Digital Resistance-Map Generation for a Magnetorheological Damper Based Platform for Rehabilitation Applications

2011 ◽  
Author(s):  
Ehsan Asadi ◽  
Siamak Arzanpour
Keyword(s):  
Mr Damper ◽  
Recovery Process ◽  
Magnetorheological Damper ◽  
Robotic Rehabilitation ◽  
Mr Dampers ◽  
Map Generation ◽  
Body Organ ◽  
Damper Control ◽  
The One ◽  
Control Methodology

This paper introduces a methodology for generating digital resistance-map that can be utilized in an MR-Damper based robotic rehabilitation. Typically, in rehabilitation procedures, patients are getting involved in the recovery process of gradually training weak and damaged muscles by constraining motion in repetitive exercises. The whole purpose of robotic rehabilitation is to restrict body organ motion to the one prescribed by the therapist at the initial steps of treatment to avoid further damages to other weak muscles while focusing on recovering a particular muscle. MR-Dampers are semi-active actuators that can potentially be employed for this application. These dampers can be activated to produce high resistance to motion, and a platform that contains sufficient number of them can be manipulated to create regions of different resistance against motion. To apply this to the robotic rehabilitation, the motion recommended by the therapist should be converted to the resistance-maps that can be used by MR-Damper for implementation. To accomplish that, procedure of generating the digital resistance map is introduced and several digital resistance-maps are created. An MR-damper control methodology is also developed to activate the dampers. This controller relies on the accurate modeling of the MR-Damper. Bouc-Wen model is used for MR-Damper modeling. A 3-D platform containing three linear MR-Dampers is modeled using SimMechanics. 1-D and 2-D models are used to develop the idea and build up 3-D model. Several simulations are carried out to investigate the performance of the systems in generating the prescribed digital resistance-maps. The promising results of the simulations indicate that the method can be adopted for robotic rehabilitation purposes.

Magnetorheological Damper With Micro-Grooves: Design and Experiment

2020 ◽  
Author(s):  
Gaoyu Liu ◽  
Fei Gao ◽  
Wei-Hsin Liao
Keyword(s):  
Power Consumption ◽  
Performance Enhancement ◽  
Mr Damper ◽  
Fast Response ◽  
Magnetorheological Damper ◽  
Viscous Force ◽  
Damping Force ◽  
Mr Dampers ◽  
Field Dependent ◽  
The One

Abstract Due to low power consumption and fast response, magnetorheological (MR) dampers are widely used in various engineering applications. To enhance the performances, efforts have been made to increase the field dependent force with the same power consumption. However, the fluid viscous force is also increased significantly, which is undesirable in practical use. To tackle this problem, the focus of this paper is to design and test a new MR damper with micro-grooves for performance enhancement. First, the detailed design of the proposed MR damper is provided. A prototype of the new MR damper is fabricated. Silicon steel circular rings with thickness of 0.25 mm are installed around the damper piston to form two-layer micro-grooves. Experimental results of the two MR dampers without and with micro-grooves are then compared. The advantages of MR damper with micro-grooves over the one without micro-grooves are validated. The damping force and controllable force range of MR damper with micro-grooves are larger than the one without micro-grooves. When designing MR damper, making micro-grooves can also decrease the increment of fluid viscous force while keeping the same increase of field dependent force. With micro-grooves, the field dependent force is increased by 92.7% with the same power consumption, while the fluid viscous force is increased by 43%.

