Automatic Controller Switching by Model-based Predictive Control for a PZT Stage

This paper applies model-based predictive control (MPC) for switching control of a precision piezoelectric transducer (PZT) stage. First, we apply robust loop-shaping techniques to design two controllers for the PZT stage: one has fast responses while the other is less oscillatory. Second, we apply MPC to combine the merits of these two controllers, i.e. to automatically switch the stage controllers so that the system responses can be as fast as the first controller and as smooth as the second one. Last, the designed controllers and switching mechanism are implemented and verified by simulation and experiments. Based on the results, the proposed algorithms are deemed effective in improving the performance of the PZT stage.