Skyhook Control of a Mixed Mode Magnetorheological Fluid Mount

2010 ◽  
Author(s):  
Shuo Wang ◽  
The Nguyen ◽  
Walter Anderson ◽  
Constantin Ciocanel ◽  
Mohammad Elahinia
Keyword(s):  
Mixed Mode ◽  
Magnetorheological Fluid ◽  
Resonance Peak ◽  
Control Algorithms ◽  
Flow Mode ◽  
Frequency Range ◽  
Mr Fluid ◽  
Working Frequency ◽  
Fluid Dampers ◽  
Mr Effect

Magnetorheological (MR) fluid mounts have their own advantages over the hydraulic mounts because they can provide extra damping and stiffness due to the MR effect. Many papers contribute to the control of MR fluid dampers, while very few papers focus on the control of MR mounts. This paper investigated skyhook control for a mixed mode MR fluid mount. The MR fluid mount can operate in two working modes: flow mode and squeeze mode. The skyhook control algorithms were developed and studied for the flow mode and squeeze mode separately and simultaneously. Simulation results show that the skyhook control can significantly reduce the resonance peak and achieve the lowest transmissibility in the whole working frequency range of the mount. When flow mode and squeeze mode are activated and controlled at the same time, the effect of squeeze mode is more obvious than that of the flow mode.

Performance of an Adaptive Magnetorheological Fluid Mount

2007 ◽  
Author(s):  
Constantin Ciocanel ◽  
The Nguyen ◽  
Christopher Schroeder ◽  
Mohammad H. Elahinia
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Magnetorheological Fluid ◽  
Flow Mode ◽  
Frequency Range ◽  
Governing Equations ◽  
Mr Fluid ◽  
System Parameters ◽  
Force Transmissibility ◽  
Working Frequency

The paper investigates the response of a magnetorheological (MR) fluid based mount that combines the squeeze and flow modes in operation. The mount governing equations are introduced and the effect of system parameters on its performance is analyzed. The proposed design yields a high static and a low dynamic stiffness in the working frequency range of the mount. The overall vibration isolation characteristic of the mount is enhanced if compared to that of existing hydraulic mounts. Displacement and/or force transmissibility can be isolated or significantly reduced, in real time, by controlling the MR fluid yield stress. An embedded electromagnet is used to activate the MR fluid that can work in either squeeze or flow modes, or in both simultaneously. The results indicate that the flow mode is less effective in reducing transmissibility than the squeeze mode. However, when the flow and squeeze modes are both activated, the effect of the flow mode becomes more obvious.

Experimental Verification of Controllability of a Mixed Mode MR Fluid Mount

2011 ◽  
Author(s):  
Shuo Wang ◽  
Mohammad Elahinia ◽  
The Nguyen
Keyword(s):  
Mixed Mode ◽  
Alternative Energy ◽  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Hybrid Vehicles ◽  
Flow Mode ◽  
Shear Mode ◽  
Mr Fluid ◽  
Set Up ◽  
Different Levels

With the advent of alternative energy and hybrid vehicles come new vibration problems and challenges that require nontraditional solutions. Semi-active vibration isolation devices are preferred to address the problem due to their effectiveness and affordability. A magnetorheological (MR) fluid mount can provide effective vibration isolation for applications such as hybrid vehicles. The MR fluid can produce different levels of damping when exposed to different levels of magnetic field. The fluid can be working in three modes which are the flow mode, shear mode and squeeze mode. A mixed mode MR fluid mount was designed to operate in a combination of the flow mode and the squeeze mode. Each of the working modes and the combined working mode has been studied. The mount’s performance has been verified in simulation and experiments. Based on the simulation and experimental results, it can be seen that the mount can provide a large range of dynamic stiffness. Given this range of dynamic stiffness, a controller has been designed to achieve certain dynamic stiffness at certain frequencies. The experiments are set up to realize the hardware-in-the-loop tests. Results from the experiments show that the mixed mode MR fluid mount is able to achieve desired dynamic stiffness which is directly related to vibration transmissibility.

Modeling and Simulation of a Magnetorheological Mount

2008 ◽  
Author(s):  
The Nguyen ◽  
Constantin Ciocanel ◽  
Mohammad Elahinia
Keyword(s):  
Magnetic Field ◽  
Modeling And Simulation ◽  
Flow Mode ◽  
Frequency Range ◽  
Flow Paths ◽  
Model Parameter ◽  
Successful Design ◽  
Mr Effect ◽  
Parameter Values ◽  
The Magnetic Field

Magnetorheological (MR) mounts have been developed to replace hydraulic mounts because the MR effect makes the mount controllable and more adaptive. An MR mount, except for the added damping due to magnetic field, operates similarly with a hydraulic mount. Therefore, the geometry of the flow paths (inertia tracks) and the distribution of the magnetic field across these paths affect significantly the mount behavior. In this study, different geometries for the flow paths of an MR mount, designed to operate in flow mode, are considered and their effect on the mount behavior is simulated. The effects of the different geometries considered are quantified through changes in displacement transmissibility of the mount over a 0 to 70 Hz frequency range. The results of the analysis provide useful insights about model parameter values and contribute to the successful design of the flow mode operating MR mount.

scholarly journals Displacement and Force Control of a Quarter Car Using a Mixed Mode MR Mount

2013 ◽  
Vol 20 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Shuo Wang ◽  
Mohammad Elahinia ◽  
The Nguyen
Keyword(s):  
Mixed Mode ◽  
Fuzzy Logic Controller ◽  
Dynamic Stiffness ◽  
Motor Units ◽  
Flow Mode ◽  
Control Force ◽  
Mr Fluid ◽  
Hydraulic Hybrid ◽  
Quarter Car ◽  
Set Up

