Vehicle drive power control apparatus, and control method

A drive power control apparatus of a vehicle, comprising:

• an engine that generates a drive power of the vehicle;
• a transmission that is connected to an output shaft of the engine and that performs a speed shift of the vehicle;
• and
• a controller that:
• calculates a target output of the engine for achieving a target drive power that is set based on a state of operation of the vehicle, and
• sets a target revolution speed of the internal combustion engine based on a speed shift line that is plotted on a graph having a pair of axes defining a revolution speed of the engine and the target output of the engine so that, within a practical region in which the state of operation of the engine is practical, a width of increase in the revolution speed of the engine to a relatively high revolution speed on the speed shift line is curbed compared with an optimal fuel consumption line determined based on at least an efficiency of the engine and an efficiency of the transmission, of an efficiency of a drive system that includes the engine and the transmission;
• and
• controls the speed ratio of the transmission so that an actual revolution speed of the engine becomes equal to the target revolution speed.

A drive control method for a vehicle that is driven by an output of an engine via a transmission, the method comprising:

• calculating a target output of the engine for achieving a target drive power that is set based on a state of operation of the vehicle;
• setting a target revolution speed of the engine based on a speed shift line that is plotted on graph having a pair of axes defining speed of the engine and the target output of the engine so that, within a practical region in which the state of operation of the engine is practical, a width of increase in the revolution speed of the engine to a relatively high revolution speed on the speed shift line is curbed compared with an optimal fuel consumption line determined based on at least an efficiency of the engine and an efficiency of the transmission, of an efficiency of a drive system that includes the engine and the transmission;
• and
• controlling the speed ratio of the transmission so that an actual revolution speed of the engine becomes equal to the target revolution speed.