Precise motion control of piezoelectric actuators using modified ZPETC-based composite controller

High speed and precision motion control of piezoelectric actuators (PEAs) over broadband frequencies is limited by its inherent rate-dependent hysteresis. The rate-dependent behavior can be well decomposed into decoupling vibration dynamics and rate-independent hysteresis. When vibration dynamics is a non-minimum phase (NMP) system, compensation of vibration dynamics is a key bottleneck for precise motion control of PEAs. A novel modified zero phase error tracking controller (MZPETC) is proposed in this paper to mitigate the vibration dynamics of PEAs whose vibration dynamics system is a NMP system. Then the feedforward controller is composed by the vibration dynamics inversion and the rate-independent hysteresis inversion. Finally, the Proportional Integral Derivative (PID) feedback controller is used to remedy the creep nonlinearity and modeling error of PEAs. The tracking error of sinusoidal trajectory at 900 Hz is reduced from 10.1 % to 2.07 % in comparison with ZPETC-based controller.