• Title, Summary, Keyword: Hysteresis

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Automotive Manual Transmission Clutch System Modeling for Foot Effort Hysteresis Characteristics Prediction (자동차 수동 변속기 클러치 시스템의 답력 이력 특성 예측 모델)

  • Lee, Byoung-Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.5
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    • pp.164-170
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    • 2008
  • A typical clutch system for automotive manual transmissions transfers hydraulic pressure generated by driver's pedal manipulation to the clutch diaphragm spring. The foot effort history during the period of push is different than the period of the clutch pedal's return. The effort or load difference is called clutch foot effort hysteresis. It is known that the hysteresis is caused by friction. The frictional force and moment are produced between various component contact points such as between the rubber seal and the inner wall inside the hydraulic cylinder and between the diaphragm spring and the pressure plate, etc. Understanding the clutch pedal foot effort hysteresis is essential for a clutch release system design and analysis. The dynamic model for a clutch release system is developed for the foot effort hysteresis prediction and a simulation analysis is performed to propose a tool for analysing a clutch system.

Pre-Sliding Friction Control Using the Sliding Mode Controller with Hysteresis Friction Compensator

  • Choi, Jeong Ju;Kim, Jong Shik;Han, Seong Ik
    • Journal of Mechanical Science and Technology
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    • v.18 no.10
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    • pp.1755-1762
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    • 2004
  • Friction phenomenon can be described as two parts, which are the pre-sliding and sliding regions. In the motion of the sliding region, the friction force depends on the velocity of the system and consists of the Coulomb, stick-slip, Streibeck effect and viscous frictions. The friction force in the pre-sliding region, which occurs before the breakaway, depends on the position of the system. In the case of the motion of the friction in the sliding region, the LuGre model describes well the friction phenomenon and is used widely to identify the friction model, but the motion of the friction in the pre-sliding such as hysteresis phenomenon cannot be expressed well. In this paper, a modified friction model for the motion of the friction in the pre-sliding region is suggested which can consider the hysteresis phenomenon as the Preisach model. In order to show the effectiveness of the proposed friction model, the sliding mode controller (SMC) with hysteresis friction compensator is synthesized for a ball-screw servo system.

Hysteresis loss of YBCO thin film strip with filamentary structure (필라멘트 구조의 YBCO 박막의 자기이력 손실)

  • Park H. W;Na D. H;Kim M. J;Chang Y. S;Kim J. M;Ri H.-C;Lee Y. H
    • Progress in Superconductivity
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    • v.6 no.2
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    • pp.99-103
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    • 2005
  • For ac applications a detailed understanding of the ac power losses associated with different conductor configurations is of crucial importance. YBCO thin films were divided into parallel filaments with widths of 1, 2, and 4 mm to reduce hysteresis losses. The measured hysteresis losses show a linear relationship between the strip width and hysteresis loss as anticipated. The influence of different inter-filament separations on the hysteresis loss is investigated.

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A Study on Double Band Hysteresis Current Control based on 3-Level Inverter to reduce the harmonic component in output current of FACTS devices (FACTS 기기의 고조파 저감을 위한 이중밴드 히스테리시스 전류 제어에 관한 연구)

  • Choi, Won-Kyoung;Choi, Jeong-Hye;Kim, Bum-Sik;Shin, Eun-Chul;Lee, Sang-Bin;Yoo, Ji-Yoon
    • Proceedings of the KIEE Conference
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    • pp.180-182
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    • 2005
  • The current control using a conventional hysteresis controller of a STATCOM based on two level VSI (Voltage Source Inverter) has high switching frequency and variable modulation frequency. This will increase the switching loss. In addition, the current error is not strictly limited So, in this paper to reduce the switching frequency and to maintain the constant modulation frequency, a novel double band hysteresis current controller based on 3-level VSI is proposed. A conventional hysteresis current control and a novel hysteresis current control was tested with digital simulation and verified the advantage of the novel hysteresis current controller.

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Modeling of Dynamic Hysteresis Based on Takagi-Sugeno Fuzzy Duhem Model

  • Lee, Sang-Yun;Park, Mignon;Baek, Jaeho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.4
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    • pp.277-283
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    • 2013
  • In this study, we propose a novel method for modeling dynamic hysteresis. Hysteresis is a widespread phenomenon that is observed in many physical systems. Many different models have been developed for representing a hysteretic system. Among them, the Duhem model is a classical nonlinear dynamic hysteresis model satisfying the properties of hysteresis. The purpose of this work is to develop a novel method that expresses the local dynamics of the Duhem model by a linear system model. Our approach utilizes a certain type of fuzzy system that is based on Takagi-Sugeno (T-S) fuzzy models. The proposed T-S fuzzy Duhem model is achieved by fuzzy blending of the linear system model. A simulated example applied to shape memory alloy actuators, which have typical hysteretic properties, illustrates the applicability of our proposed scheme.

