US Patent 8000885 Engine stop control device

Target rotation speed at a reference point, which is set at a top dead center (TDC) preceding a target stop position of engine rotation by a predetermined crank angle, is set. A target trajectory of an engine rotation behavior extending since an engine rotation stop behavior starts until the target rotation speed at the reference point is reached is calculated based on the target rotation speed at the reference point and an engine friction. Torque of an alternator (electric machinery) is controlled to conform the engine rotation behavior to the target trajectory during the engine rotation stop behavior. The target rotation speed at the reference point is set to rotation speed that is equal to or lower than lower limit rotation speed of a rotation speed range, where the torque of the alternator is generated, and that is close to the lower limit rotation speed.