Control of turbocharger

A control device for a turbocharger (50) of an engine (1), the turbocharger (50) comprising an exhaust gas turbine (52) driven by an exhaust gas of the engine (1), a compressor (55) which supplies fresh air to the engine (1) under a supercharging pressure according to a rotation of the exhaust gas turbine (52), and a mechanism (53, 54, 56, 59) which adjusts a flowpath cross-sectional area of the exhaust gas led to the exhaust gas turbine (52), the control device comprising:

• means (33 34) for detecting a running state of the engine (1);
• means (39) for detecting an intake air amount of the engine (1);
• means (41, S115, S116) for setting an open loop control value of the flowpath cross-sectional area based on the running state (S332), set a target intake air amount of the engine (1) based on the running state;
• means (41, S132) for calculating a processing value wherein predetermined smoothing is performed on the target intake air amount;
• means (S367) for calculating a feedback correction amount which makes the intake air amount coincide with the processing value;
• and
• means (41, S412) for controlling the exhaust gas flowpath cross-sectional area of the mechanism (53, 54, 56) based on the open loop control value and feedback correction amount.

A control method of a turbocharger (50) of an engine (1), the turbocharger (50) comprising an exhaust gas turbine (52) driven by an exhaust gas of the engine (1), a compressor (55) which supplies fresh air to the engine (1) under a supercharging pressure according to a rotation of the exhaust gas turbine (52), and a mechanism (53, 54, 56, 59) which adjusts a flowpath cross-sectional area of the exhaust gas led to the exhaust gas turbine (52), the control method comprising:

• detecting a running state of the engine (1);
• detecting an intake air amount of the engine (1);
• setting an open loop control value of the flowpath cross-sectional area based on the running state (S332), set a target intake air amount of the engine (1) based on the running state;
• calculating a processing value wherein predetermined smoothing is performed on the target intake air amount;
• calculating a feedback correction amount which makes the intake air amount coincide with the processing value;
• and
• controlling the exhaust gas flowpath cross-sectional area of the mechanism (53, 54, 56) based on the open loop control value and feedback correction amount.