Hot shutdown monitor for internal combustion engines

• US 6,055,470 A
• Filed: 05/29/1998
• Issued: 04/25/2000
• Est. Priority Date: 05/29/1998
• Status: Expired due to Term

• Current Assignee: Cummins Engine Company Incorporated (Cummins Incorporated)
• Original Assignee: Cummins Incorporated
• Inventors: Venable, David A., Baraban, Dmitri, Londot, Ronnie D.
• Primary Examiner(s): DOMBROSKE, GEORGE M
• Application Number:
  US09/087,252
• Time in Patent Office: 697 Days
• Field of Search: 701/112, 701/107, 701/101, 701/102, 701/26, 701/35, 701/34, 701/31, 73/116, 73/117.2, 73/117.3, 73/118.1
• US Class Current: 701/35
• CPC Class Codes: G01M 15/042 by monitoring a single specific parameter not covered by groups G01M15/06 - G01M15/12
• CPC Class Codes: G07C 3/00 Registering or indicating the condition or the working of machines or other apparatus, other than vehicles

Abstract

The present invention relates to a hot shutdown monitor for an internal combustion engine, in which the engine control module (ECM) obtains engine operating information from various sensors and calculates an instantaneous load factor of the engine based upon various factors such as engine speed, engine fueling, exhaust manifold temperature, oil temperature, etc. This instantaneous load factor is preferably heavily filtered with the output of the filter determining a cumulative weighted load factor that represents a condition of the engine (i.e. the heating and cooling of the engine components). The present invention monitors for a shutdown request both from the operator (i.e. ignition keyoff or from other ECM control algorithms (i.e. engine protection). When an engine shutdown is detected, the weighted load factor is compared to a predetermined threshold. If the threshold is exceeded, a fault indicator is set within the ECM and the current engine data is captured for later retrieval. The filter constant and weighted load factor shutdown threshold may be predetermined based upon the particular engine performance requirements. Other embodiments of the present invention are also disclosed.

Claims

1. A method for monitoring and recording hot shutdowns of an internal combustion engine, comprising the steps of:

a) determining a load factor of the engine;

b) determining if said load factor exceeds a predetermined threshold; and

c) recording a hot shutdown error if said load factor exceeds the predetermined threshold.

2. The method of claim 1, wherein step (a) comprises determining an instantaneous load factor of the engine.

3. The method of claim 1, wherein step (a) comprises:

a.1) determining an instantaneous load factor of the engine at successive instants of time; and

a.2) determining said load factor of the engine based upon a plurality of said instantaneous load factors.

4. The method of claim 3 wherein step (a.1) further comprises determining said instantaneous load factor at periodic instants of time.

5. The method of claim 3, wherein step (a.2) further comprises determining said load factor by filtering a plurality of said instantaneous load factors.

6. The method of claim 5, wherein said filtering comprises first order digital filtering.

7. The method of claim 3, wherein the instantaneous load factor is calculated from a speed of the engine, a fueling condition of the engine, an exhaust manifold temperature of the engine, and an oil temperature of the engine.

8. The method of claim 1, wherein step (c) further comprises:

c.1) determining if an operator of the engine has commanded a shutdown of the engine; and

c.2) recording a hot shutdown keyoff error if said load factor exceeded the predetermined threshold and the operator commanded a shutdown of the engine.

9. The method of claim 1, wherein step (c) further comprises:

c.1) determining if an engine control module has commanded a shutdown of the engine; and

c.2) recording a hot shutdown feature error if said load factor exceeded the predetermined threshold and the engine control module commanded a shutdown of the engine.

10. A method for monitoring and recording hot shutdowns of an internal combustion engine, comprising the steps of:

a) determining a load factor of the engine at successive instants of time;

b) recording each said load factor;

c) determining if the engine has been commanded to shut down;

d) if the engine has been commanded to shut down, determining a respective time delay since each said recorded load factor;

e) for each said recorded load factor, retrieving a predetermined time period threshold value chosen particularly for each value of recorded load factor;

f) determining if each said time delay is greater than each said respective predetermined time period threshold; and

g) recording a hot shutdown error if any said time delay is not greater than said respective predetermined time period threshold.

11. The method of claim 10, wherein step (a) comprises determining an instantaneous load factor of the engine.

12. The method of claim 10, wherein step (a) comprises:

a.1) determining an instantaneous load factor of the engine at successive instants of time; and

a.2) determning said load factor of the engine based upon a plurality of said instantaneous load factors.

13. The method of claim 12, wherein step (a.1) further comprises determining said instantaneous load factor at periodic instants of time.

14. The method of claim 12, wherein step (a.2) further comprises determining said load factor by filtering a plurality of said instantaneous load factors.

15. The method of claim 14, wherein said filtering comprises first order digital filtering.

16. The method of claim 12, wherein the instantaneous load factor is calculated from a speed of the engine, a fueling condition of the engine, an exhaust manifold temperature of the engine, and an oil temperature of the engine.

17. A method for monitoring and recording hot shutdowns of an internal combustion engine, comprising the steps of:

a) determining an instantaneous load factor of the engine at successive instants of time;

b) determining a weighted load factor based upon a plurality of said instantaneous load factors;

c) determining if said weighted load factor exceeds a predetermined threshold;

d) determining if an operator of the engine has commanded a shutdown of the engine;

e) recording a hot shutdown keyoff error if said weighted load factor exceeded said predetermined threshold and the operator commanded a shutdown of the engine;

f) determining if an engine control module has commanded a shutdown of the engine; and

g) recording a hot shutdown feature error if said weighted load factor exceeded said predetermined threshold and the engine control module commanded a shutdown of the engine.

18. The method of claim 17, wherein step (a) further comprises determining said instantaneous load factor at periodic instants of time.

19. The method of claim 17, wherein step (b) further comprises determining said weighted load factor by filtering a plurality of said instantaneous load factors.

20. The method of claim 19, wherein said filtering comprises first order digital filtering.

21. The method of claim 17, wherein the instantaneous load factor is calculated from a speed of the engine, a fueling condition of the engine, an exhaust manifold temperature of the engine, and an oil temperature of the engine.