System and method for determining oil change interval

• US 6,253,601 B1
• Filed: 12/28/1998
• Issued: 07/03/2001
• Est. Priority Date: 12/28/1998
• Status: Expired due to Term

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Wang, Jerry C., Whitacre, Shawn Douglas, Dringenburg, Dean Harlan, Schneider, Matthew L.
• Primary Examiner(s): DOMBROSKE, GEORGE M
• Application Number:
  US09/221,625
• Time in Patent Office: 918 Days
• Field of Search: 73/116, 73/117.2, 73/117.3, 73/118.1, 340/438, 340/439, 701/29, 701/30, 701/31, 701/35
• US Class Current: 73/114.55
• CPC Class Codes: F01M 11/10 Indicating devices; Other safety devices
• CPC Class Codes: F01M 2011/14 for indicating the necessity to change the oil
• CPC Class Codes: F01M 2011/1466 by considering quantity of soot
• CPC Class Codes: F01M 2011/1473 by considering temperature
• CPC Class Codes: F01M 2011/1493 by considering total base number [TBN]

Abstract

A system and method for indicating when the oil of an engine needs to be changed. The system includes measuring engine parameters such as engine temperature, fueling rate, engine speed, and engine load. At timed intervals, soot generation, viscosity increase, and total base number (TBN) depletion are estimated through a calculation for that time interval. The estimated values from the calculations are accumulated in separate loops. Once the accumulation of soot generation, oil viscosity increase, or TBN depletion reaches a predetermined magnitude for that respective oil property, then an indication or signal is provided to indicate to the engine operator that the oil needs changing. The system is supplemented with real time sensors such as an oil level sensor, a soot sensor, and a viscosity sensor which provide a back up for the calculation of estimates and also prevent catastrophic engine conditions from not being detected through electronic calculation of estimates. The system and method also can correct for the accumulation of oil consumption caused by evaporation of oil or leakage of oil. The algorithms used in the calculations can account for oil quality and fuel sulfur as well as the configuration of the engine, to allow the engine to be used in different geographic locations.

Claims

1. A method for determining the remaining life of engine oil in an engine, the engine oil having an oil life being determined by degradation of at least one oil property, wherein the degradation of at least one oil property includes a viscosity increase, comprising:

measuring a plurality of engine parameters;

periodically calculating an estimated viscosity increase based on the plurality of engine parameters;

accumulating the estimated viscosity increase; and

providing an indication when the accumulation of the estimated viscosity increase reaches a predetermined magnitude.

2. The method of claim 1 further comprising the steps of:

arranging at least one real time sensor on the engine in communication with the engine oil;

measuring an actual viscosity with the at least one real time viscosity sensor; and

signaling a display indicator if the actual viscosity has exceeded the predetermined magnitude.

3. The method of claim 2 further comprising the step of overwriting the accumulation of the estimated viscosity increase with the real time viscosity sensor provides a corresponding value that is a preset magnitude greater than the accumulation of estimated viscosity increase.

4. The method of claim 1 further comprising the steps:

arranging an oil level sensor on the engine; and

signaling a display indicator when a catastrophic condition is sensed by the oil level sensor to prevent catastrophic engine conditions from not being detected by the method.

5. The method of claim 1 wherein the step of accumulating includes providing a predetermined remaining permissible viscosity increase and periodically subtracting the estimated viscosity increase from the remaining permissible viscosity increase to compute a current remaining permissible viscosity increase.

6. The method of claim 1 further comprising the step of correcting the accumulation of estimated viscosity increase caused by consumption of oil.

7. The method of claim 1 wherein the step of providing an indication comprises displaying the accumulation on a counter device, a predetermined value on the counter device corresponding to the predetermined magnitude.

8. The method of claim 1 wherein the step of providing an indication comprises signaling a display indicator in response to the accumulation of the estimated viscosity increase reaching the predetermined magnitude.

9. The method of claim 1, wherein the degradation of at least one oil property further includes a total base number depletion, the method further comprising:

periodically calculating an estimated total base number depletion based on the plurality of engine parameters;

accumulating the estimated total base number depletion; and

providing an indication when the accumulation of the estimated total base number depletion reaches a predetermined magnitude.

10. The method of claim 9, further comprising correcting the accumulation of estimated total base number depletion caused by the consumption of oil.

11. The method of claim 1, wherein the degradation of at least one oil property further includes soot concentration, the method further comprising:

periodically calculating an estimated soot concentration based on the plurality of engine parameters;

accumulating the estimated soot concentration; and

providing an indication when the accumulation of the estimated soot concentration reaches a predetermined magnitude.

