ENGINE FRICTION BASED OIL VISCOSITY MONITOR

• US 20120303230A1
• Filed: 05/29/2012
• Published: 11/29/2012
• Est. Priority Date: 05/26/2011
• Status: Active Grant

• Current Assignee: Vitesco Technologies USA, LLC (Continental AG)
• Original Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Inventors: Qiao, Ningsheng, Bush, Kevin Joseph
• Granted Patent: US 8,880,276 B2
• Time in Patent Office: Days
• US Class Current: 701/59
• CPC Class Codes: G01N 33/18 Water
• CPC Class Codes: G01N 33/1826 Organic contamination in water
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

A powertrain control module determines engine oil properties based on friction in an engine. The powertrain control module includes an engine combustion module that models engine torque based on engine speed and engine pumping losses due to intake and exhaust gasses. A transmission module models transmission torque applied to the engine based on transmission speed and gear. An accessory loads module models torque applied to the engine by accessory loads including at least one of a power steering pump, an air conditioning compressor, a water pump, and an alternator. An oil viscosity module determines engine oil viscosity based on a friction torque and predetermined engine data that coincides with reference oils. The friction torque is based on the engine torque, transmission torque, and accessory loads torque.

Claims

1. A powertrain control module that determines engine oil properties based on friction in an engine, comprising:

an engine combustion module that models engine torque based on engine speed and engine pumping losses due to intake and exhaust gasses,

a transmission module that models transmission torque applied to the engine based on transmission speed and gear,

an accessory loads module that models torque applied to the engine by accessory loads including at least one of a power steering pump, an air conditioning compressor, a water pump, and an alternator; and

an oil viscosity module that determines engine oil viscosity based on a friction torque and predetermined engine data that coincides with reference oils and wherein the friction torque is based on the engine torque, transmission torque, and accessory loads torque.

2. The powertrain control module of claim 1 further comprising an oil classification module that determines an SAE oil grade based on the engine oil viscosity.

3. The powertrain control module of claim 1 further comprising a viscosity temperature coefficient module that determines at least one of a viscosity index and a viscosity temperature coefficient based on the estimated viscosity and an engine oil temperature.

4. The powertrain control module of claim 1 wherein the oil viscosity module further comprises first and second lookup tables that represent expected friction torques with reference engine oils of a first viscosity and a second viscosity, respectively, at a given engine speed and oil temperature.

5. The powertrain control module of claim 4 wherein the oil viscosity module further comprises third and fourth lookup tables that represent viscosities of the reference engine oils of the first viscosity and the second viscosity, respectively, at a given engine speed and oil temperature.

6. The powertrain control module of claim 6 wherein the oil viscosity module determines a viscosity interpolation factor based on the friction torque and the expected friction torques and calculates the estimated viscosity based on the viscosity interpolation factor and the viscosities of the reference engine oils of the first viscosity and the second viscosity, respectively, at a given engine speed and oil temperature.

7. A method of determining engine oil properties based on friction in an engine, comprising:

modeling engine torque based on engine speed and engine pumping losses due to intake and exhaust gasses,

modeling transmission torque applied to the engine based on transmission speed and gear,

modeling torque applied to the engine by accessory loads including at least one of a power steering pump, an air conditioning compressor, a water pump, and an alternator;

determining engine oil viscosity based on a friction torque and predetermined engine data that coincides with reference oils; and

determining friction torque based on the engine torque, transmission torque, and accessory loads torque.

8. The method of claim 7 further comprising determining an SAE oil grade based on the engine oil viscosity.

9. The method of claim 7 further comprising determining at least one of a viscosity index and a viscosity temperature coefficient based on the estimated viscosity and an engine oil temperature.

10. The method of claim 7 further comprising looking up first and second expected friction torques with reference engine oils of a first viscosity and a second viscosity, respectively, at a given engine speed and oil temperature.

11. The method of claim 10 further comprising generating looking up viscosities of the reference engine oils of the first viscosity and the second viscosity, respectively, at a given engine speed and oil temperature.

12. The method of claim 11 further comprising determining a viscosity interpolation factor based on the friction torque and the expected friction torques and calculating the estimated viscosity based on the viscosity interpolation factor and the viscosities of the reference engine oils of the first viscosity and the second viscosity, respectively, at a given engine speed and oil temperature.

13. A powertrain control module that determines engine oil properties based on friction in an engine, comprising:

engine combustion means for modeling engine torque based on engine speed and engine pumping losses due to intake and exhaust gasses,

transmission means for modeling transmission torque applied to the engine based on transmission speed and gear,

accessory loads means for modeling torque applied to the engine by accessory loads including at least one of a power steering pump means for power steering, air conditioning compressor means for air conditioning, water pump means for pumping coolant, and alternator means for charging a battery; and

oil viscosity means for determining engine oil viscosity based on a friction torque and predetermined engine data that coincides with reference oils and wherein the friction torque is based on the engine torque, transmission torque, and accessory loads torque.

14. The powertrain control module of claim 13 further comprising oil classification means for determining an SAE oil grade based on the engine oil viscosity.

15. The powertrain control module of claim 13 further comprising viscosity temperature coefficient means for determining at least one of a viscosity index and a viscosity temperature coefficient based on the estimated viscosity and an engine oil temperature.

16. The powertrain control module of claim 13 wherein the oil viscosity means further comprises first and second lookup tables that represent expected friction torques with reference engine oils of a first viscosity and a second viscosity, respectively, at a given engine speed and oil temperature.

17. The powertrain control module of claim 16 wherein the oil viscosity means further comprises third and fourth lookup tables that represent viscosities of the reference engine oils of the first viscosity and the second viscosity, respectively, at a given engine speed and oil temperature.

18. The powertrain control module of claim 17 wherein the oil viscosity means determines a viscosity interpolation factor based on the friction torque and the expected friction torques and calculates the estimated viscosity based on the viscosity interpolation factor and the viscosities of the reference engine oils of the first viscosity and the second viscosity, respectively, at a given engine speed and oil temperature.