Control apparatus of hybrid vehicle and control method thereof

Abstract

A control apparatus is used to control a hybrid vehicle having an internal combustion engine, a stepwise variable transmission capable of automatic speed shifting, a clutch disposed between the internal combustion engine and the stepwise variable transmission for discontinuing and establishing power transfer to and from the stepwise variable transmission, an electric motor, etc. The control apparatus calculates a timing of the stepwise variable transmission starting an automatic shifting operation, and gradually decreases the torque assist based on the motor torque Tm of the electric motor prior to the start of the shifting operation, so as to reduce the stepped change in the drive torque that occurs when the engine torque Te is eliminated upon disengagement of the clutch during the shifting operation. This operation of the control apparatus also gentles or reduces the gradient of torque change. The shock at the time of shifting is thus reduced.