Method and apparatus to control engine stop for a hybrid powertrain system

摘要

A control scheme is provided for stopping an internal combustion engine of a hybrid powertrain during ongoing vehicle operation. The method, executed as program code in an article of manufacture comprises the following steps in the sequence set forth. First, engine operation is controlled to stop firing the engine. A damper clutch is controlled to lock rotation of the engine and the electro-mechanical transmission. Torque outputs from the first and second electrical machines are then selectively controlled to reduce engine speed. Torque outputs from the first and second electrical machines are then selectively controlled to stop rotation of the engine substantially near a predetermined crank position.