Position tracking control of a smart flexible structure featuring a piezofilm actuator

A position tracking control of a smart flexible structure with a piezofilm actuator is presented. A governing equation of motion for a smart cantilevered beam is derived cia Hamilton's principle, and a reduced-order control model is subsequently obtained through a modal analysis. Uncertain system parameters such as frequency variations are included in the control model. A sliding-mode control theory, which has inherent robustness to system uncertainties, is adopted to design a position tracking controller for the piezofilm actuator. Using the output information from a tip displacement sensor, a full-order observer is constructed to estimate state variables of the control system. Tracking control performances for desired position trajectories represented by sinusoidal and step functions are evaluated by undertaking both simulation and experimental works.