Hybrid Hydraulic Piezo Actuator and its Control for Camless Internal Combustion Engines

This paper deals with an integration of an actuator composed by a piezo and a hydraulic part for camless engine motor applications. The idea is to use the advantages of both, the high precision of the piezo and the force of the hydraulic part. In fact, piezoelectric actuators (PEAs) are commonly used for precision positionings, despite PEAs present nonlinearities, such as hysteresis, saturations, and creep. The model of such an integrate system in which such nonlinearities must be taken into account. Because of the variegate structure of the whole device a robust sliding mode technique is proposed to track the desired trajectory of the exhaust and intake valves. Simulations with real data are shown.