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:
May. 14, 1991
Filed:
Dec. 11, 1989
Joseph H Hunter, Carmel, IN (US);
Jeffrey K Runde, Indianapolis, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
In an automatic transmission, a double transition upshift to a target range requires the release of two off-going clutches and the engagement of two on-coming clutches. The shift is made in two stages. The first stage involves a first off-going clutch and a first on-coming clutch, and begins a shift to a third range having a speed ratio lower than the target range so that input speed is decreased and power is supplied throughout the shift. The speed decrease is managed by a closed-loop control of the first on-coming clutch until the clutch reaches a synchronous speed for the target range. The closed-loop control parameter is on-coming clutch slip speed which is controlled to a calculated slip speed profile. The profile has a first steep slope and a final less steep slope so that the actual slip can smoothly go to zero in a given time period. When near synchronous speed is reached, the second off-going clutch begins to release and at the end of the closed-loop control the second on-coming clutch is applied to complete the shift to the target range.