Torque Modulation in a Hybrid Vehicle Downshift During Regenerative Braking

摘要

A controller and a control strategy minimizes shift shock in a hybrid electric vehicle during a downshift conducted while the vehicle is in a regenerative braking mode by maintaining total powertrain torque at a desired target during the downshift. The controller has three preferable modes including modulating just engine torque, modulating just electric motor torque or simultaneously modulating both motor and engine torque.

主权项

1. A method for reducing shift shock in a hybrid electric vehicle powertrain system including an engine and a step ratio automatic transmission for delivering an output torque, the method comprising:
transferring a first input torque from the engine to the transmission; effecting a downshift of the transmission during regenerative braking; and modulating the first input torque during the downshift to maintain the output torque substantially constant.