Speed ratio controller for a continuously variable transmission

摘要

A speed ratio controller for a continuously variable transmission of a vehicle is provided which sets a target speed ratio (ipo) according to a vehicle speed (VSP) and degree of accelerator pedal depression (TVO), sets a command speed ratio (ipr) according to the target speed ratio (ipo) and a predetermined dynamic characteristic, and controls the transmission so as to obtain the target speed ratio (ipo) while a real speed ratio (ipR) follows the command speed ratio (ipr). This speed ratio controller computes a deviation (eip) between the command speed ratio (ipr) and target speed ratio (ipo), and determines whether an upshift characteristic is an auto upshift, foot release upshift or foot return upshift based on the speed ratio deviation, degree of accelerator pedal depression, and variation amount of the target input shaft rotation speed. The dynamic characteristic of the command speed ratio is set according to the determination result, and the response characteristics of the transmission are thereby modified.