AVOIDANCE OF A SAFETY FUEL CUT-OFF DURING PARTIAL ENGINE OPERATION

• US 20140366835A1
• Filed: 04/15/2014
• Published: 12/18/2014
• Est. Priority Date: 06/13/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: WALTER, Frank
• Granted Patent: US 9,719,431 B2
• Time in Patent Office: Days
• US Class Current: 123/294
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04
• CPC Class Codes: F02D 2041/0012 with selective deactivation of cylinders
• CPC Class Codes: F02D 2041/227 Limping Home, i.e. taking specific engine control measures at abnormal conditions
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for operating an internal combustion engine that includes at least two cylinders, includes operating the internal combustion engine in a first operating mode in partial engine operation, in which at least one of the cylinders is not fired, monitoring the internal combustion engine during the partial engine operation for potentially torque-increasing errors, and switching over from the partial engine operation into a full engine operation in which all of the cylinders are fired when a potentially torque-increasing error is detected.

Claims

1. A method for operating an internal combustion engine that includes at least two cylinders, the method comprising:

in a first operating mode, operating, by the internal combustion engine, in partial engine operation in which at least one of the at least two cylinders is not fired;

monitoring, by processing circuitry, the internal combustion engine, during the partial engine operation, for a potentially torque-increasing error; and

responsive to a detection in the monitoring step, of the potentially torque-increasing error, switching over, by the processing circuitry, operation of the internal combustion engine from the partial engine operation to a full engine operation in which all of the at least two cylinders are fired.

2. The method of claim 1, further comprising:

in a first determination step, determining whether the potentially torque-increasing error is still present after a switch-over debounce time lapses from a time at which the potentially torque-increasing error was first detected in the monitoring step, wherein the switching over to the full engine operation is only made if the potentially torque-increasing error is detected in the determination step after the switch-over debounce time.

3. The method of claim 2, further comprising:

in a second determination step, determining whether the potentially torque-increasing error is still present after a cut-off debounce time lapses from the time at which the potentially torque-increasing error was first detected in the monitoring step; and

responsive to the potentially torque-increasing error being detected in the second determination step after the cut-off debounce time, activating a safety fuel cut-off.

4. The method of claim 3, wherein the cut-off debounce time is longer than the switch-over debounce time.

5. The method of claim 1, further comprising:

determining whether the potentially torque-increasing error is still present after a cut-off debounce time lapses from the time at which the potentially torque-increasing error was first detected in the monitoring step; and

responsive to the potentially torque-increasing error being detected after the cut-off debounce time, activating a safety fuel cut-off.

6. The method of claim 1, wherein the potentially torque-increasing error is an injection into the at least one cylinder.

7. The method of claim 6, wherein the monitoring includes checking for an injection into each of the at least two cylinders, generating an actual injection suppression mask based on the checking, and comparing the actual injection suppression mask with an expected injection suppression mask, a deviation detected in the comparing step being a detection of the potentially torque-increasing error.

8. The method of claim 1, wherein the potentially torque-increasing error is an ignition of the at least one cylinder.

9. The method of claim 8, wherein the monitoring includes checking for an ignition in each of the at least two cylinders, generating an actual ignition mask based on the checking, and comparing the actual ignition mask with an expected ignition mask, a deviation detected in the comparing step being a detection of the potentially torque-increasing error.

10. A device for operating an internal combustion engine that includes at least two cylinders, the device comprising.

processing circuitry configured to:

control the internal combustion engine to operate in a first operating mode in partial engine operation in which at least one of the at least two cylinders is not fired;

monitor the internal combustion engine, during the partial engine operation, for a potentially torque-increasing error; and

responsive to a detection in the monitoring step, of the potentially torque-increasing error, switch over operation of the internal combustion engine from the partial engine operation to a full engine operation in which all of the at least two cylinders are fired.

11. The device of claim 10, wherein the processing circuitry is further configured to:

in a first determination step, determine whether the potentially torque-increasing error is still present after a switch-over debounce time lapses from a time at which the potentially torque-increasing error was first detected in the monitoring step, wherein the switching over to the full engine operation is only made if the potentially torque-increasing error is detected in the determination step after the switch-over debounce time.

12. The device of claim 11, wherein the processing circuitry is further configured to:

in a second determination step, determine whether the potentially torque-increasing error is still present after a cut-off debounce time lapses from the time at which the potentially torque-increasing error was first detected in the monitoring step; and

responsive to the potentially torque-increasing error being detected in the second determination step after the cut-off debounce time, activate a safety fuel cut-off.

13. The device of claim 12, wherein the cut-off debounce time is longer than the switch-over debounce time.

14. The device of claim 10, wherein the processing circuitry is further configured to:

determine whether the potentially torque-increasing error is still present after a cut-off debounce time lapses from the time at which the potentially torque-increasing error was first detected in the monitoring step; and

responsive to the potentially torque-increasing error being detected after the cut-off debounce time, activate a safety fuel cut-off

15. The device of claim 10, wherein the potentially torque-increasing error is an injection into the at least one cylinder.

16. The device of claim 15, wherein the monitoring includes checking for an injection into each of the at least two cylinders, generating an actual injection suppression mask based on the checking, and comparing the actual injection suppression mask with an expected injection suppression mask, a deviation detected in the comparing step being a detection of the potentially torque-increasing error.

17. The device of claim 10, wherein the potentially torque-increasing error is an ignition of the at least one cylinder.

18. The device of claim 17, wherein the monitoring includes checking for an ignition in each of the at least two cylinders, generating an actual ignition mask based on the checking, and comparing the actual ignition mask with an expected ignition mask, a deviation detected in the comparing step being a detection of the potentially torque-increasing error.

19. A non-transitory computer-readable medium on which are stored instructions executable by a computer processor, the instructions which, when executed by the processor, cause the processor to perform a method for operating an internal combustion engine that includes at least two cylinders, the method comprising.

controlling the internal combustion engine to operate in a first operating mode in partial engine operation in which at least one of the at least two cylinders is not fired;

monitoring the internal combustion engine, during the partial engine operation, for a potentially torque-increasing error; and

responsive to a detection in the monitoring step, of the potentially torque-increasing error, switching over operation of the internal combustion engine from the partial engine operation to a full engine operation in which all of the at least two cylinders are fired.