12. The method of claim 11, further comprising correcting the accumulation of estimated soot concentration caused by the consumption of oil.

13. A method for determining the remaining life of engine oil in an engine, comprising:

measuring a plurality of engine parameters including engine speed, fueling rate, engine load, and engine temperature using a plurality of engine sensors arranged on the engine;

periodically calculating an estimated value of soot generated for a time period between periodic calculations based on the measured engine parameters using an electronic controller;

accumulating the estimated values of soot;

periodically calculating an estimated depletion of total base number for a time period between periodic calculations based on the measured engine parameters;

accumulating the estimated depletions of total base number;

periodically calculating an increase in oil viscosity a time period between periodic calculations based on the measured engine parameters;

accumulating the estimated increases in oil viscosity;

correlating the accumulations of the estimated values of soot, of the estimated depletions of total base number, and of the estimated increases viscosity to an oil life value representing the remaining life of engine oil;

providing an indication when the oil life value reaches a predetermined magnitude.

14. The method of claim 13 further comprising the steps of:

arranging at least one real time sensor on the engine in communication with the engine oil;

measuring at least one real time condition with the at least one real time sensor, the at least one real time condition being selected from the group consisting of soot contamination and viscosity; and

signaling an indicator if the actual oil condition has a predetermined magnitude.

15. The method of claim 14 further comprising the step of overwriting the accumulation of at least one selected from the group consisting of viscosity increase and soot generation, when the at least one real time sensor senses a corresponding value that is a preset magnitude greater than a current value of the accumulation.

16. The method of claim 13 further comprising the steps:

arranging an oil level sensor on the engine; and

signaling a display indicator when a catastrophic condition is sensed by the oil level sensor to prevent catastrophic engine conditions from not being detected by said method.

17. The method of claim 13 wherein the step of providing an indication comprises displaying the value on a counter device, a predetermined value on the counter device corresponding to the predetermined magnitude.

18. The method of claim 13 wherein the step of providing an indication comprises signaling a display indicator in response to the value reaching the predetermined magnitude.

19. The method of claim 13 further comprising the steps of:

determining consumption of oil caused by evaporation of oil and leakage of oil; and

correcting the accumulations of the estimated depletions of total base number, the estimated increases in oil viscosity, and the estimated quantities of soot based on the determined consumption of oil.

20. The method of claim 13 wherein the calculation of soot quantity is a function of engine speed and engine load, the calculation of total base number depletion is a function of fueling rate, and the calculation of viscosity increase is a function of engine temperature and fueling rate.

21. The method of claim 20 further comprising the step of using equations in said calculations, the equations including constants that account for an oil type, a fuel sulfur bevel, and a controlled parts lists, the constants being adjustable to allow the engine to be used in different geographic locations.

22. A oil indicator system for determining the remaining life of engine oil in an engine based upon at least one oil property including soot concentration, viscosity increase and total base number depletion, the system comprising:

a plurality of engine sensors arranged on the engine for sensing a plurality of engine parameters;

an electronic controller in electrical communication with the engine sensors, the electronic controller periodically calculating an estimated soot concentration, viscosity increase and total base number depletion of the oil, based on the sensed engine parameters;

means for respectively accumulating the estimated soot concentration, viscosity increase and total base number depletion; and

means for indicating when the respective accumulation of any of the estimated soot concentration, viscosity increase or total base number depletion reaches a respective predetermined magnitude.

23. The oil indicator system of claim 22 further comprising a viscosity sensor arranged on the engine in communication with the engine oil, the viscosity sensor electrically communicating with the electronic controller, the at least one viscosity sensor measuring an actual viscosity of the oil, the indicating means being signaled if the actual viscosity reaches a predetermined magnitude.

24. The oil indicator system of claim 22 further comprising an oil level sensor arranged on the engine in communication with the engine oil, the oil level sensor in electrical communication with the electronic controller, the electronic controller signaling the indicating means when the oil level sensor senses a catastrophic oil condition, the indicating means providing an indication of the catastrophic oil condition.

25. The oil indicator system of claim 22 further comprising means for resetting the respective accumulation of each of the estimated soot concentration, viscosity increase and total base number depletion to a starting magnitude.

26. The oil indicator system of claim 22 wherein the accumulating means and indicating means are provided integrally in a counter device.

27. The oil indicator system of claim 22 wherein the accumulating means is part of the electronic controller.

28. The oil indicator system of claim 22 wherein the electronic controller has an input connectable to receive fixed data about controlled parts list, fuel sulfur and oil quality.