Shape optimization of magnetorheological damper piston based on parametric curve for damping force augmentation

2021 ◽  
Author(s):  
Gaoyu Liu ◽  
Fei GAO ◽  
Wei-Hsin Liao
Keyword(s):  
Shape Optimization ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Physical Parameters ◽  
Damping Force ◽  
Parametric Curve ◽  
Mr Dampers ◽  
Large Current ◽  
The One ◽  
Force Range

Abstract Making full use of the magnetically controllable rheological properties of magnetorheological (MR) fluid, MR actuators have been applied in many engineering fields. To adapt to different application scenarios, parameters of MR actuators often need to be optimized. Previous MR actuator optimization was focused on finding optimal combinations of geometric dimensions and physical parameters that meet certain requirements. The parts with optimized dimensions were still in regular shape, which might not bring optimal damping performance. Therefore, in this paper, shape optimization of MR damper piston based on parametric curve is performed for the first time. First, the regional magnetic saturation problem in the previous prototype is stated. Then, the MR damper with normal piston is simulated as a reference. Later, Bezier curve, one of the typical parametric curves, is used to form the piston with optimized parameters, and the MR damper with optimized piston is also simulated. Finally, prototypes of the MR dampers with normal and optimized pistons are fabricated and tested. Compared with the MR damper with normal piston, the one with optimized piston has larger field dependent force and total damping force under relatively large current, with about 52% and 24% maximum increasing percentage, respectively. The controllable force range of the MR damper with optimized piston is also larger than that with normal piston.

The Calculation of the Equivalent Linear Damping Coefficient of the Magnetorheological Damper

2013 ◽  
Vol 336-338 ◽  
pp. 475-479 ◽  
Author(s):  
Yao Hui Guo ◽  
En Wei Chen ◽  
Qun Wu ◽  
Yi Min Lu ◽  
Zeng Qiang Xia
Keyword(s):  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Coefficient ◽  
Control Voltage ◽  
Characteristic Analysis ◽  
Equivalent Damping ◽  
Equivalent Linear ◽  
Linear Damping ◽  
Damper Control ◽  
Equivalent Damping Coefficient

MR damper (magnetorheological damper) has broad application prospects, and equivalent damping coefficient is very important of its dynamic characteristic analysis. Based on the modified Bouc_Wen model, the performance of MR damper was analyzed and the equivalent linear damping coefficient of MR damper was calculated. Based on simulation date of the modified Bouc_Wen model, the relationships between the equivalent linear damping coefficient of MR damper and the parameters of control voltage and MR dampers movement amplitude were established by the curve fitting regression analysis method. Verification results prove that the equivalent linear damping coefficient model has higher accuracy. For the vibration systems using strongly nonlinear MR damper, new model can effectively improve the efficiency of calculating the vibration analysis and the stability of the system in a certain frequency. At the same time, the model provides a theoretical basis for the application of MR damper control.

scholarly journals Design and Multiobjective Optimization of Magnetorheological Damper considering the Consistency of Magnetic Flux Density

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Zhizhen Dong ◽  
Zhimin Feng ◽  
Yuehua Chen ◽  
Kefan Yu ◽  
Gang Zhang
Keyword(s):  
Magnetic Flux ◽  
Multiobjective Optimization ◽  
Flux Density ◽  
Optimization Design ◽  
Dynamic Range ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Magnetic Flux Density ◽  
Damping Force ◽  
Mr Dampers

The consistency of magnetic flux density of damping gap (CMDG) represents the balancing magnetic flux density in each damping gap of magnetorheological (MR) dampers. It can make influences on the performances of MR dampers and the accuracy of relevant objective functions. In order to improve the mechanical performances of the MR damper with a two-stage coil, the function for calculating CMDG needs to be found. By establishing an equivalent magnetic circuit model of the MR damper, the CMDG function is derived. Then, the multiobjective optimization function and the working flow of optimal design are presented by combining the parallel-plate model of the MR damper with the function posed before. Taking the damping force, the dynamic range, the response time, and the CMDG as the optimization objective, and the external geometric dimensions of the SG-MRD60 damper as the bound variable, this paper optimizes the internal geometric dimensions of MR damper by using a NSGA-III algorithm on the PlatEMO platform. The results show that the obtained scheme in Pareto-optimal solutions has existed with better performance than that of SG-MRD60 scheme. According to the results of the finite element analysis, the multiobjective optimization design including the CMDG function can improve the uniformity of magnetic flux density of the MR damper in damping gap, which meets the requirements of manufacture and application.

