METHOD OF CONTROLLING POWERTRAIN OF VEHICLE

A method of controlling a powertrain of a vehicle is carried out such that during shifting in which a first clutch is released and a second clutch is engaged, whether a current shift phase is a torque phase or an inertia phase is determined. Different cost functions for the torque phase and the inertia phase are predefined. A control input change for minimizing the cost functions in the torque phase and the inertia phase is calculated. At least two among input torque, first clutch torque, or second clutch torque input to a transmission are controlled by applying the control input change calculated for the torque phase and the inertia phase.