A hybrid hydraulic piezo actuator modeling and hysteresis effect identification for control in camless internal combustion engines

This paper presents a hybrid actuator composed by a piezo and a hydraulic part. Moreover, a cascade PI-PIDPI control structure for camless engine motor applications is considered. The idea of this contribution is using the advantages of both: the high precision of the piezo and the force of the hydraulic part. Piezoelectric actuators (PEAs) are mostly used for precision positioning, despite PEAs present nonlinearities, such as saturations, hysteresis and creep. In the control problem this kind of nonlinearities must be taken into consideration. The Preisach dynamic model of the PEA with the above mentioned nonlinearities is considered. In particular, the hysteresis effect is considered and a model with a switching function is used also for the controller design. Simulations results are presented.