Patent ID: 7918762

Claim:
A power output apparatus that outputs power to a driveshaft, said power output apparatus comprising: an internal combustion engine; an electric power-mechanical power input output mechanism that is connected with an output shaft of the internal combustion engine and with the driveshaft and inputs and outputs power from and to the output shaft and the driveshaft through input and output of electric power and mechanical power; a motor that is capable of inputting and outputting power from and to the driveshaft; an accumulator unit that transmits electric power to and from the electric power-mechanical power input output mechanism and the motor; a charge-discharge power demand setting module that sets a charge-discharge power demand, which is to be charged into or discharged from the accumulator unit; an input/output limits setting module that sets input and output limits of the accumulator unit as chargeable and dischargeable electric powers in and from the accumulator unit; an air density-affecting physical quantity detection unit that detects a physical quantity, which affects density of the air taken into the internal combustion engine; a driving force demand setting module that sets a driving force demand required for the driveshaft; a target drive point setting module that specifies a tentative power demand to be output from the internal combustion engine corresponding to the set driving force demand and the set charge-discharge power demand, specifies the tentative power demand to a target power when the detected air density-affecting physical quantity is in a preset first range including a standard quantity, while correcting the specified tentative power demand with a correction factor based on the detected air density-affecting physical quantity to set the target power when the detected air density-affecting physical quantity is out of the preset first range, and sets a target drive point of the internal combustion engine as a combination of a target rotation speed and a target torque of the internal combustion engine based on the set target power and an efficient operation restriction for efficient operation; and a control module that controls the internal combustion engine, the electric power-mechanical power input output mechanism, and the motor to drive the internal combustion engine at the set target drive point in a range of the input limit and the output limit and to ensure output of a driving force equivalent to the set driving force demand to the driveshaft.