MR- and ER-Based Semiactive Engine Mounts: A Review

Mohammad Elahinia,The M Nguyen,Shuo Wang,Constantin Ciocanel

doi:10.1155/2013/831017

Abstract

Hybrid propulsion technologies, including hybrid electric and hydraulic hybrid, equip vehicles with nonconventional power sources (in addition to the internal combustion engine) to provide higher fuel efficiency. However, these technologies tend to lead to higher levels of noise, vibration, and harshness in the vehicles, mainly due to the switching between the multiple power sources involved. In addition, the shocks and vibrations associated with the power sources switching may occur over a wide range of frequencies. It has been proven that passive vibration isolators (e.g., elastomeric and hydraulic mounts) are unable to mitigate or totally isolate such shocks and vibrations. Active mounts, while effective, are more complex, require significant power to operate, and can lead to system instabilities. Semiactive vibration isolators have been shown to be as effective as active mounts while being less complex and requiring less power to operate. This paper presents a review of novel semiactive shock and vibration isolators developed using magnetorheological and electrorheological fluids. These fluids change their yield stress in response to an externally applied magnetic and electric field, respectively. As a result, these fluids allow one to transform a passive hydraulic vibration isolator into a semiactive device.

Highlights

In recent decades, the soaring price of fossil fuels has impacted negatively the popularity of the vehicles with internal combustion (IC) engines
The idea of using MR fluids for vibration mitigation applications was first proposed by Carlson [8], and the first reported implementation of ME fluids in mounts was made by Ahn et al [5]
The results indicate that the direct identification dynamic model using recurrent neural networks (RNN) can predict the damping force accurately, and the inverse dynamic model using RNN can act as a damper controller to generate the command voltage for the MR fluid damper in semi-active mode

Summary

Introduction

The soaring price of fossil fuels has impacted negatively the popularity of the vehicles with internal combustion (IC) engines. The electrical sources often consist of electric motors/generators, batteries, and wires [3], while the mechanical systems may be a flywheel or hydraulic system, the latter including fluid pumps/motors, pressured accumulators, and hoses/pipes. Hybridizations including both hybrid electric and hydraulic hybrid are structured in one of the two configurations: parallel (mild) or series (full) [4]. The IC engine drives a generator (or hydraulic pump), and the created energy (electricity or fluid flow) runs the motor which is integrated to the differential. The knowledge from this review is desired to be a starting point for future semiactive/active engine mounts

Magnetorheological Fluid Mounts

Mixed Mode

Findings

Conclusions