Hysteresis modeling and compensation for an XY micropositioning stage with model reference adaptive control

In this paper, a model reference adaptive controller (MRAC) is designed for a piezo-driven XY parallel micropositioning stage to compensate for the hysteresis effects aiming at a sub-micron accuracy motion tracking control. To convert the desired motion trajectory into voltage input, the inverse modified Prandtl-Ishlinskii (PI) hysteresis model is employed. The modified PI model is identified by optimizing the weight parameters through particle swarm optimization (PSO) to match the model output to experimental data. To compare with other methods, a feedforward controller based on PI model is implemented as well. The performances of MRAC and feedforward controllers are examined by extensive simulation studies. Results show that the former is superior to the latter one in terms of steady state errors especially as the increasing of input rates. Besides, the robustness of MRAC controller with rejection to external disturbances is verified as well.