Method of controlling an internal combustion engine, in particular a diesel engine

• US 8,032,293 B2
• Filed: 06/09/2008
• Issued: 10/04/2011
• Est. Priority Date: 12/09/2005
• Status: Active Grant

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler AG (Mercedes-Benz Group AG)
• Inventors: Wolf, Matthias, Kirschbaum, Frank, Schnabel, Martin, Frommelt, Alfred, Windisch, Bernd, Klier, Michael, Matassini, Lorenzo, Bogachik, Yüriy, Hellstroem, Kristina, Scheible, Karsten, Schorr, Jürgen, Muenkel, Gerhard, Binder, Simon, Moeckel-Lherbier, Heiko, Pfaff, Rudiger, Mladek, Michael
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US12/157,335
• Publication Number:
  US 20090112449A1
• Time in Patent Office: 1,212 Days
• Field of Search: 123/299, 123/300, 123/304, 123/435, 123/436, 123/478, 123/480, 123/494, 701101-105, 701/110, 701/111, 701/114, 701/115, 73/350.1, 73/350.3, 73/350.4, 73/350.9, 73/351.2, 731/140.7, 731/141.6, 731/141.7, 702182-185
• US Class Current: 701/111
• CPC Class Codes: F02D 2200/025 Engine noise, e.g. determined by using an acoustic sensor
• CPC Class Codes: F02D 35/02 on interior conditions
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 35/028 by determining the combustion timing or phasing
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/403 with pilot injections
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

In a method for controlling an internal combustion engine, in particular a diesel internal combustion engine, at least one variable is formed on a cylinder-specific basis, which variable characterizes a respective profile of a combustion in an associated combustion chamber, and the control of cylinder-specific fuel injection parameters is influenced as a function of said at least one variable which characterizes the combustion profile.

Claims

1. A method for controlling an internal combustion engine, in particular a diesel internal combustion engine, comprising the steps of:

forming at least one variable (H_XX, H₅₀) on a cylinder-specific basis, which variable characterizes a respective profile of a combustion in an associated combustion chamber on the basis of a measured combustion chamber pressure profile,

forming an indicated mean effective pressure (IMEP) value and an indicated pressure profile from the measured combustion chamber pressure profile as a function of a crank angle of a crankshaft of the internal combustion engine,

forming a variable which characterizes the combustion profile, in the form of one of an (energy) conversion point, and a combustion point (H_XX, H₅₀) or an approximation thereto from the indicated pressure profile, which variable (H_XX, H₅₀), characterizes the combustion profile and influences the time interval between a start (5) of a pilot injection (3) and the occurrence (15) of the variable (H_XX, H₅₀) and

controlling cylinder-specific fuel injection parameters as a function of said at least one variable (H_XX, H₅₀) which characterizes the combustion profile.

2. The method as claimed in claim 1, wherein the variable (H_XX, H₅₀) which characterizes the combustion profile is formed on the basis of a structure-borne noise measurement.

3. The method as claimed in claim 1, wherein the variable (H_XX, H₅₀) which characterizes the combustion profile is formed on the basis of a knock sensor output signal.

4. The method as claimed in claim 1, wherein the combustion center point (H₅₀) or an approximation thereto is formed as a characteristic variable (H_XX) from the indicated pressure profile.

5. The method as claimed in claim 1, wherein the variable (H_XX, H₅₀) which characterizes the combustion profile influences one of a start of injection (5, 6), an injection duration, an apportionment (3, 4) and a magnitude of a fuel quantity to be injected.

6. The method as claimed in claim 1, wherein the variable (H_XX, H₅₀) which characterizes the combustion profile influences a time interval between a start of an injection (5, 6) and the occurrence (15) of the variable (H_XX, H₅₀) which characterizes the combustion profile.

7. The method as claimed in claim 1, wherein the variable (H_XX, H₅₀) which characterizes the combustion profile and influences the time interval between the start (5) of the pilot injection (3) and the occurrence of the combustion center of gravity (H₅₀).

8. The method as claimed in claim 1, wherein the variable (H_XX, H₅₀) which characterizes the combustion profile influences the time interval between a start (5) of a pilot injection (3) and the start (6) of a main injection (4).

9. The method as claimed in claim 1, wherein the variable (H_XX, H₅₀) which characterizes the combustion profile influences the apportionment of the fuel quantity to be injected between an injection quantity of the pilot injection (3) and an injection quantity of the main injection (4).

10. The method as claimed in claim 1, wherein the variable (H_XX, H₅₀) which characterizes the combustion profile influences an exhaust-gas recirculation rate, an air mass or a throttle flap position.

11. The method as claimed in claim 1, wherein a noise estimation (45) is carried out on the basis of the measured combustion chamber profile.

12. The method as claimed in claim 11, wherein a variable (LVG2) formed on the basis of the noise estimation (45) is used to influence at least one of a start of injection (5, 6), an injection duration, an apportionment (3, 4) and a fuel quantity to be injected.