Method and apparatus for controlling continuously variable transmission for vehicle

摘要

Method and apparatus for controlling a continuously variable transmission operatively connecting an engine and drive wheels of a vehicle, wherein a speed ratio of the transmission is controlled such that an actual engine speed coincides with a target engine speed determined based on a currently required engine output and according to a predetermined relation between the target engine speed and the required engine output. The method and apparatus comprise a step or device for restraining a rate of variation in the speed ratio during a time span between the moment when the actual engine speed has exceeded a variation-restraint trigger speed of the engine, and the moment when the actual engine speed has reached the target speed. The trigger engine speed is lower than the target engine speed, and determined based on a transmission efficiency of the transmission. The transmission efficiency is determined based on a detected changing rate of variation in the speed ratio of the transmission.