• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.3
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• pp.482-487
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• 2009

This research proposed a dashpot type mount design using MR fluids, and derived governing equation of the proposed design considering the design parameters of the mount and the Bingham characteristics of MR fluids, which affect the damping forces of the dashpot MR fluid mount. In odor to observe the change of magnetic properties which occurs from the solenoid, the effective length of the magnetic pole and the structure of core are selected as design parameters. The magnetic field quality is calculated in compliance with an equivalent magnetic circuit method. When the effective length of pole increases, the magnetic resistance of the pole of the MR mount decreased, and the magnetic flux density is increased. The result which uses a commercial business software and the result in compliance with equivalent magnetic circuit method shows the tendency which is similar.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.696-697
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• 2009

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.5
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• pp.393-399
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• 2003

Hydraulic mounts show strong1y frequency-dependent stiffness and damping characteristics in low frequency range, which result from so called inertia track dynamics. A lumped mass has been incorporated in several mechanical models of the literature to take the inertia effect of the fluid in the track into consideration. Although complex s%illness by the mechanical model showed good agreements with the measured values, there exists a critical pitfall. In this paper, the shortcomings of mechanical models with lumped mass for hydraulic founts are clearly identified by illustrating actual measurements of the stiffness parameters for a hydraulic mount. It is conclusively discussed that the inertia effect of the fluid flow through the circular track is significant but latent. As an alternative to the mechanical model, a hydraulic model is claimed to be used for further dynamic analysis of engine/mount system or whole car system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.237-242
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• 2008

This paper presents vibration control of an active hybrid engine mount featuring magneto-rheological (MR) fluid and a piezostack actuator. On the basis of the conventional passive rubber mount, MR fluid is adopted to improve isolation performance at resonant frequencies, whereas the piezostack actuator is adopted for performance improvement at non-resonant frequencies, especially at high frequencies. Based on some particular practical requirements of engine mounts, the proposed mount is designed and manufactured. The characteristics of rubber element, piezostack actuator and MR fluid are verified for system analysis and controller synthesis. The model of the proposed mount with a supported mass (engine) is established. In this work, a sliding mode controller is synthesized for the mount system to reduce vibrations transmitted from the engine in a wide frequency range. Computer simulations are performed to evaluate the performances of the proposed active engine mount in time and frequency domains.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.500-510
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• 1996

This paper presents a new prototype of an engine mount for a passenger vehicle featuring ER(elector-rheological) fluids and piezoactuators. Conventional rubber mounts and various types of passive or semi-active hydraulic engine mounts have their own functional aims on the limited frequency band in the board engine operating frequency range. However, the proposed engine mount covers all frequency range of the engine operation. A mathematical model of the proposed engine mount is derived using the bond graph method which is inherently domain, the ER fluid is activated upon imposing electric field for vibration isolation while the piezoactuator. Computer control electric fluid for the ER fluid H.inf. cotrol technique is adopted for the piezoactuator. Computer simulation is undertaken in order to demonstrate isolation efficiency of the engine mount over wide operating frequency range.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.444-449
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• 2009

An engine is one of the most dominant noise and vibration sources in vehicle systems. Therefore, in order to resolve noise and vibration problems due to engine, various types of engine mounts have been proposed. This work presents a new type of active engine mount system featuring a magneto-rheological (MR) fluid and a piezostack actuator. As a first step, six degrees-of freedom dynamic model of an in-line four-cylinder engine which has three points mounting system is derived by considering the dynamic behaviors of MR mount and piezostack mount. In the configuration of engine mount system, two MR mounts are installed for vibration control of roll mode motion whose energy is very high in low frequency range, while one piezostack mount is installed for vibration control of bounce and pitch mode motion whose energy is relatively high in high frequency range. As a second step, linear quadratic regulator (LQR) controller is synthesized to actively control the imposed vibration. In order to demonstrate the effectiveness of the proposed active engine mount, vibration control performances are evaluated under various engine operating speeds (wide frequency range) and presented in time domain.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.6
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• pp.583-590
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• 2009

An engine is one of the most dominant noise and vibration sources in vehicle systems. Therefore, in order to resolve noise and vibration problems due to engine, various types of engine mounts have been proposed. This work presents a new type of active engine mount system featuring a magneto-rheological (MR) fluid and a piezostack actuator. As a first step, six degrees-of freedom dynamic model of an in-line four-cylinder engine which has three points mounting system is derived by considering the dynamic behaviors of MR mount and piezostack mount. In the configuration of engine mount system, two MR mounts are installed for vibration control of roll mode motion whose energy is very high in low frequency range, while one piezostack mount is installed for vibration control of bounce and pitch mode motion whose energy is relatively high in high frequency range. As a second step, linear quadratic regulator (LQR) controller is synthesized to actively control the imposed vibration. In order to demonstrate the effectiveness of the proposed active engine mount, vibration control performances are evaluated under various engine operating speeds(wide frequency range) and presented in time domain.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.11
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• pp.1150-1156
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• 2008

This paper presents vibration control of an active hybrid engine mount featuring a magneto-rheological(MR) fluid and a piezostack actuator. The MR fluid is adopted to improve isolation performance at resonant frequencies, while the piezostack actuator is adopted for performance improvement at non-resonant frequencies, especially at high frequencies. Based on some particular practical requirements of engine mounts, the proposed mount is designed and manufactured. The characteristics of rubber element, piezostack actuator and MR fluid are verified for system analysis and controller synthesis. The dynamic model of the proposed mount with a supported mass (engine) is established. In this work, a sliding mode controller is synthesized for the mount system to reduce vibrations transmitted from the engine in a wide frequency range. Computer simulations are performed to evaluate control performances of the proposed active engine mount in time and frequency domains.

• Journal of Power System Engineering
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• v.12 no.2
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• pp.23-28
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• 2008

The primary objective of this study is to truly understand reaction force be due to engine exciting force. Exciting forces of the engine apply a source of the vehicle NVH(Noise, Vibration, Harshness). To understand reaction force was applied MSC.Nastran software. Analyzed frequency response analysis of powertrain mount system. First, engine exciting force was applied field function. Also nonlinear characteristics was applied field function : such as dynamic spring constant and loss factor. And nonlinear characteristics was applied CBUSH. Generally characteristics of rubber mount is constant frequency. But characteristics of hydraulic mount depend to frequency. Therefore nonlinear characteristics was applied. Powertrain mounting system be influenced by powertrain specification, mount position, mount angle and mount characteristics etc. In this study, we was analyzed effects of powertrain mounting system. And we was varied dynamics spring constant and loss factor of mounts.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.481-486
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• 2000

This paper presents vibration control performance of a passenger vehicle installed with olectro-rheological(ER) engine mounts. As a first step, a mixed-mode ER engine mount is modeled and manufactured. After verifying the controllability of the dynamic stiffness by the intensity of the electric field, ER engine mounts are incorporated with a full-car model. The governing equation of motion is then formulated by considering engine excitation force. A skyhook controller to attenuate vibration motions is designed. The controller is implemented through hardware-in-the-loop simulation and control responses are presented in the both frequency and time domains.