A dynamic nonlinearity model for a piezo-actuated positioning system

The piezoelectric actuator (PEA) is commonly used in the micro-nano precision positioning. However, PEA exhibits nonlinearities, such as hysteresis, saturation, and creep. Also, together with the actuated stage, mechanical and electrical dynamics exist. For ultra high precision and fast response positioning control, all those dynamics and nonlinearities have to be taken into account. In this paper, a simple dynamic nonlinearity control model for a piezoactuated positioning system was proposed, in which a sandwich model was proposed for describing the nonlinearities of hysteresis and creep and a total nonlinear dynamic control block diagram with the sandwich model embedded was derived. This model makes the identification and compensation of the piezoelectric nonlinearities much easier due to the simplicity of the model.