| abstract |
Hybrid electric vehicle (HEV) powertrains and control logic for optimized regenerative braking (regen), methods for manufacturing/application of such systems and HEVs with increased regen through reduced engine and transmission friction are presented. A method of operating an HEV includes determining whether an HEV operating condition or fault is preventing initiation of regeneration control operation and, if not, reactively determining whether a torque request for the HEV's powertrain is less than a road load of the HEV. The regeneration control operation is performed in response to the torque request being less than the road load. The regeneration control operation involves the powertrain drivingly disconnecting the engine from the road wheels and the engine operating at a target engine speed. A negative torque offset to maintain a vehicle deceleration rate after disconnecting the engine from the road wheels is calculated; the traction motor outputs a negative torque based on this negative torque offset. |