The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 29, 2013
Filed:
Feb. 14, 2008
Bret M. Olson, Canton, MI (US);
Robert L. Moses, Ann Arbor, MI (US);
Randall B. Dlugoss, Royal Oak, MI (US);
Bret M. Olson, Canton, MI (US);
Robert L. Moses, Ann Arbor, MI (US);
Randall B. Dlugoss, Royal Oak, MI (US);
GM Global Technology Operations LLC, Detroit, MI (US);
Abstract
A method for controlling a clutch assembly includes controlling an actual clutch fill pressure using open-loop pressure controls when an active fill phase is detected, and using closed-loop pressure controls when the active fill phase is complete or when an overfill condition is detected. The method supplies the actual clutch pressure according to a second set of open-loop pressure controls when a step in commanded clutch pressure is detected. The method monitors a fill pressure and time during the step, and applies the clutch pressure according to the closed-loop pressure controls when either value equals a corresponding threshold value. A clutch assembly has a piston for compressing clutch disks to initiate a shift event, an algorithm for controlling the shift event, and a sensor for determining an actual clutch pressure during the shift phases. The algorithm switches between closed-loop and open-loop pressure controls in response to different shift phases.