Transmissioin clutch return spring pressure learn using PID control
US9115805B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 5, 2012 |
| Grant date | Aug 25, 2015 |
| Priority date | — |
| Expiry date | May 10, 2033 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/064
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method for determining the return spring pressure of a clutch in a vehicle transmission includes using proportion-integral-derivative (PID) control logic of a controller to introduce a calibrated error into a pressure command of a holding clutch during a coast-down maneuver of the vehicle. The calibrated error causes a slip level to occur across the holding clutch. The method includes maintaining the slip level using the PID control logic and separately commanding engine torque at different threshold low values during the coast-down maneuver. The pressure/input torque relationship for the holding clutch is recorded for both threshold low levels as the controller continues to maintain the slip. The return spring pressure is calculated using the recorded pressure/input torque relationship. The holding clutch may be controlled a subsequent shift maneuver using the learned return spring pressure. A vehicle is also disclosed having a controller configured to execute steps of the method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.