resistance, thrust voltage & stroke, frequency & stroke and so on. Therefore, these parameter were determined from the analytical and experimental method.