Magnetorheological Fluid Brake Research Articles

Optimal Design and Control Performance Evaluation of a Magnetorheological Fluid Brake Featuring a T-Shape Grooved Disc

Magnetorheological fluid brakes are a promising technology for developing high-performance drive-by-wire braking systems due to their controllability and adaptability. This research aims to design an optimal magnetorheological fluid brake for motorcycles and their performance. The proposed model utilizes mathematical modeling and finite element analysis using commercial software. Furthermore, the optimization of this MR brake is determined through multi-objective optimization with a genetic algorithm that maximizes braking torque while simultaneously minimizing weight and the cruising temperature. The novelty lies in the geometric shape of the disc, bobbin, and MR fluid channels, which results in a light MR brake weighing 6.1 kg, an operating temperature of 89.5 °C, and a power consumption of 51 W with an output braking torque of 303.9 Nm. Additionally, the control performance is evaluated using an extended Kalman filter controller. This controller effectively regulates braking torque, speed, and slip rate of both the rear and front wheels based on road characteristics and motorcycle dynamics. This study’s findings show that the front wheel necessitates higher braking torque compared to the rear wheel. Moreover, the slip rate is higher on the rear wheel than on the front wheel, but the front wheel stops earlier than the rear wheel.

Coupled Field Analysis of Phenomena in Hybrid Excited Magnetorheological Fluid Brake

The paper presents a field model of coupled phenomena occurring in an axisymmetric magnetorheological brake. The coupling between transient fluid dynamics and electromagnetic and thermal fields as well as mechanical equilibrium equations is taken into account. The magnetic field in the studied brake is of an excited hybrid manner, i.e., by the permanent magnets (PMs) and current Is in the excitation winding. The finite element method and a step-by-step algorithm have been implemented in the proposed field model of coupled phenomena in the considered brake. The nonlinearity of the magnetic circuit and rheological properties of a magnetorheological fluid (MR fluid) as well as the influence of temperature on the properties of materials have been taken into account. To solve equations of the obtained field model, the Newton-Raphson method and the coupled block over-relaxation method have been implemented. The elaborated algorithm has been successfully used in the analysis of the phenomena in the considered magnetorheological brake. The accuracy of the developed model and its usefulness have been verified by a comparative analysis of the results of simulation and laboratory tests carried out for the developed prototype of the studied brake.

Research on Control Strategy of a Magnetorheological Fluid Brake Based on an Enhanced Gray Wolf Optimization Algorithm

In order to improve the response characteristics of magnetorheological fluid brake (MRB) and reduce the braking fluctuation rate, an improved grey wolf optimization algorithm was proposed to adjust the parameters of the proportion integration differentiation (PID) controller. Firstly, an MRB system was designed and constructed, and its transfer function was determined. Moreover, by adopting the iterative method of logistic curve, an enhanced grey wolf optimization algorithm (EGWOA) was presented. Using the EGWOA, the parameters of the PID controller were optimized to improve the control performance of the system. Finally, the simulation and experiment were carried out. The results showed that EGWOA has a faster response output and overall better performance without overshoot compared with the conventional PID and grey wolf optimization algorithm (GWOA) PID controller.

A novel magnetorheological braking system with variable magnetic particle volume fractioncontrolled by utilizing shape memory alloy

To address the shortcomings of decreasing shear yield stress of magnetorheological fluid due to temperature increase, magnetic saturation phenomenon under the action of a strong magnetic field, and decreasing performance of magnetorheological brake due to magnetic particle settling, a braking system of variable particle volume fraction of magnetorheological fluid modulated by shape memory alloy spring is proposed, which solves the shortcomings of constant particle volume fraction magnetorheological brakes. The brake temperature rises and automatically increases the volume fraction of magnetorheological fluid, leading to increase in the braking torque and ensuring stable braking performance at high temperatures. The magnetorheological fluid particle settling stability is enhanced, and energy consumption at idle is reduced. Based on the shape memory effect of shape memory alloy, the relationship between the output displacement of shape memory alloy spring and temperature, squeezing pressure and volume fraction of magnetic particles is established. Based on the microscopic body-centered tetragonal structure of magnetorheological fluid, the relationship between the volume fraction of magnetic particles and the magnetic permeability of magnetorheological fluid was established. Based on the rheological characteristics of magnetorheological fluid, the relationship between the braking torque of magnetorheological fluid and the magnetic permeability and the volume fraction of magnetic particles is established; and the finite element method was applied to simulate and analyze it. The results show that the magnetic permeability increases with the increase of the volume fraction of magnetic particles and the braking torque increase with the increase of the volume fraction of magnetic particles during the evolution of the magnetorheological fluid microstructure from single chain to body-centered tetragonal structure. When the volume fraction of magnetic particles in the magnetorheological fluid increased from 15% to 45%, the magnetorheological brake torque increased to 10.1N·m, and the braking performance of the magnetorheological brake improved by 14.3%. The experimental and theoretical analyses provide a theoretical basis for the design and manufacture of magnetorheological fluid brakes with variable particle volume fractions.

