scholarly journals Semi-Active Control for a Helicopter with Multiple Landing Gears Equipped with Magnetorheological Dampers

2021 ◽  
Vol 11 (8) ◽  
pp. 3667
Author(s):  
Quoc Viet Luong ◽  
Dae-Sung Jang ◽  
Jai-Hyuk Hwang
Keyword(s):  
Mr Damper ◽  
Electrical Current ◽  
Center Of Gravity ◽  
Landing Gear ◽  
Gear System ◽  
Damping Force ◽  
Promising Candidate ◽  
Mr Dampers ◽  
Helicopter Landing ◽  
Landing Gears

Due to their extensive use in various applications, helicopters need to be able to land in a variety of conditions. Typically, a helicopter landing gear system with skids or passive wheel-dampers is designed based on only one critical touchdown condition. Thus, this helicopter landing gear system may not perform well in different landing conditions. A landing gear system with magnetorheological (MR) dampers would be a promising candidate to solve this problem. However, a semi-active controller must be designed to determine the electrical current applied to the MR damper to directly manage the damping force. This paper presents a new skyhook controller, called the skyhook extended controller, for a helicopter with multiple landing gears equipped with MR dampers to reduce the helicopter’s acceleration at the center of gravity in off-normal landing attitude conditions. A 9-DOF simulation model of a helicopter with multiple MR landing gears was built using RECURDYN. To verify the effectiveness of the proposed controller, co-simulations were executed with RECURDYN and MATLAB in different initial pitch and roll angles at touchdown. The main simulation results show that the proposed controller can greatly decrease the peak and rms acceleration of the helicopter’s center of gravity compared to a traditional skyhook controller and passive damper.

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.

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.

scholarly journals Flow Mode Magnetorheological Dampers with an Eccentric Gap

2014 ◽  
Vol 6 ◽  
pp. 931683 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley
Keyword(s):  
Constitutive Model ◽  
Mr Damper ◽  
Flow Mode ◽  
Rectangular Duct ◽  
Damping Force ◽  
Bingham Plastic ◽  
Mr Dampers ◽  
Annular Gap ◽  
Field Dependent ◽  
Viscous Field

This paper analyzes flow mode magnetorheological (MR) dampers with an eccentric annular gap (i.e., a nonuniform annular gap). To this end, an MR damper analysis for an eccentric annular gap is constructed based on approximating the eccentric annular gap using a rectangular duct with a variable gap, as well as a Bingham-plastic constitutive model of the MR fluid. Performance of flow mode MR dampers with an eccentric gap was assessed analytically using both field-dependent damping force and damping coefficient, which is the ratio of equivalent viscous field-on damping to field-off damping. In addition, damper capabilities of flow mode MR dampers with an eccentric gap were compared to a concentric gap (i.e., uniform annular gap).

Passenger Comfort Analysis in an Automotive Considering a Magneto-Rheological Damper based Suspension

2017 ◽  
Vol 8 (4) ◽  
Author(s):  
R.B. Soujanya ◽  
D.D. Jebaseelan ◽  
S. Kannan
Keyword(s):  
Ride Comfort ◽  
Mr Damper ◽  
Nonlinear Behaviour ◽  
Passive Damping ◽  
Damping Force ◽  
The Road ◽  
Mr Dampers ◽  
Moving Vehicles ◽  
Magneto Rheological ◽  
Multi Body

Passenger’s comfort in moving vehicles depends on the quality of the ride. The major cause of discomfort is the vibration transmitted to passengers due to the road irregularities. For a comfortable ride on a vehicle, vibration must stay within prescribed standards. In the present work, an attempt was made to show that, the vibrations can be limited with the use of Magneto-rheological (MR) dampers for varying road profiles than the passive damping methods. MR dampers are semi-active control devices that use MR fluids to produce controllable damping force as they are known to exhibit nonlinear behaviour. Multi body dynamic studies were done to study the response of the system using a quarter car model. In this paper, passive damping (viscous damping) was considered at natural frequency of 1.012Hz, the response of damping was observed after 10s and the acceleration was found to be 6m/s2. When MR damper is employed as the magnetic force increases, the response of the damping was better than the passive damping, at 1.2A it comes down to 0.55m/s2, and the vibration gets dampened after 1.75s. Hence, from this study it is concluded that the MR damper can be employed in automobile for better ride comfort.

Design and Performance Verification of Variable Dampers Using MR Fluid

2003 ◽  
Author(s):  
Toshihiko Shiraishi ◽  
Tomoya Sakuma ◽  
Shin Morishita
Keyword(s):  
Dynamic Range ◽  
Mr Damper ◽  
Experimental Result ◽  
Damping Force ◽  
Mr Fluid ◽  
Mr Dampers ◽  
Piston Speed ◽  
Analytical Result ◽  
And Performance ◽  
Good Agreement

Two typical types of MR damper were proposed, where the orifice for MR fluid was designed to place between the piston and the cylinder in one type, and to place on the piston in the other type. In the former design, MR fluid was expected to be subjected to shear flow in the orifice, and subjected to Poiseuille flow in the latter design. The damping force of MR dampers was experimentally measured under various conditions of piston speed, piston amplitude and applied electric current to the magnetic coil. The experimental results showed that the maximum damping force were almost the same in both types of damper under the same conditions, except for case under very little amplitude. It was also shown that typical characteristics of MR damper depended on the clearance of orifice and air volume in MR dampers, and the optimal design for the dynamic range of damping force existed in relation to the clearance of orifice. The experimental result of the damping force of these dampers showed good agreement with the analytical result.

