Method for operating an internal combustion engine, engine control unit and internal combustion engine

Patent metadata

Field	Value
Publication number	US-11293365-B2
Application number	US-202017131336-A
Country	US
Kind code	B2
Filing date	Dec 22, 2020
Priority date	Jun 26, 2018
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

A method for operating an internal combustion engine, including aligning an injection behavior of the number of injectors. Aligning the injection behavior includes switching off one injector of the number of injectors, detecting a signal of the internal combustion engine that is to be assigned to the switched off injector, determining an alignment characteristic from the signal and assigning the alignment characteristic to the switched off injector as an alignment characteristic assigned to the injector, and switching on the previously switched off injector. Aligning the injection behavior further includes performing the aforementioned steps sequentially for the other injectors of the number of injectors and correcting a control of an injector that is to be corrected using the measured value assigned to the injector that is to be corrected.

First claim

What is claimed is:

1. A method for operating an internal combustion engine, comprising:
providing a fuel system, a number of cylinders, a fuel pressure sensor arrangement, wherein the fuel system comprises a fuel collecting chamber, an injector device with a number of injectors, and a fuel feed which fluidly links the fuel collecting chamber and the injector device, so that the fuel from the fuel collecting chamber can be fed to the injector device; and
aligning an injection behavior of the number of injectors, the aligning having an absence of detecting a pressure drop in the fuel collecting chamber when carrying out a plurality of injections while a supply of the fuel to the fuel collecting chamber is stopped, which comprises the following steps:
switching off one injector of the number of injectors;
detecting a signal of the internal combustion engine that is to be assigned to the switched off injector, wherein detecting the signal includes detecting a transient fuel pressure of the internal combustion engine, wherein the transient fuel pressure is detected by the fuel pressure sensor arrangement at the fuel collecting chamber and/or the fuel feed;
determining an alignment characteristic from the signal and assigning the alignment characteristic to the switched off injector as an alignment characteristic assigned to the injector, wherein determining the alignment characteristic includes determining a measured value, by way of a transient algorithm at the transient fuel pressure, and assigning the measured value to the switched off injector of the number of injectors;
switching on the previously switched off injector;
performing the aforementioned steps sequentially for the other injectors of the number of injectors; and
correcting a control of an injector that is to be corrected, wherein the measured value assigned to the injector that is to be corrected is used.

2. The method according to claim 1 , further comprising:
identifying an injector to be corrected on the basis of the measured value assigned to the injector; and/or
correcting a control by correcting an energization to the injector that is to be corrected, using the measured value assigned to the injector to be corrected.

3. The method according to claim 1 , wherein the internal combustion engine is a liquid fuel engine, wherein the fuel collecting chamber is a common rail in which the liquid fuel is stored under high pressure.

4. The method according to claim 3 , wherein the fuel pressure sensor arrangement comprises a fuel pressure sensor which measures a fuel pressure of the fuel stored in the common rail.

5. The method according to claim 1 , wherein the internal combustion engine is a gas engine, wherein the fuel feed comprises a collective gas supply.

6. The method according to claim 5 , wherein the fuel pressure sensor arrangement comprises a fuel pressure sensor which measures a gas pressure of the gas fuel stored in the collective gas supply.

7. The method according to claim 1 , wherein the fuel pressure sensor arrangement for measuring the transient fuel pressure for determining the measurement value comprises a collective high pressure sensor, wherein the collective high pressure sensor is the only pressure sensor which is also used for fuel injection.

8. The method according to claim 1 , wherein the fuel pressure sensor arrangement for measuring the transient fuel pressure for determining the measurement value comprises a collective high pressure sensor and at least one additional fuel pressure sensor in addition to the collective high pressure sensor which is assigned to a group of cylinders, representing a subset of all cylinders, wherein the at least one additional fuel pressure sensor is arranged on a common rail which is assigned to the group.

9. The method according to claim 8 , wherein the subset of all cylinders consists of cylinders of an A-side of the common rail or cylinders of a B-side of the common rail of the internal combustion engine, wherein the at last one additional fuel pressure sensor is arranged on a side assigned to the A-side of the common rail or on a side assigned to the B-side of the common rail.

10. The method according to claim 1 , wherein the fuel pressure sensor arrangement comprises a number of sensors comprising a collective high pressure sensor and at least one additional fuel pressure sensor, wherein the at least one additional fuel pressure sensor is assigned to a group of cylinders on an A-side or a group of cylinders on a B-side of a common rail or a common rail system.

11. The method according to claim 1 , wherein a measured value assigned to a cylinder to be corrected or a value derived from the measured value is used to correct a control in a cylinder that is to be corrected.

12. The method according to claim 1 , wherein the measured value reflects an inequality in a fuel volume introduced into different cylinders of the internal combustion engine and is used for equalization of the fuel volume in the different cylinders.

13. The method according to claim 1 , wherein an average value is formed from multiple detected measured values assigned to the individual injectors, and wherein control of an injector to be corrected is corrected on the basis of a deviation of the measured value assigned to the injector to be corrected from the average value formed from the measured values.

14. The method according to claim 1 , wherein a transient fuel pressure is detected when all injectors are switched on, and from this transient fuel pressure a measured value assigned to all injectors is determined, and wherein moreover, a differential value is calculated from the difference between a measured value assigned to one injector and the measured value assigned to all injectors.

15. The method according to claim 14 , wherein an average value is formed from all differential values assigned to the individual injectors, and the control of an injector to be corrected is corrected on the basis of a deviation of the differential value assigned to the injector to be corrected from the average value formed from all differential values.

16. The method according to claim 13 , wherein the step of correcting the control of an injector is only performed if the deviation of the average value exceeds a predetermined threshold value.

17. The method according to claim 16 , wherein at least two iterations of the method are performed, wherein the process is repeated successively for the injectors of the internal combustion engine until the deviation for each of the injectors to be corrected falls below the predetermined threshold value.

18. The method according to claim 1 , wherein the detected transient fuel pressure is detected in an angle synchronous and/or a time synchronous manner.

19. An engine control unit for operating an internal combustion engine, wherein the engine control unit is designed to align an injection behavior of injectors for implementation of a method according to claim 1 .

20. An internal combustion engine, comprising:
a number of cylinders;
a fuel system comprising a fuel collecting chamber, an injector device with a number of injectors, and a fuel feed which fluidly links the fuel collecting chamber and the injector device, so that the fuel from the fuel collecting chamber can be fed to the injector device;
a fuel sensor; and
a system for aligning an injection behavior of the injectors, the system for aligning having an absence of a structure configured for detecting a pressure drop in the fuel collecting chambe

Assignees

• Mtu Friedrichshafen Gmbh
• Rolls Royce Solutions Gmbh

Inventors

• Frank Tobias
• Remele Jörg
• Toth Aron

Classifications

• F02D41/0085

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• F02D2041/288

  for performing a transformation into the frequency domain, e.g. Fourier transformation · CPC title

• F02D41/2438

  Active learning methods · CPC title

• F02D41/3809 Primary

  Common rail control systems (common rail apparatus F02M55/025, F02M63/0225) · CPC title

• F02D41/28

  Interface circuits · CPC title