Model-based control for second-order piezo actuator system with hysteresis in time-delay environment

Abstract

Piezo actuated systems are promising solutions for precision positioning applications. In this paper, a piezoelectric actuator is modeled as a second-order system using the Dahl hysteresis model and the system parameters have been identified from experimental data. The modified internal model control (M-IMC) approach is presented, which not only improves control performance but also reduces associated controller hardware resources. System dead time is approximated using first-order Padé expansion and the proposed Smith predictor-based M-IMC for piezoelectric actuators is seen to offer satisfactory stable control response even for plants with large dead time. The control performance of the M-IMC has been examined for the piezo actuator system against different set point tracking inputs in the presence of a wide range of external disturbances such as plant parameter mismatch, white noise perturbation, and time delay. Simulation results depict the efficacy and versatility of M-IMC in terms of decreased overshoot and settling time compared to traditional IMC and PID designs.