Adaptive pressure control method for synchronous downshifts in a multiple-ratio transmission

摘要

An adaptive pressure control method for synchronous downshifts in an automatic transmission that uses pressure actuated friction elements. The method uses characteristic parameters that determine downshift quality for both power-on downshifts and power-off downshifts. Selected measured variables are monitored to detect changes in the parameters. Adjustments for the friction elements are made in response to changes in the measured variables.