Duty cycle monitoring system for an engine

• US 6,601,442 B1
• Filed: 09/20/1999
• Issued: 08/05/2003
• Est. Priority Date: 09/20/1999
• Status: Expired due to Term

• Current Assignee: Cummins Engine Company Incorporated (Cummins Incorporated)
• Original Assignee: Cummins Incorporated
• Inventors: Irons, John M., Greathouse, Gregory G., Decker, Scott G.
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): STEVENS, MAURICE E
• Application Number:
  US09/400,666
• Time in Patent Office: 1,415 Days
• Field of Search: 731/173, 731/181, 701/35, 701/114, 701/115, 340/462, 123/468, 123/480, 123/488
• US Class Current: 73/114.15
• CPC Class Codes: F02D 41/2451 characterised by what is learned or calibrated
• CPC Class Codes: F02D 41/263 the program execution being modifiable by physical parameters
• CPC Class Codes: G07C 5/085 using electronic data carriers

Abstract

A system and method for monitoring engine performance utilizes a monitoring micro-controller that integrates with an engine/vehicle controller to receive data indicative of the current operating conditions of the engine/vehicle. A duty cycle map is defined within the micro-controller by a plurality of sectors bounded by a specific performance curve based on two or more engine operating parameters, such as engine torque and speed. Each sector corresponds to a range of values for the specific operating parameters. During iterations of the monitoring routine, current data indicative of the specific engine operating parameters is sensed and compared with the range of values for each duty cycle sector. A duty cycle parameter, such as elapsed time or fuel consumption, is maintained for each sector. When the current engine operating conditions fall within a particular target sector, its corresponding duty cycle parameter is updated. This process is continued over several iterations to define a duty cycle map over a predetermined number of engine operating hours. In one embodiment, a long term map is accumulated between engine rebuilds, for example. In another embodiment, the long term duty cycle map is augmented by sequentially accessed short term maps, each storing duty cycle information for much shorter engine hours. The duty cycle maps can be used to evaluate engine maintenance requirements or suggest modifications to engine control routines and fueling strategies.

Claims

1. A method for monitoring engine performance comprising the steps of:

defining an engine performance curve as a function of two or more engine operating parameters;

defining in memory a plurality of sectors bounded by the performance curve, each sector corresponding to a range of values for the two or more engine operating parameters;

during operation of the engine, sensing current data indicative of the two or more engine operating parameters;

comparing the current data to each of the ranges of values for the two or more engine operating parameters to determine a target sector, the target sector corresponding to one of the plurality of sectors that includes the current data;

updating in said memory a duty cycle parameter different from the two or more engine operating parameters unique to the target sector; and

repeating the sensing, comparing and updating steps for a predetermined number of iterations to generate a duty cycle map for the engine, the duty cycle map indicative of cumulative engine operating time spent in each of said plurality of sectors.

2. The method for monitoring engine performance according to claim 1, wherein the duty cycle parameter is the amount of time that the current data for each iteration falls within the corresponding target sector.

3. The method for monitoring engine performance according to claim 2, wherein each iteration occurs over a predetermined time interval, and the step of updating the duty cycle parameter includes incrementing the amount of time by the predetermined time interval.

4. The method for monitoring engine performance according to claim 1, wherein the duty cycle parameter is the amount of fuel consumed by the engine when the current data for each iteration falls within the corresponding target sector.

5. The method for monitoring engine performance according to claim 4, including the step of storing the current amount of fuel consumed and a time and/or date stamp associated therewith.

6. The method for monitoring engine performance according to claim 1, wherein the two or more engine operating parameters includes actual engine speed and actual engine torque.

7. The method for monitoring engine performance according to claim 1, in which the engine includes an engine control module, wherein:

the steps of comparing the current data and updating a duty cycle parameter occur in a monitoring module independent of the engine control module; and

the step of sensing includes receiving the current data from the engine control module.

8. The method for monitoring engine performance according to claim 1, further comprising the steps of:

obtaining current engine performance data; and

when updating the duty cycle parameter, storing the current engine performance data in a memory associated with the target sector.

9. The method for monitoring engine performance according to claim 8, further comprising the steps of:

calculating additional engine performance information using the current engine performance data; and

storing the additional engine performance information in a memory.

10. The method for monitoring engine performance according to claim 9, including the step of storing a time and/or date stamp with the additional engine performance information.

11. The method for monitoring engine performance according to claim 9, wherein the additional engine performance information includes the engine load factor.

12. The method for monitoring engine performance according to claim 11, comprising the additional step of calculating an engine load factor corresponding to each sector of the duty cycle map.

13. The method for monitoring engine performance according to claim 11, including the step of storing a time and/or date stamp with the additional engine performance information.

14. The method for monitoring engine performance according to claim 1, further comprising the step of displaying a visual representation of the duty cycle map after the predetermined number of iterations.

15. The method for monitoring engine performance according to claim 1, wherein the step of updating a duty cycle parameter includes concurrently updating the parameter for the predetermined number of iterations to generate a long-term duty cycle map and updating the parameter for a significantly fewer predetermined number of iterations to generate a short-term duty cycle map.

16. A system for monitoring performance of an engine controlled by an engine control module, the engine control module operable to generate a plurality of sensor signals indicative of current performance of the engine, the system comprising:

a monitoring device;

a data link between said monitoring device and the engine control module to convey a plurality of sensor signals therebetween;

a memory associated with said monitoring device;

a micro-controller associated with said monitoring device and operable to;

define an engine performance curve as a function of two or more engine operating parameters;

define in said memory a plurality of sectors bounded by said performance curve, each sector corresponding to a range of values for said two or more engine operating parameters;

over a predetermined number of iterations, read current values of selected ones of said plurality of sensor signals indicative of said two or more engine operating parameters;

at each of said predetermined number of iterations, compare said current values to said range of values to determine a target sector of said plurality of sectors that said current data falls within; and

at each of said predetermined number of iterations, update a duty cycle parameter stored in a location within said memory unique to said target sector, said duty cycle parameter different from said two or more engine operating parameters,

whereby said duty cycle parameter for each of said plurality of sectors defines a duty cycle map for the engine, the duty cycle map indicative of cumulative engine operating time spent in each of said plurality of sectors.

17. The system for monitoring the performance of an engine according to claim 16, wherein said two or more engine operating parameters includes current engine torque and current engine speed.

18. The system for monitoring the performance of an engine according to claim 16, wherein said duty cycle parameter is the amount of time that said current data for each of said iterations falls within said target sector.

19. The system for monitoring the performance of an engine according to claim 16, wherein said duty cycle parameter is the amount of fuel consumed by the engine when said current data for each of said iterations falls within said target sector.