29. The oil indicator system of claim 22 further comprising a soot sensor arranged on the engine in communication with the engine oil, the soot sensor electrically communicating with the electronic controller, the soot sensor measuring an actual soot concentration of the oil, the indicating means being signaled if the actual viscosity reaches a predetermined magnitude.

30. A method for determining the remaining life of engine oil in an engine, the engine oil having an oil life being determined by degradation of at least one oil property, wherein the degradation of at least one oil property includes a total base number depletion, the method comprising:

measuring a plurality of engine parameters;

periodically calculating an estimated total base number depletion based on the plurality of engine parameters;

accumulating the estimated total base number depletion; and

providing an indication when the accumulation of the estimated total base number depletion reaches a predetermined magnitude.

31. The method of claim 30 further comprising the steps:

arranging an oil level sensor on the engine; and

signaling a display indicator when a catastrophic condition is sensed by the oil level sensor to prevent catastrophic engine conditions from not being detected by the method.

32. The method of claim 30 wherein the step of accumulating includes providing a predetermined remaining permissible total base number depletion and periodically subtracting the estimated total base number depletion from the remaining permissible total base number depletion to compute a current remaining permissible total base number depletion.

33. The method of claim 30 further comprising the step of correcting the accumulation of estimated total base number depletion caused by consumption of oil.

34. The method of claim 30, wherein the at least one oil property further includes viscosity increase, the method further comprising:

periodically calculating an estimated viscosity increase based on the plurality of engine parameters;

accumulating the estimated viscosity increase; and

providing an indication when the accumulation of the estimated viscosity increase reaches a predetermined magnitude.

35. The method of claim 34 further comprising correcting the accumulation of estimated viscosity increase caused by consumption of oil.

36. The method of claim 34 further comprising the steps of:

arranging at least one real time viscosity sensor on the engine in communication with the engine oil;

measuring an actual viscosity increase with the at least one real time viscosity sensor; and

signaling a display indicator if the actual viscosity increase has the predetermined magnitude.

37. The method of claim 36 further comprising the step of overwriting the accumulation of the estimated viscosity increase with the actual viscosity increase if the real time viscosity sensor provides a corresponding value that is a preset magnitude greater than the accumulation of estimated viscosity increase.

38. The method of claim 30, wherein the at least one oil property further includes soot contamination, the method further comprising:

periodically calculating an estimated soot concentration based on the plurality of engine parameters;

accumulating the estimated soot concentration; and

providing an indication when the accumulation of the estimated soot concentration reaches a predetermined magnitude.

39. The method of claim 38 further comprising the steps of:

arranging at least one real time soot sensor on the engine in communication with the engine oil;

measuring an actual soot concentration with the at least one real time soot concentration sensor; and

signaling a display indicator if the actual soot concentration has the predetermined magnitude.

40. The method of claim 39 further comprising the step of overwriting the accumulation of the estimated soot concentration with the actual soot concentration if the real time soot sensor provides a corresponding value that is a preset magnitude greater than the accumulation of estimated soot concentration.

41. The method of claim 34 further comprising correcting the accumulation of estimated soot concentration caused by consumption of oil.

42. An oil indicator system for determining the remaining life of engine oil in an engine according to at least one oil property, the at least one property including an increase of viscosity in the oil, the system comprising:

a plurality of engine sensors arranged on the engine for sensing a plurality of engine parameters;

an electronic controller in electrical communication with the engine sensors, the electronic controller periodically calculating an estimated viscosity increase based on the sensed engine parameters;

means for accumulating the estimated viscosity increase; and

means for indicating when the accumulation of the estimated viscosity increase reaches a predetermined magnitude.

43. The oil indicator system according to claim 42, wherein at least one property further includes a total base number depletion, wherein the electronic controller periodically calculates an estimated total base number depletion based upon the sensed engine parameters;

the system further comprising means for accumulating the estimated total base number depletion and means for indicating when the accumulation of the estimated total base number depletion reaches a predetermined magnitude.

44. An oil indicator system for determining the remaining life of engine oil in an engine according to at least one oil property, the at least one property including a total base number depletion, the system comprising:

a plurality of engine sensors arranged on the engine for sensing a plurality of engine parameters;

an electronic controller in electrical communication with the engine sensors, the electronic controller periodically calculating an estimated total base number depletion based on the sensed engine parameters;

means for accumulating the estimated total base number depletion; and

means for indicating when the accumulation of the estimated total base number depletion reaches a predetermined magnitude.