Hybrid Hysteresis-Inversion and PSO-Tuned PID Control for Piezoelectric Micropositioning Stages

Piezoelectric actuators are used in a wide range of applications, such as micropositioning stages, due to their high resolution and fast response. However, these actuators suffer from several nonlinearities that are mainly caused by hysteresis. This paper presents a hybrid control approach to overcome the hysteresis issue in such systems. A hysteresis-inversion-based feedforward controller is combined with a proportional– integral–derivative (PID) feedback controller, which is tuned using particle swarm optimization (PSO) to form the hybrid control structure. A new fitness that reduces the steady-state error, overshoot, and the rise and settling times is proposed. The proposed fitness function shows high efficiency and flexibility when used to tune the PID controller. The results show that the hybrid controller reduced the error caused by the hysteresis from 10.501% to 0.050% of the displacement range, producing a linear relationship between the input voltage and output displacement. The findings of this work prove that the hybrid control method can be potentially used in precise micropositioning and high precision applications.