Modeling of a P2 hybrid vehicle with dual clutch transmission

In recent years the regulations are limiting the emissions released by internal combustion engines, requiring car manufacturers to modify their propulsion system, restricting engine displacement and also to adopt hybrid configurations by coupling an electric motor to the thermal one, in order to optimize their functionalities. In this regard, different configurations for the union of the two motors have been developed, ensuring advantages on one side but occasionally limiting certain aspects, in fact a perfect solution doesn’t exist. Even under the aspect of costs there are problems, in fact the choice of a hybrid architecture brings significant changes in layout, of course depending on the architecture chosen, but which may therefore require large investments on the part of the manufacturer. A particular configuration that has recently been increasingly chosen by car manufacturers is that of the so-called Mild-Hybrid, or rather combining the internal combustion engine with a small electric motor powered by a low voltage battery, in particular at 48 Volts. This considerably limits the design and production costs, always guaranteeing a reduction in emissions. The use of a dual-clutch gearbox combined with an electric motor powered by a 48-volt battery in position P2 is a configuration that not only has the advantages of DCT, but expands its operation. In this document is explained the development of a model of a Mild-Hybrid P2 dual clutch transmission using the software Matlab / Simulink. The main purpose of this model is to calculates the torque output, entering at the differential, in different manoeuvres: •??Thermal engine drive •??Pure electric drive •??Mix mode with over-boosting •??Mix mode with compensation •??Mix mode with max torque control •??Mix mode with delayed engine switch on •??Electrical braking In addition is developed a simple vehicle longitudinal model in order to perform simulation in the Matlab / Simulink environment. The following model then will be used to perform co-simulation with a more complex vehicle model with the software ADAMS Car, providing the torque output at the differential. Moreover, is developed a reference model of the P2 48V dual clutch transmission in Matlab / Simscape in order to correlate the results. The thesis is subdivided in seven chapter: the first chapter describes how the dual clutch transmission works, its characteristics and assets; in the second chapter are mentioned the major hybrid architectures; the third contains the description of the Mild-Hybrid P2 dual clutch transmission with its drive capability and potentiality; the fourth chapter describes the basic longitudinal vehicle dynamics and the theory background of the tire; the fifth contains the explanation of the Matlab / Simscape reference model with the simulations results; while the sixth chapter describes the main Matlab / Simulink model with its simulations of the various aforementioned manoeuvres, followed by a chapter of conclusions, with considerations and possible future implementation.