Magnetorheological damper behaviour in accordance with flow mode

2018 ◽  
Vol 84 (2) ◽  
pp. 21101
Author(s):  
Joanes Berasategui ◽  
Ainara Gomez ◽  
Manex Martinez-Agirre ◽  
Maria Jesus Elejabarrieta ◽  
M. Mounir Bou-Ali
Keyword(s):  
Rheological Behaviour ◽  
Mr Damper ◽  
Experimental Tests ◽  
Magnetorheological Damper ◽  
Flow Mode ◽  
Main Design ◽  
Mr Dampers ◽  
Significant Parameter ◽  
Optimal Flow ◽  
Theoretical Results

The objective of this article is to determine the optimal flow mode in an MR damper to maximize its performance. Flow mode is one of the main design issues in an MR damper, as it determines the velocity profile and the pressure drop across the gap. In this research, two MR dampers were designed and manufactured with two flow modes: valve and mixed. The response of these two dampers was compared experimentally. Additionally, the experimental tests were correlated by theoretical results that were obtained considering the rheological behaviour of the MR fluid, the shear stress distribution in the gap, and the damper movement. Interestingly, the obtained results suggest that flow mode is not a significant parameter for determining the behaviour of a MR damper.

Comparative Study of Magnetorheological Damper Models for Force Tracking

2015 ◽  
Author(s):  
Anria Strydom ◽  
Werner Scholtz ◽  
Schalk Els
Keyword(s):  
Computational Efficiency ◽  
Ride Comfort ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Suspension Systems ◽  
Mr Dampers ◽  
Damping Characteristics ◽  
Force Tracking ◽  
Control Application

Magnetorheological (MR) dampers are controllable semi-active dampers capable of providing a range of continuous damping settings. MR dampers are often incorporated in suspension systems of vehicles where conflicting damping characteristics are required for favorable ride comfort and handling behavior. For control applications the damper controller determines the required damper current in order to track the desired damping force, often by using a suitable MR damper model. In order to utilise the fast switching time capability of MR dampers, a model that can be used to directly calculate damper current is desired. Unfortunately few such models exist and other methods, which often negatively affect the computational efficiency of the model, need to be used when implementing these models. In this paper a selection of MR damper models are developed and evaluated for both accuracy and computational efficiency while tracking a desired damping force. The Kwok model is identified as a suitable candidate for the intended suspension control application.

Optimal Magnetorheological Damper Configuration Using the Taguchi Experimental Design Method

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Zekeriya Parlak ◽  
Tahsin Engin ◽  
İsmail Şahin
Keyword(s):  
Experimental Design ◽  
Dynamic Range ◽  
Design Method ◽  
Mr Damper ◽  
Fast Response ◽  
Magnetorheological Damper ◽  
Taguchi Experimental Design ◽  
Mr Dampers ◽  
Experimental Design Method ◽  
Variable Damping

Magnetorheological (MR) dampers have attracted the interest of suspension designers and researchers because of their variable damping feature, mechanical simplicity, robustness, low power consumption and fast response. This study deals with the optimal configuration of an MR damper using the Taguchi experimental design approach. The optimal solutions of the MR damper are evaluated for the maximum dynamic range and the maximum damper force separately. The MR dampers are constrained in a cylindrical container defined by radius and height. The optimal damper configurations obtained from this study are fabricated and tested for verification. The verification tests show that the dampers provide the specified damper force and dynamic range.

