Multirate-Based Composite Controller Design of Piezoelectric Actuators for High-Bandwidth and Precision Tracking

To track trajectories at rates higher than the resonant frequencies of piezoelectric actuators, this brief presents a comprehensive design method of a multirate-based composite controller consisting of a robust H∞ feedback controller and an inversion-based feedforward controller. The feedback controller is designed for stability and robustness in the presence of disturbances and modeling errors. It is designed for high-bandwidth tracking by reducing phase-lag and gain distortion to overcome the feedback limitation. The proposed composite controller is realized in a piezoelectric stage based on a DSPACE 1104 board. Finally, high-bandwidth and precision tracking are validated in the experimental studies.