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:
Sep. 04, 2001
Filed:
Mar. 20, 2000
Todd M Steinmetz, Indianapolis, IN (US);
Jeffrey Kurt Runde, Fishers, IN (US);
Gregory A Hubbard, Carmel, IN (US);
Phillip F McCauley, Zionsville, IN (US);
Charles Francis Long, Pittsboro, IN (US);
Martin Robert Dadel, Indianapolis, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An improved shift control for a hydraulic automatic transmission in which the apply chamber of an on-coming clutch is filled in the preparation phase of the shift using a hydraulic flow rate model to estimate the volume of hydraulic fluid supplied to the apply chamber. In an initial portion of the fill interval, fluid is supplied to the apply chamber at a first elevated pressure, while continuously updating the fluid volume estimate. When the remaining un-filled volume of the apply chamber reaches a reference volume, the supply pressure is reduced to a second pressure at which the next phase of the shift is to be carried out. When the chamber volume is filled, the torque capacity of the clutch rises to a level corresponding to the second pressure, and the next phase of the shift automatically ensues.