Università di Pisa
PhD School: Leonardo da Vinci
PhD Program: Land vehicles and transport systems
PhD Student:
Riccardo Bartolozzi
Tutors:
Ing. Francesco Frendo
Prof. Massimo Guiggiani
Prof. Emilio Vitale
Activity report 2008
Research activities
1. Development of a driving simulator for the analysis of driving style for safety
purposes (PRIN project);
2. Dynamic analysis a three-wheeler tilting vehicle endowed with active systems (European project carried out in cooperation with several partners like
Continental, Öhlins and Dekra and leaded by Piaggio);
3. Cooperation in the Formula SAE team of the Università di Pisa for the
suspension system project.
Publications
• R. Bartolozzi, F. Frendo, E. Vitale, Driving simulator for the analysis of driving
style and vehicle motion conditions, Proceedings of the 2nd IASTED Conference on Modelling and Simulation (AfricaMS 2008), Gaborone (Botswana),
September 8-10, 2008.
• R. Bartolozzi, F. Frendo, M. Guiggiani, Comparison between experimental
and numerical handling tests for a three-wheeled motorcycle, Proceedings of
the SAE Small Engine Technology Conference (SETC), Milwaukee (Wisconsin,
U.S.A.), September 9-11, 2008, 2008-32-0061 (SAE) - 20084761 (JSAE).
• R. Bartolozzi, F. Frendo, E. Vitale, Sviluppo di un simulatore di guida per
studi sulla sicurezza attiva dei veicoli, Atti del XXXVII Convegno Nazionale
dell’Associazione Italiana per l’Analisi delle Sollecitazioni, Roma (Italy),
September 10-13, 2008, in Italian.
• R. Bartolozzi, F. Frendo, E. Vitale, Analisi a fatica di molle per sospensioni
automobilistiche, Atti del XXXVII Convegno Nazionale dell’Associazione
Italiana per l’Analisi delle Sollecitazioni, Roma (Italy), September 10-13,
2008, in Italian.
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Riccardo Bartolozzi
PhD Activity Report 2008
Attended conferences as a speaker
• IASTED Conference on Modelling and Simulation (AfricaMS 2008), Gaborone
(Botswana), September 9-11, 2008.
• VI-Grade User’s Conference, Udine (Italy), November 4-5, 2008.
Education
• Differential Equations in Mathematical Physics course held by Prof. Villaggio.
• Automatic Controls course held by Prof. Bicchi.
• English course - level C1 at CLI (Centro Linguistico Interdipartimentale).
• Writing and Presenting Scientific Articles in English course held by Prof.
Wallwork.
• Mathematica: what makes it unique course held by Prof. Guiggiani.
Teaching activities
• Teaching support for the course Automotive Design of the M.Sc. in Land
Vehicles Engineering.
• Teaching support for the course Chemical Plants Equipment Design of the
M.Sc. in Chemical Engineering.
• M.Sc. thesis supervisor of Dario Guzzo. Thesis title: Messa a punto di un
simulatore di guida per l’analisi del livello di vigilanza del conducente di un
autoveicolo.
• M.Sc. thesis supervisor of Massimo Baldacci. Thesis title: Sviluppo di un
sistema di sospensioni per veicolo Formula SAE.
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Driving simulator
This activity is part of a project funded by the Italian Ministry of Research and
carried out in cooperation between the Dipartimento di Ingegneria Meccanica,
Nucleare e della Produzione, the Dipartimento di Ingegneria dell’Informazione of
the Università di Pisa and the Dipartimento di Meccanica e Tecnologie Industriali
of the Università degli Studi di Firenze. The main objective was to develop a
driving simulator for the analysis of the driving style in order to identify dangerous
conditions, especially those related to driver drowsiness. The basic idea is to use,
as information about the driver and the driving conditions, only signals already
available in all modern vehicles and transmitted through the CAN.
Diagnosis systems for identifying driver hypovigilance conditions have become
very important in the last years because of traffic crashes, which are worldwide
one of the main public health problems. In fact, traffic crashes are the cause of
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PhD Activity Report 2008
about 1.2 million deaths every year with a mean rate of 19 persons every 100,000
(according to the World Health Organization). Although driver drowsiness is very
difficult to identify, many accidents are demonstrated to be due to hypovigilance
conditions. Moreover, the probability of death in this kind of accidents is triple
with respect to the others. A driving simulator and data analysis procedures is
what is needed to develop diagnosis tools to avoid such accidents.
