Control strategy and method for independently controlling friction element actuators for an automatic transmission
US6385520B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2000 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Aug 10, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2306/24
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control strategy and method for controlling application and release of friction elements in an automatic transmission to effect gear ratio changes as one friction element is release and another friction element is applied during ratio changes. The transmission has an electronic controller and multiple solenoid regulator valves hydraulically coupled directly to pressure-operated friction elements. Powertrain variables are obtained and processed to calculate gear ratio control parameters derived from desired line pressure for a pressure control valve circuit that communicates with the friction elements. The desired gear ratio is determined for each given set of powertrain variables. Upshifts and downshifts are obtained by releasing one friction element in synchronism with an application of the other friction element, whereby a direct friction element to friction element torque transition is achieved with minimal inertia torque disturbances.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.