Development of an Electromagnetic Active Engine Mount

2015 ◽  
Author(s):  
Nader Vahdati ◽  
Somayeh Heidari
Keyword(s):  
Automotive Application ◽  
Electromagnetic Actuator ◽  
Functional Capability ◽  
Engine Mounts ◽  
Transmitted Force ◽  
Bond Graph Modeling ◽  
Engine Mount ◽  
Design Requirements ◽  
Active Engine ◽  
The Voice

Engine mounts need to satisfy three design requirements: (1) firmly support engine weight, (2) isolate structure from the engine’s noise and vibration, and (3) control engine motion when large shocks or engine resonances are present. In addition to these three criteria, which are common for designing all types of engine mounts (passive, semi-active, and active), two more design requirements need to be satisfied for active engine mounts. First, they should be designed such that if there is any malfunction with the actuator, the controller, or the sensors, the active engine mount should still safely operate as a passive mount. Second, the power consumption, the size and weight of the required actuator and its controller should be kept as low as possible. The current paper aims to present an active hydraulic (or fluid) engine mount design by using an electromagnetic actuator and capacitive circuit such that it is able to act as a passive mount, semi-active mount, and an active mount. In addition, the presented design has the capability to be converted to a damper as and when needed. The multi-functional capability of the proposed engine mount design (passive, semi-active, active, and damper) distinguishes the current design from the previously designed active engine mounting systems, and this multi-functional capability is explained in the paper. The proposed design consists of a conventional passive hydraulic (fluid) mount, an electromagnetic actuator (voice coil) and a capacitive circuit. The voice coil is placed in the lower chamber of the passive hydraulic mount and it can change the volumetric stiffness of the bottom chamber actively such that the engine mount has low dynamic stiffness in a wide range of frequencies. The capacitive circuit is paralleled with the voice coil and in situations when large shock inputs are present; it adds capacitance to the electromagnetic circuit and changes the characteristics of the mount from an isolator to a damper. Since the active engine mount design of this paper involves several energy domains, bond graph modeling technique is used for mathematical modeling. MATLAB simulation results are shown for an automotive application and the performance of the proposed active engine mount design is evaluated as an isolator and as a damper. Finally, an adaptive controller, based on Filtered-X LMS algorithm, is proposed and its performance is investigated. The proposed design can eliminate transmitted force from the engine to the structure in a frequency range of 15 Hz to 125 Hz.

Effective Reduction of Peak Frequency in Hydraulic Engine Mounts

2010 ◽  
Author(s):  
Reza Tikani ◽  
Nader Vahdati ◽  
Saeed Ziaei-Rad
Keyword(s):  
Dynamic Stiffness ◽  
Peak Frequency ◽  
Design Parameters ◽  
Working Fluid ◽  
Working Fluids ◽  
Engine Mounts ◽  
Cabin Noise ◽  
Transmitted Force ◽  
Effective Reduction ◽  
Engine Mount

Hydraulic engine mounts are generally applied to the aerospace and the automotive applications for the purpose of cabin noise and vibration reduction. By careful selection of hydraulic mount design parameters, at a certain frequency, namely the notch frequency, the dynamic stiffness will be smaller than the static stiffness and cabin vibration and noise reduction is provided at that frequency. Literature review indicates that in all previous hydraulic engine mount designs, the dynamic stiffness increases after the notch frequency. This phenomenon is not desirable because of the increase in transmitted force to the air-frame. Here in this paper, a new hydraulic engine mount design is proposed that uses two working fluids. This new design has two notch frequencies and two peak frequencies. In this study, effective reduction of the peak frequencies has been demonstrated by using a controllable fluid as one of the mount’s working fluids and a non-controllable fluid as the 2nd working fluid. As a result, one can obtain a hydraulic engine mount design with only one notch frequency but no peak frequency. The new hydraulic engine mount design and its mathematical model are presented in details and some discussions on the simulation results are also included.

Non-Linear Modeling and Parameter Identification of Semi-Active Engine Mounts With Air Spring

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Rong Guo ◽  
Zi-wei Zhou
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Stiffness ◽  
Superior Performance ◽  
Test Rig ◽  
Air Spring ◽  
Engine Mounts ◽  
Air Chamber ◽  
Non Linear ◽  
Engine Mount ◽  
Active Engine

Abstract Car manufacturers have been motivated to apply semi-active engine mounts to ensure superior performance in vibration attenuation during idle condition and better ability to isolate vibration which is generated by engine unbalanced force at high frequencies. This paper develops a non-linear lumped parameter model of semi-active engine mounts with air spring that focuses on the non-linearity of the rubber diaphragm and the air chamber. Then, the main rubber dynamic stiffness parameters are identified through experimental approaches with a novel-designed test rig. Other parameters including effective pumping area, main rubber spring bulge stiffness, fluid channel inertia and resistance, rubber diaphragm, and air-chamber parameters are attained through finite element analysis (FEA). Supported by the identified lumped parameters, the non-linear mathematical model could be simulated. In addition, the dynamic characteristics of the semi-active engine mount are tested through the original test rig. Therefore, comparing with the tested dynamic characteristics, the simulation result can validate the developed model and thus facilitate the structure design of the semi-active engine mount.

