Feedforward control of a parallel hybrid launch clutch

Hybrid Electrical Vehicles (HEV) are a very promising approach to save fuel and minimize exhaust emissions. The drive trains of HEV are equipped with at least one Electric Machine (EM) in addition to the Internal Combustion Engine (ICE). Therefore it is possible to operate the Internal Combustion Engine (ICE) in more efficient working points or to shut it down if the efficiency is too low. Despite of the fuel savings, the drivability can be increased by realizing gear shifts without an intermission in the wheel torque or a noticeable jerk. An important task for the HEV control is the start and the coupling of the ICE during electrical driving. This task has to also be done without an intermission in the wheel torque or a noticeable jerk to obtain a good drivability. In this paper we will describe a feedforward control for the launch clutch of a parallel HEV (pHEV) with an Automated Manual Transmission (AMT) and a dry clutch. The feedforward control is obtained using a simplified model of the drivetrain.