Image Number 4 for United States Patent #7055635.
An electric power regeneration control unit is provided for a hybrid vehicle. A motor generator is operated by a driving force received from an engine or drive wheels. A lockup clutch engages or disengages rotational members on input and output sides of a fluid torque converter, and is engaged or partially engaged after canceling fuel cut and increasing intake air quantity for the engine when an accelerator is released within a predetermined range A controller enables the motor generator to generate electric power when the accelerator is below a certain opening angle. An engagement finish determining device determines whether engagement of the lockup clutch is finished. The controller controls to prevent fuel cut, discontinue an increase in intake air quantity and starts electric power generation if the engagement finish determining device determines that lockup clutch engagement is finished.