Control device for internal combustion engine

A control device for an internal combustion engine with a turbocharger, the control device comprising:

• an exhaust bypass path that is installed in an exhaust system for the internal combustion engine to bypass the turbocharger;
• a WGV that is installed in the exhaust bypass path and capable of arbitrarily adjusting the opening thereof upon receipt of an operation request from the internal combustion engine;
• acquisition device for acquiring, during a transient operation of the internal combustion engine, an exhaust gas flow rate of exhaust gas discharged from the internal combustion engine, a WGV opening, and a boost pressure correlation value having a correlation with boost pressure of the internal combustion engine as a transient exhaust gas flow rate, a transient WGV opening, and a transient boost pressure correlation value, respectively;
• virtual exhaust gas flow rate acquisition device for acquiring, as a virtual exhaust gas flow rate, a virtual value indicative of the exhaust gas flow rate prevailing when the transient boost pressure correlation value and the transient WGV opening are achieved during a steady operation of the internal combustion engine;
• virtual turbine flow rate acquisition device for acquiring, as a virtual turbine flow rate, a virtual value indicative of a flow rate of exhaust gas passing through a turbine for the turbocharger (hereinafter referred to as a turbine flow rate), the virtual value prevailing when the transient boost pressure correlation value and the transient WGV opening are achieved during the steady operation;
• flow rate ratio acquisition device for acquiring a flow rate ratio of the virtual turbine flow rate to the virtual exhaust gas flow rate;
• and
• turbine flow rate calculation device for calculating the turbine flow rate during the transient operation by applying the flow rate ratio to the transient exhaust gas flow rate.