A survey of today's CVT controls

For over one hundred years, the principle of continuously and infinitely variable transmissions (C/IVT) has eluded practical automotive utility. With the advent of durable materials, sophisticated electronic controls, and improved lubricants, a viable assortment of C/IVT powertrain systems with innovative ratio shift control strategies is now feasible. A few of these progressive system designs are described in this survey. Pertinent fundamental relationships of C/IVT powertrains are also discussed.