Power output apparatus and control method of the same

A power output apparatus that outputs power to a drive shaft, said power output apparatus comprising:

• an internal combustion engine;
• an electric power-mechanical power input-output module that is linked to an output shaft of said internal combustion engine and to the drive shaft and outputs at least part of output power of said internal combustion engine to the drive shaft through input and output of electric powers and mechanical powers;
• an accumulator module that receives and gives electric powers from and to said electric power-mechanical power input-output module;
• and
• a control module that specifies a power demand to be output to the drive shaft and sets a target power to be output from said internal combustion engine in response to the specified power demand and a target drive point to attain the output of the target power,
• in an ordinary state, said control module executing ordinary control of said internal combustion engine and said electric power-mechanical power input-output module to drive said internal combustion engine at the target drive point and to ensure output of a required power corresponding to the power demand to the drive shaft,
• in a non-ordinary state where execution of the ordinary control causes an output power level of said internal combustion engine to exceed the target power, said control module executing non-ordinary control of said internal combustion engine and said electric power-mechanical power input-output module to keep a selected driving parameter among multiple driving parameters, which represent operating conditions of said internal combustion engine and include a rotation speed, a torque level, an ignition timing, intake and exhaust timings, and a throttle opening, at a current level, while varying at least one driving parameter other than the selected driving parameter, thus driving said internal combustion engine at a specific drive point of making the output power level of said internal combustion engine approach to the target power and ensuring the output of the required power corresponding to the power demand to the drive shaft.

A control method of a power output apparatus which includes an internal combustion engine, an electric power-mechanical power input-output module that is linked to an output shaft of said internal combustion engine and to a drive shaft and outputs at least part of output power of said internal combustion engine to the drive shaft through input and output of electric powers and mechanical powers, and an accumulator module that receives and gives electric powers from and to said electric power-mechanical power input-output module, said control method comprising the steps of:

• (a) specifying a power demand to be output to the drive shaft;
• (b) setting a target power to be output from said internal combustion engine in response to the specified power demand and a target drive point to attain the output of the target power;
• and
• (c) in an ordinary state, executing ordinary control of said internal combustion engine and said electric power-mechanical power input-output module to drive said internal combustion engine at the target drive point and to ensure output of a required power corresponding to the power demand to the drive shaft,
• while in a non-ordinary state where execution of the ordinary control causes an output power level of said internal combustion engine to exceed the target power, executing non-ordinary control of said internal combustion engine and said electric power-mechanical power input-output module to drive said internal combustion engine at a specific drive point of making the output power level of said internal combustion engine approach to the target power, while keeping a level of a throttle opening at the target drive point, and to ensure the output of the required power corresponding to the power demand to the drive shaft.

A control method of a power output apparatus which includes an internal combustion engine, an electric power-mechanical power input-output module that is linked to an output shaft of said internal combustion engine and to a drive shaft and outputs at least part of output power of said internal combustion engine to the drive shaft through input and output of electric powers and mechanical powers, and an accumulator module that receives and gives electric powers from and to said electric power-mechanical power input-output module, said control method comprising the steps of:

• (a) specifying a power demand to be output to the drive shaft;
• (b) setting a target power to be output from said internal combustion engine in response to the specified power demand and a target drive point to attain the output of the target power;
• and
• (c) in an ordinary state, executing ordinary control of said internal combustion engine and said electric power-mechanical power input-output module to drive said internal combustion engine at the target drive point and to ensure output of a required power corresponding to the power demand to the drive shaft,
• while in a non-ordinary state where execution of the ordinary control causes an output power level of said internal combustion engine to exceed the target power, executing non-ordinary control of said internal combustion engine and said electric power-mechanical power input-output module to keep a selected driving parameter among multiple driving parameters, which represent operating conditions of said internal combustion engine and include a rotation speed, a torque level, an ignition timing, intake and exhaust timings, and a throttle opening, at a current level, while varying at least one driving parameter other than the selected driving parameter, thus driving said internal combustion engine at a specific drive point of making the output power level of said internal combustion engine approach to the target power and ensuring the output of the required power corresponding to the power demand to the drive shaft.