In hydraulic hybrid vehicles (HHV), vibration in dual-mode pump/motor units should be isolated from the chassis. A mixed mode magnetorheological (MR) fluid mount was adopted to isolate this vibration and was evaluated in a quarter car model. The MR fluid mount was designed to be able to operate in flow mode and squeeze mode independently and simultaneously. For HHVs, it is desirable to control force and displacement transmissibility. These simulation results presented a basis for designing an effective algorithm to control both the displacement transmissibility and force transmissibility. Moreover, a hierarchical controller for minimizing the two requirements for transmissibility was also constructed. At last, a fuzzy logic controller was devised to closely reproduce the effect of the hierarchical controller. The experiments were set up to facilitate the hardware-in-the-loop evaluation of the mount. Results from the experiments showed that the mixed mode MR fluid mount was able to achieve desired dynamic stiffness profile to minimize the dual-transmissibility criterion.

scholarly journals Characteristics of magnetorheological fluids under single and mixed modes

2016 ◽  
Vol 231 (20) ◽  
pp. 3798-3809 ◽  
Author(s):  
Ali El Wahed ◽  
Loaie Balkhoyor
Keyword(s):  
Magnetic Field ◽  
Shear Flow ◽  
Vibration Control ◽  
Mixed Mode ◽  
Magnetorheological Fluid ◽  
Magnetorheological Fluids ◽  
Flow Mode ◽  
Mode Operation ◽  
Transmitted Force ◽  
Mixed Modes

Rheological properties of magnetorheological (MR) fluids can be changed by application of external magnetic fields. These dramatic and reversible field-induced rheological changes permit the construction of many novel electromechanical devices having potential utility in the automotive, aerospace, medical and other fields. Vibration control is regarded as one of the most successful engineering applications of magnetorheological devices, most of which have exploited the variable shear, flow or squeeze characteristics of magnetorheological fluids. These fluids may have even greater potential for applications in vibration control if utilised under a mixed-mode operation. This article presents results of an experimental investigation conducted using magnetorheological fluids operated under dynamic squeeze, shear-flow and mixed modes. A special magnetorheological fluid cell comprising a cylinder, which served as a reservoir for the fluid, and a piston was designed and tested under constant input displacement using a high-strength tensile machine for various magnetic field intensities. Under vertical piston motions, the magnetorheological fluid sandwiched between the parallel circular planes of the cell was subjected to compressive and tensile stresses, whereas the fluid contained within the annular gap was subjected to shear flow stresses. The magnetic field required to energise the fluid was provided by a pair of toroidally shaped coils, located symmetrically about the centerline of the piston and cylinder. This arrangement allows individual and simultaneous control of the fluid contained in the circular and cylindrical fluid gaps; consequently, the squeeze mode, shear-flow mode or mixed-mode operation of the fluid could be activated separately. The performance of these fluids was found to depend on the strain direction. Additionally, the level of transmitted force was found to improve significantly under mixed-mode operation of the fluid.

Dynamic characteristics of squeeze-type mount using magnetorheological fluid

2005 ◽  
Vol 219 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Y K Ahn ◽  
J-Y Ha ◽  
Y-H Kim ◽  
B-S Yang ◽  
M Ahmadian ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Experimental Analysis ◽  
Vibration Isolation ◽  
Dynamic Behaviour ◽  
Electrical Current ◽  
Magnetorheological Fluid ◽  
Test Set ◽  
Mr Fluid ◽  
Set Up ◽  
Stiffness And Damping

This paper presents an analytical and experimental analysis of the characteristics of a squeeze-type magnetorheological (MR) mount which can be used for various vibration isolation areas. The concept of the squeeze-type mount and details of the design of a squeeze-type MR mount are discussed. These are followed by a detailed description of the test set-up for evaluating the dynamic behaviour of the mount. A series of tests was conducted on the prototype mount built for this study, in order to characterize the changes occurring as a result of changing electrical current to the mount. The results of this study show that increasing electrical current to the mount, which increases the yield stress of the MR fluid, will result in an increase in both stiffness and damping of the mount. The results also show that the mount hysteresis increases with increase in current to the MR fluid, causing changes in stiffness and damping at different input frequencies.

scholarly journals Squeezing Force of the Magnetorheological Fluid Isolating Damper for Centrifugal Fan in Nuclear Power Plant

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Jin Huang ◽  
Ping Wang ◽  
Guochao Wang
Keyword(s):  
Nuclear Power ◽  
Theoretical Foundation ◽  
Fluid Dynamic ◽  
Flow Behavior ◽  
Magnetorheological Fluid ◽  
Centrifugal Fan ◽  
Parallel Channel ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Control Devices

Magnetorheological (MR) disk-type isolating dampers are the semi-active control devices that use MR fluids to produce controllable squeezing force. In this paper, the analytical endeavor into the fluid dynamic modeling of an MR isolating damper is reported. The velocity and pressure distribution of an MR fluid operating in an axisymmetric squeeze model are analytically solved using a biviscosity constitutive model. Analytical solutions for the flow behavior of MR fluid flowing through the parallel channel are obtained. The equation for the squeezing force is derived to provide the theoretical foundation for the design of the isolating damper. The result shows that with the increase of the applied magnetic field strength, the squeezing force is increased.

Frequency Shaped Semi-Active Control for Magnetorheological Fluid-Based Vibration Control Systems

2013 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley ◽  
Gregory J. Hiemenz
Keyword(s):  
Vibration Control ◽  
Control Systems ◽  
Active Control ◽  
Control Algorithm ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Model Parameters ◽  
Mr Fluid ◽  
Control Current ◽  
Active Vibration

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.

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