CONTROLLING ENGINE TORQUE TO SMOOTH TRANSMISSION SHIFT

摘要

In engine torque control in a motor vehicle having an engine and a stepping type of transmission, input and output speeds of the transmission are constantly detected by sensors disposed in input and output portions of the transmission, thereby obtaining a gear ratio (measured value) of the transmission. If the ratio of the difference between this gear ratio and a predetermined gear ratio before the gearshift (theoretical value) to the latter gear ratio before the gearshift exceeds a predetermined value, the start of gearshift is decided. If the ratio of the difference between the gear ratio of the transmission (measured value) and a predetermined gear ratio after the gearshift (theoretical value) to the latter gear ratio after the gearshift becomes smaller than a predetermined value, the end of gearshift is decided. A set level by which the torque of the engine should be reduced during the period between the start and end of the gearshift is determined by reading reduction data previously set with respect to the throttle opening and the type of gearshift. The torque output from the engine is reduced on the basis of the reduction data by controlling the ignition timing retardation angle or the fuel injection rate.