System and method for determining clutch gains in a transmission during a power downshift
US8744705B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 15, 2012 |
| Grant date | Jun 3, 2014 |
| Priority date | — |
| Expiry date | Jun 28, 2032 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0492
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method of controlling an offgoing clutch in a transmission during a power downshift includes detecting the downshift, reducing a pressure command to the offgoing clutch, and introducing a calibrated error value to a pressure command for the offgoing clutch during the inertia phase. The method also includes synchronizing the speed of the offgoing and an oncoming clutch during the torque phase, determining the offgoing clutch pressure and torque after synchronizing clutch speeds, and then recording a clutch gain as a function of the offgoing clutch pressure and torque. The recorded clutch gains are used to control a subsequent power downshift of the transmission. A controller using proportional-integral-derivative (PID) control logic introduces the error as PID error in a pressure control signal, and controls slip across the offgoing clutch. A transmission is also disclosed having an offgoing clutch and controller configured to execute the above method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.