Patent ID: 8645035

Claim:
A method of controlling a hydraulic continuously variable transmission of a vehicle; the continuously variable transmission including a driving pulley disposed on a driving shaft for rotation therewith, a driven pulley disposed on a driven shaft for rotation therewith, and a belt operatively connecting the driving pulley with the driven pulley; the driving pulley including a fixed sheave, a movable sheave, and a spring biasing the movable sheave away from the fixed sheave; the driving shaft being driven by an engine of the vehicle; the method comprising: determining a speed of rotation of the driving shaft; determining a speed of rotation of the driven shaft; determining a ratio of the speed of rotation of the driving shaft versus the speed of rotation of the driven shaft; determining an engine torque; determining a base clamping force to be applied by the driving pulley onto the belt based on the ratio and the engine torque; determining a desired speed of rotation of the driving shaft; determining a corrective clamping force by comparing the speed of rotation of the driving shaft to the desired speed of rotation of the driving shaft; and controlling a hydraulic pressure applied to the movable sheave to apply a sum of the base clamping force and the corrective clamping force onto the belt.