• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.669-672
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• 1999

In this paper, we studied the properties of small-size disk-type ultrasonic motor using travelling wave for the application to the precise control robotic joint motor and fabricated it. The diameter of the ultrasonic motor fabricated was 13mm. Also, the piezoelectric vibrator was constructed by piezoelectric ceramic and elastic material. The piezoelectric ceramic was composed to PZ-PT-PMN which was shown the high electromechanical stability under high vibration level and stainless steel was used as the elastic material in which configuration was disk-type. To conform the capability of application to robotic motor, we measured the change of rotational speed according to applied voltage and applied frequency. As the results, the small-size disk-type ultrasonic motor was able to fabricate, and the revolution speed was 350 (rpm) when input voltage was 55 (Vrms) and applied frequency 160.4 IkHz] under pre-load.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.318-319
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• 2007

In this study, novel structured thin ultrasonic rotary motor has been proposed. Ultrasonic motors are based on an elliptical motion on the surface of elastic body. ATILA ver. 5.2.4 was used for optimizing stator. The motor was fabricated by using designed stator. And characteristics of the motor were compared with simulated results. When the motor was fabricated with these results, 935[rpm] speed was obtain by input voltage of 25[Vrms] at 93.5[khz].

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.105-114
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• 2000

To chive a traveling wave type ultrasonic motor with the series""-resonant inverter, the external inductor is i lnserted between the motor and inverter. In $\psi$is paper, we proposed a novel 3Ilalysis method to design the 3 ~xternal inductor. An equivalent model of the ultrasonic motor is expressed, and a selection method of the , ;;eries inductor is proposed from the basis of the model. When the series inductor has an optimal value, it is v velified by computer simulation results that power is efficiently transmitted to the mechanical resonant c component in the motor. The frequency and speed characteristics of the ultrasonic motor are investigated by e experiments for several external inductors. The validity of the proposed method for selecting external inductor i is clarified.clarified.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1847-1852
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• 2003

Ultrasonic motors have many excellent performances. A variety of ultrasonic motors has been developed and used as an actuator in motion control systems. However, this motor has nonlinear characteristics. Therefore, it is difficult to achieve the precise position control system incorporating with the ultrasonic motor. This paper describes a position control scheme for traveling-wave type ultrasonic motor using a pseudo-derivative control with feedforward gains (PDFF) controller designed by the coefficient diagram method (CDM). The PDFF control system satisfies both the tracking and regulation performances, which are the most important for the precise position control system. The CDM is shown to be an efficient and simple method to design the parameters of PDFF controller. The effectiveness of the proposed control system is demonstrated by experiments.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1518-1520
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• 2002

Purpose of this research compares best transfer speed about applied frequency and voltage using characteristic of $L_1-B_4$ mode and $L_1-B_8$ mode linear ultrasonic motor that use piezoelectric effect. By method of study, analyzed best transfer speed measuring and comparison load status that use actuality telephone card in $L_1-B_4$ mode linear ultrasonic motor and no-load status of $L_1-B_8$ mode linear ultrasonic motor. Experiment result is applied frequency(58.4Hz) in $L_1-B_4$ mode linear ultrasonic motor (load state) and the best transfer speed by 19.8[cm/s] at applied voltage(56V) point. Also, $L_1-B_8$ mode linear ultrasonic motor (no-load state) is best transfer speed by applied frequency(27.9kHz) and 32.96[cm/s] at applied voltage (50V) point.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.122-130
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• 2005

For silent operation, Roll-Screen has been designed by using piezolelectric ultrasonic motor. To drive the ultrasonic motor, a digitally controlled drive system has been designed by using PLD. And to measure the position and velocity of Roll-Screen, encoder with 36 pulse/revolution is used. This paper proposed a new method for a precise velocity control of ultrasonic motor, in spite of using low-level encoder. The proposed method use a non-fixed sampling time and compensate the initial nonlinear characteristics of ultrasonic motors.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.891-895
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• 2005

Novel structure ultrasonic motors which have cross type stator were designed and fabricated. Driving characteristics of the motors were analyzed and measured by changing the materials of the stator. This ultrasonic motor has stator with hollowed cross bar and the stator rotate the rotor using elliptical displacement of the inside tips. This motion is generated by lateral vibration mode of cross bars. This stator was analyzed by finite element analysis depandent on stator's materials. And the cross type ultrasonic motors were made by analyzed results. The larger displacements were obtained, when the density of material was decreased. But the stress was increased when the stator's material has large density and Young's modulus. The fabricated one has high speed and torque in large stress on contact point between rotor and stator. The stress was more effected on speed and torque than the displacement.

• Transactions on Electrical and Electronic Materials
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• v.10 no.5
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• pp.156-160
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• 2009

In an ultrasonic motor, a piezoelectric ceramic material forms the active element which vibrates the stator, thus initiating the rotational motion. In the operation of ultrasonic motors, many factors exist that can affect the resonance characteristics of the piezoelectric ceramic component. For examples, these factors are the bonding conditions with the piezoelectric element, the magnitude of the input voltage, the normal force in the frictional drive and the emission of heat due to vibration and friction etc. Therefore, it is important to research properly the inclination for variation of piezoelectric ceramics in the circumstance where complex elements are involved. In this paper, we focus on the analysis of the resonance characteristics of an ultrasonic motor as a function of the magnitude of the input voltage and the normal force.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.354-356
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• 2005

Novel structure ultrasonic motors which have cross type stator were designed and fabricated. Driving characteristics of the motors were analyzed and measured by changing the materials of the stator. This ultrasonic motor has stator with hollowed cross bar and the stator rotate the rotor using elliptical displacement of the inside tips. This motion is generated by lateral vibration mode of cross bars. This stator was analyzed by finite element analysis and the ultrasonic motors were made by analyzed results. The larger displacements were obtained, when the Young's modulus was increased and the Poisson's ratio was decreased. The fabricated one has high speed in large Poisson's ratio and Young's modulus. And the torque was increased in high Young's modulus.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.79-81
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• 1998

This paper presents analytic and numerical analysis of ultrasonic motor, specially linear motion ultrasonic machine. For rough estimation of characteristics of linear ultrasonic motor, the analytic method is used and a three-dimensional numerical analysis with experimental material data using ABAQUS, is performed. The validity of analysis is confirmed by comparing experimental results with numerical ones.