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

Author(s):  
R.B. Soujanya ◽  
D.D. Jebaseelan ◽  
S. Kannan

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.

2011 ◽  
Vol 311-313 ◽  
pp. 2286-2290
Author(s):  
Jie Lai Chen ◽  
Xue Zheng Jiang ◽  
Ning Xu

The focus of this study is to experimentally investigate a semi-active magneto-rheological (MR) damper for a passenger vehicle, by using a quarter car models. After verifying that the damping force of the MR damper can be continuously tuned by the intensity of the magnetic field, a full-scale two-degree of freedom quarter car experimental set up is constructed to study the vehicle suspension. On-off skyhook controller is employed to achieve the desired damping force. The experimental results show that the semi-active vehicle suspension vibration control system based on MR dampers is feasible and can effectively improve ride comfort of vehicle.


Author(s):  
Anria Strydom ◽  
Werner Scholtz ◽  
Schalk Els

Magnetorheological (MR) dampers are controllable semi-active dampers capable of providing a range of continuous damping settings. MR dampers are often incorporated in suspension systems of vehicles where conflicting damping characteristics are required for favorable ride comfort and handling behavior. For control applications the damper controller determines the required damper current in order to track the desired damping force, often by using a suitable MR damper model. In order to utilise the fast switching time capability of MR dampers, a model that can be used to directly calculate damper current is desired. Unfortunately few such models exist and other methods, which often negatively affect the computational efficiency of the model, need to be used when implementing these models. In this paper a selection of MR damper models are developed and evaluated for both accuracy and computational efficiency while tracking a desired damping force. The Kwok model is identified as a suitable candidate for the intended suspension control application.


2019 ◽  
Vol 20 (1-2) ◽  
pp. 57-61
Author(s):  
Wiesław Grzesikiewicz ◽  
Michał Makowski

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.


1999 ◽  
Author(s):  
Mehdi Ahmadian

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.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1439-1445
Author(s):  
Xinna Ma ◽  
Shaopu Yang ◽  
Wenrui Shi

With running speed increases, the dynamics characteristic of railway vehicle system behaves intensively, such as, snaking motion, bifurcation problem, even digression accident. These questions effect ride comfort and run stationary. The magneto-rheological (MR) damper can continually change its state in a few milliseconds and has low energy requirement and insensitivity to the temperature and circumstance. MR dampers have turned out to be a promising device in vibration control. According to the nonlinear of MR damper and the vibration characteristic of semi-active suspension of high-speed vehicle, a seventeen-degree-of-freedom lateral semi-control model of high-speed whole vehicle with MR dampers is established. Taking into account of the vibrations of vehicle and electromagnetic interference, a novel adaptive fuzzy control strategy is put forward. The simulation results show that adaptive fuzzy control method can improve the ride comfort and restrain electromagnetic interference. The electromagnetic interference noise problems in high-speed railway vehicle system with MRD are analyzed and discussed according to EN 55022 for the first time.


Author(s):  
Anria Strydom ◽  
Pieter S. Els ◽  
Sudhir Kaul

Ride comfort and handling characteristics are two important aspects of vehicle dynamics that generally require contrasting suspension settings. Different damper settings of the suspension system are required in order to meet these conflicting requirements. A magneto-rheological (MR) damper allows variable suspension settings to achieve enhanced ride comfort as well as handling characteristics by providing adaptable damping. Implementation of semi-active control requires an accurate MR damper model and online identification of model parameters. However, modeling a MR damper for a wide range of input conditions is challenging, especially when there are constraints on necessary measurements that are required for modeling. Although the available literature proposes various parametric models, many of these models are computationally expensive and are not viable for online identification. This paper presents a non-parametric model as well as a recursive model to predict the damping force of a MR damper in order to implement a semi-active control algorithm on an off-road vehicle. The results of the two models are compared to a conventional parametric model. The recursive model is used to demonstrate the significance of including the measured damping force in the model. Whereas the availability of the measured damping force yields a reasonably accurate model, the lack of measured damping force significantly impairs the recursive model.


2001 ◽  
Vol 8 (3-4) ◽  
pp. 147-155 ◽  
Author(s):  
Mehdi Ahmadian ◽  
James C. Poynor

The application of magneto rheological dampers for controlling recoil dynamics is examined, using a recoil demonstrator that includes a single-shot 50 caliber BMG rifle action and a MR damper. The demonstrator is selected such that it can adequately represent the velocities that commonly occur in weapons with a recoil system, and can be used for collecting data for analyzing the effects of MR dampers on recoil dynamics. The MR damper is designed so that it can work effectively at the large velocities commonly occurring in gun recoil, and also be easily adjusted to reasonably optimize the damper performance for the recoil demonstrator. The test results show that it is indeed possible to design and use MR dampers for recoil applications, which subject the damper to relative velocities far larger than the applications that such dampers have commonly been used for (i.e., vehicle applications). Further, the results indicate that the recoil force increases and the recoil stroke decreases nonlinearly with an increase in the damping force. Also of significance is the fact that the adjustability of MR dampers can be used in a closed-loop system such that the large recoil forces that commonly occur upon firing the gun are avoided and, simultaneously, the recoil stroke is reduced. This study points to the need for several areas of research including establishing the performance capabilities for MR dampers for gun recoil applications in an exact manner, and the potential use of such dampers for a fire out of battery recoil system.


Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Tao Wang ◽  
Zhengmu Zhou ◽  
Yaqin Zhou

This paper presents the damping characteristics of a linear magneto-rheological (MR) damper with dual controllable ducts based on numerical and experimental analysis. The novel MR damper consisting of a dual-rod cylinder system and a MR valve is used to reduce the influences of viscous damping force and improve dynamic range. Driven by the dual-rod cylinder system, MR fluid flows in the MR valve. The pressure drop of the MR valve with dual independent controllable ducts can be controlled by tuning the current of two independent coils. Based on the mathematical model and the finite element method, the damping characteristics of the MR damper is simulated. A prototype is designed and tested on MTS machine to evaluate its damping characteristics. The results show that the working states and damping force of the MR damper can be controlled by the two independent coils.


2008 ◽  
Vol 56 ◽  
pp. 218-224
Author(s):  
Maguid H.M. Hassan

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.


1999 ◽  
Author(s):  
Mehdi Ahmadian ◽  
James C. Poynor ◽  
Jason M. Gooch

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.


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