Method and device for controlling an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9874171-B2
Application number	US-201113300777-A
Country	US
Kind code	B2
Filing date	Nov 21, 2011
Priority date	Nov 19, 2010
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A method for diagnosing a malfunction of a sensor system in an air system of an internal combustion engine, said sensor system comprising a first air state sensor, a second air state sensor and a third air state sensor, wherein a first value and a second value of a first comparison variable are ascertained in two different ways in an overall calculation step such that the result of a comparison between the first value and the second value is a function of each of the output variables of the first, second and third air state sensors and wherein in a fault detection step, said method recognizes as a function of the comparison between said first value and said second value of the comparison variable that a fault exists in the sensor system.

First claim

The invention claimed is:

1. A method for diagnosing a malfunction of an air-state sensor system in an air system of an internal combustion engine, said sensor system comprising a first air state sensor, a second air state sensor and a third air state sensor, wherein a first value and a second value of a first comparison variable, which characterizes a state of the air system, are ascertained in two different ways in an overall calculation step ( 1001 ) such that the result of a comparison between the first value and the second value is a function of each of the output variables of the first, second and third air state sensors and wherein in a fault detection step ( 1002 ), said method determines as a function of the comparison between the first value and the second value of the first comparison variable that a fault exists in one of the first, second and third air state sensors of said air-state sensor system.

2. The method according to claim 1 , characterized in that the first comparison variable is stated in terms of a mass flow (mEGR) across an exhaust gas recirculation valve ( 110 ).

3. The method according to claim 1 , characterized in that the first comparison variable is stated in terms of an exhaust gas back pressure (p 3 ).

4. The method according to claim 1 , characterized in that
a third value and a fourth value of a second comparison variable, which characterizes the state of the air system, are ascertained in two different ways in a second calculation step ( 1003 ),
the result of a comparison between the third value and the fourth value is a function of the output variables of the first air state sensor and the second air state sensor and is independent of the output variable of the third air state sensor, and
in a second fault detection step ( 1004 ), a conclusion is drawn as a function of the comparison of the third value and the fourth value of the second comparison variable that the third air state sensor is defective.

5. The method according to claim 1 , characterized in that a first means controlling a first air flow is actuated to close in a separation step ( 1040 , 1090 ) and therefore divides the air system into a first region, in which two of the three air state sensors lie, and a second region, in which the remaining sensor of the three air state sensors lies; thus enabling the result of the comparison between the third value and the fourth value to be a function of the output variables of the first and second air state sensor and to be independent of the output variable of the third air state sensor.

6. The method according to claim 5 , characterized in that the second comparison variable is stated in terms of a mass flow (mEGR) across an exhaust gas recirculation valve ( 110 ).

7. The method according to claim 5 , characterized in that the second comparison variable is stated in terms of an exhaust gas back pressure (p 3 ).

8. The method according to claim 5 , characterized in that the second comparison variable is stated in terms of an air charge (m 22 ) per unit of time to combustion chambers ( 80 ) of an internal combustion engine.

9. The method according to claim 1 , characterized in that
a fifth and a sixth value of a third comparison variable, which characterizes the state of the air system, are ascertained in two different ways in a third calculation step ( 1005 ) such that the result of a comparison between the fifth and the sixth value is a function of the output variables of the second air state sensor and the third air state sensor and independent of the output variable of the first air state sensor, and
in a third fault detection step ( 1006 ), a conclusion is drawn as a function of the comparison of the fifth value and the sixth value of the third comparison variable that the first air state sensor is defective.

10. The method according to claim 9 , characterized in that a second means controlling a second air flow is actuated to close in a second separation step ( 1040 , 1090 ) and therefore divides the air system into a third region, in which two air state sensors lie, and a fourth region, in which the remaining sensor of the three air state sensors lies, thus enabling the result of the comparison between the fifth value and the sixth value to be a function of the output variables of the second and third air state sensor and to be independent of the output variable of the first air state sensor.

11. The method according to claim 9 , characterized in that the third comparison value is stated in terms of a mass flow (mEGR) across an exhaust gas recirculation valve ( 110 ).

12. The method according to claim 9 , characterized in that the third comparison value is stated in terms of an exhaust gas back pressure (p 3 ).

13. The method according to claim 9 , characterized in that the third comparison value is stated in terms of an air charge (m 22 ) per unit of time to combustion chambers ( 80 ) of the internal combustion engine.

14. The method according to claim 1 , characterized in that the first air state sensor, the second air state sensor and the third air state sensor correspond in each case to one of the following sensors:
an air mass flow meter
a boost pressure sensor
an exhaust gas back pressure sensor.

15. A computer program, characterized in that it is programmed for use in a method according to claim 1 .

16. An electrical storage medium for a control and/or regulating device of an internal combustion engine, characterized in that a computer program for use in a method according to claim 1 is stored thereon.

17. A control and/or regulating device of an internal combustion engine, characterized in that said device is programmed for use in a method according to claim 1 .

Assignees

• Bleile Thomas
• Blumendeller Wilhelm
• Kuhn Daniel
• Reichel Julian
• Bosch Gmbh Robert

Inventors

• Bleile Thomas
• Blumendeller Wilhelm
• Kuhn Daniel
• Reichel Julian

Classifications

• F02D41/0072

  Estimating, calculating or determining the EGR rate, amount or flow (sensors in EGR systems F02M26/45) · CPC title

• F02D2200/0406

  Intake manifold pressure · CPC title

• F02D41/0007

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D41/1448

  the characteristics being an exhaust gas pressure · CPC title

• Y02T10/40

  Engine management systems · CPC title