Hydraulically Amplified Magnetostrictive Actuator for Active Engine Mounts

2008 ◽  
Author(s):  
Suryarghya Chakrabarti ◽  
Marcelo J. Dapino
Keyword(s):  
Electromagnetic Actuator ◽  
Frequency Bandwidth ◽  
Force Response ◽  
Frequency Range ◽  
Electromagnetic Actuators ◽  
Engine Mounts ◽  
Displacement Response ◽  
Magnetostrictive Actuator ◽  
Active Engine

A bidirectional magnetostrictive actuator with millimeter stroke and a blocked force of ± 22 N has been developed based on a simple hydraulic magnification mechanism. The purpose of the actuator is to replace the electromagnetic actuator in active engine mounts. The Terfenol-D actuator has a flat free displacement response up to 200 Hz and a flat blocked force response over a frequency range of at least 10 to 500 Hz. The actuator promises to deliver a much broader frequency bandwidth than commercial electromagnetic actuators.

Multi-input multi-output control of an automotive active engine mounting system

2011 ◽  
Vol 225 (11) ◽  
pp. 1492-1504 ◽  
Author(s):  
A J Hillis
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Adaptive Filter ◽  
Electromagnetic Actuator ◽  
Mean Square ◽  
Least Mean Square ◽  
Active System ◽  
Output Control ◽  
Engine Mounts ◽  
Active Engine

This paper describes the control of automotive active engine mounts, consisting of a conventional passive hydraulic mount and an internal electromagnetic actuator. The actuator generates a force dependent on a control signal from an algorithm implemented in real time. The filtered- x least-mean-square (FXLMS) adaptive filter is applied to a system of two active mounts fitted to a saloon car equipped with a four-cylinder turbo-diesel engine. The steady state and transient performance of the active system is experimentally evaluated, and is found to typically reduce chassis vibration by 50 per cent to 90 per cent under normal driving conditions.

Automotive Vehicle Engine Mounting Systems: A Survey

1999 ◽  
Vol 123 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Yunhe Yu ◽  
Saravanan M. Peelamedu ◽  
Nagi G. Naganathan ◽  
Rao V. Dukkipati
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Low Frequency ◽  
Frequency Range ◽  
Engine Mounts ◽  
Performance Requirements ◽  
Vehicle Engine ◽  
Engine Mount ◽  
Active Engine ◽  
Stiffness And Damping

This study divided into three portions to provide performance requirements; overview and development of various engine mounts; and the optimization of engine mount systems. The first part provides an insight about the ideal engine mount system that should isolate vibration caused by engine disturbance force in various speed range and prevent engine bounce from shock excitation. This implies that the dynamic stiffness and damping of the engine mount should be frequency and amplitude dependent. Therefore, the development of engine mounting systems has mostly concentrated on improvement of frequency and amplitude dependent properties. The second part starts discussion on the conventional elastomeric mounts that offer a trade-off between static deflection and vibration isolation. The next level, passive hydraulic mounts can provide a better performance than elastomeric mounts especially in the low frequency range. Subsequently, semi-active and active techniques are used to improve performance of hydraulic mounts by making them more tunable. The active engine mounting system can be very stiff at low frequency and be tuned to be very soft at the higher frequency range to isolate the vibration. The final part is about the optimization of engine mounting systems. An overview of the current work on this optimization shows some limitations. Further study is needed to consider the nonlinearities and variations in properties of different types of mounting systems.

Engine Mount Optimization for Vibration Isolation in Motorcycles

2006 ◽  
Author(s):  
Sudhir Kaul ◽  
Anoop K. Dhingra ◽  
Timothy G. Hunter
Keyword(s):  
Optimization Problem ◽  
Vibration Isolation ◽  
Total Force ◽  
Engine Mounts ◽  
The Road ◽  
Design Variables ◽  
Swing Arm ◽  
Engine Mount ◽  
Six Degree Of Freedom

This paper presents a comprehensive model to capture the dynamics of a motorcycle system in order to evaluate the quality of vibration isolation. The two main structural components in the motorcycle assembly - the frame and the swing-arm - are modeled using reduced order finite element models; the power-train assembly is modeled as a six degree-of-freedom (DOF) rigid body connected to the frame through the engine mounts and to the swing-arm through a shaft assembly. The engine mounts are modeled as tri-axial spring-damper systems. Models of the front-end assembly as well as front and rear tires are also included in the overall model. The complete vehicle model is used to solve the engine mount optimization problem so as to minimize the total force transmitted to the frame while meeting packaging and other side constraints. The mount system parameters - stiffness, position and orientation vectors - are used as design variables for the optimization problem. The imposed loads include forces and moments due to engine imbalance as well as loads transmitted due to irregularities in the road surface through the tire patch.

Simulation of Engine Vibration on Nonlinear Hydraulic Engine Mounts

2005 ◽  
Author(s):  
A. R. Ohadi ◽  
G. Maghsoodi
Keyword(s):  
Equations Of Motion ◽  
Low Frequency ◽  
Governing Equations ◽  
Engine Mounts ◽  
Engine Vibration ◽  
Engine Mount ◽  
Rotational Motions ◽  
The Time Domain ◽  
Nonlinear Equations Of Motion ◽  
Four Cylinders

In this paper, vibration behavior of engine on nonlinear hydraulic engine mount including inertia track and decoupler is studied. In this regard, after introducing the nonlinear factors of this mount (i.e. inertia and decoupler resistances in turbulent region), the vibration governing equations of engine on one hydraulic engine mount are solved and the effect of nonlinearity is investigated. In order to have a comparison between rubber and hydraulic engine mounts, a 6 degree of freedom four cylinders V-shaped engine under inertia and balancing masses forces and torques is considered. By solving the time domain nonlinear equations of motion of engine on three inclined mounts, translational and rotational motions of engines body are obtained for different engine speeds. Transmitted base forces are also determined for both types of engine mount. Comparison of rubber and hydraulic mounts indicates the efficiency of hydraulic one in low frequency region.

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