Patent ID: 8055436

Claim:
A method for controlling the wastegate ( 16 ) in a internal combustion engine ( 1 ) turbocharged by means of a turbocharger ( 12 ); the control method comprises the steps of: determining, during a design phase, a control law (CL) which provides an objective opening of a controlling actuator ( 35 ) of the wastegate ( 16 ) according to the supercharging pressure (P); determining an objective supercharging pressure (P obj ); measuring an actual supercharging pressure (P); determining a first open loop contribution (WG OL ) of an objective position (WG obj ) of the controlling actuator ( 35 ) of the wastegate ( 16 ) through the control law (CL) and according to the objective supercharging pressure (P obj ); determining a second closed loop contribution (WG CL1 ) of the objective position (WG obj ) of the controlling actuator ( 35 ) of the wastegate ( 16 ); calculating the objective position (WG obj ) of the controlling actuator ( 35 ) of the wastegate ( 16 ) by adding the two contributions (WG OL , WG CL1 ); controlling the controlling actuator ( 35 ) of the wastegate ( 16 ), so as to pursue the objective position (WG obj ) of the controlling actuator ( 35 ) of the wastegate ( 16 ); dividing the operation field of the wastegate ( 16 ) into at least two different operation zones according to the difference between the actual supercharging pressure (P) and the atmospheric pressure (P atm ): an intermediate-supercharging-pressure operation zone (B) in which the position of the wastegate ( 16 ) and the possibility of controlling the position of the wastegate ( 16 ) by means of the controlling actuator ( 35 ) are uncertain, and a high-supercharging-pressure operation zone (C) in which the position of the wastegate ( 16 ) can be controlled by means of the controlling actuator ( 35 ); and differentiating the kind of control according to the fact that the difference between the actual supercharging pressure (P) and the atmospheric pressure (P atm ) is in the intermediate-supercharging-pressure operation zone (B) or in the high-supercharging-pressure operation zone (C).