• Title/Summary/Keyword: Ultrasonic speed method

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Development of Compact Phase-difference Controller for an Ultrasonic Rotary Motor (회전형 초음파모터의 소형 위상차 제어기 개발)

  • Yi Dong-Chang;Lee Myoung-Hoon;Lee Eu-Hark;Lee Sun-Pyo
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.8 s.185
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    • pp.64-71
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    • 2006
  • In this paper, a uniform speed controller for an ultrasonic rotary motor is developed using the phase-difference method. The phase difference method uses traveling waves to drive the ultrasonic motor. The traveling waves are obtained by adding two standing waves that have a different phase to each other. A compact phase-difference driver system is designed and integrated by combining VCO(Voltage Controlled Oscillator) and phase shifter. Theoretically the relationship between the phase difference in time and the rotational speed of the ultrasonic motor is sine function, which is verified by experiments. Then a series of experiments under various loading conditions are conducted to characterize the motor's performance that is the relationship between the speed and torque. Proportional-integral control is adopted for the uniform speed control. The proportional control unit calculates the compensating phase-difference using the rotating speed which is measured by an encoder and fed back. Integral control is used to eliminate steady-state errors. Differential control for reducing overshoot is not used since the response of ultrasonic motor is prompt due to its low inertia and friction-driving characteristics. The developed controller demonstrates reasonable performance overcoming disturbing torque and the changes in material properties due to continuous usage.

On the Change of Fabric Mechanical properties in Ultrasonic Fabric Washing System (호부직물의 초음파 수세에 의한 역학적 특성의 변화)

  • Lee, Choon-Gil;Park, Sung-Diuk;Oh, Bong-Hyo
    • Textile Coloration and Finishing
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    • v.9 no.4
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    • pp.28-38
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    • 1997
  • Peach skin fabrics were washed by the general and ultrasonic washing systems using different conditions. The physical properties of the washed fabrics were estimated. The following results were obtained through experimental data and their analysis. The tensile properties were changed due to fabric running speed and washing methods. The lower the running speed, the higher the extensibility and resilience and the lower the linearity and tensile energy. In the general washing method, the extensibility and resilience had lower values than those of the ultrasonic washing method and the linearity and tensile energy had the higher values than those of the ultrasonic washing system. The bending properties, bending moment and histeresis, were estimated. These values were generally lower in the ultrasonic washing system than those of the general washing system. The faster the washing speed, the higher the value of hysterisis. The shear properties were affected by the fabric running speed and washing methods. Shear stiffness and hysteresis of shear forces increased according to the increase of the fabric running speed. The values were higher in the general washing system than those of the ultrasonic washing system. The compressional energy was affected by the fabric running speed. The higher the fabric speed the higher the compressional energy. The ultrasonic washing system had lower compressional energy than the general washing system. The higher the running speed, the lower the coefficient of friction and geometrical roughness. The values of geometrical roughness were infienced by the removal of the sizing agent. The higher the remaining sizing agent, the higher the fabric weight and the thicker the thickness of fabric.

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A Study on the Driving Circuit of Piezoelectric Ultrasonic Motor Using PLL Technique (PLL을 이용한 압전 초음파 모터의 구동회로에 관한 연구)

  • ;;Sergey Borodin
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.1
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    • pp.33-38
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    • 2003
  • This paper describes control principles of the piezoelectric ultrasonic motor which is operated by the ultrasonic vibration generated by the piezoelectric element. The piezoelectric ultrasonic motor has excellent characteristics such as compact size, noiseless motion, low speed, high torque and controllability, and has been recently applied for the practical utilization in industrial, consumer, medical and automotive fields. In this paper, the design of two-phase push-pull inverter for driving the piezoelectric ultrasonic motor is described, and a new control method of automatic resonant frequency tracking using PLL(Phase-Locked Loop) technique is mainly presented. the experimental results by this inverter system for driving the piezoelectric ultrasonic motor are illustrated herein. The inverter system with PLL technique improved the speed stability of the piezoelectric ultrasonic motor.

