Internal-combustion engine control apparatus for controlling waste gate valve opening degree

An internal-combustion engine control apparatus, comprising:

• a thermal efficiency calculator for calculating a deviated quantity in thermal efficiency being a deviated quantity in thermal efficiency with respect to thermal efficiency in a previous reference operating state based on thermal efficiency stored in advance in a reference operating state, and on a combination in any of ignition timing, charging efficiency, an air-fuel ratio and an exhaust gas recirculation ratio being change factors in thermal efficiency of an internal-combustion engine;
• an exhaust-gas loss calculator for calculating exhaust gas loss in a reference operating state from an exhaust gas temperature stored in advance in a reference operating state, for calculating a deviated quantity in exhaust gas loss from that in a previous reference operating state based on the deviated quantity in thermal efficiency calculated by the thermal efficiency calculator and on a combination in any of ignition timing, charging efficiency, an air-fuel ratio and an exhaust gas recirculation ratio being change factors of the exhaust gas loss, and for calculating exhaust gas loss from a deviated quantity between exhaust gas loss in the reference operating state and exhaust gas loss from that in the previous reference operating state;
• an exhaust port temperature calculator for calculating an exhaust gas temperature at an exhaust port portion based on the exhaust gas loss calculated by the exhaust-gas loss calculator;
• a target waste-gate-valve opening-degree calculator for calculating a target opening degree of a waste gate valve of a turbocharger based on the exhaust gas temperature calculated by the exhaust port temperature calculator;
• and
• a controller configured to control an opening degree of the waste gate valve based on the target opening degree calculated by the target waste-gate-valve opening-degree calculator.