Experimental Study on Multi-Mode Vibration Control of a Stay Cable with a Passive Magnetorheological Damper

2013 ◽  
Vol 361-363 ◽  
pp. 1402-1405
Author(s):  
Zhi Hao Wang
Keyword(s):  
Vibration Control ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Test Results ◽  
Stay Cable ◽  
Mr Dampers ◽  
Stay Cables ◽  
Modal Damping ◽  
Mode Vibration ◽  
Multi Mode

Effective vibration control technology for stay cables is extremely critical to safe operations of cable-stayed bridges. For super-long cables, passive linear damper cannot provide sufficient damping since it can be only optimum for a given mode of cable, while a long cable may vibrate with several modes. This paper focuses on multi-mode vibration control of stay cables with passive magnetorheological (MR) dampers. Firstly, a 21.6m-long model cable was designed and established in the laboratory.Then, control performance of the cable with a passive MR damper was tested. The test results show that modal damping ratios of the cable in the first four modes can be improved significantly with the MR damper. It is further demonstrated that optimal tuned passively operated MR damper can outperform the passive viscous damper.

Design and Test of Magnetorheological Damper with Embedded Controller

2011 ◽  
Vol 301-303 ◽  
pp. 430-435
Author(s):  
Hong Sheng Hu ◽  
Juan Wang
Keyword(s):  
Engineering Application ◽  
Mr Damper ◽  
Development Trend ◽  
Structure Design ◽  
Magnetorheological Damper ◽  
Communication Interface ◽  
Mr Dampers ◽  
Embedded Controller ◽  
Speed Up ◽  
Developing Platform

Combining with the current development trend of vehicle suspension and damper technology, different standards of MR dampers are respectively developed in this paper in order to solve problems the semi-active suspend engineering application brings, where its structure design of a certain type of MR damper is detailedly analyzed from the point of engineering view. In order to speed up the progress of MR damper development, based on 1/4 suspend hardware-in-the-loop tester, the integrated developing platform for MR damper with embedded controller is designed and developed, in which some key parts are included, such as assistant algorithm of structure design, exploitation tool of speediness testing, communication interface of CAN bus. The integrated developing platform for MR damper with embedded controller is the same with MR product’s exploitation flow. Finally, its hardware and software design of the measuring-controlling unit for MR damper with embedded controller, are introduced, and some test results are also show and analyzed. Experimental results prove that the developed MR damper with embedded controller would have a widely application prospect.

Testing and Modeling of MR Damper and Its Application to SDOF Systems Using Integral Backstepping Technique

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Sk. Faruque Ali ◽  
Ananth Ramaswamy
Keyword(s):  
Active Control ◽  
Testing Machine ◽  
Mr Damper ◽  
Control Device ◽  
Magnetorheological Damper ◽  
Input Current ◽  
Magnetorheological Dampers ◽  
Damper Control ◽  
Nonlinear Devices ◽  
Current Monitoring

Magnetorheological dampers are intrinsically nonlinear devices, which make the modeling and design of a suitable control algorithm an interesting and challenging task. To evaluate the potential of magnetorheological (MR) dampers in control applications and to take full advantages of its unique features, a mathematical model to accurately reproduce its dynamic behavior has to be developed and then a proper control strategy has to be taken that is implementable and can fully utilize their capabilities as a semi-active control device. The present paper focuses on both the aspects. First, the paper reports the testing of a magnetorheological damper with an universal testing machine, for a set of frequency, amplitude, and current. A modified Bouc–Wen model considering the amplitude and input current dependence of the damper parameters has been proposed. It has been shown that the damper response can be satisfactorily predicted with this model. Second, a backstepping based nonlinear current monitoring of magnetorheological dampers for semi-active control of structures under earthquakes has been developed. It provides a stable nonlinear magnetorheological damper current monitoring directly based on system feedback such that current change in magnetorheological damper is gradual. Unlike other MR damper control techniques available in literature, the main advantage of the proposed technique lies in its current input prediction directly based on system feedback and smooth update of input current. Furthermore, while developing the proposed semi-active algorithm, the dynamics of the supplied and commanded current to the damper has been considered. The efficiency of the proposed technique has been shown taking a base isolated three story building under a set of seismic excitation. Comparison with widely used clipped-optimal strategy has also been shown.

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