Automatic transmission control apparatus
US5741203A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 12, 1996 |
| Grant date | Apr 21, 1998 |
| Priority date | — |
| Expiry date | Jun 12, 2016 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0087
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An apparatus for controlling an automatic transmission including hydraulic friction elements each of which is operable between engaged and disengaged positions in response to a working pressure of hydraulic fluid supplied thereto so as to produce a selected one of a plurality of modes of gear change. The control apparatus is operable through successive operating modes including a precharge mode of precharging the hydraulic fluid to a corresponding one of the friction elements to complete a loss stroke of the friction element, a critical pressure retaining mode of retaining the working pressure at a critical value and a feedback control mode of controlling the working pressure. A different of the rate of change of the friction element input side speed sensed during the critical pressure retaining mode from the average rate of change of the friction element input side speed sensed during the precharge mode is calculated. The critical working pressure value is corrected in a direction to decrease the calculated difference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.