Combining extremum seeking control and tracking control for high-performance CVT operation

The design of a new controller for the variator in a pushbelt continuously variable transmission (CVT) is investigated. A conventional variator controller is typically based on a variator model with large uncertainties, which results in a limited variator efficiency. The proposed controller simultaneously optimizes the variator efficiency and tracks a transmission ratio reference, for which a detailed variator model is not required. The controller, a combination of extremum seeking control and tracking control, only uses measurements from standard sensors. Experiments on the basis of a driving cycle show that a conventional variator controller is outperformed.