J. Vinolas | Universidad Francisco de Vitoria (original) (raw)

Papers by J. Vinolas

Vehicle System Dynamics, 1996

ABSTRACT This paper presents a technique for the development of control strategies for tilting tr... more ABSTRACT This paper presents a technique for the development of control strategies for tilting trains. If control laws when tilting the vehicle are not closely adapted to the geometrical characteristics of the track layout, a loss of ride quality will appear, creating travel sickness and tiredness in the passengers. The shape of the command signal and the time that the actuation must be anticipated to the curve entrance are essential factors in the vehicle transient response. This paper shows how the Inverse Dynamics method can be used to define a control strategy to overcome the previously mentioned problems.

Vehicle System Dynamics, 2011

Suspension components play key roles in the running behaviour of rail vehicles, and therefore, ma... more Suspension components play key roles in the running behaviour of rail vehicles, and therefore, mathematical models of suspension components are essential ingredients of railway vehicle multi-body models. The aims of this paper are to review existing models for ...

Noise Control Engineering Journal, 2003

ABSTRACT The low-frequency broadband noise generated by an air-conditioning unit on a railway veh... more ABSTRACT The low-frequency broadband noise generated by an air-conditioning unit on a railway vehicle may be significant in situations where the vehicle is stopped or its speed is low. Low-frequency acoustic radiation is extremely difficult to attenuate using passive means, so in this work, active noise control (ANC) techniques were applied. Laboratory experiments were performed in which noise from two different sources, namely from loudspeakers and an axial fan, was introduced into a real air-conditioning duct, identical to that installed on a subway vehicle. The control approach used a doubled, single-input, single-output (SISO), feedforward, filtered-X LMS algorithm. Control algorithms were designed using the Matlab-Simulink program and the Real Time Windows Target toolbox of Matlab in order to run the ANC in real time. Attenuations of 15-20 dB at the error microphone locations were achieved when loudspeakers were used as primary noise generators. However, noise reduction was quite poor when noise was introduced via the axial fan. This was due to turbulence generated by the airflow, which has a negative influence on the performance of the control system. (C) 2003 Institute of Noise Control Engineering.

CIRP Annals - Manufacturing Technology, 1997

ABSTRACT This paper presents, step-by-step, the capabilities that a general-purpose simulation en... more ABSTRACT This paper presents, step-by-step, the capabilities that a general-purpose simulation environment, such as Simulink/Matlab, provides for an intuitive and efficient modelling of grinding processes. Starting from a revision of the different approaches which can be found in the technical literature the paper begins with the well-known block-diagram first presented by Snoeys. Next, the paper shows how this block-diagram is incorporated into the Simulink environment and how the different parameters for the simulation are introduced in the model (machine, grinding wheel and process parameters). Special attention is paid to the fact that nonlinear phenomena can easily be included.

Annual Reviews in Control, 2004

The benefits of substituting the conventional solid wheelset by independently rotating wheels (IR... more The benefits of substituting the conventional solid wheelset by independently rotating wheels (IRW) in actively steered trailed railway vehicles have already been presented in many works. If a traction system is included in this kind of vehicle it will interact strongly with the active steering system. This paper investigates how traction and active steering systems can be combined in an IRW bogie to produce a good curving performance. The combined steering and traction control concepts developed are implemented in simulation models and validated against a conventional passive vehicle.

Vehicle System Dynamics, 2009

The present paper describes an active centring system for railway vehicles. The proposed solution... more The present paper describes an active centring system for railway vehicles. The proposed solution is based on lateral pneumatic actuators placed between bogie and car body connected to the vertical secondary suspension air springs. The objective of the developed centring system is twofold: the improvement of the curving behaviour of the train and the decrease of the lateral acceleration perceived by the passenger in curve negotiation thanks to the reduction of the 'souplesse'coefficient. The system is described in detail in the paper ...

The paper is a contribution to the field of rail vehicle dynamic simulation and the influence of ... more The paper is a contribution to the field of rail vehicle dynamic simulation and the influence of modeling decisions taken at different stages, which have a direct effect on the accuracy of the results, and differ according to the purpose of the simulation. The goal is to contribute to the understanding of the influence of the model building process and the level of detail required in the vehicle models in dynamic railway simulations by providing two examples. As it is ra-ther difficult to establish general guidelines when dealing with vehicle modelling, some prac-tical examples have been developed in order to give some insight to the model building pro-cess and its implications on the simulation results: the influence of traction chain models in railway simulations and the influence of carbody flexibility and bogie/carbody connections.

Effective engineering formula for torsion stiffness of a long rubber bush in the frequency domain... more Effective engineering formula for torsion stiffness of a long rubber bush in the frequency domain including amplitude dependence is presented. The classical theory of elasticity is the tool used to ...

