Gear ratio control method for continuously variable transmission of a vehicle

Abstract

At an actual engine rotary speed corresponding to a partially engaged state of a starting clutch, a target gear ratio control of a continuously variable transmission is performed by determining a target gear ratio from a target engine rotary speed. At an actual engine rotary speed corresponding to an engaged state of the starting clutch, the gear ratio is controlled in a manner such that the actual engine rotary speed converges with a target engine rotary speed. Accordingly, when it is intended to start the vehicle with a comparatively large throttle opening, it is possible, at the partially engaged condition, to obviate a rise in the actual engine rotary speed with the gear ratio position sticking to a desired position, so that a predetermined driving force is attained when the starting clutch is engaged.