Resolving a non-commanded neutral state in a clutch-to-clutch transmission
AssigneeGM Global Technology Operations LLC
InventorsTodd J. Thor, David W. Wright, Brian J. Pellerito, Craig A. Brunstetter
Life of this patent
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Abstract
A method of controlling a clutch-to-clutch transmission. The method includes detecting transmission slip speed that exceeds a predetermined amount for a predetermined time period. Based on the detecting, a shift of a gear ratio of the transmission is forced. When this method is implemented in a vehicle, loss of driver control of the vehicle can be prevented in the event of a non-commanded neutral condition in the transmission.
Claims17
A vehicle including a transmission having a plurality of clutches for providing a plurality of speed ratios, the vehicle comprising a control module that:
- monitors a difference between speed of an input shaft of the transmission and speed of an output shaft of the transmission in a gear state of the transmission for an expected shift time;
- and
- based on the monitoring and a gear ratio of the gear state, forces a shift of the transmission to a different gear state if the difference exceeds a predetermined amount for longer than the expected shift time.
A method of controlling a transmission having a plurality of clutches for providing a plurality of speed ratios, the method comprising:
- detecting when a difference between speed of an input shaft of the transmission and a product of speed of an output shaft of the transmission and a gear ratio of the transmission exceeds a predetermined amount for a predetermined time period;
- and
- based on the detecting, forcing a shift of the gear ratio of the transmission.
A transmission control system for a clutch-to-clutch transmission, the control system comprising a control module configured to:
- detect when a difference between speed of an input shaft of the transmission and a product of speed of an output shaft of the transmission and a gear ratio of the transmission exceeds a predetermined amount for a predetermined time period;
- and
- based on the detecting, forcing a shift of the gear ratio of the transmission.
Dependencies are inferred from the claim text.