Magneto-rheological dampers—model influence on the semi-active suspension performance
TL;DR: The main aim of this paper is to study the effects that may appear in the closed-loop performance of an automotive suspension system when the damper model is unable to represent crucial nonlinear MR phenomena.
Abstract: Recently, automotive industry has adopted semi-active damper systems to improve handling and comfort properties of vehicles. Nowadays, Magneto-Rheological (MR) dampers are among the most effective solutions; with the control algorithm used for their operation being a key element. While basic controllers do not require mathematical damper models, improved performance can be achieved if these are available. Usually, the accuracy of a particular set of models can be assessed by evaluating standard quantitative metrics. However, two models with similar error-metrics can still have widely different qualitative properties. In this context, the main aim of this paper is to study the effects that may appear in the closed-loop performance of an automotive suspension system when the damper model is unable to represent crucial nonlinear MR phenomena. To highlight the model influence on the controller synthesis and subsequently on the suspension performance, two damper models with different accuracy levels were chosen: an ANN-based model is compared with the classical Bingham model. First, their accuracy is experimentally validated using typical error-metrics. Afterwards, the same suspension control strategy is designed using both models. Frequency-Estimation-Based control was selected because it better exploits available model data than other typical strategies such as sky-hook. The resulting performance is assessed with a software-in-the-loop approach using CarSim and complemented with a hardware-in-the-loop implementation using a CAN-bus, both closed-loop control cases use a Simulation-Oriented ANN model as benchmark to represent the MR damper nonlinearities. Results show that although the difference in error-metrics between models can be small using typical identification methods (e.g. 16% in one scenario), suspension performance in comfort and road-holding are significantly different. Error-metrics can be deceptive for assessing the effectiveness of MR damper models during the controller design phase. Accurate qualitative modeling in the pre/post-yield regions are the main factors which determine the resulting controller performance.
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TL;DR: The ELM method is applied to a meandering valve-based MR damper for damping force prediction, which has been recently developed and has comparable average accuracies with R2 values of more than 0.95, and ELM has shown less value R2 standard deviation showing its advantage to reduce the possibility of being trapped in local solution compared to the conventional ANN.
Abstract: The application of artificial neural network (ANN) models in magnetorheological (MR) damper has gained interest in various studies because of the high accuracy in predicting the damping force, especially for control purposes. However, the existing neural network models have apparent drawbacks such as relatively long training time and the possibility to be trapped in local solutions. Therefore, this paper aims to propose a new method to deal with a highly nonlinear behavior of MR damper using an extreme learning machine (ELM) method. The ELM method is applied to a meandering valve-based MR damper for damping force prediction, which has been recently developed. A simulation scheme is selected with damping force as the output, and current, velocity, and displacement as the inputs. The simulations are then carried out based on fatigue dynamic tests data in various frequencies and currents. The training times for more than nineteen thousand data points using the ELM method with 10, 100, 1000 hidden neuron numbers are less than 1.70 s, which is faster than the conventional ANN. Based on 50 times training processes, the ELM and ANN models have comparable average accuracies with R2 values of more than 0.95. ELM also has shown less value R2 standard deviation showing its advantage to reduce the possibility of being trapped in local solution compared to the conventional ANN.
19 citations
TL;DR: This work proposes a semi-active MR model based on a Hammerstein–Wiener scheme, meant not only for force estimation but also – in a more genuinely control-oriented perspective – to be proactively used in the suspension controller design.
16 citations
TL;DR: In this paper, an analytical technique was proposed to predict the damping characteristic in the case of arbitrary fluid rheology for piston-type damper geometries with either an annular gap or circular hole(s) as restriction elements.
10 citations
TL;DR: The overall results assess the ability and the accuracy of the proposed model to characterize the force delivered by ER dampers in both healthy and faulty conditions.
Abstract: This work presents a concise control-oriented model for electro-rheological (ER) dampers. This model can serve for fault-tolerant control purposes, considering automotive suspension performance enhancement. ER dampers present, basically, a resistance against shearing that varies according to a controlled electric field. The main purpose of this work is to describe the force dynamics delivered by these ER dampers with a simple/reduced-order model that catches its overall behaviour with accuracy. One of the key points in the proposed approach is to describe the dynamics of the controlled portion of the damper force as a first-order system. Synthetically, this study is twofold: (1) the first part is an analytical approach towards the dynamic modelling of the ER damper force, wherein a reduced-order model is obtained, parameters are identified, and validation results are presented; (2) the second analyses the possible faults on these dampers and incorporates their affect to the developed model, which is of paramount importance for diagnosis and reliability of suspension systems. Hence, the proposed model is adequate for the design and synthesis of fault detection and diagnosis/fault-tolerant control (FDD/FTC) schemes, being able to run fast in real time in embedded electronic control units, that usually operate within 1–10 ms. Throughout this study, simulation and experimental validation tests are performed on a real 1/5-scaled vehicle testbed. Model parameters are identified via relatively simple procedures performed in this testbed. Results are shown to illustrate how the model can be used for FDD and FTC of semi-active suspension systems. The overall results assess the ability and the accuracy of the proposed model to characterize the force delivered by ER dampers in both healthy and faulty conditions.
10 citations
Cites background from "Magneto-rheological dampers—model i..."
