Riassunto analitico
This work of thesis deals with the modeling and the simulation of
automated mechanical transmissions for agricultural tractors using a
new kind of technique called "Lock-Unlock" based on POG systems. The
POG (Power Oriented Graph) is employed to connect the physical
(mechanic and hydraulic) world with the electronic one. The
"Lock-Unlock" technique has many advantages, including the reduction
of the simulation time, the possibility to consider and read every
kind of information in every single point of the transmission, and
the ability to easy debug the system in the simulation environment.
The simulation process is divided in two phases: In the first phase
a detailed model of the transmission is proposed for real-time
simulation based on MATLAB/Simulink environment. By building vehicle
dynamic model, the analysis is made to evaluate the shifting process
of automatic transmissions. In the second phase the realized model
is linked to the control in MIL (Model in the loop) and HiL
(Hardware in the loop) systems to perform a closed loop analysis.
The obtained results have evidenced the potentiality of the
Lock-Unlock modeling technique in terms of test time reducing.
Moreover the communication between the model and the simulation
environment allows to optimize the performance of the whole system,
through new tuning configurations, both in the design phase and in
the testing one. This tool could represent an important leverage for
future designs and assist the engineer during the developing,
reducing the time and improving the quality of the simulations.
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