Control device of internal combustion engine

1. A control device of an internal combustion engine comprising:

an air-fuel ratio modulator, compulsorily performing modulation of an air-fuel ratio of an exhaust which flows in a three-way catalyst provided in an exhaust system of the internal combustion engine to activate the three-way catalyst;

a fluctuation detector, detecting a fluctuation of the internal combustion engine due to the modulation of the air-fuel ratio performed by the air-fuel ratio modulator;

a feed-back controller, performing feed-back control of a driving control parameter of the internal combustion engine so as to suppress the fluctuation detected by the fluctuation detector;

a determiner, determining whether or not a driving state of the internal combustion engine is in an operating area of the feed-back controller; and

an operator, setting a target revolution of the internal combustion engine, which is a target value for suppressing the fluctuation of the internal combustion engine, to operate the feed-back controller based on the target value, when the determiner determines that the driving state of the internal combustion engine is not in the operating area of the feed-back controller, while the air-fuel modulator performs the modulation of the air-fuel ratio.

2. The control device of the internal combustion engine according to claim 1 , wherein

the operator detects the target revolution of the internal combustion engine based on a motion equation which sets a crank angular speed or a crank angular acceleration of the internal combustion engine as an unknown function, and operates the feed-back controller so as to make an actual revolution close to the target revolution.

3. The control device of the internal combustion engine according to claim 1 , wherein

the fluctuation detector includes a revolution detector detecting an actual revolution of the internal combustion engine, and

the operator detects the target revolution of the internal combustion engine based on least squares method which uses detection result by the revolution detector, and operates the feed-back controller so as to make the actual revolution close to the target revolution.

4. The control device of the internal combustion engine according to claim 1 , wherein

the feed-back controller sets an ignition timing of the internal combustion engine to be the driving control parameter, and

the operator adjusts the ignition timing so as to reduce a deviation between a target revolution of the internal combustion engine and an actual revolution of the internal combustion engine.

5. The control device of the internal combustion engine according to claim 1 , wherein

the feed-back controller sets a throttle opening degree of a throttle valve of the internal combustion engine to be the driving control parameter, and

the operator adjusts the throttle opening degree so as to reduce a deviation between a target revolution of the internal combustion engine and an actual revolution of the internal combustion engine.

6. The control device of the internal combustion engine according to claim 1 , wherein

the feed-back controller sets a fuel injection amount of the internal combustion engine to be the driving control parameter, and

the operator adjusts the fuel injection amount so as to reduce a deviation between a target revolution of the internal combustion engine and an actual revolution of the internal combustion engine.

7. The control device of the internal combustion engine according to claim 1 , wherein

the feed-back controller sets a fuel injection timing of the internal combustion engine to be the driving control parameter, and

the operator adjusts the fuel injection timing so as to reduce a deviation between a target revolution of the internal combustion engine and an actual revolution of the internal combustion engine.

8. The control device of the internal combustion engine according to claim 1 , further comprising:

a motor, applying a positive torque or a negative torque to the internal combustion engine, wherein

the feed-back controller sets a revolution of the motor to be the driving control parameter, and

the operator adjusts the revolution of the motor so as to reduce a deviation between a target revolution of the internal combustion engine and an actual revolution of the internal combustion engine.

9. The control device of the internal combustion engine according to claim 1 , wherein

when the internal combustion engine is in an acceleration driving state, the determiner determines that the driving state of the internal combustion engine is not in the operating area of the feed-back controller.

10. The control device of the internal combustion engine according to claim 1 , wherein

when the internal combustion engine is in a normal driving state after acceleration, the determiner determines that the driving state of the internal combustion engine is not in the operating area of the feed-back controller.

11. The control device of the internal combustion engine according to claim 1 , wherein

when the internal combustion engine is in a normal driving state after deceleration, the determiner determines that the driving state of the internal combustion engine is not in the operating area of the feed-back controller.