Development of a Bimanual Wearable Force Feedback Device Composed of Pneumatic Artificial Muscles and Magnetorheological Fluid Brakes

Development of a Bimanual Wearable Force Feedback Device Composed of Pneumatic Artificial Muscles and Magnetorheological Fluid Brakes

The Torque Capacity of a Magnetorheological Fluid Brake Compared to a Frictional Disk Brake

In this technical brief, the authors compare the torque capacity of a magnetorheological (MR) fluid brake with a conventional frictional disk brake. In the development of the torque models for both brakes, a mathematical expression for the compared torque ratio is presented. For the frictional disk brake, constant pressure and constant wear theories are considered, while static torque of the MR fluid brake is considered for comparison purpose only. Throughout the analysis, the outer radius of the compared brakes is assumed to be the same to ensure similarity of size, while the inner radius is selected to achieve maximum values of braking torque for both brake designs. Reasonable values of design variables for each brake are obtained from references and adopted in this study for making comparisons between the two designs. In conclusion, it is shown that the torque capacity for a frictional disk brake is 10–18 times greater than the torque capacity for a MR fluid brake of similar size.

모듈러 구조의 멀티 디스크 타입 MR 유체 브레이크 개발

Recently the interest in miniaturization of mechanical devices has increased and magneto-rheological (MR) fluid brakes have been designed, fabricated and tested to be applied as a control element of various devices for assisting the elderly people. A multi-disk modular type of design is proposed to make an MR fluid brake that can generate high torque at the minimum size. The design parameters of the MR fluid brake were determined by mathematical modeling and the performance was predicted with magnetic analysis to maximize the design torque. A testbed was constructed and torque responses were measured and analyzed according to the input current for various rotational speeds to confirm the performance of the MR fluid brake. The experimental results showed that the MR fluid brake was applicable to actuating devices for assisting elderly people.

Multi-objective design optimization and control of magnetorheological fluid brakes for automotive applications

The magnetorheological brake (MRB) is an electromechanical device that generates a retarding torque through employing magnetorheological (MR) fluids. The objective of this paper is to design, optimize and control an MRB for automotive applications considering. The dynamic range of a disk-type MRB expressing the ratio of generated toque at on and off states has been formulated as a function of the rotational speed, geometrical and material properties, and applied electrical current. Analytical magnetic circuit analysis has been conducted to derive the relation between magnetic field intensity and the applied electrical current as a function of the MRB geometrical and material properties. A multidisciplinary design optimization problem has then been formulated to identify the optimal brake geometrical parameters to maximize the dynamic range and minimize the response time and weight of the MRB under weight, size and magnetic flux density constraints. The optimization problem has been solved using combined genetic and sequential quadratic programming algorithms. Finally, the performance of the optimally designed MRB has been investigated in a quarter vehicle model. A PID controller has been designed to regulate the applied current required by the MRB in order to improve vehicle’s slipping on different road conditions.

空気圧人工筋肉と磁気粘性流体を用いた可変粘弾性特性を有する外骨格アシストスーツの開発

In this study, a variable viscoelastic joint system comprising antagonized artificial muscles and magneto-rheological fluid brakes is proposed. This system enables human assisting devices such as robotic exoskeletons to retain structural softness when compared with the existing devices driven by motors and reduction gears, which can only achieve superficial softness. The authors had proposed the system and showed its effectiveness via experiments using a prototype with one degree of freedom in their previous works. In this study, as the next step in designing the human assisting device, a lower body assistive prototype “Airsist I” is introduced. In addition, a control method that can cooperate with the wearer without the need for an additional operation is proposed.

