Method and device for energy-saving leak testing of a fuel tank system, in particular of a motor vehicle

• US 7,043,375 B2
• Filed: 07/10/2001
• Issued: 05/09/2006
• Est. Priority Date: 08/03/2000
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Streib, Martin
• Primary Examiner(s): Nghiem, Michael
• Assistant Examiner(s): Lau, Tung
• Application Number:
  US10/343,655
• Publication Number:
  US 20040030487A1
• Time in Patent Office: 1,764 Days
• Field of Search: 702/51, 702/91, 701/114, 73/49, 737/53, 123/520, 123/142, 961/09, 961/11, 122/156, 340/447
• US Class Current: 702/51
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system
• CPC Class Codes: G01M 3/00 Investigating fluid-tightness of structures
• CPC Class Codes: G01M 3/025 Details with respect to the testing of engines or engine parts
• CPC Class Codes: G01M 3/3236 by monitoring the interior space of the containers

Abstract

In order, in a diagnostic unit for leak testing of a tank system of an internal combustion engine, to allow minimization of the energy consumption during a diagnostics test and simultaneously prevent the emission of fuel gases, a sleep/wake-up mechanism is provided. The diagnostic unit enters a sleep mode for a selected time interval after the internal combustion engine is turned off, the diagnostic unit enters a wake-up mode at the end of the first time interval and at least acquires the measurement data necessary for the diagnostics test in the wake-up mode. The diagnostic unit then enters the sleep mode again during the diagnostics period. The diagnostic unit is switched off at the end of the diagnostics period.

Claims

1. A method of operating a diagnostic unit for leak testing of a tank system of an internal combustion engine, comprising:

acquiring measurement data necessary for leak testing during a diagnostics period after the internal combustion engine is turned off;

setting the diagnostic unit to a sleep mode for a preset first time interval after the internal combustion engine is turned off;

setting the diagnostic unit to a wake-up mode after the first time interval elapses, the diagnostic unit at least acquiring the measurement data in the wake-up mode;

setting the diagnostic unit to the sleep mode again during the diagnostics period; and

switching off the diagnostic unit at an end of the diagnostics period.

2. The method of claim 1, wherein the internal combustion engine is arranged in a motor vehicle.

3. The method of claim 1, further comprising dynamically determining the diagnostics period as a function of an existence of a diagnostic result.

4. The method of claim 1, further comprising setting a length of the first time interval to progress over time.

5. The method of claim 4, wherein the length is set in the length setting step to increase exponentially.

6. The method of claim 1, wherein the diagnostic unit is set to the wake-up mode in the wake-up mode setting step within an at least second time interval and the diagnostic unit acquires at least the measurement data in the acquiring step within the at least second time interval.

7. The method of claim 1, wherein the tank system includes a switchover valve and a filter, the method further comprising:

conducting an excess fuel gas to outside via the filter in a case of overpressure in the tank system;

determining by the diagnostic unit set to the wake-up mode whether a setting of the switchover valve is to be changed; and

if necessary, inducing the change by the diagnostic unit.

8. A device for operating a diagnostic unit for leak testing of a tank system of an internal combustion engine, comprising:

a sensor system configured to acquire measurement data necessary for leak testing;

an arrangement configured to detect a shutoff of the internal combustion engine;

a timer arrangement configured to specify a first time interval; and

a sleep/wake-up arrangement configured to set the diagnostic unit in a sleep mode, during which the diagnostic unit is turned off, and, at the end of the first time interval, in a wake-up mode, in which at least the measurement data is acquired.

9. The device of claim 8, wherein the internal combustion engine is arranged in a motor vehicle.

10. The device of claim 8, wherein the tank system includes a switchover valve and a filter configured to conduct excess fuel gas to outside via the filter in the case of overpressure in the tank system, and wherein the diagnostic unit includes a processor arrangement configured to determine whether a valve setting is to be changed and to induce a change in the valve setting if necessary.

11. A diagnostic unit for leak testing of a tank system of an internal combustion engine, comprising:

a sleep operation mode and a wake-up operation mode, the diagnostic unit configured to perform a method including;

acquiring measurement data necessary for leak testing during a diagnostics period after the internal combustion engine is turned off;

setting the diagnostic unit to the sleep mode for a preset first time interval after the internal combustion engine is turned off;

setting the diagnostic unit to the wake-up mode after the first time interval elapses, the diagnostic unit at least acquiring the measurement data in the wake-up mode;

setting the diagnostic unit to the sleep mode again during the diagnostics period; and

switching off the diagnostic unit at an end of the diagnostics period.

12. The diagnostic unit of claim 11, wherein the internal combustion engine is arranged in a motor vehicle.

13. The diagnostic unit of claim 11, wherein the method further includes dynamically determining the diagnostics period as a function of an existence of a diagnostic result.

14. The diagnostic unit of claim 11, wherein the method further includes setting a length of the first time interval to progress over time.

15. The diagnostic unit of claim 14, wherein the length is set in the length setting step to increase exponentially.

16. The diagnostic unit of claim 11, wherein the diagnostic unit is set to the wake-up mode in the wake-up mode setting step within an at least second time interval and the diagnostic unit acquires at least the measurement data in the acquiring step within the at least second time interval.

17. The diagnostic unit of claim 11, wherein the tank system includes a switchover valve and a filter, the method further including:

conducting an excess fuel gas to outside via the filter in a case of overpressure in the tank system;

determining by the diagnostic unit set to the wake-up mode whether a setting of the switchover valve is to be changed; and

if necessary, inducing the change by the diagnostic unit.

18. The diagnostic unit of claim 11, further comprising:

a timer arrangement configured to specify a first time interval; and

an arrangement configured to make the switch from the sleep operation mode to the wake-up operation mode upon elapse of the first time interval.

19. The diagnostic unit of claim 18, further comprising at least one compare-register configured to record the first time interval.

20. The diagnostic unit of claim 11, further comprising a processor arrangement configured to determine whether a valve setting is to be changed, and to induce a change in the valve setting, if necessary, the tank system including a switchover valve and a filter configured to conduct excess fuel gas to the outside via the filter in a case of overpressure in the tank system.