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 New Non-Parametric Model Based on Neural Network for a MR Damper

2008 ◽  
Author(s):  
Mari´a Jesu´s L. Boada ◽  
Jose´ Antonio Calvo ◽  
Beatriz L. Boada ◽  
Vicente Di´az
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Mr Damper ◽  
Parametric Model ◽  
Time Response ◽  
Suitable Model ◽  
Lazy Learning ◽  
Mr Dampers ◽  
Mr Fluids ◽  
Non Parametric

Currently dampers based on magnetorheological (MR) fluids are being used in many applications such as construction, biomechanical and semi-active suspension to improve their behaviour. The main advantage of MR dampers is its very low time response (≈ 10 ms). In many cases, it is necessary to establish a suitable model of MR damper which characterizes its behaviour so that this model can be used in the simulation stage. In this paper, a new non-parametric model is proposed based on neural networks using a recursive lazy learning to model the MR damper behaviour. The proposed method is validated by comparison with experimental obtained responses. Results show that the estimated model correlates very well with the data obtained experimentally and learns quickly.

scholarly journals Non-Parametric Model of Magneto-Rheological (MR) Damper Based on Adaptive Neuro-Fuzzy Inference System (ANFIS)

2011 ◽  
Vol 2-3 ◽  
pp. 1059-1066 ◽  
Author(s):  
Ling Zheng ◽  
Fei Liu ◽  
Zhong Yong Zhou
Keyword(s):  
Fuzzy Inference ◽  
Mr Damper ◽  
Parametric Model ◽  
Control Voltage ◽  
Nonlinear Relationship ◽  
Damping Force ◽  
Inference System ◽  
Neuro Fuzzy ◽  
Magneto Rheological ◽  
Non Parametric

Magneto-rheological (MR) damper is a typical non-linear actuator. The nonlinear relationship between the input and the output of MR damper should be characterized accurately in order to produce a required control action supplied by MR damper. The challenges of the conventional parametric model are the time-consuming and the requirement of complex parameter identification for MR damper. In this paper, a non-parametric model of MR damper based on the adaptive neuro-fuzzy system theory is presented to overcome the drawbacks of the conventional parametric model. This non-parametric model is developed by means of two adaptive neural fuzzy sub-systems which are designed to describe the nonlinear relationship in MR damper successfully. One sub-system is used to characterize the dependence of the damping force on velocity and acceleration, the other sub-system is used to characterize the dependence of the damping force level on the control voltage. The proposed non-parametric model is identified by experimental results. Furthermore, the accuracy of the model is investigated and evaluated. The model supplies a key technical support to achieve excellent control performances for semi-active suspension systems with MR dampers in vehicle.

Effective Test Procedures for Evaluating Force Characteristics of Magneto-Rheological Dampers

2003 ◽  
Author(s):  
Mehdi Ahmadian ◽  
James C. Poynor
Keyword(s):  
Relative Velocity ◽  
Test Procedure ◽  
Mr Damper ◽  
Electrical Current ◽  
Test Results ◽  
Test Procedures ◽  
Vehicle Suspensions ◽  
Mr Dampers ◽  
Magneto Rheological ◽  
Force Characteristics

This paper will provide a new test procedure for determining the force characteristics of magneto rheological (MR) dampers that are commonly used for vehicle suspensions. Force characteristics of a damper, in this case, refers to establishing the amount of force that the damper can provide at different relative velocities across the two ends of the damper, Force characteristics of a damper, which are commonly presented as a plot of force versus relative velocity—commonly known as force-velocity curve—are established in a shock (or damper) dynamometer in which one end of the damper is kept fixed and the other end is moved in a cyclical manner at a prescribed displacement and frequency. The peak damper force at each velocity is measured and plotted as discrete data points versus relative velocity across the damper. This is a well-understood and commonly used procedure for passive shock absorbers or dampers. For magneto rheological dampers, however, our study shows that such procedures do not necessarily provide an accurate assessment of the force characteristics of MR dampers in all damping conditions. The damping condition of MR dampers can be changed by a small amount of electrical current that can be provided to the damper. The inaccuracies are mainly due to the changing dynamics of the MR fluid inside the damper at different damping conditions. This paper will provide the test results for a MR damper, using the new and the conventional test procedures. The test results indicate that the use of the new test procedure will procedure will allow for an accurate representation of the MR damper force at all velocities, within the range of the currents that the damper is designed for.

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.

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.

Passenger Comfort Analysis in an Automotive Considering a Magneto-Rheological Damper based Suspension

2017 ◽  
Vol 8 (4) ◽  
Author(s):  
R.B. Soujanya ◽  
D.D. Jebaseelan ◽  
S. Kannan
Keyword(s):  
Ride Comfort ◽  
Mr Damper ◽  
Nonlinear Behaviour ◽  
Passive Damping ◽  
Damping Force ◽  
The Road ◽  
Mr Dampers ◽  
Moving Vehicles ◽  
Magneto Rheological ◽  
Multi Body

Passenger’s comfort in moving vehicles depends on the quality of the ride. The major cause of discomfort is the vibration transmitted to passengers due to the road irregularities. For a comfortable ride on a vehicle, vibration must stay within prescribed standards. In the present work, an attempt was made to show that, the vibrations can be limited with the use of Magneto-rheological (MR) dampers for varying road profiles than the passive damping methods. MR dampers are semi-active control devices that use MR fluids to produce controllable damping force as they are known to exhibit nonlinear behaviour. Multi body dynamic studies were done to study the response of the system using a quarter car model. In this paper, passive damping (viscous damping) was considered at natural frequency of 1.012Hz, the response of damping was observed after 10s and the acceleration was found to be 6m/s2. When MR damper is employed as the magnetic force increases, the response of the damping was better than the passive damping, at 1.2A it comes down to 0.55m/s2, and the vibration gets dampened after 1.75s. Hence, from this study it is concluded that the MR damper can be employed in automobile for better ride comfort.

