PREISACH MODEL OF ER FLUIDS CONSIDERING TEMPERATURE VARIATIONS

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1325-1331 ◽  
Author(s):  
Y. M. HAN ◽  
S. B. CHOI ◽  
H. J. CHOI
Keyword(s):  
Tracking Error ◽  
Preisach Model ◽  
Hysteresis Model ◽  
Temperature Variations ◽  
New Approach ◽  
Model Inversion ◽  
Nonlinear Hysteresis ◽  
Discrete Manner ◽  
Er Fluids ◽  
Er Fluid

This paper presents a new approach for hysteresis modeling of an electro-rheological (ER) fluid. The Preisach model is adopted to describe change of an ER fluid hysteresis with temperature, and its applicability is experimentally proved by examining two significant properties under two dominant temperature conditions. As a first step, the polymethylaniline (PMA)-based ER fluid is made by dispersing the chemically synthesized PMA particles into non-conducting oil. Then, using the Couette type electroviscometer, multiple first order descending (FOD) curves are constructed to consider temperature variations in the model. Subsequently, a nonlinear hysteresis model of the ER fluid is formulated between input (electric field) and output (yield stress). A compensation strategy is also formulated in a discrete manner through the Preisach model inversion to attain desired shear stress of the ER fluid. In order to demonstrate the effectiveness of the identified hysteresis model and the tracking performance of the control strategy, the field-dependent hysteresis loop and tracking error responses are experimentally evaluated in time domain and compared with responses obtained from Bingham model.

Hysteretic Behaviors of Yield Stress in Smart ER/MR Materials: Experimental Results

2006 ◽  
Vol 326-328 ◽  
pp. 1459-1462
Author(s):  
Young Min Han ◽  
Quoc Hung Nguyen ◽  
Seung Bok Choi ◽  
Kyung Su Kim
Keyword(s):  
Yield Stress ◽  
Smart Materials ◽  
Hysteretic Behavior ◽  
Preisach Model ◽  
Hysteresis Model ◽  
First Order ◽  
Input Field ◽  
Nonlinear Hysteresis ◽  
Field Dependent ◽  
Discrete Manner

This paper experimentally investigates the hysteretic behaviors of yield stress in electrorheological (ER) and magnetorheological (MR) materials which are known as smart materials. As a first step, the PMA-based ER material is prepared by dispersing the chemically synthesized polymethylaniline (PMA) particles into non-conducting oil. For the MR material, commercially available one (Lord MRF-132LD) is chosen for the test. Using the rheometer, the torque resulting from the shear stress of the ER/MR materials is measured, and then the yield stress is calculated from the measured torque. In order to describe the hysteretic behavior of the fielddependent yield stress, a nonlinear hysteresis model of the ER/MR materials is formulated between input (field) and output (yield stress). Subsequently, the Preisach model is identified using experimental first order descending (FOD) curves of yield stress in discrete manner. The effectiveness of the identified hysteresis model is verified in time domain by comparing the predicted field-dependent yield stress with the measured one.

Shear stress tracking control of an electrorheological fluid considering hysteresis non-linearity

2004 ◽  
Vol 218 (2) ◽  
pp. 183-194 ◽  
Author(s):  
Y M Han ◽  
S B Choi
Keyword(s):  
Shear Stress ◽  
Tracking Control ◽  
Silicone Oil ◽  
Electrorheological Fluid ◽  
Preisach Model ◽  
Temperature Dependent ◽  
Model Inversion ◽  
Control Robustness ◽  
Discrete Manner ◽  
Er Fluid

This paper presents shear stress tracking control of an electrorheological (ER) fluid actuator subjected to the hysteresis non-linearity. As a first step, polymethylaniline (PMA) particles are prepared and mixed with silicone oil to make an ER fluid. The Couette-type electroviscometer is employed to achieve the field-dependent shear stress. The Preisach model for the PMA-based ER fluid is identified using experimental first-order descending (FOD) curves. A compensation strategy is then formulated in a discrete manner through the Preisach model inversion to achieve the desired shear stress of the ER fluid. A proportional-intergal-derivative (PID) feedback controller is also integrated with the compensator in order to guarantee control robustness to uncertainty due to temperature-dependent hysteresis variation. The tracking performance of the control strategy is experimentally evaluated for two different desired shear stress trajectories.

Control Algorithm for Nanoscale Positioning of a 6DOF Stewart Platform

2007 ◽  
Author(s):  
Yung Ting ◽  
Ho-Chin Jar ◽  
Chun-Chung Li
Keyword(s):  
Measurement Method ◽  
Control Algorithm ◽  
Cost Effective ◽  
Stewart Platform ◽  
Preisach Model ◽  
Hysteresis Model ◽  
Nonlinear Hysteresis ◽  
Control Scheme ◽  
Feedforward Controller ◽  
Minimum Points

A 6DOF Stewart platform driven by piezoelectric actuators was designed for applications in need of nanoscale positioning. By using flexural joints and an error compensation model based on a minimum-points-3-axes measurement method, the manufacturing and assembly errors can be offset. The design of a feedforward controller that is able to reduce the nonlinear hysteresis effect of the piezoelectric actuator is the focus of this article. A dynamic Preisach model is developed to improve the accuracy of hysteresis model, whose inverse model is used as the feedforward controller. Such a control scheme is cost-effective without employing expensive sensors for feedback control. Experimental data shows that the platform can achieve the objective of nanoscale positioning.

