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Digital archive of theses discussed at the University of Pisa


Thesis etd-04132011-181543

Thesis type
Tesi di dottorato di ricerca
Thesis title
DYNAMIC ANALYSIS OF VEHICLE SYSTEMS Development of a driving simulator Analysis and design of an automatic transmission for motor-scooters
Academic discipline
Course of study
tutor Prof. Guiggiani, Massimo
tutor Prof. Frendo, Francesco
  • automatic transmission
  • driving simulator
  • dynamic analysis
  • motor-scooter
  • powertrain dynamics
  • road safety
  • vehicle model
Graduation session start date
In this work, two researches in the field of dynamic analysis of vehicle
systems are presented.
The first part of the thesis deals with the development of a driving
simulator. This activity was carried out in the framework of a research
project co-funded by the Italian Ministry of Education, Universities and
Research (MIUR). It aimed at developing a driving simulator for the
analysis of the driving style, in order to identify potentially dangerous
conditions coming from a non proper interaction between driver, vehicle
and environment, especially those related to low driver’s attention. As
core part of the driving simulator, a vehicle simulation model, which
reproduces the behaviour of the main vehicle systems, was developed.
The simulator is made of a fixed driving platform, a single channel visual
system and allows to acquire all driver’s inputs and vehicle motion signals.
The system was involved in experimental campaigns which allowed the
development of the driving style analysis techniques and demonstrated
the reliability and the capability of the system.
The second part of the thesis treats the dynamic analysis and design
of a high efficiency automatic transmission for motor-scooters and was
carried out in the framework of the Italian MUSS project funded by the
Italian Ministry of Economic Development. Motor-scooters are currently
almost always equipped with CVT transmission with rubber belt. This
transmission can be very cheap to manufacture, it has good comfort
performance but low mechanical efficiency. An alternative automatic
transmission was analysed and different architectures were studied. The
system is based on a discrete ratio gear box with mechanical control
of the gear shit by means of centrifugal clutches and free wheels. A
dynamic model of the transmission was developed and its behaviour was
investigated by means of results of simulated manoeuvres, highlighting the
positive and negative aspects of the system. Finally, a preliminary design
was also carried out with reference to an application of the transmission
in a hybrid powertrain.