Development of a simulation tool for virtual design, calibration and validation of hybrid vehicle control systems

The goal of this work of thesis is to analyze the control strategies implemented in an electric-hybrid vehicle and transfer them into a virtual environment. In this perspective, a simulation tool, including the complete plant model of the vehicle and the electronic control unit (ECU) of the Powertrain, has been developed and integrated with torque management strategies for the control and the coordination between electric and internal combustion propulsion. The whole tool is MATLAB/Simulink based. The starting point has been an existing plant model of a conventional vehicle composed of thermal engine, automatic transmission and vehicle dynamics. The model has been analyzed and upgraded to integrate the electric motors, organized in a P1P4 configuration (Electric AWD). At this point the torque split strategies actually used in real hybrid vehicles have been evaluated, including the concept of cost function, and integrated in the simulation tool. Measurements already available from experimental tests on a prototype vehicle had a crucial role to properly validate the development of the simulation model. One of the most interesting achievements of this work of thesis could be the possibility to mimic the behaviour of significant parts of an HCU (Hybrid Control Unit) without passing through HIL simulations (Hardware In the Loop) or vehicle itself. In this way, it is possible to understand in which direction the attention has to be focused to have important improvements according to the desired application in a more cost effective and faster way. Starting from the results achieved in this thesis, several future developments are possible, including the implementation of new control strategies, faster calibration of parameters and the introduction of other elements of the vehicle inside the model.