Optimization of an innovative modular software architecture enabling the transformation of vintage cars with ICE powertrain into vehicles with electric propulsion

Electric retrofit is an innovative technique to convert vehicles with an internal combustion engine (ICE) into electric vehicles. Retrofitting an older vehicle not only ensures that the user can once again drive a car that would otherwise be out of circulation but also represents a solution against climate change. It reduces CO2 emissions into the atmosphere, and it is a viable alternative to the disposal of the combustion car park. This thesis project aims to develop and optimise a software architecture embedded in a vehicle control unit (VCU), capable of controlling various functions of the retrofitted vehicle, such as its propulsion unit, reducing as much as possible the workload of the motor control unit (MCU) linked to the inverter. However, in addition to the management of torque demand, the VCU is also responsible to perform the following tasks: identification and evaluation of system errors, management of the battery recharging process in cooperation with the BMS, and management of the CAN communication interface. The architecture is developed in LabView and consists of a series of timed-loop blocks that guarantee real-time execution of the system within a specific period. The VCU is programmed as a finite-state machine (FSM) characterised by nine possible states. To simulate this logic, case structures are used to switch from one state to another according to certain conditions. Concerning CAN communication, a special model is developed for writing and reading messages while queues are provided to transcribe messages within a certain period and thus with a certain priority. Furthermore, a database is integrated to facilitate and speed up the conversion of the binary payload into a physical signal and vice versa. After the design phase, a test phase is carried out using a rapid prototyping control unit to optimise the algorithm and meet time requirements. Finally, to test the entire system operation, a LabView model is used to simulate the behaviour of an inverter and a three-phase synchronous electric motor with permanent magnets (PMSM), which is controlled via a closed-loop control system.