Improvement of Hysteresis Characteristics of Low Temperature Poly-Si TFTs (저온 Poly-Si TFT 소자의 Hysteresis 특성 개선)

  • Chung, Hoon-Ju;Cho, Bong-Rae;Kim, Byeong-Koo
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.1
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    • pp.3-9
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    • 2009
  • Although Active matrix organic light emitting diode (AMOLED) display has a better image quality in terms of viewing angle, contrast ratio, and response time than liquid crystal displays (LCDs), it still has some critical issues such as lifetime, residual images, and brightness non-uniformity due to non-uniformity in electrical characteristics of driving TFTs and IR drops on supplied power line. Among them, we improved irrecoverable residual images of AMOLED displays which is mainly related to the hysteresis characteristics of driving TFTs. We consider four kinds of surface treatment conditions before gate oxide deposition for improving hysteresis characteristics. We can reduce the hysteresis level of p-channel TFT to 0.23 V, interface trap states between the poly-Si layer and gate insulator to $3.11{\times}10^{11}cm^{-2}$, and output current variation of p-channel TFT to 3.65 % through the surface treatment using ultraviolet light and H2 plasma. Therefore, the recoverable residual image problem of AMOLED displays can be improved by surface treatment using ultraviolet light and $H_2$ plasma.

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Inverse Hysteresis Modeling for Piezoelectric Stack Actuators with Inverse Generalized Prandtl-Ishlinskii Model (Inverse Generalized Prandtl-Ishlinskii Model를 이용한 압전 스택 액추에이터의 역 히스테리시스 모델링)

  • Ko, Young-Rae;Kim, Tae-Hyoung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.2
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    • pp.193-200
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    • 2014
  • Piezoelectric actuators have been widely used in various applications because they have many advantages such as fast response time, repeatable nanometer motion, and high resolution. However Piezoelectric actuators have the strong hysteresis effect. The hysteresis effect can degrade the performance of the system using piezoelectric actuators. In past study, the parameters of the inverse hysteresis model are computed from the identified parameters using the Generalized Prandtl-Ishlinskii(GPI) model to cancel the hysteresis effect, however according to the identified parameters there exist the cases that can't form the inverse hysteresis loop. Thus in this paper the inverse hysteresis modeling mothod is proposed using the Inverse Generalized Prandtl-Ishlinskii(IGPI) model to handle that problem. The modeling results are verified by experimental results using various input signals.

Preisach Model of Shape Memory Alloy Actuators Using Proportional Relationship of The Major Loop of Hysteresis (히스테리시스 주 루프의 비례관계를 이용한 형상기억합금 엑츄에이터의 Preisach 모델)

  • Choe, Byeong-Jun;Lee, Yeon-Jeong;Choe, Bong-Yeol
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.9
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    • pp.736-746
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    • 2002
  • There has been a great demand for smart actuators in the field of micro-machines. However, the control accuracy of smart actuators, e.g., a shape memory alloy(SMA) and a piezoceramic actuator, is limited due to the inherent hysteresis nonlinearity. The Preisach hysteresis model has emerged as an appropriate model f3r the behavior of those smart actuators. Yet it is still not easy to construct a practical model of hysteresis using the classical Preisach model. Accordingly, in this paper, we propose a new simple method for modeling of the hysteresis nonlinearity of SMA. Using only the proportional relation of the major loop of hysteresis, the proposed method makes the computation of the Preisach model easy. We prove the efficacy of the proposed model through the comparative the experimentation with the classical Preisach model.

Analysis of Hysteresis Characteristics of Flux-Lock Reactor (자속구속 리액터의 히스테리시스 특성 분석)

  • Lim, Sung-Hun;Choi, Hyo-Sang;Kang, Hyeong-Gon;Ko, Seok-Cheol;Lee, Jong-Hwa;Han, Byoung-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.255-258
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    • 2003
  • The hysteresis characteristics of flux-lock reactor, which is an essential component of flux-lock type superconducting fault current limiter (SFCL), was investigated. The hysteresis loss of iron core in flux-lock type SFCL does not happen due to its winding's structure especially in the normal state. From the equivalent circuit for the flux-lock type SFCL and the fault current limiting experiments, the hysteresis curves could be drawn. Through the hysteresis curves together with the fault current level due to the inductance ratio for the 1st and 2nd winding, the increase of the number of turns in the 2nd winding of the flux-lock type SFCL had a role to prevent the iron core from saturation.

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A Study of Using Optimal Hysteresis Band Amplitude Tuning for Direct Torque Control of Induction Motor (최적의 히스테리시스 대역폭을 이용한 유도전동기 직접토크제어에 관한 연구)

  • Jeong, B.H.;Cho, G.B.;Choi, C.J.;Baek, H.L.;Hwang, J.S.;Kim, Y.M.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.598-601
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    • 2003
  • Most of all, DTC drive is very simple in its implementation because it needs only two hysteresis comparator and switching vector table for both flux and torque control. The switching strategy of a conventional direct torque control scheme which is based on hysteresis comparator results in a variable switching frequency which depends on the speed, flux, stator voltage and the hysteresis of the comparator. The amplitude of hysteresis band greatly influences on the drive performance such as flux and torque ripple and inverter switching frequency. In this paper the influence of the amplitudes of flux and torque hysteresis bands and sampling time of control program on the torque and flux ripples are investigated. Simulation results confirm the superiority of the DTC under the proposed method over the conventional DTC.

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