Abstract
Impulse start (or bump start) in HEV and PHEV is a process of finely controlled actions for the smooth and quick start (or re-start) of an Internal Combustion Engine (ICE), from for example pure electric driving, via an E-Motor (EM) and through a slipping separation clutch CL0 (Figure 1). This hybrid function is very challenging to develop, as it is critical both with respect to the time taken and driveability (comfort and performance response), especially at high EM speed and or from high propulsion power levels. Satisfying impulse start functionality requires early, detailed, and accurate specification of mechanical, electrical, hydraulic HW (hardware) systems, as well as the development of sophisticated and closely coordinated control functions and SW (software including application calibration), for ICE, separation clutch, EM, transmission (TM) etc. For this AVL has developed and proven a novel and sophisticated office based co-simulation toolchain for the reliable virtual development of HW and SW and to ensure impulse start driveability targets are met from the early concept phase to SOP and beyond.