Mild-Hybrid Electric Vehicle: EM management to prevent dry clutch overheating

Heat power generated in dry clutch systems during repeated engagements could result in marked uncomfort and manifest damage clutch facing materials. Indeed, recent studies have highlighted as during a single launch manoeuvre the interface temperature can amount about 30-35 Celsius degree. Consequently, after only few repeated engagements in short time the clutch material temperature can attain critical values, i.e. 250-300 Celsius degree. For this reason, the electric motor contribution to reduce overheating of clutch material during the slipping phase could represent a good solution to avoid dry clutch damage. In this paper a high-level Model Predictive Controller with time-variant penalty weights accordingly with working conditions has been implemented. The goal of this study is to manage both internal combustion engine and electric motor during clutch engagements in order to relieve dry clutch during a critical launch manoeuvre. Particularly, the following scenario has been assumed: high initial clutch temperature due to previous repeated engagements, up-hill start-up manoeuvre and low initial SOC.