Methods and systems for powertrain NVH control in a vehicle

Patent metadata

Field	Value
Publication number	US-10214219-B2
Application number	US-201715403010-A
Country	US
Kind code	B2
Filing date	Jan 10, 2017
Priority date	Jan 10, 2017
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

Methods and systems are provided for adjusting noise, vibration, and harshness (NVH) limits for a vehicle based on a number of occupants in the vehicle. In one example, a method may include responsive to detecting zero occupants, reducing NVH constraints for operating the vehicle and adjusting one or more vehicle operating parameters based on the reduced NVH constraints.

First claim

The invention claimed is:

1. A method for operating a vehicle, comprising:
during an autonomous mode of vehicle operation, altering noise, vibration, and harshness (NVH) limits from a lower NVH threshold to a higher NVH threshold for a powertrain of the vehicle responsive to detecting zero occupants within the vehicle to improve fuel economy, and
adjusting a desired torque converter slip based on the higher NVH threshold, wherein the desired torque converter slip decreases as the NVH threshold increases.

2. The method of claim 1 , wherein altering the NVH limits responsive to detecting zero occupants includes setting the higher NVH threshold with respect to the lower NVH threshold when one or more occupants are present in the vehicle, and adjusting one or more parameters of powertrain operation based on the higher NVH threshold.

3. The method of claim 2 , wherein the powertrain includes an engine coupled to a transmission through a torque converter and adjusting the one or more parameters of the powertrain operation based on the higher NVH threshold includes adjusting one or more of an idle operation of the engine, a variable displacement engine (VDE) mode of engine operation, shut off fuel supplied to the engine during deceleration (DFSO) operation, and an exhaust gas recirculation percentage of recirculated exhaust gas and air inducted into the engine for combustion.

4. The method of claim 3 , wherein adjusting the one or more parameters of the powertrain operation based on the higher NVH threshold further includes switching to the VDE mode of engine operation during an idle condition, and increasing an amount of spark retard applied to engine combustion during the idle condition.

5. The method of claim 3 , wherein adjusting the one or more parameters of the powertrain operation based on the higher NVH threshold further includes, during the VDE mode of engine operation, deactivating a number of cylinders of the engine based on the higher NVH threshold, the number of cylinders deactivated increasing with an increase in the NVH threshold.

6. The method of claim 1 , further comprising adjusting the NVH limits during lugging conditions of an engine.

7. The method of claim 6 , wherein adjusting the NVH limits during the lugging conditions includes decreasing torque converter slip during the lugging conditions, a percentage of decrease in the torque converter slip increasing with an increase in the NVH limits.

8. The method of claim 2 , wherein adjusting the one or more parameters of the powertrain operation based on the higher NVH threshold includes, responsive to a deceleration greater than a threshold, transitioning immediately to a deceleration fuel shut off (DFSO) operation during which fuel supplied to an engine of the powertrain for combustion is shut off, where the threshold is based on the higher NVH threshold.

9. The method of claim 1 , wherein adjusting one or more parameters of powertrain operation based on the higher NVH threshold includes delaying exit from a deceleration fuel shut off (DFSO) operation where fuel supplied to an engine of the powertrain is shut off; and wherein delaying exit from the DFSO operation includes decreasing a vehicle speed threshold below which deactivated fuel injectors are reactivated.

10. A method for operating a vehicle, comprising:
setting different noise, vibration, and harshness (NVH) limits for a vehicle powertrain to one of a first NVH tolerance threshold, a second NVH tolerance threshold, and a third NVH tolerance threshold based on one or more of a number of occupants detected within the vehicle and an occupant-selected setting selected by an occupant through a vehicle interface, the third NVH tolerance threshold being higher than the second NVH tolerance threshold and lower than the first NVH tolerance threshold.

11. The method of claim 10 , wherein setting the NVH limits includes, responsive to detecting zero occupants, setting the first NVH tolerance threshold, and adjusting one or more operating parameters of the vehicle based on the first NVH tolerance threshold.

12. The method of claim 11 , wherein setting the NVH limits includes, responsive to detecting one or more occupants, setting the second, NVH tolerance threshold, and adjusting the one or more operating parameters of the vehicle based on the second NVH tolerance threshold, the first NVH tolerance threshold higher than the second NVH tolerance threshold.

13. The method of claim 11 , wherein setting the NVH limits includes, responsive to the occupant-selected setting, indicating a preference for fuel economy over NVH, setting the third NVH tolerance threshold, and adjusting the one or more operating parameters of the vehicle based on the third NVH tolerance threshold.

14. The method of claim 11 , wherein adjusting the one or more operating parameters of the vehicle based on the first NVH tolerance threshold includes increasing one or more of a desired EGR amount, an operating range of VDE, a number deactivated cylinders during VDE mode, and an operating range of DFSO operation.

15. The method of claim 11 , wherein the vehicle powertrain includes an engine coupled to a transmission through a torque converter and adjusting the one or more operating parameters of the vehicle based on the first NVH tolerance threshold includes one or more of decreasing a percentage of torque converter slip, and adjusting a transmission shift schedule to upshift early and reduce a number of downshifts.

16. A vehicle system, comprising:
a variable displacement engine (VDE) including a plurality of cylinders, where one or more of the cylinders are deactivated in a variable displacement mode of engine operation, the VDE being coupled to a transmission through a torque converter;
an occupant sensing system for detecting presence of an occupant within a vehicle, the occupant sensing system including one or more seat pressure sensors coupled to each vehicle seat;
one or more autonomous driving sensors; and
an in-vehicle computing system including an autonomous driving module, the autonomous driving module including instructions for operating the vehicle in an autonomous mode based on signals received from the one or more autonomous driving sensors; and a processor and a storage device, the storage device storing instructions executable by the processor to:
detect a number of occupants within the vehicle;
during a first condition, including when one or more occupants are detected within the vehicle, adjusting one or more vehicle operating parameters based on a lower noise, vibration, and harshness (NVH) threshold of the vehicle;
during a second condition, including when zero occupants are detected within the vehicle, adjusting one or more vehicle operating parameters based on a higher NVH threshold of the vehicle for increasing fuel economy improvement while compromising NVH; and

during an engine lugging condition, decreasing a torque converter slip based on the higher NVH threshold of the vehicle;
wherein the one or more vehicle operating parameters include a desired amount of exhaust gas recirculated into the engine (EGR), a first engine speed and load range for the variable displacement mode of engine operation, a number of cylinders deactivated during the variable displacement mode of engine operation, a second engine speed and load range for shut off of fuel supplied to the VDE during deceleration (DFSO) operation, the torque converter slip, and a transmission shift schedule.

17. The system of claim 16 , wherein adjusting the one or more vehicle operating parameters based on the higher NVH thre

Assignees

• Ford Global Tech Llc

Inventors

• Richards Adam J
• Banker Adam Nathan
• Karnik Amey Y
• Rollinger John Eric

Classifications

• B60W2540/049

  Number of occupants · CPC title

• B60W60/0023

  in response to energy consumption · CPC title

• B60W60/0013

  specially adapted for occupant comfort · CPC title

• F02P5/1512

  with particular means concerning an individual cylinder · CPC title

• F02P5/045

  combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02) · CPC title