Bond Graph Analysis of Automatic Transmission Shifts including Potential of Extra Clutch Control

Event
SAE 2016 World Congress and Exhibition
Authors Abstract
Content
New generation of torque converter automatic transmissions (AT) include a large number of gears for improved fuel economy. Control requirements for such transmissions become more demanding, which calls for the development of new shift optimization and analysis tools. This paper presents two contributions to the field of transmission dynamics analysis: (i) bond graph method-based shift transient analysis, and (ii) deriving a unique set of conditions for beneficial use of a third (normally-open) clutch for any upshift or downshift, with emphasis on inertia phase. The derived conditions are examined on an example of 10-speed AT based on the clutch torque input trajectory optimization results. The examination results point out that the extra clutch has a potential of significant performance improvement for any single-transition upshift in the inertia phase, in terms of reduced vehicle jerk RMS value due to the suppressed inertia bump effect. The shift quality improvement is possible in the torque phase, as well, but it is of much smaller extent when compared to that related to the inertia phase.
Meta TagsDetails
DOI
https://doi.org/10.4271/2016-01-1146
Pages
17
Citation
Ranogajec, V., Deur, J., and Coric, M., "Bond Graph Analysis of Automatic Transmission Shifts including Potential of Extra Clutch Control," SAE Int. J. Engines 9(3):1929-1945, 2016, https://doi.org/10.4271/2016-01-1146.
Additional Details
Publisher
Published
Apr 5, 2016
Product Code
2016-01-1146
Content Type
Journal Article
Language
English