Modular Techcnical Model for Extended V-Cycle Design of Electric Powertrains

The automotive industry is experiencing a radical change as it is moving towards electrification; car manufacturers are strongly investing in the development and production of Electric Vehicles (EVs), since climate change and the ban on the sale of the ICE vehicles imposed by the European Union, starting from 2035, are boosting this transition. Moreover, international governments are offering economic incentives to promote the adoption of EVs, providing also an expanding charging infrastructure in order to deal with the constantly increasing demand. Although some obstacles are still present, like vehicle range anxiety, long charging time, low battery life and high initial costs, this electrification trend is set to increase in time as long as the technology will keep on evolving and the request for sustainable means of transport will be maintained high. Hence, this conversion towards EVs and electrification is going to have a substantial influence on the automotive industry, modifying the concept of vehicles and urban transportation as we know it. In this scenario, the objective of this thesis work was to model the powertrain of an electric vehicle's retrofit kit, developing a Modular Technical Model and to align the Virtual, Semi Real and Real Prototypes of the vehicle itself, applying the Extended V-Cycle methodology. The Extended V-Cycle is a methodology adopted in software development to facilitate this shift toward electrification; it is based on an efficient and flexible process that allows a reduction both in time and in cost of software projects. The aim of this methodology is to produce an optimized development process, considering the constantly changing and intricate aspects of software development. The major phases that compose this method are five, with four additional sub phases: Phase 1 has the purpose of defining the functional requirements, based on the customer's needs. In Phase 2, these requirements are transformed into technical specifications, in accordance with the automotive safety standard (ISO26262), following two different guidelines: the preliminary study and the user experience; the first one is applied to estimate the size and the characteristics of the retrofit components, while the second describes how the vehicle should work in terms of states and transitions. Sub-phases 2.1-2.2 involve the construction and validation of the Virtual Prototype, which is the complete module of the vehicle, including the control logic. The Virtual Prototype is created using the Modular Technical Model (MTM), which is a template tool built using MATLAB/Simulink; it has a modular architecture comprising different modules (Environment, Plant, Control, HMI, User), each of which is improved by an iterative MIL process. In sub-phases 2.3-2.4, the control logic is downloaded onto a powerful and real VMU (dSpace) and is tested on the testbench. This step constitutes the Semi-Real Prototype, where some parts of the Plant and Human Machine Interface are no longer models but real components. After the creation of the Virtual Prototype and the Semi-Real Prototype, the Extended V-Cycle proceeds to the next stages. In Phase 3, the control logic is downloaded onto a commercial VMU, and in Phase 4, the same validation tests, both of the model and of the VMU, are repeated on the testbench. Finally, when the tests are effectively concluded, the project shifts to Phase 5 which includes road testing of the Real Prototype.