METHOD FOR REGULATING AN INTERNAL COMBUSTION ENGINE, COMPUTER PROGRAM AND CONTROL UNIT

• US 20090182485A1
• Filed: 12/11/2008
• Published: 07/16/2009
• Est. Priority Date: 01/15/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Graf, Gerald, Fischer, Wolfgang, Karrelmeyer, Roland, Haering, Juergen, LOEFFLER, Axel
• Granted Patent: US 9,217,387 B2
• Time in Patent Office: Days
• US Class Current: 701/103
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 2041/1412 using a predictive controller
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 35/024 using an estimation
• CPC Class Codes: F02D 35/028 by determining the combustion timing or phasing
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/006 using internal EGR control of valve overlap for internal EGR F02D13/0261; arrangements for internal EGR F02M26/01
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/1454 the characteristics being an oxygen content or concentration or the air-fuel ratio
• CPC Class Codes: F02D 41/3035 a mode being the premixed charge compression-ignition mode
• CPC Class Codes: F02D 41/3064 with special control during transition between modes
• CPC Class Codes: F02D 41/402 Multiple injections

Abstract

A method for regulating an internal combustion engine that is operable, at least in a part-load range, in an operating mode with auto-ignition and a combustion process of which is influenced by a manipulated variable, the method includes the steps of determining a desired value of a combustion position feature of the combustion process; determining the manipulated variable by predictive closed-loop control based on a modeling of the combustion position feature as a function of the manipulated variable in the combustion process; and determining, as the manipulated variable, a value at which the difference between the desired value of the combustion position feature and a model-based predicted combustion position feature is minimized.

Claims

1. A method for regulating an internal combustion engine that is operable, at least in a part-load range, in an operating mode with auto-ignition and a combustion process of which is influenced by a manipulated variable, comprising:

determining a desired value of a combustion position feature of the combustion process;

determining the manipulated variable by predictive closed-loop control based on a modeling of the combustion position feature as a function of the manipulated variable in the combustion process; and

determining, as the manipulated variable, a value at which the difference between the desired value of the combustion position feature and a model-based predicted combustion position feature is minimized.

2. The method as recited in claim 1, wherein the internal combustion engine is a gasoline engine that is operable in a first part-load range in a first operating mode with spark-ignition and in a second part-load range in a second operating mode with auto-ignition, further comprising:

determining whether the internal combustion engine is being operated in the first or the second operating mode; and

performing the steps of determining the desired value, determining the manipulated variable by predictive closed-loop control, and determining the value at which the difference is minimized, when it is determined that one of the following conditions is met;

(i) the internal combustion engine is being operated in the second operating mode,

(ii) a changeover from the first to the second operating mode is taking place, and

(iii) a changeover from the second to the first operating mode is taking place.

3. The method as recited in claim 1, further comprising:

selecting the combustion position feature to correspond to a crankshaft angle at which a specific quantity of the combustion energy of a combustion cycle has been converted in a cylinder of the internal combustion engine.

4. The method as recited in claim 3, wherein the combustion position feature is the 50% mass fraction burnt, which corresponds to a crankshaft angle at which approximately 50% of the combustion energy of a combustion cycle has been converted in the cylinder of the internal combustion engine.

5. The method as recited in claim 1, further comprising:

selecting the manipulated variable to correspond to a crankshaft angle at which one of an intake valve and an exhaust valve of a cylinder of the internal combustion engine is opened or closed.

6. The method as recited in claim 1, further comprising:

selecting the manipulated variable to correspond to one of a time at which fuel is injected and an apportionment ratio of the injected fuel.

7. The method as recited in claim 1, further comprising:

selecting the model to be a data-driven model that predicts the combustion position feature as a linear function of the manipulated variable.

8. The method as recited in claim 1, further comprising:

selecting the model to be a physical model that predicts the combustion position feature by reference to a predicted changing of state features of the combustion process, the model taking into consideration a planned control intervention on the basis of the manipulated variable.

9. The method as recited in claim 1, further comprising:

subjecting the manipulated variable to cylinder-individual, continuous, closed-loop control.

10. The method as recited in claim 1, further comprising:

determining a difference between an actual value of the combustion position feature, which actual value is ascertained for a combustion cycle, and a predicted value of the combustion position feature for the same combustion cycle;

determining an offset correction value based on the determined difference between the actual and predicted values of the combustion feature; and

correcting the desired value of the combustion position feature by the offset correction value.

11. The method as recited in claim 10, further comprising:

determining the offset correction value by;

multiplying the determined difference between the actual and predicted values of the combustion position feature by a constant, and

integrating the product obtained by the multiplication over the combustion cycles.

12. The method as recited in claim 10, further comprising:

determining the offset correction value by subjecting the determined difference between the actual and predicted values of the combustion position feature to low-pass filtering.

13. The method as recited in claim 10, further comprising:

determining the offset correction value by averaging the determined difference between the actual and predicted values of the combustion position feature over a plurality of combustion cycles.

14. The method as recited in claim 10, further comprising:

determining the offset correction value for each cylinder of the internal combustion engine individually; and

determining cylinder-individually corrected desired values based on the offset correction values determined cylinder-individually.

15. A computer-readable storage medium containing program code configured to, when executed on a program-controlled device, perform the steps of a method for regulating an internal combustion engine that is operable, at least in a part-load range, in an operating mode with auto-ignition and a combustion process of which is influenced by a manipulated variable, the method comprising:

determining a desired value of a combustion position feature of the combustion process;

determining the manipulated variable by predictive closed-loop control based on a modeling of the combustion position feature as a function of the manipulated variable in the combustion process; and

determining, as the manipulated variable, a value at which the difference between the desired value of the combustion position feature and a model-based predicted combustion position feature is minimized.

16. A control unit for an internal combustion engine, the control unit comprising at least one arrangement configured to perform the steps of a method for regulating an internal combustion engine that is operable, at least in a part-load range, in an operating mode with auto-ignition and a combustion process of which is influenced by a manipulated variable, the method including:

determining a desired value of a combustion position feature of the combustion process;

determining the manipulated variable by predictive closed-loop control based on a modeling of the combustion position feature as a function of the manipulated variable in the combustion process; and

determining, as the manipulated variable, a value at which the difference between the desired value of the combustion position feature and a model-based predicted combustion position feature is minimized.