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

• US 20090182484A1
• Filed: 11/25/2008
• Published: 07/16/2009
• Est. Priority Date: 01/15/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Fischer, Wolfgang, Karrelmeyer, Roland, Loeffler, Axel, Graf, Gerald
• Granted Patent: US 8,406,979 B2
• Time in Patent Office: Days
• US Class Current: 701/103
• CPC Class Codes: F02D 2041/1432 the system including a filter, e.g. a low pass or high pass filter
• CPC Class Codes: F02D 2200/025 Engine noise, e.g. determined by using an acoustic sensor
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 41/2458 with an additional dither signal
• CPC Class Codes: F02D 41/3035 a mode being the premixed charge compression-ignition mode
• CPC Class Codes: F02D 41/403 with pilot injections

Abstract

A method for operating an internal combustion engine, especially an internal combustion engine that is operable, at least in a part-load range, in an operating mode with auto-ignition, in which, at an abrupt change in load and/or at a changeover between an operating mode with auto-ignition and an operating mode without auto-ignition, a parameter of the combustion process correlating with the combustion noise is adapted stepwise over a plurality of combustion cycles from a first parameter value before the abrupt change in load or the changeover to a second parameter value after the abrupt change in load or the changeover, by influencing a combustion position of the combustion process.

Claims

1. A method for operating an internal combustion engine operable, at least in a part-load range, in an operating mode with auto-ignition, the method comprising:

adapting stepwise, at at least one of (a) an abrupt change in load and (b) a changeover between the operating mode with auto-ignition and an operating mode without auto-ignition, a parameter of a combustion process correlating with a combustion noise over a plurality of combustion cycles, from a first parameter value before at least one of (a) the abrupt change in load and (b) the changeover between operating modes to a second parameter value after at least one of (a) the abrupt change in load and (b) the changeover between operating modes, by influencing a combustion position of the combustion process.

2. The method according to claim 1, wherein the parameter includes a maximum pressure gradient in a combustion chamber of the internal combustion engine.

3. The method according to claim 1, wherein the combustion position corresponds to a crankshaft angle at which a specific quantity of a combustion energy of a combustion cycle has been converted in a combustion chamber of the internal combustion engine.

4. The method according to claim 1, wherein the parameter value is adapted over at least three, preferably at least five, and especially at least ten, combustion cycles.

5. The method according to claim 1, wherein a transition during the adapting from the first parameter value to the second parameter value corresponds to a ramped transition.

6. The method according to claim 1, wherein a transition during the adapting from the first parameter value to the second parameter value corresponds to a low-pass-filtered abrupt change.

7. The method according to claim 1, further comprising:

regulating the combustion process in the operating mode with auto-ignition by closed-loop control, wherein the combustion position is used as a reference variable, and wherein the stepwise adapting of the parameter includes modifying the reference variable.

8. The method according to claim 7, wherein the closed-loop control in the operating mode with auto-ignition includes a model-based predictive closed-loop control procedure, and a desired value of the combustion position is adapted in preparation before the changeover from the operating mode with auto-ignition to the operating mode without auto-ignition.

9. The method according to claim 7, wherein the closed-loop control in the operating mode with auto-ignition includes a model-based predictive closed-loop control procedure, and a desired value of the combustion position is adapted subsequently after the changeover from the operating mode without auto-ignition to the operating mode with auto-ignition.

10. The method according to claim 1, further comprising:

injecting fuel by direct injection into a combustion chamber of the internal combustion engine; and

shifting a quantity of fuel injected during the stepwise adapting from a main injection to a cooling injection.

11. The method according to claim 10, wherein the cooling injection takes place during a compression phase in the combustion process.

12. A computer program having program code means, wherein the program code means are configured to carry out a method for operating an internal combustion engine operable, at least in a part-load range, in an operating mode with auto-ignition, when the computer program is executed with a program-controlled device, the method comprising:

adapting stepwise, at at least one of (a) an abrupt change in load and (b) a changeover between the operating mode with auto-ignition and an operating mode without auto-ignition, a parameter of a combustion process correlating with a combustion noise over a plurality of combustion cycles, from a first parameter value before at least one of (a) the abrupt change in load and (b) the changeover between operating modes to a second parameter value after at least one of (a) the abrupt change in load and (b) the changeover between operating modes, by influencing a combustion position of the combustion process.

13. A computer program product having program code means stored on a computer-readable data medium in order to carry out a method for operating an internal combustion engine operable, at least in a part-load range, in an operating mode with auto-ignition, when the program product is executed on a program-controlled device, the method comprising:

adapting stepwise, at at least one of (a) an abrupt change in load and (b) a changeover between the operating mode with auto-ignition and an operating mode without auto-ignition, a parameter of a combustion process correlating with a combustion noise over a plurality of combustion cycles, from a first parameter value before at least one of (a) the abrupt change in load and (b) the changeover between operating modes to a second parameter value after at least one of (a) the abrupt change in load and (b) the changeover between operating modes, by influencing a combustion position of the combustion process.

14. A control unit for operating an internal combustion engine operable, at least in a part-load range, in an operating mode with auto-ignition, the control unit comprising:

an arrangement for adapting stepwise, at at least one of (a) an abrupt change in load and (b) a changeover between the operating mode with auto-ignition and an operating mode without auto-ignition, a parameter of a combustion process correlating with a combustion noise over a plurality of combustion cycles, from a first parameter value before at least one of (a) the abrupt change in load and (b) the changeover between operating modes to a second parameter value after at least one of (a) the abrupt change in load and (b) the changeover between operating modes, by influencing a combustion position of the combustion process.