METHOD AND SYSTEM FOR REDUCING DRIVELINE NVH

• US 20140378273A1
• Filed: 06/21/2013
• Published: 12/25/2014
• Est. Priority Date: 06/21/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Gibson, Alex O'Connor, Fujii, Yuji, Nedorezov, Felix, Kraska, Marvin Paul
• Granted Patent: US 9,925,972 B2
• Time in Patent Office: Days
• US Class Current: 477/5
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/17 for noise reduction
• CPC Class Codes: B60W 2050/0054 Cut-off filters, retarders, delaying means, dead zones, threshold values or cut-off frequency
• CPC Class Codes: B60W 2050/0056 Low-pass filters
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: Y10S 903/902 Prime movers comprising electrical and internal combustion motors

Abstract

A method and a system for reducing driveline speed oscillations related to a driveline resonance frequency are described. Driveline speed oscillations may be reduced via slipping a driveline clutch or adjusting torque of a driveline motor/generator. The method and system may be activated during select vehicle operating conditions.

Claims

1. A driveline operating method, comprising:

adjusting torque of a generator in a driveline in response to a band pass filtered driveline speed in a first mode; and

adjusting slip of a clutch in the driveline in response to the band pass filtered driveline speed in a second mode in response to a generator condition.

2. The driveline operating method of claim 1, where the clutch is a forward clutch of a transmission.

3. The driveline operating method of claim 1, where the clutch is a torque converter bypass clutch.

4. The driveline operating method of claim 1, where a negative torque of the generator is increased in response to an increase in the band pass filtered driveline speed.

5. The driveline operating method of claim 1, where a positive torque of the generator is increased in response to a decrease in the band pass filtered driveline speed.

6. The driveline operating method of claim 1, where adjusting slip of the clutch in response to the band pass filtered driveline speed is performed only when a transmission in the driveline is in a predetermined gear.

7. The driveline operating method of claim 1, where adjusting torque of the generator in response to the band pass filtered driveline speed is performed only when a transmission in the driveline is in a predetermined gear.

8. The driveline operating method of claim 1, where the band pass filtered driveline speed is filtered at a frequency based on a driveline resonance frequency, the driveline resonance frequency based on a driveline including a U-joint positioned between two driveshaft halves.

9. A driveline operating method, comprising:

adjusting torque of a generator in a driveline in response to a band pass filtered driveline speed in a first mode; and

increasing slip of a clutch in the driveline in response to the band pass filtered driveline speed exceeding first and second threshold speeds in a second mode in response to a generator condition.

10. The driveline operating method of claim 9, further comprising decreasing slip of the clutch in the driveline in response to the band pass filtered driveline speed not exceeding the first and second thresholds, the first threshold a positive speed, the second threshold a negative speed.

11. The driveline operating method of claim 9, where the clutch is a driveline disconnect clutch positioned in the driveline between the generator and an engine.

12. The driveline operating method of claim 11, where the generator condition is the generator not consuming or generating electrical energy.

13. The driveline operating method of claim 9, where the generator condition is the generator lacking torque to reduce driveline speed oscillations by more than a threshold amount of speed.

14. The driveline operating method of claim 9, further comprising selecting speed sensors at different driveline locations at times to provide the band pass filtered driveline speed.

15. The driveline operating method of claim 9, where the band pass filtered driveline speed is filtered at a frequency based on a driveline resonance frequency, the driveline resonance frequency based on a driveline including a U-joint positioned between two driveshaft halves.

16. A vehicle system, comprising:

an engine;

a driveline disconnect clutch coupled to the engine;

a motor/generator coupled to the driveline disconnect clutch;

a plurality of driveline speed sensors;

a torque converter coupled to the motor/generator;

a transmission coupled to the torque converter; and

a controller including executable instructions stored in non-transitory memory, the executable instructions providing for selecting a driveline speed sensor from the plurality of driveline speed sensors in response to driveline conditions, band pass filtering output of the selected driveline speed sensor, and reducing driveline speed oscillations via the motor/generator or a clutch.

17. The vehicle system of claim 16, where the clutch is the driveline disconnect clutch.

18. The vehicle system of claim 16, where the clutch is a lockup clutch of the torque converter.

19. The vehicle system of claim 16, where the plurality of driveline speed sensors includes wheel speed sensors, a turbine speed sensor, and a transmission output speed sensor.

20. The vehicle system of claim 16, where selection of the driveline speed sensor is based on slippage of a clutch.