Control device for internal combustion engine

A control device for an internal combustion engine including a first cylinder group to which a first intake manifold and a first exhaust manifold are connected;

• a second cylinder group to which a second intake manifold and a second exhaust manifold are connected;
• a first upstream intake passage and a second upstream intake passage that are connected to the first intake manifold and the second intake manifold via a common downstream intake passage;
• a first air bypass valve provided in a passage bypassing a first compressor mounted to the first upstream intake passage;
• a second air bypass valve provided in a passage bypassing a second compressor mounted to the second upstream intake passage;
• a first wastegate valve provided in a passage bypassing a first turbine that is mounted to the first exhaust manifold and that is connected to the first compressor;
• and a second wastegate valve provided in a passage bypassing a second turbine that is mounted to the second exhaust manifold and that is connected to the second compressor, the control device comprising:
• a throttle valve that is provided in the downstream intake passage;
• a pressure sensor that measures a pressure upstream of the throttle valve in the downstream intake passage;
• feedback control means configured to correct opening degrees of the first wastegate valve and the second wastegate valve so that a measured turbocharging pressure by the pressure sensor approaches a target turbocharging pressure;
• first reduction speed calculating means configured to issue an opening command to the first air bypass valve at a time of deceleration of the internal combustion engine when an absolute value of a feedback correction amount by the feedback control means exceeds a predetermined value, and calculating a first reduction speed of the measured turbocharging pressure;
• second reduction speed calculating means configured to issue an opening command to the second air bypass valve at the time of deceleration of the internal combustion engine when the absolute value exceeds the predetermined value again after calculation of the first reduction speed, and calculating a second reduction speed of the measured turbocharging pressure;
• and
• abnormality determining means configured to determine to which one of the first air bypass valve, the second air bypass valve, the first wastegate valve, and the second wastegate valve, an abnormality occurs, based on the feedback correction amount, the first reduction speed, and the second reduction speed.