El trabajo que aqui se presenta se ha centrado en el estudio de sistemas de insonorizacion para r... more El trabajo que aqui se presenta se ha centrado en el estudio de sistemas de insonorizacion para ruedas de ferrocarril y, en concreto, en el analisis de sistemas de bajo costo y que puedan ser aplicados a corto plazo. Dentro de este grupo se han estudiado los aros de insonorizacion, conocidos como "ring dampers" o "friction dampers". El objetivo de esta tesis es el establecimiento del principio de funcionamiento y la optimizacion de los aros de insonorizacion. Esta tesis se ha realizado de forma paralela al proyecto de investigacion Brite Euram denominado "Silent Freight", cuyo objetivo ha sido el desarrollo de metodologias de analisis y el establecimiento de medidas para la reduccion del ruido emitido por los trenes de mercancias. Se han desarrollado modelos de uno y dos grados de libertad mediante los cuales se estudia el amortiguamiento por rozamiento empleando metodos analiticos. Estos modelos pueden considerarse como una primera aproximacion del sis...

In a crosswind scenario, the risk of high-speed trains overturning increases when they run on via... more In a crosswind scenario, the risk of high-speed trains overturning increases when they run on viaducts since the aerodynamic loads are higher than on the ground. In order to increase safety, vehicles are sheltered by fences that are installed on the viaduct to reduce the loads experienced by the train. Windbreaks can be designed to have different heights, and with or without eaves on the top. In this paper, a parametric study with a total of 12 fence designs was carried out using a two-dimensional model of a train standing on a viaduct. To asses the relative effectiveness of sheltering devices, tests were done in a wind tunnel with a scaled model at a Reynolds number of 1 × 105, and the train’s aerodynamic coefficients were measured. Experimental results were compared with those predicted by Unsteady Reynolds-averaged Navier-Stokes (URANS) simulations of flow, showing that a computational model is able to satisfactorily predict the trend of the aerodynamic coefficients. In a second ...

Dynamic characterisation of different magneto-sensitive natural rubbers for application in vibrat... more Dynamic characterisation of different magneto-sensitive natural rubbers for application in vibration isolation

Railway wheel manufacturers are challenged to get a silent wheel, which in combination with a sil... more Railway wheel manufacturers are challenged to get a silent wheel, which in combination with a silent track, would drastically reduce noise disturbance due to rail traffic. Many different possibilities are nowadays offered. The paper describes in detail a cost-effective solution to add damping to the wheel that has been investigated in the framework of the Brite-Euram project ”SILENT FREIGHT”. It consists basically of a ring fitted under the tread and fixed to the wheel by bolts, that was called CAF ring damper. A description of the system is included and the differences with conventional ring dampers -steel rings fitted inside grooves cut under the wheel rimare outlined. Results of the experimental work carried out in the laboratory and obtained in track tests are presented. 1 INTRODUCTION The high-pitched intense noise generated by railway wheels traversing narrow curves is known as squeal noise. Unlike traditional noise reduction systems (tuned dampers, compressed-layer damper, re...

Currently, the testing for the acceptance of running characteristics of railway vehicles in Europ... more Currently, the testing for the acceptance of running characteristics of railway vehicles in Europe is ruled by EN-14363 which is derived in essential parts from UIC 518. This standard is based on present state of the art which is generally applicable for test procedures and the evaluation of stationary and ‘ontrack’ tests. It defines testing scenarios, analysis conditions and experimental measurements, and proposes limiting values for a number of different parameters mainly associated with vehicle safety and ride quality. Variables to be measured are specified for each method. The method referred to as “normal”, which is applied to the cases of the highest level of criticality (high speed and/or high axle loading) requires the measurement of forces transmitted through wheel-rail contact at several wheelsets of the vehicle.

Ring-dampers for railway wheels can be very effective in suppressing squeal noise. An effort is m... more Ring-dampers for railway wheels can be very effective in suppressing squeal noise. An effort is made to understand the mechanisms by which damping is provided. The main aspects of wheel/ring intera ...

$Research paper thumbnail of Dynamic stiffness prediction of filled rubber mounts : Comparison between a fractional derivative viscoelastic-elastoplastic model and a simplified procedure$

A time domain non-linear model is presented to predict the dynamic stiffness of rubber isolators ... more A time domain non-linear model is presented to predict the dynamic stiffness of rubber isolators using a FE code. The problem of simultaneously modelling elastic, viscoelastic and friction contributions is removed by additively splitting them. Viscoelastic response is modelled via a fractional derivative model, while amplitude dependency is considered through Coulomb friction elements. Nevertheless, determination of the dynamic stiffness takes long time and requires large amount of memory, as well as the estimation of the transfer function between applied excitation and resulting forces at different frequency and amplitude values. This is why a frequency domain simplified procedure is also proposed to obtain the dynamic stiffness. The technique is based on providing a generalized Maxwell model with the adequate material data set, once the dynamic strain amplitude, to which the mount is subjected, is estimated from quasi-static strain values. The methodology has proved to be efficien...