Model-based control of an automatic transmission garage shift
US6358184B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 2000 |
| Grant date | Mar 19, 2002 |
| Priority date | — |
| Expiry date | May 10, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60W2710/1016
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An improved control for an automatic transmission garage shift, wherein a dynamic model of the transmission is used to estimate the transmission input torque during the shift and to schedule the on-coming clutch pressure in accordance with the estimated input torque to achieve a desired input shaft trajectory. The transmission input torque is estimated based on two different methodologies —one suited to steady-state engine idle conditions, and the other suited to engine output torque transient conditions. A fuzzy summation of the input torques provided by the two methodologies is utilized in transitions between the two conditions. Shift quality variations due to variations in mechanical and/or hydraulic stiffness are minimized by a pause or hold interval inserted between the end of the fill period and the initiation of on-coming clutch pressure control, which results in a reasonably consistent degree of perceived transmission-to-transmission hydraulic and mechanical compliance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.