Funnel Control for Piezoelectric Positioning Platform with Input-Output Constraints

In response to the demand for high-precision control of piezo-driven positioning platforms, this paper proposes a funnel controller for dealing with the input-output constraints. Firstly, a model that cascades a Preisach-Ishlinskii (PI) hysteresis representation with a second-order linear transfer function is used to capture both the actuator's nonlinear hysteresis and platform's dynamic behavior. Secondly, a funnel control theory based system design is proposed for controlling the platform, by incorporating a feedforward inverse-compensation strategy derived from the identified PI model. With the funnel-control scheme, the tracking error within prescribed funnel boundaries. Finally, experimental simulation is done by comparing with an adaptive-control, simulation results show that the proposed funnel control strategy delivers more accurate tracking, smaller steady-state error.