DYNAMICALLY VARYING AN AMOUNT OF SLIPPAGE OF A TORQUE CONVERTER CLUTCH PROVIDED BETWEEN AN ENGINE AND A TRANSMISSION OF A VEHICLE

• US 20170370301A1
• Filed: 08/21/2017
• Published: 12/28/2017
• Est. Priority Date: 05/06/2016
• Status: Active Grant

• Current Assignee: Tula Technology, Incorporated
• Original Assignee: Tula Technology, Incorporated
• Inventors: SRINIVASAN, Vijay
• Granted Patent: US 10,100,754 B2
• Time in Patent Office: Days
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04
• CPC Class Codes: F02D 2200/021 Engine temperature
• CPC Class Codes: F02D 2200/025 Engine noise, e.g. determined by using an acoustic sensor
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 2200/702 Road conditions
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/0225 in relation with the gear ratio or shift lever position
• CPC Class Codes: F02D 41/047 Taking into account fuel evaporation or wall wetting; special correction after fuel cut-off F02D41/126
• CPC Class Codes: F02D 41/1406 with use of a optimisation method, e.g. iteration
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables
• CPC Class Codes: F02P 5/1512 with particular means concerning an individual cylinder
• CPC Class Codes: F02P 9/002 Control of spark intensity, intensifying, lengthening, suppression by means of current control in the storage devices F02P3/05, F02P3/09, during starting F02P15/12

Abstract

A system and method for dynamically varying an amount slippage of a Torque Converter Clutch (TCC) provided between an engine and a transmission of a vehicle in response to non-powertrain factors. By varying a slippage output signal, the amount of TCC slippage between the engine and the transmission can be adjusted. Small amounts of slippage, relative to large amounts of slippage, provide (a) improved vehicle fuel economy, but (b) induce more powertrain noise and vibration in the vehicle cabin. By dynamically adjusting the slippage, a tradeoff between improved fuel economy vs. a satisfying driver experience can be realized.

Claims

1. A system for dynamically varying an amount of slippage of a Torque Converter Clutch (TCC) provided between an engine and a transmission input shaft of a vehicle, the system comprising:

a controller for varying a slippage output signal applied to the TCC in order to vary the amount of slippage between the engine rotation rate and the transmission input shaft, the amount of slippage varying based on one or more non-powertrain factors.

2. The system of claim 1, wherein the one or more non-powertrain factors are selected from the group consisting of non-powertrain noise and vibration sources, ambient temperature, and driver preferences regarding NVH and fuel economy trade-offs.

3. The system of claim 1, wherein the non-powertrain factors are selected from the group consisting of:

(a) road surface smoothness/roughness;

(b) noise level in the cabin of the vehicle;

(c) volume level of radio or entertainment system in the vehicle;

(d) open or closed windows or sunroof in the cabin of the vehicle;

(e) type of tires used on the vehicle;

(f) weather conditions, including but not limited to precipitation, rain, snow, hail, wind, or a lack thereof; and

(g) ambient temperature.

4. The system of claim 3, wherein the road surface smoothness/roughness is determined by a vehicle mounted sensor.

5. The system of claim 1, wherein the amount of slippage is determined using a look-up table.

6. The system of claim 1, wherein the amount of slippage is determined using an algorithm.

7. The system of claim 1, wherein the amount of slippage varies between 0 and 100 RPM.

8. The system of claim 1, wherein the controller is further configured to receive a base slippage value for a measured torque request, firing fraction, transmission gear, and speed of the engine.

9. The system of claim 1, wherein the controller is further configured to generate the slippage output signal applied to the TCC in response to (a) a base slippage value for a torque request, firing fraction, gear and speed of the engine and (b) one or more signals indicative of the magnitude of non-powertrain noise and/or vibration in a cabin of the vehicle.

10. The system of claim 1, wherein the controller is further configured to either:

(a) reduce the slippage of the TCC, improving fuel economy at the expense of increased powertrain noise and vibration;

or

(b) increase slippage of the TCC, decreasing powertrain noise and vibration at the expense of worse fuel economy.

11. The system of claim 1, wherein the controller is further configured to operate in cooperation with an economy mode of the vehicle, the controller decreasing the slippage of the TCC to improve fuel economy when the vehicle is operating in the economy mode.

12. The system of claim 1, wherein the controller is further configured to operate in parallel with a skip fire engine controller arranged to manage firing of cylinders of the engine in a skip fire manner.

13. The system of claim 1, wherein the engine is either a variable displacement engine or a fixed displacement engine.

14. A method comprising dynamically varying slippage of a Torque Converter Clutch (TCC) provided between an engine and a transmission of a vehicle depending on varying conditions as defined by one or more non-powertrain factors, the slippage adjusted to tradeoff improve fuel economy of the vehicle at the expense of an increase of powertrain noise and vibration experienced in a cabin of the vehicle.

15. The method of claim 14, wherein the one or more non-powertrain factors are selected from the group consisting of non-powertrain noise and vibration sources, ambient temperature, and driver preferences regarding noise, vibration and harshness versus fuel economy.

16. The method of claim 14, wherein dynamically varying slippage of the TCC depending on varying conditions as defined by the one or more non-powertrain factors further comprises:

receiving signals indicative of non-powertrain sources of noise and vibration;

estimating a base powertrain level of noise and vibration; and

dynamically varying the slippage of the TCC based on a comparison of the non-powertrain sources of noise and vibration and the estimated base powertrain level of noise and vibration respectively.

17. The method of claim 14, wherein the one or more non-powertrain factors are selected from the group including but not limited to:

(a) road surface smoothness/roughness;

(b) noise level in the cabin of the vehicle;

(c) volume level of radio or entertainment system in the vehicle;

(d) open or closed windows or sunroof in the cabin of the vehicle;

(e) type of tires used on the vehicle;

(f) weather conditions, including but not limited to precipitation, rain, snow, hail, wind, or a lack thereof; and

(g) ambient temperature.

18. The method of claim 14, further comprising dynamically reducing the slippage of the TCC to improve fuel economy at the expense of increased powertrain noise and vibration.

19. The method of claim 14, further comprising dynamically increasing the slippage of the TCC to decrease powertrain noise and vibration at the expense of worse fuel economy.

20. The method of claim 14, varying the slippage output signal to increase the TCC to increase powertrain noise and vibration at the expense of improved fuel economy if the vehicle is operating in an economy mode.

21. The method of claim 14, further comprising operating the engine in a skip fire manner in parallel with dynamically varying the TCC.

22. The method of claim 14, wherein the engine is either a variable displacement engine or a fixed displacement engine.