Effect of surface texture and working gap on the braking performance of the magnetorheological fluid brake

In this paper, the effect of the surface textures of braking disc on the braking performance is experimentally investigated under the conditions of different working gaps and applied currents. For this purpose, a new configuration of magnetorheological fluid brake (MRB) with adjustable working gap is developed to improve the manufacturing accuracy and cost, and to reduce the problem of replacing the braking disc. In addition, the braking discs with three types of surface texture are designed and machined. Based on the test bed developed for the proposed MRB, a series of experiments are carried out on the manufactured prototype and the results are presented to obtain the relationship among the surface texture of the braking disc, applied current, working gap and the braking performance. The results show that the braking torque is significantly influenced by the working gap and surface texture of the braking disc, and the maximum braking torque is obtained on the conditions of 0.25 mm working gap and the braking disc with square surface texture.

Design and Analysis of Magneto-Rheological Fluid Brake (MRB)

Magneto-rheological fluids are smart fluids displaying flow properties that can be adjusted by the introduction of magnetic fields. Conventional brakes require complex mechanical parts to dissipate energy, they are having more weight, produce less braking torque and the time of response is about 300-500 milliseconds and hence brake distance is high. A Magneto-rheological fluid brake is more efficient than conventional braking system in terms of the weight reduction, and response time. In this paper an improved MRB design is made, taking into account the temperature effects and more accurate description of the material properties as well. The proposed work is concerned with the development of a new Brake-by-wire system which employs MRF as working medium. The design procedure comprises the selection of materials for MRB, creating an analytical model for finding the braking torque produced by the MRB and Finite Element Analysis of the MRB. Finite element models are built to provide a means to analyze the performance of the magneto-rheological brake system. The formulation of these models (including the definition of the geometry, material properties, boundary conditions and meshing process, as well as necessary assumptions) are described. The results obtained with the finite element models are presented and analyzed using SolidWorks 2013® and COMSOL Multiphysics 4.3b®.

Preparation of MR Fluid and Modeling of Magneto Rheological Fluid Brake (MRB)

Magneto-rheological fluids are smart fluids displaying flow properties that can be adjusted by the introduction of magnetic fields. Conventional brakes require complex mechanical parts to dissipate energy, they are having more weight, produce less braking torque and the time of response is about 300-500 milliseconds and hence brake distance is high. A Magneto-rheological fluid brake is efficient than conventional braking system in terms of the weight reduction, and response time. In this paper MR fluid is prepard and an improved MRB design is made, taking into account the temperature effects and more accurate description of the material properties as well. The proposed work is concerned with the development of a new Brake-by-wire system which employs MRF as working medium. The design procedure comprises the selection of materials for MRB, creating an analytical model for finding the braking torque produced by the MRB and Finite Element Analysis of the MRB.

Modelling and Control Design of a Magnetorheological Fluid Brake

An experimental/theoretical activity concerning the modelling and the adaptive control design of a magnetorheological fluid brake is described. The parametric uncertainty that characterizes the system suggests the employment of an adaptive control finalized to track the reference braking torque. This feedback control method is able to minimize the tracking error in presence of a plant characterized by a known dynamics and uncertain parameters. Numerical simulations have been carried out and the obtained results confirm the goodness of the proposed approach.

Optimal design of a new 3D haptic gripper for telemanipulation, featuring magnetorheological fluid brakes

In this research work, a new configuration of a 3D haptic gripper for telemanipulation is proposed and optimally designed. The proposed haptic gripper, featuring three magnetorheological fluid brakes (MRBs), reflects the rolling torque, the grasping force and the approach force from the slave manipulator to the master operator. After describing the operational principle of the haptic gripper, an optimal design of the MRBs for the gripper is performed. The purpose of the optimization problem is to find the most compact MRB that can provide a required braking torque/force to the master operator while the off-state torque/force is kept as small as possible. In the optimal design, different types of MRBs and different MR fluids (MRFs) are considered. In order to obtain the optimal solution of the MRBs, an optimization approach based on finite element analysis (FEA) integrated with an optimization tool is used. The optimal solutions of the MRBs are then obtained and the optimized MRBs for the haptic gripper are identified. In addition, discussions on the optimal solutions and performance of the optimized MRBs are given.

