Control method and apparatus for continuously variable transmissions

摘要

A control system for continuously variable transmissions is operative in a number of functional modes. A "neutral mode" fully disengages a clutch and sets a variable ratio to an extreme low ratio when a gear shift is in a neutral position. A "hold mode" slightly engages the clutch to cause a finite amount of vehicle creep when the gear shift is in a forward or reverse position and a throttle is fully released. A "normal start mode" partially engages the clutch when the gear shift is in a forward or reverse position and the throttle is depressed. A "drive mode" fully engages the clutch and sets the variable ratio to maintain a predetermined engine speed when the vehicle is travelling at greater than a predetermined minimum vehicle speed and the clutch is slipping at less than a predetermined amount of clutch slip.