CONTROL DEVICE FOR AUTOMATIC TRANSMISSION FOR VEHICLE

摘要

PURPOSE: To prevent the shift shock in shifting gears from a driving gear stage where correction of learning is difficult to a non-driving gear stage effectively regardless of the individual difference or deterioration with age of a friction engaging device and its control system, etc. CONSTITUTION: The duty ratio DSL3A of the linear solenoid SL3 at the constant pressure standby time when a clutch C1 is released for shifting gears from the 'D' to the 'N' range is calculated according to the following expression using the reference duty ratio dsdn at the constant pressure standby time, a correction value dsdntmp for the AT oil temperature TOIL, a correction value dsnne for the engine rotation speed NE, and learning correction values gdndlrn and gdcstapl at the time of gear-shifting from the 'N' to the 'D' range for engaging the clutch C1 and at the time of coast down-shifting from the fourth to the third speed range respectively; DSL3A=dsdn+dsdntmp+-dsdnne+ Kxgdndlrn+(1-K)gdcstapl. In the expression, K is a coefficient and set as a prescribed value in the range 0≤K≤1.