Coating of Polyaniline with an Insulating Polymer to Improve the Power Efficiency of Electrorheological Fluids

1999 ◽  
Vol 13 (14n16) ◽  
pp. 1931-1939 ◽  
Author(s):  
J. Akhavan ◽  
K. Slack ◽  
V. Wise ◽  
H. Block
Keyword(s):  
Power Efficiency ◽  
Electrorheological Fluids ◽  
Emeraldine Base ◽  
Heavy Duty ◽  
Base Form ◽  
Static Yield ◽  
High Fields ◽  
Er Fluids ◽  
Er Fluid ◽  
A Current

Currents drawn under high fields often present practical limitations to electrorheological (ER) fluids usefulness. For heavy-duty applications where large torques have to be transmitted, the power consumption of a ER fluid can be considerable, and for such uses a current density of ~100μ A cm -2 is often taken as a practical upper limit. This investigation was conducted into designing a fluid which has little extraneous conductance and therefore would demand less current. Selected semi-conducting polymers provide effective substrates for ER fluids. Such polymers are soft insoluble powdery materials with densities similar to dispersing agents used in ER formulations. Polyaniline is a semi-conducting polymer and can be used as an effective ER substrate in its emeraldine base form. In order to provide an effective ER fluid which requires less current polyaniline was coated with an insulating polymer. The conditions for coating was established for lauryl and methyl methacrylate. Results from static yield measurements indicate that ER fluids containing coated polyaniline required less current than uncoated polyaniline i.e. 0.5μ A cm -2. The generic type of coating was also found to be important.

Constructive Proof of Preisach Right Inverse With Applications to Inverse Compensation of Smart Actuators With Hysteresis

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Yangyang Dong ◽  
Hong Hu ◽  
Zijian Zhang
Keyword(s):  
Iterative Algorithm ◽  
Control Design ◽  
Geometric Interpretation ◽  
Constructive Proof ◽  
Preisach Model ◽  
Compensation Scheme ◽  
Fundamental Idea ◽  
Model Inversion ◽  
Significant Challenge ◽  
Piezoelectric Stack Actuator

Hysteresis poses a significant challenge for control of smart material actuators. If unaccommodated, the hysteresis can result in oscillation, poor tracking performance, and potential instability when the actuators are incorporated in control design. To overcome these problems, a fundamental idea in coping with hysteresis is inverse compensation based on the Preisach model. In this paper, we address systematically the problem of Preisach model inversion and its properties, employing the technique of three-step composition mapping and geometric interpretation of the Preisach model. A Preisach right inverse is achieved via the iterative algorithm proposed, which possesses same properties with the Preisach model. Finally, comparative experiments are performed on a piezoelectric stack actuator (PEA) to test the efficacy of the compensation scheme based on the Preisach right inverse.

The Place of Dielectric Spectroscopy in Probing Electrorheology

1999 ◽  
Vol 13 (14n16) ◽  
pp. 1829-1836 ◽  
Author(s):  
S. Kyvelidis ◽  
G. M. Maistros ◽  
P. Rattray ◽  
H. Block ◽  
J. Akhavan ◽  
...  
Keyword(s):  
Electric Fields ◽  
Working Conditions ◽  
High Shear ◽  
Empirical Correlations ◽  
Electrical Parameters ◽  
Shear Rates ◽  
Uniform Shear ◽  
High Shear Rates ◽  
Er Fluids ◽  
Er Fluid

The measurement of the dielectric spectra of PAnQR based ER fluids under shear and electric fields is discussed and results presented. Data in which either but not both shear or electric fields are present are submitted to analysis in terms of known theories. For flow alone, that analysis provides information on the attenuation of polarization by the uniform shear fields whilst the polarization of quiescent fluids by electric fields may lead to estimates of particles packing within the columns. Permittivity data when both fields are acting is presented, but in the absence of suitable theory, not modelled quantitatively. Empirical correlations are discussed and the conclusion drawn that fibrillation is readily suppressed by even moderate shear rates, although long range dipolar forces still persist to high shear rates. The dc conductance of these fluids have also been measured. This together with permittivity data under ER fluid working conditions has importance in establishing the electrical parameters for any ER fluid.

scholarly journals ASCII KS Discrete Matcher: A Different and a New Approach to String Matching using Pattern in Discrete Manner

2012 ◽  
Vol 56 (2) ◽  
pp. 18-19
Author(s):  
Kuljinder SinghBumrah ◽  
Saurabh Rawat ◽  
Anushree Sah ◽  
Sumit Pundir
Keyword(s):  
String Matching ◽  
New Approach ◽  
Discrete Manner
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