Method for controlling an internal combustion engine

1. A method for controlling an internal combustion engine ( 1 ) supercharged by a turbocharger ( 12 ) provided with a turbine ( 13 ) and with a compressor ( 14 ) and further comprises a number (W) of cylinders ( 3 ) which are connected to a same intake manifold by a respective intake valve and to a same exhaust manifold ( 5 ) by a respective exhaust valve, the control method comprising steps of:

determining the total target torque (C i _ objt ) required to be delivered for the operation of the internal combustion engine ( 1 );

determining a number (Wa) of active cylinders ( 3 ) to be controlled, in use, for injection and combustion, wherein the number (Ws) of active cylinders ( 3 ) is any number comprised between 0and the number (W) of cylinders ( 3 );

determining a number (Ws) of inactive cylinders ( 3 ) which are, in use, controlled to aspirate the most air possible so as to increase the supercharging pressure; wherein said number (Ws) of inactive cylinders ( 3 ) are not controlled, in use, for injection and combustion and wherein the most air possible is determined as a function of the engine point which is identified by the rpm and the load

determining the target torque (C i _ obj ) required to be delivered for the operation of the internal combustion engine ( 1 ) for said number of active cylinders ( 3 ) to be controlled, in use, for injection and combustion; and

controlling the internal combustion engine ( 1 ) as a function of the target torque (C i _ obj ) required to be delivered for the operation of the internal combustion engine ( 1 ) for said number of active cylinders ( 3 ) to be controlled, in use, for injection and combustion.

2. A method according to claim 1 , wherein at least one of the number (Wa) of active cylinders ( 3 ) to be controlled for injection and combustion and the number (W) of cylinders ( 3 ) are even.

3. A method according to claim 1 , wherein the step of determining the total target torque (C i _ objt ) required to be delivered for the operation of the internal combustion engine ( 1 ) comprises the further steps of:

determining an actual torque (Ceobj) required to be delivered for the operation of the internal combustion engine ( 1 ) by the requests of the user acting on the accelerator pedal;

determining a plurality of correction parameters, such as friction, pumping work and auxiliary loads; and

determining the total target torque (C i _ objt ) required to be delivered for the operation of the internal combustion engine ( 1 ) as a function of the actual torque (Ceobj) required to be delivered for the operation of the internal combustion engine ( 1 ) and of the correction parameters.

4. A method according to claim 1 , wherein the step of determining the target torque (C i _ obj ) required to be delivered for the operation of the internal combustion engine ( 1 ) for each one of the active cylinders ( 3 ) comprises calculating the ratio between the total actual torque (Ceobj) requested to the drive shaft and the number (Wa) of active firing cylinders ( 3 ).

5. A method according to claim 1 and comprising the further steps of:

determining at least one of the applied spark advance efficiency and the EGR efficiency and the mixture efficiency; and

determining the combustion air mass (mobj) for each active cylinder ( 3 ) as a function of at least one of the applied spark advance efficiency and of the EGR efficiency and of the mixture efficiency and as a function of the target torque (C i _ obj ) required to be delivered for the operation of the internal combustion engine ( 1 ) for each one of the active cylinders ( 3 ).

6. A method according to claim 1 and comprising the further step of injecting fuel into said number (Ws) of inactive cylinders ( 3 ).

7. A method according to claim 1 and comprising the further step of controlling said number (Ws) of inactive cylinders ( 3 ) for combustion but not for torque generation.

8. A method for controlling an internal combustion engine ( 1 ) supercharged exclusively by a single turbocharger ( 12 ) provided with a turbine ( 13 ) and with a compressor ( 14 ); the internal combustion engine ( 1 ) further comprises a number (W) of cylinders ( 3 ) which are connected to a same intake manifold by a respective intake valve and to a same exhaust manifold ( 5 ) by a respective exhaust valve;

the control method comprises the steps of:

determining the total target torque (Ci_objt) required to be delivered for the operation of the internal combustion engine ( 1 );

determining a number (Wa) of active cylinders ( 3 ) to be controlled, in use, for injection and combustion, wherein the number (Ws) of active cylinders ( 3 ) is any number comprised between 0and the number (W) of cylinders ( 3 );

