Device and Method for Controlling an Internal Combustion Engine of a Motor Vehicle

• US 20100012085A1
• Filed: 08/14/2009
• Published: 01/21/2010
• Est. Priority Date: 03/10/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: ALBRECHT, Marc
• Granted Patent: US 7,788,021 B2
• Time in Patent Office: Days
• US Class Current: 123/350
• CPC Class Codes: F02D 31/009 for maximum speed control
• 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 device for controlling an internal combustion engine of a motor vehicle, including a control unit for monitoring and limiting the rotational speed of the internal combustion engine that are designed in such a manner that after a predetermined first speed threshold an integral formation of the current present values over time occurs, and that, on reaching a predetermined integral limit value, the rotational speed is automatically limited.

Claims

1. Device for controlling an internal combustion engine of a motor vehicle, comprising:

a control unit that monitors and limits the rotational speed of the internal combustion engine, wherein

after a predetermined first speed threshold at least one of an integral formation of speed values and an integral formation of the speed values, correlating to the speed values, over time occurs for the duration of time, during which the speed threshold is exceeded, and

on reaching a predetermined integral limit value, the rotational speed is automatically limited.

2. Device, as claimed in claim 1, wherein the speed threshold is dimensioned in terms of amount so as to be greater than the idle speed of the internal combustion engine.

3. Device, as claimed in claim 1, wherein the speed threshold is dimensioned in terms of amount so as to be less than the cut-off speed of the internal combustion engine.

4. Device, as claimed in claim 1, wherein the speed threshold is dimensioned so as to be variable.

5. Device, as claimed in claim 4, wherein the speed threshold is variable as a function of at least one of the vehicle speed and the gear stage.

6. Device, as claimed in claim 1, further comprising:

a monitoring unit that monitors the state of the vehicle to determine whether the vehicle is currently stationary,

wherein the rotational speed is monitored by the control unit only during the stationary phase of the vehicle.

7. Device, as claimed in claim 1, wherein

different speed ranges above the speed threshold are weighted differently, in such a manner that higher speeds result in a steeper rise in the integral value than lower speeds.

16. Device, as claimed in claim 2, wherein the speed threshold is dimensioned in terms of amount so as to be less than the cut-off speed of the internal combustion engine.

17. Device, as claimed in claim 2, wherein the speed threshold is dimensioned so as to be variable.

18. Device, as claimed in claim 2, further comprising:

a monitoring unit that monitors the state of the vehicle to determine whether the vehicle is currently stationary,

wherein the rotational speed is monitored by the control unit only during the stationary phase of the vehicle.

8. Method for controlling an internal combustion engine of a motor vehicle, comprising the acts of:

monitoring the rotational speed of the internal combustion engine in relation to a predetermined first speed threshold, wherein

at least one of an integral formation of the present speed values and an integral formation of values, correlating to the speed values, over time occurs for the duration of time, during which the speed threshold is exceeded; and

limiting the rotational speed to a predetermined speed limit value in such a manner that on reaching a predetermined integral limit value, the rotational speed is automatically limited to the predetermined speed limit value.

9. Method, as claimed in claim 8, wherein the predetermined speed limit value is approached in the form of a ramp within a predetermined, variable period of time.

10. Method, as claimed in claim 8, wherein on reaching or exceeding a predetermined integral value that is less than the predetermined integral limit value, a warning signal, which can be perceived by the driver, is generated.

11. Method, as claimed in claim 8, wherein the current integral value is decremented by a first predetermined value, when a signal change-over of the ignition ON/OFF signal is detected.

12. Method, as claimed in claim 8, wherein the current integral value is decremented by a second predetermined value, as a function of an operating parameter that correlates to the temperature of the internal combustion engine.

13. Method, as claimed in claim 8, wherein the current integral value is decremented by a third predetermined value, when the overshooting of a predetermined vehicle speed is detected.

14. Method, as claimed in claim 8, wherein the monitored speed threshold is varied as a function of at least one of the engaged gear stage and the vehicle speed.

15. Method, as claimed in claim 8, wherein the method is carried out only in the presence of a vehicle in the stationary phase with an interrupted force closure between the internal combustion engine and the drive wheels.

19. Method, as claimed in claim 9, wherein on reaching or exceeding a predetermined integral value that is less than the predetermined integral limit value, a warning signal, which can be perceived by the driver, is generated.

20. Method, as claimed in claim 9, wherein the current integral value is decremented by a first predetermined value, when a signal change-over of the ignition ON/OFF signal is detected.