Invention Grant
- Patent Title: Method for improving shift quality in an automatic transmission
- Patent Title (中): 改善自动变速箱换档质量的方法
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Application No.: US13061335Application Date: 2009-07-27
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Publication No.: US08690730B2Publication Date: 2014-04-08
- Inventor: David W. Wright , Philippe Ramet , Morgan Postic
- Applicant: David W. Wright , Philippe Ramet , Morgan Postic
- Applicant Address: US MI Detroit
- Assignee: GM Global Technology Operations LLC
- Current Assignee: GM Global Technology Operations LLC
- Current Assignee Address: US MI Detroit
- Agency: Ingrassia Fisher & Lorenz, P.C.
- Priority: GB0815600.2 20080828
- International Application: PCT/EP2009/005436 WO 20090727
- International Announcement: WO2010/022835 WO 20100304
- Main IPC: B60W10/04
- IPC: B60W10/04

Abstract:
A method is provided for improving shift quality in an automatic transmission. In many automatic transmissions, the shift quality during lift foot upshifts is unsatisfying. Generally, two types of complaints concerning shift quality are known: harsh feel right after the shift order and bump at the synchronization of the shift. In order to provide an automatic transmission which overcomes these two problems, a first and a second positive torque requests are initiated on upshift coasts. This measure improves the global shift feel by controlling the engine toque level at shift order and at synchronization: the engine torque level at the beginning of the gear shift is smoothly decreased to reduce the initial bump and is controlled at the synchronization to reduce the amplitude of underlap when the clutch capacity is rising.
Public/Granted literature
- US20110154931A1 METHOD FOR IMPROVING SHIFT QUALITY IN AN AUTOMATIC TRANSMISSION Public/Granted day:2011-06-30
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