scholarly journals A novel inverse dynamic model for a magnetorheological damper based on network inversion

2017 ◽  
Vol 24 (15) ◽  
pp. 3434-3453 ◽  
Author(s):  
MJL Boada ◽  
BL Boada ◽  
V Diaz

Semi-active suspensions based on magnetorheological (MR) dampers are receiving significant attention, especially for control of vibration isolation systems. The nonlinear hysteretic behavior of MR dampers can cause serious problems in controlled systems, such as instability and loss of robustness. Most of the developed controllers determine the desired damping forces which should be produced by the MR damper. Nevertheless, the MR damper behavior can only be controlled in terms of the applied current (or voltage). In addition to this, it is necessary to develop an adequate inverse dynamic model in order to calculate the command current (or voltage) for the MR damper to generate the desired forces as close as possible to the optimal ones. Due to MR dampers being highly nonlinear devices, the inverse dynamics model is difficult to obtain. In this paper, a novel inverse MR damper model based on a network inversion is presented to estimate the necessary current (or voltage) such that the desired force is exerted by the MR damper. The proposed inverse model is validated by carrying out experimental tests. In addition, a comparison of simulated tests with other damper controllers is also presented. Results show the effectiveness of the network inversion for inverse modeling of an MR damper. Thus, the proposed inverse model can act as a damper controller to generate the command current (or voltage) to track the desired damping force.

Author(s):  
Ming Cheng ◽  
Zhaobo Chen ◽  
S. Nima Mahmoodi

This paper studies the vibration damping characteristics of a magnetorheological (MR) damper. A single-degree-of-freedom vibration isolation system with pedestal motion containing MR dampers has been experimentally investigated. Results show that the transmissibility at the resonance frequency does not constantly decrease as expected. It gradually decreases at the beginning, then increase unexpectedly as the input current increases. In addition, the resonant frequency of the system increases continuously. In order to explore the mechanism behind the experimental phenomenon, a centralized parameterized model of the MR damper is established. Hardening coefficient, a parameter that characterizes the dynamic characteristics of the MR damper is introduced, and the influence of the structural parameters and dynamic parameters of the MR damper on the hardening coefficient is analyzed. Simultaneously, a dynamic model of the MR damper is derived based on the Bingham model, and the damping characteristics of the MR damper are predicted and compared with the experimental results. Further, based on a simplified and equivalent dynamic model of the system, the relationship between transmissibility of the system and load mass, stiffness, and damping reveals the physical laws behind the experimental phenomenon. Finally, theoretical results are derived and compared with the experimental results, which demonstrates the rationality of the theoretical analysis.


2010 ◽  
Vol 63 (1) ◽  
pp. 3-23 ◽  
Author(s):  
Peter Paul Pott ◽  
Achim Wagner ◽  
Essameddin Badreddin ◽  
Hans-Peter Weiser ◽  
Markus L. R. Schwarz

2017 ◽  
Vol 24 (13) ◽  
pp. 2832-2852 ◽  
Author(s):  
Xiufang Lin ◽  
Shumei Chen ◽  
Guorong Huang

An intelligent robust controller, which combines a shuffled frog-leaping algorithm (SFLA) and an H∞ control strategy, is designed for a semi-active control system with magnetorheological (MR) dampers to reduce seismic responses of structures. Generally, the performance of mixed-sensitivity H∞ (MSH) control highly depends on expert experience in selecting the parameters of the weighting functions. In this study, as a recently-developed heuristic approach, a multi-objective SFLA with constraints is adopted to search for the optimal weighting functions. In the proposed semi-active control, firstly, based on the Bouc–Wen model, the forward dynamic characteristics of the MR damper are investigated through a series of tensile and compression experiments. Secondly, the MR damper inverse model is developed with an adaptive-network-based fuzzy inference system (ANFIS) technique. Finally, the SFLA-optimized MSH control approach integrated with the ANFIS inverse model is used to suppress the structural vibration. The simulation results for a three-story building model equipped with an MR damper verify that the proposed semi-active control method outperforms fuzzy control and two passive control methods. Besides, with the proposed strategy, the changes in structural parameters and earthquake excitations can be satisfactorily dealt with.


2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Zhizhen Dong ◽  
Zhimin Feng ◽  
Yuehua Chen ◽  
Kefan Yu ◽  
Gang Zhang

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.


2018 ◽  
Vol 84 (2) ◽  
pp. 21101
Author(s):  
Joanes Berasategui ◽  
Ainara Gomez ◽  
Manex Martinez-Agirre ◽  
Maria Jesus Elejabarrieta ◽  
M. Mounir Bou-Ali

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.


Author(s):  
Anria Strydom ◽  
Werner Scholtz ◽  
Schalk Els

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.


Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1849
Author(s):  
Jianbo Liu ◽  
Rongqiang Guan ◽  
Yongming Yao ◽  
Hui Wang ◽  
Linqiang Hu

In this paper, we propose a novel kinematic and inverse dynamic model for the flybar-less (FBL) swashplate mechanism of a small-scale unmanned helicopter. The swashplate mechanism is an essential configuration of helicopter flight control systems. It is a complex, multi-loop chain mechanism that controls the main rotor. In recent years, the demand for compact swashplate designs has increased owing to the development of small-scale helicopters. The swashplate mechanism proposed in this paper is the latest architectures used for hingeless rotors without a Bell-Hiller mixer. Firstly, the kinematic analysis is derived from the parallel manipulators concepts. Then, based on the principle of virtual work, a methodology for deriving a closed-form dynamic equation of the FBL swashplate mechanism is developed. Finally, the correctness and efficiency of the presented analytical model are demonstrated by numerical examples and the influence factors of the loads acted on actuators are discussed.


Author(s):  
The M. Nguyen ◽  
Mohammad H. Elahinia

This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHV). The hybrid subsystem can potentially improve the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. High pressure hydraulic fluid “assists” the engine in the initial acceleration period. Noise and vibration are an issue with these systems due to the variable hydraulic loads that are applied to the regenerative hybrid element. This study looks into the possibility of reducing the transmitted noise and vibration to the vehicle’s chassis by using smart magnetorheological (MR) dampers. MR dampers utilize MR fluid which is made of pure iron particles suspended in a carrier fluid. MR fluids deliver variable yield stress under the effect of a controllable electromagnetic field. To this end, an MR damper is modeled and simulated. In the simulation both shock and vibration loads are considered. The simulation results are compared with the performance of regular elastomer isolators. It is shown that the MR damper can effectively reduce the vibration for different working cycles of the regenerative system.


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