Bidirectional Motion Modeling and Fuzzy PID Control of Piezoelectric Linear Actuators

Piezoelectric linear actuators (PLAs) have emerged as a promising technology for ultrahigh-accuracy positioning applications. This study proposes a PLA design capable of bidirectional motion through stick-slip/slip-stick dual actuation mechanisms. The proposed mechanism distinguishes itself from conventional counterparts by achieving motion direction reversal through strategic phase modulation of driving signals. Finite element analysis (FEA) quantitatively resolves the stick-slip transitions and interfacial transitions in friction dynamics, with the developed dynamic model further revealing hysteresis nonlinearities through systematic characterization of contact mechanics. Experimental results demonstrate frequency-dependent velocity characteristics with maximum forward/reverse velocities of 2.83−3.02 mm/s at 350/400 Hz (100 V<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p-p</sub>), revealing structural frequency thresholds. Model validation shows 0.1548 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i>m maximum root mean square error (RMSE), confirming nanometer-scale agreement between simulations and experimental data. The proposed fuzzy proportional-integral-derivative (PID)-regulated hybrid control strategy achieves a 49% reduction in error compared to conventional PID control and maintains an accuracy of 0.11 μm during reverse actuation through real-time parameter adaptation. Furthermore, the system achieves nanometer-level dual-positioning accuracy through the proposed control methodology.