A robust sliding mode control of a hybrid hydraulic piezo actuator for camless internal combustion engines

This paper deals with a hybrid actuator composed by a piezo and a hydraulic part and with a robust sliding mode control structure 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. In the control problem such nonlinearities must be taken into account. In this paper the Preisach dynamic model with the above mentioned nonlinearities is considered together with a robust sliding mode technique. Simulations with real data are shown.