Method and system for reducing driveline NVH

• US 9,925,972 B2
• Filed: 06/21/2013
• Issued: 03/27/2018
• 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
• Primary Examiner(s): Hodge, Robert W
• Assistant Examiner(s): Dodd, Ryan P
• Application Number:
  US13/923,758
• Publication Number:
  US 20140378273A1
• Time in Patent Office: 1,740 Days
• Field of Search: None
• 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:

receiving sensor inputs to a controller;

increasing slip of a clutch in a driveline via the controller in response to a band pass filtered driveline speed exceeding first and second threshold speeds, and

adjusting slip of the clutch when the clutch has capacity to adjust slip at a rate of driveline resonance frequency multiplied by a value of four during driveline speed oscillations, and slipping the clutch continuously when the clutch does not have capacity to adjust slip at the rate of driveline resonance frequency multiplied by the value of four during driveline speed oscillations.

2. The driveline operating method of claim 1, 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 threshold speeds, the first threshold speed a positive speed, the second threshold speed a negative speed.

3. The driveline operating method of claim 1, where the clutch is a driveline disconnect clutch positioned in the driveline between a transmission and an engine.

4. The driveline operating method of claim 3, further comprising adjusting torque of a driveline integrated starter/generator in response to a torque capacity of the driveline integrated starter/generator minus a present torque output of the driveline integrated starter/generator being greater than a torque to compensate driveline speed oscillations.

5. The driveline operating method of claim 1, further comprising selecting a wheel speed sensor at a first location to provide the band pass filtered driveline speed in response to the wheel speed sensor being available, and selecting a second speed sensor at a second location to provide the band pass filtered driveline speed in response to the wheel speed sensor being unavailable.

6. 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 the driveline including a U-joint positioned between two driveshaft halves.

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

8. The driveline operating method of claim 1, where increasing slip is provided when driveline speed is oscillating.

9. The driveline operating method of claim 1, further comprising increasing slip of the clutch in response to a vehicle speed being in a range where a natural resonance frequency of the driveline is present.

10. The driveline operating method of claim 1, where the band pass filtered driveline speed is filtered via a band pass filter set to capture a natural frequency of the driveline.