Integrated control method for engine and transmission

An integrated control method for an engine and a transmission, the integrated control method comprising:

• a required-power calculation step of calculating, by a control unit, a required power of a vehicle based on factors reflecting a driving state of the vehicle;
• an engine-operating-point calculation step of calculating, by the control unit, a target engine torque and a target engine revolution per minute (RPM) that are needed to output the required power corresponding to a driver's intention to accelerate;
• a shift-ratio calculation step of calculating, by the control unit, a target shift ratio based on a relationship between the target engine RPM and a vehicle speed;
• and
• an integrated control step of controlling the engine and the transmission by the control unit such that a current engine torque, a current engine RPM, and a current shift ratio converge to the target engine torque, the target engine RPM, and the target shift ratio, respectively,
• wherein, in the engine-operating-point calculation step, a permissible engine torque range is determined by obtaining a minimum value and a maximum value for the engine torque that output the required power, on an equivalent power curve determined based on the driver's intention to accelerate, and
• wherein the target engine torque is determined within the permissible engine torque range based on a driver's acceleration level.