Study on the lubrication control of a WET Dual Clutch Transmission

The following thesis work has been carried out in collaboration with the Powertrain Transmission Systems department of Magneti Marelli SPA located in Venaria Reale (Turin). The core business of this company division is the development of control units for automotive transmissions, taking care of the software part. All the working phases, from system specification analysis to code generation and testing, are completely accomplished in the same office. In particular, the software developed for this project are model based generated. ???? The goal of this thesis was to design a lubrication controller for a WET DCT able to command an open loop oil flow thrugh a QPV inside the clutches chambers. The aim of the controller is to keep the temperature of the clutches disks inside a certain range. It has been created in order to work in both continuous and high power conditions, taking into account also safety guidelines. ???? A simplified driveline model of a DCT was developed for simulation of working conditions purposes. It includes both thermal (including the whole hydraulic circuit) and dynamical description of the system. The model describes the behaviour of all the shafts dynamics even if it has been restricted to a two gears driveline; it also accurately describes thermal behaviour. The whole models have been identified on data coming from the actual driveline. ???? Finally, a closed loop micro-slip controller has been designed in order to better simulate the actual working conditions. This is intended to generate a current signal for the clutch actuation PPV in order to regulate a certain slip speed between engine shaft and primary transmitting shaft.