Papers by Keyword: MR Damper

Abstract: In this research, a shear-mode MR damper that can replace conventional passive damper of a front-loaded washing machine is designed, manufactured and an experiment based model is employed to characterize hysteresis behavior of the damper. Firstly, an optimized MR damper for front loaded washing machine is manufactured and an experimental system is set up for testing hysteresis behaviour of the damper. The experimental test is then conducted and presented. From experiential results, hysteresis of the damper is investigated and a suitable hysteresis model is proposed for the damper. The proposed hysteresis model of damper is then evaluated through experimental results.

Abstract: Magnetorheological damper (MR damper) is one of the promising vibration control systems, applicable for damping seismic induced vibrations in structures, because of their ability to be controlled and to adapt their mechanical properties by varying the magnetic field, their high damping force, their low energy input required and their simple use. This paper presents the experimental results carried out to study the use of Nano Fe₃O₄ as component of MR fluid. The Nano Fe₃O₄ particles are obtained by an indigenous process to convert a waste product of chemical industry. The performance of Nano Fe₃O₄ MR fluid is compared with five commercially available samples in the market namely, Mill scale, cast iron (1), cast iron (2), carbonyl iron and white iron oxide. Surface morphology was identified using SEM & the average particle size was analysed using XRD. Viscosity & settling measurements were also performed for all the six samples. Shake table tests were conducted to study the performance of steel frame with MR damper. The model for the study was a single bay three storey steel frame where the response of the structure, in terms of acceleration, velocity and displacement was observed. It was observed that the percentage of reduction in displacement, velocity, acceleration, approximately 40 – 67% for structure with MR damper.

Abstract: This paper discussed an elastic-plastic time-history analysis on a structure with MR dampers based on member model, in which the elastoplastic member of the structure is assumed to be single component model and simulated by threefold line stiffness retrograde model. In order to obtain better control effect, Linear Quadratic Gaussian (LQG) control algorithm is used to calculate the optimal control force, and Hrovat boundary optimal control strategy is used to describe the adjustable damping force range of MR damper. The effectiveness of the MR damper based on LQG algorithm to control the response of the structure was investigated. The results from numerical simulations demonstrate that LQG algorithm can effectively improve the response of the structure against seismic excitations only with acceleration feedback.

Abstract: This paper presents experimental and analytical study of magnetorheological damper. The experimental study has been conducted at 1.5 Hz frequency with varying current values by using hydraulic dynamic testing facility. The Bhingam MR damper model has been adopted to predict nonlinear hysteretic behaviour of magnetorheological (MR) damper and compare the results with experimental investigations. The result shows, good agreement between them.

Abstract: In this paper, a finite element analysis of a Magneto Rheological (MR) damper is carried over. A finite element model was constructed to analyse and examine the MR damper. The optimal current value for achieving the required damping force is found out. The results of the work can be used to develop more efficient and reliable MR damper, thereby reducing the time involved in prototyping the product.

Abstract: This paper proposed semi active controller scheme for magnetorheological (MR) damper of a heavy vehicle suspension known as Tire Force Control (TFC). A reported algorithm in the literature to reduce tire force is Groundhook (GRD). Thus, the objective of this paper is to investigate the effectiveness of the proposed TFC algorithm compared to GRD. These algorithms are applied to a quarter heavy vehicle models, where the objective of the proposed controller is to reduce unsprung force (tire force). The simulation model was developed and simulated using MATLAB Simulink software. The use of semi active MR damper using TFC is analytically studied. Ride test was conducted at three different speeds and three bump heights, and the simulation results of TFC and GRD are compared and analysed. The results showed that the proposed controller is able to reduced tire force significantly compared to GRD control strategy.

Abstract: This paper proposed semi active controller scheme for magnetorheological (MR) damper of a heavy vehicle suspension known as Ground Semi Active Damping Force Estimator (gSADE), where it was modified from Semi Active Damping Force Estimator (SADE) algorithm. A reported algorithm known as Groundhook (GRD) was developed where its aim to minimize tire road forces and hence reduce road damage. Thus, the objective of this paper is to investigate the effectiveness of the proposed gSADE algorithm compared to GRD and SADE. These algorithms are applied to a quarter heavy vehicle models and the simulation model was developed and simulated using MATLAB Simulink software. Ride test was conducted at three different speeds and three bump heights, and the simulation results of gSADE, SADE and GRD are compared and analysed. The results showed that the proposed controller is able to reduced tire force significantly compared to GRD control strategy.

Abstract: The semi-active control of MR damper is established, using a simplified model of landing gear system and DSP2812 as the code control board. The fuzzy control system is created based on software fuzzyTECH and simulation mode was established in matlab\simulink. Compared with passive control, the fuzzy control damping effect of the aircraft body vertical acceleration, body relative displacement and wheel dynamic load at different moments in the process of plane's taking off and landing. Software fuzzyTECH platform can generate the corresponding code for the DSP controller, applied directly to the fuzzy control system design and debugging, and shorten the development cycle of fuzzy algorithm control. Passive control and fuzzy control test are carried out on the landing gear vibration test platform. The results show that the application of fuzzy algorithm controller has higher adaptability and more real-time control effect, fuzzy control is better than passive control.

Abstract: The main function of a suspension system is to isolate and absorb the impact from road surface to vehicle body. To provide good riding comfort, a damper with variable and wide-range damping is highly needed. This paper presents a complete procedure from design, optimization to experiment for a magnetorheological (MR) damper with multiple poles. This new designed damper is entirely different from those conventional single-pole MR dampers, effectively by extending the range of damping force. Magnetic simulation has been done in the paper to provide an optimal structure of the damper which significantly enhances the damping force while avoids magnetic saturation. The new damper was also manufactured and tested. The experimental results show that the provided damping force can be significantly increased with the increase of input current from low to high speeds. Damping force can be varied by 7.41 times. It proves that this new MR damper with high damping force can be controlled adaptively at wide range of operation conditions. It is suitable to be an adaptively variable damping source in semi-active suspension systems.

Abstract: The paper deals with the problem of suppressing vibration of the arm of Motoman SSF200 robot within the frame of the technological process. Based on an overview of literature, a semi-active vibration control system was selected and a double ended magnetorheological damper (MR) was designed. After testing the acceleration of the robot arm in milling operation without the MR damper, the device was employed and the acceleration of the robot arm in four operation modes was experimentally tested.The conducted research has proved that the double ended MR damper can be practically applied for suppressing the vibration of the robot arm. The higher power to the electromagnet of the MR damper is exposed, the better vibration suppression is. This means that by changing the strength of current, the technological process of the robot arm is under control. Thus, control over the technological process is simplified when the physical characteristics of the milled material, milled tool or operation vary.