Design and Development of Magneto Rheological Dampers for Bicycle Suspensions

1999 ◽  
Author(s):  
Mehdi Ahmadian
Keyword(s):  
Dynamic Performance ◽  
Mr Damper ◽  
Test Results ◽  
Design And Development ◽  
Damping Force ◽  
Mr Fluid ◽  
Performance Improvements ◽  
Mr Dampers ◽  
Force Velocity ◽  
Magneto Rheological

Abstract The design and fabrication of a magneto rheological (MR) damper for bicycle suspension applications is addressed. Two 1998 Judy® Dampers are retrofitted with MR valves, to achieve the damping force adjustability that the MR fluid offers. One design attempts to use as many of the Judy® Damper components as possible. The second design significantly modifies the Judy® Damper, to better accommodate the MR valve and ease of fabrication and assembly, although fitting into the same envelope as the Judy® damper for a direct retrofit. The two MR dampers are fabricated and assembled for force-velocity characterization testing. The test results show that properly-designed MR dampers can provide significant dynamic performance improvements, as compared to conventional passive bicycle dampers.

Improving Vehicle Performance and Operator Ergonomics: Commercial Application of Smart Materials and Systems

2011 ◽  
Author(s):  
Douglas Ivers ◽  
Douglas LeRoy
Keyword(s):  
Smart Materials ◽  
Mr Damper ◽  
Electrical Current ◽  
Step Response ◽  
Commercial Application ◽  
Material Technology ◽  
Mr Fluid ◽  
Mr Dampers ◽  
Magneto Rheological ◽  
Scale Step

This paper will discuss how controllable material technology, such as the use of active magneto-rheological (MR) dampers, improves vehicle primary and secondary suspensions. Although relatively new to the marketplace, semi-active suspensions in commercial automobiles and off-highway vehicles have been proven through the use of active MR dampers since 1998. In fact, MR suspension dampers are found today on the commercial vehicles of an increasing number of automotive OEMs and leading off-highway OEMs. MR fluid dampers are simple in design and have the advantage of no moving parts. The resistive force from an MR damper is generated as iron particles, suspended in the magneto-rheological fluid (MR fluid); pass through a magnetic field controlled by the electrical current passing through an electric coil contained within a moving piston surrounded by fluid. By adjusting the current to the damper coil in response to feedback from vehicle sensors and a controller, the damping response of the suspension can be optimized and controlled in real time to provide optimal operator comfort. The MR Damper System has a full-scale step response of less than 10 milliseconds. Sophisticated control algorithms adapt to large changes in payload, enabling the vehicle to meet ride metrics without pneumatic load leveling. Other benefits of the MR damping system include higher speed in NATO double-lane change tests, reduced risk of roll-over, improved accuracy of mounted weapons, and improved vehicle durability and readiness.

A Review on the Development of Dampers Utilizing Smart Magnetorheological Fluids

2019 ◽  
Vol 4 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Jong-Seok Oh ◽  
Seung-Bok Choi
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Significant Contribution ◽  
Mr Damper ◽  
Fast Response ◽  
Damping Force ◽  
Mr Dampers ◽  
Comparative Advantages ◽  
Designed Materials ◽  
The Military

It is generally known that MR fluid is a kind of designed materials whose rheological properties are controllable with the application of an external magnetic field. Based on these features, MR dampers have gained much attention of researchers owing to their salient properties such as controllable damping force and relatively fast response time. This article offers a recent review on the MR damper technology, particularly focusing on the application to various fields. Conceivable limitations, challenges, and comparative advantages of MR damper are critically analyzed. In order to promote the practical use of MR damper in application from the automobile to the military sector, this review summarizes different MR dampers and their significant contribution.

Semi-Active Control of a Vehicle Suspension Based on Magneto-Rheological Damper

2011 ◽  
Vol 311-313 ◽  
pp. 2286-2290
Author(s):  
Jie Lai Chen ◽  
Xue Zheng Jiang ◽  
Ning Xu
Keyword(s):  
Ride Comfort ◽  
Mr Damper ◽  
Vehicle Suspension ◽  
Damping Force ◽  
Mr Dampers ◽  
Quarter Car ◽  
Set Up ◽  
Magneto Rheological ◽  
Two Degree Of Freedom ◽  
The Magnetic Field

The focus of this study is to experimentally investigate a semi-active magneto-rheological (MR) damper for a passenger vehicle, by using a quarter car models. After verifying that the damping force of the MR damper can be continuously tuned by the intensity of the magnetic field, a full-scale two-degree of freedom quarter car experimental set up is constructed to study the vehicle suspension. On-off skyhook controller is employed to achieve the desired damping force. The experimental results show that the semi-active vehicle suspension vibration control system based on MR dampers is feasible and can effectively improve ride comfort of vehicle.

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