RICERCA ITALIANA     

Research program

THE ENHANCEMENT OF MECHANICAL TRANSMISSIONS FOR THE REDUCTION OF THE ENERGY CONSUMPTION

University Co-ordinator

Università degli Studi di FIRENZE - ENERGETICA - FIRENZE(FI)

Research Unit Leader

Benedetto ALLOTTA

Description

Turin and Florence research group will actively cooperate in order to share techologies and knowledge concerning the simulation of the hil simulation of transmisions and drivelines, thanks to the common scientific and technological background between railway and automotive applications studied by the two groups.
Also the Florence group will share its knowledge and the HIL experimental testing apparatus that has previously developed for the 2002 COFIN project with Bari research group.
Tecnology transfer from automotive applications it's a convenient way of thinking in order to achieve greater cost and time savings. Also product time to market and know-how for Research and developement can be more affordable.
DMU(Diesel multiple units) are a typical example of hybrid tecnology:
They are structured like light trains, however they are motorized through an array of Power-Pack that are derived from automotive-truck technology. Power Pack is composed by a diesel motor and all the drive line. All this components must be modified or revamped to be installed on a railway vehicle in oder to respect different specifications:
1)Different vehicle features such as higher inertial load, different suspension system, different structural behaviour, rather "strange" transition load introduced by the different behaviour of the wheel-rail interface.
2)Operating and maintenance conditions: maintenance intervals are quite longer (more than 1000.000 km) required specifications concerning temperature and wheater condition are very harsh.
3)Wheel-rail interation is quite different from tire-road one. great axle sliding due to degraded adhesion are possible even at high speed with low torques applied. Ciclical loss of adhesion coupled with modal behaviour of the system may introduce unpredictable vibration phenomena that can be really dangerous both for comfort and structural integrity.
University of Florence group is well suited to study this phenomena for his past experiences in railway sectors (studies on wheel rail interaction and wsp systems) and mechatronics (COFIN 2002 activities on selespeed, MI-6 HIL test rig for Trenitalia).
Aim of this research activities is the developement of wheel-rail adhesion models that can be used to simulate the effect of wheel rail sliding transients on the whole driveline of a real application the PowerPack (Diesel motor and Driveline) of IC4, a DMU recently developed by AnsaldoBreda for danish railways. Thanks to the wide experience and to the strong commercial interest of such as industrial patner technical documenttion and experimental data will be avaliable for this activity. Also links between the world of university and the local industrial tissue will be reinforced by this collaboration
The project is articulated in sixt phases with different task that can be easily recognized. The aim of this project is a real time model of railway trasmission and drivelines that can be easily applied to the developement of calibration and simulation tools for industrial applications.
Different simulation environment such as Matlab-Simulink, Amesim, Msc Adams will be used thanks to cosimulation features that support the simulataneus use of this products in a single numerical model.
In particular Matlab and Amesim have been chosen for their abiilty of automatic generation of real-time code. Also both the simulation tools can be easily integrated in user friendly interface for autimatic pre- and post processing of data.

In the following pages a brief scheme of the proposed research program is shown:

Step 1: Lumped Matlab-Simulink model of the trasmision system. This simplified model will be used to verify the modal response of the driveline according experimental data and avaiable technical documentation. In this step an ideal adhesion betheen rolling surfaces of wheel and rail is simulated. Also the inertial propreties of the vehicle are simulated through a simplified lumped system.
beginning of the activity: beginning of the 1st month
end of the activity: end of 6th month
Cost: 10000 Euro
Expected Results: Modal validation of the system, first approach to modelling.

Step 2: Non linear Amesim model with full actuation system and clutch model
beginning of the activity:beginning of the 6th month
end of the activity:end of 10th month
Cost: 10000 Euro
Expected Results: validation of Amesim model with previous results and or with data from the manifacturer. Simulation of the gearbox manouvers transients with full wheel-rail adhesion. Indications for further optimization of the trasmission may also arise.

Step 3: Bidimensional models for wheel-rail interaction with high slidings
beginning of the activity: beginning of the 9th month
end of the activity: end of 12th month
Cost: 10000 Euro
Expected Results: developement of a wheel rail adhesion model able to simulate high slidings that are typical of low adhesion patterns.
Simulation of typical phenomena like the dependency from relative wheel rail slidings and/or from the amount of dissipated mechanical energy between the rolling surfaces.


Step 4: Merging of the model developed in the previous step of the project in a single general model.
beginning of the activity: beginning of the 13th month
end of the activity: end of 18th month
Cost: 10000 Euro
Expected Results: accurate simulaiotion of trasmission behaviour with degraded adhesion conditions, further trasmission optimization. Analisys of interaction between cyclical adhesion losses and the dynamical response of the trasmision system induced by the heavy speed/torque transients involved.

Step 5: Real Time Model
beginning of the activity: beginning of the 15th month
end of the activity: end of 24th month
Cost: 10000 Euro
Expected Results: model optimization and task scheduling for real time execution like DSPACE boards or Matlab XPC. Developement of tools for system calibration.
Step 6: reporting e produzione di articoli scientifici e memorie per conferenze
beginning of the activity: beginning of the 21th month
end of the activity: end of 24th month
Cost: 6000 Euro
Expected Results: the final task of the project will be concerned with the production of technical reports and scientific publication in order to reorder, consolidate and diffuse the achieved results.
Reporting activities may increase the interest of possible industrial patner to this kind of research with the possibility of further collaboration and financing of future research projects.
This activities will involve the cooperation of personell of the Trasportation Engineering Faculty of Pistoia(a branch of university of Florence).