Aggressive Torque Converter Clutch Slip Control and Driveline Torsional Velocity Measurements

In automatic transmissions, an open torque converter transmits torque from the engine to the transmission using fluid coupling. Although torque converters are ideal launch devices for automatic transmissions, they are inefficient in steady-state operations. An electronically controlled capacity clutch (ECCC) is implemented to control the slip between the pump and turbine of the torque converter, thereby increasing its energy transfer efficiency and increasing vehicle fuel economy. Even though reducing torque converter slip minimizes losses due to fluid coupling, it also decreases the damping provided by a slipping torque converter and as a result increases the sensitivity of the driveline to engine excitations. This investigation uses driveline torsional velocity response measurements to evaluate the effects of using slip feedback closed-loop control with a very aggressive torque converter ECCC slip schedule in automatic transmissions. Experimental results for a General Motors Sport Utility Vehicle equipped with a 6-speed Rear-Wheel-Drive automatic transmission with and without all-wheel-drive, and different torque converter isolator configurations are presented. The effects of the very aggressive ECCC slip strategy on vehicle drivability are also discussed.

• Record URL:
  • https://doi.org/10.4271/2008-01-1584
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/19463952
• Supplemental Notes:
  • Abstract reprinted with permission of SAE International.
• Authors:
  • Otanez, Paul
  • Samie, Farzad
  • Lee, Chunhao Joseph
  • Kao, Chi-Kuan
• Conference:
  • 2008 SAE International Powertrains, Fuels and Lubricants Congress
  • Location: Shanghai , China
  • Date: 2008-6-23 to 2008-6-25
• Publication Date: 2008-6-23

Language

• English

Media Info

• Media Type: Web
• Features: References;
• Pagination: pp 883-892
• Serial:
  • SAE International Journal of Fuels and Lubricants
  • Volume: 1
  • Issue Number: 1
  • Publisher: SAE International
  • ISSN: 1946-3952
  • EISSN: 1946-3960
  • Serial URL: https://www.sae.org/publications/collections/content/E-JOURNAL-04/

Subject/Index Terms

• TRT Terms: Automatic transmissions; Clutches; Experiments; Noise; Rear wheel drive; Slip boundary conditions; Spark ignition engines; Sport utility vehicles; Torque converters
• Identifier Terms: General Motors automobiles
• Subject Areas: Energy; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01637117
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2008-01-1584
• Files: TRIS, SAE
• Created Date: May 31 2017 4:09PM