Development of a piezo-driven 3-DOF stage with T-shape flexible hinge mechanism

Abstract

This paper presents a 3-DOF (Degree of freedom) stage with T-shape flexible hinge mechanism for the applications in the precision measurement equipments and micro/nano manipulation systems. The stage is driven by three piezoelectric actuators (PEAs) and guided by a flexible hinge based mechanism with three symmetric T-shape hinges. The proposed T-shape flexible hinge mechanism can provide excellent planar motion capability with high stability, and thus guarantee the outstanding dynamics characteristics. The theoretical modeling of the stage was carried out and the stiffness and the dynamic resonance frequency have been obtained. The kinematic model of the 3-DOF stage was established and the workspace has been analyzed. The characteristics of the stage were investigated using finite element analysis (FEA). Experiments were conducted to examine the performance of the stage, through this stage, X-axis translational motion stroke of 6.9?m, Y-axis translational motion stroke of 8.5?m and rotational motion stroke along Z-axis of 289?rad can be achieved. A hybrid feedforward/feedback control methodology has been proposed to eliminate the nonlinear hysteresis, the trajectory tracking performances and to reduce external disturbance of the 3-DOF stage. The stage is driven by three piezoelectric actuators (PEAs) and guided by a flexible hinge based mechanism with three symmetric T-shape hinges. The T-shape flexure hinge is composed of three leaf-spring hinge subsections connected at the together like a T-joint. Thus, the T-shape flexure hinge can provide the in plane motion with relatively large out-of-plane stiffness. It is demonstrated from the computational analyses that the proposed T-shape flexure hinge can provide high natural frequency, large working range and high motion dexterity. The experiments results showed that the stage can provide for good performance.