determining a number (Ws) of inactive cylinders ( 3 ) which are, in use, controlled to aspirate the most air possible so as to increase the supercharging pressure; wherein said number (Ws) of inactive cylinders ( 3 ) are not controlled, in use, for injection and combustion and wherein the most air possible is determined as a function of the engine point which is identified by the rpm and the load;

determining the target torque (Ci_obj) required to be delivered for the operation of the internal combustion engine ( 1 ) for said number of active cylinders ( 3 ) to be controlled, in use, for injection and combustion; and

controlling the internal combustion engine ( 1 ) as a function of the target torque (Ci_obj) required to be delivered for the operation of the internal combustion engine ( 1 ) for said number of active cylinders ( 3 ) to be controlled, in use, for injection and combustion.

9. The method according to claim 8 , wherein the number (Wa) of active cylinders ( 3 ) to be controlled for injection and combustion and/or the number (W) of cylinders ( 3 ) are even and, preferably, timed.

10. A method according to claim 8 , wherein the step of determining the total target torque (Ci_objt) required to be delivered for the operation of the internal combustion engine ( 1 ) comprises the further steps of:

determining an actual torque (Ceobj) required to be delivered for the operation of the internal combustion engine ( 1 ) by means of the requests of the user acting on the accelerator pedal;

determining a plurality of correction parameters, such as friction, pumping work and auxiliary loads;

determining the total target torque (Ci_objt) required to be delivered for the operation of the internal combustion engine ( 1 ) as a function of the actual torque (Ceobj) required to be delivered for the operation of the internal combustion engine ( 1 ) and of the correction parameters.

11. A method according to claim 8 , wherein the step of determining the target torque (Ci_obj) required to be delivered for the operation of the internal combustion engine ( 1 ) for each one of the active cylinders ( 3 ) comprises calculating the ratio between the total actual torque (Ceobj) requested to the drive shaft and the number (Wa) of active firing cylinders ( 3 ).

12. A method according to claim 8 and comprising the further steps of:

determining the applied spark advance efficiency and/or the EGR efficiency and/or the mixture efficiency;

determining the combustion air mass (mobj) for each active cylinder ( 3 ) as a function of the applied spark advance efficiency and/or of the EGR efficiency and/or of the mixture efficiency and as a function of the target torque (Ci_obj) required to be delivered for the operation of the internal combustion engine ( 1 ) for each one of the active cylinders ( 3 ).

13. A method according to claim 8 and comprising the further step of injecting fuel into said number (Ws) of inactive cylinders ( 3 ).

14. A method according to claim 8 and comprising the further step of controlling said number (Ws) of inactive cylinders ( 3 ) for combustion but not for torque generation.

15. A method for controlling an internal combustion engine ( 1 ) supercharged by means of a turbocharger ( 12 ) provided with a turbine ( 13 ) and with a compressor ( 14 ); the internal combustion engine ( 1 ) further comprises a number (W) of cylinders ( 3 ) which are connected to a same intake manifold by a respective intake valve and to a same exhaust manifold ( 5 ) by a respective exhaust valve;

the control method comprises the steps of:

determining the total target torque (Ci_objt) required to be delivered for the operation of the internal combustion engine ( 1 );

determining a number (Wa) of active cylinders ( 3 ) to be controlled, in use, for injection and combustion, wherein the number (Ws) of active cylinders ( 3 ) is any number comprised between 0and the number (W) of cylinders ( 3 );

determining a number (Ws) of inactive cylinders ( 3 ) which are, in use, controlled to aspirate the most air possible so as to increase the supercharging pressure;

determining the target torque (Ci_obj) required to be delivered for the operation of the internal combustion engine ( 1 ) for said number of active cylinders ( 3 ) to be controlled, in use, for injection and combustion;

controlling the internal combustion engine ( 1 ) as a function of the target torque (Ci_obj) required to be delivered for the operation of the internal combustion engine ( 1 ) for said number of active cylinders ( 3 ) to be controlled, in use, for injection and combustion; and

injecting a quantity of fuel into said number (Ws) of inactive cylinders to increase the exhaust temperature in order to heat up a catalyst and in order to provide more power to the turbine ( 13 ) of the turbocharger ( 12 ).