A Basic Research on Estimation of Material Condition by Using Stress Dependency of Sound Speed (음속의 응력의존성을 이용한 재료 상태평가에 대한 기초적 연구)

  • Kim, K.J.;Jhang, K.Y.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.4
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    • pp.53-60
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    • 1996
  • In the conventional linear elasticity, sound speed is determined by only elastic modulus and density of the medium. In actual, however, sound speed depends on the stress and this dependency becomes nonlinear as the stress increases. These phenomena can be introducing nonlinear elastic modulus. In this paper, relationships between nonlinear elastic modulus up to 4th order and the internal status of materials are discussed through computer simulations and experiments. For the measurement of sound speed, a new type of measurement system using ultrasonic wave is proposed on the basis of ultrasonic pulse echo method which has been generally used in nondestructive ultrasonic test equipment. In order to confirm the stress dependency of sound speed, several experiments are carried out for alumina specimen.

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Analysis of Ultrasonic Linear Motor Using the Finite Element Method and Equivalent Circuit

  • Park, Jong-Seok;Joo, Hyun-Woo;Lee, Chang-Hwan;Jung, Hyun-Kyo
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.3B no.4
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    • pp.159-164
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    • 2003
  • In this paper, a three-dimensional finite element method and construction of equivalent-circuit for a linear ultrasonic motor are presented. The validity of three-dimensional finite element routine in this paper is experimentally confirmed by analyzing impedance of a piezoelectric transducer. Using this confirmed finite element routine, impedance and vibration mode of a linear ultrasonic motor are calculated. Elliptical motion of contact point between vibrator and rail of the linear ultrasonic motor is shown for determination of contact points. By using the finite element method and analytic equations, characteristics of the linear ultrasonic motor, such as thrust force, speed, losses, powers and efficiency, are calculated. The results are confirmed by experiment. Finally, equivalent circuit parameters of the linear ultrasonic motor are obtained using the three-dimensional finite element method and analytic equations.

Comparison of Characteristics between $L_1-B_4$ mode and $L_1-B_8$ mode Ultrasonic Motors ($L_1-B_4$모드와 $L_1-B_8$모드 초음파 선형 전동기의 특성 비교)

  • U, Sang-Ho;Kim, Dong-Yeon;Kim, Jin-Soo
    • 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.

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Speed Sensorless Control of Ultrasonic Motors Using Neural Network

  • Yoshida Tomohiro;Senjyu Tomonobu;Nakamura Mitsuru;Urasaki Naomitsu;Funabashi Toshihisa;Sekine Hideomi
    • Journal of Power Electronics
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    • v.6 no.1
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    • pp.38-44
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    • 2006
  • In this paper, a speed sensorless control for an ultrasonic motor (USM) using a neural network (NN) is presented. In the proposed method, rotor speed is estimated by a three-layer NN which adapts nonlinearities associated with load torque and motor temperature into control. The intrinsic properties of a USM, such as high torque for low speeds, high static torque, compact size, etc., offer great advantages for industrial applications. However, the speed property of a USM has strong nonlinear properties associated with motor temperature and load torque, which make accurate speed control difficult. These properties are considered in designing a control method through the application of mathematical models. In these strategies, a detailed speed model of the USM is required which makes actual applications impractical. In the proposed method, a three-layer NN estimates the speed of the USM from the drive frequency, the root mean square value of input voltage and the surface temperature of the USM, where no mechanical speed sensor is needed. The NN speed based estimator enables inclusion of variations in driving conditions due to input signals of the NN involved during the driving state of the USM. The disuse of sensors offers many advantages on both the cost and maintenance front. Moreover, the model free sensorless control method offers practical controller construction within a small number of parameters. To validate the proposed speed sensorless control method for a USM, experiments have been executed under several conditions.

