| US 7,491,151 B2 | ||
| Selectable one-way clutch control | ||
| Joel M. Maguire, Northville, Mich. (US); and Scott H. Wittkopp, Ypsilanti, Mich. (US) | ||
| Assigned to GM Global Technology Operations, Inc., Detroit, Mich. (US) | ||
| Filed on Oct. 31, 2005, as Appl. No. 11/263,179. | ||
| Prior Publication US 2007/0099758 A1, May 03, 2007 | ||
| Int. Cl. B60W 10/06 (2006.01) | ||
| U.S. Cl. 477—107 | 17 Claims |
| 1. A method for controlling a selectable one-way clutch (SOWC) that is selectively engageable to connect a member of a planetary
gear set to a stationary member of a transmission to thereby allow engine braking of a vehicle, the method comprising:
identifying a manual downshift command from drive to a manual first gear, the downshift command being generated in response
to an operator of the vehicle shifting from drive to the manual first gear;
releasing an off-going clutch in response to the downshift command;
increasing an engine speed after releasing the off-going clutch, until a relative speed across the SOWC is approximately zero;
engaging the SOWC after the relative speed across the SOWC reaches approximately zero to thereby connect the member of the
planetary gear set to the stationary member such that minimal impact load is absorbed during engagement of the SOWC, and such
that the engine braking is enabled as the vehicle decelerates in the manual first gear.
|