...[70] discuss the influence of a good model in SA suspension control performance, for the case of MR dampers....
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TL;DR: In this paper, an optimization algorithm, i.e., the Particle Swarm Optimization (PSO) algorithm, is utilized to identify the models' parameters, distinctively controlling the best fit value by minimizing marginal error through root-mean-square error between the models and the empirical response.
Abstract: The nonlinearity behaviour of magnetorheological fluid (MRF) can be described using a number of established models such as Bingham and Modified Bouc-Wen models. Since these models require the identification of model parameters, there is a need to estimate the parameters’ value carefully. In this paper, an optimization algorithm, i.e., the Particle Swarm Optimization (PSO) algorithm, is utilized to identify the models’ parameters. The PSO algorithm distinctively controls the best fit value by minimizing marginal error through root-mean-square error between the models and the empirical response. The validation of the algorithm is attained by comparing the resulting modified Bouc-Wen model behaviour using PSO against the same model’s behaviour, identified using Genetic Algorithm (GA). The validation results indicate that the application of PSO is better in identifying the model parameters. Results from this estimation can be used to design a controller for various applications such as prosthetic limbs.
10 citations
References
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TL;DR: In this article, a model for controllable fluid dampers is proposed that can effectively portray the behavior of a typical magnetorheological (MR) damper and compared with experimental results for a prototype damper.
Abstract: Semiactive control devices have received significant attention in recent years because they offer the adaptability of active control devices without requiring the associated large power sources. Magnetorheological (MR) dampers are semiactive control devices that use MR fluids to produce controllable dampers. They potentially offer highly reliable operation and can be viewed as fail-safe in that they become passive dampers should the control hardware malfunction. To develop control algorithms that take full advantage of the unique features of the MR damper, models must be developed that can adequately characterize the damper's intrinsic nonlinear behavior. Following a review of several idealized mechanical models for controllable fluid dampers, a new model is proposed that can effectively portray the behavior of a typical MR damper. Comparison with experimental results for a prototype damper indicates that the model is accurate over a wide range of operating conditions and is adequate for control design an...
1,897 citations
TL;DR: A type of force generator which can respond to general feedback signals from a vibrating system in order to control the vibration but which does not require the power supply of a servomechanism is described.
Abstract: A type of force generator which can respond to general feedback signals from a vibrating system in order to control the vibration but which does not require the power supply of a servomechanism is described. Computer simulation studies show that performance comparable to that of fully active vibration control systems can be achieved with the semi-active type of device. Physical embodiments of the concept are discussed and compared to hardware used in active and passive vibration control systems.
1,315 citations
"Magneto-rheological dampers—model i..." refers background in this paper
...In this regard it is important to note that in current literature it is common to propose suspension controllers without considering the actual behavior of the damper, i.e. dissipativity, saturation, friction, etc (Karnopp et al 1974, Valasek et al 1997, Hong et al 2002)....
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...Examples of this dependency can be found in several control strategies such as the classical sky-hook or ground-hook approaches with the damping coefficient (Karnopp et al 1974, Valasek et al 1997, Lozoya-Santos et al 2011) or with the best damping combination in (Tudon-Martinez et al 2018)....
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TL;DR: In this paper, an overview of the essential features and advantages of magnetorheological (MR) materials and devices is given, followed by the derivation of a quasi-static axisymmetric model of MR dampers, which is then compared with both a simple parallel-plate model and experimental results.
719 citations
"Magneto-rheological dampers—model i..." refers methods in this paper
...Examples of these models are the classical Bingham model (Stanway et al 1987), the Bouc–Wen models (Spencer et al 1996, Werely et al 1998, Yang et al 2002, Dutta and Chakraborty 2014, Waubke and Kasess 2016) and the algebraic models proposed in (Guo et al 2006, Kwok et al 2006, Çesmeci and Engin…...
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459 citations
"Magneto-rheological dampers—model i..." refers methods in this paper
...…based on techniques such as Artificial Neural Networks (ANN), fuzzy logic, statistical inference and polynomial approximations, can be found in (Choi et al 2001, Chang and Zhou 2002, Hong et al 2002, Guo et al 2004, Du et al 2005, 2006, Savaresi et al 2005, Zapateiro et al 2009, Metered et al…...
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Book•
01 Sep 2007TL;DR: In this paper, a comprehensive coverage of the design, installation and use of the shock absorber is provided, including fluid dynamics, valve characteristics, damper characteristics, installation, and motion ratios, and influence on vehicle ride and handling.
Abstract: This book provides comprehensive coverage of the design, installation and use of the shock absorber. Among the subjects highlighted are fluid dynamics, valve characteristics, damper characteristics, installation and motion ratios, and influence on vehicle ride and handling. Numerous example installations are described and discussed. Testing machines, as well as methods of laboratory testing, are also described in detail. The widely varying characteristics of variable dampers, and the relationship to their design features, are explained.
459 citations
"Magneto-rheological dampers—model i..." refers background in this paper
...In this context, Magneto-Rheological (MR) dampers present several attractive properties such as: low power requirement, fast response, simple structure and a wide range of adjustable damping coefficient (Dixon 2007)....
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...While it is possible to adjust the suspension elements passively by mechanical design, it has been shown that active or semi-active systems can improve performance (Dixon 2007, Savaresi et al 2010, Fijalkowski 2011)....
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