Semi-Active Damping of Ground Resonance in Helicopters Using Magnetorheological Dampers

2000 ◽  
Author(s):  
Norman M. Wereley ◽  
Nicolas Costes
Keyword(s):  
Mr Damper ◽  
Active Damping ◽  
Rotor System ◽  
Magnetorheological Dampers ◽  
Resonance Analysis ◽  
Mr Dampers ◽  
Resonance Behavior ◽  
Ground Resonance ◽  
And Control

Abstract We will assess the capabilities of physically motivated MR dampers to mitigate ground resonance instability and control the damping level of rotor lag modes. The objectives of this research are threefold: (1) develop a methodology for the integration of the MR damper into a classic linear ground resonance analysis assuming an isotropic rotor hub (all dampers and blades similar) and an anisotropic rotor hub (due to lag damper dissimilarity due to damage, for example), (2) assess whether MR dampers can stabilize a rotor system that exhibits unstable ground resonance, (3) assess whether MR dampers can stabilize a rotor which exhibits unstable ground resonance behavior due to lag damper degradation or damage. The analyses developed in this study show that MR dampers are feasible for achieving these goals.

scholarly journals Modeling of Magnetorheological Dampers under Various Impact Loads

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
K. Sarp Arsava ◽  
Yeesock Kim
Keyword(s):  
Structural Control ◽  
Experimental Studies ◽  
Mr Damper ◽  
Impact Behavior ◽  
Impact Loads ◽  
Mr Dampers ◽  
Fuzzy Models ◽  
Control Signals ◽  
And Control ◽  
The Impact

Magnetorheological (MR) damper has received great attention from structural control engineering because it provides the best features of both passive and active control systems. However, many studies on the application of MR dampers to large civil structures have tended to center on the modeling of MR dampers under seismic excitations, while, to date, there has been minimal research regarding the MR damper model under impact loads. Hence, this paper investigates nonlinear models of MR dampers under a variety of impact loads and control signals. Two fuzzy models are proposed for modeling the nonlinear impact behavior of MR dampers. They are compared with mechanical models, the Bingham and Bouc-Wen models. Experimental studies are performed to generate sets of input and output data for training, validating, and testing the models: the deflection, acceleration, velocity, and current signals. It is demonstrated that the proposed fuzzy models are effective in predicting the complex nonlinear behavior of the MR damper subjected to a variety of impact loads and control signals. The proposed fuzzy model resulted in an accuracy of 99% to predict the impact forces of the MR damper.

Design and Control of Semi-Active Railway Vehicle Suspension Featuring MR Damper

2014 ◽  
Author(s):  
Jong-Seok Oh ◽  
Hwan-Choong Kim ◽  
Seung-bok Choi
Keyword(s):  
Mr Damper ◽  
Design Parameters ◽  
Vehicle Suspension ◽  
Railway Vehicle ◽  
Damping Force ◽  
Bogie Frame ◽  
Car Body ◽  
Mr Dampers ◽  
Vehicle Suspension System ◽  
And Control

In this work, control performance of a semi-active railway vehicle suspension system featuring MR damper is evaluated. Firstly, a mathematical model for railway vehicle which contains car body, bogie frame and wheel-set is derived to represent lateral, yaw and roll motions. From this model, design parameters of MR damper are optimally determined. And then, MR dampers which can generate proper damping force to control the unwanted vibration of the railway vehicle are manufactured and evaluated experimentally. In order to attenuate the vibration of railway vehicle, in this work, skyhook controller is designed and implemented. Control performances of MR damper for railway vehicle including car body lateral motion and acceleration of MR damper are evaluated using test rig composed of a car body and two bogies.