Experimental Approach for Finding the Response Time of MR Dampers for Vehicle Applications

2003 ◽  
Author(s):  
Fernando D. Goncalves ◽  
Jeong-Hoi Koo ◽  
Mehdi Ahmadian
Keyword(s):  
Response Time ◽  
Time Constant ◽  
Constant Velocity ◽  
Mr Damper ◽  
Initial State ◽  
Final State ◽  
Mr Dampers ◽  
Automotive Suspension ◽  
Magneto Rheological ◽  
Time Required

This paper offers a method and an experimental example of determining the response time of Magneto-Rheological (MR) dampers. The response time of MR dampers for automotive suspension applications is valuable information because it is one of the key factors that determine the practical effectiveness of the use of MR dampers in vehicles. However, a detailed description of the response time of MR dampers is seldom given in the literature. Furthermore, the methods of computing the response time are not discussed in detail. Therefore, this study intends to develop a method for experimental determination of the response time of MR dampers for automotive suspensions. A triangle wave that maintains a constant velocity across the damper is proposed as the input to use in experiments. This triangle wave ensures a constant velocity across the damper in order to accurately evaluate the response time of the MR damper. The response time was defined as the time required to make the transition from the initial state to 63.2% of the final state, or one time constant. The time constant is a measure of how long it takes a system to respond to a given input. In other words, the response time is the time necessary for the damper to achieve the desired force upon activation. To demonstrate the method, the response time was found for an MR damper particularly designed and fabricated for vehicle applications. Two cases were considered: activation response time of the damper and deactivation response time of the damper. Both cases were studied during the rebound stroke of the damper. It was found that the response time of the MR damper under activation and deactivation was 15.4 ms and 13.9 ms respectively. The results are comparable to those found in the literature.

scholarly journals Vibration modeling of a vehicle equipped with MR damper and aerodynamic elements

2019 ◽  
Vol 20 (1-2) ◽  
pp. 57-61
Author(s):  
Wiesław Grzesikiewicz ◽  
Michał Makowski
Keyword(s):  
High Speed ◽  
Mr Damper ◽  
Road Surface ◽  
Vehicle Model ◽  
Numerical Investigations ◽  
The Road ◽  
Mr Dampers ◽  
On The Road ◽  
Magneto Rheological ◽  
Vibration Modeling

We considered of a vehicle model equipped with controlled magneto-rheological (MR) dampers and controlled aerodynamic elements. The vibrations of the vehicle moving at high speed during acceleration and braking are analysed. The purpose of this analysis is to determine the effect of forces generated on aerodynamic elements on vehicle vibrations and changes in wheel pressure on the road surface during acceleration and braking. The presented work presents the results of numerical investigations obtained on the basis of the developed vehicle model.

Modeling of a Magneto-Rheological Damper Using System Identification

2010 ◽  
Author(s):  
Sudhir Kaul
Keyword(s):  
System Identification ◽  
Mr Damper ◽  
Operating Conditions ◽  
Parametric Models ◽  
Model Parameters ◽  
Recursive Models ◽  
Recursive System ◽  
Set Up ◽  
Magneto Rheological ◽  
Improved Model

This paper proposes the use of three recursive system identification techniques for modeling a magneto-rheological (MR) damper. The results of the three models are compared to one another and to two parametric models that have been commonly used in the existing literature for modeling MR dampers. An MR damper has been built in-house and an experimental set-up has been fabricated as part of this work. The set-up is used for data collection and the data is used for building the recursive models. The results from the system identification models are compared to the measured data as well as to the parametric models. While the parametric models are seen to work well within limited bounds of input variables and operating conditions, these models can be used outside the range of these bounds only after carrying out a new characterization of the model parameters. The recursive system identification models, on the other hand, continuously update all model parameters as and when data becomes available, as demonstrated by the three recursive models presented in this paper. The advantages of the recursive models are conclusively established by lower measures of error, a better representation of hysteresis and saturation phenomena exhibited by the MR damper and significantly improved model tracking. This is a major improvement over the commonly used parametric models, thereby making the recursive models specifically conducive to adaptive control algorithms.

Design and Development of Magneto Rheological Dampers for Bicycle Suspensions

1999 ◽  
Author(s):  
Mehdi Ahmadian
Keyword(s):  
Dynamic Performance ◽  
Mr Damper ◽  
Test Results ◽  
Design And Development ◽  
Damping Force ◽  
Mr Fluid ◽  
Performance Improvements ◽  
Mr Dampers ◽  
Force Velocity ◽  
Magneto Rheological

Abstract The design and fabrication of a magneto rheological (MR) damper for bicycle suspension applications is addressed. Two 1998 Judy® Dampers are retrofitted with MR valves, to achieve the damping force adjustability that the MR fluid offers. One design attempts to use as many of the Judy® Damper components as possible. The second design significantly modifies the Judy® Damper, to better accommodate the MR valve and ease of fabrication and assembly, although fitting into the same envelope as the Judy® damper for a direct retrofit. The two MR dampers are fabricated and assembled for force-velocity characterization testing. The test results show that properly-designed MR dampers can provide significant dynamic performance improvements, as compared to conventional passive bicycle dampers.

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