The driver simulator developed at the DIMNP is a fixed base simulator with a
single channel frontal view, which represents the view of the driver with a threedimensional scenario. The driving platform has instrumented pedals and steering
wheel which acquire all driver inputs during the simulation. The pedals have passive
feedbacks whereas, on the steering column, a brushless motor applies the steering
torque feedback.
The heart of the system is the vehicle model, which is running in real-time
during the simulation in a dedicated computer. This model has a block architecture
which allows to modify each subsystem (tire model, engine, clutch, gear box, vehicle
dynamics, etc.) at a time. The model receives, as inputs, the signals from the
pedals and the steering wheels (driver inputs) and computes several output signals,
which represent all the kinetic and dynamic quantities available in the model. Some
of these outputs are used by the graphical software to update the graphical scenario
and by the steering feedback system. All the output signals are acquired and stored,
during the simulation, by a data receiver for off-line analyses.
A first experimental campaign with 10 persons was carried out during this year.
Highway driving and some typical urban manoeuvres were reproduced in order to
identify different driving styles among the tested sample group. The analysis of
data from this experimental campaign is still ongoing.
A second experimental campaign is currently in progress. In these tests people
are asked to drive in normal (rested) conditions and in tired conditions. In this
second campaign the influence of distractions, such as the use of mobile phones,
and reaction times of the driver are also investigated.
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Three-wheeler dynamics
This research is within the European Project SIM (Safety in Motion), in cooperation
with several partners like Piaggio (project leader), Continental, Öhlins and Dekra.
This project aims at analysing the dynamics of a three-wheeler tilting vehicle
(Piaggio MP3) and at developing a prototype three-wheeler (based on Piaggio MP3)
endowed with active and passive safety systems.
In order to study the dynamics of the standard Piaggio MP3, especially its
handling behaviour, a multibody model of the vehicle was developed. This model
consists in several rigid bodies connected by joints, a tire model (obtained by
experimental characterisation performed by TNO) and a virtual driver model.
A correlation activity was carried out between simulation results and experimental tests. To this aim, some typical handling manoeuvres, such as steering
pads, lane changes and U-turns, were performed with an instrumented vehicle.
The same manoeuvres were replicated in simulation environment obtaining good
results from the correlation. The developed driver model was able to reproduce
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PhD Activity Report 2008
the manoeuvres and the results showed also how the tilting three-wheeler is driver
very much like an ordinary two-wheeler. In addition, to find the causes of some
differences between simulation and experimental results, the effect of the driver
position was also investigated.
In the simulation environment the prototype three-wheeler model with active
systems was developed and tested. These systems include ABS (Anti-lock Braking
System) and active suspensions. In order to support the partners involved in
developing these systems, several simulations of typical manoeuvres were carried
out varying their most important parameters.
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Formula SAE
The University of Pisa challenged for the first time in a Formula SAE competition in
September 20-22 in the Fiorano circuit (Modena, Italy) participating at the Formula
SAE Italy (Formula ATA) event. The E-Team Squadra Corse was established at
the end of 2007 and began its activities at the beginning of 2008. During the nine
months before the event, the team designed and built completely a new race car
according to the Formula SAE rules. After the Formula SAE Italy event, the team
was renewed to prepare the car for the next season and some tests on the 2008 car
were carried out in these months.
The work in this activity was in part related to organization tasks, but mainly
focused on the suspension project. The goal was to design and built a race
suspension system, with no initial experience, which should allow the car to have
high performance and which could be tunable as much as possible.
In the first stage of the design activity, simplified models (such as spreadsheets)
were developed and used to have the first configuration of the suspension architecture
as well as the values of damping and stiffness. In a second stage a multibody model
of the car was developed and the final configuration of the suspension system was
defined evaluating its performance by simulation results. Before defining the final
drafts of all the system components, FEM analyses were carried out to verify the
main parts subjected to higher loads in acceleration, braking and cornering. The
system was finally built and used in the car during the Formula SAE Italy event
with good results in terms of reliability and performance.
During the last months an experimental campaign was carried out, in order
to tune the suspension system and to find the influence of some fundamental
parameters. The car was tested with several suspension settings, following a
DOE (Design Of Experiments) approach and using some setting tools, which were
developed to guide regulations on tunable parameters. These tests highlighted the
influence of some important parameters on the cornering performance of the car
(e.g. the tire pressure) and showed how the car is able to get good results in the
skid pad event (one of the Formula SAE dynamic events).
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