Closed-loop torque phase control for shifting automatic transmission gear ratios based on friction element load sensing
US8255130B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2009 |
| Grant date | Aug 28, 2012 |
| Priority date | — |
| Expiry date | Nov 11, 2030 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2342/044
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A closed loop shift control apparatus and method based on friction element load controls a torque transfer phase when shifting from a low gear configuration to a high gear configuration for an automatic transmission system. When pressure actuated friction elements are selectively engaged and released to establish torque flow paths in the transmission, measurements or estimates of torsional load exerted on the off-going friction element are used to predict the optimal off-going friction element release timing for achieving a consistent shift feel. The ideal timing to release the off-going friction element is uniquely defined when torque load exerted onto the off-going friction element becomes substantially zero. An on-coming clutch engagement process is controlled by a closed loop control based on measurements or estimates of on-coming clutch torque capacity for a constant shift feel under dynamically changing conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.