A Novel Pushbelt CVT Actuation System and Control Strategy*

The CVT hydraulic actuation system almost adopt pressure sensors to feedback the pulley cylinder pressure to traction control unit (TCU), which is complex structure, high cost and poor reliability. A new electro-hydraulic actuation system that gets rid of the pressure sensors will be described in detail. It is for the clamping force control of CVT to adopt the bang-bang control and use the piecewise optimal method to control the gear ratio. Then, the rapid control prototype (RCP) of CVT is produced to evaluate the new CVT actuation system. At last, the new electro-hydraulic actuation system and its control strategy are tested on vehicle. The experimental results also confirm that the new CVT hydraulic system is stability and rapid response to actuate the CVT variator.