Engine system and engine control method

An engine system comprising:

• an engine main body;
• an intake pipe that is connected to an intake side of the engine main body;
• a mass flow sensor that is provided in the intake pipe and outputs a measurement value of an amount of air passing through the intake pipe;
• an exhaust pipe that is connected to an exhaust side of the engine main body;
• a removal device that is provided in the exhaust pipe and removes an air pollutant included in an exhaust gas passing through the exhaust pipe;
• a recirculation pipe that connects the exhaust side of the engine main body and the intake pipe;
• a recirculation valve that controls a flow rate of the exhaust gas flowing from the recirculation pipe to the intake pipe;
• a regeneration control unit that closes the recirculation valve to perform a process of regenerating the removal device;
• an air amount calculation unit that calculates a theoretical value of an amount of air flowing to the intake side of the engine main body on the basis of a quantity of state of the engine main body during the regeneration process;
• and
• a correction unit that corrects the measurement value on the basis of the measurement value and the theoretical value during the regeneration process.