Design and Analysis of Magneto-Rheological Dampers under Impact Loads

2013 ◽  
Vol 295-298 ◽  
pp. 2045-2048
Author(s):  
Xiao Ming Han ◽  
Yu Cheng Bo ◽  
Qiang Li ◽  
Ji Huang
Keyword(s):  
Control Strategy ◽  
Test Bench ◽  
Mr Damper ◽  
Second Law ◽  
Impact Loads ◽  
Structure Parameter ◽  
Mr Dampers ◽  
Recoil Force ◽  
Magneto Rheological ◽  
And Control

In order to improve recoil mechanism’s buffering function of automatic weapon, using Newton’s second law, its recoil movement is analyzed and design model of magneto-rheological (MR) damper under impact loads is built. Structure parameter and control strategy are defined. Dampers’ characteristic curves at different magnetizing currents and different recoil speeds are tested on a damper indicator test bench. Some weapon’s recoil forces are artificially computed. The research results indicate that MR dampers have a perfect damping plateau effect. Recoil force of automatic weapon will be reduced by a big margin using the property that MR fluid can change at applied magnetic to control damping rules.

Semi-Active Damping of Ground Resonance in Helicopters Using Magnetorheological Dampers

2004 ◽  
Vol 49 (4) ◽  
pp. 468-482 ◽  
Author(s):  
Yongsheng Zhao ◽  
Young-Tai Choi ◽  
Norman M. Wereley
Keyword(s):  
Active Damping ◽  
Magnetorheological Dampers ◽  
Ground Resonance

A Reliability Assessment Model for MR Damper Components within a Smart Structural Control Scheme

2008 ◽  
Vol 56 ◽  
pp. 218-224
Author(s):  
Maguid H.M. Hassan
Keyword(s):  
Structural Control ◽  
Inverse Dynamics ◽  
Mr Damper ◽  
Assessment Model ◽  
Resistance Force ◽  
Mr Dampers ◽  
Control Scheme ◽  
Smart Control ◽  
Control Devices ◽  
Magneto Rheological

Smart control devices have gained a wide interest in the seismic research community in recent years. Such interest is triggered by the fact that these devices are capable of adjusting their characteristics and/or properties in order to counter act adverse effects. Magneto-Rheological (MR) dampers have emerged as one of a range of promising smart control devices, being considered for seismic applications. However, the reliability of such devices, as a component within a smart structural control scheme, still pause a viable question. In this paper, the reliability of MR dampers, employed as devices within a smart structural control system, is investigated. An integrated smart control setup is proposed for that purpose. The system comprises a smart controller, which employs a single MR damper to improve the seismic response of a single-degree-of-freedom system. The smart controller, in addition to, a model of the MR damper, is utilized in estimating the damper resistance force available to the system. On the other hand, an inverse dynamics model is utilized in evaluating the required damper resistance force necessary to maintain a predefined displacement pattern. The required and supplied forces are, then, utilized in evaluating the reliability of the MR damper. This is the first in a series of studies that aim to explore the effect of other smart control techniques such as, neural networks and neuro fuzzy controllers, on the reliability of MR dampers.

The Modelling of Hysteresis in Magnetorheological Dampers Using a Generalised Prandtl-Ishlinskii Approach

2010 ◽  
Author(s):  
Kun Wang ◽  
Ying Zhang ◽  
Richard W. Jones
Keyword(s):  
Mr Damper ◽  
Control Analysis ◽  
Sigmoid Function ◽  
Magnetorheological Dampers ◽  
Operating Characteristics ◽  
Major Drawback ◽  
Analysis And Design ◽  
Force Velocity ◽  
Play Operator ◽  
Fidelity Model

The major drawback of magnetorheological dampers (MR) lies in their non-linear and hysteretic force-velocity response. To take full advantage of the operating characteristics of these devices a high fidelity model is required for control analysis and design. In this contribution the ability of a generalised PI operator-based model to represent the characteristics of a commercially available MR damper is examined. This approach allows the user to define the PI operator to best match the hysteresis characteristics. For the MR damper the force-velcoity hysteresis characteristic is ‘S’ shaped and constrained. Two possibilities will be examined here for the generalised play operator; an hyperbolic tan function and a symmetric sigmoid function.

