LMI-based non-overshooting pressure control design for a wet clutch

A Hydromechanical Variable Transmission is a device able to efficiently transmit non-constant mechanical torque from a source to a load. To suitably control this torque, Dana Rexroth has developed a hybrid transmission that combines a hydrostatic pathway and a mechanical one. The power transmitted along each pathway can be controlled by means of clutches. The torque and so the power transferred by each clutch depends on the oil pressure inside it. For this reason in this work we investigate a novel strategy for oil pressure control. First, we developed a simplified model for filled clutch systems and the related identification technique. Second, we developed a controller that ensures a fast rise time and a non-overshooting behavior. The controller synthesis relies on a convex Linear Matrix Inequalities formulation. The experimental tests show desirable rise time, overshoot and good robustness with respect to modeling errors and noise.