Basic Research of “MR-PLEMO”: 2-D Passive-Type Rehabilitation System for Upper Limbs Using MR Fluid Brake

Rehabilitation for the upper limbs is important for elderly people, people who have suffered strokes, and so on. In recent years, the need for rehabilitation support systems is increasing that use force display systems. When using a force display system, it is most important to ensure safety mechanically in order to prevent operators from hurting subjects. Conventional force display systems are active systems with actuators and these systems may become dangerous when going out of control. Passive force display systems with only passive elements are, however, thought to be an effective method for assuring inherent safety. In this paper, we evaluate force display ability for a 2-D passive-type force display system using fast-response MR (Magneto-Rheological) fluid brakes in order to apply this system to rehabilitation training.

Magnetorheological Fluid Brake – Basic Performances Testing with Magnetic Field Efficiency Improvement Proposal

A review of all magnetorheological brake types was presented. Based on overall braking torque analytical comparison for all magnetorheological brake types and other relevant parameters, the most promising design was selected. A test rig, utilizing selected brake type filled with magnetorheological fluid – Basonetic 5030 was manufactured and then tested. To analyze the effect produced by magnetic field on magnetorheological fluid and hence at overall braking torque, the authors used amplification factor. Results were discussed and the magnetic field efficiency improvements were proposed.

Design of an adaptive control for a magnetorheological fluid brake with model parametersdepending on temperature and speed

This paper describes experimental/theoretical activities carried out on a magnetorheologicalfluid brake (MRFB) prototype. A device model is derived and a detailed evaluation of theinfluence of temperature and speed on its parameters is performed. It can be seenthat temperature and speed act as modifying inputs for the system model andchange the value of some of its parameters. More specifically, time constant andtorque/current gain are affected by velocity whereas fluid viscosity is only affected bytemperature. The presence of the above modifying input suggests the employment of anadaptive approach for MRFB feedback control based on the torque measurementonly. Starting from the proposed model, a model reference adaptive control isdesigned, ensuring that the tracking error converges to zero as time . Simulation activity, carried out on the device validated model, confirms the effectivenessof the proposed adaptive controller.

Serpentine flux path for high torque MRF brakes in haptics applications

This research aimed to address two main goals in the development of a rotary magnetorheological fluid (MRF) brake: (1) design of a compact and powerful brake and (2) low friction sealing technique to reduce the off-state braking torque and prevent the fluid from leaking. Using magnetically conductive and non-conductive rings a serpentine flux path was developed to weave the magnetic flux through the MRF. Experimental results showed that, when compared to a commercial MRF brake, our 33% smaller prototype MRF brake could generate 2.7 times more torque (10.9 Nm). A ferro-fluidic sealing technique was developed that resulted in sealing in the fluid and decreased the off-state friction. Further reduction in the off-state torque was obtained by applying a reverse current pulse to collapse a residual magnetic field in the brake. A 1-DOF haptic interface employing the brake enabled crisp virtual wall collision and Coulomb friction simulations.

Proposed Isocontraction Training with Muscle Strengthening and Evaluation Using MR Fluid Brakes

Isokinetic exercises used in rehabilitation to strengthen muscles often require expensive exercise equipment. The safe isokinetic exercise system we developed uses only brakes with electrorheological (ER) or magnetorheological (MR) functional fluid. Rapid fluid response gives this equipment good response and control. In the sections that follow, we give basic isokinetic exercise concepts using an MR fluid brake, focusing on high-speed control of 900 deg/s at the elbow. We also suggest a new training mode we call isocontraction exercise.

1P1-K04 コンパクトMR流体ブレーキを用いたインテリジェント短下肢装具(I-AFO) : 足関節弛緩性麻痺患者への適応と小型軽量化

Ankle-Foot Orthoses (AFOs) are orthotic devices supporting movements of ankles of disables people for example hemiplegia, polio, peroneal nerve palsy, guillain-barre, etc. In our research, we developed a passive controllable AFO (Intelligent-AFO) which can control its ankle's torque by using a compact Magneto-Rheological fluid brake (MRB). The brake in which the Magneto-Rheological fluid is used as a working field has a simple structure and rapid response. In this paper, we describe an application of the I-AFO for a guillain-barre patient and the result of the experiment. In addition, we describe a newly developed AFO which has lower weight than previous.