Target speed control strategy for power-off shifts in a hybrid electric vehicle

摘要

A method for controlling a power-off shift from a current gear to a target gear in a hybrid electric powertrain including an engine, electric motor and automatic transmission includes the steps of determining an initial target speed for the current gear, operating the motor at the initial target speed, repetitively determining a current gear ratio, a output shaft speed during the gear ratio change, a time rate of change of output shaft speed, using the current gear ratio, the current speed of the output shaft and the time rate of change of output shaft speed repetitively to determine a current target speed, and operating the motor at the current target speed until a gear change to the next gear is completed.