The “Two-Drive-Transmission with Range-Extender (DE-REX)” is an innovative hybrid powertrain concept whose design is characterized by the fact that both the two identical electric motors and the combustion engine can be connected to the vehicle's side shafts via a transmission. The transmission is a dedicated hybrid transmission that is designed as an automated manual transmission consisting of two subtransmissions with two gears each. The shift elements within the transmission are positive-locking dog clutches. Based on the functional integration of the electric motors into the transmission, the speed synchronization required for gear and mode change sis implemented via active speed control of the electric motors and the combustion engine.

Parallel to the development, production and integration of the novel powertrain into the demonstrator vehicle, the software of the transmission and drive control was developed and tested in a simulation environment. The transmission control developed in the simulation environment was transferred to a prototyping control unit in the demonstrator vehicle, tested and optimized.

The DE-REX demonstrator vehicle offers various possibilities for the development and optimization of software functions for powertrain and transmission control based on both, objective and subjective evaluation criteria. Focal points include shifting comfort with dog clutches in electric and hybrid operating modes and acoustic comfort in hybrid operation with combustion engine. The DE-REX demonstrator vehicle is also the proof-of-concept for a hybrid version of the modular Two-Drive-Transmission powertrain family developed at the IMS.