CONTROL OF TORQUE REDUCTION DURING GEAR SHIFTING IN AUTO-TRANSMISSION HEV SYSTEM

摘要

A control method for reducing torque of a hybrid electric vehicle during gear shifting is provided to satisfy quick response property for the controls of torque reduction by easily reducing torque of an output shaft of an engine by supplying torque in the opposite direction of engine torque through a motor during gear shifting. A control method for reducing torque of a hybrid electric vehicle during gear shifting comprises the steps of: executing shifting; judging whether to reduce torque or not, by detecting the torque and RPM(Revolution Per Minute) of an input shaft of a transmission, vehicle speed, and gear level during gear shifting; requesting to reduce torque by determining the necessary torque reduction degree, if torque is needed to be reduced; judging whether a torque reduction request value is within a torque limit range of a motor or not; reducing the torque of the output shaft of the engine by driving the motor to supply torque in the opposite direction of engine torque, if the torque reduction request value is in a torque limit range of the motor; and restoring the original torque of the output shaft of the engine by finishing torque reduction controls after gear shifting.