Application of Magneto Rheological Dampers for Controlling Shock Loading

1999 ◽  
Author(s):  
Mehdi Ahmadian ◽  
James C. Poynor ◽  
Jason M. Gooch
Keyword(s):  
Dynamic System ◽  
Shock Loading ◽  
Closed Loop ◽  
Shock Absorber ◽  
Mr Damper ◽  
Test Results ◽  
Closed Loop System ◽  
Mr Dampers ◽  
Shock Dynamics ◽  
Magneto Rheological

Abstract This study will examine the effectiveness of magneto-rheological (MR) dampers for controlling shock dynamics. Using a system that includes a 50-caliber rifle and a magneto-rheological damper, it is experimentally shown that MR dampers can be quite effective in controlling the compromise that commonly exists between shock forces and strokes across the shock absorber mechanism. A series of tests are conducted to demonstrate that different damping forces by the MR damper can result in different shock-force/stroke profiles. The test results further show that MR dampers can be used in a closed-loop system to adjust the shock loading characteristics in a manner that fits the dynamic system constraints and requirements.

On the Efficacy of Magnetorheological Dampers for Seismic Response Reduction

1997 ◽  
Author(s):  
S. J. Dyke ◽  
B. F. Spencer ◽  
M. K. Sain ◽  
J. D. Carlson
Keyword(s):  
Control Systems ◽  
Structural Response ◽  
Mr Damper ◽  
Seismic Protection ◽  
Seismic Excitations ◽  
One Dimensional ◽  
Mr Dampers ◽  
Earthquake Motion ◽  
Intrinsic Nonlinearity ◽  
Series Of Experiments

Abstract In this paper, the efficacy of magnetorheological (MR) dampers for seismic protection of structures is investigated through a series of experiments in which an MR damper is used to control a three story test structure subjected to a one-dimensional earthquake motion. Because of the intrinsic nonlinearity of the MR damper, several earthquake amplitudes are considered to investigate the performance, in terms of both peak and rms responses, of this control systems over a range of loading conditions. The results indicate that the MR damper is quite effective for structural response reduction over a wide class of seismic excitations.

A Non Parametric Model for Magneto Rheological Dampers

1999 ◽  
Author(s):  
Mehdi Ahmadian ◽  
Xubin Song
Keyword(s):  
Test Data ◽  
Mr Damper ◽  
Parametric Model ◽  
Parametric Models ◽  
Magnetic Saturation ◽  
Mr Dampers ◽  
Electro Magnetic ◽  
Magneto Rheological ◽  
Force Characteristics ◽  
Non Parametric

Abstract A non-parametric model for magneto-rheological (MR) dampers is presented. After discussing the merits of parametric and non-parametric models for MR dampers, the test data for a MR damper is used to develop a non-parametric model. The results of the model are compared with the test data to illustrate the accuracy of the model. The comparison shows that the non-parametric model is able to accurately predict the damper force characteristics, including the damper non-linearity and electro-magnetic saturation. It is further shown that the parametric model can be numerically solved more efficiently than the parametric models.

A shuffled frog-leaping algorithm based mixed-sensitivity H∞ control of a seismically excited structural building using MR dampers

2017 ◽  
Vol 24 (13) ◽  
pp. 2832-2852 ◽  
Author(s):  
Xiufang Lin ◽  
Shumei Chen ◽  
Guorong Huang
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Structural Parameters ◽  
Mr Damper ◽  
Inverse Model ◽  
Shuffled Frog Leaping Algorithm ◽  
Weighting Functions ◽  
Inference System ◽  
Mr Dampers ◽  
Shuffled Frog Leaping

An intelligent robust controller, which combines a shuffled frog-leaping algorithm (SFLA) and an H∞ control strategy, is designed for a semi-active control system with magnetorheological (MR) dampers to reduce seismic responses of structures. Generally, the performance of mixed-sensitivity H∞ (MSH) control highly depends on expert experience in selecting the parameters of the weighting functions. In this study, as a recently-developed heuristic approach, a multi-objective SFLA with constraints is adopted to search for the optimal weighting functions. In the proposed semi-active control, firstly, based on the Bouc–Wen model, the forward dynamic characteristics of the MR damper are investigated through a series of tensile and compression experiments. Secondly, the MR damper inverse model is developed with an adaptive-network-based fuzzy inference system (ANFIS) technique. Finally, the SFLA-optimized MSH control approach integrated with the ANFIS inverse model is used to suppress the structural vibration. The simulation results for a three-story building model equipped with an MR damper verify that the proposed semi-active control method outperforms fuzzy control and two passive control methods. Besides, with the proposed strategy, the changes in structural parameters and earthquake excitations can be satisfactorily dealt with.

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