Method for controlling an internal combustion engine

• US 9,334,814 B2
• Filed: 06/12/2013
• Issued: 05/10/2016
• Est. Priority Date: 06/12/2012
• Status: Active Grant

• Current Assignee: Marelli Europe SPA
• Original Assignee: Magneti Marelli S.p.A.
• Inventors: Panciroli, Marco
• Primary Examiner(s): Vo, Hieu T
• Assistant Examiner(s): Castro, Arnold
• Application Number:
  US13/915,892
• Publication Number:
  US 20130345948A1
• Time in Patent Office: 1,063 Days
• Field of Search: 123/90.15, 123345-348, 701/103
• US Class Current: 1/1
• CPC Class Codes: F02D 23/02 the engines being of fuel-injection type
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method for controlling an internal combustion engine comprising a number of cylinders and wherein the air mass trapped in each cylinder is adjusted by means of a respective intake valve by means of an actuation device with variable opening law; the method includes determining the required total target torque to be delivered; determining a number of active cylinders and a number of inactive cylinders; determining the angle for controlling the intake valve of the number of active cylinders and of the number of inactive cylinders, respectively; and controlling the internal combustion engine as a function of the control angle of the intake valves of the number of active cylinders and of the number of inactive cylinders.

Claims

1. A method for controlling an internal combustion engine (1) by a turbocharger (12) provided with a turbine (13) and with a compressor (14) and comprising, furthermore, an intake manifold (4) and a number (W) of cylinders (3), which are connected to the intake manifold (4) and in which the air mass trapped in each cylinder (3) for each engine cycle can be adjusted in an independent manner through a respective intake valve by a valve actuation device with a variable opening, 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 the injection and the combustion;

whereas a number (Ws) of cylinders (3) are not active and are not controlled for the combustion and the torque generation, but for sucking in an air mass;

determining the angle with which the intake valve has to be controlled by the valve actuation device with a variable opening of the number (Wa) of active cylinders (3);

determining the angle with which the intake valve has to be controlled by the valve actuation device with a variable opening of the number (Ws) of inactive cylinders (3); and

controlling the internal combustion engine (1) as a function of the angle with which the intake valve has to be controlled by the valve actuation device with a variable opening of the number (Wa) of active cylinders (3) and as a function of the angle with which the intake valve has to be controlled by the valve actuation device with a variable opening of the number (Ws) of inactive cylinders (3).

2. A method according to claim 1 and comprising the further step of determining a target pressure (Pobj) of the intake manifold that is such as to guarantee the total target torque (Ci_objt) required to be delivered for the operation of the internal combustion engine (1).

3. A method according to claim 2 and comprising, in case of a supercharged internal combustion engine (1), the further step of determining the target supercharge pressure (Ptobj) that is such as to guarantee the target pressure (Pobj) of the intake manifold.

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

determining the target scavenge flow rate (Mscav), which represents the air quantity that optimizes the performances of the internal combustion engine (1), and determining the target scavenge mass (mscav) for each one of the number (Ws) of inactive cylinders (3); and

determining, by a first filling model, the angle with which the intake valve has to be controlled by the valve actuation device with a variable opening of the number (Ws) of inactive cylinders (3) as a function of the target scavenge mass (mscav).

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

determining the operating mode of the number (Ws) of inactive cylinders (3) among a plurality of possible operating modes; and

determining the angle with which the intake valve has to be controlled by the valve actuation device with a variable opening of the number (Ws) of inactive cylinders (3) as a function of the operating mode of the number (Ws) of inactive cylinders (3).

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

determining the combustion air mass (mobj) for each one of the number (Wa) of active cylinders (3) as a function of at least one of the efficiency of the spark advance applied and of the efficiency of the EGR and of the efficiency of the titer 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); and

determining, by a second filling model, the angle with which the intake valve has to be controlled by the valve actuation device with a variable opening of the number (Wa) of active cylinders (3) as a function of the combustion air mass (mobj) for each one of the number (Wa) of active cylinders (3) as a function of at least one of the efficiency of the spark advance applied and of the efficiency of the EGR and of the efficiency of the titer and as a function of the target torque (C_{i_objt}) required to be delivered for the operation of the internal combustion engine (1) for each one of the active cylinders (3).

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

determining the operating mode of the number (Wa) of active cylinders (3) among a plurality of possible operating modes; and

determining the angle with which the intake valve has to be controlled by the valve actuation device with a variable opening of the number (Wa) of active cylinders (3) as a function of the operating mode of the number (Wa) of active cylinders (3).

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

determining a temporary number (Watemp) of active cylinders (3) to be controlled, in use, for the injection and the combustion as a function of the engine operation point;

determining the potential torque that can be delivered for the operation of the internal combustion engine (1) by the temporary number (Watemp) of active cylinders (3);

comparing the potential torque that can be delivered for the operation of the internal combustion engine (1) by the temporary number (Watemp) of active cylinders (3) and the total target torque (C_{i_objt}) required to be delivered for the operation of the internal combustion engine (1); and

determining the number (Wa) of active cylinders (3) as a function of the comparison between the potential torque that can be delivered for the operation of the internal combustion engine (1) by the temporary number (Watemp) of active cylinders (3) and the total target torque (C_{i_objt}) required to be delivered for the operation of the internal combustion engine (1).

9. A method according to claim 8 and comprising, in an initial phase, the further steps of:

determining a reference number (Warif) of active cylinders (3) to be controlled, in use, for the injection and the combustion as a function of the engine operation point; and

initializing the temporary number (Watemp) of active cylinders (3) to be controlled, in use, for the injection and the combustion as a function of the engine operation point at the reference number (Warif) of active cylinders (3).

10. A method according to claim 8 and comprising the further step of causing the reference number (Warif) of active cylinders (3) to be equal to the temporary number (Watemp) of active cylinders (3), only in case the potential torque that can be delivered for the operation of the internal combustion engine (1) by the temporary number (Watemp) of active cylinders (3) is either of higher than and equal to the total target torque (C_{i_objt}) required to be delivered for the operation of the internal combustion engine (1).

11. A method according to claim 9 and comprising the further steps of:

determining, in a preliminary adjustment and set-up phase, a deviation number (A) of cylinders (3) to be added to the combustion; and

updating the temporary number (Watemp) of active cylinders (3) by the deviation number (Δ

) of cylinders (3), only in case the potential torque that can be delivered for the operation of the internal combustion engine (1) by the temporary number (Watemp) of active cylinders (3) is lower than the total target torque (C_{i_objt}) required to be delivered for the operation of the internal combustion engine (1).

12. A control method according to claim 11, wherein the deviation number (Δ

) of cylinders (3) to be either of added to and subtracted from the combustion is equal to 2.

13. A control method according to claim 4 and comprising the further step of determining the target scavenge mass (Mscav), which represents the air quantity that optimizes the performances of the internal combustion engine (1), in a transient phase by the formula:

Mscav=Mscavrif (C,n)+Δ

(derivative(Ciobjt))

wherein;

Mscavrif (C,n);

reference target scavenge mass, as a function of the engine operation point determined by the load and by the number of revolutions per minute; and

Ciobjt;

total actual torque required to the drive shaft.

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

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