Ratio shift control system and method for a multiple-ratio automatic transmission

摘要

A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated friction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a powertrain source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a powertrain source is modulated. A perceptible transmission output torque reduction during an upshift is avoided.