The Study on Elongation and Torque Measurement in Large Bolt by using Ultrasonic Technology (초음파를 이용한 대형볼트 신장량 및 체결력 측정연구)

  • Ahn, Y.S.;Gil, D.S.;Park, S.G.
    • Journal of Power System Engineering
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    • v.13 no.3
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    • pp.40-46
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    • 2009
  • This study on the bolt elongation and torque measuring method by ultrasonic nod-destructive method. In the past, The dial gage was used for the elongation measurement of gas turbine bolts. The purpose of this study is to improve the traditional bolt elongation measurement method. The old method using dial gage measures the elongation of the gas turbine bolt. If the length differences among the loading bolts are within the required range, The loading torques of bolts consider as acceptable. But this method can not give the information about torque differences among the loading bolts. It could bring out vibration of turbine due to loading torque differences among the bolts. So the elongation and torque must be measured simultaneously. The new technology using ultrasonic non-destructive method can give the information about bolt elongation and torque. The ultrasonic method basically measures the speed in the bolt material for the calculation the bolt elongation. But the ultrasonic speed varies according to temperature and loading torque of bolts. So the factors of temperature and loading power were investigated and reflected to the calculation of bolt elongation and torque. The results of this study shows the big difference among the bolts torque in the old method and the torque differences among the bolts can be adjusted by reflecting the result of this study. And this torque adjusting method can decrease gas turbine vibration problem due to torque difference among the bolts. So this paper shows ultrasonic method is better than old method for the measurement of bolt elongation and torque.

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A Novel Method for Improving the Positioning Accuracy of a Magnetostrictive Position Sensor Using Temperature Compensation (온도 보상을 이용한 자기변형 위치 센서의 정확도 향상 방법)

  • Yoo, E.J.;Park, Y.W.;Noh, M.D.
    • Journal of Sensor Science and Technology
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    • v.28 no.6
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    • pp.414-419
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    • 2019
  • An ultrasonic based magnetostrictive position sensor (MPS) provides an indication of real target position. It determines the real target position by multiplying the propagation speed of ultrasonic wave and the time-of-flight between the receiving signals; one is the initial signal by an excitation current and the other is the reflection signal by the ultrasonic wave. The propagation speed of the ultrasonic wave depends on the temperature of the waveguide. Hence, the change of the propagation speed in various environments is a critical factor in terms of the positioning accuracy in the MPS. This means that the influence of the changes in the waveguide temperature needs to be compensated. In this paper, we presents a novel way to improve the positioning accuracy of MPSs using temperature compensation for waveguide. The proposed method used the inherent measurement blind area for the structure of the MPS, which can simultaneously measure the position of the moving target and the temperature of the waveguide without any additional devices. The average positional error was approximately -23.9 mm and -1.9 mm before and after compensation, respectively. It was confirmed that the positioning accuracy was improved by approximately 93%.

A Study on the Wet Type Ultrasonic Flow-meter System Development (습식방식의 초음파 유량계 시스템 개발에 관한 연구)

  • Lee Eung-Suk;Kwon Oh-Hoon;Rho Myung-Hwan;Lee Hyung-Suk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.12 s.243
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    • pp.1638-1644
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    • 2005
  • This paper suggests fur the study on a fluid velocity measuring system using ultrasonic transducer. In general, the time difference method to measure the distance between transducers has been known. In this paper, the practical technology for manufacturing ultrasonic flow meter system is studied using the time difference method. The ultrasonic transducer was designed and manufactured. The transmission and receiving algorithm for ultrasonic signal was studied. The ultrasonic flow measuring system was experimented in laboratory using a water reservoir for verifying the distance measuring accuracy. Finally, it was tested in flow calibration laboratory for the velocity measuring performance. The system, designed in this study, showed 0.3 mm resolution in distance measurement. For precise flow measurement, a high speed triggering algorithm is required for ultrasonic signal receiving.