Self-adapting model for variable stiffness magnetorheological dampers

Author(s):  
Xinyu Lian ◽  
Huaxia Deng ◽  
Guanghui Han ◽  
mengchao ma ◽  
Zhong Xiang ◽  
...  

Abstract Variable stiffness magnetorheological fluid (MRF) dampers inherently have special nonlinear characteristics and complex structures. An accurate model describing the nonlinearity is the key for the damper to operate under variable conditions. This paper proposes a self-adapting model to characterize the variable stiffness MRF dampers through corresponding optimized algorithm. The experimental results verify the capability of the self-adapting of the model parameters. The model can describe the nonlinear characteristics of the variable stiffness MRF damper when conditions are changed. The proposed self-adaptive model improves the model accuracy which provide an approach for modeling complex dampers under variable working conditions.

2019 ◽  
Author(s):  
Joseph John Pyne Simons ◽  
Ilya Farber

Not all transit users have the same preferences when making route decisions. Understanding the factors driving this heterogeneity enables better tailoring of policies, interventions, and messaging. However, existing methods for assessing these factors require extensive data collection. Here we present an alternative approach - an easily-administered single item measure of overall preference for speed versus comfort. Scores on the self-report item predict decisions in a choice task and account for a proportion of the differences in model parameters between people (n=298). This single item can easily be included on existing travel surveys, and provides an efficient method to both anticipate the choices of users and gain more general insight into their preferences.


2020 ◽  
Vol 29 (3) ◽  
pp. 255-260
Author(s):  
Joseph Cesario ◽  
David J. Johnson ◽  
Heather L. Eisthen

A widespread misconception in much of psychology is that (a) as vertebrate animals evolved, “newer” brain structures were added over existing “older” brain structures, and (b) these newer, more complex structures endowed animals with newer and more complex psychological functions, behavioral flexibility, and language. This belief, although widely shared in introductory psychology textbooks, has long been discredited among neurobiologists and stands in contrast to the clear and unanimous agreement on these issues among those studying nervous-system evolution. We bring psychologists up to date on this issue by describing the more accurate model of neural evolution, and we provide examples of how this inaccurate view may have impeded progress in psychology. We urge psychologists to abandon this mistaken view of human brains.


2015 ◽  
Vol 24 (8) ◽  
pp. 085021 ◽  
Author(s):  
Shuaishuai Sun ◽  
Jian Yang ◽  
Weihua Li ◽  
Huaxia Deng ◽  
Haiping Du ◽  
...  

2018 ◽  
Vol 8 (11) ◽  
pp. 2028 ◽  
Author(s):  
Xin Lai ◽  
Dongdong Qiao ◽  
Yuejiu Zheng ◽  
Long Zhou

The popular and widely reported lithium-ion battery model is the equivalent circuit model (ECM). The suitable ECM structure and matched model parameters are equally important for the state-of-charge (SOC) estimation algorithm. This paper focuses on high-accuracy models and the estimation algorithm with high robustness and accuracy in practical application. Firstly, five ECMs and five parameter identification approaches are compared under the New European Driving Cycle (NEDC) working condition in the whole SOC area, and the most appropriate model structure and its parameters are determined to improve model accuracy. Based on this, a multi-model and multi-algorithm (MM-MA) method, considering the SOC distribution area, is proposed. The experimental results show that this method can effectively improve the model accuracy. Secondly, a fuzzy fusion SOC estimation algorithm, based on the extended Kalman filter (EKF) and ampere-hour counting (AH) method, is proposed. The fuzzy fusion algorithm takes advantage of the advantages of EKF, and AH avoids the weaknesses. Six case studies show that the SOC estimation result can hold the satisfactory accuracy even when large sensor and model errors exist.


2018 ◽  
Vol 72 (10) ◽  
pp. 951-957 ◽  
Author(s):  
Maria Fleischmann ◽  
Ewan Carr ◽  
Baowen Xue ◽  
Paola Zaninotto ◽  
Stephen A Stansfeld ◽  
...  

BackgroundModifications in working conditions can accommodate changing needs of chronically ill persons. The self-employed may have more possibilities than employees to modify their working conditions. We investigate how working conditions change following diagnosis of chronic disease for employed and self-employed older persons.MethodsWe used waves 2–7 from the English Longitudinal Study of Ageing (ELSA). We included 1389 participants aged 50–60 years who reported no chronic disease at baseline. Using fixed-effects linear regression analysis, we investigated how autonomy, physical and psychosocial job demands and working hours changed following diagnosis of chronic disease.ResultsFor employees, on diagnosis of chronic disease autonomy marginally decreased (−0.10, 95% CI −0.20 to 0.00) and physical job demands significantly increased (0.13, 95% CI 0.01 to 0.25), whereas for the self-employed autonomy did not significantly change and physical job demands decreased on diagnosis of chronic disease (−0.36, 95% CI −0.64 to –0.07), compared with prediagnosis levels. Psychosocial job demands did not change on diagnosis of chronic disease for employees or the self-employed. Working hours did not change for employees, but dropped for self-employed (although non-significantly) by about 2.8 hours on diagnosis of chronic disease (−2.78, 95% CI −6.03 to 0.48).ConclusionImprovements in working conditions after diagnosis of chronic disease were restricted to the self-employed. This could suggest that workplace adjustments are necessary after diagnosis of chronic disease, but that the self-employed are more likely to realise these. Policy seeking to extend working life should consider work(place) adjustments for chronically ill workers as a means to prevent early exit from work.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Pan ◽  
Zhengtao Yan ◽  
Jingjun Lou ◽  
Shijian Zhu

In order to get a better description to the nonlinear characteristics of magnetorheological dampers, the magic formula is introduced into the general method of parametric modelling of magnetorheological dampers to propose a new parameterized model called magic formula-hysteresis loop model (MFM). The new model is simple in structure, the physical meaning of each parameter is clear, and the parameter identification is convenient. The fitting and experimental data of MFM and the phenomenon model under different conditions are applied for error analysis and comparison. The results show that the errors of MFM are more accurate and have better fitting and experimental data under different working conditions, which also have better adaptability and versatility.


Author(s):  
Byamakesh Nayak ◽  
Sangeeta Sahu ◽  
Tanmoy Roy Choudhury

<p>This paper explains an adaptive method for estimation of unknown parameters of transfer function model of any system for finding the parameters. The transfer function of the model with unknown model parameters is considered as the adaptive model whose values are adapted with the experimental data. The minimization of error between the experimental data and the output of the adaptive model have been realised by choosing objective function based on different error criterions. Nelder-Mead optimisation Method is used for adaption algorithm. To prove the method robustness and for students learning, the simple system of separately excited dc motor is considered in this paper. The experimental data of speed response and corresponding current response are taken and transfer function parameters of  dc motors are adapted based on Nelder-Mead optimisation to match with the experimental data. The effectiveness of estimated parameters with different objective functions are compared and validated with machine specification parameters.</p>


Author(s):  
Piotr Balcerowicz

Kundakunda and Umāsvāti are among the first philosophers in Jainism to lay foundations for of Jaina philosophy of mind. A key concept in their philosophy of mind is that of a cognitive faculty, located in and constitutive of the self. Cognitive faculties should be understood as processes or manners through which the self makes use of the physical sensory apparatus, as well as the actual application of the self’s cognitive potential. This chapter discusses the complex structures of cognitive faculties. Kundakunda takes the self, the cognitive subject, to consist in cognition, a claim which influences the way both thinkers classify cognitive faculties and the important distinction between perceptual experience and cognition.


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