• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.2
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• pp.160-166
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• 2013

This paper proposes a driver supportive device with haptic cue function which can be applicable for vehicles adopting manual transmission system to transmit gear-shifting information to a driver by kinesthetic forces. This haptic cue function is implemented on accelerator pedal by utilizing magnetorheological(MR) fluid and clutch mechanism. In order to achieve this goal, an MR clutch mechanism is devised to be capable of rotary motion of accelerator pedal. The proposed MR clutch is then optimally designed and manufactured under consideration of spatial limitation of vehicles. After transmission torque is experimentally evaluated according to field intensity. The manufactured MR clutch is integrated with accelerator pedal and electric motor to establish the haptic cue device. Control performances are experimentally evaluated via a simple feed-forward control algorithm.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.10
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• pp.979-986
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• 2009

This paper presents a dynamic modeling of a military vehicle suspension featuring disc spring and MR valve. Firstly, the dynamic model of the disc spring is established with respect to the load and pressure. The nonlinear behavior of the spring is incorporated with the model. Secondly, the dynamic model of the MR valve is derived by considering the pressure drop due to the viscosity and yield stress of MR fluid. The governing characteristics of the proposed suspension system are then investigated by presenting the field-dependent pressure drop of the MR valve and spring force of the gas spring.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.1
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• pp.34-41
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• 2009

In this paper, a novel MR brake with permanent magnet is developed. This system consists of rotary disk, permanent magnet, spring and MR fluid. Permanent magnets are attached to the rotary disk and moves in the direction of radius. The magnets are linked to rotor axis by spring. As rotation speed increases, the magnets move outward from the center of the system by centrifugal force in the MR fluid. A proper design of stator or case makes the system have unique torque characteristics. The research is performed like following procedures. First, the electromagnetic characteristic of the system is analyzed using Maxwell. Next, torque is calculated using the results of the electromagnetic analysis. Finally, the performance of various types of the brake systems are investigated and compared with each other.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.957-962
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• 2008

This paper presents vibration control performances and stability evaluations of railway vehicle featuring controllable magnetorheological (MR) damper. The MR damper model is developed and then incorporated with the governing equations of motion of the railway vehicle which includes vehicle body, bogie and wheel-set. A cylindrical type of MR damper is devised and its damping force is evaluated by considering fluid viscosity and MR effect. Design parameters are determined to achieve desired damping force level applicable to real railway vehicle. Subsequently, computer simulation of vibration control and stability analysis is performed using Matlab Simulink.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.169-172
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• 2004

This paper proposes a new MR(magneto-rheological) brake utilizing composite modes of MR fluid. Its basic structure and design scheme are almost the same with the conventional MR brake, but for slots in a rotating disk or shell. The slots enable the proposed MR brake to use a new mode, so-called, ‘direct cutting chain mode’as well as shear mode, which results in increasing the braking force(almost 150% compared to the case without slots). Some experimental results show that the proposed MR brake provide the sufficient braking force to be adopted for small portable force feedback devices.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.7
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• pp.732-740
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• 2008

This paper presents vibration control performances and stability evaluations of railway vehicle featuring controllable magnetorheological(MR) damper. The MR damper model is developed and then incorporated with the governing equations of motion of the railway vehicle which includes vehicle body, bogie and wheel-set. A cylindrical type of MR damper is devised and its damping force is evaluated by considering fluid viscosity and MR effect Design parameters are determined to achieve desired damping force level applicable to real railway vehicle. Subsequently, computer simulation of vibration control and stability analysis is performed using Matlab Simulink.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.291-298
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• 2017

In recent years, the increase of secondary controls within vehicles requires a mechanism to integrate various controls into a single device. This paper presents control performance of an integrated magnetorheological (MR) haptic device which can adjust various in-vehicle comfort instruments. As a first step, the MR fluid-based haptic device capable of both rotary and push motions within a single device is devised as an integrated multi-functional instrument control device. Under consideration of the torque and force model of the proposed device, a magnetic circuit is designed. The proposed MR haptic device is then manufactured and its field-dependent torque and force are experimentally evaluated. Furthermore, an inverse model compensator is synthesized under basis of the Bingham model of the MR fluid and torque/force model of the device. Subsequently, haptic force-feedback maps considering in-vehicle comfort functions are constructed and interacts with the compensator to achieve a desired force-feedback. Control performances such as reflection force are experimentally evaluated for two specific comfort functions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.93-99
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• 2012

This paper presents an optimal design of magnetorheological (MR) fluid based mount (MR mount in short) which can be applicable to vibration control of diesel engine of ship. In this work, a mixed - mode including squeeze mode, flow mode and shear mode is proposed and designed. In order to determine actuating damping force of MR mount required for efficient vibration control, excitation force from diesel engine is analyzed. In this analysis, a model of V-type engine is considered and the relationship between velocity and pressure of gas in torque of the piston is derived. Subsequently, by integrating the field-dependent rheological properties of commercially available MR fluid with the excitation force an appropriate size of MR mount is designed. In addition, in order to achieve maximum actuating force with geometric constraints design optimization is undertaken using ANSYS software. Through the magnetic density analysis, optimal design parameters such as bottom gap and radius of coil are determined.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.899-900
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• 2011

• 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.